Public Comment and
Response Document
for the Long Term 2
Enhanced Surface Water
Treatment Rule
Volumes I - IV: Chapters 1 - 22
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Office of Water (4606-M) EPA 815-R-06-003 December 2005 www.epa.gov/safewater
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Public Comment and
Response Document
for the Long Term 2
Enhanced Surface Water
Treatment Rule
Volume I: Chapters 1 - 7
Comment Response for LT2ESWTR
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TABLE OF CONTENTS
Volume I: Chapters 1-7
1. INTRODUCTION 1-1
2. HOW TO USE THIS DOCUMENT 2-1
3. GENERAL COMMENTS: COMMENT CODES 100-180 3-1
3.1 COMMENT CODE 100, GENERAL COMMENTS 3-1
3.2 COMMENTCODE 110, SUPPORT ASDWA's COMMENTS 3-50
3.3 COMMENTCODE 111, SUPPORT AW WA'S COMMENTS 3-51
3.4 COMMENTCODE 115, SUPPORT WESTERN COALITION OF ARID STATES' COMMENTS 3-52
3.5 COMMENTCODE 116, SUPPORT AMWA's COMMENTS 3-52
3.6 COMMENTCODE 117, SUPPORT ACWA's COMMENTS 3-53
3.7 COMMENTCODE 150, AGREEMENT IN PRINCIPLE/FACA PROCESS 3-53
3.8 COMMENTCODE 180, PREAMBLE EDITS 3-57
4. NEW DATA USED TO DEVELOP THE RULE: COMMENT CODES 200-251...
4-1
4.1 COMMENT CODE 220, CRYPTOSPORIDIUM OCCURRENCE 4-1
4.1.1 Comment Code 221, Analytical Method Performance 4-3
4.1.2 Comment Code 222, Modeling of Occurrence 4-4
4.1.3 Implications of New Occurrence Data 4-8
4.1.3.1 Comment Code 225, Unfiltered Systems 4-8
4.1.3.2 Comment Code 226, Use of Occurrence Data Sets in Benefit and Cost Analyses 4-10
4.2 COMMENT CODES 240, PHYSICAL REMOVAL OF CRYPTOSPORIDIUM 4-15
4.2.1 Comment Code 241, Conventional treatment 4-17
4.3 INACTIVATION OF CRYPTOSPORIDIUM 4-20
4.3.1 Comment Code 251, Other than UV, ozone, and chlorine dioxide (UV, O3, and CIO2 comments
should be categorized under toolbox) 4-20
5. FILTERED SYSTEM MONITORING REQUIREMENTS (PARAMETERS,
FREQUENCY, LOCATION): COMMENT CODES 300-471 5-1
5.1 COMMENT CODE 300, FILTERED SYSTEM MONITORING REQUIREMENTS (PARAMETERS, FREQUENCY,
LOCATION) 5-1
5.2 COMMENT CODE 310, LARGE SYSTEM MONITORING REQUIREMENTS 9
5.3 COMMENTCODE 320, SMALL SYSTEM MONITORING REQUIREMENTS 25
5.3.1 Comment Code 321, E. coli monitoring frequency and duration 37
5.3.2 Comment Code 322, Cryptosporidium monitoring frequency and duration 39
5.4 COMMENT CODE 330, USE OF E. COLI AS TRIGGER FOR CRYPTO MONITORING 48
5.4.1 Comment Code 331, E. coli and Crypto relationships in occurrence data sets 55
5.4.2 Comment Code 332, E. coli trigger concentrations 55
5.4.3 Comment Code 333, How to classify source water type 58
5.4.4 Comment Code 334, Process for revising trigger based on large system results 62
5.4.5 Comment Code 335, Alternative indicators 68
5.5 COMMENT CODE 340, SAMPLING LOCATION 71
5.5.1 Comment Code 341, Prior to treatment 85
5.5.2 Comment Code 342, Presedimentation basins 87
5.5.3 Comment Code 343, Raw water off-stream storage 95
Comment Response for LT2ESWTR i December 2005
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5.5.4 Comment Code 344, Bank filtration 5-96
5.5.5 Comment Code 345, Plants using multiple water sources 5-99
5.5.6 Comment Code 346, Filter backwash recycle 5-105
5.5.7 Comment Code 347, Sampling one source with multiple intakes 5-125
5.6 COMMENT CODES 360, SAMPLING SCHEDULE 5-127
5.6.1 Comment Code 361, 5-day sampling window and allowable exceptions 5-138
5.6.2 Comment Code 365, Submitting monitoring plan (date and location) 5-168
5.7 COMMENT CODE 370, REPORTING MONITORING RESULTS 5-183
5.7.7 Comment Code 371, Reporting large system results directly to EPA and role of States 5-185
5.7.2 Comment Code 372, Electronic data reporting and review system 5-192
5.7.3 Comment Code 375, Time-frame for reporting 5-203
5.8 COMMENT CODES 380, USE OF PREVIOUSLY COLLECTED DATA (I.E., GRANDEATHERING) 5-206
5.8.1 Comment Codes 381, Sample acceptance criteria (frequency, volume, analytical method) 5-213
5.8.2 Comment Code 382, Approaches for collecting additional samples to complete data sets 5-246
5.8.3 Comment Code 383, Impact of changes to the analytical method 5-248
5.8.4 Comment Code 384, Data reporting and certification requirements 5-249
5.8.5 Comment Code 385, Schedule for data reporting and EPA decisions 5-250
5.8.6 Comment Code 386, Grandfathering E. coli data 5-256
5.8.7 Comment Code 388, Sample location criteria 5-257
5.8.8 Comment Codes 389, Specific to Grandfathered Data Guidance Manual 5-261
5.9 COMMENT CODE 400, ONGOING SOURCE ASSESSMENT (WATERSHED REVIEW DURING SANITARY SURVEY)
5-264
5.10 COMMENT CODE 410, SECOND ROUND OF MONITORING 5-267
5.10.1 Comment Code 411, Stakeholder process for second monitoring round 5-2 72
5.10.2 Comment Code 412, Bin classification based on second monitoring round. 5-275
5.11 COMMENT CODE 420, PROVIDING ADDITIONAL TREATMENT INSTEAD OF MONITORING 5-279
5.12 COMMENT CODE 430, MONITORING FOR SYSTEMS THAT USE SURFACE WATER ONLY PART OF THE YEAR
5-280
5.13 COMMENT CODE 440, PENALTY/BIN ASSIGNMENT FOR SYSTEMS THAT FAIL TO COMPLETE REQUIRED
MONITORING 5-293
5.14 COMMENT CODE 450, MONITORING FOR NEW PLANTS AND SOURCES 5-345
5.15 COMMENT CODE 460, RULE LANGUAGE EDITS 5-355
5.16 COMMENT CODE 470, GUIDANCE 5-356
5.16.1 Comment Code 471, Specific to Source Water Monitoring Guidance Manual 5-35$
6. FILTERED SYSTEM TREATMENT REQUIREMENTS: COMMENT CODES
500-560 6-1
6.1 COMMENT CODE 500, FILTERED SYSTEM TREATMENT REQUIREMENTS 6-1
6.2 COMMENT CODE 510, MICROBIAL FRAMEWORK APPROACH 6-7
6.3 COMMENT CODE 520, BIN CONCENTRATION RANGES AND TREATMENT REQUIREMENTS 6-11
6.4 COMMENT CODE 530, PROCEDURES FOR CALCULATING BIN CLASSIFICATION 6-16
6.4.1 Comment Code 532, Small systems 6-22
6.4.2 Comment Code 533, Role of States in making or reviewing bin classification 6-23
6.5 CREDIT FOR TREATMENT IN PLACE 6-31
6.5.1 Comment Code 541, Conventional, softening, slow sand, and DE plants 6-31
6.5.2 Comment Code 545, Implications for Giardia treatment credit 6-35
6.6 COMMENT CODE 547, COMPLIANCE FUNDS WOULD BE BETTER SPENT ON OTHER DRINKING WATER NEEDS
6-37
6.7 COMMENT CODE 550, RULE LANGUAGE EDITS 6-38
6.8 COMMENT CODE 560, GUIDANCE 6-39
7. UNFILTERED SYSTEMS MONITORING AND TREATMENT
REQUIREMENTS: COMMENT CODES 600-640 7-1
7.1 COMMENT CODE 600, UNFILTERED SYSTEMS MONITORING AND TREATMENT REQUIREMENTS 7-1
7.2 COMMENT CODE 610, MONITORING REQUIREMENTS 7-5
Comment Response for the LT2ESWTR ii December 2005
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7.2.7 Comment Code 611, Parameters, frequency, and duration 7-6
7.2.1.1 Comment Code 612, Lack of E. coli indicator for small unfiltered systems 7-7
7.3 COMMENT CODE 620, CRYPTOSPORIDIUM TREATMENT REQUIREMENTS 7-8
7.3.1 Comment Code 621, Proposed treatment levels 7-14
7.3.2 Comment Code 622, Allowance to miss treatment requirement once-per-month for ozone and
chlorine dioxide and 5% of time for UV 7-18
7.3.3 Comment Code 623, Treatment requirements for systems with higher Cryptosporidium levels 7-18
7.4 COMMENT CODE 625, COMPLIANCE FUNDS WOULD BE BETTER SPENT ON OTHER DRINKING WATER NEEDS
7-24
7.5 COMMENT CODE 630, USE OF Two DISINFECTANTS TO MEET TOTAL TREATMENT REQUIREMENTS.... 7-27
7.6 COMMENT CODE 640, RULE LANGUAGE EDITS 7-38
Volume II: Chapters 8-10
8. OPTIONS FOR MEETING TREATMENT REQUIREMENTS: COMMENT CODES 700-970 8-1
8.1 COMMENT CODE 700, OPTIONS FOR MEETING TREATMENT REQUIREMENTS 8-1
8.2 COMMENT CODE 710, MICROBIAL TOOLBOX GENERAL COMMENTS 8-3
8.3 COMMENT CODE 720, WATERSHED CONTROL PROGRAM 8-39
8.3.1 Comment Code 721, Proposed credit 8-47
8.3.2 Comment Code 722, Program requirements 8-56
8.3.3 Comment Code 723, Reduced frequency for watershed survey 8-75
8.3.4 Comment Code 724, Data on methods to reduce Cryptosporidium Contamination 8-88
8.3.5 Comment Code 725, Data on delineating area of influence 8-92
8.3.6 Comment Code 726, Confidentiality and water shed annual reports 8-94
8.3.7 Comment Code 72 7, Expiration of treatment credit after second round of monitoring 8-98
8.3.8 Comment Code 728, Rule Language Edits 8-106
8.3.9 Comment Code 729, Guidance 8-107
8.4 COMMENT CODE 740, ALTERNATIVE SOURCE/INTAKE/INTAKE MANAGEMENT STRATEGY 8-108
8.4.1 Comment Code 741, Proposed monitoring and reporting requirements 8-109
8.4.2 Comment Code 742, Intake management strategies 8-111
8.4.3 Comment Code 743, Representative monitoring prior to new intake construction 8-113
8.4.4 Comment Code 744, Application to plants with multiple sources 8-114
8.4.5 Comment Code 745, Rule Language Edits 8-115
8.5 COMMENT CODES 750, OFF-STREAM RAW WATER STORAGE 8-116
8.5.1 Comment Codes 751, Decision not to grant credit based on existing data 8-117
8.5.2 Comment Codes 752, Additional data on off-stream storage 8-121
8.5.3 Comment Codes 753, Addressing contamination due to algae, birds, runoff, etc 8-121
8.5.4 Comment Codes 754, Rule Language Edits 8-122
8.6 PRESEDIMENTATION BASIN WITH COAGULANT 8-123
8.6.1 Comment Code 761, Credit and criteria for awarding credit 8-123
8.6.1.1 Comment Code 762, Conditions that would affect compliance with criteria 8-129
8.6.2 Comment Code 763, Additional data on presedimentation 8-130
8.6.3 Comment Code 766, Credit for existing basins 8-131
8.7 COMMENT CODES 770, BANK FILTRATION 8-132
8.7.1 Comment Codes 771, Credits and criteria for awarding credit 8-138
8.7.1.1 Comment Codes 772, Aquifer type/core characteristics 8-145
8.7.1.2 Comment Codes 773, Separation distance 8-145
8.7.1.3 Comment Codes 775, Turbidity monitoring 8-146
8.7.2 Comment Codes 780, Indicator/surrogate measurements suitable for predicting removal 8-148
Comment Response for the LT2ESWTR Hi December 2005
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8.7.2 Comment Codes 780, Indicator/surrogate measurements suitable for predicting removal 8-148
8.7.3 Comment Codes 781, Alternative methods for determining site suitability 8-150
8.7.4 Comment Codes 782, Data on effectiveness of bank filtration at existing sites 8-151
8.7.5 Comment Codes 783, Data on GWUDI systems using bank filtration alone 8-154
8.7.6 Comment Codes 785, Procedures for making site-specific decisions on bank filtration credit. 8-155
8.7.7 Comment Codes 786, Rule Language Edits 8-157
8.7.8 Comment Codes 787, Guidance 8-158
8.8 COMMENT CODES 790, LIME SOFTENING 8-159
8.8.1 Comment Codes 791, Credit and criteria for awarding credit 8-160
8.8.2 Comment Codes 792, Additional data on lime softening 8-169
8.8.3 Comment Codes 793, Rule Language Edits 8-171
8.9 COMMENT CODES 800, COMBINED FILTER PERFORMANCE 8-172
8.9.1 Comment Codes 801, Credit and criteria for awarding credit 8-174
8.9.2 Comment Codes 802, Additional data on filtration performance 8-181
8.9.3 Comment Codes 803, Turbidity monitoring accuracy at low levels 8-182
8.9.4 Comment Codes 804, Rule Language Edits 8-189
8.9.5 Comment Codes 805, Guidance 8-189
8.10 COMMENT CODES 810, ROUGHING FILTERS 8-190
8.10.1 Comment Codes 811, Decision not to award credit 8-191
8.11 COMMENT CODES 820, SLOW SAND FILTRATION 8-194
8.11.1 Comment Codes 821, Credit and criteria for awarding credit 8-196
8.12 COMMENT CODES 830, MEMBRANE FILTRATION 8-199
8.12.1 Comment Codes 831, Credit and criteria for awarding credit 8-201
8.12.2 Comment Codes 832, Additional data on membrane filtration performance 8-212
8.12.3 Comment Codes 833, Inclusion of membrane cartridge filters that can be integrity tested 8-213
8.12.4 Comment Code 834, Applicability of credit and criteria to Giardia 8-214
8.12.5 Comment Codes 835, Appropriate surrogates for challenge testing 8-215
8.12.6 Comment Codes 836, Use of non-destructive performance testing 8-215
8.12.7 Comment Codes 83 7, Minimum direct integrity testing frequency 8-219
8.12.8 Comment Codes 838, Reporting frequency for not meeting integrity criteria 8-222
8.12.9 Comment Codes 839, Rule Language Edits 8-223
8.12.10 Comment Codes 840, Guidance 8-223
8.12.11 Comment Codes 841, Membrane Guidance Manual (specific to the guidance manual) 8-225
8.13 COMMENT CODES 850, BAG AND CARTRIDGE FILTRATION 8-226
8.13.1 Comment Codes 851, Credits and criteria for awarding credits 8-228
8.13.1.1 Comment Codes 852, Use of 1 log safety factor 8-231
8.13.1.2 Comment Codes 853, Limiting log credit to 2 log (bag) and 3 log (cartridge) 8-233
8.13.2 Comment Codes 860, Additional data on bag and cartridge filter performance 8-234
8.13.2.1 Comment Codes 861, Other challenge test requirements 8-234
8.13.3 Comment Codes 871, Applicability of process monitoring to verify integrity 8-235
8.13.4 Comment Codes 874, Rule Language Edits 8-235
8.13.5 Comment Codes 875, Guidance 8-235
8.14 COMMENT CODE 880, SECONDARY FILTRATION 8-236
8.14.1 Comment Code 881, Credit and criteria for awarding credit 8-238
8.14.2 Comment Code 883, Minimum depth for secondary filter 8-243
8.14.3 Comment Code 884, Credit for both second clarification stage and lower finished water
turbidity 8-245
8.14.4 Comment Code 886, Guidance 8-246
8.15 COMMENT CODES 890, OZONE AND CHLORINE DIOXIDE 8-247
8.15.1 Comment Codes 891, Credit and criteria for awarding credit 8-250
8.15.1.1 Comment Codes 892, Determination of CT , including confidence bounds 8-261
8.15.2 Comment Codes 893, Additional data on inactivation for CT tables 8-266
8.15.3 Comment Codes 894, Site-specific determination ofCT 8-268
Comment Response for the LT2ESWTR iv December 2005
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8.15.4 Comment Codes 896, Compliance with bromate and chlorite MCLs 8-269
8.15.5 Comment Codes 898, Guidance 8-273
8.16 COMMENT CODES 910, UV LIGHT 8-275
8.16.1 Comment Code 911, Credit and criteria for awarding credit 8-283
8.16.1.1 Comment Codes 912, UV dose tables Individual Comments on Code 912 8-304
8.16.1.2 Comment Codes 913, Reactor validation testing 8-323
8.16.1.3 Comment Codes 914, Reactor monitoring 8-338
8.16.1.4 Comment Codes 916, Compliance determination for filtered systems 8-341
8.16.1.5 Comment Codes 917, Off-spec operation 8-346
8.16.2 Comment Codes 920, Additional data on UV disinfection 8-357
8.16.3 Comment Code 921, Rule Language Edits 8-358
8.16.4 Comment Codes 922, Guidance 8-358
8.16.5 Comment Codes 923, Guidance on UV 8-425
8.17 COMMENT CODES 930, INDIVIDUAL FILTER PERFORMANCE 8-427
8.17.1 Comment Codes 931, Proposed credit and criteria for awarding credit. 8-433
8.17.2 Comment Codes 933, Different or additional criteria for awarding credit 8-449
8.17.3 Comment Codes 934, Existing peer review programs eligible for credit 8-453
8.17.4 Comment Codes 935, Use of 0.15 NTUrather than 0.1 NTU 8-458
8.18 COMMENT CODES 950, OTHER DEMONSTRATION OF PERFORMANCE 8-462
8.18.1 Comment Codes 951, Proposed approach for awarding credit 8-467
8.18.2 Comment Codes 952, Approaches that should be considered or excluded 8-476
8.18.3 Comment Codes 953, Minimum elements for testing 8-478
8.18.4 Comment Codes 954, Safety factor 8-478
8.18.5 Comment Codes 955, Credit for unit processes 8-479
8.18.6 Comment Codes 957, Guidance 8-481
8.19 COMMENT CODE 970, TOOLBOX GUIDANCE MANUAL (SPECIFIC TO THE GUIDANCE MANUAL) 8-482
9. DISINFECTION BENCHMARKS: COMMENT CODES 1000-1020 9-1
9.1 COMMENT CODE 1000, DISINFECTION BENCHMARKS 9-1
9.2 COMMENT CODE 1020, GUIDANCE 9-16
10. UNCOVERED FINISHED WATER RESERVOIRS: COMMENT CODES 1100-1170 10-1
10.1 COMMENT CODE 1100, UNCOVERED FINISHED WATER RESERVOIRS 10-1
10.2 COMMENT CODE 1110, RISK MITIGATION OR TREATMENT INSTEAD OF COVERING 10-7
10.3 COMMENT CODE 1120, REQUIRING INACTIVATION OF CRYPTOSPORIDIUM AND GIARDIA 10-13
10.4 COMMENT CODE 1130, DATA ON CONTAMINATION OF UNCOVERED RESERVOIRS 10-15
10.5 COMMENT CODE 1140, DATA ON WEATHER, EFFECT ON CORROSION CONTROL 10-16
10.6 COMMENTCODE 1150, CHANGING DEFINITION OF UNCOVERED FINISHED WATER RESERVOIRS 10-16
10.7 COMMENT CODE 1170, GUIDANCE 10-19
Volume III: Chapters 11-22
11. COMPLIANCE SCHEDULES: COMMENT CODES 1200-1250 11-1
11.1 COMMENTCODE 1200, COMPLIANCE SCHEDULES 11-1
11.2 COMMENTCODE 1210, A. LARGE SYSTEM MONITORING AND TREATMENT 11-30
11.3 COMMENTCODE 1220, SMALL SYSTEM MONITORING AND TREATMENT 11-45
11.3.1 Comment Code 1221, Lag Between Large and Small System Monitoring 11-47
11.4 COMMENTCODE 1230, SCHEDULE FOR CONSECUTIVE SYSTEMS, STAGE2DBPR 11-53
11.5 COMMENTCODE 1240, UNCOVERED FINISHED WATER RESERVOIRS 11-54
11.6 COMMENTCODE 1250, RULE LANGUAGE EDITS 11-55
Comment Response for the LT2ESWTR v December 2005
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12. PUBLIC NOTIFICATION: COMMENT CODES 1300-1340 12-1
12.1 COMMENT CODE 1300, PUBLIC NOTIFICATION 12-1
12.2 COMMENT CODE 1310, TIER 2 NOTICE FOR TREATMENT VIOLATIONS 12-6
12.3 COMMENT CODE 1320, HEALTH EFFECTS LANGUAGE 12-14
12.4 COMMENT CODE 1340, GUIDANCE 12-18
13. VARIANCES AND EXEMPTIONS : COMMENT CODES 1400-1420 13-1
13.1 COMMENT CODE 1400, VARIANCES AND EXEMPTIONS 13-1
13.2 COMMENT CODE 1410, PROPOSAL NOT TO PERMIT VARIANCES 13-7
13.2.1 Comment Code 1411, Unfiltered systems 13-12
13.3 COMMENT CODE 1420, PROPOSAL NOT TO PERMIT EXEMPTIONS 13-14
14. REPORTING REQUIREMENTS: COMMENT CODES 1500-1530 14-1
14.1 COMMENT CODE 1500, REPORTING REQUIREMENTS 14-1
14.2 COMMENT CODE 1510, MONTHLY REPORTING ON COMPLIANCE WITH TOOLBOX REQUIREMENTS 14-6
14.2.1 Comment Code 1511, Alternative Requiring Systems to keep Records Onsite 14-13
14.2.2 Comment Code 1522, Bin classification 14-15
14.3 COMMENT CODE 1530, RULE LANGUAGE EDITS 14-16
15. COMMENT CODE 1600: RECORDKEEPING REQUIREMENTS 15-1
15.1 COMMENT CODE 1600, XII. RECORDKEEPING REQUIREMENTS 15-1
16. ANALYTICAL METHODS: COMMENT CODES 1700-1760 16-1
16.1 COMMENT CODE 1700, XIII. ANALYTICAL METHODS 16-1
16.2 COMMENT CODES 1710, CRYPTOSPORIDIUM 16-2
16.2.1 Comment Code 1711, Minimum sample volume, packed pellet volume, number of filters 16-4
16.2.2 Comment Code 1712, Use of different versions of Method 1622/1623, performance-based approaches,
and alternate test procedures 16-10
16.2.3 Comment Code 1713, Matrix spike recoveries, poor recoveries, data adjustment 16-14
16.1.3.1 Comment Code 1714, Frequency of matrix spike analyses 16-16
16.2.4 Reporting total oocysts 16-21
16.2.4.1 Comment Code 1716, Adjustment for empty or non-infectious oocysts 16-21
16.2.5 Comment Code 1717, Subjectivity of microscopy, third-party review of slides 16-24
16.2.6 Comment Code 1719, Approach to matrix spike samples when sampling above 10 L 16-26
16.2.7 Comment Code 1720, Other comments on use of Method 1623 16-28
16.2.8 Comment Code 1721, Rule Language Edits 16-37
16.2.9 Comment Code 1722, Guidance 16-38
16.2.10 Comment Code 1723, Specific to LT2 Microbial Sampling Guidance Manual 16-40
16.2.11 Comment Code 1724, Method 1622 or 1623 June 2003 draft 16-49
16.3 E. COLI 16-93
16.3.1 Comment Code 1731, Proposed methods 16-93
16.3.2 Comment Code 1732, Additional methods 16-96
16.3.3 Comment Code 1733, Extension of holding time 16-97
16.3.4 Comment Code 1734, Data on cost and availability of overnight delivery in rural areas 16-107
16.4 COMMENT CODE 1750, TURBIDITY 16-108
16.4.1 Comment Code 1751, Proposed methods 16-113
16.4.2 Comment Code 1752, Additional methods 16-117
16.5 COMMENT CODE 1760, EXTENSION OF HOLDING TIME FOR OTHER PARAMETERS 16-119
Comment Response for the LT2ESWTR vi December 2005
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17. LABORATORY APPROVAL AND CAPACITY: COMMENT CODES 1810-1870 17-1
17.1 COMMENT CODE 1810, CRYPTOSPORIDIUM LABORATORY APPROVAL 17-1
17.1.1 Comment Code 1811, Process and criteria for laboratory Approval 17-3
17.1.1.1 Comment Code 1812, Analyst experience criteria 17-5
17.1.2 Comment Code 1820, State programs to approve laboratories 17-10
17.1.2.1 Comment Code 1821, How to demonstrate equivalence 17-12
to federal program 17-12
17.1.3 Laboratory disapproval process 17-13
17.2 CRYPTOSPORIDIUM LABORATORY CAPACITY 17-14
17.2.1 Need for EPA estimate 17-17
17.2.2 Comment Code 1832, Adequacy of current capacity 17-34
17.2.2.1 Need to delay or modify rule implementation schedule 17-56
17.2.3 Comment Code 1834, Approaches to increase capacity 17-69
17.3 COMMENT CODE 1840, E.COLI LABORATORY APPROVAL 17-70
17.4 COMMENT CODE 1850, TURBIDITY ANALYST APPROVAL 17-73
17.5 COMMENT CODE 1870, GUIDANCE 17-74
18. SANITARY SURVEY REQUIREMENTS FOR SYSTEMS WHERE EPA HAS PRIMACY:
COMMENT CODE 1900 18-1
18.1 COMMENT CODE 1900, XV. SANITARY SURVEY REQUIREMENTS FOR SYSTEMS WHERE EPA HAS
PRIMACY 18-1
19. STATE IMPLEMENTATION: COMMENT CODES 2000-2090 19-1
19.1 COMMENT CODE 2000, STATE IMPLEMENTATION 19-1
19.2 COMMENT CODES 2010, SPECIAL STATE PRIMACY REQUIREMENTS 19-2
19.2.1 Comment Codes 2030, Assessing changes in watershed as part of sanitary survey process 19-5
19.2.2 Comment Codes 2040, Determining adequacy of risk mitigation plans for uncovered finished
water reservoirs 19-6
19.3 COMMENT CODE 2090, INTERIM PRIMACY 19-7
20. ECONOMIC ANALYSIS: COMMENT CODES 2200-2280 20-1
20.1 COMMENT CODE 2200, ECONOMIC ANALYSIS 20-1
20.2 COMMENT CODE 2220, RISK ASSESSMENT 20-21
20.2.1 Comment Code 2221, Dose-response (including infectivity and morbidity) 20-22
20.2.2 Comment Code 2222, Drinking water consumption (including averting behavior) 20-29
20.2.3 Comment Code 2223, Comparison with epidemiological data 20-33
20.2.4 Comment Code 2224, Sensitive subpopulations 20-44
20.2.5 Comment Code 2225, Uncertainty. 20-45
20.2.6 Comment Code 2226, Cases of illness compared to IESWTR or LT1ESWTR estimates 20-47
20.3 COMMENT CODE 2230, BENEFITS 20-50
20.3.1 Comment Code 2231, Valuation of Non-fatal Cryptosporidiosis 20-51
20.3.2 Comment Code 2232, Valuation of Mortality 20-53
20.3.3 Comment Code 2234, Nonquantifiable benefits 20-55
20.4 COMMENT CODE 2240, COSTS 20-56
20.4.1 Comment Code 2250, Water System Costs 20-57
20.4.1.1 Comment Code 2251, Monitoring 20-59
20.4.1.2 Comment Code 2252, Treatment 20-63
20.4.1.2.1 Comment Code 2253, Incorporation of toolbox technologies 20-65
20.4.1.3 Comment Code 2254, Uncovered finished water reservoirs 20-66
20.4.2 Comment Code 2255, Household costs. 20-67
20.4.3 Comment Code 2256, State costs 20-68
20.5 COMMENT CODE 2280, BENEFIT/COST DETERMINATION 20-74
Comment Response for the LT2ESWTR vii December 2005
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21. STATUTORY AND EXECUTIVE ORDER REVIEWS: COMMENT CODES 2300-2420 21-1
21.1 COMMENT CODE 2300, STATUTORY AND EXECUTIVE ORDER REVIEWS 21-1
21.2 COMMENT CODE 2350, EXECUTIVE ORDER 13132: FEDERALISM 21-2
21.3 COMMENT CODE 2360, EXECUTIVE ORDER 13175: CONSULTATION WITH INDIAN TRIBAL
GOVERNMENTS 21-3
21.4 COMMENT CODE 2400, EXECUTIVE ORDER 12898 ENVIRONMENTAL JUSTICE 21-4
21.5 COMMENT CODE 2410, CONSULTATIONS WITH THE SCIENCE ADVISORY BOARD, NATIONAL DRINKING
WATER ADVISORY COUNCIL, AND THE SECRETARY OF HEALTH AND HUMAN SERVICES 21-4
21.6 COMMENT CODE 2420, PLAIN LANGUAGE 21-5
22. REFERENCES: COMMENT CODE 2510-2511 22-1
22.1 COMMENT CODE 2510, AMENDMENTS TO SWTR, IESWTR, OR LT1ESWTR 22-1
22.2 COMMENT CODE 2511, AMENDMENTS TO PUBLIC NOTIFICATION RULE 22-7
Volume IV: APPENDICES
Appendix A Commenter Information Log
Appendix B List of Letters with Multiple Signatories
Appendix C Comment Tables and Graphics
Appendix D Attachments and Appendix Materials Submitted with Comment Letters:
Code 9999
Appendix E Greetings, Signatures, Commenter Background, and Introductory Statements:
Codes 9990-9997
Comment Response for the LT2ESWTR
December 2005
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1. Introduction
The purpose of this document is to present public comments and EPA's corresponding responses
for the National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water Treatment
Rule (LT2ESWTR). The comment period began for this rule began with the August 11, 2003 proposal
(68 FR 47640). This comment period was extended from an initial 90 days to a final 150 days (total) with
the October 8, 2003 National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface
Water Treatment Rule; Extension of Comment Period (68 FR 58057).
EPA received 200 comment letters; these letters are listed in Appendix A. Most letters were
submitted to the docket in response to the proposal published in the Federal Register; however, EPA also
received some letters on the rule that were not part of the public comment process (e.g., some commenters
submitted comments after public hearings for stakeholders, and some submitted their comments directly
to the EPA Administrator or other EPA staff). Some commenters submitted more than one letter.
Comment letters were logged into the Office of Water Docket and assigned a docket identification
number (Appendix A notes those that are not in the docket, if any).
Each letter was then posted (as a .pdf file) to E-Docket, an electronic version of the public docket
available through the Internet. EPA no longer uses E-Docket; its electronic docket files have been
transferred to www.regulations.gov. This website may be used to view the public comment letters listed
in this document, as well as to access other documents in the public docket that are available
electronically. From the home page, click on "Advanced Search" at the top of the page, select "Docket
Search," select EPA as the agency docket you are searching, and enter the Docket ID for the LT2ESWTR,
OW-2002-0039. Use the list in Appendix A to find the Docket ID number of the letter you wish to view.
EPA imported these comment letters to a comment/response database. EPA assigned each letter
an EPA Letter ID, which in most cases is taken from last 3 digits of the letter's Docket ID number in E-
Docket and www.regulations.gov. The text of the comment letters was imported verbatim, although
minor spelling errors and formatting issues within the comments were in some cases corrected for this
document. EPA added bracketed text to the comment letter text in cases where the comment needed
clarification or where the commenter refers to a graphic or table that could not be imported into the
comment field of the database. These graphs and tables are included in Appendix C of this document.
EPA then created comment codes, as listed in the table of contents, for the purpose of organizing
the information in the comment letters. As indicated by the comment code descriptions in the table of
contents, the codes represent distinct subject matter areas. The codes generally follow the structure of the
preamble to the LT2ESWTR Proposal, although only those sections of the preamble for which there were
comments are included in Chapters 3-22 of this document. After reviewing the comment letters, using
the comment/response database, EPA assigned one or more comment codes to each comment within a
comment letter. A comment is a portion of the letter that expresses a complete idea on a distinct subject.
Exhibit 1-1 shows an excerpt of a comment letter, and Exhibit 1-2 shows how the comments
within that letter were assigned comment codes.
Note that throughout this document, some comments begin or end with partially complete
sentences (see the last line of the example in Exhibit 1-3). This is due to the process by which comments
were coded. Comments were defined by line numbers rather than by sentences. That is, if discussion of
one topic ended in the middle of a line of text, and another topic began in the same line, the entire line of
text was included in both comments. Thus, in the last line of Exhibit 1-3, a partially complete sentence on
Comment Response for LT2ESWTR 1-1 December 2005
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one topic appears after a full comment on risk mitigation for uncovered finished water reservoirs. This
partially complete sentence is included in its entirety in a comment on the relevant topic. EPA has
considered and addressed all complete sentences in at least one place in this document.
For each comment code, EPA then provided comprehensive responses that address the comments
associated with that code. This response is called a response to comment codes (see the example in
Exhibit 1-5) or a megaresponse. In many cases, EPA divided the responses into subsections. In some
cases, EPA also wrote a separate summary of issues raised by the commenters.
Exhibit 1-1. Sample Portion of a Comment Letter
131. We have already been testing for Cryptosporidium for years, but
14 labs that can do this type of testing are not in grand supply. I am
15 concerned with the extra testing that my agency will have to perform, and
16 those agencies that will now need to undertake testing, there will not be
17 enough qualified labs to perform the test in a timely manner. We have had
18 difficulties already, and it will only be worse.
19
20 2.1 am also concerned that our treatment plant could go into a Bin 4
21 designation if we fail to meet certain source water monitoring
22 parameters. For one issue, the timing to perform some of the testing/lake
23 sampling should give us more flexibility for each monthly reporting. I
24 can foresee problems in trying to maintain the tight schedule.
Comment Response for the LT2ESWTR 1-2 December 2005
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Exhibit 1-2. Sample Comment Letter and Assigned Comment Codes
EPA Comment Code 361: 5-day sampling window and allowable exceptions
20 2.1 am also concerned that our treatment plant could go into a Bin 4
21 designation if we fail to meet certain source water monitoring
22 parameters. For one issue, the timing to perform some of the testing/lake
23 sampling should give us more flexibility for each monthly reporting. I
24 can foresee problems in trying to maintain the tight schedule.
EPA Comment Code 1832: Adequacy of current capacity
131. We have already been testing for Cryptosporidium for years, but
14 labs that can do this type of testing are not in grand supply. I am
15 concerned with the extra testing that my agency will have to perform, and
16 those agencies that will now need to undertake testing, there will not be
17 enough qualified labs to perform the test in a timely manner. We have had
18 difficulties already, and it will only be worse.
Exhibit 1-3. Sample Comment with Incomplete Sentence
EPA Comment Code 1110: A. Risk Mitigation or Treatment Instead of Covering
1 I would like to second the comment made that the environmental loophole
2 of uncovered finished water reservoirs needs to be closed. In a study by
3 LeChevallier (AWWA Journal 1997, September), showed that cysts and oocysts in
4 the inlet and outlet were statistically significant, the median difference
5 between inlet and outlet effluent crypotsporidium concentrations was nearly
6 sevenfold. The article states "Source water for these reservoirs is highly
7 treated, so it is possible to observe small increases in oocyst concentration
8 from nonpoint sources of contamination" and further states "Any contamination of
9 the water supply poses a risk of water borne cryptosporidiosis". So, the 4 logs
10 of virus inactivation would not inactivate crypto, the only option should be to
11 cover these reservoirs. The article states that possible sources of
EPA also wrote individual responses to each comment that refer the reader to a particular
response to comment codes and to a particular issue or subsection within the response. Some individual
responses refer the reader to more than one response to comment codes. This means that in some cases,
the reader will need to refer to another section and code to find the complete response to a comment. In a
few cases, points raised by a comment did not fall under the response to a comment code and were
addressed in the individual response for that comment.
Comment Response for the LT2ESWTR
1-3
December 2005
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Chapters 3 through 22 present all comments and EPA responses organized by comment code.
Each chapter represents a distinct subject matter area, each of which may contain one or more related
comment codes. For example, Chapter 4 addresses new data used to develop the rule and includes
comment codes 200 to 251. Appendix D contains attachments and appendices that EPA received along
with the actual comments. Appendix E contains the text of greetings, signatures, and other text that is not
relevant to this rule (for example, comments on the Stage 2 DBPR).
For each comment code, the response to that code, and in some cases a summary of comments
under that code, are presented prior to the comments in each chapter. Comments then follow; with
individual responses directly following each comment, as shown in the following exhibits. Exhibit 1-4
summarizes the terms used throughout Chapters 3-22. Exhibit 1-5 shows excerpts of the comments,
individual responses, and response to comment code for code 400 (Ongoing Source Assessment).
The comment/response process was designed to address all relevant issues raised by commenters.
EPA recognizes that some of the referenced responses address more issues than may be raised by a
particular comment. Nonetheless, EPA believes it is important to take the opportunity to address not only
specific issues raised by a particular commenter, but also to explain the larger context in which the issues
arise. EPA reviewed each comment related to a particular comment code and drafted a response
addressing all comments. Comments and responses for each comment code were further reviewed by
Agency management and legal staff.
Exhibit 1-4. Terms Used in This Document
EPA Letter ID—Unless otherwise noted, the EPA Letter ID is the last three digits of
the letter's Docket ID number.
Commenter—The first signature on the letter. If the commenter did not sign the
letter, the commenter was assigned the name "Anonymous" combined with the EPA
Letter ID number. This field also includes the commenter's title and organization, if
known. A complete list of commenters is provided in Appendix A.
EPA Comment ID—The unique identification number assigned by the database to
each comment.
Comment Code—Code and description used to categorize comments on a particular
subject.
Comment—A portion of a letter that expresses a complete idea on a distinct subject.
Response—Response associated with a specific comment; usually the individual
response refers to all or a portion of a response written for an entire comment code.
Response to Comment Code—Comprehensive response that addresses the comments
grouped within a comment code.
Summary of Issues—Where provided, a summary of the comments that are assigned
a particular comment code, or a list of the subsections in the response to comment
codes.
Comment Response for the LT2ESWTR 1-4 December 2005
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Exhibit 1-5: Example of Comments and Responses to Code 400
EPA Comment Code: 400 H. Ongoing Source Assessment (watershed review during sanitary survey)
Comment Summary: Comments were submitted requesting that States should be allowed to utilize other
measures of watershed changes other than sanitary surveys. Possible suggestions included source water
protection assessments. Several commenters expressed concern that long term trends should be used to
characterize watershed changes and that these changes may be incorrectly identified using the sanitary
surveys.
Response to Comment Code: (A) Commenters asked for greater flexibility in the requirement for States to
determine whether there have been significant changes in the watersheds of their PWSs that could lead to
increased contamination. The proposed rule specified that States must make this determination during
sanitary surveys. However, several commenters noted that some States perform source water protection
assessments on the same frequency as sanitary surveys, and these detailed assessments might be a better
mechanism to monitor changes in the watershed. EPA agrees and today's rule allows States to determine
whether significant changes have occurred in the watershed through either a sanitary survey or an equivalent
review of the source water under another program.
(B) Some commenters were concerned about how States would implement these assessments and required
treatment changes and the guidance that would be available to them to determine significant changes in
pathogen control at the intake. EPA agrees with the comment that perhaps PWSs should be granted time to
collect additional data to support the assessed change, and the final rule allows States the option of requiring
additional monitoring. Regarding concerns that watershed impairment can only be noted on a long term
trend, EPA believes that States will correctly use their discretion to look at long term impairment trends as
well as short term. Potential sources of Cryptosporidium are generally known, such as wastewater treatment
plants, combined sewer overflows, feedlots and runoff, and EPA believes that States will utilize this
understanding in determining changes in pathogens at the intake through their standard sanitary survey and
watershed assessment practices.
Individual Comments
Commenter Name: Anonymous458
Commenter Organization: West Virginia Bureau for Public Health, Office of Environmental Health
Services
EPA Letter ID: 458
EPA Comment ID: 10969
Comment: Page 47677 - It is stated that the Sanitary Survey is envisioned to be the
mechanism to determine if changes in the watershed may lead to increased
potential contamination. The Source Water Protection Assessment would be a
better mechanism to monitor changes. A sanitary survey must address eight
elements, the watershed being one of the eight. During the source water
assessment, the watershed is the only item that is reviewed, in detail. The
Source Water assessment is being done on the same frequency as Sanitary Surveys
in West Virginia, and this may be true in other states as well..
Individual Response: See Response 400(A).
Commenter Name: Christopher Jones
Commenter Organization: State of Ohio Environmental Protection Agency
EPA Letter ID: 591
EPA Comment ID: 12143
Comment Response for the LT2ESWTR 1-5 December 2005
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Comment: 16. §142.16(n)(l), (Page 47795)
This section of the proposed rule requires the State to assess significant
changes in the watershed and source water as part of the sanitary survey process
and determine appropriate follow-up action. Ohio EPA requests that the reference
to the sanitary survey process be removed from the paragraph so as to afford
states the latitude to make watershed and source water assessments as part of
another process or function besides a sanitary survey. In addition, we request
Individual Response: See Response 400(A).
Commenter Name: Gary P. Martinez
Commenter Organization: Sangre De Cristo Water Division, City of Santa Fe
EPA Letter ID: 646
EPA Comment ID: 13571
Comment: The requirement for a watershed survey by a state certified third party is
excessive. Rather, EPA should utilize the existing sanitary survey and source
water protection programs to accomplish this task. The 1995 EPA/State Joint
Guidance on Sanitary Survey includes a review of source waters. Additionally,
the primacy agency recently completed a source water assessment on the Santa Fe
system, which included an evaluation and assessment of the watershed. These
tools used together achieve the goal EPA is seeking, while minimizing the impact
on states programs and communities.
Individual Response: See Response 400(A).
Commenter Name: Florence Reynolds
Commenter Organization: Salt Lake City Public Utilities
EPA Letter ID: 662
EPA Comment ID: 14024
Comment: IV. Discussions of Proposed LT@ESWTR Requirements.
A. Additional Cryptosporidium Treatment Techniques for Filtered Systems
(page 47667)
Comment on the proposal to have States determine during Sanitary Survey that
significant changes have occurred in the watershed that could lead to increased
contamination of the source water, the State may require systems to implement
specific actions to address the contamination. These actions include
implementing options from the microbial toolbox.
Watershed impairment can only be noted on a long term trend, Any changes to the
requirements for implementation of the microbial toolbox should be based on
identified long term microbial increases. Some changes in the watershed do not
necessarily lead to increased contamination when appropriately addressed during
the planning process.
Comment Response for the LT2ESWTR 1-6 December 2005
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Individual Response: See Response 400(B).
Commenter Name: Shazelle Terry
Commenter Organization: Jordan Valley Water Conservancy District
EPA Letter ID: 673
EPA Comment ID: 13975
Comment: IV. Discussions of Proposed LT@ESWTR Requirements.
A. Additional Cryptosporidium Treatment Techniques for Filtered Systems
(page 47667)
Jordan Valley Water comment on the proposal to have States determine during
Sanitary Survey that significant changes have occurred in the watershed that
could lead to increased contamination of the source water, the State may require
systems to implement specific actions to address the contamination. These
actions include implementing options from the microbial toolbox.
The proposal to allow States to determine that significant changes in the
watershed have increased the potential for contamination and require systems to
implement specific technology seems unwarranted without data to support the
State-s assessment of perceived impact. If water systems are required to
implement additional treatment, sufficient time must be granted to gather
additional data to support the State-s assessment.
Individual Response: See Response 400(B).
Comment Response for the LT2ESWTR 1-7 December 2005
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2. How to Use This Document
Readers may search for comments and responses by comment code, commenter, or EPA
Letter ID.
By Subject/Comment Code
To search for comments on a particular subject, turn to the table of contents to find the
relevant comment code. Then turn to the chapter that discusses that comment code. You may
choose to read the response to the comment code first. Or you may wish to read the individual
comments first and the response to the comment code last. You may also read each comment and
its response, referring to the recommended subsection of the response(s) to the comment code(s)
as you go.
By Commenter/Letter ID
To search for comments from a particular commenter, look at Appendix A to find the
commenter's EPA Letter ID. Within each chapter and under each response to comment code,
comments are listed in order by Letter ID and then by Comment ID. To avoid looking through
every chapter to find comments by a particular commenter, you might want to look at this
document electronically (a .pdf version is available on the docket website).
To Search Electronically
To search electronically, open the .pdf version of this document using Adobe Acrobat
Reader. Go to Appendix A to find the list of commenters and Letter IDs. Use the Search (in
newer versions of Acrobat Reader) or Find function under Edit on the toolbar (or click on the
binoculars icon). Enter the Letter ID or the commenter name or organization for which you are
searching. If using Find, click on Next or select Find Again to find the next mention of the Letter
ID or commenter. If you are using Search, you should see a list of links to other places in the
document where your search term can be found.
Comment Response for LT2ESWTR 2-1 December 2005
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3. General Comments: Comment Codes 100-180
3.1 Comment Code 100, General Comments
Response to Code 100
a. Thank you for your comments. In developing today's final rule, EPA has considered all comments
submitted on the proposal.
b. As described in the LT2ESWTR Economic Analysis and preamble to today's final rule, EPA has used
the best available data to establish the monitoring and treatment requirements of the LT2ESWTR and to
assess the benefits and costs of these requirements.
c. EPA appreciates the investments that public water systems have made to provide safe water. EPA
recognizes that the LT2ESWTR will result in additional costs to public water systems. However, as
discussed in the LT2ESWTR Economic Analysis and preamble to today's final rule, EPA believes that
the costs of the LT2ESWTR are appropriate due to the health benefits from reduced exposure to
Cryptosporidium and other microbial pathogens that the rule will achieve. Further, as recommended by
the Advisory Committee, the LT2ESWTR targets treatment requirements to higher risk systems, so that
the burden on systems with higher quality source waters will be relatively lower.
d. Today's final rule does not modify the existing MCLG for Cryptosporidium. However, as described in
the LT2ESWTR Economic Analysis, EPA believes that epidemiologic (outbreak) data, along with
laboratory and clinical studies, indicate that a single oocyst can cause infection.
e. EPA and the Advisory Committee considered the concept of "protective immunity" associated with
ingesting low concentrations of Cryptosporidium. The Agency concluded that exposure to
Cryptosporidium, even at low levels, creates the risk of severe illness, in particular for people with
weakened immune systems. Consequently, EPA believes that the LT2ESWTR is appropriate in order to
protect public health by reducing exposure to Cryptosporidium and other pathogenic microorganisms.
f As discussed in the LT2ESWTR Economic Analysis, Cryptosporidium has been associated with large
waterborne disease outbreaks by the Centers for Disease Control. This association has been based on the
presence of Cryptosporidium both in the stools of sick persons and in drinking water supplies with no
other likely source of broad exposure. While other etiologic agents cause waterborne disease, the best
available data are compelling that Cryptsporidium causes waterborne disease. Further, evidence that
Cryptosporidium causes endemic waterborne disease through drinking water is significant. This evidence
includes the widespread finding of Cryptosporidium in drinking water sources, the limitations of
treatment plants in removing Cryptosporidium, the finding of Cryptosporidium in treated drinking water,
and clinical data on the potential for Cryptosporidium to cause infection when ingested.
Cryptosporidium has been directly linked to fatalities in persons with severely compromised immune
systems. Consequently, by reducing cases of disease due to Cryptosporidium, the LT2ESWTR will also
reduce deaths due to this disease. Overall, EPA believes that while uncertainty remains in the precise risk,
the best available data indicate that the LT2ESWTR will significantly reduce morbidity and mortality
associated with Cryptosporidium in drinking water.
g. EPA agrees with the importance of limiting pathogen loading of surface waters, particularly those used
Comment Response for LT2ESWTR 3-1 December 2005
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Chapter 3: General Comments Comment Codes 100-180
as drinking water sources. However, today's final rule does not address the design, operation, and
maintenance of publicly owned treatment works (i.e., wastewater plants). Rather, it addresses appropriate
treatment levels for Cryptosporidium by public water systems based on their source water quality, as EPA
is authorized to do under the Safe Drinking Water Act. EPA is currently exploring the development of
water quality criteria for Cryptosporidium for consideration in future guidance or rulemaking.
h. EPA develops additional regulations, including today's final rule, as science and information related to
risk and mitigation options evolves, consistent with applicable statutes. The Code of Federal Regulations
comprises a unified set of federal requirements for drinking water treatment by public water systems.
i. As discussed in the preamble to today's final rule, EPA believes that the LT2ESWTR maintains the
spirit and substance of the Stage 2 M-DBP Agreement in Principle. Consistent with the Agreement, the
LT2ESWTR includes the following: source water monitoring to establish risk-targeted treatment
requirements, specified binning algorithms and treatment requirements, screening analyses to reduce
source water monitoring costs for small systems, a staggered implementation schedule based on system
size, a large number of available Cryptosporidium treatment and management strategies with the
microbial toolbox.
j. Today's final rule clarifies that monitoring is generally required for "... each plant that treats a surface
water or GWUDI source. Where multiple plants draw water from the same influent, such as the same pipe
or intake, the State may approve one set of monitoring results to be used to satisfy the requirements... for
all plants." If a consecutive system purchases surface water that a wholesaler has monitored to meet the
requirements of the LT2ESWTR, the purchasing (consecutive) system is not required to conduct
additional monitoring of the source. For plants using multiple sources, systems should sample a blended
tap if available. If a blended tap is not available and a system chooses to monitor sources individually,
only surface water or GWUDI sources must be monitored.
k. EPA has followed plain English guidelines in writing today's final rule and has attempted to limit the
length and complexity of the rule to the degree necessary to explain clearly the regulatory requirements.
In addition, EPA is developing guidance documents to assist systems in complying with the LT2ESWTR,
including a small entity compliance guide that is specifically designed to help small systems. EPA is also
developing fact sheets to help the public understand the rule.
1. The preamble to today's final rule states, "The Agency has concluded that it is not currently
economically or technologically feasible for PWSs to determine the level of Cryptosporidium in finished
drinking water for the purpose of compliance with a finished water standard." As described in the
preamble, the LT2ESWTR is designed to protect public health by lowering the level of infectious
Cryptosporidium in finished drinking water to less than 1 oocyst/10,000 L. Approved Cryptosporidium
analytical methods are not sufficient to routinely determine the level of Cryptosporidium at this
concentration. Consequently, the LT2ESWTR relies on treatment technique requirements, rather than a
finished water MCL, to reduce health risks from Cryptosporidium in PWSs.
EPA believes that current methods are sufficient to determine Cryptosporidium levels above 0.075
oocysts/L. Under today's final rule, this level is a source water standard used to determine whether a
filtration plant should provide additional Cryptosporidium treatment. This is not a finished water standard
and is not comparable to an MCL.
Today's rule determines the need for additional treatment requirements using the arithmetic mean of
individual source water Cryptosporidium analysis results. With this calculation, samples in which no
oocysts are detected are assigned a value of zero. Under this approach, a method detection limit for
individual samples is not applicable and today's rule does not establish one.
Comment Response for the LT2ESWTR 3-2 December 2005
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Chapter 3: General Comments Comment Codes 100-180
m. Today's rule incorporates risk-based provisions that result in relatively lower costs to systems with
high quality source water and/or high performing treatment plants while achieving additional public
health protection. Because additional treatment requirements are based on source water monitoring
results, filtered systems with very low levels of Cryptosporidium in their sources (i.e., low-risk sources)
typically will not be required to provide additional treatment. Where additional treatment is required,
systems can achieve additional treatment credit under the microbial toolbox through demonstrating
excellent plant performance results. This includes credit for meeting performance standards similar to
those established by the Partnership for Safe Water. Systems that already provide the highest level of
treatment the LT2ESWTR requires do not have to monitor under the rule.
n. Today's rule defines all monitoring and reporting violations associated with the regulatory
requirements. The proposed rule provided the opportunity for public comment on all such violations.
Significant non-compliance (SNC) relates to enforcement actions by EPA and primacy agencies when
violations occur. They are not a part of the regulatory requirements and, thus, were not included for public
comment with the proposal. Rather, SNC is defined after the regulatory requirements and associated
violations are established.
o. EPA intended the organization of the proposed LT2ESWTR and related documents to facilitate finding
desired information. These documents were the length necessary to provide appropriate supporting
information for the proposed requirements. To improve access, EPA made the proposal and supporting
documents available in electronic formats and in hard copy. The proposal provided direction on how to
obtain copies of documents. In order to allow sufficient time for public comment on the proposed rule and
draft guidance, EPA extended the public comment period to five months.
p. EPA recognizes the important partnership between Federal and State governments and local water
systems in providing safe water. In today's final rule, EPA has included provisions that provide flexibility
when things go wrong for water systems that make good faith efforts to comply. For example, water
systems that are unable to report a valid analytical result for a scheduled sampling date due to equipment
failure, loss of or damage to the sample, or failure of a laboratory to analyze the sample as required have
21 days to collect a replacement sample without penalty. Further, this time may be extended if the system
demonstrates that collecting a replacement sample within this time frame is not feasible or the State
approves an alternative resampling date.
q. Under today's final rule, initial compliance actions with monitoring requirements (e.g., reporting
sampling schedule and location) are required for the largest systems (serving at least 100,000 people)
within 3 months following rule promulgation. EPA believes that these systems will be able to comply
within this time frame given their relatively greater resources and, in most cases, prior experience with
Cryptosporidium monitoring under the ICR. Smaller systems will have additional time to comply.
Further, EPA is developing materials to train systems and States on compliance with the rule, including
the use of data management software (i.e., the LT2 data system).
r. Today's rule establishes treatment technique requirements for Cryptosporidium, as authorized under the
Safe Drinking Water Act. Under these requirements, systems have two basic options: (1) conduct source
water monitoring to determine the required degree of treatment or (2) do not monitor the source water and
provide the highest degree of treatment under the rule. EPA believes that requiring systems to provide the
highest degree of treatment if they fail to monitor is appropriate. A system's source may contain a high
level of Cryptosporidium such that a high degree of treatment is necessary to protect public health.
However, today's rule does not require systems to provide the highest level of treatment for a monitoring
violation (e.g., failure to collect a required sample). In these cases, systems must collect replacement
samples.
Comment Response for the LT2ESWTR 3-3 December 2005
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Chapter 3: General Comments Comment Codes 100-180
The Agreement in Principle specifies that EPA will delay implementation of the LT2ESWTR and Stage 2
DBPR if laboratory capacity is not sufficient. EPA believes that laboratory capacity to support the
Cryptosporidium and E. coli monitoring required under today's rule will be sufficient. Through EPA's
laboratory approval program, the Agency has evaluated capacity at Cryptosporidium laboratories. Based
on information provided by laboratories, EPA believes that current capacity at Cryptosporidium
laboratories will be sufficient for the monitoring that PWSs serving at least 100,000 people will begin six
months after the rule is effective. Commercial laboratories have also suggested that they will increase
capacity as needed to serve the demand of smaller PWSs that begin monitoring later. EPA believes that
such an increase is reasonable, and the staggered compliance schedule should allow time for laboratories
to hire and train staff as necessary. EPA will continue to monitor laboratory capacity and the ability of
PWSs to contract with laboratories to meet their monitoring requirements under the LT2ESWTR. If
evidence emerges during implementation of the rule that PWSs are experiencing problems with
insufficient laboratory capacity, the Agency will undertake appropriate action at that time.
Today's rule provides flexibility for systems that are unable to monitor in the required time frame. If a
system is unable to collect a sample due to extreme circumstances, the system may sample at the next
feasible date without penalty. If a system is unable to report a valid sample result due to circumstances
like loss of the sample or failure by a laboratory to analyze the sample properly, the system may collect a
replacement sample within 21 days without penalty.
EPA believes that the assessment of benefits and costs in the LT2ESWTR Economic Analysis reflects the
best available data and analyses. Both the Science Advisory Board and external peer reviewers have
reviewed this document. These reviewers were generally supportive of the analyses. Further, the version
of the Economic Analysis that supports today's final rule reflects modifications made in response to these
reviews and includes revised compliance cost figures that reflect public comment.
s. EPA believes that the Agency has appropriately characterized uncertainty in estimates of benefits and
costs for today's final rule. As described in the Economic Analysis, EPA used multiple data sets for key
risk parameters like Cryptosporidium occurrence and infectivity, distributions rather than point estimates
for many benefit and cost values, and multiple risk models. As discussed in the preamble to today's final
rule, the Agency considered this uncertainty when developing the LT2ESWTR.
t. EPA believes that the Cryptosporidium management and treatment options in the microbial toolbox of
today's rule reflect the intent of the Agreement in Principle. The LT2ESWTR includes those options from
the Agreement where available data support awarding treatment credit. In addition to UV light, this
includes source water protection, bank filtration, membranes, bag/cartridge filters, ozone, low filtered
water turbidity, and other options. As described in the LT2ESWTR Economic Analysis, today's rule
provides affordable alternatives to UV for all system sizes. EPA has focused primarily on the removal or
inactivation of Cryptosporidium when assigning Cryptosporidium treatment credit to these processes.
EPA believes that this approach is appropriate, since the purpose of adding these processes under the
LT2ESWTR is to improve public health protection against Cryptosporidium. EPA recognizes that certain
processes may also improve overall treatment stability and performance. If this results in improved
Cryptosporidium removal beyond the standard credit awarded in today's rule, systems may receive higher
credit through a demonstration of performance.
u. In developing the LT2ESWTR, EPA used national data sets, including the ICR and ICR Supplemental
Surveys, for the occurrence of Cryptosporidium, E. coli, and other parameters. As described in the
preamble, these data indicate that E. coli, when used in a screening analysis with the trigger
concentrations in today's final rule, can identify systems with low Cryptosporidium levels that should not
be required to monitor for Cryptosporidium. However, because available data are limited, EPA will use
Comment Response for the LT2ESWTR 3-4 December 2005
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Chapter 3: General Comments Comment Codes 100-180
the additional data generated by large system monitoring to confirm or refine the E. coli trigger levels for
small systems. Since large systems will monitor prior to small systems, the implementation schedule in
today's final rule will allow EPA to make decisions regarding E. coli trigger levels prior to the initiation
of small system monitoring. Consequently, EPA believes that separating small system E. coli monitoring
from large system monitoring in two rules, as the commenter recommends, is unnecessary. Further,
because system specific monitoring leads to system specific treatment requirements under today's rule,
EPA believes that both monitoring and treatment requirements should be contained in the same rule.
v. EPA believes that today's final rule appropriately balances targeted risk reduction with simplicity and
flexibility. The rule establishes site-specific treatment requirements based on source water monitoring
results. While this approach is necessarily more complex than requiring all systems to provide the same
level of treatment, it will target public health expenditures to systems with the highest risk. The microbial
toolbox provides a wide array of treatment and management options to give systems flexibility in meeting
additional treatment requirements. Additional provisions increase flexibility. For example, systems may
collect source water samples outside of scheduled sampling dates if sampling during the scheduled period
is not feasible.
EPA is also developing guidance to assist systems and States with understanding and complying with
today's rule. While this guidance in total is lengthy, EPA expects that systems will only read the portions
of guidance that apply to their situation. Further, EPA believes that guidance must be long enough to
clearly explain the rule and compliance options to systems and States.
w. New analytical methods may be approved for today's rule through the alternative testing procedures
program. In general, new methods must demonstrate equivalent performance to currently approved
methods to qualify for approval.
x. EPA agrees that the Agency has an important role in providing direction on the use of technologies and
consensus standards for regulatory compliance. Today's rule includes criteria and associated guidance for
management and treatment processes in the microbial toolbox. EPA has identified these to be appropriate
for meeting additional Cryptosporidium treatment requirements. Further, EPA recognizes that new and
effective technologies for Cryptosporidium treatment may be developed. Today's rule allows States to
grant treatment credit for the use of such technologies, as the commenter recommends, under a
demonstration of performance. EPA cannot create legally binding requirements on the Agency for a
specific process for reviewing new technologies as recommended by the commenter. However, in
practice, the Agency regularly evaluates new technologies and consensus standards. Where appropriate,
EPA provides direction on the use of these technologies or standards through new or updated regulations
and guidance.
y. Systems achieve treatment credit for microbial toolbox options on a monthly basis by meeting the
regulatory performance criteria specified in today's rule. As stated in today's final rule, failure by a
system in any month to achieve treatment credit for microbial toolbox options that is at least equal to the
level of required treatment is a violation of the treatment technique requirement.
z. Today's rule follows existing laws and regulations for State primacy and enfo rcement. During the
period when EPA has primacy for today's rule, the Agency will work with States on implementation.
aa. EPA believes that the Stage 2 M-DBP Federal Advisory Committee included effective representatives
from a broad range of stakeholders and that the resultant Agreement in Principle was not dominated by
any single interest group, including those with a financial interest in UV light. Future Advisory
Committees will establish the ground rules under which they operate, consistent with applicable statutes.
Comment Response for the LT2ESWTR 3-5 December 2005
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bb. EPA considered the Calgon Carbon patent for UV inactivation of Cryptosporidium and the associated
license fee when developing the LT2ESWTR. The Agency believes that UV remains a feasible
technology for meeting additional Cryptosporidium treatment requirements under today's rule. In the
Economic Analysis for the LT2ESWTR, the projected household costs account for this license fee.
Individual Comments on Code 100
EPA Letter ID: 101
Comment ID: 10914
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: NRWA believes and the Safe Drinking Water Act directs the Agency to use sound science
and use good judgment to protect public health. In an effort to support the position of the nation's over
23,000 communities NRWA has developed scientifically sound white papers. We have taken the time to
summarize these positions below and have attached the regulatory white papers as appendices for your
use in setting the regulation for the LT 2 and Stage 2 Final Rules. We strongly encourage EPA to use the
concepts and positions that support the regulatory positions that NRWA has adopted on behalf of the over
23,000 small and rural communities across the country.
Response: See Response lOO.a.
EPA Letter ID: 101
Comment ID: 10915
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Regulatory Conservatism
In the development of a regulation that concerns protection of the public health, any agency charged with
this responsibility would be prudent to be conservative in its judgments and assumptions so as to be "safe
rather than sorry". However, the degree of conservatism used has a direct effect on the cost of the
regulation, and if the conservatism is extreme, there is a risk that the regulation will be so costly that
potential benefits are outweighed by unhealthful tradeoffs which consumers are forced into because of the
regulation. Historically, EPA has tended toward ultra conservatism in three areas of its regulation
development; (1) in the selection of values for parameters involved in the calculation of MCL values; (2)
in the methodology and numbers used in the evaluation of benefits versus costs of regulations required by
the 1996 Amendments to the SDWA; and (3) in the evaluation of the effect of magnitude, duration and
frequency of exposure to a contaminant on the choice of the MCL value and on the flexibility of its
subsequent enforcement. The following policy positions speak to NRWA's concerns in these three areas.
Response: See Response lOO.b.
EPA Letter ID: 390
Comment ID: 10490
Comment Response for the LT2ESWTR 3-6 December 2005
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Commenter: Jeff Taylor, Deputy Director, City of Houston Public Utilities Division
Commenter Category: Regulated Community (Utilities)
Comment: The City of Houston appreciates the opportunity to offer comments on the Proposed Long
Term 2 Enhanced Surface Water Treatment Rule. While we are in substantial agreement with most of the
terms and assumptions in this rule, we would like to offer the following comments:
Response: See Response lOO.a.
EPA Letter ID: 391
Comment ID: 10497
Commenter: Ricardo Nelson Rios,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: disinfection byproducts. We support the EPA's proposed rule as a positive step to keep our
drinking water free from harmful chemicals. Constant monitoring and reporting of drinking water
conditions reinforces our agreement of the rule. Even further making such information available will also
provide the community with a tighter grasp on any possible terrorist attempts. In turn it will enhance our
homeland security and trim down the possibility of any deliberate poisoning of our drinking water. And,
for the most part, we believe that US EPA's own existing Interim Enhanced Surface Water Treatment
Rule (IESWTR) Audit Policy is consistent needs to be enhanced. Stepping back from the specifics,
however, we are concerned about the larger picture created by these incremental changes to the current
audit policy.
Cryptosporidium. This improvement will have a tremendous impact in the health and economical system
of The United States. This rule will reduce dramatically the drinking water. Thereby, reducing both illness
and death associated with cryptosporidiosis. Patients with cryptosporidiosis in sensitive subpopulations,
such as infants the elderly, and AIDS patients are at risk for severe illness, including risk of death.
Although, there are substantial benefits from this rule due to reduce rates; there are also other potentially
significant benefits that remain unqualified yet. The time frame used for both health benefit and cost
evaluated including predictions of costs and benefits. The Advisory Committee because provides
significant health benefits in terms or sensitive subpopulations, expect a positive result of this propose
rule.
Response: See Response lOO.aand lOO.b.
EPA Letter ID: 417
Comment ID: 10522
Commenter: Kenneth Brown, Authority Manager, Stroudsburg Municipal Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: The Authority agrees with the new rule changes "in principle" as the AWWA does, but is
concerned about several areas which it feels need to be addressed prior to implementation:
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 3-7 December 2005
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EPA Letter ID: 417
Comment ID: 10527
Commenter: Kenneth Brown, Authority Manager, Stroudsburg Municipal Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: The Authority has spent over $7 million dollars the last 10 years to upgrade its
treatment facilities, add groundwater sources and increase testing procedures. It has been involved in
numerous studies, and programs to enhance its ability to provide the safest water possible and is planning
on more investments in the future.
It is addressing its Vulnerability Assessment/Emergency planning and will spend $300,000 - $500,000 on
security measures over the next 5 years. It does not need a new financial/regulatory burden placed on it
that is not ready to go. The USEPA must better address the many questions and issues of LTZESWTR
prior to plementation.
Response: See Response lOO.c.
EPA Letter ID: 423
Comment ID: 10567
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: CS Title: Comment referring to " the states being relegated to a bystander's role", submitted
by Robert L. Foster, Jr., Deputy Director, Tennessee Division of Water Supply
Response: See Response lOO.a.
EPA Letter ID: 424
Comment ID: 10839
Commenter: Frank Ray,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: Comment: The EPA has set the MCLG for Cryptosporidium at zero based on the belief that a
single oocyst can cause infection. However, this belief is not based on direct observation, but rather on a
statistical modelling of data. This is not using the best available science, which EPA is required to utilize
in its rulemaking process. Furthermore, the complete removal of Cryptosporidium from
Response: See Response lOO.d.
Comment Response for the LT2ESWTR 3-8 December 2005
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EPA Letter ID: 424
Comment ID: 10840
Commenter: Frank Ray,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: rulemaking process. Furthermore, the complete removal of Cryptosporidium from all water
sources may have a negative impact on human health in that it could compromise the immune system
development of healthy individuals. Cryptosporidium ingested at low concentrations may impart an
immunological benefit to healthy individuals, protecting them from subsequent exposure and infection by
Cryptosporidium encountered in ingested water or from other environmental sources. The EPA has not
measured the possible negative effect of compromising the immune systems of healthy individuals
against the possible positive protection afforded to the immunocomromised via completed elimination of
Cryptosporidium from all drinking water sources. Frank Ray 1109 SE 76th Avenue
Response: See Response lOO.e.
EPA Letter ID: 427
Comment ID: 10585
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: -Waterborne outbreaks are the primary stimulus for the regulation. Drinking water exposure
to sewage has been the common denominator with the large drinking water outbreaks. Bull Run has
LT2ESWR has been based on two major premises;
-Cryptosporidium parvum has been responsible for significant waterborne disease outbreaks Large
waterborne outbreaks have all been associated with sewage discharge, and millions of pathogenic
organisms that go with it. To include Cryptosporidium spp. were the sole etiological agent cannot be
scientifically supported.
-It is likely the organism is responsible for reports of significant endemic disease as well
There is no direct, indirect, or collateral evidence reported to or from public health service agencies
indicating municipal treated drinking water is associated with endemic disease from Cryptosporidium
spp. The scope and awareness of these studies in the medical community has has been broad enough and
long enough to show me indicator of disease if there was a direct relationship.
There is no direct, indirect or collateral evidence of deaths to be saved from LT2.No deaths have been
attributed to Cryptosporidium spp. for almost ten years, since 1993.
In the end the LT2ESWR baseline data is inconclusive. There is so much variation among and within the
methods and interpretations, the results cannot be scientifically reproduced. The ability to repeat or
reproduce experimental scientific data that generates an unbiased outcome is the hallmark of the
Scientific Method. It is on this principle I base my scientific conclusion.
Response: See Response lOO.f.
Comment Response for the LT2ESWTR 3-9 December 2005
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EPA Letter ID: 441
Comment ID: 10766
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Overall, DEP supports EPA's efforts to increase public health protection by reducing adverse
health risks from microbial contaminants. DEP is providing the following comments in response to EPA's
request for comments, "National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface
Water Treatment Rule."
Federal agency coordination
Under LT2, EPA has recognized that Cryptosporidium oocysts in surface water sources is a public health
threat. This is a different approach from previous rules, which seek to address the threat from oocysts in
treated drinking water. DEP requests that EPA's programs coordinate
closely to ensure federal regulations and policies are compatible. As one example, EPA's proposed policy
titled, "National Pollutant Discharge Elimination System Permit Requirements for Municipal Wastewater
Treatment Discharges During Wet Weather Conditions" (Docket ID No. OW-2003-0025) allows
pathogen loading through bypassing and blending practices during
the most challenging time for public water suppliers (i.e., during rapidly changing, turbid water conditions
when treatment is difficult). In effect, the policy does not require long-term plans to improve the design,
operation and maintenance of publicly owned treatment works or the
collection systems in order to reduce Cryptosporidium concentrations. In this instance, close coordination
at the federal level would decrease adverse public health risks and help reduce the LT2-mandated design,
operation and maintenance expenses associated with the installation of expensive technologies at public
water supplies.
Response: See Response lOO.g.
EPA Letter ID: 445
Comment ID: 10822
Commenter: James Fay, Chair, PSW Steering Committee, The Partnership for Safe Water
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The PSW appreciates this opportunity to comment on this important regulation, and shares
EPA's goal of reducing risk of Cryptosporidium through optimization of water treatment plants. If the
PSW can assist EPA in furthering our common
Response: See Response lOO.a.
EPA Letter ID: 447
Comment ID: 10794
Commenter: Michael Barsotti, Water Quality Director, Camplain Water District
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 3-10 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Comment: proposed regulations. Regulation of cryptosporidium inactivation/removal is important to
protect the public health. CWD has achieved the Partnership for
Response: See Response lOO.a.
EPA Letter ID: 452
Comment ID: 10933
Commenter: Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Commenter Category: Regulated Community (Utilities)
Comment: We support the effort to reduce microbial disease incidents by targeting additional treatment
requirements to higher risk systems. We have important
Response: See Response lOO.a.
EPA Letter ID: 453
Comment ID: 10945
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: 4. We should end up with one surface-water treatment rule instead of the SWTR,
modified by the IESWTR, modified by the LT2ESWTR. It-s confusing.
Response: See Response lOO.h.
EPA Letter ID: 457
Comment ID: 11881
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Register (68 FR 49547), respectively. Our comments generally reflect the comments that have
been provided by the Association of State Drinking Water Administrators (ASDWA) that represents the
collective interests of the nation's state drinking water programs responsible for the implementation of the
Federal safe Drinking Water Act. Although we have provided our comments through ASDWA, we again
provide them here separately.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 3-11 December 2005
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Chapter 3: General Comments Comment Codes 100-180
EPA Letter ID: 457
Comment ID: 11883
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Overall Approach for the LT2EWSTR
We concur with the risk-based approach proposed under the LT2ESWTR in which surface water systems
monitor for microbial contaminants and only those systems finding higher levels of contaminants in their
source waters are required to provide additional protection against Cryptosporidium. This
Response: See Response lOO.a.
EPA Letter ID: 457
Comment ID: 11912
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: We concur with the risk-based approach proposed under the LT2ESWTR in which surface
water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium. This includes the
proposed requirement for
Response: See Response lOO.a.
EPA Letter ID: 466
Comment ID: 11006
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: Overall, we support EPA-s efforts to increase public health protection by concurrently
addressing risks from microbial contaminants and disinfection byproducts (DBPs). ND concurs with the
riskbased approach proposed under the
Response: See Response lOO.a.
EPA Letter ID: 468
Comment ID: 11048
Commenter: Michael L. McGlinchy, Public Utilities Bureau Manager, City of Akron Public Utilities
Bureau
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 3-12 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Comment: CS Title: Comment referring to "The FACA committee developed the microbial toolbox to
provide alternatives to ultraviolet (UV) disinfection, and to promote drinking water treatment
technologies with a broader range of water quality benefits" submitted by
Response: See Response lOO.a.
EPA Letter ID: 470
Comment ID: 11060
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: We appreciate the opportunity to comment on this proposed rule. We have raised some issues
where we do not agree with the Agency-s approach to this necessary regulation; however, we strongly
support the premises on which the rule is built. We believe that the public health protections that the rule
addressescan be achieved with the suggested improvements that we have provided. [SEE PDF]
Response: See Response lOO.a.
EPA Letter ID: 471
Comment ID: 11103
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "The Final Rule must be protective of public health while
flexible enough to account for the difficult realities and scientific and technical uncertainties facing
drinking water utilities" submitted by John R. Griffin, General Manager
Response: See Responses 100.a and 100.i.
EPA Letter ID: 471
Comment ID: 11106
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: customers. The WSSC appreciates this opportunity to comment on the Long-Term 2
Enhanced Surface Water Treatment Rule (LT2ESWTR). We believe there have been positive
achievements as a result of the Federal Advisory Committee Act (FACA) process, and we commend the
efforts of those involved in that process. Because of these efforts, we, along with many other utilities,
strongly believe that the spirit of the Agreement in Principle developed by the FACA process must be
maintained in the final rule. The Final Rule must be protective of public health while flexible enough to
account for the difficult realities and scientific/technical uncertainties facing drinking water utilities. It is
with
Comment Response for the LT2ESWTR 3-13 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Response: See Response lOO.i.
EPA Letter ID: 471
Comment ID: 11160
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "The Final Rule must be protective of public health while
flexible enough to account for the difficult realities and scientific and technical uncertainties facing
drinking water utilities" submitted by John R. Griffin, General Manager
Response: See Response lOO.i.
EPA Letter ID: 471
Comment ID: 11163
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: customers. The WSSC appreciates this opportunity to comment on the Long-Term 2
Enhanced Surface Water Treatment Rule (LT2ESWTR). We believe there have been positive
achievements as a result of the Federal Advisory Committee Act (FACA) process, and we commend the
efforts of those involved in that process. Because of these efforts, we, along with many other utilities,
strongly believe that the spirit of the Agreement in Principle developed by the FACA process must be
maintained in the final rule. The Final Rule must be protective of public health while flexible enough to
account for the difficult realities and scientific/technical uncertainties facing drinking water utilities. It is
with
Response: See Response lOO.i.
EPA Letter ID: 472
Comment ID: 11152
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: COP, thou not an active participant, supports the Stage 2 Microbial/Disinfection Byproducts
(Stage 2 M/DBP) Agreement in Principle and the basic components of that Agreement as reflected in the
Long Term 2 Enhance Surface Water Treatment Rule (LT2ESWTR) proposal. This includes: (1)
monitoring of Cryptosporidium to facilitate bin determinations, (2) the binning algorithm and specific bin
boundaries, (3) the microbial toolbox, and (4) implementation sequence.
Response: See Responses 100.a and 100.i.
Comment Response for the LT2ESWTR 3-14 December 2005
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Chapter 3: General Comments Comment Codes 100-180
EPA Letter ID: 473
Comment ID: 10709
Commenter: Mary Carol Wagner, Water Quality Manager, Northern Kentucky Water District
Commenter Category: Regulated Community (Utilities)
Comment: quality of our Drinking Water. Overall we support the proposed Long Term 2 Enhanced
Surface Water Treatment Rule (LT2ESWTR). There are a few issues that we
Response: See Response lOO.a.
EPA Letter ID: 480
Comment ID: 11225
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: We do believe there are important rule requirement and implementation issues yet
to be resolved. Following are our specific comments.
Response: See Response lOO.a.
EPA Letter ID: 480
Comment ID: 11226
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: EPA should more precisely describe which systems it intends to regulate under this rule. A
system using purchased surface (a -consecutive system- under the Stage 2 definition) and groundwater
sources would be technically characterized as a -subpart H System. Statements like the following could
therefore lead to confusion about the source water characterization responsibilities:
-All subpart H systems, including wholesale systems, must characterize their source water to determine
what (if any) additional treatment is necessary for Cryptosporidium— (§141.701 (a))
It is recommended that EPA tie the characterization monitoring requirement to any Subpart H system that
provides treatment to the raw water.
Response: See Response lOO.j.
EPA Letter ID: 483
Comment ID: 11256
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
Comment Response for the LT2ESWTR 3-15 December 2005
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Chapter 3: General Comments Comment Codes 100-180
MA
Commenter Category: Regulated Community (Utilities)
Comment: The LT2ESWTR will require a major compliance effort by the SWSC. EPA should strive to
reduce the length and complexity of this rule. It-s difficult enough for large systems, small systems will
be overwhelmed. Laboratory costs are also
Response: See Response lOO.k.
EPA Letter ID: 491
Comment ID: 10661
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: water regulations. ACWD supports EPA efforts to improve protection from Cryptosporidium
and other pathogens through the development of the LT2 rule. In addition, we would like to commend the
EPA and the other parties that have contributed to the development of this rule for all of their hard work
on the important issues involved.
While ACWD supports the main objectives of the LT2 rule, there are a few issues that could benefit from
thoughtful reconsideration. The following paragraphs outline ACWD-s comments on these issues.
Again, ACWD would like to emphasize that we support the implementation of the LT2 rule and the
increased public health protection it will provide. We
Response: See Response lOO.a.
EPA Letter ID: 496
Comment ID: 10685
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: In general, the Mobile Area Water and Sewer System (MAWSS) supports the LT2ESWTR.
Though the EPA has worked closely with water organization representatives to develop many
aspects of the rule and is commended on their efforts, parts of the EPA's implementation of
the rule are unacceptable, and others could be improved.
Response: See Response lOO.a.
EPA Letter ID: 499
Comment ID: 10714
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
Comment Response for the LT2ESWTR 3-16 December 2005
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of Health and Environment
Commenter Category: State/Tribe Government
Comment: Water Treatment Rule (LT2 Rule). KDHE is vitally concerned with the safety and
protection of public water supplies as well as promoting the public-s ability to comply with reasonable
and appropriate regulatory requirements in both a timely and fiscally feasible manner.
In general, KDHE agrees with the principle, design, and process of the proposed LT2 Rule as described
by EPA for meeting the stated objectives. Overall, Kansas supports those components of the proposals
which afford a maximum amount of discretionary authority to primacy agencies while incurring an
absolute minimum of imposition, burden, and cost on the regulated entities. Any and all
Response: See Response lOO.a.
EPA Letter ID: 502
Comment ID: 10630
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: The Columbus Division of Water is principally in support of the LT2ESWTR,
however, there are several parts of the rule on which we feel compelled to provide additional commentary
and request modification consideration. The attached comments are prepared with the intent to continue
our effective working relationship with the USEPA, as we strive to provide water, a life sustaining
resource, for the well-being and economic vitality of our community. This is our mission.
Response: See Response lOO.a.
EPA Letter ID: 503
Comment ID: 10619
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment: WaterOne has the following concerns with the Long Term 2 Enhanced Surface Water
Treatment Rule as it is proposed:
Response: See Response lOO.a.
EPA Letter ID: 504
Comment ID: 11343
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 3-17 December 2005
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Comment: (AIP). While we find major portions of the proposed rule acceptable and well-suited to
achieving rule objectives, we have focused our comments on areas of the proposal that we find
troublesome or in need of alteration to serve the needs of public water supply and public health
protections in the context of the responsibilities of a municipal water supply utility. We hope that our
Response: See Response lOO.a.
EPA Letter ID: 504
Comment ID: 11349
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: We encourage the EPA to continue working with the public water supply industry and
incorporate comments and suggestions as provided in our attachment to produce a regulation that will
provide control for microbial risk in a practical and efficient manner. The LT2ESWTR represents a
proactive step by the drinking water utility community and commitment to further enhance public health
in spite of significant uncertainty regarding projected results.
Response: See Response lOO.a.
EPA Letter ID: 509
Comment ID: 11478
Commenter: Greg Parker,, Florida Department of Environmental Protection Drinking Water Program
Commenter Category: State/Tribe Government
Comment: 141.700 Clarify that the requirements only apply to subpart H systems that use raw surface
water or water under the direct influence of surface water as their source. The requirements should not
apply to subpart H systems that purchase or receive treated surface water as their source.
Response: See Response lOO.j.
EPA Letter ID: 510
Comment ID: 11826
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: The LT2ESWTR is a landmark step forward in protection of public health. The rule
ushers in not only additional attention to an important pathogen of concern, Cryptosporidium, but opens
up the possibility for better control of disinfection byproducts through the development of enhanced and
optimized disinfection treatments and strategies.
We are very happy to support the initiatives embodied in the LT2ESWTR and the UVDGM, with our
attached submission.
Comment Response for the LT2ESWTR 3-18 December 2005
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Response: See Response lOO.a.
EPA Letter ID: 512
Comment ID: 11492
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comments focusing on "CCWD supports the Stage 2 Microbial and Disinfection
Byproducts Agreement in Principle and the basic components of that Agreement as reflected in the
LT2ESWTR proposal" submitted by Jerry Brown, Dir.
Response: See Response lOO.i.
EPA Letter ID: 512
Comment ID: 11494
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: CCWD supports the Stage 2 Microbial/Disinfection Byproducts Agreement in Principle and
the basic components of that Agreement as reflected in the LT2ESWTR proposal. CCWD recognizes the
efforts of EPA staff, who worked closely
Response: See Response lOO.i.
EPA Letter ID: 516
Comment ID: 11702
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: The New York City Department of Environmental Protection (-DEP-) appreciates
this opportunity to comment on the proposed Long-Term 2 Enhanced Surface Water Treatment Rule (-
LT2-), which, when implemented will have a tremendous impact on the operation of New York City-s
water supply and surface water supplies nationwide. As commissioner of the nation-s largest unfiltered
drinking water
Response: See Response lOO.a.
EPA Letter ID: 516
Comment ID: 11709
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 3-19 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Comment: The New York City Department of Environmental Protection (-DEP-) appreciates this
opportunity to comment on the proposed -Long Term 2 Enhanced Surface Water Treatment Rule.- DEP
commends the USEPA for soliciting comments from a broad spectrum of stakeholders, and for convening
a FACA process for the development of these regulations. While DEP remains committed to the
execution of the spirit and intent of the Agreement in Principle which was the outcome of the FACA
process, we have a number of concerns with the regulations as proposed, and the documentation
presented by EPA to justify and clarify the regulations. We are
Response: See Response lOO.a.
EPA Letter ID: 516
Comment ID: 11741
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: p. 47645. EPA concludes that it is not currently economically or technologically feasible for
PWSs to determine the level of Cryptosporidium in finished drinking water. This statement, as worded, is
misleading. DEP-s experience is that the current method is generally reliable and reproducible at the 1
particle per 50 liter range. Regarding cost, the cost for sampling and analysis is relatively small compared
with the decision that the sampling results rest upon. (Consider the cost of sampling, say, with the cost of
the decision that the results of sampling determine). What EPA should clarify, is that it has been unable to
develop an acceptable level (or an MCL) for Cryptosporidium, and that the analytical methodologies are
not sensitive enough within the lower range of concentrations that might be considered appropriate
MCLs. Note that for the purposes of assessing a Microbial Index, EPA indicates (p 4-51 of the
Occurrence and Exposure Assessment (OEA), a Cryptosporidium -level of concern- of 0.075 oocysts/L.
This is equivalent to 3.5 oocysts/50 L, a level similar to the lowest alert level proposed by DEP as part of
its Cryptosporidium Action Plan. DEP has a substantial amount of data, based on seven years of weekly
source water sampling, which shows that this number can be reliably detected. DEP carefully monitors
crypto recovery in source water samples, by analyzing at least one matrix spike per week (or per sampling
event). Matrix spike duplicates are included at a rate of once per month. Rather than use broad
generalizations about the method limitations, DEP believes that the Agency has sufficient data to define,
quantitatively, a practical quantitation limit or method detection limit that at least the best laboratories or
water systems are capable of achieving. Even EPA-s regional laboratories (at least EPA Region II) has
been able to establish precision and accuracy control limits that provide acceptance criteria for crypto
analyses. That is not consistent with the statement about not feasible for determining the level of
Cryptosporidium in drinking water.
Response: See Response 100.1.
EPA Letter ID: 520
Comment ID: 11556
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 3-20 December 2005
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Comment: IEPA concurs with the risk-based approach proposed under the LT2ESWTR in which surface
water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11557
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA supports EPA's efforts to construct rules that address the needs of the various
stakeholders through use of the Federal Advisory Committee Act (FACA). The proposed Long Term 2
Enhanced Surface Water Treatment Rule (LT2ESWTR) appear to be consistent with the FACA
Agreement in Principle with a few exceptions that EPA clearly indicates are not consistent with the
Agreement and provides justification for the departure from the Agreement.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11558
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA also commends EPA for providing pre-publication versions of both rules as well as
additional time for review and comment of the proposed rules. We believe that both actions will
ultimately improve the quality of the final rules.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11559
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Overall Approach for the LT2EWSTR
IEPA concurs with the risk-based approach proposed under the LT2ESWTR in which surface water
systems monitor for microbial contaminants and only those systems finding higher levels of contaminants
are required to provide additional protection against Cryptosporidium. This includes the proposed
Comment Response for the LT2ESWTR 3-21 December 2005
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requirement for large systems to perform Cryptosporidium monitoring to determine risk from microbial
contamination as well as the proposed requirement for small systems to perform indicator monitoring to
determine the need to perform Cryptosporidium
monitoring. However, IEPA does have concerns with the proposed implementation
Response: See Response lOO.a.
EPA Letter ID: 522
Comment ID: 14127
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: First, that the overall broad structure of the proposed regulation represents the generally
reasonable compromises of the Agreement in Principle. These include moving beyond the "one size fits
all" approach of the original Surface Water Treatment Rule to treatment requirements locally tailored to
source water quality, a measured step forward on the control of
Cryptosporidium, and recognition of ultraviolet light (UV) as a significant cost-effective new treatment
technology.
Response: See Response lOO.a.
EPA Letter ID: 522
Comment ID: 14128
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Second, that the devil is in the details, and that we were less comfortable with many of the
implementing details in the regulation and guidance documents. This is particularly obvious with UV:
what the broad outline
Response: See Response lOO.a.
EPA Letter ID: 523
Comment ID: 11668
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As it relates specifically to the provisions directly affecting unfiltered surface water supplies,
we believe that the draft as published is in substantial agreement with the AIP. We have reviewed the
many thousands of pages of rule
Comment Response for the LT2ESWTR 3-22 December 2005
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Response: See Response lOO.a.
EPA Letter ID: 523
Comment ID: 11680
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As it relates specifically to the provisions directly affecting unfiltered surface water supplies,
we believe that the draft as published is in substantial agreement with the AIP. We have reviewed the
many thousands of pages of rule
Response: See Response lOO.a.
EPA Letter ID: 524
Comment ID: 12207
Commenter: Gary Larimore, Executive Director, Kentucky Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: In general, KRWA agrees with the comments submitted by the Kentucky Division of
Water (KDOW) and the National Rural Water Association (NRWA). However, KRWA wishes to provide
additional comments in a few areas. They are as follows:
Response: See Response lOO.a.
EPA Letter ID: 526
Comment ID: 11764
Commenter: Nick Jackson,, Knoxville Utilities Board
Commenter Category: Local Government
Comment: Dockett. We feel the legislation will be a great enhancement to the Clean Water Act and
provide some much-needed standards with regard to pathogen-related issues.
Response: See Response lOO.a.
EPA Letter ID: 527
Comment ID: 10844
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As might be expected, there are a number of areas where we believe that EPA-s proposed
implementation of the agreement could be improved. Additionally, we feel that EPA has altered the intent
Comment Response for the LT2ESWTR 3-23 December 2005
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of the agreement in a few areas
Attached is a summary of aspects of the current proposal that require revision as the Agency finalizes the
LT2ESWTR. The following comments should be taken as part of our continuing effort to support prudent
regulatory action in the face of significant uncertainties in virtually every aspect of the occurrence, health
effects, and economic analysis information underlying the proposed rule. Nevertheless we appreciate
EPA-s efforts to insure that a formal risk assessment
was conducted and used as the process by which judgments are made about Cryptosporidium-s potential
to cause harm to humans in drinking water.
Response: See Responses 100.a and 100.i.
EPA Letter ID: 527
Comment ID: 10844
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As might be expected, there are a number of areas where we believe that EPA-s proposed
implementation of the agreement could be improved. Additionally, we feel that EPA has altered the intent
of the agreement in a few areas
Attached is a summary of aspects of the current proposal that require revision as the Agency finalizes the
LT2ESWTR. The following comments should be taken as part of our continuing effort to support prudent
regulatory action in the face of significant uncertainties in virtually every aspect of the occurrence, health
effects, and economic analysis information underlying the proposed rule. Nevertheless we appreciate
EPA-s efforts to insure that a formal risk assessment
was conducted and used as the process by which judgments are made about Cryptosporidium-s potential
to cause harm to humans in drinking water.
Response: See Responses 100.a and 100.i.
EPA Letter ID: 528
Comment ID: 12240
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Overall, we support EPA-s efforts to increase public health protection by concurrently
addressing risks from microbial contaminants. We concur with the risk-based approach proposed under
the LT2ESWTR in which surface water systems monitor for microbial contaminants and only those
systems finding higher levels of contaminants are required to provide additional protection against
Cryptosporidium.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 3-24 December 2005
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EPA Letter ID: 536
Comment ID: 11774
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Overall, Colorado supports EPA-s efforts to increase public health protection by concurrently
addressing risks from microbial contaminants and disinfection byproducts (DBPs). We concur with the
risk-based approach proposed under the LT2ESWTR in which surface water systems monitor for
microbial contaminants and only those systems finding higher levels of contaminants are required to
provide additional protection against Cryptosporidium. At the same time, Colorado is concerned that this
regulation does not go far enough to incorporate a risk-
based approach. It continues the top down, command and control approach to public health protection
through regulation that relies on resource intensive reporting and oversight. While the proposed rule will
define violations, and guidance will be provided on significant non-compliance (an additional issue), the
rule does not provide a means to reduce the implementation costs to public water systems or state
programs for those systems that truly have excellent performance results and present low risks to their
consumers. Colorado strongly recommends that EPA incorporate a more robust risk-based regulation that
will: build on an excellence approach (such as the Partnership for Safe Drinking Water), provide some
regulatory relief for systems that demonstrate excellent performance, and reduce the implementation costs
for systems and state primacy agencies.
Response: See Response lOO.m.
EPA Letter ID: 536
Comment ID: 11776
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Colorado is concerned that the materials provided to date do not define significant non-
compliance (SNC) for the proposed rule, but point to such definition at some future date. Colorado
believes that this approach is not appropriate and if SNC is to be defined for a new regulation, it should be
included in the materials available for comment at the time that the rule is
proposed. SNC definitions have a profound effect on state implementation decisions, business processes,
and the primacy agency-s relationship with regulated entities. The relationship between the primacy
agency and public water systems must be built on predictability and trust if we are to succeed in ensuring
the continuous delivery of safe drinking water. Defining SNC after the rule is promulgated significantly
impairs this relationship.
Response: See Response lOO.n.
EPA Letter ID: 548
Comment ID: 12150
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
Comment Response for the LT2ESWTR 3-25 December 2005
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California
Commenter Category:
Comment: Metropolitan supports EPA-s goal of reducing disease incidence associated with
Cryptosporidium and other pathogenic microorganisms and believes that this may be attained through
compliance with the monitoring and treatment requirements that are proposed under the LT2ESWTR.
Metropolitan agrees with EPA in many aspects of the proposed rule, in general, but suggests some
changes that could more effectively ease implementation and clarify certain areas where information
may be missing.
Response: See Response lOO.a.
EPA Letter ID: 554
Comment ID: 12223
Commenter: Wayne Price, Water Plant Superintendent, Broad River Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Isue 4: The Federal Register document located at http://www.epa.gov/fedrgstr/EPA-
WATER/2003/August/Day-11/w 18295a.htm. gives a lot of data and information. The document is
difficult to read and quickly find desired information. Some errors also seem to exist.
Response: See Response lOO.o.
EPA Letter ID: 556
Comment ID: 12036
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As a member of the Stage 2 Microbial / Disinfection By-Product Federal Advisory
Committee (FACA), AMWA sought to assist in the development of a rule that would consider new
information on the occurrence and health effects of Cryptosporidium in source water. AMWA remains in
strong support of the Stage 2 M/DBP Agreement in Principle (AIP), and believes that EPA has captured
the vast majority of the letter and spirit of the FACA agreement in the present proposal.
Response: See Response lOO.a.
EPA Letter ID: 556
Comment ID: 12040
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 3-26 December 2005
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Comment: Overall, AMWA believes that -flexibility- should be a key thought in all aspects of
implementation of the rule. Data collection efforts between Stage-1 and Stage-2 FACA discussions amply
illustrated that, even with the best of intentions and efforts, things can and do go wrong with approvals,
sampling methods, data collection, data verification, databases, samples, schedules, and scores of others
necessary activities in complex undertakings. In the event of problems, there needs to be sufficient
flexibility to acknowledge good faith efforts by drinking water utilities. This is in keeping with the
historically excellent cooperation between the vast majority of water suppliers and regulatory authorities.
AMWA believes that all regulations should acknowledge the Federal, State, and local water system
partnership in this effort and continue to build and foster that relationship.
Response: See Response lOO.p.
EPA Letter ID: 556
Comment ID: 12043
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Basic Principle from the FACA Discussions: Implementation of the rule will be
very demanding for water systems and primacy agencies alike. This tension between federal requirements
and flexibility by primacy agencies and water suppliers was evident and acknowledged in all FACA
discussions. The intent of the FACA was that these problems be minimized in order for the rule to be
successfully implemented.
Discussion: The timeframes in the rule start as early as two months after promulgation. To meet such a
schedule requires water systems to begin planning and to initiate consultant and possibly analytical
laboratory contracts even before the rule is finalized otherwise face noncompliance. It is therefore critical
that an outreach program of communication, education and cooperation be
developed and implemented in advance of rule promulgation to inform and facilitate action by water
systems and State primacy authorities. This is a function that EPA typically undertakes with any rule, but
it is far more critical in this case because of the scope and timelines of the effort. Of particular interest in
the success of the entire effort is training for water suppliers, laboratories, primacy agencies and others in
the required data management software system. In the following comments, AMWA recommends
increased flexibility in setting and meeting timelines but believes that, regardless of changes, an outreach
program will prove both necessary and beneficial.
Recommendation: AMWA recommends that EPA begin thinking about how to structure and develop a
program of communication, education and cooperation well in advance of rule promulgation so that water
systems will know what is expected of them and have sufficient time to act to comply with rule
requirements. In this regard the effort should cover all normal efforts at stakeholder training, but should
also include a clear focus on data management software use. This effort should be undertaken in
cooperation with stakeholders. AMWA is ready to meet
with EPA to discuss such programs and how AMWA might assist in -getting the word out-.
Response: See Response lOO.q.
Comment Response for the LT2ESWTR 3-27 December 2005
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EPA Letter ID: 560
Comment ID: 14974
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Canadian provinces, Puerto Rico, and Chile. The issues involved in the management of
microbial pathogens and disinfection byproducts impact American Water, including significant capital
expense for changes in treatment processes. These costs as well as the more stringent limits set by the rule
will affect our customers in terms of increased water rates and reduced public health risks. The issues
raised below are intended to improve the final rule.
Response: See Response lOO.a.
EPA Letter ID: 560
Comment ID: 14996
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Guidance Manual. This ongoing spirit of collaborative effort with this complex rule is an
effective approach to a consensus between health regulators and the water industry. Overall, the proposed
rule is a good translation of the FACA Agreement into regulatory preamble and rule language. Our
primary concerns and recommended corrections are listed above, and are drawn from our research on the
LT2 topics and from our broad experience in applying regulatory concepts in daily practice. We look
forward to EPA modifying the proposed rule accordingly. Our comments are intended to promote the
promulgation of appropriate regulations that can be cost effectively applied to all sizes of public water
systems in the interest of protecting public health.
Response: See Response lOO.a.
EPA Letter ID: 562
Comment ID: 12332
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.13 Legal Issues
If the agency were to promulgate the final rule as proposed, AWWA believes that such action would be
contrary to law, arbitrary and capricious, and an abuse of discretion for the following reasons:
1. The Safe Drinking Water Act (SDWA) does not authorize EPA to mandate a treatment requirement for
failure to monitor.
2. The FACA process and the resultant proposalagency will violates the Administrative Procedures Act
(APA) because the agency did not conduct if the agency does not ensure the assessment of adequate
laboratory capacity for Cryptosporidium and E. coli monitoring as
required by the Agreement in Principle.
3. EPA would abuse its discretion if it subjected public water systems to penalties for failure to comply
with monitoring requirements during what is an unreasonably short timeframe due to during a period of
Comment Response for the LT2ESWTR 3-28 December 2005
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inadequate limited laboratory capacity.
4. The Economic Analysis (EA) is arbitrary and capricious and an abuse of discretion as it overstates the
risk and benefits of the proposed rule, is based on an inappropriate statistical analysis, and understates the
compliance costs.
Response: See Response lOO.r.
EPA Letter ID: 562
Comment ID: 12334
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: with the Stage 2 M/DBP Agreement in Principle. AWWA recommends that the agency
adequately characterize the proactive nature of this rulemaking in the face of an uncertain risk in the
preamble of the final rule. AWWA recommends that the agency reflect this balance both when the agency
is finalizing the specific regulatory requirements and when it communicates the costs and benefits of this
rule to the drinking water utilities, primacy agencies, and their customers the public.
Response: See Response 100.s.
EPA Letter ID: 562
Comment ID: 12337
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: In crafting the proposed rule, EPA has focused exclusively on adding additional
demonstrated inactivation or removal, and has excluded benefits associated with overall treatment
stability and performance (e.g., increased consistency in plant performance, resilience to upset, greater
responsiveness to atypical water quality events). This almost exclusive focus on removal/inactivation has
resulted in a rule structure that encourages utilities to add ultraviolet light disinfection as the only
technology that assures regulatory compliance at what is projected to be an -affordable- cost. This
endpoint is dramatically different from the Stage 2 M/DBP Agreement In Principle. The intent of the
Agreement In Principle was to encourage investment in source water protection and robust treatment
alternatives such as membranes and bank filtration, to retain ozone feasibility, and to reward utilities that
have invested in achieving optimum operating proficiency in their conventional facilities. The
Response: See Response lOO.t.
EPA Letter ID: 562
Comment ID: 12338
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 3-29 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Comment: Significant barriers continue to impede broad implementation of UV disinfection in the U.S.
(i.e., ongoing litigation, lack of certainty regarding validation protocols, lack of state regulator
familiarity). In order for utilities to comply with the LT2ESWTR on the required schedule, the
LT2ESWTR cannot limit compliance to a single technology.
As currently written, the LT2ESWTR is a UV-disinfection rule. This conclusion is not simply AWWA-s
informed opinion, as the agency-s own cost/benefit analysis further substantiates this conclusion. Exhibit
6.9
Response: See Response lOO.t.
EPA Letter ID: 562
Comment ID: 12341
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3.2.4 Balance Between State Flexibility and Agreement in Principle
The proposed LT2ESWTR creates substantial tension between fixed federal requirements and achieving
implementation flexibility for States and operating flexibility for utilities. In general, AWWA supports
the level of detail provided in the rule language. Similarly, AWWA believes that release of the draft
guidance documents in conjunction with the proposed rule substantially improve the public-s
understanding of the proposed rule provisions.
Response: See Response lOO.a.
EPA Letter ID: 562
Comment ID: 12355
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3.5.1 Commitment to Agreement by EPA in the Final Rule
The AIP is limited by providing a generally accepted and agreed upon framework for the proposed
LT2ESWTR. However, the AIP does not bind EPA to that framework in the development of the final
LT2ESWTR. EPA should recognize that the success of the M/DBP FACA process, and the even broader
NDWAC stakeholder process that developed subsequent to the 1996 SDWA Amendments, lies in the
agency-s following through on such generally agreed
frameworks all the way to final rule and implementation guidance.
Response: See Response lOO.i.
Comment Response for the LT2ESWTR 3-30 December 2005
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EPA Letter ID: 585
Comment ID: 11955
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment:
In general, we find that the rules as proposed follow the "Agreement in Principal" developed by the
federal advisory committee for this rule. However, since new data is available that was not available at
the time of the "Agreement in Principal", there are some issues that we wish to address as well as other
specific comments on the rule.
Response: See Response lOO.a.
EPA Letter ID: 586
Comment ID: 12196
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: will offer significant savings to many small systems. However, we believe that there are a few
other requirements that should be reconsidered, especially with respect to small system operation.
Response: See Response lOO.a.
EPA Letter ID: 590
Comment ID: 12029
Commenter: Steve Robbins, General Manager-Chief Engineer, Coachella Valley Water District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 2200 XVII. Economic Analysis
Comment: Although Coachella Valley Water District supports, in principle, the aims of the proposed
LT2ESWTR, we believe the economic analysis by the EPA is flawed.
Response: See Response lOO.r.
EPA Letter ID: 591
Comment ID: 12118
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: GENERAL COMMENT:
Ohio EPA recommends that the proposed rule be separated into two rules that would be promulgated
successively. U.S. EPA acknowledges that the lack of a known correlation between E. coli and
Comment Response for the LT2ESWTR 3-31 December 2005
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Comment Codes 100-180
Cryptosporidium occurrence in source waters creates a strong possibility of later revising the proposed
levels of E. coli that will trigger water systems serving less than 10,000 to conduct Cryptosporidium
monitoring. The uncertainty associated with the proposed trigger levels coupled with the expansive scope
of the rule in terms of both time and potential treatment requirements lead us to believe that
implementation would be more manageable by promulgating two separate rules. The first rule should
focus on data gathering/analysis with the second rule building on the first by using the new data to help
set more reliable triggers for Cryptosporidium monitoring by small systems and implementing treatment
requirements.
Cryptosporidium data is collected and analyzed. As stated in the General Comments, we believe
implementation would be more manageable by promulgating two
separate rules.
Response: See Response lOO.u.
EPA Letter ID: 592
Comment ID: 12095
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: and environmental hardship. The proposed LT2 rules represent anunjustifiable economic
hardship that the people of Maine and Maine-s drinking water purveyors will not be able to support, as
currently written.
Response: See Response lOO.c.
EPA Letter ID: 592
Comment ID: 12112
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Simplify the rule
Much of the terminology in this proposed rule is vague and/or confusing and will present a peat challenge
when trying to explain it to the public. The bin system alone will never be understood outside of this
industry and this will create an added burden when drinking water purveyors need to go to the public to
explain why they need to spend more money and raise rates again. This rule as proposed rural states with
unfiltered surface water sources. While the goals of this proposal are laudable, the actual rules need to be
simpler, more flexible and less demanding if any reasonable level of compliance is ever expected.
Response: See Responses lOO.k and lOO.v.
EPA Letter ID: 593
Comment ID: 11814
Comment Response for the LT2ESWTR
3-32
December 2005
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Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: which was published August 11, 2003 in the Federal Register (68FR47639). The
Environmental Protection Agency (EPA) has worked closely with water utility representatives to develop
many aspects of LT2ESWTR and should be commended for its efforts.
The proposed rule will significantly impact the operation of many water utilities, and it is palpably
important to the protection of public health.
Response: See Response lOO.a.
EPA Letter ID: 593
Comment ID: 11815
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: 1. Section 141.701(a) requires that sub-part H systems characterize their source water, A
system may have many public water supply wells, only one or a few of which are subject to sub-part H.
Sections 141.701(a) and 141.702(a)(l) are not specific as to whether such systems must characterize all of
their source water, or only those particular wells that may be subject to sub-part H. The present ambiguity
in the proposed rules could inadvertently require substantial expenditures, and unnecessary sampling,
testing, analysis and characterization of all water sources, including those not subject to sub-part H, solely
because a system has one sub-part H source. The proposed rules should be clarified to provide that only
those sources that are subject to sub-part H, not entire -systems- must be characterized.
Response: See Response lOO.j.
EPA Letter ID: 595
Comment ID: 12572
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: In general, the Maine Drinking Water Program supports EPA-s efforts to increase
the protection of public health by simultaneously addressing risks associated with both microbial
contaminants, as well as disinfection byproducts. The State agrees that only those surface water systems
finding elevated levels of microbial contaminants during monitoring should be required to provide
additional microbial inactivation.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 3-33 December 2005
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EPA Letter ID: 595
Comment ID: 12573
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Maine-s surface water supplies are among the most pristine in the country. Maine
water suppliers are diligent in providing safe water to their customers. Consumers have noticed
improvements in their water quality and have also been footing the bill. In response to the 1986 Surface
Water Treatment Rule utilities improved their facilities by investing in capital bonds for disinfection,
treatment and watershed protection efforts. These bonds have 20 year payment periods, most of which
will be still in force until 2011 or 2013.
Response: See Response lOO.c.
EPA Letter ID: 595
Comment ID: 12577
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: The complexity of the LT2ESWTR and the Stage 2 DBPR will create a significant hardship
on already strained state resources. States have had to manage more and more complex rules with
shrinking state budgets and flat federal funding. In the state of Maine we take the mission of protecting
public health very seriously. However, we are forced to balance increasing demands of more complex
rules with the same resources. We hope that EPA will explore ways of reducing the complexity of the
rules while providing strong public health protection.
Response: See Response lOO.v.
EPA Letter ID: 595
Comment ID: 12606
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Guidance Documents
Maine will submit comments to EPA on the guidances associated with this rule. Maine recommends that
the EPA modify guidances based on changes made to the final rule in response to comments received.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 3-34 December 2005
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EPA Letter ID: 598
Comment ID: 12616
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: Comment Deadline
The original comment deadline for the proposal was November 10,2003. The Utility requested an
extension of the deadline because of the large amount of material to be reviewed in guidance manuals,
background documents, and the companion Stage 2 Disinfectants and Disinfection Byproducts Rule. We
appreciate EPA-s granting of a 60 day extension of the deadline and the additional time to review the
proposed rule.
Response: See Response lOO.a.
EPA Letter ID: 601
Comment ID: 12998
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 510 A. Microbial Framework Approach
Comment: Utah supports EPA's efforts to increase public health protection by concurrently addressing
risks from microbial contaminants and disinfection byproducts (DBPs) and concur with the risk-based
approach proposed under the LT2ESWTR in which surface water systems monitor for microbial
contaminants and only those systems finding higher levels of contaminants are required to provide
additional protection against Cryptosporidium.
Response: See Response lOO.a.
EPA Letter ID: 601
Comment ID: 12999
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah supports EPA's efforts to construct rules that address the needs of the various
stakeholders through use of the Federal Advisory Committee Act (FACA). In fact, Dr. Eva Nieminski, a
Utah staff member participated as a FACA member.
Utah finds the proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) appears to
be consistent with the FACA Agreement in Principle with a few exceptions. Utah has a few concerns with
the rule which are addressed in the following attachment [SEE PDF].
Response: See Responses 100.a and 100.i.
Comment Response for the LT2ESWTR 3-35 December 2005
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Comment Codes 100-180
EPA Letter ID: 601
Comment ID: 13050
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: The requirements for the LT2ESWTR were provided in the Federal Register Notice
dated August 11, 2003 totaling 135 pages. The EPA subsequently issued the following guidance manuals:
* Source Water Monitoring Guidance Manual for Public Water Systems for the Long-Term 2 Enhanced
Surface Water Treatment Rule (LT2 Rule)
* Microbial Laboratory Manual for the Long-Term 2 Enhanced Surface Water Treatment Rule (LT2
Rule)
* Ultraviolet Disinfection Guidance Manual
* Ultraviolet Disinfection Guidance Manual Workbook
* Membrane Filtration Guidance Manual
* Long Term 2 Enhanced Surface Water Treatment Rule Toolbox Guidance Manual
* Guidance on Generation and Submission of Grandfathered Cryptosporidium Data for Bin Classification
Under the Long Term 2 Enhanced Surface Water Treatment Rule
* Guidance on Grandfathering Cryptosporidium Data For the Long Term 2 Enhanced Surface Water
Treatment Rule
Utah asserts that this massive volume of new regulations with accompanying guidance manuals is too
complex to be clearly understood. In addition, the Stage 2 D/DBPR is being developed simultaneously
with the LT2ESTWR. Between the two rules, the EPA issued a combined total of over 2,400 pages of
proposed rules and guidance documents that has placed a significant burden on the resources of water
systems and State agencies interpret and plan for compliance with this
regulation.
Response: See Response lOO.v.
EPA Letter ID: 603
Comment ID: 12639
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: to provide comments on this rule. The Washington State Department of Health supports the
collaborative process used to craft the proposed rule and the flexibility provided to water systems to meet
the overall public health goals, with treatment targeted only for higher risk sources.
Response: See Response lOO.a.
EPA Letter ID: 603
Comment ID: 12643
Comment Response for the LT2ESWTR
3-36
December 2005
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Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: The proposed LT2ESWTR and associated guidance are significant steps forward towards
improved public health protection from Cryptosporidium and other waterborne pathogens. Those
involved in the development of these documents
Response: See Response lOO.a.
EPA Letter ID: 608
Comment ID: 13134
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: We also request that the EPA incorporate into the Rule a pathway to qualify emerging
technologies for water testing, in lieu of old-fashioned expensive wet-lab techniques.
Response: See Response lOO.w.
EPA Letter ID: 610
Comment ID: 12982
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: On behalf of the City of Monroe Water Department, I would like to generally express my
support for the Stage 2M/DBP Agreement in Principle and the basic components of that agreement as
reflected in the LT2ESWTR Proposal as follows:
(1) Monitoring of Cryptosporidium to facilitate bin determinations
(2) The binning algorithm and specific bin boundaries
(3) The microbial toolbox
(4) The implementation sequence
Response: See Response lOO.a.
EPA Letter ID: 610
Comment ID: 12983
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment Response for the LT2ESWTR 3-3 7 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Comment: We are very much concerned about some of the specific aspects of the proposed rules. The
most critical issue is that the failure to meet the proposed
Response: See Response lOO.a.
EPA Letter ID: 610
Comment ID: 12991
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: however, the Guidance Manual does not list the Ozone CT Table anywhere. The proposed
rule almost exclusively focuses on inactivation, and has resulted in a rule structure that encourages
utilities only to add ultraviolet light disinfection to their treatment process to achieve regulatory
compliance. The State 2M/DBP Agreement in Principle intended to encourage investment in source water
protection, robust treatment alternatives, such as ozone, membranes, bank filtration, and rewarding
utilities that have invested in achieving optimum operating proficiency in their convention facilities. This
was not intended to be a "UV" rule.
Response: See Response lOO.t.
EPA Letter ID: 612
Comment ID: 13160
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: 5. State Specific Rule Making:
The LT2 rule specifies that the states will have the jurisdiction to prescribe alternative monitoring
methods for the different toolbox technologies that differ from those that are discussed (CFR 47737).
However, the alternative criteria must meet or exceed performance criteria provided in the LT2
specification.
Discussion:
Specific state rule making is not and has not proven to be an effective avenue for the consideration and
allowance of new technologies. This includes both treatment and monitoring technologies. With few
exceptions, most states have do not have the resources, education, or the experience to consider the use of
alternate technologies. With the vast array of new treatment toolbox options that will be available by LT2,
most states will be forced to defer to the federal regulations and guidelines. In addition, state specific rule
making brings up several concerns. First, many states have constitutional budgetary requirements that
mandate that they will only regulate the federal regulations, nothing more and nothing less. Thus, if new
technologies are developed, providing decree to many states may not be possible. Also, this provides a
shortcoming due to the lack of consistency and best practices across the drinking water industry and
jeopardizes the development of new and innovative technologies that would advance the quality of
drinking water measurement due to the lack of standardization. It is often the case that states want to be
part of the integration of new and better technologies, but without the direct
Comment Response for the LT2ESWTR 3-38 December 2005
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Chapter 3: General Comments Comment Codes 100-180
endorsement and prompt guidance by the Agency, the states often have no foundation to move forward
with new advancements.
The LT2 regulation will likely be the sole source of technologies and education for the majority of states.
In lieu of this, it is imperative that LT2 be as educational as possible, with respect to the presentation of
the technologies associated with the monitoring of the effectiveness of the toolbox options, to the state
agencies. For those new or more complex technologies, LT2 prefers delegation to the states (e.g.
membranes and UV disinfection).
Summary:
The current mechanisms for technology evaluation by the states is restrictive and provides substantial
burden on any state that would like to consider new treatment or monitoring technologies. The Agency
should provide an active mechanism for the consideration of new technologies by the states. Two
suggestions are provided. These can serve as starting points for such mechanisms and LT2 should be
modified to reflect a better means for adoption of such
technologies (CFR47737):
1. State Adoption of New Technologies: Upon this proposal, states would have the ability to evaluate a
new technology that provides inherent benefits over an existing method. Upon the adoption of the
technology by a state, the Agency would be then be required review the technology and determine
whether it should be appended to LT2. Information related to the specific technology, how to use it and
what additional regulatory requirements, if any surround the new technology would be included in the
appended document or in a guidance manual.
2. Consensus Committee Participation: Once the technology is approved through a consensus committee
and becomes a recognized standard, the Agency would be required to perform a timely review of the new
standard and consider determine whether the new standard can in the rule where appropriate. This path
would also provide proof that the Agency is active in fulfilling the legal requirements with respect to the
National Technology and Technology Transfer Act.
If the agency were to deny the acceptance of the new technologies (in either proposed mechanism) it
would have to provide justification as to the denial and actively work with those parties to resolve the
issues that resulted in the rejection. This process should be conducted in a timely manor.
Response: See Response 100.x.
EPA Letter ID: 612
Comment ID: 13161
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: 6. National Technology and Transfer of Technology Act (NTTAA, CFR 47768-47769):
This act directs the EPA to use voluntary consensus standards in its regulatory activities unless to do so
would be inconsistent with applicable law. The NTTAA further directs the EPA to provide congress,
through OMB, explanations when the Agency decides not to use available and applicable voluntary
consensus standards.
Comment Response for the LT2ESWTR 3-39 December 2005
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Discussion:
There are many consensus standards that have been recently developed by consensus organizations that
provide improved monitoring methods over current established Agency methods. These consensus
organizations are typically abreast of what the industry requires with respect to the technology and any
performance monitoring of that technology. What these organizational bodies lack is the regulatory
support and guidance. The consensus standards organizations are commonly the avenue for integrating
new technologies into the drinking water
industry and the EPA should play a more active role in the development of the standards. It is critical that
the Agency be involved in consensus standards development throughout the entire standard development
process, if new and better technologies have a chance of success in those applications where regulatory
monitoring is required. Further, it is critical that the Agency actively provide feedback back to these
standard development workgroups within the respective consensus organizations as to what they interpret
as the needs are of the drinking industry. Ultimately, the Agency is the key avenue of communication
between public health risk reduction and the development of technologies that will aid in establishing this
risk reduction. As mentioned previously, new technologies are available and become available at a rapid
pace.
There currently is no consistent or demonstrated avenue that is provided by the Agency for the assessment
and adoption of new and innovative methods. With the legislation such as LT2 extending more than a
decade into the future, there is a need for consistency and timeliness when considering the application and
use of new innovative technologies that become available for use.
Summary:
The Agency should be mandated to become actively involved in appropriate consensus organizations that
develop methods that translate the health of the general population. This can be demonstrated using a
number of avenues including: consensus committee participation and attendance, stringent timelines for
new method reviews, and required communication between representatives of the Agency and consensus
committee workgroups.
Response: See Response 100.x.
EPA Letter ID: 614
Comment ID: 12968
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Violations
* The whole issue of treatment technique violations needs to be clarified: do violations remove toolbox
credits, and, if so, for how long and what is the Requalification period?
Response: See Response lOO.y.
EPA Letter ID: 617
Comment ID: 13253
Comment Response for the LT2ESWTR 3-40 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: Manchester Water Works supports the approach taken in the Stage 2 M/DBP greement in
Principle and the basic components of that Agreement as reflected in the LT2ESWTR proposal. Our
Water Supply Administrator, Mr. David Paris took part in the negotiations and is a signatory of the
agreement on behalf of AWWA.
Response: See Responses 100.a and 100.i.
EPA Letter ID: 620
Comment ID: 13281
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment:
SPWRS has several concerns regarding the proposed LT2ESWTR language among which are:
Response: See Response lOO.a.
EPA Letter ID: 620
Comment ID: 13285
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: SPRWS is aware of the complexity of developing of rules such as this. We will
Response: See Response lOO.a.
EPA Letter ID: 621
Comment ID: 13164
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Other EPA Comment Codes and Descriptions: 520 B. Bin Concentration Ranges and Treatment
Requirements; 710 A. Microbial Toolbox General Comments
Comment: Data on Log Removal of Cryptosporidium and Removal Credits
I support your approach in controlling Cryptosporidium, your requirements according to source water bin
classification, and your log removal credits. For
Comment Response for the LT2ESWTR 3-41 December 2005
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Comment Codes 100-180
Response: See Response lOOa.
EPA Letter ID: 624
Comment ID: 13174
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: regulation. These comments are prepared with the intended spirit of cooperation between
GCWW and the USEPA. It is our strong belief that open communication and sharing of expertise will
best protect our customers' interest in abundant, wholesome, and affordable drinking water.
Response: See Response lOO.a.
EPA Letter ID: 624
Comment ID: 13175
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: We support the Stage 2 M/DBP Agreement in Principle (AIP) and the basic components
reflected in the agreement for the LT2ESWTR: (a) monitoring of Cryptosporidium to facilitate bin
determination, (2) the bin algorithm and specific bin boundaries, and (3) the microbial toolbox. Our most
significant
Response: See Responses 100.a and 100.i.
EPA Letter ID: 628
Comment ID: 12834
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: a. Requirements for consecutive systems are unclear. It is unclear how proposed rule applies
to a consecutive system that purchases all its water supply from the treated water wholesaler. If a
consecutive system that purchases all its water supply from a wholesaler is not required to conduct
Cryptosporidium monitoring, be bin classified, and provide treatment, the SFPUC recommends the EPA
explicitly state that in the final rule to avoid confusion.
Response: See Response lOO.j.
EPA Letter ID: 631
Comment ID: 13227
Comment Response for the LT2ESWTR
3-42
December 2005
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Chapter 3: General Comments Comment Codes 100-180
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: August 11, 21303 (68 Federal Register 47639). We believe that the attached comments are
substantially more constructive having benefited from the Agency extending the comment period for the
proposal (68 Federal Register 58057).
Response: See Response lOO.a.
EPA Letter ID: 631
Comment ID: 13228
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: The City of Albuquerque is planning for construction of a 92 million gallon per
day surface water plant. Review of the proposed regulation gave rise to questions relating to specific
circumstances in the planning, design, and operation of the plant. Specific comments are included as
appropriate in each section. These areas include:
1. Source Water Monitoring Location
2. Sampling Schedule and Failure to Complete Monitoring
3. Grandfathering Data
4. Laboratory capacity
5. Microbial Toolbox.
Comments on each of these areas are provided in the attached document.
Response: See Response lOO.a.
EPA Letter ID: 631
Comment ID: 13229
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: These comments focus on problem areas in monitoring requirements and the
microbial toolbox.
The City of Albuquerque is planning for construction of a 92 million gallon per day surface water
treatment plant. Review of the proposed regulation gave rise to questions relating to specific
circumstances in the planning, design, and operation of the plant. Specific comments that address
LT2ESVVTR monitoring requirements and microbial toolbox options for the plant are included as
appropriate in each section.
Comment Response for the LT2ESWTR 3-43 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Response: See Response lOO.a.
EPA Letter ID: 633
Comment ID: 13263
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: LTZESWTR Issues: Overall, Des Moines Water Works supports the rule. However, some
aspects of EPA-s implementation of the rule that are unacceptable and others could be improved through
added flexibility as detailed in the following.
Response: See Responses lOO.aand lOO.p.
EPA Letter ID: 634
Comment ID: 13273
Commenter: Michael A. Neher, Environmental Services Manager, City of Henderson
Commenter Category: Local Government
Comment: of Arid States, and the Southern Nevada Water Authority. We understand that those agencies
also will be submitting comments. The draft LT2ESWTR is quite complex and in need of simplification
and clarification. We are hopeful that comments provided by these organizations will be used to further
improve the rule-s effectiveness.
Response: See Responses lOO.aand lOO.v.
EPA Letter ID: 634
Comment ID: 13277
Commenter: Michael A. Neher, Environmental Services Manager, City of Henderson
Commenter Category: Local Government
Comment: Thank you for this opportunity to comment on the LT2ESWTR. We are hopeful the
rule can be made easier to understand and more proportionate to the available health science.
Response: See Responses lOO.a, lOO.k, and lOO.f.
EPA Letter ID: 637
Comment ID: 13110
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 3-44 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Comment: The requirements for the LT2ESWTR were provided in the Federal Register Notice dated
August 11, 2003 totaling 135 pages. The EPA subsequently issued the eight guidance manuals. In
addition, the Stage 2 D/DBPR is being developed simultaneously with the LT2ESTWR. Between the two
rules, EPA has issued a combined total of over 2,400 pages of proposed rules. All of these documents
being issued within such a short time frame is to voluminous for the available staff of a system to digest
and effectively comment on. This places a
significant burden on the resources of water systems and State agencies to interpret and plan for
compliance.
Response: See Response lOO.o.
EPA Letter ID: 641
Comment ID: 13597
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Implementation and enforcement, however, should be the responsibility of the States as they
are more familiar with the systems.
Response: See Response lOO.z.
EPA Letter ID: 643
Comment ID: 12700
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Overall, states support EPA-s efforts to increase public health protection by concurrently
addressing risks from microbial contaminants and disinfection byproducts (DBPs). States concur with the
risk-based approach proposed under the LT2ESWTR in which surface water systems monitor for
microbial contaminants and only those systems finding higher levels of contaminants are required to
provide additional protection against Cryptosporidium. States also support the
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12703
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and
Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR) appear to be consistent with the
FACA Agreement in Principle with a few exceptions that EPA clearly indicates are not consistent with
the Agreement and provides justification for the departure from the Agreement.
Comment Response for the LT2ESWTR 3-45 December 2005
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Chapter 3: General Comments Comment Codes 100-180
States are suggesting changes to the proposed rules that vary from the Agreement in Principle in areas
where states believe an alternative approach will provide equal or greater public health protection. These
changes are discussed in detail later in these comments.
Response: See Response lOO.aand 100.i.
EPA Letter ID: 643
Comment ID: 12704
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States concur with the risk-based approach proposed under the LT2ESWTR in which surface
water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium. This includes the
proposed requirement for
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12765
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States concur with the risk-based approach proposed under the LT2ESWTR in
which surface water systems monitor for microbial contaminants and only those systems finding higher
levels of contaminants are required to provide additional protection against Cryptosporidium. This
includes the proposed requirement for
Response: See Response lOO.a.
EPA Letter ID: 647
Comment ID: 12864
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Overall, MDE support EPA-s efforts to increase public health protection by concurrently
addressing risks from microbial contaminants and disinfection byproducts (DBFs). MDE concurs that a
risk-based approach proposed under the LT2ESWTR in which surface water systems monitor for
microbial contaminants and that only those systems finding higher levels of contaminants are required to
provide additional protection against Cryptosporidium makes sense in theory, but
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 3-46 December 2005
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Chapter 3: General Comments Comment Codes 100-180
EPA Letter ID: 647
Comment ID: 12868
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: MDE supports EPA-s efforts to construct rules that address the needs of the various
stakeholders through use of the Federal Advisory Committee Act (FACA). The proposed Long Term 2
Enhanced Surface Water Treatment Rule (LT2ESWTR) and Stage 2 Disinfectants and Disinfection
Byproducts Rule (Stage 2 DBPR) appear to be consistent with the FACA Agreement in Principle with a
few exceptions that EPA clearly indicates are not consistent with the Agreement and provides justification
for the departure from the Agreement.
MDE suggests changes to the proposed rules that vary from the Agreement in Principle in areas where an
alternative approach will provide equal or greater public health protection. These changes are discussed in
detail later in these comments.
Response: See Responses 100.a and 100.i.
EPA Letter ID: 647
Comment ID: 12869
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: MDE concurs with the risk-based approach proposed under the LT2ESWTR in which surface
water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium. This includes the
proposed requirement for
Response: See Response lOO.a.
EPA Letter ID: 647
Comment ID: 12912
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: MDE concurs with the risk-based approach proposed under the LT2ESWTR in which
surface water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium. This includes the
proposed requirement for
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 3-47 December 2005
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Chapter 3: General Comments Comment Codes 100-180
EPA Letter ID: 668
Comment ID: 13884
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: (August 11, 2003). NRDC supports the LT2ESWTR in general, all provisions in it that were
agreed to by the Microbial and Disinfection Byproducts Federal Advisory Committee-s Agreement in
Principle (-Agreement-), and most of EPA-s proposals to implement and carry out that Agreement (such
as the detailed recommended criteria for qualifying for the -microbial toolbox- credits). However, NRDC
is concerned about some of the details in the proposal, including the apparent underestimate of likely
benefits of waterborne disease avoided by the proposed rule, and certain provisions in the draft.
Response: See Responses 100.a and 100.r.
EPA Letter ID: 677
Comment ID: 13948
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Comment: Register. The City of Sacramento (City) believes the Proposed LT 2 Rule should be reviewed
carefully with additional detail provided on several key implementation issues. Upon reviewing the
Proposed LT 2 Rule the City has several concerns, including:
Response: See Response lOO.aand lOO.k.
EPA Letter ID: 678
Comment ID: 14654
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We would like to congratulate the EPA staff on this Herculean task. Although our comments
will provide some criticisms and suggestions, we want to praise EPA for its thorough analysis and
thoughtful requests for feedback. We hope our attached comments, along with those submitted
Response: See Response lOO.a.
EPA Letter ID: 678
Comment ID: 14658
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: II. Specific Comments on Sections of Proposed LT2 Rule
Comment Response for the LT2ESWTR 3-48 December 2005
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Chapter 3: General Comments Comment Codes 100-180
1. Section 141.700 - It is unclear how the proposed rule applies to a consecutive system that purchases all
its water supply in a treated form from a wholesaler? The rule should explicitly identify the requirements
for a consecutive system that purchases potable/treated water supply from a wholesaler. If a consecutive
system that purchases all of its water supply from a wholesaler is not bin classified, not required to
conduct Cryptosporidium monitoring nor
provide treatment, it should be explicitly stated in the rule for clarity.
Response: See Response lOO.j.
EPA Letter ID: 683
Comment ID: 14756
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
Comment: August 11, 2003 (68 Federal Register 47639). We believe that the attached comments are
substantially more constructive having benefited from the Agency extending the comment period for the
proposal (68 Federal Register 58057).
The City of Albuquerque is planning for construction of a 92 million gallon per day surface water
treatment plant. Review of the proposed regulation gave rise to questions relating to specific
circumstances in the planning, design, and operation of the plant. Specific comments are included as
appropriate in eachsection. These areas include:
These comments focus on problem areas in monitoring requirements and the microbial toolbox.
The City of Albuquerque is planning for construction of a 92 million gallon per day surface water
treatment plant. Review of the proposed regulation gave rise to questions relating to specific
circumstances in the planning, design, and operation of the plant. Specific comments that address
LT2ESWTR monitoring requirements and microbial toolbox options for the plant are included as
appropriate in each section.
Response: See Response lOO.a.
EPA Letter ID: 704
Comment ID: 14803
Commenter: Steven G. Gould, Chairman, New York State American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 8. The burden of cryptosporidium removal is entirely borne by the water system, regardless of
the source of cryptosporidium. Wastewater discharges represent a source of cryptosporidium in water
supplies. Provisions should be included in this rule to couple with the Clean Water Act so that, where
appropriate, the burden of cryptosporidium control is allocated appropriately between water and
wastewater systems.
Response: See Response lOO.g.
Comment Response for the LT2ESWTR 3-49 December 2005
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Chapter 3: General Comments Comment Codes 100-180
EPA Letter ID: 707
Comment ID: 14815
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: Overall, Kentucky supports EPA's efforts to increase public health protection by
addressing risks from microbial contaminants and disinfection byproducts (DBPs).
Response: See Response lOO.a.
EPA Letter ID: 712
Comment ID: 16581
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Overall, NYSDOH supports the Environmental Protection Agency-s (EPA-s) proposal to
provide additional protection from microbial contaminants, particularly cryptosporidium, in public
drinking water supplies. NYSDOH concurs with the risk-based approach of requiring additional
protection at systems with higher levels of contaminants. NYSDOH, however, is concerned with the
proposed implementation schedule, reporting requirements, and the presumptive credit allowed for
specific treatment processes or protection initiatives proposed byEPA.
Response: See Response 300, 370, 600, 721, 761, 766, 771, 791, 801, 821, 831, 851, 881, 891, 911, 931,
and 951.
3.2 Comment Code 110, Support ASDWA's Comments
Individual Comments on Code 110
EPA Letter ID: 588
Comment ID: 12090
Commenter: Lance Nielson, Manager, Idaho Drinking Water Program, Department of Environmental
Quality
Commenter Category: State/Tribe Government
Comment: Idaho drinking water staff participated in discussions leading to preparation of
comments to be submitted on behalf of member States by the Association of State Drinking Water
Administrators (ASDWA). On reviewing the final draft of these comments, we find that they are an
accurate and comprehensive reflection of the views held by our program. We respectfully ask that you
refer to the ASDWA submittal for the bulk of Idaho's comments on this rule.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 3-50 December 2005
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Chapter 3: General Comments Comment Codes 100-180
EPA Letter ID: 707
Comment ID: 14817
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: that meets DBP standards. In General, Kentucky agrees with the comments submitted by the
Association of State Drinking Water Administrators (ASDWA) with the following differences and
additions.
Response: See Response lOO.a.
3.3 Comment Code 111, Support AWWA's Comments
Individual Comments on Code 111
EPA Letter ID: 488
Comment ID: 15034
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Having worked closely with the AWWA in preparing comments for this rulemaking we
generally support the AWWA-s position and comments with respect to most aspects of this rule.
Additionally, we have prepared the following comments regarding
Response: See Response lOO.a.
EPA Letter ID: 677
Comment ID: 13960
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 117 Supports ACWA's comments
Comment: program. The City would also like to encourage USEPA to carefully review the detailed
technical comments provided by the American Water Works Association (AWWA) and the Association
of California Water Agencies (ACWA). We would like to
Response: See Response lOO.a.
EPA Letter ID: 678
Comment ID: 14655
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 3-51 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Comment: We would also like to fully endorse the comments submitted by the American Water Works
Association. These comprehensive and well-analyzed comments deserve full consideration by EPA.
Response: See Response lOO.a.
EPA Letter ID: 703
Comment ID: 14781
Commenter: Rich Weirich, Plant Superintendent, Frenchtown Water Treatment
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 116 Support AMWA's comments
Comment: First I would like to say that I support the comments detailed by the AWWA and
AMWA. I support the stage 2M/DBP Agreement as reflected in the LT2ESWTR
Response: See Response lOO.a.
3.4 Comment Code 115, Support Western Coalition of Arid States'
Comments
Individual Comments on Code 115
EPA Letter ID: 635
Comment ID: 13116
Commenter: Robert A. Hollander, Compliance and Regulatory Affairs Administrator, City of Phoenix,
Water Services Department
Commenter Category: Regulated Community (Utilities)
Comment: In addition to the above comments, the City of Phoenix supports the comments provided by
the Western Coalition of Arid States (WESTCAS) to the EPA regarding the proposed Long Term 2
Enhanced Surface Water Treatment Rule. These comments address lab capacity and data management,
failure to complete monitoring, and sampling schedule issues.
Response: See Response lOO.a.
3.5 Comment Code 116, Support AMWA's Comments
Individual Comments on Code 116
EPA Letter ID: 654
Comment ID: 13118
Commenter: William Brant, Director, Miami-Dade Water and Sewer Department
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 3-52 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Comment: technologies for potable water. In addition to our comments, the MDWASD supports
the comments submitted by the Association of Metropolitan Water Agencies (AMWA). MDWASD
respectfully submits the following comments.
Response: See Response lOO.a.
EPA Letter ID: 703
Comment ID: 14781
Commenter: Rich Weirich, Plant Superintendent, Frenchtown Water Treatment
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 111 Support AWWA's comments
Comment: First I would like to say that I support the comments detailed by the AWWA and
AMWA. I support the stage 2M/DBP Agreement as reflected in the LT2ESWTR
Response: See Response lOO.a.
3.6 Comment Code 117, Support ACWA's comments
Individual Comments on Code 117
EPA Letter ID: 677
Comment ID: 13960
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 111 Support AWWA's comments
Comment: program. The City would also like to encourage USEPA to carefully review the detailed
technical comments provided by the American Water Works Association (AWWA) and the Association
of California Water Agencies (ACWA). We would like to
Response: See Response lOO.a.
3.7 Comment Code 150, Agreement in Principle/FACA Process
Individual Comments on Code 150
EPA Letter ID: 488
Comment ID: 15035
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 3-53 December 2005
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Chapter 3: General Comments
Comment Codes 100-180
Comment: We believe that the concept of proportional treatment that emerged from the two year FACA
process for this rule represents a good new direction for Safe Drinking Water Act (SDWA) regulations.
This concept presents an imporant step in aligning goals of the Clean Water Act (CWA) and SDWA and
and in developing beneficial synergies between regulations under the two mandates. However, this
concept also presents a huge challenge with respect to ensuring that levels of risk associated with specific
drinking water sources are reasonably well characterized before proceeeding with costly treatment
mandates that could detract resources away from other much more certain public health risks.
Response: See Response lOO.c.
EPA Letter ID: 560
Comment ID: 14971
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: with disinfection byproducts. American Water was a signatory to the Federal Advisory
Committee agreement in principle and has participated with EPA in Technical Workgroups and other
discussions in the development of this rule. American Water continues to support the M/DBP FACA
Agreement in Principle and the following comments in no way conflict with our commitment to the
Agreement in Principle document as signed on September 25, 2000.
Response: See Response lOO.i.
EPA Letter ID: 562
Comment ID: 12284
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We affirm our support for the Stage 2 M/DBP Agreement in Principle (AIP)
developed by the Stage 2 Microbial/Disinfection By-Product (M/DBP) Federal Advisory Committee
(FACA) and the basic components of that AIP that are reflected in the LT2ESWTR proposal: (1)
monitoring of Cryptosporidium to facilitate bin determinations, (2) the binning algorithm and specific bin
boundaries, (3) the microbial toolbox, and (4) the implementation sequence.
AWWA reviewed the Federal Register notice and supporting documents for the proposed LT2ESWTR,
the Agreement in Principle (AIP) and the relevant sections of the Safe Drinking Water Act (SDWA). In
our comments, we identify many areas of substantial agreement. Additionally, we believe our
recommended technical revisions will substantially improve implementation of this rulemaking.
Response: See Response lOO.i.
EPA Letter ID: 562
Comment ID: 12291
Comment Response for the LT2ESWTR
3-54
December 2005
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Chapter 3: General Comments Comment Codes 100-180
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA-s comments are consistent with our continued commitment to the Agreement in
Principle as signed on September 25, 2000. AWWA believes that the FACA
process for the Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and Stage 2
Disinfectants and Disinfection By-Product Rule (Stage 2 DBPR) was a successful stakeholder endeavor.
The purpose of this review is to provide
Response: See Response lOO.i.
EPA Letter ID: 562
Comment ID: 12292
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.1 Agreement in Principle
AWWA participated in the Stage 2 M/DBP FACA and signed the Agreement in Principle (AIP) in
September 2000 because the FACA recognized the considerable uncertainties in the available information
on these issues and reflected those uncertainties in a limited, but proactive, set of regulatory
recommendations. AWWA remains fully committed to the execution of the spirit
and intent of the Stage 2 M/DBP FACA-s recommendations as stated in the Agreement in Principle.
With three important exceptions, AWWA believes EPA faithfully reflected the Stage 2 M/DBP FACA
AIP with the proposed LT2ESWTR. The three inconsistent components of the proposed LT2ESWTR are:
1. Failure to meet the proposed requirement for consecutive monthly Cryptosporidium samples triggers
automatic placement of a treatment plant into the bin with the strictest treatment requirements (Bin 4);
2. The proposal briefly mentions laboratory capacity but does not include a demonstration of adequate
laboratory capacity for the required Crytosporidium and E. coli monitoring; and
3. The EPA has been overly restrictive in its specifications for proper design and implementation of
microbial toolbox elements. The agency did not achieve the AIP-s intention of flexible
solutions to bin determinations.
Response: See Responses lOO.i, 100.r, and lOO.t.
EPA Letter ID: 562
Comment ID: 12357
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3.5.3 UV Representatives
AWWA remains concerned that some representatives to the Stage 2 M/DBP FACA process, with clear
financial interests in a single technology (ultraviolet light), participated in the FACA as advocates of this
single technology. More importantly, an alternate representative participated in the FACA process
without disclosing that his company was simultaneously undertaking an
Comment Response for the LT2ESWTR 3-55 December 2005
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Chapter 3: General Comments Comment Codes 100-180
individual corporate strategy to patent the technology the company was advocating as a central
component to the Stage 2 M/DBP Agreement in Principle.*
AWWA remains concerned that the license fee now required by Calgon Carbon may be a significant
impediment to the adoption and use of UV by many water utilities. AWWA strongly encourages EPA to
take measures in the crafting of future FACAs to establish ground rules that require full disclosure of
business and personal interests so that similar situations are avoided in
future FACAs.
Response: See Responses lOO.t, 100.aa, and lOO.bb.
EPA Letter ID: 562
Comment ID: 12358
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
*U.S. Patent 6,129,893, Issued October, 2000.
Response: See Response lOO.bb.
EPA Letter ID: 580
Comment ID: 12626
Commenter: Bruce Aptowicz, Chairman, Water Utility Council of the Pennsylvania American
Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We affirm our support for the Stage 2 WDBP Agreement in Principle (AIP) developed by the
Stage 2 Microbial/Disinfection By-product (M/DBP) Federal Advisory Committee (FACA) and the basic
components of that AIP that are reflected in the LT2ESWTR proposal: (1) monitoring of
Cryptosporidium to facilitate bin determinations, (2) the binning algorithm and specific bin boundaries,
(3) the microbial toolbox, and (4) the implementation sequence.
AWWA reviewed the Federal Register notice and supporting documents for the proposed LT2ESWTR,
the Agreement in Principle (AIP) and the relevant sections of the Safe Drinking Water Act (SDWA). In
our comments, we identify many areas of substantial agreement. Additionally, we believe our
recommended technical revisions will substantially improve implementation of this rulemaking.
Response: See Response lOO.i.
EPA Letter ID: 597
Comment ID: 12609
Commenter: Roger Hulbert, Senior Assistant Director, City of Houston Department of Public Works and
Comment Response for the LT2ESWTR 3-56 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Engineering
Commenter Category: Regulated Community (Utilities)
Comment: and is fully operational. In Item 2.1 la -Implementation Schedule of the Agreement in
Principle with the Federal Advisory Committee Act (FACA), EPA agreed that monitoring,
implementation, and compliance schedules would be delayed by an equivalent time period, if there were a
delay in establishing adequate laboratory capacity, or data management system readiness. EPA should not
unilaterally reject their agreement with the FACA on this issue. The entire FACA process is dependent on
each party honoring the agreement. By ignoring their obligation under Item 2.1 la, EPA is calling into
question the integrity of the FACA process, and jeopardizing the trust of the regulated community that the
Agency will honor any future agreements.
Response: See Response lOO.r.
EPA Letter ID: 643
Comment ID: 12702
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States support EPA-s efforts to construct rules that address the needs of the various
stakeholders through use of the Federal Advisory Committee Act (FACA).
Response: See Response lOO.a.
EPA Letter ID: 703
Comment ID: 14782
Commenter: Rich Weirich, Plant Superintendent, Frenchtown Water Treatment
Commenter Category: Regulated Community (Utilities)
Comment: AMWA. I support the stage 2M/DBP Agreement as reflected in the LT2ESWTR
Proposal: (1) Monitoring of Cryptosporidium to facilitate bin determination, (2) the binning algorithm
and specific bin boundaries, (3) the microbial toolbox, and (4) the implementation sequence.
Response: See Response lOO.i.
3.8 Comment Code 180, Preamble Edits
Response to Code 180
Thank you for these suggested corrections or improvements to the preamble. Where applicable, EPA has
considered these comments in writing the preamble to the final LT2ESWTR. These comments do not
address requirements in the proposed or final LT2ESWTR.
Comment Response for the LT2ESWTR 3-57 December 2005
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Chapter 3: General Comments Comment Codes 100-180
Individual Comments on Code 180
EPA Letter ID: 601
Comment ID: 13049
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah recommends that a comprehensive list of all of the questions or issues on which EPA is
requesting comment be provided at the end of the preamble. A comprehensive list of all of the questions
would reduce the amount of time required to identify and respond to all of the requests.
Response: Response 180.
EPA Letter ID: 621
Comment ID: 13163
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: On page 47662 of the Federal Register you describe dissolved air flotation (DAF)
and cite Gregory and Zabel (1990). This is an old edition of the book. I recommend you cite the most
recent edition (also it is nice for me since I am a co-author). Therefore on p. 47662 you should write
Gregory, Zabel, and Edzwald (1999). On p. 47771 the citation should read Gregory, R., T. Zabel, and J.
Edzwald (1999). Sedimentation and Flotation in Water Quality and Treatment: A Handbook of
Community Water Supplies. R.D. Letterman, ed., American Water Works Association, 5th ed. New York,
McGraw-Hill, 7.47-7.80.
Response: Response 180.
EPA Letter ID: 621
Comment ID: 13168
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: jar tests. Likewise, some of my own bench-scale work is given (Plummer et al
(1995))-note, I did not see this in your reference list on p. 47773; it should be Plummer, J., J Edzwald,
and M. Kelley, 1995, Removing Cryptosporidium by Dissolved Air Flotation, Journal AWWA, Vol. 87,
(No. 9), pp. 85-95. Bench-scale
Response: Response 180.
Comment Response for the LT2ESWTR 3-58 December 2005
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Chapter 3: General Comments Comment Codes 100-180
EPA Letter ID: 673
Comment ID: 14004
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: Jordan Valley Water recommends that a comprehensive list of all of the questions or issues
that EPA is requesting comment on be provided at the end of the preamble. A comprehensive list of all of
the questions would reduce the amount of time required to identify and respond to all of the requests.
Response: Response 180.
Comment Response for the LT2ESWTR 3-59 December 2005
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4. New Data Used to Develop the Rule: Comment Codes
200-251
4.1 Comment Code 220, Cryptosporidium Occurrence
Response to Code 220
1. In regard to Cryptosporidium occurrence the Agency received significant comments on the following
issues:
o Quality of the ICR and ICR Supplemental Survey data sets and whether the estimates derived from
them should be regarded as equally plausible.
o Utilizing other (collected prior to the IESWTR or collected following the ICR Supplemental surveys)
source water monitoring data.
o Improving clarity of the statistical model (e.g., definition of "true zeros") and assumptions (e.g., prior
probability distributions) applied to the occurrence data.
o Need to conduct sensitivity analyses.
2. Regarding the overall quality of the ICR versus ICR Supplemental Surveys, EPA agrees that the survey
estimates differ significantly in predicting the number of systems with high occurrence levels, but does
not believe that the Supplemental Surveys necessarily provide the better estimates. While the
measurement method employed in the Supplemental Surveys had higher recovery and less variable
volumes assayed, the ICR produced a greater number of assays and source waters sampled. There is not
sufficient cause to discard either Survey and EPA has used both in estimating costs and benefits for
today's final rule. A number of commenters agreed that there is no strong basis for rejecting any survey
and that the three separate estimates should be maintained to represent uncertainty about occurrence.
3. A few commenters suggested new data that could be used to inform the ICR and ICR Supplemental
Survey estimates. These other data sets provide local estimates and these may be used to inform our
understanding of local issues such as the effectiveness of watershed control programs or temporal trends
and patterns. One commenter described finished water monitoring data that were consistent with EPA's
assumptions about occurrence and conventional treatment. Another commenter described new data from
an unfiltered source water with very low occurrence levels. While new data are useful for estimating
occurrence in selected sources, only the ICR and ICR Supplemental Surveys provide data of the scope
necessary for producing national estimates. One commenter suggested that finished water monitoring data
could provide more direct, and therefore more accurate information on finished water occurrence. We
agree that future investigations of both source and finished water occurrence may be useful for improving
our understanding of treatment effectiveness. However, until methods are capable of efficiently counting
oocysts in very large volumes of finished water, some combination of occurrence and treatment modeling
will be necessary for estimating occurrence at the national level.
4. Several commenters expressed concern about the complexity or appropriateness of the statistical
treatment. Some commenters misconstrued some aspects of the analysis model, while others reported that
its description was unclear. In response, EPA has revised the Occurrence and Exposure Assessment
document to clarify and enhance its description of both the statistical model and the model's assumptions.
Mathematical model equations clearly and unambiguously communicate significant details to specialists;
additional text and figures were added to communicate these features to non-specialists. The revised
discussion also includes quality assurance checks (to ensure the model provides reasonable estimates
when model assumptions are valid, but also when model assumptions are violated to some degree) and
Comment Response for LT2ESWTR 4-1 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
quality control diagnostics (to ensure the estimation procedures were performing properly and that the
priors were having minimal undue influence on the results).
5. One commenter remarked that the majority of zero counts (no oocysts identified in the volume
assayed) were from samples that truly contained zero oocysts and was concerned that our model assumed
a low probability of such a "true negative." While EPA's model assumed that a small fraction of source
waters truly contained zero oocysts all of the time (our definition of "true zero"), we hadn't assessed the
probability that individual samples contained zero oocysts. Following through on the commenter's
remark, EPA estimated the probability of a "true negative," given a source water of median occurrence
(average concentration 0.1 oocyst / liter), typical variability (natural log of concentration is normally
distributed with standard deviation 1.8), and 10-liter volume assayed by the ICR method. Based on
10,000 simulated samples and measurements, the results were as follows:
70% of the samples contained zero oocysts
93% of the measurement results were zeros
75% of those measured zeros were from samples containing zero oocysts
6. It is interesting to note that the percentage of zero results was the same as that of the entire ICR survey.
More significant, however, was the result that 75% of the measured zeros were "true negatives," that is,
from samples that actually contained zero oocysts. This supports the commenter's claim that most of the
zero results were from samples that actually contained zero oocysts, but it also demonstrates that EPA's
model allows a high probability for "true negatives" to occur (in contrast to some comments). At each
iteration, the estimation algorithm (called Markov Chain Monte Carlo) estimates the likelihood of the data
(with all of the zeros included) and selects parameter values on that basis, preferentially selecting values
that are consistent with the data over values that are not. The algorithm does not adjust the data,
themselves, in any way. Zeros remain zeros and their likelihood conveys information about the model
parameters.
7. A number of sensitivity analyses were conducted to ensure that important features of the model were
recognized and treated appropriately. Other analyses were performed to ensure the priors were
sufficiently diffuse that the estimates derived primarily from the likelihood function. These and other
quality checks are described in the revised Occurrence and Exposure Assessment document.
Individual Comments on Code 220
EPA Letter ID: 522
Comment ID: 14139
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Ongoing monitoring by MWRA of its finished water indicates that the exposure assumptions
for Cryptosporidium levels used by EPA in the preamble may be extremely conservative. Based on over
two years of weekly composite samples of 1,000 liters each taken with the IDEXX foam filter (a total of
124,000 liters sampled and analyzed using Method 1623) MWRA's actual levels are averaging 0.05
oocysts per 100 liters: more than an order of magnitude lower than the average levels cited for unfiltered
utilities from the ICR, and almost 2 orders lower than the median. This is particularly note worthy given
that these results are based on using sample volumes and analytic techniques which are at least 50 to 100
times more sensitive than the very low volumes and low recoveries of many ICR samples used as the data
source for much of
the analysis cited in the preamble.
Comment Response for the LT2ESWTR 4-2 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
Response: See Response 220.3.
EPA Letter ID: 562
Comment ID: 12544
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Also, the ultimate objective is to better understand finished water quality. Thus, greater focus
on monitoring finished water (rather than analyzing source water and then projecting finished water
quality before and after projected treatment) seems to be a more suitable path for future investigation.
Limited finished-water data suggest that oocyst levels may be more uniform across facilities, regardless
of source water, than EPA projects in the EA.
Response: See Response 220.3.
EPA Letter ID: 668
Comment ID: 13907
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: [See pdf for City of Milwaukee 2003 source water monitoring data]
Response: See Response 220.3.
4.1.1 Comment Code 221, Analytical Method Performance
Individual Comments on Code 221
EPA Letter ID: 427
Comment ID: 10582
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: FR - Random spiking tests took place reflecting a 12% national recovery
average.
Comment - High quality water was "averaged in" with other water types, leading to more variability.
FR - ICRSS took place over a one year period March 1999 and ended February 2000 using a newly
introduced methods 1622 and 1623. 1622 was used for the first four months. 1623 was used for the next
eight months.
Comment Response for the LT2ESWTR 4-3 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
Comment - improvements in concentration, separation, staining, microscope examination procedures, etc.
v. IESWTR and ICR methods changed data reliability again. Standardized 10L samples were different
from previous studies and were taken twice per month. National recovery
methods approached 43% average and thus accuracy differed from the previous IESWTR and ICR data
base. (PDX used 3 filter brands) Although the 1622 and 1623 have several advantages over the ICR, they
also have some of the same limitations. These methods cannot determine
if a cyst or oocyst is viable or infectious. Subjective lab interpretation of the sample preparation and
microscopic evaluation must again be acknowledged.
Response: See Response 220.2.
4.1.2 Comment Code 222, Modeling of Occurrence
Individual Comments on Code 222
EPA Letter ID: 427
Comment ID: 10584
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: The following summarize the scope of data that provide starting point parameters for
statistical hierarchal analysis, that will influence EPA policy.
-Low oocyst recovery from water sample
-Variable oocyst recovery from water sample
-Small water volumes analyzed -difference in sensitivity
-Sample events having small number, and variation between studies
-Variation in inter-lab and intra-lab interpretation
-Variation in source water leading to unfair averages
-Variation in lab sample filter apparatus
-Small number of participants between three dose - response studies
-No fewer than 10 oocysts administered, leading to unsupported extrapolation of data and conclusion
about impact of lower numbers
-Data thrown out based on unknown infectious v. recovery offsetting numbers.( 13)
-No provision for animal, human genotype variation
-No provision for infectivity variation. Human dose-response studies assume oocyst 100% infectivity.
Recent studies show calf origin has lower number of organisms that are infective -5% (14)
Comment - Additional inconclusive data have been observed in this version of LT2 and have been
incorporated into statistical decisions that witl formulate policy. Relying too much on statistical
summaries that do not reflect actual situations because of small data pools will bring credibility into
question. Many variable parameters including location, month, source water type and turbidity were used
to build a mathematical model to interpret the data. A second separate mathematical model was used to
produce a large number of estimate sets.
Each parameter has a high order of magnitude of variability within its unit. With each additional
parameter and its inherent order of magnitude of variation, the true interpretation of data may be
uncertain.
Comment Response for the LT2ESWTR 4-4 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
SUMMARY
Standardization between the studies, continuity between the methods, and broad surveys within the
experiments are all missing. Bayesian methods must rely on solid standardized data. Markov Chain
Monte Carlo cannot correct for all uncertain results.
Response: See Response 220.4.
EPA Letter ID: 488
Comment ID: 11838
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Bayesian analysis to generate an estimated distribution for the entire data set.
Although this type of analysis is based on established statistical theory the fact remains that estimated
results for 93% of ICR samples were generated from analytical results for the small remaining fraction of
samples, together with highly uncertain assumptions (e.g. false positive rate). This analysis yielded
estimated P50 and P90 ICR Cryptosporidium concentrations of 0.05 and 1.3 oocysts/L, respectively.
Though the ICR data indicated overall substantially lower source water Cryptosporidium levels than
found in the prior study, the EPA cites the much higher P90/P50 ratio (27 compared to 4.6 from the
earlier data) from these statistics as evidence for a subset of high-risk source waters needing additional
treatment under the new rule. This comparison is critically flawed. If the P90/P50 ratios from these two
data sets are to be compared on an equal footing the earlier data should first be processed through the
same type of Bayesian analysis as the ICR data. In other words, the lower 93% of data from the previous
study should be censored and filled in with a Bayesian-derived distribution. This would afford a valid
basis for comparison.
Lower and consistent detection limits associated with the Supplemental Survey data allowed direct
determination of P50 and P90 statistics from the sample analytical results. These values were 0.05 and
0.33, respectively, for the SSM, and 0.045 and 0.24, respectively, for the SSL. In both cases the P90/P50
ratio agreed closely with that found in the earlier 1995 study (6.6 for SSM and 5.3 for SSL compared to
the earlier value of 4.6). Thus, the only actual evidence for EPA-s contention about a subset of high-risk
source waters is the Bayesian analysis. At the very least the EPA must reanalyze the other data sets with
the same statistical methods (using the same censoring level) if they wish to base conclusions on
comparisons between the distribution percentile ratios from different data sets.
Response: See Responses 220.4 and 220.5.
EPA Letter ID: 488
Comment ID: 11839
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Comments
The Bayesian statistical analysis is not transparent. An inappropriate weight of evidence seems to be
applied to its results. Although we have no reason to doubt that the methodology was applied in a sound
Comment Response for the LT2ESWTR 4-5 December 2005
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manner adhering to accepted statistical theory, we have serious concerns about the fact that the
characterized distribution is based on known values for only 6.9% of measured samples. It runs counter to
common sense to place more credence on percentile ratios derived from this distribution than on those
derived from the much higher quality SS data sets. Accordingly, the assertion that the new data indicate a
high-risk sub-population of source waters needing additional treatment is questionable.
Response: See Responses 220.4, 220.5, and 220.6.
EPA Letter ID: 562
Comment ID: 12322
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. EPA applies a Bayesian interpretation to the ICR and ICRSS data that is suspect and driven
by unsubstantiated and perhaps extreme assumptions. For example, EPA imposes an assumption that only
1 out of every 1000 -zeroes- observed in the database is truly a zero. The agency is thus estimating
occurrence and risk based on a presumption that 999 out of every 1000 observed zeroes in the database
are instead one oocyst or more.
Response: See Responses 220.5 and 220.6.
EPA Letter ID: 562
Comment ID: 12542
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.4.2 Occurrence Model
The conclusions EPA reached using Bayesian modeling are highly dependent on the assumptions made,
many of which are not -prior knowledge.- EPA should carefully document and justify these assumptions
and opinions. It should also run sensitivity analyses and document them in ranges that a wide array of
experts agree to. EPA should ascertain, communicate, and consider the
effects on the rule and on the benefits of these assumptions.
Response: See Responses 220.4 and 220.7.
EPA Letter ID: 562
Comment ID: 12545
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Considerable uncertainty exists about the accuracy of presence/absence findings and numbers
of oocysts derived in the ICR and ICRSS findings (more so with the ICR because of the lower recovery of
the analytic method). For example, a high likelihood of false positives exists because of limitations in the
Comment Response for the LT2ESWTR 4-6 December 2005
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IF A methodology. False positives would erroneously push more systems into higher bins. A large
percentage of sample observations are zero oocyst counts. This may be because Cryptosporidium oocysts
were not present in many samples and/or because recovery rates were low (especially for the ICR data).
Positive samples were noted for only 7% of ICR sample observations (93% were zeros).
Because of its concern about the large percentage of non-detects and low and variable method recovery,
EPA applied Bayesian statistical techniques to the ICR and ICRSS data. An integral part of the Bayesian
approach is the use of-informed priors- that reflect what knowledge or outcomes the researchers believe
to be true (e.g., using probabilities based on known data). The
specific priors that are applied in Bayesian applications typically drive the outcomes that are derived from
the analysis. In other words, the priors typically determine the outcomes. By way of example, EPA-s
model included a parameter for false positives (Zi); the prior (assumption) was a value of at 0.001% or
0.001 depending on the reference in the EA (EPA staff have confirmed values employed was 0.1%). In
discussions with individuals expert in Cryptosporidium analytical methods outside EPA, it appears that a
false positive rate well in excess of. 1% would be more consistent with expert opinion and that a more
credible rate would be in the range of 25%, particularly for the ICR data. Changing this one prior
(assumption) would dramatically change the distribution of oocysts predicted by the Bayesian model.
Conversation with EPA staff suggests that this change is unlikely to affect the estimated occurrence of
oocysts in the portion of the distribution relevant to the bin algorithm. This response is unsatisfactory.
The use of
priors that are not consistent with practical experience in the broader community raises concern with the
analysis and cast doubt on the relevance of its outcome.
In the EA, EPA describes the true zero prior as -the true proportion of systems with source water that is
completely free of the target microbe.- This is not the definition of true zeros employed during the Stage
2 M/DBP FACA. As described to EPA by an impartial expert panel in 1999, zero observations are simply
that, observations that are zero. The assumption described above can be restated as an oocyst observations
should almost never be zero. This is clearly a statement at odds with observations made in the ICR,
ICRSS, and in subsequent monitoring, even monitoring using experimental molecular assays to identify
Cryptosporidium oocysts.
Given that EPA-s results are driven by assumptions (over which there was considerable disagreement
with experts) rather than -prior knowledge,- the agency must:
1. Identify explicitly and label clearly what assumptions are being used (i.e., identify them clearly as
assumptions);
2. Provide a clear and cogent rationale why those assumptions are indeed reasonable and defensible;
3. Develop and/or accept alternative assumptions that are equally defensible or more plausible;
4. Conduct sensitivity analyses to understand and reveal how the alternative assumptions (priors) affect
the outcomes of the analysis;
5. Present the results of the sensitivity analyses in a clear, objective, and informative manner; and
6. Use the results of the sensitivity analyses to inform the decision-making process (and document the
same).
For example, analyzing the effect of using total Cryptosporidium oocyst counts from the ICR data versus
non-empty oocysts versus oocysts with internal structure would be informative in understanding the logic
behind why the total oocyst count was used in the occurrence assessment. Initial sensitivity analyses run
during the FACA process suggested that total oocyst count is one log higher than the non-empty count,
which is one log higher than the internal structure count. The probability of false positives is markedly
higher with the total oocyst count compared to the non-empty and internal structure count. AWWA
recommends that the agency give serious
Comment Response for the LT2ESWTR 4-7 December 2005
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Response: See Responses 220.4, 220.5, 220.6, and 220.7.
EPA Letter ID: 562
Comment ID: 12546
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: consideration to:
1. Reducing its reliance on statistical analyses that are by their nature difficult to understand and
distinguish observation from assumptions.
2. Including a detailed description in plain English of the basis for any assumptions, use of sensitivity
analyses, and results when it employs complex statistical procedures to describe those analyses; and
3. Checking its statistical analyses against expert observation, so that the results of the analysis are
consistent with actual field experience.
Response: See Response 220.7.
4.1.3 Implications of New Occurrence Data
4.1.3.1 Comment Code 225, Unfiltered Systems
Individual Comments on Code 225
EPA Letter ID: 427
Comment ID: 10581
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: For unfiltered systems, the EPA evaluated monitoring results from several unfiltered systems
that had been summarized by the Seattle Water Department and Montgomery Watson, 1995. These data
set the baseline standards for unfiltered system Cryptosporidium spp. occurrence and Subsequent
expectations of organism orders of magnitude reduction v. filtered plants. Averages for future policy
decisions regarding the unfiltered systems were established.
Comment - Early data should be recognized as an introduction period for Cryptosporidium spp. sampling
procedures that reflect a steep methodology learning curve. Sample protocol regarding filter equipment,
lab interpretation, reagents, technician training, false positives, sample frequency, and organism recovery
between the filtered and unfiltered data should be considered inconclusive. Laboratory variations alone
should raise questions. (12) These points of inconsistency, in effect comparing apples to oranges occurred
when analyzing data from the filtered and unfiltered systems. These data would later influence current
EPA policy. Sampling variations, such as in the Information Collection Rule (ICR) and Information
Collection Rule Supplemental Survey (ICRSS) were also observed. Such differences when allowed to be
used to make policy only exaggerate inconclusive results when explaining the final product to the public.
Comment Response for the LT2ESWTR 4-8 December 2005
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Subsequent to proposing IESWTR, data from the Information Collection Rule and the Information
Collection Rule Supplemental Survey were obtained, These studies were anticipated to provide improved
estimates of occurrence on a national basis.
- FR-p.47653 The Information Collection Rule required large public water systems to collect microbial
data over an 18 month period from July 1997 to December 1998. Samples for Cryptosporidium spp. were
taken once per month. The Information Collection Rule Protozoan Method (ICR Method) water sample
site was not standardized. Sample volume varied widely up to IOOL and the average quantity was
3L.(PDX 20L-100L) The volume analyzed directly clearly influences the sensitivity of the analytical
method. Larger sample volumes produce greater sensitivity. Samples were processed and oocysts were
stained and counted. Differential interference contrast (DIC) microscopy was used to examine the internal
structures.
Comment - inconsistent sampling data can be expected from the extremely small sample base, lack of
long term seasonal variation, uncertain random analysis, uncertain recovery of organism and irregular
sample size. Without conclusive evidence it was believed undercounting took place
and a provision was added through subsequent modeling. This would provide an estimate for the
parameter used in subsequent modeling, but true numbers would not be known.
Response: See Responses 220.5 and 220.6.
EPA Letter ID: 522
Comment ID: 14133
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: byproducts (or a lost opportunity to realize a reduction). Ongoing monitoring by MWRA and
several of the largest unfiltered utilities indicates that the exposure assumptions for Cryptosporidium
levels used by EPA in the preamble may be extremely conservative.
Response: See Response 220.3.
EPA Letter ID: 645
Comment ID: 13557
Commenter: Kathy Moriarty, Water Quality Manager, Bangor Water District
Commenter Category: Regulated Community (Utilities)
Comment: III. New Information on Cryptosporidium Health Risks and Treatment
C. Cryptosporidium Occurrence [pp. 47652-47659]
Request for Comment: Information Collection Rule and ICRSS data sets
Suggested Comments:
The proposed rule uses old data to base decisions on log removal or inactivation for future treatment for
unfiltered water supplies assuming the Cryptosporidium levels meet at least a 2 log inactivation. Based on
Comment Response for the LT2ESWTR 4-9 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
the data available at the time of IESWTR promulgation, it was believed that unfiltered water systems with
a watershed control plan was at the same risk level as a filtered system compliant with IESWTR.
Subsequent to IESWTR, new occurrence data suggested that
Cryptosporidium levels in the treated water of unfiltered systems were substantially higher than in the
treated water of filtered systems, therefore, Cryptosporidium treatment by unfiltered systems was needed
to achieve equivalent public health protection. EPA is uncertain about which data set to use. The
reliability of the Cryptosporidium data is clearly in question. The cost of
inactivation or removal is extreme if the data is unreliable. Certain unfiltered water supplies may be so
highly protected that Cryptosporidium may not be detected using current methods. New data needs to be
collected based on current Cryptosporidium methodologies in order to establish if removal or inactivation
is needed.
Response: See Response 220.3.
4.1.3.2 Comment Code 226, Use of Occurrence Data Sets in
Benefit and Cost Analyses
Individual Comments on Code 226
EPA Letter ID: 470
Comment ID: 11063
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Cryptosporidium Occurrence pp. 47652-47659
Due to the significant impact that the choice of data set has on exposure, cost, and benefit estimates for
this rule and the lack of any clear criterion for favoring one data set over the other, Vermont supports
EPA conducting the analyses for this proposed rule separately for each data set and presenting a range of
estimates based on the three data sets.
Response: See Response 220.2.
EPA Letter ID: 485
Comment ID: 11280
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department has no objection to the approach of evaluating each
data set separately and looks forward to any new information that may be available in determining the
cost, exposure and benefits of this rule.
Response: See Response 220.2.
Comment Response for the LT2ESWTR 4-10 December 2005
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EPA Letter ID: 516
Comment ID: 11725
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: used in other parts of the risk, cost, and benefit analysis. EPA compounds the problem by
using the ICR data (despite EPA-s stated concerns about the quality of the ICR data), which drives the
upper bound estimates of fatalities, and by extension maximizes the predicted net benefits of the rule.
Response: See Response 220.2.
EPA Letter ID: 516
Comment ID: 11745
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: p. 47659. EPA requests comments on conducting the analysis for each data set
(ICR and ICRSS) recognizing that the choice has a significant effect on exposure, cost, and benefit
estimates of the LT2. Given what the agency has said about the ICR data, DEP believes that the ICR data
should not be used for the cost and benefit analysis.
Response: See Response 220.2.
EPA Letter ID: 520
Comment ID: 11612
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Due to the significant impact the choice of data set has on exposure, cost, and benefit
estimates for the LT2ESWTR and the lack of any clear criterion for favoring one data set over the other,
IEPA supports EPA conducting the analyses for this proposed rule separately for each data set and
presenting a range of estimates based on the three data sets.
Response: See Response 220.2.
EPA Letter ID: 548
Comment ID: 12154
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment Response for the LT2ESWTR 4-11 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
Comment: Metropolitan agrees with EPA in considering a range of estimates based on the three data
sets. The ICRSS data would be more reliable for estimating individual plant occurrence, while the ICR
data, because of the large number of samples, may be more reliable for estimating national occurrence.
Response: See Response 220.2.
EPA Letter ID: 560
Comment ID: 14982
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Since the completion of the ICR and SS, American Water has produced additional
data to assess the finished water risk of Cryptosporidium infection (Aboytes and LeChevallier, 2002) (see
attachment). These data do not have to rely on uncertain measurements of source water levels, and
extrapolations of treatment efficacies. Rather the research directly measured the occurrence of infectious
oocysts in the effluents of 82 conventional surface water treatment plants. The researchers estimate an
average concentration of infectious oocysts in conventionally treated surface water was 0.00044
oocysts/L. This value was 3.3 logs lower than the mean source water oocyst level determined by the ICR
modeling (0.59 oocysts/L), supporting the 3-log credit provided to conventional surface water filter
plants.
The Aboytes and LeChevallier (2002) data also suggest that significant Cryptosporidium risk exists for
conventionally treated water (an annual risk of 1 infection in 193 per year, 80% credible interval of 1
infection in 84 to 1,110 per year). Clearly, these data are interesting and warrant more research. However,
American Water does not believe that they should be used in lieu of the
more complete ICR and ICRSS data. It is strongly encouraged that EPA support funding of research to
replicate the Aboytes and LeChevallier research. Indeed, the utility sponsored Awwa Research
Foundation has identified such a project for potential funding in 2004, and EPA support of the research
through Congressionally earmarked funded should be of the highest priority.
Response: See Response 220.3.
EPA Letter ID: 562
Comment ID: 12321
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. The ICRSS data indicate a much smaller percentage of systems will end up in bins 3 and 4
under the proposed rule than do the analyses based on the ICR data, implying that the net benefits
(benefits minus costs) of the proposed rule may be 20% of the high end estimates shown by EPA (all else
equal). The ICRSS data are better predictors than the ICR data of what the impact of the rule will be as
proposed.
Response: See Response 220.2.
Comment Response for the LT2ESWTR 4-12 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
EPA Letter ID: 562
Comment ID: 12326
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The ICRSS data are more indicative of what the rule-s impacts will be because they (1)
probably are more accurate Than the ICR data (ICRSS results are based on Method 1622/1623 with
higher recovery rates than the IFA method applied in the ICR data) and (2) reflect the method
(1622/1623) that utilities will apply in their compliance monitoring.
Response: See Response 220.2.
EPA Letter ID: 562
Comment ID: 12541
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.4.1 Occurrence Data
EPA uses data collected under the Information Collection Rule (ICR) and two subsequent smaller ICR
Supplemental Surveys (ICRSS) to assess the presence of Cryptosporidium oocysts in source waters. Both
sets of data were collected explicitly to support the LT2ESWTR rulemaking. Participants in the 1992
Reg-Neg process agreed to the ICR, and EPA developed the the supplemental surveys to improve the cost
estimate for the rule. Appreciable differences exist
between the results generated by the initial ICR and the follow-up ICRSS. For example, the ICR data
assign 7.6% of the systems into either bin 3 or bin 4, whereas the ICRSS assign an average of less than
1.2% of the systems to those bins - a difference factor of over 6.4 (7.6/1.2).
Response: See Response 220.2.
EPA Letter ID: 562
Comment ID: 12543
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 2220 B. Risk Assessment; 2221 1. Dose-response;
2222 2. Drinking water consumption (including averting behavior); 2224 4. Sensitive subpopulations;
2225 5. Uncertainty; 2226 6. Cases of illness compared to IESWTR or LT1ESWTR estimates; 2230 C.
Benefits; 2231 1. Valuation of Non-fatal Cryptosporidiosis
Comment: Figure 3. Factors Affecting Benefit Analysis
[SEE FIGURE 3, P.83 IN PDF]
Response: See Responses 2200b, 2221.7, and 2221.6. Thank you for your comment. EPA agrees that
additional data will provide an improved understanding of the national occurrence picture for all sizes and
types of systems. Such data will become available after LT2 rule is implemented.
Comment Response for the LT2ESWTR 4-13 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
EPA Letter ID: 595
Comment ID: 12578
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Section 1II.C Cryptosporidium Occurrence (pages 47652-47659)
The State of Maine Drinking Water Program (Maine) supports the EPA conducting the analyses for the
proposed rule separately for each data set and presenting a rage of estimates based on the three data sets.
Response: See Response 220.2.
EPA Letter ID: 643
Comment ID: 12763
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section III.C Cryptosporidium Occurrence (pages 47652-47659)
Due to the significant impact the choice of data set has on exposure, cost, and benefit estimates for the
LT2ESWTR and the lack of any clear criterion for favoring one data set over the other, states support
EPA conducting the analyses for this proposed rule separately for each data set and presenting a range of
estimates based on the three data sets.
Response: Thank you for your comment. EPA has followed this approach in today's final rule.
EPA Letter ID: 678
Comment ID: 14703
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: III. Comments on Issues Raised in Preamble-s Request for Comment
Sections
1. The EPA has conducted the analyses for this proposed rule separately for each, and presents a range of
estimates based on the three data sets [ICR1997 and ICR1998 and Supplemental Survey Data sets]
requests comment on this approach. The EPA will continue to evaluate the relative strengths and
limitations of the three data sets, as well as any new data that may become available for the final rule.
[47659, Cl]
Comment: The EPA compared the three data sets and found that the -median values are 0.048, 0.050, and
0.045 oocysts/L, respectively, while the 90th percentile values are 1.3, 0.33, and 0.24 oocysts/L-. It is
clear that median values are very close and therefore appear to agree with each other, while the 90th
Comment Response for the LT2ESWTR 4-14 December 2005
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percentile values do not. This discrepancy was also shown upon comparing the results for the subset of 40
plants that were in both the ICR and the ICRSS large system surveys. The EPA found that the medians
were 0.13 and 0.045 oocysts/L, respectively, while the 90th percentiles were 1.5 and 0.24 oocysts/L,
suggesting that the different sample groups in the full data sets are not the primary factor that accounts for
the different results. It appears that the source of differences in the data sets may be the different methods
used for the two surveys - the ICR Protozoa Method and EPA Methods 1622/1623 for the ICRSS. The
latter methods used for the ICRSS have better quality control and higher recovery (43% vs. 12% for the
ICR method) but the survey sample size was much smaller (40 vs. 350 for the ICR). The ICRSS data
would be
more reliable for estimating individual plant occurrence, while the ICR data, because of the large number
of samples, may be more reliable for estimating national occurrence.
Response: Response 220.2.
4.2 Comment Codes 240, Physical Removal of Cryptosporidium
Response to Code 240
a. EPA believes that the Agency's analysis of Cryptosporidium treatment efficiences by filtration plants
accurately reflects expected performance under existing regulations based on the best available data. As
discussed in the preamble, studies show that conventional filtration treatment can achieve more than 3-log
Cryptosporidium removal under optimal conditions. However, studies also demonstrate that removal
efficiencies can be significantly less for suboptimal plant set-up and operation. EPA does not expect that
all plants will operate under optimal conditions at all times, and existing regulations do not require this.
Consequently, today's rule awards a 3-log credit to conventional plants complying with the IESWTR or
LT1ESWTR. This credit reflects a recommendation by the Stage 2 Federal Advisory Committee. Today's
rule awards a 2.5 log credit for direct filtration plants because they lack the clarification process prior to
filtration that a conventional plant has. Systems that achieve higher levels of removal may receive higher
treatment credit through showing very low finished water turbidity or through a State-approved
demonstration of performance.
b. EPA does not agree that in the analysis of filtration plant treatment efficiency, records involving filter
runs with turbidity above 0.3 NTU should be excluded from consideration. Under existing regulations,
conventional and direct filtration systems can operate with filter effluent turbidity above 0.3 NTU up to 5
percent of the time. As discussed in the preamble to the proposal, data show that filter removal
performance can decrease significantly at higher effluent turbidities. A brief period of relatively poor
removal can substantially lower the overall log removal of Cryptosporidium that a plant achieves.
For estimating Cryptosporidium log removal values from the individual studies, EPA believes that relying
on values reported by the authors in the peer reviewed studies is appropriate. Consequently, EPA has not
reanalyzed the data to account for possible right censoring of removal performance (i.e., data points
where Cryptosporidium levels after filtration were below detection limits).
c. EPA believes that the proposed LT2ESWTR accurately characterized the performance of softening and
riverbank filtration under routine operational conditions based on the best available data. As discussed in
the preamble to the proposed rule, the level of treatment these processes can achieve varies widely
depending on water quality, design, and operational conditions. The treatment credit for these processes
in today's final rule reflects a recognition by EPA that they will not perform optimally at all times and
Comment Response for the LT2ESWTR 4-15 December 2005
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that short periods of suboptimal performance will decrease overal treatment efficiencies. Further, today's
rule allows systems to receive State-approval of alternative operational criteria or higher treatment credit
through a demonstration of performance.
d. Today's rule retains the use of the term "conventional treatment" because this term is used in existing
regulations and is widely understood by public water systems and States. However, EPA agrees with the
intent of this comment, and the preamble to today's final rule specifies that the requirements for
conventional treatment plants apply to "... a treatment train using separate, sequential, unit processes for
coagulation/flocculation, clarification, and granular media filtration. Clarification includes any
solid/liquid separation process following coagulation where accumulated solids are removed during this
separate component of the treatment system." Under this definition, the treatment trains the commenter
identifies will qualify for the 3-log Cryptosporidium removal credit awarded to conventional treatment.
As the commenter recommends, two-stage lime softening can receive 3.5-log credit. To qualify for the
higher credit, chemical addition and hardness precipitation must occur in two separate and sequential
softening stages prior to filtration.
e. EPA agrees with the commenter that bench scale data are appropriate for considering relative
performance and not absolute performance. In the proposed LT2ESWTR, the bench scale studies by
Harrington et al. (2001) and Plummer et al. (1995), which the commenter notes, are cited to consider the
relative (not absolute) performance of dissolved air flotation (DAF) vs. conventional sedimentation for
Cryptosporidium removal. Based on these and other studies cited in the preamble, EPA concluded that a
treatment plant using DAF plus filtration can achieve levels of Cryptosporidium removal equivalent to or
greater than a conventional treatment plant with gravity sedimentation (i.e., made a conclusion regarding
relative, not absolute, removal). EPA regrets the omission of Plummer et al. (1995) from the reference
list.
f EPA appreciates the additional data submitted by the commenter. EPA agrees with the commenter that
these data support EPA's conclusions based on studies cited in the preamble. These include the 3-log
Cryptosporidium removal credit for conventional treatment; the higher treatment credit awarded for very
low filtered water turbidity, based on the recognition that higher removals can be achieved under optimal
conditions; and recognizing that DAF prior to filtration can achieve equal or better performance than
conventional treatment and, therefore, should receive equal treatment credit.
Individual Comments on Code 240
EPA Letter ID: 488
Comment ID: 11840
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: In the database of treatment study information reviewed by the EPA low levels of
removal were almost always associated with either low challenge waters or deliberate sub-optimal
treatment conditions (e.g. purposely stressed filters) employed for pilot runs. Results associated with low
challenge waters provide only a lower bound for removal performance. Inefficient removal associated
with treatment deficiency is already regulated and therefore not relevant for this analysis. We recommend
a reanalysis wherein records involving filter runs
yielding elevated turbidity (>0.3 NTU) are excluded and right censoring of removal performance is
accounted for using appropriate statistical methods. At a minimum, only Cryptosporidium data associated
Comment Response for the LT2ESWTR 4-16 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
with treated turbidity jUO.30 ntu should be included when evaluating Cryptosporidium protection
capability for systems in compliance with IESWTR
Response: See Responses 240.b and 240.a.
4.2.1 Comment Code 241, Conventional treatment
Individual Comments on Code 241
EPA Letter ID: 420
Comment ID: 14091
Commenter: Eddie Partlow, General Manager, THE OLD HICKORY UTILITY DISTRICT
Commenter Category: Regulated Community (Development): Housing, FEEP, NAHB
Other EPA Comment Codes and Descriptions: 771 1. Credits and criteria for awarding credit; 791 1.
Credit and criteria for awarding credit
Comment: Included in the Agreement in Principle is a hearty list of alternatives to installation of UV
disinfection. In the preamble to the LT2ESWTR the level of treatment that can be achieved through
routine operation of softening, riverbank filtration, and conventional treatment is underrated. Due to that
fact, the proposed rule and associated guidance include overly stringent operational criteria that will cause
utilities to make unnecessary significant investment in new treatment technologies.
Response: See Responses 240.a and 240.c.
EPA Letter ID: 621
Comment ID: 13167
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: First, I wish to point out a weakness in your case on Cryptosporidium removals with regard to
material in the Federal Register on pp. 47661-47662. You cite data in some detail giving specific numbers
of Cryptosporidium log removals from the work of Harrington et al. (2001), some of which was obtained
by bench-scale jar tests. Likewise, some of my own bench-scale work is given (Plummer et al (1995))-
note, I did not see this in your reference list on p. 47773; it should be Plummer, J., J Edzwald, and M.
Kelley, 1995, Removing Cryptosporidium by Dissolved Air Flotation, Journal AWWA, Vol. 87, (No. 9),
pp. 85-95. Bench-scale clarification, whether it be sedimentation or dissolved air flotation (DAF), cannot
provide absolute numbers on particle removal (this case, Cryptosporidium lag removal) for continuous
flow pilot or full-scale plants. The bench-scale tests were batch systems with no flow, and the results do
not directly scale-up. What you can use the bench-scale data for are relative performance effects - e.g.,
DAF was better than settling or higher removals were obtained at higher water temperature, and so on.
Response: See Response 240.e.
Comment Response for the LT2ESWTR 4-17 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
EPA Letter ID: 621
Comment ID: 13169
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: The second point is that there exists considerable additional data on Cryptosporidium
removals that I recommend you use to support your case on pp. 47660-47662 under New Information on
Treatment for Control of Cryptosporidium. These data were collected using continuous flow pilot plants
so you can use scale-up (directly) to full-scale plants. These data were collected as part of an AWWA
Research Foundation Project in which I was the PI. It is high quality data because of the team that carried
out the research, because of the AWWARF Project Advisory Committee that provided peer review, and
because of the peer review process for the journal publications. The AWWARF Project Advisory
Committee consisted of Kim Fox (EPA-Cincinnati), David Hartman (City of Cincinnati), Michael
MacPhee (at the time with Environmental Engineering and Technology), and Tom Marston (Connecticut
Water). Three pertinent publications are brought to your attention as described next.
AWWA Research Foundation Report. This was published in 2001: Edzwald, J.K., et al., 2001, Impacts of
Filter Backwash Recycle on Clarification and Filtration, AWWA Research Foundation and AWWA,
Denver, CO. The project dealt with the effects of recycling waste filter backwash water hence the title;
however, much more work was done on Cryptosporidium removals without recycle of backwash water
and that is the focus of my remarks. The AWWA Research Foundation report has the details, and I have
provided a copy of the Executive Summary, but it is the two peer reviewed journal papers that are more
valuable and from which I will cite
Cryptosporidium log removal data.
Journal AWWA, December 2000 Paper (copy enclosed). Edzwald, J.K., et al. 2000. Giardia and
Cryptosporidium Removals by Clarification and Filtration Under Challenge Conditions, Journal AWWA,
Vol. 92 (No. 12), pp. 70-84.
The research results presented in this paper is of particular interest for several reasons. First, it was done
under challenge conditions, short term events with very high Cryptosporidium concentrations to
determine process removals. Second, it compares a plate sedimentation plant and a DAF plant bath using
dual media filters. Third, it compares removals achieved by Sedimentation and DAF. Fourth, the data
were collected for design clarification and filtration
hydraulic loadings - this is the conservative case. Fifth, the effect of cold water conditions was evaluated.
Sixth, a considerable effort was made to insure that the Cryptosporidium removals were obtained for
optimum coagulation conditions so that the process removals achieved by clarification and filtration could
be assessed, and the optimum coagulation conditions insured filtered water turbidities < 0.1 ntu.
The Cryptosporidium removal data are presented in the paper (copy enclosed), but briefly the key
findings follow.
1. DAF clarification performed better than plate sedimentation. Average
Cryptosporidium log removals by DAF for were 2.1 + 0.3 compared to 0.91-1.1 + 0.3 forplate
sedimentation.
2. Poorer performance occurred for cold water temperatures for both clarification methods.
Comment Response for the LT2ESWTR 4-18 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
3. Overall Cryptosporidium log removal performance by clarification and filtration was about the same
for the DAF versus plate sedimentation plant at about 5-log removal or higher. For the plate settling train,
the filters had to remove more of the oocysts than the filters in the DAF train.
Journal of Water Supply: Research and Technology (Aqua), 2003 Paper (copy enclosed). Edzwald, J.K.,
et al. 2003. Evaluation of the Effect of Recycle of Waste Filter Backwash Water on Plant Removals of
Cryptosporidium, Journal of Water Supply: Research and Technology (Aqua), Vol. 52 (No. 4), pp. 243-
258.
This paper deals with the effect of recycle of waste filter backwash water, but does contain extensive data
for the control case - no recycle. It is of particular interest for the same reasons of two through six listed
earlier for the other journal publication, but differs in the strategy of Cryptosporidium spiking. Unlike the
above study, Cryptosporidium was continuously fed to the raw water for the entire length of a filter run
20-24 hours and process removals determined. The Cryptosporidium removal data are presented in the
enclosed copy of the paper, but briefly the key findings follow:
1. For DAF, Cryptosporidium log removals were about 2 log for both summer and winter. Plate
sedimentation achieved about 2 log removal in the summer, but under the cold water temperatures in the
winter, it achieved about 1 log removal of oocysts.
2. DAF clarification exceeded plate settling performance for turbidity, particle removal, and oocyst
removals for both seasons and especially, under cold water conditions.
3. No oocysts were found for either season in the effluent of the dual media filters from either pilot train
(DAF or plate sedimentation). Based on the plant influent oocyst concentrations and detection limits fix
oocysts in the filter effluent samples, cumulative (clarification plus dual media filtration) oocyst log
removals were 4-5 for both plant types.
Response: See Response 240.f
EPA Letter ID: 621
Comment ID: 13171
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: I have some technical comments and additional Cryptosporidium data that are supportive of
your 3 log removal credit for conventional treatment with an additional 1 log credit for filtered water
turbidity O.lntu.
Response: See Response 240.f
Comment Response for the LT2ESWTR 4-19 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
4.3 Inactivation of Cryptosporidium
4.3.1 Comment Code 251, Other than UV, ozone, and chlorine dioxide
(UV, O3, and CIO2 comments should be categorized under
toolbox).
Response to Code 251
a. As the commenter notes, very limited data suggest that chlorine followed by ammonia addition to form
chloramine (sequential chloramination) may achieve greater inactivation than either disinfectant species
applied alone, (Finch et al., 1997 - full citation in proposed LT2ESWTR). However, available data are
not sufficient to predict the degree of Cryptosporidium inactivation that sequential chloramination can
achieve.
Further, available data suggest the level of Cryptosporidium inactivation that sequential chloramination
can achieve falls far short of that required of unfiltered systems, including the Bull Run system the
commenter notes. One study observed that under optimal warm water conditions, the highest doses of
chlorine and chloramines that public water systems could apply would only achieve around 0.5-log
inactivation of Cryptosporidium, and the effect would be hindered at lower temperatures (Finch et al.,
1997). In comparison, today's rule requires unfiltered sources to achieve at least 2-log Cryptosporidium
inactivation.
For these reasons, EPA has not developed criteria to award Cryptosporidium treatment credit for
sequential chloramination in today's final rule. The LT2ESWTR does, though, allow systems to request
treatment credit for processes not addressed in the rule through a demonstration of performance.
b. Data cited in the proposed LT2ESWTR on chlorine's effectiveness (or lack thereof) for
Cryptosporidium inactivation included studies that used in vivo assays, as the commenter suggests. See,
for example, Finch et al., 1997 (full citation in the proposed LT2ESWTR). This is the same assay used for
UV inactivation of Cryptosporidium in studies cited in the proposal.
Individual Comments on Code 251
EPA Letter ID: 427
Comment ID: 10579
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: 2. The Bull Run water system is disinfected with free chlorine followed by ammonia. This
sequential method has served our system well and rewarded the consumer with no disease incidents. The
sequential chlorine / ammonia / chloramine method is being adopted by more utility systems because of
the low disinfectant by-product properties, and subsequent relation to the Stage 2 Disinfectant By-Product
Rule. In the 90's,experimental data showed chlorine followed by ammonia resulting in chloramine as a
promising method for inactivating
Cryptosporidium spp. (4)
More research that is relevant to actual drinking water disinfection situations needs to be conducted. Past
experiments and study data do not truly represent the comprehensive organism challenges during the
Comment Response for the LT2ESWTR 4-20 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
drinking water disinfection process. Studies show contact time under
laboratory conditions and subsequent data interpolations that do nut reflect actual drinking water
disinfection. Methodology was not always standardized and some individual studies have sequential
chemical contact time data that are unclear. The past experiments regarding
sequential chloramination provide a place to start, but not a place to eliminate disinfection options or
generate conclusions that may dismiss sequential chloramination as another inactivation option.
For example, the whole question of synergistic v. sequential disinfection has not been satisfactorily
answered. Some propose that synergism is merely a lag time of individual chemical action on the
organism, followed by another lag time of a secondary chemical. This would suggest each individual
chemical could provide a similar disinfection process over a longer period of time.
However, each chemical may individually react with a different organism system to give a collectively
better result than one chemical activity alone. For example, chlorine and water produces hypochlorous
acid that can react with the cell wall, cell contents, and denature proteins. (5)(6) It is neutrally charged
and can move through the cell. The acidic environment
generated from hypochlorous acid and hydrochloric acid certainly cannot be interpreted to generate a "no
effect" experience for the organism cell wall and the internal contents. The impact from chlorine begins
early in the disinfection process.
The ammonia is added to form chbramine residual. Non-bound chlorine, and free ammonia ions are able
to penetrate the devitalized and disrupted cell wall leading to further inactivation. The ammonia ion can
attack the marry different cell systems it comes in contact with such as the
mitochondria, thus disrupting ATP (energy) production. Chloramination sequence methodology, contact
times, and environmental challenges to Cryptosporidium spp. have not yet been completely replicated or
satisfactorily demonstrated scientifically.
Basic immunology provides another example of chlorine -> chloramine disinfection process.
Phagocytosis demonstrates the inactivation of Cryptosporidium spp. using the following chemical
sequence model. White blood cells such as neutrophils and macrophages use the precursors
myeloperoxidase and hydrogen peroxide in the phagocytosis process to neutralize organisms such as
Cryptosporidium spp.. Inside the white blood cell lysosome, myeloperoxidase cleaves hydrogen peroxide
in the presence of free chlorine ions and hypochlorous acid is formed.
The neutrally charged hypochlorous acid moves through the invading organism cell wall to react with
amino acids and form chloramine from the amine (ammonia -like) portion of the molecule. (7)(8) This
natural model of inactivating microorganisms is extremely effective, and forms one basis for continued
investigation regarding chlorine/ammonia disinfection,
Response: See Response 251.a.
EPA Letter ID: 516
Comment ID: 11746
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: p. 47660 (and p. 47663). EPA notes the limitations of early UV disinfection studies using
only in vitro assays such as excystation and vital dye staining to measure loss of infectivity. EPA
indicates that these early studies were inconclusive and shown to overestimate the UV dose required.
Comment Response for the LT2ESWTR 4-21 December 2005
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Chapter 4: New Data Used to Develop the Rule Comment Codes 200-251
More accurate results were provided through in vivo assays and cell culture techniques. In that context,
Exhibit 2.4 lists the disinfectants tested against Cryptosporidium, and for chlorine lists only excystation
tests (to demonstrate chlorine-s ineffectiveness). It would help enhance EPA-s argument about chlorine if
the Agency included data assessing chlorine-s effectiveness or lack thereof, based on the same
benchmark tests (in vivo assays and cell culture) used for UV.
Response: See Response 251.b.
Comment Response for the LT2ESWTR 4-22 December 2005
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5. Filtered System Monitoring Requirements (parameters,
frequency, location): Comment Codes 300-471
5.1 Comment Code 300, Filtered System Monitoring Requirements
(parameters, frequency, location)
Response to Code 300
(A) Cost and burden of monitoring
As described in the LT2ESWTR Economic Analysis and preamble to today's final rule, EPA has used the
best available data to establish the monitoring and treatment requirements of the LT2ESWTR and to
assess the benefits and costs of these requirements. (Response 100 b). EPA believes that the Agency has
appropriately characterized uncertainty in estimates of benefits and costs for today's final rule. As
described in the Economic Analysis, EPA used multiple data sets for key risk parameters like
Cryptosporidium occurrence and infectivity, distributions rather than point estimates for many benefit and
cost values, and multiple risk models. As discussed in the preamble to today's final rule, the Agency
considered this uncertainty when developing the LT2ESWTR. (Response 100 s)
EPA appreciates the investments that public water systems have made to provide safe water. EPA
recognizes that the LT2ESWTR will result in additional costs to public water systems. However, as
discussed in the LT2ESWTR Economic Analysis and preamble to today's final rule, EPA believes that
the costs of the LT2ESWTR are appropriate due to the health benefits from reduced exposure to
Cryptosporidium and other microbial pathogens that the rule will achieve. Further, as recommended by
the Advisory Committee, the LT2ESWTR targets treatment requirements to higher risk systems, so that
the burden on systems with higher quality source waters will be relatively lower and consist primarily of
the costs for monitoring. EPA has also attempted to limit the costs for PWSs that serve less than 10,000
people by providing the option for lower-cost monitoring for an indicator organism, E. coli. (Response
100 c)
(B) Monitoring complexity and flexibility
EPA believes that today's final rule appropriately balances targeted risk reduction with simplicity and
flexibility. The rule establishes site-specific treatment requirements based on source water monitoring
results. While this approach is necessarily more complex than requiring all systems to provide the same
level of treatment, it will target public health expenditures to systems with the highest risk. (Response 100
v)
EPA has established monitoring flexibility to the extent possible while continuing to assure that sampling
is representative of source water quality. For example, PWSs have a 5-day window for collecting a
sample as scheduled, and there are allowances for samples that are collected outside the window if
extreme conditions or situations exist that may pose a danger to the sample collector or that cannot be
avoided. Also, PWSs that collect a sample as scheduled but are unable to have the sample analyzed as
required due to problems like shipping or laboratory analysis may collect a replacement sample within 21
days of receiving information that one is needed, unless the PWS demonstrates that collecting a
replacement sample within this time frame is not feasible. Furthermore, PWSs are required to collect
samples prior to chemical treatment, but the State may approve sampling after chemical treatment if
collecting a sample prior to treatment is not feasible and the State determines that the chemical treatment
Comment Response for LT2ESWTR 5-1 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
is unlikely to have a significant adverse effect on analysis. PWSs with multiple sources have the
flexibility to composite a sample or weight samples results from all sources, if they cannot collect a
sample from a common tap after the sources have been combined. These options, and the opportunity to
work with a State to determine the proper sampling location after submitting the required sampling
location description, provide a great deal of flexibility in the monitoring. Finally, the microbial toolbox
provides a wide array of treatment and management options to give systems flexibility in meeting
additional treatment requirements.
Individual Comments on Code 300
EPA Letter ID: 417
Comment ID: 10523
Commenter: Kenneth Brown, Authority Manager, Stroudsburg Municipal Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: The LT2ESWTR monitoring requirements are of concern. They do not allow the utilities the
flexibility in sampling procedures to show that it is in compliance with the new regulations. These
procedures need to be more realistic and allow for differences in treatment systems and source waters.
Response: See Response 300(B).
EPA Letter ID: 449
Comment ID: 10837
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: The Kenosha Water Utility understands the need to supply safe drinking water to all of its
consumers and is committed to doing so. In order to justify the costs associated with the implementation
of these new regulations, EPA should carefully weigh the positive effects of the new regulations with the
thousands of dollars that utilities would have to spend to implement these regulations. Based on
information that is already accessible to regulators through monthly
reporting and sanitary surveys, we feel that there is enough data available to determine which systems are
most vulnerable and need to explore new treatment technologies without requiring all systems to perform
extensive testing.
Response: See Response 300(A) and 500(h).
EPA Letter ID: 466
Comment ID: 11022
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: ND is concerned about second round monitoring for source water. Instead of across-the-board
sampling for all systems, we would prefer an approach were we could use existing information, such as
source water assessment results, sanitary surveys, and ambient water quality monitoring to determine the
need for additional source water monitoring for each system individually.
Comment Response for the LT2ESWTR 5-2 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Response: See Response 410(A).
EPA Letter ID: 497
Comment ID: 10643
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Comments have been provided to the United States Environmental Protection Agency
(EPA) in the past on the complexity of rule implementation. We believe the EPA should reduce complex
monitoring patterns in the rule to allow water systems to concentrate on water treatment issues that
improve water quality rather than spending considerable time and effort to avoid monitoring violations.
Response: See Response 300(B).
EPA Letter ID: 499
Comment ID: 10716
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: 1. KDHE supports the risk-based approach in which surface water systems monitor
for microbial contaminants and only those systems finding higher levels of contaminants are required to
provide additional protection against Cryptosporidium. This includes the proposed requirement for large
systems to
5. KDHE supports a modified monitoring requirement for systems which only use surface water on a
seasonal basis. It is reasonable to limit monitoring to the period in which water is being used with the
additional requirement that sampling occur more frequently during the time when the source is initially
reactivated during the season of use. The timing of samples which are collected
is more important than a strict adherence to a preplanned schedule which is adopted years in advance of
anticipated uses.
Response: See response 100aand430.
EPA Letter ID: 504
Comment ID: 11354
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 500 III. Filtered System Treatment Requirements
Comment: The consequence of the benefit overestimation is distortion of priorities for
regulators and utilities and misinformation to the public. It also calls into question the fundamental need
for such a stringent regulation.
Comment Response for the LT2ESWTR 5-3 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
We suggest that EPA reexamine the model and assumptions used to develop benefit estimates and
rationalize the model results with epidemiologic evidence of cryptosporidiosis occurrence. Following
reassessment of benefits we suggest that EPA should reconsider the full range of proposed rule
requirements.
Response: See Response 300(A).
EPA Letter ID: 516
Comment ID: 11744
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 721 1. Proposed credit
Comment: P. 47655. EPA makes a point that there was greater variability in occurrences of
Cryptosporidium in flowing stream sources than in reservoir and lakes. Given this greater variability,
EPA should discuss why the proposed sampling frequency for binning purposes is the same for reservoirs
and lakes, and why the same log credit for watershed protection is given for systems on reservoirs and
lakes compared with flowing streams. By ignoring the fact that some watersheds are more stable than
others regarding the potential for episodic crypto events, such
as the watersheds of unfiltered systems, EPA undervalues the benefits of robust watershed protection
programs, such as those developed by unfiltered systems, and overvalues the protections afforded by
engineered solutions.
Response: Source water variability is one factor that influences the number of samples needed to
accurately classify plants in LT2ESWTR treatment bins. As variability increases, more samples are
needed to determine the mean Cryptosporidium level with high confidence. Statistical analysis from
studies performed in the ICR and ICRSS indicate that Cryptosporidium concentration values detected for
bin classification are independent of the source water type, i.e., lake/reservoir or flowing stream sources.
Statistical analyses also indicate that it is necessary for PWSs to collect at least 24 samples in order to
keep the likelihood of both false positives and false negatives at five percent or less. See the proposed
LT2ESWTR for additional details on this analysis (USEPA 2003a). Based on the results of this analysis,
EPA concluded that PWSs operating year-round should collect at least 24 samples when they monitor for
Cryptosporidium. This number of samples ensures a high likelihood of appropriate bin classification.
Today's rule does not allow bin classification based on fewer samples (except in the case of part-year
PWSs) as this would involve unacceptably high false positive or false negative rates and would, therefore,
be an inappropriate basis to determine Cryptosporidium treatment requirements. EPA does believe,
though, that PWSs should have the choice to collect more than 24 samples to further improve the
accuracy of bin classification, and today's rule allows this.
EPA Letter ID: 520
Comment ID: 11613
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 320 B. Small System Monitoring Requirements; 510 A.
Microbial Framework Approach
Comment Response for the LT2ESWTR 5-4 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: IEPA concurs with the risk-based approach proposed under the LT2ESWTR in which
surface water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium. This includes the
proposed requirement for large systems to perform Cryptosporidium monitoring to determine risk from
microbial contamination as well as the proposed requirement for small systems to perform indicator
monitoring to determine the need to perform Cryptosporidium
monitoring. Additional IEPA comments on the overall approach are included in the above.
Response: See response 100.a.
EPA Letter ID: 540
Comment ID: 12083
Commenter: Manja Blazer, Government Affairs and Market Development Manager, IDEXX
Laboratories
Commenter Category: Independent Laboratories
Comment: IDEXX believes that water systems should be required to monitor for Cryptosporidium
during and after treatment installation. This monitoring is necessary to document treatment effectiveness,
and to confirm proper bin assignment. It should not be presumed that Cryptosporidium removal or
inactivation is satisfactory after treatment installation to meet bin requirements in the absence of follow-
up monitoring.
Response: See Response 100 1.
EPA Letter ID: 562
Comment ID: 12369
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1. Source water characterization is a key first step in the LT2ESWTR
regulatory structure,
EPA has reflected each of these components in the proposed rule. AWWA continues to believe that each
of these five recommendations is sound and appropriate for the LT2ESWTR. AWWA is concerned about
the specifics of EPA-s implementation of these general recommendations.
Response: See Response 310(C).
EPA Letter ID: 562
Comment ID: 12370
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 380 G. Use of Previously Collected Data (i.e.,
grandfathering)
Comment Response for the LT2ESWTR 5-5 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: 2. Both defined monitoring and previously collected Cryptosporidium oocyst data are
appropriate for binning,
EPA has reflected each of these components in the proposed rule. AWWA continues to believe that each
of these five recommendations is sound and appropriate for the LT2ESWTR. AWWA is concerned about
the specifics of EPA-s implementation of these general recommendations.
Response: See Responses 380 and 310(C).
EPA Letter ID: 601
Comment ID: 13004
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: To truly protect public health, monitoring must occur at appropriate locations at appropriate
frequencies, including microbial monitoring to determine appropriate treatment under the LT2ESWTR.
Failure to monitor at both the appropriate location and frequency may lead to treatment decisions that are
not appropriate, incurring unnecessary costs.
Response: See Response 310(B) regarding State involvement in implementation.
EPA Letter ID: 603
Comment ID: 12645
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47777) Section 141.701(d)-
It is not clear that those sources that meet the criteria for a limited alternative to filtration (LAP) should
monitor for Cryptosporidium in the same manner as those sources that are unfiltered and meet the
filtration avoidance criteria in 4141.71. Please consider modifying the proposed rule to clarify
theCryptosporidium monitoring and follow-up actions required for sources that meet
the LAP requirements.
Response: Systems that use alternative filtration technologies are considered filtered systems, as
indicated in 40 CFR 141.173, and are therefore subject to the requirements for filtered systems under
today's rule.
EPA Letter ID: 607
Comment ID: 12980
Commenter: Cam Ferguson, Manager of Water Resources, Greenville Water System
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-6 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: 3) There seems to be no provision for a utility to be able to repeat a sample
due to confirmed laboratory error. A utility must be held accountable for a contract lab error.
Response: See Response 300(B).
EPA Letter ID: 609
Comment ID: 14110
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Comments have been provided to the United States Environmental Protection Agency
(USEPA) in the past on the complexity of rule implementation. We believe the USEPA should reduce
complex monitoring patterns in the rule to allow water systems to concentrate on water treatment issues
that improve water quality rather than spending considerable time and effort to avoid monitoring
violations.
Response: See Response 300(B).
EPA Letter ID: 637
Comment ID: 13088
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: Also, a provision should be included in the proposed rule to allow a water system to request
consideration for bin reclassification by the State if significant improvements in water quality can be
demonstrated or if it can be shown that the samples taken during compliance sampling were not
representative.
Response: See Response 500 m. If a PWS believes that any individual sample is unrepresentative, it can
contest the sample result and provide an explanation through the LT2 Data Collection System.
EPA Letter ID: 666
Comment ID: 14019
Commenter: Wellington H. Jones, Engineer-Director, Frederick County Sanitation Authority
Commenter Category: Regulated Community (Utilities)
Comment: 1. The monitoring requirements are too rigid with regards to monthly sampling
periods, temperature, handling of missing data, and acceptance of grand fathered data. These
requirements appear to be established to make the utility fail so it will automatically be forced to achieve
additional Cryptosporidium removal. This utility has monitored for Cryptosporidium for several years.
All samples have shown none present. It would be a waste of our rate payers' (your taxpayers') money to
require enhanced treatment because of failure to meet the inflexible monitoring provisions.
Comment Response for the LT2ESWTR 5-7 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
In summary, your proposed monitoring requirements invite failure. This can result in wasting funds to
remove Cryptosporidium that may not be present. The treatment and you impose an exorbitant safety
factor. It is important to protect the public, but don't needlessly waste their money.
Response: See Response 300(B) and Response 440, regarding penalty for failure to complete monitoring.
EPA Letter ID: 703
Comment ID: 14783
Commenter: Rich Weirich, Plant Superintendent, Frenchtown Water Treatment
Commenter Category: Regulated Community (Utilities)
Comment: I am very concerned with the cost associated with each sample. With the amount
of samples required and the recommendation to double the required sampling amount, most facilities do
not have that kind of money for sampling. The biggest
Response: See Response 300(A).
EPA Letter ID: 711
Comment ID: 16554
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: Once again, in this section as in some of the other sections, it is not clear if-system- is used
instead of-plant- because a system could have very different source waters for each treatment plant. One
system could have one plant that would fall under Bin 2 when the rest may fall under Bin 1.
Response: The rule specifies that monitoring, bin classification and treatment requirements are plant
specific.
EPA Letter ID: 711
Comment ID: 16578
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 7.141.709 (d) - As written, it is unclear what would happen if a system gets
Response: See Response 410(B) regarding timeframe to install treatment after the second round of
monitoring.
EPA Letter ID: 711
Comment ID: 16579
Comment Response for the LT2ESWTR 5-8 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 2. EPA should re-evaluate the use of system-wide Cryptosporidium data in determining bin
classification versus plant specific Cryptosporidium data. We recommend changing the bin classification
to be plant specific instead. Many systems have multiple plants and it is possible that lone of the plants
could have higher Cryptosporidium oocyst concentrations in the source water, thereby elevating the
system's mean Cryptosporidium concentration enough to kick the entire system into a higher bin. If a
system has only one plant with source water that has higher Cryptosporidium concentrations, installing
Cryptosporidium inactivation equipment at all plank would be a waste of public funds.
Response: The rule specifies that monitoring, bin classification and treatment requirements are plant
specific.
5.2 Comment Code 310, Large System Monitoring Requirements
Summary of Issues
Comments were received expressing concern over the difficulty in preparing and submitting a monitoring
plan within three months and beginning monitoring within six months of rule promulgation. Other
comments suggested that many systems will miss initial samples and the level of follow-up with EPA will
be extensive, with others wanting more time between rule promulgation and required monitoring
depending of their system size. Comments were also received concerning the rationale for turbidity
measurements within LT2ESWTR. Clarification is needed on a comment regarding PWSs that would like
to cease Cryptosporidium monitoring and begin planning for additional treatment. Many comments were
received expressing support of the LT2ESWTR's risk-based approach, in which systems finding higher
levels of contaminants are required to provide additional protection against Cryptosporidium, and how the
sampling duration, frequency and ample number of samples will account for seasonal variability and give
a true representation of the PWS source water which allows for proper placement into bin classifications.
Response to Code 310
(A) Difficulty in meeting time requirements after rule promulgation
Commenters were concerned that some PWSs, in particular PWSs serving 10,000 to 50,000 people,
would need more than the three months allowed under the proposed rule to report sampling schedules and
to plan and budget for implemention of the first round of monitoring. Also, to develop sampling
schedules, PWSs must establish contracts with laboratories, which may involve using municipal
procurement procedures. For smaller PWSs, budgeting for this expense may require substantial time and
planning.
EPA recognizes this concern and today's final rule provides significantly more time for most PWSs to
submit sampling schedules and implement monitoring. Specifically, PWSs serving 50,000 to 99,999
people and those serving 10,000 to 49,999 people, must submit sampling schedules 9 months and 21
months after rule promulgation, respectively, and begin monitoring 3 months after that. EPA believes that
these PWSs will have sufficient time to develop sampling schedules with these compliance dates. Today's
rule still requires PWSs serving at least 100,000 people to submit sampling schedules 3 months after rule
promulgation. Because these PWSs have monitored for Cryptosporidium previously, however, EPA
Comment Response for the LT2ESWTR 5-9 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
believes that this compliance date is feasible for them. EPA is also implementing an extensive training
and outreach effort to assist PWSs in meeting their requirements.
This staggered implementation will also allow more time for laboratory capacity to grow to meet demand.
Once the rule is promulgated, EPA believes that lab capacity will be more than sufficient to meet the
demand generated by the largest systems, as the laboratories that are "pending approval" under the EPA
Laboratory Quality Assurance program are converted to "approved."
(B) Implementation and State involvement in oversight
Several commenters expressed concern about EPA implementation of the rule requirements. Others
specifically recommended that States, rather than EPA, oversee monitoring due to States' existing
relationships with and knowledge of their PWSs, including the determination of sampling location.
Commenters were concerned that some States will not participate in early implementation activities and
indicated that States would prefer monitoring to begin 24 months after rule promulgation. States indicated
that they need sufficient time to become familiar with the rule, train their staff, prepare primacy packages,
and train PWSs.
In general, EPA would prefer that States oversee monitoring by their PWSs and will work with States to
facilitate their involvement with rule implementation. Where States are unable to implement today's rule,
however, EPA is prepared to oversee implementation. Moreover, EPA believes that the staggered
compliance schedule in today's final rule will enhance the ability of States and EPA to implement the
rule. EPA has initiated a rigorous and extensive training program to prepare PWSs, States and EPA
Regional offices for implementation. EPA is also developing a tracking system to assure proper
implementation of rule requirements, including review of plans and schedule; sampling results, methods
and QA/QC; and grandfathered data.
(C) Two year time frame for monitoring and time between E. coli and Cryptosporidium monitoring
In regard to the time frame for LT2ESWTR monitoring, EPA considered the trade-off between
monitoring over a long period to better capture temporal fluctuations and the desire to prescribe additional
treatment quickly to PWSs with higher Cryptosporidium levels. Today's rule requires large PWSs to
evaluate their source water Cryptosporidium levels using two years of monitoring, and allows small
systems that monitor for Cryptosporidium the option to conduct it over two years. This will account for
some degree of yearly variability, without significantly delaying additional public health protection where
needed.
Some commenters suggested that small systems will need more than 6 months after E. coli monitoring to
plan and arrange for Cryptosporidium monitoring if they exceed the E. coli trigger levels. EPA disagrees.
Small systems do not have to begin E. coli monitoring until 2.5 years after promulgation. This is
sufficient for small systems to make contingency plans to conduct the Cryptosporidium monitoring if
needed.
(D) Turbidity measurements
EPA is requiring large systems (over 10,000 people served) to monitor for E. coli and turbidity in addition
to Cryptosporidium because EPA will use this data to further evaluate the use of indicator monitoring, as
recommended by the Microbial-Disinfection Byproduct Advisory Committee (USEPA 2000a). In
addition, PWSs using conventional or direct filtration may achieve additional Cryptosporidium treatment
credit by demonstrating very low turbidity in the combined filter effluent.
Comment Response for the LT2ESWTR 5-10 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
(E) Ceasing Cryptosporidium monitoring and begin additional treatment
Filtered systems are not required to conduct source water monitoring under the LT2 Rule if the systems
will provide a total of at least 5.5-log of treatment for Cryptosporidium, equivalent to meeting the
treatment requirements of Bin 4 in 40 CFRpart 141.711.
Unfiltered systems are not required to conduct source water monitoring under the LT2 Rule if the systems
will provide a total of at least 3-log Cryptosporidium inactivation, equivalent to meeting the treatment
requirements for unfiltered systems with a mean Cryptosporidium concentration of greater than 0.01
oocysts/L in 40 CFRpart 141.712.
If a system chooses to provide the level of treatment as described above, rather than start source water
monitoring, the system must submit written notification no later than the date the system is otherwise
required to submit a sampling schedule for monitoring. Alternatively, a system may choose to stop
sampling at any point after it has initiated monitoring if it provides written notification that it will provide
this level of treatment. Systems must install and operate technologies to provide this level of treatment by
the applicable treatment compliance date as stated in 40 CFRpart 141.713.
(F) Two-year time frame for monitoring
In regard to the time frame for LT2ESWTR monitoring, the Agency considered the trade-off between
monitoring over a long period to better capture temporal fluctuations and the desire to prescribe additional
treatment quickly to PWSs with higher Cryptosporidium levels. Today's rule requires large PWSs to
evaluate their source water Cryptosporidium levels using two years of monitoring. This will account for
some degree of yearly variability, without significantly delaying additional public health protection where
needed.
Individual Comments on Code 310
EPA Letter ID: 387
Comment ID: 10477
Commenter: Anonymous387,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: The costs for monitoring for Crypto, and the issues of lab capacity, are very concerning.
There are many states without labs able to do Methods 1623, and the costs at private labs in other states
run about $500 per sample. So a small water system, serving let's say 11,000, must spend $12,000 for the
24 samples required to monitor. That is very high. The Crypto monitoring should be population based, not
just cut off at letting systems <10,000 start with E coli. Why not require small systems (10,000 - 50,000)
monitor for just one year. If no Crypto is found in that 12 samples, then let them be exempt from a second
year of Crypto monitoring. The saved $6000 is very significant to a small system.
Response: See Responses 300(A) and 310(F).
EPA Letter ID: 393
Comment ID: 10513
Commenter: Anonymous393,,
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-11 December 2005
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Comment: I researched the cost of those Cryptosporidium analyses with Method 1623, and it's almost
$500, all we can use is private labs. It looks like with my plant serving aout 12000 people, and since we
use surface water, we have to sample at least 24 times, or spend at least $12,000 - no more ecause of the
matrix spikes. We are a little community, and cannot afford to spend so much on JUST one rule? Why
does a big city using surface water like a city of 100,000...
also have to spend the same amount, they can afford it but we can't? Please dont think that small systems
are only those below 10,000 population, let systems below 50,000 at least also try to use E coli
monitoring first, before forcing us to sample for Crypto.
Response: See Response 300(A) and 335(B).
EPA Letter ID: 408
Comment ID: 10544
Commenter: Craig Barsness, Chief Plant Operator, Shoshone Municipal Pipeline
Commenter Category: Regulated Community (Utilities)
Comment: sampling? I am also concerned with the cost of these tests. At $500/sample and
24 samples, it will cost us $12,000 over two years (not including overnight shipping).This is excessive.
We must also submit a sampling schedule, in
Response: See Response 300(A).
EPA Letter ID: 412
Comment ID: 10507
Commenter: Illegible 0412,, PWS WY5600045
Commenter Category: Regulated Community (Utilities)
Comment: After attending a class to discuss the proposed LT2 regulation, I have come to the conclusion
that this regulation would be devastating to the medium and small communities in Wyoming. The big
issues for this regulation will be the cost of the testing and the time to collect and deliver the samples.
It will be very expensive to conduct the testing. The new sampling requirement for this regulation for the
first year will cost well over $12,000.00 (this is the case for our system). This expense will have to be
passed on to the customers. If EPA continues to come up with these expensive regulation requirements,
the cities will not be able to supply water to its customers at a reasonable price. It may possibly put the
smaller communities in Wyoming out of the drinking water business.
Wyoming is a very rural state. Most of the smaller communities are a long distance away from a
laboratory. Most times the operator has to deliver the samples because UPS or FedEx won't pick up in
their town or the lag time from when they pick it up til the time it reaches the lab is too long. Most of the
labs in Wyoming can't perform the analysis so the testing has to be farmed out
which takes even longer to get results back.
I know that we in this business strive to produce safe drinking water to our customers but I believe EPA is
hindering us from doing so. Please make the right decisions on this issue.
Comment Response for the LT2ESWTR 5-12 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Response: See Response 300(A) and 1734.
EPA Letter ID: 423
Comment ID: 10571
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: Small subpart H systems are allowed to conduct e-coli monitoring in lieu of cryptosporidium
monitoring. Apparently EPA believes e-coli monitoring is an adequate
substitute for cryptosporidium monitoring if the system serves less than 10,000 persons. Why not give the
large subpart H systems the same option to use e-coli monitoring results?
Response: See Response 300(A).
EPA Letter ID: 442
Comment ID: 10783
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: 40CFR141.702 Source Water Monitoring
Small subpart H systems are allowed to conduct e-coli monitoring in lieu of cryptosporidium monitoring.
Apparently EPA believes e-coli monitoring is an adequate substitute for cryptosporidium monitoring if
the system serves less than 10,000 persons. Why not give the large
subpart H systems the same option to use e-coli monitoring results?
Response: Repeat of above comment.
EPA Letter ID: 449
Comment ID: 10826
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 335 5. Alternative indicators
Comment: Because of a shortage of manpower and the costs associated with implementing the
new regulations, we feel that systems of any size should be held to the same standard as small systems
regarding total coliform results. In section 141.720 it states that systems serving over 10,000 people must
conduct source water monitoring for cryptosporidium , e-coli, and turbidity. In section 141.702, it states
that in systems serving less than 10,000 people, testing for
cryptosporidium e-coli and turbidity only needs to be performed if the system exceeds 10 colonies per
100 ml in e-coli testing. It is our feeling that total coliform test results can be used as a valuable tool to
determine which systems need to perform more in depth cryptosporidium testing. One way to examine the
Comment Response for the LT2ESWTR 5-13 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
effectiveness of this theory would be to study systems that used
earlier cryptosporidium methods and have same day e-coli test results. This would provide a more
manageable number of systems to oversee while still gathering information for EPA and protecting the
public from the highest risk water sources.
Response: See Responses 300(A) and 335(B).
EPA Letter ID: 457
Comment ID: 11884
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 320 B. Small System Monitoring Requirements
Comment: We concur with the risk-based approach proposed under the LT2ESWTR in which surface
water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants in their source waters are required to provide additional protection against Cryptosporidium.
This includes the proposed requirement for large public water systems to perform Cryptosporidium
monitoring to determine risk from microbial contamination as well as the proposed requirement for
smaller systems to perform indicator monitoring, to determine the need to perform Cryptosporidium
monitoring. We
Response: See Response lOOa.
EPA Letter ID: 457
Comment ID: 11890
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: We concur that large filtered systems should monitor for Cryptosporidium for two years, as
this will allow for the collection of an ample number of samples as well as account for seasonal
variability.
Response: See Response lOOa.
EPA Letter ID: 457
Comment ID: 11913
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 320 B. Small System Monitoring Requirements
Comment Response for the LT2ESWTR 5-14 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: We concur with the risk-based approach proposed under the LT2ESWTR in which surface
water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium. This includes the
proposed requirement for large systems to perform Cryptosporidium monitoring to determine risk from
microbial contamination as well as the proposed requirement for small systems to perform indicator
monitoring to determine the need to perform Cryptosporidium monitoring.
Response: See Response lOOa.
EPA Letter ID: 483
Comment ID: 11257
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: for large systems, small systems will be overwhelmed. Laboratory costs are also an issue. The
SWSC will most likely incur a total cost of $12,000 to $15,000 for analysis, not including staff time for
monitoring, reporting and recordkeeping. These costs increases are significant, especially for small
systems.
Response: See Response 300(A).
EPA Letter ID: 488
Comment ID: 11842
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: What is the rationale for requiring that turbidity measurements be reported together with
source water Cryptosporidium monitoring data?
Response: See Response 310(D).
EPA Letter ID: 499
Comment ID: 10717
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: Cryptosporidium. This includes the proposed requirement for large systems to perform
Cryptosporidium monitoring to determine risk from microbial contamination as well as the proposed
requirement for small systems to perform
Response: See Response lOOa.
Comment Response for the LT2ESWTR 5-15 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 513
Comment ID: 11527
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: We have two general questions related to microbial monitoring: (1) If a large system exceeds
the Cryptosporidium concentration of 3 oocysts/L (which would place the system in Bin 4) BEFORE the
24 months of monitoring have been completed, will the system have the option of ceasing
Cryptosporidium sampling, and focusing on plans for the required additional treatment?
Response: See Response 310(E).
EPA Letter ID: 520
Comment ID: 11565
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Large System Ability to Prepare for and Execute Monitoring
Although three months lead time may be acceptable for larger systems that have been following the rule,
provided there are no major changes based on comments received, large systems on the smaller side of
the definition, such as those between 10,000 and 50,000 people, may have difficulty preparing and
submitting a monitoring plan within three months of rule promulgation and beginning monitoring within
six months. Further, if EPA makes significant changes to the
final rule based on comments received, large systems will need time to review and understand the
changes and then prepare for initial compliance activities accordingly.
Large systems must be allowed reasonable time to budget for Cryptosporidium sampling and contract
with a laboratory for the analysis. While some larger systems may be able to absorb these costs under
their current budget, the costs could pose a significant problem for some larger systems unless the rule
happens to be promulgated just before the system begins budgeting for the fiscal year when sampling
occurs.
Depending upon the content of the final rule, it may not be possible for large systems to prepare a
complete monitoring plan within 90 days of rule promulgation. Although this effective date may be
reasonable if there are no major revisions resulting from public comment, the schedule presumes that
systems are familiar with the content of the proposed rule and have begun
preparing their plans prior to rule promulgation.
Response: See Response 310(A).
EPA Letter ID: 520
Comment ID: 11566
Comment Response for the LT2ESWTR 5-16 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Follow-up Activities for Large Systems
Even if large systems are able to begin Cryptosporidium monitoring in the required timeframe, IEPA is
concerned that many systems will miss the first sample (or first few months of sampling) and that the
level of follow-up activity IEPA or EPA would need to undertake will be extensive. Follow-up activities
will be time consuming, as direct contact with individual systems will be required. EPA is reminded that
although some states may opt to assist EPA in such communications under early implementation, some
states do not plan to participate in any early implementation activities. In those states, EPA will need to
undertake the follow-up activities directly.
Response: See Response 310 (A) and (B).
EPA Letter ID: 520
Comment ID: 11575
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA concurs that large filtered systems should monitor for Cryptosporidium for
two years, as this will allow for the collection of an ample number of samples as well as account for
seasonal variability.
Response: See Response lOOa.
EPA Letter ID: 520
Comment ID: 11580
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: lakes/reservoirs and 50 E. coli /100 mL for flowing streams. IEPA also supports
large system collection of E. coli and turbidity data to determine if different triggers would be more
appropriate.
Response: See Response lOOa.
EPA Letter ID: 521
Comment ID: 11758
Comment Response for the LT2ESWTR 5-17 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Commenter: Leslie Rush,, Dalton Utilities
Commenter Category: Regulated Community (Utilities)
Comment: We are concerned with the unknown costs for implementing a microbial monitoring
program and the resulting effect on rates for the customers of the utility.
Response: See Response 300(A).
EPA Letter ID: 528
Comment ID: 12254
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: We concur that large filtered systems should monitor for Cryptosporidium for two
years, as this will allow for the collection of an ample number of samples as well as account for seasonal
variability.
Response: See Response lOOa.
EPA Letter ID: 534
Comment ID: 12009
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: EPA needs to be sure that implementation of the various parts of the LT2ESWTR
is timed appropriately so that there are sufficient resources to enable water systems to comply. Until the
LT2ESWTR is finalized, laboratories are technically unable to be certified because the criteria do not
officially exist. Does
Response: See Response 310(A).
EPA Letter ID: 536
Comment ID: 11779
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Large System Ability to Prepare for and Execute Monitoring
Three months lead time may be acceptable for larger systems that have been following the rule
development process, provided there are no major changes based on comments received. However, large
systems on the smaller side of the definition, such as those between 10,000 and 50,000 people (which
constitute a larger population of our systems), will have difficulty preparing and submitting a monitoring
Comment Response for the LT2ESWTR 5-18 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
plan within three months of rule promulgation and beginning monitoring within six months. Further, if
EPA makes significant changes to the
final rule based on comments received, large systems will need time to review and understand the
changes and then prepare for initial compliance activities accordingly.
Large systems must be allowed reasonable time to budget for Cryptosporidium sampling costs and to
contract with a laboratory for the analysis. While some larger systems may be able to absorb these costs
under their current budget, the costs could pose a significant problem for some larger systems unless the
rule happens to be promulgated just before the system begins budgeting for the fiscal year when sampling
occurs.
Depending upon the content of the final rule, it may not be possible for large systems to prepare a
complete monitoring plan within 90 days of rule promulgation. Although this effective date may be
reasonable if there are no major revisions resulting from public comment, the schedule presumes that
systems are familiar with the content of the proposed rule and have begun
preparing their plans prior to rule promulgation.
Response: See Responses 310(A).
EPA Letter ID: 536
Comment ID: 11780
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Follow-up Activities for Large Systems
Even if large systems are able to begin Cryptosporidium monitoring in the required timeframe, Colorado
is concerned that many systems will miss the first sample (or first few months of sampling) and that the
level of follow-up activity needed will be extensive. Follow-up activities will be time consuming, as
direct contact with individual systems will be required. EPA is reminded that although some states may
opt to assist EPA in such communications under
early implementation, Colorado is unable at this time to guarantee it will have sufficient resources
available to participate in any early implementation activities. In the event we are unable to participate,
EPA will need to undertake the follow-up activities directly, and as stated above, we believe this
undermines our primacy relationship with public water systems.
Response: See Response 310 (A) and (B).
EPA Letter ID: 536
Comment ID: 11787
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-19 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: -Stagger Cryptosporidium monitoring for large systems over three phases:
[see pdf for table]
System size: Cryptosporidium
Monitoring: Bin Determination
Date: Compliance
Date
>50K: 2 years of monitoring beginning 1 year after rule promulgation~3.5 years after rule promulgation
6.5 years after rule promulgation
30K-50K: 2 years of monitoring beginning 2 year after rule promulgation~4.5 years after rule
promulgation 7.5 years after rule promulgation
10K-30K: 2 years of monitoring beginning 3 year after rule promulgation~5.5 years after rule
promulgation 8.5 years after rule promulgation
Colorado recognizes that this will delay compliance with any new treatment requirements for some
systems, but believes that public health protection will ultimately be increased since the delay will ensure
that water systems that are subject to monitoring under the rule monitor at appropriate locations at
appropriate frequencies.
Response: See Response 310(A).
EPA Letter ID: 536
Comment ID: 11789
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Microbial Monitoring for Filtered Systems
Colorado concurs that large filtered systems should monitor for Cryptosporidium for two years, as this
will allow for the collection of an ample number of samples as well as account for seasonal variability.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12371
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. Twenty-four months are a practical monitoring period on which to
base bin determination,
EPA has reflected each of these components in the proposed rule. AWWA continues to believe that each
of these five recommendations is sound and appropriate for the LT2ESWTR. AWWA is concerned about
the specifics of EPA-s implementation of these general recommendations.
Comment Response for the LT2ESWTR 5-20 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Response: See Response lOOa, and Response 310(B) regarding implementation.
EPA Letter ID: 585
Comment ID: 11959
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: Cryptosporidium monitoring schedule accelerates sampling costs for systems that are least
capable of affording it and increases the number of erroneously low bin classifications when compared to
the monthly, 24-month sampling schedule being implemented for large systems.
p. 47672 [and §141.709(b)(3) on p. 47781]
Table IV-6 describes a number of monitoring approaches that can be used for the bin classification
process. The TCEQ concurs with the EPA proposal to allow large systems to rely on a 24-sample,
maximum running annual average. We realize that this monitoring approach will slightly increase the
probability that a system will provide more treatment than is required to achieve the desired
public health goals. However, the TCEQ recommends that EPA should follow an
Response: See Response lOOa, and Response 320(C)regarding small system monitoring options.
EPA Letter ID: 601
Comment ID: 13001
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 320 B. Small System Monitoring Requirements
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to perform indicator monitoring to determine the need
to perform Cryptosporidium monitoring.
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12705
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to
Comment Response for the LT2ESWTR 5-21 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12713
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Large System Ability to Prepare for and Execute Monitoring
Although three months lead time may be acceptable for larger systems that have been following the rule,
provided there are no major changes based on comments received, large systems on the smaller side of
the definition, such as those between 10,000 and 50,000 people, may have difficulty preparing and
submitting a monitoring plan within three months of rule promulgation and beginning monitoring within
six months. Further, if EPA makes significant changes to the
final rule based on comments received, large systems will need time to review and understand the
changes and then prepare for initial compliance activities accordingly.
Large systems must be allowed reasonable time to budget for Cryptosporidium sampling and contract
with a laboratory for the analysis. While some larger systems may be able to absorb these costs under
their current budget, the costs could pose a significant problem for some larger systems unless the rule
happens to be promulgated just before the system begins budgeting for the fiscal year when sampling
occurs.
Depending upon the content of the final rule, it may not be possible for large systems to prepare a
complete monitoring plan within 90 days of rule promulgation. Although this effective date may be
reasonable if there are no major revisions resulting from public comment, the schedule presumes that
systems are familiar with the content of the proposed rule and have begun
preparing their plans prior to rule promulgation. Any changes that occur based on comments received will
exacerbate the difficulties large systems will have preparing a monitoring plan in such a short time frame.
To minimize these difficulties, EPA will need to ensure that adequate outreach materials that outline the
rule requirements and highlight significant changes are available at the time of rule promulgation.
Response: See Response 310(A).
EPA Letter ID: 643
Comment ID: 12714
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Follow-up Activities for Large Systems
Even if large systems are able to begin Cryptosporidium monitoring in the required timeframe, states are
concerned that many systems will miss the first sample (or first few months of sampling) and that the
level of follow-up activity states or EPA would need to undertake will be extensive. Follow-up activities
will be time consuming, as direct contact with individual systems
will be required. EPA is reminded that although some states may opt to assist EPA in such
Comment Response for the LT2ESWTR 5-22 December 2005
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communications under early implementation, some states do not plan to participate in any early
implementation activities. In those states, EPA will need to undertake the follow-up activities directly.
Response: See Response 310 (A) and (B).
EPA Letter ID: 643
Comment ID: 12725
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States concur that large filtered systems should monitor for Cryptosporidium for two years, as
this will allow for the collection of an ample number of samples as well as account for seasonal
variability.
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12730
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: lakes/reservoirs and 50 E. coli /100 mL for flowing streams. States also support large system
collection of E. coli and turbidity data to determine if different triggers would be more appropriate.
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12766
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to
Response: See Response lOOa.
EPA Letter ID: 647
Comment ID: 12870
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-23 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to
Response: See Response lOOa.
EPA Letter ID: 647
Comment ID: 12876
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Large System Ability to Prepare for and Execute Monitoring
Although three months lead time may be acceptable for larger systems that have been following the rule,
provided there are no major changes based on comments received, large systems on the smaller side of
the definition, such as those between 10,000 and 50,000 people, may have difficulty preparing and
submitting a monitoring plan within three months of rule promulgation and beginning monitoring within
six months. Further, if EPA makes significant changes to the
final rule based on comments received, large systems will need time to review and understand the
changes and then prepare for initial compliance activities accordingly.
Large systems must be allowed reasonable time to budget for Cryptosporidium sampling and contract
with a laboratory for the analysis. While some larger systems may be able to absorb these costs under
their current budgets, the costs could pose a significant problem for some larger systems unless the rule
happens to be promulgated just before the systems begins budgeting for the fiscal year when sampling
occurs.
Depending upon the content of the final rule, it may not be possible for large systems to prepare a
complete monitoring plan within 90 days of rule promulgation. Although this effective date may be
reasonable if there are no major revisions resulting from public comment, the schedule presumes that
systems are familiar with the content of the proposed rule and have begun
preparing their plans prior to rule promulgation.
Response: See Response 310(A).
EPA Letter ID: 647
Comment ID: 12877
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Follow-up Activities for Large Systems
Even if large systems are able to begin Cryptosporidium monitoring in the required timeframe, many
systems will miss the first sample (or first few months of sampling), which will require follow-up activity
by states or EPA. Follow-up activities will be time consuming, as direct contact with individual systems
will be required. EPA is reminded that although some states may opt to assist EPA in such
communications under early implementation, some states do not plan
Comment Response for the LT2ESWTR 5-24 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
to participate in any early implementation activities. In those states, EPA will need to undertake the
follow-up activities directly.
Response: See Response 310 (A) and (B).
EPA Letter ID: 647
Comment ID: 12885
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Large filtered systems should monitor for Cryptosporidium for two years, as this
will allow for the collection of an ample number of samples as well as account for seasonal variability.
Response: See Response lOOa.
EPA Letter ID: 647
Comment ID: 12913
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to
Response: See Response lOOa.
5.3 Comment Code 320, Small System Monitoring Requirements
Summary of Issues
Comments were received expressing concern on the cost burden and implementation schedule placed on
small systems, while other comments acknowledged the indicator monitoring will be economically
feasible for small systems. These commenters also believe that small systems should be allowed to bypass
indicator monitoring, to lessen the cost burden, and proceed directly to Cryptosporidium monitoring.
Another group of comments suggested small system options for monitoring, including collecting fewer
than 24 samples for Cryptosporidium. Supportive comments were also received that supported the risk-
based approach under the LT2ESWTR, in which systems finding higher levels of contaminants are
required to provide additional protection against Cryptosporidium.
Comment Response for the LT2ESWTR 5-25 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Response to Code 320
(A) Small system cost burden
EPA disagrees with commenters who suggested that the monitoring requirements are too costly for small
systems. Nevertheless, although this final rule will not have a significant economic impact on a
substantial number of small systems, EPA has tried to reduce the impact of this rule on small systems.
Small filtered PWSs will monitor for E. coli as a screening analysis for source waters with low levels of
fecal contamination. Cryptosporidium monitoring will only be required of small filtered PWSs if they
exceed the E. coli trigger value. Survey data indicate that approximately 75 to 80 percent of small PWSs
will not exceed the E. coli trigger values and, consequently, will not be required to monitor for
Cryptosporidium. Because E. coli analysis is much cheaper than Cryptosporidium analysis, the use of E.
coli as a screen will significantly reduce monitoring costs for the majority of small PWSs. Further, small
PWSs will not be required to initiate their monitoring until large PWS monitoring has been completed.
This will provide small PWSs with additional time to become familiar with the rule and to efficiently
prepare for monitoring and other compliance activities.
Today's final rule also provides an option for small systems that must monitor for Cryptosporidium to do
so over two years if desired. Small PWSs that must monitor for Cryptosporidium may collect the 24
required samples over just one year or they can spread their 24 Cryptosporidium samples over two years.
Spreading the Cryptosporidium monitoring over two years will reduce the monitoring costs a PWS incurs
in a single year.
The risk-targeted approach of the LT2ESWTR will impose additional treatment requirements only on the
subset of PWSs with the highest vulnerability to Cryptosporidium, as indicated by source water pathogen
levels. This approach will spare the majority of PWSs from the cost of installing additional treatment.
Also, development of the microbial toolbox under the LT2ESWTR will provide both large and small
PWSs with broad flexibility in selecting cost-effective compliance options to meet additional treatment
requirements.
Funding may be available from programs administered by EPA and other Federal agencies to assist small
PWSs in complying with the LT2ESWTR. The Drinking Water State Revolving Fund (DWSRF) assists
PWSs with financing the costs of infrastructure needed to achieve or maintain compliance with Safe
Drinking Water Act requirements. Through the DWSRF, EPA awards capitalization grants to States,
which in turn can provide low-cost loans and other types of assistance to eligible PWSs.
(B) Bypass E. coli indicator monitoring and go directly to Cryptosporidium monitoring
EPA agrees with comments that suggest small systems can bypass E. coli indicator monitoring and
proceed directly to Cryptosporidium sampling if the system desires. Therefore, the final rule allows small
filtered PWSs to elect to skip E. coli monitoring if they notify the State that they will monitor for
Cryptosporidium. PWSs must notify the State no later than three months prior to the date the PWS is
required to begin monitoring.
(C) Small system Cryptosporidium monitoring
EPA agrees with comments suggesting that small system Cryptosporidium monitoring should be allowed
to occur over two years at the option of the PWS, and that budgeting for Cryptosporidium monitoring by
small PWSs may be easier if it is spread over two years. Therefore, today's rule allows small PWSs that
are required to monitor for Cryptosporidium to conduct this monitoring using either of two frequencies:
Comment Response for the LT2ESWTR 5-26 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
(1) sample at least twice-per-month for a period of one year or (2) sample at least once-per-month for a
period of two years. Selecting the two-year Cryptosporidium sampling frequency does not extend
Cryptosporidium treatment compliance deadlines.
EPA disagrees with commenters who suggested that small systems that must monitor for
Cryptosporidium be allowed to take fewer than 24 samples, such as 12 or 8, if they acknoledge the risk of
higher false positives and agree to provide treatment based on the results of the smaller sample set. As
described in the proposed rule, sample sets of 12 and 8 samples would result in a probability of systems
being misclassified into Bin 2 of 47% and 66%, respectively. EPA continues to believe that these reduced
sampling schemes would unfairly result in excessive and costly treatment requirements for those systems;
therefore, the final rule requires a minimum of 24 samples to limit false positives.
Regarding suggestions that that EPA work to develop a less expensive bin classification scheme using E.
coli and turbidity criteria based on the large system monitoring results, EPA has agreed to use large
system E. coli and turbidity data to verify or refine the indicator trigger values for small systems. After
one year of large system monitoring, EPA will begin analyzing monitoring data to assess whether
alternative indicator strategies would be appropriate.
Individual Comments on Code 320
EPA Letter ID: 101
Comment ID: 10874
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: LT 2 Monitoring Small System Cryptosporidium Monitoring
The monitoring requirements for small systems are overly burdensome and will be too costly. The EPA
must rely on the community to make the best decision based on inexpensive methods and site specific
concerns. Small communities do not resist regulations and monitoring when it is in their best interest.
Local governments can, and will, act on behalf of their own self-interest. Small communities support
retaining all local government authority over their water system and the associated monitoring
requirements. This assures the best possible decisions for the local citizens. Considering all the
complexity of determining local public health policy (cost, benefits, tradeoffs, etc.), there is not a better
mechanism for determining the best local public health policy than the local citizens' choice.
Response: See Response 320(A).
EPA Letter ID: 429
Comment ID: 10590
Commenter: Janet Montz, Environmental Specialist, OCI Wyoming, L.P.
Commenter Category: Regulated Community (Utilities)
Comment: 2- LT2 sampling is expensive. Most small water systems cannot afford. Why such a
rigorous monitoring schedule. What is justification?
3 - Labs are too far away to meet the sampling requirements. Most systems cannot get a sample to a lab
within 24 hours even with overnight delivery.
Comment Response for the LT2ESWTR 5-27 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
5 - Don't sanitary surveys identify systems that have problems? If systems continue to meet existing
requirements, what is the benefit of more vigorous testing?
Response: See Response 320(A), 500(h) regarding other sources of information such as source water
assessments, and 1734 regarding overnight delivery.
EPA Letter ID: 457
Comment ID: 11884
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 310 A. Large System Monitoring Requirements
Comment: We concur with the risk-based approach proposed under the LT2ESWTR in
which surface water systems monitor for microbial contaminants and only those systems finding higher
levels of contaminants in their source waters are required to provide additional protection against
Cryptosporidium. This includes the proposed requirement for large public water systems to perform
Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for smaller systems to perform indicator monitoring, to determine the
need to perform Cryptosporidium monitoring. We
Response: See Response lOOa.
EPA Letter ID: 457
Comment ID: 11885
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: monitoring, to determine the need to perform Cryptosporidium monitoring. We
believe that the smaller systems should be given the flexibility and the choice to perform
Cryptosporidium monitoring, without performing the indicator monitoring.
Response: See Response 320(B).
EPA Letter ID: 457
Comment ID: 11891
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-28 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: We also support small filtered system indicator monitoring to determine the need to monitor
for Cryptosporidium, as indicator monitoring will be more economically feasible for small systems.
However, we strongly believe that small systems should be allowed to bypass indicator monitoring and
proceed directly to two years of Cryptosporidium monitoring, if the system so desires.
Response: See Response lOOa and Response 320(B).
EPA Letter ID: 457
Comment ID: 11913
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 310 A. Large System Monitoring Requirements
Comment: We concur with the risk-based approach proposed under the LT2ESWTR in which surface
water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium. This includes the
proposed requirement for large systems to perform Cryptosporidium monitoring to determine risk from
microbial contamination as well as the proposed requirement for small systems to perform indicator
monitoring to determine the need to perform Cryptosporidium
monitoring.
Response: See Response lOOa.
EPA Letter ID: 457
Comment ID: 11943
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: To reduce the economic burden on the states and the small systems, EPA should allow small
systems to follow the 24-month, one Cryptosporidium sample per month sampling strategy that is
available to large systems. This is our preferred approach. This approach will greatly reduce the financial
strain on small systems and the states by spreading the sampling cost out over a two-year period instead
of compressing the entire cost into a single 12-month period.
Response: See Response 320(C).
EPA Letter ID: 466
Comment ID: 11017
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-29 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: one year to secure funding. ND agrees small systems should be allowed the option
of monitoring for Cryptosporidium instead of monitoring for the indicator bacteria E. coli.
Response: See Response 320(B).
EPA Letter ID: 470
Comment ID: 11093
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Allow small systems two options for monitoring for Cryptosporidium:
Option 1: Monitor over a two-year period. Small systems would not perform indicator monitoring under
this approach. To be consistent with the deadlines included in the proposed rule, monitoring would need
to begin three years after rule promulgation (monitoring would occur in Years 3 and 4) and systems
would be required to comply with new bin requirements 8.5 years after rule promulgation. Small systems
would use the same bin determination approaches available to large systems (dependent on the total
number of samples taken). EPA would need to carefully consider laboratory capacity under this approach
as systems serving 10,000-30,000 people and small systems would be monitoring for Cryptosporidium at
the same time. If capacity is indeed an issue, EPA should consider delaying small system
Cryptosporidium monitoring in order to provide this opportunity for small systems to gather more
meaningful information in a
more cost-effective manner even if this extends the overall compliance schedule.
Option 2: Monitor over a one-year period, but allow small systems the option of taking 8, 12, or 24
samples. Bin determinations would be made using the 8-sample maximum value, 12-sample second
highest value, or 24-sample arithmetic mean, respectively. The system would need to acknowledge the
risk of higher -false positives- under the first two approaches and agree to provide the treatment indicated
based on the number of samples associated with the approach. To be consistent with EPA-s proposed
schedule, Cryptosporidium monitoring would occur
in Year 4 and small systems would be required to comply with new bin requirements 8.5 years after rule
promulgation. Small systems would have an opportunity to perform indictor monitoring under this
approach, with indicator monitoring beginning 2.5 years after rule promulgation. EPA may need to adjust
this schedule depending on the need for small systems to have additional time
between indicator monitoring and Cryptosporidium monitoring in order to secure funding and contract
with a laboratory for analysis (currently six months is provided), or any delay in the two-year scheme
described above (possibly based on laboratory capacity).
A tabular representation of the small system approaches is provided below. The table assumes EPA-s
proposed compliance deadline and the date of bin determination and the date of compliance will be 5.5
years after rule promulgation and 8.5 years after rule promulgation, respectively.
[SEE TABLE, PAGE 5 OF PDF]
Response: See Response 320(C).
Comment Response for the LT2ESWTR 5-30 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 483
Comment ID: 11258
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: analysis, not including staff time for monitoring, reporting and recordkeeping.
These costs increases are significant, especially for small systems.
Response: See Response 320(A).
EPA Letter ID: 499
Comment ID: 10718
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: contamination as well as the proposed requirement for small systems to perform
indicator monitoring to determine the need to perform Cryptosporidium monitoring.
Response: See Response lOOa.
EPA Letter ID: 520
Comment ID: 11574
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: - Allow small systems the option of monitoring for Cryptosporidium:
o Over a two-year period beginning three years after rule promulgation (monitoring would occur in Years
3 and 4). Small systems would not perform indicator monitoring under this approach and would be
required to comply with new bin requirements 8.5 years after rule promulgation (which is consistent with
EPA's proposed schedule). EPA would need to carefully consider laboratory
capacity under this approach as systems serving 10,000-30,000 people and small systems would be
monitoring for Cryptosporidium at the same time. If capacity is indeed an issue, EPA should consider
delaying small system Cryptosporidium monitoring until Years 4 and 5 (which would delay compliance
for small systems by one year from the proposed approach) in order to provide this opportunity forsmall
systems to gather more meaningful information in a more cost-effective
manner.
o Over a one-year period, but allow small systems the option of taking 8, 12, or 24 samples. Bin
determinations would be made using the 8-sample maximum value, 12-sample second highest value or,
24-sample arithmetic mean, respectively. The system would need to acknowledge the risk of higher "false
positives" under the first two approaches and agree to provide the treatment indicated based on the lower
number of samples. Cryptosporidium monitoring would occur in Year 4 and small systems would be
Comment Response for the LT2ESWTR 5-31 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
required to comply with new bin requirements 8.5 years
after rule promulgation (which is consistent with EPA's proposed schedule). Small systems would have
an opportunity to perform indictor monitoring under this approach, with indicator monitoring beginning
2.5 years after rule promulgation. EPA may need to adjust this schedule depending on the need for small
systems to have additional time between indicator monitoring and Cryptosporidium monitoring in order
to secure funding and contract with a laboratory for analysis (currently six months is provided) or any
necessary delay due to laboratory capacity.
Response: See Response 320(C).
EPA Letter ID: 520
Comment ID: 11576
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA also supports small filtered system indicator monitoring to determine the need to
monitor for Cryptosporidium, as indicator monitoring will be more economically feasible for small
systems. However, IEPA also believes that small systems should be allowed to bypass indicator
monitoring and proceed directly to two years of Cryptosporidium monitoring if the system so desires.
Response: See Response 320(B).
EPA Letter ID: 520
Comment ID: 11613
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 300 II. Filtered System Monitoring Requirements
(parameters, frequency, location); 510 A. Microbial Framework Approach
Comment: IEPA concurs with the risk-based approach proposed under the LT2ESWTR in which
surface water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium. This includes the
proposed requirement for large systems to perform Cryptosporidium monitoring to determine risk from
microbial contamination as well as the proposed requirement for small systems to perform indicator
monitoring to determine the need to perform Cryptosporidium monitoring. Additional IEPA comments on
the overall approach are included in the above.
Response: See response 100.a.
EPA Letter ID: 536
Comment ID: 11788
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
Comment Response for the LT2ESWTR 5-32 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
and Environment
Commenter Category: State/Tribe Government
Comment: -Allow small systems the option of monitoring for Cryptosporidium:
oOver a two-year period or for one year using a reduced number of samples beginning four years after
rule promulgation (monitoring would occur in Years 4 and 5). This approach would delay compliance for
small systems by one year (9.5 years after rule promulgation instead of 8.5 years under the proposed
approach), but, as discussed previously, will provide more meaningful information in a more cost-
effective manner for small systems. Small systems would still have an
opportunity to perform indictor monitoring, but would need to coordinate with the state to determine
appropriate timing. At a minimum, indicator monitoring would need to be completed and analyzed prior
to the beginning Year 5 in order to allow the small system to perform one year of Cryptosporidium
monitoring if needed. Compliance under this approach would be delayed by one year for small systems
that perform Cryptosporidium monitoring.
oFor only one year using the 12-sample second highest value or the 8-sample maximum value to
determine their bin classifications. The system would need to acknowledge the risk of-false positives-
and agree to provide the treatment indicated based on the lower number of samples. If monitoring were to
be required in Year 4, small systems would be in compliance 8.5 years after rule promulgation, which is
consistent with EPA-s proposed schedule.
oFor two years using E. coli and turbidity bin classification criteria based on the results of the large
system monitoring in lieu of Cryptosporidium monitoring.
Response: See Response 320(C).
EPA Letter ID: 536
Comment ID: 11790
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Colorado also supports small filtered system indicator monitoring to determine
the need to monitor for Cryptosporidium, as indicator monitoring will be more economically feasible for
small systems. Colorado also believes that small systems should be allowed to bypass indicator
monitoring and proceed directly to two years of Cryptosporidium monitoring if the system so desires,
however, Colorado prefers that EPA work to develop a less expensive bin classification scheme using E.
coli and turbidity criteria based on the large system monitoring
results.
Response: See Response lOOa, and Response 320(C) regarding your comment about bin classification
schemes using E. coli and turbidity.
EPA Letter ID: 601
Comment ID: 13001
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Comment Response for the LT2ESWTR 5-33 December 2005
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Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 310 A. Large System Monitoring Requirements
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to perform indicator monitoring to determine the need
to perform Cryptosporidium monitoring.
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12706
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to perform indicator monitoring to determine the need
to perform Cryptosporidium monitoring. States do have concerns with the proposed implementation
schedule.
Response: See Response lOOa, and Response 310(A) regarding changes to the implementation schedule.
EPA Letter ID: 643
Comment ID: 12724
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: * Allow small systems two options for monitoring for Cryptosporidium:
- Option 1: Monitor over a two-year period. Under this approach, small systems would monitor for
Cryptosporidium following the same approach used for large systems and the same methods for bin
determination available to large systems. This approach would allow small systems to spread out the cost
of Cryptosporidium monitoring over two years and potentially use the more accurate bin determination
method based on the 48-sample arithmetic mean. In order for
systems to have the option of performing indicator monitoring, the compliance deadline would need to be
extended at least one year to 9.5 years after rule promulgation. This schedule may need to be further
extended based on the length of time small systems need between the end of indicator monitoring and the
beginning of Cryptosporidium monitoring as described previously.
In addition to the concerns raised above regarding requiring too large a number of systems to perform
Cryptosporidium monitoring at the same time, states are concerned that strictly adhering to the
compliance date for small systems in the proposed rule (8.5 years after rule promulgation) could prevent
small systems from being able to perform indicator monitoring under this approach. The time needed for
states to approve monitoring locations and the system to then perform
the monitoring may not be adequate to allow the system to the time needed to develop a Cryptosporidium
Comment Response for the LT2ESWTR 5-34 December 2005
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Comment Codes 300-471
monitoring schedule, budget for Cryptosporidium monitoring, and begin monitoring, if such monitoring is
necessary based on the indicator monitoring results.
- Option 2: Monitor over a one-year period, but allow small systems the option of taking 8, 12, or 24
samples. Bin determinations would be made using the 8-sample maximum value, 12-sample second
highest value or, 24-sample arithmetic mean, respectively. The system would need to acknowledge the
risk of higher
-false positives- under the first two approaches and agree to provide the treatment indicated based on the
number of samples associated with the approach.
- A tabular representation of the small system approaches is provided below.
[SEE TABLE, P. 13 (OF 42) IN PDF]
Response: See Response 320(C).
EPA Letter ID: 643
Comment ID: 12726
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States also support small filtered system indicator monitoring to determine the need to
monitor for Cryptosporidium, as indicator monitoring will be more economically feasible for small
systems. However, states also believe that small systems should be allowed to bypass indicator
monitoring and proceed directly to two years of Cryptosporidium monitoring if the system so desires.
Response: See Response lOOa, and Response 320(B) regarding small systems bypassing indicator
monitoring.
EPA Letter ID: 643
Comment ID: 12767
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to perform indicator monitoring to determine the need
to perform Cryptosporidium monitoring. Additional state comments on the overall approach are included
in Attachment 1.
Response: See Response lOOa.
EPA Letter ID: 647
Comment ID: 12865
Comment Response for the LT2ESWTR
5-35
December 2005
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Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 530 C. Procedures for Calculating Bin Classification;
1700 XIII. Analytical Methods
Comment: we have significant concerns about the laboratory techniques and accuracy, cost
of sample collection for small water systems, and the effect of climate conditions on the variability of
Cryptosporidium levels. MDE also supports the
Response: See Response 320(A) regarding small system sampling costs. (Also see Responses SOO.o,
SOO.p, lOO.c, lOO.i, and 1700 for other comments).
EPA Letter ID: 647
Comment ID: 12871
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to perform indicator monitoring to determine the need
to perform Cryptosporidium monitoring. States do have concerns with the proposed implementation
schedule.
Response: See Response lOOa. Also see Response 310(A) regarding changes to the implementation
schedule.
EPA Letter ID: 647
Comment ID: 12883
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: - Allow small systems the option of monitoring for Cryptosporidium:
- Over a two-year period beginning three years after rule promulgation (monitoring would occur in Years
3 and 4). Small systems would not perform indicator monitoring under this approach and would be
required to comply with new bin requirements 8.5 years after rule promulgation
(which is consistent with EPA-s proposed schedule). EPA would need to carefully consider laboratory
capacity under this approach as systems serving 10,000-30,000 people and small systems would be
monitoring for Cryptosporidium at the same time. If capacity is indeed an issue, EPA should consider
delaying small system Cryptosporidium monitoring until
Years 4 and 5 (which would delay compliance for small systems by one year from the proposed
approach) in order to provide this opportunity for small systems to gather more meaningful information in
a more cost-effective manner.
- Over a one-year period, but allow small systems the option of taking 8, 12, or 24 samples. Bin
determinations would be made using the 8-sample maximum value, 12-sample second highest value or,
24-sample arithmetic mean, respectively. The system would need to acknowledge
Comment Response for the LT2ESWTR 5-36 December 2005
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the risk of higher -false positives- under the first two approaches and agree to provide the treatment
indicated based on the lower number of samples. Cryptosporidium monitoring would occur in Year 4 and
small systems would be required to comply with new bin requirements 8.5 years after rule promulgation
(which is consistent with EPA-s proposed schedule). Small systems would have an opportunity to
perform indictor monitoring under this approach, with indicator monitoring beginning 2.5 years after rule
promulgation. EPA may need to adjust this schedule
depending on the need for small systems to have additional time between indicator monitoring and
Cryptosporidium monitoring in order to secure funding and contract with a laboratory for analysis
(currently six months is provided) or any necessary delay due to laboratory capacity.
Response: See Response 320(C).
EPA Letter ID: 647
Comment ID: 12886
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: MDE supports small filtered system indicator monitoring to determine the need to
monitor for Cryptosporidium, as indicator monitoring will be more economically feasible for small
systems. However, small systems should be allowed to bypass indicator monitoring and proceed directly
to two years of Cryptosporidium monitoring if the system so desires. In addition, Maryland has more than
two
Response: See Response lOOa. Also see Response 320(B) regarding bypassing indicator monitoring.
EPA Letter ID: 647
Comment ID: 12914
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: protection against Cryptosporidium. This includes the proposed requirement for
large systems to perform Cryptosporidium monitoring to determine risk from microbial contamination as
well as the proposed requirement for small systems to perform indicator monitoring to determine the need
to perform Cryptosporidium monitoring.
Response: See Response lOOa.
5.3.1 Comment Code 321, E. coli monitoring frequency and duration
Summary of Issues
Comments expressed support for allowing small systems that anticipate exceeding E. coli trigger levels to
bypass E. coli monitoring and implement Cryptosporidium monitoring. Clarification regarding
monitoring frequency and reporting requirements for small systems monitoring for Cryptosporidium in
Comment Response for the LT2ESWTR 5-3 7 December 2005
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lieu of E. coli was also requested. One comment expressed concern regarding the method used to
calculate the E. coli annual mean concentration and requested that specific guidance be provided by EPA.
Response to Code 321
E. coli annual mean calculations
EPA disagrees with the commenter who suggested that it is not clear how a small system determines its
mean E. coli level. Small systems must conduct E. coli monitoring every two weeks for twelve months.
The annual mean E. coli concentration of this 12 months of sampling is compared to the appropriate E.
coli trigger level. EPA has provided specific guidance for calculating the E. coli annual mean in both the
Microbial Laboratory Guidance Manual for the Long Term 2 Enhanced Surface Water Treatment Rule
(LT2 Rule) and Source Water Monitoring Guidance Manual for Public Water Systems for the Long Term
2 Enhanced Surface Water Treatment Rule (LT2 Rule}.
Individual Comments on Code 321
EPA Letter ID: 513
Comment ID: 11528
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: (2) Will a small system that anticipates exceeding the E. coli threshold for Cryptosporidium
monitoring have the option of foregoing E. coli monitoring in favor of commencing Cryptosporidium
monitoring?
Response: See Response 320(B).
EPA Letter ID: 520
Comment ID: 11578
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: to suggest different triggers than those proposed in the rule. IEPA supports one
year of indicator monitoring for small systems followed by one year of
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12728
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-38 December 2005
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Comment: data to suggest different triggers than those proposed in the rule. States
support one year of indicator monitoring for small systems followed by one year
Response: See Response lOOa.
EPA Letter ID: 675
Comment ID: 13967
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: monitoring for large systems over three phases. We also recommend EPA modify
some requirements of monitoring at small water systems. Specifically, we suggest allowing all small
systems the option of bypassing indicator (E. coli) monitoring for Cryptosporidium monitoring. Also, the
six-month window for
Response: See Response 320(B).
EPA Letter ID: 678
Comment ID: 14659
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. Sections 141.701(c), 141.702(b)(l) and (2) - The EPA has not described how the annual
mean E. Coli concentration is determined for a small system. There are many ways of calculating the
annual mean value, such as based on the annual average of weekly results or
the annual average of monthly average of weekly results. The resulting annual mean E. Coli
concentrations using different calculation methods may end up with different monitoring and
treatment requirements for Cryptosporidium. The EPA should establish the determination method for
consistency purpose.
Response: See Response 321.
5.3.2 Comment Code 322, Cryptosporidium monitoring frequency
and duration
Summary of Issues
Many comments were received suggesting that small systems should follow the identical
Cryptosporidium monitoring schedule and frequency, i.e., one sample per month for 24 months, as large
systems do under the LT2ESWTR. To avoid financial burden on smaller systems, commenters suggested
allowing less than 24 samples to fulfill LT2ESWTR requirements. Commenters also recommend that
adequate time be allowed for small systems to budget for Cryptosporidium monitoring and contract with a
Comment Response for the LT2ESWTR 5-39 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
laboratory for analysis. Other comments propose using EPA's Monte Carlo analysis to determine bin
classification.
Response to Code 322
Responses to comments under this comment code are found in responses 310(A), 310(C) and 320(C).
Individual Comments on Code 322
EPA Letter ID: 101
Comment ID: 10876
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Initial Monitoring
If historical data indicates that the source water is of good quality and no violations of the Total Coliform
Rule over the past year, then small systems should not be subject to the initial monitoring requirements.
The systems could take one sample for cryptosporidium during the historically high months and use
this result to determine which bin they must comply with.
Small systems were given the option of E. Coliform monitoring because of the high cost of monitoring
for cryptosporidium 24 times over a two year period. This proposal makes these small systems do the 24
samples over a 12 month period if their E. coliform levels are high. If small systems cannot afford 24
samples over two years, they surely cannot afford it in a single year. We assume that it costs about $350
to $400 per sample and 24 samples would cost between $8400 and $9600. This amount exceeds most
small systems ANNUAL budget. This requirement is setting up systems to fail even before the treatment
requirements have been established. A better alternative is to have the community assign a shorter
period of sampling for cryptosporidium, at a rate based on local conditions, during the months of highest
risk to cryptosporidium. This could be determined by the community but could be based on E. coliform
samples and the turbidity samples - Many small communities struggle to afford the existing monitoring
and other regulatory requirements without the burden of additional rules. If a minimum was established
by EPA, it should be three samples per year.
Response: See Response 320(C).
EPA Letter ID: 520
Comment ID: 11567
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Small System Activities
Although IEPA supports the use of indicator monitoring for small systems, IEPA is concerned that the
final rule needs to include adequate timing for small systems to budget for Cryptosporidium monitoring
and contract with a laboratory for the analysis. The six-month window included in the proposed rule may
not be adequate. Some systems will most likely need at least one year to secure the necessary funding.
Comment Response for the LT2ESWTR 5-40 December 2005
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Response: See Response 310(C).
EPA Letter ID: 520
Comment ID: 11568
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Further, small systems that are required to monitor for Cryptosporidium must
collect the same number of samples as large systems but must collect them at twice the rate. This proposal
places an extreme economic impact on small systems that are much less likely to have the financial
reserves necessary to implement such costly monitoring program on such an aggressive schedule.
To reduce the economic burden on small systems, EPA could allow small systems to follow the 24-
month, one Cryptosporidium sample per month sampling strategy that is available to large systems. This
approach will reduce the financial strain on small systems by spreading the sampling cost out over a two-
year period instead of compressing the entire cost into a single 12-month period. However, this approach
would extend the compliance date for small systems that are required to monitor for Cryptosporidium by
twelve months.
Another option would be to allow small systems to use the 12-sample second highest value or the 8-
sample maximum value to determine their bin classifications. This approach is based on EPA's Monte
Carlo analysis that reveals that these sampling protocols also produce extremely low "false
negative" bin classifications. While EPA's analysis indicates that each of these two methodologies
produce extremely high "false positive" rates, public water systems should be given the option of
reducing the monitoring requirements if they are willing to provide the additional treatment that would
result from a higher risk bin classification.
Response: See Response 320(C).
EPA Letter ID: 520
Comment ID: 11579
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 332 2. E. coli trigger concentrations
Comment: year of indicator monitoring for small systems followed by one year of Cryptosporidium
monitoring based on triggers of 10 E. coli/100 mL for lakes/reservoirs and 50 E. coli /100 mL for flowing
streams. IEPA also supports
Response: See Response lOOa.
Comment Response for the LT2ESWTR 5-41 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 528
Comment ID: 12249
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Further, small systems that are required to monitor for Cryptosporidium must
collect the same number of samples as large systems but must collect them at twice the rate. This proposal
places an extreme economic impact on small systems that are much less likely to have the financial
reserves necessary to implement such costly monitoring program on such an aggressive schedule as well
as the State implementation activities.
To reduce the economic burden on small systems, EPA could allow small systems to follow the 24-
month, one Cryptosporidium sample per month sampling strategy that is available to large systems. This
approach will reduce the financial strain on small systems by spreading the sampling cost out over a two-
year period instead of compressing the entire cost into a single 12-month period. However, this approach
would extend the compliance date for small systems that are required to monitor for Cryptosporidium by
twelve months.
- Small systems monitoring for Cryptosporidium:
o Monitor E. Coli for one year to determine need for Cryptosporidium monitoring based on the trigger
levels as proposed. Then monitor Cryptosporidium over a two-year period starting 5 years after
promulgation. Under this approach, small systems would monitor for Cryptosporidium following the
same approach used for large systems and the same methods for bin determination available to large
systems. This approach would allow the state / small systems to spread out the
cost of Cryptosporidium monitoring over two years and potentially use the more accurate bin
determination method based on the 48-sample arithmetic mean. This schedule may need to be further
extended based on the length of time small systems need between the end of indicator monitoring and the
beginning of Cryptosporidium monitoring as described previously.
Response: See Response 320(C)
EPA Letter ID: 533
Comment ID: 12216
Commenter: Edward Urheim,,
Commenter Category: Consultants: (where self-identified)
Comment: For small water systems that are triggered and must perform Cryptosporidium
monitoring, EPA should allow small systems to follow the 24-month, one Cryptosporidium sample per
month sampling strategy that is available to large systems. This approach could reduce the financial strain
on small systems by spreading the sampling cost out over a two-year period instead of compressing the
entire cost into a single 12-month period.
Response: See Response 320(C).
Comment Response for the LT2ESWTR 5-42 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 536
Comment ID: 11781
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Small System Activities
Although Colorado supports the use of indicator monitoring for small systems, we are concerned that the
final rule needs to include adequate timing for small systems to budget for Cryptosporidium monitoring
costs and contract with a laboratory for the analysis. The six-month window included in the proposed rule
may not be adequate. Some systems will most likely need at least one year to secure the necessary
funding.
Response: See Response 310(C).
EPA Letter ID: 536
Comment ID: 11782
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Further, small systems that are required to monitor for Cryptosporidium must
collect the same number of samples as large systems but must collect them at twice the rate. This proposal
places an extreme economic impact on small systems that are much less likely to have the financial
reserves necessary to implement such costly monitoring program on such an aggressive schedule.
To reduce the economic burden on small systems, EPA could allow small systems to follow the 24-
month, one Cryptosporidium sample per month sampling strategy that is available to large systems. This
approach will reduce the financial strain on small systems by spreading the sampling cost out over a two-
year period instead of compressing the entire cost into a single 12-month period. However, this approach
would extend the compliance date for small systems that are required to monitor for Cryptosporidium by
twelve months.
Another option would be to allow small systems to use the 12-sample second highest value or the 8-
sample maximum value to determine their bin classifications. This approach is based on EPA-s Monte
Carlo analysis that reveals that these sampling protocols also produce extremely low -false negative- bin
classifications. While EPA-s analysis indicates that each of these two methodologies produce extremely
high -false positive- rates, public water systems should be given the option of reducing the monitoring
requirements if they are willing to provide the additional treatment that would result from a higher risk
bin classification.
A final, and our preferred, option would be for EPA to use the results of the large system sampling results
to develop a risk bin classification scheme based on the E. coli and turbidity results directly in lieu of
making small and very small systems test for Cryptosporidium per se.
Response: See Response 320(C).
Comment Response for the LT2ESWTR 5-43 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 585
Comment ID: 11960
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: public health goals. However, the TCEQ recommends that EPA should follow an identical
24-month, one-sample per month sampling strategy when implementing Cryptosporidium sampling at
small systems. This approach will reduce the financial strain on small systems by spreading the sampling
cost over a two-year period instead of compressing the entire cost into a single 12-month period.
Furthermore, the Monte Carlo analysis indicates that the 24-sample arithmetic mean results in four times
as many erroneously low bin classifications as a 24-sample running annual average.
Response: See Response 320(C).
EPA Letter ID: 585
Comment ID: 11961
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: The TCEQ also recommends that EPA give small systems the option of using the 12-
sample second highest value and the 8-sample maximum value to determine their bin classifications. This
recommendation is based on EPA's Monte Carlo analysis that reveals that these sampling protocols also
produce extremely low "false negative" bin classifications. While the analysis indicates that each of these
two methodologies produce extremely high "false positive" rates, public water systems should be given
the option of reducing monitoring requirements if they are willing to provide the additional treatment that
would result from a higher risk bin classification.
Response: See Response 320(C).
EPA Letter ID: 585
Comment ID: 11965
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47677 [and §141.709(b)(3) on p. 47781]
As noted during our discussion of Table IV-6, the TCEQ does not concur with the provision which would
require small systems to collect 24 Cryptosporidium samples over a 12-month period (in the event that
they were required to monitor based on E. coli results).
The TCEQ recommends that small systems be given the option of collecting fewer samples since this
approach should not result in erroneously low bin classifications. However, if EPA elects to promulgate a
rule requiring 24 samples, we recommend that these samples be collected over a 24-month period
rather than a 12-month period; this approach will reduce the number of false negative bin classifications
Comment Response for the LT2ESWTR 5-44 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
as well as reduce the rate at which the increased sampling costs are incurred at the systems which are least
capable of handling increased spending rates.
Response: See Response 320(C).
EPA Letter ID: 585
Comment ID: 11991
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: 5) Small systems that are required to monitor for Cryptosporidium must collect the same
number of samples as large systems but must collect them at twice the rate. This proposal places an
extreme economic hardship on small systems. Moreover, the proposed bi-weekly sampling process
produces a higher rate of false-positive results that could unnecessarily increase the capital and
operating costs for small systems.
Response: See Response 320(C).
EPA Letter ID: 603
Comment ID: 12682
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1832 2. Adequacy of current capacity
Comment: The currently limited laboratory capacity is a concern. Not so much for the large systems,
many of which are currently collecting data in preparation for grandfathering, but for the small systems
that will be required to collect 24 samples over 12 months, which roughly corresponds to $9,600. We
recommend that EPA allow small water systems to decrease the number of samples that they collect over
one year and/or extend the collection period to two years to decrease impact on small water systems and
laboratories during this part of rule implementation.
Response: See Response 320(C).
EPA Letter ID: 643
Comment ID: 12716
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Small System Activities
Although states support the use of indicator monitoring for small systems, states are concerned that the
final rule needs to include adequate timing for small systems to budget for Cryptosporidium monitoring
Comment Response for the LT2ESWTR 5-45 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
and contract with a laboratory for the analysis. The six-month window included in the proposed rule may
not be adequate. Some systems will most likely need at least one year to secure the necessary funding.
Response: See Response 310(C).
EPA Letter ID: 643
Comment ID: 12717
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Further, small systems that are required to monitor for Cryptosporidium must
collect the same number of samples as large systems but must collect them at twice the rate. This proposal
places an extreme economic impact on small systems that are much less likely to have the financial
reserves necessary to implement such costly monitoring program on such an aggressive schedule.
To reduce the economic burden on small systems, EPA could allow small systems to follow the 24-
month, one Cryptosporidium sample per month sampling strategy that is available to large systems. This
approach will reduce the financial strain on small systems by spreading the sampling cost out over a two-
year period instead of compressing the entire cost into a single 12-month period. However, this approach
would extend the compliance date for small systems that are required to monitor for Cryptosporidium by
twelve months.
Another option would be to allow small systems to using the 12-sample second highest value or the 8-
sample maximum value to determine their bin classifications. This approach is based on EPA-s Monte
Carlo analysis that reveals that these sampling protocols also produce extremely low -false negative- bin
classifications. While EPA-s analysis indicates that each of these two methodologies produce extremely
high -false positive- rates, public water systems should be given the option of reducing the monitoring
requirements if they are willing to provide the additional treatment that would result from a higher risk
bin classification.
Response: See Response 320(C).
EPA Letter ID: 643
Comment ID: 15033
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 332 2. E. coli trigger concentrations
Comment: data to suggest different triggers than those proposed in the rule. States support one year of
indicator monitoring for small systems followed by one year of Cryptosporidium monitoring based on
triggers of 10 E. coli/100 mL for lakes/reservoirs and 50 E. coli /100 mL for flowing streams. States also
Response: See Response lOOa.
Comment Response for the LT2ESWTR 5-46 December 2005
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EPA Letter ID: 647
Comment ID: 12878
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Small System Activities
MDE is concerned that the final rule needs to include adequate timing for small systems to budget for
Cryptosporidium monitoring and contract with a laboratory for the analysis. The six-month window
included in the proposed rule may not be adequate. Some systems will most likely need at least one year
to secure the necessary funding.
Response: See Response 310(C).
EPA Letter ID: 647
Comment ID: 12879
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Further, small systems that are required to monitor for Cryptosporidium must collect the same
number of samples as large systems but must collect these samples at twice the rate. This proposal places
an extreme economic impact on small systems that are much less likely to have the financial reserves
necessary to implement such costly monitoring program on such an aggressive schedule.
To reduce the economic burden on small systems, EPA could allow small systems to follow the 24-
month, one Cryptosporidium sample per month sampling strategy that is available to large systems. This
approach will reduce the financial strain on small systems by spreading the sampling cost out over a two-
year period instead of compressing the entire cost into a single 12-month period. However, this approach
would extend the compliance date for small systems that are required to monitor for Cryptosporidium by
twelve months.
Another option would be to allow small systems to use the 12-sample second highest value or the 8-
sample maximum value to determine their bin classifications. This approach is based on EPA-s Monte
Carlo analysis that reveals that these sampling protocols also produce extremely low -false negative- bin
classifications. While EPA-s analysis indicates that each of these two methodologies produce extremely
high -false positive- rates, public water systems should be given the option of reducing the monitoring
requirements if they are willing to provide the additional treatment that would result from a higher risk
bin classification.
Response: See Response 320(C).
EPA Letter ID: 678
Comment ID: 14660
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-47 December 2005
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Comment: 3. Section 141.701(e) - Considering the relatively high cost of analyzing samples for
Cryptosporidium and the limited resources available to small systems, the rule should only require
monthly sampling instead of the currently proposed twice per month.
Response: See Response 320(C).
5.4 Comment Code 330, Use of E. coli as trigger for Crypto
monitoring
Summary of Issues
Most comments supported the use of E. coli as an indicator for small filtered PWSs to determine
the need to monitor for Cryptosporidium. One comment requested that the E. coli trigger level for
lakes/reservoirs (10 E. coli /100 mL) be applied to all ground water under the direct influence of surface
water (GWUDI) sources.
Response to Code 330
Use of E. coli as a trigger indicator
EPA disagrees with commenters who suggest that there are no indicators that could substitute for
Cryptosporidium monitoring for some PWSs. Data from the ICR and ICRSS identified E. coli as an
indicator that can be used to identify some of the water sources that are unlikely to exceed a
Cryptosporidium level of 0.075 oocysts/L - the level at which filtered PWSs must provide additional
treatment under the LT2ESWTR.
EPA also disagrees with commenters who suggest that the use of a single E. coli trigger for all source
waters would be appropriate. The use of two triggers 10 E. coli/100 mL (lakes/reservoirs) and 50 E.
coli/100 mL (flowing streams) is based on E. coli and Cryptosporidium data collected during the ICR and
ICRSS. The analysis of E. coli concentrations that could trigger Cryptosporidium monitoring was based
on false negative and false positive rates. For plants with flowing stream sources, a mean E. coli trigger
concentration of 50/100 mL produced zero false negatives for both ICR and ICRSS data sets. This means
that in these data sets, all plants that exceeded mean Cryptosporidium concentrations of 0.075 oocysts/L
also exceeded the E. coli trigger concentration. The false positive rate for this trigger concentration was
near 50 percent, meaning it was not highly specific in targeting only those plants with high
Cryptosporidium levels. However, at a higher E. coli trigger concentration, such as 100/100 mL, the false
negative rate increased without a significant reduction in the false positive rate. For plants with lake or
reservoir sources, a mean E. coli trigger of 10/100 mL resulted in a false negative rate of 20 percent with
ICR data and 67 percent with ICRSS data. While this false negative rate in the ICRSS data set appears
high, it is based on just three plants in this survey that used a reservoir/lake source and had a mean
Cryptosporidium level above 0.075 oocysts/L. With a lower E. coli trigger concentration, such as 5 /100
mL, the number of false negatives in both data sets decreased by one plant, but the false positive rate
increased from 20 to 40 percent.
EPA also does not agree that the E. coli trigger level for lakes/reservoirs (10 E. coli /100 mL) should be
applied to all GWUDI sources. EPA continues to believe, in the absence of contrary data, that it is most
appropriate for PWSs using GWUDI sources to comply with E. coli levels that apply to the nearest
Comment Response for the LT2ESWTR 5-48 December 2005
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surface water body. If no surface water body is nearby, the system must comply based on the
requirements that apply to systems using lake/reservoir sources.
As noted in the preamble to the rule, EPA will evaluate the Cryptosporidium, E. coli, and turbidity data
generated by large filtered PWSs under LT2ESWTR, to verify or if necessary, further refine the use of E.
coli, and potentially turbidity, as indicators for monitoring by small filtered PWSs, as recommended by
the Advisory Committee. In analyzing the performance of an E. coli level as a screen to trigger
Cryptosporidium monitoring, EPA evaluated false positive and false negative results for the trigger values
being assessed. EPA expects to complete a similar analysis with the large system data generated under the
LT2 rule. EPA will also be assessing advances in analytical methods and treatment between the first and
second round of monitoring and will consider such developments in assessing trigger levels.
Individual Comments on Code 330
EPA Letter ID: 466
Comment ID: 11015
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: ND supports the use of E. coli as an indicator for small system monitoring. We
Response: Thank you for your support.
EPA Letter ID: 485
Comment ID: 11303
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department supports the requirements as outlined. However we
suggest that additional clarification concerning the ability of small water systems to use the E Coli. trigger
monitoring vs. actual Cryptosporidium monitoring of the existing GWUDI sources for purposes of bin
classification. It is the Department-s understanding that small water systems will not have to perform
Cryptosporidium monitoring if the E Coli. levels in their GWUDI source
are less than the trigger levels and can still be credited the bank filtration removal for Cryptosporidium if
they meet the distance and turbidity stipulations outlined in the proposed rule. We also assume the
removal credit allowed for Cryptosporidium will also apply to giardia, as these organisms are similar and
larger in size. This is an assumption we have made for all toolbox
Cryptosporidium credit allowed in the proposed rule.
Response: See Response 330, Response 770 (paragraph on today's rule) and Response 500.y.
EPA Letter ID: 488
Comment ID: 11843
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-49 December 2005
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Comment: It is unclear exactly how the EPA will use the E. coli data. The statistical
treatment of these data is not addressed. The Agency seems to have determined that a utility can reliably
differentiate between measurements of 50 and 80 cfu/lOOmL but there are significant questions about
resolution of the measurement system within this range. Assuming sufficient numbers of samples and
appropriate data handling it is safe to assume that orders of magnitude
distinctions between counts are meaningful. But E. Coli results are not the same as chemical results,
especially when dilutions are made for membrane filtration or the MPN statistic is derived. We cannot
adequately review or support the requirements for E. Coli analysis until the EPA shows its experimental
design and data analysis plans.
Further questions remain about the validity of representing the pathogenic characteristics of small system
source waters with data from large systems. Given the enormous uncertainties associated with the LT2
monitoring program as a means for characterizing plant-specific risks at large systems, it is a further leap
of faith to assume that the proposed (E. coli/Cryptosporidium) correlation will result in meaningful risk
characterizations for small systems. With all these layers of uncertainty it almost seems that the
importance of-getting a number, any number- has superseded the importance of obtaining a meaningful
risk characterization.
Adding an extra monitoring burden to large utilities (E. coli monitoring) in order to facilitate
implementation of the rule for small utilities is problematic. Large utilities bore the entire cost of the ICR
(outside of EPA-s own costs) and that effort was supposed to provide data needed to support this
regulation. At the vary least the EPA needs to provide a better outline of how
these data will be employed and why they expect the proposed correlation to yield meaningful risk
characterizations for small systems.
Response: See Response 330.
EPA Letter ID: 520
Comment ID: 11577
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: o Over a one-year period, but allow small systems the option of taking 8, 12, or
24 samples. Bin determinations would be made using the 8-sample maximum value, 12-sample second
highest value or, 24-sample arithmetic mean, respectively. The system would need to acknowledge the
risk of higher "false positives" under the first two approaches and agree to provide the treatment indicated
based on the lower number of samples. Cryptosporidium monitoring would occur in Year 4 and small
systems would be required to comply with new bin requirements 8.5 years after rule promulgation (which
is consistent with EPA's proposed schedule). Small systems would have an opportunity to perform
indictor monitoring under
this approach, with indicator monitoring beginning 2.5 years after rule promulgation. EPA may need to
adjust this schedule depending on the need for small systems to have additional time between indicator
monitoring and Cryptosporidium monitoring in order to secure funding and contract with a laboratory for
analysis (currently six months is provided) or any necessary
delay due to laboratory capacity.
Views on LT2EWSTR
Comment Response for the LT2ESWTR 5-50 December 2005
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Microbial Monitoring for Filtered Systems
IEPA concurs that large filtered systems should monitor for Cryptosporidium for two years, as this will
allow for the collection of an ample number of samples as well as account for seasonal variability.
IEPA also supports small filtered system indicator monitoring to determine the need to monitor for
Cryptosporidium, as indicator monitoring will be more economically feasible for small systems.
However, IEPA also believes that small systems should be allowed to bypass indicator monitoring and
proceed directly to two years of Cryptosporidium monitoring if the system so desires.
IEPA supports using E. coli as the small system indicator and do not have data to suggest different
triggers than those proposed in the rule. IEPA supports one
Response: See Responses lOOa, 320(B)and 320(C).
EPA Letter ID: 528
Comment ID: 12248
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: We support the use of indicator monitoring for small systems, and are concerned
Response: See Response lOOa.
EPA Letter ID: 528
Comment ID: 12255
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: We also support small filtered system indicator monitoring to determine the need to monitor
for Cryptosporidium, as indicator monitoring will be more economically feasible for small systems.
Response: See Response lOOa.
EPA Letter ID: 536
Comment ID: 11791
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Colorado supports using E. coli as the small system indicator and does not have
data to suggest different triggers than those proposed in the rule.
Comment Response for the LT2ESWTR 5-51 December 2005
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Response: See Response lOOa.
EPA Letter ID: 585
Comment ID: 11962
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47673 [and §141.702(b)(l)-(3) on p. 47778]
The TCEQ supports the EPA proposal to allow small systems to use E.coli as a screening tool to
determine the need to monitor for Cryptosporidium. Based on
Response: See Response lOOa.
EPA Letter ID: 586
Comment ID: 12194
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 1221 1. Lag between large and small system
monitoring
Comment: We would first like to say that we appreciate the extended compliance timeframe
and phased monitoring approach proposed for small treatment systems. Using
Response: See Response lOOa.
EPA Letter ID: 586
Comment ID: 12195
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: and phased monitoring approach proposed for small treatment systems. Using
inexpensive E. coli monitoring to identify systems at risk, followed by more expensive Cryptosporidium
monitoring for those that exceed a benchmark value, will offer significant savings to many small systems.
However, we believe that
Response: See Response lOOa.
EPA Letter ID: 591
Comment ID: 12128
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-52 December 2005
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Comment: Comment
Because we do not have data that correlates the occurrence of E. Coli to the occurrence of
Cryptosporidium in ground water under the direct influence of surface water (GWUDI) sources, Ohio
EPA recommends applying the E. Coli trigger proposed for reservoirs to GWUDI sources. This is based
on our belief that the microbiological profiles of GWUDI sources probably more closely resemble that of
reservoirs than streams. However, that is not to say Ohio EPA believes the proposed E. Coli trigger is a
reliable indicator for GWUDI sources any more than it is for reservoirs; the uncertainty of the correlation
between E. Coli and Cryptosporidium occurrence for streams and reservoirs also applies to the use of the
proposed E. Coli triggers for GWUDI sources.
Response: See Response 330.
EPA Letter ID: 592
Comment ID: 12097
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Correlation of Cryptosporidium and E. coli
Alllarge systems are being asked to begin monitoring for Cryptosporidium in conjunction with E. Coli
and turbidity. At present there is no clear correlation between the presence of E. coli. and
Cryptosporidium. This part of the rule is essentially an information collection phase. Until a correlation
between E. coli and Cryptosporidiumis in fact established there should be no expectationthat all of the
smaller systems also need to begin testing for E. coli. Maine has many
small water systems that already face serious economic challenges. They should not be asked to spend
scant resources to monitor for a pathogen that may have no correlation with another.
Response: See Response 330 and 320(B).
EPA Letter ID: 601
Comment ID: 13020
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on how to apply the E. coil criteria for triggering Cryptosporidium
monitoring to systems using multiple types of sources and GWUDI sources.
(page 47679)
Utah supports small filtered system indicator monitoring to determine the need to monitor for
Cryptosporidium, as indicator monitoring will be more economically feasible for small systems; however,
we also believe that small systems should be allowed to bypass indicator monitoring and proceed directly
to two years of Cryptosporidium monitoring if the system so desires.
Response: See Response lOOa, and Response 320(B) regarding bypassing E. coli monitoring.
Comment Response for the LT2ESWTR 5-53 December 2005
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EPA Letter ID: 643
Comment ID: 12727
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States support using E. coli as the small system indicator and do not have data to suggest
different triggers than those proposed in the rule. States
Response: See Response lOOa.
EPA Letter ID: 668
Comment ID: 13895
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - We strongly support the default that all systems should have to retest for Crypto if EPA is
unable to revise the rule and find suitable surrogates (p. 46667)
Response: See Response 330.
EPA Letter ID: 673
Comment ID: 13986
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on how to apply the E. coil criteria for triggering Cryptosporidium
monitoring to systems using multiple types of sources and GWUDI sources.
(page 47679)
Jordan Valley Water has no objections to the proposal to use E. coli monitoring data to verify or further
refine the proposed trigger value for systems to begin Cryptosporidium monitoring. However, a change in
the trigger value should be
Response: See Response lOOa.
EPA Letter ID: 678
Comment ID: 14665
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5. Section 141.702(b)(4) - If a small filtered system chooses to monitor source water for
Cryptosporidium in lieu of E. Coli or other alternative indicator in its initial round of monitoring, what
Comment Response for the LT2ESWTR 5-54 December 2005
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would be the required monitoring frequency and reporting requirements? We
request that EPA define and include these requirements in the rule.
Response: See Response 320(B)and (C).
5.4.1 Comment Code 331, E. coli and Crypto relationships in occurrence
data sets
Summary of Issues
One commenter expressed concern that E. coli concentrations would not present a realistic picture
of the Cryptosporidium threat.
Response to Code 331
See Response 330.
Individual Comments on Code 331
EPA Letter ID: 441
Comment ID: 10771
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: * EPA proposes to use E. coli as a surrogate for Cryptosporidium presence at small water
suppliers. Nieminski and Bellamy have also provided extensive rationale for not using E. coli. The
following excerpt was one of the study's major findings: "The search for a Giardia and Cryptosporidium
surrogate in natural waters should be put on hold pending the development of more sensitive and accurate
analytical methods for these organisms." E. coli detection and concentration in ambient waters is unlikely
to reflect a realistic picture of the Cryptosporidium threat.
Response: See Response 330.
5.4.2 Comment Code 332, E. coli trigger concentrations
Summary of Issues
Comments supported the use of E. coli concentrations to trigger Cryptosporidium sampling for
small systems. However, some comments suggested the use of a single E. coli trigger level (50 E. coli
/100 mL) for all source waters.
Comment Response for the LT2ESWTR 5-55 December 2005
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Response to Code 332
See Response 330.
Individual Comments on Code 332
EPA Letter ID: 101
Comment ID: 10884
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Source Water Type and Triggering Cryptosporidium Monitoring
Two different mean E. coli concentrations for flowing streams and reservoirs are not needed. 50 E.
coli/100 ml should be the single standard used to trigger additional monitoring.
Response: See Response 330.
EPA Letter ID: 480
Comment ID: 11228
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: The analysis behind the 50 CPU/100 mL trigger in the proposal appears
reasonable, however we believe this single example clearly illustrates a
Response: See Response lOOa.
EPA Letter ID: 499
Comment ID: 10721
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: 6. KDHE does not support a modified monitoring triggering standard for small
systems using multiple sources and groundwater under the influence of surface water. The triggering
standard for Cryptosporidium monitoring in all small systems should remain at 50 E. coli/100 mL
regardless of the source. The standard should be equitable across source types as the potential danger
being measured is the same whether the source is a lake, stream, or GWUDI. Also,
Response: See Response 330.
EPA Letter ID: 520
Comment ID: 11579
Comment Response for the LT2ESWTR 5-56 December 2005
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Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 322 2. Cryptosporidium monitoring frequency and
duration
Comment: year of indicator monitoring for small systems followed by one year of Cryptosporidium
monitoring based on triggers of 10 E. coli/100 mL for lakes/reservoirs and 50 E. coli /100 mL for flowing
streams. IEPA also supports
Response: See Response lOOa.
EPA Letter ID: 528
Comment ID: 12256
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: We support using E. coli as the small system indicator and do not have data to suggest
different triggers than those proposed in the rule. (i.e. one year of indicator monitoring for small systems
followed by one year of Cryptosporidium monitoring based on triggers of 10 E. coli/100 mL for
lakes/reservoirs and 50 E. coli /100 mL for flowing streams)
Response: See Response lOOa.
EPA Letter ID: 585
Comment ID: 11963
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: screening tool to determine the need to monitor for Cryptosporidium. Based on the data
presented in the proposal, the TCEQ agrees with the initial E. coli "Trigger Levels" proposed by the EPA.
While we acknowledge that it might be
Response: See Response lOOa.
EPA Letter ID: 601
Comment ID: 13021
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah supports using E. coli as the small system indicator with one year of indicator
monitoring for small systems followed by one year of Cryptosporidium monitoring based on triggers of
Comment Response for the LT2ESWTR 5-57 December 2005
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10 E. coli/100 mL for lakes/reservoirs (we are curious as to why the E. coli trigger level was lowered
from 20/100 ml) and 50 E. coli /100 mL for flowing streams.
Response: See Response lOOa and 330.
EPA Letter ID: 643
Comment ID: 15033
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 322 2. Cryptosporidium monitoring frequency and
duration
Comment: data to suggest different triggers than those proposed in the rule. States support one year of
indicator monitoring for small systems followed by one year of Cryptosporidium monitoring based on
triggers of 10 E. coli/100 mL for lakes/reservoirs and 50 E. coli /100 mL for flowing streams. States also
Response: See Response lOOa.
5.4.3 Comment Code 333, How to classify source water type
Summary of Issues
Commenters suggested that source water quality rather than source water type is a better indicator for
Cryptosporidium sampling, while other comments propose that source water type classification is
dependent upon which source is being used by the system. Guidance is requested for defining Ground
Water Under the Direct Influence of Surface Water (GWUDI) sources, lake/reservoir sources, and
flowing stream sources, with clarification on how intakes located behind small diversion structures will
be classified. Another comment proposed how to classify indicator triggers for systems that use multiple
sources.
Response to Code 333
(A) E. coli trigger levels for multiple source monitoring
Some commenter requested clarification on the use of E. coli trigger levels for multiple source
monitoring. The LT2ESWTR requires that systems with plants that use multiple water sources, including
multiple surface water sources and blended surface water and ground water sources, must collect samples
from the source water in use on the designated sampling date following normal operating procedures, as
stated in 40 CFRpart 141.703(f). If multiple sources are in use at that time, the sample must be
composited or multiple samples must be proportionately weighted. Regardless of which source is in use at
that time, the rule requires for any PWS that uses a lake reservoir source, the annual mean E. coli trigger
concentration is 10 E. coli per 100 mL.
(B) Clarification on small impoundments
Comment Response for the LT2ESWTR 5-58 December 2005
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Commenters needed guidance on how to classify intakes behind small diversion structures behind source
water and the following definition should provide clarification on this topic. The plant intake refers to the
works or structures at the head of a conduit through which water is diverted from a source (e.g., river or
lake) into the treatment plant. A lake/reservoir source water refers to a natural or man made basin or
hollow on the Earth's surface in which water collects or is stored that may or may not have a current or
single direction of flow. A flowing stream is a course of running water flowing in a definite channel.
Source water that is diverted via small impoundments from either a lake/reservoir or flowing stream
source to the plant intake, should be classified as that particular source water and must follow the
requirements in the LT2ESWTR pertaining to that particular source water type.
Individual Comments on Code 333
EPA Letter ID: 441
Comment ID: 10774
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: flowing stream sources is 50/100 ml. If the E. coli monitoring is retained in
the final LT2 rule, DEP believes that source water quality rather than source type is a better indicator of
the need to conduct Cryptosporidium monitoring. EPA should use the same annual mean E. coli
concentration as a trigger to conduct Cryptosporidium monitoring for all small suppliers using surface
sources, regardless of source type.
Response: See Response 330.
EPA Letter ID: 444
Comment ID: 10812
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment: e. The trigger level for E Coli, above which Crypto monitoring will be required
for small systems, is different for lake/reservoir sources and stream sources. NH urges EPA to distinguish
between these source types in regulations or guidance. NH has several water systems which draw from
small impoundments on streams where it is not clear which trigger would apply.
Response: See Response 333(B).
EPA Letter ID: 458
Comment ID: 10976
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-59 December 2005
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Comment Codes 300-471
Comment: should require the maximum log inactivation. EPA needs to establish criteria for
small ground water under the influence sources in addition to flowing streams
and impoundments, as a cutoff for not requiring Cryptosporidium sampling.
Response: See Response 330.
EPA Letter ID: 548
Comment ID: 12162
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * Source water type classification (based on E. coli criteria for triggering Cryptosporidium
monitoring) for systems that use multiple and GWUDI sources
Metropolitan believes that source water type classification be made depending on which source is being
used or used more often during the year by the system.
Response: See Response 333(A).
EPA Letter ID: 603
Comment ID: 12644
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Although the definitions of "flowing stream" and "lake/reservoir" are logical,
they should be modified to properly classify intakes located behind small diversion structures. Some
intakes in this State are located behind small diversion structures on creeks and streams. These diversion
structures aredesigned to provide a relatively constant water surface elevation and divert water towards an
intake on a small stream. It is not clear that such a small impoundment would meet either of the
definitions in this section. Please consider the following definitions, with modifications in italics, which
shouldprovide greater clarity between the two definitions:
- "Flowing stream is a course of running water flowing in a definite channel with no significant instream
storage at the point of diversion."
- "Lake/Reservoir refers to a natural or constructed basin or hollow on the Earth's surface in which water
collects or is stored and has a total volume greater than the average dayflow through the basin."
Response: See Response 333(B).
EPA Letter ID: 603
Comment ID: 12668
Comment Response for the LT2ESWTR
5-60
December 2005
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Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Source Water Type Classification for GWUDI Sources -It is expected that most
sources that are classified as groundwater under the direct influence (GWUDI) of surface water will be
classified in the lowest risk bin due to the degree of natural or bank filtration that occurs between an open
surface water and a source. Approached logically, the E. coli thresholds for a GWUDI source should be
those for the nearest surface water body (i.e. if the nearest surface water body is a flowing stream, the
50/100 mL criteria should apply). However, this approach begs the question of how spring sources should
be classified. Either threshold is a possibility. Any approach should be checked for consistency with the
requirements for monitoring sources that employ bank filtration.
Response: A spring that is classified as surface water would be considered a flowing stream because it is
a course of running water flowing in a definite channel.
EPA Letter ID: 647
Comment ID: 12888
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: consideration as indicator monitoring as appropriate. The proposed rule is not
clear on what coliform level will trigger Cryptosporidium monitoring for small water systems that utilize
ground water under the influence.
Response: See Response 330.
EPA Letter ID: 688
Comment ID: 14740
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Page 47679 - Source Water Type Classification for Systems That Use Multiple
Sources (141.702(b))
The simplest method to determine how to apply the E. coli criteria to trigger the Cryptosproidium
monitoring is to use the criteria from whichever source composes the majority of the flow under normal
operating conditions. If the percentages are equal or can not be determined, then the more restrictive
criteria for lakes/reservoirs should apply.
Response: See Response 333(A).
Comment Response for the LT2ESWTR 5-61 December 2005
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5.4.4 Comment Code 334, Process for revising trigger based on large
system results
Summary of Issues
The majority of commenters do not believe that revisions should be based on large system results
and applied to small systems when large system initial monitoring is complete. These commenters
suggested that EPA make any changes to these indicator triggers through a technical correction or as a
part of the Six-Year Review. Comments also indicated that it would be difficult for States to implement
guidance criteria that differ from the established regulation. Other commenters stated that changes based
on the results of large system results will result in new regulatory limits and that small systems must be
allowed sufficient time to prepare for Cryptosporidium monitoring.
Response to Code 334
Process for revising trigger indicators based on large system monitoring
EPA plans to review indicator data from large PWS monitoring. EPA continues to believe that if
necesssary, it is appropriate and sufficient to issue guidance to States on alternative indicator triggers
prior to when small PWSs begin monitoring. Today's rule allows States to approve alternative approaches
to indicator monitoring for small PWSs. The State may approve small filtered PWSs to monitor for an
indicator other than E. coli. The State also may approve an alternative E. coli concentration to trigger
Cryptosporidium monitoring. This approval must be based on a State determination that the alternative
indicator and/or trigger level will more accurately identify whether a PWS will exceed the Bin 1
Cryptosporidium level of 0.075 oocysts/L. EPA will issue guidance to States on alternative indicators and
trigger levels, if warranted, based on large PWS monitoring results.
EPA has staggered compliance schedules for PWSs between these two size categories in order to
facilitate implementation of any changes to indicator levels. EPA may also revisit the plan to issue
guidance to accomplish this, rather than rulemaking or technical correction, depending on the results of
the large system monitoring and further discussions with the States.
Individual Comments on Code 334
EPA Letter ID: 466
Comment ID: 11019
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: While ND acknowledges that it might be desirable to refine trigger levels (10 E.
coli/100 mL for lakes/reservoirs and 50 E. coli/100 mL for flowing streams) for indicator monitoring of
small systems, we do not believe that such revisions be implemented solely through guidance. We suggest
that EPA make any changes to the indicator triggers through a technical correction or as part of the Six-
Year-Review.
Response: See Response 334.
Comment Response for the LT2ESWTR 5-62 December 2005
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EPA Letter ID: 520
Comment ID: 11571
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Coordination Between Large System and Small System Monitoring
IEPA acknowledges that it might be desirable to refine these trigger levels based on the results of the
sampling that will be done by large systems, IEPA does not believe that such revisions could be
implemented solely through guidance. IEPA will have already developed state rules and will have
difficulty implementing guidance criteria that differs from an established regulatory
mandate. Further, the public should have the opportunity to review and comment on any proposed
revision to the trigger criteria before it becomes a mandatory change.
Even if EPA provided additional time between the end of large system Cryptosporidium monitoring and
small system indicator monitoring to allow adequate time for public review of a technical correction,
IEPA would still need time to incorporate the technical correction, if approved, into state regulations.
Also, as indicated previously, any substantial lag between large system Cryptosporidium monitoring and
small system Cryptosporidium monitoring could be a disincentive for laboratories to provide analytical
services. IEPA therefore suggests that EPA make any changes to the indicator triggers through a technical
correction, if timing allows, or as part of the Six-Year Review.
Response: See Response 334.
EPA Letter ID: 520
Comment ID: 11581
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: While IEPA acknowledges that it might be desirable to refine these trigger levels based on the
results of the sampling that will be done by large systems, IEPA does not believe that such revisions
could be implemented solely through guidance. IEPA will have already developed state rules and will
have difficulty implementing guidance criteria that differs from an established regulatory mandate.
Further, the public should have the opportunity to review and comment on any proposed revision to the
trigger criteria before it becomes a mandatory change.
Even if EPA provided additional time between the end of large system Cryptosporidium monitoring and
small system indicator monitoring to allow adequate time for public review of a technical correction,
IEPA would still need time to incorporate the technical correction, if approved, into state regulations.
Also, as indicated previously, any substantial lag between large
system Cryptosporidium monitoring and small system Cryptosporidium monitoring could be a
disincentive for laboratories to provide analytical services. IEPA suggests that EPA make any changes to
the indicator triggers through a technical correction, if timing allows, or as part of the Six-Year Review.
Response: See Response 334.
Comment Response for the LT2ESWTR 5-63 December 2005
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EPA Letter ID: 528
Comment ID: 12250
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Coordination Between Large System and Small System Monitoring We acknowledge that it
might be desirable to refine the trigger levels based on the results of the sampling proposed for large
systems, most states do not believe that such revisions could be implemented solely through guidance.
Such states will have already developed their own state rules and will have
difficulty implementing guidance criteria that differs from an established regulatory mandate. Further, the
public should have the opportunity to review and comment on any proposed revision to the trigger criteria
before it becomes a mandatory change.
Even if EPA provided additional time between the end of large system Cryptosporidium monitoring and
small system indicator monitoring to allow adequate time for public review of a technical correction,
states would still need time to incorporate the technical correction, if approved, into state regulations.
Also, as indicated previously, any substantial lag between large
system Cryptosporidium monitoring and small system Cryptosporidium monitoring could be a
disincentive for laboratories to provide analytical services. Therefore we suggest that EPA make any
changes to the indicator triggers through a technical correction, if timing allows, or as part of the Six-Year
Review.
Response: See Response 334.
EPA Letter ID: 536
Comment ID: 11785
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Coordination Between Large System and Small System Monitoring
While Colorado acknowledges that it might be desirable to refine the trigger levels based on the results of
the sampling that will be done by large systems, we do not believe that such revisions could be
implemented solely through guidance. Colorado will have already developed its own state rules and will
have difficulty implementing guidance criteria that differs from an established
regulatory mandate. Further, the public should have the opportunity to review and comment on any
proposed revision to the trigger criteria before it becomes a mandatory change.
Even if EPA provided additional time between the end of large system Cryptosporidium monitoring and
small system indicator monitoring to allow adequate time for public review of a technical correction,
Colorado would still need time to incorporate the technical correction, if approved, into regulations. Also,
as indicated previously, any substantial lag between large system Cryptosporidium monitoring and small
system Cryptosporidium monitoring could be a disincentive for laboratories to provide analytical
services. Colorado therefore suggests that EPA make any changes to the indicator triggers through a
technical correction, if timing allows, or as part of the Six-Year Review.
Comment Response for the LT2ESWTR 5-64 December 2005
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Response: See Response 334.
EPA Letter ID: 585
Comment ID: 11964
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: "Trigger Levels" proposed by the EPA. While we acknowledge that it might be desirable to
refine these trigger levels based on the results of the sampling that will be done by large systems, we do
not believe that such revisions should be implemented solely through guidance. The public should have
the opportunity to review and comment on any proposed revision to the trigger criteria before it
becomes a mandatory change. Furthermore, some primacy agencies may have difficulty implementing a
guidance criteria that differs from an established regulatory mandate. Consequently, the TCEQ
recommends that the EPA adopt the proposed 10 colony-forming unit and 50 colony forming units trigger
levels.
Response: See Response 334.
EPA Letter ID: 601
Comment ID: 13022
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah will not be able to change the triggers used in rule implementation based on EPA
guidance provided three years after rule promulgation, even if large system collection of E. coli and
turbidity data demonstrates that different triggers would be more appropriate. We will have already
developed and adopted our own rules that will include the regulatory triggers from the promulgated rule
and will not be able to change these regulatory triggers based on guidance.
EPA will have to make any changes to the indicator triggers through a technical
correction or as part of the Six-Year Review.
Response: See Response 334.
EPA Letter ID: 643
Comment ID: 12718
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Coordination Between Large System and Small System Monitoring
While states acknowledge that it might be desirable to refine these trigger levels based on the results of
the sampling that will be done by large systems, most states do not believe that such revisions could be
implemented solely through guidance. States will have already developed their own state rules and will
Comment Response for the LT2ESWTR 5-65 December 2005
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have difficulty implementing guidance criteria that differs from an
established regulatory mandate. Further, the public should have the opportunity to review and comment
on any proposed revision to the trigger criteria before it becomes a mandatory change.
Even if EPA provided additional time between the end of large system Cryptosporidium monitoring and
small system indicator monitoring to allow adequate time for public review of a technical correction,
states would still need time to incorporate the technical correction, if approved, into state regulations.
Also, as indicated previously, any substantial lag between large
system Cryptosporidium monitoring and small system Cryptosporidium monitoring could be a
disincentive for laboratories to provide analytical services. States therefore suggest that EPA make any
changes to the indicator triggers through a technical correction, if timing allows, or as part of the Six-Year
Review.
Response: See Response 334.
EPA Letter ID: 643
Comment ID: 12731
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: While states acknowledge that it might be desirable to refine these trigger levels based on the
results of the sampling that will be done by large systems, most states do not believe that such revisions
could be implemented solely through guidance. States will have already developed their own state rules
and will have difficulty implementing guidance criteria that differs from an established regulatory
mandate. Further, the public should have the opportunity to review and comment on any proposed
revision to the trigger criteria before it becomes a mandatory change.
Even if EPA provided additional time between the end of large system Cryptosporidium monitoring and
small system indicator monitoring to allow adequate time for public review of a technical correction,
states would still need time to incorporate the technical correction, if approved, into state regulations.
Also, as indicated previously, any substantial lag between large
system Cryptosporidium monitoring and small system Cryptosporidium monitoring could be a
disincentive for laboratories to provide analytical services. States suggest that EPA make any changes to
the indicator triggers through a technical correction, if timing allows, or as part of the Six-Year Review.
Response: See Response 334.
EPA Letter ID: 647
Comment ID: 12881
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Coordination Between Large System and Small System Monitoring
While MDE acknowledges that it might be desirable to refine these trigger levels based on the results of
the sampling that will be done by large systems, such revisions could not be implemented solely through
Comment Response for the LT2ESWTR 5-66 December 2005
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guidance. States will have already developed their own state rules and will have difficulty implementing
guidance criteria that differs from an established regulatory
mandate. Further, the public should have the opportunity to review and comment on any proposed
revision to the trigger criteria before it becomes a mandatory change.
Even if EPA provided additional time between the end of large system Cryptosporidium monitoring and
small system indicator monitoring to allow adequate time for public review of a technical correction,
states would still need time to incorporate the technical correction, if approved, into state regulations.
Also, as indicated previously, any substantial lag between large
system Cryptosporidium monitoring and small system Cryptosporidium monitoring could be a
disincentive for laboratories to provide analytical services. MDE therefore suggests that EPA make any
changes to the indicator triggers through a technical correction, if timing allows, or as part of the Six-Year
Review.
Response: See Response 334.
EPA Letter ID: 647
Comment ID: 12889
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: While it might be desirable to refine the Cryptosporidium trigger levels based
on the results of the sampling that will be done by large systems, such revisions could not be implemented
solely through guidance. States will have already developed their own state rules and will have difficulty
implementing guidance criteria that differs from an established regulatory mandate. Further, the public
should have the opportunity to review and comment on any proposed
revision to the trigger criteria before it becomes a mandatory change.
Even if EPA provided additional time between the end of large system Cryptosporidium monitoring and
small system indicator monitoring to allow adequate time for public review of a technical correction,
states would still need time to incorporate the technical correction, if approved, into state regulations.
Also, as indicated previously, any substantial lag between large
system Cryptosporidium monitoring and small system Cryptosporidium monitoring could be a
disincentive for laboratories to provide analytical services. EPA should make any changes to the indicator
triggers through a technical correction, if timing allows, or as part of the Six-Year Review.
Response: See Response 334.
EPA Letter ID: 660
Comment ID: 14076
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on how to apply the E. coil criteria for triggering Cryptosporidium
monitoring to systems using multiple types of sources and GWUDI sources.
(page 47679)
Comment Response for the LT2ESWTR 5-67 December 2005
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For small system E. coli monitoring levels (10/50) should not be changed based upon the large systems
Cryptosporidium and E. coli monitoring results. This could potentially results in new regulatory limits.
This constitutes a change in the LT2ESWTR regulation that should be subject to the entire rule making
process.
Response: See Response 334.
EPA Letter ID: 673
Comment ID: 13987
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: Cryptosporidium monitoring. However, a change in the trigger value should be
addressed as a change to the rule, and small systems must be allowed sufficient time to prepare for
Cryptosporidium monitoring.
Response: See Response 334.
EPA Letter ID: 675
Comment ID: 13971
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: The State of Minnesota recommends against revising microbial trigger levels
solely through guidance. EPA should consider making any indicator trigger changes through a technical
correction or as part of the Six-Year Review.
Response: See Response 334.
5.4.5 Comment Code 335, Alternative indicators
Summary of Issues
Several commenters stated that a number of the smaller utilities would prefer if fecal coliform
would be acceptable as an alternative trigger as opposed to E. coli, as many of these labs already monitor
routinely for total and fecal coliform, which is relatively inexpensive. The utilities assert that under the
Total Coliform Rule, fecal coliform and E. coli are interchangeable. States expressed concern that they
would not have the resources to review an alternative organism or establish an alternative trigger level,
but that they would appreciate guidance developed in this area from other States, and suggested that EPA
include data in the rule rather than require each state to review the data and establish different trigger
levels. One comment suggested that the alternative organism testing ought to be allowed not only at the
smaller utilities, but also at the larger utilities serving more than 10,000 people, as some of these utilities
Comment Response for the LT2ESWTR 5-68 December 2005
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have shortages in manpower, and because it is expensive to implement the new Cryptosporidium
monitoring regulations.
Response to Code 335
(A) State approval of alternative indicators
EPA agrees that smaller PWSs should be allowed to monitor for alternative indicators other than E. coli to
determine if Cryptosporidium monitoring is required when data support this alternative. Under today's
final rule, the State may approve small filtered PWSs to monitor for an indicator other than E. coli. The
State also may approve an alternative E. coli concentration to trigger Cryptosporidium monitoring. This
approval must be based on a State determination that the alternative indicator and/or trigger level will
more accurately identify whether a PWS will exceed the Bin 1 Cryptosporidium level of 0.075 oocysts/L.
EPA will issue guidance to States on alternative indicators and trigger levels, if warranted, based on large
PWS monitoring results. The State must include in its application for approval of the State program
revision a description of how the State will approve an alternative trigger, if applicable.
(B) Use of alternative indicators at large utilities
EPA does not agree that large PWSs serving at least 10,000 people should be allowed to use alternative
indicators to determine if Cryptosporidium monitoring will be necessary. EPA evaluated data from the
ICR and ICRSS monitoring and evaluated the results, including assessment of false negative and false
positive results. After evaluating these results, the Federal Advisory Committee recommended that all
large PWSs monitor for Cryptosporidium, rather than using E. coli in a screening analysis. EPA
concurred with this recommendation because it achieves the highest certainty that these PWSs will be
classified in the correct Cryptosporidium treatment bin and provide the appropriate level of public health
protection.
Individual Comments on Code 335
EPA Letter ID: 440
Comment ID: 10801
Commenter: Gary Hum, Director of Source & Treatment, Central Arkansas Water
Commenter Category: Regulated Community (Utilities)
Comment: 2. E. coli monitoring: Fecal coliform monitoring should be accepted in
place of E.coli monitoring. Many utility labs routinely run membrane filtration for total coliforms with
confirmation for fecal coliforms. Under the Total Coliform Rule, fecal coliform and E. Coli analysis are
interchangeable.
Response: See Response 335(A).
EPA Letter ID: 449
Comment ID: 10826
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 310 A. Large System Monitoring Requirements
Comment Response for the LT2ESWTR 5-69 December 2005
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Comment: Because of a shortage of manpower and the costs associated with implementing the
new regulations, we feel that systems of any size should be held to the same standard as small systems
regarding total coliform results. In section 141.720 it states that systems serving over 10,000 people must
conduct source water monitoring for cryptosporidium , e-coli, and turbidity. In section 141.702, it states
that in systems serving less than 10,000 people, testing for
cryptosporidium e-coli and turbidity only needs to be performed if the system exceeds 10 colonies per
100 ml in e-coli testing. It is our feeling that total coliform test results can be used as a valuable tool to
determine which systems need to perform more in depth cryptosporidium testing. One way to examine the
effectiveness of this theory would be to study systems that used
earlier cryptosporidium methods and have same day e-coli test results. This would provide a more
manageable number of systems to oversee while still gathering information for EPA and protecting the
public from the highest risk water sources.
Response: See Responses 300(A) and 335(B).
EPA Letter ID: 591
Comment ID: 12141
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: 14. §141.701(c), (Page 47776)
The rule allows the state to approve a different organism other than E. coli for source water monitoring
which would require the state to approve an alternative trigger level. Although Ohio EPA appreciates the
consideration for flexibility in implementing the rule, we request removing the alternative organism and
alternative trigger level from the rule because we do not have the resources to review an alternative
organism or establish an alternative trigger level. If other states are aware of alternative organisms and
alternative trigger levels which are acceptable, we recommend the data be presented to U.S. EPA to
include in the rule instead of requiring each state to review the data and establish different trigger levels.
In addition, an alternative indicator does not seem necessary as E. Coli is a standard, relatively
inexpensive test with which many
small systems are familiar. Keeping this provision in the rule without identifying practical alternative
trigger organisms and trigger levels puts Ohio and some other states in the position of either adopting
rules with flexibility that cannot be practically administered or adopting rules without the flexibility,
which makes the state's rules more stringent. Trying to adopt state a rule more stringent than the Federal
counterpart will cause us to expend considerable resources to support our position that the flexibility in
the Federal rule is not practicable for Ohio. Ohio EPA is interested, however, in any guidance developed
on approving alternative organisms and establishing alternative trigger levels.
Response: See Response 335(A).
EPA Letter ID: 603
Comment ID: 12648
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-70 December 2005
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Comment: (Pg. 47778) Section 141.702-
In this state, many systems monitor for fecal coliform as one means of determining watershed risk. Fecal
coliform at the same E. Coli thresholds as in the proposed rule would be more stringent than the federal
requirements and as such qualify as an alternative indicator trigger. However, in §142.14(9)(i), it is not
clearly spelled out that the alternative indicator needs to be recorded by the state for review by the EPA.
We would appreciate if the requirements of an alternative indicator could be more clearly defined. In
addition, water
Response: See Response 335(A).
EPA Letter ID: 667
Comment ID: 14010
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: 5. Crypto testing is a very expensive procedure would like to see some other yardstick which
could be used to achieve the same goals.
Response: See Response 335(A).
5.5 Comment Code 340, Sampling Location
Summary of Issues
Comments were received suggesting that EPA change the description of the required "source water"
monitoring to "influent water characterization" to reflect the intent of the regulation and to avoid
confusion as to where a system must monitor. Guidance is needed on the following topics: the
requirements for a plant that has multiple treatment trains, the intent of monitoring, defining what EPA
refers to as influent water, and on changing of the sampling location point within the same source water
used for submitting grandfathered data. Commenters stated that the LT2ESWTR doesn't offer flexibility
in the required sampling location, and that increased flexibility and simplification of requirements would
be possible if systems were allowed to pick appropriate sampling locations as part of their monitoring
plan. Other commenters suggest that these concerns about flexibility should be addressed on a case-by-
case basis, to better ensure State participation. Commenters also recommend that a schematic of the water
treatment plant train, including the location of chemical addition and pretreatment processes, should be
reviewed by the State to ensure correct sample collection location. Two commenters state that E. coli
sampling should represent the raw source water only, and that Cryptosporidium sampling should be
required to monitor at a point that will represent the quality of water that is entering the primary treatment
processes at the plant, regardless of chemical and pretreatment processes. A few commenters are
concerned about the sampling location after pretreatment processes, like presedimentation basins and
bank filtration, since the proposed rule didn't allow sampling prior to these processes.
Response to Code
(A) Description of source water monitoring
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EPA disagrees with commenters who said that the description of source water monitoring should be
changed to influent water characterization. EPA believes it is clear to most people that the intent of the
monitoring is to show a true representation of the source water in use at the time the sample is collected.
Furthermore, EPA clarifies in the preamble that the sample must be collected from a location that
represents the influent to the treatment plant.
(B) Sampling location clarity and flexibility
EPA disagrees with commenters' statements that the LT2ESWTR is confusing because it provides too
much information about too many sampling situations and does not offer flexibility in the required
sampling location. EPA has attempted to provide details on several general sample location variations
(multiple sources, bank filtration, part-year systems) so that most systems will be clear on their sampling
location by reading the regulation. For those systems that need more guidance, figures have been
developed to illustrate the correct sample collection location within the LT2 Source Water Monitoring
Guidance Manual. Primacy Agencies will be available to provide assistance as needed to establish a
representative sampling location, and will be working with PWSs to ensure representative locations
during review of the sampling location descriptions submitted by the PWSs.
The rule language is clear that where multiple plants receive all of their water from the same influent,
such as plants that draw water from the same intake or pipe, the State may approve one set of monitoring
results to be applied to all plants. This situation would include plants that have multiple treatment trains
with a common influent. All Cryptosporidium, E. coli, and turbidity source water samples collected under
LT2ESWTR requirements must be collected from the same appropriate sampling location.
The rule language is also clear that systems using multiple sources during monitoring must either sample
from a sampling tap if it is available where the sources are combined prior to treatment, or they must
composite samples or analzye samples separately and calculate a weighted average of the results.
PWSs have the flexibility to manually collect source water samples at the intake, establish a sampling
location prior to treatment, and upon State approval, sample after chemical treatment if the State can
determine that collecting a sample prior to chemical treatment is not feasible for the PWS and that the
chemical treatment is unlikely to have a significant adverse affect on the analysis of the sample.
The requirements in today's final rule for source water sample collection location are designed to
characterize the influent water to the treatment plant at the time each sample is collected. That is the basis
for requiring PWSs that use multiple sources to either analyze a blended source sample or to calculate a
weighted average of sources that reflects the influent at the time of sample collection.
Individual Comments on Code
EPA Letter ID: 439
Comment ID: 10756
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: EPA should change the description of the required "source water" monitoring to
"influent water characterization' to reflect the intent of the regulation and to avoid confusion as to where a
system must monitor. Systems should be allowed to
Response: See Response 340(A).
Comment Response for the LT2ESWTR 5-72 December 2005
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EPA Letter ID: 439
Comment ID: 10758
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: avoid confusion as to where a system must monitor. Systems should be allowed to
monitor at a point that reflects influent water quality for the specific system, not necessarily at that sample
point that EPA has defined. Also, since the EPA
Response: See Response 365 regarding PWS submission of sampling location descriptions.
EPA Letter ID: 463
Comment ID: 11031
Commenter: Richard Wilson, Environmental Services Manager, Anaheim Public Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment: 4. Section 141.702 Source Water Monitoring
The term "source water monitoring" does not seem to fit the monitoring requirement for surface water
treatment plants. It is recommended that the term be replaced with "influent water characterization"
because it better describes the actual purpose of the sampling effort. The term, "source water," should be
reserved for the lakes or rivers upstream of the plant.
Response: See Response 340(A).
EPA Letter ID: 493
Comment ID: 11245
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment: 40 CFR 141.704 does not appear to specifically address source water monitoring
sampling requirements when a plant has multiple treatment trains. The term -multiple treatment trains-
should be defined. It is recommended that the term include -instances when water is treated in different
treatment facilities (such as new plants installed at a later date than the original treatment plant, but
generally on the same physical site as the original treatment plant, for the
purpose of increasing production) but the treated water eventually combines and
Response: See Response 340(B).
Comment Response for the LT2ESWTR 5-73 December 2005
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EPA Letter ID: 496
Comment ID: 10693
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 6. Monitoring Key Issue 6 Monitoring Location: This proposal requires monitoring
after pre-treatment unit operations, such as off-stream storage, pre-sedimentation, and river bank
filtration, but before conventional treatment. EPA has attempted to identify many of the situations that
will occur such as blended sources, multiple sources, and part-year operations. This has made the
selection of an appropriate monitoring location unnecessarily confusing and complex for many systems
and it lacks flexibility to accommodate situations that will doubtlessly materialize. Also, the requirements
Response: See Responses 340(B).
EPA Letter ID: 496
Comment ID: 10695
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: Comments for Key Issue 6 ( Monitoring Location): Monitoring locations should change the
description of the monitoring from "Source Water Monitoring" to Influent Water Characterization" to
more accurately reflect the intent of the regulation. EPA should define influent water as the water that
enters the conventional treatment process, or when alternate treatment technologies (membranes) are
employed at a similar point as established by the governing agency. EPA should allow monitoring at
Response: See Response 340(A).
EPA Letter ID: 506
Comment ID: 10736
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: o Monitoring Location - The proposed rule requires monitoring after pre-treatment unit
operations but before conventional treatment. While CWD appreciates USEPA-s intent in trying to
identify so many different scenarios, the result has been to make the selection of a monitoring location
more complicated and confusing than necessary. To help make the issue less confusing, CWD
recommends that the monitoring be described as -influent water characterization- and it be defined as
water that enters the conventional treatment train. EPA should allow monitoring at a point that reflects
influent water quality as well as the water system-s anticipated improvement options, if additional
treatment becomes necessary. Additionally, CWD thinks that it would
Response: See Response 340(A).
Comment Response for the LT2ESWTR 5-74 December 2005
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EPA Letter ID: 507
Comment ID: 11465
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 2. Monitoring Location, IV.A.l.b., pg 47666.
The proposed rule concerning source water monitoring offers many different and often confusing
monitoring scenarios. We recommend that EPA allow utilities the flexibility in determining their
respective monitoring locations and suggest EPA change the monitoring descriptions from -source water
monitoring- to -influent monitoring characterization.- This description would more accurately reflect the
intent of the proposed rule. Consideration should also be given to utilities
Response: See Response 340(A).
EPA Letter ID: 509
Comment ID: 11481
Commenter: Greg Parker,, Florida Department of Environmental Protection Drinking Water Program
Commenter Category: State/Tribe Government
Comment: 141.704 Consider the use of state or regionally gathered data from the watershed
at upstream locations near high risk sites rather than just data gathered by the systems at their intake
structures.
Response: See Response 340(A) and 400 (regarding use of sanitary surveys and watershed assessments).
EPA Letter ID: 512
Comment ID: 11506
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Source Water Monitoring
a. Flexibility in monitoring locations is important to adequately address site specific considerations best
understood by the utility and primacy agency
Response: See Responses 340(B) and 365 (regarding State review of PWS sampling location
descriptions).
EPA Letter ID: 520
Comment ID: 11614
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Comment Response for the LT2ESWTR 5-75 December 2005
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Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1200 VIII. Compliance Schedules
Comment: With respect to the specific issues on which EPA requested comment, IEPA believes that
EPA should provide flexibility to address these concerns on a case-by-case basis. The need to address
these issues is another example of why EPA should modify the LT2ESWTR implementation schedule to
better ensure state participation.
Response: See Responses 340(B), 365, 1200.C, and 1200.f.
EPA Letter ID: 527
Comment ID: 10852
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Monitoring Location: The proposal requires monitoring after pre-treatment unit
operations, like off-stream storage, pre-sedimentation, and riverbank filtration but before conventional
treatment. EPA has also attempted to identify many site-specific situations that will occur such as blended
sources, multiple sources, and part year operations. These provisions are overly complicated and make the
selection of an appropriate monitoring location needlessly confusing and difficult for many systems while
lacking flexibility to accommodate situations
that will come up. Additionally, the requirements could foreclose the option of using grandfathered data if
the specified monitoring location is different from the location historically sampled. Increased flexibility
and simplification of requirements would be possible if systems were allowed to pick appropriate
locations as part of their monitoring plan.
We recommend EPA change the description of monitoring from -source water monitoring- to -influent
water characterization- to more accurately reflect the intent of the regulation. We suggest that EPA define
influent water as the water that enters the conventional treatment train, or when alternative treatment
technologies (i.e. membranes) are employed, at a similar point as established by the primacy agency. We
recommend that EPA allow monitoring at a point that reflects influent water quality and the utility-s
anticipated improvement options should additional treatment become necessary. Because of the many
Response: See Responses 340(A) and (B) and 388.
EPA Letter ID: 527
Comment ID: 10852
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Monitoring Location: The proposal requires monitoring after pre-treatment unit
operations, like off-stream storage, pre-sedimentation, and riverbank filtration but before conventional
treatment. EPA has also attempted to identify many site-specific situations that will occur such as blended
sources, multiple sources, and part year operations. These provisions are overly complicated and make the
selection of an appropriate monitoring location needlessly confusing and difficult for many systems while
Comment Response for the LT2ESWTR 5-76 December 2005
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lacking flexibility to accommodate situations
that will come up. Additionally, the requirements could foreclose the option of using grandfathered data if
the specified monitoring location is different from the location historically sampled. Increased flexibility
and simplification of requirements would be possible if systems were allowed to pick appropriate
locations as part of their monitoring plan.
We recommend EPA change the description of monitoring from -source water monitoring- to -influent
water characterization- to more accurately reflect the intent of the regulation. We suggest that EPA define
influent water as the water that enters the conventional treatment train, or when alternative treatment
technologies (i.e. membranes) are employed, at a similar point as established by the primacy agency. We
recommend that EPA allow monitoring at a point that reflects influent water quality and the utility-s
anticipated improvement options should additional treatment become necessary. Because of the many
Response: See Responses 340(A) and (B) and 388.
EPA Letter ID: 556
Comment ID: 12057
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 6. Monitoring Location
Basic Principle from the FACA Discussions: The intent of specifying monitoring locations is to ensure
that the level of Cryptosporidium entering the treatment plant is known for binning purposes.
Discussion: The proposal requires monitoring after presently existing pre-treatment unit operations, such
as off-stream storage, pre-sedimentation, and riverbank filtration, but before conventional treatment. The
proposal also identifies many site-specific situations that will occur, such as blended sources, multiple
sources, and part year operations. The provisions are complicated and make the selection of an
appropriate monitoring location confusing and difficult for many systems. Additionally, the provisions
lack the flexibility to accommodate situations that can be anticipated but are not covered. The
requirements could foreclose the option of using grandfathered data if the specified monitoring location is
different from the location historically sampled. Increased flexibility and simplification of requirements
would be possible if systems were allowed to pick appropriate locations as part of their monitoring plan.
Recommendations: AMWA recommends that EPA change the description of monitoring from -source
water monitoring- to -influent water characterization- to more accurately reflect the intent of the
regulation. We suggest that EPA define influent water as the water that enters the conventional treatment
train, or when alternative treatment technologies (i.e. membranes) are employed, at a similar point as
established by the primacy agency.
We recommend that EPA allow monitoring at a point that reflects influent water quality and the utility-s
anticipated improvement options should additional treatment become necessary.
Response: See Response 340 (A) and (B) and 388.
Comment Response for the LT2ESWTR 5-77 December 2005
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EPA Letter ID: 562
Comment ID: 12299
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.3 Source Water Monitoring and Data
The specific regulatory language on -source water monitoring- presents challenges to utilities with
respect to sampling locations and schedules. AWWA recommends that EPA clarify that the intent of
monitoring is to characterize water as it enters the conventional treatment train (influent
water). EPA should also modify the compliance schedule to incorporate review
Response: See Response 340(A).
EPA Letter ID: 562
Comment ID: 12374
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: treatment unit operations. Source water monitoring is perhaps better called plant influent
water characterization.
Response: See Response 340(A).
EPA Letter ID: 562
Comment ID: 12376
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: recognizes that some PWSs that will have to monitor under the LT2ESWTR only
operate a particular water treatment plant for a portion of the year.
Consequently, EPA-s implementation the FACA-s recommendation on -source water monitoring- has
become much more complicated than it needs to be. AWWA recommends that EPA change the proposal
in the following ways:
1. Change the nomenclature used from -source water monitoring- to -influent water characterization-.
2. Define influent water as the water that enters the conventional treatment train or, when alternative
treatment technologies (i.e., membranes) are employed, a similar point as established by the primacy
agency. Section 141.704(a) provides that except as otherwise specified in the rule, utilities should sample
prior to -any treatment.- with the example given as chemical addition at an intake. EPA must more fully
describe what constitutes -any treatment.- In order to comply with the Stage 1 DBPR, IESWTR, and
achieve other treatment objectives, a significant number of utilities add chemicals at the intake and at
various points between the intake and the conventional treatment train. Additions may include chemicals
such as chlorine, potassium permanganate, cationic polymer, acids, PAC, and lime. Typically, the doses
used are small and are not of a nature that available research suggests would significantly affect
Cryptosporidium oocysts. The addition of a coagulant is commonly added prior to pre-sedimentation.
Such addition should not preclude sampling after pre-sedimentation. Any residual coagulant would be
Comment Response for the LT2ESWTR 5-78 December 2005
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minimal and should not affect analytical results. AWWA recommends that -any- be removed from
§141.704(a) and that in guidance the agency provide examples of levels of chemical addition or other
actions that constitute -treatment- in this context and that would alter the source water monitoring
location. Also, the monitoring plan submitted to the primacy agency for approval should include a
schematic of the water treatment plant treatment train and indicate where and what chemical additions
take place, in particular, additions or actions that take place prior to the proposed LT2ESWTR monitoring
location. For utilities that have planned alterations to treatment that impact influent water quality, allow
monitoring at a point that reflects the influent water quality following the improvements.
These recommendations are in keeping with the FACA-s direction in that the FACA recommended that a
water treatment plant provide increased treatment when the influent water it treated on average (either
maximum rolling annual average or arithmetic average) contained elevated levels of Cryptosporidium
oocysts above certain levels. This proposed approach achieves this goal while providing clear logic for
subsequent guidance and primacy agency
decisions.
Response: See Response 340(A), 341, 342 and 365.
EPA Letter ID: 585
Comment ID: 11970
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: The TCEQ recommends that E. coli sampling at small systems occur at a point that
represents the raw source water quality only. However, systems monitoring for Cryptosporidium should
be required to monitor at a point that will represent the quality of water that is entering the primary
treatment processes at the plant rather than at a point that represents only a portion of the water being
treated. If a single monitoring point is unavailable, the system should be required to prepare a composite
sample or sample multiple sources and calculate the weighted average Cryptosporidium concentration.
Response: See Response 340(B).
EPA Letter ID: 593
Comment ID: 11820
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: 5. Monitoring Location: The proposal requires monitoring after pretreatment unit operations,
including off-stream storage, pre-sedimentation, and riverbank filtration but before conventional
treatment. EPA has attempted to identify many of the situations that will occur such as blended sources,
multiple sources, and part year operations. Additionally, the requirements could foreclose the option of
using grand-fathered data if the. specified monitoring location is different fi-om the location historically
used. SAWS recommends the following: Change the
description of the monitoring fiom -source water monitoring- to -influent water characterization- to
more accurately reflect the intent of the regulation. Define influent water as the water that enters the
conventional treatment train, or when alternative treatment technologies (Le. membranes) are employed,
Comment Response for the LT2ESWTR 5-79 December 2005
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at a similar point as established by the primacy agency. Allow monitoring at a point that reflects influent
water quality and the utilities anticipated improvement
options should additional treatment become necessary. The compliance schedule is modified to
incorporate review and approval of the LT2ESWTR monitoring plan by the primacy agency prior to
initiation of the required monitoring.
Response: See Response 340(A) and (B).
EPA Letter ID: 614
Comment ID: 12958
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Source Water Monitoring
* We are concerned that regulatory language of source water monitoring is unclear and provides
insufficient guidance on sampling locations and schedules. EPA needs to clarify that the purpose of
monitoring is to characterize water as it enters the treatment chain. Both the EPA and the State should
review the
Response: See Response 340(B).
EPA Letter ID: 625
Comment ID: 13143
Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 6) Monitoring location
The CCMWA is currently sampling the raw water sources for our two plants. These locations were
selected based on the guidance for collecting data t at would be grandfathered. One of the plants has a
small raw water reservoir ahead of conventional treatment. However the plant returns the plant recycle
head of that reservoir. Every system is somewhat different. Therefore should be allowed in picking
appropriate locations for monitoring.
Response: See Response 340(B) and 388.
EPA Letter ID: 628
Comment ID: 12841
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-80 December 2005
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Comment: b. Allow flexibility for sampling location selection. The proposed rule allows
water systems to collect source water samples after pretreatment such as settling in the presedimentation
basin, off-stream storage, or bank filtration. The proposed rule calls for samples to be collected at plant
influent. If the EPA considers that presedimentation and bank filtration are not part of the
Cryptosporidium removal process, then the SFPUC would request the allowance of
source water sampling at a location downstream of a treatment process that is not part of the tool box and
is not credited for any Cryptosporidium inactivation. A taste and odor removal proves, such as the
injection of potassium permanganate, or a pH adjustment process for corrosion control in a raw water
transmission pipeline should not impact the Cryptosporidium monitoring.
Response: See Response 340(B), 341 and 342.
EPA Letter ID: 630
Comment ID: 13065
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 7.Monitoring Key Issue 6 Monitoring Location: The proposal requires monitoring
after pre-treatment unit operations, like off-stream storage, pre-sedimentation, riverbank filtration but
before conventional treatment. EPA has attempted to identify many of the situations which will occur
such as blended sources, multiple sources, and part year operations. This has made the selection of an
appropriate monitoring location needlessly confusing and difficult for many
systems and lacks flexibility to accommodate situations that will come up. Additionally, the requirements
could foreclose the option of using grandfathered data if the specified monitoring location is different
from the location historically used. Increased flexibility and simplification of requirements would be
possible if systems were allowed to pick appropriate locations as part
of their monitoring plan.
8. Monitoring Key Issue -Source Water Monitoring-: Recommend EPA change the description of
monitoring from -source water monitoring- to -influent water characterization- to more accurately
reflect the intent of the regulation. EPA should define influent water as the water that enters the
conventional treatment process, or when alternative treatment technologies (i.e. membranes) are
employed, at a similar point as established by the primacy agency. EPA should
allow monitoring at a point that reflects influent water quality and the utility-s anticipated improvement
options should additional treatment become necessary. Allow for the compliance schedule to be modified
to incorporate review and approval of the LT2ESWTR monitoring plan by the primacy agency prior to
initiation of the required monitoring.
Response: See Response 340(A), 340(B), 365 and 388.
EPA Letter ID: 633
Comment ID: 13268
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-81 December 2005
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Comment: 2. Monitoring Location
The proposal requires monitoring after pre-treatment unit operations, such as our pre-sedimentation
basins or riverbank filtration, but before conventional treatment. An attempt has been made to identify
many of the situations which will occur such as blended sources or multiple sources but this has made the
selection of an appropriate monitoring location confusing and difficult for systems like ours. Increased
flexibility and simplification of requirements would be possible if systems were allowed to pick
appropriate locations as part of their monitoring plan, with approval by the primacy agency.
Response: See Response 340(B) and 365.
EPA Letter ID: 637
Comment ID: 13089
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: District comment on Monitoring Location requirements
The proposed rule makes the selection of source water monitoring locations too complicated. Changing
the term to an influent sample instead of a source water sample would simplify the need for complicated
clarification. This can be defined as the point when the water enters the conventional treatment train or
alternative treatment process or a similar representative point that has been accepted by the primacy
agency. The compliance schedule should be modified to incorporate review and approval of the
LT2ESWTR monitoring plan by the primacy agency prior to initiation of the required monitoring.
Response: See Response 340(A) and 365.
EPA Letter ID: 646
Comment ID: 13567
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: Monitoring Location - Santa Fe recommends that EPA allow monitoring at a point
that reflects influent water quality entering the conventional treatment train. Influent water quality more
accurately reflects EPA-s intent to sample water that has undergone pretreatment. Influent water quality
should include filter
Response: See Response 340(A).
EPA Letter ID: 667
Comment ID: 14011
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-82 December 2005
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Comment: 6. Influent water should be defined as the water that enters the conventional
treatment train and at a point that reflects the influent water quality.
Response: See Response 340(A).
EPA Letter ID: 668
Comment ID: 13892
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: Monitoring Should be Representative, and Should be Post-Addition of Backwash
The rule should require monitoring that is fully representative of the actual quality of the water going into
treatment-including water during precipitation and other high risk events. Data show that these events can
substantially increase Crypto and other pathogen loading due to high runoff (see attached [SEE PDF
FILE]). In addition, monitoring should occur after any backwash is added,
Response: See Response 340(A) and 346.
EPA Letter ID: 678
Comment ID: 14667
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 6. Section 141.704 - We recommend the EPA change the description of the
monitoring from -source water monitoring- to -influent water characterization- to more accurately
reflect the intent of the rule. The final rule should define influent water as the water that enters the
conventional treatment train, or when alternative treatment technologies (i.e. membranes) are employed,
at a similar point as established by the State primacy agency. The compliance schedule
Response: See Response 340(A) and 365.
EPA Letter ID: 678
Comment ID: 14669
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: of the required monitoring. Additionally, the EPA should allow monitoring at a point that
reflects influent water quality and the system-s anticipated improvement options if additional treatment
becomes necessary. By allowing systems to pick appropriate locations as part of their monitoring plans,
the rule would provide increased flexibility and simplify the implementation requirements.
Response: See Response 340(A) and (B).
Comment Response for the LT2ESWTR 5-83 December 2005
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EPA Letter ID: 678
Comment ID: 14671
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 7. Sections 141.704(b), (c) and (d) - Permitting the collection of source water samples after
pretreatment such as settling in the presedimentation basin, off-stream storage, or bank filtration appears
to be inconsistent with the proposed requirement of collecting source water samples from the plant intake
prior to any treatment, as specified in Section 141.704(a). If, for the purpose of Cryptosporidium
monitoring, presedimentation and bank filtration
are not considered Cryptosporidium removal processes, it is then unclear on what basis the EPA would
not allow source water sampling at a location downstream of a treatment process that is not part of the
tool box and is not credited for any Cryptosporidium inactivation. A taste and odor removal process, such
as the injection of potassium permanganate, or a pH adjustment process for
corrosion control in a raw water transmission pipeline should not impact the Cryptosporidium monitoring.
Response: See Response 340(B), 341 and 342.
EPA Letter ID: 683
Comment ID: 14758
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
Comment: The City requests that EPA reconsider the intent of the monitoring in defining
the monitoring locations. The requirements would be simplified if systems were allowed to choose
monitoring locations that best reflect influent water quality as part of their monitoring plan. The
monitoring locations should also reflect anticipated construction or improvement options should
additional treatment become necessary. As is already the process for approval of monitoring plans for
other contaminants, the primacy agencies should have flexibility to
establish monitoring points while giving due consideration to the water system operational characteristics
and planned improvements.
Response: See Response 340(B) and 365.
EPA Letter ID: 699
Comment ID: 14775
Commenter: David A. Visintainer, Water Comissioner, City of Saint Louis
Commenter Category: Regulated Community (Utilities)
Comment: This section also defines sampling location for -source water monitoring- as
after pretreatment unit operations such as pre-sedimentation basins. This monitoring would be better
described as -influent water characterization- and be sampled at the point where the influent water enters
the conventional filtration treatment train.
Comment Response for the LT2ESWTR 5-84 December 2005
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Response: See Response 340(A).
EPA Letter ID: 706
Comment ID: 14810
Commenter: John Spatz, Deputy Commissioner, City of Chicago Department of Water Management
Commenter Category: Regulated Community (Utilities)
Comment: 4. MONITORING LOCATION
Source Water
The water being monitored should be labeled Influent Water not Source Water because only the water
which enters the plant for treatment is being monitored.
Response: See Response 340(A).
5.5.1 Comment Code 341, Prior to treatment
Summary of Issues
Comments were submitted expressing concern over sample collection prior to or after presedimentation
basins, proposed treatment credits, and chemical addition issues used during the monitoring period for
Cryptosporidium. These comments expressed concern over the proposed rule's restriction of sample
collection to only after presedimentation basins and the treatment credits involved. With respect to
sampling location requirements, several commenters recommended that PWSs be allowed to collect
samples either before or after pretreatment chemical processes because these processes represent normal
operating conditions. These commenters stated that the chemicals used in pretreatment processes are
unlikely to affect the analysis of Cryptosporidium at typical concentrations.
Response to Code 341
Sampling before treatment
EPA disagrees with comments that pretreatment processes are unlikely to affect the analysis of
Cryptosporidium at typical concentrations. Interference by pretreatment chemicals potentially may
include degradation of oocyst epitopes and prevention of antibody-based procedures in the methods
(immunomagnetic separation [IMS] and antibody staining) from capturing or staining the organisms
during sample processing. This potentially could result from the use of oxidizing agents, such as
potassium permanganate and chlorine. Interference also may be manifested as reduced elution efficiency
after filtration, biasing method recovery by reducing the potential to detect organisms when they are
present. This potentially could result from the use of coagulants, such as alum and ferric chloride. EPA
conducted literature searches and consultations with experts and did not identify any published data or
unpublished research that provided clear indication of a lack of effect of any of the chemicals or treatment
techniques used prior to conventional treatment. EPA continues to believe that common pretreatment
chemicals like oxidants and coagulants have the potential to adversely affect the performance of
Cryptosporidium analytical methods. Available data are not sufficient to identify a concentration at which
such effects would be negligible.
Comment Response for the LT2ESWTR 5-85 December 2005
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Therefore, today's rule requires PWSs to sample upstream of chemical addition. This also means that
PWSs that operate presedimentation basins using coagulants must sample prior to the presedimentation
basin. However, in the final rule, EPA provides some flexibility for alternative sampling location. The
State may approve a PWS to collect a source water sample after chemical treatment if the State
determines that collecting a sample prior to treatment is not feasible for the PWS and that the chemical
treatment is unlikely to have a significant adverse effect on the analysis of the sample.
Individual Comments on Code 341
EPA Letter ID: 496
Comment ID: 10696
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: similar point as established by the governing agency. EPA should allow monitoring at
a point that reflects influent water quality and the utility's anticipated improvement options, if additional
treatment becomes necessary. The compliant schedule should be
Response: See Response 340(A).
EPA Letter ID: 560
Comment ID: 14977
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Two - Monitoring Prior to -Any Treatment-:
Section 141.704(a) provides that except as otherwise specified in the rule utilities should sample prior to -
any treatment- where the example given is chemical addition at an intake. American Water has already
encountered problems with sample collection, particularly where potassium permanganate is added at the
intake. For example, one subsidiary has an intake in Lake Erie where Zebra Mussel and taste and odor
control are issues. Collection of water samples at the
lake shore is not representative of the intake water and there is no separate sample line out to the intake
point. Recommendations by Agency personnel that potassium permanganate be turned off for 6 hours
prior to LT2 sample collection was met with vehement opposition by plant operations. Pre-oxidation not
only controls Zebra Mussels, and taste and odor, but also is important for removal of metals, organic
carbon, and particulates. It is unreasonable to put the treatment process at risk simply to collect a
Cryptosporidium sample, especially when potassium permanganate will have no effect on the oocysts.
American Water recommends that -any- be removed from §141.704(a) and that in guidance the Agency
provide a list of chemical additions or other actions that do not interfere with Cryptosporidium analyses.
Response: See Response 341.
Comment Response for the LT2ESWTR 5-86 December 2005
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5.5.2 Comment Code 342, Presedimentation basins
Summary of Issues
Comments were submitted expressing concern over sample collection prior to or after presedimentation
basins, proposed treatment credits, and chemical addition issues used during the monitoring period for
Cryptosporidium. These comments expressed concern over the proposed rule's restriction of sample
collection to only after presedimentation basins and the treatment credits involved. With respect to
sampling location requirements, several commenters recommended that PWSs be allowed to collect
samples either before or after pretreatment chemical processes because these processes represent normal
operating conditions. These commenters stated that the chemicals used in pretreatment processes are
unlikely to affect the analysis of Cryptosporidium at typical concentrations.
Response to Code 342
Presedimentation basin sample location
EPA agrees with comments that EPA should not require collecting samples after presedimentation basins
due to concerns about the effects of coagulants on method recovery. Under today's final rule
requirements, PWSs must sample prior to any chemical treatment. Therefore, PWSs that use
presedimentation with coagulation or any other chemical treatment must sample prior to
presedimentation. This is a change from the proposal, which required sampling after presedimentation.
Due to this change, PWSs using presedimentation with coagulation are eligible for toolbox treatment
credit for this process. PWSs are not eligible for Cryptosporidium treatment credit for a presedimentation
process if their sampling point for the source water Cryptosporidium monitoring used for bin
classification was after (i.e., downstream of) the presedimentation process.
Individual Comments on Code 342
EPA Letter ID: 390
Comment ID: 10493
Commenter: Jeff Taylor, Deputy Director, City of Houston Public Utilities Division
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 766 5. Credit for existing basins
Comment: a. Systems practicing presedimentation, as defined in the proposed rule, but required to
perform the Cryptosporidium sampling upstream of the basin, should be allowed credit for use of the
presedimentation basin. The presence of a disinfectant in the water entering the basin should have no
effect on the physical efficiency of the presedimentation process and failure to allow the system credit
could result in the decision to move the point of chlorination after the basin. Such a move could have a
deleterious effect on CT, DBP formation, or both.
If Cryptosporidium is not the controlling factor in the system's disinfection scheme, then they are
needlessly sacrificing the time factor in the CT calculation, forcing them to increase the concentration of
the disinfectant. If DBP formation becomes a problem, due to this change, the system will be forced into a
new method of disinfection, involving large capital expense, and lengthy construction times.
Response: See Response 342.
Comment Response for the LT2ESWTR 5-87 December 2005
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EPA Letter ID: 452
Comment ID: 10934
Commenter: Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Commenter Category: Regulated Community (Utilities)
Comment: EPA should not require sampling after presedimentation basins (141.704(b)). EPA
has not provided a reasonable explanation for this requirement. The source water sample collection point
for the purpose of bin classification should be located at an appropriate point that is representative of the
influent water. Samples collected before presedimentation basins are certainly appropriate points that are
representative of influent water. The preamble is not consistent with the rule as to whether systems may
(p. 47668) or (p. 47778) collect samples after
presedimentation. Disqualifying data because samples were collected before
Response: See Response 342.
EPA Letter ID: 453
Comment ID: 10943
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: There should be a clarification that systems using multiple presedimentation
processes should sample (if they are sampling the presedimentation effluent) at the end of all the
processes, in other words at the influent to the conventional treatment process.
Response: See Responses 341 and 342.
EPA Letter ID: 453
Comment ID: 10944
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: 3. Pre-sedimentation basin effluent samples are often treated water. If these
samples must be collected before chemical treatment, it will jeopardize water quality. (Page 47691). If we
do sample treated water the samples may be difficult to elute if treated with coagulants and may clog
sample filters if treated with powdered activated carbon.
One solution is to require untreated samples but allow two to four weeks for the sampling window to find
a time when the pre-treatment is not needed. Perhaps a State approved monitoring plan provision would
be effective in addressing special circumstances.
Another solution may be to allow sampling of pre-treated water but have special flexibility on the sample
to compensate for sampling difficulties. Perhaps the laboratory and utility could be given sampling
protocol options and allow for smaller samples if the filter clogs.
Comment Response for the LT2ESWTR 5-88 December 2005
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Response: See Response 342.
EPA Letter ID: 458
Comment ID: 10977
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Page 47691 - Presedimentation - The rule and preamble language seem to be conflicting with
other options allowed. The system should be required to monitor the source water before
presedimentation or after pre sedimentation, at the option of the PWS. If sampling was done prior to
presedimentation, then a 0.5 log reduction credit can be claimed, and if the sampling was performed after
presedimentation, then no log reduction would be allowed for the existing presedimentation basin. This
would be consistent with the proposal for Bank Filtration.
Response: See Response 342.
EPA Letter ID: 485
Comment ID: 11301
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: monitoring and performance conditions stipulated in your proposal. The Department also
concurs with the requirement that systems with existing pre-sedimentation be required to sample after the
existing pre-sedimentation basin for purposes of determining their bin classification.
Response: See Response 342.
EPA Letter ID: 488
Comment ID: 11841
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Clarification is needed on the required source water monitoring location. Many
systems with existing raw water pre-sedimentation basins apply treatment chemicals in these basins, at
least seasonally, so there is an inherent conflict between the requirement that samples be collected at the
basin effluent but before any treatment. For example, we apply potassium permanganate in our raw water
basins on a seasonal basis for algae control. If there is no intent to
obtain toolbox credit for the pre-sedimentation basin then there does not appear to be any reason for
prohibiting sampling prior to the basin. One way to solve this problem would be to define -treatment-,
for the purposes of this clause, as meaning anything that would be a candidate for toolbox credit (i.e. that
might affect oocyst levels). In any case, facilities that have already collected data from locations prior to a
pre-treatment basin, or who choose to do so in the future, should not be penalized.
Comment Response for the LT2ESWTR 5-89 December 2005
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Response: See Response 342.
EPA Letter ID: 503
Comment ID: 10620
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment: Issue No. 1 - Presedimentation Facilities and Cryptosporidium Monitoring
The rule requires monitoring cryptosporidium, E. Coli, and turbidity on river sources for 24 consecutive
months. The rule calls for the samples to be taken downstream of presedimentation facilities but before
any other treatment. This comment is in direct response to EPA-s request for comment on this issue.
WaterOne practices predisinfection at our presedimentation facilities as well as coagulation and
sedimentation. It is WaterOne-s recommendation that the Final
Rule explicitly allow utilities to sample before the presedimentation facilities, if they choose to, and base
the bin placement on the results of the sampling. This would resolve any concerns of the influence of the
disinfection, coagulation and sedimentation processes on the cryptosporidium concentration.
Response: See Response 342.
EPA Letter ID: 503
Comment ID: 10621
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment: Furthermore, EPA has provided no valid reason for why utilities that sample
upstream of existing presedimentation facilities, and have their bin placement based on those sample
results, should not receive the 0.5 log presumptive credit. In this situation, provided the existing
presedimentation facilities meet the turbidity removal and other requirements of new presedimentation
facilities, it is recommended that the existing presedimentation facilities
receive the same presumptive credit as new presedimentation facilities. If
Response: See Response 342 and 760.
EPA Letter ID: 503
Comment ID: 10622
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment: receive the same presumptive credit as new presedimentation facilities. If utilities choose to
sample downstream of the presedimentation facilities and use the results for bin placement, EPA should
be explicit about what treatment processes are allowed to be used at the presedimentation facilities and
require other existing processes to be moved downstream of the sampling point before conducting the
sampling.
Comment Response for the LT2ESWTR 5-90 December 2005
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Response: See Response 342.
EPA Letter ID: 513
Comment ID: 11529
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: If systems will be required to collect samples for Cryptosporidium from water
following presedimentation basins with chemical addition, we are concerned about the possibility of
compromised water quality and the possibility that systems will not be able to process samples as
required. Coagulants and activated carbon in the sample may interfere with sample processing (e.g., clog
filters).
We are requesting a more flexible approach to sampling after pre-sedimentation basins with coagulant
addition. One solution to the issue of problematic sample processing might be to allow smaller sample
volumes to be filtered in the event that filters become clogged.
Response: See Response 342.
EPA Letter ID: 534
Comment ID: 11998
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: The proposal as written appears to be inconsistent. Facilities which already have a
presedimentation process are to sample after this pre-treatment process, while facilities which install
presedimentation in response to LT2ESWTR are to sample ahead of the presedimentation process. If the
intent of the sampling is to determine the Cryptosporidium levels entering the conventional treatment
train, it would be reasonable for all facilities which have a presedimentation process, regardless of when it
was installed, to sample after presedimentation. This would put all facilities with presedimentation on an
equal footing and relieve any concerns the SAB might have had about whether any removal credits
were appropriate for this unit process.
Response: See Response 342.
EPA Letter ID: 556
Comment ID: 12067
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. Presedimentation with Coagulant
AMWA finds the following statement on presedimentation confusing:
Comment Response for the LT2ESWTR 5-91 December 2005
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-Today-s proposal requires systems using presedimentation to sample after the presedimentation basin,
and these systems are not eligible to receive additional presumptive Cryptosporidium removal credit for
presedimentation. However, systems are also required to collect samples prior to chemical treatment, and
EPA recognizes that some plants provide chemical treatment to water prior to, or during,
presedimentation. EPA requests comment on how this situation should be
handled under the LT2ESWTR.-(68 FR 47691)
Sampling in general should be in influent water to the plant where plant is defined as specified elsewhere
in the rule (conventional filtration, direct filtration, etc.) receiving removal credit in its own right, as
specified in the Table IV-4, 68 FR 47668 (also in Section 141.720 of the proposed rule (68 FR 47783)).
Sampling for toolbox credit must be before the plant as defined to insure an accounting for the given
credit. Therefore, sampling would be before any chemical addition in the plant as defined. However,
sampling does not have to be before chemical addition to presedimentation basins or to reservoirs that are
before the plant. Chemical addition to these points should not be prohibited since it is common and
necessary.
Response: See Response 342.
EPA Letter ID: 562
Comment ID: 12487
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
Today-s proposal requires systems using pre-sedimentation to sample after the pre-sedimentation basin,
and these systems are not eligible to receive additional presumptive Cryptosporidium removal credit for
pre-sedimentation. However, systems are also required to collect samples prior to chemical treatment, and
EPA recognizes that some plants provide chemical treatment to
water prior to, or during, pre-sedimentation. EPA requests comment on how this situation should be
handled under the LT2ESWTR.
Response
Detailed comments on LT2ESWTR monitoring for source water bin determination are provided in
Section 4.1. In response to this specific request for comment, EPA should make the revisions to the
monitoring location requirements described in Section 4.1. In making these corrections, EPA should
continue to encourage monitoring under §141.702(e) to take place after existing pre-sedimentation basins
(as well as BF and off-stream storage) when such facilities are in place. EPA should also provide a
mechanism for monitoring prior to these technologies when appropriate and especially with respect to
pre-existing data submitted under §141.708.
With respect to chemical treatment during pre-sedimentation interfering with monitoring observations,
EPA Method 1623 is a performance-based method which includes a number of components geared
toward ensuring that the laboratory can provide enumeration across a range of matrices, including pre-
sedimentation clarifier effluent. Some of these components include:
1. Matrix spikes to assist the laboratory to make changes to accommodate the characteristics of particular
samples,
2. Ability to use a range of sampling procedures including use of a range of filters, and
Comment Response for the LT2ESWTR 5-92 December 2005
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3. Latitude to modify the method within the bounds of demonstrated performance via Tier I or II studies
as outlined by Office of Science and Technology for verification of method modification.
Method requirements are imposed by the LT2ESWTR §141.705(a)(l), which include obtaining a
minimum sample volume. This sample volume is ensured through requirement to take a 10-liter sample
or processing a minimum of 2 ml of packet pellet. Section 141.705 also includes provision that utilities
must process a minimum number of two filters.
Response: See Responses 341 and 342.
EPA Letter ID: 635
Comment ID: 13113
Commenter: Robert A. Hollander, Compliance and Regulatory Affairs Administrator, City of Phoenix,
Water Services Department
Commenter Category: Regulated Community (Utilities)
Comment: There are three possible chemical addition operating scenarios for systems with
existing presedimentation basins: systems that never add coagulants, systems that intermittently add
coagulants prior to or during presedimentation, and systems that always add coagulants prior to or during
presedimentation. Systems that never add coagulants and recycle should sample downstream of the
presedimentation basin for bin classification. These systems should be allowed
the option of obtaining the presumptive 0.5 log Cryptosporidium removal credit if the routine operating
procedures are changed to meet the requirements imposed on systems that install new presedimentation
basins to obtain the presumptive removal credit.
Systems that intermittently add coagulants prior to or during presedimentation with or without recycle
flows should sample downstream of the presedimentation basin for bin classification. During the
sampling cycle for bin classification, the mode of operation during presedimentation should be recorded
by the system. These systems should be allowed the option of obtaining the presumptive 0.5 log
Cryptosporidium removal credit if the routine operating procedures are changed to meet the requirements
imposed on systems that install new presedimentation
basins to obtain the presumptive removal credit.
Systems that always add coagulants prior to or during presedimentation with or without recycle should
sample downstream of the presedimentation basin for bin classification. However, these systems should
not be allowed the presumptive 0.5 log Cryptosporidium removal credit. As written, the proposed rule
does not allow systems with existing presedimentation basins the option of obtaining the presumptive 0.5
log Cryptosporidium removal credit. If these systems elect to continuously operate the presedimentation
basin for all flows, continuously add a coagulant to the presedimentation basin, and demonstrate on a
monthly basis at least 0.5 log reduction of turbidity through the presedimentation process in at least 11 of
the 12 previous consecutive months they should qualify for the same presumptive credit awarded to
systems that install and operate new presedimentation basins in the same manner.
Response: See Responses 341 and 342.
Comment Response for the LT2ESWTR 5-93 December 2005
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EPA Letter ID: 664
Comment ID: 14054
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.C. - OPTIONS FOR SYSTEMS TO MEET CRYPTOSPORIDIUM
TREATMENT
REQUIREMENTS
3. Alternate Sources
4. Off Stream Raw Water Storage
5. Pre-Sedimentation
Our Utility obtains surface water source directly from Lake Winnebago at the surface rather than a deeper
water intake. Potassium Permanganate is fed at the entrance of the water to a 10 million gallon holding
basin where up to 30-days of detention time is provided. The permanganate is added to control zebra
mussels, taste and odor control and control of algae. We are unclear as to where the proposed rule would
establish the sampling location for cryptosporidium; at the intake to the basin or the intake to the plant (at
the end of the basin). It is our experience that the 30-days of detention time offers a significant and
important level of treatment in that our raw water turbidity, algae counts, plate counts and odor numbers
in the water leaving the pre-treatment basin are all mostly improved from similar sources on the lake
which have deeper water intakes (Appleton and Neenah) and from the raw water which enters the basin.
The raw water sampling procedures would be simplified and less costly and it is likely that the oocyst
counts would be different at these two locations. We would suggest that water entering the plant at the
end of the pre-treatment basin more accurately reflects our raw water source as compared to the water
entering the basin and should be the monitoring location. We would, therefore, also not be expecting
treatment credit for this treatment process.
Response: See Responses 341 and 342.
EPA Letter ID: 678
Comment ID: 14695
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 0.5 log credit for Cryptosporidium credit appears unwarranted. If the EPA believes the
presedimentation process helps reduce Cryptosporidium in the source water, then the source water
monitoring should take place at a location prior to the presedimentation process.
Response: See Response 342.
Comment Response for the LT2ESWTR 5-94 December 2005
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5.5.3 Comment Code 343, Raw water off-stream storage
Summary of Issues
Two of the commenters were concerned about their situation regarding the sampling location from an off-
stream storage reservoir due to construction of the structure. This commenter needs guidance on how to
correctly sample in their situation to comply with the LT2ESWTR. The other two comments concur with
EPA and support the LT2ESWTR.
Response to Code 343
Raw water off-stream storage
EPA has removed from the final rule any specific requirements concerning sampling after raw water off
stream storage. The final rule requirements for PWSs to sample before any chemical treatment also apply
in this situation, and PWSs may sample before or after off stream storage as necessary to meet this
requirement. EPA agrees that if there is no chemical treatment at the off stream storage location, samples
could be taken on the downstream side of the storage to reflect any changes in Cryptosporium
concentrations due to settling in the storage facility. PWS are required to submit sampling location
descriptions to the Primacy Agency before beginning sampling. Any concerns about proper sampling
location or possible changes in sampling location can be addressed at that time.
Individual Comments on Code 343
EPA Letter ID: 485
Comment ID: 11298
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 751 1. Decision not to grant credit based on existing
data
Comment: Response: The Department concurs with the finding and supports the LT2ESWTR
monitoring requirements for off stream raw water storage reservoirs. Monitoring at this site will allow the
utilities using off-stream storage to receive actual credit that may be greater or less than that previously
proposed. This monitoring should be in addition to the source water monitoring unless all source water is
passed through the off stream storage prior to treatment.
Response: See Response 343.
EPA Letter ID: 631
Comment ID: 13230
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: Source Water Monitoring Location: For the planned Albuquerque plant, the off-stream
storage location specified for monitoring in the proposal has not yet been constructed. Yet if monitoring
samples have been collected at the river intake to be used to define bin classification for the plant design,
Comment Response for the LT2ESWTR 5-95 December 2005
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the results may not be deemed adequate for consideration to meet monitoring requirements. Neither the
location of sample collection, nor the method used to obtain the result can correspond to the proposed
requirements.
Response: See Response 343.
EPA Letter ID: 641
Comment ID: 13600
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47687 - RFC - Off-stream raw water storage - Systems using off-stream raw water
storage should collect samples at the reservoir (raw water storage) outlet to accurately reflect the quality
of the water entering the plant, including any changes from source water Crypto concentrations (both
decreases in Crypto due to settling and increases due to inputs.).
Response: See Response 343.
EPA Letter ID: 683
Comment ID: 14757
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
Comment: Source Water Monitoring Location: For the planned Albuquerque plant, the
off-stream storage location specified for monitoring in the proposal has not yet been constructed. Yet if
monitoring samples have been collected at the river intake to be used to define bin classification for the
plant design, the results may not be deemed adequate for consideration to meet monitoring requirements.
Neither the location of sample collection, nor the method used to obtain the result can correspond to the
proposed requirements.
Response: See Response 343.
5.5.4 Comment Code 344, Bank filtration
Summary of Issues
Comments were received concerning the topic of bank filtration. One commenter requests that systems
who claim the bank filtration credit should be allowed to utilize either the river or well water as their raw
water source. The other commenter points out a situation where the rule could require sampling which
could not be done, and proposes that state approval of monitoring plans would alleviate this.
Comment Response for the LT2ESWTR 5-96 December 2005
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Response to Code 344
Bank filtration sampling location
PWSs using existing bank filtration as pretreatment to a filtration plant under today's rule must sample
the well for the purpose of determining bin classification. In these cases, the performance of the bank
filtration process in reducing Cryptosporidium levels will be reflected in the monitoring results and bin
classification. These PWSs are not eligible to receive additional treatment credit for bank filtration.
PWSs using bank filtration without additional filtration must collect source water samples in the surface
water (i.e., prior to bank filtration) to determine bin classification unless the State approves an alternative
monitoring location. This applies to systems using bank filtration to meet the Cryptosporidium removal
requirements of the IESWTR or LT1ESWTR under the provisions for alternative filtration demonstration
in 40 CFR 141.173(b) or 141.552(a).
EPA does not agree that systems claiming or planning to claim riverbank filtration credits should be able
to choose to sample either the river or the well water.
Individual Comments on Code 344
EPA Letter ID: 453
Comment ID: 10942
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: Related to the above, systems claiming or planning to claim riverbank filtration credits should
be able to choose the river or the well water as their raw water.
Response: See Response 344.
EPA Letter ID: 453
Comment ID: 10950
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: 7. The draft regulation could require some systems to take samples of water that
don-t always exist. The situation is GWUDI, the system does not filter, it has been granted a bank
filtration credit, and is located on an intermittent stream. Part IV, C, 6 states they typically will be
required to sample the surface water which they will not always be able to obtain.
A State approved monitoring plan would also help address unusual situations such as this.
Response: See Response 360, 361, 365 and 440.
Comment Response for the LT2ESWTR 5-97 December 2005
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EPA Letter ID: 455
Comment ID: 10957
Commenter: Kirk Stacker, Director of Utilities, City of Kearney Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment: The City of Kearney draws its water from ground water wells in the Platte Paver.
The wells have been determined to be under the direct influence of surface water and we have received a
filtration credit for the natural filtration that takes place in the aquifer.
Our comments regarding the proposed rule involve the monthly monitoring of the source water for
cryptosporidium as described in Section IV. We are concerned about this requirement because the Platte
River in central Nebraska goes dry frequently, and during the past few years of drought the river has
remained dry for several days and has at times remained dry for weeks at a time. These dryriver events
may make it impossible for us to collect monthly samples from the
river or source water because the water is not there. We believe that this inability to collect a sample
should not adversely impact our water system in as far as compliance or increased monitoring is
concerned. It could be said that when the river is dry that our wells are not under the influence of
surfacewater and could be considered exempt from the monitoring regulations.
Additionally, during prolonged cold periods in the winter the river freezes over and the water moves very
swiftly under the ice making sample collection difficult and very dangerous for our employees. Because
our wells are vertical wells and the water in the wells meets the filtration requirements we have no other
location other than the river to collect a source water sample. We do not want a missed sampling event,
due to these circumstances, to affect our compliance status or cause us to be placed into the bin 4
classification. The resulting treatment requirements will be very costly to our citizens and actual results
may show that the additional treatment is unnecessary.
Response: See Response 360, 361, 365 and 440.
EPA Letter ID: 513
Comment ID: 11525
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: City of Kearney Cryptosporidium sampling
One example of a large public water system in Nebraska that likely will not be able to take monthly
Cryptosporidium samples for 24 consecutive months is the City of Kearney (serving approximately
28,000 people). The City of Kearney utilizes a wellfield on an island in the Platte River as its primary
source of drinking water. The wells are ground water under the direct influence of surface water. The City
was granted bank filtration credit and provides no additional
filtration of the water, so Cryptosporidium sampling will be done from the Platte River.
In the most recent two years, the Platte River adjacent to the Kearney wellfield has been dry for weeks at
a time. Water operators for the City anticipate that this pattern will continue in the future. It is possible
that the City will miss multiple sampling events (and potentially miss consecutive sampling events)during
the 24-month Cryptosporidium monitoring period because the river is dry.
We are very confident that City personnel will make every possible effort to collect Cryptosporidium
Comment Response for the LT2ESWTR 5-98 December 2005
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samples when the sampling is scheduled. To require the City to install the highest level of additional
treatment because samples cannot be collected is unreasonable punishment for a condition that is
completely beyond the control of the City and the State.
We propose that the City of Kearney be permitted to skip Cryptosporidium sampling when the Platte
River is dry at the City-s wellfield. The City-s sampling period could be extended until 24 months of
samples have been collected, or bin assignment could be based on the samples collected during the 24-
month -standard- sampling period. If EPA is not receptive to this proposal, another possible solution is to
have the Cryptosporidium samples collected from one of the City-s island wells when the River is dry.
Response: See Response 360, 361, 365 and 440.
5.5.5 Comment Code 345, Plants using multiple water sources
Summary of Comments
Comments were received concerning systems which utilize multiple water sources. Several commenters
expressed the opinion that these systems should be required to sample each water source independently
instead of submitting blended composite samples. Multiple commenters requested clarification on
composite sampling, suggesting it should be based on daily average flows. Several commenters believed
that states should have the flexibility to decide how multiple source systems would sample on a case-by-
case basis. Several commenters who use multiple sources only intermittently inquired how they would be
required to sample.
Response to Code 345
EPA disagrees with those who commented that sampling of multiple water sources should consist of
sampling only the worst quality source, or separate sampling of all sources. The requirements in today's
final rule for the source water sample collection location are similar to those in the proposed rule. They
are designed to characterize the influent water to the treatment plant at the time each sample is collected.
To achieve this goal, there are several requirements for how the sampling takes place.
The use of multiple sources at the time of sampling must be consistent with routine operational practice.
Therefore, secondary or infrequent sources should be used based on routine operational criteria, and if
they are used on the day of sampling they will be included.
Also, for plants that use multiple water sources, EPA has provided alternative approaches to sampling.
PWSs must collect samples from a tap where the sources are combined prior to treatment, if available. If a
blended source tap is not available, PWSs must either collect samples from each source and analyze a
weighted composite (blended) sample, or analyze samples from each source separately and determine a
weighted average of the results, based on the proportionate flow of the sources at the time of sampling.
The only alternative to compositing samples is to perform separate analyses which would increase costs
for PWS. Compositing samples need not be problematic with logical planning and coordination among
the PWS and the laboratory.
EPA believes that regular sampling for 24 months will be sufficient to characterize the quality of the
combination of the mixed sources without costly sampling of all sources individually. In addition, the
second round of sampling will further characterize the sources and identify any changes in the quality of
Comment Response for the LT2ESWTR 5-99 December 2005
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the water sources.
The final rule allows the State to approve one set of monitoring results from all plants that draw water
from the same influent, such as the same pipe or intake. EPA and the States will be reviewing sample
location descriptions and have some flexibility to determine when sample locations can be considered the
same influent.
Individual Comments on Code 345
EPA Letter ID: 101
Comment ID: 10879
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Systems with multiple sources, leading through a single treatment plant, should be only
sampling the source which is at most risk. Sampling low risk sources, such as ground waters under the
direct influence of surface water, when there is also a direct surface water source, doesn't make sense. If
the system is able to meet the requirements for the worst source, other sources will only act to dilute the
risk.
Response: See Response 345.
EPA Letter ID: 409
Comment ID: 10482
Commenter: Leslie Gryder,, City of Lynchburg Utilities
Commenter Category: Regulated Community (Utilities)
Comment: 11/12/2003 11:49 AM
To: Group Ow-Docket@EPA
cc:
Subject: LT2ESWTR
How will secondary sources be addressed in the LT2ESWTR? We utilize our primary source during
normal operations. We supplement or substitute with our secondary source (river) during periods when
the reservoir level is very low, or when there is a break in the line from the reservoir or some other
maintenance issue. Most years we do not use this source at all, or use it only for a few weeks a year, but
last year, during the drought, we utilized it exclusively for several months. What will the monitoring
requirements be in this case, and if we are required to monitor this secondary source and our primary
source is classified as Bin 1 but our secondary is in Bin 2, 3, or 4, will we be required to implement the
treatment requirement for Bin 2,3, or 4 because of our secondary source?
Response: See Response 345.
EPA Letter ID: 457
Comment ID: 11919
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Comment Response for the LT2ESWTR 5-100 December 2005
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Branch
Commenter Category: State/Tribe Government
Comment: With respect to the specific issues on which EPA requested comment, we believe that EPA
should provide the states with flexibility to address these concerns on a case-by-case basis. The EPA
could present the following specific issues as a way of guidance to the states:
* Source water type classification for systems that use multiple sources.
Response: See Responses 346, 347, 360(c), 380, 440 and 450.
EPA Letter ID: 458
Comment ID: 10975
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Source Water Type Classification - multiple source systems should monitor all
sources year round to maximize their potential use, and the primacy agency should require the maximum
log inactivation. EPA needs to establish criteria for
Response: See Response 345.
EPA Letter ID: 470
Comment ID: 11069
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: For those systems that use multiple sources and/or different sources during the year, the most
stringent criteria should determine the source water type classification and therefore the related
monitoring. However, if a system plans to conduct separate sampling of the sources, then the respective
source water type classification should be applied.
Response: See Response 345.
EPA Letter ID: 472
Comment ID: 11137
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment Response for the LT2ESWTR 5-101 December 2005
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Comment Codes 300-471
Comment: - Source water type classification for systems that use multiple sources
In the COP case, sources change throughout the year. Our source water, SRP canal, is composed of four
sources with differing mix ratios throughout the year. These sources include the Salt River, Verde River,
Colorado River via the Central Arizona Project (CAP), and groundwater. The mix of source water is
determined by SRP and is usually seasonal, but there can be exceptions. Drought in the Southwest United
States has required an increased use of CAP and groundwater. It could be several years before the Salt
and Verde River sources, though still currently used, return to normalcy.
The 24-month monitoring period would include these seasonal variations and COP should not be
penalized with additional monitoring due to source water changes that are not in our control. If the
drought mitigates before the next six year monitoring cycle, the Salt and Verde River -normal mix-
would be sampled and evaluated at that time.
Response: See Response 345.
EPA Letter ID: 485
Comment ID: 11288
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes systems should evaluate each source independently and
assign appropriate bin classifications based on monitoring of each source. If sources are blended prior to
use, the ability to monitor the blended source should be allowed if approved by the State.
Response: See Response 345.
EPA Letter ID: 520
Comment ID: 11620
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Source water type classification for systems that use multiple sources
IEPA generally believes that systems should evaluate each source independently and assign appropriate
bin classifications based on monitoring of each source. If the sources are blended prior to use, the ability
to monitor only the blended source should be allowed at the discretion of the state.
Response: See Response 345.
EPA Letter ID: 562
Comment ID: 12375
Comment Response for the LT2ESWTR
5-102
December 2005
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA has contacted most of the commercial laboratories experienced in
handling Cryptosporidium oocyst samples regarding compositing of Cryptosporidium oocyst samples
(e.g., §141.704(2)). Their advice was that such compositing can be problematic to undertake and
consequently should be avoided if alternative approaches are available. Additionally, the agency
Response: See Response 345.
EPA Letter ID: 628
Comment ID: 12836
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: c. Composite sample should be based on daily average flows. The proposed rule is
unclear regarding whether instantaneous flows or daily average flows of plant influents should be used in
determining a composite sample. Due to many reasons, samples from multiple sources may not be
collected at the same time. If composite sample is based on instantaneous plant influent flows, it may not
result in a more accurate weighted-average than using the daily average flow rates. For practical and
operational reasons, the SFPUC recommends composite samples be based on daily average flows.
Response: See Response 345.
EPA Letter ID: 634
Comment ID: 13275
Commenter: Michael A. Neher, Environmental Services Manager, City of Henderson
Commenter Category: Local Government
Comment: (3) treatment plants, they share the same source and equivalent processes. The
proposed rule (141.602) allows states .the discretion to consider multiple wells from the same aquifer to
be one -treatment plant.- A similar provision should be made available to surface water systems with
similarly uniform water quality from multiple treatment plants using the same source.
Response: See Response 347.
EPA Letter ID: 643
Comment ID: 12775
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-103 December 2005
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Comment: Source water type classification for systems that use multiple sources
States generally believe that systems should evaluate each source independently and assign appropriate
bin classifications based on monitoring of each source. If the sources are blended prior to use, the ability
to monitor only the blended source should be allowed at the discretion of the state.
Response: See Response 345.
EPA Letter ID: 643
Comment ID: 12787
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: * States generally believe that plants that use multiple sources, which
enter a plant through a common conduit, should be required to conduct Cryptosporidium monitoring of
each source to determine the Cryptosporidium levels of each source. Monitoring each source will allow
the system to know the amount of Cryptosporidium loading to expect at the plant if the ratio of flows
from the different sources changes significantly. This approach would also extend to plants that use
separate sources that enter the plant at different points.
Response: See Response 345.
EPA Letter ID: 647
Comment ID: 12921
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Source water type classification for systems that use multiple sources
Systems should evaluate each source independently and assign appropriate bin classifications based on
monitoring of each source. If the sources are blended prior to use, the ability to monitor only the blended
source should be allowed at the discretion of the state.
Response: See Response 345.
EPA Letter ID: 647
Comment ID: 12929
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: - Plants that use multiple sources, which enter a plant through a common
conduit, should be required to conduct Cryptosporidium monitoring of each source to determine the
Cryptosporidium levels of each source. Monitoring each source will allow the system to know the amount
Comment Response for the LT2ESWTR 5-104 December 2005
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of Cryptosporidium loading to expect at the plant if the ratio of flows from the different sources changes
significantly. This approach would also extend to plants that use separate sources that enter the plant at
different points. States should have flexibility to determine if the source water quality is substantially the
same as other sources in order to waive unnecessary
testing.
Response: See Response 345.
EPA Letter ID: 678
Comment ID: 14672
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 8. Sections 141.704(e)(2)(i) and (ii) - Should the composite sample be based on instantaneous
flows or daily average flows of plant influents? Due to many reasons, samples from multiple sources may
not be collected at the same time. A composite sample based on instantaneous plant influent flows may
not result in a more accurate weighted-average than using the daily average flow rates. We recommend
composite samples be based on daily average flows.
Response: See Response 345.
5.5.6 Comment Code 346, Filter backwash recycle
Summary of Issues
Comments were received pertaining to Cryptosporidium sampling in relation to the recycling of filter
backwash. Many of the commenters believed that all issues pertaining to filter backwash were adequately
dealt with in the Filter Backwash Recycling Rule (EPA 2001) and need not be included in LT2ESWTR.
Several commenters believed PWSs should sample at a point in the system prior to introduction of
recycled water, while several others believed sampling was more appropriate at a point after introduction
of recycled water. Several commenters requested more flexibility in sample location, so that the
individual states could decide on a case-by-case basis.
Response to Code 346
Filter Backwash Recycle
The requirements for sample collection location are designed to characterize the influent water to the
treatment plant at the time each sample is collected and ensure that samples are not affected by treatment
chemicals that could interfere with Cryptosporidium analysis. It is EPA's position that PWSs that recycle
filter backwash must sample prior to backwash addition because the backwash contains chemicals like
coagulants that adversely affect analytical method recovery. Furthermore, backwash is often recycled at a
point where other treatment chemicals have already been added. Therefore, the final rule requires sample
collection prior to addition of filter backwash, and no State flexibility is provided for this decision. This
requirement is also reflected in the recommendations of the Source Water Monitoring Guidance Manual.
Comment Response for the LT2ESWTR 5-105 December 2005
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Individual Comments on Code 346
EPA Letter ID: 101
Comment ID: 10880
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Monitoring for Systems Who Recycle Filter Backwash
The Agency already has a rule that places strict requirements on systems that recycle their backwash
water. No further explanation or regulatory requirements are needed for this practice. If any regulatory
action is needed for cryptosporidium and the location of monitoring for more cryptosporidium
monitoring, then the Agency should address this in the Filter Backwash Rule - and through the
appropriate means set up by the Safe Drinking Water Act - The six year review of regulations.
Response: See Response 346.
EPA Letter ID: 439
Comment ID: 10762
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: Filter Backwash Recycle Issue 1 Accounting for Recycle Practices in LT2
Monitoring
Recycle practices are already regulated by the Filter Backwash Recycle Rule, so it should not be
necessary to cover it in this regulation. Monitoring for this regulation should be before a recycle point
under approval of the primacy agency (see Monitoring Issue 6 above.)
Response: See Responses 346.
EPA Letter ID: 441
Comment ID: 10769
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Recycling processes can concentrate pathogens, such as Cryptosporidium. As a result, a
sample location downstream of the recycle point might result in a higher Bin requirement. Conversely,
large quantities of pretreatment chemicals and floe particles—often present in the recycled water and at
this downstream location—might hinder the ability to recover
oocysts from a sample, and hinder their detection and quantification in the laboratory. EPA should
examine available research to determine the effect of recycled wastewater on Cryptosporidium sample
results. DEP believes that, based on the research findings, LT2 should require suppliers to use a sample
location with the highest concentration of oocyst detection. EPA should specify the proper location in
order to improve sampling consistency among all suppliers in the nation.
Comment Response for the LT2ESWTR 5-106 December 2005
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If the final LT2 includes sampling downstream of the recycle point, EPA should require suppliers to
include information on recycle practices in their sampling schedule. Most suppliers that practice recycling
do so intermittently. Thus, the suppliers' sampling schedules should specify
when recycle practices normally occur. In addition, sampling should occur when recycle streams are
turned on.
Response: See Response 346.
EPA Letter ID: 444
Comment ID: 10809
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment: b. NH believes that source water monitoring for Crypto or E Coli should be performed at a
point after the addition of recycled backwash water to the raw water stream and within the time period
that recycling is occurring. Monitoring otherwise provides an artificially low picture of typical influent
pathogen levels.
Response: See Response 346.
EPA Letter ID: 457
Comment ID: 11914
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: With respect to the specific issues on which EPA requested comment, we believe that EPA
should provide the states with flexibility to address these concerns on a case-by-case basis. The EPA
could present the following specific issues as a way of guidance to the states:
* How to address plants that recycle filter backwash water;
Response: See Response 346.
EPA Letter ID: 458
Comment ID: 10971
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-107 December 2005
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Comment: Recycled flows - A recommendation is made to require composite sampling,
proportioned in accordance with the average flow of recycled to un-recycled water (before treatment).
Based on historical records, the system uses 90% of the water from the source, and 10% from the recycled
water, the composite sample should reflect this mix. This should give a good representation of the amount
of cryptosporidium entering the treatment stream. Compositing for e-coli would not be acceptable, due to
the inactivation that would occur to the recycled water of e-coli, which would not occur to the
Cryptosporidium.
Response: See Response 346.
EPA Letter ID: 463
Comment ID: 11033
Commenter: Richard Wilson, Environmental Services Manager, Anaheim Public Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment: 6. Response to request for comment on filter backwash recycling
Anaheim believes that the Filter Backwash Recycling Rule provides adequate regulation of this activity.
Response: See Response 346.
EPA Letter ID: 470
Comment ID: 11065
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Changes to LT2ESWTR monitoring in relation to the effect of recycling filter
backwash should be left to the states to require based upon a review of the treatment plant characteristics.
Response: See Response 346.
EPA Letter ID: 471
Comment ID: 11123
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: Filter Backwash Recycle
1. Allowable recycle practices at treatment plants are regulated by the Filter Backwash Recycle Rule
(FBRR). The intent of the FBRR is to encourage implementation of recycle practices Washington
Suburban Sanitary Commission comments on proposed LT2ESWTR that do not negatively impact
performance of a treatment plant. In other words, facilities operated using practices consistent with the
Comment Response for the LT2ESWTR 5-108 December 2005
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FBRR should achieve equivalent, or superior, performance to the same facility operated without recycle.
Consequently, other regulations do not need to incorporate provisions for recycle because all
consequences of recycle practices are accounted for in systems complying with the FBRR. Since
monitoring is intended to characterize influent water to the plant, we believe that monitoring should
normally be before recycle.
Response: See Response 346.
EPA Letter ID: 472
Comment ID: 11146
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: - Monitoring for systems that recycle filter backwash. How should filter backwash be
considered in LT2ESWTR monitoring?
The COP recycles filter backwash through a filter backwash recovery tank and sedimentation blow down
or sludge through a sludge thickener process. The thickener supernatant and filter backwash recovery tank
flows are returned to the plant headworks at a controlled rate. This combined recycle flow is processed
through our pre-sedimentation basin before chemical addition. The combined recycle flow is being
returned on a daily basis, so it will be difficult to collect our Cryptosporidium samples after
presedimentation and before chemical addition without the combined recycle included. This aspect of
recycle flows will require documentation in any reporting to regulatory agencies as water treatment plants
across the country will have various return flow configurations.
The COP believes filter backwash recycle and all recycle flows need to be included in the sampling
protocol as it represents what the water treatment system is processing.
Response: See Response 346.
EPA Letter ID: 484
Comment ID: 10682
Commenter: Anonymous484,, Metro Nashville Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Filter Backwash Recycling:
Monitoring should be conducted before recycling. Monitoring should characterize influent(source water)
to the plant.
Response: See Response 346.
EPA Letter ID: 485
Comment ID: 11284
Comment Response for the LT2ESWTR 5-109 December 2005
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Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes that systems that recycle backwash water
should be required to monitor downstream of the introduction of the recycle flow. The monitoring should
also be done during a return cycle to best evaluate the water quality. If monitoring is not conducted during
return flow conditions the results may not adequately reflect the conditions of highest source water
pathogen load.
Response: See Response 346.
EPA Letter ID: 491
Comment ID: 10670
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: 7. The effect of recycling filter backwash water should not be considered in LT2
monitoring. The Filter Backwash Recycle Rule (FBRR) itself encourages recycling practices that will not
impact plant processes, and systems are already complying with this rule. Monitoring or regulation of
filter backwash recycle in addition to that already required by the FBRR is not necessary.
Response: See Response 346.
EPA Letter ID: 496
Comment ID: 10707
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: D. Filter Backwash Recycle
The effects of recycling filter backwash considerations in LT2ESWTR monitoring.
1. Filter Backwash Recycle Key Issue 1: Accounting for Recycle Practices in LT2ESWTR Monitoring:
EPA asks how the effects of recycling filter backwash should be considered in LT2ESWTR monitoring.
Recycle practices at treatment plants are regulated by the Filter Backwash Recycle Rule (FBRR). The
FBRR encourages implementation of recycle practices that do not negatively influence performance of a
treatment plant. Facilities operating under practices consistent with the FBRR will achieve performance
equivalent, or superior to, the same facility operated without recycle capabilities. Therefore, other
regulations do not need to incorporate provisions for recycle because all consequences of recycle
practices are accounted for in systems complying with the FBRR.
Comments for Filter Backwash Recycle Key Issue 1 (Accounting for Recycle Practices in LT2ESWTR
Monitoring): EPA should remember that monitoring is intended to characterize influent water to the plant.
Monitoring should therefore normally be before recycle. The recommendation in Monitoring Key Issue 6
(Monitoring Location) above, concerning system
selection of an appropriate site subject to state review, is sufficient to cover any inconsistent situations.
Comment Response for the LT2ESWTR 5-110 December 2005
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Response: See Response 346.
EPA Letter ID: 497
Comment ID: 10650
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Monitoring For Systems That Recycle Filter Backwash
The MDEQ believes the states should be allowed to determine on a case by case basis consideration of
the recycle stream. It may be appropriate to sample downstream of the recycled flow or to sample the
recycled flow separately. It may be acceptable to collect samples from both the source water and the
recycle stream and analyze a weighted composite. The MDEQ believes this should be addressed as
guidance in the Source Water Monitoring Guidance Manual rather than by rule.
Response: See Response 346.
EPA Letter ID: 506
Comment ID: 10745
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: - Filter Backwash Recycle - Accounting for Recycle Practices in LT2 Monitoring -
The Filter Backwash Recycle Rule regulates allowable recycle practices at water treatment plants. As
CWD understands it, the intent of the FBRR was to encourage implementation of recycle practices that do
not negatively impact the treatment plant-s performance. Other regulations do not need to incorporate
recycle provisions because consequences of these practices are accounted for in complying with the
FBRR. Since monitoring is intended to characterize influent water to the plant, monitoring should
normally be before recycle. The previous recommendation for State review of the monitoring plan would
deal with any unusual situations.
Response: See Response 346.
EPA Letter ID: 507
Comment ID: 11474
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 7. Filter Backwash Recycle, IV.A.3., pg 47678
In response to EPA-s request for comment concerning filter backwash recycling relative to the proposed
rule, FCWA feels that the Filter Backwash Recycle Rule adequately addresses treatment plant filter
backwash recycle and that it is not necessary for the LT2ESWTRto also address filter backwash. The
intent of the proposed rule is to characterize influent water to the plant, not filter backwash recycle.
Comment Response for the LT2ESWTR 5-111 December 2005
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Response: See Response 346.
EPA Letter ID: 511
Comment ID: 11487
Commenter: Keith W. Cartnick, Director Water Quality Assurance, United Water New Jersey
Commenter Category: Regulated Community (Utilities)
Comment: Comment: Monitoring for cryptosporidium in filter backwash water would be difficult due to
the fact that coagulant would bind the cysts into the floe, making them difficult to count and examine. If
systems have very high levels of cryptosporidium (target level to be determined), perhaps monitoring of
the filter effluent should be considered. This monitoring could be combined with, or determined by,
evaluation of IESWTR individual filter turbidity compliance data.
Response: See Response 346.
EPA Letter ID: 520
Comment ID: 11616
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Monitoring for systems that recycle filter backwash water
Although consideration of the recycle stream may not be necessary in all situations, states need flexibility
to determine how to address recycle streams in those instances where the state deems such action to be
necessary. In some cases, monitoring downstream of the introduction of the recycle flow would be
appropriate, while in other cases, supplemental monitoring on the return stream may be more suitable.
EPA should provide guidance to States on systems that recycle filter backwash, to reflect the fact that
recycling practices can increase levels of crypto in the finished water. The guidance should address the
potential increase of crypto levels due to recycling practices, and the frequency of backwash/recycling
performed by the system, and recommend a number or percentage of samples be collected when a system
is brought back on-line after backwashing, based on the
frequency of backwashing.
Response: See Response 346.
EPA Letter ID: 527
Comment ID: 10854
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Accounting for Recycle Practices in LT2ESWTR Monitoring: Allowable recycle
practices at treatment plants are regulated by the Filter Backwash Recycle Rule (FBRR). The intent of the
Comment Response for the LT2ESWTR 5-112 December 2005
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FBRR is to encourage implementation of recycle practices that do not negatively impact performance of a
treatment plant. In other words, facilities operated using practices consistent with the FBRR should
achieve equivalent, or superior, performance to the same facility operated without recycle. Consequently,
other regulations do not need to incorporate
provisions for recycle because all consequences of recycle practices are accounted for in systems
complying with the FBRR. The proposed log credits for treatment allowed in the proposed rule should not
be discounted with respect to recycle practices. The Cryptosporidium removal was independent of recycle
practices in the data sets used to develop the credits. Additional attention to recycle practices under the
FBRR should serve to increase removal.
Response: See Response 346.
EPA Letter ID: 527
Comment ID: 10854
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Accounting for Recycle Practices in LT2ESWTR Monitoring: Allowable recycle
practices at treatment plants are regulated by the Filter Backwash Recycle Rule (FBRR). The intent of the
FBRR is to encourage implementation of recycle practices that do not negatively impact performance of a
treatment plant. In other words, facilities operated using practices consistent with the FBRR should
achieve equivalent, or superior, performance to the same facility operated without recycle. Consequently,
other regulations do not need to incorporate provisions for recycle because all consequences of recycle
practices are accounted for in systems complying with the FBRR. The proposed log credits for treatment
allowed in the proposed rule should not be discounted with respect to recycle practices. The
Cryptosporidium removal was independent of recycle practices in the data sets used to develop the
credits. Additional attention to recycle practices under the FBRR should serve to increase removal.
Response: See Response 346.
EPA Letter ID: 538
Comment ID: 14096
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: The City of Wichita Falls believes that recycled filter backwash should not be
considered in the LT2ESWTR. This is beyond the scope of this regulation. The EPA had the opportunity
to include monitoring in its new Filter Backwash Recycle Rule and any new monitoring of this flow
should be considered in any amendments to the FBRR and not the LT2.
Response: See Response 346.
Comment Response for the LT2ESWTR 5-113 December 2005
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EPA Letter ID: 548
Comment ID: 12158
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * Monitoring for systems that recycle filter backwash that may increase Cryptosporidium
concentration in the water that enters the treatment train
Since adding filter backwash water may increase the concentration of Cryptosporidium in the water that
enters the treatment train, Metropolitan suggests that for systems that recycle filter backwash, the water
should be monitored at the point where the backwash is added/mixed before it enters the treatment train.
Response: See Response 346.
EPA Letter ID: 556
Comment ID: 12059
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 7. Accounting for Recycle Practices in LT2ESWTR Monitoring:
Basic Principle from the FACA Discussions: EPA separated the discussion of recycle practices from the
FACA discussions since they were to be handled in the Filter Backwash Recycle Rule (FBRR). EPA now
asks if recycle practices need to be considered.
Discussion: Allowable recycle practices at treatment plants are regulated by the FBRR. The intent of the
FBRR is to encourage implementation of recycle practices that do not negatively impact performance of a
treatment plant. In other words, facilities operated using practices consistent with the FBRR should
achieve equivalent, or superior, performance to the same facility operated
without recycle. Consequently, other regulations do not need to incorporate provisions for recycle
because the consequences of recycle practices are accounted for in systems complying with the FBRR.
The foregoing is supported by
The proposed log credits for treatment allowed in the proposed rule should not be discounted with respect
to recycle practices. The Cryptosporidium removal was independent of recycle practices in the data sets
used to develop the credits. Additional attention to recycle practices under the FBRR should serve to
increase removals actually experienced.
Recommendation: Recycle practices were considered in the FBRR and need not be considered in the
present proposal.
Response: See Response 346.
Comment Response for the LT2ESWTR 5-114 December 2005
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EPA Letter ID: 561
Comment ID: 12231
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Monitoring For Systems the Recycle Filler Backwash Water
For those systems where filtered backwash water is returned to the process, if the raw water monitoring is
conducted after the return of the recycle stream, several issues arise:
- Many of the source water (raw water) monitoring issues raised under other sections of the Rule would
not apply.
- If the filter backwash water were returned to the point of initial chemical addition (ie, rapid mix basin),
it would be difficult to obtain a representative raw water sample, as the sample would be influenced by
coagulant chemicals and the hydraulic effects of a fully mixed basin.
If a system were to recycle its backwash water, certainly all of the issues relating to raw water monitoring
at the source would be moot, as well as the concerns with cryptosporidium monitoring of a highly turbid
source. Since there is most always some form of pretreatment with chemicals provided after the raw water
intake and prior to addition of the primary coagulant and return of the filter backwash water, the effect of
monitoring at this location would likely be different than directly at the raw water intake. This does seem
to be the intent of this Rule, however.
Response: See Response 346.
EPA Letter ID: 562
Comment ID: 12414
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The Filter Backwash Recycle Rule (FBRR) regulates allowable recycle practices
at treatment plants. The intent of the FBRR is to encourage implementation of recycle practices that do
not negatively impact performance of a treatment plant. In other words, facilities operated using practices
consistent with the FBRR should achieve equivalent, or superior performance to the same facility
operated without recycle. Consequently, other regulations do not need to incorporate provisions for
recycling because all consequences of recycling practices are accounted for in systems complying with
the FBRR.
Cornwell and MacPhee 2001, Cornwell et al. 2001, and Nieminski and Bellamy 2000 provide data
supporting the contention that recycle practices consistent with FBRR do not negatively impact
performance of clarification systems, or the combined performance of a clarification plus filtration
system. Cornwell et al. and Cornwell and MacPhee reported results from pilot studies involving impact of
SFBW recycle on a system with clarification (plate settler) followed by a dual media filter.,, Aerobic
spore and Cryptosporidium data from these published papers is summarized and analyzed in Appendix 1.
AWWA concludes from this analysis and our previous experience reviewing the Filter Backwash Recycle
Rule (FBRR) that recycle issues are adequately addressed in context of FBRR and should not be part of
LT2ESWTR.
Response: See Response 346.
Comment Response for the LT2ESWTR 5-115 December 2005
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EPA Letter ID: 585
Comment ID: 11969
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47678 [and §141.704(a), (c), & (e) on p. 47778-9]
The TCEQ does not concur with the proposal to require Cryptosporidium to be sampled prior to the
addition of reclaimed water. This approach is inconsistent with mandates to sample downstream of an
existing "raw water off-stream storage" reservoir, an existing presedimentation basin (where a coagulant
is being applied), or an existing sample tap that is located downstream of a location where multiple
sources (including groundwater and surface water sources) are blended. In many cases, reclaimed water is
returned to a point upstream of these designated sampling sites.
Response: See Response 346.
EPA Letter ID: 591
Comment ID: 12124
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Ohio EPA agrees with the monitoring location proposed in the LT2ESWTR regardless of filter backwash
recycling practices.
Response: See Response 346.
EPA Letter ID: 593
Comment ID: 11823
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: D. Filter Backwash Recycle
1. Accounting for Recycle Practices: The Filter Backwash Recycle Rule (FBRR) is to encourage
implementation of recycle practices that do not negatively impact performance of a treatment plant.
Consequently, other regulations do not need to incorporate provisions for recycle because all
consequences of recycle practices are accounted for in systems complying with the FBRR. SAWS-
recommends that monitoring should be before recycle and that any unusual situations should be addressed
by a site-specific sampling plan.
2. Provisions that exclude returned decant storage for Groundwater production plants: EPA has not made
any provisions that would eliminate recycled-decant storage water, in open reservoirs, to be returned to
the water treatment plant. This is done to control liquid levels in reservoirs and balance sludge returns.
However, the FBRR indicates that any systems that recycle regardless of population are subject to the
Comment Response for the LT2ESWTR 5-116 December 2005
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rule. Moreover; the decant return liquid volumes, compared to most groundwater production are minimal
and does not seem to be a deterrent that would require any additional treatment. SAWS recommends that
decant storage waters be allowed into the process with out the mitigation of the FBRR, if the primacy
agency determines ratios and amounts of water returned to the process are not affecting the finished water
(established by sampling). Furthermore, the Groundwater process could have additional treatment that
could inactivate or remove Giardia and Cryptosporidia successfully in the low volumes that would be
present in the decant return water. In theses circumstances; SAWS further recommends that, the
maximum return rate (of decant water) be established by a registered professional engineer. In theses two
cases; SAWS recommends that, the FBRR not apply to the open reservoirs return decant water.
Response: See Response 346.
EPA Letter ID: 595
Comment ID: 12582
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Monitoring for systems that recycle filter backwash water
Maine needs flexibility to determine how to address any issues with recycled filter backwash water on a
case-by-case basis.
Response: See Response 346.
EPA Letter ID: 601
Comment ID: 13011
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on monitoring for systems that recycle filter backwash
(page 47678)
Utah contends that this issue was previously resolved when treatment plants submitted data to comply
with the Filter Backwash Recycle Rule, and should not be included in the LT2ESWTR.
Response: See Response 346.
EPA Letter ID: 609
Comment ID: 14117
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-117 December 2005
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Comment: Monitoring For Systems That Recycle Filter Backwash
The MDEQ believes the states should be allowed to determine on a case-by-case basis consideration of
the recycle stream. It may be appropriate to sample downstream of the recycled flow or to sample the
recycled flow separately. It may be acceptable to collect samples from both the source water and the
recycle stream and analyze a weighted composite. The MDEQ believes this should be addressed as
guidance in the Source Water Monitoring Guidance Manual rather than by rule.
Response: See Response 346.
EPA Letter ID: 614
Comment ID: 12974
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Filter Backwash Recycle
* This regulation does not need to incorporate provisions for recycle as all consequences of recycle
practices are accounted for in systems complying with the Filter Backwash Recycle Rule (FBRR).
Response: See Response 346.
EPA Letter ID: 620
Comment ID: 13309
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 1: Accounting for Recycle Practices in LT2 Monitoring.
Comments: Facilities operating under the existing Filter Backwash Recycle Rule should be considered
equivalent to those without recycle. SPRWS believes adequate coverage exists in the Backwash Rule and
no further requirement is needed in LT2SWTR.
Response: See Response 346.
EPA Letter ID: 625
Comment ID: 13144
Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: B. Filter Backwash Recycle
1) Accounting for Recycle Practices in LT2 Monitoring
The Authority believes all issues involving recycle should be contained in the Filter Backwash Recycle
Comment Response for the LT2ESWTR 5-118 December 2005
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Rule (FBRR) to avoid confusion by utilities in complying with the various regulations. Monitoring for
Cryptosporidium should be before recycle to characterize the influent water to the plant.
Response: See Response 346.
EPA Letter ID: 629
Comment ID: 12831
Commenter: Melinda Rho, Manager of Regulatory Affairs and Consumer Protection, Los Angeles
Department of Water and Power
Commenter Category: Regulated Community (Utilities)
Comment: Effects of Filter Backwash Recycle Water
EPA requested comments on how the effects of recycling filter backwash should be
in LT2ESWTR monitoring.
LADWP believes that the Filter Backwash Recycle Rule (FBRR) regulates allowable
recycle practices at treatment plants. The intent of the FBRR is to encourage implementation of recycle
practices that do not negatively impact performance of a treatment plant. Facilities operated using
practices consistent with the FBRR should achieve equivalent, or superior, per the same facility operated
without recycle. Consequently, other regulations do I incorporate provisions for recycle because all
consequences of recycle practices are accounted for in systems complying with the FBRR. LADWP
practices recycling of backwash water, as water conservation is a necessity for water systems in arid
southwest states.
Monitoring is intended to characterize influent water to the plant. Therefore, monitoring should logically
be conducted before recycle. In order to evaluate any unusual situations, LADWP recommends that
review and approval of the LT2ESWTR monitoring plan should be done by the primacy agency prior to
the initiation of the required monitoring.
Response: See Response 346.
EPA Letter ID: 630
Comment ID: 13075
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: D. Filter Backwash Recycle
Background: EPA asks how the effects of recycling filter backwash should be
considered in LT2ESWTR monitoring.
1. Filter Backwash Recycle Key Issue Accounting for Recycle Practices in LT2 Monitoring: EPA asks
how the effects of recycling filter backwash should be considered in LT2ESWTR monitoring. Allowable
recycle practices at treatment plants are regulated by the Filter Backwash Recycle Rule (FBRR). The
intent of the rule is to encourage implementation of recycle practices that do not negatively impact
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performance of a treatment plant. In other words, facilities operated using practices consistent with the
filter backwash rule should achieve equivalent, or superior, performance to the same facility operated
without recycle. Consequently, other regulations do not need to incorporate provisions for recycle
because all consequences of recycle practices are accounted for in systems complying with the filter
backwash rule.
Monitoring is intended to characterize influent water to the plant, monitoring should therefore normally
be before recycle. The recommendation in Monitoring Key Issue 6 Monitoring Location above
concerning system selection of an appropriate site subject to state review is sufficient to cover any
anomalous situations.
Response: See Response 346.
EPA Letter ID: 635
Comment ID: 13112
Commenter: Robert A. Hollander, Compliance and Regulatory Affairs Administrator, City of Phoenix,
Water Services Department
Commenter Category: Regulated Community (Utilities)
Comment: A system's routine operating procedures should determine the sampling point and
the award of the additional presumptive Cryptosporidium removal credit for presedimentation. The
impact of the Filter Backwash Recycle Rule (FBRR) must be considered in selecting the sampling point.
The intent of the FBRR is to ensure that recycle flows are introduced at the beginning of the treatment
process which is typically presedimentation. Because recycle flows have the potential tointroduce
additional Cryptosporidium oocysts, facilities that recycle should
sample downstream of the presedimentation basins.
Response: See Response 346.
EPA Letter ID: 637
Comment ID: 13084
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on monitoring for systems that recycle filter backwash
(page 47678)
This is only an issue for a system with higher bin classifications and is not related to whether a system
recycles or not. The Filter Backwash Recycle Rule will ensure that all recycle flows will be treated and
returned appropriately for this issue and it should not be addressed in this rule.
Response: See Response 346.
Comment Response for the LT2ESWTR 5-120 December 2005
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EPA Letter ID: 641
Comment ID: 13593
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Systems That Recycle Filter Backwash - These systems should collect LT2 samples
after (downstream of) addition of filter backwash to the influent flow, and be classified according the
source water + filter backwash water results. To sample only the source water would not adequately
reflect the water feeding the plant.
Response: See Response 346.
EPA Letter ID: 643
Comment ID: 12771
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Monitoring for systems that recycle filter backwash water
Although consideration of the recycle stream may not be necessary in all situations, states need flexibility
to determine how to address recycle streams in those instances where the state deems such action to be
necessary. In some cases, monitoring downstream of the introduction of the recycle flow would be
appropriate, while in other cases, supplemental monitoring on the return stream may be more suitable.
Response: See Response 346.
EPA Letter ID: 646
Comment ID: 13568
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: that has undergone pretreatment. Influent water quality should include filter
backwash recycle flows (note comment below). Include in the compliance schedule
Response: See Response 346.
EPA Letter ID: 646
Comment ID: 13572
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
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Comment: Filter Backwash Monitoring - The recycle backwash rule requires that the
Reintroduction point of the recycle water is prior to the convention treatment train. Monitoring of influent
water quality should include flows of the recycle stream.
Response: See Response 346.
EPA Letter ID: 647
Comment ID: 12917
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Monitoring for systems that recycle filter backwash water
Although consideration of the recycle stream may not be necessary in all situations, states need flexibility
to determine how to address recycle streams in those instances where the state deems such action to be
necessary. In some cases, monitoring downstream of the introduction of the recycle flow would be
appropriate, while in other cases, supplemental monitoring on the return stream may be more suitable.
Response: See Response 346.
EPA Letter ID: 660
Comment ID: 14072
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on monitoring for systems that recycle filter backwash
(page 47678)
This issue was dealt with sufficiently in the Filter Backwash Recycle Rule and should not be included in
the LT2ESWTR.
Response: See Response 346.
EPA Letter ID: 662
Comment ID: 14031
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on monitoring for systems that recycle filter backwash
(page 47678)
This monitoring is addressed in the Filter Backwash Rule.
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Response: See Response 346.
EPA Letter ID: 664
Comment ID: 14051
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Monitoring For Systems the Recycle Filler Backwash Water
For those systems where filtered backwash water is returned to the process, if the raw water monitoring is
conducted after the return of the recycle stream, several issues would arise:
- Many of the source water (raw water) monitoring issues raised under other sections of the Rule would
not apply.
- If the filter backwash water were returned to the point of initial chemical addition (ie, rapid mix basin),
it would be difficult to obtain a representative raw water sample, as the sample would be influenced by
coagulant chemicals and the hydraulic effects of a fully mixed basin.
If a system were to recycle its backwash water, certainly all of the issues relating to raw water monitoring
at the source would be moot, as well as the concerns with cryptosporidium monitoring of a highly turbid
source. Since there is most always some form of pretreatment with chemicals provided after the raw water
intake and prior to addition of the primary coagulant and return of the filter backwash water, the effect of
monitoring at this location would likely be different than directly at the raw water intake. This does seem
to be the intent of this Rule, however.
Response: See Response 346.
EPA Letter ID: 667
Comment ID: 14017
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: D.
1. Monitoring of influent water should be done before backwash recycling since backwash is already
regulated by the Filter Backwash Recycle Rule.
Response: See Response 346.
EPA Letter ID: 668
Comment ID: 13893
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment Response for the LT2ESWTR 5-123 December 2005
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Comment: PDF FILE]). In addition, monitoring should occur after any backwash is added,
or the monitoring will present an unrealistic and unrepresentative picture of the quality of the water that is
being treated, (p. 47678)
Response: See Response 346.
EPA Letter ID: 668
Comment ID: 13906
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - The rule should require monitoring of the water after any backwash is added,
or the monitoring will present an unrealistic and unrepresentative picture of the quality of the water that is
being treated, (p. 47678)
Response: See Response 346.
EPA Letter ID: 673
Comment ID: 13981
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on monitoring for systems that recycle filter backwash
(page 47678)
Jordan Valley Water contends that this issue has been adequately addressed by the Filter Backwash
Recycle Rule, and should not be included in the LT2ESWTR.
Response: See Response 346.
EPA Letter ID: 678
Comment ID: 14707
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. The EPA requests comment how the effect of recycling filter backwash
should be considered in LT2 monitoring. [47678, C3]
Comment: Allowable recycle practices at treatment plants are regulated by the Filter Backwash Recycle
Rule (FBRR). The intent of the FBRR is to encourage implementation of recycle practices that do not
negatively impact performance of a treatment plant. In other words, facilities operated using practices
consistent with the FBRR should achieve equivalent, or superior, performance to the same facility
Comment Response for the LT2ESWTR 5-124 December 2005
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operated without recycle. Consequently, other regulations do not need to incorporate provisions for
recycle because all consequences of recycle practices are accounted for in systems complying with the
FBRR. It would only get cumbersome and confusing to try and squeeze in too many requirements,
making source water sampling extremely difficult. To simplify, we recommend the Cryptosporidium
samples be taken before the point of filter backwash. We urge the EPA to leave the regulation of filter
backwash recycle to the FBRR. Any anomalous monitoring situations should be subject to review by the
State Primacy Agency.
Response: See Response 346.
EPA Letter ID: 711
Comment ID: 16562
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 3. EPA requests comment how the effect of recycling filter backwash should be
considered in LT2 monitoring. [47678, C3]
Comment: There is already a Filter Backwash Recycle Rule (FBRR) in effect from the EPA addressing
the effects of recycling filter backwash water. Therefore, LT2 should not repeat or muddle the existing
FBRR. It would only get cumbersome and confusing trying to squeeze in too many requirements making
source water sampling a nightmare. At this point, the Crypto samples need to be taken before any
treatment and it would be difficult if it were to change to be after the
point of filter backwash return since many systems could have chemical addition before that point. We
need to leave filter backwash recycle requirements to the FBRR.
Response: See Response 346.
5.5.7 Comment Code 347, Sampling one source with multiple intakes
Summary of Issues
Comments were received concerning the sampling of one source with multiple intakes. Several
commenters were interested in the situation where a single PWS has multiple intakes on the same source
which are located in different areas. One commenter requested flexibility in situations where multiple
systems took water from the same source to avoid sampling redundancy.
Response to Code 347
One plant, multiple intakes
For plants that use multiple water sources at the same time, PWSs must collect samples from a tap where
the sources are combined prior to treatment, if available. If a blended source tap is not available, PWSs
must collect samples from each source and either analyze a weighted composite (blended) sample or
analyze samples from each source separately and determine a weighted average of the results. The
weighting of sources must reflect the relative usage of the different sources by the treatment plant at the
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time the sample is collected.
Multiple systems drawing from the same source
In general, sampling must be performed for each plant that treats a surface water or GWUDI source.
However, where multiple plants receive all of their water from the same influent, such as plants that draw
water from the same intake or pipe, the State may approve one set of monitoring results to be applied to
all plants. These situations should be described in the sampling location description that the PWSs submit
prior to beginning sampling.
Individual Comments on Code 347
EPA Letter ID: 409
Comment ID: 10483
Commenter: Leslie Gryder,, City of Lynchburg Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Also, we have two intakes at this secondary source, approximately 15 miles apart, if we are
required to monitor this source would we have to monitor at both intakes.
Response: See Response 347.
EPA Letter ID: 473
Comment ID: 10712
Commenter: Mary Carol Wagner, Water Quality Manager, Northern Kentucky Water District
Commenter Category: Regulated Community (Utilities)
Comment: Another point that we would like to see addressed is the monitoring locations.
We need to have a more defined monitoring location and the consideration of allowing a utility that has
two treatment plants on the same source but not the same intake within a reasonable distance to combine
the sampling to one representative sampling location. This will help cut some of the cost for the utility.
The laboratory cost for each utility monitoring for the LT2ESWTR is
going to be an additional financial issue. Any combined sampling that can be accepted will be very
helpful.
Response: See Response 347.
EPA Letter ID: 493
Comment ID: 11246
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment: generally enters the distribution system by one common pipe-. In such a case, you may have
more than one intake pipe in the source water; however, the intake pipes would be very close, within feet,
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of one another. In such cases, the rule should allow the PWS to only collect one set of source water
monitoring samples if the intakes are located at essentially the same latitude/longitude on the same
source. When plant intakes located on the same source are miles from one another, of course, source
water samples would then need to be collected individually.
Response: See Response 347.
EPA Letter ID: 561
Comment ID: 12232
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 4101. Second Round of Monitoring
Comment: On-Going Source Assessment & Second Record of Monitoring
If there are multiple users of a single water supply source, where more than one water supply is obtained
from the same source and the initial two years of monitoring has adequately characterized the source
water quality, we would suggest that requiring a full second round of sampling from each user at a future
date is redundant. Perhaps a single set of monitoring would be conducted at that future date to compare to
the data obtained from the initial set of monitoring. Please provide flexibility here to reflect this scenario.
Response: See Responses 410(A).
5.6 Comment Codes 360, Sampling Schedule
Summary of Issues
Comments were submitted concerning the Cryptosporidium monitoring sampling schedule. Many
commenters requested that PWSs be given greater flexibility in scheduling sampling dates to collect
samples. In addition, commenters identified situations that interfere with sample collection, such as plant
interruptions and laboratory or transportation problems, and noted that some of these are outside the
conditions under which the proposal allowed a PWS to collect a delayed or replacement sample without
penalty. Several comments also requested more flexibility in the allowable timeframe for situations where
resampling is needed. Multiple commenters expressed the concern that a PWS's sampling schedule
should be approved by the primacy agency prior to the beginning of sampling. One commenter inquired
as to the rule's approach to systems which only operate for a portion of the year. A commenter also
suggested that PWSs build dates into the sampling schedule to account for missed samples that may occur
during the required monitoring.
Response to Code 360
(A) Sampling schedule flexibility, 5-day sampling window and replacement samples
EPA disagrees with commenters who suggest that the sampling schedule requirements and the 5-day
window for sampling do not provide sufficient sampling flexibility. EPA believes that for routine sample
collection, a 5-day window provides sufficient flexibility, given that PWSs will pick the sampling days
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and can schedule around holidays, weekends, and other times when sampling would be problematic.
Today's rule also allows PWSs to sample outside of this window without penalty if necessary due to
unforeseen emergency conditions such as floods, storms, power outages, etc. Further, if a PWS collects a
sample but is unable to have it analyzed due to problems with equipment, transportation or at the
laboratory, today's rule allows the PWS to collect a replacement sample without penalty. PWSs also have
the flexibility to collect more samples than are required if the sampling frequency is evenly spaced
throughout the monitoring period. PWSs also have the flexibility to select sampling dates that meet their
needs, for example, selecting the first Tuesday of every month, or selecting the 15th of every month.
EPA considers it preferable for PWSs to collect missed or replacement samples as close as is feasible to
scheduled sampling dates. However, if there is a significant delay with respect to the original sampling
date, collecting make-up samples at an alternate time may be appropriate to ensure that sampling results
are seasonally representative. Therefore, today's rule requires PWSs to collect a missed sample as close
as is feasible to the scheduled sampling date, and to collect replacement samples within 21 days of
receiving notification from the laboratory that one is needed, unless doing so within this time frame is not
feasible. This is a minor change from the proposal, which allowed only 14 days. However, the State can
approve alternative sampling dates. EPA expects that States will grant such approval where necessary to
ensure that sampling is seasonally representative. This could include sampling during the same time in the
following year if the missed sample occurred during the first year of monitoring, or sampling after the end
of the scheduled monitoring period.
EPA also disagrees with commenters who suggest that the sampling schedule must be flexible enough to
allow PWSs to change sampling dates to collect samples during worst-case conditions. As discussed in
the preamble to the proposed rule, EPA believes that the mean Cryptosporidium level in a system's
source water is the appropriate metric to determine the need for additional treatment requirements.
Available data suggest that the mean concentration directly relates to the average risk of the exposed
population (i.e., drinking water consumers). Further, with a limited number of samples, the mean can be
estimated more accurately than a high result, such as a 90th percentile estimate, as the commenter
recommends.
For this reason, today's rule requires monitoring to be conducted according to a predetermined schedule.
EPA recognizes that Cryptosporidium levels will vary seasonally and in response to weather events like
storms. The Agency considered this variability when assessing the performance of the required
monitoring for bin classification. Sampling on a predetermined schedule will capture periods when
Cryptosporidium levels are higher and lower and provide the best representation of the mean. In contrast,
altering a schedule to collect samples during a storm when Cryptosporidium levels are expected to be
high, as a commenter recommends, would lead to an overestimate of the mean. Similarly, classifying
systems in a higher bin if their sampling doesn't include any significant storm events would not achieve
the goal of basing bin classification on the mean source water Cryptosporidium level.
(B) Approval of sampling schedule
PWSs must submit sampling schedules no later than three months prior to the date the PWS must begin a
round of monitoring. Unless the State approves an alternative procedure, large PWSs (serving at least
10,000 people) must report their sampling schedule for initial source water monitoring to EPA using the
LT2ESWTR electronic data reporting and review system described in the preamble. Schedules for initial
monitoring by small PWSs and for the second round of monitoring by all PWSs must be reported to the
State. PWSs should verify that their laboratory can accommodate the scheduled sampling dates before
submitting the schedule.
EPA will not formally approve sampling schedules but will notify PWSs if their sampling schedules do
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not meet the requirements of today's rule (e.g., do not include the required number of samples). If aPWS
does not receive notification from the State or EPA regarding the sampling schedule, the PWS must begin
monitoring according to the reported sampling schedule.
(C) Non-continuous monitoring (Part-year plants)
EPA agrees that monitoring of part-year plants under today's rule should be conducted only during
months when the plant is operating, unless the State determines that a longer monitoring period is
appropriate due to historical operating practices. Further, part-year plants should maintain the same
sampling frequency as plants operating year-round, with the exception that plants monitoring for
Cryptosporidium must collect at least six samples per year to allow for appropriate bin classification. EPA
does not believe extending monitoring over more years in part-year plants is appropriate, as this would
delay the installation of additional treatment where needed.
Individual Comments on Code 360
EPA Letter ID: 439
Comment ID: 10753
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: Also, water systems should not be held responsible for missing sample results due to lab
failures. Sampling schedules should be flexible to allow for extra sampling events as needed.
Response: See Response 360(A).
EPA Letter ID: 442
Comment ID: 10784
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: 40CFR141.703 Sampling Schedules
The EPA requirement for cryptosporidium sampling within two days of the dates indicated in the
sampling schedule seems arbitrary. It seems more important to require sampling to be based on source
water conditions. Samples collected when cryptosporidium may be at its highest concentration would
seem to be more important from a public health protection standpoint. Consumers do not drink average
water. They drink water that is supplied at their taps. Infectious
doses of cryptosporidium are not likely due to average concentrations. Infectious doses are most likely to
occur during worst-case source water conditions. Samples should also be collected if there is a POTW
bypassing upstream or other incidents that could be expected to increase the
cryptosporidium concentration in the source water such as failure of a dam on a CAFO manure lagoon.
The goal of the regulation should be to describe the worst case conditions so that treatment plants could
protect public health at all times regardless of source water conditions. Exceptions could be made for
systems that can purchase water from other utilities or that have an alternate protected source.
Response: See Response 360(A).
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EPA Letter ID: 444
Comment ID: 10808
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment: a. NH has several small and large surface water systems which switch seasonally
between or among water sources. In some cases, the switch is governed by contractual constraints, where
in others the switch is governed by precipitation, source yield and water quality. NH finds that either of
the options outlined in the proposed rule is acceptable under certain circumstances, but we urge flexibility
in the final rule for the state to allow waivers or
modification of the sampling schedule to accommodate a wide range of alternate source use strategies.
Response: See Response 360(C).
EPA Letter ID: 485
Comment ID: 11283
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: The Department would also recommend that documentation concerning the ability of
the recommended monitoring frequency to catch a pathogen loading incident such as occurred in
Milwaukee in April 1993 be explained in the language justifying the rules suggested monitor frequencies.
If such pathogen loading storms may not be detected, how can one be assured that the public will be
adequately protected with the proposed bin classification and treatment plant reduction requirements?
Response: See Response 360(A).
EPA Letter ID: 499
Comment ID: 10722
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: measured is the same whether the source is a lake, stream, or GWUDI. Also,
additional flexibility for sampling during times of potentially heightened Cryptosporidium occurrences
should be provided wherever possible. The timing of samples which are collected is more important than
a strict adherence to a preplanned schedule which is adopted years in advance of anticipated uses.
Response: See Response 360(A).
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EPA Letter ID: 509
Comment ID: 11480
Commenter: Greg Parker,, Florida Department of Environmental Protection Drinking Water Program
Commenter Category: State/Tribe Government
Comment: 141.703 Allow for some flexibility in sampling schedules to ensure that systems
can sample source water shortly after rainfall events rather than on a fixed day.
Response: See Response 360(A).
EPA Letter ID: 512
Comment ID: 11507
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: b. A break in sequence of samples currently has unreasonable implications that
could place a Public Water System (PWS) in Bin 4 with no added public health
benefit, and no scientific justification but with significant public cost.
Response: See Responses 360(A) and 440 (regarding automatic bin-4 classification for failure to
complete monitoring).
EPA Letter ID: 512
Comment ID: 11509
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: d. Provisions for replacement samples at the end of the monitoring period to make up for
samples that could not be re-sampled in a reasonable timeframe must be implemented
Response: See Response 360(A).
EPA Letter ID: 527
Comment ID: 10853
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: options should additional treatment become necessary. Because of the many
different situations expected to occur in selection of monitoring sites, we strongly recommend that the
compliance schedule be modified to incorporate review and approval of the LT2ESWTR monitoring plan
by the primacy agency prior to initiation of the required monitoring.
Response: See Response 365.
Comment Response for the LT2ESWTR 5-131 December 2005
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EPA Letter ID: 527
Comment ID: 10853
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: options should additional treatment become necessary. Because of the many
different situations expected to occur in selection of monitoring sites, we strongly recommend that the
compliance schedule be modified to incorporate review and approval of the LT2ESWTR monitoring plan
by the primacy agency prior to initiation of the required monitoring.
Response: See Response 365.
EPA Letter ID: 556
Comment ID: 12055
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA must acknowledge that missed samples will happen. We suggest that, in
addition to broadening the proposed re-sampling provisions, EPA have utilities build dates into their
sampling schedules for additional samples in the event of missed samples. (One possibility is to include
30 sampling dates in the monitoring schedule so that six extra dates above the minimum requirement of
24 be available if samples are missed).
Response: See Response 360(A).
EPA Letter ID: 560
Comment ID: 14979
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Four - Procedures for Replacement Samples:
American Water is very concerned that the Agency-s current interpretation that the 24 month sampling
period must be an unbroken record of samples. This requirement is without basis in the Agreement in
Principle or implementation logistics. As currently written §141.703(c)-(d), the Rule anticipates that
replacement samples may be needed, but does not allow sufficient flexibility in planning for replacement
samples. Already, American Water has encountered situations in its LT2 (grandfather) monitoring
program where emergencies (power outages) required operators to forego sample collection in order to
focus on the safe operations of the treatment plant. Many other problems have been encountered with
receipt of samples outside the acceptable temperature range. Anticipating that as many as 10% of the
samples may be problematic, EPA should automatically add a 3-month window to the end of the 24
month sampling schedule for resampling any lost due to circumstances beyond the control of the system.
Comment Response for the LT2ESWTR 5-132 December 2005
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If more than 10% of the samples require replacement, then the system would have to contact EPA for a
readjustment of the sampling schedule.
Response: See Response 360(A).
EPA Letter ID: 562
Comment ID: 12382
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.1.2 Sample Schedule
The approach to sample scheduling outlined in proposal fact sheet is sound assuming the Office of
General Counsel (OGC), the Office of Enforcement and Compliance Assistance (OECA), and state
primacy agencies understand the deliberate openness in the way the requirements are written.
Response: See Response lOOa.
EPA Letter ID: 593
Comment ID: 11818
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: within the proposal and the present provision is unacceptable. This approach will change the
historical approach EPA has used to acknowledge that 99% of systems will make a good faith effort to
comply with rules and should not be inappropriately penalized if operating in good faith. The failure to
complete monitoring, which could happen for any number of innocent reasons, should not require
maximum treatment. In addition, it is appropriate to maintain the general relationship of trust with the
drinking water community rather than implement actions, which imply an adversarial relationship.
Therefore, SAWS recommends the following: Use existing compliance procedures coupled with a
system-s rights to appeal noncompliance decisions. Any problems of non-compliance should be
addressed with the mechanisms already in place for such a violation. Reasonable provisions should be
provided for re-sampling Have
utilities build dates into their sampling schedules for additional samples in the event of missed samples,
and provide reasons why the samples were missed. Make reasonable provisions for make-up samples.
Response: See Response 360(A).
EPA Letter ID: 601
Comment ID: 13007
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-133 December 2005
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Comment: Utah recommends that additional clarification be added regarding the requirement
to collect samples on a particular date. It is unclear whether systems must choose a specific date each
month, or if a consistent day of the month meets this requirement.
Response: See Response 360(A).
EPA Letter ID: 610
Comment ID: 12985
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: As we read the text, twenty-four (24) monthly samples will be required along
with two (2) spike samples. These monthly samples must be taken within forty-eight (48) hours of a
specific day. The City of Monroe treats its intakes in Lake Erie for Zebra Mussel Control. The treatment
requires a minimum 6-week treatment which will make taking unchlorinated raw water samples a
problem. (Per Rule 1.2.2.2/141.704 the samples must be taken prior to any treatment technologies). We
believe a more appropriate sampling regiment would be during a
two week interval every quarter. Further, the rules should not unfairly penalize
Response: See Response 360(A).
EPA Letter ID: 618
Comment ID: 13249
Commenter: Craig Bryant, Director, Chesterfield County Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: We suggest a two-week window around submitted sampling dates to collect samples
and a two-week repeat sample collection window when the contract lab does not accept samples. In
addition, samples lost due to contract laboratory error should cease to be a compliance issue. Instead, an
additional sample date shouldbe added to the end of the sample schedule.
Response: See Response 360(A).
EPA Letter ID: 620
Comment ID: 13292
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: minor procedural error. The penalty does not fit the crime. It is common for
laboratories to occasionally lose samples or for samples to be lost or destroyed in transit. The EPA should
allow for such incidents by providing additional dates on the sampling calendar for "make up" sampling.
Comment Response for the LT2ESWTR 5-134 December 2005
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Response: See Response 360.
EPA Letter ID: 624
Comment ID: 13187
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 4. Missed Sampling: We feel that water utilities should not be held responsible for missed
sampling or sample results due to commercial laboratory errors/failures. We hope that such issues are
addressed by EPA in the sampling requirements taking into account that samples are and missing them
generally impact public health. EPA should build into their sampling schedule additional samples in the
event of missed sample(s), and require utilities to provide reasons as to why the samples were missed.
Response: See Response 360(A).
EPA Letter ID: 631
Comment ID: 13233
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: Sample collection can be impacted by unexpected or emergency situations at a
treatment plant or with treatment plant staff that must be the priority. EPA
Response: See Response 360(A).
EPA Letter ID: 631
Comment ID: 13235
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: A sample schedule might be missed due to unavoidable problems in transporting
samples to an out of state laboratory (Le. the United Parcel Service strike that prevented timely submittal
of Information Collection Rule samples), insufficient laboratory capacity, or a laboratory that is
overworked and misses holding times. Water systems should not be held responsible far missing sample
results due to lab failures.
Response: See Response 360(A).
EPA Letter ID: 633
Comment ID: 13267
Comment Response for the LT2ESWTR 5-135 December 2005
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Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: a violation. Reasonable provisions should be provided for re-sampling.
Response: See Response 360(A).
EPA Letter ID: 641
Comment ID: 13583
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: -Scheduled sampling dates should be (insert: approximately) evenly distributed
throughout the monitoring period, but may be arranged to accommodate holidays-.-
Response: See Response 360(A).
EPA Letter ID: 653
Comment ID: 14063
Commenter: Tim Stefanich, Environmental Engineer, Sioux Falls Water Purification, City of Sioux Falls
Commenter Category: Local Government
Comment: It is suggested that EPA clarify how systems can build in extra sampling times into their
sampling schedules in the event of a missed sampling event. One suggestion is for those systems that
want to sample twice per month - go to every other week sampling. This will build 2 extra samples into
their sampling schedule every year.
For those systems that plan to sample monthly - suggest taking an extra sample during two of the months
that contain more than 4 of the days that they select for sampling. Ex. If the water system selects the
second Wednesday of every month, then they should select two months where more than 4 Wednesdays
occur during the year (in 2004 that includes March, June, September, and December.) It would be up to
the system to select which months they will collect the extra sample and report this to EPA.
Response: See Response 360(A).
EPA Letter ID: 662
Comment ID: 14028
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Monitoring locations and schedules should be appropriately established with
recognized flexibility when circumstances arise (like lost samples, construction impacting sampling sites,
Comment Response for the LT2ESWTR 5-136 December 2005
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or laboratory error) that do not automatically influence the Bin placement of the entity. The monthly
window sampling
Response: See Responses 360(A) and 440.
EPA Letter ID: 667
Comment ID: 14009
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: 3. Provision should be made for good faith efforts and situations beyond ones
control which could result in a monitoring violation.
4. Allow more flexiblity for sample collection.
Response: See Response 360(A).
EPA Letter ID: 673
Comment ID: 13976
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
A. 3. Request for Comment
(pages 47678-47679)
EPA requests comment on all aspects of the monitoring and treatment requirements
proposed in this section.
(page 47678)
Jordan Valley Water recommends that clarification be added to the requirement to collect samples on a
particular date. It is unclear whether systems must choose a specific calendar date each month, or would
be able to choose a set day of the month. Jordan Valley Water recommends a set day of the month (i.e. the
2nd Tuesday of the month) would be more reasonable for both water systems and laboratories, and meet
the intent of the rule to sample at consistent intervals.
Response: See Response 360(A).
EPA Letter ID: 677
Comment ID: 13950
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
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Comment: 1. Continuous monitoring requirements for plants which are off-line for operational or
construction purposes (page 47678). USEPA will require 24 months of continuous data collection, with
either monthly or bi-weekly sampling. The purpose of this monitoring is to characterize the source water
levels of Cryptosporidium. The Proposed LT 2 Rule states that systems that are operated seasonally shall
only collect samples during periods of operation, during the 24-month period. There is no clear direction
on monitoring requirements for
plants that are periodically off-line, either for operational or construction purposes.
The City recommends that USEPA add text which indicates that plants which are off-line for operational
or construction purposes are not required to monitor during those months. The City also recommends that
water systems Comments on Proposed LT 2 Rule do not need to restart the monitoring program, rather
just continue the monitoring program for a total of 24 monthly samples. This will allow for breaks in
sample collection, while still requiring the full
24 samples to be collected for compliance calculations.
Response: See Response 360(A).
5.6.1 Comment Code 361, 5-day sampling window and allowable
exceptions
Summary of Issues
Comments were submitted concerning the five-day window in which a system must collect their samples
to avoid penalty. Several commenters requested that PWSs be given a time window larger than 5 days
around scheduled sampling dates to collect samples. Recommended alternatives included a 7 or 9-day
window, or only requiring that PWSs collect a sample within a specified month. In addition, commenters
identified situations that interfere with sample collection, such as plant interruptions and laboratory or
transportation problems, and noted that some of these are outside the conditions under which the proposal
allowed a PWS to collect a delayed or replacement sample without penalty. Commenters also disagreed
with the time frame for collecting missed or replacement samples, while recommending a number of
alternative approaches. These include adding extra sampling days to the original sampling schedule,
which a PWS could then use in the event of missed sampling dates, and allowing PWSs to collect make-
up samples either immediately after the scheduled sampling date or at the end of the monitoring period.
Response to Code 361
See Response 360(A)
Individual Comments on Code 361
EPA Letter ID: 101
Comment ID: 10875
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Sampling and Monitoring Plans
Small systems and State Primacy Agency's that collect samples for small systems have a difficult time
Comment Response for the LT2ESWTR 5-138 December 2005
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ensuring that samples are collected within the required month. It is unrealistic, problematic, and an
unachievable requirement for systems to collect a sample on a specified day. Systems can be encouraged
to collect samples on certain calendar schedules, but the rule should only require the sample be collected
within a specified month. Otherwise, every State and many systems will be heavily burdened with M&R
violations that do not reflect a decrease in public health protection. In addition, the rule should allow a
sample to be recollected within 30 days not the 14 days that has been proposed by EPA.
Response: See Response 360(A)
EPA Letter ID: 414
Comment ID: 10516
Commenter: John Amodeo, General Manager and Chief Engineer, Vista Irrigation District
Commenter Category: Regulated Community (Utilities)
Comment: 2.1 am also concerned that our treatment plant could go into a Bin 4
designation if we fail to meet certain source water monitoring parameters. For one issue, the timing to
perform some of the testing/lake sampling should give us more flexibility for each monthly reporting. I
can foresee problems in trying to maintain the tight schedule.
Response: See Response 360(A) and 440.
EPA Letter ID: 419
Comment ID: 10501
Commenter: Billy Turner, President, Columbus Water Works
Commenter Category: Regulated Community (Utilities)
Comment:
1) Failure to meet source water monitoring provisions should not trigger water treatment plant placement
in Bin 4. The Agency should revise the source water monitoring requirements reflecting more realistic
data quality and scheduling expectations. For example, the Agency should provide reasonable latitude in
available sampling period windows each month, sample temperature requirements, handling of missing
data, and acceptance of grandfathered data.
Response: See Responses 360(A), 381, and 440.
EPA Letter ID: 423
Comment ID: 10572
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: The EPA requirement for cryptosporidium sampling within two days of the dates indicated in
the sampling schedule seems arbitrary. It seems more important to require sampling to be based on source
water conditions. Samples collected when cryptosporidium may be at its highest concentration would
Comment Response for the LT2ESWTR 5-139 December 2005
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seem to be more important from a public health protection standpoint. Consumers do not drink average
water. They drink water that is supplied at their taps. Infectious doses of cryptosporidium are not likely
due to average concentrations. Infectious doses are most likely to occur during worst-case source water
conditions. Samples should also be collected if there is a POTW bypassing upstream or other incidents
that could be expected to increase the cryptosporidium concentration in the source water such as failure of
a dam on a CAFO manure lagoon. The goal of the regulation should be to describe the worst case
conditions
so that treatment plants could protect public health at all times regardless of source water conditions.
Exceptions could be made for systems that can purchase water from other utilities or that have an
alternate protected source. Monitoring violations should not occur in all cases where a system fails to
report the minimum number of samples required by the regulations. Multiple examples of EPA regulatory
flexibility can be found in the air regulations specifically at 40CFR50 and EPA document EPA-454/R-98-
004 Quality Assurance Handbook for Air Pollution Measurement Systems. The EPA by having inflexible
rules increases the number of reportable violations and does not necessarily indicate increasing adverse
public health consequences.
Response: See Response 361.
EPA Letter ID: 431
Comment ID: 10597
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Comment: Colorado Springs Utilities (PWSID # CO0121150) finds the proposed
requirement that systems collect samples within two days of their sampling schedule or be in
noncompliance to be unacceptable. For example:
- Plants going off-line or coming on-line due to both scheduled and unscheduled reasons such that a
scheduled sample collection date may be missed. Colorado Springs Utilities has four surface water
treatment plants of its own to sample as well as a fifth for another system.
- Laboratory or transport failures which prevent prescribed resampling due to inability to get sampling
equipment or due to laboratory capacity conflicts.
- Filtering apparatus failures and inability to get new units in time.
- Weather problems such as severe snowstorms which prevent employees from being able to get to work
or to get to the plants to perform sampling.
Colorado Springs Utilities has four surface water treatment plants of its own to sample as well as a fifth
for another system. Any one difficulty may result in a domino affect. Utilities making a reasonable good-
faith effort to comply need to be given reasonable alternatives. In order to accommodate the laboratory's
schedule, the sampling should be within seven day of the sampling schedule and failure to comply with
even that period should not lead to noncompliance if the
system has a good reason for missing the sample.
Response: See Response 360(A)
Comment Response for the LT2ESWTR 5-140 December 2005
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EPA Letter ID: 439
Comment ID: 10754
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: The proposal states that systems must sample within two days of the sampling
schedule or be deemed as non-compliant. This proposal is inappropriate for many reasons (seee above.)
Response: See Response 360(A)
EPA Letter ID: 440
Comment ID: 10800
Commenter: Gary Hum, Director of Source & Treatment, Central Arkansas Water
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 381 1. Sample acceptance criteria (frequency, volume,
analytical method); 1720 8. Other comments on use of Method 1623
Comment: 1. Cryptosporidium monitoring for bin placement: The source water monitoring requirements
should allow increased flexibility for sample collection and data quality. More latitude should be allowed
in regards to the available sampling period window, the sample temperature requirements, missing data,
and acceptance of grandfathered data.
Response: See Responses 360(A) and 381(A) and (B).
EPA Letter ID: 452
Comment ID: 10937
Commenter: Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Commenter Category: Regulated Community (Utilities)
Comment: Under 141.709(e),there are no assurances for replacement samples collected according to
141.703(c)and (d). For unavoidable conditions that prevent sampling according to the schedule, systems
must sample as close to the required date as possible and submit an explanation for alternative sampling
dates according to 141.703(c). However, there is no assurance that the alternative sampling dates will be
accepted and keep the system from automatic classification into Bin 4. The rule should affirm that a
system that submits alternative sampling (in compliance with the sampling schedule requirements) shall
not be automatically classified into Bin 4.
Response: See Responses 360(A) and 381.
EPA Letter ID: 452
Comment ID: 10938
Commenter: Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Commenter Category: Regulated Community (Utilities)
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Comment: Similarly, if a system is unable to report a valid Cryptosporidimn analytical result due to a
failure in quality control requirements (such as sample temperature greater than 10 degrees centigrade or
sample volume less than 10 liters), the system is required to collect a replacement sample within 14 days
of being notified by the laboratory (141.703(d)). The rule should affirm that the system that meets these
replacement sample requirements should not
automatically be placed in Bin 4.
Response: See Responses 360(A) and 440..
EPA Letter ID: 457
Comment ID: 11897
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: also strongly disagree with EPA-s proposal that a water system must take all microbial
samples within two days of the planned monitoring date. We recognize the need for the water systems to
collect an adequate number of samples and that the samples need to be distributed across the entire
monitoring period. However, it should also be recognized that the sampling dates can be missed due to
various unpredictable situations. The States can address these on a case-by case basis. We prefer to have
the flexibility to determine the consequences of a
missed sample or missed sampling dates on a case-by-case basis.
Response: See Response 360(A).
EPA Letter ID: 460
Comment ID: 10993
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: 3. Sampling Schedule:
City-s position: Samples could be collected anytime during a -sampling week-. Exceptions should be
allowed where good reasons exist for missing the deadline.
Response: See Response 360(A).
EPA Letter ID: 461
Comment ID: 10988
Commenter: Greg Merrigan, Chair, South Dakota Section of the American Waterworks Association
(SDAWWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-142 December 2005
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Comment Codes 300-471
Comment: Sampling Schedule - EPA states that systems must collect their samples within 2
days of the dates indicated in their sampling schedule (141.703 4 (b)). We feel that EPA should provide
more flexibility to water systems in collecting the required samples. When submitting a sampling
schedule, samplers are not going to know their vacation schedules or other requirements for the next two
years. Most systems are going to have one person who will be responsible for collecting the samples. If
that person is called away in and around the sampling time, there may be no one to collect the sample.
This is especially true for small systems, which have limited personnel and resources.
Also, based on the current language in the rule, if the system collects their sample on Monday, the only
option they have is to collect the sample on Tuesday or Wednesday (Most labs and couriers do not accept
shipments or samples on Saturday or Sunday). This limits most sampling to Monday thru Thursday each
week.
Response: See Response 360(A).
EPA Letter ID: 463
Comment ID: 11030
Commenter: Richard Wilson, Environmental Services Manager, Anaheim Public Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment: 3. Section 141.703(b) states, "Systems must collect samples within two days of the dates
indicated in their sampling schedule."
This requirement is excessively strict and doesn't appear justified. There should be an acceptable range of
plus or minus at least 7 days for the sampling requirement. This becomes extremely important if a single
act of non-compliance causes an automatic requirement for increased treatment.
Response: See Response 360(A).
EPA Letter ID: 466
Comment ID: 11008
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: additional protection against Cryptosporidium. However, the EPA requirement for
Cryptosporidium sampling within two days of the dates indicated in a sample schedule seems arbitrary. It
seems more important to require system-specific sampling based on source water conditions, such as a
period when Cryptosporidium may be at its highest concentration, than a pre-determined set date.
Response: See Response 360(A).
EPA Letter ID: 467
Comment ID: 11036
Comment Response for the LT2ESWTR
5-143
December 2005
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Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: beyond the utility-s control. For example, the requirements defines a very narrow sampling
window each month and very specific sampling locations. Although these requirements intend to limit
sampling manipulation, they sometimes create logistic problems for utilities. For instance, floods and
tornados have occurred in the LWC service area which would inhibit sampling. Monitoring requirements
LWC opposes this provision and asks EPA to remove it from the final rule. In addition, LWC suggests
EPA revise the source water monitoring requirements to reflect more realistic data quality and scheduling
expectations. For example, EPA should provide reasonable latitude in available sampling period windows
each month, sampling temperature requirements and handling missing data.
Response: See Response 360(A).
EPA Letter ID: 471
Comment ID: 11111
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: available if samples are missed). Also, the allowable timing of resamples currently proposed
makes this provision impractical and may unfairly put utilities at jeopardy of compliance. Therefore, we
suggest that the rule-s resample provision be extended beyond 2 days (to perhaps 3 or 4 days) and that a
system not be considered in non-compliance if there is a legitimate reason for missing the resample date.
We believe that this approach would be more
appropriate since it affirms the general relationship of trust with the drinking water community (which is
largely operating in good faith on these and other regulations).
Response: See Response 360(A).
EPA Letter ID: 474
Comment ID: 11193
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: In addition to our concern about how EPA proposes to deal with missed samples,
we are equally concerned with the consequence EPA is proposing for failing to meet the established
sampling schedule. We understand the intent behind the sampling design, and believe that most utilities
will bend over backwards to try to accomplish the required sample collection within the 2 days allowed.
But we believe that EPA needs to acknowledge that there are times when it simply may not be feasible (or
safe) to do so. It is totally inappropriate to penalize a
utility for this reality by requiring it to install the highest level of treatment, especially when current data
show that randomized sampling is equivalent if not superior to time-series sampling designs (Frey et al,
1998). Thus, providing some flexibility to be used in the event of unusual
circumstances would make sense to include in this rule.
Comment Response for the LT2ESWTR 5-144 December 2005
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We believe that it would be appropriate and prudent for EPA to make reasonable provisions for flexibility
regarding both the dates of sample collection and for re-sampling given that unforeseen circumstances
may (and do) happen. But, should a really egregious example of missed sampling or scheduling issues
occur, we recommend that EPA use existing compliance procedures coupled with a system's rights to
appeal these kinds of actions as a more appropriate action.
Response: See Response 360(A).
EPA Letter ID: 478
Comment ID: 11216
Commenter: Anonymous478,,
Commenter Category: Unknown
Comment: We agree that States and Systems should have more flexibility regarding the sampling dates.
Response: See Response 360(A).
EPA Letter ID: 480
Comment ID: 11229
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: While a utility may make every effort to sample on precisely the planned day of
a schedule developed one or two years in advance, operational realities, or failures in sample transport
and handling may preclude this, and the apparent penalties for failure are high. The following specific
recommendations are offered:
- Revise §141.703(b) from +/-two days to +/- four days.
- Revise §141.703(d) to allow a replacement sample if notified by the laboratory that a sample was
broken in transport, or failed to arrive, or some other unforeseen problem occurred. The current limitation
allowing replacement samples only in the event of analytical method requirements is too restrictive.
Response: See Response 360(A).
EPA Letter ID: 483
Comment ID: 11263
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: compliance decisions as a more appropriate action. Reasonable provisions should
be provided for resampling. The 2 day timeframe for sampling outside the predetermined sample schedule
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should be extended to plus or minus 3 or 4 days, as 2 days is unreasonable. Also, water utilities should not
be held responsible for missing sample results due to lab failures. EPA should make reasonable
provisions for make-up samples.
Response: See Response 360(A).
EPA Letter ID: 491
Comment ID: 10662
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: conditions. However, sometimes a sample can be missed, even by those with the
best intentions, due to resource constraints or other legitimate reasons. EPA
2. A larger window around the scheduled source water sample dates for collecting samples should be
allowed. Allowing systems to deviate only two days before or after the scheduled sample date does not
allow enough flexibility in the event of unplanned plant shutdowns, short-term staffing problems, and
unexpected emergencies. The time frame allowed should be widened to three or four days before and
after the scheduled sample date. If this is not possible, at the very least, the two days allowed should
include the two business days prior to and following the scheduled date to accommodate systems that
plan sampling events at the beginning or end of the week and do not have the option to reschedule to a
weekend day. In addition, utilities should be allowed to reschedule sampling dates if the need for an
extended plant shutdown arises.
Response: See Response 360(A).
EPA Letter ID: 496
Comment ID: 10691
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: There are many justifiable reasons that a sample could be missed, not the least of
which is the possibility of insufficient laboratory capacity, or a laboratory that isoverworked and misses
holding times or similar requirements. EPA allows for
Water utilities should not be held responsible for missing sample results due to lab failures. In addition,
EPA should allow for the probability that missed samples do sometimes happen. EPA should have
utilities build dates into their sampling schedules
(because of Bin 4 placement), this is completely inappropriate. There are many valid reasons for not being
able to sample within 2 days. Moreover, this requirement insinuates that water systems might "game" the
system by monitoring when they know that Cryptosporidium is present. Current data shows that random
sampling is equivalent, if not superior to, time-series sampling designs.
Response: See Response 360(A).
Comment Response for the LT2ESWTR 5-146 December 2005
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Comment Codes 300-471
EPA Letter ID: 502
Comment ID: 10633
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: 3. Sampling Schedule: The proposed rule requires systems to collect samples
within 2 days of their sampling schedule or they will be considered in noncompliance. We currently
sample the first and second Monday of every month, but occasionally we may have to change our
sampling schedule to meet staffing or contract laboratory-s needs. A window of at least 3 or 4 days would
be more reasonable. We would like to request consideration of a schedule based on a monthly sample (ie.
first Monday), as opposed to every 30 days. Also, failure to
comply with the sampling window should not result in automatic bin 4 classification if the system has a
valid reason for missing the dates and is willing to document such reason.
Response: See Response 360(A).
EPA Letter ID: 504
Comment ID: 11361
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 381 1. Sample acceptance criteria (frequency, volume,
analytical method)
Comment: 5. Sampling Flexibility
Sampling requirements are rigid and do not allow for factors out of water utility control. We do not
disagree with the basic logic of asking sampling to be conducted on a fixed and predetermined schedule
in so far as practical. However, we believe that all of the objectives of the regulation can be met fairly and
accurately by providing for sampling flexibility to accommodate the exigencies of sample collection by a
utility with many water quality needs and many existing regulations that must be met. This is particularly
important to judging the acceptability of data collected prior to rule promulgation and eligibility for
grandfathering.
We suggest that EPA consider the benefit of providing greater flexibility to utilities to enable more
realistic ability to comply with the objective of accurately characterizing Cryptosporidium concentrations
in source water. Relaxing criteria for determining acceptability of samples meeting the schedule
requirements and extending the required period for completion of BIN monitoring
to provide for replacement samples would assist water utilities to meet the spirit and the letter of the
proposed regulation.
Response: See Responses 360(A) and 381(A) and (B).
EPA Letter ID: 506
Comment ID: 10735
Comment Response for the LT2ESWTR
5-147
December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: o Sampling Schedule - The proposed rule requires that a water system collect
samples within 2 days of the sampling schedule or be in non-compliance. This is not appropriate. CWD
suggests that 3 or 4 days would be more appropriate. Additionally, the water system should be provided
with more time if they can supply a good reason for the delay.
Response: See Response 360(A).
EPA Letter ID: 507
Comment ID: 11467
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 3. Sampling Schedule.3, IV.A.l.b, pg 47666
The proposed rule requires systems to collect samples within 2 days before or 2 days after a scheduled
sampling date thus comprising a 5-day sampling window. FCWA, and other utilities that incorporate off-
shore intakes with pretreatment chemical capabilities at the intake structure may find it difficult to comply
with the 5-day window due to prolonged periods of inclement weather. For example, over the past year
we have encountered several instances of prolonged
inclement weather that prohibited intake sampling for at least a week. Although the proposed rule
anticipates severe conditions for sampling, FCWA would have had to sample approximately 4 to 5 times
outside the 5-day window and be required to submit an explanation for each event. We respectfully
request that the sampling window be expanded to a minimum 9-day window to preclude such events.
In addition, it would be advantageous for EPA to incorporate extra sampling dates into a utilities
sampling schedule. By incorporating the flexibility of extra dates, laboratory failures such as misplaced
samples, damaged containers, etc. would not jeopardize a utility and put it in a non-compliant position.
Response: See Response 360(A).
EPA Letter ID: 512
Comment ID: 11508
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: c. Provisions for re-sampling in a reasonable timeframe must be implemented
Response: See Response 360(A).
Comment Response for the LT2ESWTR 5-148 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 516
Comment ID: 11751
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: The 2 day sample retake time frame is too short, especially for labs with numerous clients. It
is quite reasonable that resamples may need to be taken within the time frame that other samples are
needed to be taken for the first time within a week if only 2 days are allowed. Extending this time frame
to 4 or 5 days would still keep the resample with in the same -week- and still be collected before the next
weeks samples are needed if a weekly schedule is
chosen by the utility.
Response: See Response 360(A).
EPA Letter ID: 520
Comment ID: 11587
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: highest level of protection against Cryptosporidium. IEPA also disagrees with
EPA's proposal that a water system must take all microbial samples within two days of the planned
monitoring date. IEPA recognizes the need for systems to collect an adequate number of samples and that
the samples need to be distributed across the entire monitoring period. However, based on everyday work
with water systems, IEPA also recognizes that sampling dates can be missed and have protocols to
address these events when they occur. IEPA would prefer to
continue to use this flexibility and determine the consequences of a missed sample or missed sampling
dates on a case-by-case basis.
Response: See Response 360(A).
EPA Letter ID: 521
Comment ID: 11762
Commenter: Leslie Rush,, Dalton Utilities
Commenter Category: Regulated Community (Utilities)
Comment: We have difficulty with the EPA's proposal that a water system be required to take all
microbial samples within two days of the sample date. This seriously limits the flexibility of the system to
operate their facilities to meet system demand or for unpredictable circumstances.
Response: See Response 360(A).
Comment Response for the LT2ESWTR 5-149 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 522
Comment ID: 14144
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Treatment Issues Affecting Both Filtered and Unfiltered Systems:
Implications of Missing or Un-Approved Cryptosporidium Samples: As currently drafted the rule requires
that a 24 month sampling period must be an unbroken record of samples; any missing samples, or
samples which for whatever reason fail to meet laboratory quality assurance standards result in the system
being required to provide the maximum level of treatment. The Agreement in
Principle does not require this, nor is it required by good sampling design. Any number of unintentional
utility or laboratory errors or accidents could result in a missing sample. A missing sample does not alter
the source water quality nor the underlying public health risk health. A missed sample costing few
hundred dollars could result in the expenditure of tens to hundreds of
millions of dollars when there was no basis in public health risk. To so severely penalize these
commonplace occurrences is unacceptable public policy.
We urge EPA to consider allowing resampling and the addition of additional samples at the tail end of the
sampling period. Both are needed for particular circumstances, and neither influences the resultant source
water concentration estimation. We are supportive of AWWA's more detailed
Response: See Responses 360(A) and 440.
EPA Letter ID: 522
Comment ID: 14145
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: concentration estimation. We are supportive of AWWA's more detailed recommendations on
this topic:
* Additional provisions to take replacement samples at the end of the defined monitoring period,
* Greater flexibility in handling of missed samples when utility collected 48 or more samples, and
* Greater flexibility in handling of missed samples in pre-existing data.
The latter two provisions are of particular interest to unfiltered utilities as many already collect source
water samples regularly or expect to conduct more frequent sampling for the purposes of the LT2 rule.
Response: See Responses 360(A) and 382.
Comment Response for the LT2ESWTR 5-150 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 523
Comment ID: 11678
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Implications of Missing or Un-Approved Cryptosporidium Samples: As currently
drafted, the rule requires that a 24 month sampling period must be an unbroken record of samples; any
missing samples, or samples which for whatever reason fail to meet laboratory QA standards result in the
system being required to provide the maximum level of treatment. This requirement is not based on
anything in the Agreement in Principle, nor is it required by good sampling design. Any number of
unintentional utility or laboratory errors or accidents could result in a missing sample, without altering the
source water quality or underlying public health risk health. The commonplace occurrence of a missed
sample costing a few hundred dollars could result in the expenditure of tens to hundreds of millions of
dollars when there was no basis in public health risk.
We urge EPA to consider allowing resampling and the addition of additional samples at the tail end of the
sampling period. Both are needed for particular circumstances, and neither influences the resultant source
water concentration.
Response: See Responses 360(A) and 440.
EPA Letter ID: 523
Comment ID: 11686
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We are supportive of AWWA's more detailed recommendations on this topic:
* Additional provisions to take replacement samples at the end of the defined monitoring period,
* Greater flexibility in handling of missed samples when utility collected 48 or more samples, and
* Greater flexibility in handling of missed samples in pre-existing data.
The latter two provisions are of particular interest to the unfiltered utilities as many of us already collect
source water samples regularly or expect to conduct more frequent sampling for the purposes of the LT2
rule.
Response: See Responses 360(A) and 382.
EPA Letter ID: 526
Comment ID: 11767
Commenter: Nick Jackson,, Knoxville Utilities Board
Commenter Category: Local Government
Comment Response for the LT2ESWTR 5-151 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: 3. The current proposal requires the utility collect samples within two days of
the established calendar date for sampling. Although the calendar sampling schedule for the two year
period must be established three months prior to monitoring, there are many unexpected circumstances
that could impact successful sampling within such a brief time window. We suggest the EPA consider
sampling within five to seven days of the calendar date to avoid noncompliance due to sampling
problems, especially if sampling error can contribute to placement in the most stringent treatment
category.
Response: See Responses 360(A) and 440.
EPA Letter ID: 527
Comment ID: 10851
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: in place for such a violation. Additionally, we strongly recommend that EPA include
reasonable provisions for resampling.
EPA must acknowledge that missed samples will happen. We suggest that, in addition to broadening the
proposed re-sampling provisions, EPA have utilities build dates into their sampling schedules for
additional samples in the event of missed samples.
Sampling Schedule: The proposal requires that systems collect samples within 2 days of their sampling
schedule or be in noncompliance. Since EPA is proposing (but should not promulgate) that
noncompliance leads to an immediate requirement to install UV,(because of Bin 4 placement) this is
completely inappropriate. A utility may not be able to sample within 2 days for many reasons. Moreover,
this requirement stems from the thought that water utilities could -game- the system by monitoring when
they knew Cryptosporidium would not show up. Current data show that randomized sampling is
equivalent, if not superior, to time-series sampling designs (Frey et al, 1998).
We believe that plus or minus 3 or 4 days would be a more appropriate requirement, and that failure to
comply with even that period should not lead to noncompliance if the system has a good reason for
missing the sample.
Response: See Responses 360(A) and 440.
EPA Letter ID: 527
Comment ID: 10851
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: in place for such a violation. Additionally, we strongly recommend that EPA include
reasonable provisions for resampling.
EPA must acknowledge that missed samples will happen. We suggest that, in addition to broadening the
Comment Response for the LT2ESWTR 5-152 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
proposed re-sampling provisions, EPA have utilities build dates into their sampling schedules for
additional samples in the event of missed samples.
Sampling Schedule: The proposal requires that systems collect samples within 2 days of their sampling
schedule or be in noncompliance. Since EPA is proposing (but should not promulgate) that
noncompliance leads to an immediate requirement to install UV,(because of Bin 4 placement) this is
completely inappropriate. A utility may not be able to sample within 2 days for many reasons. Moreover,
this requirement stems from the thought that water utilities could -game- the system by monitoring when
they knew Cryptosporidium would not show up. Current data show that randomized sampling is
equivalent, if not superior, to time-series sampling designs (Frey et al, 1998).
We believe that plus or minus 3 or 4 days would be a more appropriate requirement, and that failure to
comply with even that period should not lead to noncompliance if the system has a good reason for
missing the sample.
Response: See Responses 360(A) and 440.
EPA Letter ID: 528
Comment ID: 12263
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: highest level of protection against Cryptosporidium. We also disagree with EPA-s
proposal that a water system must take all microbial samples within two days of the planned monitoring
date. We recognize the need for systems to collect an adequate number of samples and that the samples
need to be distributed across the entire monitoring period. However, based on their everyday work with
water systems, states also recognize that sampling dates can be missed and have protocols to address
these events when they occur. We would prefer to
continue to use this flexibility and determine the consequences of a missed sample or missed sampling
dates on a case-by case basis.
Response: See Response 360(A).
EPA Letter ID: 533
Comment ID: 12218
Commenter: Edward Urheim,,
Commenter Category: Consultants: (where self-identified)
Comment: I strongly disagree with EPA-s proposal that a water system must take all
Microbial samples within two days of the planned monitoring date. While I recognize that the collection
of water samples needs to be distributed across the entire monitoring period, two days is too constrictive.
Sampling dates can be missed due to various unpredictable situations (remember the UPS strike during
the start of the ICR). I recommend the two day requirement be increased to at least five days. The State
Primacy Agency should also have the flexibility to determine the consequences of a missed sample or
missed sampling
dates on a case-by-case basis.
Comment Response for the LT2ESWTR 5-153 December 2005
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Response: See Response 360(A).
EPA Letter ID: 536
Comment ID: 11797
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: the highest level of protection against Cryptosporidium. Colorado also disagrees with EPA-s
proposal that a water system must take all microbial samples within two days of the planned monitoring
date. Colorado recognizes the need for systems to collect an adequate number of samples and that the
samples need to be distributed across the entire monitoring period. However, based on everyday work
with water systems, we also recognize that sampling dates can be missed and we can develop protocols to
address these events when they occur. Colorado would prefer to continue to use this flexibility and
determine the consequences of a missed sample or missed sampling dates on a case-by-case basis.
Response: See Response 360(A).
EPA Letter ID: 556
Comment ID: 12054
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: discussion. Additionally, we strongly recommend that EPA include more reasonable, more
inclusive provisions for re-sampling that would acknowledge good faith efforts.
Response: See Response 360(A).
EPA Letter ID: 562
Comment ID: 12300
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA is concerned that EPA-s desire to ensure unbiased Cryptosporidium data
has led to overly prescriptive monitoring requirements. The agency-s requirement for two years of
monthly sampling as an unbroken record with no gaps in the sampling period is not realistic or feasible on
a national scale. EPA-s provisions in the proposal for replacement samples, and mechanisms to address
unforeseen sampling or analysis problems are inadequate.
AWWA recommends that monitoring plans under §141.701(e) allow make-up sample(s) to compensate
for a gap in accepted sampling results. When evaluating previously collected (grandfathered) data, gaps in
sequence are likely to occur. The agency should identify the availability of 24, 48, or more samples as a
demonstration of data adequacy that allows more flexible use of pre-existing data.
Comment Response for the LT2ESWTR 5-154 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Response: See Responses 360(A) and 381.
EPA Letter ID: 562
Comment ID: 12383
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Breaks in Sequence
While not explicitly stated in the rule language, EPA is interpreting any missing samples within the
defined 24-month monitoring period (§ 141.701) or in 24-month monitoring period of previously
collected data (§141.708) as a break-in sequence that requires restarting the 24-month monitoring period.
This provision, in combination with the agency-s lack of a determination of
adequate laboratory capacity to undertake the rule and the limited nature of re-sampling provisions in the
rule ((§ 141.703(c)), and §141.709(e) described above, result in a situation where utilities making good-
faith efforts to comply will be subject to penalty, potentially even punitive placement in Bin 4.
AWWA is very concerned about the agency-s current interpretation that the 24-month sampling period
must be an unbroken record of samples. This requirement is without basis in the Agreement in Principle
or implementation logistics. Moreover, such a provision hinders rather than advances implementation.
As currently written, §141.703(c)-(d) limits when utilities may take replacement samples to two
situations:
(c) If extreme conditions or situations exist that may pose danger to the sample collector, or which are
unforeseen or cannot be avoided and which cause the system to be unable to sample in the required time
frame,
(d) Systems that are unable to report a valid Cryptosporidium analytical result for a scheduled sampling
date due to failure to comply with the analytical method requirements, including the quality control
requirements in § 141.705*
A conservative interpretation of these provisions would not allow a replacement sample under the
following example conditions:
1. Sample processing failure,
2. Laboratory backlog,
3. Sample equipment or material failure (e.g., blown filter, inadequate stock of filters for sampling
conditions, etc.),
4. Failure by personnel to follow standard operating procedures for sampling,
5. Improper addressing of a sample so it does not reach a laboratory,
6. Express service failure to deliver sample to laboratory,
7. Labor stoppage that impedes delivery of sample to laboratory,
8. Transport company refusal to ship, or
9. Receiving laboratory exceeds handling capacity, loses approval, or ceases to operate.
Many of these situations impeded sampling in the ICR and could reoccur during the LT2ESWTR
monitoring. A creative interpretation of § 141.703(d) may provide a basis for the Agaency to allow re-
sampling, but explicit regulatory language or guidance is needed to provides utilities assurances that the
primacy agency staff overseeing data submittal will allow the latitude
intended in these provisions.
Comment Response for the LT2ESWTR 5-155 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
AWWA has good reason to believe that the above examples represent fact and not conjecture. As stated
earlier, the problems listed above reflect utility and laboratory experiences during implementation of the
ICR and recent experience of utilities shipping samples in anticipation of grandfathering LT2ESWTR
occurrence data. One story relayed to AWWA described a laboratory
that had to reject three subsequent sample shipments from a single laboratory utility attempting to meet
the EPA Method 1623 QA/QC criteria alone. One shipment failed temperature criteria on arrival at
laboratory, a second shipment broke open during transport, and a third sample was delivered at
temperature (a QA/QC criteria that was arbitrarily selected in development of
the method) but did not weigh in at the required volume (e.g., not 10 L but almost 10 L). Laboratories
describe a range of success in timely sample transport alone - experiences range from less than 10 to
more than 20 percent of large volume samples failing to arrive, arriving late, or arriving damaged. EPA-s
own experience preparing and distributing Performance Evaluation (PE) samples mirrors the types of
experiences described above. These events and other similar mishaps are a reasonable expectation given
the tremendous number of samples that will be shipped under the LT2ESWTR. Unfortunately, when the
rule is implemented, utilities have a legitimate concern that such stories sound like excuses and, given the
workload facing
primacy agencies, such stories will not be accepted as fact but discounted and re-sampling opportunities
lost.
AWWA is especially concerned at the prospect of limited opportunities to re-sample when the agency is
proposing that any failure to monitor per the provisions of the rule is justification to assign that water
treatment facility to Bin 4, and then impose the associated treatment requirements.
Alternative Approaches
AWWA recommends four changes to the proposal with respect to missed samples:
1. Expansion of the sample monitoring plans to include -extra- sample events,
2. Additional provision to take replacement samples at the end of the defined monitoring period,
3. Greater flexibility in handling of missed samples when a utility collected 48 or more samples, and
4. Greater flexibility in handling of missed samples in pre-existing data.
AWWA recommends that the monitoring plans submitted to the primacy agency under §141.703(a)
include three to six identified monitoring events that could be used to compensate for missed samples not
addressed through the re-sample provisions of §141.703(4)(c). These sample events would only be
utilized if re-sampling were either not applicable or failed to occur.
AWWA recommends that during monitoring under §141.701(e) utilities should be able to take make-up
sample(s) not only immediately after scheduled sample events fail per §141.703(c)-(d) but also at the end
of the 24 month sampling period should there be a gap in scheduled sampling. This recommendation is
independent of the previous recommendation regarding sample plans, but can be integrated with that
recommendation to advance a more comprehensive solution.
Additional samples would be subject to all the QA/QC and frequency requirements of any other sample
taken under §141.701(e). EPA's own research illustrates that randomized sampling is equivalent if not
superior to time-series sampling designs.* These recommendations simply build on the current sampling
approach recommended by the Stage 2 M/DBP FACA and would be consistent with the statistical
premise for the current monitoring framework. The proposal also
limits the monitoring timeframe by the due date for submittal of the monitoring data to the primacy
agency for bin assignment. The primacy agency then has the opportunity to make a bin determination
based on the available data or to enter into an action plan with the PWS on how it will come into
compliance with the LT2ESWTR provisions.
Comment Response for the LT2ESWTR 5-156 December 2005
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When utilities pursue a more extensive monitoring effort to obtain 48 or more samples, the likelihood
increases that sample sequence regularity will be broken. These utilities are making a greater investment
in obtaining samples, and they will have a more substantial pool of samples from which to characterize
the influent water. Consequently, these utilities should have greater
flexibility in handling missing samples in the planned monitoring plan. In addition to having the ability to
take additional samples at the end of the defined monitoring period, these utilities should be able to
calculate their bin placement based on the arithmetic mean using 48 or more available observations where
the sampling sequence was discontinuous in a limited number of instances.
Moreover, when evaluating pre-existing oocyst occurrence data, gaps in sequence are likely to occur.
Utilities monitoring on a good faith, proactive basis are unlikely to view rapid re-sampling to be a critical
aspect of the ongoing monitoring. Utilities engaged in developing Cryptosporidium occurrence data in
advance of the rule are not only being proactive on behalf of their customers; these utilities are providing
the sample workload to maintain the existing baseline level EPA Method 1622/1623 laboratory capacity.
AWWA recommends that the agency identify the availability of 48 or more samples as a demonstration
of data adequacy that allows more flexible use of pre-existing data with respect to discontinuity in
monitoring sequence.
Response: See Responses 360(A), 382 and 440.
EPA Letter ID: 562
Comment ID: 12386
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: *LT2ESWTR, Proposed Rule, 68 FR 47778
Response: Source footnote to another comment, no response needed.
EPA Letter ID: 562
Comment ID: 12387
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: *Frey MM and Rosen JS, A framework for modeling the fate and transport of
Giardia and Cryptosporidium in Surface Waters, 1998
Response: Source footnote to another comment, no response needed.
EPA Letter ID: 589
Comment ID: 13055
Commenter: Lawrence Libeu, President, The Western Coalition of Arid States
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-157 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: Issue 3: Sampling Schedule
Systems should be allowed to collect samples within at least 3-4 days of their sampling schedule. The
current proposal of 2 days is difficult to attain. It is especially difficult for systems that use commercial
laboratories for both Cryptosporidium and E. coli. Many commercial labs do not operate on weekends
and samples for E. coli with short hold times usually have to be submitted Monday through Thursday.
Extending the sampling schedule would also allow the possibility of re-sampling in the event of a
laboratory QC failure because samples can typically be processed within 3 days. Having an extra 1 or 2
days would make sampling more manageable without compromising regularly spaced sampling and may
minimize the need for utilities to have to devote valuable time and resources to justifying why samples
could not be taken within the proposed sampling timeframe.
Response: See Response 360(A).
EPA Letter ID: 592
Comment ID: 12105
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Sampling time for Cryptosporidium and non-compliance
The sampling window proposed on the rule is much too limiting for both the laboratories and utilities and
could result in a utility being in noncompliance despite all good intentions. To allow for only a 2-day
window will create an unreasonable hardship should unforeseen events occur on the scheduled sampling
date. A more reasonable time frame would be plus or minus 5 working days from the scheduled date to
allow for testing on Thursdays and Fridays. The non-
Response: See Response 360(A).
EPA Letter ID: 593
Comment ID: 11819
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: 4. Sampling Schedule: The proposal states that systems collect samples within 2
days of their sampling schedule or be in non-compliance. Since noncompliance leads to an immediate
requirement to install UV (because of Bin 4 placement) this is completely inappropriate. SAWS-
recommends that systems collect samples within 7 days of the sampling schedule or be in non-
compliance. This will allow more flexibility for the utilities.
Response: See Response 360(A).
EPA Letter ID: 597
Comment ID: 12612
Commenter: Roger Hulbert, Senior Assistant Director, City of Houston Department of Public Works and
Comment Response for the LT2ESWTR 5-158 December 2005
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Engineering
Commenter Category: Regulated Community (Utilities)
Comment: to the sampling schedule. EPA should build more flexibility into the sampling
schedule to allow for sampling errors, shipping problems, laboratory accidents etc. While we would agree
that any system, which fails to monitor, could be
Response: See Response 360(A).
EPA Letter ID: 597
Comment ID: 12613
Commenter: Roger Hulbert, Senior Assistant Director, City of Houston Department of Public Works and
Engineering
Commenter Category: Regulated Community (Utilities)
Comment: willful violations. Over a two-year sampling process, events will inevitably occur, which
cause a delay or interruption in the monitoring process. Utilities
Response: See Response 360(A).
EPA Letter ID: 598
Comment ID: 12623
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: later after pump repairs were made. Page 47666 of the preamble discusses collection of
samples within a 5-day window of scheduled sampling dates, which was not a known requirement at the
time of sampling. We would hope that EPA understands that such circumstances arise, and would allow
flexibility as mentioned in the conditions listed on page 47666.
Response: See Response 381.
EPA Letter ID: 601
Comment ID: 13014
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah also disagrees with EPA-s proposal that a water system must take all microbial samples
within two days of the planned monitoring date. Although we recognize the need for systems to collect an
adequate number of samples and that the samples need to be distributed across the entire monitoring
period, Utah foresees several circumstances that would preclude that schedule: 1) Utah has a number of
surface water sources that are used seasonally; 2) shut down of a surface water source for maintenance or
Comment Response for the LT2ESWTR 5-159 December 2005
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repair; etc.
Utah suggests that, based on our every day work with water systems, states also recognize that sampling
dates can be missed and have protocols to address these events when they occur. Utah requests to
continue to use this flexibility to determine the consequences of a missed sample or missed sampling
dates on a case-by-case basis.
Response: See Responses 360(A) and (C).
EPA Letter ID: 607
Comment ID: 12978
Commenter: Cam Ferguson, Manager of Water Resources, Greenville Water System
Commenter Category: Regulated Community (Utilities)
Comment: should no automatically trigger placement into a lower bin assignment. There may
be several reasons for a utility not being able to collect the required number of samples that may be
unavoidable. There could be weather delays, personnel problems or shipping difficulties. Additionally, if
a utility must collect samples later during a month and the certified laboratory makes a mistake, there
might be little or no time left to re-collect. Some form of "exception
provision" needs to take these factors into consideration.
Response: See Response 360(A).
EPA Letter ID: 610
Comment ID: 12986
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: two week interval every quarter. Further, the rules should not unfairly penalize
systems for missed samples if the system is operating in good faith. There are many innocent reasons that
a sample could be missed, not the least of which is the possibility of insufficient laboratory capacity.
Response: See Response 360(A).
EPA Letter ID: 610
Comment ID: 12992
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: I would like to reiterate that the sampling regiment must have enough flexibility to allow for
lost or bad samples. We are all human and prone to error. It would be a shame to cause a water system to
Comment Response for the LT2ESWTR 5-160 December 2005
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unnecessarily invest hundreds of thousands of dollars due to the Post Offices' delay in delivery of a
sample or a broken sample.
Response: See Response 360(A).
EPA Letter ID: 618
Comment ID: 13247
Commenter: Craig Bryant, Director, Chesterfield County Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: or may not occur. Additionally, sample holding conditions for contract lab analysis, sampling
difficulties and shipping issues are sometimes encountered irrespective of the diligence applied by the
utility. These factors and many other possible innocent reasons make the proposal requirement that
systems collect samples within two days of their sampling schedules or be in non-compliance totally
unreasonable. Further, this monitoring related noncompliance
Response: See Response 360(A).
EPA Letter ID: 620
Comment ID: 13294
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 4: Sampling Schedule
Comments: Current 2-day provision is too narrow. 3 or 4 days would be more appropriate. Systems such
as SPRWS, which have lake impoundments for source water, do not experience flashy source water
conditions; therefore a restrictive sampling schedule has no benefit to the data collection process.
Response: See Response 360(A).
EPA Letter ID: 625
Comment ID: 13140
Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 4) Sampling schedule
The requirement of a plus or minus 2 day window for sampling is inappropriate. This would better be set
at a plus or minus 3-4 day window, or sampling schedules to not specify a day, but a week of the month
in which samples would be collected. As noted by others, randomized sampling, gives at least equivalent
data to time-series sampling designs. This would minimize the potential for selective sampling, while
giving the system flexibility to adapt to unexpected
delays. Missing a sample should not lead to non-compliance, with the caveat that the missed sampling
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occurred for good reason. Again, the burden of Bin 4 for a missed sample is completely out of proportion
to the act, plus the imposition of such a penalty does not necessarily ensure any heightened public health
benefit. The missed sample should be collected in a timely fashion, and used in the compliance scheme.
Response: See Response 360(A).
EPA Letter ID: 627
Comment ID: 12635
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: 3. Sampling Schedule:
City-s position: Samples could be collected anytime during a -sampling week.- Exceptions should be
allowed where good reasons exist for missing the deadline.
The requirement to collect samples within two days of their sampling schedule or be forced to install UV
is totally inappropriate. Obviously, these regulations were written by those who have never had to manage
an environmental sampling program. As stated before, when dealing with people, machinery, and the
weather, unplanned events happen more often than not.
Response: See Response 360(A) and 440.
EPA Letter ID: 628
Comment ID: 12838
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: Throughout the monitoring period, the SFPUC has attempted to take samples on a
set schedule basis with weekly sampling for the unfiltered water system and monthly sampling for the
two filtered water systems. There were several months where holidays, laboratory capacity, safety hazards
due to inclement weathers, or other operational procedures prevented those samples from being collected
according to original schedules. Additionally, there were some samples collected from the centers of
reservoirs that are considered representative of the source water conditions. The SFPUC believes that the
two-day variance for sample collection and the limited sampling locations that the EPA is proposing are
inappropriate, too restricted, and unrealistic.
Response: See Response 360(A) and 381.
EPA Letter ID: 633
Comment ID: 13265
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
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Comment: proposal also requires that systems collect samples within 2 days of their sampling schedule
or be in non compliance. This timing seems overly restrictive. The proposal allows for submission of re-
samples but places such restrictive requirements on their use that the provision is not helpful. EPA
acknowledges
Response: See Response 360(A).
EPA Letter ID: 643
Comment ID: 12738
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: install the highest level of protection against Cryptosporidium. States also disagree with
EPA-s proposal that a water system must take all microbial samples within two days of the planned
monitoring date. States recognize the need for systems to collect an adequate number of samples and that
the samples need to be distributed across the entire monitoring period. However, based on their everyday
work with water systems, states also recognize that sampling dates can
be missed and have protocols to address these events when they occur. States would prefer to continue to
use this flexibility and determine the consequences of a missed sample or missed sampling dates on a
case-by-case basis.
Response: See Response 360(A).
EPA Letter ID: 646
Comment ID: 13566
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: Monitoring - The requirement to sample within two days of the sampling schedule
is not realistic. Many laboratories have restricted times for accepting samples and problems may arise
with backlogs. EPA should consider extending the time frame to limit problems that may result.
Response: See Response 360(A).
EPA Letter ID: 647
Comment ID: 12896
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: the highest level of protection against Cryptosporidium. MDE also disagrees
with EPA-s proposal that a water system must take all microbial samples within two days of the planned
monitoring date. MDE recognizes the need for systems to collect an adequate number of samples and that
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the samples need to be distributed across the entire monitoring period. However, based on past work with
water systems, sampling dates can be missed and there are protocols to
address these events when they occur. MDE prefers to continue using this flexibility and to determine the
consequences of a missed sample or missed sampling dates on a case-by-case basis.
Response: See Response 360(A).
EPA Letter ID: 653
Comment ID: 14064
Commenter: Tim Stefanich, Environmental Engineer, Sioux Falls Water Purification, City of Sioux Falls
Commenter Category: Local Government
Comment: Sampling Schedule - EPA states that systems must collect their samples within
2 days of the dates indicated in their sampling schedule (141.703 4 (b)). We feel that EPA should provide
more flexibility to water systems in collecting the required samples. When submitting a sampling
schedule, samplers are not going to know their vacation schedules or other requirements for the next two
years. Most systems are going to have one person who will be responsible for
collecting the samples. If that person is called away in and around the sampling time, there may be no one
to collect the sample. This is especially true for small systems, which have limited personnel and
resources.
Also, based on the current language in the rule, if the system collects their sample on Monday, the only
option they have is to collect the sample on Tuesday or Wednesday (Most labs and couriers do not accept
shipments or samples on Saturday or Sunday). This limits most sampling to Monday thru Thursday each
week.
Response: See Response 360(A).
EPA Letter ID: 654
Comment ID: 13122
Commenter: William Brant, Director, Miami-Dade Water and Sewer Department
Commenter Category: Regulated Community (Utilities)
Comment: penalty currently proposed. The MDWASD also requests that the EPA change the
proposed re-sampling provisions to allow for a 5-day grace period to resample instead of the very
constrictive 2 days that are currently proposed.
Response: See Response 360(A).
EPA Letter ID: 662
Comment ID: 14029
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
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Comment: influence the Bin placement of the entity. The monthly window sampling requirement may
not allow for resampling in case of problems flexibility should be included in the rule to allow for
exceptions to the Cryptosporidium sampling schedule when systems are operating in good faith.
Response: See Response 360(A).
EPA Letter ID: 673
Comment ID: 13977
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: Jordan Valley also recommends that the requirement for systems to collect samples within 2
days of their sampling schedule plan to be in compliance is extremely punitive. Extending the time period
for collecting samples to plus or minus 4 days would be more appropriate and allow for occasional
extenuating circumstances.
Response: See Response 360(A).
EPA Letter ID: 677
Comment ID: 13952
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Comment: Through the monitoring period the City has attempted to take samples on a
monthly basis with approximately 4 weeks between samples. There were several months where holidays,
laboratory capacity, or other operational procedures prevented those samples from being collected on the
cycle. The City believes that the two-day variance for sample collection that USEPA is proposing is
inadequate, provided that monthly timing of sample collection by
water systems is not obviously contrived.
Response: See Responses 360(A) and 381.
EPA Letter ID: 688
Comment ID: 14736
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Five day window surrounding sample date (141.703(b)) ~ There is a five-day
window surrounding the scheduled sample date for collecting samples. If the sample is not collected
during this time there will be a monitoring violation. This period is too short to accommodate routine
monitoring especially for small systems that may not have full time operators. A week on either side of
the scheduled sampling date would allow the operator more flexibility and assure that there are not
meaningless monitoring violations. This variation from the
Comment Response for the LT2ESWTR 5-165 December 2005
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set sampling date should not be a significant factor in the determination of Cryptosporidium occurrence
since the natural levels of crypto can not be controlled by the operator and any day is as likely to be a -
peak- as a-valley.- From the state-s perspective the possibility of creating numerous monitoring
violations with no true value is a concern. We as state regulators need to be able to focus our efforts on
those systems who failed to collect samples at all rather than those that missed an arbitrary sample date by
a few days. The extremely close tracking of samples that will be necessary to determine these violations
will also be a burden.
Response: See Response 360(A).
EPA Letter ID: 699
Comment ID: 14774
Commenter: David A. Visintainer, Water Comissioner, City of Saint Louis
Commenter Category: Regulated Community (Utilities)
Comment: This section also requires that samples be collected within 2 days of their sampling schedule
or the system will be in noncompliance and would then be placed in Bin 4. Greater flexibility should be
given in this scheduling. We suggest plus or minus 5 days and failure to monitor in this timeframe should
not result in automatic placement in Bin 4.
Response: See Responses 360(A) and 440.
EPA Letter ID: 704
Comment ID: 14795
Commenter: Steven G. Gould, Chairman, New York State American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The sampling window that must be established before the first sample is taken
has a window of ±2 days of the selected sample date. This may be too narrow a window, especially with
the strict sample acceptance criteria built into the LT2 rule language. If many samples arrive at a contract
lab in unacceptable condition at one time and a re-sample is ordered for each, then the lab may end up
with a large backlog of samples that continues to pile up as new samples continue to arrive. It could be
possible that rule violations will be met through simply a backlog of samples jamming up a lab-s
capacity.
Response: See Response 360(A).
EPA Letter ID: 704
Comment ID: 14802
Commenter: Steven G. Gould, Chairman, New York State American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-166 December 2005
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Comment: 7. Source water monitoring requirements, sample schedule.
The sampling requirements indicate that source water samples must be collected within a two-day
window of the scheduled date. No provision for modifying the sampling has been provided to account for
an unusual event, such as a major storm or hurricane, other than for situations that -may pose a danger to
the sampler.- Should systems collect samples during major storm events? . . . during a hurricane? This
may result in conditions that are not representative of normal variations in raw water quality. The risk
analysis does not take into consideration return frequencies of storms that may be sampled and create
highercryptosporidium concentrations. The risk evaluations should consider return frequencies of storm
events and allow for invalidation of a sample during a particular storm event that would not significantly
increase risk.
Response: See Response 360(A).
EPA Letter ID: 711
Comment ID: 16542
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 1. EPA should relax the sample collection dates to be within say 5 days of the
date indicated on a system's sampling plan instead of the 2 days currently in the proposed rule. Water
systems will generally attempt to adhere to a sampling plan unless they run into unforeseen situations, By
extending this requirement, water systems will have more breathing room and not be unnecessarily
constricted by their sampling plan. This will also cut down on the number of reports that would have to be
generated to give explanations as to why a sample might not
have been collected on schedule.
Response: See Response 360(A).
EPA Letter ID: 711
Comment ID: 16546
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 1. Section 141.703(b) - We suggest EPA relax the sample collection dates to be
within say 5 days of the date indicated on a system's sampling plan instead of 2. Water systems will
generally attempt to adhere to a sampling plan unless they run into unforeseen situations. By extending
this requirement, water systems would have more breathing room and not be unnecessarily constricted by
their sampling plan. This will also cut down on the number of reports that would have to be generated to
give an explanation as to why a sample could not be collected on schedule.
Response: See Response 360(A).
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5.6.2 Comment Code 365, Submitting monitoring plan (date and location)
Summary of Issues
Comments were submitted concerning the location and scheduling of source water sampling. The
majority of the commenters expressed that State involvement in sampling location and scheduling was
important to ensure that each system's sampling location and compliance schedule is appropriate for that
system. Commenters also believed that State approval of systems' sampling locations and schedules was
needed to ensure that all systems would be collecting appropriate samples.
Response to Code 365
Sample location description requirements
EPA agrees with commenters who suggested that there should be State review of a source water
monitoring location description for their PWSs. Review of monitoring plans will help to prevent
confusion and prevent PWSs from sampling at an incorrect locations. A review of monitoring location
plans will also ensure that PWSs collect source water samples at the correct location and determine the
appropriate level of public health protection within required compliance dates.
Consequently, today's rule requires PWSs to report a description of their monitoring location to the State.
This requirement is a change from the proposed rule, which did not require PWSs to report a description
of their sampling location. This change reflects public comment on the proposal which strongly supported
State review of monitoring locations.
To facilitate review of the sampling location descriptions, the rule requires the sampling location
description to address the position of the sampling location in relation to the PWS's sources and treatment
processess, including pretreatment, points of chemical treatment and filter backwash recycle.
Furthermore, guidance on sampling location is provided in the Source Water Monitoring Guidance
Manual that accompanies the rule, and EPA will work with State in reviewing these descriptions.
EPA agrees that States should be involved in review of the location descriptions wherever possible, and is
encouraging States to take an active role in plan review. Where necessary, EPA will make those
determinations based on the information provided. EPA believes that the reviews can be completed within
the three months provided and is prepared to assure resources are available to complete the reviews. EPA
agrees that PWSs should be notified regarding the acceptability of the description, but does not believe
that sampling should be suspended pending such notification. Therefore, if a PWS does not hear back
from the State by the time it is scheduled to begin sampling, it may assume that its monitoring location is
acceptable and proceed with sampling.
Individual Comments on Code 365
EPA Letter ID: 457
Comment ID: 11892
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
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Comment: As indicated previously, state involvement in identifying microbial sampling locations and
establishing sampling schedules is critical to ensure that the data collected is useful in determining
appropriate treatment requirements.
Response: See Response 365.
EPA Letter ID: 466
Comment ID: 11012
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: ND believes that we should work with each water system individually to ensure
that the proposed monitoring location for the system is appropriate. This is the only way to be assured that
public health is truly be served. We would approve the submitted monitoring plans to ensure that all large
and small systems are aware of their monitoring requirements at least three months before sampling
begins.
Response: See Response 365.
EPA Letter ID: 467
Comment ID: 11037
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: Issue 2: Time Frame of LT2ESWTR Monitoring
The proposed LT2ESWTR states that large water systems must submit their sampling plan within 3
month of rule promulgation and must start the monitoring within 6 month of the rule promulgation. LWC
believes that water system should not be responsible for monitoring until somebody approves the
monitoring plan (schedule and sites). Therefore, LWC recommends EPA revise the 6 month requirements
in the final rule to reflect the approval process. All subsequent deadlines should proceed from the
approval date.
Response: See Responses 365 and 310(A).
EPA Letter ID: 470
Comment ID: 11090
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Systems should be required to submit a microbial monitoring plan three months before
monitoring is required to begin and receive approval of the plan.
Comment Response for the LT2ESWTR 5-169 December 2005
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Response: See Response 365.
EPA Letter ID: 493
Comment ID: 11243
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment: 40 CFR 141.703(a)(l) requires systems to submit a sampling schedule for initial
source water monitoring directly to EPA electronically within three months of publication of the final
rule. This, in my opinion, is quite unreasonable. Is EPA going to require that the system specify the
sampling locations selected as well in the schedule? If not, the schedule will essentially be meaningless
since it could be expected that many sample sites the system selects on its own maybe incorrect. If
sampling locations are included in the schedule, is EPA going to review the schedules to ensure proper
sample locations have been selected? It is felt that EPA should give much more time for large systems to
develop a proposed sampling schedule and should include a requirement that the States review the
schedules, including specific sampling locations. This will help to ensure that the funds expended for
laboratory services is well spent and the data received is meaningful.
Response: See Response 365.
EPA Letter ID: 496
Comment ID: 10697
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: options, if additional treatment becomes necessary. The compliant schedule should be
modified to include review and approval of the LT2ESWTR monitoring plan by thegoverning agency
prior to initiation of the required monitoring.
Response: See Response 365.
EPA Letter ID: 504
Comment ID: 11358
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: If EPA cannot complete the approval process within the 3-month period the rule
as written provides utilities no flexibility for beginning required monitoring. Beginning monitoring no
later than 6-months following promulgation is stated as an absolute requirement. The implication of a
delay is noncompliance, which is unacceptable to utilities.
Response: See Response 365.
Comment Response for the LT2ESWTR 5-170 December 2005
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EPA Letter ID: 506
Comment ID: 10737
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: additional treatment becomes necessary. Additionally, CWD thinks that it would
be appropriate to modify the compliance schedule so that the State primacy agency could review and
approve monitoring plans prior to the start of monitoring.
Response: See Response 365.
EPA Letter ID: 520
Comment ID: 11564
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Identification and Approval of Monitoring Locations
Although guidance from EPA on appropriate monitoring locations is appreciated, IEPA does not believe
that guidance can replace direct consultation with individual water systems. IEPA believes that, in most
cases, IEPA will need to work with each water system to ensure the proposed monitoring location for the
system is appropriate. EPA has requested comment on a number of instances where IEPA believes direct
state-water system interaction will be necessary, including requirements for systems that use surface
water for only part of the year, monitoring for systems that recycle filter backwash water, and
requirements for systems that use multiple source types.
IEPA believes that the water system should receive approval, in writing, of the acceptability of
LT2EWSTR monitoring locations in order to prevent debate or confusion later. The proposed rule
requires that systems submit a monitoring plan, but does not indicate if the plans will be approved. If EPA
intends to approve the plans, including locations, IEPA is cocerned that EPA, especially EPA HQ, will
not have the manpower or knowledge of system-specific situations to
approve every monitoring plan. If EPA does not intend to approve plans, we request supporting
justification for requiring systems to submit a plan. IEPA does not support requiring monitoring plans just
to ensure systems are aware of their monitoring requirements or to check that samples were taken on a
specific date.
Response: See Response 365.
EPA Letter ID: 520
Comment ID: 11572
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-171 December 2005
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Comment: - Require systems to submit a microbial monitoring plan three months before monitoring is
required to begin.
Response: See Response 365.
EPA Letter ID: 520
Comment ID: 11582
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: As indicated previously, IEPA involvement in identifying microbial sampling
locations and establishing sampling schedules is critical to ensure that the data collected is useful in
determining appropriate treatment requirements.
Response: See Response 365.
EPA Letter ID: 528
Comment ID: 12243
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Identification and Approval of Monitoring Locations
Although guidance from EPA on appropriate monitoring locations is appreciated, we do not believe that
guidance can replace direct consultation with individual water systems. We believe that, in most cases, we
will need to work witheach water system to ensure the proposed monitoring location for the system is
appropriate.
We have a long standing commitment to our water systems to provide technical assistance, monitoring
and onitoring locations. The proposed rule requires that systems submit a monitoring plan, but EPA HQ,
will not have the manpower or knowledge of system-specific situations to approve every monitoring plan.
Additionally, it would be a duplication of work in our case. If EPA does not intend to approve plans, EPA
should provide justification for requiring large systems to submit a plan to EPA. We do not support
requiring monitoring plans just to ensure systems are aware of their monitoring requirements or to check
that samples were taken on a specific date.
- Systems should be required to submit a microbial monitoring plan three months
before monitoring is required to begin and receive approval of the plan.
Response: See Response 365.
EPA Letter ID: 528
Comment ID: 12257
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
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Comment: State involvement and flexibility in identifying microbial sampling locations
nd establishing sampling schedules is critical to ensure that the data collected is useful in determining
appropriate treatment requirements.
Response: See Response 365.
EPA Letter ID: 536
Comment ID: 11778
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Identification and Approval of Monitoring Locations
Although guidance from EPA on appropriate monitoring locations is appreciated, Colorado does not
believe that state or EPA written guidance can replace direct consultation with individual water systems.
We believe that, in most cases, we will need to work with water systems to ensure the proposed
monitoring location for the system is appropriate.
We believe that the water system should receive approval, in writing, of the acceptability of LT2EWSTR
monitoring locations in order to prevent debate or confusion later. This is a very important and sensitive
issue that was expressed directly to us by very large public water systems such as Denver and Aurora
during our previous stakeholder work group meetings to adopt LT1. The proposed rule requires that
systems submit a monitoring plan, but does not indicate if the plans will be approved. If EPA intends to
approve the plans, including locations, states are concerned that EPA will not have the manpower or
knowledge of system-specific situations to approve every monitoring plan. More importantly, a
requirement for our systems to work directly with EPA causes them to question the value of our program
retaining primacy, particularly when water systems are paying fees to support our program. Finally, if
EPA does not intend to approve plans, supporting justification for requiring systems to submit a plan is a
necessity. Colorado does not support requiring monitoring plans just to ensure systems are aware of their
monitoring requirements or to check that samples were taken on a specific date.
Response: See Response 365.
EPA Letter ID: 536
Comment ID: 11786
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: -Require systems to submit a microbial monitoring plan three months before monitoring is
required to begin.
Response: See Response 365.
Comment Response for the LT2ESWTR 5-173 December 2005
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EPA Letter ID: 536
Comment ID: 11792
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: As indicated previously, state involvement in identifying microbial sampling
locations and establishing sampling schedules is critical to ensure that the data collected is useful in
determining appropriate treatment requirements.
Response: See Response 365.
EPA Letter ID: 556
Comment ID: 12058
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Because of the many different situations expected to occur in selection of
monitoring sites, we strongly recommend that the regulation call for systems to include the monitoring
point in their sampling plans. Further, the compliance schedule should be modified to incorporate review
and approval of the LT2ESWTR monitoring plan and sampling point by the primacy agency prior to
initiation of the required monitoring.
Response: See Response 365.
EPA Letter ID: 562
Comment ID: 12301
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: water). EPA should also modify the compliance schedule to incorporate review
and approval of the LT2ESWTR monitoring plan by the primacy agency, prior to initiation of the
required monitoring.
Response: See Response 365.
EPA Letter ID: 562
Comment ID: 12353
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-174 December 2005
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Comment: AWWA believes an approved sampling plan is necessary for each utility to
ensure that the sampling locations chosen by the utility are in accordance with the regulatory
requirements. Utilities should not be in a situation where they are notified at the end of the sampling
period that samples were taken at an unacceptable location. The schedule for implementation of the rule
must provide sufficient time and resources at the primacy agency to
allow each utility the opportunity to have its sampling plan reviewed and approved prior to the start of
sampling.
Response: See Response 365.
EPA Letter ID: 562
Comment ID: 12363
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 385 5. Schedule for data reporting and EPA decisions
Comment: 3.7 Implementation Schedule
The Stage 2 D/DBP FACA constructed a very aggressive implementation schedule for the LT2ESWTR.
As EPA lays out the specifics of implementation in the stakeholder draft, proposed rule, associated
support documents, and in the Draft State Implementation Guidance, the practicality of the schedule
reflected in the Agreement in Principle has become more questionable. Of particular concern in the
LT2ESWTR are these two issues:
1. Approval of pre-existing data for bin determination, and
2. Approval of defined monitoring sample plan and schedule.
Response: See Responses 365 and 385.
EPA Letter ID: 562
Comment ID: 12367
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: months after promulgation). Submittal of sampling plans appears to be a particular problem
because developing the sample schedule will involve contract negotiation with the laboratory, plus
completion of a procurement of services agreement using typical municipal procurement procedures, and
all of this occurring between rule promulgation and submittal of the sample plan.
Response: See Response 365.
EPA Letter ID: 562
Comment ID: 12368
Comment Response for the LT2ESWTR
5-175
December 2005
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The agency has communicated its its perspectives and priorities in the text of the proposal.
ThereforeGiven these considerations, AWWA recommends that primacy agency approval of the
monitoring plan and schedule should take place prior to initiation of defined monitoring. Utilities have a
much stronger and more detailed rapport with state primacy agencies than with EPA regional offices and
EPA headquarters. Consequently, interaction with the state rather than EPA regions or EPA headquarters
in Washington would be more efficient
and effective than the other available options.
Response: See Response 365.
EPA Letter ID: 562
Comment ID: 12377
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: monitoring location. Also, the monitoring plan submitted to the primacy agency for approval
should include a schematic of the water treatment plant treatment train and indicate where and what
chemical additions take place, in particular, additions or actions that take place prior to the proposed
LT2ESWTR monitoring location.
These recommendations are in keeping with the FACA-s direction in that the FACA recommended that a
water treatment plant provide increased treatment when the influent water it treated on average (either
maximum rolling annual average or arithmetic average) contained elevated levels of Cryptosporidium
oocysts above certain levels. This proposed approach achieves this goal while providing clear logic for
subsequent guidance and primacy agency
decisions.
Response: See Response 365.
EPA Letter ID: 562
Comment ID: 12379
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. Modify the compliance schedule to incorporate review and approval of the LT2ESWTR
monitoring plan by the primacy agency prior to initiation of the required monitoring under described in
(§141.701(e)).
These recommendations are in keeping with the FACA-s direction in that the
FACA recommended that a water treatment plant provide increased treatment when the influent water it
treated on average (either maximum rolling annual average or arithmetic average) contained elevated
levels of Cryptosporidium oocysts above certain levels. This proposed approach achieves this goal while
providing clear logic for subsequent guidance and primacy agency decisions.
Comment Response for the LT2ESWTR 5-176 December 2005
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Response: See Response 365.
EPA Letter ID: 562
Comment ID: 12380
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Flexibility in selecting a monitoring location and primacy agency approval of the monitoring
plan prior to initiation of monitoring is essential for several reasons. At some water treatment plants,
monitoring locations can be physically constrained (i.e., sources may merge in buried facilities or within
unit operations). In some circumstances, use of, and blending of,
multiple sources is complex and dependant on conditions as they arise on an hourly basis (e.g., changes in
demand, withdrawal permit or purchase agreement conditions, and changes in source water quality).
Individual utilities will be best able to decide whether monitoring before or after a
pre-treatment process is most representative of their source water.
Response: See Response 365.
EPA Letter ID: 562
Comment ID: 12388
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Sample Schedules
Currently, §141.703(a) requires PWSs complying with §141.701(e) to submit a sample schedule in
advance of initiating monitoring. AWWA recommends modifying this submittal to also include a
schematic with the proposed monitoring location. AWWA also recommends that upon submittal, the
primacy agency have a fixed period of time (e.g. three months) to review, approve,
and formally inform the PWS that the schedule and monitoring location are approved. Within a fixed
period of time (e.g., 60 or 90 days) upon receipt of primacy agency approval, the PWS should initiate
monitoring. This review will allow the primacy agency to resolve any conflicts prior to the start of
monitoring. A simple and clear appeal process should exist for any issues
raised by the primacy agency. Also, the PWS should not be responsible for initiating defined monitoring
until the primacy agency has indicated that the monitoring schedule and monitoring location are
appropriate.
Response: See Response 365.
EPA Letter ID: 601
Comment ID: 13005
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-177 December 2005
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Comment: Utah believes that Utah is the appropriate regulator to determine appropriate monitoring
locations and frequencies for Utah water systems. Through 25 years of implementation of the SDWA, we
have established a solid relationship with our water systems. Utah knows its water systems, understands
the issues that affect each of them and has a first hand knowledge of which systems are appropriate for a
cookie cutter approach to monitoring and which systems contain complexities that will need to be handled
on a case by case basis.
This relationship will allow Utah and our water systems to work together to determine rule applicability,
appropriate monitoring requirements, and whether a waiver from monitoring should be granted, especially
for complex rules that affect water systems with advanced treatment trains and/or intricate distribution
systems
Response: See Response 365.
EPA Letter ID: 601
Comment ID: 13023
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: As indicated previously, state involvement in identifying microbial sampling locations and
establishing sampling schedules is critical to ensure that the data collected is useful in determining
appropriate treatment requirements.
Response: See Response 365.
EPA Letter ID: 609
Comment ID: 14112
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: We believe that the MDEQ rather than the USEPA Regional Office is the
appropriate regulator to provide oversight and review monitoring plans. However, the USEPA should not
anticipate state participation if the proposed rule includes early implementation compliance schedules.
Response: See Response 365.
EPA Letter ID: 614
Comment ID: 12959
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-178 December 2005
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Comment: it enters the treatment chain. Both the EPA and the State should review the
LT2ESWTR monitoring plan prior to initiation of monitoring.
Response: See Response 365.
EPA Letter ID: 620
Comment ID: 13297
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: points. The compliance schedule should include time for the utility to consult with the
primacy agency on sampling location.
Response: See Response 365.
EPA Letter ID: 631
Comment ID: 13231
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: The City requests that EPA reconsider the intent of the monitoring in defining the monitoring
locations. The requirements would be simplified if systems were allowed to choose monitoring locations
that best reflect influent water quality as part of their monitoring plan. The monitoring locations should
also reflect anticipated construction or improvement options should additional treatment become
necessary. As is already the process for approval of monitoring plans for other contaminants, the primacy
agencies should have flexibility to establish
monitoring points while giving due consideration to the water system operational characteristics and
planned improvements.
Response: See Response 365.
EPA Letter ID: 633
Comment ID: 13269
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: systems like ours. Increased flexibility and simplification of requirements would be possible
if systems were allowed to pick appropriate locations as part of their monitoring plan, with approval by
the primacy agency.
Response: See Response 365.
Comment Response for the LT2ESWTR 5-179 December 2005
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EPA Letter ID: 641
Comment ID: 13580
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: -Large systems must submit a sampling schedule to the EPA within 3 months after
promulgation— This section should be re-written to -Large systems must submit a sampling schedule
and their selection of a laboratory to the EPA on or before the date of collection of their first round of
sampling (within 6 months after Promulgation). Reasons for this request are as follow: (a) This should
include a reference to coordinating sampling schedule with selected laboratory - PWSs that submit a
schedule to EPA first and then look for a lab to accept that schedule could be in trouble due to scheduling
conflicts, etc. with samples from other utilities
that have already confirmed schedules with the lab. (b) Also, requiring sampling
Response: See Response 365.
EPA Letter ID: 641
Comment ID: 13628
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 6.3 - Paragraph 3
"-required to submit their source water monitoring schedule to the EPA within 3
months of promulgation-"
(Repeated from ASI comments on Proposed Rule, Pg 47666, above) This section should be re-written to
-Large systems must submit a sampling schedule and their selection of a laboratory to the EPA on or
before the date of collection of their first round of sampling (within 6 months of Promulgation). Reasons
for this request are as follow: (a) This should include a reference to
coordinating sampling schedule with selected laboratory - PWSs that submit a schedule to EPA first and
then look for a lab to accept that schedule could be in trouble due to scheduling conflicts, etc. with
samples from other utilities that have already confirmed schedules with the lab. (b) Also, requiring
sampling
Response: See Response 365.
EPA Letter ID: 641
Comment ID: 13636
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Lab Coordination - ASI supports encouraging PWSs to verify their intended sampling
schedules with their laboratory.
Response: See Response lOOa.
Comment Response for the LT2ESWTR 5-180 December 2005
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EPA Letter ID: 643
Comment ID: 12710
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Identification and Approval of Monitoring Locations
Although guidance from EPA on appropriate monitoring locations is appreciated, states do not believe
that guidance can replace direct consultation with individual water systems. States believe that, in most
cases, states will need to work with each water system to ensure the proposed monitoring location for the
system is appropriate. EPA has requested comment on a number of instances where states believe direct
state-water system interaction will be necessary, including requirements for systems that use surface
water for only part of the year, monitoring for systems that recycle filter backwash water, and
requirements for systems that use multiple source types.
States believe that the water system should receive approval, in writing, of the acceptability of
LT2EWSTR monitoring locations in order to prevent debate or confusion later. The proposed rule
requires that systems submit a monitoring plan, but does not indicate if the plans will be approved. If EPA
intends to approve the plans, including locations, states are concerned that EPA, especially EPA HQ, will
not have the manpower or knowledge of system-specific situations to approve every monitoring plan. If
EPA does not intend to approve plans, states request supporting justification for requiring systems to
submit a plan. States do not support requiring monitoring plans just to ensure systems are aware of their
monitoring requirements or to check that samples were taken on a specific date.
Response: See Response 365.
EPA Letter ID: 643
Comment ID: 12719
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: * Systems should be required to submit a microbial monitoring plan three months
before monitoring is required to begin and receive approval of the plan from the agency with primary
enforcement authority at the time of approval (preferably the state).
Response: See Response 365.
EPA Letter ID: 643
Comment ID: 12732
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As indicated previously, state involvement in identifying microbial sampling locations and
establishing sampling schedules is critical to ensure that the data collected is useful in determining
appropriate treatment requirements.
Comment Response for the LT2ESWTR 5-181 December 2005
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Response: See Response 365.
EPA Letter ID: 646
Comment ID: 13569
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: the requirement for review and approval of the LT2ESWTR monitoring plan by the
primacy agency.
Response: See Response 365.
EPA Letter ID: 647
Comment ID: 12875
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Identification and Approval of Monitoring Locations
Although guidance from EPA on appropriate monitoring locations is appreciated, guidance cannot replace
direct consultation with individual water systems. MDE believes that, in most cases, states will need to
work with each water system to ensure the proposed monitoring location for the system is appropriate.
EPA has requested comment on a number of instances where states
believe direct state-water system interaction will be necessary, including requirements for systems that
use surface water for only part of the year, monitoring for systems that recycle filter backwash water, and
requirements for systems that use multiple source types.
The water system should receive approval, in writing, of the acceptability of LT2EWSTR monitoring
locations in order to prevent debate or confusion later. The proposed rule requires that systems submit a
monitoring plan, but does not indicate if the plans will be approved. If EPA intends to approve the plans,
including locations, MDE is concerned that EPA, especially EPA HQ, will not have the manpower or
knowledge of system-specific situations to approve every
monitoring plan. If EPA does not intend to approve plans, MDE requests supporting justification for
requiring systems to submit a plan. MDE does not support requiring monitoring plans just to ensure
systems are aware of their monitoring requirements or to check that samples were taken on a specific
date.
Response: See Response 365.
EPA Letter ID: 647
Comment ID: 12882
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Comment Response for the LT2ESWTR 5-182 December 2005
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Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1210 A. Large System Monitoring and Treatment
Comment: Based on the foregoing discussion, MDE recommends the following approach for
implementing the LT2ESWTR:
- Require systems to submit a microbial monitoring plan three months before monitoring is required to
begin.
- Stagger Cryptosporidium monitoring for large systems over three phases:
[SEE TABLE, P. 9 (OF 32) IN PDF]
Response: See Responses 365, 1200.h, and 1200.C.
EPA Letter ID: 647
Comment ID: 12890
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: As indicated previously, state involvement in identifying microbial sampling locations and
establishing sampling schedules is critical to ensure that the data collected is useful in determining
appropriate treatment requirements.
Response: See Response 365.
5.7 Comment Code 370, Reporting Monitoring Results
Summary of Issues
One commenter recommends that systems keep track and report a rolling 12-month average after the first
12 monitoring samples for LT2ESWTR are collected, to help with delays associated with resampling, and
thus affecting the PWS bin classification. Another commenter questions why data needs to be submitted
monthly, when the biweekly data points have no significance except as data for future calculations. The
last commenter concurred with EPA and offered support on how EPA has changed the required reporting
elements and reduced the amount of reporting data for grandfathering.
Response to Code 370
(A) 12-month rolling average
EPA agrees that it would be helpful for systems to begin tracking their rolling 12 month average after the
first 12 Cryptosporidium samples are collected and has suggested this in the Source Water Monitoring
Guidance.
(B) Reporting E. coli results monthly
Comment Response for the LT2ESWTR 5-183 December 2005
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EPA requires monthly reporting of results so that the PWS, EPA and the States can detect and resolve
monitoring problems early in the monitoring period, perhaps saving valuable time and expense and
minimizing compliance actions.
Individual Comments on Code 370
EPA Letter ID: 560
Comment ID: 14980
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Recognizing that delays in resampling might delay the utilities- assessment of
their bin category, we recommend that systems keep track and report the rolling 12-month average after
the first 12 samples are completed. Any system exceeding the bin levels can immediately begin to make
treatment plans. Although subsequent monitoring may result in a higher bin classification, the utility will
begin to evaluate its toolbox options. Finally, when the last samples are completed, the bin classifications
will also be completed.
Response: See Response 370 (A).
EPA Letter ID: 586
Comment ID: 12201
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: 4. Reporting requirements for E. coli and Cryptosporidium data.
Section 141.707(d) requires that all source water monitoring analysis results be submitted on a monthly
basis.
With respect to small systems, only the mean of one year of E. coli data is compared to the benchmark
value to determine whether or not Cryptosporidium monitoring must be conducted. And only the mean of
one year of Cryptosporidium data is used to determine the system's Bin classification.
Why is data required to be submitted monthly, when the biweekly data points have no significance except
as data for future calculations? It is doubtful that any State has the resources to review monthly data
provided by the hundreds of water systems under its purview. All required data can be submitted as a
package with the mean E. coli
We request that EPA reconsider the monthly reporting requirement, specifically with respect to the value
of the discrete data points being reported.
Response: See Response 370(B).
Comment Response for the LT2ESWTR 5-184 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 598
Comment ID: 12620
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: Required Data Elements to be Reported
In our comments to EPA on the Draft LT2ESWTR, we pointed out the extensive reporting requirements
for such items as holding times, laboratory quality control information and lab bench sheet information.
We are pleased to see that EPA has changed the required reporting elements and commend EPA on
reducing the amount of reporting data. As an example, EPA will allow systems such as ours, with
previously collected data (grandfathered data), to submit a letter from the laboratory stating that all QC
was performed and was acceptable, rather than
reporting all that data for each sample set.
Response: See Response lOOa.
5.7.1 Comment Code 371, Reporting large system results directly to
EPA and role of States
Summary of Issues
A number of the comments addressed concern with the issue of initial data reporting for large utility
systems serving over 10,000 individuals going to the EPA, and then reporting to the individual states once
they assume primacy. The majority of the statements expressed the view that initial reporting to the EPA
was unnecessary for a number of reasons: EPA does not have the resources to manage the data, problems
have already been encountered with the ICR and UCMR electronic reporting to EPA (though
improvements to the data reporting system have been made), and utilities would prefer to deal with only
one regulatory agency rather than switching their data reporting procedures once the States assume
primacy. Some of the commenters recommended the need for EPA to ensure that the data reporting
system is ready and reliable, and emphasized the need for a "dual primacy" wherein the EPA and States
will need to work together to solve any problems associated with the transfer of large amounts of data.
Response to Code 371
(A) Data system readiness
EPA has developed an LT2 data collection system that has been beta and gamma tested and is ready for
use by laboratories, PWSs, States and EPA to submit and review monitoring results. During development
of the data system, EPA involved stakeholders in a joint requirements workgroup, which made
recommendations for data system characteristics, reviewed problems with the UCMR database, and
participated in beta and gamma testing. The system has been designed to include tracking features that
will assist States and EPA in implementing the rule and determining monitoring problems, violations,
problems with the use of the data system and early binning status. Inventory changes can be made on the
data system, and EPA will be working with States to assure that those changes are reflected in SDWIS
where appropriate.
(B) Guidance
Comment Response for the LT2ESWTR 5-185 December 2005
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EPA has developed a user's guide for laboratories, PWSs, States and EPA to help when submitting and
reviewing data via the LT2 data collection system. EPA also plans to conduct webcasts about the data
system soon after rule promulgation, and will provide written instructions to laboratories, PWSs and
States regarding system registration and use. Finally, EPA will have a web based help line and provide a
phone number to call regarding problems utilizing the data system.
(C) State involvement and transfer of data
In general, EPA would prefer that States oversee monitoring by their PWSs and is working with States to
facilitate their involvement with rule implementation. Where States are unable to implement today's rule,
however, EPA is prepared to oversee implementation and therefore has developed the LT2 data collection
system to assist in that process. Moreover, EPA believes that the staggered compliance schedule in
today's final rule will enhance the ability of States and EPA to implement the rule. EPA has initiated an
extensive training process to prepare PWSs, States and EPA Regional offices for implementation,
including training workshops, webcasts, guidance documents, mailings and help lines. EPA has also been
working with States to address their concerns about electronic reporting of data to EPA and data transfer.
EPA has designed a tracking system that will help assure proper implementation of rule requirements,
including review of plans and schedule; sampling results, methods and QA/QC; and grandfathered data.
EPA has established a central processing center for submittal of all information, called the
Implementation Processing and Management Center (IPMC). Laboratories and States can submit
information via the data collection system or via the IPMC, where scanning and distribution of all
information will occur. All information will be accessible on the data collection system for access by
laboratories, PWSs, States and EPA. EPA has also developed schema that will be used to transfer
information to the States electronically, which will help in the smooth transfer of the program when States
obtain primacy.
(D) Contesting results
Through the LT2 data collection system, PWSs can contest a result if they have reason to believe the
sample is not representative or the analysis is incorrect. When contesting a result, a PWS must provide
sufficient explanation for EPA or the State to determine that invalidating a result is appropriate.
Otherwise, the result will count as valid and be used in the bin concentration calculation.
(E) Lack of computers
EPA believes that all laboratories approved to conduct monitoring under the LT2 rule have access to
computers. This will enable them to report results via the LT2 data collection system. EPA also believes
that all large public water systems (greater than 10,000 people served) have access to a computer to
review their results via the web based data collection system. Systems serving less than 10,000 will
submit data to the State and EPA will be working with the States to assure adequate means for them to
review data.
Individual Comments on Code 371
EPA Letter ID: 423
Comment ID: 10570
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-186 December 2005
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Comment: 40CFR141.701 Compliance Requirements Table
The EPA FACA Agreement in Principle was signed and published in September 2000. Approximately
three years later the EPA is proposing to promulgate rules triggering early
implementation of monitoring by Subpart H systems for cryptosporidium. Public water systems must file
a monitoring plan and report data directly to the EPA bypassing the state primacy agency. If EPA felt this
proposed rule was so important it should have published it
in late 2000 and allowed the states to carryout the role assigned them by the Safe Drinking Water Act.
Due to the states being relegated to a bystander's role, public water systems will eventually decide that do
not need to continue to support state activities and may attempt to have state
funding decreased. The health risks caused by lack of additional cryptosporidium control will pale in
comparison to the public health risk caused by underfunded and ineffective state programs. The EPA does
not have the resources to take over the responsibilities of state
programs.
Response: See Response 371(A).
EPA Letter ID: 441
Comment ID: 10778
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Records kept by States
Before the State agencies have primacy, EPA will be collecting the results of Cryptosporidium source
water monitoring, letters from laboratories, and letters from water suppliers. EPA should provide all
copies of the monitoring results and correspondence to the States.
Response: See Response 371(C).
EPA Letter ID: 497
Comment ID: 10645
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: We believe that the MDEQ rather than the EPA Regional Office is the appropriate
regulator to provide oversight and review monitoring plans. However, the EPA
Response: See Response 371(C).
EPA Letter ID: 520
Comment ID: 11607
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Comment Response for the LT2ESWTR 5-187 December 2005
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Comment Codes 300-471
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: With respect to LT2ESWTR reporting and recordkeeping requirements, IEPA is
concerned about the requirement for electronic reporting for large systems due to problems encountered
in ICR and UCMR reporting (although states do recognize that improvements have been made since the
ICR and UCMR reporting began). In this regard, EPA should consider the language in the FACA
Agreement pertaining to potential delays in implementation based on the availability of data management
software. Additionally, EPA and IEPA will need to work together to resolve any issues that may arise
when EPA tries to transfer large system data to us.
Response: See Responses 371(A) and (C).
EPA Letter ID: 528
Comment ID: 12246
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Large System Cryptosporidium Results Being Reported Directly to EPA
We have expressed concern about the proposed requirement that large system Cryptosporidium results be
reported directly to EPA. We have reservations about deviating from the traditional water system-to-state
reporting scheme as well as using a data system similar to the system used under the ICR and UCMR due
to problems encountered in those. Since we will be working directly with the systems in Arkansas to
assure monitoring and reporting, we feel that electronic
reporting to EPA from the system is unnecessary. We request state flexibility in this area.
Response: See Responses 371(A) and (C).
EPA Letter ID: 533
Comment ID: 12213
Commenter: Edward Urheim,,
Commenter Category: Consultants: (where self-identified)
Comment: implementation. I believe that the State Primacy Agency in each State is the
appropriate agency to implement the final rule. Through the years, during the implementation of the
SDWA, the State Programs have established good working relationships with the public water systems
they regulate. I believe that the States and the water systems will work together and do a better job
implementing this important rule, resulting in better public health protection. I also
Response: See Response 371(C).
EPA Letter ID: 536
Comment ID: 11809
Comment Response for the LT2ESWTR
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Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: With respect to LT2ESWTR reporting and record keeping requirements, Colorado is
concerned about the requirement for electronic reporting for large systems due to problems encountered
in ICR and UCMR reporting (although we do recognize that improvements have been made since the ICR
and UCMR reporting began). In this regard, EPA should consider the language in the FACA Agreement
pertaining to potential delays in implementation based on the availability of data management software.
Additionally, EPA and states will need to work together to resolve any issues that may arise when EPA
tries to transfer large system data to individual states.
Response: See Responses 371(A) and (C).
EPA Letter ID: 588
Comment ID: 12092
Commenter: Lance Nielson, Manager, Idaho Drinking Water Program, Department of Environmental
Quality
Commenter Category: State/Tribe Government
Comment: prepare a primacy package. Early implementation may require EPA to deal directly
with Idaho water systems until the State can legally do so. EPA does not have the resources to do this
effectively, and such a "dual primacy" approach may undermine working relationships that the State has
established with its water systems.
Response: See Response 371(C).
EPA Letter ID: 598
Comment ID: 12617
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: Reporting Overview
Section 1V.J beginning on page 47724, and phrases in other places of the preamble, state that large
systems serving 10,000people or more will report cryptosporidium monitoring results from the initial
round directly to EPA through an electronic data system. This monitoring and reporting begins prior to
rule implementation by the state primacy agency, which have two years to adopt
the LT2ESWTR. We do not take issue with the need to monitor or begin the process in a timely fashion.
But when we, as a utility, have to report data to EPA, and they in turn send it to the states after the state
obtains primacy, this sets a circuitous reporting mechanism in place. It would be much simpler to report
directly to the state primacy agency. The Stage 2 Disinfectants and Disinfection By-products Rule, which
was proposed concurrently with the LT2ESWTR, recognizes the early implementation and compliance
monitoring issue, makes some recommendations and requests comments on what to do about it. EPA
should employ this same understanding and rational in the LT2ESWTR rules. We suggest the EPA give
automatic extensions, interim primacy, or a similar process to the state regulatory agencies so that the
utility only has one regulatory agency to coordinate with.
Comment Response for the LT2ESWTR 5-189 December 2005
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Response: See Response 371(C).
EPA Letter ID: 601
Comment ID: 13015
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1210 A. Large System Monitoring and Treatment
Comment: This need for states and water systems to work together to address deviations
from monitoring plans and missed samples is another example of the need to delay microbial monitoring
by 18 months. Without such a delay, many Utah water
Response: See Responses 371(C) and 1200.c.
EPA Letter ID: 601
Comment ID: 13016
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: microbial monitoring by 18 months. Without such a delay, many Utah water systems would
need to work with EPA Region 8 to address these issues until Utah obtains primacy. Utah water systems
have expressed a strong desire to not set up protocols to first report to and work long distance with EPA
and then switch to the State, they much prefer to work closely with the state, up front, to address the
requirements in the rule and implement those requirements in a
timely and efficient manner.
Response: See Response 371(C).
EPA Letter ID: 603
Comment ID: 12650
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47780) Section 141.707(a)-
It makes sense that EPA receive monitoring results directly from water systems that serve at least 10,000
people with such a short period between rule promulgation and the deadline for Submission of monitoring
results. There is some concern that the monitoring information may not be received by the States in a
timely and manner. Inserting the text "which EPA will forward to the states within 30 days of receipt of
the results." after the last paragraph for these two system categories should relieve this concern. We
encourage EPA to consider similar language when real or perceived public health concerns drive actions
faster than the state can establish primacy for a particular regulation.
Comment Response for the LT2ESWTR 5-190 December 2005
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Response: See Response 371(C).
EPA Letter ID: 637
Comment ID: 13106
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: Please see District comments on compliance schedule. Initial reporting to EPA then
transferring compliance reporting to States is inappropriate and will place undo burden on water systems.
Response: See Response 371(C).
EPA Letter ID: 643
Comment ID: 12715
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Large System Cryptosporidium Results Being Reported Directly to EPA
Some states have expressed concern about the proposed requirement that large system Cryptosporidium
results be reported directly to EPA. States appreciate EPA-s intention to provide direct implementation of
the early implementation requirements of the LT2ESWTR, but have reservations about deviating from the
traditional water system-to-state reporting scheme as well as using a data system similar to the system
used under the ICR and UCMR due to problems
encountered in those initiatives (although states do recognize that improvements have been made since
the ICR and UCMR reporting began). In this regard, EPA should carefully consider the readiness and
reliability of the electronic data system. If the data system is not ready, EPA should consider employing
the language in the FACA Agreement (cited previously) pertaining to potential delays in implementation
based on the availability of data management software.
States are also concerned about the transfer of Cryptosporidium data from EPA to individual states. EPA
and states will need to work together to resolve any issues that may arise related to this data transfer.
Response: See Response 371(A) and (C).
EPA Letter ID: 643
Comment ID: 12759
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As indicated previously, some states have expressed concern about the proposed
requirement that large system Cryptosporidium results be reported directly to EPA, the reporting system
to be used, and potential problems transferring of Cryptosporidium data from EPA to individual states.
EPA should carefully consider each of these issues when developing the final rule.
Comment Response for the LT2ESWTR 5-191 December 2005
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Response: See Response 371(C).
EPA Letter ID: 647
Comment ID: 12908
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: With respect to LT2ESWTR reporting and recordkeeping requirements, MDE is
concerned about the requirement for electronic reporting for large systems due to problems encountered
in ICR and UCMR reporting. MDE is also concerned with
Response: See Response 371(A).
5.7.2 Comment Code 372, Electronic data reporting and review system
Summary of Issues
Comments were submitted concerning the data management system. Comments suggested that the data
management system would need to be beta-tested and in place before the rule is promulgated or the
monitoring schedule would need to be delayed. Comments also suggested including user training,
software documentation, help screens, help desk functions, a notification system, and an oocyst
countdown meter. Commenters were also concerned about data submission where some systems do not
have access to a computer. One commenter requested that the data management system have a function
that allows laboratories or PWSs to invalidate sample data analysis that is out of the normal range of a
water system, so that the PWS will not potentially be place into the incorrect bin classification. A final
commenter suggests that the LT2ESWTR should identify all the violations that can be incurred rather
than identify the lack of a violation.
Response to Code 372
See Response 371.
Individual Comments on Code 372
EPA Letter ID: 457
Comment ID: 11905
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Data Management Issues
EPA must be aware of the impact the requirements of this rule will have on data management systems,
especially with consideration of the proposed requirements for electronic reporting by large systems
directly to EPA. If the data management aspects of this rule are not properly addressed at the time the rule
Comment Response for the LT2ESWTR 5-192 December 2005
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is promulgated, the states and the water systems may not be able to
implement the rule.
Response: See Response 371(A) and (C).
EPA Letter ID: 457
Comment ID: 11907
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: With respect to LT2ESWTR reporting and recordkeeping requirements, we are
concerned about the requirement for electronic reporting for large systems due to previous problems
encountered in ICR reporting. EPA must consider delays in implementation of the rule based on the
availability of data management software.
Response: See Response 371(A).
EPA Letter ID: 466
Comment ID: 11024
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: ND is concerned about the following data management issues as they pertain to the
LT2ESWTR. The requirement for electronic reporting for large systems because of problems encountered
in the ICR and UCMR. We are also concerned with the
Response: See Response 371(A).
EPA Letter ID: 483
Comment ID: 11260
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: the capacity available is sufficient. EPA should have a database that has been
beta-tested, is in place, and operational prior to rule implementation.
Response: See Response 371(A).
Comment Response for the LT2ESWTR 5-193 December 2005
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EPA Letter ID: 483
Comment ID: 11261
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: - EPA does not address or allow for invalidation of sample data that meets all QA/QC
requirements but still may not be representative of a water system-s source. For example, it has been our
experience that laboratory analytical results which are outside the typical range the system experiences
can occur without any explanation as to the cause of the inconsistent result i.e. statistical outlier. Mistakes
can occur even when all QA/QC requirements are met. The Rule does not address how a system can
invalidate unusual or inconsistent data. Without a means of invalidating data, the system is subject to
reporting inaccurate data which could potentially put them in a different Bin Classification resulting in
significant but unnecessary financial consequences. The regulation should address how -outliers- can be
handled so that water
systems can avoid being placed in a higher Bin Classification due to errors in the sampling and/or
analysis.
Response: See Response 371(D).
EPA Letter ID: 493
Comment ID: 11244
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment: In addition, some systems may not have a computer to submit data electronically to EPA.
This is not addressed within this section?
Response: See Response 371(E).
EPA Letter ID: 520
Comment ID: 11605
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Data Management Issues
EPA must be cognizant of the impact the requirements of this rule will have on data management
systems, especially with consideration of the proposed requirements for electronic reporting by large
systems directly to EPA. If the data management aspects of this rule are not properly addressed, IEPA
will not be able to implement the rule as intended.
Response: See Response 371(C).
Comment Response for the LT2ESWTR 5-194 December 2005
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EPA Letter ID: 528
Comment ID: 12266
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Data Management Issues
EPA must be cognizant of the impact the requirements of this rule will have on data management
systems, especially with consideration of the proposed requirements for electronic reporting by large
systems directly to EPA. If the data management aspects of this rule are not properly addressed, states
will not be able to implement the rule.
Response: See Response 371(C).
EPA Letter ID: 534
Comment ID: 12005
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: Previous experience with EPA-s electronic data systems (Unregulated Contaminants
Monitoring Rule and Information Collection Rule) was nothing short of miserable for water systems. This
proposal involves an even larger number of systems and samples. Because the electronic data system is
central to the success of the rule, it is imperative that EPA make sure that full tested, userfriendly data
management software is available and in place prior to
finalizing the LT2ESWTR. The rule should provide sufficient flexibility to adjust monitoring and
compliance schedules in the event that appropriate data management software is unavailable or available
data management software is inadequate.-
Response: See Response 371(A).
EPA Letter ID: 534
Comment ID: 12011
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Other EPA Comment Codes and Descriptions: 1831 1. Need for EPA estimate
Comment: this mean -grandfathered- data is invalid? Due to the timeframes, the number of
water systems affected, and the potential for significant capital investment, it is imperative that EPA
ensures the laboratory and data management capabilities are in place so that water systems have a
reasonable potential to comply.
Response: See Responses 371(C) and 1830.
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EPA Letter ID: 536
Comment ID: 11807
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Data Management Issues
EPA must be cognizant of the impact the requirements of this rule will have on data management
systems, especially with consideration of the proposed requirements for electronic reporting by large
systems directly to EPA. If the data management aspects of this rule are not properly addressed, states
will not be able to implement the rule as intended.
Response: See Response 371(C).
EPA Letter ID: 556
Comment ID: 12049
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Both the Information Collection Rule and the Unregulated Contaminants Monitoring
Rule became virtual nightmares for water systems and regulators alike because of problems with data
management software. Because of the greater number of systems and samples that are involved in the
present proposal compared to these two rules, it is vital that the system be in place, fully tested, and users
fully trained prior to fmalization of the rule.
Recommendation: Data management software is so central to the Agreement in Principle and ultimate
success of the rule that it calls for special consideration. AMWA recommends that at least six months
prior to finalizing the LT2ESWTR and accompanying Stage 2 DBPR, EPA issue a NODA outlining data
management software availability in addition to laboratory capacity as recommended above. At that time
the Agency will know whether or not the software is available and sufficiently user friendly to allow
timely implementation of the rule. If the software is not available, the monitoring schedule should be
delayed as specified in the agreement.
Additionally, it is possible that data management software will prove inadequate for timely
implementation of the rule after the rules are finalized even though EPA determined prior to finalizing the
rule that the software was ready and sufficient for its purpose. It is therefore necessary that both rules
contain specific provisions that allow for changes in compliance schedules based on data management
software availability. Such a provision is required to meet the commitment made by the Agency in the
Agreement in Principle.
Response: See Response 371(A).
EPA Letter ID: 562
Comment ID: 12304
Comment Response for the LT2ESWTR
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: is valid under the LT2ESWTR. In defining performance of EPA Method 1622/1623
and describing the LT2ESWTR data reporting process, EPA has provided an opportunity for utilities to
contest- specific monitoring results. EPA should further elaborate on the data reporting process to
provide for (1) appropriate documentation of sample results by laboratories and (2) an administrative
review of contested data. Such review should include the involvement of microbiologists with relevant
skills and experience.
Response: See Response 371(B) and (D).
EPA Letter ID: 562
Comment ID: 12354
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA believes that the key to success in implementing the data management
software includes:
1. Provision of adequate user training, software documentation, help screens, and a help desk function for
the software system.
2. A notification system that will warn EPA, laboratories, and utilities when data are not submitted in a
timely manner. This will allow the parties to troubleshoot the data entry process to correct missing or
erroneous data.
3. Implementation of an oocyst countdown meter. This meter would indicate how many oocysts could be
counted in future samples before the utility reaches the treatment requirements of bin 2, 3, or 4.
AWWA believes that EPA needs to be prepared to assist in future LT2ESWTR implementation in cases
where a state has not been granted primacy at the time when a bin determination is needed. EPA will need
to engage in dialogue with utilities in states where primacy has not been established and be able to issue a
bin determination.
Response: See Response 371(A), (B) and (C).
EPA Letter ID: 593
Comment ID: 11816
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 1832 2. Adequacy of current capacity
Comment: 2. Monitoring Lab Capacity: EPA appears to be taking the position that if the agency requires
monitoring, then monitoring capability will be expanded to meet market demand. SAWS- believes that it
is unreasonable to develop additional capacity for a short duration of time. In the past, databases for data
management were not in place or had problems prior to rule promulgation (e.g., the Information
Collection Rule and the Unregulated Contaminant Monitoring Rule databases are examples that lead to
Comment Response for the LT2ESWTR 5-197 December 2005
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Comment Codes 300-471
significant compliance problems). SAWS
recommends the following: EPA conform to requirements of the Agreement in Principle so that water
systems are not held responsible for meeting impossible schedules and falling into non-compliance if
analytical capacity or data management system is unavailable. EPA publishes a formal determination in
the Federal Register open for comments that laboratory capacity and database management software are
available. Develop a database that has been beta-tested, is in-place, and operational prior to rule
implementation.
Response: See Responses 371(A) and 1830.
EPA Letter ID: 598
Comment ID: 12618
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: Reporting Process
Section IV.J on page 47726, and in other places, mentions that EPA is developing an Internet-based
electronic data collection and management system similar to that used for the Unregulated Contaminant
Monitoring Rule (UCMR) for systems to use in reporting cryptosporidium monitoring data. We
recommend that EPA have a database that has been beta tested, is in-place, and operational prior to rule
implementation. This will minimize potential data handling problems similar to those experienced in the
Information Collection Rule and UCMR. Also, as we
Response: See Response 371(A).
EPA Letter ID: 601
Comment ID: 13039
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: With respect to LT2ESWTR reporting and recordkeeping requirements, states are
concerned about the requirement for electronic reporting for large systems due to problems encountered
in ICR and UCMR reporting (although states do recognize that improvements have been made since the
ICR and UCMR reporting began). In this regard, EPA should consider the language in the FACA
Agreement pertaining to potential delays in implementation based on the availability of data management
software. Additionally, EPA and states will need to work together to resolve any issues that may arise
when EPA tries to transfer large system data to individual states.
Response: See Response 371(A)and(C).
EPA Letter ID: 620
Comment ID: 13288
Comment Response for the LT2ESWTR
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Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: analysis is also unclear to SPRWS. EPA should also ensure that the data management
software is in place and functional prior to the data collection period beginning. If laboratory capacity is
inadequate or if data collection
Response: See Response 371(A).
EPA Letter ID: 625
Comment ID: 13137
Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: capacity and quality is available. Software used in this program should be beta-
tested and fully functional before this rule is implemented.
Response: See Response 371(A).
EPA Letter ID: 630
Comment ID: 13058
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: effective. Additionally, EPA should have a database that has been beta-tested,
is in-place, and operational prior to rule implementation.
Response: See Response 371(A).
EPA Letter ID: 631
Comment ID: 13242
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: Finally, databases for data management were not in place or had problems prior
to rule promulgation for both the ICR and UCMR databases. Prior to implementation of the rule, EPA
should have a database that has been beta-tested, is in-place, and is operational.
Response: See Response 371(A).
Comment Response for the LT2ESWTR 5-199 December 2005
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EPA Letter ID: 643
Comment ID: 12757
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Data Management Issues
EPA must be cognizant of the impact the requirements of this rule will have on data management
systems, especially with consideration of the proposed requirements for electronic reporting by large
systems directly to EPA. If the data management aspects of this rule are not properly addressed, states
will not be able to implement the rule as intended.
Response: See Response 371(C).
EPA Letter ID: 647
Comment ID: 12906
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Data Management Issues
EPA must be cognizant of the impact the requirements of this rule will have on data management
systems, especially with consideration of the proposed requirements for electronic reporting by large
systems directly to EPA. If the data management aspects of this rule are not properly addressed, states
will not be able to implement the rule as intended.
Response: See Response 371(C).
EPA Letter ID: 662
Comment ID: 14026
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: compliance with this rule. The same concerns hold for lack of appropriate
databases to handle the information.
Response: See Response 371(A).
EPA Letter ID: 668
Comment ID: 13894
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment Response for the LT2ESWTR 5-200 December 2005
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Comment: Specific Response to Requests for Comments
- EPA should indeed require electronic data reporting for all results (p. 47666)
Response: Thank you for your support.
EPA Letter ID: 678
Comment ID: 14661
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 1832 2. Adequacy of current capacity
Comment: 4. Section 141.702 - We are concerned that there may be monitoring compliance issues
caused by factors beyond the control of many water systems. These factors may include a lack of
sufficient laboratory capacity and unavailability of data management software from the
EPA. The Agreement in Principle states that the compliance schedules for the LT2 Rule will be tied to the
availability of sufficient analytical capacity for Cryptosporidium at approved
laboratories and the availability of data management software. If either is unavailable, the monitoring,
implementation, and compliance schedules for the LT2 Rule will be delayed an equivalent period of time.
As written, the proposed rule indicates the EPA is taking the position that if the agency requires
monitoring then the monitoring capability will be expanded to meet the market demand. Some water
systems with analytical capabilities and laboratories, however, state that it is unreasonable for them to
develop additional capacity just for a short duration of time to meet the first and second rounds of
monitoring. Furthermore, the past history (e.g., the ICR and UCMR databases) shows that appropriate
data management software was not in place or had problems prior to the final rule promulgation.
Response: See Responses 371(A) and 1830.
EPA Letter ID: 678
Comment ID: 14663
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: rule becomes effective. We also recommend the EPA have a database that has been beta-
tested, is in-place, and is operational prior to rule implementation. Prior to issuing the final rule, the EPA
Response: See Response 371(A).
EPA Letter ID: 683
Comment ID: 14764
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
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Comment: Finally, databases for data management were not in place or had problems
prior to rule promulgation for both the ICR and UCMR databases. Prior to implementation of the rule,
EPA should have a database that has been beta-tested, is in-place, and is operational.
Response: See Response 371(A).
EPA Letter ID: 706
Comment ID: 14807
Commenter: John Spatz, Deputy Commissioner, City of Chicago Department of Water Management
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 1832 2. Adequacy of current capacity
Comment: 1. PROMULGATION OF RULE
Laboratory Capacity and Software Availability
The EPA should be sure to have the laboratory space and software available to perform the analyses and
accept the information requested for the LT2SWTR prior promulgation of the rule.
Response: See Response 1830.
EPA Letter ID: 711
Comment ID: 16548
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 3. Section 141.707(a) - Since EPA expects data submittal to be done electronically, EPA
should have a database that has been beta-tested, is in-place, and operational prior to rule implementation.
Otherwise, the rule should include specific alternatives clearly stating what submittal methods should be
followed if the database is not ready. This is also true elsewhere in the proposed rule where electronic
submittal is indicated.
Response: See Response 371(A).
EPA Letter ID: 712
Comment ID: 16585
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Section IV.J.4.b mentions an electronic data collection system similar to that
used by the UCMR. How this system would respond to inventory data changes should be addressed. The
UCMR database was not capable of responding to State changes in the PWS inventory. This resulted in
confusion when several systems attempted to add data directly into the UCMR database.
Response: See Response 371(A).
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EPA Letter ID: 712
Comment ID: 16587
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: LT2-Section Iv.J.2.b- states in part -A system will not incur a violation...-.
The regulations should identify all the violations that can be incurred rather than identify the lack of a
violation.
Response: See Response 371(A).
5.7.3 Comment Code 375, Time-frame for reporting
Summary of Issues
Comments were submitted concerning the data reporting requirements. Commenters suggested editing the
rule language concerning the deadline for data submission from "10 days after the end of the month
following the month when the sample is collected" to 72 days after the sample was collected" to allow
samples to be more evenly spread throughout the month for laboratories and to give public water systems
the maximum amount of time to report data. Comments suggested that late reporting should be allowed if
there are laboratory capacity issues. Commenters also expressed concern in preparing water suppliers for
monitoring and reviewing results. Comments suggested moving monitoring back an additional 18 months
from the proposed 6 months. One commenter suggested the turnaround time required for submitting
monitoring results be by postmark date or electronic data release date, not a receipt date.
Response to Code 375
Data Reporting
EPA believes that the rule language concerning the deadline for data submission of "10 days after the end
of the month following the month when the sample is collected" is appropriate and allows for adequate
time for data reporting. It is also consistent with reporting requirements for other EPA drinking water
regulations and will therefore result in less confusion. Submission and review of results via the LT2 Data
Collection System will also result in quicker submission and review times. EPA has staggered the
implementation of monitoring for large systems and believes that laboratory capacity will be sufficient
and provisions for late reporting will not be necessary.
Early Implementation
In general, EPA would prefer that States oversee monitoring by their PWSs and will work with States to
facilitate their involvement with rule implementation. Where States are unable to implement today's rule,
however, EPA is prepared to oversee implementation. Moreover, EPA believes that the staggered
compliance schedule in today's final rule will enhance the ability of States and EPA to implement the
rule. EPA has initiated a rigorous and extensive training program to prepare PWSs, States and EPA
Regional offices for implementation. EPA has also developed a tracking system to assure proper
Comment Response for the LT2ESWTR 5-203 December 2005
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implementation of rule requirements, including review of plans and schedule; sampling results, methods
and QA/QC; and grandfathered data.
Individual Comments on Code 375
EPA Letter ID: 398
Comment ID: 10537
Commenter: Ron Kailey, Laboratory Supervisor, Cheyenne Board of Public Utilities
Commenter Category: Regulated Community (Utilities)
Comment: If we cannot do the testing in-house, then the WTP needs more time (72 day reporting period)
to get the results back from the contract labs.
Response: See Response 375.
EPA Letter ID: 406
Comment ID: 10531
Commenter: Anonymous406,,
Commenter Category: Regulated Community (Utilities)
Comment: EPA is exasperating the lab capacity problem by its current reporting requirements of
reporting by the 10th of the second month after sample collection. We have been trained to take the
sample as early in the monitoring period as possible to ensure compliance. So many systems will be
taking their samples in the first week of the month overwhelming lab capacity. If you simply changed the
time when reporting was due to 72 days (the max time when a system samples on the first of the month of
a 31 day month and then skips a 31 day month and reports by the 10th of the third month) then systems
could monitor any time during the month and still have the maximum amount of time to report, it would
spread samples out for the laboratory. This simple change would be mutually beneficial to water systems
and labs and make the implemenation of this rule more successful
Response: See Response 375.
EPA Letter ID: 435
Comment ID: 10605
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Comment: Colorado Springs Utilities (PWSID # CO0121150) recommends that the
proposed reporting requirement that "results must be submitted not later than ten days after the end of the
month following the month when the sample is collected" be changed to "results must be submitted no
later than 72 days after the sample is collected." This will allow laboratories and utilities to more
uniformly schedule sampling throughout the month. As proposed, most utilities
will want the same sampling dates resulting in increased pressures to the laboratories.
Response: See Response 375.
Comment Response for the LT2ESWTR 5-204 December 2005
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EPA Letter ID: 463
Comment ID: 11028
Commenter: Richard Wilson, Environmental Services Manager, Anaheim Public Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment: 1. Section 141.707(d) requires monitoring results to be submitted within 10 days
of the end of the month that the samples were collected.
No water utility should be held to this schedule if sufficient laboratory capacity is not available for
Cryptosporidium analyses. A mechanism should be provided to allow late reporting in cases where
laboratory capacity issues were the reason for the delay.
Response: See Response 375.
EPA Letter ID: 497
Comment ID: 10646
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: regulator to provide oversight and review monitoring plans. However, the EPA
should not anticipate state participation if the proposed rule includes early implementation compliance
schedules.
Early Implementation
The EPA proposes to assume responsibility for large system monitoring and reporting under the
LT2ESWTR. The EPA will not be prepared to guide our water suppliers through this early monitoring
and to review results. Specifically, compliance dates for monitoring should be moved back an additional
18 months from the proposed 6 months after rule promulgation.
Response: See Response 375.
EPA Letter ID: 641
Comment ID: 13624
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 5.1.5.3, Page 29 - Data Turnaround Requirements -
3rd Paragraph, 3rd sentence This includes up to 4 days between sample collection and initiation of the
elution step, which effectively is the maximum time for any shipping delay—
A reader could infer from this that samples can be sent by other than overnight priority courier, which
should be strongly discouraged. If samples are not sent by overnight priority delivery, it is very likely that
they will rejected due to sample temperatures outside the acceptance criteria. We recommend it be clearly
Comment Response for the LT2ESWTR 5-205 December 2005
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stated that all samples should be sent by overnight priority delivery or courier the day of collection or the
following day to assure laboratory receipt within accepted sample processing times and conditions. In
general, the turnaround time section is needlessly complex. It should be revised to simply state (or at least
conclude): -Given method hold times and time for data validation, EPA recommends a TAT of 20
calendar days. This will allow the laboratory adequate time to process the sample, and to review and input
the data, while also
ensuring the PWS has time to comply with data submittal requirements .-
Response: The guidance manuals have been revised to clearly recommend overnight shipping and to
simplify the turnaround time section.
EPA Letter ID: 641
Comment ID: 13625
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 4th Paragraph
—The same date can be specified for both submission of electronic data and receipt of hardcopy
materials.-
Obviously, laboratories have no control over US Mail delivery. A more practical suggestion would be for
PWSs to specify turnaround time by postmark date or electronic data release date, not a receipt date.
Response: See Response 375.
5.8 Comment Codes 380, Use of Previously Collected Data (i.e.,
grandfathering)
Summary of Issues
Fourteen comments supported the acceptance of grandfathered data in addition to or in lieu of the
required monitoring. The comments supported the use of grandfathered data to reward proactive utilities,
reduce the laboratory capacity burden, increase the monitoring time period, and provide the utility more
time to implement treatment changes if needed. Of the fourteen comments, two requested data are
accepted only if methodology and defined criteria were met. One of the fourteen comments disagreed that
the acceptance of grandfathered data as stated in the rule rewarded the proactive utility and developed lab
capacity. Comments also were received supporting LT2ESWTR's risk-based approach.
Response to Code 380
Acceptance of grandfather data
EPA agrees that data collected prior to the promulgation of the rule may be acceptable in lieu of or in
addition to conducting new monitoring under the rule. EPA agrees that the acceptance of equivalent
previously collected data will provide a number of benefits, including early determination of LT2ESWTR
compliance needs, increasing laboratory capacity, rewarding proactive PWS's, and allowing PWSs to
Comment Response for the LT2ESWTR 5-206 December 2005
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determine their bin classification using a larger, and potentially more representative, data set.
However, EPA believes that data quality standards should be uniformly applied under today's rule, so that
previously collected data should not be held to a lower standard than new data or evaluated differently
from State to State. The requirements in today's rule with respect to Cryptosporidium analytical methods
and minimum sample volume reflect recommendations of the Advisory Committee, which also
recommended that the same data quality standards be applied for grandfathering. Further, because today's
rule allows PWSs to collect make-up samples to address gaps in previously collected data sets, PWSs will
have the opportunity to collect make-up samples for results that are rejected due to data quality standards
without losing an entire data set.
Individual Comments on Code 380
EPA Letter ID: 439
Comment ID: 10750
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: Grandfathering of data should be allowed since water systems that use this data would not
have to send samples out to the contract laboratories. Grandfathering data then would actually help reduce
lab capacity issues as mentioned in issue 1 above. Also, data collected prior to rule implementation could
be used by the water system to determine bin classification earlier so that corrective measures could be
initiated to ensure compliance. The data gathered under ICR
Response: See Response 380.
EPA Letter ID: 457
Comment ID: 11916
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: With respect to the specific issues on which EPA requested comment, we believe that EPA
should provide the states with flexibility to address these concerns on a case-by-case basis. The EPA
could present the following specific issues as a way of guidance to the states:
* How to consider previously collected monitoring data that do not meet
QC requirements;
Response: See Response 381.
EPA Letter ID: 460
Comment ID: 10992
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-207 December 2005
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Comment: 2. Grandfathered Data:
City-s position: The City believes using grandfathered data is appropriate and should be included as long
as approved methodologies have been used to generate the data. This would also help avoid the
overloading of certified laboratories.
If the intent of the language in the proposed Rule is to have a nationwide collection of data from a single
time frame, a snapshot, that essentially duplicates the ICR. It seems that this data set would be subject to
the same limitations. It is the City-s contention that data collected over a long period
of time will ultimately be more reflective of actual occurrence. A specific example is that our system, and
many like it, can experience several to many years in a row of uneventful weather.
Should the Rule-s mandated sampling period occur at such a time, and should the Rule allow only data
collected during that time, there is the possibility that the data would be of little or no actual use to the
Utility or EPA in evaluating the potential vulnerability of the supply. On the other hand, the City of
Norfolk has a wealth of data that covers several remarkable weather events, including a recent drought
and several hurricanes.
Response: See Response 380.
EPA Letter ID: 506
Comment ID: 10730
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: o Grandfathering Data - CWD supports the Agreement in Principle, which allowed
for grandfathering of previous source water monitoring data. This allows water systems that have been
proactively performing monitoring to take advantage of it and be rewarded for their efforts. A greater
number of samples will help ensure that the water system is placed in the correct bin. A system that
utilizes grandfathered data to determine that additional treatment is necessary would then have more time
to implement changes. Additionally, grandfathering of data would help alleviate the problem of
laboratory capacity discussed above.
Response: See Response 380.
EPA Letter ID: 512
Comment ID: 11498
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Grandfathering data - EPA should encourage and facilitate the use of
grandfathered data
Since the Information Collection Rule (ICR) started, and in some cases long before, many utilities have
voluntarily undertaken significant efforts to monitor for Cryptosporidium in their source waters (Contra
Costa Water District has done so since 1991). Every effort to incorporate this pool of data into the Bin
determinant phase of this rule must be made. EPA has proposed stringent
Comment Response for the LT2ESWTR 5-208 December 2005
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requirements that were not in place during previous data collection efforts. The requirements should be
revised with a focus on the goal of ensuring that systems are classified in the appropriate bin rather than
adherence to strict analytical and monitoring specifications.
Response: See Response 380.
EPA Letter ID: 512
Comment ID: 11510
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Grandfathering Data
a. The pool of existing data can ease some of the burden of lab capacity issues and should be utilized to
the full extent
Response: See Response 380.
EPA Letter ID: 526
Comment ID: 11768
Commenter: Nick Jackson,, Knoxville Utilities Board
Commenter Category: Local Government
Comment: 4. KUB has a considerable amount of Cryptosporidium and Giardia data collected
since the early 1990s as well as ICR data run by an outside laboratory. We are very much interested in
grandfathering this data. While we are aware source water quality changes overtime, we suggest EPA
consider a reduced monitoring period for those systems with sufficient existing data provided the latest
monitoring is consistent with the grandfathered data. (Perhaps demonstrate consistency over three
months?) This would reduce analytical loads for approved
laboratories, allow utilities who were proactive in implementing monitoring to recoup their investments
and still accomplish the intent of the law.
Response: See Response 381.
EPA Letter ID: 534
Comment ID: 12000
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: In addition, the -source water- sampling location used by facilities with Existing
presedimentation unit processes during the ICR and ICRSS would no longer be valid, making the data
from these efforts ineligible for -grandfathering- under this rule.
Comment Response for the LT2ESWTR 5-209 December 2005
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Response: See Response 381.
EPA Letter ID: 562
Comment ID: 12370
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 300 II. Filtered System Monitoring Requirements
(parameters, frequency, location)
Comment: 2. Both defined monitoring and previously collected Cryptosporidium oocyst data are
appropriate for binning,
EPA has reflected each of these components in the proposed rule. AWWA continues to believe that each
of these five recommendations is sound and appropriate for the LT2ESWTR. AWWA is concerned about
the specifics of EPA-s implementation of these general recommendations.
Response: See Responses 380 and 310(C).
EPA Letter ID: 562
Comment ID: 12392
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: sampling approach and approve re-sampling events. AWWA will not assert that
EPA-s handling of grandfathered data is contrary to the Agreement in Principle, as the agreement clearly
contains grandfathering provisions. However, the agency is not proposing a rule that meets the intent of
the Agreement in Principle, as the agency is not:
1. Rewarding utilities that are engaged in proactive source water monitoring that occurred prior to the
FACA Agreement (September 2000) or
2. Developing increased lab capacity by encouraging additional monitoring prior to LT2ESWTR
implementation.
The previous comments above provide a possible solution for the presence of gaps in a preexisting sample
data set. EPA-s Source Water Monitoring
Response: See Response 380.
EPA Letter ID: 625
Comment ID: 13138
Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
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Comment: 2) Grandfathered data
Systems such as the Cobb County -Marietta Water Authority should be rewarded for being proactive in
implementing this rule by taking advantage of the grandfather proposals that were included in the
Agreement in Principle. Furthermore, such a proactive position enhances the protection of the citizenry in
that the utility has the opportunity to select the most competent laboratory for the analytical task. The rush
to comply with the regulation will overload the qualified laboratories, possibly leading to the use of
marginal laboratories by some utilities. The Cobb County -Marietta Water Authority, in order to ensure
space in one of the better laboratories, began monthly monitoring of its two raw water sources in May of
2003, collecting 16 samples to date. Additionally, there is available 12 months of Supplemental ICR data
that should be included in bin classification.
Response: See Response 380.
EPA Letter ID: 627
Comment ID: 12634
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: 2. Grandfathered Data:
City-s position: The City believes using grandfathered data is appropriate and included as long as
approved methodologies have been used to generate the data. This would also help avoid the overloading
of certified laboratories.
If the intent of the language in the proposed Rule is to have a nationwide collection of data from a single
time frame, a snapshot, that essentially duplicates the ICR
It seems that this data set would be subject to the same limitations. It is the City-s contention that data
collected over a long period of time will ultimately be more reflective of actual occurrence. A specific
example is that our system, and many like it, can experience several to many years in a row of uneventful
weather.
Should the Rule-s mandated sampling period occur at such a time, and should the Rule allow only data
collected during that time, there is the possibility that the data would be of little or no actual use to the
Utility or EPA in evaluating the potential vulnerability of the supply. On the other hand, the City of
Norfolk has a wealth of data that covers several remarkable weather events, including a recent drought
and several hurricanes.
Response: See Response 380.
EPA Letter ID: 630
Comment ID: 13061
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-211 December 2005
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Comment: lab failures. In addition, EPA must allow for the probability that missed samples may (and
do) happen. EPA should have utilities build dates into their sampling schedules for additional samples in
the event of missed samples, and provide reasons why the samples were missed, (e.g. it could be
something like 30 sampling dates so that 6 extra dates above the minimum requirement of 24 be available
if samples are missed). EPA should make reasonable provisions for
Response: See Responses 360 and 380.
EPA Letter ID: 641
Comment ID: 13590
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47677 d. Basis for accepting previously collected data - ASI agrees with all four stated
objectives for accepting of previously collected data.
Response: See Response 381.
EPA Letter ID: 641
Comment ID: 13655
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Comments on the Grandfathering Guidance Manual for LT2 (April 2003)
Section 2.0
" -Under the Agreement, grandfathered data may be used in lieu of, in addition to, results generated
during LT2 implementation- "
ASI supports the allowance of grandfathered data to spread out the monitoring and to allow PWSs to
submit more data.
Response: See Response 380.
EPA Letter ID: 711
Comment ID: 16549
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 4. Section 141.708 (b)(3) and (c)(l) - Due to the term "system" being used instead of
addressing each plant influent more directly, interpreting whether our previously collected data meet the
criteria in this section is difficult. Previously collected data that meet the criteria for the different plants
might actually fall in different time periods. For example, our previously collected data were collected
Comment Response for the LT2ESWTR 5-212 December 2005
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after 1/99. However, the data that meet the criteria for one of the plants could be from 6/99 to 5/01
whereas another plant's data could be from 1/00 to 12/01. It is unclear whether both sets of data would
meet the grandfathering criteria reading this verbiage.
Response: See Response 381.
5.8.1 Comment Codes 381, Sample acceptance criteria (frequency,
volume, analytical method)
Summary of Issues
The majority of comments requested that flexibility be incorporated into the grandfathered data
acceptance criteria. It was suggested that flexibility be incorporated by determining acceptance on a case-
by-case basis, letting the States determine the data criteria, and accepting data with variations in the
sample collection schedule, sample collection window, sample collection frequency including data gaps,
sample temperature requirements, subsampling, method versions, compliance with analytical
requirements including holding times and QC, and the analyses of matrix spike samples which are not
being utilitized. Sixteen comments stated that the acceptance of grandfathered data should focus on
appropriate bin placement not on strict compliance to analytical requirements. These comments included
acceptance of ICR data which may be more appropriate because of more data points, data collected from
the accepted EPA method at the time of sample collection, and acceptance of data as long as sample
collection accounts for seasonality. Four additional comments also stated that data collected using the
ICR method should be acceptable because more data points would result in more accurate bin placement.
Other suggestions for acceptable data included data generated from Method 1623 (any version), data not
necessarily of equivalent quality, data collected in good faith, data representing seasonal variation, data
generated by the ICR method, data collected a maximum of 12 months prior to promulgation, and data
meeting minimum QA/QC standards. Several commenters expressed concerns that the data requirements
were so stringent that some data generated by Method 1623 analyses would not be acceptable.
Commenters also expressed concern regarding acceptance of data generated by labs approved by the EPA
before rule promulgation or by unapproved laboratories. It was suggested that data be flagged and
monitoring extended for replacement samples. Concerns were expressed regarding grandfathering data
from seasonal plants, rejection of grandfathered data, and the requirement of submitting grandfathered
data.
Response to Code 381
(A) Acceptance criteria for grandfathered data
EPA has determined that monitoring results collected previously must be equivalent in data quality to the
results collected through the monitoring required by the rule and the PWS must comply with reporting
requirements. This approach reflects the Stage 2 M-DBP Advisory Committee recommendation that EPA
accept Cryptosporidium data collected prior to the rule that are "equivalent in sample number, frequency,
and data quality (e.g. volume analyzed, percent recovery) to data that would be collected under the
LT2ESWTR...to determine bin classification in lieu of further monitoring".
EPA believes that the data quality standards should be uniformly applied, so that previously collected data
should not be held to a lower or higher standard than new data or evaluated differently from State to State.
Comment Response for the LT2ESWTR 5-213 December 2005
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EPA agrees that defined data criteria are necessary to ensure data quality and proper bin classification,
wihch provides the level of public health protection anticipated by today's final rule.
To be grandfathered, the sample results and analysis must meet the following criteria:
• Analysis of Cryptosporidium samples must meet the criteria of a validated version of EPA Method 1622
or 1623, which are described in USEPA 1999a, USEPA 1999b, USEPA 2001c, USEPA 2001d, USEPA
2005c, and USEPA 2005d.
• The volume analyzed for each sample must be at least 10 L of sample or at least 2 mL of packet pellet
volume or as much volume as two approved filters can accommodate before clogging
• The sampling location must meet the criteria for LT2ESWTR monitoring (prior to addition of treatment
chemicals and filter backwash recycle).
• The samples were representative of the source water(s) and the source water(s) have not changed.
• For Cryptosporidium samples, the sampling frequency must be at least monthly and on a regular
schedule. Note that the five day sampling window in the final rule does not apply to grandfathered data.
• An approved laboratory is not required as no laboratories were approved before rule promulgation.
Method and QA/QC requirements must be met.
• Data collected after January 1999 may be acceptable if the conditions above are met.
Today's rule requires the use of methods 1622 or 1623 because they are the best available methods that
have undergone full validation testing. Methods 1622 and 1623 incorporate improvements in the
concentration, separation, staining, and microscope examination procedures. During the ICRSS, which
required the use of Method 1622 or 1623, a spiking study demonstrated a mean Cryptosporidium
recovery of 43 percent. Thus, mean Cryptosporidium recovery with Methods 1622 and 1623 was more
than 3.5 times higher compared to the ICR Method performance in the earlier spiking study.
EPA recommends in the Source Water Monitoring Guidance that PWSs that have data with minor
deviations from the criteria above should submit the data for evaluation.
(B) Gaps in data sets and deviations in sampling frequency
EPA recognizes that when PWSs collected Cryptosporidium data prior to the proposed or final
LT2ESWTR, there may be months when a PWS either failed to collect or lost a sample due to problems
with equipment, transportation, laboratory analysis, or other reasons. If the PWS did not collect a
replacement sample, gaps in the previously collected data set occurred. EPA believes grandfathering of
such a data set despite these gaps may be appropriate if the PWS conducts additional monitoring, as
necessary, to "fill-in" gaps and ensure the data set is unbiased. Consequently, today's rule allows
grandfathering of data with gaps in the sampling frequency if approved by the State.
Deviations in the sampling frequency of previously collected data are allowed under the following
conditions: (1) PWSs may grandfather data where there are gaps in the sampling frequency if the State
approves and if the PWS conducts additional monitoring when specified by the State to ensure the data
used for bin classification are seasonally representative and unbiased; and (2) PWSs may grandfather data
where the sampling frequency varies (e.g., one year of sampling monthly and one year of sampling twice-
per-month); monthly average sample concentrations must be used to calculate the bin classification.
Grandfathered data may substitute for an equivalent number of months at the end of the monitoring
period. Further, because the rule allows PWSs to collect make-up samples to address gaps in previously
collected data sets, PWSs will have the opportunity to collect make-up samples for results that are
rejected due to data quality standards without losing an entire data set.
(C) Seasonal plants
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Seasonal plants may grandfather data which meets the requirements including sample collection during
the months when the treatment plant operates. The rule requires fewer samples from seasonal treatment
plants because source water quality typically varies less during the shorter operating period. EPA has
determined that for plants operating for six months per year or less, collecting a minimum of six samples
per year over two years will allow bin classification with comparable accuracy to that achieved by year-
round plants sampling monthly.
(D) Subsampling
EPA disagrees that the minimum sub-sampling analysis is a requirement of only the last published
version of Method 1622/1623 and should be removed from the grandfathered data criteria. Both the 1999
and 2001 versions of the Method 1622/1623 (40 CFR 141.707(c)(l)) included options for complete pellet
analysis and partial pellet analysis for pellets larger than 0.5 mL and guidance on the analysis of
minimum subsamples using one of these options has been widely distributed. Today's rule follows one of
these options and is consistent with guidance that has been distributed since rule proposal.
(E) 10 L volume requirement
EPA disagrees that the 10 L volume requirement is significant limitation to existing data. All versions of
Method 1622/1623 have stated that a 10 L samples should be collected. Per the rule, for each
Cryptosporidium sample, the laboratory analyzes at least 10 L of sample or at least 2 mL of packed pellet
or as much volume as could be filtered by 2 filters using the EPA approved methods. The requirements in
today's rule with respect to Cryptosporidium analytical methods and minimum sample volume reflect
recommendations of the Advisory Committee, which also recommended that the same data quality
standards be applied for grandfathering.
Individual Comments on Code 381
EPA Letter ID: 101
Comment ID: 10883
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Use of Previous Monitoring Data (Grandfathered Data)
No stipulations should be placed on using data collected prior to the effective date of the LT 2 Rule
except the samples should be analyzed by EPA approved methods. All other stipulations listed in the
proposed rule should be removed. The quality, location, frequency, quantity and representativeness of
samples and the means to average the samples should be left up to the State Primacy Agency.
This is the method EPA has used for grandfathered data in the past. EPA should not be inconsistent with
grandfathering provisions. EPA has set precedence for grandfathering data in the Arsenic Rule,
Radionuclides Rule, Radon Rule, and the Phase II/V Rules. EPA should simply extrapolate the
grandfathering provisions from these rules and adopt them for the LT 2 Final Rule.
Response: See Response 381(A).
Comment Response for the LT2ESWTR 5-215 December 2005
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EPA Letter ID: 420
Comment ID: 14089
Commenter: Eddie Partlow, General Manager, THE OLD HICKORY UTILITY DISTRICT
Commenter Category: Regulated Community (Development): Housing, FEEP, NAHB
Comment: quality and scheduling expectations. EPA should allow leeway in available sampling period
windows each month, sample temperature requirements, handling of missing data and acceptance of
grandfathered data.
Response: See Response 381.
EPA Letter ID: 439
Comment ID: 10751
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: could be initiated to ensure compliance. The data gathered under ICR requirements would
provide a great number of data points so that systems would have a better chance of correct bin
placement.
Response: See Response 381(A).
EPA Letter ID: 440
Comment ID: 10800
Commenter: Gary Hum, Director of Source & Treatment, Central Arkansas Water
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 361 1. 5-day sampling window and allowable
exceptions; 1720 8. Other comments on use of Method 1623
Comment: 1. Cryptosporidium monitoring for bin placement: The source water monitoring requirements
should allow increased flexibility for sample collection and data quality. More latitude should be allowed
in regards to the available sampling period window, the sample temperature requirements, missing data,
and acceptance of grandfathered data.
Response: See Responses 360(A) and 381(A) and (B).
EPA Letter ID: 446
Comment ID: 10805
Commenter: James Scanlan,, Fort Worth Water Department
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-216 December 2005
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Comment: CS Title: Comment focusing on "the provisions for use of previously collected
data, as proposed in Section 141.708, should be as flexible as possible for those proactive utilities that
have gathered Cryptosporidium data" submitted by James Scanlan
The staff of the Fort Worth Water Department have reviewed the proposed LT2ESWTR, and generally
agree with the proposed requirements. In order to reduce monitoring costs for large utilities and reduce
the problem of potential insufficient laboratory capacity, the provisions for use of previously collected
data, as proposed in Section 141.708, should be as flexible as possible for those proactive utilities that
have gathered Cryptosporidium data.
Response: See Response 381(B).
EPA Letter ID: 473
Comment ID: 10710
Commenter: Mary Carol Wagner, Water Quality Manager, Northern Kentucky Water District
Commenter Category: Regulated Community (Utilities)
Comment: We would like to make sure that the EPA takes into consideration the Utilities
that have been proactive and have collected Cryptosporidium data over the last several years and allow
this data to be grandfathered in. We are aware that the data from the ICR requirements may not be able to
be used because of the detection limits but if samples analyzed under the USEPA Method 1623 would be
considered acceptable. We would like to recommend that this data would be taken into consideration and
the requirements for grandfathering data is not too stringent that any data collected previous to this rule
could not be used. The capability of grandfathering this data will not only help the utilities that have been
proactive but will also help lessen the sample load on the few Laboratories that have the analytical
capabilities for analysis of Cryptosporidium.
Response: See Response 381(A) and (B).
EPA Letter ID: 474
Comment ID: 11191
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: As an unfiltered system, we would expect to need the full amount of available
time to make the kinds of treatment changes contemplated by this proposed rule. By initiating source
water monitoring early, we give ourselves the greatest amount of time to develop and implement
whatever changes may be needed. So, we have carefully reviewed the LT2 provisions for grandfathering
source water monitoring data collected as part of the risk binning process.
In its LT2 proposal, EPA has suggested requirements for grandfathered data that would require that data
to meet stringent requirements not presently in place or typically employed. This is a serious problem
because many utilities have invested substantial amounts of money over the last few years, prior to the
issuance of EPA-s June 2003 guidance on Source Water Monitoring, to develop high quality information
about their source waters. Utilities strongly supported the provision for grandfathering data in the EPA
sponsored discussions about LT2 and its companion, the Stage 2 Disinfectant/Disinfection Byproducts
Comment Response for the LT2ESWTR 5-217 December 2005
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Rule. We did so for four reasons:
1. The way data is used to determine which treatment bin a system falls in is such that the more data
points used the smaller the likelihood of being misclassified. Analysis demonstrated that large systems
taking only the minimum 24 samples have a much greater chance of being isclassified than those taking
48 or more samples;
2. Systems that were proactive in gathering Cryptosporidium data should be rewarded for their efforts by
not having to needlessly repeat sampling;
3. Systems that established which bin they were in at an early point would have additional time to initiate
corrective measures to insure compliance, if needed; and
4. Every system that used grandfathered data would reduce the realistically anticipatable problem of
insufficient laboratory capacity.
We believe that the criteria for grandfathered data should be more flexible and that any requirements for
such data should focus on the goal of insuring that systems are classified in the appropriate bin rather than
strict compliance to analytical requirements that have not historically been in place and are impossible to
conform with retroactively. The multiple benefits of allowing for grandfathering data clearly support such
an approach.
Response: See Responses 380 and 381(A) and (B).
EPA Letter ID: 485
Comment ID: 11282
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department does not recommend that public water systems should be
allowed to use previously collected data if the QA/QC criteria for the grandfathered data does not meet
the current criteria. Failure to meet the more stringent QA/QC data throws into question the accuracy and
precision of the data set. Given most microbiological methods do not have practical quantitation limits
associated with them (those that do, like the MPN whose -values- are based on a statistical distribution
that can cover a 5 fold concentration range), we do not know what recoveries are like at low
concentrations. Many recovery studies use relatively high concentrations of microorganisms to achieve
recoveries of 40% or better, but recoveries of low concentration spikes may drop to as little as 2%. This
means that the probability of recovering and getting a hit at low pathogen concentrations is very unlikely.
This also means the specificity of the bin classifications may not match the degree of sensitivity of the
analytical method. What is at stake here are fundamental differences between grand fathering in chemical
data, based on analytical methods with practical quantitation limits and method detection limits, and the
use of waterquality data that does not have those controls. Primacy agency field staff may be of the
opinion that a source is bad, but the analytical methods associated with historical data may not be as
sensitive as current methods and may not provide staff engineers with the appropriate information on
which to base an informed decision.
Response: See Response 381(A).
Comment Response for the LT2ESWTR 5-218 December 2005
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EPA Letter ID: 488
Comment ID: 11844
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Given that the bin structure is tied to Ml623 it is understandable that the Agency wants to
restrict grandfathered data to those collected using this method. This is specified in the Agreement in
Principle. However, we are very concerned that in an effort to strictly control data quality and make the
structure of grandfathered data sets exactly match those that would be collected under the standard
monitoring scenario, the Agency will reject perfectly valid
data that deviates in insubstantial ways from the strict provisions written for the standard, future
monitoring requirements. In addition to the unnecessary expense of further data collection such rejection
would incur for utilities who planned to grandfather data, including such restrictive requirements for
grandfathered data would add to the strain that LT2 monitoring will impose on
commercial laboratories. It is inevitable that LT2 data collected under the standard program will suffer
from minor irregularities that will have to be accommodated in order to make the data collection feasible
on a national scale. We urge the EPA not to place an effectively higher standard on grandfathered data
sets just because they are fewer in number and may have come under closer scrutiny during an earlier
review process.
For some insight into the types of anomalies to be expected not only from grandfathered data sets but also
from standard LT2 data collection efforts we have provided the following list of specific departures from
the strict letter of the provisions that were encountered in the course of conducting two years of biweekly
monitoring (52 samples) in anticipation of this rule. It should be noted that our laboratory has passed the
Ml623 laboratory approval process (provisional until LT2ESWTR promulgation).
1. Sampling was conducted at treatment plant intakes, upstream of presedimentation basins. The
presedimentation basins are considered part of the treatment train and are subject to chemical additions in
the spring and summer seasons.
2. The phosphate buffer specified in the April 1999 version of M1623 was employed rather than the new
buffer specified in the April 2001 method revision. Our method was implemented (IPR conducted) prior
to the latter revision and adhered to the previously published protocol.
3. Fewer than 3 filters per specimen cup were used on occasion. Following discussions with EPA
(February 2002 email correspondence with Maryanne Feige) we commenced using 3 filters per specimen
cup for all quality assurance samples, demonstrating that the methodology indeed worked.
4. We use polycarbonate track edge filters (PCTE) which are not included in the list of filters specified in
the published method. We have understood this to be acceptable as per the performance-based method
approval process. The EPA should be aware of this method detail because it was outlined in our
submission for PE evaluation.
5. One out of the 52 samples was sent to a contract laboratory for analysis because the analyst was on
Jury duty.
6. We did not draft a formal sampling plan prior to implementing the 2-years of monitoring. However the
predetermined sampling schedule is evident from the fact that samples were collected routinely on
Comment Response for the LT2ESWTR 5-219 December 2005
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alternate Mondays over the course of 24 months.
7. Because of our schedule of biweekly sampling (alternate Mondays) coupled with the intention to
collect 2 years of data the final data set is comprised of 52 samples rather than 48.
8. The matrix spike requirement was interpreted to mean one matrix spike was required after every 20
samples (not for every 20 samples). Under this assumption two matrix spike would be performed within a
series of 52 samples, not three.
4.3 Future Monitoring and Reassessment
Two years of monthly source water Cryptosporidium monitoring is to be repeated 6 years after initial bin
classification (9 years after rule promulgation) in order to reassess plant-specific risks and reassign bins
accordingly, if necessary.
Response: See Response 381(A) and (B).
EPA Letter ID: 491
Comment ID: 10664
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: 3. More reasonable latitude should be provided in allowing the use of grandfathered data.
Systems that have been proactive in monitoring for Cryptosporidium should be rewarded for their efforts
rather than be required to repeat monitoring only because their data did not fall within the strict
requirements for data collection that are only now being introduced. Use of
previously collected data should be evaluated by the primacy agency on a case- by-case basis so that data
without significant deviations from the LT2 requirements can be used for rule compliance. For example,
systems with a long history of monitoring have a large amount of data that can be used to characterize
their source water and show seasonal trends, even if it was not
collected on a strict monthly schedule. Additionally, systems that have data outside the strict quality
control limits laid out in the LT2 proposal cannot comply with these requirements retroactively even if
their data is still of good quality. Disallowing the use of previously collected data effectively discourages
systems from proactively monitoring for new regulations in the future.
Response: See Response 381(A) and (B).
EPA Letter ID: 496
Comment ID: 10689
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 2. Monitoring Key Issue 2 Grandfathering Data: The way data is used to determine
which treatment bin a system falls into is such that the more data points used, the smaller the likelihood of
being misclassified. Large systems taking only the minimum 24 samples have a much greater chance of
being misclassified than those taking 48 or more samples. Systems that were proactive in gathering
Cryptosporidium should be rewarded for their efforts by not having to needlessly repeat sampling.
Comment Response for the LT2ESWTR 5-220 December 2005
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Systems that established which bin they were in at an early point would have additional time to initiate
corrective measures to ensure compliance, if necessary. Every system that used grandfathered data would
reduce the problem of insufficient laboratory capacity as discussed in Monitoring Key Issue 1.
EPA has suggested requirements for grandfathered data that would require the data to meet stringent
requirements not presently established or typically employed.
Comments for Monitoring Key Issue 2 (Grandfathering Data): EPA should acknowledge the reasons for
allowing grandfathered data as listed above. The requirements should focus on the goal of ensuring that
systems are classified in the appropriate bin rather than strict compliance to analytical requirements that
have not historically been in place and are impossible to conform with retroactively. There is a trade-off
between the analytical accuracy of the samples and the number of samples taken (i.e. systems that have
hundreds of samples meeting ICR standards can have as good or better information for binning purposes
as a system taking the minimum number under more rigorous requirements). Reasonable requirements
should be placed on grandfathering existing data that meets ICR requirements. We can summarize any
data we have that supports these comments.
Response: See Response 381(A).
EPA Letter ID: 502
Comment ID: 10631
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: 1. Grandfathering Data: Numerous utilities have been monitoring Cryptosporidium
for many years in the hopes that their data may be used for compliance monitoring of the LT2ESWTR.
The requirements should focus on the goal of insuring that systems are classified in the correct bin rather
than strict compliance to analytical requirements that have not historically been in place and are
impossible with which to conform retroactively. For instance, our data was collected to meet ICR
standards and provides a long-term evaluation of our surface water sources, rather than a short two-year
window. From a statistical standpoint, reliability of results increases as the number of collected data
points increases (as opposed to using a smaller number required to meet a more rigid guideline).
Therefore, early monitoring by proactive utilities should not
result in a detriment. Grandfathering of data should result in a reduction of the large sample burden placed
on laboratories.
Response: See Response 381(A).
EPA Letter ID: 503
Comment ID: 10623
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment: Issue No. 2 - Grandfathering Data
WaterOne feels strongly that the requirements for grandfathering data are too strict. More emphasis
should be placed on making sure that utilities are placed in the right bin than meeting stringent
Comment Response for the LT2ESWTR 5-221 December 2005
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requirements that could hinder correct placement for utilities that have more data from previous years and
alternate sampling locations. The stringent requirements will likely cause some utilities to needlessly
waste money repeating sampling that will yield bin placement that
is no more accurate than could be achieved using existing data. For example, data from samples taken
directly from the source water should be acceptable as long as the analysis method used was acceptable to
the EPA at the time the sample was taken.
Response: See Response 381(A).
EPA Letter ID: 504
Comment ID: 11361
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 361 1. 5-day sampling window and allowable
exceptions
Comment: 5. Sampling Flexibility
Sampling requirements are rigid and do not allow for factors out of water utility control. We do not
disagree with the basic logic of asking sampling to be conducted on a fixed and predetermined schedule
in so far as practical. However, we believe that all of the objectives of the regulation can be met fairly and
accurately by providing for sampling flexibility to accommodate the exigencies of sample collection by a
utility with many water quality needs and many existing regulations that must be met. This is particularly
important to judging the acceptability of data collected prior to rule promulgation and eligibility for
grandfathering.
We suggest that EPA consider the benefit of providing greater flexibility to utilities to enable more
realistic ability to comply with the objective of accurately characterizing Cryptosporidium concentrations
in source water. Relaxing criteria for determining acceptability of samples meeting the schedule
requirements and extending the required period for completion of BIN monitoring
to provide for replacement samples would assist water utilities to meet the spirit and the letter of the
proposed regulation.
Response: See Responses 360(A) and 381(A) and (B).
EPA Letter ID: 506
Comment ID: 10731
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: CWD feels that the USEPA would better serve the needs of consumers by focusing
on ensuring that utilities are placed in the correct bin, not just on stringent compliance with current
analytical requirements. CWD recommends that USEPA place reasonable standards on grandfathered
data, such as meeting the ICR testing requirements. A larger volume of data (collected and tested with
ICR protocols) would provide belter information on the correct bin a system should fall into than a
smaller number of samples collected under current requirements.
Comment Response for the LT2ESWTR 5-222 December 2005
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Response: See Response 381(A).
EPA Letter ID: 507
Comment ID: 11468
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 4. Cryptosporidium Monitoring - Grandfathered Data, IV.A.l.d., pg 47677
FCWA feels that the provisions for accepting previous (grandfathered) Cryptosporidium data should not
penalize utilities that were proactive in acquiring Cryptosporidium data even if that data is not of
equivalent quality to data that will be collected following LT2ESWTR promulgation. It is reasoned that
since bin status is determined by Cryptosporidium data, the larger sample number (greater than 24
samples) will more accurately determine a utilities- bin
status.
Response: See Response 381(A).
EPA Letter ID: 514
Comment ID: 11540
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: 1) Grandfather Temperature Exceedance Data: In the proposed June 2003 version,
samples are not valid if the temperature exceeds > 10° but in the April 2001 version, this data was
flagged. In order to achieve a balance between the application of consistent data quality standards to all
Cryptosporidium data and the benefit of accommodating historical monitoring data, we propose the
following options:
a. Accept the historical data that is flagged. The sample temperature range of samples received at this
laboratory the last two years was 1° to 19° within the 96 hour holding time (most received within 24
hours). Is there data to show an adverse effect on Cryptosporidium recovery at temperatures between 10°
and 20 °C within 24 hours?
OR
b. Allow the facilities and laboratories to perform an additional matrix sample in the same season during
the next year but at a similar temperature that caused the exceedance and compare the recovery and
precision with the previous matrix spike. A suggestion for acceptance criteria may be the following: if the
recovery is within 2 SD and the RSD is within 55% of the previous MS result, the historical temperature
exceedance data is acceptable. If not acceptable, than option c or d may apply below.
c. Allow for replacement samples in the same month or season during the next year.
d. Extend the grandfather monitoring period by the number of months that replacement samples are
necessary (e.g. if 4 samples exceeded the temperature requirement during the previous 24-months, then
the monitoring will be extended 4 months. For those facilities that are going to continue monitoring after
LT2 promulgation, this would be an attractive option.
Comment Response for the LT2ESWTR 5-223 December 2005
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Response: See Response 381(A) and (B).
EPA Letter ID: 527
Comment ID: 10848
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Grandfathering Data: All of our organizations worked very hard to ensure that
the Agreement in Principle allowed for grandfathering of Cryptosporidium monitoring data collected
prior to implementation of the final rule. There are four main reasons for this provision. First, the
averaging method for bin determination is such that the more data points used, the smaller the likelihood
of being misclassified. Systems taking only the minimum number of required samples (24) have a much
greater chance of being misclassified than those taking
48 or more samples. Second, systems that were proactive in gathering Cryptosporidium occurrence data
should be rewarded for their efforts by not having to needlessly repeat sampling. Third, the sooner
systems establish which bin they are in, the more time they have to initiate any needed corrective
measures to ensure compliance. Fourth, every system using grandfathered data
would reduce the problem of insufficient laboratory capacity previously discussed.
EPA has proposed requirements for grandfathered data that would require the data to meet stringent
requirements. We recommend that EPA acknowledge the four reasons for allowing grandfathered data as
listed above. The requirements for grandfathered data and in fact all Cryptosporidium data collected
under LT2ESWTR, should focus on the goal of ensuring that systems are classified in the appropriate bin
rather than strict compliance with analytical requirements. Minor technical deficiencies that are unlikely
to significantly affect the data
set should be allowed.
Response: See Responses 380 and 381(A).
EPA Letter ID: 527
Comment ID: 10848
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Grandfathering Data: All of our organizations worked very hard to ensure that
the Agreement in Principle allowed for grandfathering of Cryptosporidium monitoring data collected
prior to implementation of the final rule. There are four main reasons for this provision. First, the
averaging method for bin determination is such that the more data points used, the smaller the likelihood
of being misclassified. Systems taking only the minimum number of required samples (24) have a much
greater chance of being misclassified than those taking 48 or more samples. Second, systems that were
proactive in gathering Cryptosporidium occurrence data should be rewarded for their efforts by not
having to needlessly repeat sampling. Third, the sooner systems establish which bin they are in, the more
time they have to initiate any needed corrective measures to ensure compliance. Fourth, every system
using grandfathered data would reduce the problem of insufficient laboratory capacity previously
discussed.
Comment Response for the LT2ESWTR 5-224 December 2005
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EPA has proposed requirements for grandfathered data that would require the data to meet stringent
requirements. We recommend that EPA acknowledge the four reasons for allowing grandfathered data as
listed above. The requirements for grandfathered data and in fact all Cryptosporidium data collected
under LT2ESWTR, should focus on the goal of ensuring that systems are classified in the appropriate bin
rather than strict compliance with analytical requirements. Minor technical deficiencies that are unlikely
to significantly affect the data set should be allowed.
Response: See Responses 380 and 381(A).
EPA Letter ID: 529
Comment ID: 13125
Commenter: Anonymous529,,
Commenter Category:
Comment: CS Title: Anonymous Comment focusing on "EPA should be more lenient in accepting
historical data particularly with respect to the variation with the scheduled sampling dates"
Response: See Response 381(A).
EPA Letter ID: 529
Comment ID: 13128
Commenter: Anonymous529,,
Commenter Category:
Comment: 2. We have spent considerable time and money monitoring for Cryptosporidium with
the intent to submit this data under the grandfathering provisions. We have repeatedly question the EPA
to ensure we are following proper protocol - often times little feedback or guidance was provided. For this
reason we believe the EPA should be more lenient in accepting historical data particularly with
respect to the variation with the scheduled sampling dates. A 10 day rather than 2 should be allowed.
Response: See Response 381(A).
EPA Letter ID: 534
Comment ID: 12007
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: Because existing data may not demonstrate strict compliance with the analytical requirements
and timing for samples in the proposal it is recommended that EPA consider issuing guidance on this
point. It is important that the final LT2ESWTR provide the necessary flexibility so that this issue can be
addressed.
Comment Response for the LT2ESWTR 5-225 December 2005
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Response: See Response 381(A)and(B).
EPA Letter ID: 534
Comment ID: 12010
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: systems to comply. Until the LT2ESWTR is finalized, laboratories are technically
unable to be certified because the criteria do not officially exist. Does this mean -grandfathered- data is
invalid? Due to the timeframes, the number of
Response: See Response 381(A).
EPA Letter ID: 540
Comment ID: 12084
Commenter: Manja Blazer, Government Affairs and Market Development Manager, IDEXX
Laboratories
Commenter Category: Independent Laboratories
Comment: IDEXX believes that grandfathering of data should be limited in time so that
current source water quality is accurately represented. For example, grandfathering of data should be
allowed no earlier than 12 months prior to the final regulation. The most current monitoring data is
preferable to past data, because source waters typically deteriorate overtime. Grandfathering of
Cryptosporidium data that is too old (i.e., back to January 1999) will not
provide an accurate assessment of current source water quality. Therefore, a more recent time limit should
be imposed.
Response: See Response 381(A).
EPA Letter ID: 548
Comment ID: 12151
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: 1. Grandfathering of Cryptosporidium monitoring data. Metropolitan requests that EPA
should consider grandfathered data valid as long as they meet all the method requirements for frequency
of sampling and holding times during sample processing and analysis.
Response: See Response 381(A).
Comment Response for the LT2ESWTR 5-226 December 2005
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EPA Letter ID: 548
Comment ID: 12157
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Grandfathered data may not have the exact QC requirements and sampling frequency
requirements as data required during the LT2ESWTR. Metropolitan requests that EPA should consider
grandfathered data valid as long as they meet all the method requirements for frequency of sampling as
well as holding times during sample processing and analysis. Taking the arithmetic mean of all the results
may average data collected at varying frequencies. Metropolitan also believes that EPA will be able to
easily determine acceptability of grandfathered data particularly when the data places the system in risk
bin 1 that does not need additional treatment.
Response: See Response 381(A).
EPA Letter ID: 556
Comment ID: 12050
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Discussion: AMWA believes allowing grandfathered data is important for a
variety of reasons including:
-The way data is used to determine which treatment bin a system falls in is such that there is less
likelihood of being misclassified if more data points are used. Therefore, systems taking only the
minimum number of required samples (24) have a much greater chance of being misclassified than those
taking 48 or more samples.
-Systems that are proactive in gathering Cryptosporidium occurrence data should be rewarded for their
efforts by not having to needlessly repeat sampling.
-The sooner systems establish which bin they are in the more time they have to initiate any needed
corrective measures to ensure compliance.
-Every system that uses grandfathered data will reduce the problem of insufficient laboratory capacity
discussed previously under section B.I of our comments.
EPA has proposed requirements for grandfathered data that would require the data to meet stringent
requirements not presently in place or typically employed. For example, the requirement that -allowances
for deviations from a sampling schedule specified" under the rule be applied to grandfathered data, is
needlessly strict. Samples should be allowed as long as they were collected at intervals that would take
into account any possible seasonality.
We recommend that EPA acknowledge the four reasons for allowing grandfathered data as listed above.
The requirements for grandfathered data, and in fact all Cryptosporidium data collected under
LT2ESWTR, should focus on the goal of ensuring that systems are classified in the appropriate bin rather
Comment Response for the LT2ESWTR 5-227 December 2005
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than strict compliance with analytical requirements. Minor technical deficiencies that are unlikely to
significantly affect the data set should be allowed.
Recommendations: AMWA recommends that the rule focus on the goal of ensuring that systems are
classified in the appropriate bin rather than strict compliance with analytical requirements and timing of
sample requirements. Minor technical deficiencies that are unlikely to significantly affect the data set
should be allowed. Such exceptions to strict compliance are an appropriate subject of guidance, and
AMWA is willing to continue working with EPA on all guidance
documents until they are finalized.
Response: See Responses 380 and 381(A) and (B).
EPA Letter ID: 562
Comment ID: 12365
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Given the expectations described in the proposal, AWWA is uncertain how many utilities will pursue
grandfathering data. In particular, AWWA is concerned about the rigidity with which QA/QC will be
treated during the review and especially the expectation for no breaks in sequence of 24 or 48 samples
submitted. These two requirements pose tremendous conflicts. Strict adherence to QA/QC criteria is
certain to lead to breaks in a continuous sequence of evenly spaced samples and these must be expected.
AWWA has encouraged member utilities to pursue grandfathering pre-existing data and/or prepare for the
Response: See Response 381(B).
EPA Letter ID: 562
Comment ID: 12389
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.1.3 Grandfathering Provisions
AWWA generally supports the grandfathered data provisions with several outstanding concerns. AWWA
believes EPA should address the following concerns:
1. QA/QC requirements for previously collected data almost exclusively limit data submittals to data
collected after release of a fact sheet distributed in early 2003 and made available on the EPA web site.
2. Compliance with sample location requirements articulated in the proposal limits data at interested
utilities to data collected after June 2003.
3. Compliance with fixed periodicity is unlikely, and large datasets with a continuous, uninterrupted
period of record in data collected prior to June 2003 are even more unlikely.
Response: See Response 381(A) and (B).
Comment Response for the LT2ESWTR 5-228 December 2005
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EPA Letter ID: 562
Comment ID: 12391
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Consequently, the provisions of the proposed rule have effectively truncated the pool of
available preexisting data from data collected after January 1999 to data collected after June 2003, a
period of 54 months*. More importantly, the rigidity projected in the rule language and guidance creates a
disincentive for utilities to collect data until there is a primacy agency to approve their sampling approach
and approve re-sampling events. AWWA will not assert that EPA-s handling of grandfathered data is
contrary to the Agreement in Principle,
Response: See Response 381(A)and(B).
EPA Letter ID: 562
Comment ID: 12396
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Minimum sub-sampling analysis is a new component of the last published version of EPA
Method 1622/1623. There was not a fixed requirement for this until EPA undertook the recent
refinements of the method and emphasized this component. Prior to this version, based on ongoing
discussion with the approved protozoan analysis laboratories, sub-sampling occurred based on the
professional judgment of the analyst. Informal polling of approved protozoan analysis laboratories
suggests that less than 10% of Method 1622/1623 samples require sub-sampling per the current method
criteria. Consequently, AWWA does not believe that sub-sampling is as significant a concern with EPA
Method 1622/1623 as it was for the ICR Method and, moreover, analysts employ sub-sampling when
necessary as a matter of good laboratory practice. Therefore, the proposed criterion is unnecessary and
should be removed from the grandfathered data QA/QC criteria.
Response: See Response 381(A), (B) and (D).
EPA Letter ID: 562
Comment ID: 12397
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: *A more generous interpretation would be that the 2001 Stakeholder Draft for
LT2ESWTR contained enough information to guide practice substantially similar to August 11, 2003
proposal. Were this the case, then December 2001 would have been the earliest possible date for valid
data collection and the resulting period would be 35 months
Response: See Response 381(A).
Comment Response for the LT2ESWTR 5-229 December 2005
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EPA Letter ID: 562
Comment ID: 12409
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA began the Protozoan Laboratory Approval Process in 2002. Consequently,
grandfathered data falls into three classes:
1. Data collected since a laboratory has been approved by EPA but prior to rule initiation.
2. Data collected by laboratories with EPA Method 1622/1623 prior to being approved by EPA.
3. Data collected by laboratories using methods other than EPA Method 1622/1623 per se but
demonstrated (with documentation) to be equivalent to that analyzed by laboratories adhering to EPA
Method 1622/1623 QA/QC procedures and PT sample performance.
In the proposal, EPA has already addressed the first category of data, but has not addressed the second or
third class of data described above. Using data in the second class above would require the laboratory to
demonstrate a history of meeting the QA/QC and performance testing criteria indicated in EPA Method
1622/1623 within the limits of accepted practice at the time the samples were taken.
Response: See Response 381(A).
EPA Letter ID: 562
Comment ID: 12410
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: With respect to the third class of data, EPA Method 1622/1623 is a performance-based
method. Through a Tier 1 or Tier 2 evaluation, as appropriate under EPA-s performance-based methods
guidance, individual laboratories can demonstrate equivalent performance and submit data from methods
that are not a step-by-step implementation of the EPA Method
1622/1623 procedure. Rather, the method allows for any modification other than the determinative step
(i.e., differential interference contrast (DIC) microscopy) that achieves comparable recovery, precision,
and accuracy. Inferred from the FACA-s recommendations is a requirement for analysis of at least a 10-
liter sample, and an average recovery similar to that assumed in the FACA binning algorithm (average of
40%).
The 10-liter sample provision in the LT2ESWTR proposal stems directly from the Stage 2 M/DBP FACA
agreement and AWWA supports the provision. However, this criterion does represent a significant
limitation on existing data. AWWA suggests that the basis for the 10-liter sample is actually a product of
the binning algorithm, which requires 240 L or 480 L of sample volume be collected. One means of
accommodating smaller individual sample sizes while
remaining consistent with the Agreement in Principle would be allow samples where the total volume of
samples were representative across time and, in total, represented 480 L or more of total sample volume.
Response: See Response 381(B) and (E).
Comment Response for the LT2ESWTR 5-230 December 2005
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EPA Letter ID: 562
Comment ID: 12411
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As noted above, the basic sampling framework recommended by the Stage 2 M/DBP
FACA was:
1. Random sample,
2. Minimum period of 24 months,
3. Reward larger data sets (i.e., 48 samples get to use arithmetic average ratherthan maximum rolling 12-
month average),
4. Minimum of 240 L sampled, and
5. Desired average recovery rate of 40%.
Data collected both prior to, and after the rule is finalized, are unlikely to rigidly adhere to a fixed
monitoring frequency within the sampling window described in the proposal. The implications of a
missed sample point were not apparent from the rule, preamble, or supporting guidance, but rather
through verbal communication with EPA staff. The FACA-s interest in setting a fixed
schedule was to ensure that events that might increase oocyst occurrence were not avoided over the
course of the defined monitoring period. The goal of the sampling program must be to obtain sufficient
representative source water quality data to allow appropriate placement of the treatment plant into the
correct bin. Strict adherence to a schedule as described by EPA is not necessary to achieve the FACA-s
objective and is unlikely to have been met in older data sets. Consequently, the agency should afford
greater flexibility in handling missed sample events and lack of fixed periodicity with increasing number
of samples particularly when 48 or more samples have been
obtained.
Grandfathered data sets may encompass longer periods of record and are likely to contain gaps in
sampling events. Having a longer period of record is desirable and should not cause the data to be
unacceptable. Where only 24 samples are available, the algorithm used to determine a treatment bin is the
maximum 12-month rolling average in period. Similarly, where 48 samples are
available, the arithmetic mean of all of those values should be employed. In the event more than 48
samples are collected, then the samples selected should first be screened for data quality and the most
recent 48 values employed to calculate an arithmetic mean. The rationale behind this
recommendation is that laboratory practices and analytical techniques are improving over time, so using
the most recent data will capture the highest quality data and reward a utility for initiating its monitoring
early and maintaining an ongoing monitoring effort.
Response: See Response 381(B).
EPA Letter ID: 585
Comment ID: 11968
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47678
Since EPA reported that it was unable to identify alternative standards for data quality, the TCEQ
Comment Response for the LT2ESWTR 5-231 December 2005
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recommends that the EPA prohibit the use of "grandfathered" data that does not meet minimum QA/QC
standards.
Response: See Response lOOa.
EPA Letter ID: 591
Comment ID: 12123
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Ohio EPA believes states should be given the authority to review existing data that a water system has,
which do not meet quality control requirements, on a case-by-case basis to determine if they meet the
intent of the monitoring requirements.
Response: See Response 381(A).
EPA Letter ID: 592
Comment ID: 12104
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: established. It is appreciated that we will be allowed to grandfather testing
that has been performed before the requirements of LT2 go into effect, but because this test is so
inherently inaccurate and the EPA sampling criteria is so restrictive, most water utilities will be slow to
begin testing and the few laboratories that are licensed to perform the tests are most likely going to be
swamped when and if the process begins. All previous good faith Cryptosporidium
tests should be grandfathered.
Response: See Response 381(A).
EPA Letter ID: 597
Comment ID: 12610
Commenter: Roger Hulbert, Senior Assistant Director, City of Houston Department of Public Works and
Engineering
Commenter Category: Regulated Community (Utilities)
Comment: ISSUE 2 -Grandfathering of Data
The City of Houston appreciates the need for a guarantee of data quality when considering grandfathered
data. We, like many large utilities, have routinely monitored, on a monthly basis, for Giardia and
Cryptosporidium in our source and treated waters since 1993. We have always required that any
laboratory contracted by us utilize the most current EPA accepted or recommended method, including all
Comment Response for the LT2ESWTR 5-232 December 2005
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requisite QNQC procedures. Since the Information Collection Rule, a laboratory approved for that rule,
and used either Method 1622 or 1623 has
analyzed all of our data. These laboratories have maintained strict compliance with the QNQC protocols
required by the ICR, and are awaiting approval under Long Term 2. Such grandfathered data should be
considered equivalent to the requirements that EPA is proposing for the Long Term 2 Rule, and accepted
upon demonstration of completeness.
EPA has proposed that systems utilizing two water sources filter a composited sample when conducting
source water monitoring. The City of Houston has two water sources and has sampled each one on a
monthly basis. We feel that systems that can show historically that their individual water sources meet the
requirements for classification as Bin 1, should be allowed to submit that data, and be excused from the
compositing requirements.
Response: Under this scenario, analysis of the two sources separately would be acceptable. Also see
Response 381(A).
EPA Letter ID: 598
Comment ID: 12622
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: Use of previously collected grandfathered data
Section 1V.A on pages 47668 and 47677 discuss l.d. Use of previously collected data and 2.d. Basis for
accepting previously collected data. The Utility is currently collecting cryptosporidium monitoring data
for the purposes of submitting this data as grandfathered data. We started this monitoring in July 2002
when we felt comfortable that our data collection would be suitable as
grandfathered data as allowed under the Agreement in Principle. We also had the benefit of reading the
draft LT2ESWTR, reading the EPA Laboratory Quality Assurance Program (Federal Register, volume
67, number 42, March 2,2002), and discussing our plans with EPA staff. This led us to conclude that we
were meeting the objectives outlined on page 47677 which include:
1) credit for data collection by proactive utilities
2) early determination of bin classification allows for planning of any appropriate action
3) use of grandfathereddata would reduce the problem of insufficient laboratory capacity which EPA and
the Agreement in Principle encouraged to lessen the load on approved labs
4) allowing utilities to include more data points for appropriate bin classification.
As we read the preamble, EPA discusses the issue of acceptance of previously collected data that are
equivalent to data collected under this proposed rule. This proposed rule contains more information on
sample schedules, sample collection and other requirements that were not known to Utilities such as ours
when grandfathered data collection was initiated. EPA should be reasonable on accepting grandfathered
data with the understanding that the best information
and methods were in use at the time of sample collection, and not retroactively impose additional
requirements that were unknown at the time of sampling. This would defeat the purpose of the objectives
as listed above. As an example, our Utility is collecting sample volumes of about 50 liters twice per
month from our three plant intakes. On one sampling event, a raw water screen wash pump used as the
pressure source for the filters experienced operational problems such that
we were only able to collect 20 liters instead of the normal 50 liters. The lab rejected our sample stating
Comment Response for the LT2ESWTR 5-233 December 2005
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Comment Codes 300-471
that we had to collect the same sample volume each time, apparently because of wording in the draft
LT2ESWTR rule (which we no longer see in this proposed rule). We were able to recollect the sample
one week later after pump repairs were made. Page 47666 of the preamble discusses collection of samples
within a 5-day window of scheduled sampling dates, which was not a known requirement at the time of
sampling. We would hope that EPA understands that such circumstances arise, and would allow
flexibility as mentioned in the conditions listed on page 47666.
Response: See Response 381(A)and(B).
EPA Letter ID: 601
Comment ID: 13010
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on previously collected data that do not meet QC equirements
(page 47678)
Utah supports the issue of allowing water systems to submit grandfathered Cryptosporidium results as
long as the samples collected are representative of seasonal variations and meet the requirements of the
analytical method. Provisions should also be made to address treatment plants that do not operate year-
round.
In addition, Utah agrees that if grandfathered data is rejected or results in a higher bin classification due to
concerns about data quality, systems should be allowed to re-submit new data collected after the rule was
promulgated.
Response: See Response 381(A)and(B).
EPA Letter ID: 614
Comment ID: 12973
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Grandfathering Data
* The requirements should focus on the goal of insuring that systems are classified in the appropriate bin
rather than strict compliance to analytical requirements that have not historically been in place and are
impossible to can form with retroactively.
Response: See Response 381(A).
EPA Letter ID: 620
Comment ID: 13290
Comment Response for the LT2ESWTR
5-234
December 2005
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Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 2: Grand fathering Data
Comments: If utilities have existing Cryptosporidium data collected under prior EPA rules such as the
ICR, or have collected samples voluntarily and proactively, said data should be allowed into the data set
used for bin determination. This would reduce the manpower costs and laboratory costs associated with
data collection by shortening or even eliminating sampling under
the new rule, as well as provide for a larger data set for bin determination for those collecting additional
samples.
Response: See Response 381(A).
EPA Letter ID: 624
Comment ID: 13185
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 2. Grandfathering of Data: The stakeholders involved in developing AIP worked
very hard to ensure that proactive utilities are not penalized for early monitoring of Cryptosporidium to
determine the microbial vulnerability of their source waters. It is a proven notion that the more data points
that are collected, the higher the probability of documenting realistic risks. EPA's data-grandfathering
requirements should focus on the ultimate goal
of appropriate Bin classification rather than strict compliance to analytical requirements whose bias will
have already been smoothed out with the higher number of samples. We believe such an approach will
ease the laboratory burden as well.
Response: See Response 381(A).
EPA Letter ID: 628
Comment ID: 12837
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: 2. Source Water Monitoring Requirements
a. Proposed requirements are unreasonably stringent. The proposed Cryptosporidium monitoring
requirements are unreasonably strict and inflexible. The strict requirements on data quality control,
sampling locations, and sampling frequency places significant barriers for the water systems to apply their
previously collected data for grandfathering with regards to sample
volume, timing, and collection of matrix spikes. In an attempt to be proactive, the SFPUC initiated
Cryptosporidium monitoring at its surface water sources in 2000. Prior to the release date of the proposed
LT2 Rule, the SFPUC has collected Cryptosporidium data from its water systems as follows:
[SEE TABLE, P.2 IN PDF]
Comment Response for the LT2ESWTR 5-235 December 2005
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All results identified above were obtained using EPA Method 1623.
Response: See Response 381(A).
EPA Letter ID: 630
Comment ID: 13059
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 3. Monitoring Key Issue 2 Grandfathering Data: Utility associations worked very
hard to insure that the Agreement in Principle allowed for grandfathering of Cryptosporidium monitoring
data collected prior to implementation of the final rule. There were four main reasons for this. First, the
way data is used to determine which treatment bin a system falls in is such that the more data points used,
the smaller the likelihood of being misclassified. Large systems
taking only the minimum 24 samples have a much greater chance of being misclassified than those taking
48 or more samples. Second, systems that were proactive in gathering Cryptosporidium should be
rewarded for their efforts by not having to needlessly repeat sampling. Third, systems that established
which bin they were in at an early point would have additional time to initiate corrective measures to
insure compliance if needed. Fourth, every system that used grandfathered data would reduce the problem
of insufficient laboratory
capacity discussed above. EPA has suggested requirements for grandfathered data that would require the
data to meet stringent requirements not presently in place or typically employed.
EPA should acknowledge the four reasons for allowing grandfathered data as listed above. The
requirements should focus on the goal of insuring that systems are classified in the appropriate bin rather
that strict compliance to analytical requirements that have not historically been in place and are
impossible to conform with retroactively. There is a tradeoff between the analytical accuracy of the
samples and the number of samples taken (i.e. systems that have hundreds of samples meeting ICR
standards can have as good or better information for binning purposes as a system taking the minimum
number under more stringent requirements). Systems should recommend that reasonable requirements be
placed on grandfathering existing data that meets ICR requirements.
Response: See Responses 380 and 381(A).
EPA Letter ID: 630
Comment ID: 13062
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: available if samples are missed). EPA should make reasonable provisions for
make-up samples. It is more appropriate to maintain the general relationship of
Response: See Response 381(B).
Comment Response for the LT2ESWTR 5-236 December 2005
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EPA Letter ID: 630
Comment ID: 13063
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 5. Monitoring Key Issue Sampling Schedule: Note: The proposal requires that
systems collect samples within 2 days of their sampling schedule or be in non compliance. Since
noncompliance leads to an immediate requirement to install UV,(because of Bin 4 placement) this is
inappropriate. There are many innocent reasons for not being able to sample within 2 days. A plus or
minus 3 or 4 days would be more appropriate. Moreover, this requirement stems from the thought that
water systems could -game- the system by monitoring when they knew Cryptosporidium would show up.
Current data show that randomized sampling is equivalent if not superior to time-series sampling designs
(Freyetal, 1998).
Response: See Response 381(B).
EPA Letter ID: 631
Comment ID: 13237
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: Grandfathering Data: EPA has proposed atypical and new requirements for grandfathered
data. In effect, systems that have collected data prior to the implementation of the rule could be penalized
even if the historical data was collected to meet EPA monitoring requirements such as for the ICR.
Response: See Response 381(A).
EPA Letter ID: 637
Comment ID: 13082
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on previously collected data that do not meet QC requirements (page
47678)
EPA should remember the benefits and purpose for allowing grandfathering of data. It allows for more
data to be used in the bin determination resulting in a more accurate classification, it acknowledges
proactive systems for sampling beyond regulatory requirements, it allows systems required to implement
additional treatment technologies time to prepare and it will alleviate
potential lab capacity issues. EPA should focus on the goal of ensuring that systems are classified
appropriately rather than strict compliance to analytical requirements that have not been in place long
enough to apply to systems that have been sampling since the 1623 method was available and are
impossible to conform with retroactively.
Response: See Response 381(A).
Comment Response for the LT2ESWTR 5-23 7 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 641
Comment ID: 13584
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47668 d. Use of previously collected data
-Samples were collected in equal intervals of time over the entire collection period—
This section should be revised to clarify that a (planned) changed monitoring schedule is acceptable
during the grandfathering period. Further, ASI recommends that the same flexibility be extended to PWSs
monitoring during the compliance period. To avoid confusion, we recommend that only one change of
sampling frequency be allowed during the 24 month period.
Response: See Response 381(B).
EPA Letter ID: 641
Comment ID: 13592
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Previously Collected Data That Do Not Meet the QC Requirements - Sampling frequency -
Minimum number of samples should be met; therefore all submitted data sets should have at least 1 valid
data point per month. PWSs that collect more than the required number of samples, but do not have the
same number of data points for each month, should be handled as suggested above (see: Pg 47668 d. Use
of previously collected data).
Response: See Response 381.
EPA Letter ID: 641
Comment ID: 13641
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Appendix B - Checklist for Submitting Grandfathered Data
Sampling Schedule : "Does the data package include a sample collection schedule established before
beginning monitoring ?"
Many utilities have been routinely sampling for some time, following LT2 guidelines but with sample
collection scheduled by week but not necessarily to the exact date. Therefore, the schedule will be
established after the collection of the data set!
Response: See Response 381(A).
Comment Response for the LT2ESWTR 5-238 December 2005
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EPA Letter ID: 641
Comment ID: 13642
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Detailed Quality Control Info :
Sample temperature requirement: Revise from 0 - 8 °C to <10 °C and not frozen.
Response: See Response 381(A).
EPA Letter ID: 641
Comment ID: 13658
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 3.2
Paragraph 4 - Seasonally operated plants.
ASI agrees that systems that use a source only part of the year should only have to sample during the use
period, but there should be a minimum number of data points to adequately represent that source water.
The proposed sampling of seasonal sources (-twice per month or 12 per year, whichever is smaller-)
minimum is acceptable. Further, it should be clarified whether a source water sampled for only a part of
the year will be subsequently allowed to be used during other (non-sampled) parts of the year.
Response: See Response 381(C).
EPA Letter ID: 641
Comment ID: 13659
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Last paragraph - This section needs to be revised to include varying sampling
frequencies, and how the binning number will be calculated if the sampling frequency changes. Please see
discussion above (Proposed Rule, Pg 47668 d. Use of previously collected data).
Response: See Response 381(B).
EPA Letter ID: 641
Comment ID: 13662
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Also, ASI supports EPA-s proposal to allow sample volumes to vary throughout the
samplig period. Our experience indicates that many PWSs have difficulty repeatedly collecting a specific
Comment Response for the LT2ESWTR 5-239 December 2005
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target volume, and requiring consistency would result in more rejected samples without improving data
quality.
Response: See Response 381(A).
EPA Letter ID: 641
Comment ID: 13663
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 3.3.2
ASI endorses the following items in this section:
- Allowing filtering all but 10L MS samples (please see previous comments)
- Allowing MS collection using a split stream OR collection before/after the field sample.
- No resampling required for MS "failures".
Response: See Response 1719.
EPA Letter ID: 643
Comment ID: 12770
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Previously collected monitoring data that do not meet QC requirements
Some states do not support allowing public water systems to use previously collected data if the QA/QC
criteria for the grandfathered data does not meet the current criteria because failure to meet the more
stringent QA/QC data throws into question the accuracy and precision of the data set. The concern is that
the probability of recovery and detection at low pathogen concentrations is very unlikely. This means the
specificity of the bin classifications may not match the degree of sensitivity of the analytical method.
Response: See Response 381(A).
EPA Letter ID: 646
Comment ID: 13564
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: Grandfather Data - Santa Fe has initiated monitoring for Cryptosporidium well in
advance of the effective date of this rule. Santa Fe requests that EPA set reasonable requirements for the
use of grandfather data so long as ICR requirements met.
Comment Response for the LT2ESWTR 5-240 December 2005
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Response: See Response 381(A)and(B).
EPA Letter ID: 660
Comment ID: 14071
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on previously collected data that do not meet QC
requirements (page 47678)
CUWCD supports allowing water systems to submit grandfathered Cryptosporidium results as long as the
samples collected are representative of seasonal variations and meet the requirements of the analytical
method. Provisions should also be made to address treatment plants that do not operate year-round.
Utilities will not be able to grandfather data if the current QA/QC are as rigid as they are now. Many of
these requirements where not developed until Spring 2003. Many plants have been monitoring since 1999
with Method 1622/1623 in order to have a better data set. Because of the newly implemented
requirements this data would not be allowed for grandfathering.
Response: See Response 381(A),(B)and(C).
EPA Letter ID: 662
Comment ID: 14030
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on previously collected data that do not meet QC
requirements (page 47678)
Grandfathered Cryptosporidium results collected seasonally over past years, despite minor variations to
the analytical method, may be more significant than those collected over a shorter term. The data will
cover a longer time frame and perhaps significant climatic variations. The value of these analyses should
not be lost due to minor variations in method or new method requirements like recording temperature.
Utilities should be allowed to take advantage of significant improvements in their watersheds, as
demonstrated by monitoring, and allowed to be moved to a lower bin as a consequence.
Response: See Response 381(A)and(B).
EPA Letter ID: 673
Comment ID: 13980
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-241 December 2005
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Comment: EPA requests comment on previously collected data that do not meet QC
requirements (page 47678)
Jordan Valley Water supports allowing water systems to submit grandfathered Cryptosporidium results as
long as the samples collected are representative of seasonal variations and meet the requirements of the
analytical method. Provisions should also be made to address treatment plants that do not operate year-
round.
Jordan Valley Water suggests EPA be flexible in considering the analytical methods and QC requirements
that have changed. As long as the data submitted for grandfathering has met the requirements of the
Cryptosporidium method at the time of analysis, EPA should not try to make new requirements
retroactive and exclude reasonable data from being used for bin classification.
Jordan Valley Water supports being able to submit a new set of data (collected after promulgation of the
rule) if data submitted for grandfathering is rejected.
Response: See Response 381(A)and(B).
EPA Letter ID: 677
Comment ID: 13951
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Comment: 2. Acceptance of grandfathered Cryptosporidium data (page 47678). USEPA
has developed a detailed list of requirements for quality assurance and quality control (QA/QC) of the
Cryptosporidium monitoring data. This also applies to data which water systems have collected or are
currently collecting to meet the requirements of the Proposed LT 2 Rule. The City believes that there is
insufficient latitude in accepting historical data with regards to sample
volume, timing, and collection of matrix spikes. In an attempt to be proactive and assist with the
laboratory capacity concerns, the City initiated Cryptosporidium monitoring at its surface water treatment
plants in 2001. This means that we have collected over 24 monthly samples for both our Sacramento and
American River sources.
The USEPA requires 10 liters per sample and plans to disregard samples that do not meet this
requirement. This process does not allow for human inspection of any of the data for qualification. For
our Sacramento River source, two samples had volumes less than 10 L (8.5 and 9.5 L), and all other
QA/QC criteria were met for these samples. All of the samples for this source had total IFA counts of
zero, including the two samples with insufficient olume. Assuming that average recovery rates apply to
our samples, then 50% recovery would be representative and it would be highly likely that these samples
would have remained non-detect if the full volumes had been analyzed, based on all the historical data. It
seems inappropriate to disqualify these samples since their results are similar to all other data points. If
these samples are disqualified and continuous monitoring is required then the City will need to conduct a
minimum of 11 additional months of samples, and incur costs including $5,000 in analytical costs.
Through the monitoring period the City has attempted to take samples on a monthly basis with
approximately 4 weeks between samples. There were several months where holidays, laboratory capacity,
or other operational procedures prevented those samples from being collected on the cycle. The City
believes that the two-day variance for sample collection that USEPA is proposing is inadequate, provided
Comment Response for the LT2ESWTR 5-242 December 2005
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that monthly timing of sample collection by water systems is not obviously contrived.
The need for matrix spike samples to be collected, but not utilized, seems inappropriate. The City
understands that USEPA would like to have companion data to evaluate the overall accuracy of the
monitoring programs, but to disallow grandfathered data that doesn-t meet the exact requirements for this
item is not fair. The City believes that provided two matrix spike samples were collected during the entire
monitoring period, the timing of those samples should not be
critical for grandfathered data and systems should not be penalized.
The City recommends that the USEPA create a process for human review of the validity of the
questionable grandfathered data to qualify the data rather than disallow. We also continue to support the
above comment on the ability to submit non-continuous data to meet the 24-sample minimum.
Response: See Response 381(A)and(B).
EPA Letter ID: 678
Comment ID: 14674
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 10. Section 141.708 - To allow for grandfathering data, the EPA has proposed stringent
requirements that were not in place during previous data collection efforts. These requirements have
created situations in which many of the previously collected data may not be
used for grandfathering. We request that the EPA focus the LT2 monitoring on the goal of insuring that
systems are classified in the appropriate bin rather than strict compliance to monitoring and analytical
requirements that have not historically been in place and are impossible to conform with retroactively.
In balancing the requirements between the analytical accuracy of samples and the number of samples
taken, we request the EPA consider the following factors. First, the way data is used to determine which
bin a system falls in is such that the more data points used, the smaller the likelihood of being
misclassified. Second, systems that were proactive in gathering Cryptosporidium data should be rewarded
for their efforts by not having to needlessly repeat
sampling. Third, every system that used grandfathered data would reduce the problem of insufficient
laboratory capacity discussed previously. Thus, systems having abundant Cryptosporidium monitoring
results that meet ICR standards can have as good or better information for binning purposes as a system
taking the minimum number under more stringent requirements. We recommend the EPA provide
additional flexibility to allow systems to use existing data that meets ICR requirements for
grandfathering.
Response: See Response 381(A).
EPA Letter ID: 678
Comment ID: 14706
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-243 December 2005
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Comment: 3. The EPA requests comments on previously collected monitoring data that do not meet QC
requirements [47678, C2]
Comment: We believe the proposed rule has included very strict QC and sampling plan requirements that
many systems will not be able to exactly meet. The limited flexibility provided in the rule may cause the
EPA to not accept historical data with regards to sample volume, timing, and collection of matrix spikes.
Further, the two-day variance for sample collection that the EPA is proposing is inappropriate, provided
that monthly timing of sample collection by
water systems is not obviously contrived. The need for matrix spike samples to be collected, but not
utilized, also seems inappropriate. While we understand that the EPA would like to have companion data
to evaluate the overall accuracy of the monitoring programs, it is unfair for the Agency to disallow
grandfathered data that do not exactly meet this requirement. We believe that the timing of those samples
should not be critical for grandfathered data and systems should not be penalized, provided two matrix
spike samples were collected during the entire monitoring period.
We recommend that the EPA create a review process to determine the validity of questionable data for
grandfathering rather than disallowance. We also request the EPA consider grandfathered data valid as
long as they meet all the method requirements for frequency of sampling as well as holding times during
sample processing and analysis. Taking the arithmetic mean of all the results may average data collected
at varying frequency. We believe that the EPA will be able to easily determine acceptability of
grandfathered data particularly when the data set places the system in risk Bin 1 that does not require
additional treatment.
Response: See Response 381(A)and(B).
EPA Letter ID: 678
Comment ID: 14709
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: collected. As previously indicated, we also urge the EPA to provide additional flexibility in
QC and monitoring requirements and grandfathering the existing Cryptosporidium data.
Response: See Response 381(A).
EPA Letter ID: 683
Comment ID: 14761
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
Comment: Grandfathering Data: EPA has proposed atypical and new requirements for grandfathered
data. In effect, systems that have collected data prior to the implementation of the rule could be penalized
even if the historical data was collected to meet EPA monitoring requirements such as for the ICR. While
there is a tradeoff between the analytical accuracy of the samples and the number of samples taken, the
monitoring requirements should focus on the goal
Comment Response for the LT2ESWTR 5-244 December 2005
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of insuring that systems are classified in the appropriate bin, rather that strict compliance to analytical
requirements that were not in place when the samples were collected and are impossible to conform with
retroactively. Instead of rejecting historical data, such increased monitoring should be rewarded as the
reliability of results overtime is likely to be enhanced.
Response: See Response 381(A).
EPA Letter ID: 688
Comment ID: 14738
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Page 47678 - Previously Collected Monitoring Data That Do Not Meet QC
Requirements
Missouri would like to be as flexible as possible in accepting previous Cryptosporidium results to set bin
classifications. We are concerned that there may be lab capacity issues and using existing results as much
as possible should reduce the competition for limited laboratory capacity. The historical monitoring that
many systems have done was intended to see if there was a Cryptosporidium problem before any
regulatory requirements came along. As such, it was more likely to be targeted toward a worst case
scenario and would be biased toward higher Cryptosporidium counts. The chances of not assigning
stringent enough treatment using this data are low.
Response: See Response 381(A)and(B).
EPA Letter ID: 706
Comment ID: 14808
Commenter: John Spatz, Deputy Commissioner, City of Chicago Department of Water Management
Commenter Category: Regulated Community (Utilities)
Comment: 2. DATA
Grandfather Data
The EPA should give the Water Utilities credit for information (such as ICR). The utilities should not
have to repeat these analyses. This grandfathered information should also be included to place the utilities
in the correct bin.
Response: See Response 381(A).
EPA Letter ID: 711
Comment ID: 16551
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-245 December 2005
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Comment: Also, if a system has enough grandfathered data but continues to collect additional Crypto
data, does the system have to submit the additional data to EPA or could the system just monitor and keep
its own data for its own monitoring purposes?
Response: PWSs must report the dates of the first and last sample collected for grandfathering, and
certify that the reported monitoring results include all the PWS generated in that period. The PWS does
not need to include results of any other sampling.
EPA Letter ID: 711
Comment ID: 16561
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 2. EPA requests comment on previously collected monitoring data that do not meet
QC requirements [47678, C2]
Comment: The proposed sampling plan is quite strict in terms of when the source water samples have to
be taken. It is possible for many systems to not meet monitoring requirements as specified here but the
data should still be grandfathered if they are reasonable which means they did not skip a whole month or
two somewhere while a plant is on-line without a good explanation. It is
highly probable that many existing Crypto sampling plans did not plan for the tight specification of 2 days
variance and most likely only followed the intention of monthly Crypto sampling. Therefore, it is our
opinion that as long as a Crypto sample is collected for each source water every month, the data set
should be grandfathered.
Response: See Response 381(B).
5.8.2 Comment Code 382, Approaches for collecting additional
samples to complete data sets
Summary of Issues
Comments were submitted concerning approaches to filling in data gaps submitted by utilities to avoid
nullifying otherwise useful data. All commenters approved of settling on an approach to allow
grandfathered data sets that include gaps to be used. One commenter suggests using a statistical approach
to determine if data sets with gaps are valid. Another commenter requested that if concerns about data
quality resulted in a higher bin classification, then a system should be allowed to re-submit new data
collected after the rule was promulgated.
Response to Code 382
See Response 381(B).
Comment Response for the LT2ESWTR 5-246 December 2005
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Individual Comments on Code 382
EPA Letter ID: 512
Comment ID: 11499
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: As suggested in our comments above on the proposed source water monitoring, a
gap in grandfathered data should be handled within the statistical analysis rather than invalidating a whole
data string. To eliminate the ability of utilities to use valid data because of minor data gaps is not
supported by the science. A whole body of statistical science is available to deal with this issue (one that
is common to all fields of scientific research and data analysis), and it is unreasonable to ignore it or
pretend it does not exist. Additionally it will further burden the existing lab capacity by forcing those
utilities that would otherwise be exempt from the planned monitoring into the larger pool of utilities
competing for a certified lab to do their analyses.
Response: See Response 381(B).
EPA Letter ID: 512
Comment ID: 11511
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: b. Accommodation needs to be made for data gaps in pre-existing data where an otherwise
large enough data set is available
Response: See Response 381(B).
EPA Letter ID: 628
Comment ID: 12840
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: and location requirements. The SFPUC also supports the approach that water
systems are allowed to submit non-continuous data to meet the 24-sample minimum.
Response: See Response 381(B).
EPA Letter ID: 637
Comment ID: 13083
Comment Response for the LT2ESWTR 5-247 December 2005
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Comment Codes 300-471
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: In addition, District agrees that if grandfathered data is rejected or results in a higher bin
classification due to concerns about data quality, systems should be allowed to re-submit new data
collected after the rule was promulgated.
Response: See Response 381(B).
5.8.3 Comment Code 383, Impact of changes to the analytical method
Summary of Issues
This commenter addressed the possible reluctance of shifting from an established method version to a
new method version that the commenter believed had an unknown reproducibility rate. The commenter
also stated that labs that were not willing to perform the new method should not be penalized in
LT2ESWTR source water monitoring grandfathering provision.
Response to Code 383
EPA believes that reluctance to shift to the newest method version may impact data quality and laboratory
approval. The new rule could not be carried out effectively if all labs were not required to follow the
method to become approved. The rule requires the use of the newest revised versions (2005) of Method
1622 and 1623. EPA agrees that laboratories generating data prior to promulgation should not be
penalized; therefore, PWSs may grandfather data generated with earlier approved versions of these
methods.
Individual Comments on Code 383
EPA Letter ID: 411
Comment ID: 10564
Commenter: Devon Cole,, Utah Department of Health Laboratory
Commenter Category: State/Tribe Government
Comment:
June 2003 versions of Method 1622/1623 state that Crypto samples received at >10 C are to be rejected
unless received same day as collection, however previous method versions state that exceeded holding
temps (>8 C) are only to be qualified by the laboratory. In preparation for grandfathering Crypto results
using previous method versions, how will data associated with exceeded holding temps be received, even
when all other QC pass method criteria (i.e. matrix
spike recoveries)?
Response: See Response 381.
EPA Letter ID: 562
Comment ID: 12405
Comment Response for the LT2ESWTR
5-248
December 2005
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Improvements to EPA Method 1622/1623 are important and beneficial, but the
assumption that method adoption will occur rapidly upon release of method updates is unreasonable. A
review of the history of this method-s development has been one of fits and starts. Consequently,
laboratories and utilities have taken a wait-and-see approach to adoption of method enhancements and
have focused on ensuring that lab staff was able to perform a particular approach as well as possible. This
reluctance to shift from established practice to an untried variant with unknown reproducibility should not
be penalized in LT2ESWTR source water monitoring grandfathering provisions.
Response: See Response 383.
EPA Letter ID: 631
Comment ID: 13238
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: While there is a tradeoff between the analytical accuracy of the samples and the
number of samples taken, the monitoring requirements should focus on the goal of insuring that systems
are classified in the appropriate bin, rather that strict compliance to analytical requirements that were not
in place when the samples were collected and are impossible to conform with retroactively. Instead of
rejecting historical data, such increased monitoring should be rewarded as the reliability of results over
time is likely to be enhanced.
Response: See Response 381(A).
5.8.4 Comment Code 384, Data reporting and certification
requirements
Summary of Issues
Comments were submitted in acceptance of using a letter from the laboratory stating that all QC criteria
were met and found to be acceptable, rather than reporting all QC data for each sample.
Response to Code 384
Data Reporting and Certification Requirements
EPA agrees with the comment to accept using a letter from the laboratory stating that all QC criteria were
met and found to be acceptable, rather than reporting all QC data for each sample. EPA believes that the
letter will suffice as certification of samples meeting QC requirements and will simplify the process.
Laboratories will still have the option to submit QC data for all samples.
Comment Response for the LT2ESWTR 5-249 December 2005
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Individual Comments on Code 384
EPA Letter ID: 598
Comment ID: 12621
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: amount of reporting data. As an example, EPA will allow systems such as ours, with
previously collected data (grandfathered data), to submit a letter from the laboratory stating that all QC
was performed and was acceptable, rather than reporting all that data for each sample set.
Response: See Response 384.
5.8.5 Comment Code 385, Schedule for data reporting and EPA
decisions
Summary of Issues
In regard to notification of the acceptability of data for grandfathering, most commentary stated concern
that the PWS would be penalized if they were not notified about data that was accepted or rejected in time
for them to respond and meet the rule requirements. Some commentary recommended that if previously
collected data submitted by a PWS are rejected, the PWS should have at least two months between
notification and the date new monitoring must be initiated. The comments also noted that these two
months will give the PWS time to address rejection of the data and prepare for sampling.
Additionally, commentary recommended the following: EPA outline and confirm the availability of
resources and procedures to review grandfathered data, EPA communicate with the State in a timely
manner, and copy the primacy agency on all correspondence with the system.
Response to Code 385
Meeting the deadline for submittal of additional data
EPA agrees with this recommendation. Under today's rule, if a PWS properly submits a complete data set
for grandfathering and the PWS must conduct new monitoring due to rejection of some or all of the data,
the PWS has at least two months following notification by the State to initiate sampling.
Availability of resources and procedures to review grandfathered data
The EPA believes the resources and procedures to review grandfathered data are available. Today's rule
requires PWSs that plan to grandfather monitoring data to notify the State regarding the number and time
span of sample results no later than three months prior to when the PWS must begin monitoring;
concurrent with the timing for submission of a sampling schedule. This notice will assist EPA and States
in determining and providing the resources necessary to ensure timely review of grandfathered data.
PWS must submit the grandfathered data within two months of the date when they are required to begin
monitoring under today's rule. EPA expects that some PWSs will submit the data earlier than required,
spreading out the EPA/State review effort.
Comment Response for the LT2ESWTR 5-250 December 2005
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EPA will seek to involve States in any communications with and decisions for their PWSs and will allow
States to take responsibility for these activities if they choose to do so. However, because monitoring for
the largest systems begins before States will have had time to assume primacy, EPA is prepared to
oversee review and approval of grandfathered data for these PWSs where States are unable to do so.
Individual Comments on Code 385
EPA Letter ID: 527
Comment ID: 10849
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: In this regard, systems submitting grandfathered data should receive timely notification of
decisions to accept or reject the data so that they can act responsibly in meeting their obligations under the
rule. Accordingly, we recommend that the rule provide that delays in approvals or disapprovals do not
impact a system-s total compliance timeframe. Additionally, we recommend that EPA outline and
confirm the availability of resources and procedures to review
grandfathered data in the previously recommended NODA to be issued prior to promulgation of the final
rule.
Response: See Response 385.
EPA Letter ID: 527
Comment ID: 10849
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: In this regard, systems submitting grandfathered data should receive timely notification of
decisions to accept or reject the data so that they can act responsibly in meeting their obligations under the
rule. Accordingly, we recommend that the rule provide that delays in approvals or disapprovals do not
impact a system-s total compliance timeframe. Additionally, we recommend that EPA outline and
confirm the availability of resources and procedures to review
grandfathered data in the previously recommended NODA to be issued prior to promulgation of the final
rule.
Response: See Response 385.
EPA Letter ID: 534
Comment ID: 12006
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment Response for the LT2ESWTR 5-251 December 2005
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Comment Codes 300-471
Comment: It is critical that systems submitting grandfathered data receive timely Notification of
decisions to accept or reject the data so that they can act responsibly in order to meet their obligations
under the rule. Systems should not be penalized for any failure on the part of primacy authorities to
review and approve submitted data in a timely fashion.
Response: See Response 385.
EPA Letter ID: 556
Comment ID: 12051
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: In this regard, it is critical that systems submitting grandfathered data receive timely
notification of decisions to accept or reject the data so that they can act responsibly in order to meet their
obligations under the rule. Systems should not be penalized for any failure on the part of primacy
agencies to review and approve submitted data in a timely fashion.
Additionally, the rule should specify that delays in approvals or disapprovals of grandfathered data that
are not the fault of the system do not impact a system-s total compliance timeframe. As it now stands, the
rule states:
-Unless EPA notifies the system in writing that the previously collected data are sufficient for bin
determination, the system must conduct source water Cryptosporidium monitoring-"
This provision puts any system seeking to use grandfathered data at risk and discourages the use of such
data.
Response: See Response 385.
EPA Letter ID: 556
Comment ID: 12052
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Lastly, we recommend that EPA outline and confirm the availability of resources and
procedures to review grandfathered data in the previously recommended NODA to be issued prior to
promulgation of the final rule.
Response: See Response 385.
EPA Letter ID: 562
Comment ID: 12363
Comment Response for the LT2ESWTR
5-252
December 2005
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 365 2. Submitting monitoring plan (date and location)
Comment: 3.7 Implementation Schedule
The Stage 2 D/DBP FACA constructed a very aggressive implementation schedule for the LT2ESWTR.
As EPA lays out the specifics of implementation in the stakeholder draft, proposed rule, associated
support documents, and in the Draft State Implementation Guidance, the practicality of the schedule
reflected in the Agreement in Principle has become more questionable. Of particular concern in the
LT2ESWTR are these two issues:
1. Approval of pre-existing data for bin determination, and
2. Approval of defined monitoring sample plan and schedule.
Response: See Responses 365 and 385.
EPA Letter ID: 562
Comment ID: 12366
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: utilities to pursue grandfathering pre-existing data and/or prepare for the initiation of
monitoring under the LT2ESWTR defined monitoring provisions. However, given the volume of
guidance associated with this proposal and the issues that need additional consideration by the agency,
AWWA questions the feasibility of meeting the proposed deadlines for submittal of pre-existing data for
approval (two months after promulgation) or sampling plans (three months after promulgation). Submittal
of sampling plans appears to be a
Response: See Response 385.
EPA Letter ID: 562
Comment ID: 12390
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. AWWA recommends that language be added to Section IV.A.4.d stating:
-Failure of EPA to notify the grandfathering plant of its bin determination within four months of
promulgation shall delay the required sampling for that plant until two months after receipt of
EPA-s notification of the plant of the acceptance or non-acceptance of the grandfathered data.- The two
months will allow the plant utility to challenge the rejection of the data and / or develop the required
sampling plan for the new sampling.
Response: See Response 385.
Comment Response for the LT2ESWTR 5-253 December 2005
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EPA Letter ID: 598
Comment ID: 12619
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: those experienced in the Information Collection Rule and UCMR. Also, as we
understand the rule requirements, we must submit our data within 2 months after rule promulgation, then
EPA has four months to accept it or the Utility must conduct additional monitoring. This short time frame
for acceptance of grandfathered data allows no time to work out problems of data handling and
transmission issues.
Response: See Response 385.
EPA Letter ID: 603
Comment ID: 12647
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (pg. 47777) Section 141.701(e)-
Compliance Requirements Table; Items (1) & (2)-
It is not clear how or when the EPA will forward the sampling results to the states for Subpart H systems
serving > 10,000. The department is concerned that information may not be received in a timely manner.
Inserting the text "which EPA will forward to the states within 30 days of receipt of the results." after the
last paragraph for these two system categories should relieve this concern
and allow states timely access to information that will likely affect future allocation of state resources.
Response: See Response 385.
EPA Letter ID: 603
Comment ID: 12651
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47780) Section 141.707(f) -
Similar to the comments for §141.707(a), for systems that "grandfather" their data, the EPA should copy
the expected primacy agency on all correspondence from the EPA to the water system.
Response: See Response 385.
EPA Letter ID: 603
Comment ID: 12652
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-254 December 2005
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Comment: (Pg. 47781) Section 141.707(g) &(h) -
The selection of an 8 month deadline following rule promulgation for submission of "grandfathered" data
seems odd considering a water system serving at least 10,000is supposed to submit a monitoring plan 3
months after rule promulgation and start monitoring 6 months after rule promulgation. Requiring
submission of "grandfathered" data 3-6 months after rule promulgation seems more logical.
Response: See Response 385.
EPA Letter ID: 628
Comment ID: 12839
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: The SFPUC requests the EPA implement a standard review process to expedite the
evaluation of validity of any questionable grandfathered data and to qualify the data rather than simply
rejecting all that may not meet the proposed scheduling and location requirements. The SFPUC also
supports the approach that water
Response: See Response 385.
EPA Letter ID: 678
Comment ID: 14676
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 12. Section 141.708 (f) - ACWA disagrees with EPA's proposal for further water system
monitoring when there-s a delay due to the Agency-s review of data and subsequent notification to the
system about the acceptability of the data. Also, if a system has enough
Response: See Response 385.
EPA Letter ID: 711
Comment ID: 16550
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 5. Section 141.708 (f) - It would be unfair for EPA to put the burden on the water system to
monitor further should there be an EPA delay in reviewing the data and subsequently notifying the system
on the acceptability of the data.
Response: See Response 385.
Comment Response for the LT2ESWTR 5-255 December 2005
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5.8.6 Comment Code 386, Grandfathering E. coli data
Summary of Issues
Comment suggested that the rule be revised to allow for the grandfathering of E. coli or alternate indicator
in lieu of Cryptosporidium data to reduce the burden on the states.
Response to Code 386
Grandfathering E. coli data
EPA agrees that systems should have the option to grandfather E. coli data, and this is allowed in today's
rule, as stated in 40 CFR part 141.707. If the State approves, small PWSs may comply with the initial
source water monitoring requirements of LT2ESWTR [40 CFR part 141.701(a)] by using (i.e.,
grandfathering) sample results collected before the PWS is required to begin monitoring. PWSs may
grandfather monitoring results either in lieu of or in addition to conducting new monitoring under the
rule. To be eligible for grandfathering, monitoring results must be equivalent in data quality to monitoring
PWSs conduct under LT2ESWTR and the PWS must comply with reporting requirements. Analysis of E.
coli samples must meet the analytical method and approved laboratory requirements for source water
monitoring under LT2ESWTR [40 CFR part 141.707(a & b)].
Individual Comments on Code 386
EPA Letter ID: 603
Comment ID: 12649
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: systems should be allowed to "grandfather" such data to spread out the implementation
burden of this rule on States. Please consider revising the rule to allow grandfathering of E. coli or an
alternative indicator approved by the State.
Response: See Response 386.
EPA Letter ID: 647
Comment ID: 12887
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: monitoring if the system so desires. In addition, Maryland has more than two years of
bacteriological monitoring, that meets the frequency and method established by EPA, for all surface water
systems that should be eligible for consideration as indicator monitoring as appropriate. The proposed
rule is not
Response: See Response 386.
Comment Response for the LT2ESWTR 5-256 December 2005
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5.8.7 Comment Code 388, Sample location criteria
Summary of Issues
Comments were received suggesting that EPA change the description of the required "source water"
monitoring to "influent water characterization" to reflect the intent of the regulation and to avoid
confusion as to where a system must monitor. Guidance is needed on the following topics: the
requirements for a plant that has multiple treatment trains, the intent of monitoring, defining what EPA
refers to as influent water, and on changing of the sampling location point within the same source water
used for submitting grandfathered data. Commenters stated that the LT2ESWTR doesn't offer flexibility
in the required sampling location, and that increased flexibility and simplification of requirements would
be possible if systems were allowed to pick appropriate sampling locations as part of their monitoring
plan. Other commenters suggest that these concerns about flexibility should be addressed on a case-by-
case basis, to better ensure State participation. Commenters also recommend that a schematic of the water
treatment plant train, including the location of chemical addition and pretreatment processes, should be
reviewed by the State to ensure correct sample collection location. Two commenters state that E. coli
sampling should represent the raw source water only, and that Cryptosporidium sampling should be
required to monitor at a point that will represent the quality of water that is entering the primary treatment
processes at the plant, regardless of chemical and pretreatment processes. A few commenters are
concerned about the sampling location after pretreatment processes, like presedimentation basins and
bank filtration, since the proposed rule didn't allow sampling prior to these processes.
Response to Code 388
Intent of monitoring and defining influent water
The intent of monitoring for LT2ESWTR is to ensure that the data used to comply with the initial source
water monitoring requirements of 40 CFRpart 141.701(a) are seasonally representative and unbiased,
showing a true representation of the source water in use at the time the sample is collected on the
designated sampling date following normal operating procedures.
The LT2ESWTR requires PWSs using surface water or ground water under the direct influence
(GWUDI) of surface water to monitor their source water (i.e., the influent water entering the treatment
plant) to determine an average Cryptosporidium level. Monitoring results determine the extent of
Cryptosporidium treatment requirements under the LT2ESWTR.
Sampling location
The requirements in today's final rule for source water sample collection location are similar to those in
the proposed rule. They are designed to achieve two objectives: (1) characterize the influent water to the
treatment plant at the time each sample is collected and (2) ensure that samples are not affected by
treatment chemicals that could interfere with Cryptosporidium analysis.
The first objective is the basis for requiring PWSs that use multiple sources to either analyze a blended
source sample or to calculate a weighted average of sources that reflects the influent at the time of sample
collection. It is also the reason that PWSs are required to sample after certain pretreatment processes like
bank filtration that do not involve chemical addition.
The second objective is why PWSs are generally required to sample upstream of chemical addition and
prior to backwash addition (for PWSs that recycle filter backwash). However, EPA recognizes that in
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some situations, sampling prior to chemical addition will not be feasible and discontinuing chemical
addition for a period of time prior to sampling will not be advisable. This situation could occur when a
treatment chemical is added at an intake that is difficult to access. Further, some treatment chemicals may
not interfere with Cryptosporidium analyses when present at very low levels. Consequently, today's rule
allows States to approve PWSs sampling after chemical addition when the State determines that collection
prior to chemical treatment is not feasible and the treatment chemical is not expected to interfere with the
analysis of the sample.
The requirement in today's final rule to sample prior to the basin for PWSs that use presedimentation with
coagulation is a change from the proposal, which required sampling after presedimentation. This change
is based on the recognition that sampling prior to presedimentation will be necessary when a PWS adds
coagulant to the basin, as residual coagulant may be present in the basin effluent. Due to this change,
PWSs using presedimentation with coagulation are eligible for additional treatment credit for this unit
process.
Where multiple plants receive all of their water from the same influent, such as plants that draw water
from the same intake or pipe, the State may approve one set of monitoring results to be applied to all
plants. This situation would include plants that have multiple treatment trains with a common influent. All
Cryptosporidium, E. coli, and turbidity source water samples collected under LT2ESWTR requirements
must be collected from the same appropriate sampling location.
EPA disagrees with commenters' statements that the LT2ESWTR does not offer flexibility in the required
sampling location. Options are available for systems that will need guidance on correct sampling
locations under LT2ESWTR. For example, systems in these situations can manually collect source water
samples at the intake, establish a sampling location prior to treatment, and upon State approval, PWSs
may discontinue chemical treatment until the chemical is not detected. Figures have been developed to
illustrate the correct sample collection location within the Source Water Monitoring Guidance Manual for
Public Water Systems under the Long Term 2 Enhanced Surface Water Treatment Rule. This document
provides guidance on sampling location, procedures for collecting and shipping samples, contracting with
laboratories, and related topics to assist PWSs in complying with LT2ESWTR monitoring requirements.
Submitting sampling location description and State involvement
EPA believes that States should review source water monitoring locations for their PWSs. Commenters
indicated that State review and approval of monitoring plans will help to prevent confusion and PWSs
potentially sampling at an incorrect location. State review of monitoring locations will ensure that PWSs
collect source water samples at the correct location and, thereby, determine the appropriate level of public
health protection within required compliance dates. Consequently, today's rule requires PWSs to report a
description of their monitoring location to the State. This requirement is a change from the proposed rule,
which did not require PWSs to report a description of their sampling location. This change reflects public
comment on the proposal which strongly supported State review of monitoring locations. If a PWS does
not hear back from the State by the time it is scheduled to begin sampling, it must assume that its
monitoring location is acceptable.
Changing of sample collection location when grandfathering
Systems must follow the requirements of the LT2ESWTR, as stated in 40 CFR part 141.703, and monitor
from the source water intake in use on the designated sample collection date following normal operating
procedures. The LT2ESWTR allows the sample collection location to change between initiation of
monitoring for grandfathernig and completion if such change reflects routine, ongoing, operational
changes (i.e., if the plant routinely shifts sources, the grandfathered data should reflect this). However,
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grandfathered data must reflect the overall use of sources at the time the data are submitted (i.e., the data
cannot be submitted if they reflect a source the plant no longer uses).
Individual Comments on Code 388
EPA Letter ID: 439
Comment ID: 10757
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: avoid confusion as to where a system must monitor. Systems should be allowed to
monitor at a point that reflects influent water quality for the specific system, not necessarily at that sample
point that EPA has defined. Also, since the EPA definitions of this point may not be applicable for every
system grandfathering historic Cryptosporidium data would then be negated for these systems. The
Response: See Response 340/388.
EPA Letter ID: 452
Comment ID: 10935
Commenter: Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Commenter Category: Regulated Community (Utilities)
Comment: presedimentation. Disqualifying data because samples were collected before
presedimentation basin (which is often at the same location as the ICR monitoring site) would create a
needless hardship for systems that planned to submit previously collected data.
Response: See Response 340/388.
EPA Letter ID: 496
Comment ID: 10694
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: to accommodate situations that will doubtlessly materialize. Also, the requirements
could exclude the option of using grandfathered data, if the specified monitoring location is different from
the location historically used.
Response: See Response 340/388.
EPA Letter ID: 507
Comment ID: 11466
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
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Comment: intent of the proposed rule. Consideration should also be given to utilities that intend to have
previous data grandfathered but have changed monitoring locations, albeit from the same raw water
source. As an example, within the past year, FCWA has been withdrawing water from a newly
constructed off-shore intake in the Potomac River approximately 720 feet from the previous shore line
intake and we would like to -grandfather- this existing data. We feel that our raw water is essentially
being delivered by the same source (Potomac River) and that the rule should include that degree of
flexibility.
Response: See Response 340/388.
EPA Letter ID: 512
Comment ID: 11512
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: c. Flexibility in the use of ICR sites that don-t meet the current monitoring location definition
would promote a larger available pool of data and maintain a continuity in the data set while still being
protective of the public health in bin determination
Response: See Response 340/388.
EPA Letter ID: 562
Comment ID: 12381
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The monitoring location is also of concern to utilities that will grandfather data. The current
regulatory language and guidance would preclude submittal of raw water samples drawn from a water
treatment plant-s source (i.e., river, lake, reservoir, well from which the plant draws water) if one of the
pre-treatment toolbox technologies is in place at the plant.*, ** Based on this
regulatory language and guidance, some utilities that continued to monitor at its Information Collection
Rule (ICR) monitoring site using EPA Method 1623 would be unable to grandfather its data. Even though
such utilities are acting proactively and taking action well beyond regulatory requirements, this
potentially grandfathered data would be lost due to the overly restrictive requirements on monitoring
location.
Response: See Response 340/388.
EPA Letter ID: 562
Comment ID: 12384
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
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Comment: *§141.708(b)(4), 68 FR 47780
Response: Not a comment, source reference to another comment, no response needed.
EPA Letter ID: 562
Comment ID: 12385
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: * * Section 2.1.1., Source Water Monitoring Guidance Manual for Public Water
Systems for the Long Term 2 Enhanced Surface Water Treatment Rule, June 2003 Draft
Response: Not a comment, source reference to another comment, no response needed.
5.8.8 Comment Codes 389, Specific to Grandfathered Data Guidance
Manual
Summary of Issues
Comments were received detailing suggested changes to the guidance document for grandfathered data
including clarification of sampling interval, method version for Cryptosporidium analyses, minimum
sample volume, number of samples for seasonally operated plants, rule promulgation date, continuation of
data collection, and application of all data to LT2 binning. Changes to the Checklist for Submitting
Grandfathered Cryptosporidium Data were also suggested including changing the temperature
requirement, completing sentences, and clarifying the matrix spike frequency for plants sampling more
than once a month.
Response to Code 389
Suggested guidance manual changes
EPA agrees that changes were necessary in the guidance for grandfathered data to accurately reflect the
rule. EPA will publish a revised guidance manual to support today's rule. The guidance for grandfathered
data is in Section 5 of the Source Water Monitoring Guidance Manual for Public Water Systems for the
LT2ESWTR.
EPA believes that bullet #5 in Section 5.2 of the draft Source Water Monitoring Guidance Manual
provides useful recommendations but has provided additional detail in Section 5.3.1.1. EPA chooses not
to incorporate the clarification suggested by one commenter regarding the minimum sample volume and
subsample analyses for collected sample volumes >10 L. As stated in the guidance manual Section 4.2.1,
systems may analyze volumes larger than 10 L, and larger volumes analyzed should increase analytical
sensitivity (detection limit) and representativeness, provided method performance is acceptable. EPA
encourages systems to analyze similar sample volumes throughout the monitoring period. However, data
sets including different samples volumes will be accepted, provided the system analyzes the minimum
sample volume requirements.
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EPA believes the guidance manual accurately reflects the potential need for continuation of monitoring by
stating that grandfathering of previously collected data may be approved where there are time gaps in the
sampling frequency if the system conducts additional monitoring as specified by EPA/the State to ensure
that the data used to comply with the initial source water monitoring requirements of 40 CFR part
141.701 (a) are seasonally representative and unbiased.
Guidance regarding the minimum number of samples for the seasonally operated plants is given in
Section 3.2.1 of the manual. This guidance follows the requirements in 40 CFR part 141.701 (e). Systems
must sample their source water only during the months that the part-year plant operates, unless the State
specifies another monitoring period based on plant operating practices. Systems with part-year plants that
operate less than six months per year and that monitor for Cryptosporidium must collect at least six
Cryptosporidium samples per year during each of two years of monitoring. Samples must be evenly
spaced throughout the monitoring period. Water treatment plants that use surface water or ground water
under the direct influence (GWUDI), but are operated only seasonally (e.g., during times of high-water
demand) should monitor at least monthly during the period when the plant is in operation.
No reference to the rule promulgation date is given in the guidance manual. The Checklist for Submitting
Grandfathered Cryptosporidium Data has been updated to reflect the suggested changes except the matrix
spike frequency clarification.
Individual Comments on Code 389
EPA Letter ID: 641
Comment ID: 13656
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 3.0
Bullet #4 : " Samples were collected in equal intervals of time over the entire
collection period-"
This phrase needs to be revised to allow for changes in sampling intervals, as ASI understands from the
EPA is allowable. Please see related comments above (Proposed rule, Pg 47668 d. Use of previously
collected data).
Response: See Response 389.
EPA Letter ID: 641
Comment ID: 13657
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Bullet #5 : "(see details below - -data from monitoring not directed towards LT2
binning will not be a component of the binning set-"
ASI recommends this phrase be deleted, as it creates confusion. This subject is adequately expounded on
later in 4.1.1.
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Response: See Response 389.
EPA Letter ID: 641
Comment ID: 13660
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 3.3 Crypto analytical Methods for GF Data
This section needs to be updated to include the June 2003 version of Method 1623. Also, it would be
helpful to detail the "Notable differences" between 2001 and June 2003 versions (as was done for the
1999 and 2001 versions).
Response: See Response 389.
EPA Letter ID: 641
Comment ID: 13661
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 3.3.1 Minimum Sample Volume and Subsample Analysis
This section is much clearer than other passages on sample volume and the 3-bullet approach should be
used a s a model throughout. However, we suggest further clarification by adding that ("Note: For
maximum sensitivity, EPA recommends analyzing the entire sample, however, only these minimum
criteria must be met. Therefore, for example, if a SOL sample yields a 2 mL pellet, only the equivalent of
10L of sample (0.4 mL of packed pellet) needs to be examined.")
Response: See Response 389.
EPA Letter ID: 641
Comment ID: 13664
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 4.1.1
ASI recommends that this section include a caution to PWSs to continue monitoring after selected
grandfathering period - until their data has been submitted to EPAand been approved for LT2 binning
classification.
Response: See Response 389.
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EPA Letter ID: 678
Comment ID: 14733
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: VII. Comments on the Guidance on Generation and Submission of Grandfathered
Cryptosporidium Data for Bin Classification Under the LT2 Rule
1. Section 3.2, Sample Collection Schedule, 1st paragraph, p. 5
The EPA requests comments on whether a minimum number of samples should be required for seasonally
operated plants. We believe that a minimum number of samples should be required for such plants as in
other plants, e.g. at least one sample every month that the plant is in operation.
2. Section 3.4, Cryptosporidium Laboratories for Grandfathered Data, 1st paragraph, 6th line, p. 7
The most recent information on the schedule for promulgation is June 2005.
3. Checklist for Submitting Grandfathered Cryptosporidium Data, Detailed quality control information,
a. Sample temperature requirements
The temperature requirement stated in this section is -between 0°C and 8°C upon receipt- while portions
of the Microbial Laboratory Manual indicate that the samples must be at <10°C and not frozen. The
requirement here must be reconciled with that in the Microbial Lab Manual.
b. Staining control results
The sentence is incomplete: - Were positive and negative staining controls acceptable for all-
Response: See Response 389.
5.9 Comment Code 400, Ongoing Source Assessment (watershed
review during sanitary survey)
Summary of Issues
Comments were submitted requesting that States should be allowed to utilize other measures of watershed
changes other than sanitary surveys. Possible suggestions included source water protection assessments.
Several commenters expressed concern that long term trends should be used to characterize watershed
changes and that these changes may be incorrectly identified using the sanitary surveys.
Response to Code 400
(A) Commenters asked for greater flexibility in the requirement for States to determine whether there
have been significant changes in the watersheds of their PWSs that could lead to increased contamination.
The proposed rule specified that States must make this determination during sanitary surveys. However,
several commenters noted that some States perform source water protection assessments on the same
frequency as sanitary surveys, and these detailed assessments might be a better mechanism to monitor
changes in the watershed. EPA agrees and today's rule allows States to determine whether significant
changes have occurred in the watershed through either a sanitary survey or an equivalent review of the
source water under another program.
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(B) Some commenters were concerned about how States would implement these assessments and
required treatment changes and the guidance that would be available to them to determine significant
changes in pathogen control at the intake. EPA agrees with the comment that perhaps PWSs should be
granted time to collect additional data to support the assessed change, and the final rule allows States the
option of requiring additional monitoring. Regarding concerns that watershed impairment can only be
noted on a long term trend, EPA believes that States will correctly use their discretion to look at long term
impairment trends as well as short term. Potential sources of Cryptosporidium are generally known, such
as wastewater treatment plants, combined sewer overflows, feedlots and runoff, and EPA believes that
States will utilize this understanding in determining changes in pathogens at the intake through their
standard sanitary survey and watershed assessment practices.
Individual Comments on Code 400
EPA Letter ID: 458
Comment ID: 10969
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Page 47677 - It is stated that the Sanitary Survey is envisioned to be the mechanism to
determine if changes in the watershed may lead to increased potential contamination. The Source Water
Protection Assessment would be a better mechanism to monitor changes. A sanitary survey must address
eight elements, the watershed being one of the eight. During the source water assessment, the watershed
is the only item that is reviewed, in detail. The Source Water assessment is being done on the same
frequency as Sanitary Surveys in West Virginia, and this may be true in other states as well.
Response: See Response 400(A).
EPA Letter ID: 591
Comment ID: 12143
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: 16. § 142.16(n)(l), (Page 47795)
This section of the proposed rule requires the State to assess significant changes in the watershed and
source water as part of the sanitary survey process and determine appropriate follow-up action. Ohio EPA
requests that the reference to the sanitary survey process be removed from the paragraph so as to afford
states the latitude to make watershed and source water assessments as part of another process or function
besides a sanitary survey. In addition, we request
Response: See Response 400(A).
EPA Letter ID: 646
Comment ID: 13571
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Comment Response for the LT2ESWTR 5-265 December 2005
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Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: The requirement for a watershed survey by a state certified third party is excessive. Rather,
EPA should utilize the existing sanitary survey and source water protection programs to accomplish this
task. The 1995 EPA/State Joint Guidance on Sanitary Survey includes a review of source waters.
Additionally, the primacy agency recently completed a source water assessment on the Santa Fe system,
which included an evaluation and assessment of the watershed. These
tools used together achieve the goal EPA is seeking, while minimizing the impact on states programs and
communities.
Response: See Response 400(A).
EPA Letter ID: 662
Comment ID: 14024
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussions of Proposed LT@ESWTR Requirements.
A. Additional Cryptosporidium Treatment Techniques for Filtered Systems (page 47667)
Comment on the proposal to have States determine during Sanitary Survey that significant changes have
occurred in the watershed that could lead to increased contamination of the source water, the State may
require systems to implement specific actions to address the contamination. These actions include
implementing options from the microbial toolbox.
Watershed impairment can only be noted on a long term trend, Any changes to the requirements for
implementation of the microbial toolbox should be based on identified long term microbial increases.
Some changes in the watershed do not necessarily lead to increased contamination when appropriately
addressed during the planning process.
Response: See Response 400(B).
EPA Letter ID: 673
Comment ID: 13975
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussions of Proposed LT@ESWTR Requirements.
A. Additional Cryptosporidium Treatment Techniques for Filtered Systems (page 47667)
Jordan Valley Water comment on the proposal to have States determine during Sanitary Survey that
significant changes have occurred in the watershed that could lead to increased contamination of the
Comment Response for the LT2ESWTR 5-266 December 2005
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source water, the State may require systems to implement specific actions to address the contamination.
These actions include implementing options from the microbial toolbox.
The proposal to allow States to determine that significant changes in the watershed have increased the
potential for contamination and require systems to implement specific technology seems unwarranted
without data to support the State-s assessment of perceived impact. If water systems are required to
implement additional treatment, sufficient time must be granted to gather
additional data to support the State-s assessment.
Response: See Response 400(B).
5.10 Comment Code 410, Second Round of Monitoring
Summary of Issues
Comments were submitted concerning the process for determining the appropriateness of second round
monitoring. Some commenters supported the proposed requirement for a second round of source water
monitoring, but most opposed requiring it for all PWSs. These commenters recommended that States
should be authorized to use sanitary surveys, source water assessments, ambient water quality data,
treatment plant data, and other information to determine if a second round of monitoring is necessary for a
PWS. Several commenters felt that second round monitoring would be unjustly expensive and
burdensome. Other commenters suggested that the second round of monitoring should focus on finished
water, as opposed to source water, and that scenarios where multiple systems draw from the same source
water allow for redundancy of multiple tests which should be avoided. One commenter believes the
timeframe for installation of additional treatment for systems whose bin classification changes between
the two rounds of monitoring was unclear.
Response to Code 410
(A) Second round of monitoring
EPA disagrees with commenters who suggested that a second round of monitoring is unnecessary because
there will be other information available regarding significant changes in the source water from sanitary
surveys, other watershed assessments, or community water protection plans. EPA agrees that such
information is useful, and had provided options for States to use such information to address changes in
the source water. However, currently available information does not support the use of other data types
for bin classification since such data may not provide a quantitative assessment of the mean source water
Cryptosporidium level. This includes source water assessments, other than Cryptosporidium monitoring
or the E. coli monitoring for small filtered systems. (Response 500 h.) EPA continues to believe that
PWSs should conduct a second round of monitoring to determine if the level of treatment required as a
result of the first round of monitoring is still appropriate and if the quality of the source has changed.
Consequently, today's rule requires this. It does not require additional monitoring beyond the second
round.
EPA also may initiate a stakeholder process after initial bin characterization to review available methods
and bin characterization structures, as recommended by the Advisory committee. EPA would conduct the
stakeholder process to determine the appropriate analytical method, monitoring frequency, monitoring
location and other details for the second round of monitoring. EPA anticipates that stakeholder input, data
from the first round of sampling, and new studies, data, and method developments, would contribute
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useful information to that process. EPA anticipates that other future reviews of the regulation will be
conducted as part of the six-year review process.
(B) Timeframe for installation of treatment when bin classification changes after the second round of
monitoring
If the bin classification changes following the second round of source water monitoring, the system must
provide the level of treatment for Cryptosporidium required on a schedule the State approves. At the
State's discretion, this will include time required for capital improvements.
Individual Comments on Code 410
EPA Letter ID: 101
Comment ID: 10882
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Second Round of Initial Monitoring
Requiring systems to conduct another costly and burdensome round of initial data every six years is
unnecessary and cost prohibitive. Systems must not be required to conduct another round of monitoring.
The States will have the authority through the sanitary survey process to revaluate the monitoring
requirements if significant changes to potential sources are identified. The Agency must rely on the State
and more importantly the community to identify when potential problems or changes may impact the
quality of the source water. Communities will constantly be evaluating their watershed through their
source water protection plans or other means and will take any necessary actions to enhance protection if
necessary. No federally mandated program to force communities to spend resources on additional sample
collection and analysis is necessary or prudent.
Response: See Response 410(A).
EPA Letter ID: 478
Comment ID: 11217
Commenter: Anonymous478,,
Commenter Category: Unknown
Comment: We agree that the State should have flexibility in determining whether or not
each successive round of monitoring is needed.
Response: See Response 410(A).
EPA Letter ID: 505
Comment ID: 11175
Commenter: Darron Busch, Administrator, Department of Environment and Natural Resources,
Comment Response for the LT2ESWTR 5-268 December 2005
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Drinking Water Program
Commenter Category:
Comment: - We do not support second round of source water monitoring as proposed. We prefer and
approach where states could use existing information about a water system, such as source water
assessments, water quality monitoring information, and sanitary surveys, to determine the need for
additional source water monitoring.
Response: See Response 410(A).
EPA Letter ID: 560
Comment ID: 14983
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: In addition, American Water suggests that EPA begin immediately to standardize
cell culture analysis of Cryptosporidium oocysts in finished water in preparation of the phase II
monitoring. If the Aboytes and LeChevallier data are supported by subsequent research, then the second
round of monitoring should focus on finished water analysis rather than continued testing of source water.
Only through a commitment today supporting such a line of research by the
Agency, will the necessary tests and capabilities be ready for such a monitoring program in the future.
Response: See Response 410(A).
EPA Letter ID: 561
Comment ID: 12232
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 347 7. Sampling one source with multiple intakes
Comment: On-Going Source Assessment & Second Record of Monitoring
If there are multiple users of a single water supply source, where more than one water supply is obtained
from the same source and the initial two years of monitoring has adequately characterized the source
water quality, we would suggest that requiring a full second round of sampling from each user at a future
date is redundant. Perhaps a single set of monitoring would be conducted at that future date to compare to
the data obtained from the initial set of monitoring. Please provide flexibility here to reflect this scenario.
Response: See Responses 410(A).
EPA Letter ID: 562
Comment ID: 12403
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-269 December 2005
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Comment: dialogue to evaluate appropriate analytical methods and associated bin structures.
Perspectives on the risk of cryptosporidiosis from drinking water will likely change in the future based on
new analytical methods, observations drawn from the initial bin determinations, and health effects
research. One example of new research is the Aboytes and LeChevallier paper, which is discussed below.
EPA should be extremely careful to allocate sufficient time and resources to agreed-upon discussion with
stakeholders prior to the second round of LT2ESWTR monitoring. Additionally, EPA needs to ensure
that PWSs are informed with an ample amount of time to react and prepare for initiation of this second
round of monitoring. EPA also needs to
ensure appropriate funding for microbial and disinfection byproduct research.
Aboytes and LeChevallier, 2003
Aboytes and LeChevallier presented findings from a recent study of 82 surface water treatment plants,
which enumerated Cryptosporidium oocysts using a combination of techniques including
immunomagnetic separation (IMS) to recover oocysts, HCT-8 cell culture to select for viable oocysts,
polymerase chain-reaction (PCR) reactions for DNA amplification, and agarose gel
electrophoresis as a sensitive detection method for viable, infectious oocysts. This effort represents a
useful proof of concept study combining not only the development of analytical techniques, but also
illustrating application of the method across a variety of water matrices. In total, more than 1,800 samples
were processed. This study has generated significant interest in the drinking water community because its
findings are provocative. The findings include:
1. Observed occurrence of oocysts in finished water was independent of observed source water quality,
2. Little apparent relationship between system size, land use, or age of plant and observed oocyst
occurrence in finished water,
3. Observed occurrence of oocysts in finished water was independent of observed finished water turbidity.
Each of these observations is at odds with the underlying precepts of the LT2ESWTR proposal. AWWA
found these study findings to be interesting and potentially informative. AWWA is recommending that
potential funding organizations support conducting a similar, robustly designed study to verify this initial
study-s findings. AWWA found these results difficult to
reconcile with recent epidemiological studies in the U.S. and Australia. These studies have not
demonstrated discernable levels of waterborne disease attributable to drinking water supplies believed to
be positive for Cryptosporidium (e.g., Melbourne, Australia, and Davenport, Iowa).
Aboytes and LeChevallier illustrates that if EPA and its research partners maintain an active research
agenda, potential developments in analytical techniques and the science generally regarding
Cryptosporidium could change (1) our collective view on the need for a second round of monitoring, (2)
the tools and techniques used to undertake future monitoring, and (3) the
sampling plan for such future monitoring.
Response: See Response 410(A).
EPA Letter ID: 585
Comment ID: 11966
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
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Comment: p. 47677 [and §141.702(d) on p. 47778]
The TCEQ concurs with EPA that a second round of source monitoring may be needed in some cases. For
example, it may be appropriate to require periodic monitoring at unfiltered systems. However, the TCEQ
does not concur that this second round of monitoring should be mandatory for all systems that do not
meet Bin 4 treatment requirements.
The TCEQ recommends that the EPA give the primacy agencies the option of requiring a second round of
monitoring if sanitary surveys or source water vulnerability assessments indicate that a degradation in
source water quality may have occurred, especially if these changes have occurred at unfiltered systems.
Similarly, the primacy agency should have the authority to require a second round of monitoring if a
public water system makes design or operational changes (such as the construction of an off-stream
storage reservoir or the relocation of an intake) that will likely impact the quality of raw water reaching
the primary treatment processes. However, the proposed rule presents no evidence to suggest that a
second round of monitoring will produce any significant change in the bin classification without a change
in source water quality due to other factors. Consequently, the additional monitoring appears to be an
unnecessary expense for public water systems.
Response: See Response 410(A).
EPA Letter ID: 641
Comment ID: 13589
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47677 iii. Future Monitoring -
-Unless EPA modifies the LT2ESWTR to allow for an improved analytical method or a revised bin
structure based on new risk information, the second round of monitoring will be conducted under the
same requirements that apply to the initial round of sampling-.
ASI concurs that there should be a second round of monitoring to determine whether source water
conditions have changed, as an expectation of static source water conditions is unrealistic. Further, EPA
should expect and incorporate analytical advances (improved sensitivity, specificity, etc.) into the future
round, and allow for a revised bin classification system as appropriate, but otherwise keep the Rule
similar in concept.
Response: See Response 410(A).
EPA Letter ID: 664
Comment ID: 14052
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment: On-Going Source Assessment & Second Record of Monitoring
If there are multiple users of a single water supply source, where more than one water supply is obtained
from the same source and the initial two years of monitoring has adequately characterized the source
water quality, we would suggest that requiring a full second round of sampling from each supply source at
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a future date is redundant. Perhaps a single set of monitoring would be conducted at that future date to
compare to the data obtained from the initial set of monitoring. Please provide flexibility here to reflect
this scenario.
Response: See Response 410(A).
EPA Letter ID: 704
Comment ID: 14805
Commenter: Steven G. Gould, Chairman, New York State American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 10. Second round of sampling.
The second round of sampling appears to be routine monitoring. We suggest that the second round of
sampling only be required when a State Sanitary Survey indicates a change in watershed protection (or
raw water quality) that may indicate degradation of quality from that determined in the first round of
sampling.
Response: See Response 410(A).
EPA Letter ID: 711
Comment ID: 16553
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 7. 141.709 (d) - As written, it is unclear what would happen if a system gets classified in Bin
1 from the 1st round of monitoring and yet gets classified in Bin 2 from the 2nd round. The timeline for
meeting installation of additional treatment if a system is required to is based on time after publication of
the final rule which would not apply to a system that is not required to do any additional treatment
following the first round of monitoring but may be required to do so after the 2nd round. The final
regulation needs to have the same time extension given for a system that might be required to install
additional treatment after the 2nd round of monitoring as it did for a system that is required to install
additional treatment after the 1st round of monitoring.
Response: See Response 410(B).
5.10.1 Comment Code 411, Stakeholder process for second
monitoring round
Summary of Issues
Comments were submitted concerning the process for determining the appropriateness of second round
monitoring. Some commenters supported the proposed requirement for a second round of source water
monitoring, but most opposed requiring it for all PWSs. These commenters recommended that States
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should be authorized to use sanitary surveys, source water assessments, ambient water quality data,
treatment plant data, and other information to determine if a second round of monitoring is necessary for a
PWS.
Response to Code 411
See Response 410(A).
Individual Comments on Code 411
EPA Letter ID: 411
Comment ID: 17017
Commenter: Devon Cole,, Utah Department of Health Laboratory
Commenter Category: State/Tribe Government
Comment: June 2003 versions of Method 1622/1623 list OPRpass criteria for Crypto as 11-
100%, however Appendix D of the Microbial Guidance Manual lists 24% as the minimum recovery for
acceptable Crypto results. Which standard is to be followed during LT2 rule monitoring?
Response: For LT2 monitoring, the OPR passing criteria for Crypto of 11-100% as listed in the June
2003 versions of Method 1622/1623 should be followed. Appendix D in the Laboratory Guidance manual
has been corrected to read: The OPR sample for the QC batch was acceptable (recovery was at least
11%). This criteria is consistent with the criteria in the December 2005 version of Methods 1622/23.
EPA Letter ID: 457
Comment ID: 11895
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Need to Perform a Second Round of Source Water Monitoring
We support the need to review available information, such as risk information and analytical capabilities,
to determine possible revisions to the LT2ESWTR and suggest that the Six-Year Review process required
under the SDWA is the appropriate forum to explore these issues. However, we are concerned that the
status quo will be a second round of across-the-board source water monitoring for all surface water
systems six years after initial bin determination. We would prefer an approach where the states are
allowed to use existing information, such as source water assessment results, sanitary surveys, and
ambient water quality monitoring, to determine the need for additional source water monitoring.
Response: See Response 410(A).
EPA Letter ID: 520
Comment ID: 11585
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
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Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Need to Perform a Second Round of Source Water Monitoring
IEPA supports the need to review available information, such as risk information and analytical
capabilities, to determine possible revisions to the LT2ESWTR and suggest that the Six-Year Review
process required under the SDWA is the appropriate forum to explore these issues. IEPA concurs that
stakeholder input into such a review is vital and note that stakeholder involvement is an integral part of
the Six-Year Review process.
Response: See Response 410(A).
EPA Letter ID: 528
Comment ID: 12260
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Need to Perform a Second Round of Source Water Monitoring
We support the need to review available information, such as risk information and analytical capabilities,
to determine possible revisions to the LT2ESWTR and suggest that the Six-Year Review process required
under the SDWA is the appropriate forum to explore these issues. Stakeholder input into such a review is
vital and stakeholder involvement should continue to be an integral part of the Six-Year Review process.
Response: See Response 410(A).
EPA Letter ID: 536
Comment ID: 11795
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Need to Perform a Second Round of Source Water Monitoring
Colorado supports the need to review available information, such as risk information and analytical
capabilities, to determine possible revisions to the LT2ESWTR and suggests that the Six-Year Review
process required under the SDWA is the appropriate forum to explore these issues. Colorado concurs that
stakeholder input into such a review is vital and notes that stakeholder involvement is an integral part of
the Six-Year Review process.
Colorado is concerned that the status quo will be a second round of across-the-board source water
monitoring for all surface water systems six years after initial bin determination. Colorado would prefer
an approach where states could use existing information, such as source water assessment results, sanitary
surveys, and ambient water quality monitoring, to determine the need for
additional source water monitoring.
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Response: See Response 410(A).
EPA Letter ID: 560
Comment ID: 14981
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Five - Second Round of Source Water Monitoring:
The proposed rule provides for a second round of monitoring six years after completion of initial bin
characterization. The Stage 2 M/DBP FACA explicitly provided for stakeholder dialogue to evaluate
appropriate analytical methods and associated bin structures.
Response: See Response 410(A).
EPA Letter ID: 643
Comment ID: 12735
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Need to Perform a Second Round of Source Water Monitoring
States support the need to review available information, such as risk information and analytical
capabilities, to determine possible revisions to the LT2ESWTR and suggest that the Six-Year Review
process required under the SDWA is the appropriate forum to explore these issues. States concur that
stakeholder input into such a review is vital and note that stakeholder involvement is an integral part of
the Six-Year Review process.
Response: See Response 410(A).
5.10.2 Comment Code 412, Bin classification based on second
monitoring round
Summary of Issues
Several comments addressed concern regarding how the LT2 rule bin classification will evolve to
incorporate improved knowledge of waterborne endemic cryptosporidiosis. One comment asserted that
routine monitoring (i.e. quarterly or monthly monitoring) will likely be adopted by many utilities; such
data should be acceptable. For example, it was suggested that six years of quarterly monitoring may
provide a more representative assessment of water quality than 24 months of monthly monitoring.
Another comment suggested the use of statistical methods that would be able to identify apparent
Cryptosporidium concentration differences in data between initial and 6 year bin classification due solely
to improvements in the monitoring method and not to actual changes in concentrations. Several comments
also expressed concern that across-the-board source water monitoring for all surface water systems six
years after initial bin determination will occur rather than taking other factors into account to determine if
second round monitoring is necessary (i.e. existing information, ambient water quality monitoring).
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Lastly, one comment stated that the rule was unclear in describing how the situation would be handled if a
utility was originally classified as Bin 1 based on the first round of monitoring and then reclassified to
Bin 2 based on the second round of monitoring.
Response to Code 412
See Responses 410(A) and (B).
Individual Comments on Code 412
EPA Letter ID: 488
Comment ID: 11845
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Comments
The rule-s requirement for future monitoring in six-year cycles to determine bin allocation introduces a
host of questions that cannot be answered at this time but nevertheless should be acknowledged. The bin
structure is predicated on the use of M1623 for Cryptosporidium measurement together with the best
available science about occurrence, treatment, and infectivity. It is likely that all of these factors will
change substantially between now and the time for future
monitoring (at least 10 years from now). Moreover it is hoped that a much better understanding of the true
occurrence of waterborne endemic cryptosporidiosis is available to allow for a more robust risk
evaluation. How will such developments be accommodated in a future monitoring and bin/toolbox
structure?
Response: See Response 410(A).
EPA Letter ID: 488
Comment ID: 11846
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Some utilities may wish to establish a routine source water Cryptosporidium
monitoring program subsequent to the LT2 monitoring period. In such cases, assuming for the moment
that the analytical methodology and bin structure remain fixed, it would be reasonable to allow systems to
use these data for future bin assignment. A data set of 24 monthly samples might not provide a more
representative picture of Cryptosporidium occurrence over time than, for
example, 6 years of routine quarterly sampling. Options for ongoing monitoring would allow utilities to
spread out monitoring costs and logistical burdens and also provide more consistent workloads to contract
or in-house laboratories. The EPA should recognize that many utilities are likely to establish ongoing
source water Cryptosporidium monitoring programs after initial bin assignment. We hope the EPA will
give some thought to the role such data might play in future bin assignments.
Response: See Response 410(A).
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EPA Letter ID: 504
Comment ID: 11366
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: 9. BIN Creep
EPA has characterized the required BIN monitoring method for Cryptosporidium analysis (EPA 1622/23)
as performance based and flexible to accommodate improvements. Improvement in the method will
almost certainly occur over the next 6-years. This will most likely result in higher recovery efficiency in
application of the method during the proposed 6-year re-sampling (40CFR141.702 (d) (1)). Even if
Cryptosporidium concentrations were in reality unchanged
from the initial BIN monitoring period, the higher recovery efficiency would find more oocysts resulting
in an increase the proportion of systems falling in BINs 2, 3, and 4 without any change in actual
concentration and inferred risk to the water consumer.
To provide for fair and equitable assessment of true changes in concentrations that may have occurred in
the six years since initial BIN monitoring, an objective basis for relating concentrations in the two periods
is needed. Utilities and EPA alike must recognize that some improvements, or simply changes without
qualitative implications, may occur without laboratory or agency knowledge. An example might be
alteration of IMS reagent components that could
affect recovery. If recovery efficiency were to increase even by a small margin (as illustrated in Item 4
above) a significant number of utilities would be pushed from BIN 1 to BIN 2 (or between higher BINS)
without any change in the true background Cryptosporidium concentration.
We suggest that EPA consider providing for utilities to index data in the 6-year resampling to initial BIN
monitoring conditions. This could conceivably involve careful and statistically supportable recovery
efficiency measurement for each source during both the initial and +6-year BIN monitoring. Comparison
between recovery efficiency measurements during the two monitoring periods should be able to account
for apparent concentration differences that were due solely to improvements in the monitoring method.
Response: See Response 410(A).
EPA Letter ID: 520
Comment ID: 11586
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA is concerned that the status quo will be a second round of across-the-board
source water monitoring for all surface water systems six years after initial bin determination. IEPA
would prefer an approach where we could use existing information, such as source water assessment
results, sanitary surveys, and ambient water quality monitoring, to determine the need for additional
source water monitoring.
Response: See Response 410(A).
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Comment Codes 300-471
EPA Letter ID: 528
Comment ID: 12261
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: We are concerned that the status quo will be a second round of across-the-board
source water monitoring for all surface water systems six years after initial bin determination. We would
prefer an approach where the state could use existing information, such as source water assessment
results, sanitary surveys, and ambient water quality monitoring, to determine the need for additional
source water monitoring.
Response: See Response 410(A).
EPA Letter ID: 643
Comment ID: 12736
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States are concerned that the status quo will be a second round of across-the-board source
water monitoring for all surface water systems six years after initial bin determination. States would
prefer an approach where states could use existing information, such as source water assessment results,
sanitary surveys, and ambient water quality monitoring, to determine the need for additional source water
monitoring.
Response: See Response 410(A).
EPA Letter ID: 647
Comment ID: 12894
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment:
Need to Perform a Second Round of Source Water Monitoring
MDE is concerned that the status quo will be a second round of across-the-board source water monitoring
for all surface water systems six years after initial bin determination. MDE would prefer an approach
where states could use existing information, such as source water assessment results, sanitary surveys,
and ambient water quality monitoring, to determine the need for additional source water monitoring.
Response: See Response 410(A).
EPA Letter ID: 678
Comment ID: 14679
Comment Response for the LT2ESWTR
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Comment Codes 300-471
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 14. Section 141.709 (d) - It is unclear from the proposed rule-s verbiage what would happen
if a system has been classified to Bin 1 based on the first round of monitoring and is re-classified to Bin 2
as a result of the second round of monitoring. The timeline for meeting the requirement of installation of
additional treatment (if a system is so required) is based on when the final rule is promulgated, which
won-t apply to a system that is not required to
do any treatment following the first round of monitoring but may be required to do so after the second
round. We recommend the final
Response: See Response 410(B).
5.11 Comment Code 420, Providing Additional Treatment Instead of
Monitoring
Summary of Issues
Comments were submitted in support of the proposed rule that systems that achieve the level of treatment
required by Bin 4 (5.5-log credit) should be exempted from all source water quality monitoring
requirements.
Response to Code 420
EPA has reviewed all comments on this topic and appreciates the commenters' support.
Individual Comments on Code 420
EPA Letter ID: 562
Comment ID: 12402
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.1.5 5.5-Log Treatment Exemption
Utilities that proactively commit to investment in advanced treatment should not be burdened with
unnecessary monitoring requirements or administrative procedures. The proposed rule contains provision
in §141.701(f) where systems that achieve the level of treatment required by Bin 4 (i.e., 5.5 log credit)
may notify the primacy agency in lieu of monitoring for oocysts in
their influent water. This procedure is sound given the other rule requirements and should be retained in
the final rule.
Response: See Response lOOa.
EPA Letter ID: 585
Comment ID: 11971
Comment Response for the LT2ESWTR
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Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47678 [and §141.709(e) on p. 47781]
The TCEQ agrees that systems that have installed or will install facilities to meet the treatment
requirements of Bin 4 should be exempted from all the source water quality monitoring requirements in
the proposed rule. However, the TCEQ
Response: See Response lOOa.
5.12 Comment Code 430, Monitoring for Systems that Use Surface
Water Only Part of the Year
Summary of Issues
Comments were submitted concerning the sampling schedule for Cryptosporidium for those systems that
only operate for parts of a year. Almost all commenters agreed that systems should only be required to
sample their source waters during times of operation. Multiple commenters suggested alternate schedules
that these facilities could utilize to obtain their required 24 samples, including: taking 24 samples at
regular intervals during the months of the year the system is operational, and taking a sample every
operational month until 24 are reached. Several commenters expressed the concern that States should be
allowed the flexibility to determine an intermittent system's sampling schedule since they would be most
familiar with local conditions and most qualified to make these judgments on a case-to-case basis.
Response to Code 430
Part-year plant monitoring
All commenters suggested that plants that operate only part year should only sample during months of
operation. EPA concurs with this approach, and the final rule requires a PWS to sample only during the
months when a treatment plant operates. Source water monitoring under the LT2ESWTR is used to
establish treatment requirements, and these should be based on the water quality when a plant is in
operation.
Number of samples required
Commenters expressed varying opinions on the minimum number of samples that should be collected at a
part-year plant. EPA believes that the mean Cryptosporidium level used for bin classification can be
determined with fewer samples in part-year plants because source water quality typically varies less
during the shorter operating period. Source water variability is one factor that influences the number of
samples needed to accurately classify plants in LT2ESWTR treatment bins. As variability increases, more
samples are needed to determine the mean Cryptosporidium level with high confidence. EPA does not
have data on source water variability specifically in part-year plants. However, survey data show that
pathogen levels vary seasonally, and plants operating part-year will generally experience less variability
during a given year than plants operating year-round. Consequently, fewer samples are typically needed
to determine the mean Cryptosporidium level during the period of operation for a part-year plant.
Nevertheless, even when a plant operates for only a few months per year and source water exhibits little
variability, a minimum number of samples are necessary for bin classification. This is due to the relatively
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low sample volume, variable method recovery, nonhomogeneous distribution of Cryptosporidium in
water, and other factors that limit the accuracy of any individual sample for characterizing the source
water. EPA has determined that for plants operating for six months per year or less, collecting a minimum
of six samples per year over two years will allow bin classification with comparable accuracy to that
achieved by year-round plants sampling monthly (USEPA 2004a). Small part-year systems monitoring
for E. coli are required to monitor bi-weekly during the period of operation, with no minimum number of
samples required, because the mean E. coli concentration is used as an indicator and is not direct factor in
bin determination.
State input and flexibility
EPA agrees that there may be situations where State input is critical to determining the appropriate
monitoring period because States may have historical knowledge of plant operating practices. Therefore,
the rule specifies that monitoring under today's rule should be conducted only during the months when
the plant is operating, but the State may specify another monitoring period based on plant operating
practices. States should be able to make this determination during the review of sampling location
descriptions and schedules.
Limited outages
Some commenters described situations where a plant may be shut down for a limited time for
maintenance or construction. If the plant normally operates all year, these would not be considered part-
year plants. PWSs would need to work with the Primacy Agency to determine whether samples can be
collected regardless of the shutdown, or when to collect make-up samples for the plant down time.
Individual Comments on Code 430
EPA Letter ID: 101
Comment ID: 10878
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Surface water systems that only utilize a source for a part of the year should analyze for
source water quality only during those months that the water is normally in use. Many systems shut off
their water supplies due to freezing temperatures, or large population variations. Sampling source waters
when they are not in use is not practicable.
By collecting one E. coli sample per month or six samples per year for intermittent sources, whichever is
smaller, the system could use the means to determine if they were below the levels needed to avoid crypto
monitoring. Once this determination is made the requirement for further sampling should automatically be
waived. If the mean average was higher than the trigger level, then the system should work in
consultation with the State to determine the most appropriate action.
Response: See Response 430.
EPA Letter ID: 452
Comment ID: 10939
Comment Response for the LT2ESWTR
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Commenter: Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Commenter Category: Regulated Community (Utilities)
Comment: There should be provisions in 141.709(b)(2), Bin Classification, for large plants that operate
fewer than 12 consecutive months. EPA alluded to such provisions on p. 47678, however they were not
addressed in the rule. On p. 47678, EPA states that large systems that operate only part of the year could
be required to collect samples either twice per month or 12 samples per year, whichever is smaller. This
should be included in the rule. It should also be acceptable for plants to collect at least 24 samples by
either adding make-up samples at the end or by using previously collected data. An example is as follows:
a plant that was not operating during months 11, 12, 13, 22, 23, and 24 could collect monthly make-up
samples during months 25 through 30. The plant would collect 24 samples and report the highest
arithmetic mean of all sample concentrations in any 12 consecutive samples during the initial (e.g. 30-
month) monitoring period. See enclosed Figure 1. EPA should provide flexible methods for calculating
the Cryptosporidium bin concentration using make-up samples if there are unavoidable gaps in the data.
[See Figure 1 on page 3 of PDF file]
Response: See Response 430.
EPA Letter ID: 457
Comment ID: 11915
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: With respect to the specific issues on which EPA requested comment, we believe that EPA
should provide the states with flexibility to address these concerns on a case-by-case basis. The EPA
could present the following specific issues as a way of guidance to the states:
* Requirements for systems that use surface water for only a part of the
year;
Response: See Response 430.
EPA Letter ID: 458
Comment ID: 10970
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Page 47678 - Systems that use a surface source for only part of a year: Year
round systems -Based on WV-s experience, the time that a particular source is used may vary from year
to year, depending on weather conditions and other factors. As such, the base line monitoring, for systems
that are treating water year round, monitoring should be conducted for the entire year, even if current
conditions the system is only using a surface/gudi source for part of the year. If only part of the year is
monitored, then the primacy agency would only be able to grant the PWS permission to use the source for
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the time period that was monitored. Also, with the additional information, a better decision can be made,
if the PWS wishes to extend the time of use of the source, whether additional log reduction removal
should be required .
Seasonal systems: this should be on a -case by case- basis. If the primacy agency believes that the
likelihood of the source being used in a time period not currently being used is remote, less than a year of
data should be allowed. The only problem anticipated in less than a year is the modeling discussed
indicates a minimum number of samples are needed for determining a satisfactory degree of confidence.
This may require more intense monitoring for the seasonal
system.
Response: See Response 430.
EPA Letter ID: 470
Comment ID: 11064
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Additional Cryptosporidium Treatment Technique Requirements for Filtered Systems
pp.47665-47679
For systems that use surface water for only part of the year, we believe that monitoring should only be
required during the time period that the system is in operation. In Vermont, many of our seasonal systems
do not have operators available year-round to take samples, and this proposal would create unnecessary
logistical and financial burdens for these systems. We are in support of the approach for the state to grant
waivers for additional E. coli monitoring when surface water is only used for part of the year.
Response: See Response 430.
EPA Letter ID: 472
Comment ID: 11145
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: - Requirements for systems that use surface water for only part of the year.
This is an issue for COP as one of our water treatment plants shuts down for four to six weeks per year
for canal maintenance. It was also a specific question COP staff asked during the Internet stakeholder
meeting of October 9, 2003. Sampling will not be possible during this period and COP should not be
penalized for canal operation, which is controlled by the Salt River Project
(SRP). SRP routinely discontinues raw water supply for canal maintenancepurposes. During these periods
of canal maintenance, the COP utilizes its 25 groundwater wells.
Response: See Response 430.
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EPA Letter ID: 472
Comment ID: 11147
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: - Bin Assignment for systems that fail to complete the required monitoring.
This is an important concern for COP since one of our water treatment plant is supplied solely through an
SRP canal which dries up annually. Thus, we have no ability to meet the 24-month monitoring period as
stipulated in §141.701. We should not be penalized for raw water supply interruptions, and thus sampling
continuity interruptions that we do not control. This will be an issue for all surface water treatment plants
in the Greater Phoenix area. We can collect 24-
months of samples, not just in a 24-month consecutive period.
Response: See Response 430.
EPA Letter ID: 475
Comment ID: 11208
Commenter: Edmund G. Archuleta, General Manager, El Paso Water Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "The El Paso system will not be able to collect 24
consecutive months since the plants are only in operation four to eight months of the year" submitted by
Edmund G. Archuleta, General Manager, El Paso Water Utilities
Response: See Response 430.
EPA Letter ID: 475
Comment ID: 11211
Commenter: Edmund G. Archuleta, General Manager, El Paso Water Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Cryptosporidium, E. coli, and turbidity at least once each month. The El Paso
system will not be able to collect 24 consecutive months since the plants are only in operation four to
eight months of the year. The proposed rule on page 47666 states: "Any filtered system that fails to
complete LT2ESWTR monitoring requirements must meet the treatment requirements for Bin 4". The
inability to collect 24 months of consecutive samples should not penalize our Cryptosporidium bin
determination and placement.
Secondly, we are required to calculate and report our Cryptosporidium bin determination no later than 36
months after the Rule is published. Depending on the date the Final Rule is published, 36 months may be
too soon for the El Paso System to have 24 months of source monitoring data.
Comment Response for the LT2ESWTR 5-284 December 2005
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Response: See Response 430.
EPA Letter ID: 475
Comment ID: 11213
Commenter: Edmund G. Archuleta, General Manager, El Paso Water Utilities
Commenter Category: Regulated Community (Utilities)
Comment: In general, the proposed rule does not appear to have the flexibility for plants
that operate intermittently. This is the case for El Paso System's two surface water plants that operate 4 to
8 months of the year.
Response: See Response 430.
EPA Letter ID: 485
Comment ID: 11281
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes that large or small systems, which use surface
water only part of the year, should be required to monitor according to the rule frequency during the
months of operation. Monitoring should be conducted over several years until an equivalent number of
samples have been collected to equal the total number collected by a system operating for a full year and
the samples collected are sufficient to characterize temporal water quality. Treatment bin classification
should be then determined based on the sample results. However,
if a system has used the plant in the past for the entire year they should be required to monitor for the full
two years unless they will certify that in the future the plant will never be used during the season for
which no sampling is conducted. The Department also does not object to the collection of additional
samples per month to enable 24 samples to be collected in a shorter time period,
but, as previously stated, the monitoring must cover the period of time during which the plant will be
operated.
Response: See Response 430.
EPA Letter ID: 520
Comment ID: 11615
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Requirements for systems that use surface water for only part of the year
IEPA needs to be involved in making monitoring determinations for systems that use surface water for
only part of the year. IEPA may have historical knowledge that the source has been used on a more
permanent basis, in which case, complete monitoring would be appropriate.
Comment Response for the LT2ESWTR 5-285 December 2005
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However, in instances when a surface water source is truly only used for part of the year, IEPA and water
systems will need to work together to determine an appropriate monitoring strategy. This might entail
increased monitoring (more than two samples per month) to complete the monitoring over a shorter time
frame. Another approach may be to allow the system to collect the required number of samples over a
longer period of time (e.g., taking two samples per operational month for three or more years). IEPA
input into determining the appropriate monitoring plan is critical. For systems that use surface water only
part of the year, EPA should provide guidance to States, outlining options for conducting source water
monitoring, and allow States the flexibility to determine source water monitoring requirements for these
systems.
Response: See Response 430.
EPA Letter ID: 548
Comment ID: 12156
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: EPA has proposed that systems that use surface water for only part of the year must monitor
for Cryptosporidium (for large systems) or E. coli (for small systems) during that period when surface
water is in use. It is appropriate to conduct monitoring during these periods to evaluate potential risk.
Even though E. coli has limitations as a surrogate for Cryptosporidium, it can provide information on the
level of fecal contamination. The frequency of the sample and trigger level requirements must follow
those of systems that use surface water all year round.
Response: See Response 430.
EPA Letter ID: 562
Comment ID: 12378
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. Some PWSs that will have to monitor under the LT2ESWTR only operate
a particular water treatment plant for a portion of the year (e.g., a utility that operates a plant as a summer
peaking supply). The rule should be specific about the monitoring requirements for
plants that operate part of a year. AWWA recommends that these defined monitoring entail a minimum of
plants be required to take 12 samples a year for two years distributed evenly over the time period that the
plant operates. If more than 24 samples are taken, they should be evenly distributed.
These recommendations are in keeping with the FACA-s direction in that the FACA recommended that a
water treatment plant provide increased treatment when the influent water it treated on average (either
maximum rolling annual average or arithmetic average) contained elevated levels of Cryptosporidium
oocysts above certain levels. This proposed approach achieves this goal while providing clear logic for
subsequent guidance and primacy agency
decisions.
Comment Response for the LT2ESWTR 5-286 December 2005
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Response: See Response 430.
EPA Letter ID: 562
Comment ID: 12408
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Plants that operate only part of the year should take source water samples
only during the period of operation. Samples should be taken on a frequency that results in a minimum of
12 samples obtained during the annual period of operation. This will require sampling more frequently
than once per month. Samples should be distributed evenly throughout the operational period. The
monitoring plan for LT2ESWTR should reflect this compression of 12 samples into the plant operational
period. Approval of this monitoring plan by the primacy agency prior to the start of sampling is essential
to provide these plants with assurance that their monitoring results will be accepted for compliance
purposes.
Response: See Response 430.
EPA Letter ID: 585
Comment ID: 11967
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47678
EPA did not include the results of a Monte Carlo analysis for fewer than eight samples in Table IV-6.
Therefore, it is difficult to assess the accuracy of the bin classifications for systems that collect fewer than
eight Cryptosporidium samples. Nevertheless, TCEQ recommends that EPA allow systems that use
surface water sources to monitor only during those months that surface water is typically used. If such a
monitoring approach is necessary to eliminate "false negative" bin classifications, EPA should extend the
sampling cycle over two or three years until the system has collected enough data to assure that adequate
levels of treatment are being provided. In terms of overall public health protection, it makes no difference
whether the 12-month exposure occurs over a continuous period or over a series of shorter periods that
total 12 months. Consequently, extending the sampling period may delay the installation of additional
treatment at systems that use surface water on an intermittent basis but it will not increase the overall risk
that Cryptosporidium poses to the customers of a particular system. In addition, it may allow some small
systems time to identify alternate groundwater or purchased water sources.
Response: See Response 430.
EPA Letter ID: 591
Comment ID: 12121
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-287 December 2005
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Comment: Comment
Ohio EPA agrees that sampling should be conducted only during the period the system is operational. For
systems that use different sources through the year, the system should collect samples which are
representative of the source(s) normally used during each month.
Response: See Response 430.
EPA Letter ID: 595
Comment ID: 12581
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Requirements for systems that use surface water for only part of the year
Maine should have flexibility in determining monitoring requirements for systems using surface water for
only part of the year.
Response: See Response 430.
EPA Letter ID: 601
Comment ID: 13009
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on the requirement for systems that use surface water for
only part of the year.
(page 47678)
This wording is vague and lacks clarification for unexpected situations such as shutdowns due to
maintenance/repairs or low water demand. Utah recommends that provisions be added to the regulation to
allow for short periods of time that a plant has to go off-line and cannot collect samples. For seasonal
sources, Utah recommends extending the monitoring period beyond two years to allow for a
representative set of samples (the representative set may mean samples that
account for seasonal variation or representative for the period of operation for that source, i.e. summer
months).
Response: See Response 430.
EPA Letter ID: 603
Comment ID: 12665
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 5-288 December 2005
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Comment: Preamble Comments
(Pg. 47665) Section 1V.A Additional Cryptosporidium Treatment Technique
Requirements for Filtered Systems
Seasonal Sources -As acknowledged in this section, the proposed rule does not define sampling
requirements for seasonal sources. The framework for sampling seasonal sources outlined in the preamble
is logical; the system should collect either a total number of samples equal to that of a permanent source
or samples on a frequency of about twice that of the requirements for a permanent source. The
samplingplan should be submitted to the State at the same time as required
for permanent sources of the same size.
Response: See Response 430.
EPA Letter ID: 628
Comment ID: 12842
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: c. Allow break in Cryptosporidium monitoring. The proposed rule does not include
provisions for water treatment plants that may be occasionally off-line for operational or construction
purposes. The SFPUC recommends that the EPA allows no monitoring during those months in which the
plants are off-line for operational or construction purposes. Additionally, water systems should not restart
the monitoring program after the off-line period. Rather, they should be allowed to continue the
monitoring program to complete the required 24 monthly
samples. This allowance for breaks in sample collection as a result of plant shut down due to operational
or construction reasons maximizes the best use of the limited resources that the SFPUC has without
compromising the Cryptosporidium characterization program and public health protection.
Response: See Response 430.
EPA Letter ID: 637
Comment ID: 13081
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on the requirement for systems that use surface water for
only part of the year.
(page 47678)
This wording is vague and lacks clarification for unexpected situations such as shut-downs due to
maintenance/repairs or low water demand. The District recommends extending the monitoring period to
allow for a set number of samples, or allowing systems to collect as many samples as possible during a
specified monitoring period.
Response: See Response 430.
Comment Response for the LT2ESWTR 5-289 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 641
Comment ID: 13591
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47678 3. Request for Comment (RFC)
Requirements for Systems that use source water for only part of year - ASI agrees that systems that use a
source only part of the year should only have to sample during the use period, but there should be a
minimum number of data points to adequately represent that source water. The proposed minimum
requirement for sampling seasonal sources (-twice per month or 12 per year,
whichever is smaller-) is acceptable. Further, ASI recommends that it be clarified whether a source water
sampled for only a part of the year will be subsequently allowed to be used during other (non-sampled)
parts of the year.
Response: See Response 430.
EPA Letter ID: 643
Comment ID: 12769
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Requirements for systems that use surface water for only part of the year
States need to be involved in making monitoring determinations for systems that use surface water for
only part of the year. States may have historical knowledge that the source has been used on a more
permanent basis, in which case, complete monitoring would be appropriate.
However, in instances when a surface water source is truly only used for part of the year, the state and
water system will need to work together to determine an appropriate monitoring strategy. This might
entail increased monitoring (more than two samples per month) to complete the monitoring over a shorter
time frame. Another approach may be to allow the system to collect the
required number of samples over a longer period of time (e.g., taking two samples per operational month
for three or more years). State input into determining the appropriate monitoring plan is critical.
Response: See Response 430.
EPA Letter ID: 647
Comment ID: 12916
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Requirements for systems that use surface water for only part of the year
Comment Response for the LT2ESWTR 5-290 December 2005
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Comment Codes 300-471
States need to be involved in making monitoring determinations for systems that use surface water for
only part of the year. States may have historical knowledge that the source has been used on a more
permanent basis, in which case, complete monitoring would be appropriate.
However, in instances when a surface water source is truly only used for part of the year, the state and
water system will need to work together to determine an appropriate monitoring strategy. This might
entail increased monitoring (more than two samples per month) to complete the monitoring over a shorter
time frame. Another approach may be to allow the system to collect the required number of samples over
a longer period of time (e.g., taking two samples per operational month for three or more years). State
input into determining the appropriate monitoring plan is critical.
Response: See Response 430.
EPA Letter ID: 660
Comment ID: 14070
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on the requirement for systems that use surface water for
only part of the year.
(page 47678)
This wording is vague and lacks clarification for unexpected situations such as shutdowns due to
maintenance/repairs or low water demand. Provisions need to be added to the regulation to allow for short
periods of time that a plant has to go off-line and cannot collect samples. Extending the monitoring period
to allow for a set number of samples, or allowing systems to collect as many
samples as possible during a specified monitoring period would help to eliminate this problem.
Response: See Response 430.
EPA Letter ID: 662
Comment ID: 14027
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 530 C. Procedures for Calculating Bin Classification
Comment: Detection levels, results that are below the detection limits, and non continuous data due to a
plant that may not operate continuously should be specifically addressed.
Response: See Responses 430 and 500.1.
EPA Letter ID: 673
Comment ID: 13979
Comment Response for the LT2ESWTR
5-291
December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on the requirement for systems that use surface water for
only part of the year, (page 47678)
Jordan Valley Water recommends that provisions be added to the regulation to allow for periods of time
when a plant may be off-line and cannot collect samples due to seasonal operation or extended
maintenance requirements. Many water systems cannot collect source water samples when they are off-
line. EPA could either extend the monitoring period to allow for a set number of samples, or allow
systems to collect as many samples as possible during a specified
monitoring period.
Response: See Response 430.
EPA Letter ID: 678
Comment ID: 14705
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. The EPA requests comment on the requirements for systems that use
surface water for only part of the year [47678, Cl]
Comment: The Proposed LT2 Rule states that systems that are operated seasonally shall only collect
samples during periods of operation, during the 24-month period. There is no clear direction on
monitoring requirements for plants that are periodically off-line, either for operational or construction
purposes. We recommend that if a plant is not using surface water for a few months in a year or if it is
shutdown for a few months in a year, then it should not be
required to monitor for Cryptosporidium in the plant intake for those months. Additionally, the EPA
should add a provision for plants that are off-line for operational or construction purposes so
that they are not required to monitor during those months. We also request that water systems do not need
to restart the monitoring program after the off-line period. Instead, the plant should simply continue the
monitoring program to complete a total of 24 monthly samples. This approach will allow for breaks in
sample collection, while still requiring the full 24 samples to be collected for compliance calculations.
Response: See Response 430.
EPA Letter ID: 711
Comment ID: 16560
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: Response to EPA-s Request for Comment Section
1. EPA requests comment on the requirements for systems that use surface water for only part of the year
[47678, Cl]
Comment Response for the LT2ESWTR 5-292 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: If a plant is not using surface water for a few months in a year or if it is shutdown for a few
months in a year, then it should not be required to monitor for Crypto in the plant intake for those months.
Response: See Response 430.
5.13 Comment Code 440, Penalty/Bin Assignment for Systems that
Fail to Complete Required Monitoring
Summary of Issues
Comments were submitted concerning the penalty/bin assignment for systems that fail to complete
required monitoring. Most commenters opposed automatically classifying PWSs in the highest treatment
bin (Bin 4) if they fail to complete required monitoring, as the proposed rule stipulated. Commenters
suggested alternative approaches, such as giving States the flexibility to address missed samples using
current enforcement mechanisms, classifying a PWS only one level higher than the bin determined by the
collected data, allowing an additional year of sampling, and allowing States to use other information (e.g.,
sanitary surveys, other monitoring data) to aid in the classification. A few commenters, however,
supported Bin 4 classification for PWSs that fail to monitor, on the basis that any other approach would
create an incentive for PWSs to stop testing if poor water quality is suspected. Other commenters
expressed the opinion that the two day window on either side of scheduled sampling dates was too narrow
to account for unforeseen complications that could interrupt the normal sampling schedule and requested
more flexibility when collecting replacement samples.
Response to Code 440
EPA agrees with commenter who suggested that automatic bin 4 classification for any monitoring
violation is inappropriate and that bin classification should be based on water quality data where possible.
In today's final rule, EPA has significantly changed requirements for those PWSs that fail to complete
monitoring. These changes are intended to give States more flexibility in working with PWSs to fulfill
monitoring requirements and ensure they achieve the appropriate Cryptosporidium treatment level.
In today's final rule, PWSs must provide a Tier 3 public notification for the first two missed samples,
which is standard for this type of violation under an NPDWR. However, if a PWS fails to collect three or
more Cryptosporidium samples, the violation is elevated to a Tier 2 violation with special public notice.
The reason for elevating the public notice at this point is the persistence of the violation and the difficulty
the PWS will have in collecting the required number of samples for bin classification by the compliance
date.
Today's rule requires bin classification within six months following the end of the monitoring period
specified for the PWS. This six-month period provides some opportunity for collecting and analyzing
missed samples. The number of samples that can be made up in this period is limited, though, due to the
need for samples to be seasonally representative, as well as the time needed for PWSs to evaluate
monitoring results to determine bin classification and report the classification by the required date. In
consideration of these factors, EPA believes that elevating the public notice when a PWS has missed three
or more Cryptosporidium samples is appropriate. The schedule for completing missed monitoring is
determined by the State, and the violation will end when the State determines that the PWS has begun
sampling on that schedule to collect the required number of samples.
Comment Response for the LT2ESWTR 5-293 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Individual Comments on Code 440
EPA Letter ID: 101
Comment ID: 10877
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Failing to monitor or report cryptosporidium data must not result in automatically placing a
system in Bin 4. Designating a system for failing to collect a sample in the same category as a system
using severely contaminated source water and requiring the installation of numerous additional treatment
trains to meet the Bin 4 requirements is inappropriate and unduly punitive. If the failure to monitor is due
to a system's inability to afford the very costly monitoring requirements, they will not be able to afford the
requirements that will be used on only the worst source water systems. There is no basis for assigning a
Bin 4 designation on source waters that are known to be of reasonable quality just because of this
requirement. The community must be allowed to decide whether adequate sampling has been done and
what activities are necessary to determine the source water quality, and determine what the appropriate
treatment (or bin number) is for their drinking water. Mandating a system to install multiple treatment
levels as a result of no monitoring (and no information to indicate that the need for additional treatment)
is unnecessary and not protective of public health.
Response: See Response 440.
EPA Letter ID: 407
Comment ID: 10558
Commenter: Anonymous407,,
Commenter Category: Regulated Community (Utilities)
Comment: If a filtered system fails to complete the crypto monitoring the rule requires us to go to bin 4,
provide 2.5 logs of crypto kill and add major water treatment processes like membranes, Ozone, UV. That
is a ridculous penalty to pay for failing to monitor. A system would be required to spend millions of
dollars just for failing to monitor ~ that is an unreasonable regulatory requirment. Something more
reasonable would be to sample during the month/s missed in the following year and take the average.
Worst case hire a contractor to retake all the samples the following year and charge the city but don't
make us spend millions of dollars just because we failed to monitor. Besides this unfairly punishes small
systems they are typically the ones who have monitoring violations. This is especially severe considering
that unfiltered systems have
no requirement to filter even if they have as high a crypto level as filtered systems in bin 4.
Response: See Response 440.
EPA Letter ID: 413
Comment ID: 10509
Commenter: Thomas C. Sliwoski, Director of Public Works, City of Staunton, Virginia
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-294 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: Issue 1 Failure to Meet Source Water Quality
Failure to meet the requirements for source water quality should not automatically trigger mandatory
sampling criteria under Bin 4 ..Each Agency for the State (Health Department, Division of Water
Programs in Virginia) should be granted the flexibility to enforce or grant limited concessions based on
engineering studies or best available technology.
Response: See Response 440.
EPA Letter ID: 415
Comment ID: 10518
Commenter: Miguel Arroyo, Water and Wastewater Treatment Manager, City of Fort Lauderdale Public
Services Department
Commenter Category: Regulated Community (Utilities)
Comment: * I do not concur that an utility should automatically be placed on bin
4. The various parameters under which samples are taken should be taken into consideration and
sufficient latitude provided.
Response: See Response 440.
EPA Letter ID: 420
Comment ID: 14088
Commenter: Eddie Partlow, General Manager, THE OLD HICKORY UTILITY DISTRICT
Commenter Category: Regulated Community (Development): Housing, FEEP, NAHB
Comment: If a Utility fails to meet source water monitoring provisions, this should not trigger water
treatment plant placement in Bin 4. EPA should revise the source water monitoring requirements to
reflect more realistic data quality and scheduling expectations. EPA should revise the source water
monitoring requirements to reflect more realistic data quality and scheduling expectations. EPA should
allow leeway in
Response: See Response 440.
EPA Letter ID: 431
Comment ID: 10598
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: schedule, the sampling should be within seven day of the sampling schedule and
failure to comply with even that period should not lead to noncompliance if the system has a good reason
for missing the sample.
Comment Response for the LT2ESWTR 5-295 December 2005
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Response: See Response 361 regarding the five-day sampling window.
EPA Letter ID: 432
Comment ID: 13909
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Comment: Colorado Springs Utilities (PWSID # CO0121150) finds the proposed
requirement that any filtered system that fails to complete LT2ESWTR monitoring requirements must
meet the treatment requirements for Bin 4 to be unacceptable. There are many legitimate reasons why
monitoring may be incomplete. For example:
- Plants going off-line or coming on-line due to both scheduled and unscheduled reasons such that a
scheduled sample collection date may be missed. Colorado Springs Utilities has four surface water
treatment plants of its own to sample as well as a fifth for another system.
- Events occurring that disrupt overnight delivery of samples to laboratories such as courier or airline
strikes, bad weather delaying plane flights, or gasoline shortages.
- Laboratory failures.
- Filtering apparatus failures and inability to get new units in time.
Treatment requirements should not be based on failure to complete monitoring. Water utilities must not
be held responsible for missing sample results due to lab failures. Missed samples and transport problems
do happen. Utilities making a reasonable good-faith effort to comply need to be given alternatives or at a
minimum due process should be followed.
Response: See Responses 440 and 361.
EPA Letter ID: 439
Comment ID: 10752
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: The provision stating that "a water system that fails to complete LT2ESWTR
monitoring requirements must meet the treatment requirements for Bin 4" is unprecedented and should be
removed prior to rule finalization. Failure to complete monitoring could happen for any number of
reasons and a system would then be required to use maximum treatment. EPA should provide reasonable
provisions for a system to achieve compliance (mechanisms for solving non-
compliance problems are already in place by the EPA.)
Response: See Response 440.
EPA Letter ID: 441
Comment ID: 10768
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
Comment Response for the LT2ESWTR 5-296 December 2005
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& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Sampling schedules
EPA's proposal includes a provision for water suppliers that fail to complete all of the required
Cryptosporidium monitoring. As proposed, these suppliers would be classified in Bin 4 if they miss one
sample. DEP anticipates that, on occasion, water suppliers will miss a Cryptosporidium
sample. However, DEP prefers to respond to the supplier's failure to monitor on a case-by-case basis and
have the flexibility to establish the appropriate response when these events occur.
Response: See Response 440.
EPA Letter ID: 442
Comment ID: 10785
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: Monitoring violations should not occur in all cases where a system fails to report the
minimum number of samples required by the regulations. Multiple examples of EPA regulatory flexibility
can be found in the air regulations specifically at 40CFR50 and EPA document EPA-454/R-98-004
Quality Assurance Handbook for Air Pollution Measurement Systems. The EPA by having inflexible
rules increases the number of reportable violations and does not necessarily
indicate increasing adverse public health consequences.
Response: See Response 440 and 361.
EPA Letter ID: 444
Comment ID: 10810
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment: c. NH supports a bin classification one level higher for a system which fails to
complete the required monitoring for up to two months (or two monitoring events). Failure to monitor for
more than two months should result in classification in the highest bin.
Response: See Response 440.
EPA Letter ID: 451
Comment ID: 14159
Comment Response for the LT2ESWTR 5-297 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Commenter: Eric Abrams, Superintendent, McMinnville Water and Light
Commenter Category: Regulated Community (Utilities)
Comment: Comment #1: Our utility uses outside labs to perform most of the required
testing. It seems to me that the proposed requirement of failing to meet source water monitoring
provisions should not automatically trigger placing the water treatment plant in "Bin 4". Reasonable
latitude should be available with sampling window, missing data, and existing data. The decision to place
a plant in "Bin 4" should be based on test data, not the lack of this information or because the test was
late.
Response: See Responses 440 and 361.
EPA Letter ID: 452
Comment ID: 10936
Commenter: Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Commenter Category: Regulated Community (Utilities)
Comment: Automatic classification to Bin 4 for systems that fail to monitor (141.709(e))
according to 141.701 through 141.707 is punitive and inappropriate. Monitoring deficiencies do not
represent the actual health risk from microbial contaminants. This requirement should be deleted from the
rule. Due process provisions that already exist are adequate for investigating and correcting a situation
where a system fails to monitor.
Response: See Response 440.
EPA Letter ID: 453
Comment ID: 10941
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: 1. Monitoring failures of any kind appear to force a system into the bin 4
classification. Monitoring failures could be caused by a number of reasons, including laboratory error or a
lack of laboratory capacity. The resulting capital and operating costs for a moderately sized plant could
easily reach tens of millions of dollars. Actual results may well show that the additional treatment was
unnecessary! Expensive, unneeded treatment does not promote public
health and is not a wise use of our resources!
Response: See Response 440.
EPA Letter ID: 457
Comment ID: 11896
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Comment Response for the LT2ESWTR 5-298 December 2005
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Branch
Commenter Category: State/Tribe Government
Comment: Failure to Monitor/Deviation from the Monitoring Schedule
We strongly disagree with EPA-s proposal that a water system that misses one microbial sample
automatically be placed in Bin 4 and required to install the highest level of protection against
Cryptosporidium.. A more appropriate approach may be to classify those sources that fail to complete all
their monitoring into a bin one level higher than indicated based upon the data
collected or require the system to conduct up to an additional year of sampling in lieu of automatically
being classified into a higher or the highest bin. We
Response: See Response 440.
EPA Letter ID: 457
Comment ID: 11917
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: With respect to the specific issues on which EPA requested comment, we
believe that EPA should provide the states with flexibility to address these concerns on a case-by-case
basis. The EPA could present the following specific issues as a way of guidance to the states:
* Bin assignment for systems that fail to complete required monitoring;
Response: See Response 440.
EPA Letter ID: 458
Comment ID: 10972
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Bin Assignment that fail to complete required monitoring - A system that does no
monitoring should be required to provide 5.5 log reduction. A system that completes over 90% of the
required sampling, but for some good plausible reason did not perform 100%, should not be penalized
(assuming the monitoring indicates that a 5.5 log reduction is not warranted) to this extent. There should
be a tiered system established to be equitable, but also not forsake the public
health in doing so.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-299 December 2005
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EPA Letter ID: 460
Comment ID: 10991
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: 1. Failure to Complete Monitoring:
City-s position: Bin classification should be based solely on occurrence data,
not on monitoring compliance.
The Rule proposes a -bin- system of categories based upon occurrence data, and additionally upon
adherence to a strict schedule of sampling and reporting. Placing a system in Bin 4 for failure to complete
the required monitoring is unacceptable. Anyone who has collected and analyzed environmental samples
can tell you, things can and do happen in the real world that cannot be controlled. Sufficient measures
already exist to inform the public of monitoring violations. Specifically, the Consumer Confidence Rule
clearly spells out the nature of a
deviation, and gives the consumer the opportunity to evaluate the relative risk posed. Promulgation of this
proposed language could lead to a bin classification that would potentially confuse and unnecessarily
alarm the public served by the water provider, undermining many years of competent stewardship.
Response: See Response 440.
EPA Letter ID: 460
Comment ID: 10994
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: The requirement to collect samples within two days of their sampling schedule or
be forced to install UV is totally inappropriate. Obviously, these regulations were written by those who
have never had to manage an environmental sampling program. As stated before, when dealing with
people, machinery, and the weather, unplanned events happen more often than not.
Response: See Responses 440 and 361.
EPA Letter ID: 461
Comment ID: 10987
Commenter: Greg Merrigan, Chair, South Dakota Section of the American Waterworks Association
(SDAWWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Failure to Complete Monitoring - EPA states in the LT2ESWTRthat any filtered system that
fails to complete the monitoring requirements must meet the treatment requirements for bin 4 (Page
47666). We feel that this requirement is inappropriate and unacceptable. No system should be forced into
requiring maximum treatment based on the failure to complete monitoring - even those ystems that
intentionally fail to sample. There are many innocent reasons why a system may not have sampled at the
appropriate time - such as lab failure or insufficient lab capacity. It is recommended that EPA use
Comment Response for the LT2ESWTR 5-300 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
existing compliance procedures along with a system-s right to appeal noncompliance for missed sampling
issues.
EPA should clarify how they intend to deal with those systems that intentionally fail to monitor. They
should also clarify how systems may appeal rulings by EPA on monitoring failures. It is suggested that
EPA clarify how systems can build in extra sampling times into their sampling schedules in the event of a
missed sampling event. One suggestion is for those systems that want to sample twice per month - go to
every other week sampling. This will build 2 extra samples
into their sampling schedule every year.
For those systems that plan to sample monthly - suggest taking an extra sample during two of the months
that contain more than 4 of the days that they select for sampling. Ex. If the water system selects the
second Wednesday of every month, then they should select two months where more than 4 Wednesdays
occur during the year (in 2004 that includes March, June, September, and December.) It would be up to
the system to select which months they will collect the extra
sample and report this to EPA.
Response: See Response 440.
EPA Letter ID: 463
Comment ID: 11029
Commenter: Richard Wilson, Environmental Services Manager, Anaheim Public Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment: The EPA should not require additional water treatment if a water utility is unable to complete
monitoring due to legitimate reasons. These reasons could include lack of laboratory capacity, plant
maintenance activities or many other causes. A reasonable monitoring plan should allow missed samples
to be made-up at a later date or forgiven, depending on the circumstances. As stated above, a mechanism
should be provided to allow late reporting in cases where laboratory capacity issues were the reason for
the delay.
Response: See Response 440.
EPA Letter ID: 466
Comment ID: 11023
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: We strongly disagree with EPA-s proposal that a water system that misses one
microbial sample automatically is placed in Bin 4 and required to install the highest level of protection
against Cryptosporidium. As stated before, we disagree with the proposal that a water system must take
all LT2ESWTR samples within two days of the planned monitoring date. We recognize the need for
systems to collect an adequate number of samples and that the samples need to be distributed across the
entire monitoring period. We have protocols already in place for other rules that handle systems who fail
to complete the appropriate monitoring in a timely manner. These protocols can be used as framework to
deal with systems regarding this rule as well. A more appropriate approach would be to place them one
Comment Response for the LT2ESWTR 5-301 December 2005
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bin higher than the data they do collect. Some flexibility should be provided for systems to complete up to
an additional year of sampling in lieu of automatically being classified into a higher or the highest bin.
Response: See Response 440.
EPA Letter ID: 467
Comment ID: 11035
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: Issue 1: Failure to Comply with LT2ESWTR Monitoring Requirements
The proposed LT2ESWTR states that -systems that fail to complete the required Cryptosporidium
monitoring will be classified in Bin 4-. LWC believes this penalty is overly severe and requests EPA
remove it from the final rule.
LWC believes that all utilities will make the best effort to comply with the monitoring requirements of the
LT2ESWTR. However, the monitoring requirements are problematic and may result in monitoring
failures due to circumstances beyond the utility-s control. For example, the requirements defines a very
narrow sampling window each month and very specific sampling locations. Although these requirements
intend to limit sampling manipulation, they sometimes create logistic problems for utilities. For instance,
floods and tornados have occurred in the LWC service area which would inhibit sampling. Monitoring
requirements and subsequent punitive action should not be designed to require adverse consequences for
events beyond the water supplier-s control. Water suppliers should also have more latitude for setting
daily priorities given the many daily issues they must address. As proposed, such failure will automatic
place
utilities in Bin 4 and force them to achieve 2.5 logs of additional Cryptosporidium removal for
conventional filtration systems. This provision is punitive and unprecedented in the history of Safe
Drinking Water Act. Therefore, LWC opposes this provision and asks EPA to remove it from the final
rule. In
Response: See Response 440.
EPA Letter ID: 470
Comment ID: 11066
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: 1 We agree with the proposed bin assignment of Bin 4 for systems that fail to
complete the required monitoring. The health protections provided for in this proposed rule are substantial
and this bin classification is supportive of this.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-302 December 2005
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EPA Letter ID: 471
Comment ID: 11110
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 2. Furthermore, because of the above concerns with lab capacity and data management, we
have tremendous concerns regarding the proposed rule-s language for failure to comply with monitoring
requirements. We find it entirely unacceptable to require very costly maximum treatment (Bin 4) simply
based on failure to complete monitoring which could happen for any number of legitimate reasons, not
the least of which is insufficient lab capacity or untried data management systems. This is especially
inappropriate given EPA-s belief that the majority of systems would fall into the no-action bin. We urge
EPA to use existing compliance procedures coupled with a system's rights to appeal noncompliance
decisions as a more appropriate action. Any problems of non-compliance should be addressed with the
mechanisms already in place for such a violation. Utilities should not be held responsible for missing
sample results due to lab failures. Rather, the rule should allow for the probability that missed samples
may (and do) happen. We suggest that the rule have utilities build dates into their sampling schedules for
additional samples in the event of missed samples, and provide reasons why the samples were missed
(e.g., provide 30 sampling dates so that 6 extra dates above the minimum requirement of 24 are available
if samples are missed). Also, the allowable timing of resamples
Response: See Response 440.
EPA Letter ID: 472
Comment ID: 11143
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: 1. Concern: The proposed LT2ESWTR monitoring requirements may result in
monitoring failures even thou utilities are attempting to comply. All utilities that do not meet source water
quality monitoring requirements appear to default to a classification in Bin 4. This default classification is
very punitive. One could say this standard for compliance monitoring is presuming guilt until innocence
is proven.
Remedy: Failure to meet source water monitoring requirements should not default to placement in Bin 4.
The Agency should revise the source water monitoring requirements to reflect a more balanced data
quality and scheduling opportunity. For example, the Agency should provide more leeway in the
sampling period each month, sample temperature requirements, and treatment of missing data.
Response: See Response 440.
EPA Letter ID: 473
Comment ID: 10711
Commenter: Mary Carol Wagner, Water Quality Manager, Northern Kentucky Water District
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 5-303 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: We would also ask that the EPA reconsider the -Failure to Complete Monitoring
Requirements.- Please readdress this issue and make reasonable provisions for the utilities to re-sample
or make-up missed samples. There are so many times samples cannot be completed because of unforeseen
conditions or was collected and the lab did not receive the sample. Please consider this and the extreme
financial burden that a utility will have by placing the utility in bin 4 because of a very tight sampling
schedule window of only 2 days.
Response: See Response 440.
EPA Letter ID: 474
Comment ID: 11192
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: As we reviewed the proposed monitoring requirements, we identified two other
issues we believe are significant: the consequence of failing to complete monitoring and the consequence
of failing to comply with the established monitoring schedule.
Although, as we read the language, we would not be directly affected by the LT2 language regarding
missed samples, we feel strongly that EPA needs to reconsider the provision that would require that -any
filtered system that fails to complete LT2ESWTR monitoring requirements must meet the treatment
requirements for Bin 4.-
This provision is unacceptable and fails to recognize that there are many situations why a scheduled
sample would be missed that are beyond the control of the water utility and not included in the proposed
list of exception conditions. Our own experience bears this out: We are one year into our two-year
sampling program collecting Cryptosporidium monitoring data under the data grandfathering provisions.
We have already had to resample twice due to problems with the shipment of the sample to the lab. As
this example demonstrates, the problem was beyond our control, and as such it would be unreasonable for
EPA to require a utility to provide the maximum treatment as a result of such unforeseeable and
uncontrollable reasons.
One approach EPA might pursue to address the potential for missed samples would be to suggest that
utilities build dates into their sampling schedules for additional samples in the event of missed samples,
and provide reasons why the samples were missed, (e.g., it could be something like 30 sampling dates so
that 6 extra dates above the minimum requirement of 24 be available if samples are missed) or make other
reasonable provisions for make-up samples during the sampling period.
Response: See Response 440.
EPA Letter ID: 476
Comment ID: 10674
Commenter: Anonymous476,, Department of Defense
Commenter Category: Other: Other hard to categorize commenters
Comment Response for the LT2ESWTR 5-304 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: 1. Bin Assignment for Systems that Fail to Complete Monitoring Requirements
Requirement. As proposed, the LT2ESWTR would classify systems that do not fulfill monitoring
requirements as Bin 4, the highest treatment bin.
Comment. Classifying systems that do not fulfill all monitoring requirements as Bin 4 will require those
systems to implement Cryptosporidium treatment measures beyond what is most likely required to protect
public health.
Discussion. If for some reason a system is unable to fulfill all monitoring requirements, it is unduly
punitive to classify the system as Bin 4. This would require the system to comply with the strictest
Crytosporidium treatment standards at great cost and would not necessarily be in the public-s best
interest. On the other hand, there should be some penalty associated with not complying with monitoring
requirements; the system should not be classified into a bin based on the data the system has collected..
The best solution seems to be classifying the system in a bin one level higher than the bin indicated by the
data the system has collected.
Recommendation. Classify systems that do not fulfill monitoring requirements in a bin one level higher
than the bin indicated by the data the system has collected.
Response: See Response 440.
EPA Letter ID: 478
Comment ID: 11218
Commenter: Anonymous478,,
Commenter Category: Unknown
Comment: We agree that one failure to monitor should not place a system in the highest bin
classification. The State should have some flexibility on this.
Response: See Response 440.
EPA Letter ID: 479
Comment ID: 11220
Commenter: Brad Joyner, Superintendent, Town of Forest City WTP
Commenter Category: Local Government
Comment: In regards to the LT2ESWTR monitoring requirements as proposed, will definitely
cause unintentional violations that may be out of the control of the system at hand. There are too many
variables that can trigger the violation which will be very harsh on a system that is making the best effort
possible to comply. There needs to be different and more levels of monitoring requirements than
automatic placement into Bin 4 when a utility fails to meet the testing provision.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-305 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 483
Comment ID: 11262
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: —Any filtered system that fails to complete LT2ESWTR monitoring requirements
must meet the treatment requirements for Bin 4.- This provision is unacceptable. Action to require
maximum treatment should not be based on failure to complete monitoring which could happen for any
number of innocent reasons. EPA should use existing compliance procedures coupled with a system-s
rights to appeal non-compliance decisions as a more appropriate action. Reasonable provisions should
Response: See Response 440.
EPA Letter ID: 484
Comment ID: 10679
Commenter: Anonymous484,, Metro Nashville Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Failure to Complete Monitoring:
Water systems should not be automatically placed into Bin 4 for failure to complete LT2ESWTR
monitoring requirements due to reasons beyond the contol of the utility. Examples are laboratory capacity
or missed samples. Provisions should be made to address these issues.
An automatic default to Bin 4 and the mandatory use of UV is unacceptable.
Sampling Schedule:
Sytems should be allowed greater flexibility in scheduling. There are many reasons why a sample
schedule might be altered. Being placed in Bin 4 and being required to install UV treatment is to costly
and unrealistic.
Response: See Response 440.
EPA Letter ID: 485
Comment ID: 11285
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes that if additional monitoring data on the same
source of supply and a watershed sanitary survey is available, the primacy agency should be allowed to
make a determination concerning bin classification based on this information. It is prudent to allow
additional time to collect source data rather than immediately requiring systems to provide additional
treatment that may not be necessary. However, if a system refuses to collect the necessary data they
should be required to provide the treatment level of bin 4.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-306 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 487
Comment ID: 11235
Commenter: Janice Skadsen, Water Quality Manager, City of Ann Arbor Water Plant
Commenter Category: Regulated Community (Utilities)
Comment: We are concerned over the proposed requirement that would trigger water treatment plant
placement into Bin 4 in the event that a consecutive monthly sample is not properly submitted. This is an
excessive response that would result in significant capital and O&M costs for a monitoring failure. We do
not believe that there is a public health issue that can justify this level of expenditure.
Response: See Response 440.
EPA Letter ID: 491
Comment ID: 10663
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: 1. Failure to complete source water monitoring should not result in a Bin 4 assignment. It is
our belief that water systems generally make good faith efforts to complete the required monitoring
within the allotted time and conditions. However, sometimes a sample can be missed, even by those with
the best intentions, due to resource constraints or other legitimate reasons. EPA should allow systems
operating in good faith to complete their monitoring, at
the very least, before making a bin assignment. This will result in a more accurate assessment of the
appropriate bin rather than punishing well- intentioned utilities with a bin assignment that is expensive
and likely unnecessary. In the event of missed samples, completion of monitoring could be done through
the inclusion of additional -contingency samples- in the monitoring
schedule that would be taken, if needed, should the utility miss a sample.
Response: See Response 440.
EPA Letter ID: 496
Comment ID: 10690
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 3. Monitoring Key Issue 3 Failure to Complete Monitoring: The LT2ESWTR
Proposal on page 47666 states:
"Any filtered system that fails to complete LT2ESWTR monitoring requirements must meet the treatment
requirements for Bin 4". This requirement is unprecedented and inappropriate and must be removed prior
to finalizing the rule. This changes the historical approach EPA has used, which is to acknowledge that 99
% of systems will do their very best to ensure they comply with rules and should not be inappropriately
penalized if operating in good faith. Procedures and authorities that are currently established, related to
compliance, should be used by EPA.
Comment Response for the LT2ESWTR 5-307 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
There are many justifiable reasons that a sample could be missed, not the least of which is the possibility
of insufficient laboratory capacity, or a laboratory that is overworked and misses holding times or similar
requirements. EPA allows for submission of re-samples, but places such strict requirements on their use
that the provision is futile. EPA acknowledges that the majority of systems are expected to fall into Bin 1,
or the "no action" bin, so the default to mandatory UV (which is necessary to meet Bin 4 requirements) is
inappropriate for missed samples.
Comments for Monitoring Key Issue 3 (Failure to Complete Monitoring): This provision is unacceptable.
Action to require maximum treatment should not be based on failure to complete monitoring which could
happen for any number of legitimate reasons. EPA should use existing compliance procedures coupled
with a system's right to appeal non-compliance decisions as a more appropriate action. Any problems of
non-compliance should be addressed with the mechanisms already established for such a violation.
Reasonable provisions should be made for re-sampling.
Water utilities should not be held responsible for missing sample results due to lab failures. In addition,
EPA should allow for the probability that missed samples do sometimes happen. EPA should have
utilities build dates into their sampling schedules in the event of missed samples and provide reasons why
the samples were missed. (It could be something like 30 sampling dates so that 6 extra dates above the
minimum requirement of 24 be available if samples are missed). EPA should make reasonable provisions
for make-up samples. EPA should also take into consideration that it is appropriate to maintain the
general relationship of trust with the drinking water community rather than implement actions that imply
an antagonistic relationship.
4. Monitoring Key Issue 4 Sampling Schedule: This proposal requires that systems collect samples within
2 days of their sampling schedule or they will be in non-compliance. Since non-compliance leads to an
immediate requirement to install UV (because of Bin 4 placement), this is completely inappropriate.
There are many valid reasons for not being able to sample within 2 days. Moreover, this requirement
insinuates that water systems might "game" the system by monitoring when they know that
Cryptosporidium is present. Current data shows that random sampling is equivalent, if not superior to,
time-series sampling designs.
Comments for Monitoring Key Issue 4 (Sampling Schedule): EPA should be reminded of the above
points and it should be suggested that plus or minus 3 or 4 days would be more appropriate. Failure to
comply with even that period should not lead to non-compliance if the system has a justifiable reason for
missing the sample.
Response: See Responses 440 and 361.
EPA Letter ID: 497
Comment ID: 10649
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: bin determinations. The EPA proposes to classify systems that fail to complete
required monitoring in Bin 4, the highest treatment bin. The penalty for failure to complete required
monitoring is adequately addressed in the Michigan Safe Drinking Water Act and generally involves
public notification, fines, or additional monitoring. Capital improvements required by unnecessary Bin 4
Comment Response for the LT2ESWTR 5-308 December 2005
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classification may result in not addressing other, more appropriate plant improvements. This could have
the unintended effect of a decrease in public health benefits. The MDEQ believes bin classification should
be based solely onavailable data and not on the compliance status of monitoring. The MDEQ would
prefer to use flexibility and determine the appropriate response to a missed sample or missed sampling
date on a case-by-case basis.
Response: See Response 440.
EPA Letter ID: 499
Comment ID: 10720
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: 4. KDHE does not support the -penalty- of a-Bin 4- classification and subsequent required
implementation of upgraded treatment processes for those entities which fail to monitor for
Cryptosporidium under the 24 sample requirement. This is an overly severe response to a monitoring
violation, given the fact that a Cryptosporidium problem may not even exist in the system. This approach
is also unprecedented, e.g., there is no requirement to install packed tower aeration treatment when a
system fails to monitor for a volatile organicchemical. A reasonable alternative might be to require an
additional year of sampling for every sampling event missed (up to a maximum of three additional years)
in substitution for delay of treatment processes. Systems which do not comply with the monitoring
substitution plan could then be reclassified into an appropriate bin classification based on an investigation
/ determination by EPA.
Response: See Response 440.
EPA Letter ID: 502
Comment ID: 10632
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: 2. Failure to complete monitoring: EPA states that if a system fails to meet the
monitoring requirements they will automatically be placed bin 4- the highest and most costly bin
classification for systems to work from. The penalty of immediate classification in bin 4 is an inordinately
severe consequence. There are many possible reasons why a system may miss a sample collection. Valid
reasons that are beyond the control of the system, such as an inadvertent
laboratory problem, that would not necessarily indicate a chronic regulatory failure on the system-s part.
There are already proper procedures and agencies in place to handle monitoring violations. Systems do
their best to comply with rules and should not be penalized while operating in good faith.
monthly sample (ie. first Monday), as opposed to every 30 days. Also, failure to comply with the
sampling window should not result in automatic bin 4 classification if the system has a valid reason for
missing the dates and is willing to document such reason.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-309 December 2005
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EPA Letter ID: 503
Comment ID: 10625
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment: Issue No. 4 - Failure to Complete Monitoring
The Proposed Rule states -any filtered system that fails to complete LTESWTR
monitoring requirements must meet the treatment requirements for Bin 4.- In this case mandatory UV
treatment would have to be installed. This provision is unacceptable, unnecessary, and not in keeping with
procedures and authorities that are presently in place related to compliance issues. There are many
innocent reasons a sample could be delayed or missed. Utilities operating in
good faith, which represent the vastly overwhelming majority, should not be needlessly penalized in this
fashion. Consumers would be better served if EPA would address any problems of non-compliance with
existing mechanisms already in place for such a violation.
Response: See Response 440.
EPA Letter ID: 504
Comment ID: 11348
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: 4. We believe that a failure to meet strict requirements must not trigger
assignment of a water treatment plant to BIN 4. As long as a utility makes a good faith effort to meet
proposed requirements for BIN monitoring, BIN assignment should be consistent with the overall
concentration level indicated by the monitoring data.
Response: See Response 440.
EPA Letter ID: 504
Comment ID: 11365
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: 8. Consequence of Monitoring Failure
Automatic assignment to BIN 4 for monitoring noncompliance is unreasonable, unwarranted, and
unacceptable. Under the proposed regulation many circumstances leading to a utility being judged as
noncompliant could be due to unforeseen and unavoidable problems either in sampling, transport, or
contract lab procedures. A significant share of such conditions would not be under the specific control of
the utility. This provision must be changed to provide for a more logical
consequence of not meeting the letter of sampling and monitoring provisions.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-310 December 2005
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EPA Letter ID: 505
Comment ID: 11174
Commenter: Darron Busch, Administrator, Department of Environment and Natural Resources,
Drinking Water Program
Commenter Category:
Comment: - We absolutely do not agree with the EPA position that one missed microbial sample causes
the water system to automatically be placed in a Bin 4 category. There could be a variety of valid reasons
for missing a sample. States should have the flexibility to evaluate, on a case-by-case basis, the reason for
missing a sample. It is also foreseeable that a system collects the sample and submits to the laboratory,
but the laboratory rejects the sample or there is an accident at the laboratory (and does not provide timely
notice of the rejection or the accident) creating a situation for a missed sample. We think systems
should be allowed one miss - for a valid reason. Unless the reason for the missed sample is a laboratory
problem, a system should be able to correct the problem causing the missed sample. If a laboratory is
continually causing problems, EPA (being the approving agency for methodology) needs to investigate
the laboratory and be prepared to revoke certification.
Response: See Responses 440 and 361.
EPA Letter ID: 506
Comment ID: 10732
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: o Failure to Complete Monitoring - CWD finds the provision in the proposed rule
that would require a water system to meet the treatment requirements of Bin 4 for incomplete monitoring
totally unacceptable. There are many reasons a utility could not complete the monitoring while making a
good faith effort to meet the requirements. A great deal of CWD-s concern on this issue stems from our
doubts about sufficient laboratory capacity, as previously mentioned. With a potentially larger volume of
samples than the lab is prepared to handle, there
is the greater potential for mistakes. CWD previously received a violation when a commercial laboratory
failed to report some of our data to our State primacy agency. It was bad enough to receive a violation for
the laboratory-s mistake and to be required to notify the public, but in this case it would be far worse. A
utility would be required to spend a great deal of money to meet the treatment requirements of the rule
when the actual quality of the source water did not require it. USEPA should provide reasonable
requirements for re-sampling so that systems making a good faith effort will be able to meet the
requirements. USEPA should recommend that water systems build extra dates in their sampling schedule
that could be used to make up for missed samples. This requirement in the proposed rule creates the
impression that USEPA does not trust water systems to act in good faith to try to comply with the
monitoring without imposing outrageous consequences on the utility for failure to comply.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-311 December 2005
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EPA Letter ID: 512
Comment ID: 11496
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Source Water Monitoring - Failure to meet monitoring requirements must not
trigger water treatment plant placement into the highest risk -bin.-
With the increasingly complex requirements placed on water agencies for monitoring under the various
regulations already on the books, it is unrealistic to expect that there will not be instances of minor
monitoring delays, lab errors, or other sampling difficulties when meeting the tight, protracted monitoring
schedule required under this rule. To be penalized by being elevated to Bin 4, the highest risk bin, for
what may amount to a scheduling problem, exclusive of the quality of the overall data set, is not
supported by the science. Resampling within a reasonable timeframe will not affect the statistical validity
of the overall data set. Provisions must be made to allow
for reasonable timelines for repeat samples.
Bin placement should rest on the potential public health exposure as determined by the statistics of the
data set, not on an arbitrary schedule for monitoring. Provisions should be established to obtain the
highest quality data set possible under the constraints and difficulties of sampling in the real world. The
potential costs associated with additional treatment needed to meet Bin 4
requirements can be significant and are wholly unwarranted where otherwise unsupported by the data set.
If Bin 4 placement for minor monitoring delays or errors is truly the intent of the EPA, then EPA must
demonstrate it as being supported by sound science and must do so prior to implementation of the rule as
proposed. On the face of it, the proposal would appear to overstep the Agency-s authority under the Safe
Drinking Water Act.
Response: See Response 440.
EPA Letter ID: 513
Comment ID: 11524
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: The State of Nebraska does not support the provision to classify systems that
fail to complete monitoring requirements into Bin 4. We believe the monitoring requirements are unduly
restrictive, and the consequences of missing a sampling event unreasonably severe. Forcing a system to
install more treatment without adequate evidence of higher concentrations of Cryptosporidium in the
source water is not an appropriate use of regulatory authority, and does not provide additional public
health protection for those consuming the water (and paying
for the additional treatment). There are justifiable reasons samples may be missed. We believe that,
working with the system and with existing sampling provisions, the issue of missing samples can be dealt
with on a case-by-case basis.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-312 December 2005
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EPA Letter ID: 520
Comment ID: 11555
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Failure to Monitor/Deviation from the Monitoring Schedule
IEPA strongly disagrees with EPA's proposal that a water system that misses one microbial sample
automatically be placed in Bin 4 and required to install the highest level of protection against
Cryptosporidium. IEPA also disagrees with
The sampling requirements of the proposed rule are complex and are expected to be difficult to
implement for very small systems, which may inadvertently miss a limited number of samples. The
automatic classification of systems that have sampling difficulties into the highest risk bin is overly
stringent. A more appropriate approach may be to classify those sources that fail to complete all their
monitoring into a bin one level higher than indicated based upon the data
collected. Some flexibility should be provided for systems to complete up to an additional year of
sampling in lieu of automatically being classified into a higher or the highest bin.
Response: See Response 440.
EPA Letter ID: 520
Comment ID: 11617
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Bin assignment for systems that fail to complete required monitoring
IEPA does not support EPA's proposal that a system that fails to complete required monitoring be
automatically assigned to Bin 4. Please refer to comments above for further detail on this issue.
Response: See Response 440.
EPA Letter ID: 521
Comment ID: 11761
Commenter: Leslie Rush,, Dalton Utilities
Commenter Category: Regulated Community (Utilities)
Comment: We find that the EPA's proposal that a water system that misses one microbial sample
automatically be placed in Bin 4 and be required to install the highest level of protection against
Cryptosporidium to be overly punitive.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-313 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 526
Comment ID: 11766
Commenter: Nick Jackson,, Knoxville Utilities Board
Commenter Category: Local Government
Comment: 2. EPA should not consider occasional noncompliance due to sampling/analytical
error as an automatic indicator of poor operation or the inability to produce safe potable water.
Insufficient lab capacity could result in unavoidable lab errors or increased opportunities for sample
holding times to expire. Outside lab services will be used by many utilities requiring offsite shipment, and
sample preservation conditions or holding times can easily be compromised during transport. Despite a
utility's best effort to sample with the scheduled time frame, factors beyond their control could impact the
required monitoring, placing the utility under the strictest treatment requirements. If subsequent sampling
establishes consistent acceptable effluent quality there is no reason to unconditionally impose Bin 4
requirements on a treatment facility. Utilities
should have the ability to appeal such requirements if imposed, with the opportunity to demonstrate
consistent acceptable treatment without additional mandatory processes.
Response: See Response 440.
EPA Letter ID: 527
Comment ID: 10850
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Failure to Complete Monitoring: The proposed rule on page 47666 states:
-Any filtered system that fails to complete LT2ESWTR monitoring requirements
must meet the treatment requirements for Bin 4.-
We strongly disagree with this requirement. We believe that the penalty proposed far exceeds the crime,
and therefore EPA should remove this provision prior to finalizing the rule.
A sample could be missed for many innocent reasons, not the least of which is the possibility of
insufficient laboratory capacity, or a laboratory that is overworked and misses holding times or similar
requirements outside the control of a water system. EPA allows for submission of resamples but places
such strict requirements on their use that the provision is meaningless. EPA acknowledges that the
majority of systems are expected to fall into Bin 1, -the no-action
bin- so the mandatory placement in Bin 4 (i.e., install UV disinfection) is inappropriate simply based on
missed samples.
Any problems of non-compliance should be addressed with the mechanisms already in place for such a
violation. Additionally, we strongly recommend that EPA
Response: See Response 440.
Comment Response for the LT2ESWTR 5-314 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 527
Comment ID: 10850
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Failure to Complete Monitoring: The proposed rule on page 47666 states:
-Any filtered system that fails to complete LT2ESWTR monitoring requirements
must meet the treatment requirements for Bin 4.-
We strongly disagree with this requirement. We believe that the penalty proposed far exceeds the crime,
and therefore EPA should remove this provision prior to finalizing the rule.
A sample could be missed for many innocent reasons, not the least of which is the possibility of
insufficient laboratory capacity, or a laboratory that is overworked and misses holding times or similar
requirements outside the control of a water system. EPA allows for submission of resamples but places
such strict requirements on their use that the provision is meaningless. EPA acknowledges that the
majority of systems are expected to fall into Bin 1, -the no-action
bin- so the mandatory placement in Bin 4 (i.e., install UV disinfection) is inappropriate simply based on
missed samples.
Any problems of non-compliance should be addressed with the mechanisms already in place for such a
violation. Additionally, we strongly recommend that EPA
Response: See Response 440.
EPA Letter ID: 528
Comment ID: 12262
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Failure to Monitor/Deviation from the Monitoring Schedule
We strongly disagree with EPA-s proposal that a water system that misses one microbial sample
automatically be placed in Bin 4 and required to install the highest level of protection against
Cryptosporidium. We also disagree with EPA-s
Response: See Response 440.
EPA Letter ID: 533
Comment ID: 12217
Commenter: Edward Urheim,,
Commenter Category: Consultants: (where self-identified)
Comment: I strongly disagree with EPA-s proposal that a water system that misses one
Microbial sample automatically be placed in Bin 4 and required to install the highest level of protection
against Cryptosporidium [reference 141.709 (e)]. A more appropriate approach may be to classify those
sources that fail to complete all their monitoring into a bin one level higher than indicated based upon the
Comment Response for the LT2ESWTR 5-315 December 2005
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data collected or require the system to conduct up to an additional year of sampling in lieu of
automatically being classified into a higher or the highest
bin.
Response: See Response 440.
EPA Letter ID: 534
Comment ID: 12004
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: It is a fact that samples can be missed for a variety of reasons beyond the Control of a water
system. This proposed rule is new territory for the regulated community, laboratories and the regulators.
This provision appears arbitrary and heavy-handed. If allowed to stand, it could conceivably result in a
water system being forced into Bin 4 due to something beyond the control of the system (i.e. a missed
holding time or lost sample shipment) even though EPA acknowledges that the majority of systems are
expected to fall into Bin 1. EPA should remove
this provision in its entirety. The Agency already has methods to address violations which allow for due
process.
Response: See Response 440.
EPA Letter ID: 536
Comment ID: 11796
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Failure to Monitor/Deviation from the Monitoring Schedule
Colorado strongly disagrees with EPA-s proposal that a water system that misses one microbial sample
automatically be placed in Bin 4 and required to install the highest level of protection against
Cryptosporidium. Colorado also
The sampling requirements of the proposed rule are complex and are expected to be difficult to
implement for very small systems, which may inadvertently miss a limited number of samples. The
automatic classification of systems that have sampling difficulties into the highest risk bin is overly
stringent. A more appropriate approach may be to classify those sources that fail to complete all their
monitoring into a bin one level higher than indicated based upon the data
collected. Some flexibility should be provided for systems to complete up to an additional year of
sampling in lieu of automatically being classified into a higher or the highest bin.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-316 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 548
Comment ID: 12159
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: far collected. Metropolitan understands EPA-s intent to classify systems that do not monitor
in Bin 4, which would require them to provide 5.5 log of treatment. Clearly, this is the most conservative
approach in protection of public health. Given the substantial costs potentially associated with treatment,
Metropolitan recommends that EPA implement measures that encourage monitoring. In addition, it is
essential that EPA clarify monitoring requirements, e.g. how many samples are needed to satisfy
monitoring requirements. EPA should clearly define these requirements before penalizing, i.e., no utility
should fall into this situation without ample opportunity to collect the required samples.
Response: See Response 440.
EPA Letter ID: 554
Comment ID: 12220
Commenter: Wayne Price, Water Plant Superintendent, Broad River Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Comment: The monitoring requirements are for two years of monthly
sampling for Cryptosporidium and E. coli. We feel that a monitoring failure should not place a utility in
the Bin 4 class. Bin classifications should be only for monitoring results.
Response: See Response 440.
EPA Letter ID: 556
Comment ID: 12038
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: In several instances, the intent and spirit of the agreement appear to have been
lost in developing the details. Provisions such as triggering a system into the highest levels of treatment
for missing a consecutive monthly sample result in a punishment that far exceeds the crime. Other areas
where the proposal would be
Response: See Response 440.
EPA Letter ID: 556
Comment ID: 12056
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
Comment Response for the LT2ESWTR 5-317 December 2005
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(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5. Sampling Schedule
Basic Principle from the FACA Discussions: Several FACA members were concerned
that water systems might be able to avoid monitoring on days when high levels of Cryptosporidium
would be found. The underlying principle is that the monitoring should ensure that systems are
appropriately classified.
Discussion: The proposal requires that systems collect samples within two days of their sampling
schedule or be in noncompliance. Since EPA is proposing (but should not promulgate) a provision that
noncompliance leads to an immediate requirement to install UV (because of Bin 4 placement), this is
completely inappropriate. This requirement appears to stem from the thought that water utilities could -
game- the system by monitoring when they know Cryptosporidium
would not show up. It appears from the available data that randomized sampling has a similar probability
of finding high Cryptosporidium levels as time-series sampling designs (Frey et al, 1998), therefore this
thought is unfounded.
Recommendations: There are several reasons why a system acting in good faith could miss a sample.
EPA should include in the rule a provision that failure to comply with the two-day period does not result
in automatic noncompliance if the system has a compelling reason for missing the sample. If a sample is
missed through no fault of the system, then the sample should be taken as soon as possible and the state
notified as to the circumstances.
Response: See Responses 440 and 361.
EPA Letter ID: 556
Comment ID: 16534
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. Failure to Complete Monitoring
Basic Principle from the FACA Discussions: The foundation of the FACA discussions was that all
members were dedicated to an effort to monitor and collect data, to use that data to see what additional
treatment might be required, and to undertake necessary steps to protect public health.
Regulations should acknowledge the Federal, State, and local water system partnership in this effort, and
continue to build and foster that relationship.
Discussion: The proposed rule on page 47666 states:
-Any filtered system that fails to complete LT2ESWTR monitoring requirements must meet the treatment
requirements for Bin 4.-
There are many innocent reasons why a sample could be missed. For example, insufficient laboratory
capacity, or an overworked laboratory misses holding times or similar requirements; these are outside the
Comment Response for the LT2ESWTR 5-318 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
control of a water system. EPA allows for submission of resamples but places severe restrictions on their
use. Additionally, EPA does not provide provisions for resampling which cover the myriad of things
outside a water system-s control that could go wrong. EPA acknowledges that the majority of systems are
expected to fall into Bin 1, -the
no-action bin- so the mandatory placement in Bin 4 (i.e., install UV disinfection) is inappropriate simply
based on missed samples which would lead to noncompliance with monitoring requirements.
Recommendations: We strongly urge EPA to delete this provision. We feel it is extreme particularly
given the newness, complexity and magnitude of the rule. Any problems of non-compliance should be
addressed with the mechanisms already in place for such violations that allow appropriate avenues of
appeal and discussion. Additionally, we strongly recommend that EPA include more
Response: See Response 440.
EPA Letter ID: 556
Comment ID: 16538
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. Failure to Complete Monitoring
Basic Principle from the FACA Discussions: The foundation of the FACA discussions was that all
members were dedicated to an effort to monitor and collect data, to use that data to see what additional
treatment might be required, and to undertake necessary steps to protect public health.
Regulations should acknowledge the Federal, State, and local water system partnership in this effort, and
continue to build and foster that relationship.
Discussion: The proposed rule on page 47666 states:
-Any filtered system that fails to complete LT2ESWTR monitoring requirements must meet the treatment
requirements for Bin 4.-
There are many innocent reasons why a sample could be missed. For example, insufficient laboratory
capacity, or an overworked laboratory misses holding times or similar requirements; these are outside the
control of a water system. EPA allows for submission of resamples but places severe restrictions on their
use. Additionally, EPA does not provide provisions for resampling which cover the myriad of things
outside a water system-s control that could go wrong. EPA acknowledges that the majority of systems are
expected to fall into Bin 1, -the
no-action bin- so the mandatory placement in Bin 4 (i.e., install UV disinfection) is inappropriate simply
based on missed samples which would lead to noncompliance with monitoring requirements.
Recommendations: We strongly urge EPA to delete this provision. We feel it is extreme particularly
given the newness, complexity and magnitude of the rule. Any problems of non-compliance should be
addressed with the mechanisms already in place for such violations that allow appropriate avenues of
appeal and discussion. Additionally, we strongly recommend that EPA include more
Response: See Response 440.
Comment Response for the LT2ESWTR 5-319 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 562
Comment ID: 12286
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA has identified four major aspects of the proposal that require revision:
1. Failure to meet the proposed requirement for consecutive monthly samples must not trigger placement
of a water treatment plant into
Bin 4.
Response: See Response 440.
EPA Letter ID: 562
Comment ID: 12293
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1. Failure to meet the proposed requirement for consecutive monthly Cryptosporidium
samples triggers automatic placement of a treatment plant into the bin with the strictest treatment
requirements (Bin 4);
Response: See Response 440.
EPA Letter ID: 562
Comment ID: 12359
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: the LT2ESWTR provisions are being developed. If the agency proceeds to
promulgate the final rule as proposed, AWWA believes that such action is contrary to law, arbitrary and
capricious, and an abuse of discretion for the following reasons:
1. The Safe Drinking Water Act (SOWA) does not authorize EPA to
mandate a treatment requirement for failure to monitor.
Response: See Response 440.
EPA Letter ID: 562
Comment ID: 12412
Comment Response for the LT2ESWTR 5-320 December 2005
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: This topic is discussed in detail in Section 4.1.2 above. Under no circumstances should the
final LT2ESWTR include punitive provisions that force a utility to take on a higher level of treatment
than is needed based on documented occurrence of Cryptosporidium oocysts in the influent water to the
facility.
Response: See Response 440.
EPA Letter ID: 580
Comment ID: 12628
Commenter: Bruce Aptowicz, Chairman, Water Utility Council of the Pennsylvania American
Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA has identified four major aspects of the proposal that require revision:
1. Failure to meet the proposed requirement for consecutive monthly samples must not trigger placement
of a water treatment plant into Bin 4.
Response: See Response 440.
EPA Letter ID: 585
Comment ID: 11972
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: water quality monitoring requirements in the proposed rule. However, the TCEQ recommends
that the bin classification for systems that fail to complete Cryptosporidium monitoring be based on
available data whenever possible. For example, Table IV-6 indicates systems that collect only eight
samples run the risk of "false positive" bin classifications but run little risk of "false negative" bin
classifications if the classification is based on the maximum Cryptospridium level detected.
Consequently, assuming the sample results present a realistic temporal representation of the water
entering the primary treatment process, primacy agencies should be allowed to base the bin classification
on actual data rather than be required to assign a Bin 4 classification to the system. However, the TCEQ
does concur that primacy agencies should be allowed to assign a system to higher bins in situations where
the possibility of a "false negative" classification would exceed the 6.2% error rate described in Table IV-
6 for the 24-sample, arithmetic mean.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-321 December 2005
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Comment Codes 300-471
EPA Letter ID: 586
Comment ID: 12197
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: 1. Default bin classification of systems due to lack of data.
EPA proposes, under 141.709(e), any system that fails to complete monitoring requirements must meet
the treatment requirements for Bin 4.
We believe this is an extreme reaction. A small treatment system that takes no steps to comply with
monitoring requirements, or is unable to complete the monitoring program, most likely does so because of
financial inability or lack of understanding of the regulatory requirements. To burden such a system with
the most stringent treatment processes, with the associated added capital and operation expenses, would
be counter-productive.
There needs to be a provision through which a small system struggling with meeting requirements of new
regulations can work with the state to develop an implementation plan. This plan should include an
extension of compliance deadlines, and address the specific problems the system may be incurring.
Response: See Response 440.
EPA Letter ID: 589
Comment ID: 13054
Commenter: Lawrence Libeu, President, The Western Coalition of Arid States
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Issue 2: Failure to Complete Monitoring
Systems that fail to meet source water monitoring requirements should not automatically be classified into
Bin 4. There are many reasons that could cause a sample to be missed that are out of the control of a
water system. Automatically placing a system in Bin 4is inappropriate and the EPA should revise this
provision prior to rule promulgation. We recommend that EPA use
existing compliance enforcement procedures to address these situations (e.g. monitoring violations).
Reclassifying a system to Bin 4 for a monitoring violation can result in unnecessary additional treatment
with capital expenditures that could penalize the system far more than a monitoring violation. The public
notice and resulting negative publicity should be sufficient incentive for systems to endeavor to complete
the monitoring. Perhaps there are other mechanisms that can be used to emphasize the importance of
completing the monitoring without taking the excessive approach in the proposed rule. This could include
extending the monitoring period to allow the utility to complete the monitoring with the understanding
that not implementing controls to be in compliance with the rule by the effective date could result in more
serious violations.
Response: See Response 440.
EPA Letter ID: 591
Comment ID: 12125
Comment Response for the LT2ESWTR
5-322
December 2005
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Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Ohio EPA recommends that the rule provide flexibility for the State to determine whether or not a
system's source water monitoring results are complete on a case-by-case basis. The State should be able to
make this determination based on a review of the number of samples that were collected, where the
samples were collected and whether or not the samples were collected at appropriate times during the
year. The rule should also provide the State flexibility to require
an alternative sampling schedule for systems which are missing a portion of the source water sampling
requirements prior to the state making a bin classification for the system. In addition, the rule should
provide the State the flexibility to determine a system's bin classification based on the system's source
water monitoring data.
Finally, Ohio EPA recommends providing the flexibility to allow a system to conduct a complete year of
sampling, whenever it chooses, to determine if reclassification into another bin is appropriate.
Response: See Response 440.
EPA Letter ID: 592
Comment ID: 12106
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: the scheduled date to allow for testing on Thursdays and Fridays. The non-
compliance that would result from not sampling within 2 days is also unjustified. Automatically
classifying a utility into Bin 4for missing a sample date could be regarded as cruel and unusual
punishment. A Bin 4classification would force a utility to install expensive treatment equipment where it
may not be necessary and would not improve public health. A more reasonable alternative would be the
following 3-step approach
1. Require the utility to collect a sample as soon as possible after the missed scheduled sampling period.
2. Collect an additional month of sampling at the end of the one or two year sampling period.
3. Require the utility to conduct public notification as a tier 3 monitoring violation.
Response: See Response 440.
EPA Letter ID: 593
Comment ID: 11817
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: 3. Failure to Complete Monitoring: The proposal on page 47666 states: -Any filtered system
that fails to complete LT2ESWTR monitoring requirement must meet the treatment requirement for Bin
4.- SAWS believe that this is a critical issue within the proposal and the present provision is
unacceptable. This approach will change the historical approach EPA has used to acknowledge that 99%
of systems will make a good faith effort to comply with rules and should not be inappropriately penalized
Comment Response for the LT2ESWTR 5-323 December 2005
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if operating in good faith. The failure to complete monitoring, which could happen for any number of
innocent reasons, should not require maximum treatment. In addition, it is appropriate to maintain the
general relationship of trust with the drinking water community rather than implement actions, which
imply an adversarial relationship. Therefore, SAWS recommends the following: Use existing compliance
procedures coupled with a system-s rights to appeal noncompliance decisions. Any problems of non-
compliance should be addressed with the mechanisms already in place for such a
violation. Reasonable provisions should be provided for re-sampling Have
Response: See Response 440.
EPA Letter ID: 595
Comment ID: 12583
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Bin assignment for systems that fail to complete required monitoring
Maine does not agree that a system failing to complete required monitoring be automatically assigned to
Bin 4.
Response: See Response 440.
EPA Letter ID: 597
Comment ID: 12611
Commenter: Roger Hulbert, Senior Assistant Director, City of Houston Department of Public Works and
Engineering
Commenter Category: Regulated Community (Utilities)
Comment: ISSUE 3 -Sampling Schedules and Failure To Complete Monitoring
The City of Houston stresses that utilities cannot be considered non-compliant, and forced into Bin 4 as a
result of accidental, or unintentional interruptions to the sampling schedule. EPA should build more
flexibility into the sampling schedule to allow for sampling errors, shipping problems, laboratory
accidents etc. While we would agree that any system, which fails to monitor, could be forced into a Bin 4
categorization, this should only be applied to flagrant or
willful violations. Over a two-year sampling process, events will inevitably occur, which cause a delay or
interruption in the monitoring process. Utilities should not be held responsible for such instances, when
they can demonstrate that they have been in compliance with the monitoring schedule, and are making
good faith efforts to correct any problems, which occur along the way.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-324 December 2005
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EPA Letter ID: 601
Comment ID: 13013
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah strongly disagrees with EPA-s proposal that a water system that misses one
microbial sample automatically be placed in Bin 4 and required to install the highest level of protection
against Cryptosporidium.
Response: See Response 440.
EPA Letter ID: 603
Comment ID: 12666
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Bin Assignment for Systems that Fail to Complete Required Monitoring -The
sampling requirements of the proposed rule are complex and are expected to be difficult to implement for
very small systems, which may inadvertently miss a limited number of samples. The automatic
classification of systems that have sampling difficulties into the highest risk bin is overly stringent. A
more appropriate approach may be to classify those sources that fail to complete all their monitoring into
a bin one level higher than indicated based upon the data
collected. Some flexibility should be provided for systems to complete up to an additional year of
sampling in lieu of automatically being classified into a higher or the highest bin.
In reality, it is difficult to imagine a system that willfully fails to complete the required monitoring
installing additional treatment instead. However, the proposed rule provides the basis for taking more
aggressive action to protect public health where this is the case.
Response: See Response 440.
EPA Letter ID: 607
Comment ID: 12977
Commenter: Cam Ferguson, Manager of Water Resources, Greenville Water System
Commenter Category: Regulated Community (Utilities)
Comment: 1) A failure to meet the proposed requirement for consecutive monthly samples
should no automatically trigger placement into a lower bin assignment. There may be several reasons for
a utility not being able to collect the required number of samples that may be unavoidable. There could be
weather delays, personnel problems or shipping difficulties. Additionally, if a utility must collect samples
later during a month and the certified laboratory makes a mistake, there might be little or no time left to
re-collect. Some form of "exception
provision" needs to take these factors into consideration.
Response: See Responses 440 and 361.
Comment Response for the LT2ESWTR 5-325 December 2005
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EPA Letter ID: 609
Comment ID: 14116
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: making bin determinations. The USEPA proposes to classify systems that fail to
complete required monitoring in Bin 4, the highest treatment bin. The penalty for failure to complete
required monitoring is adequately addressed in the Michigan Safe Drinking Water Act, 1976 PA 399, as
amended, and generally involves public notification, fines, or additional monitoring. Capital
improvements required by unnecessary Bin 4 classification may result in not
addressing other, more appropriate plant improvements. This could have the unintended effect of a
decrease in public health benefits. The MDEQ believes bin classification should be based solely on
available data and not on the compliance status of monitoring. The MDEQ would prefer to use flexibility
and determine the appropriate response to a missed sample or missed sampling date on
a case-by-case basis.
Response: See Response 440.
EPA Letter ID: 610
Comment ID: 12984
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: rules. The most critical issue is that the failure to meet the proposed requirement for
consecutive monthly samples triggers Water Treatment Plant placement into Bin 4.
Response: See Response 440.
EPA Letter ID: 610
Comment ID: 12993
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: error. It would be a shame to cause a water system to unnecessarily invest hundreds of
thousands of dollars due to the Post Offices' delay in delivery of a sample or a broken sample.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-326 December 2005
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Comment Codes 300-471
EPA Letter ID: 614
Comment ID: 12960
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: * We are concerned that two years of monthly cryptosporidium monitoring with no
gaps is unrealistic. Mechanisms should be placed in the regulation to more adequately cover replacement
samples and unforeseen sampling or analysis problems without automatically placing the water treatment
plant into Bin 4.
Response: See Response 440.
EPA Letter ID: 617
Comment ID: 13257
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 1. We feel the provisions regarding an inadvertent failure to meet the
proposed requirement for consecutive monthly samples must not trigger the water supply being arbitrarily
placed into Bin 4.
While it is important to provide a statistically significant sampling of a water supply in order to establish
bin classification, this provision could effectively defeat a utility's past or proposed plans for watershed
protection as a result of what is essentially a monitoring violation. EPA should determine another remedy
for monitoring violations when they are based
on inadvertent circumstances that will not automatically place a utility in bin 4, One such remedy would
be additional sampling.
Response: See Response 440.
EPA Letter ID: 618
Comment ID: 13248
Commenter: Craig Bryant, Director, Chesterfield County Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: compliance totally unreasonable. Further, this monitoring related noncompliance
would lead to an immediate requirement to install UV (bin 4 placement). This is again highly
inappropriate.
Response: See Response 440.
EPA Letter ID: 618
Comment ID: 13250
Comment Response for the LT2ESWTR
5-327
December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Commenter: Craig Bryant, Director, Chesterfield County Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Monitoring non-compliance should not result in automatic bin 4 placement but
should necessitate additional sample requirements. If a utility continues to be unable or unwilling to
complete the monitoring, they should be dealt with as a chronic violator of the Safe Drinking Water Act
(SDWA).
Response: See Response 440.
EPA Letter ID: 620
Comment ID: 13282
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: 1. The failure to complete the monitoring as scheduled must not cause the utility to perform
maximum treatment. The failure could be due to many reasons beyond our control.
Response: See Response 440.
EPA Letter ID: 620
Comment ID: 13291
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 3: Failure to Complete Monitoring
Comments: SPRWS finds this provision unacceptable. Neither the EPA nor the utility have complete
control over the laboratories performing the Cryptosporidium analysis, and should not be responsible for
delayed or lost samples. Under the existing language the utility would incur heavy penalty for a minor
procedural error. The penalty does not fit the crime. It is common for
Response: See Response 440.
EPA Letter ID: 620
Comment ID: 13293
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Finally, this provision seems punitive to a point of undermining the fundamental
trust that exists between the Agency, the utility and the consumer.
Comment Response for the LT2ESWTR 5-328 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Response: See Response 440.
EPA Letter ID: 624
Comment ID: 13176
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: specific bin boundaries, and (3) the microbial toolbox. Our most significant
concerns are:
1. EPA indicates that failure to complete monitoring will automatically put that source into Bin 4
requiring 99.9997% reduction. We strongly disagree that monitoring violations should require such costly
treatment upgrades.
Response: See Response 440.
EPA Letter ID: 624
Comment ID: 13186
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 3. Failure to Complete Monitoring: This issue is one of most severe flaws in
the regulation! We believe that regulatory agencies and water utilities must work in good faith to protect
public health against waterborne diseases. EPA indicates that failure to complete monitoring will
automatically put that source into Bin 4 requiring 99.9997% reduction.
This requirement is unprecedented and inappropriate and clearly demonstrates the lack of EPA's trust in
water utilities. We strongly oppose such a requirement. There are a whole host of occurrences which
could be classified as "failure to complete monitoring" despite every good
faith effort by the water utilities. GCWW recommends that EPA use the procedures and authorities that
are currently in place related to monitoring compliance.
Response: See Response 440.
EPA Letter ID: 625
Comment ID: 13139
Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 3) Failure to complete monitoring
This provision makes a significant number of systems doomed to failure. There are numerous reasons a
sample may have been missed. In such a broad program, samples will be missed due to laboratory error,
overextended laboratories, shipping errors, etc. That most systems will fall into Bin 1 makes it
inappropriate for reversion to Bin 4 for FTCM violations. In most circumstances
Comment Response for the LT2ESWTR 5-329 December 2005
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a missed sample would not indicate a significant risk imposed on the public or significantly impact the
data generated by the LT2ESWTR. Replace merit samples, when collected in an appropriate time frame
(even if such time frame extended past the sampling window) would provide such protection and
validation of data. Requirements that prevent selective sampling are easily developed. The requirement
that a system be forced to install W reactors for missing a sample is ludicrous at best. Such a requirement
is onerous and burdensome both financially and technically and to impose it for reason4 other than
demonstrated risks is irresponsible.
Response: See Response 440.
EPA Letter ID: 625
Comment ID: 13141
Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: the missed sampling occurred for good reason. Again, the burden of Bin 4 for a
missed sample is completely out of proportion to the act, plus the imposition of such a penalty does not
necessarily ensure any heightened public health benefit. The missed sample should be collected in a
timely fashion, and used in the
Response: See Response 440.
EPA Letter ID: 627
Comment ID: 12633
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: 1. Failure to Complete Monitoring:
City-s position: Bin classification should be based solely on occurrence data, not on monitoring
compliance.
The Rule proposes a -bin- system of categories based upon occurrence data, additionally upon adherence
to a strict schedule of sampling and reporting. Placing a system in Bin 4 for failure to complete the
required monitoring is unacceptable. Anyone who has collected and analyzed environmental samples can
tell you, things can and do happen in the real world that cannot be controlled. Sufficient measures already
inform the public of monitoring violations. Specifically, the Consumer Confidence Rule clearly spells out
the nature of a deviation, and gives the consumer the opportunity to evaluate the relative risk posed.
Promulgation of this proposed language could lead to a bin classification that would potentially confuse
and unnecessarily alarm the served by the water provider, undermining many years of competent
stewardship.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-330 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 628
Comment ID: 12843
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: d. Automatic Bin 4 treatment requirement for failing to complete source water
monitoring is inappropriate. This provision requiring any filtered system that fails to complete LT2 Rule
monitoring must meet the Bin 4 treatment requirements is unprecedented and inappropriate. This changes
the historical approach the EPA has used which is to acknowledge that 99% of systems will do their very
best to insure they comply with rule and should not be inappropriately penalized if operating in good
faith. There are many innocent reasons that a sample could be missed not the least of which is the
possibility of insufficient laboratory capacity, or a laboratory that is overworked and misses holding times
or similar requirements. The EPA must allow for the probability that missed samples may (and do)
happen. Although the proposed rule allows for submission of re-samples, the EPA has put in such strict
requirements on their use that the provision is meaningless. Additionally, the EPA acknowledges in the
preamble and elsewhere that the majority of systems are expected to fall into Bin 1 or the no action bin,
so the default to mandatory UV (which is necessary to meet Bin 4 requirements) is inappropriate for
missed samples. The SFPUC recommends removing this provision prior to finalizing the rule.
Response: See Response 440.
EPA Letter ID: 629
Comment ID: 12827
Commenter: Melinda Rho, Manager of Regulatory Affairs and Consumer Protection, Los Angeles
Department of Water and Power
Commenter Category: Regulated Community (Utilities)
Comment: EPA requested comments on monitoring in the LT2ESWTR proposal. Specifically we are
concerned with the following provision on page 47666 of the proposed rule which states: -Any filtered
system that fails to complete LT2ESWTR monitoring requirements must meet the treatment requirements
for Bin 4.-
LADWP believes this is an extreme position that appears to penalize water systems -that follow the
required monitoring programs, but encounter situations where a sample could be missed, lost, or subject
to laboratory accidents. EPA allows for submission of resamples but placed such strict requirements on
their use that the provision appears not to be effective. EPA acknowledges that the majority of systems
are expected to fall into Bin 1 (the -no action- bin requiring no further treatment) so the default to
mandatory ultra-violet light treatment (UV), which is necessary to meet Bin 4 requirements, is
inappropriately severe for missed samples. For LADWP UV is not desirable for our treatment plant
configuration due to the high volume of water treated. Any problems of non-compliance due to
monitoring should be addressed with the regulatory mechanisms in place, such as notices of violations.
Action to require maximum treatment should not be based on failure to complete monitoring, which could
happen for any number of unforeseen or unavoidable reasons.
LADWP recommends EPA should use existing compliance procedures rights to appeal noncompliance
decisions as a more appropriate action, and less restrictive provisions should be provided for resampling.
Comment Response for the LT2ESWTR 5-331 December 2005
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Response: See Response 440.
EPA Letter ID: 630
Comment ID: 13060
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 4. Monitoring Key Issue Failure to Complete Monitoring: The proposal on page
47666 states:
"Any filtered system that fails to complete LT2ESWTR monitoring requirements must meet the treatment
requirements for Bin 4.- This requirement is unprecedented and inappropriate and must be removed prior
to finalizing the rule. This changes the historical approach EPA has used which is to acknowledge that
99% of systems will do their very best to insure they comply with rules and should not be inappropriately
penalized if operating in good faith. Procedures and authorities that are presently in place related to
compliance should be used by EPA.
There can be innocent reasons that a sample could be missed not the least of which is the possibility of
insufficient laboratory capacity, or a laboratory that is overworked and misses holding times or similar
requirements. EPA allows for submission of re-samples but places such strict requirements on their use
that the provision is meaningless. EPA acknowledges that the majority of systems are expected to fall into
Bin 1 or the no action bin so the default to mandatory
UV (which is necessary to meet Bin 4 requirements) is inappropriate for missed samples.
Action to require maximum treatment should not be based on failure to complete monitoring which could
happen for any number of innocent reasons. EPA should use existing compliance procedure coupled with
a system's rights to appeal noncompliance decisions as a more appropriate action. Any problems of non-
compliance should be addressed with the mechanisms already in place for such a violation. Reasonable
provisions should be provided for re-sampling.
Water utilities should not be held responsible for missing sample results due to lab failures. In addition,
EPA must allow for the probability that missed samples may (and do) happen. EPA should have utilities
build dates into their sampling schedules for additional samples in the event of missed samples, and
provide reasons why the samples were missed, (e.g. it could be something like 30 sampling dates so that 6
extra dates above the minimum requirement of 24 be available if samples are missed). EPA should make
reasonable provisions for make-up samples. It is more appropriate to maintain the general relationship of
trust with the drinking water community rather than implement actions which imply an adversarial
relationship.
Response: See Response 440.
EPA Letter ID: 631
Comment ID: 13232
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment Response for the LT2ESWTR 5-332 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: Sampling Schedule and Failure to Complete Monitoring: The proposal requires
that water systems collect samples within 2 days of their sampling schedule or be non-compliant. This
approach should be reconsidered.
Response: See Response 361.
EPA Letter ID: 631
Comment ID: 13234
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: treatment plant or with treatment plant staff that must be the priority. EPA
must believe that most water systems will make good faith attempts to fulfill all monitoring requirements
to avoid noncompliance designation.
Response: See Response 440.
EPA Letter ID: 631
Comment ID: 13236
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: Failure to comply with monitoring requirements should not lead to noncompliance
if the system has a good reason for missing the sample schedule. The primacy agencies must have
flexibility to consider the reasons for missed samples and to make decisions regarding noncompliance
status.
Such a punitive approach to LT2EWTR monitoring sets a new precedence. Non-compliance procedures
already in place as required by other Safe Drinking Water Act regulations should continue to be used to
implement this proposed rule. Finally, water systems must be afforded a process to appeal non-
compliance designations.
Response: See Response 440.
EPA Letter ID: 631
Comment ID: 13240
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: Water systems cannot be held responsible for monitoring requirements if these
implementation tools are unavailable. Because failure to comply with monitoring requirements is
punishable by delegation to the most conservative bin, water systems must insist that EPA conform to the
requirements of the Agreement in Principle.
Comment Response for the LT2ESWTR 5-333 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Response: See Response 440.
EPA Letter ID: 633
Comment ID: 13264
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 1. Defaulting to Placement in Bin 4
Des Moines Water Works believes it is inappropriate to default systems into Bin 4 based on reasons other
than the existence of Cryptosporidium in their source water. The proposal on page 47666 states: -Any
filtered system that fails to complete LT2ESWTR monitoring as required must meet the treatment
requirements for Bin 4.— This requirement is unprecedented and inappropriate and must be removed
prior to finalizing the rule. There are many reasons that a sample could be missed including laboratory
failures, such as exceeding hold times. The
Response: See Response 440.
EPA Letter ID: 633
Comment ID: 13266
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: requirements on their use that the provision is not helpful. EPA acknowledges
that the majority of systems are expected to fall into Bin 1 so the default to Bin 4 requirements is
inappropriate for failure to meet monitoring requirements or because of laboratory failures.
EPA should use existing compliance procedures coupled with a system-s rights to appeal noncompliance
decisions as a more appropriate action. Any problems of non-compliance should be addressed with the
mechanisms already in place for such a violation. Reasonable provisions should be provided for re-
sampling.
Response: See Response 440.
EPA Letter ID: 637
Comment ID: 13085
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on Bin assignments for systems that fail to complete
required monitoring (page 47678)
District comment on the statement that -Any Filtered system that fails to comply with LT2ESWTR
monitoring requirements must meet the treatment requirements of Bin 4.-
Comment Response for the LT2ESWTR 5-334 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
This requirement in unprecedented and inappropriate. Systems will comply with the rules in good faith
and should not be unduly penalized for emergency situations or for events beyond their control.
Procedures and authorities presently in place by the States will be able to appropriately handle systems
that are acting in good faith as well as those that are blatantly disregarding
the sampling requirements. Systems should also not be held accountable for laboratory failures. An
appropriate provision would be to allow for representative resampling to occur.
Response: See Response 440.
EPA Letter ID: 641
Comment ID: 13585
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Also, ASI recommends that PWSs that have exceeded the required minimum by
collecting more than 1 sample per month (but were unable to collect multiple samples in 1 or more
months) should not be penalized by being put in Bin 4. As long as the minimum requirements are met,
ASI recommends one -data excursion- be allowed per year of monitoring.
Response: See Response 440.
EPA Letter ID: 641
Comment ID: 13594
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Systems that Fail to Complete Required Monitoring - Systems that fail to complete the
monitoring during the compliance period of LT2 should be classified into Bin 4. Note: -Fail to complete-
should be defined as -submits less than the required minimum number of sample results or fails to
comply with the recommended schedule change allowances put forth by ASI (see comments Pg. 47668,
above). This stringent requirement will protect public health and establish a substantial incentive for LT2
compliance. However, we recommend this NOT include
PWSs that sample more than the minimum number of samples but do not have the same number of results
for each month. (See: Pg 47668 d. Use of previously collected data).
Response: See Response 440.
EPA Letter ID: 643
Comment ID: 12737
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 5-335 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: Failure to Monitor/Deviation from the Monitoring Schedule
States strongly disagree with EPA-s proposal that a water system that misses one microbial sample
automatically be placed in Bin 4 and required to install the highest level of protection against
Cryptosporidium. States also
Response: See Response 440.
EPA Letter ID: 643
Comment ID: 12740
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The sampling requirements of the proposed rule are complex and are expected
to be difficult to implement for very small systems, which may inadvertently miss a limited number of
samples. The automatic classification of systems that have sampling difficulties into the highest risk bin is
overly stringent. A more appropriate approach may be to classify those sources that fail to complete all
their monitoring into a bin one level higher than indicated based upon the data collected. Some flexibility
should be provided for systems to complete up to an additional year of sampling in lieu of automatically
being classified into a higher or the highest bin.
Response: See Response 440.
EPA Letter ID: 643
Comment ID: 12772
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Bin assignment for systems that fail to complete required monitoring
States do not support EPA-s proposal that a system that fails to complete required monitoring be
automatically assigned to Bin 4. Please refer to Attachment 1 for further detail on this issue.
Response: See Response 440.
EPA Letter ID: 646
Comment ID: 13565
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: Monitoring - The provision that automatically places systems in Bin 4 for failure to complete
LT2ESWTR monitoring requirements is unacceptable. EPA must allow for the inevitable missed sample
Comment Response for the LT2ESWTR 5-336 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
due to lab failures. Existing compliance procedures are available to EPA to address monitoring problems.
Santa Fe expects to be placed in Bin 1 and EPA acknowledges that the majority of systems are expected
to fall into this category. Santa Fe has direct experience with holding time exceedances and other
laboratory problems. If these problems reoccur and a sample is missed, an improper Bin classification
may result.
Response: See Response 440.
EPA Letter ID: 647
Comment ID: 12895
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Failure to Monitor/Deviation from the Monitoring Schedule
MDE strongly disagrees with EPA-s proposal that a water system that misses one microbial sample
automatically be placed in Bin 4 and required to install the highest level of protection against
Cryptosporidium. MDE also disagrees
Response: See Response 440.
EPA Letter ID: 647
Comment ID: 12898
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: The sampling requirements of the proposed rule are complex and are expected to be difficult
to implement for very small systems, which may inadvertently miss a limited number of samples. The
automatic classification of systems that have sampling difficulties into the highest risk bin is overly
stringent. A more appropriate approach may be to classify those sources that
fail to complete all of their monitoring into a bin one level higher than indicated based upon the data
collected. Some flexibility should be provided for systems to complete up to an additional year of
sampling in lieu of automatically being classified into a higher or the highest bin.
Response: See Response 440.
EPA Letter ID: 647
Comment ID: 12918
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Bin assignment for systems that fail to complete required monitoring
Comment Response for the LT2ESWTR 5-33 7 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
MDE does not support EPA-s proposal that a system that fails to complete required monitoring be
automatically assigned to Bin 4. Please refer to Attachment 1 for further detail on this issue.
Response: See Response 440.
EPA Letter ID: 653
Comment ID: 14062
Commenter: Tim Stefanich, Environmental Engineer, Sioux Falls Water Purification, City of Sioux Falls
Commenter Category: Local Government
Comment: Failure to Complete Monitoring - EPA states in the LT2ESWTR that any filtered
system that fails to complete the monitoring requirements must meet the treatment requirements for bin 4
(Page 47666). We feel that this requirement is inappropriate and unacceptable. No system should be
forced into requiring maximum treatment based on the failure to complete monitoring. There are many
innocent reasons why a system may not have sampled at the appropriate time - such as lab failure,
insufficient lab capacity, or major weather events to
name a few. It is recommended that EPA use existing compliance procedures along with a system's right
to appeal noncompliance for missed sampling issues.
Response: See Response 440.
EPA Letter ID: 653
Comment ID: 14066
Commenter: Tim Stefanich, Environmental Engineer, Sioux Falls Water Purification, City of Sioux Falls
Commenter Category: Local Government
Comment: If there fails to be adequate laboratory capacity there may be some systems that are caught in
the Failure To Complete Monitoring requirement and thus be forced to meet the treatment requirements
of bin 4.
Response: See Response 440.
EPA Letter ID: 654
Comment ID: 13121
Commenter: William Brant, Director, Miami-Bade Water and Sewer Department
Commenter Category: Regulated Community (Utilities)
Comment: Another concern with the proposed regulation is the condition that any system
that fails to complete the LT2 monitoring requirements will have to meet the treatment requirements for
Bin 4. The MDWASD feels that his proposed penalty is excessive. If the EPA already stated that they
believe most systems will fall into Bin 1, there is not need to require such extreme treatment measure for
a missed sample. The EPA already has established mechanisms to address non-compliance issues. The
MDWASD requests that the EPA implement these established mechanisms into the proposed regulation
Comment Response for the LT2ESWTR 5-338 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
instead of the extremely stringent penalty currently proposed. The MDWASD also requests that the EPA
change the
Response: See Response 440.
EPA Letter ID: 660
Comment ID: 14073
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on Bin assignments for systems that fail to complete
required monitoring (page 47678)
If a water system fails to meet source water monitoring provisions this should not be an automatic trigger
for placement into Bin 4. States should be given flexibility to address systems that may have specific
challenges in meeting the monitoring requirements of the rule, as long as the system is making a good
faith effort. Adjustments should be made to reflect more realistic data quality
and scheduling expectations. As seen in the ICR, many unexpected events interfered with sampling on a
set schedule, including, shipment issues, weather conditions, plant disruptions, etc.
Response: See Response 440.
EPA Letter ID: 662
Comment ID: 14032
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on Bin assignments for systems that fail to complete
required monitoring (page 47678)
Placement in Bin 4 for failure to complete sampling is an unacceptable protocol. Issues may arise that
complicate the sampling while a system is operating in good faith. This would be an unnecessary and
punitive practice. Several factors, including laboratory capacity or mistake, could cause non-compliance,
States should be allowed reasonable jurisdiction to allow for problems, address the issues and help
maintain systems compliance, rather than punitive measures
Response: See Response 440.
EPA Letter ID: 668
Comment ID: 13896
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment Response for the LT2ESWTR 5-339 December 2005
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Comment: - If a system fails to test as required, it should be automatically classified as -Bin 4.- To
provide otherwise would be to create a strong incentive to stop testing or not test at all if a system
suspects poor quality source water, to the clear detriment of public health. EPA should not reward bad
actors, (p. 47678)
Response: See Response 440.
EPA Letter ID: 673
Comment ID: 13982
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on Bin assignments for systems that fail to complete
required monitoring (page 47678)
Jordan Valley Water supports allowing water systems to be classified in a bin based on available data the
system has collected. If a water system fails to meet source water monitoring provisions, this should not
be an automatic trigger for placement into Bin 4. States should be given the flexibility to address systems
that may have specific challenges in meeting the monitoring requirements of the rule, as long as the water
system is making a good faith effort to comply.
Response: See Response 440.
EPA Letter ID: 678
Comment ID: 14681
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 15. Section 141.709(e) - This provision, which requires filtered systems that fail to complete
LT2 Rule monitoring to meet the Bin 4 treatment requirements, is unprecedented and inappropriate and
should be removed prior to finalizing the rule. This provision changes the approach to compliance the
EPA has historically used which is to acknowledge that 99% of systems will do their best to ensure they
comply with the rule and are not inappropriately penalized if operating in good faith. There are many
innocent reasons that a sample could be missed, not the least of which is the possibility of insufficient
laboratory capacity or a laboratory that is overworked and misses holding times or similar requirements.
The EPA must allow for the probability that missed samples may (and do) happen. Although the proposed
rule allows for submission of re-samples, the EPA has put in such strict requirements on their use that the
provision is meaningless. Additionally, the EPA acknowledges in the preamble and elsewhere that the
majority of systems are expected to fall into Bin 1 or the no action bin, so the
default to mandatory UV (which is necessary to meet Bin 4 requirements) is inappropriate for missed
samples.
We believe it is important to maintain a trusting relationship between the drinking water community and
the EPA in implementing the LT2 Rule. As such, we urge the EPA to continue using the compliance
procedures and authorities that are presently in place and provide
more flexibility (such as allowing for re-sampling or additional sampling at the end of the monitoring
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period to make up for the missing samples) in the final rule to resolve the issue of missing samples due to
reasons beyond a system-s control. Additionally, the final rule should include procedures that allow a
system to appeal noncompliance decisions.
Response: See Response 440.
EPA Letter ID: 678
Comment ID: 14708
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5. On bin assignment for systems that fail to complete required monitoring, the EPA requests
comment on alternative approaches for systems that fail to complete required monitoring, such as
classifying the system in a bin based on data the system has collected, or classifying the system in a bin
one level higher than the bin indicated by the data the system has collected. [47678, C3]
Comment: An automatic trigger to a higher bin treatment requirement for systems that fail to complete the
required monitoring without considering the reasons for the failure is unreasonable and inappropriate. If a
system fails to complete required monitoring, there is no assurance that the source water would have
Cryptosporidium concentrations that would put the system in a bin
one level higher or lower or in a bin indicated by the data so far collected. As previously indicated, we
also urge the EPA to
Response: See Response 440.
EPA Letter ID: 683
Comment ID: 14759
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
Comment: Sampling Schedule and Failure to Complete Monitoring: The proposal requires that water
systems collect samples within 2 days of their sampling schedule or be non-compliant. This approach
should be reconsidered. Sample collection can be impacted by unexpected or emergency situations at a
treatment plant or with treatment plant staff that must be the priority. EPA must believe that most water
systems will make good faith attempts to fulfill all monitoring requirements to avoid non-compliance
designation.
A sample schedule might be missed due to unavoidable problems in transporting samples to an out of
state laboratory (i.e. the United Parcel Service strike that prevented timely submittal of Information
Collection Rule samples), insufficient laboratory capacity, or a laboratory that is overworked and misses
holding times. Water systems should not be held responsible for missing sample results due to lab
failures.
Failure to comply with monitoring requirements should not lead to noncompliance if the system has a
good reason for missing the sample schedule. The primacy agencies must have flexibility to consider the
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reasons for missed samples and to make decisions regarding non-compliance status.
Such a punitive approach to LT2EWTR monitoring sets a new precedence. Noncompliance procedures
already in place as required by other Safe Drinking Water Act regulations should continue to be used to
implement this proposed rule. Finally, water systems must be afforded a process to appeal noncompliance
designations.
Response: See Response 440 and 361.
EPA Letter ID: 688
Comment ID: 14737
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Providing Additional Treatment Instead of Monitoring (141.709(e))
The State accepts that any system that fails to quantify its risk for Cryptosporidium should have to apply
the maximum treatment possible (Bin 4) to adequately protect its customers. The rule, however, is an all
or nothing proposition. It does not seem reasonable to force a water system to install expensive treatment
when one or two samples over a two-year period were missed and the remaining sample results indicated
little or no Cryptosporidium in the source water. That goes against one of the stated principles of the rule,
which was to only make systems with high-risk install additional treatment. The regulation should employ
a percentage to allow systems to select their bin based on remaining sample results. The wording in
141.709(e) could read -any filtered
system or unfiltered system that is required to install filtration that fails to collect at least 80% of the
samples required in 141.701 through 141.707 and meets all other requirements of 141.701 through
141.707 or chooses not to monitor pursuant to 141.701(f) must meet the treatment requirements for Bin 4
under 141.720 by the date applicable under 141.701(e).-
Response: See Response 440.
EPA Letter ID: 699
Comment ID: 14773
Commenter: David A. Visintainer, Water Comissioner, City of Saint Louis
Commenter Category: Regulated Community (Utilities)
Comment: 1. Section IV.A.l.b (page 47666) - Samples could be missed by a utility for a
number of reasons beyond their control. Mandatory placement in Bin 4 as the result of missed samples is
overly harsh in the light of EPA-s expectation that the majority of water systems will be assigned to the
lowest -no action- Bin 1. An alternative would be to require utilities to schedule makeup samples as
extras or allow the use of scheduled matrix spike samples as makeup samples if needed.
This section also requires that samples be collected within 2 days of their sampling schedule or the system
will be in noncompliance and would then be placed in Bin 4. Greater flexibility should be given in this
scheduling. We suggest plus or minus 5 days and failure to monitor in this timeframe should not result in
automatic placement in Bin 4.
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Response: See Response 440.
EPA Letter ID: 703
Comment ID: 14784
Commenter: Rich Weirich, Plant Superintendent, Frenchtown Water Treatment
Commenter Category: Regulated Community (Utilities)
Comment: amount, most facilities do not have that kind of money for sampling. The biggest
issue associated with the sampling requirements is the penalties for one missed sample. I feel the
punishment doesn't the crime. I feel all water systems will do their best to assure they stay in compliance.
There could be a very innocent reason that a sample was missed, not to mention lab testing errors. With
the amount of sampling required and the time frame in which to have the sample received and tested, I
feel that the consequences are too harsh and should be changed.
Response: See Response 440.
EPA Letter ID: 704
Comment ID: 14789
Commenter: Steven G. Gould, Chairman, New York State American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. Section 141.709.d.e. Filtered Systems That Fail to Complete the Source Water
Monitoring.
Systems that fail to complete the source water monitoring are automatically placed in Bin 4 (highest level
of treatment). We believe that a more appropriate penalty for not completing the required source water
monitoring is public notification of the violation and an enforcement order for the State to complete
monitoring. This provision will likely affect smaller systems who may be least able to afford the
treatment requirements of Bin 4, and may not have to provide
any treatment, or a treatment less than Bin 4, if they had monitored.
Response: See Response 440.
EPA Letter ID: 706
Comment ID: 14809
Commenter: John Spatz, Deputy Commissioner, City of Chicago Department of Water Management
Commenter Category: Regulated Community (Utilities)
Comment: 3. MONITORING REQUIREMENTS
Failure to Complete Monitoring
A Water Utility should not be placed in Bin 4 because of lack of monitoring. There could be several
reasons that cause incomplete monitoring. Bin 4 represents the greatest number of additional operating
and capital expenses. Bin 4 (Cryptosporidium oocysts >3.0/L) requires much more treatment (whether
ozone, chlorine dioxide or UV light). If a utility based upon data collected shows less than 0.075
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oocysts/L, it will be assigned to Bin 1. The same utility assigned to Bin 1, should not have to add
additional treatment for cryptosporidium to satisfy the LT2SWTR monitoring requirements. There should
be a monitoring violation penalty. The facilities should not have to change proven historical treatment
techniques for a monitoring violation.
Response: See Response 440.
EPA Letter ID: 711
Comment ID: 16543
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 3. Failure to meet source water monitoring provisions should not automatically
trigger a water treatment plant to be placed in a higher bin than other data indicates. EPA should consider
options such as a second chance to collect additional monitoring data. Requiring maximum treatment is a
serious imposition and can have significant monetary implications. EPA should use existing compliance
procedures coupled with a system's rights to appeal noncompliance decisions as a more appropriate
action.
Response: See Response 440.
EPA Letter ID: 711
Comment ID: 16563
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 4. EPA requests comment on alternative approaches for systems that fail to
complete required monitoring, such as classifying the system in a bin based on data the system has
collected, or classifying the system in a bin one level higher than the bin indicated by the data the system
has collected. [47678, C3]Comment: There could be many reasons why a system may fail to complete the
required monitoring. A system should be given a second chance to make up any missed samples once
EPA notifies the system that its data set does not meet the monitoring requirements. EPA can elect to
classify a system in a bin based on the data the system has collected if a system missed only one or two
samples and has good reasons for why it occurred. The act of placing a system in a bin higher than what
the collected data indicates should be reserved only for systems that for some reason refuse to make up
the missed samples and do not
have good reasons for the initial missed sampling.
Response: See Response 440.
Comment Response for the LT2ESWTR 5-344 December 2005
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5.14 Comment Code 450, Monitoring for New Plants and Sources
Summary of Issues
Comments were submitted concerning multiple aspects of monitoring requirements for new systems.
Many commenters supported the proposed approach that monitoring and treatment requirements for new
systems be equivalent to those in place for existing systems. However, several commenters expressed
concern that the States should be given more flexibility to evaluate monitoring requirements for new
systems on a case-by-case basis. Other commenters believe that the utilities themselves needed more
flexibility in the monitoring requirements to allow them to shift to sources of a higher quality or to new
sources which have no existing data. Multiple commenters also inquired if a new plant that would be
providing the 5.5-log of treatment would be subject to the monitoring requirement.
Response to Code 450
Monitoring requirements for new sources
Most commenters recommended that new plants and sources undergo monitoring equivalent to that
required for existing plants and sources. Some commenters suggested that States should have flexibility to
determine new source monitoring requirements on a case-by-case basis. EPA believes that new sources
must provide the same level of public health protection as existing sources, and therefore requires PWS to
conduct source water monitoring that meets the same requirements of today's final rule. Under this
approach, PWSs that serve less than 10,000 would be able to conduct indicator monitoring to determine if
Cryptosporidium is required. Systems would also be able to avoid source water monitoring if they agree
to provide 5.5 log of treatment for the new source.
Flexibility on timing of new source monitoring and available guidance
However, EPA also believes that some State discretion to determine when monitoring should take place is
appropriate. Therefore, today's rule requires PWS to conduct source water monitoring for new plants and
sources on a schedule approved by the State. This schedule must include dates for the PWS to determine
its treatment bin classification and, if necessary, comply with additional Cryptosporidium treatment
requirements. EPA has provided guidance regarding new source monitoring in the Source Water
Monitoring Guidance Manual.
Individual Comments on Code 450
EPA Letter ID: 101
Comment ID: 10881
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Monitoring Requirements for New Systems
EPA should leave new plant monitoring requirements up to the State permitting authorities. Every State
has monitoring requirements for new sources built into their permitting requirements. No new regulatory
hurdles need to be placed on State Primacy Agencies - they are already doing a great job - why should the
Agency try to fix something that is not broken.
Response: See Response 450.
Comment Response for the LT2ESWTR 5-345 December 2005
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EPA Letter ID: 444
Comment ID: 10811
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment: d. NH agrees with source monitoring for new water sources which is equivalent to that
required for existing sources.
Response: See Response lOOa.
EPA Letter ID: 457
Comment ID: 11918
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: With respect to the specific issues on which EPA requested comment, we believe that EPA
should provide the states with flexibility to address these concerns on a case-by-case basis. The EPA
could present the following specific issues as a way of guidance to the states:
* Monitoring and treatment requirements for new plants and plants
switching sources; and,
Response: See Response 450.
EPA Letter ID: 458
Comment ID: 10973
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: New Sources - There should be no difference between required monitoring for a proposed
new source versus an existing source as far as required monitoring is concerned. Cryptosporidium should
be monitored regardless of the proposed population to be served.
Response: See Response 450.
EPA Letter ID: 470
Comment ID: 11067
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Comment Response for the LT2ESWTR 5-346 December 2005
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Environmental Conservation
Commenter Category: State/Tribe Government
Comment: In general, we support the monitoring requirements for new plants and sources
should begin one year prior to bringing the plant on-line. We believe that this does not create an unusual
hardship for new plants or sources and allows for a significant amount of information to be collected.
However, exceptions may need to be made. For this reason, we encourage EPA to allow states to have
flexibility to address concerns on a case-by-case basis.
Response: See Response 450.
EPA Letter ID: 471
Comment ID: 11112
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment:
3. A final comment we have on the monitoring portion of the proposed rule involves the timing for
determination of bin requirements. WSSC has a unique situation because we are in the process of
studying an alternate intake location (mid-river instead of existing shoreline) for one of our water
treatment plants. In this case, it is preferable to wait until the location of the alternate
intake location is better known (probably mid 2005) before we proceed with the -binning- sampling since
that would likely be more representative of our future source water. Since the design of the system is
currently proceeding assuming the most conservative case (the Bin 4 2.5-log requirement), the -binning-
would be utilized only to determine our future UV system operating requirements and would be
completed prior to the 2007/2008 on-line date for the system. While the proposed rule makes provision
for waiving sampling if a system is designed/operated for Bin 4 (cf § 141.701(f)), it does not address this
situation in which the binning is primarily focused on operating requirements which may be far less
Washington Suburban Sanitary Commission comments on proposed LT2ESWTR restrictive than design
conditions. Thus, we suggest allowing utilities more flexibility regarding the sampling period for -
binning-to accommodate such situations.
Response: See Response 450.
EPA Letter ID: 472
Comment ID: 11136
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: - Monitoring requirements for new plants and sources.
Since COP has future treatment plants in our capital improvement program this is a concern. Possible
solutions are; 1) conduct required monitoring within 30 months after new plant startup, 2) if source is
available, conduct monitoring during/prior to construction to coordinate completion of 24-month
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sampling with treatment plant startup. If source is not available 365 days per year, conduct 24-months of
monitoring when source is available.
Response: See Response 450.
EPA Letter ID: 485
Comment ID: 11286
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: Development of a new source is normally undertaken over sufficient
time to allow for monitoring. Therefore, the Department believes that such systems should be required to
collect the data prior to treatment plant design to allow for construction of the facilities necessary for
proper treatment. The Department also recognizes that some systems under emergency conditions switch
to sources for which no data is available. These systems should then be required to collect the required
data from the sources as soon as possible and adjust plant treatment to the appropriate bin based on the
sampling results. New plants on a source that has available data should be allowed to use data from a
nearby plant if watershed sanitary survey information indicates this data should be representative of the
water treated at the new plant.
Response: See Response 450.
EPA Letter ID: 520
Comment ID: 11618
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Monitoring requirements for new plants and new sources
Development of a new source is typically a multiple year process. In most cases, there will be adequate
time to conduct source water quality monitoring prior to treatment plant design to allow for construction
of the facilities necessary for proper treatment.
However, in some cases, systems switch to alternate sources under emergency conditions without having
extensive data available for the alternate source. States need the discretion to be able to allow a system to
use such a sources based on available data and then require the system to collect the required data from
the source while the source is in use. The state would ultimately make a bin classification for the source
and the system would be required to make appropriate changes based on the classification, but would still
be able to use the alternate source in the interim.
Response: See Response 450.
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EPA Letter ID: 548
Comment ID: 12160
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * Monitoring requirements for new plants and sources (before it is brought on-line or initiated
some time period afterward)
Metropolitan believes that EPA should require systems with new plants and sources to conduct
monitoring equivalent to that of existing plants or sources. The monitoring may be started within one year
before or after the plant or source is brought on-line.
Response: See Response 450.
EPA Letter ID: 561
Comment ID: 12230
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Monitoring Requirements for New Plants & Sources
This proposal would require new plants that will be completed after the monitoring schedule, but before
the compliance date, conduct source water monitoring for cryptosporidium to determine the required level
of treatment. What if the proposed new plant will provide the 5.5 log of treatment which would avoid the
requirement for monitoring? Would the Rule provide that the monitoring requirement for this situation be
waived?
Response: See Response 450.
EPA Letter ID: 562
Comment ID: 12413
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: New facilities should conduct 24 months of monitoring employing EPA Method
1622/1623 for Cryptosporidium oocysts. As with existing facilities, new facilities should be afforded the
opportunity to take 24 or 48 samples and average accordingly. Each primacy agency should identify in its
permitting guidance when in the design process the information must be submitted to the primacy agency.
New water treatment facilities should be designed based on
the log credit system reflected in the microbial toolbox and inactivation provisions identified in
LT2ESWTR.
Response: See Response 450.
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EPA Letter ID: 591
Comment ID: 12126
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Ohio EPA believes this should be a state decision on a case-by-case basis. In Ohio, the Cryptosporidium
monitoring could be incorporated into the monitoring normally required for a new surface water source as
part of the plan approval process. Based on the monitoring results, the treatment requirements could be
reviewed as part of the plan approval process for the new plant.
Response: See Response 450.
EPA Letter ID: 595
Comment ID: 12584
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Monitoring requirements for new plants and new sources
Monitoring requirements should be modified as needed, pending state approval.
Response: See Response 450.
EPA Letter ID: 598
Comment ID: 12624
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: Monitoring Requirements for New Plants
Page 47678 requests comments on monitoring requirements for new plants and sources. The Utility is
currently in the early design stages of a new water treatment plant and understands the need to address
cryptosporidium treatment requirements in the design process. However, our design process will not
allow us to collect 24 months of monitoring data prior to design, nor do we have a raw water intake
constructed which would make sampling convenient and representative of the source. The best suggestion
we can make to address this issue is to use
any existing representative water quality data for the raw water source and/or collect a few sets of
samples (2 or 3 months) if possible.
This data along with design allowances to add treatment such as Ultraviolet light in the future, if needed,
would be an appropriate recommendation. Once a plant is constructed and in operation, a full set of
monitoring data at the next sampling round required by the LT2ESWTR rules would be appropriate, with
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treatment installed according to timeframes in the rule (i.e. 3 years to install
with a 2 year possible extension).
Response: See Response 450.
EPA Letter ID: 601
Comment ID: 13017
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on monitoring requirements for new plants and sources
(page 47678)
Utah supports the proposal for systems to monitor for Cryptosporidium before a new plant or source is
brought on line.
This would allow for proper pilot testing to occur to ensure that the treatment processes installed are
adequate protection for the level of Cryptosporidium contamination.
Response: See Response 450.
EPA Letter ID: 603
Comment ID: 12667
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Monitoring Requirements for New Sources -Source development is typically a
multiple year process. In most cases, there will be adequate time to conduct source water quality
monitoring prior to source approval and use of the source. Requiring source monitoring prior to bringing
the source on-line is appropriate. However, flexibility should be provided to allow systems to switch to a
higherquality source and complete source monitoring within two years of notifying the State of the intent
to use a source. This approach would allow for more rapid
use of higher quality source waters as approved by the State.Response: See Response 450.
EPA Letter ID: 637
Comment ID: 13086
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on monitoring requirements for new plants and sources
(page 47678)
District supports the proposal for new plants or sources to be subject to an equal level of sampling for bin
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placement and that prior sampling be encouraged to allow for appropriate pilot testing and technology
implementation. However, pre-sampling should not be required. There is often not enough time between
the development of a water source and its need to be utilized for a full
sampling set to be collected. The System should be required to take the samples as soon as is practical.
Response: See Response 450.
EPA Letter ID: 641
Comment ID: 13595
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Monitoring Requirements for New Sources - ASI agrees that plants switching sources or new
facilities, should comply with LT2 monitoring to determine the level of treatment required.
Response: See Response 450.
EPA Letter ID: 643
Comment ID: 12773
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Monitoring requirements for new plants and new sources
Development of a new source is typically a multiple year process. In most cases, there will be adequate
time to conduct source water quality monitoring prior to treatment plant design to allow for construction
of the facilities necessary for proper treatment.
However, in some cases, systems switch to alternate sources under emergency conditions without having
extensive data available for the alternate source. States need the discretion to be able to allow a system to
use such a sources based on available data and then require the system to collect the required data from
the source while the source is in use. The state would ultimately make a bin classification for the source
and the system would be required to make appropriate changes based on the classification, but would still
be able to use the alternate source in the interim.
Response: See Response 450.
EPA Letter ID: 647
Comment ID: 12919
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
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Comment: Monitoring requirements for new plants and new sources
Development of a new source is typically a multiple year process. In most cases, there will be adequate
time to conduct source water quality monitoring prior to treatment plant design to allow for construction
of the facilities necessary for proper treatment.
However, in some cases, systems switch to alternate sources under emergency conditions without having
extensive data available for the alternate source. States need the discretion to be able to allow a system to
use such a source based on available data and then require the system to collect the required data from the
source while the source is in use. The state would ultimately make a
bin classification for the source and the system would be required to make appropriate changes based on
the classification, but would still be able to use the alternate source in the interim.
Response: See Response 450.
EPA Letter ID: 664
Comment ID: 14050
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.A. - ADDITIONAL CRYPTOSPORIDIUM TREATMENT TECHNIQUE
REQUIREMENT FOR FILTERED SYSTEMS
Monitoring Requirements for New Plants & Sources
This proposal would require new plants that will be completed after the monitoring schedule, but before
the compliance date, conduct source water monitoring for cryptosporidium to determine the required level
of treatment. What if the proposed new plant will provide the 5.5 log of treatment which would avoid the
requirement for monitoring? Would the Rule provide that the monitoring requirement for this situation be
waived?
Response: See Response 450.
EPA Letter ID: 668
Comment ID: 13897
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - New plants or sources should have to comply with monitoring and treatment
requirements when they come on line, with no delays, (p. 47678)
Response: See Response 450.
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EPA Letter ID: 673
Comment ID: 13983
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on monitoring requirements for new plants and sources
(page 47678)
Jordan Valley Water supports the proposal for systems to monitor for Cryptosporidium before a new plant
or source is brought on line. This would allow for proper pilot testing to occur to ensure that the treatment
processes installed are adequate protection for the level of Cryptosporidium contamination.
Response: See Response 450.
EPA Letter ID: 678
Comment ID: 14710
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 6. The EPA requests comment on monitoring and treatment requirements
for new plants and sources. [47678, C3]
Comment: For plants already under design, the monitoring for new plants and sources should be similar
to an existing plant. Within six months before or after the plant or source is brought on-line, a plant
should start collecting monitoring data for the next 24 months for bin determination. However, most
utilities would prefer to monitor sources water Cryptosporidium before hand to ensure their new treatment
plant-s design includes appropriate facilities for compliance with LT2. It is not practical for the EPA to
be prescriptive in monitoring requirements for these types of
situations. This is better left to the State Primacy Agency and the utility.
Response: See Response 450.
EPA Letter ID: 688
Comment ID: 14739
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Monitoring Requirements for New Plants and Sources
Systems bringing new sources on line or new water systems should begin their source Comments water
Cryptosporidium monitoring within a year of activating the source or the date of system activation. The
year time frame for monitoring could begin before or after the activation date. Small systems should be
given the same flexibility as existing systems have under the rule to start with E. coli monitoring, and
only be triggered into Cryptosporidium monitoring if necessary.
Response: See Response 450.
Comment Response for the LT2ESWTR 5-354 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 711
Comment ID: 16564
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 5. EPA requests comment on monitoring and treatment requirements for new plants
and sources. [47678, C3]
Comment: Monitoring for new plants should be similar to an existing plant where within 6 months of
plant startup, a plant needs to start collecting monitoring data for the next 24 months to be used for bin
determination. As for a new source, no new requirements should be added unless a new source will now
be replacing an existing source entirely for a plant. If it is simply adding one more source to other existing
sources, then the system should be allowed to wait until the 2nd round of sampling to collect the Crypto
samples. It should be an extreme case where a plant is changing sources entirely that a new round of
sampling similar to a new plant would be required between the scheduled 1st and 2nd rounds of sampling.
Response: See Response 450.
5.15 Comment Code 460, Rule Language Edits
Summary of Issues
The first comment points out a misspelling in the rule. The second comment suggests changing the
description of monitoring from "source water monitoring" to "influent water characterization" to reduce
confusion with other existing source water protection programs.
Response to Code 460
See individual responses below.
Individual Comments on Code 460
EPA Letter ID: 603
Comment ID: 12655
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47784) Section 141.722(a) -
The word "following" is misspelled "follwing".
Response: Thank you, the spelling has been corrected.
EPA Letter ID: 620
Comment ID: 13296
Comment Response for the LT2ESWTR 5-355 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 6: Monitoring Location
Comments: SPRWS recommends changing the description of monitoring from "source water monitoring"
to "influent water characterization". "Source water monitoring" is vague, and can be confused with other
existing source water protection programs already underway by our utility. Systems with complex surface
water reservoir systems need to be specific to exact location of sample points. The compliance schedule
should include time for the utility to consult
Response: See Response 340(A).
5.16 Comment Code 470, Guidance
Summary of Issues
Comments centered on the primacy agency's involvement with the PWS and bin placement. Clarification
was requested regarding the bin assignment for raw water off-stream storage, presedimentation basins,
and bank filtration systems, how to determine changes in pathogen control at the intake, and sampling
dates.
Response to Code 470
See individual responses below.
Individual Responses on Code 470
EPA Letter ID: 562
Comment ID: 12400
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.1.4 State Role in Bin Placement
The question of the state-s role in bin placement is an important one. In fact, EPA poses the question
directly in §IV(C)(2)(c). The Stage 2 M/DBP FACA and the agency both recognized in developing the
Agreement in Principle and the rule itself that the "bin borders" reflected in § 141.709 reflect a high
degree of conservatism. Consequently, the placement of individual
utilities within individual bins must involve an opportunity for dialogue with the primacy agency. This
dialogue should focus on three essential components:
1. The mean Cryptosporidium concentration and bin placement derived from the data submitted in the
defined monitoring period (§141.701(e)) or grandfathered data (§141.708),
2. The quality of the available data, and
3. Other data available to the utility such as additional monitoring at the required monitoring site.
Each of these components should be factored into the bin determination.
Comment Response for the LT2ESWTR 5-356 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
AWWA recommends that EPA expand the LT2ESWTR Guidance to reflect an appropriate evaluation
process and dialogue between the affected PWS and the primacy agency. This process should include an
administrative process for handling of contested monitoring data, and the discussion of additional data
developed by the utility.
Response: See Response 500t regarding bin classification.
EPA Letter ID: 591
Comment ID: 12144
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: another process or function besides a sanitary survey. In addition, we request additional
guidance on how to determine significant changes in relation to pathogen control at the intake.
Response: See Response 400 regarding sanitary surveys and watershed assessments.
EPA Letter ID: 660
Comment ID: 14068
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: CUWCD recommends that additional clarification be added regarding the sample
collection dates for Cryptosporidium samples. It is not clear whether a system must select a numeric date
or a consistent time interval (4 week of the month) to meet the sampling requirements.
Response: See Response 360(A) regarding sampling date flexibility.
EPA Letter ID: 678
Comment ID: 14675
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 11. Section 141.708 (b)(3) and (c)(l) - Due to the term -system- being used instead of
addressing each plant influent more directly, interpreting whether the previously collected data meet the
criteria in this section is difficult. Previously collected data that meet the criteria for the different plants
might actually fall in different time periods. For example, previously collected data that meet the criteria
for one of the plants could be from 6/99 to 5/01 whereas another plant-s data could be collected from
1/00 to 12/01. In this situation, it is unclear whether both sets of data would meet the grandfathering
criteria based on the verbiage of the proposed rule.
Response: See Response 381.
Comment Response for the LT2ESWTR 5-357 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 678
Comment ID: 14677
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: about the acceptability of the data. Also, if a system has enough grandfathered data but
continues to collect additional Cryptosporidium data, it is not clear if the system has to submit
the additional data to the EPA or continue its monitoring without including this data in determining bin
classification. We request that EPA clarify this requirement.
Response: See Response 381.
5.16.1 Comment Code 471, Specific to Source Water Monitoring
Guidance Manual
Summary of Issues
Comments were submitted concerning the consistencies between the April 2003 and June 2003 draft
versions of the Source Water Monitoring Guidance Manual and how the final version of the manual
should accurately reflect the final rule. Commenters suggested changes in procedures for collecting and
shipping samples, allowing for modification of sampling schedule and rewording of certain information
to clarify how the rule needs to be implemented. Commenters advised purchasing sampling filters from
the laboratory instead of directly through the vendor to help with costs and that PWSs should clarify
contract proposals to state whether the filters are included in the contract with the laboratory. Commenters
also noted that there is an associated cost with archiving slides and that these costs should be brought to
the attention of the PWS. Another commenter recommended that hardcopy laboratory data originals
should remain with the laboratory, and that copies can be sent to the requesting PWS, for an additional
fee. Comments were also received expressing revision of the manual to provide for accurate maximum
operating pressure and flow rates for filters used in sample collection. Commenters also supported the
purpose of this manual and that it should be maintained and be revised to reflect the final rule.
Response to Code 471
Revising the guidance manual to reflect today's rule
EPA has reviewed and revised the guidance manual to accurately reflect today's rule. Specific changes as
recommended in the comments were reviewed and addressed in the final guidance manual when they
were found to be valid provide useful information in implementing the LT2ESWTR. EPA thanks the
commenters for reviewing the manual and appreciates the feedback, allowing this document to fulfill its
purpose.
Please note that the guidance manual is provided to help implement the LT2ESWTR. The guidance
document does not, however, substitute for the LT2ESWTR or any of the analytical methods approved
for use under the rule. The material presented within the guidance manual is intended solely for guidance
and does not alter any regulatory or analytical method requirements not altered by the LT2ESWTR itself.
Comment Response for the LT2ESWTR 5-358 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Individual Comments on Code 471
EPA Letter ID: 641
Comment ID: 13618
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Comments on the Draft PWS Guidance Manual for LT2 Table 1-1
The Manual should be revised to allow an opportunity or mechanism for a PWS to modify a previously
submitted sampling schedule if necessary.
Reason : If the PWS has not contracted with a laboratory and cleared the schedule with the lab before
schedule submittal, the lab may not be able to accept additional samples on the scheduled weeks. (It is our
experience that everyone wants to schedule their samples for the second week of the month !)
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13620
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 5.1.2.2
—.If filtered samples will be sent, indicate which filter you will use—
Filter - The PWS need not have a preference for which filter to use as stated here. It is better stated in
5.1.4.2 that all approved filters would be acceptable, unless they have a specific preference based on their
own experience.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13621
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: —you should consider purchasing filters directly from the vendor—
The PWS may want to consider purchasing filters directly, however, they should be advised that they are
unlikely to be able to purchase filters at a lower unit price than the laboratory, particularly a high volume,
commercial laboratory provider that buys in bulk quantities. The PWS should just insure that lab
proposals clarify whether the filters are included in the pricing or not.
Response: See Response 471.
Comment Response for the LT2ESWTR 5-359 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 641
Comment ID: 13622
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 5.1.2.5 - Extra Services - Bullet #3, Archiving
Archiving slides is problematic due to shelf life. ASI does not recommend photographic archiving
without some specifications regarding format, resolution, etc. Further, there is no justification or rationale
for archiving presented - if it is to be done, there will be an associated cost, which should be justified.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13623
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 5.1.5.2 - Hardcopy Data Deliverables
" - If your PWS will store and maintain all sample results, rather than the
laboratory, then the original forms should be requested-. "
Original forms should stay at the laboratory. Copies could be sent if needed. If bench sheets etc are
requested on a monthly basis, the PWS should expect an additional charge from the lab.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13626
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 5.3.2 - Primary and Backup Laboratory Contracts
—you should plan to award a primary contract and a backup contract—
This recommendation appears to be confusing some PWSs. ASI has received Requests for Quotes that
include, as a term of the contract, asking that the primary laboratory establish a contingency relationship
with another laboratory to serve as a backup laboratory. We have several objections to this; (1) the
relationship should be between the PWS and the secondary laboratory directly rather than involving a -
middleman,- (2) establishing such a relationship in a competitive
bidding situation is problematic, and could lead to instances, or the appearance of, collusion, and (3)
lastly, it may not be feasible to arrange reliable backup laboratory status for every single sample, as none
of the major laboratories are likely to be willing to reserve such excess capacity without substantial
charges. More specifically, ASI will have capacity in excess of 500 samples per month - this may
represent several hundred clients (or more). It is impractical for ASI to prearrange a backup lab(s) for this
Comment Response for the LT2ESWTR 5-360 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
many samples. At a minimum, we recommend this section be re-worded to clarify the relationship
between the PWS and the secondary laboratory, and suggest the backup laboratory concept be
reconsidered entirely.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13627
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 5.4.1 The EPA should not direct PWSs to necessarily award contracts to
the lowest bidder. This section, and all similar references, should be re-written to read that "-the contract
should be awarded to the bidder of the utilities choice, as dictated by technical, purchasing and other
requirements as determined by the utility."
Response: EPA has deleted all references that seem to suggest using the lowest bid as the only criteria for
selecting a laboratory.
EPA Letter ID: 641
Comment ID: 13630
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 6.4
There are 2 sections labeled "Section 6.4" (See page 39)
Response: Thank you, the error has been corrected.
EPA Letter ID: 641
Comment ID: 13635
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Appendix A Checklist for Beginning Grandfathered Crypto Monitoring
In general, this is a helpful document and should be maintained.
Response: Thank you for your support, the checklist is in the final guidance.
Comment Response for the LT2ESWTR 5-361 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
EPA Letter ID: 641
Comment ID: 13637
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Method Version : Revise to indicate the June 2003 version of Method 1623.
Response: The current (2005) version is referenced in the guidance.
EPA Letter ID: 641
Comment ID: 13638
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Sample volume issues - The lab is not necessarily going to know whether a PWS-s
samples are likely to clog filters of require subsamples. If the PWS has not done any previous Cryptro
monitoring, EPA may want to suggest they consider performing one or more "test" sample(s).
Response: Thank you, EPA is advising water systems to practice sampling.
EPA Letter ID: 641
Comment ID: 13643
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Appendix D - Example Procedure for Collection Bulk Water Samples-
Section 1.0
Bullet #8 - Revise to "Ice or the equivalent number of ice packs sufficient to
maintain the sample within temperature acceptance criteria."
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13644
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 3.0 Packing the Sample
Item 3.4. ASI recommends that the Sample Collection Form be sealed inside a Ziploc baggie and placed
inside the cooler on top of all other materials. ASI also recommends that the EPA require the use of
waterprook ink for the completion of all forms.
Comment Response for the LT2ESWTR 5-362 December 2005
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Comment Codes 300-471
Response: Thank you, guidance now recommends ziploc baggies and waterproof ink.
EPA Letter ID: 641
Comment ID: 13645
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Appendix E: Example Field Filtering Protocol for Envirochek and Envirochek HV
(PWS guidance Manual (June 2003).
1.0 Materials list - Should be just -Materials- not -Required Materials.- Not everything on the list is
mandatory; a number of items are listed as -or equivalent- however others do not include this
designation. All materials should be listed -as equivalent— perhaps as an introduction statement to the
list.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13646
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 2.0 This section seems to only list -Envirochek- and not the -HV- version. Both
filters should be referenced throughout. Also, need to differentiate between instructions for Envirochek
and the HV - see below.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13647
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 2.1.4 The recommended flow rate for the HV should be changed. According to Rick
Jones (Pall Gelman) - The HV filter was validated at 4 LPM, not 2 LPM. This change will obviously
halve the flushing and sampling times. There is no reason to decrease the validated flow rate by 50%.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13648
Comment Response for the LT2ESWTR
5-363
December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 2.1.4 The recommendation for-high pressure (>20 psig)- sites incorporating a
pressure regulator may be appropriate for the Envirochek, but is unnecessary for the HV. According to
Rick Jones of Pall Gelman, the Envirochek is rated for 30 PSID and the Envirochek HV is rated for 60
PSID (not PSIG) and therefore in most situations the pressure regulator would be unnecessary. ASI
recommends that this be changed to >30 PSIG for Envirochek and >60 PSIG for Envirochek HV for
pressures in which the use of a pressure regulator would be recommended.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13649
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 2.1.4. Continued - This section does not give recommended pressure to set outlet
of pressure regulator to if using Envirochek. The standard Envirochek the pressure limit is 30 PSID;
therefore an inlet pressure of 30 PSIG would be very conservative and this section should include that
reference.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13650
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 2.1.4 Continued - communication with Pall-Gelman on 1/7/04 indicates that the
acceptable working pressure for the Envirochek or Envirochek HV is 100 PSIG with a maximum of 60
PSID. ASI recommends that EPA communicate with Pall-Gelman to confirm this pressure and include
the correct manufacturer-s specifications in this guidance document. Assuming it is 100 PSIG with a 60
PSID tolerance for the HV, then most sites that are pressurized up to 100 PSIG would not require the use
of a pressure regulator.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13651
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment Response for the LT2ESWTR 5-364 December 2005
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Chapter 5: Filtered System Monitoring Requirements Comment Codes 300-471
Comment: 2.1.4 Continued - Sample System for Sites <20 PSIG - The recommendation to use a
sampling setup without a pump on sites substantially less than 20 PSIG should be changed. Although it
may be possible, in most cases it will be impractical or undesirable. For example, depending on the
sampling system components used, the backpressure of the components may be such that a supply
pressure of less than 20 PSIG is insufficient to provide acceptable flow rates. More importantly, low
pressure can result in the unnecessary use of 2 filters to collect the required 10L minimum volume. ASI
recommends that determination of appropriate sampling
system (with or without pump) be determined by the utility and/or laboratory.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13652
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 2.1.6 -Allow at least 20L to flush the system— Using a standard unit, with a
new piece of inlet hose, there is nothing to flush except the tap itself (the rest of the unit is downstream of
the filter). Flushing is always a good idea, but we propose 20L be a recommendation rather than a
requirement.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13653
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 2.1.6.1 Statement regarding setting regulator to 30 PSI or 60 PSI is obsolete if
using HV and site is less than 60 PSI.
Response: See Response 471.
EPA Letter ID: 641
Comment ID: 13654
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: General - use of a flow totalizer is recommendedby EPA. However, no recommendation or
requirement for accuracy checks on that device are included. If such a device is used, it should be a
requirement that the accuracy of that totalizing device is checked prior to each sampling event using a
stopwatch and calibrated vessel. EPA should place limits on the acceptable deviations in the accuracy of
the device.
Comment Response for the LT2ESWTR 5-365 December 2005
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Response: See Response 471.
EPA Letter ID: 678
Comment ID: 14732
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: VI. Comments on Draft Source Water Monitoring Guidance Manual for LT2 Rule
1. Source Water Monitoring Guidance Manual, June 2003 Draft
a. Section 5.1.3, 3rd paragraph, p. 26:
Last line must read - -to establish a schedule that is will comply with LT2 rule—.
b. Section 6.2.2, 4th paragraph, p. 37:
Substitute -2 oocysts/L- for -1 oocyst/L- in the equation.
c. Section 6.4.1, p. 40
Requested analysis should be a required data element during sample collection. Sample collection (start
and end) time should also be required as it is important for the holding time requirement of the method.
e. Section 6.4.5, 4th paragraph, p. 46
The procedure refers to receipt of samples at <10° and not frozen, and rejection of samples received at
>10°C or frozen. It does not address samples that are at 10°C. If these are acceptable or not, then it should
be stated as such.
f Section 6.4.5, 5th paragraph, p. 47
Since stick-on temperature strips are not as precise as the other options, perhaps its use should be
eliminated. Incorrect temperature readings may cause a sample to be rejected by the laboratory, resulting
in wasted material, time and effort in collecting the sample.
g. Section 7.5.3.1, p. 55
Determining the Volume of Resuspended Concentrate to Use for Packed Pellets >0.5 mL
(Insert bolded value.)
2. Appendix SWM-B: Checklist for Submitting Grandfathered Cryptosporidium Data
The checklist specifies sample temperature requirements as between 0°C and 8°C upon receipt.
Temperature requirements must be consistent throughout the documents, e.g. -at <10°C and not frozen-.
3. Appendix SWM-G: Example Procedure for Source Water Samples for E. coli Analysis
The required materials should include a temperature measuring device or thermometer so that the sample
temperature can be measured in the field and during transport.
4. Appendix SWM-I: Analytical Method for Turbidity Measurement, GLI Method 2
a. Section 3.1, Line 1, p. 1 One of the choices for sample containers is a -soft-glass container-.
This needs to be either explained or deleted.
b. Section 3.1, Line 2, p. 1
The sample is required to be refrigerated or iced to 4°C - it may be more realistic to have a range of
Comment Response for the LT2ESWTR 5-366 December 2005
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transport/storage temperature, e.g. 1-4°C, instead of an exact value.
5. Appendix SWM-J: Analytical Method for Turbidity Measurement, Method 180.1
a. Section 3.1, Line 1, p. 1 (referto 4.a. above)
b. Section 3.1, Line 2, p. 1 (referto 4.b. above)
Response: See Response 471.
EPA Letter ID: 710
Comment ID: 14813
Commenter: Kemon Papacosta, ASTM Member D19, ASTM
Commenter Category: Unknown
Comment: Regarding the source water monitoring Guidance Manual For Public Water Systems
for the Long Term 2 Enhanced Surface Water Treatment (LT2 Rule)
June, 2003 Draft
Section 6.4.4.2. General Quality Control For Turbidity Measurements
0 It states -AMCO-AEPA-1 (available from Advanced Polymer Systems)- is an acceptable primary
standard.
0 AMCO-AEPA-1 name has been changed to AMCO CLEAR-. It is now manufactured by
GFS Chemicals, in Columbus, Ohio.
Appendix J Method 180.1 - Section 2.1.2. and 6.5
0 The same name and manufacturer changes apply: AMCO CLEAR-, GFS Chemicals,
Columbus, Ohio.
Response: See Response 471.
Comment Response for the LT2ESWTR 5-367 December 2005
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6. Filtered System Treatment Requirements: Comment
Codes 500-560
6.1 Comment Code 500, Filtered System Treatment Requirements
Response to Code 500
a. Bacteriological testing is not an appropriate indicator for the risk from Cryptosporidium in finished
water. Bacteria are highly susceptible to chlorine disinfection, while Cryptosporidium is highly resistant
to chlorine. Thus, a system could have infectious Cryptosporidium in its treated water even if testing
shows that bacteria have been adequately disinfected.
b. As discussed in the preamble and Economic Analysis for the LT2ESWTR, EPA has considered
epidemiologic evidence of cryptosporidiosis occurrence. EPA does not believe that available
epidemiologic data provide an appropriate basis for estimating the risk associated with Cryptosporidiom
in drinking water because most cases of illness are not reported. However, the limited available data are
generally consistent with EPA's risk estimates for the LT2ESWTR. As cited in the Economic Analysis,
researchers from the Centers for Disease Control (Mead et al., 1998) estimated 270,000 cases of
waterborne cryptosporidiosis annually resulting in a physician visit. Data from the 1993 Milwaukee
outbreak suggest that approximately 12 percent of people with cryptosporidiosis see a physician. When
applied to the Mead et al. estimate, this figure results in a projection of approximately 2,250,000 total
waterborne cryptosporidiosis cases annually. While waterborne cases include cases due to sources other
than drinking water (e.g., swimming), this total number significantly exceeds the number of
cryptosporidiosis cases EPA has estimated due to drinking water (range from 89,375-1,459,126).
Similarly, EPA does not believe that the absence of documented illness is a particular community
attributed to Cryptosporidium from drinking water indicates that the requirements of the LT2ESWTR are
unnecessary for that community. As discussed in the preambles to the proposed LT2ESWTR and today's
final rule, most cryptosporidiosis cases are undiagnosed. Most persons with cryptosporidiosis do not visit
a physician. Among those that do, diagnostic tests for Cryptosporidium may not be ordered or, if
conducted, may not detect Cryptosporidium when it is present. If Cryptosporidium is detected, it may not
be attributed to a specific source like drinking water and, finally, may not be reported. Consequently, EPA
believes that PWSs should conduct the source water monitoring the LT2ESWTR requires to determine
what, if any, level of additional treatment for Cryptosporidium is necessary.
c. EPA has carefully considered the requirements of today's final rule in regard to the estimated risk
associated with Cryptosporidium in drinking water and the benefits and costs of reducing this risk. The
Agency believes that these requirements, which reflect recommendations from the Stage 2 M-DBP
Advisory Committee, are appropriate to reduce risk from Cryptosporidium in vulnerable systems. In light
of the risk assessment, these requirements are consistent with the Agency's mandate under the Safe
Drinking Water Act.
d. EPA believes that the best available data indicate that in general, the risk of Cryptosporidium in a
system's treated drinking water relates to the level of Cryptosporidium in the source. As described in the
preamble to the proposed rule, studies have shown that the degree of Cryptosporidium removal a filtration
plant can achieve is limited. Further, studies have not shown that the removal efficiency increases with
higher Cryptosporidium concentrations in the source for the levels of Cryptosporidium that occur in
natural waters. Consequently, EPA believes, consistent with the Advisory Committee's
recommendations, that systems with higher levels of Cryptosporidium in their sources should provide a
Comment Response for LT2ESWTR 6-1 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
higher degree of treatment. Today's rule requires this.
The findings of Aboytes and LeChevallier (2003), which the commenter cites, reflect a very small amount
of data. Specifically, Cryptosporidium oocysts were found in a total of 24 finished-water samples from 22
sources and no corresponding source water data were collected. EPA does not believe these data are
sufficient to indicate a significant finding respecting the relationship between source water and finished
water Cryptosporidium levels.
e. EPA agrees that if analytical methods with adequate sensitivity were available, finished water
monitoring would be a more direct indicator than source water monitoring of risk from Cryptosporidium
in drinking water. However, as stated in the preamble, EPA has concluded determining the level of
Cryptosporidium in finished drinking water for the purpose of compliance with a drinking water standard
is not currently economically or technologically feasible for systems. The LT2ESWTR is designed to
protect public health by lowering the level of infectious Cryptosporidium in finished drinking water to
less than 1 oocyst/10,000 L. Approved Cryptosporidium analytical methods are not sufficient to routinely
determine the level of Cryptosporidium at this concentration. EPA may consider finished water
Cryptosporidium monitoring in the future if improvements in analytical methods make this feasible.
f While the sample collection and laboratory procedures for source water monitoring are not perfect, as
the comment notes, EPA's analysis indicates that they are sufficient to classify filtered systems into the
different treatment bins. As discussed in the preamble to the proposed rule, the Agency made this analysis
using the performance of the required analytical methods for Cryptosporidium (EPA Methods 1622 or
1623) in the ICR Supplemental Surveys. Because this survey involved source water monitoring under
conditions nearly identical to those required in the LT2ESWTR, EPA believes that the results are
indicative of the performance that will occur under today's final rule. EPA considered the statistical
likelihood of an oocyst present in a water source being counted by an analyst, along with factors like false
positives and negatives. The potential for bin misclassification was assessed for systems with different
source water Cryptosporidium levels. The results of this analysis show that the monitoring required under
today's final rule can achieve relatively low misclassification rates for systems with source water
Cryptosporidium levels at least 0.5-log above or below a bin boundary, including Bins 1 and 2.
Because bin classification is based on mean Cryptosporidium levels from at least 12 samples, rather than
a single sample, the method detection limit for a single sample does not indicate a concentration limit for
bin determination.
g. EPA believes that requiring treatment plants in Bins 3 or 4 to achieve at least 1-log of the additional
treatment requirement using UV, ozone, chlorine dioxide, membranes, bag filters, cartridge filters, or
bank filtration is appropriate. These processes will serve as significant additional treatment barriers for
systems with the highest levels of pathogens in their sources. Further, this requirement reflects a
recommendation by the M-DBP Advisory Committee. EPA notes that Bins 3 and 4 will require
conventional filtration systems to achieve 2.0 and 2.5-log additional treatment, respectively. Thus,
systems in these bins can use options like watershed control programs or improved treatment performance
to achieve the remaining treatment requirement for the bin, as the commenter recommends.
h. The source water monitoring requirements in today's final rule reflect EPA's assessment of the
minimum necessary to appropriately classify systems into different treatment bins. Systems may meet
these monitoring requirements through grandfathering equivalent data collected prior to the required start
date for monitoring. Available information does not support the use of other data types for bin
classification since such data may not provide a quantitative assessment of the mean source water
Cryptosporidium level. This includes source water assessments, other than Cryptosporidium monitoring
or the E. coli monitoring for small filtered systems.
Comment Response for the LT2ESWTR 6-2 December 2005
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i. Procedures for averaging Cryptosporidium concentrations to determine treatment requirements reflect
recommendations of the M-DBP Advisory Committee. The differences in calculation procedures that the
commenter notes are based either on different treatment requirements (filtered vs. unfiltered systems) or
different sampling programs among filtered systems.
Unfiltered systems use a different calculation procedure than filtered systems because the bin
classification for filtered systems does not apply to unfiltered systems. Among filtered systems, the
calculation differs depending on the sampling frequency and duration. As described in the preamble to the
proposed rule, if a system collects monthly samples over 24 months, the maximum running annual
average is used to determine bin classification in order to achieve a low false negative rate. However, if a
system collects samples twice-per-month over 24 months, a low false negative rate can be achieved by
averaging all samples. Small systems may complete their Cryptosporidium monitoring in one year. In this
case, the system must average all samples collected over the year of monitoring to determine an annual
average. EPA believes that all these calculation procedures are amenable to automated compliance
determinations, as the commenter recommends.
j. As discussed in the preamble to the proposed rule, EPA believes that the mean Cryptosporidium level in
a system's source water is the appropriate metric to determine the need for additional treatment
requirements. Available data suggest that the mean concentration directly relates to the average risk of the
exposed population (i.e., drinking water consumers). Further, with a limited number of samples, the mean
can be estimated more accurately than a high result, such as a 90th percentile estimate, as the commenter
recommends.
For this reason, today's rule requires monitoring to be conducted according to a predetermined schedule.
EPA recognizes that Cryptosporidium levels will vary seasonally and in response to weather events like
storms. The Agency considered this variability when assessing the performance of the required
monitoring for bin classification. Sampling on a predetermined schedule will capture periods when
Cryptosporidium levels are higher and lower and provide the best representation of the mean. In contrast,
altering a schedule to collect samples during a storm when Cryptosporidium levels are expected to be
high, as a commenter recommends, would lead to an overestimate of the mean. Similarly, classifying
systems in a higher bin if their sampling doesn't include any significant storm events would not achieve
the goal of basing bin classification on the mean source water Cryptosporidium level.
k. Source water monitoring requirements in the LT2ESWTR are intended to determine an appropriate
Cryptosporidium treatment level for plants using surface water sources, based on bin classification. For
plants using multiple sources, the bin classification should reflect the aggregate source water quality
entering the plant - bin classification does not apply to individual sources, as the commenter suggests.
Thus, plants using multiple sources must sample a blended tap, where available. Otherwise, plants must
manually aggregate individual sources into a blended sample for analysis, or must have samples analyzed
separately and average the results. These procedures will capture the aggregate water quality entering the
plant on the sampling date, which is the intended basis for bin classification under the LT2ESWTR.
1. As the commenter recommends, today's rule specifies how to determine bin classification with samples
results in which no oocysts are detected (i.e., below the method detection limit for a single sample) and
for plants that do not operate continuously (e.g., seasonal plants).
m. Today's rule specifies a second round of monitoring to reclassify systems in treatment bins six years
after initial bin classification. This second round of monitoring should capture significant improvements
or degradation in source water quality that would warrant a change in treatment requirements.
Comment Response for the LT2ESWTR 6-3 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA does not believe that a provision for bin reclassification on an earlier timeframe is appropriate or
practical. For most systems, two years of source water monitoring are required for bin classification. After
initial bin classification, systems have three years to comply with any additional treatment requirements.
If systems could be reclassified in a bin at any point, some systems would be unlikely to comply with the
treatment requirements associated with their initial bin classification. Instead, such systems would
continue monitoring in the hope of achieving a lower bin classification. This would not achieve the public
health protection intended with today's final rule.
n. Today's final rule allows systems to determine bin classification where the sampling frequency varies
by first calculating monthly averages, as the commenter recommends. Because systems must determine
their sampling schedule in advance, systems cannot change their sampling frequency during monitoring
under today's rule. However, EPA will allow systems to grandfather data sets where the sampling
frequency varies if the State approves. EPA is making this allowance because systems may not have been
aware of the requirements in today's final rule when collecting data for grandfathering and these data may
still provide an appropriate basis for bin classification.
o. Under today's rule, approved laboratories must analyze Cryptosporidium and E. coli samples. EPA
believes this provision will ensure that laboratories analyze samples using appropriate techniques and
achieve the accuracy necessary for bin classification in today's final rule.
p. EPA recognizes that source water Cryptosporidium levels may vary in response to changing climate
conditions. Today's rule requires large systems to monitor for Cryptosporidium over two years and
requires small systems to monitor for one or two years. Thus, this monitoring will capture season
variability for all systems and some degree of annual variability for systems that monitor over two years.
EPA believes that these monitoring timeframes are an appropriate balance between the need to monitor
over a long time to capture variability and the need to quickly identify systems with high source water
Cryptosporidium levels in order to provide additional public health protection.
q. Systems must sample according to a schedule they submit prior to initiating monitoring and they must
then report results for all sample dates on their schedule. Thus, a system could not schedule 48 or more
samples and report results for only 24. However, a system could collect samples on days in addition to its
scheduled sampling dates and not report these results.
r. Today's rule requires small filtered systems to calculate the mean of all E. coli samples collected over
one year of monitoring to determine if Cryptosporidium monitoring is required. Calculating the mean
simply refers to determining the average value of all samples collected during the monitoring period.
Systems must sample at least once every two weeks and may sample more frequently if sampling is
evenly spaced over the monitoring period. Thus, calculating individual weekly or monthly averages is
unnecessary. Source water monitoring guidance available with today's final rule provides direction to
small systems on E. coli monitoring.
s. EPA recognizes the seasonal effects on Cryptosporidium occurrence the commenter notes. In today's
final rule, bin classification for small systems that monitor for only one year is based on the average of
samples collected over the entire year, rather than just six months as in the proposal.
t. Today's final rule requires systems to calculate a bin concentration based on their source water
monitoring results, determine their bin classification, and report these values to the primacy agency for
approval. Thus, today's rule requires the system, and not the state or EPA, to determine the bin
classification, but the primacy agency must approve the result. EPA believes that this approach is
appropriate because systems will have access to their monitoring results and will benefit by understanding
how their source water quality affects their treatment requirements. EPA will provide guidance to systems
Comment Response for the LT2ESWTR 6-4 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
on determining the bin concentration. Because the bin determination significantly affects treatment
requirements and the resulting level of public health protection, States should review the bin
determination to ensure it was made correctly. Where States have primacy, systems will report this
information to the State. Where States do not have primacy, EPA will work with States on
implementation roles.
u. In today's final rule, EPA has modified the implementation schedule from the one in the proposal to
push back the monitoring start date by six months for systems serving 50,000 to 99,999 people and by 18
months for systems serving 10,000 to 49,999 people. EPA expects that this revised schedule will provide
more time for these systems to prepare for monitoring and for States to participate in overseeing this
monitoring.
v. Today's final rule does not reduce log treatment credits for systems that recycle filter backwash.
w. Today's final rule awards 3.0-log credit for slow sand filtration when used as a stand-alone process
and 2.5-log credit as a toolbox add-on. The preambles to the proposed LT2ESWTR and today's final rule
describe the basis for these credits. Under the Demonstration of Performance option in the microbial
toolbox of the LT2ESWTR, States may approve higher treatment credit where supported by site-specific
studies.
x. Today's rule awards a 3-log credit to single stage lime softening, equivalent to a conventional filtration
treatment plant, and 3.5-log credit to two-state softening, provided chemical additional and hardness
precipitation occur in each stage. The preambles to the proposed LT2ESWTR and today's final rule
describe the basis for these credits. Under the Demonstration of Performance option in the microbial
toolbox of the LT2ESWTR, States may approve higher treatment credit where supported by site-specific
studies.
y. The LT2ESWTR does not establish new treatment requirements for Giardia, with the exception of
systems using uncovered finished water reservoirs (which must provide the inactivation currently required
of unfiltered systems). Consequently, today's rule does not specify pretreatment or other removal credits
for Giardia. Rather, States should continue to make decisions regarding removal credits for compliance
with Giardia treatment requirements under the SWTR. However, as discussed in the preamble to the
proposal, studies have shown that Giardia and Cryptosporidium behave similarly in many physical
removal processes (e.g., sedimentation and granular media filtration). Thus, States may choose to
consider the Cryptosporidium removal credits established in today's rule when assessing Giardia removal
credits.
z. Today's rule does not modify the requirement of the IESWTR and LT1ESWTR for large and small
systems, respectively, to achieve 2-log Cryptosporidium removal. EPA continues to believe that this
standard is important for public health protection. It requires water systems to ensure that their filtration
systems achieve at least a minimal level of performance to remove pathogenic microorganisms and
particulate matter that could interfere with subsequent disinfection.
As discussed in the preamble, EPA agrees that UV light represents a valuable new tool for protecting
against Cryptosporidium and certain other pathogens. However, EPA does not believe that UV is an
effective substitute for a well-performing filtration process for several reasons: (1) Studies show that UV
is relatively less effective against certain microorganisms for reasons that are unclear, whereas filtration
generally is effective against a broad spectrum of microorganisms; (2) the effectiveness of UV against
pathogens attached to or entrained within particles is unknown, whereas filtration is generally effective at
removing such particles and associated pathogens; and (3) particulate matter can interfere with the
effectiveness of UV if not removed by filtration first. For these reasons, EPA agrees with the focus of the
Comment Response for the LT2ESWTR 6-5 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
comment on multiple barriers of protection, but regards a well-performing filtration system, as required
by the IESWTR and LT1ESWTR, as a critical barrier in such a scheme.
Available data indicate that certain bag and cartridge filters, which are typically feasible for small
systems, can achieve 2-log or greater Cryptosporidium removal when used in series.
aa. Thank you for identifying this error in the proposed rule. Where applicable, EPA has made this
correction in today's final rule.
bb. The requirements of today's rule apply to public water systems. The use of "systems" is an
abbreviation for public water systems.
Individual Comments on Code 500
EPA Letter ID: 429
Comment ID: 10591
Commenter: Janet Montz, Environmental Specialist, OCI Wyoming, L.P.
Commenter Category: Regulated Community (Utilities)
Comment: 4 - If monthly bacteriological testing has shown no problems, isn't this sufficient along with
log treatment credit? 5.5 log seems a bit overkill.
Response: See Response 500.a.
EPA Letter ID: 504
Comment ID: 11354
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 300 II. Filtered System Monitoring Requirements
(parameters, frequency, location)
Comment: The consequence of the benefit overestimation is distortion of priorities for regulators and
utilities and misinformation to the public. It also calls into question the fundamental need for such a
stringent regulation.
We suggest that EPA reexamine the model and assumptions used to develop benefit estimates and
rationalize the model results with epidemiologic evidence of cryptosporidiosis occurrence. Following
reassessment of benefits we suggest that EPA should reconsider the full range of proposed rule
requirements.
Response: See Response 300(A).
Comment Response for the LT2ESWTR 6-6 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
6.2 Comment Code 510, Microbial Framework Approach
Individual Comments on Code 510
EPA Letter ID: 463
Comment ID: 11032
Commenter: Richard Wilson, Environmental Services Manager, Anaheim Public Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment: 5. General comment on the Microbial Toolbox
The rule should acknowledge that, per the FACA discussions, the purpose of the microbial toolbox is to
provide options for overall risk reduction for various treatment techniques. It appears that the rule is
focused on log removal of Cryptosporidium, which in turn may force the use of UV disinfection rather
than allow utilities to employ a variety of risk reduction techniques.
Response: See Response lOO.t.
EPA Letter ID: 466
Comment ID: 11007
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: byproducts (DBPs). ND concurs with the riskbased approach proposed under the
LT2ESWTR in which surface water systems monitor for microbial contaminants and only those systems
finding higher levels of contaminants are required to provide additional protection against
Cryptosporidium. However, the EPA requirement for
Response: See Response lOO.a.
EPA Letter ID: 470
Comment ID: 11061
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: The risk-based approach proposed under this rule appears to be an appropriate
method for addressing concerns relating to microbial contaminants and Cryptosporidium. The use of the
microbial toolbox appears to give systems the necessary flexibility to address the potential health effects.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 6-7 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA Letter ID: 520
Comment ID: 11613
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 300 II. Filtered System Monitoring Requirements
(parameters, frequency, location); 320 B. Small System Monitoring Requirements
Comment: IEPA concurs with the risk-based approach proposed under the LT2ESWTR in which
surface water systems monitor for microbial contaminants and only those systems finding higher levels of
contaminants are required to provide additional protection against Cryptosporidium. This includes the
proposed requirement for large systems to perform Cryptosporidium monitoring to determine risk from
microbial contamination as well as the proposed requirement for small systems to perform indicator
monitoring to determine the need to perform Cryptosporidium
monitoring. Additional IEPA comments on the overall approach are included in the above.
Response: See response 100.a.
EPA Letter ID: 562
Comment ID: 12336
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
3.2.1 Maintaining a Balanced Approach to Treatment
For microbial pathogens, the Stage 2 M/DBP FACA recognized that systems with poor quality source
waters might need to provide additional protection against Cryptosporidium. This concept is captured in
the overall regulatory framework for the LT2ESWTR. The FACA also provided guidance about
appropriate
Response: See Response lOO.a.
EPA Letter ID: 585
Comment ID: 11956
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: The TCEQ supports the proposal to incrementally increase the treatment requirements for
Subpart H systems based on the results of source water Cryptosporidum monitoring. This regulatory
approach provides additional levels of public health protection for consumers, especially those sensitive
individuals such as infants, the elderly, and persons with compromised immune systems.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 6-8 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA Letter ID: 595
Comment ID: 12579
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Section IV.A Additional Cryptosporidium Treatment Technique Requirements for
Filtered Systems (pages 47665-47679)
Maine concurs with the risk-based approach proposed under the LT2ESWTR in which surface water
systems monitor for microbial contaminants and only those systems finding higher levels of contaminants
are required to provide additional protection against Cryptosporidium
Response: See Response lOO.a.
EPA Letter ID: 601
Comment ID: 12998
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 100 General Comments
Comment: Utah supports EPA's efforts to increase public health protection by concurrently addressing
risks from microbial contaminants and disinfection byproducts (DBPs) and concur with the risk-based
approach proposed under the LT2ESWTR in which surface water systems monitor for microbial
contaminants and only those systems finding higher levels of contaminants are required to provide
additional protection against Cryptosporidium.
Response: See Response lOO.a.
EPA Letter ID: 601
Comment ID: 13000
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Comments on additional Cryptosporidium treatment technique requirements for
filtered water systems.
Utah concurs with the risk-based approach proposed under the LT2ESWTR in which surface water
systems monitor for microbial contaminants and only those systems finding higher levels of contaminants
are required to provide additional protection against Cryptosporidium. This includes the proposed
requirement for
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 6-9 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA Letter ID: 617
Comment ID: 13254
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: Of particular significance we support the identified risk approach to regulatory
standards that recognizes certain supplies to be at higher risk than others. We
Response: See Response lOO.a.
EPA Letter ID: 662
Comment ID: 14023
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: A. 1. What is the EPA Proposing Today?
(pages 47665-47679)
Comment on additional Cryptosporidium treatment technique requirements for filtered water systems.
Salt Lake City agrees that the risk based approach in LT2ESWTR in which surface water systems monitor
for microbial contamination, and only those systems with higher levels of Cryptosporidium are required
to provide additional treatment.
Response: See Response lOO.a.
EPA Letter ID: 673
Comment ID: 13974
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: A. 1. What is the EPA Proposing Today?
(pages 47665-47679)
Jordan Valley Water comment on additional Cryptosporidium treatment technique requirements for
filtered water systems.
Jordan Valley Water agrees with the risk-based approach proposed for LT2ESWTR in which surface
water systems monitor for microbial contamination, and only those systems with higher levels of
Cryptosporidium are required to provide additional treatment. In addition, Jordan Valley Water supports
EPA-s combination of the Stage 2 D/DBPR with LT2ESWTR as essential to creating a balanced
approached between DBP control and microbial risk.
Comment Response for the LT2ESWTR 6-10 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Response: See Response lOO.a.
EPA Letter ID: 707
Comment ID: 14816
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: Kentucky agrees with the risk-based approach proposed under the LT2ESWTR in
which surface water systems monitor for microbial contaminants and only those systems finding higher
levels of contaminants provide additional protection against Cryptosporidium. Kentucky also agrees with
the Stage 2 DBPR premise
Response: See Response lOO.a.
6.3 Comment Code 520, Bin Concentration Ranges and Treatment
Requirements
Individual Comments on Code 520
EPA Letter ID: 417
Comment ID: 10525
Commenter: Kenneth Brown, Authority Manager, Stroudsburg Municipal Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: The Bin 4 issue is of concern because it is unclear how a utility could successfully convince
the regulatory agencies of the value of its Source Water Protection efforts, Partnership for Safe Water
efforts, etc. versus the need to just go and spend money on a UV system (estimated cost for the
Stroudsburg Municipal Authority is over $500,000 and $28,000 O + M costs/year).
Response: See Response lOO.t.
EPA Letter ID: 441
Comment ID: 10770
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Analytical methods / Treatment requirements for filtered systems
LT2 requires water suppliers using surface water sources to monitor for Cryptosporidium in the source.
Currently, the sample collection and laboratory procedures are not yet perfected. Thus, the current
methods may not accurately reflect Cryptosporidium occurrence and concentrations.
Nieminski and Bellamy ("Application of Surrogates to Improve Treatment Plant Performance," AWWA
Research Foundation, 2000) conducted a study at 23 surface water treatment plants and one unfiltered
Comment Response for the LT2ESWTR 6-11 December 2005
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Chapter 6: Filtered System Treatment Requirements
Comment Codes 500-560
source in the United States and Canada. Their research concluded, "all of the statistical analyses of the
data collected indicated that...it is effectively impossible to precisely measure the occurrence of Giardia
and Cryptosporidium."
DEP has four concerns about the use of Cryptosporidium and E. coli concentrations to establish LT2
requirements for water systems:
* The higher Cryptosporidium concentrations (i.e., in Bins 3 and 4) require at least 1 log of additional
treatment using bag filters, bank filtration, cartridge filters, chlorine dioxide, membranes, ozone, and/or
UV. Because the Cryptosporidium analytical methods are imprecise,
DEP believes that water suppliers should have the flexibility to meet the Bin requirements using any of
the toolbox options. This approach would provide incentives to also develop a watershed control program
or improve treatment performance in lieu of a single requirement to install new
technologies.
Response: See Responses 500.f and SOO.g.
EPA Letter ID: 457
Comment ID: 11893
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Bin Determinations
We support the use of four bins for classifying filtered water systems. We do not have data that suggests
different average Cryptosporidium concentrations for determining bin breakpoints or data to suggest
different additional treatment requirements (e.g., the additional level of Cryptosporidium protection
required for each bin).
Response: See Response lOO.a.
EPA Letter ID: 466
Comment ID: 11020
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: We support the use of four bins for classifying filtered water system. We
Response: See Response lOO.a.
EPA Letter ID: 504
Comment ID: 11347
Comment Response for the LT2ESWTR
6-12
December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: 3. The analytical method available for Cryptosporidium concentration measurement
is far from perfect with many poorly appreciated and significant consequences for individual utilities as it
will be applied. We strongly urge EPA to review application of required monitoring particularly to
discriminating between BIN 1 and BIN 2 concentrations that are largely below the method-s (1622/23)
limit of detection.
Response: See Response SOO.f
EPA Letter ID: 504
Comment ID: 11360
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: Once basic parameters of the rule have been established (BIN concentration
thresholds), the statistical distribution of Cryptosporidium concentrations in the water from a given source
at a specific sampling point is of overriding importance to an individual utility.
The BIN concentration thresholds drive a utility-s concern. For example, if a utility finds 8 oocysts over
12 consecutive samples the running average concentration is 0.067 oocysts/L and the source would be in
BIN 1. If 9 oocysts were found instead, the concentration would be 0.075 oocysts/L and the source would
be classified as BIN 2. However, the limit of detection of method 1622/23, calculated at a recovery
efficiency of 40% using a 10 L sample, is 1 oocyst in 4 L or 0.25 oocysts/L. Thus, it is likely that only the
nonuniform statistical distribution of oocysts in water, particularly at the low end of the concentration
spectrum, will result in any detection below the theoretical limit of detection. This implies that chance
alone will determine the BIN
classification for a proportion of affected utilities. We argue that this is unsupportable and unreasonable.
The importance of the statistical distribution of Cryptosporidium in water at an individual source appears
not to have been taken into account by EPA in formulating important features of the proposed rule. We
suggest that EPA carefully analyze this aspect of preceding (ICR and ICRSS) data and consider possible
adjustments to BIN threshold and monitoring requirements that may
be appropriate to account for this problem.
Response: See Response 500.f
EPA Letter ID: 520
Comment ID: 11583
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Bin Determinations
Comment Response for the LT2ESWTR 6-13 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
IEPA supports the use of four bins for classifying filtered water systems. IEPA does not have data that
suggests different average Cryptosporidium concentrations for determining bin breakpoints or data to
suggest different additional treatment requirements (e.g., the additional level of Cryptosporidium
protection required for each bin).
Response: See Response lOO.a.
EPA Letter ID: 521
Comment ID: 11760
Commenter: Leslie Rush,, Dalton Utilities
Commenter Category: Regulated Community (Utilities)
Comment: We believe that sound engineering data should be the basis for determining the
bin classification and treatment required for Cryptosporidium removal.
Response: See Response lOO.b.
EPA Letter ID: 536
Comment ID: 11793
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Bin Determinations
Colorado does not have data that suggests different average Cryptosporidium concentrations for
determining bin breakpoints or data to suggest different additional treatment requirements (e.g., the
additional level of Cryptosporidium protection required for each bin).
Response: See Response lOO.a.
EPA Letter ID: 562
Comment ID: 12335
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: reflected in the proposed rule. The bin structure recommended by the FACA
constitutes a sound basis for final promulgation of LT2ESWTR. AWWA anticipates that future research
on Cryptosporidium occurrence and infectivity will inform EPA and the water community whether
restructuring the bins is necessary in a future rulemaking.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 6-14 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA Letter ID: 601
Comment ID: 13012
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah supports the issue of allowing systems to be classified in a bin based on
available data the system has collected.
Response: See Response SOO.h.
EPA Letter ID: 621
Comment ID: 13164
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Other EPA Comment Codes and Descriptions: 100 General Comments; 710 A. Microbial Toolbox
General Comments
Comment: Data on Log Removal of Cryptosporidium and Removal Credits
I support your approach in controlling Cryptosporidium, your requirements according to source water bin
classification, and your log removal credits. For
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12733
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Bin Determinations
States support the use of four bins for classifying filtered water systems. States do not have data that
suggests different average Cryptosporidium concentrations for determining bin breakpoints or data to
suggest different additional treatment requirements (e.g., the additional level of Cryptosporidium
protection required for each bin).
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 6-15 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA Letter ID: 647
Comment ID: 12891
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Bin Determinations
The use of four bins for classifying filtered water systems is appropriate. We do not have data that
suggests different average Cryptosporidium concentrations for determining bin breakpoints or data to
suggest different additional treatment requirements (e.g., the additional level of Cryptosporidium
protection required for each bin).
Response: See Response lOO.a.
EPA Letter ID: 668
Comment ID: 13885
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: Overall, while obviously we would have preferred a stronger rule, NRDC supports
the Agreement, and the proposal-s requirement for inactivation of Cryptosporidium by filtered surface
water systems that are categorized as higher risk based upon their source water Crypto levels placing
them in -Bin- 2, 3, or 4. We also strongly support requiring that unfiltered surface water systems
Response: See Responses lOO.aand SOO.g.
6.4 Comment Code 530, Procedures for Calculating Bin
Classification
Individual Comments on Code 530
EPA Letter ID: 441
Comment ID: 10775
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Bin classification—calculating average Cryptosporidium concentrations
Cryptosporidium treatment requirements are determined by the average Cryptosporidium concentration
observed during source water monitoring. EPA proposes to compute the average value differently, based
on system type and the number of samples collected. To simplify automated compliance determinations,
all systems should use the same method to compute the average concentration.
Response: See Response SOO.i.
Comment Response for the LT2ESWTR 6-16 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA Letter ID: 509
Comment ID: 11482
Commenter: Greg Parker,, Florida Department of Environmental Protection Drinking Water Program
Commenter Category: State/Tribe Government
Comment: 141.709 Consider the use of the high results to determine Bin Classification
rather than averaging all the results. Crypto problems develop often as a result of relatively rare events.
Average conditions may mask the risks that should be controlled.
Response: See Response 500.J.
EPA Letter ID: 595
Comment ID: 12586
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Source water type classification for systems that use multiple sources
Maine believes that each source should be evaluated independently and assigned a bin classification based
on individual monitoring of that source. The State should have the flexibility to determine monitoring
requirements for blended sources on a case-by-case basis.
Response: See Response 500.k.
EPA Letter ID: 601
Comment ID: 13008
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 560 F. Guidance
Comment: Utah recommends that instructions on calculating the RAA for bin classification
be included in the rule as well as the guidance manual. This should include how to handle results that are
below the detection limits, and non-continuous data due to plants that may not operate continuously.
Response: See Response 500.1.
EPA Letter ID: 601
Comment ID: 13019
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Comment Response for the LT2ESWTR 6-17 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Also, a provision should be included in the proposed rule to allow a water system to request
consideration for bin reclassification by the State if significant improvements in water quality can be
demonstrated.
Response: See Response 500.ni.
EPA Letter ID: 637
Comment ID: 13080
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: Language needs to be included in the rule (not just the guidance manual) that
makes it clear that non-detects are to be treated as zeros for the purposes of calculating compliance
averages.
Clarification is needed on how to handle seasonal sources in the average calculations. We have several
sources in the West that are only used or available for certain parts of the year, therefore uninterrupted
sampling is not possible.
Response: See Response 500.1.
EPA Letter ID: 641
Comment ID: 13586
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: A simple mechanism to handle these situations would be to add the following
wording to the bin classification system:
-Any PWS that collected and analyzed more than the minimum number of samples, but that does not
have the same number of samples for each month, can meet the requirements by averaging each month-s
results to calculate a single Crypto concentration for each month. The bin classification will then de
determined from the highest 12 month running average of the resulting data points. (A minimum of one
valid sample per month is a prerequisite.)- PWSs that intend to change sampling frequency during the
compliance period, as described above, should be required to notify the EPA in advance. Several
examples of scenarios that might arise are listed below.
Example 1. The bin concentration for a PWS that monitored for 2 years, and analyzed 1 sample
approximately every week (4 per month), except for a 3-week period during which no sample was
analyzed (generating 95 sample results), would be determined first by calculating the mean concentration
for each month, then by calculating the highest arithmetic mean in any 12 consecutive months. Example
2. The bin calculation for a PWS that monitored for 2 years, and analyzed 1 sample approximately every
week (4 per month) for the first year and 1 sample per month the second year (generating 60 sample
results), would be determined first by calculating the mean concentration for each month, then by
calculating the highest arithmetic mean in any 12 consecutive months.
Comment Response for the LT2ESWTR 6-18 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Example 3. A scenario in which samples were not collected in equal intervals, but at least 2 samples were
collected each month (resulting in a straight average bin calculation, rather than a max rolling annual
average): The bin concentration for a PWS that monitored for 2 years, and analyzed 4 samples/month for
half the months, and 3 samples/month for the other half (generating 84 sample results), would be
determined first by calculating the mean concentration for each month, then calculating the arithmetic
mean of all monthly mean concentrations.
Response: See Response SOO.n.
EPA Letter ID: 647
Comment ID: 12865
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 320 B. Small System Monitoring Requirements; 1700
XIII. Analytical Methods
Comment: we have significant concerns about the laboratory techniques and accuracy, cost
of sample collection for small water systems, and the effect of climate conditions on the variability of
Cryptosporidium levels. MDE also supports the
Response: See Response 320(A) regarding small system sampling costs. (Also see Responses SOO.o,
SOO.p, lOO.c, lOO.i, and 1700 for other comments).
EPA Letter ID: 647
Comment ID: 12893
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: States should be given the opportunity to include the results of the source water assessments
in evaluating the appropriate bin for surface water systems (section 141.709). MDE is comfortable with
the strictly mathematical approach based on data collected for cryptosporidium analysis only on
prescheduled days in deciding the bins. Variable climatic conditions will greatly affect cryptosporidium
concentrations and therefore monitoring on
preselected dates may underepresent the risk if storms do not occur on these dates. The variability of
cryptosporidium levels is documented in the summary of our study of cryptosporidium occurrence in the
Potomac Basin (see attachment). States should be given the opportunity to increase the Bin designation of
a source by one bin if the collected data does not include any
testing during significant storm events, by evaluating cryptosporidium data along with other factors - such
as identified source of contaminants, size of watershed, E. coli levels, and type of source (lake, reservoir
or free flowing stream). Alternatively the monitoring requirements could be structured to include
sampling of at least two storm events, where the sampling includes
collection during multiple times during an event. MDE is also concerned that the analytical method
selected by the EPA is not that effective at separating cysts from other colloidal material that would be
present during storm events and that monitoring during these periods would also underepresent the level
of risk.
Comment Response for the LT2ESWTR 6-19 December 2005
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Chapter 6: Filtered System Treatment Requirements
Comment Codes 500-560
Response: See Responses 500.f, SOO.h and 500.J.
EPA Letter ID: 660
Comment ID: 14069
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: CUWCD recommends that instructions on calculating the RAA for bin classification
be included in the rule as well as the guidance manual. This should include how to handle results that are
below the detection limits, and non-continuous data due to plants that operate seasonally. Because the
calculation of RAA for bin classification is so critical, this data handling issue needs to be in the
regulation not just in the guidance manual.
Response: See Response 500.1.
EPA Letter ID: 660
Comment ID: 14075
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: Also, a provision should be included in the proposed rule to allow a water system to request
consideration for bin reclassification by the State if significant improvements in water quality can be
demonstrated.
Response: See Response 500.m.
EPA Letter ID: 662
Comment ID: 14027
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 430 K. Monitoring for Systems that Use Surface Water
Only Part of the Year
Comment: Detection levels, results that are below the detection limits, and non continuous data due to a
plant that may not operate continuously should be specifically addressed.
Response: See Responses 430 and 500.1.
EPA Letter ID: 667
Comment ID: 14008
Comment Response for the LT2ESWTR
6-20
December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: 2. Systems which have data which would relate to Cryptosporidium vulnerability
should be given consideration as to which bin they would fall into or be able to use grandfathered data.
Response: See Response SOO.h.
EPA Letter ID: 673
Comment ID: 13978
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: Jordan Valley Water recommends that the method for calculating the RAA for bin
classification be included in the rule as well as the guidance manual. This should include treating results
that are below the detection limits as zero, and how address non-continuous data resulting from seasonal
plant shutdowns.
Response: See Response 500.1.
EPA Letter ID: 673
Comment ID: 13985
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: Also, a provision should be included in the proposed rule to allow a water system to request
consideration for bin reclassification by EPA or the State if significant improvements in water quality can
be demonstrated.
Response: See Response 500.m.
EPA Letter ID: 711
Comment ID: 16552
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 6. Section 141.709 (b)(l)&(2) - It is unclear the leeway a system is given the way this is
written. Would it be possible for a system to have collected more than 48 samples but still choose to
submit 24 samples and use the highest arithmetic mean of all sample concentrations in any 12 consecutive
months?
Response: See Response 500.q.
Comment Response for the LT2ESWTR 6-21 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
6.4.1 Comment Code 532, Small systems
Individual Comments on Code 532
EPA Letter ID: 628
Comment ID: 12835
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: b. Determination of E. Coli concentration is unclear. The EPA has not described how the
annual mean E. coli concentration is determined for small systems. There are many ways of calculating
the annual mean value, such as based on the annual average of weekly results or the annual average of
monthly average of weekly results. The resulting annual mean E. coli concentrations using different
calculation methods may end up with different monitoring and treatment requirements for
Cryptosporidium. The SFPUC recommends the EPA describe the
calculation method for clarity and consistency purpose.
Response: See Response SOO.r.
EPA Letter ID: 704
Comment ID: 14790
Commenter: Steven G. Gould, Chairman, New York State American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. The following comments are specific to the LT2ESWTR Laboratory Guidance
Manual.
Section 1.3.1.
For small systems (serving< 10,000) bins are based on highest 6 month running average (instead of 12
months) based on one year of monitoring (instead of the 2 year period used for larger systems). This may
end up having a more significant impact on smaller systems. There are potentially seasonal changes in
Cryptosporidium abundances. Therefore, larger systems, by using a 12 month RAA based on 1 sample
per month, will have a more seasonal distribution of data
points to -dampen down- any seasonal spikes observed for Cryptosporidium, while smaller systems may
end up with higher RAA-s based on seasonal spikes, even though both large and small systems have an
equal number of sampling events.
Response: See Response 500.s.
Comment Response for the LT2ESWTR 6-22 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
6.4.2 Comment Code 533, Role of States in making or reviewing bin
classification
Individual Comments on Code 533
EPA Letter ID: 457
Comment ID: 11894
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: We believe that bin determinations need to be approved by the regulating agency (state
drinking water primacy agency). This will avoid any confusion as to the level of treatment each surface
water system is required to provide.
Response: See Response SOO.t.
EPA Letter ID: 458
Comment ID: 10974
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Bin Classification Determination - Since EPA will receive all of the data for systems over
10,000 population, EPA should notify the systems of the bin determination. Systems under 10,000
population would be determined by the Primacy Agency, as the States will have been granted primacy or
in process of being reviewed by that time.
Response: See Response SOO.t.
EPA Letter ID: 466
Comment ID: 11021
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: We support the use of four bins for classifying filtered water system. We believe that bin
determinations need to be approved by the State. This will avoid any confusion as to the level of
treatment each surface water system is required to provide.
Response: See Response SOO.t.
EPA Letter ID: 470
Comment ID: 11068
Comment Response for the LT2ESWTR 6-23 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: With respect to whether the state should make or review the bin classification made by a
system, we believe that states should have the flexibility to determine which method to use. Allowing
individual states to determine how to best manage their programs taking into consideration available
resources, confidence in water systems- capabilities and other factors will provide for better
implementation of the rule at the state and system level. The state could
determine which method the state will use as part of a special primacy condition.
Response: See Response SOO.t.
EPA Letter ID: 497
Comment ID: 10648
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Bin Determination
Implementation costs for water suppliers and the level of public health protection are determined by what
Cryptosporidium bin classification results from source water monitoring. States should not be removed
from the bin determination process. We strongly object to the EPA bypassing states in making bin
determinations. The EPA proposes to classify systems that fail to complete
Response: See Response SOO.t.
EPA Letter ID: 499
Comment ID: 10723
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: 7. KDHE supports the conduct or review of bin classifications by states. KDHE
supports in principle those components of the LT2 Rule which affords maximum discretionary authority
to primacy agencies.
Response: See Response SOO.t.
EPA Letter ID: 520
Comment ID: 11584
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Comment Response for the LT2ESWTR 6-24 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA believes that bin determinations need to be approved by the regulating agency. This will
avoid any confusion as to the level of treatment each surface water system is required to provide.
Response: See Response SOO.t.
EPA Letter ID: 528
Comment ID: 12258
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Bin Determinations
We believe that bin determinations need to be approved by the regulating agency. This will avoid any
confusion as to the level of treatment each surface water system is required to provide. We suggest that
EPA provide a presumptive
Response: See Response 500.t.
EPA Letter ID: 536
Comment ID: 11794
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Colorado believes that bin determinations need to be approved by the primacy agency. This
will avoid any confusion as to the level of treatment each surface water system is required to provide.
Response: See Response 500.t.
EPA Letter ID: 548
Comment ID: 12161
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * Determination of LT2ESWTR Bin Classification (should it be made or reviewed by States?)
Metropolitan believes that bin classification should be made or reviewed by EPA unless a State has
applied for and has been approved primacy over LT2ESWTR.
Response: See Response 500.t.
Comment Response for the LT2ESWTR 6-25 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA Letter ID: 591
Comment ID: 12127
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Ohio EPA believes that states are better able to review and approve sampling plans and make bin
classifications, however, the proposed implementation schedule makes that impossible for systems that
serve a population of at least 10,000. If the timeline of the rule is changed to allow 18 months for
implementation in accordance with the early implementation comment from the
Association of State Drinking Water Administrators (ASDWA), Ohio EPA recommends that source water
monitoring plans and results be reviewed and bin classifications be made by the State. If the proposed
timeline of the rule is not changed, we recommend U.S. EPA review the source water monitoring plans
and results and make the bin classifications for the systems which serve a population of at least 10,000.
Response: See Responses SOO.t and SOO.u.
EPA Letter ID: 595
Comment ID: 12580
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Maine believes that EPA should provide the primacy agency with the flexibility
to address these concerns on a case-by-case basis.
Response: See Response 500.t.
EPA Letter ID: 595
Comment ID: 12585
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Determination of LT2ESWTR bin classification
Maine should have final determination of bin assignment to ensure consistency
for all systems.
Response: See Response 500.t.
Comment Response for the LT2ESWTR 6-26 December 2005
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Chapter 6: Filtered System Treatment Requirements
Comment Codes 500-560
EPA Letter ID: 595
Comment ID: 12587
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: bin classification based on individual monitoring of that source. The State should have the
flexibility to determine monitoring requirements for blended sources on a case-by-case basis.
Response: See Response 500.k.
EPA Letter ID: 601
Comment ID: 13018
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on determination of LT2ESWTR Bin classification
(page 47678-47679)
Utah strongly encourages EPA to allow States to review and assign bin classifications as they are the
most familiar with the particular treatment plant operations within their respective State. In addition, it is
an increased burden on water systems to first submit data to EPA then have to make the transition to
reporting to the States when they achieve primacy.
Response: See Response SOO.tand 1500.b.
EPA Letter ID: 609
Comment ID: 14115
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Bin Determination
Implementation costs for water suppliers and the level of public health protection are determined by what
Cryptosporidium bin classification results from source water monitoring. States should not be removed
from the bin determination process. We strongly object to the USEPA bypassing states in making bin
determinations. The USEPA proposes to classify systems that fail to
Response: See Response 500.t.
EPA Letter ID: 637
Comment ID: 13087
Comment Response for the LT2ESWTR
6-27
December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on determination of LT2ESWTR Bin classification
(page 47678-47679)
District strongly encourages EPA to allow States to review and assign bin classifications as they are the
most familiar with the particular treatment plant operations within their respective State. In addition, it is
an additional burden on water systems to first submit data to EPA then have to make the transition to
reporting to the States when they achieve primacy. This could be achieved by delaying the compliance
schedule to be in line with the primacy schedule
Response: See Responses SOO.t and SOO.u.
EPA Letter ID: 641
Comment ID: 13596
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Determination of Bin Classification - We recommend that Bin Classification
should be made by the EPA, not the States. EPA personnel are trained and familiar with LT2 in all
respects, and LT2 is a federal regulation. Dumping the final determination on the States shifts the burden
inappropriately, and likely without requisite funding. Also, a single set of criteria and data interpretation
should apply nationwide; leaving it up to individual states provides the likely scenario of inconsistent
determinations from state to state.
Response: See Responses SOO.t and SOO.u.
EPA Letter ID: 643
Comment ID: 12734
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States believe that bin determinations need to be approved by the regulating agency (either
the state drinking water program or the delegated county health department). This will avoid any
confusion as to the level of treatment each surface water system is required to provide.
Response: See Response SOO.t.
EPA Letter ID: 643
Comment ID: 12774
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 6-28 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Comment: Determination of LT2ESWTR bin classification
As indicated in Attachment 1, states believe that bin determinations need to be approved by the regulating
agency (either the state drinking water program or the delegated county health department). This will
avoid any confusion as to the level of treatment each surface water system is required to provide.
Response: See Response SOO.t.
EPA Letter ID: 647
Comment ID: 12892
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Bin determinations need to be approved by the regulating agency (either
the state drinking water program or the delegated county health department). This will avoid any
confusion as to the level of treatment each surface water system is required to provide.
Response: See Response SOO.t.
EPA Letter ID: 647
Comment ID: 12920
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Determination of LT2ESWTR bin classification
Bin determinations need to be approved by the regulating agency (either the state drinking water program
or the delegated county health department). This will avoid any confusion as to the level of treatment each
surface water system is required to provide.
Response: See Response SOO.t.
EPA Letter ID: 660
Comment ID: 14074
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on determination of LT2ESWTR Bin classification
(page 47678-47679)
CUWCD strongly encourages EPA to allow States to review and assign bin classifications as state
regulators are the most familiar with the particular treatment plant operations within their respective State.
Comment Response for the LT2ESWTR 6-29 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
In addition, it is an additional burden on water systems to first submit data to EPA then have to make the
transition to reporting to the States when they achieve primacy.
Response: See Response SOO.tand ISOO.b.
EPA Letter ID: 662
Comment ID: 14033
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on determination of LT2ESWTR Bin classification
(page 47678-47679)
States should be allowed to review and assign bin classifications as they are more familiar with the
treatment plant operations and source water quality within their respective State. Dual reporting to EPA
and the State is burdensome and counterproductive,
Response: See Response SOO.t.
EPA Letter ID: 668
Comment ID: 13898
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - Bin classifications must be completed by states, not by the utilities. This is
an inherently governmental function that should not and cannot legally be delegated to private parties, (p.
47679)
Response: See Response SOO.t.
EPA Letter ID: 673
Comment ID: 13984
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on determination of LT2ESWTR Bin classification
(page 47678-47679)
Jordan Valley Water strongly encourages EPA to allow States to review and assign bin classifications as
they are the most familiar with the particular treatment plant operations within their respective State. In
addition, it is an additional burden on water systems to first submit data to EPA then make the transition
to reporting to the States when they achieve primacy.
Comment Response for the LT2ESWTR 6-30 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Response: See Response SOO.tand ISOO.b.
EPA Letter ID: 678
Comment ID: 14711
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 7. The EPA requests comment on whether bin classifications should formally be made or
reviewed by States. [47678-9, C3/C1]
Comment: Bin classification should be made or reviewed by the EPA unless a State has applied for and
has been approved primacy over LT2 Rule.
Response: See Response SOO.t.
6.5 Credit for Treatment in Place
6.5.1 Comment Code 541, Conventional, softening, slow sand, and
DE plants
Individual Comments on Code 541
EPA Letter ID: 390
Comment ID: 10492
Commenter: Jeff Taylor, Deputy Director, City of Houston Public Utilities Division
Commenter Category: Regulated Community (Utilities)
Comment: 2. We agree that well operated conventional treatment plants meeting required turbidity
criteria should be given a 3-log Cryptosporidium removal credit. EPA's rationale for this determination is
sound.
Response: See Response lOO.a.
EPA Letter ID: 415
Comment ID: 10519
Commenter: Miguel Arroyo, Water and Wastewater Treatment Manager, City of Fort Lauderdale Public
Services Department
Commenter Category: Regulated Community (Utilities)
Comment: * Not enough credit is given for conventional treatment, softening, etc. This has the potential
of having to implement higher cost alternatives unnecessarily.
Response: See Responses 200.a and 200.c.
Comment Response for the LT2ESWTR 6-31 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA Letter ID: 554
Comment ID: 12222
Commenter: Wayne Price, Water Plant Superintendent, Broad River Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Issue 3: We have a concern that the LT2ESWTR may understate the level of
treatment achievable through conventional treatment. If this is the case many utilities may be required to
make unnecessary investments to their treatment plants.
Comment: EPA should re-evaluate Crytptosporidium removal data to make sure that conventional
tratment plants are given adequate log removal credits.
Response: See Response 200.a.
EPA Letter ID: 562
Comment ID: 12415
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1. Conventional dual-media or mono-media filtration following clarification treatment are
capable of demonstrating 4.0 log or greater removal, often 5.0 log or greater, and typically demonstrated
greater removal than the 3.0 log baseline Cryptosporidium log credit in the LT2ESWTR toolbox.
Therefore, some toolbox credit is needed to correct or adjust the assumed median 3.0 log performance
upward to the actual 4.0 log or higher removal at which many facilities routinely operate.
Response: See Response 200.a.
EPA Letter ID: 562
Comment ID: 12416
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. Clarification technologies suitable for the 3.0-log Cryptosporidium
baseline credit, if followed by a conventional dual-media or mono-edia filter operating in compliance
with the Interim Enhanced Surface Water Treatment Rule (IESWTR), include: gravity sedimentation
basins, tube settlers, plate settlers, sand-ballasted coagulation, dissolved air flotation (DAF), upflow solids
contact reactor-clarifiers, or buoyant or non-buoyant media upflow clarifiers.
This analysis and these findings provide an important factual basis for the recommendations AWWA
offers in the following comments. AWWA-s review includes both research and data identified in the
LT2ESWTR proposal. AWWA believes the analysis in Appendix 1 and reflected in these comments more
correctly reflects the performance of some of these treatment technologies than the discussion provided in
the Federal Register notice and Microbial Toolbox Guidance. In addition to the literature and analysis
presented in Appendix 1 and Appendix 2, AWWA will also provide information and analysis with respect
Comment Response for the LT2ESWTR 6-32 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
to watershed control programs, bank filtration, ozone disinfection and UV disinfection.
4.2.1 Regulatory -Preference- vs. Agreement in Principle
Response: See Responses lOO.aand 200.d.
EPA Letter ID: 562
Comment ID: 12427
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 14. Available studies demonstrate that recycle of spent filter backwash water, using
acceptable practices consistent with the Filter Backwash Recycle Rule, will not deteriorate
Cryptosporidium removal during conventional clarification plus filtration technologies, nor should it
deteriorate log credits assigned for individual toolbox components.
Response: See Response SOO.v.
EPA Letter ID: 586
Comment ID: 12202
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: 5. Underestimation of level of treatment provided by some technologies.
EPA has apparently underestimated the level of treatment provided by some commonly used treatment
methods, such as softening and conventional treatment. This has led to very tight operational criteria that
may cause utilities to invest in what may ultimately be unnecessary treatment methodologies.
We request that EPA take another look at data available on technologies included in EPA's microbial
toolbox. A treatment system should also be allowed to
Response: See Responses 200.a, 200.c, and lOO.t.
EPA Letter ID: 621
Comment ID: 13165
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: the latter, I am particularly supportive of the conventional log removal credit of 3 log and the
additional 1 log removal credit for filtered water turbidity < 0.1 ntu (Federal Register: pp. 47667-47668).
Comment Response for the LT2ESWTR 6-33 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
I have collected substantial Cryptosporidium removal data that verifies these log removal credits - more
on this issue below. I am very pleased that on p. 47667 you include DAF plants
Response: Response 240.f.
EPA Letter ID: 621
Comment ID: 13166
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: this issue below. I am very pleased that on p. 47667 you include DAF plants under the
definition of conventional water treatment. I would hope that EPA would do this for all regulations
involving conventional treatment for two reasons. First, scientifically it makes sense because
sedimentation and flotation are both gravity particle separation processes - i.e., both are
clarification processes. The other reason is that both sedimentation and flotation plants provide two
barriers of clarification and granular media filtration preventing passage of pathogens (other than source
water protection and disinfection).
Response: See Response 200.d.
EPA Letter ID: 624
Comment ID: 13196
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 2. Enhanced Filtration: a. Demonstration of Performance (DOP). Current endospore,
turbidity, and Cryptosporidium data underestimate log-removal by conventional filtration plants in
compliance with IESWTR. Table 1 ,a listing of data published both prior to and after the IESWTR, reveals
that a conventional water treatment plant operated in compliance with IESWTR, would achieve 4.5 log
removal of Cryptosporidium surrogates. In fact, the actual removal capabilities of these systems may be
even greater than indicated. This is due to the high
percent of filter effluent samples that were below detection. Figure 2 shows endospore reduction at the
GCWW's surface water treatment plant between February 2003 and October 2003 (N = 41). The average
reduction for the overall treatment plant (between raw and finished water) is 4.09 with a range between
2.81 to 5.34-log removal.
[SEE PAGE 6 OF PDF FOR TABLE 1]
[SEE PAGE 7 OF PDF FOR FIGURE 2]
Response: See Response 200.a.
Comment Response for the LT2ESWTR 6-34 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
EPA Letter ID: 666
Comment ID: 14020
Commenter: Wellington H. Jones, Engineer-Director, Frederick County Sanitation Authority
Commenter Category: Regulated Community (Utilities)
Comment: 2. The rule does not recognize the level of treatment achievable through proper
operation of conventional treatment. This will result in unnecessary capital and operational costs for new
treatment techniques.
result in wasting funds to remove Cryptosporidium that may not be present. The wasting of funds is
compounded when you don't recognize the potential of current treatment and you impose an exorbitant
safety factor. It is important to protect
Response: See Response 200.a.
6.5.2 Comment Code 545, Implications for Giardia treatment credit
Individual Comments on Code 545
EPA Letter ID: 485
Comment ID: 11317
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Unless directed otherwise, the Department will assume the pretreatment credits
and other removal credits for treatment technologies are extended to include Giardia. For example, will
the 0.5 log removal credit for sedimentation for Cryptosporidium be extended to Giardia? Such removal
credit at present is not explicitly spelled out under the SWTR. It is implied because the log removal credit
granted the filters is 2.0 for direct filtration (no sedimentation) and 2.5 for full conventional treatment
(with sedimentation). Do all forms of
sedimentation qualify? How are contact clarification systems handled? Are these considered roughing
filters?
Response: See Responses 500.y and 200.d.
EPA Letter ID: 603
Comment ID: 12684
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Attachment B
Alternative Filtration Technologies and Federal Requirements for Cryptosporidium Removal
Washington State Department of Health, Office of Drinking Water
Comment Response for the LT2ESWTR 6-35 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
January 5,2004
On May 2,2002, the department sent a letter with a memorandum attached to Cynthia Dougherty at the
USEPA recommending language in the proposed LT2ESWTRthat would allow States to approve the use
of alternate filtration technologies that, in combination with effective disinfection, meet the microbial risk
reduction objectives of both the LT1ESWTR and the LT2ESWTR. As emphasized in the previous letter,
the department does not advocate the elimination of effective filtration. Rather, we propose providing a
balanced approach to filtration, focused on Giardia lamblia removal, along with effective disinfection to
meet public health objectives.
This attachment reiterates many of the points in the original memorandum and presents a detailed
perspective of the department on certain regulatory issues related to the Long Term 1 Enhanced Surface
Water Treatment Rule and the proposed Long Term 2 Enhanced Surface Water Treatment Rule. We are
specifically concerned about the requirement for 2-log removal of Cryptosporidium through alternative
filtration processes (40 CFR 141S52) and propose modifications to allow inactivation of Cryptosporidium
consistent with the toolbox options in the
LT2ESWTR.
Background
In Washington State, alternative filtration technologies have been historically limited to bag, cartridge,
and membrane filters. While the focus of this attachment is the narrow group of small public water
systems that currently depend on bag and cartridge filters as their physical barrier, we believe the issues
are generally applicable to all system seeking alternative filtration technology approval. We recognize
that the EPA must generate regulations and regulatory options that apply across all technologies and all
system sizes.
In Washington State, there are a total of 43 very small water systems that currently use bag and cartridge
filters for Giardia lamblia removal. Of the 43 systems, 38 are very small transient noncommunity (TNC)
or non-transient non-community (NTNC) systems such as National Park Service campgrounds and
church camps. In many cases, achieving this level of compliance has been a long and resource intensive
effort for the department. These systems are typically remote, some of which are staffed by part time
and/or volunteer operators who do not have the resources or capacity to operate a more complex treatment
system. Operator turnover and retraining is a continuous problem for these systems, highlighting the
importance for simple and effective technologies. Each of these systems uses a bag or cartridge that has
been approved for use and has demonstrated at least 2-log removal of Giardia lamblia cysts. Currently,
these treatment systems are not capable of removing the smaller sized Cryptosporidium oocysts to the
same degree. Based upon the currently available information, the department is very concerned about the
possibility of substantial non-compliance with the LT1ESWTR for these systems.
The Giardia and Cryptosporidium Paradigm
The Surface Water Treatment Rule, promulgated June 29, 1989, defined filtration and disinfection
treatment techniques to control Giardia lamblia, viruses, Legionella, and heterotrophic bacteria. Control
of Giardia and viruses typically involved a combination of filtration and disinfection that adequately
addresses bacterial risk. A fundmental result of this approach has been a strategy where the most resistant
organism (in general Giardia) defined the disinfection treatment requirements.
During development of the IESWTR and the LT1ESWTR, there were no accepted disinfection
technologies that could inactivate Cryptosporidium at the levels desired, and across the range of
environmental conditions common in surface water. For the purpose of defining a tighter filtration
standard, it was a model organism to regulate: relatively small, very resistant to common chemical
disinfectants, and of clear public health significance. To address these points, EPA had no choice but to
Comment Response for the LT2ESWTR 6-36 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
require effective filtration for Cryptosporidium control, and used this argument as the basis for tightening
turbidity standards for rapid sand filtration plants, and mandating removal through alternative filtration
technologies.
In the last three years, the understanding and acceptance of ultraviolet (UV) disinfection for
Cyptosporidium inactivation has matured and is clearly part of the LT2ESWTR. It is now clear that UV
doses required for effective control of Cryptosporidium and Giardia lamblia are very low, making the
application of UV widely applicable for the control of pathogenic protozoa. Concurrently, it is clear that
UV is not effective against all viruses of public health concern.
Equivalent or Greater Public Health Protection
The department understands that while specific microorganisms (e.g. Giardia and Cryptosporidium) are
targeted in federal regulations, there may be other organisms that are as yet unknown or whose public
health significance has not yet been determined. We therefore do not advocate a position allowing
disinfection as the single and complete barrier for systems required to filter. We recommend that States
can make site specific and technology specific assessments of filtration plus disinfection combinations
that will meet the organism-specific requirements of the IESWTR, LTIESWTR, and LTZESWTR, and
provide abroad range of protection. One example is a bag filter that provides 2-log removal of Giardia,
followed by a validated W reactor that provides at least 3-log inactivation of Cryptosporidium and
Giardia, followed by a chlorine disinfection system capable of 1-log inactivation of Giardia and greater
than 4 log inactivation of viruses. This approach expands the multiple barrier philosophy of the Surface
Water Treatment Rule to confront a broad range of microbial contaminants both currently regulated and
potentially regulated in the future.
The department acknowledges that a complete shift from a chemical disinfectant to UV for Giardia and
Cryptosporidium control could result in a lesser degree of protection against viruses and unknown
pathogens. However, UV represents a valuable new tool in our ongoing effort to balance feasible
microbial protection and the formation of disinfection byproducts. The department believes that driving
very small utilities towards inappropriate or overly expensive
filtration technologies (i.e. coagulation or membrane plants in a very small, transient system setting)
poses a substantial risk to public health and is expected to greatly exceed the financial capacity of many
systems.
Response: See Response SOO.z.
6.6 Comment Code 547, Compliance funds would be better spent on
other drinking water needs
Individual Comments on Code 547
EPA Letter ID: 429
Comment ID: 10589
Commenter: Janet Montz, Environmental Specialist, OCI Wyoming, L.P.
Commenter Category: Regulated Community (Utilities)
Comment: 1- No outbreaks of Crypto in Wyoming. Why spend money on a problem that doesn't
exist in Wyoming.
Comment Response for the LT2ESWTR 6-3 7 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Response: See Responses SOO.b and SOO.c.
EPA Letter ID: 492
Comment ID: 11238
Commenter: Anonymous492,, City of Walla Walla Public Works/Water Division
Commenter Category: Regulated Community (Utilities)
Comment: Though we certainly recognize the public health value of decreasing the risk of a
cryptosporidium outbreak, we are concerned that, under the current proposed rule, the negative financial
impacts upon smaller revenue generating communities that have low incidence and low historical
epidemiological evidence may outweigh any potential small reduction in risk. Some allowance should be
made for
Response: See Responses lOO.c and SOO.b.
6.7 Comment Code 550, Rule Language Edits
Individual Comments on Code 550
EPA Letter ID: 493
Comment ID: 11247
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment: 40 CFR 141.722(a) has the word -following- misspelled.
Response: See Response 500.aa.
EPA Letter ID: 554
Comment ID: 12224
Commenter: Wayne Price, Water Plant Superintendent, Broad River Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Comment: On page 47667, in the table IV-2, it shows Cryptosporidium less than or equal to
3.0.L would place a Filtered system in Bin 4. Should this not read greater than or equal to 3.0/L?
Response: See Response 500.aa.
EPA Letter ID: 678
Comment ID: 14704
Comment Response for the LT2ESWTR 6-38 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additionally, the formula for percent of plants with >0.075 Cryptosporidium per L shown in
Figure IV-1.- Microbial Indicator System Template (p. 47675) is missing the sign -(-. The formula
should read as D / (C + D).
Response: See Response 500.aa.
6.8 Comment Code 560, Guidance
Individual Comments on Code 560
EPA Letter ID: 601
Comment ID: 13008
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 530 C. Procedures for Calculating Bin Classification
Comment: Utah recommends that instructions on calculating the RAA for bin classification
be included in the rule as well as the guidance manual. This should include how to handle results that are
below the detection limits, and non-continuous data due to plants that may not operate continuously.
Response: See Response 500.1.
EPA Letter ID: 678
Comment ID: 14656
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1. The word -systems- has been used indiscriminately throughout the rule. It creates
confusion when a system has multiple plants with multiple source waters. It is possible for one of the
plants owned and operated by a -system- to be classified into Bin 1 whereas another plant may fall under
Bin 2. It is unclear from the proposed rule what the monitoring and treatment requirements would be if
that is the case since the term -system- is used instead of-plant-. The EPA needs to clarify the term -
system- and better define -consecutive system- and its requirements. We also recommend the regulation
be revised to use -plants- wherever -systems- was used to avoid confusion.
Response: See Responses lOO.j and SOO.bb.
EPA Letter ID: 678
Comment ID: 14678
Comment Response for the LT2ESWTR 6-39 December 2005
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Chapter 6: Filtered System Treatment Requirements Comment Codes 500-560
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 13. Section 141.709 (b)(l)&(2) - It is unclear, based on the way the proposed requirement is
written, what flexibility a system will be allowed under this requirement. For example, would it be
possible for a system to have collected more than 48 samples but still choose to submit 24 samples and
use the highest arithmetic mean of all sample concentrations in any 12 consecutive months? We request
that EPA clarify this requirement.
Response: See Response SOO.q.
Comment Response for the LT2ESWTR 6-40 December 2005
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7. Unfiltered Systems Monitoring and Treatment
Requirements: Comment Codes 600-640
7.1 Comment Code 600, Unfiltered Systems Monitoring and
Treatment Requirements
Response to Code 600
a. Today's rule is not revising the filtration avoidance criteria established under the SWTR. Further, EPA
does not believe that the E. coli trigger for Cryptosporidium monitoring by small filtered systems under
today's final rule is a basis for revising the fecal coliform filtration avoidance criterion, as the commenter
suggests. EPA believes that filtration is a critical treatment barrier for most systems using surface water
sources. The filtration avoidance criteria established by the SWTR are intended to identify systems with
very high quality sources where adequate public health protection can be achieved without filtration. In
contrast, the E. coli trigger under today's rule is intended to identify those small filtered systems that
should monitor for Cryptosporidium to determine if additional treatment beyond filtration is needed.
b. EPA recognizes that today's final rule will require unfiltered water systems to spend funds to provide
treatment for Cryptosporidium. As discussed in the preambles to the proposed LT2ESWTR and today's
final rule, EPA believes that these treatment requirements, which reflect recommendations by the M-DBP
Advisory Committee, are necessary to protect public health. The ICR and ICR Supplemental Surveys
have shown that Cryptosporidium occur in the protected watersheds of unfiltered systems. While the
origin of this Cryptosporidium is unknown, studies have shown that Cryptosporidium can pass from
animals to humans. Thus, even if the Cryptosporidium in unfiltered system watersheds is of animal
origin, data suggest that it may be infectious to humans. Consequently, EPA continues to regulate
Cryptosporidium at the genus, rather than species, level. With available technologies, monitoring to show
that Cryptosporidium is not present at levels that present a public health concern is not feasible. As
discussed in the LT2ESWTR Economic Analysis, EPA believes that the treatment requirements for
unfiltered systems in today's rule will achieve a significant reduction in disease associated with
Cryptosporidium in drinking water.
c. EPA has not established a risk goal for today's rule. Rather, EPA is following the SDWA requirement
to reduce risks from Cryptosporidium to the extent feasible with available treatment techniques. UV
provides a feasible treatment technique for unfiltered systems of all sizes to achieve 2- or 3-log
Cryptosporidium inactivation, as today's rule requires.
d. EPA recognizes that Cryptosporidium levels may vary among the watersheds of different unfiltered
systems and that within a given watershed, levels will vary over time. However, the Agency is not
establishing a waiver from the treatment requirements for unfiltered systems, including small systems, in
today's final rule, as some commenters recommended. As discussed in the preamble to today's final rule,
EPA has concluded that determining the level of Cryptosporidium in finished drinking water for the
purpose of compliance with a finished water standard is not economically or technologically feasible for
PWSs with available methods. The LT2ESWTR is designed to protect public health by lowering the level
of infectious Cryptosporidium in finished drinking waterto less than 1 oocyst/10,000 L. Approved
Cryptosporidium analytical methods are not sufficient to routinely determine the level of
Cryptosporidium at this concentration. Consequently, EPA has not identified a technical basis to issue a
waiver from the treatment technique requirements that today's rule establishes for unfiltered systems.
Comment Response for LT2ESWTR 7-1 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Similarly, EPA has not identified a sound technical approach through monitoring to identify unfiltered
systems where reducing the minimum Cryptosporidium treatment requirement from 2- to 1-log, as some
commenters recommended, would meet the public health protection goals of today's rule. Further, as
shown in EPA's Economic Analysis for the LT2ESWTR, achieving only 1-log inactivation would result
in little cost savings compared to achieving 2-log inactivation for most systems. EPA's analysis indicates
that no systems would use chlorine dioxide to achieve 1-log Cryptosporidium inactivation due to chlorite
formation.
EPA notes that under SDWA (Title 42, chapter 6A, subchapter XII, Part B, subpart 300g-4, paragraph
(a)(l)(B)), "A State which has primacy enforcement responsibility for public water systems may grant to
one or more public water systems within its jurisdiction one or more variances from any provision of the
national primary drinking water regulation which requires the use of a specified treatment technique with
respect to a contaminant if the public water system applying for the variance demonstrates to the
satisfaction of the State that such treatment technique is not necessary to protect the health of persons
because of the nature of the raw water source of the system. A variance granted under this subparagraph
shall be conditioned on such monitoring and other requirements as the Administrator may prescribe."
As stated above, EPA has not identified a practical approach that is economically or technologically
feasible for a PWS to demonstrate such a low level of Cryptosporidium to support granting a variance.
This is due to the extremely large volume and number of samples that would be necessary to make such a
demonstration with confidence. However, unfiltered PWSs may choose to pursue the development and
implementation of monitoring programs to apply for a variance from Cryptosporidium inactivation
requirements based on the nature of the raw water source. A sufficient monitoring program may be
feasible in site-specific circumstances or with the use of innovative approaches.
e. EPA has not identified a technical basis to adopt a HACCP approach as an alternative to the unfiltered
system treatment requirements in today's rule, as some commenters have recommended. A HACCP
approach would be based on protecting water from pathogen contamination and monitoring to verify that
pathogen contamination hadn't occurred. However, as described in the preamble, Cryptosporidium have
been found in the protected watersheds of unfiltered systems, and monitoring to show that
Cryptosporidium aren't present at levels of public health concern isn't feasible.
f Available data on Cryptosporidium occurrence suggest that no unfiltered PWSs will measure a mean
level of 0.075 oocysts/L or higher. Moreover, establishing a 4-log treatment requirement on the
precautionary basis that an unfiltered PWS might measure a high level of Cryptosporidium has a
significant cost—it would require any unfiltered PWS to provide 4-log, rather than 3-log, inactivation to
avoid Cryptosporidium monitoring. EPA expects that many small unfiltered PWSs will choose to provide
3-log Cryptosporidium inactivation rather than monitor for Cryptosporidium. Accordingly, EPA has
concluded that establishing a 4-log Cryptosporidium treatment requirement for unfiltered PWSs that
measure a Cryptosporidium level of 0.075 oocysts/L or higher is unnecessary and inappropriate at this
time. In the event that an unfiltered PWS does measure Cryptosporidium at this level, the State can
require the PWS to take steps to reduce the contamination under existing watershed control program
requirements for unfiltered PWSs.
g. EPA believes that the requirement in today's rule that unfiltered systems using chlorine dioxide or
ozone achieve the required Cryptosporidium inactivation every day except any one day per month is
appropriate. As discussed in the preamble to the proposed LT2ESWTR and today's final rule, this
requirement mirrors the existing requirement established by the SWTR in 1989 for Giardia and virus
inactivation by unfiltered systems. EPA believes that maintaining a consistent standard for compliance
Comment Response for the LT2ESWTR 7-2 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
with pathogen treatment requirements by unfiltered systems is beneficial. Because unfiltered systems
have been required to comply with the "every day except any one per month" standard for Giardia and
virus inactivation for many years, EPA expects that extending this same standard to the Cryptosporidium
inactivation requirements in today's rule will facilitate compliance by unfiltered systems. Conversely,
EPA does not see a significant benefit to modifying this standard or changing it, as some commenters
suggested. Because unfiltered systems typically will have only one treatment barrier against
Cryptosporidium, this barrier should operate as continuously as feasible. EPA is concerned that
suggestions by commenters for modifying this standard, or for an alternative standard, would be weaker
and lead to less compliance, thereby reducing public health protection.
h. EPA believes that the benefits of both redundancy and a broad spectrum of microbial protection justify
requiring the use of two disinfectants by unfiltered systems of all sizes. Because unfiltered systems rely
solely on inactivation for microbial treatment, an unfiltered system using only one disinfectant would
provide no primary microbial treatment if that disinfection process were to fail. While disinfection
processes should be designed for a high level of reliability, they are not generally 100 percent reliable.
Existing regulations and today's rule recognize this limitation by allowing unfiltered systems to fail to
achieve required disinfection levels one day per month. Consequently, EPA believes that for effective
public health protection, unfiltered PWSs should use at least two primary disinfection processes. If one
process fails, a second process will provide some degree of protection against pathogens.
A second advantage of a PWS using multiple disinfectants is that this approach will typically be more
effective against a broad spectrum of pathogens. The efficacy of disinfectants against different types of
pathogens varies widely. For example, UV light appears to be very effective for inactivating protozoa like
Cryptosporidium and Giardia lamblia, but is less effective against certain enteric viruses like adenovirus.
Chlorine, however, is highly effective against enteric viruses but less effective against protozoa. In
general, a system that uses multiple disinfectants to meet its overall pathogen inactivation requirements
will provide better public health protection that a system using only a single disinfectant.
Further, requiring each disinfectant to achieve the full inactivation of one target pathogen establishes a
minimal performance level so that each disinfectant will serve as a substantive pathogen barrier. In most
cases, systems will comply with this requirement by using UV or ozone to inactivate Giardia lamblia and
Cryptosporidium and using chlorine to inactivate viruses.
EPA believes that with available technologies like UV, the requirement to use two disinfectants will not
constrain unfiltered systems from reducing DBP levels. Most unfiltered systems currently use chlorine to
inactivate Giardia and viruses. Under today's rule, unfiltered systems will mostly install UV, which
doesn't form DBFs, to inactivate Cryptosporidium and Giardia. Because they will no longer be required to
use chlorine to inactivate Giardia, they will be able to greatly reduce the amont of chlorine they use. They
can apply a much smaller dose of chlorine to inactivate viruses (which are much less resistant to chlorine
than Giardia) and maintain a residual in the distribution system. This reduction in chlorine dose in
combination with a disinfectant, UV, that doesn't form DBFs will allow a significant reduction in DBP
levels.
Further, EPA does not believe that this requirement significantly reduces flexibility for unfiltered systems
in meeting their overall treatment requirements. The only feasible options EPA has identified for
unfiltered systems to meet the Cryptosporidium treatment requirements of today's rule are UV and ozone.
The requirement to use two disinfectants has no effect on this choice. Further, unfiltered systems must
continue to add chlorine to maintain a residual disinfectant, as required by the SWTR. The only effect of
today's requirement to use two disinfectants is that unfiltered systems must add enough chlorine to
achieve 4-log virus inactivation. This level of virus inactivation is achieved at much lower chlorine doses
than what most unfiltered systems currently apply since current doses are typically designed to achieve 3-
Comment Response for the LT2ESWTR 7-3 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
log Giardia inactivation. Thus, unfiltered systems retain the flexibility to significantly reduce chlorine
doses if they choose.
Individual Comments on Code 600
EPA Letter ID: 474
Comment ID: 11190
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 1100 VII. Uncovered Finished Water Reservoirs
Comment: As an unfiltered system with uncovered finish water reservoirs, the proposed rule would have
profound impacts on the Portland water systems and on the rates our customers pay for water service.
We estimate, for example, that the cost of treatment improvements for Cryptosporidium for the Bull Run
source (250 MGD capacity) would range from a low of about $55 million(l) for ultraviolet light
disinfection improvements to a high of about $202 million for a direct filtration or membrane filtration
plant.
(1) Costs presented for Bull Run treatment are in 2001 dollars as developed for the use by the Citizens
Panel on Bull Run Treatment
Response: See Response lOO.c and 1100.1.
EPA Letter ID: 480
Comment ID: 11227
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: The source water monitoring regime proposed for small systems highlights an interesting
regulatory paradox. Based on the analysis presented in the preamble, EPA suggests that a small (serving <
10,000 people) filtering system monitoring for E.coli from a flowing stream may have a mean
concentration of E. coli of up to 50 CPU /100 mL before there is concern of a need for additional
Cryptosporidium removal. Yet under LT2 (and by reference the original Surface Water Treatment Rule),
an unfiltered system providing at least 3-log
inactivation of Cryptosporidium, 3-log inactivation of Giardia, and 4-log inactivation of viruses that
exceeds 20 CPU/100 mL of fecal coliform in more than 10% of samples (a broader spectrum of
organisms and a tighter standard) would be required to add filtration to an already robust disinfection
system.
The analysis behind the 50 CPU/100 mL trigger in the proposal appears reasonable, however we believe
this single example clearly illustrates a significant disconnect between the proposed LT2, and the now 15
year old fecal coliform filtration trigger. Recent studies have shown that UV can remain very effective
when turbidity exceeds 5 NTU; EPA should revisit the science behind
this trigger, and reaffirm that its basis is adequate and still relevant to drive the expenditure of, in some
cases, enormous public resources.
Response: See Response 600.a.
Comment Response for the LT2ESWTR 7-4 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
7.2 Comment Code 610, Monitoring Requirements
Summary of Issues
Comments were submitted expressing support for the approach that both large and small unfiltered
systems would be required to monitor for Cryptosporidium. All commenters were in agreement on this
issue.
Individual Comments on Code 610
EPA Letter ID: 457
Comment ID: 11921
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Section IV.B Unfiltered System Treatment Technique Requirements for Cryptosporidium
(pages 47679-47681)
We support, in general, the proposed approach under which both large and small unfiltered systems
would be required to monitor for Cryptosporidium. We
Response: Thank you for your support.
EPA Letter ID: 520
Comment ID: 11621
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA supports the proposed approach under which both large and small unfiltered
systems would be required to monitor for Cryptosporidium. IEPA agrees that indicator monitoring for
small unfiltered systems should not be allowed.
Response: Thank you for your support.
EPA Letter ID: 643
Comment ID: 12741
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Requirements for Unfiltered Systems
Comment Response for the LT2ESWTR 7-5 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
States support the proposed approach under which both large and small unfiltered systems would be
required to monitor for Cryptosporidium. States agree that
Response: Thank you for your support.
EPA Letter ID: 643
Comment ID: 12776
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Section IV.B Unfiltered System Treatment Technique Requirements for Cryptosporidium (pages 47679-
47681)
States support the proposed approach under which both large and small unfiltered systems would be
required to monitor for Cryptosporidium. States
Response: Thank you for your support.
7.2.1 Comment Code 611, Parameters, frequency, and duration
Summary of Issues
One commenter needed clarification on the monitoring requirements for small unfiltered systems. The
second commenter agreed with EPA's approach.
Individual Comments on Code 611
EPA Letter ID: 509
Comment ID: 11479
Commenter: Greg Parker,, Florida Department of Environmental Protection Drinking Water Program
Commenter Category: State/Tribe Government
Comment: 141.701 Clarify the monitoring requirements for small systems that don-t filter.
They have to monitor for E. coli once every two weeks (26 samples) and for Cryptosporidium twice a
month (24 samples). Make the sampling interval the same.
Response: All unfiltered PWSs serving fewer than 10,000 people (i.e., small systems) must monitor for
Cryptosporidium, unless they choose to provide 3-log Cryptosporidium inactivation. The E. coli
screening analysis used by small filtered PWSs is not applicable to small unfiltered PWSs.
EPA Letter ID: 520
Comment ID: 11589
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Comment Response for the LT2ESWTR 7-6 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Requirements for Unfiltered Systems
IEPA supports the proposed approach under which both large and small unfiltered systems would be
required to monitor for Cryptosporidium. IEPA agrees that
Response: Thank you for your support.
7.2.1.1 Comment Code 612, Lack of E. coli indicator for
small unfiltered systems
Summary of Issues
All comments submitted were in agreement over the proposal, which states that indicator monitoring for
small unfiltered systems should not be allowed and that these systems would be required to monitor for
Cryptosporidium, as stated in today's rule.
Individual Comments on Code 612
EPA Letter ID: 457
Comment ID: 11922
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: small unfiltered systems would be required to monitor for Cryptosporidium. We
agree that indicator monitoring for small unfiltered systems should not be allowed.
Response: Thank you for your support.
EPA Letter ID: 520
Comment ID: 11590
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: indicator monitoring for small unfiltered systems should not be allowed.
Response: Thank you for your support.
Comment Response for the LT2ESWTR 7-7 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
EPA Letter ID: 520
Comment ID: 11622
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: systems would be required to monitor for Cryptosporidium. IEPA agrees that
indicator monitoring for small unfiltered systems should not be allowed.
Response: Thank you for your support.
EPA Letter ID: 643
Comment ID: 12742
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: systems would be required to monitor for Cryptosporidium. States agree that indicator
monitoring for small unfiltered systems should not be allowed.
Response: Thank you for your support.
EPA Letter ID: 643
Comment ID: 12777
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: unfiltered systems would be required to monitor for Cryptosporidium. States agree that
indicator monitoring for small unfiltered systems should not be allowed.
Response: Thank you for your support.
7.3 Comment Code 620, Cryptosporidium Treatment Requirements
Individual Comments on Code 620
EPA Letter ID: 427
Comment ID: 10577
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Other EPA Comment Codes and Descriptions: 700 V. Options for Meeting Treatment Requirements
Comment: 1.Summary of Bull Run Treatment -An Independent Review -Long-Term 2
Enhanced Surface Water Treatment Rule
Comment Response for the LT2ESWTR 7-8 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
[SEE .PDF FILE FOR ITEM #1 - SUMMARY OF BULL RUN TREATMENT -AN
INDEPENDENT REVIEW -LONG-TERM 2 ENHANCED SURFACE WATER
TREATMENT RULE]
-PART A - Comment on the rationale for considering additional organism inactivation provisions other
than those presented in LT2ESWTR. These would be based on currently successful
Individual water utility disinfection methods and protected watersheds
Response: See Responses 600.b, lOO.f, 100.1, 250.a, 600.c, 600.d, and 600.e.
EPA Letter ID: 427
Comment ID: 10586
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: PART A
The unfiltered Bull Run drinking water system has never had a reported illness from any organism. The
historical lack of human entry for recreation and building purposes, and no sewage exposure of any kind
exemplify the pristine nature of the protected Bull Run watershed.
1. We know Cryptosporidium spp. exist in the environment and some have been found in Bull Run water
preceding chlorine/ammonia treatment. We also know:
-The organisms found in the Bull Run watershed originate in wildlife
-Wildlife Crvptosporidium spp. are unlikely to infect humans (1)
-The organisms found in Bull Run wildlife are cattle in origin
-Calf oocysts have a low ~5% infection rate
-Because of the absence sewage, Cryptosporidium hominis has not been isolated in the Bull Run
C. hominis is emerging as the genotype of interest, and its relationship to humans supports the many
observed phenomena we see in the Cryptosporidium spp. disease process.
-Waterborne outbreaks are the primary stimulus for the regulation. Drinking water exposure to sewage
has been the common denominator with the large drinking water outbreaks. Bull Run has
no sewage exposure.
-In our state, day care centers are recognized as the primary source of infection and outbreaks (2)
-Recreational swimming pools are another large source of outbreaks
-Evidence supports direct person to person, or indirect hygiene incidents as the point of origin.
Environmental origins are less likely.
The EPA has established a goal of drinking water illness rate of 1/10,000 persons. The region being
served by the Bull Run currently has a Cryptosporidium spp. rate of 3.57 100,000 (.35/10,000) from all
sources of Cryptosporidium spp.exposure over the past 10 years. This would include a public swimming
pool incident that involved a large number of persons in 1998. Removing that incident brings the rate to
.25/10,000 for the last ten years. Additionally, state data shows a large variation between age groups.
Ages 1-10 show the greatest rate with a very large drop-off after the age of 50. If disease originated from
drinking water, the epidemiology would be illustrated by a uniform distribution of cases through the age
brackets. The data clearly does not reflect that drinking water is a point of origin, or concern. (2)(3) There
Comment Response for the LT2ESWTR 7-9 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
is no direct, indirect, or
collateral evidence of endemic disease from drinking water.
Response: See Responses 600.b, SOO.b, lOO.f, and 600.c.
EPA Letter ID: 456
Comment ID: 10960
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 1100 VII. Uncovered Finished Water Reservoirs
Comment: The Friends of the Reservoirs of Portland, OR, disagree with the proposed
requirement that unfiltered source water systems and systems with uncovered finished storage should
build additional treatment, no matter how pure its water is. The EPA should not require massive
expenditures without a clearly defined benefit to be gained.
Response: See Responses 600.b and 1100.1.
EPA Letter ID: 456
Comment ID: 10961
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: We agree with this statement from Dan Saltzman, Portland Commissioner in charge
of the Water Bureau, in his comment letter to EPA dated 11-19-03, regarding the LT2SWTR: -Based on
the real or perceived low benefit to cost ratio of modifying treatment to address Cryptosporidium I request
that EPA include a waiver provision in the Cryptosporidium treatment requirement of the forthcoming
Long Term 2 Enhanced Surface Water Treatment Rule (LT2SWTR). Such a provision would allow those
with protected, low risk drinking water sources, such as the Bull Run, to avoid substantial expenditures
that may potentially provide very little benefit.... A waiver from the Cryptosporidium treatment
requirement of the
Response: See Responses 600.b, 600.c, and 600.d.
EPA Letter ID: 456
Comment ID: 10963
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: The EPA should impose performance standards only. The proposed Rule recognizes
this principle for filtering water systems. The principle should be expanded to include nonfiltering
systems and systems with open finished storage. The Rule should not impose a mitigation, especially a
hugely expensive one, where there is no documented problem or likelihood of a problem. There have
Comment Response for the LT2ESWTR 7-10 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
been no reported cases of cryptosporidiosis or other water-borne illness caused by caused by water from
Portland-s unfiltered source, the Bull Run, or from water from
Portland-s uncovered finished water reservoirs. (1) Communities whose source water is protected from
sewage, and who have no history of drinking water related illness, should be able to continue to provide
clean water without additional treatment as long as they are able to document that they meet performance
standards.
(1) Report and Recommendations of the Bull Run Treatment Panel, p. 13.
http://www.bullrun.ci.portland.or.us/PUBINV/ADDITIONAL/OPT_RecFinal_Full.pdf
Response: See Responses 600.a, 600.b, 600.c, 100.1, SOO.b, 600.d., and 1100.1.
EPA Letter ID: 456
Comment ID: 10965
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: The Friends of the Reservoirs propose that the EPA formally recognize the Hazard
Analysis Critical Control Point (HACCP) program as the framework for documenting that source water,
water in storage, and water throughout the distribution system continues to meet performance standards.
This program was developed in the 1960-s by the Pillsbury Corporation in an effort to provide quality-
assured food for NASA. The goal is to establish a series of check points during processing. This program
is currently in effect with the FDA and the USDA (seafood and juice processing) and is being adopted by
the food processing industry in Canada. Under this program, multiple check points from the source and
throughout the distribution system would undergo continuous monitoring. (2) This program actually
creates the possibility of cleaner, safer water than the interventions imposed by the LT2SWTR.
(2) -Summary of Bull Run Water Treatment Findings: Phase One, an Independent Review 2003- by
Scott Fernandez, M.Sc., a member of the Portland Utilities Review Board.
Response: See Response 600.e.
EPA Letter ID: 522
Comment ID: 14131
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment:
Requests for comments on the treatment requirements for unfiltered systems:
As it relates to those provisions directly affecting unfiltered surface water supplies, MWRA believes that
the draft as published is in substantial agreement with the Agreement in Principle.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 7-11 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
EPA Letter ID: 592
Comment ID: 12108
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Given the fact that the reliability of the testing information is in question, as evidenced by the
EPA's uncertainty about which data set to use, it is possible that there are many pristine sources where
there is no Cryptosporidium present. If that be the case then millions of dollars would be wasted to protect
the public from a non-existent problem. The financial resources that would be spent to solve this non-
existent problem would better serve the public health interest by being spent on upgrading ageing
distribution system problems and other issues that will be addressed in the upcoming proposed new
coliform rule revisions. Waiver criteria must be established and made available for those utilities that can
show that Cryptosporidium is not an issue with their source.
Response: See Responses 600.b, 600.c, and 600.d.
EPA Letter ID: 592
Comment ID: 12111
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: public health is protected. Waivers must be provided for those systems that
choose to prove that there is no Cryptosporidium present. The EPA role must be to set criteria and to
allow utilities to make the difficult financial decisions.
Response: See Response 600.d.
EPA Letter ID: 608
Comment ID: 13131
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 1100 VII. Uncovered Finished Water Reservoirs
Comment: The Friends of the Reservoirs of Portland, OR, disagree with the proposed
requirement that unfiltered source water systems and systems with uncovered finished storage should
build additional treatment, no matter how pure its water is. The EPA should not require massive
expenditures without a clearly defined benefit to be gained.
The EPA should impose performance standards only. The proposed Rule recognizes this principle for
filtering water systems. The principle should be expanded to include nonfiltering systems and systems
with open fished storage. The Rule should not impose a mitigation, especially a hugely expensive one,
where there is no documented problem or likelihood of a problem. There have been no reported cases of
cryptosporidiosis or other water-borne illness caused by caused by water from Portland's unfiltered
source, the Bull Run, or from water from Portland's uncovered finished water reservoirs. (1) Communities
Comment Response for the LT2ESWTR 7-12 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
whose source water is protected from sewage, and who have no history of drinking water related illness,
should be able to continue to provide clean water without additional treatment as long as they are able to
document that they meet performance standards.
(1) Report and Recommendations of the Bull Run Treatment Panel, p. 13.
http://www.bullrun.ci.portland.or.us/PUBINV/ADDITIONAL/OPT_RecFinal_Full.pdf
Response: See Responses 600.b, 600.c, 100.1, SOO.b, 600.d, and 1100.1.
EPA Letter ID: 608
Comment ID: 13133
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 1100 VII. Uncovered Finished Water Reservoirs
Comment: The Friends of the Reservoirs propose that the EPA formally recognize the Hazard
Analysis Critical Control Point (HACCP) program as the framework for documenting that source water,
water in storage, and water throughout the distribution ystem continues to meet performance standards.
This program was developed in the 1960's by the Pillsbury Corporation in an effort to provide quality-
assured food for NASA. The goal is to establish a series of check points during processing. This program
is currently in effect with the FDA and the USDA (seafood and juice processing) and is being adopted by
the food processing industry in Canada. Under this program, multiple check points from the source and
throughout the distribution system would undergo continuous monitoring. (2) This program actually
creates the possibility of cleaner, safer water than the interventions imposed by the LT2SWTR.
We are confident that the unfiltered Bull Run source water, and water in our uncovered open reservoirs at
Mt Tabor Park and Washington Park, can meet any reasonable performance standards with a minimum of
low-tech investment. The EPA must make this pathway available.
(2) "Summary of Bull Run Water Treatment Findings: Phase One, an Independent
Review-2003" by Scott Fernandez, M.Sc., a member of the Portland Utilities
Review Board.
Response: See Response 600.c, 600.e, 600.d, and 1100.2.
EPA Letter ID: 668
Comment ID: 13886
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: 4. We also strongly support requiring that unfiltered surface water systems inactivate
Cryptosporidium at least 2 or 3 logs, depending upon their source water quality (though we believe that to
be consistent with the requirements for risky filtered systems, an unfiltered system with unusually bad
source water containing over 0.075 oocysts/liter should provide 4 logs or more inactivation).
Response: See Responses 100.a and 600.f
Comment Response for the LT2ESWTR 7-13 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
7.3.1 Comment Code 621, Proposed treatment levels
Individual Comments on Code 621
EPA Letter ID: 394
Comment ID: 10555
Commenter: Marian Rose, President, Croton Watershed Clean Water Coalition Inc.
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: CWCWC will present arguments why EPA 's requirement for a 2-log reduction in
Cryptosporidium concentrations for source waters where such concentrations are below detectable levels
will result in unnecessary expenditures of funds that could better be used to prevent more immediate
threats to public health.
New York City Department of Environmental Protection 's (DEP) Cryptosporidium and Giardia
Background Information and Monitoring Program
The following is a quote from DEP 's web-site. "DEP 's Pathogen Laboratory was approved by USEPA to
perform the USEPA ICR method, and more recently has also been approved to perform Method 1623
under the Laboratory Quality Assurance Evaluation Program for Analysis of Cryptosporidium in
preparation of the Long-Term 2 Enhanced Surface Water Treatment Rule. DEP works constantly to
improve its monitoring and analytical methods, but there are deficiencies with the current water testing
process. The method is not intended to determine whether Cryptosporidium and Giardia found in water
samples are dead, alive, or infectious. DEP is working with CDC to develop and use new analytical
methods to identify the genotype of Cryptosporidium recovered from environmental samples. Genotyping
provides information regarding the potential source of the oocysts. Results indicate that stormwater
samples largely contain Cryptospuridium from wildlife sources. These results are important, because
oocysts from non-human sources are unlikely to infect humans. Currently, there are no numerical
drinking water standards for Cryptosporidium and Giardia (emphasis added).
USEPA has proposed new regulations known as the Long-Term 2 Enhanced Surface Water Treatment
Rule. Monitoring results with Method 1623HV indicate that New York City 's source waters are well
below the treatment threshold required in the proposed regulations. (Emphasis added)
Eight years of monitoring data by the DEP at the Croton intake shows that the mean number of confirmed
Cryptosporidium oocysts is only 0.000017 oocysts per liter.(3) If one compares the mean concentration of
oocysts (total) in the Croton water to similar results for other filtered and unfiltered source waters in the
US, the results are revealing:
Filtered Systems Source Water: 0.068 oocysts/liter Unfiltered Systems Source Water: 0.002 oocysts/liter
Croton Source Water (Total): 0.0012 oocysts/liter
The results for the Croton show that the concentration of Cryptosporidium oocysts is, at least, an order of
magnitude less than the proposed cutoff value where EPA is advocating a 2-log reduction.
There is a pressing need for an enforceable, well-funded scientific plan to protect the Croton watershed
and its reservoirs. Such a plan, if it does exist on paper, is not being carried out. Yet, since Croton water is
high quality and fulfills all present N Y S and federal health standards, it would be more economical,
Comment Response for the LT2ESWTR 7-14 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
more sustainable and more effective to protect the water at its
source rather than spend more than a billion dollars on a filtration plant. A fraction of this sum could buy
significant amounts of land in the watershed or be used to buy conservation easements. A
Cryptosporidium log reduction of from 0.5 to 1.0 could be assigned such a program depending on how
much protection it provides for the watershed.
A 2-log reduction is unnecessary and scientifically unjustifiable. A 1-log reduction would suffice. An
added advantage would be a sufficiently small CT to make chlorine dioxide an effective and relatively
inexpensive disinfectant in addition to chlorine. Chlorine dioxide, together with UV and ozone, is one of
the three disinfectants considered effective against Cryptosporidium by EPA. The more than 21 mile
length of the New Croton Aqueduct would allow ample reaction time for chlorine dioxide to be effective,
even at doses below 800 micrograms/L, its maximum allowable limit.
If a system such as the Croton has a level of Cryptosporidium below most filtered systems in the US, then
the justification for the 2-log reduction becomes even more tenuous. Spending large sums of money on a
supposed health threat that is minimal, means that real threats to health such as pollutants carried in
stormwater runoff, old leaking sewer and water pipes that need repair, sewage treatment plants that need
upgrades, and failing septics, get less attention and funding than they need.
A 2-log reduction cannot be justified on scientific grounds. In addition, placing this unnecessary financial
burden on water providers means that public health could be endangered since the more immediate threats
cannot be given the full attention they deserve.
A 1-log reduction in Cryptosporidium oocysts should be sufficient to guard against the threat of
cryptosporidiosis for systems that have levels of Cryptosporidium below 0.01 oocysts/L.
(1) In 1994,these concentrations were 300 micrograms per liter, (ig/L for C1O2 and 80 (ig/L for chlorite.
In 1998,these were increased respectively to 800 (ig/L and 800 (igL.
(2) These are displayed in Tables IV-19 and IV-20, page 251.
(3) An Alternative Treatment Technique to Filtration for a Public Drinking Water Supplv -Croton Water
Supplv New York City -by Ripple Engineering, P.C., James W.Roberts, P.E., April 2002 (unpublished)
(3) An Alternative Treatment Technique to Filtration for a Public Drinking Water Supplv -Croton Water
Supplv New York City -by Ripple Engineering, P.C., James W.Roberts, P.E., April 2002 (unpublished)
Response: See Responses 600.b, 600.c, and 600.d.
EPA Letter ID: 480
Comment ID: 11231
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: The preamble states: - New occurrence data suggest that typical Cryptosporidium
levels in the treated water of unfiltered systems are substantially higher than in the treated water of
filtered systems.- While the data show that some unfiltered water systems have Cryptosporidium levels
higher than in some filter plant effluents, the statement can not be made that this is universal, or even -
typical-. During the past 36 months of monthly testing using the best available prescribed method (EPA
Method 1623), Tacoma Water has been unable to detect a
Comment Response for the LT2ESWTR 7-15 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
single oocyst. This has recently included some event-based monitoring at elevated turbidity (~5 NTU).
Tacoma Water does not believe its watershed is necessarily -Cryptosporidium free-, but the language
should recognize that there are significant differences between unfiltered watersheds. Based on this, the
following are recommended:
- EPA should seriously evaluate the development of an additional -bin- for unfiltered systems that
recognizes superior raw water quality (i.e. <0.1 oocyst/100 L). This may be especially important for
GWUDI systems. This bin would require 1-log inactivation of Cryptosporidium.
Response: See Response 600.d.
EPA Letter ID: 520
Comment ID: 11623
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: As indicated above, IEPA believes that the level of Cryptosporidium reduction for systems
that have mean Cryptosporidium concentrations above 0.075 oocysts/L should be consistent for both
filtered and unfiltered systems. Although IEPA concurs with EPA's determination on page 47681 of the
preamble that very few, if any, unfiltered systems will measure mean Cryptosporidium concentrations
above 0.075 oocysts/L, we believe that 4 log reduction of Cryptosporidium should be required above this
level in order to provide consistency in requirements across systems.
Response: See Response 600.f
EPA Letter ID: 522
Comment ID: 14138
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Responses to other aspects the treatment requirements for unfiltered systems:
Minimum level of Cryptosporidium inactivation required: The preamble described the process used to
establish the required two log (99%) inactivation requirement. The analysis uses the simplifying
assumption that the ICR data for unfiltereds is only about 10 times lower than that of
utilities required to filter, and than further assumes that a well operated filtration plant can achieve an
average of 3 log reduction (1). Unfiltered systems are required to utilize disinfection with a regulatory
required target of a minimum of 2 logs inactivation: in practice to reliably achieve the minimum
requirement, systems must employ a margin of safety to account for normal variations in flow,
temperature and pH as well as disinfectant dosing. For example, MWRA routinely sets a target of 130 to
150 percent of the required CT as its operational target. Both by the use of minimum rather than average,
and by the very conservative exposure assumptions, the draft regulations require more treatment than the
actual risk would warrant. This in effect diverts resources away from other investments that would have a
higher water quality or public health benefit.
Comment Response for the LT2ESWTR 7-16 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Ongoing monitoring by MWRA of its finished water indicates that the exposure assumptions for
Cryptosporidium levels used by EPA in the preamble may be extremely conservative. Based on over two
years of weekly composite samples of 1,000 liters each taken with the IDEXX foam filter (a total of
124,000 liters sampled and analyzed using Method 1623) MWRA's actual levels are averaging 0.05
oocysts per 100 liters: more than an order of magnitude lower than the average levels cited for unfiltered
utilities from the ICR, and almost 2 orders lower than the median. This is particularly note worthy given
that these results are based on using sample volumes and analytic techniques which are at least 50 to 100
times more sensitive than the very low volumes
and low recoveries of many ICR samples used as the data source for much of the analysis cited in the
preamble.
MWRA urges EPA to consider adding at least one additional bin for unfiltered systems with lower levels
of Cryptosporidium in their source waters. This would move the regulatory approach for unfiltereds more
nearly in line with that filtered systems, and open up additional treatment flexibility for systems which
already have treatment facilities which might be modified to
achieve 1-log Cryptosporidium inactivation and for groundwater under the direct influence of surface
waters (GWUDI) systems which may have very low Cryptosporidium levels. Filtered systems have four
separate bins - it is not unreasonable that the unfiltered systems have at least three.
(1) A review of the preamble reveals that virtually every reference to filtration performance cites average
performance, rather than the minimum performance of the particular technology. Given the higher
likelihood of extreme variability in an uncontrolled and unprotected source water,
attention to minimum performance for filtration technologies would have seemed commonsensical. Given
that literature available does not seem to support the ability to achieve this, some explicit
acknowledgement of the disparate approaches might be appropriate in the final rule documents.
Response: See Response 240.a and 600.d.
EPA Letter ID: 523
Comment ID: 11673
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Minimum level of Cryptosporidium inactivation required: The preamble described
the process used to establish the required two log (99%) inactivation requirement. The analysis uses the
simplifying assumption that the ICR data for unfiltereds is only about 10 times lower than that of utilities
required to filter, and then further assumes that a well operated filtration plant can achieve an average of 3
logs reduction (1). The rule will require that unfiltered systems utilize disinfection with a regulatory
required target of a minimum of 2 logs inactivation of Cryptosporidium: in practice, to reliably achieve
the minimum requirement systems must employ a margin of safety to account for normal variations in
flow, temperature and pH as well as disinfectant dosing. Both by the use of minimum rather than average,
and by the very conservative exposure assumptions, the draft regulations require more treatment than the
actual risk would warrant, increasing treatment investment with little or no public health benefit.
The Unfiltered Working Group urges EPA to consider adding at least one additional bin for unfiltered
systems with lower levels of Cryptosporidium in their source waters. Those systems with source water
levels below 0.1 oocysts per 100 liters should be required to provide 1 log of inactivation. This would
Comment Response for the LT2ESWTR 7-17 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
move the regulatory approach of treatment tailored to exposure for unfiltereds more nearly in line with
that filtered systems. Most systems adding new treatment will opt for technology and sizing to allow for
achievement of at least 2 logs, and probably 3 logs, but this approach would open up additional flexibility
for systems which already have treatment facilities in place which might be modified to achieve 1 log
Cryptosporidium inactivation, and for
groundwater systems under the influence of surface water. Such an approach could be coupled with a
requirement for higher volume sampling to increase the sensitivity of Cryptosporidium detection.
(1) A review of the preamble reveals that virtually every reference to filtration performance cites average
performance, rather than the minimum performance of the particular technology. Given the higher
likelihood of extreme variability in an uncontrolled and unprotected source water, attention to minimum
performance for filtration technologies would have seemed commonsensical. Given that literature
available does not seem to support the ability to achieve this, some explicit acknowledgement of the
disparate approaches might be appropriate.
Response: See Response 240.a and 600.d.
7.3.2 Comment Code 622, Allowance to miss treatment requirement
once-per-month for ozone and chlorine dioxide and 5% of time
forUV
Individual Comments on Code 622
EPA Letter ID: 678
Comment ID: 14684
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 18. Section 141.721(c)(l) - The rule proposes that unfiltered systems using chlorine dioxide
or ozone and failing to achieve the Cryptosporidium log inactivation on more than one day in the calendar
month are in violation of the treatment technique requirement. This may be unfair to the system if it
happens to have two separate but back-to-back inactivation failures occur before and after mid-night and
these failures are attributed to the same cause. We recommend changing -more than one day- to -more
than one 24-hour period in the calendar month-. The proposed change would avoid penalizing the system
that may be investigating or in the process of
remedying the problem that caused the initial failure.
Response: See Response 600.g.
7.3.3 Comment Code 623, Treatment requirements for systems with
higher Cryptosporidium levels
Individual Comments on Code 623
EPA Letter ID: 387
Comment ID: 10475
Comment Response for the LT2ESWTR 7-18 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Commenter: Anonymous387,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: (1) It is irresponsible for EPA to propose a rule that does not require unfiltered surface water
systems (meeting filtration avoidance) to filter if significant levels of Crypto are found in the water. The
LT2 rule is silent on that issue - only requires 3 logs of inactivation instead of 2 for the higher levels of
Crypto. An upper bound should be set to require filtration - obviously the watershed control program is
not working!! (2) All uncovered finished water
Response: See Response 600.f
EPA Letter ID: 470
Comment ID: 11071
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: In general, we agree with the proposed treatment requirements for unfiltered systems with
higher Cryptosporidium levels because of the proposed source water and watershed control program
associated with these types of systems. We believe that the multi-barrier approach will provide long-term
and consistent public health protection. Requiring this level of treatment along with source water
protection measures is supportive of our current approach with Vermont-s public water systems.
Response: See Response lOO.a.
EPA Letter ID: 474
Comment ID: 11196
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: We are not aware of any large unfiltered system that would be required to meet
even the already provided for requirement to inactivate 3 log of Cryptosporidium, so we aren-t sure why
EPA is raising this issue. None of the data considerable amount of data from unfiltered systems that EPA
has seen would indicate that this action is necessary. If EPA should decide to proceed to included it, we
believe that it should include a justification for it, including presenting data, that would indicated that
including this provision is necessary.
Response: See Response 600.f
EPA Letter ID: 485
Comment ID: 11290
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 7-19 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Comment: Response: Recognizing that unfiltered systems only provide inactivation, the Department
recommends that the rule require unfiltered and filtered systems to provide the same level of
Cryptosporidium reduction or inactivation and that there be no differentiation between unfiltered and
filtered systems.
Response: See Response 600.f
EPA Letter ID: 522
Comment ID: 14137
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: EPA also solicited comments on whether or how this possibility of unfiltered
systems having a mean source water Cryptosporidium level of 0.075 oocysts/L or higher should be
addressed.
Based on the current data available to MWRA and the other unfiltered systems, and to EPA, this does not
appear to be a realistic scenario. However, there are three significant physical and regulatory differences
between filtered systems with unprotected sources, and those systems that meet the SWTR filtration
waiver criteria which we believe render the question moot.
First, all unfiltered systems have source water watersheds which must be annually reviewed by the state
primacy agency for adequate control of potential health threats: the Interim Enhanced Surface Water
Treatment Rule has already made the inclusion of Cryptosporidium control a required goal of watershed
protection plans. Any evidence of an actual source of Cryptosporidium at levels high enough to affect
source water quality at the intake should already be grounds for the state primacy agency to take action to
order the elimination of the threat or the additional of filtration. No new regulatory restrictions or
authority is required.
Second, by their nature, the source waters of unfiltered supplies are significantly more likely to have a
higher fraction of older, more degraded, and non-infectious oocysts, and to have a lower fraction of
potentially human infectious oocysts. While for the purpose of the binning procedure in the Agreement in
Principle, the unfiltered systems agreed with the simplifying approach to treat all enumerated oocysts the
same way, they are not. Many filtered systems have direct discharges of sewerage treatment effluent to
their sources, in some cases in large volumes and in close proximity. This is certainly an opportunity for
fresh, human infectious oocysts to arrive at
their treatment plants. This is not the case for unfiltered systems. The detention time in most unfiltered
systems is substantial: not hours or days from pollutant source to source water sampling point, but months
or years. For example, MWRA's reservoir system has a detention time of almost 5 years. The physical
nature of such systems serves to allow for natural degradation, reducing the potential of any given
enumerated oocystto be infectious. And
finally, because of their well-protected watersheds, it is likely that any occysts present came from non-
human sources.
Third, all unfiltered systems are required to have some type of outbreak monitoring program in place and
annually must demonstrate that there have been no water-borne disease outbreaks to their state primacy
agency. Filtered utilities are not required to do this. In MWRA's case, we fund approximately four staff at
Comment Response for the LT2ESWTR 7-20 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
the Boston Public Health Commission and the state Department of
Public Health to conduct active disease surveillance of both endemic levels and outbreaks. This additional
layer of vigilance and oversight provides an additional opportunity to discover any actual threat to public
health, and any evidence of a source water related disease outbreak would be grounds forthe primacy
agency to withdraw the waiver of filtration status.
Response: See Response 600.f
EPA Letter ID: 523
Comment ID: 11672
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA also solicited comments on whether or how this possibility of unfiltered systems having
a mean source water Cryptosporidium level of 0.075 oocysts/L or higher should be addressed.
Based on the occurrence data available to the Unfiltered Systems Working Group, and to EPA, this does
not appear to be a realistic scenario. However, there are three significant physical and regulatory
differences between filtered systems with unprotected sources, and those systems that meet the SWTR
filtration waiver criteria, and an examination of them suggests that EPA does not need to take any
additional action on this topic.
First, all unfiltered systems have source water watersheds which must be annually reviewed by the state
primacy agency for adequate control of potential health threats: the Interim Enhanced Surface Water
Treatment Rule has already made the inclusion of Cryptosporidium control a required goal of watershed
protection plans. Any evidence of an actual source of Cryptosporidium at levels high enough to affect
source water quality at the intake should already be grounds for the state primacy agency to take action to
order the elimination of the threat or the addition of filtration. No new regulatory restriction or authority is
required.
Second, by their nature, the source waters of unfiltered supplies are significantly more likely to have a
higher fraction of older, more degraded, and non-infectious oocysts, and a smaller proportion of human
infectious oocysts. While forthe purpose of the binning procedure in the proposed rule, the unfiltered
systems agreed with the simplifying approach to treat all enumerated
oocysts as if they were the same, they are not. Many filtered systems have direct discharges of sewage
treatment effluent to their sources, in some cases in large volumes and in close proximity to their intakes.
This is certainly an opportunity for fresh, human-infectious oocysts to arrive at their treatment plants.
This is not the case for unfiltered systems. The detention time in most
unfiltered systems is substantial: not hours or days from pollutant source to intake, but months or years.
The physical nature of these systems serves to allow for natural degradation, reducing the potential of any
given enumerated oocyst to be infectious, and the well protected watersheds mean that any viable oocysts
are less likely to be of human origin.
Third, all unfiltered systems are required to have some type of outbreak monitoring program in place and
annually must demonstrate that there have been no water-borne disease outbreaks to their state primacy
agency. Filtered utilities are not required to do this. This additional layer of vigilance and oversight
provides an additional opportunity to discover any actual threat to
public health, and any evidence of a source water related disease outbreak would be grounds for the
Comment Response for the LT2ESWTR 7-21 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
primacy agency to withdraw the waiver of filtration status. Many of the largest unfiltered systems
aggressively undertake this responsibility in partnership with local or state health agencies. This includes
in many cases directly funding dedicated staff at the health agencies to conduct active surveillance. San
Francisco PUC funds 2 full-time staff at the county health department. MWRA funds 2 staff at the state
Department of Public Health and 2 additional at the Boston Public Health Commission. New York City
DEP has had a decade long partnership with the city health department. If there was an outbreak of
cryptosporidiosis or an increase in endemic rates due to the source water, it would be detected.
Response: See Response 600.f
EPA Letter ID: 523
Comment ID: 11684
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA also solicited comments on whether or how this possibility of unfiltered
systems having a mean source water Cryptosporidium level of 0.075 oocysts/L or higher should be
addressed.
Based on the occurrence data available to the Unfiltered Systems Working Group, and to EPA, this does
not appear to be a realistic scenario. However, there are three significant physical and regulatory
differences between filtered systems with unprotected sources, and those systems that meet the SWTR
filtration waiver criteria, and an examination of them suggests that EPA does not need to take any
additional action on this topic.
First, all unfiltered systems have source water watersheds which must be annually reviewed by the state
primacy agency for adequate control of potential health threats: the Interim Enhanced Surface Water
Treatment Rule has already made the inclusion of Cryptosporidium control a required goal of watershed
protection plans. Any evidence of an actual source of Cryptosporidium at levels high enough to affect
source water quality at the intake should already be grounds for the state primacy agency to take action to
order the elimination of the threat or the addition of filtration. No new regulatory restriction or authority is
required.
Second, by their nature, the source waters of unfiltered supplies are significantly more likely to have a
higher fraction of older, more degraded, and non-infectious oocysts, and a smaller proportion of human
infectious oocysts. While for the purpose of the binning procedure in the proposed rule, the unfiltered
systems agreed with the simplifying approach to treat all enumerated
oocysts as if they were the same, they are not. Many filtered systems have direct discharges of sewage
treatment effluent to their sources, in some cases in large volumes and in close proximity to their intakes.
This is certainly an opportunity for fresh, human-infectious oocysts to arrive at their treatment plants.
This is not the case for unfiltered systems. The detention time in most
unfiltered systems is substantial: not hours or days from pollutant source to intake, but months or years.
The physical nature of these systems serves to allow for natural degradation, reducing the potential of any
given enumerated oocyst to be infectious, and the well protected watersheds mean that any viable oocysts
are less likely to be of human origin.
Third, all unfiltered systems are required to have some type of outbreak monitoring program in place and
annually must demonstrate that there have been no water-borne disease outbreaks to their state primacy
Comment Response for the LT2ESWTR 7-22 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements
Comment Codes 600-640
agency. Filtered utilities are not required to do this. This additional layer of vigilance and oversight
provides an additional opportunity to discover any actual threat to public health, and any evidence of a
source water related disease outbreak would be grounds for the primacy agency to withdraw the waiver of
filtration status. Many of the largest unfiltered systems aggressively undertake this responsibility in
partnership with local or state health agencies. This includes in many cases directly funding dedicated
staff at the health agencies to conduct active surveillance. San Francisco PUC funds 2 full-time staff at the
county health department. MWRA funds 2 staff at the state Department of Public Health and 2 additional
at the Boston Public Health Commission. New York City DEP has had a decade long partnership with the
city health department. If there was an outbreak of cryptosporidiosis or an increase in endemic rates due
to the source water, it would be detected.
Response: See Response 600.f
EPA Letter ID: 641
Comment ID: 13598
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47681 RFC - Treatment Requirements for Unfiltered Systems With Higher Crypto Levels
Unfiltered systems that develop Crypto occurrence data of >0.075 oocysts/L should be subject to the
same treatment requirements as filtered systems, that is, 4 log or more. Allowing an unfiltered system to
provide less treatment than a filtered system with the same indigenous Crypto load does not serve the goal
of protecting public health, not is it likely to be legally defensible.
Response: See Response 600.f
EPA Letter ID: 643
Comment ID: 12744
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States believe that the level of Cryptosporidium reduction for systems that have mean
Cryptosporidium concentrations above 0.075 oocysts/L should be consistent for both filtered and
unfiltered systems. Although states concur with EPA-s determination on page 47681 of the preamble that
very few, if any, unfiltered systems will measure mean Cryptosporidium concentrations above 0.075
oocysts/L, states believe that 4 log reduction of Cryptosporidium should be required above this level in
order to provide consistency in requirements across systems.
Response: See Response 200.f
EPA Letter ID: 643
Comment ID: 12778
Comment Response for the LT2ESWTR
7-23
December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements
Comment Codes 600-640
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As indicated in Attachment 1, states believe that the level of Cryptosporidium reduction for
systems that have mean Cryptosporidium concentrations above 0.075 oocysts/L should be consistent for
both filtered and unfiltered systems. Although states concur with EPA-s determination on page 47681 of
the preamble that very few, if any, unfiltered systems will measure mean Cryptosporidium concentrations
above 0.075 oocysts/L, states believe that 4 log reduction of Cryptosporidium should be required above
this level in order to provide consistency in requirements across systems.
Response: See Response 600.f
EPA Letter ID: 668
Comment ID: 13900
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - Unfiltered systems with over 0.075 oocysts per liter should have to achieve 4
log removal/inactivation to assure comparable health protection to filtered systems, (p. 47681)
Response: See Response 600.f
7.4 Comment Code 625, Compliance funds would be better spent on
other drinking water needs
Individual Comments on Code 625
EPA Letter ID: 394
Comment ID: 10557
Commenter: Marian Rose, President, Croton Watershed Clean Water Coalition Inc.
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: As a further example -using the EPA approved Method 1623HV to analyze 50-liter
samples, DEP monitoring of the New Croton Reservoir from March 24,2003 to September 15,2003
reveals zero Cryptosporidium oocysts. Reducing these undetectable levels by 2-log could entail building
costly ozonation or UV facilities, or even a $1.5 billion chemical treatment /filtration plant as is now
being mandated by EPA. Such expenditure is not warranted. Indeed it could be harmful to the quality of
the Croton system's drinking water and consequently, to public health because funding and manpower
would not be available for more pressing needs.
Response: See Response 600.b and 600.d.
EPA Letter ID: 410
Comment ID: 10488
Comment Response for the LT2ESWTR
7-24
December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Commenter: Dan Saltzman, Commissioner-in-Charge, Portland Water Bureau
Commenter Category: Regulated Community (Utilities)
Comment: processes to comply with those rules. In anticipation of the forthcoming Long
Term 2 Enhanced Surface Water Treatment Rule the bureau initiated a public decision-making process in
April 2001 to evaluate the four treatment options available to achieve two logs of inactivation or removal
of Cryptosporidium. The Bull Run Treatment Citizens Panel spent considerable time working through the
risks associated with Cryptosporidium and reached the following conclusion:
"The Panel's perspective is that the risk of disease from Cryptosporidium is relatively small for Bull Run
users. While it recognizes its responsibility to be cautious in interpreting the evidence, the Panel believes
that treatment will add only a small degree of safety to the Bull Run water
supply - one that probably will not be measurable. The Panel bases this belief on three findings:
1) the protected nature of the Bull Run watershed, whichhas eliminated human and bovine sources of
Cryptosporidium,
2) monitoring results that reveal Cryptosporidium only atlow levels, and
3) the absence of epidemic logical evidence of epidemic or endemic transmission of Cryptosporidium via
Bull Run water."
The Citizens Panel came to a majority recommendation on a treatment method, basing its decision to
recommend membrane filtration on the multiple benefits, including improved system reliability and
access to additional supply in existing watershed storage reservoirs. However, members of the community
have continued to raise the question of the need to modify treatment at all. Consistent with the comment
about the low risk associated with Cryptosporidium, the Panel recommendations included the following
statement:
"The Panel notes that the least expensive way to achieve compliance with the anticipated regulations is by
installing ozone or UV treatment. UV carries the lowest cost of the four treatment options. The Panel
observes, therefore, that if the City wished only to achieve
regulatory compliance at the lowest cost, it would select UV treatment.(It should be noted that several
Panel members believe UV treatment should not be considered under any circumstances because UV
technology provides few benefits beyond Cryptosporidium removal and because of other uncertainties
associated with this technology.)"
Based on the real or perceived low benefit to cost ratio of modifying treatment to address
Cryptosporidium I request that EPA include a waiver provision in the Cryptosporidium treatment
requirement of the forthcoming Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR).
Such a provision would allow those with protected, low risk drinking water sources, such as the Bull Run,
to avoid substantial expenditures that may potentially provide very little benefit.
Local governments do not have resources to spare on potentially low-value investments, and the City of
Portland is no exception. The financial burden to our community of addressing combined sewer over-
flows have driven Portland's combined water and wastewater bill to the highest among 36 large municipal
systems in the country. Portland ratepayers currently bear the sole burden of continuing increases in
wastewater rates to fund completion of this major
investment.
Meanwhile, the City also faces mounting deferred maintenance costs to improve water system security
and infrastructure and additional regulatory actions to bring the Bull Run source into compliance with
other federal regulations including the Endangered Species and Clean Water acts. A waiver from the
Comment Response for the LT2ESWTR 7-25 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Cryptosporidium treatment requirement of the LT2ESWTR would allow the City to invest its limited and
highly constrained local resources in programs, projects and initiatives with solid benefit-to-cost ratios
that achieve these outcomes.
Response: See Response 600.b and 600.d.
EPA Letter ID: 456
Comment ID: 10962
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: benefit.... A waiver from the Cryptosporidium treatment requirement of the LT2SWTR would
allow the City to invest its limited and highly constrained local resources in programs, projects and
initiatives with solid benefit-to-cost ratios that achieve these outcomes.-
Response: See Response 600.b and 600.d.
EPA Letter ID: 592
Comment ID: 12109
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: the public from a non-existent problem. The financial resources that would be spent to solve
this non-existent problem would better serve the public health interest by being spent on upgrading ageing
distribution system problems and other issues that will be addressed in the upcoming proposed new
coliform rule revisions. Waiver criteria must be established and made available for those utilities that can
show that Cryptosporidium is not an issue with their source.
Response: See Response 600.b and 600.d.
EPA Letter ID: 608
Comment ID: 13132
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: We agree with this statement from Dan Saltzman, Portland Commissioner in charge
of the Water Bureau, in his comment letter to EPA dated 11-19-03, regarding the LT2SWTR "Based on
the real or perceived low benefit to cost ratio of modifying treatment to address Cryptosporidium I request
that EPA include a waiver provision in the Cryptosporidium treatment requirement of the forthcoming
Long Term 2 Enhanced Surface Water Treatment Rule (LT2SWTR). Such a provision would allow those
with protected, low risk drinking water sources, such as the Bull Run, to avoid substantial expenditures
that may potentially provide very little benefit....A waiver from the Cryptosporidium treatment
requirement of the LT2SWTR would allow the City to invest its limited and highly constrained local
Comment Response for the LT2ESWTR 7-26 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
resources in programs, projects and initiatives with solid benefit-to-cost ratios that achieve these
outcomes."
Response: See Response 600.d.
7.5 Comment Code 630, Use of Two Disinfectants to Meet Total
Treatment Requirements
Individual Comments on Code 630
EPA Letter ID: 101
Comment ID: 10885
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: inactivation requirement for at least one regulated pathogen. NRWA supports the alternative
approach to allow unfiltered systems to meet the inactivation requirements using any combination of one
or more disinfectants or other treatment technologies that achieve the required inactivation level for
cryptosporidium. This gives systems greater flexibility to decide what best meets the needs of the
community.
Response: See Response 600.h.
EPA Letter ID: 444
Comment ID: 10813
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment: a. NH agrees with the proposed requirement that unfiltered systems use two disinfectants.
However, waivers of this requirement should be made available for small systems (<500 people) where a
very low level of Crypto detection can be demonstrated. This approach is consistent with Sate and EPA
efforts to maintain affordable supplies for all systems, including those with a very limited customer base.
Response: See Response 600.d and 600.h.
EPA Letter ID: 470
Comment ID: 11070
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: For unfiltered systems, the use of two disinfectants and for each disinfectant
to meet by itself the inactivation requirement for at least one regulated pathogen is an appropriate
approach. This approach is supportive of the multi-barrier approach that Vermont has supported for many
years and is supported by our current regulatory framework.
Comment Response for the LT2ESWTR 7-27 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Response: See Response lOO.a.
EPA Letter ID: 474
Comment ID: 11194
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: We concur with the proposed requirement for the use of two disinfectants. This
requirement augments the public health protections of unfiltered utility watershed and source water
protection programs that are an important part of our multiple barrier system for public health protection.
By continuing to meet the filtration avoidance criteria and augmenting disinfection capabilities, unfiltered
systems enhance the reliability and resiliency of the management and treatment practices that our
communities depend on to provide safe, high quality
water to them under every circumstance.
Response: See Response lOO.a.
EPA Letter ID: 474
Comment ID: 11195
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: While supporting the provision for two disinfectants, we oppose any proposal
that would specify an inactivation requirement for each disinfectant because it may unnecessarily limit
our ability to minimize DBFs while optimally meeting microbial inactivation requirements. On the other
hand, EPA-s alternate proposal that would allow inactivation to be achieved by using a combination of
one or more disinfectants would provide the flexibility to achieve LT2 inactivation requirements while
also allowing utilities to configure and operate treatment
processes to minimize DBF's. While this alternative approach may provide marginally less protection
against unregulated pathogens, it would be more protective against the potential formation of unregulated
disinfection byproducts.
Response: See Response 600.h.
EPA Letter ID: 481
Comment ID: 11253
Commenter: Michael Kumm, General Manager, Sturgeon Bay Utilities
Commenter Category: Regulated Community (Utilities)
Comment: August 11, 2003) EPA 40 CFR Parts 141 and 142 Docket ID No. OW-2002-0039. This
comment speaks to Section IV.B - Unfiltered System Treatments Technique Requirement for the use of
two (2) disinfectants, with each disinfectant individually required to meet the inactivation requirement. In
the case of ground water under the influent of surface waters where there has been no detection of
cryptosporidium, the current regulation for use of a single
Comment Response for the LT2ESWTR 7-28 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
disinfection process is sufficient. If the concern is the failure of the primary disinfection system, the
discontinuation of use of that source is warranted and is current practice. The use of multiple barriers
using two primary disinfectants such as ozone with UV, ozone with MF or UF, UV with MF or UF or
other combinations at multiple well station sites using ground water is hopefully not the intent of this
Rule and certainly is not warranted solely on the basis of providing multiple barriers, especially when
there is no record of these pathogens in the source water. The use of a primary disinfection and a
secondary disinfectant such as chlorine is reasonable. The Rule does not suggest, however, a treatment
level for the secondary disinfectant. A minimum chlorine residual entering the system, as currently
required under the SWTR, is reasonable.
Response: See Response 600.h.
EPA Letter ID: 485
Comment ID: 11289
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Section IV Unfiltered Treatment: EPA requests comment on the requirement for
unfiltered systems to use two disinfectants and for each disinfectant to, by itself, provide the inactivation
requirement of at least one regulated pathogen.
Response: The Department strongly supports this requirement for the reasons outlined in the rule
document, which include improved inactivation against a wide variety of pathogens and improved
treatment reliability through the multibarrier approach.
Response: See Response lOO.a.
EPA Letter ID: 516
Comment ID: 11735
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 5) DISINFECTION REQUIREMENTS FOR UNFILTERED SYSTEMS The proposed
language which defines disinfection requirements for unfiltered systems appears to be
unreasonably restrictive and should be modified. While the proposed language poses no difficulty for
DEP under the City-s current and planned disinfection regimes (i.e., chlorination and UV for DEP-s
Catskill/Delaware supplies), the proposed language unnecessarily limits disinfection options - and this
could pose a difficulty for various water systems (including DEP, should we want to modify our
disinfection strategy in the future).
The LT2 proposed disinfection requirement is included below, and the particularly troublesome clause is
highlighted in bold print. In the LT2 (p. 47679, column 3 under -treatment requirements-) it states:
-In addition, unfiltered systems are required to use at least two different disinfectants to meet their overall
inactivation requirements for viruses (4 log), Giardia lamblia (3 log), and cryptosporidium (2 or 3 log).
Further, each of the two disinfectants much achieve by itself the total inactivation required for one of
these three pathogen types-..In all cases unfiltered systems must continiue to meet disinfectant residual
Comment Response for the LT2ESWTR 7-29 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements
Comment Codes 600-640
requirements for the distribution
system.-
This limitation goes beyond the wording of the AIP which on this matter merely requires that -overall
inactivation requirements must be met using a minimum of 2 disinfectants.- If the basis of the LT2 is
public health protection, as long as the required pathogen inactivation levels are achieved, it should not
matter which disinfection process achieves which portion of the inactivation? The restriction is
troublesome given the goal to reduce DBF levels . The proposed
language could limit a water system-s options for reducing DBF levels.
Response: See Response 600.h.
EPA Letter ID: 520
Comment ID: 11591
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA also supports the proposed requirement that unfiltered systems must meet
the combined Cryptosporidium, Giardia lamblia, and virus inactivation requirements using a minimum of
two disinfectants, and that each disinfectant must separately achieve the total inactivation required for
either Cryptosporidium, Giardia lamblia, and virus inactivation. This requirement will result in improved
inactivation against a wide variety of pathogens and improved treatment reliability through the multi-
barrier approach.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11624
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA also supports the proposed requirement that unfiltered systems must meet
the combined Cryptosporidium, Giardia lamblia, and virus inactivation requirements using a minimum of
two disinfectants, and that each disinfectant must separately achieve the total inactivation required for
either Cryptosporidium, Giardia lamblia, and virus inactivation. This requirement will result in improved
inactivation against a wide variety of pathogens and
improved treatment reliability through the multi-barrier approach.
Response: See Response lOO.a.
EPA Letter ID: 522
Comment ID: 14132
Comment Response for the LT2ESWTR
7-30
December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: EPA solicited comments on the proposed requirement for unfiltered systems to
use two disinfectants and for each disinfectant to meet by itself the inactivation requirement for at least
one regulated pathogen.
While no specific compelling technical argument is made for its inclusion in the regulation, the
requirement as detailed in the draft regulations and preamble meets the intent of the FACA Agreement in
Principle (AIP). As the risk analysis for unfiltered systems already assumed meeting a minimum
inactivation (rather than the average removal credited to filtration plants),
and given that by their very nature unfiltered sources have low Cryptosporidium levels, there may no
demonstrable health benefit from adding a second disinfectant at all times. In fact, depending on the
choice of the disinfectants, there may be an increase in exposure to disinfection byproducts (or a lost
opportunity to realize a reduction). Ongoing monitoring
Response: See Response 600.h.
EPA Letter ID: 522
Comment ID: 14135
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: MWRA is also concerned that while the preamble makes it clear that the second
primary disinfectant only meet the full disinfection requirement for one pathogen, such as the example of
4-log virus inactivation, the regulatory language may be subject to misinterpretation by primacy agencies
as they draft their own regulations. In addition, it is also possible that there
could be misinterpretation if a system used three disinfectants, rather than two. The language in the
regulation itself should be as clear as possible. EPA solicited comments on an alternate approach that
would allow systems to meet the inactivation requirements using any combination of one or more
disinfectants that achieved the required inactivation level for all pathogens.
This approach would allow utilities additional flexibility to design and operate treatment plants that are
responsive to the unique local water quality conditions. It does not appear to have any substantive
disadvantages over the more rigid proposal in the current draft, and may allow more systems to
effectively leverage their existing treatment investments with less expensive treatment process additions.
More importantly, it may allow some systems to minimize their reliance on chlorine. MWRA is
supportive of this additional flexibility.
Response: See Response 600.h.
EPA Letter ID: 522
Comment ID: 14136
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
Comment Response for the LT2ESWTR 7-31 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: EPA solicited comments on whether the proposed requirements for use of two
disinfectants establish an adequate level of multiple barriers in the treatment provided by unfiltered
systems.
The form of the solicitation ignores the unique distinction of the unfiltered systems. By virtue of
complying with stringent source water quality and watershed control criteria contained in the Surface
Water Treatment Rule, unfiltered systems already have a substantive barrier in place prior to treatment.
The addition of the second primary disinfectant requirement represents not just the traditional "belt and
suspenders" of high quality well protected source water and effective disinfection, but an approach of
belt, suspenders and two guys holding up your pants". The proposed regulation proposes no similar
degree of extreme redundancy for the substantially more
at risk systems with wholly unprotected source waters that rely for substantially all of their
Cryptosporidium risk reduction on the single barrier of filtration. Bin 1 systems have no source water
protection, and rely on the average performance of their filters to achieve the required 3-
log reduction of Cryptosporidium. The risk analysis suggests that Bin 2 utilities need 4-reduction, but
redundancy is only required for 1-log. And so on. There simply does not appear to be a data supported,
internally consistent argument for this modification to the proposed rule. MWRA urges EPA not to adopt
this modification.
In response to all three of these requests for comment on the second primary disinfectant requirement,
MWRA urges that the current proposal represent the most stringent disinfection requirement that EPA
considers in drafting the final regulations. Given the lack of a demonstrable health benefit, we urge EPA
to include as much flexibility for utilities to make site-specific
decisions as possible.
Response: See Response 600.h.
EPA Letter ID: 523
Comment ID: 11669
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: While no specific technical argument is made for its inclusion in the regulation, the
requirement as detailed in the draft regulations and preamble meets the intent of the FACA Agreement in
Principle (AIP). As the risk analysis for unfiltered systems already assumed meeting a minimum
inactivation, and given that by their very nature unfiltered sources have low and stable Cryptosporidium
levels, there may be no demonstrable health benefit from adding a second disinfectant at all times. In fact,
depending on the choice of the disinfectants, there may be an increase in exposure to disinfection
byproducts (or a lost opportunity to realize a reduction). Ongoing monitoring by several of the largest
unfiltered utilities indicates that the exposure assumptions for Cryptosporidium levels used by EPA in the
preamble may be extremely conservative. The Unfiltered Working Group urges EPA to carefully conduct
a risk analysis based on current occurrence and health data before finalizing the two primary disinfectants
requirement. As discussed below, a more flexible approach makes more sense, at lower cost.
Response: See Response 600.h.
Comment Response for the LT2ESWTR 7-32 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
EPA Letter ID: 523
Comment ID: 11670
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA solicited comments on an alternate approach to allow systems to meet the
inactivation requirements using any combination of one or more disinfectants that achieved the required
inactivation level for all pathogens.
This approach would allow utilities additional flexibility to design and operate treatment plants that are
responsive to the unique local water quality conditions. It does not appear to have any substantive
disadvantages over the more rigid proposal in the current draft, and may allow more systems to
effectively leverage their existing treatment investments with less expensive treatment process additions.
More importantly, if two primary disinfectants are required in the final rule, this more flexible approach
may allow some systems to minimize their reliance on chlorine.
Response: See Response 600.h.
EPA Letter ID: 523
Comment ID: 11671
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA solicited comments on whether the proposed requirements for use of two
disinfectants establish an adequate level of multiple barriers in the treatment provided by unfiltered
systems.
The Unfiltered Working Group believes that the proposed requirement, or preferable a more flexible
version, provides more than adequate protection. By complying with the stringent source water quality
and watershed control criteria contained in the Surface Water Treatment Rule, unfiltered systems already
have a substantive barrier in place prior to treatment. The addition of the second primary disinfectant
requirement represents not just the traditional "belt and suspenders" of high-quality we 11-protected source
water and effective disinfection, but an approach of "belt, suspenders and two guys holding up your
pants". The draft regulation proposes no similar degree of extreme redundancy for the substantially more
at risk systems with wholly unprotected source waters that rely for substantially all of their
Cryptosporidium risk reduction on the single barrier of filtration. Bin 1 systems have no source water
protection, and rely only on the average performance of their filters to achieve the required 3-log
reduction of Cryptosporidium, with essentially no redundancy. The risk analysis suggests that Bin 2
utilities need 4-reduction, but 3-logs are assumed for the filters and an additional 1-log is required from
the toolbox or inactivation, but no redundancy is required for either. And so on. There simply does not
appear to be a data-supported, internally consistent argument for any additional degree of redundancy
than provided by the existing SWTR provisions redundant disinfection systems combined with the
provisions for two primary disinfectants agreed to in the AIP and presented in the draft rule. The
Unfiltered Working Group urges EPA not to adopt this modification.
In response to all three of these requests for comment on the second primary disinfectant requirement, the
Comment Response for the LT2ESWTR 7-33 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Unfiltered Utilities Working Group recommends that the current proposal represent the most stringent
disinfection requirement that EPA considers in drafting the final regulations. Given the lack of a
demonstrable health benefit, if the two primary disinfectants requirement is to remain in the final rule, we
urge EPA to include as much flexibility for
utilities to make site specific decisions as possible.
Response: See Response 600.h.
EPA Letter ID: 523
Comment ID: 11681
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: While no specific technical argument is made for its inclusion in the regulation, the
requirement as detailed in the draft regulations and preamble meets the intent of the FACA Agreement in
Principle (AIP). As the risk analysis for unfiltered systems already assumed meeting a minimum
inactivation, and given that by their very nature unfiltered sources have low and stable Cryptosporidium
levels, there may be no demonstrable health benefit from adding a second disinfectant at all times. In fact,
depending on the choice of the disinfectants, there may be an increase in exposure to disinfection
byproducts (or a lost opportunity to realize a reduction). Ongoing monitoring by several of the largest
unfiltered utilities indicates that the exposure assumptions for Cryptosporidium levels used by EPA in the
preamble may be extremely
conservative. The Unfiltered Working Group urges EPA to carefully conduct a risk analysis based on
current occurrence and health data before finalizing the two primary disinfectants requirement. As
discussed below, a more flexible approach makes more sense, at lower cost.
Response: See Response 600.h.
EPA Letter ID: 523
Comment ID: 11682
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA solicited comments on an alternate approach to allow systems to meet the
inactivation requirements using any combination of one or more disinfectants that achieved the required
inactivation level for all pathogens.
This approach would allow utilities additional flexibility to design and operate treatment plants that are
responsive to the unique local water quality conditions. It does not appear to have any substantive
disadvantages over the more rigid proposal in the current draft, and may allow more systems to
effectively leverage their existing treatment investments with less expensive treatment process additions.
More importantly, if two primary disinfectants are required in the final rule, this more flexible approach
may allow some systems to minimize their reliance on chlorine.
Response: See Response 600.h.
Comment Response for the LT2ESWTR 7-34 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
EPA Letter ID: 523
Comment ID: 11683
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA solicited comments on whether the proposed requirements for use of two
disinfectants establish an adequate level of multiple barriers in the treatment provided by unfiltered
systems.
The Unfiltered Working Group believes that the proposed requirement, or preferable a more flexible
version, provides more than adequate protection. By complying with the stringent source water quality
and watershed control criteria contained in the Surface Water Treatment Rule, unfiltered systems already
have a substantive barrier in place prior to treatment. The addition of the second primary disinfectant
requirement represents not just the traditional "belt and suspenders" of high-quality we 11-protected source
water and effective disinfection, but an approach of "belt, suspenders and two guys holding up your
pants". The draft regulation proposes no similar degree of extreme redundancy for the substantially more
at risk systems with wholly unprotected source waters that rely for substantially all of their
Cryptosporidium risk reduction on the single barrier of filtration. Bin 1 systems have no source water
protection, and rely only on the average performance of their filters to achieve the required 3-log
reduction of Cryptosporidium, with essentially no redundancy. The risk analysis suggests that Bin 2
utilities need 4-reduction, but 3-logs are assumed for the filters and an additional 1-log is required from
the toolbox or
inactivation, but no redundancy is required for either. And so on. There simply does not appear to be a
data-supported, internally consistent argument for any additional degree of redundancy than provided by
the existing SWTR provisions redundant disinfection systems combined with the provisions for two
primary disinfectants agreed to in the AIP and presented in the draft rule. The
Unfiltered Working Group urges EPA not to adopt this modification.
In response to all three of these requests for comment on the second primary disinfectant requirement, the
Unfiltered Utilities Working Group recommends that the current proposal represent the most stringent
disinfection requirement that EPA considers in drafting the final regulations. Given the lack of a
demonstrable health benefit, if the two primary disinfectants requirement is to remain in the final rule, we
urge EPA to include as much flexibility for utilities to make site specific decisions as possible.
Response: See Response 600.h.
EPA Letter ID: 592
Comment ID: 12107
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Unfiltered, waivered water sources
Because Maine has mostly pristine clean water sources, many of the state drinking water purveyors are
waivered, unfiltered sources. All unfiltered sources are being asked to treat the water twice, under the
presumption that there may be Cryptosporidium in the water even if none is ever found. This represents a
Comment Response for the LT2ESWTR 7-35 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
very expensive knee-jerk response to the Milwaukee outbreak.
Establishing variance or waiver criteria
Response: See Response 600.d and 600.h.
EPA Letter ID: 592
Comment ID: 12110
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Use of multiple disinfectants
Unfiltered systems must be allowed to meet the requirements by using any proven combination of
disinfectants. Several systems in Maine use ozone to protect for Giardia, the pathogen of concern 10 years
ago. But as these rules are proposed ozone treatment is rendered efSectively obsolete. Use of two
disinfectants does establish an adequate level of multiple barriers in treatment for unfiltered systems. The
criteria for an unfiltered system waiver are already based on a multi barrier approach. The decision as to
whether it is economically feasible for an unfiltered system to demonstrate that its water source is 3 logs
lower than the cut-off for bin 1 for filtered systems and, thus provide comparable protection without
additional inactivation must be a utility decision. The utility is in a better position than the EPA to decide
whether it is prudent to spend money for additional monitoring or money for improved treatment. The
water quality of some sources is such that large volumes of source water could be filtered, thus providing
the added sensitivity required to ascertain that the public health is protected. Waivers must be provided
for those systems that
Response: See Response 600.d and 600.h.
EPA Letter ID: 643
Comment ID: 12743
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States also support the proposed requirement that unfiltered systems must meet the combined
Cryptosporidium, Giardia lamblia, and virus inactivation requirements using a minimum of two
disinfectants, and that each disinfectant must separately achieve the total inactivation required for either
Cryptosporidium, Giardia lamblia, or virus inactivation. This requirement will result in improved
inactivation against a wide variety of pathogens and improved treatment reliability through the multi-
barrier approach.
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12779
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 7-36 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Comment: States also support the proposed requirement that unfiltered systems must meet
the combined Cryptosporidium, Giardia lamblia, and virus inactivation requirements using a minimum of
two disinfectants, and that each disinfectant must separately achieve the total inactivation required for
either Cryptosporidium, Giardia lamblia, and virus inactivation. This requirement will result in improved
inactivation against a wide variety of pathogens and improved treatment reliability through the multi-
barrier approach.
Response: See Response lOO.a.
EPA Letter ID: 645
Comment ID: 13558
Commenter: Kathy Moriarty, Water Quality Manager, Bangor Water District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
B. Unfiltered System Treatment Technique Requirements for Cryptosporidium [pp.47679- 47681]
Request for Comment: Use of two disinfectants
Suggested Comments:
Unfiltered systems must be allowed to meet the requirements by using any proven combination of
disinfectants. Allow systems to meet the inactivation requirements using a combination of one or more
disinfectants. Use of two disinfectants in combination does establish an adequate level of multiple barriers
in treatment for unfiltered systems. Filtration waiver criteria for an unfiltered system are based on a multi-
barrier approach. Source water protection requirements are addressed by the utility in their Watershed
Control Plans. These plans are reviewed by the State and followed by watershed inspections. At the
treatment plant, a barrier of protection is met by meeting CT requirements.In the distribution system,
disinfectant residual is measured by a detectableresidual. Cross connection program is yet another barrier.
Response: See Response 600.h.
EPA Letter ID: 668
Comment ID: 13899
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - We support requiring two disinfectants for unfiltered systems, in order to assure multiple
barriers to waterborne disease, (p. 47681)
Response: See Response lOO.a.
EPA Letter ID: 678
Comment ID: 14712
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 7-3 7 December 2005
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Chapter 7: Unfiltered Systems Monitoring and Treatment Requirements Comment Codes 600-640
Comment: 8. The EPA requests comment on the proposed requirement for unfiltered
systems to use two disinfectants and for each disinfectant to meet by itself the inactivation requirement
for at least one regulated pathogen. [47681, C2]
Comment: We believe the requirement for two disinfectants is not necessary. The EPA should focus on
the level of inactivation achieved through the overall treatment and not be prescriptive on how it is
achieved. There is no reason for being so prescriptive.
Response: See Response 600.h.
7.6 Comment Code 640, Rule Language Edits
Individual Comments on Code 640
EPA Letter ID: 480
Comment ID: 11233
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: Subpart (d) reads:
-(d) Unfiltered systems must meet the combined Cryptosporidium, Giardia lamblia,
and virus inactivation requirements of this section and § 141.72(a) using a minimum of two disinfectants,
and each disinfectant must separately achieve the total inactivation required for either Cryptosporidium,
Giardia lamblia, or viruses.-
This language should be clarified. The preamble cites an example of using UV disinfection for 2-log
Cryptosporidium & 2-log Giardia inactivation, and chlorine for 4-log virus and 1-log Giardia inactivation,
however interpretation of rule language may not lead to the same conclusion, with a possible
interpretation that splitting the inactivation of Giardia between UV and chlorine is not acceptable. As
well, if a utility used three disinfectants (ozone, UV and chlorine, for example), it appears that the
language as written would require each of the three to independently, or -separately achieve the total
inactivation required for either Cryptosporidium, Giardia lamblia, or
viruses.- (i.e. all Cryptosporidium inactivation with UV, all Giardia inactivation with ozone, and all virus
inactivation with chlorine.)
Response: See Responses SOO.aa and 600.h.
Comment Response for the LT2ESWTR 7-38 December 2005
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Public Comment and
Response Document
for the Long Term 2
Enhanced Surface Water
Treatment Rule
Volume II: Chapters 8-10
Comment Response for LT2ESWTR December 2005
-------
TABLE OF CONTENTS
8. OPTIONS FOR MEETING TREATMENT REQUIREMENTS: COMMENT CODES 700-970 8-1
8.1 COMMENT CODE 700, OPTIONS FOR MEETING TREATMENT REQUIREMENTS 8-1
8.2 COMMENT CODE 710, MICROBIAL TOOLBOX GENERAL COMMENTS 8-3
8.3 COMMENT CODE 720, WATERSHED CONTROL PROGRAM 8-39
8.3.1 Comment Code 721, Proposed credit 8-47
8.3.2 Comment Code 722, Program requirements 8-56
8.3.3 Comment Code 723, Reduced frequency for watershed survey 8-75
8.3.4 Comment Code 724, Data on methods to reduce Cryptosporidium Contamination 8-88
8.3.5 Comment Code 725, Data on delineating area of influence 8-92
8.3.6 Comment Code 726, Confidentiality and watershed annual reports 8-94
8.3.7 Comment Code 727, Expiration of treatment credit after second round of monitoring 8-98
8.3.8 Comment Code 728, Rule Language Edits 8-106
8.3.9 Comment Code 729, Guidance 8-107
8.4 COMMENT CODE 740, ALTERNATIVE SOURCE/INTAKE/INTAKE MANAGEMENT STRATEGY 8-108
8.4.1 Comment Code 741, Proposed monitoring and reporting requirements 8-109
8.4.2 Comment Code 742, Intake management strategies 8-111
8.4.3 Comment Code 743, Representative monitoring prior to new intake construction 8-113
8.4.4 Comment Code 744, Application to plants with multiple sources 8-114
8.4.5 Comment Code 745, Rule Language Edits 8-115
8.5 COMMENT CODES 750, OFF-STREAM RAW WATER STORAGE 8-116
8.5.1 Comment Codes 751, Decision not to grant credit based on existing data 8-117
8.5.2 Comment Codes 752, Additional data on off-stream storage 8-121
8.5.3 Comment Codes 753, Addressing contamination due to algae, birds, runoff, etc 8-121
8.5.4 Comment Codes 754, Rule Language Edits 8-122
8.6 PRESEDIMENTATION BASIN WITH COAGULANT 8-123
8.6.1 Comment Code 761, Credit and criteria for awarding credit 8-123
8.6.1.1 Comment Code 762, Conditions that would affect compliance with criteria 8-129
8.6.2 Comment Code 763, Additional data on presedimentation 8-130
8.6.3 Comment Code 766, Credit for existing basins 8-131
8.7 COMMENT CODES 770, BANK FILTRATION 8-132
8.7.1 Comment Codes 771, Credits and criteria for awarding credit 8-138
8.7.1.1 Comment Codes 772, Aquifer type/core characteristics 8-145
8.7.1.2 Comment Codes 773, Separation distance 8-145
8.7.1.3 Comment Codes 775, Turbidity monitoring 8-146
8.7.2 Comment Codes 780, Indicator/surrogate measurements suitable for predicting removal 8-148
8.7.3 Comment Codes 781, Alternative methods for determining site suitability 8-150
8.7.4 Comment Codes 782, Data on effectiveness of bank filtration at existing sites 8-151
8.7.5 Comment Codes 783, Data on GWUDI systems using bank filtration alone 8-154
8.7.6 Comment Codes 785, Procedures for making site-specific decisions on bank filtration credit 8-155
8.7.7 Comment Codes 786, Rule Language Edits 8-157
8.7.8 Comment Codes 787, Guidance 8-158
8.8 COMMENT CODES 790, LIME SOFTENING 8-159
8.8.1 Comment Codes 791, Credit and criteria for awarding credit 8-160
8.8.2 Comment Codes 792, Additional data on lime softening 8-169
8.8.3 Comment Codes 793, Rule Language Edits 8-171
8.9 COMMENT CODES 800, COMBINED FILTER PERFORMANCE 8-172
8.9.1 Comment Codes 801, Credit and criteria for awarding credit 8-174
8.9.2 Comment Codes 802, Additional data on filtration performance 8-181
8.9.3 Comment Codes 803, Turbidity monitoring accuracy at low levels 8-182
8.9.4 Comment Codes 804, Rule Language Edits 8-189
8.9.5 Comment Codes 805, Guidance 8-189
8.10 COMMENT CODES 810, ROUGHING FILTERS 8-190
Comment Response for LT2ESWTR i December 2005
-------
8.10.1 Comment Codes 811, Decision not to award credit 8-191
8.11 COMMENT CODES 820, SLOW SAND FILTRATION 8-194
8.11.1 Comment Codes 821, Credit and criteria for awarding credit 8-196
8.12 COMMENT CODES 830, MEMBRANE FILTRATION 8-199
8.12.1 Comment Codes 831, Credit and criteria for awarding credit 8-201
8.12.2 Comment Codes 832, Additional data on membrane filtration performance 8-212
8.12.3 Comment Codes 833, Inclusion of membrane cartridge filters that can be integrity tested 8-213
8.12.4 Comment Code 834, Applicability of credit and criteria to Giardia 8-214
8.12.5 Comment Codes 835, Appropriate surrogates for challenge testing 8-215
8.12.6 Comment Codes 836, Use of non-destructive performance testing 8-215
8.12.7 Comment Codes 837, Minimum direct integrity testing frequency 8-219
8.12.8 Comment Codes 838, Reporting frequency for not meeting integrity criteria 8-222
8.12.9 Comment Codes 839, Rule Language Edits 8-223
8.12.10 Comment Codes 840, Guidance 8-223
8.12.11 Comment Codes 841, Membrane Guidance Manual (specific to the guidance manual) 8-225
8.13 COMMENT CODES 850, BAG AND CARTRIDGE FILTRATION 8-226
8.13.1 Comment Codes 851, Credits and criteria for awarding credits 8-228
8.13.1.1 Comment Codes 852, Use of 1 log safety factor 8-231
8.13.1.2 Comment Codes 853, Limiting log credit to 2 log (bag) and 3 log (cartridge) 8-233
8.13.2 Comment Codes 860, Additional data on bag and cartridge filter performance 8-234
8.13.2.1 Comment Codes 861, Other challenge test requirements 8-234
8.13.3 Comment Codes 871, Applicability of process monitoring to verify integrity 8-235
8.13.4 Comment Codes 874, Rule Language Edits 8-235
8.13.5 Comment Codes 875, Guidance 8-235
8.14 COMMENT CODE 880, SECONDARY FILTRATION 8-236
8.14.1 Comment Code 881, Credit and criteria for awarding credit 8-238
8.14.2 Comment Code 883, Minimum depth for secondary filter 8-243
8.14.3 Comment Code 884, Credit for both second clarification stage and lower finished water
turbidity 8-245
8.14.4 Comment Code 886, Guidance 8-246
8.15 COMMENT CODES 890, OZONE AND CHLORINE DIOXIDE 8-247
8.15.1 Comment Codes 891, Credit and criteria for awarding credit 8-250
8.15.1.1 Comment Codes 892, Determination of CT , including confidence bounds 8-261
8.15.2 Comment Codes 893, Additional data on inactivation for CT tables 8-266
8.15.3 Comment Codes 894, Site-specific determination ofCT 8-268
8.15.4 Comment Codes 896, Compliance with bromate and chlorite MCLs 8-269
8.15.5 Comment Codes 898, Guidance 8-273
8.16 COMMENT CODES 910, UVLIGHT 8-275
8.16.1 Comment Code 911, Credit and criteria for awarding credit 8-283
8.16.1.1 Comment Codes 912, UV dose tables Individual Comments on Code 912 8-304
8.16.1.2 Comment Codes 913, Reactor validation testing 8-323
8.16.1.3 Comment Codes 914, Reactor monitoring 8-338
8.16.1.4 Comment Codes 916, Compliance determination for filtered systems 8-341
8.16.1.5 Comment Codes 917, Off-spec operation 8-346
8.16.2 Comment Codes 920, Additional data on UV disinfection 8-357
8.16.3 Comment Code 921, Rule Language Edits 8-358
8.16.4 Comment Codes 922, Guidance 8-358
8.16.5 Comment Codes 923, Guidance on UV. 8-425
8.17 COMMENT CODES 930, INDIVIDUAL FILTER PERFORMANCE 8-427
8.17.1 Comment Codes 931, Proposed credit and criteria for awarding credit 8-433
8.17.2 Comment Codes 933, Different or additional criteria for awarding credit 8-449
8.17.3 Comment Codes 934, Existing peer review programs eligible for credit. 8-453
8.17.4 Comment Codes 935, Use of 0.15 NTUrather than 0.1 NTU 8-458
8.18 COMMENT CODES 950, OTHER DEMONSTRATION OF PERFORMANCE 8-462
8.18.1 Comment Codes 951, Proposed approach for awarding credit 8-467
8.18.2 Comment Codes 952, Approaches that should be considered or excluded 8-476
8.18.3 Comment Codes 953, Minimum elements for testing 8-478
Comment Response for LT2ESWTR ii December 2005
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8.18.4 Comment Codes 954, Safety factor 8-478
8.18.5 Comment Codes 955, Credit for unit processes 8-479
8.18.6 Comment Codes 957, Guidance 8-481
8.19 COMMENT CODE 970, TOOLBOX GUIDANCE MANUAL (SPECIFIC TO THE GUIDANCE MANUAL) 8-482
9. DISINFECTION BENCHMARKS: COMMENT CODES 1000-1020 9-1
9.1 COMMENT CODE 1000, DISINFECTION BENCHMARKS 9-1
9.2 COMMENT CODE 1020, GUIDANCE 9-16
10. UNCOVERED FINISHED WATER RESERVOIRS: COMMENT CODES 1100-1170 10-1
10.1 COMMENTCODE 1100, UNCOVERED FINISHED WATER RESERVOIRS 10-1
10.2 COMMENT CODE 1110, RISK MITIGATION OR TREATMENT INSTEAD OF COVERING 10-7
10.3 COMMENT CODE 1120, REQUIRING INACTIVATION OF CRYPTOSPORIDIUM AND GIARDIA 10-13
10.4 COMMENT CODE 1130, DATA ON CONTAMINATION OF UNCOVERED RESERVOIRS 10-15
10.5 COMMENT CODE 1140, DATA ON WEATHER, EFFECT ON CORROSION CONTROL 10-16
10.6 COMMENTCODE 1150, CHANGING DEFINITION OF UNCOVERED FINISHED WATER RESERVOIRS 10-16
10.7 COMMENT CODE 1170, GUIDANCE 10-19
Comment Response for LT2ESWTR in December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
8. Options for Meeting Treatment Requirements: Comment
Codes 700-970
8.1 Comment Code 700, Options for Meeting Treatment
Requirements
Individual Comments on Code 700
EPA Letter ID: 101
Comment ID: 10921
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Risk Management
NRWA believes that USEPA has given insufficient attention to the compounding effects of regulations.
(Pontius 2001) [SEE P. 142 OF .PDF FILE]
NRWA supports, whenever feasible, non-regulatory approaches and incentives to achieve the goal of
providing public health protective drinking water.
NRWA believes that (1) the risk level associated with contaminants in drinking water is an important
element in public health, (2) the level of acceptable risk for a drinking water contaminant must be defined
taking into consideration competing risks and risk trade-offs, and (3) the use of a fixed upper bound of
acceptable risk (1/10,000 or 10-4) is neither mandated nor appropriate in establishing a health based
standard. (Cohen 2001) [SEE P. 30 OF .PDF FILE]
Response: See response lOO.c regarding EPA's attention to the compounding effects of regulations. See
section 2.6 of the Economic Analysis for the LT2ESWTR regarding the economic rationale for regulation
under this rule. The EA presents a detailed risk assessment supporting today's final rule. However, in
developing today's rule, EPA has not used a fixed upper bound of acceptable risk. Rather, as described in
the preamble, EPA has followed SDWA requirements for establishing treatment technique requirements.
These specify the use of treatment techniques that prevent adverse health effects to the extent feasible.
Further, EPA has closely followed the recommendations of the Advisory Committee in identifying
feasible treatment techniques for today's rule.
EPA Letter ID: 101
Comment ID: 10922
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: NRWA supports the development of new approaches for decentralized treatment and
dual system alternatives. (Cotruvo 2003) - With the increasing cost of regulations, many small systems
Comment Response for LT2ESWTR 8-1 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
can no longer afford the luxury of treating water used for non-human consumption to high levels of
purity. Flexibility in meeting the overriding goal of public health protection is needed and alternative
approaches for providing safe drinking water are available that, for some small systems, may be less
costly than the conventional approach of centralized treatment. Cotruvo (2003) has reviewed the
approaches available for providing potable water in small systems.
Response: See Response lOOa.
EPA Letter ID: 101
Comment ID: 10926
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: NRWA believes that consolidation must be a local choice, and not mandated.
NRWA believes that the decision to privatize must be a local choice, and not mandated.
- Consolidation is often raised as a possible approach for small water systems, especially in discussions
of water service affordability. Consolidation incentives exist in the SDWA. Furthermore, State drinking
water programs are required to assess the applicability of consolidation when reviewing system
compliance options, funding applications, and new system formation. Efforts to exert pressure to
consolidate or mandate consolidation beyond these requirements are not necessary for consolidation to be
applied to those situations where appropriate.
- Privatization is an option that may be available to some small water systems in order to respond to the
increasing challenges of providing safe drinking water to consumers. There are advantages and
disadvantages of private ownership, contract operations, public-private partnerships, and municipal
ownership.
- Privatizing all or part of a small water system operation may or may not enable the system to more
easily comply with drinking water regulations, because the costs of compliance must still be paid for by
that system, regardless of ownership. Privatization should only be considered an option where feasible,
and where it is freely chosen by the community as the preferred approach to providing public health
protection for consumers.
Benefit-Cost Analysis
NRWA believes that (1) both benefits and costs are an important consideration in setting drinking water
standards and (2) in balancing the benefits and costs of regulations, the appropriate parameter to use is
incremental net benefits. (Raucher 2001) [SEE P. 89 OF .PDF FILE]
Response: See Response lOOa.
EPA Letter ID: 427
Comment ID: 10577
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
Comment Response for L T2ESWTR 8-2 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
students, Non-university scientists, Non-university engineers, etc.
Other EPA Comment Codes and Descriptions: 620 B. Cryptosporidium Treatment Requirements
Comment: 1.Summary of Bull Run Treatment -An Independent Review -Long-Term 2
Enhanced Surface Water Treatment Rule
[SEE .PDF FILE FOR ITEM #1 - SUMMARY OF BULL RUN TREATMENT -AN
INDEPENDENT REVIEW -LONG-TERM 2 ENHANCED SURFACE WATER
TREATMENT RULE]
-PART A - Comment on the rationale for considering additional organism inactivation provisions other
than those presented in LT2ESWTR. These would be based on currently successful Individual water
utility disinfection methods and protected watersheds
Response: See Responses 600.b, lOO.f, 100.1, 250.a, 600.c, 600.d, and 600.e.
EPA Letter ID: 439
Comment ID: 10760
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: Microbial Toolbox Issue 1 Log Credit vs. Strict Log Removal
EPA should provide explanation the concept of "credit" as it applies to overall risk reduction of microbial
contaminants and DBFs, not only on strict "log
Response: See Response 710a.
8.2 Comment Code 710, Microbial Toolbox General Comments
Response to Code 710
a)EPA believes that the Cryptosporidium management and treatment options in the microbial toolbox of
today's rule reflect the intent of the Agreement in Principle. The LT2ESWTR includes those options from
the Agreement where available data support awarding treatment credit. This includes source water
protection, bank filtration, membranes, bag/cartridge filters, ozone UV light, low filtered water turbidity,
and other options. EPA recognizes that a treatment plant or a unit treatment process may be capable of
providing greater removal or inactivation of Cryptosporidium than is awarded as treatment credit in the
LT2ESWTR. Systems may receive higher Cryptosporidium treatment credit for a plant or unit process
through a demonstration of performance to the State. This provides systems and States with flexibility in
addressing the LT2ESWTR treatment requirements
EPA has focused primarily on the removal or inactivation of Cryptosporidium when assigning
Cryptosporidium treatment credit to these processes. EPA believes that this approach is appropriate, since
the purpose of adding these processes under the LT2ESWTR is to improve public health protection
Comment Response for L T2ESWTR 8-3 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
against Cryptosporidium. EPA recognizes that certain toolbox options may also improve overall treatment
stability and performance and provide a positive public health benefit. If this results in improved
Cryptosporidium removal beyond the standard credit awarded in today's rule, systems may receive higher
credit through a demonstration of performance.
In response to public comments, EPA has modified the applicable design, operational and performance
criteria for many of the toolbox options in the final LT2ESWTR. These modifications should result in
more toolbox options becoming viable options for more systems and should decrease the burden
associated with a particular toolbox option. Systems achieve treatment credit for microbial toolbox
options on a monthly basis by meeting the regulatory performance criteria specified in today's rule. These
performance criteria are based on the available data that support Cryptosporidium treatment credits. These
criteria are necessary to ensure both reliable Cryptosporidium treatment and national consistency. Under
the demonstration of performance toolbox option, States may specify site or unit process specific
performance and monitoring criteria. If allowed by the State, PWSs may also use different microbial
toolbox options in different months to comply with Cryptosporidium treatment requirements under
today's rule. This approach is intended to provide greater operational flexibility to PWSs. It allows a
PWS to receive treatment credit for a microbial toolbox option in any month the PWS is able to meet
required operational criteria, even if the PWS does not meet these criteria during all months of the year.
(b)The intent of the Cryptosporidium treatment requirements for unfiltered PWSs in today's final rule is
to ensure that they achieve public health protection equivalent to that achieved by filtered PWSs. These
requirements are unchanged from the proposal and they reflect consensus recommendations by the Stage
2 M-DBP Advisory Committee The available data suggest that unfiltered PWSs must take additional
steps to achieve public health protection against Cryptosporidium equivalent to that provided by filtered
PWSs.
In occurrence data from the ICR, the median Cryptosporidium level in unfiltered PWS sources was
0.0079 oocysts/L, which is approximately 10 times less than the median level of 0.052 oocysts/L in
filtered PWS sources. In translating these source water levels to finished water concentrations, EPA and
the Advisory Committee assumed that conventional filtration treatment plants in compliance with the
IESWTR or LT1ESWTR achieve an average of 3-log (99.9 percent) removal of Cryptosporidium.
Existing regulations do not require unfiltered PWSs to provide any treatment for Cryptosporidium.
If the median source water Cryptosporidium level in filtered PWSs is approximately 10 times higher than
in unfiltered PWSs, and filtered PWSs achieve 3-log Cryptosporidium removal, then the median finished
water Cryptosporidium level in filtered PWSs is approximately 100 times lower than in unfiltered PWSs.
Thus, these data suggest that most unfiltered PWSs must provide 2-log Cryptosporidium treatment to
ensure equivalent public health protection.
Individual Comments on Code 710
EPA Letter ID: 101
Comment ID: 10873
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Principle. The Agency significantly constrains the applicability and utility of some of the
toolbox elements through regulatory language and guidance. The Agency must recognize the importance
of maximum flexibility for small systems to comply with this rule. All barriers and impediments to
flexibility must be removed from the rule and guidance regarding the microbial toolbox.
Comment Response for L T2ESWTR 8-4 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Response: See Response 710a.
EPA Letter ID: 101
Comment ID: 10907
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Multiple Disinfectants
If a system uses multiple disinfectants, or has other treatment in place beyond basic treatment, then the
system should be given the Bin credit that the additional treatment goes with. For example: a filtration
system with chlorination and ultraviolet disinfection should automatically be given a Bin 2 credit,
regardless of other water quality or treatment concerns.
Response: See Response 710a.
EPA Letter ID: 419
Comment ID: 10503
Commenter: Billy Turner, President, Columbus Water Works
Commenter Category: Regulated Community (Utilities)
Comment:
3) EPA should re-evaluate available data, including date submitted to the docket, on toolbox technologies
with the objective of assigning sound, operationally achievable treatment credit for Cryptosporidium
removal for softening, enhanced filtration (i.e., individual and combined filter effluent credits), riverbank
filtration, and demonstration of performance.
Response: See Responses 790,800,930 and 950.
EPA Letter ID: 427
Comment ID: 10580
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: 3.The proposed LT2ESWR did not provide similar water treatment options for unfiltered
water systems, as the filtered water systems received. Unfiltered systems were not given a "toolbox" of
additional steps they could take to reduce organism counts and achieve log credits for such efforts. This
should be reviewed and some additional provisions should be put forth for unfiltered systems "toolbox" as
well.
The point of drinking water regulations is to provide additional protection for public health, through
inactivation or rendering the organism not infectious. All options for unfiltered systems should be left on
the table for continued discussion. The greatest way to prevent infection is to keep the organism out of the
Comment Response for L T2ESWTR 8-5 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
water in the watershed. More can be done to acknowledge the benefits of a protected watershed.
Permanent credits should be given for any additional "enhanced protection" improvements for unfiltered
watersheds. An example might include removal of unused roads and replacing them with vegetative
strips. This would obstruct the movement of oocysts into the road drainage system leading to the drinking
water supply.
Log-credit should come to those unfiltered systems that: -Multiple reservoir storage - microbial
degradation of oocysts in an open water reservoir storage can render the organism inactive (9)
-Demonstrate no sewage exposure, or implement a long term sewage mitigation program
-Demonstrate programs that further reduce turbidity -Provide a dedicated drinking water public health
surveillance program in the drinking water service area
-Demonstrate early warning water system surveillance (HACCP)
The New York City DEP and the San Francisco PUC each are examples of model programs for unfiltered
systems. Their sample frequency, methodology, system surveillance, and public health - awareness are to
be recognized for their superior efforts.
Response: See Response 71 Ob.
EPA Letter ID: 439
Comment ID: 10761
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: removal" of Cryptosporidium. Also EPA should allow other viable options to select from in
the proposed toolbox. Not all systems will be able to use UV disinfection
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of Iternatives
to meet LT2ESWTR treatment requirements and provide viable options other than UV disinfection for ost
systems.
EPA Letter ID: 440
Comment ID: 10803
Commenter: Gary Hum, Director of Source & Treatment, Central Arkansas Water
Commenter Category: Regulated Community (Utilities)
Comment: 4. Toolbox technologies: Toolbox technologies should be re-evaluated, using available data,
so as not to understate the effectiveness of these levels of treatment for cryptosporidium removal.
Response: See Response 710a.
Comment Response for L T2ESWTR 8-6 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 457
Comment ID: 11886
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: We support the use of the microbial toolbox for those systems that need
to
provide additional protection against Cryptosporidium. The use of the toolbox will offer systems the
needed flexibility to choose the option(s) for their specific situation.
Response: See Response lOOa.
EPA Letter ID: 457
Comment ID: 11899
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Microbial Toolbox
We support the use of the microbial toolbox for those systems that need to provide additional protection
against Cryptosporidium. The use of the toolbox will give systems the needed flexibility to choose the
option(s) that best suit their specific situation. However, we are concerned with different aspects of the
toolbox concept including: some of the presumptive credits that EPA is proposing for various tools;
states- ability to determine appropriate credit for some tools where EPA does not offer a presumptive
credit; the design criteria related to some tools; and the level of reporting needed to receive credit for
the use of various tools.
Response: See Response 710a.
EPA Letter ID: 457
Comment ID: 11923
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Section IV.C Options for Systems to Meet Cryptosporidium Treatment Requirements
(pages 47681-47715)
We support the use of the microbial toolbox for those systems that need to provide additional protection
against Cryptosporidium, in order to give systems the flexibility to choose option(s) that best suit their
specific situation. However, we have concerns with different aspects of the toolbox concept including:
some of the presumptive credits EPA is proposing for various tools as well as states- ability to determine
appropriate credit for some tools where EPA does not offer a presumptive credit.
Comment Response for L T2ESWTR 8- 7 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Response: See Response 710a.
EPA Letter ID: 468
Comment ID: 11051
Commenter: Michael L. McGlinchy, Public Utilities Bureau Manager, City of Akron Public Utilities
Bureau
Commenter Category: Regulated Community (Utilities)
Comment: 1. The requirements for many of the microbial toolbox options are too restrictive and will
prevent utilities, like Akron, who have been proactive in implementing these options from receiving
appropriate Cryptosporidium removal credits.
The FACA discussions leading to the Agreement-in-Principle focused on the multiple benefits achieved
by the microbial toolbox options, such as reduction in the concentrations of other contaminants (e.g.,
disinfection byproduct precursors) and reduction in pathogens other than Cryptosporidium. The FACA
committee developed the microbial toolbox to provide alternatives to ultraviolet (UV) disinfection, and to
promote drinking water treatment technologies with a broader range of water quality benefits.
Akron believes the microbial toolbox provides alternatives to UV disinfection; however, in its current
state, the rule is too prescriptive in its dealing with many of the microbial toolbox options. As such, it will
be difficult for many utilities already employing toolbox options to receive the recommended log removal
credit.
By focusing solely on additional removal or inactivation of Cryptosporidium, to the exclusion of the
additional collateral benefits associated with many of the toolbox options, EPA has essentially biased the
toolbox toward UV disinfection. It seems to us that the implementation and demonstration requirements
for many of the toolbox options are too onerous and costly to implement. EPA should adopt a strategy
that encourages rather than discourages the use of toolbox options other than UV disinfection.
It is our belief that EPA should first enumerate those benefits, other than the reduction in
Cryptosporidium, associated with each of the toolbox options. EPA should then re-evaluate available
data, including data submitted to the docket, on toolbox technologies with the objective of assigning
sound, operationally-achievable treatment credits for Cryptosporidium, particularly where utilities
have proactively implemented such technologies to improve public health protection.
Response: See Response 710a.
EPA Letter ID: 471
Comment ID: 11122
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 4. We would also like to suggest adding clarifications for toolbox implementation.
Specifically, we believe that the toolbox options should have the flexibility to be used as needed in
different conditions monthly, daily, or even hourly basis to achieve compliance. For example, WSSC may
Comment Response for L T2ESWTR 8-8 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
wish to base the operation of our UV systems on the performance of our plant. Since we are committed to
Partnership goals in our operations, we would request credits for low individual or combined filter
turbidity and operate at a reduced UV dose. However, in extreme situations (e.g., high water demands or
unusual raw water quality problems) where we may have difficulty meeting our Partnership goals, we
believe it would be adequately protective to simply increase our UV dose to make up for the plant-s
reduced treatment efficiency. While the regulation clearly allows for a combination of microbial toolbox
options, it does not state if these combinations can be varied hour-to-hour, day-today, or month-to-month.
This will be a very important operational consideration that should be addressed.
Response: See Response 710a. EPA notes that individual tools have differing monitoring and
performance requirements. A utility may use any combination of tools to meet its LT2ESWTR treatment
requirments but must meet the specific performance requirements for each toolbox option. EPA believes
that most utilities will use more than toolbox option to provide redundancy and as a matter of good
practice.
EPA Letter ID: 487
Comment ID: 11236
Commenter: Janice Skadsen, Water Quality Manager, City of Ann Arbor Water Plant
Commenter Category: Regulated Community (Utilities)
Comment: We also recommend that EPA re-evaluate the toolbox technologies to better allow credit for
some elements. As written this rule is essentially a -UV- rule. There are many other appropriate methods
for Cryptosporidium protection which should be given appropriate credit, such as watershed control,
reductions in combined filter effluent turbidity, improve filtration performance and others.
Response: See Response 710a.
EPA Letter ID: 488
Comment ID: 11847
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4.4 Options for Systems to Meet Cryptosporidium Treatment Requirements Generally
speaking, many of the toolbox elements have been rendered unusable by placing upon them overly
restrictive and unmanageable requirements. Thus, what appears on face value to be a large menu of
options for consideration will boil down to very few choices for most utilities. The toolbox was intended
to provide a suite of treatment techniques that utilities could employ to meet the required log credits. The
intent of the Agreement in Principal was to provide utilities with compliance options ranging from source
protection to process optimization to advanced treatment. However, with excessively stringent
requirements and the tendency to equate log credits with log removal, the current proposal falls short of
providing a toolbox that meets the intent of the Ageement. We believe that the Agency should be more
clear in expressing the intent of the FACA that toolbox credits were not intended to be synonymous with
log removal.
Response: See Response 710a.
Comment Response for L T2ESWTR 8-9 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 491
Comment ID: 10671
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: 8. ACWD supports the -microbial toolbox- approach that provides a variety of options to
systems to comply with treatment requirements. We commend the EPA and the involved stakeholders on
their creative approach to improving pathogen protection with a variety of treatment alternatives.
Response: See Response lOOa.
EPA Letter ID: 496
Comment ID: 10702
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 1. Microbial Toolbox Key Issue 1 Overly Conservative Assumptions: EPA's focus on strict
log removal applies excessively conservative restrictions on the use of technologies to comply with the
regulation.
Conservative assumptions are made at every turn. The conservative assumptions are then compounded
leading to overly conservative endpoints. The potential risks of Cryptosporidium tend to be exaggerated
while potential treatment effectiveness tends to be understated. Worse yet, the additional benefits of
individual technologies are mentioned, but not taken into consideration, in determining credit. Taking
this approach upsets the balancing of uncertainties.
Comments for Microbial Toolbox Key Issue 1 (Overly Conservative Assumptions): The EPA should
ensure a balancing of uncertainties and not be extremely conservative in allowing log removal "credit" for
technologies other than UV.
Response: See response 710a. See response lOOf
EPA Letter ID: 497
Comment ID: 10655
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Microbial Toolbox
We generally support presumptive credit for various toolbox options. To reduce the complexity of the
LT2ESWTR regulations, EPA should remove the microbial toolbox options from the LT2ESWTR
regulatory language and instead specify the allowable credits as guidance in the Microbial Toolbox
Guidance Manual.
Comment Response for L T2ESWTR 8-10 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Response: See Response lOOa.
EPA Letter ID: 499
Comment ID: 10724
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: 8. KDHE supports the use of the microbial toolbox methodology for those systems that need
to provide additional protection against Cryptosporidium. The microbial toolbox will give systems much
needed flexibility to choose the option(s) that best suit their specific situation.
Response: See Response lOOa.
EPA Letter ID: 503
Comment ID: 10626
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment: Issue No. 5 - Overly Conservative Assumptions
Conservative assumptions are made at every turn related to the credit given to technologies in the
microbial toolbox. Focus on strict log removal, inflated potential risks of Cryptosporidium, and deflated
potential treatment effectiveness lead to overly conservative endpoints which needlessly cost consumers
more money. A more reasonable balance of uncertainties should be made.
Response: See Response 710aand Response lOOf
EPA Letter ID: 504
Comment ID: 11344
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 1200 VIII. Compliance Schedules
Comment: 1. We believe that EPA should make an explicit and direct comparison between its predicted
benefits (numbers of cryptosporidiosis cases likely to be avoided by implementation of the proposed rule)
and available epidemiologic data on the occurrence of cryptosporidiosis. If the result is a lower estimate
of benefits then we believe EPA should reconsider other elements of the rule, in particular, the need for
early implementation and the justification for conservative evaluation of treatment credits for toolbox
components.
Response: See Responses 1200.b, 100.t, and 500.b.
Comment Response for L T2ESWTR 8-11 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 506
Comment ID: 10741
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: - Microbial Toolbox
o Log Credit vs. Strict Log Removal - CWD supports the concept of the toolbox as developed by the
FACA since it gives water systems options to choose from to meet the treatment requirements, not just
UV. The Agreement in Principle focused on log -credit- for use of various alternative technologies, as
identified in the toolbox. CWD is concerned that USEPA may be departing from the Agreement by
focusing on strict, and possibly overly conservative, log -removal-.
Response: See Response 710a.
EPA Letter ID: 507
Comment ID: 11471
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 6. Microbial Toolbox, IV.C.l., pg 47681
FCWA supports the concept of viable alternatives included in the microbial toolbox approach. This
approach will provide a greater deal of flexibility for utilities in selecting effective LT2ESWTR
compliance strategies. We would like to comment though, that the intent of the microbial toolbox concept
was not just a focus on Cryptosporidium inactivation and log removal. LT2ESWTR Advisory Committee
(FACA) discussions also included benefits in other areas as well to include other pathogen reductions,
process stabilization, and the reduction of other contaminants (TOC, DBP-s, etc.). The FACA
understanding was that a broader focus would be placed on a concept of credits as opposed to strict
Cryptosporidium log inactivation.
Response: See Response 710a.
EPA Letter ID: 507
Comment ID: 11473
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: We anticipate that a utility such as ours using ozone would be evaluated on a broader concept
of credit versus strict Cryptosporidium inactivation. Therefore, we recommend that EPA not be overly
conservative in their approach to alternative toolbox options.
Response: See Response 710a.
Comment Response for L T2ESWTR 8-12 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 512
Comment ID: 11495
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Microbial Toolbox - EPA must balance the toolbox elements, rather than focusing
exclusively on advanced treatment, specifically, UV treatment. Much good work has gone into
developing the components of the proposed rule. However, when combined as proposed, the result is a
heavy reliance on advanced treatment (specifically ultraviolet (UV) treatment) and a de-emphasis of the
multi-barrier approach. In revising the rule, EPA should focus on encouraging investment in source water
protection and treatment alternatives such as ozone, membranes, and bank filtrations, and should reward
utilities that have invested in achieving optimum operating proficiency in their conventional facilities.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems.
EPA Letter ID: 520
Comment ID: 11560
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: We support the use of the microbial toolbox for those systems that need to provide additional
protection against Cryptosporidium. The use of the toolbox will give systems much needed flexibility to
choose the option(s) that best suit their specific situation.
Response: See Response lOOa.
EPA Letter ID: 520
Comment ID: 11594
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Microbial Toolbox
IEPA supports the use of the microbial toolbox for those systems that need to provide additional
protection against Cryptosporidium. The use of the toolbox will give systems much needed flexibility to
choose the option(s) that best suit their specific situation.
Response: See Response lOOa.
Comment Response for L T2ESWTR 8-13 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 520
Comment ID: 11595
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: However, IEPA does have concerns with different aspects of the toolbox concept including:
some of the presumptive credits EPA is proposing for various tools; our ability to determine appropriate
credit for some tools where EPA does not offer a presumptive credit; the design criteria related to some
tools; and the level of reporting needed to receive credit for the use of various tools. These concerns are
addressed further below.
Under the LT2 proposal, systems will be placed in bins according to source water crypto levels. Systems
would then choose from a list of microbial toolbox options to achieve the required additional logs of
inactivation or removal. In the original SWTR, and in the subsequent IESWTR and LT1 ESWTR, specific
credits for removal/inactivation methods were not included explicitly in regulation. To reduce the
complexity of the LT2 regulations, EPA should consider removing the microbial toolbox options from the
LT2 regulatory language and instead specify the allowable credits as guidance in the Microbial Toolbox
Guidance Manual.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR requirement and provide viable options other than UV disinfection for
most systems.
EPA Letter ID: 520
Comment ID: 11625
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA supports the use of the microbial toolbox for those systems that need to provide
additional protection against Cryptosporidium. The use of the toolbox will give systems much needed
flexibility to choose the option(s) that best suit their specific situation.
Response: See Response lOOa.
EPA Letter ID: 520
Comment ID: 11626
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment:
However, IEPA does have concerns with different aspects of the toolbox concept including: some of the
presumptive credits EPA is proposing for various tools as well as states' ability to determine appropriate
credit for some tools where EPA does not offer a presumptive credit.
Comment Response for L T2ESWTR 8-14 December 2005
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Response: See Response 710a.
EPA Letter ID: 526
Comment ID: 11770
Commenter: Nick Jackson,, Knoxville Utilities Board
Commenter Category: Local Government
Comment: 6. The Microbial Toolbox should be a broad array of viable treatment options whose primary
criteria for selection is the ability to enhance the treatment capability in a particular facility. Log removal
criteria should not automatically force utilities towards any particular technology but rather utilities
should choose based upon the actual effectiveness of a technology as demonstrated by pilot studies or
other valid means.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems.
EPA Letter ID: 527
Comment ID: 10858
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: the Agreement in Principle. A key part of the letter and spirit of that agreement on our part,
and one clearly expressed in the FACA meetings was that making this a -UV Rule- was unacceptable.
The requirements presently placed on areas of the microbial toolbox other than UV inactivation are such
that common use of these tools is denied.
Response: See Response 710a.
EPA Letter ID: 527
Comment ID: 10858
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: the Agreement in Principle. A key part of the letter and spirit of that agreement on our part,
and one clearly expressed in the FACA meetings was that making this a -UV Rule- was unacceptable.
The requirements presently placed on areas of the microbial toolbox other than UV inactivation are such
that common use of these tools is denied.
Response: See Response 710a.
Comment Response for L T2ESWTR 8-15 December 2005
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EPA Letter ID: 527
Comment ID: 10859
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Credit vs. Strict Log Removal: EPA should bring the microbial toolbox requirements in line
with FACA discussions by explaining the overall concept of credit (not based on strict log removal
alone), and by enumerating the additional benefits of each toolbox item.
The FACA was not focused on Cryptosporidium alone, but on overall risk reduction from other microbial
contaminants and from DBFs. Neither was the FACA focused on strict log removal. That is why the
discussion used the term -credit-. In addition to data available on Cryptosporidium oocyst removal for a
specific toolbox item, the FACA also considered other benefits such as:
- Reducing peaks in occurrence of pathogens,
- Making other processes more stable or effective,
- Reducing other contaminants (i.e. TOC, DBF formation), etc. and
- Reducing other pathogens.
The FACA also wanted to encourage the use of a variety of technologies that achieve Cryptosporidium
removal and ensure that there are viable alternatives to UV disinfection, and to provide removal options
that are independent of the failure modes (such as lamp burnout or power loss) that UV disinfection faces
(multiple barriers).
We strongly support the concept of having a toolbox of viable alternatives to select from. If options are
effectively limited to UV, we believe that the agreement is effectively breached.
Overly Conservative Assumptions: It follows from EPA-s focus on strict log removal that the Agency
would choose to apply overly conservative restrictions on the use of technologies to comply with the
regulation.
Conservative assumptions are made at every turn. The conservative assumptions are then compounded
leading to overly conservative endpoints. The potential risks of Cryptosporidium tend to be inflated while
potential treatment effectiveness tends to be deflated. Worse, the additional benefits of individual
technologies are mentioned but not taken into consideration in determining credit. EPA must ensure a
balancing of uncertainties and not be overly conservative in assigning -credit- for technologies other than
UV.
Response: See Response 710a.
EPA Letter ID: 527
Comment ID: 10859
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Credit vs. Strict Log Removal: EPA should bring the microbial toolbox requirements in line
with FACA discussions by explaining the overall concept of credit (not based on strict log removal
alone), and by enumerating the additional benefits of each toolbox item.
Comment Response for L T2ESWTR 8-16 December 2005
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The FACA was not focused on Cryptosporidium alone, but on overall risk reduction from other microbial
contaminants and from DBFs. Neither was the FACA focused on strict log removal. That is why the
discussion used the term -credit-. In addition to data available on Cryptosporidium oocyst removal for a
specific toolbox item, the FACA also considered other benefits such as:
- Reducing peaks in occurrence of pathogens,
- Making other processes more stable or effective,
- Reducing other contaminants (i.e. TOC, DBF formation), etc. and
- Reducing other pathogens.
The FACA also wanted to encourage the use of a variety of technologies that achieve Cryptosporidium
removal and ensure that there are viable alternatives to UV disinfection, and to provide removal options
that are independent of the failure modes (such as lamp burnout or power loss) that UV disinfection faces
(multiple barriers).
We strongly support the concept of having a toolbox of viable alternatives to select from. If options are
effectively limited to UV, we believe that the agreement is effectively breached.
Overly Conservative Assumptions: It follows from EPA-s focus on strict log removal that the Agency
would choose to apply overly conservative restrictions on the use of technologies to comply with the
regulation.
Conservative assumptions are made at every turn. The conservative assumptions are then compounded
leading to overly conservative endpoints. The potential risks of Cryptosporidium tend to be inflated while
potential treatment effectiveness tends to be deflated. Worse, the additional benefits of individual
technologies are mentioned but not taken into consideration in determining credit. EPA must ensure a
balancing of uncertainties and not be overly conservative in assigning -credit- for technologies other than
UV.
Response: See Response 710a.
EPA Letter ID: 529
Comment ID: 13127
Commenter: Anonymous529,,
Commenter Category:
Comment: 1. We urge the EPA to adhere to the intent and spirit of the Agreement in Principle and avoid
adding conservatism and safety factors in regulations were the health risks are not quantifiable or
uncertain
Response: See response to Comment Code 710a.
EPA Letter ID: 534
Comment ID: 12012
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment Response for L T2ESWTR 8-17 December 2005
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Comment: Options included in the microbial toolbox are included because they have been demonstrated
to be effective in preventing cryptosporidium in delivered drinking water. It would appear that these
options would have at least some positive effect, regardless of the source water cryptosporidium
concentration. Thus, all of the options should remain on the table for utilization.
Response: See Response 710a.
EPA Letter ID: 536
Comment ID: 11802
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Microbial Toolbox
Colorado supports the use of the microbial toolbox for those systems that need to provide additional
protection against Cryptosporidium. The use of the toolbox will give systems much needed flexibility to
choose the option(s) that best suit their specific situation.
Response: See Response lOOa.
EPA Letter ID: 536
Comment ID: 11803
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: However, Colorado does have concerns with different aspects of the toolbox concept
including: some of the presumptive credits EPA is proposing for various tools; states- ability to determine
appropriate credit for some tools where EPA does not offer a presumptive credit; the design criteria
related to some tools; and the level of reporting needed to receive credit for the use of various
tools.
Response: See Response 710a.
EPA Letter ID: 556
Comment ID: 12039
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 9111. Credit and criteria for awarding credit; 1832 2.
Adequacy of current capacity
Comment Response for L T2ESWTR 8-18 December 2005
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Comment: punishment that far exceeds the crime. Other areas where the proposal would be improved by
referring to the intent of the FACA and AIP include: ensuring the availability of adequate laboratory
capacity; ensuring that the toolbox provides reasonable; achievable alternatives to UV disinfection; and
ensuring that safety factors and conservative assumptions do not needlessly add to the costs of
implementing UV.
Response: See Responses 1830, 910.f, 910.h, and lOO.t.
EPA Letter ID: 556
Comment ID: 12060
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Basic Principles from the FACA Discussions: The FACA was not focused on
Cryptosporidium alone, but on overall risk reduction from other microbial contaminants and from DBFs.
Neither was the FACA focused on strict log removal. That is why FACA discussions used the term -
credit-. In addition to data available on Cryptosporidium oocyst removal for a specific toolbox item, the
FACA also considered other benefits such as:
- Reducing peaks in occurrence of pathogens;
- Making other processes more stable or effective;
- Reducing other contaminants (i.e., TOC, DBP formation); etc. and,
- Reducing other pathogens.
The FACA also wanted to encourage the use of a variety of technologies that achieve Cryptosporidium
removal, ensure that there are viable alternatives to UV disinfection, and provide removal options that are
independent of the failure modes (such as lamp burnout or power loss) that UV disinfection faces
(multiple barriers).
Discussion: The FACA chose to look broadly on the concept of risk reduction while the proposal has a
narrow focus on strict removal credit for Cryptosporidium. This change of focus adversely impacts the
entire Microbial Toolbox. The requirements presently placed on areas of the Microbial Toolbox other
than disinfection are such that common use of these tools may be denied which is clearly not the intent of
the agreement.
In the proposal, EPA states:
-The purposes of the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) are to
improve control of microbial pathogens, including specifically the protozoan Cryptosporidium, in
drinking water and to address risk-risk trade-offs with the control of disinfection byproducts.- (68 FR
47640).
This acknowledges that a broad focus as discussed by the FACA is the appropriate basis for consideration
of toolbox items.
Recommendations: As a FACA participant, EPA should embrace the intent of the FACA in accepting and
incorporating in the Agreement in Principle the concept of-credit- as outlined above. AMWA requests
Comment Response for L T2ESWTR 8-19 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
that EPA continue to gather data and analyze information on all toolbox items with an eye toward the
other benefits discussed by the FACA. In the event a credit has the potential to be increased or may be
borderline, these additional benefits should be accepted in favor of credit approval.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems.
EPA Letter ID: 556
Comment ID: 12061
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. Conservative Assumptions with Regard to the Toolbox:
Discussion: The focus on strict log removal has unfortunately resulted in restrictions on the practical use
of several technologies other than disinfection to comply with the regulation.
Part of the FACA-s comfort in supporting the concept of-credit- was based on the knowledge that the
estimates of risk from Cryptosporidium were being developed by a risk assessment process that tended to
be conservative. The present risk assessment bears out this conception. It appears that the potential risks
of Cryptosporidium tend to be inflated through the compounding of numerous conservative assumptions.
At the same time, the potential treatment effectiveness of toolbox items tends to be deflated when
additional benefits are not included. This narrow focus upsets the balancing of uncertainties which was
a major concern of the FACA.
Recommendation: EPA should ensure a balancing of uncertainties and not be overly conservative in
assigning -credit- for technologies other than UV. In light of the above discussion, AMWA strongly
recommends that no toolbox item credit currently proposed be reduced in the final rule. The discussion
and data accompanying each item fully support the credit proposed or higher, and the additional benefits
provided add to that justification. Additionally, AMWA believes that no additional criteria for obtaining
the proposed credits are necessary.
AMWA believes that the requirement for turbidity reduction in pre-sedimentation basins will effectively
eliminate their usefulness as a toolbox item and is not appropriate in view of their overall benefit. EPA
should consider reverting to overflow values found in the data as an appropriate measure and give full
consideration to other benefits of the technology.
Response: See Response VIOaand Response 760.
EPA Letter ID: 562
Comment ID: 12288
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR 8-20 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Comment: 3. EPA should re-evaluate the toolbox technologies with the objective of assigning sound and
operationally achievable credits for each toolbox element. The agency should pay particular attention to
providing credit for watershed protection, enhanced filtration (i.e., peer review or individual filter credits
and combined filter effluent credits), bank filtration, and demonstration of performance.
Response: See Responses 720,770,800,930 and 950.
EPA Letter ID: 562
Comment ID: 12295
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. The EPA has been overly restrictive in its specifications for proper design and
implementation of microbial toolbox elements. The agency did not achieve the AIP-s intention of flexible
solutions to bin determinations.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems.
EPA Letter ID: 562
Comment ID: 12306
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.5 Microbial Toolbox
In crafting the proposed rule, EPA has focused exclusively on adding additional inactivation or removal.
The agency has excluded benefits associated with improving overall treatment stability and performance
through improved Combined Filter Effluent (CFE) and Individual Filter Effluent (IFE) performance
measures. This focus on inactivation has resulted in a rule structure that encourages utilities only to add
ultraviolet light disinfection to achieve regulatory compliance at what EPA considers an -affordable-
cost. This endpoint is dramatically different from the Stage 2 M/DBP Agreement lin Principle?. It The
Stage 2 M/DBP FACA intended to encourage investment in source water protection and robust treatment
alternatives such as membranes and bank filtration, as well as reward utilities that have invested in
achieving optimum operating proficiency in their conventional facilities.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems.
EPA Letter ID: 562
Comment ID: 12356
Comment Response for LT2ESWTR 8-21 December 2005
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 1831 1. Need for EPA estimate
Comment: Cryptosporidium oocyst monitoring / reporting. While a number of outstanding issues still
remain, two specific issues from the stakeholder draft remain a fundamental concern. The two issues are:
(1) the absence of an assessment of laboratory capacity and (2) the agency-s failure to craft a fair and
implementable microbial toolbox.
3.5.3 UV Representatives
AWWA remains concerned that some representatives to the Stage 2 M/DBP FACA process, with clear
financial interests in a single technology (ultraviolet light), participated in the FACA as advocates of this
single technology. More importantly, an alternate representative participated in the FACA process
without disclosing that his company was simultaneously undertaking an
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems. Also see response 1830 regarding lab capacity.
EPA Letter ID: 562
Comment ID: 12428
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Before, during, and after the FACA negotiations, EPA has favored particular
tools within the microbial toolbox, especially inactivation (UV) and, in two instances, removal (i.e.,
combined filter effluent, and membranes) over others. The proposed rule and associated guidance
manuals reflect this favoritism, particularly in the definitions and requirements assigned to other toolbox
alternatives. Where the agency does not eliminate the toolbox element, the following severe constraints
make most of the toolbox technologies unattainable:
1. EPA has defined requirements for credits that are unachievable at most facilities that will need the
credits, particularly with respect to individual filter effluent and new pre-sedimentation
basins turbidity requirements.
2. EPA has included provisions that make toolbox alternatives unattractive to utilities that might
otherwise choose them (i.e., demonstration of performance (DOP) and watershed control program
(WCP)).
3. EPA provided misleading information that discourages utilities from using or even investigating some
toolbox alternatives.
The following section reviews each of the toolbox elements and provides a number of recommendations
for improvement of the proposed rule and associated guidance.
The proposed rule and guidance manuals either include unrealistic requirements for some of the credits or
do not include adequate assurance to utilities that a credit will be sustainable for the utility (e.g., see WCP
discussion). If a utility cannot reliably depend on a credit, it will have to choose other credits types it
believes will be available. A credit that a utility cannot depend upon is not really a credit. As proposed,
the Microbial Tool includes several tools that are credits in name only. If the proposal remains unchanged
when it is promulgated as a final rule, facilities in Bin 2 will essentially only have membranes and
Comment Response for L T2ESWTR 8-22 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
inactivation as compliance alternatives. Though the CFE credit will also probably be available, it is only
worth 0.5 credits so additional credits via inactivation or membranes will still be needed if no other 0.5
credit options are realistically available.
Given the much higher cost of membranes, with the possible exception of bag and cartridge filters for
small systems, UV will be only practical means of compliance. Although UV inactivation has enormous
potential benefit for the water treatment industry, reliance on a single technology is potentially prone to
error if any future difficulties develop with the respect to UV disinfection. This is inconsistent with the
Stage 2 M/DBP Agreement in Principle. The capital cost for UV is relatively inexpensive in comparison
to other toolbox technologies, but the operation and maintenance cost could be significant, and is not well
defined by industry experience.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems.
EPA Letter ID: 562
Comment ID: 12429
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: In order for the microbial toolbox concept to work as originally intended, to provide a variety
of alternatives, and to allow establishment of credit that existing facilities already deserve:
1. Several of the requirements for some of the credits needs to be refined, and
2. Additional information needs to be provided to more objectively present the benefits of some of the
toolbox alternatives to utilities that might use them.
In particular, while some facilities with two-stage filtration or clarification may get some benefit from
these specific credits, and some systems with existing BF or pre-sedimentation may get an indirect benefit
because they will be collecting Cryptosporidium bin assignment samples from the end of these processes,
the four toolbox alternatives that will probably have the most widespread use are CFE, IFE, DOP, and
WCP. If these are properly defined, many utilities will be able to use existing facilities to meet
requirements for Bin 2, or they can add 0.5 credit with WCP if they need the additional credit or if they
want an additional 0.5 credit safety factor. Even though utilities in Bin 3 or 4 can use inactivation and
membrane alternatives to meet all of their treatment requirements, utilities should be encouraged to use
CFE, IFE, DOP, or WCP. CFE, IFE, DOP, and WCP are ongoing performance based measures that
enhance existing barriers in a multiple-barrier treatment strategy.
WCP, IFE, CFE, and DOP credits should be encouraged because these microbial toolbox components
have far-reaching positive benefits for Cryptosporidium protection. For example, a realistically defined
IFE credit will not mean the credit will be easy to achieve. Careful management and operational practices
from source water through all stages of treatment will be required for this credit. Encouraging improved
performance, and rewarding facilities that already achieve a suitably high level of performance, meets
LT2ESWTR objectives and promotes well-designed and well-managed drinking water treatment
facilities. Many forward-thinking utilities will strive to achieve this level of performance without needing
the additional motivation of the IFE credit. Still, AWWA recommends that EPA include a more realistic
definition of the IFE credit (see section 4.2.6) in order to encourage more utilities to try to improve
Comment Response for L T2ESWTR 8-23 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
performance to meet the credit. The IFE credit as currently defined is so prohibitive that utilities are
unlikely to even attempt meeting its requirements. Consequently, an important incentive for utilities to
improve filtration performance has been lost.
The WCP credit is another toolbox alternative that can have far-reaching and long-lasting benefits for
facilities that perform WCP related activities. However, the WCP credit as currently defined provides
little, if any, motivation for utilities to attempt to achieve this credit. Facilities that might have tried for a
more realistically defined credit will not gain the broad benefits which WCP related activities could
provide (see section 4.2.2).
As the WCP, DOP, and IFE provisions are currently described, they do not properly credit the
Cryptosporidium protection achieved at existing utilities. Moreover, they represent a missed opportunity
to encourage practices and programs that have potential long-term benefits as barriers not only for
Cryptosporidium but also for other contaminants that may be identified in the future. The treatment
alternatives encouraged by the proposed rule rely on high cost, technology intensive treatment processes
that are inserted into existing treatment processes. This dependency on add-on, single purpose,
disinfection technologies runs counter to the known benefits of multi-barrier approaches to treatment.
AWWA-s comments include important changes to the proposed microbial toolbox that EPA should
incorporate so that the agency, utilities, and the public may obtain the benefits anticipated under the
toolbox framework as structured by the Stage 2 M/DBP FACA.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems.
EPA Letter ID: 580
Comment ID: 12630
Commenter: Bruce Aptowicz, Chairman, Water Utility Council of the Pennsylvania American
Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. EPA should re-evaluate the toolbox technologies with the objective of assigning sound and
operationally achievable credits for each toolbox element. The agency should pay particular attention to
providing credit for watershed protection, enhanced filtration @e., peer review or individual filter credits
and combined filter effluent credits), bank filtration, and demonstration of performance.
Response: See Responses 720,770,800,930 and 950.
EPA Letter ID: 593
Comment ID: 11822
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: C. Microbial Toolbox
1. Log Credit vs. Strict Log Removal: SAWS supports the concept of having a toolbox of viable
Comment Response for L T2ESWTR 8-24 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
alternatives to select from. However, FACA was not focused on Cryptosporidium alone, but on overall
risk reduction from other microbial contaminants and from Disinfection By-products (DBF). The focus of
the FACA was on reducing peaks in occurrence of pathogens, making other processes ore stable or
effective, reducing other contaminants (i.e. Total Organic Carbon (TOC), DBF formation), etc and
reducing other pathogens. FACA encourage the use a variety of technologies that achieve
Cryptosporidium removal and ensure that there are viable alternatives to W disinfection, and to provide
removal options that are independent of the failure modes that W disinfection faces (multiple barriers.
Furthermore, the rule does not provide provisions for additional log removal credit for technologies such
as membrane filtration. The potential risks of Cryptosporidium tend to be inflated while potential
treatment effectiveness tends to be deflated. SAWS- recommends that an appropriate application of the
log credit be given to other disinfection alternatives such as membrane filtration (Le. Micro vs. Ultra vs.
Nano).
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provides viable options other than
disiinfcation for most systems.
EPA Letter ID: 595
Comment ID: 12588
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Section IV.C Options for Systems to Meet Cryptosporidium Treatment Requirements
pages 47581-47715)
Maine supports the use of the microbial toolbox for those systems that need to provide additional
protection against Cryptosporidium. The use of the toolbox will give systems much needed flexibility to
choose the option(s) that best suit their specific situation. However, the State should have some flexibility
in modifying credit when applicable.
Response: See Response lOOa. EPA notes that under the Demonstration of Performance toolbox option a
system may demonstrate to the State a higher log removal for a unit process or plant to meet LT2ESWTR
treatment requirements.
EPA Letter ID: 601
Comment ID: 13002
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah supports the use of the microbial toolbox for those systems that need to provide
additional protection against Cryptosporidium. The use of the toolbox will give systems much needed
flexibility to choose the option(s) that best suit their specific situation.
Response: See Response 710a.
Comment Response for L T2ESWTR 8-25 December 2005
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EPA Letter ID: 601
Comment ID: 13024
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah supports EPAs use of the toolbox approach and the flexibility it gives PWSs to provide
additional protection against Cryptosporidium.
Utah is concerned with the additional -safety- factors for dosing being written in rule guidance. EPA
should be cautious that its guidance not be misrepresentative of actual promulgated dosage standards.
Response: See Response lOOa. The commenter's concern regarding safety actors for doses in guidance is
unclear. CT values and UV are established in the rule language. Systems operating chemical feed systems
for inactivation would apply doses adequate to meet demand and inactivation requirements and good
practice would be to apply doses to ensure adequate inactivation while considering variations in demand,
flows, and instrumentation.
EPA Letter ID: 609
Comment ID: 14122
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Microbial Toolbox
We generally support presumptive credit for various toolbox options. To reduce the complexity of the
LT2ESWTR regulations, the USEPA should remove the microbial toolbox options from the LT2ESWTR
regulatory language and instead specify the allowable credits as guidance in the Microbial Toolbox
Guidance Manual.
Response: See Response 710a.
EPA Letter ID: 614
Comment ID: 12961
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Microbial Toolbox
* We are concerned that many of the toolbox credits are not realistically feasible. EPA should pay
particular attention to providing credit for Watershed Protection, Individual Filter Effluent, Combined
Filter Effluent, and Demonstration of Performance (DOP).
Response: See Response 710a.
Comment Response for L T2ESWTR 8-26 December 2005
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EPA Letter ID: 614
Comment ID: 12964
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: * EPA needs to insure a balancing of uncertainties and not be overly conservative in allowing
log removal "credit1 for technologies other than UV.
Response: See Response 710a.
EPA Letter ID: 617
Comment ID: 13256
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: resources. With this in mind we strongly encourage EPA to retain feasible incentives within
the microbial toolbox that will entice utilities to develop programs to pursue protection, bank filtration,
offline storage, filter optimization and plant performance, and other techniques identified within the
toolbox that have ecological, environmental, and public health benefits.
Response: See Response 710a.
EPA Letter ID: 617
Comment ID: 13259
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 3. EPA should re-evaluate the toolbox technologies with the objective of assigning sound and
operationally feasible credits for each toolbox element. The Agency should pay particular attention to
providing credit for watershed protection, enhanced filtration (i.e., peer review or individual filter credits
and combined filter effluent credits), riverbank filtration, and demonstration of performance for
conventional treatment. The restrictive operational and reporting requirements presently associated with
toolbox elements are out of balance with the interest of the FACA in establishing incentives for utilities to
pursue these solutions which we believe are in the better interest of a long term solution benefiting the
public interest. In short we recommend that the Agency endeavor to maintain the toolbox elements with
incentives and not penalties.
Response: See Responses 720, 770, 790,800,930 and 950.
EPA Letter ID: 620
Comment ID: 13284
Comment Response for L T2ESWTR 8-2 7 December 2005
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Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: 3. While SPRWS supports the use of the "microbial toolbox" of viable alternatives to select
from, we believe that alternatives other than UV should be considered. It appears that other time-tested
technologies are discouraged in this rule to make UV the preferable treatment. The rule is too
conservative in the credits given for technologies other than UV.
Response: See Response lOOa.
EPA Letter ID: 620
Comment ID: 13300
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 1: Log Credit vs. Strict Log Removal
Comments: SPRWS strongly encourages the use of the toolbox for viable alternatives to Cryptosporidium
removal. Systems that have large surface water
Response: See Response lOOa.
EPA Letter ID: 620
Comment ID: 13302
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: SPRWS also anticipates using other toolbox options if needed. These include off stream water
storage, lime softening, combined filter performance and individual filter performance.
Response: See Response lOOa.
EPA Letter ID: 620
Comment ID: 13303
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 2: Overly Conservative Assumptions
Comments: Log removal credits for some of the toolbox options appear too small.
Response: See Response 710a.
Comment Response for L T2ESWTR 8-28 December 2005
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EPA Letter ID: 621
Comment ID: 13164
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Other EPA Comment Codes and Descriptions: 100 General Comments; 520 B. Bin Concentration
Ranges and Treatment Requirements
Comment: Data on Log Removal of Cryptosporidium and Removal Credits
I support your approach in controlling Cryptosporidium, your requirements according to source water bin
classification, and your log removal credits. For
Response: See Response lOOa.
EPA Letter ID: 630
Comment ID: 13070
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 1. Microbial Toolbox Key Issue Log Credit vs Strict Log Removal: It is very important that
EPA bring the microbial toolbox requirements in line with FACA discussions by explaining the overall
concept of credit (not based on strict log removal alone), and by enumerating the additional benefits of
each toolbox item.
The FACA was not focused on Cryptosporidium alone, but on overall risk reduction from other microbial
contaminants and from DBFs. Neither was the FACA focused on strict log removal. That is why the
discussion used the term -credit-. In addition to data available on Cryptosporidium oocyst removal for a
specific toolbox item, the FACA also considered other benefits such as:
- Reducing peaks in occurrence of pathogens,
- Making other processes more stable or effective,
- Reducing other contaminants (i.e. TOC, DBP formation), etc. and
- Reducing other pathogens.
The FACA also wanted to encourage the use of a variety of technologies that achieve Cryptosporidium
removal and ensure that there are viable alternatives to UV disinfection, and to provide removal options
that are independent of the failure modes (such as lamp burnout or power loss) that UV disinfection faces
(multiple barriers).
We support the concept of having a toolbox of viable alternatives to select from. The toolbox was not to
be a -UV- rule. The focus of the FACA was on multiple objectives as outlined above, and the concept of
credit rather than strict (and overly conservative)log removal.
2. Microbial Toolbox Key Issue Overly-Conservative Assumvtions: EPA-s focus is not only focusing on
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strict log removal but is also applying overly conservative restrictions on the use of technologies to
comply with the regulation.
Several conservative assumptions are made. The conservative assumptions are then compounded leading
to overly conservative endpoints. The potential risks of Cryptosporidium tend to be inflated while
potential treatment effectiveness tends to be deflated. The additional benefits of individual technologies
are mentioned but not taken into consideration in determining credit. Taking this approach upsets the
balancing of uncertainties.
It is recommend that EPA insure a balancing of uncertainties and not be overly conservative in allowing
log removal -credit- for appropriate technologies.
3. Microbial Toolbox Key Issue Watershed Protection Credit: The problems with EPA-s overall approach
to log removal credit, and its divergence from the FACA-s intentions is well illustrated in the Watershed
Protection Credit requirements.
Response: See Response 710a.
EPA Letter ID: 631
Comment ID: 13243
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: The toolbox provides an important source of treatment alternatives and management practices
that water systems might select as the most appropriate and cost-effective treatment processes for their
specific conditions. However, it is important that the risk reduction benefits considered for each treatment
process not be limited to Cryptosporidium inactivation alone. Benefits of reduction of other microbial
contaminants and from DBFs must also be considered in determining treatment credit. FACA discussion
of the overall -credit- concept did not focus solely on Cryptosporidium removal, but considered other
benefits such as reducing peaks in the occurrence of pathogens, making processes more stable or
effective, reduction of other contaminants, and reduction of occurrence of other pathogens.
Response: See Response 710a.
EPA Letter ID: 633
Comment ID: 13270
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 3. Conservative Assumptions in the Microbial Toolbox
We support the concept of having a toolbox of viable alternatives to select from in developing a cost
effective LT2ESWTR compliance strategy. Unfortunately, however, it seems as if conservative
assumptions regarding treatment effectiveness are being compounded resulting in overly conservative
endpoints while the existence of Cryptosporidium or the required level of treatment is being inflated.
These two tendencies combine to make compliance more difficult and expensive.
Comment Response for L T2ESWTR 8-3 0 December 2005
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Response: See Response 710a.
EPA Letter ID: 637
Comment ID: 13093
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: District applauds EPA-s use of the toolbox approach and the flexibility it gives systems to
provide additional protection against Cryptosporidium. The toolbox provides for the use of multiple
barriers and needs to reflect the benefits of log credit as opposed to a strict log removal concept. The
District intends to install ozone into its treatment facilities and the toolbox will appropriately -credit- our
system for the additional protection to public health that Ozone provides. The District will also be looking
for credits from other tools such as watershed control programs and enhanced treatment performance. By
allowing other alternatives for handling Cryptosporidium this rule avoids becoming a UV rule and is
more robust.
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12708
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States support the use of the microbial toolbox for those systems that need to provide
additional protection against Cryptosporidium. The use of the toolbox will give systems much needed
flexibility to choose the option(s) that best suit their specific situation.
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12747
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Microbial Toolbox
States support the use of the microbial toolbox for those systems that need to provide additional
protection against Cryptosporidium. The use of the toolbox will give systems much needed flexibility to
choose the option(s) that best suit their specific situation.
Response: See Response lOOa.
Comment Response for L T2ESWTR 8-31 December 2005
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EPA Letter ID: 643
Comment ID: 12748
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: However, states do have concerns with different aspects of the toolbox concept including:
some of the presumptive credits EPA is proposing for various tools; states- ability to determine
appropriate credit for some tools where EPA does not offer a presumptive credit; the design criteria
related to some tools; and the level of reporting needed to receive credit for the use of various
tools. These concerns are addressed further in Attachment 2.
Response: See Response 710a.
EPA Letter ID: 643
Comment ID: 12780
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section IV.C Options for Systems to Meet Cryptosporidium Treatment Requirements
(pages 47681-47715)
States support the use of the microbial toolbox for those systems that need to provide additional
protection against Cryptosporidium. The use of the toolbox will give systems much needed flexibility to
choose the option(s) that best suit their specific situation.
However, states do have concerns with different aspects of the toolbox concept including: some of the
presumptive credits EPA is proposing for various tools as well as states- ability to determine appropriate
credit for some tools where EPA does not offer a presumptive credit.
Response: See Response 710a.
EPA Letter ID: 647
Comment ID: 12873
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: MDE supports the use of the microbial toolbox for those systems that need to provide
additional protection against Cryptosporidium. The use of the toolbox will give systems much needed
flexibility to choose the option(s) that best suit their specific situation.
Response: See Response lOOa.
Comment Response for L T2ESWTR 8-32 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 647
Comment ID: 12901
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment:
Microbial Toolbox
MDE supports the use of the microbial toolbox for those systems that need to provide additional
protection against Cryptosporidium. The use of the toolbox will give systems much needed flexibility to
choose the option(s) that best suit their specific situation.
Response: See Response lOOa.
EPA Letter ID: 647
Comment ID: 12902
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: However, there are concerns with different aspects of the toolbox concept including: some of
the presumptive credits EPA is proposing for various tools; states- ability to determine appropriate credit
for some tools where EPA does not offer a presumptive credit; the design criteria related to some tools;
and the level of reporting needed to receive credit for the use of various tools.
Response: See Response 710a.
EPA Letter ID: 647
Comment ID: 12922
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Section IV.C Options for Systems to Meet Cryptosporidium Treatment Requirements
(pages 47681-47715)
MDE supports the use of the microbial toolbox for those systems that need to provide additional
protection against Cryptosporidium. The use of the toolbox will give systems much needed flexibility to
choose the option(s) that best suit their specific situation.
However, MDE has concerns with different aspects of the toolbox concept including: some of the
presumptive credits EPA is proposing for various tools as well as states- ability to determine appropriate
credit for some tools where EPA does not offer a presumptive credit.
Response: See Response 710a.
Comment Response for L T2ESWTR 8-33 December 2005
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EPA Letter ID: 654
Comment ID: 13123
Commenter: William Brant, Director, Miami-Dade Water and Sewer Department
Commenter Category: Regulated Community (Utilities)
Comment: The MDWASD appreciates EPA-s efforts to offer alternatives in the Microbial toolbox. The
MDWASD suggest that the Watershed Protection Credit proposed be
Response: See Response lOOa.
EPA Letter ID: 660
Comment ID: 14077
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
C. 1. Microbial Toolbox Overview
(pages 47681-47715)
For each microbial toolbox component, EPA requests comment on: (1) Whether available data support
the proposed presumptive credits, including the design and implementation conditions under which the
credit would be awarded, (2) whether available data are consistent with the decision not to award
presumptive credit for roughing filters and raw water off-stream storage, and (3) whether additional data
are available on treatment effectiveness of toolbox components for reducing Cryptosporidium levels. EPA
will consider modifying today's proposal for microbial toolbox components based on new information
that may be provided. EPA particularly solicits comment on the performance of alternative filtration
technologies that are currently being used, as well as ones that systems are considering for use in the
future.
CUWCD supports the use of microbial toolbox.
Response: See Response lOOa.
EPA Letter ID: 662
Comment ID: 14034
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
C. 1. Microbial Toolbox Overview
(pages 47681-47715)
For each microbial toolbox component, EPA requests comment on: (1) Whether available data support
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the proposed presumptive credits, including the design and implementation conditions under which the
credit would be awarded, (2) whether available data are consistent with the decision not to award
presumptive credit for roughing filters and raw water off-stream storage, and (3) whether additional data
are available on treatment effectiveness of toolbox components for reducing Cryptosporidium levels. EPA
will consider modifying today's proposal for microbial toolbox components based on new information
that may be provided. EPA particularly solicits comment on the performance of alternative filtration
technologies that are currently being used, as well as ones that systems are considering for use in the
future.
EPA-s inclusion of viable alternatives to select from in the toolbox is commendable.
Response: See Response lOOa.
EPA Letter ID: 667
Comment ID: 14015
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: C.
1. The Toolbox should not viewed as a UV rule only, other options should be given credit rather than
strict log removal.
2. Balance of uncertainties and not be overly conservative in allowing log removal credit for technologies
other than UV.
Response: See Response 710a.EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems.
EPA Letter ID: 668
Comment ID: 13888
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: -Microbial -Toolbox- Needs to Include Detailed Criteria to Assure Health
Protection
The Agreement envisioned a series of specific steps that a surface water system could take in order to
qualify for certain -potential log credits- for Crypto removal/inactivation. Specifically, the Agreement
provides that the LT2ESWTR should -employ a -toolbox- approach, and that the following tools when
properly designed and implemented receive [specified] log credit-EPA must employ the best information
available in developing the final rule and will request comment on the proposed log credits assigned in
the following table- Agreement 4.1.c(2)(emphasis added). The proposed LT2ESWTR follows this
agreement closely, proposing very specific criteria and designs that must be followed in order for
approaches in the microbial toolbox. NRDC strongly supports the inclusion of very specific, detailed
criteria in the regulation itself to guide whether a specific type of action (such as watershed control,
pretreatment, improved treatment, or alternative source) could qualify for log credit. Unless such very
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clear regulatory criteria are established, each state and water system would be left to fight out what the
parameters are in order to qualify for log credit. Many States lack the resources and expertise to do this,
and in any event there is a need for a national, uniform set of enforceable criteria to ensure public health
protection from Crypto.
Response: See Response lOOa. EPA notes that most of the toolbox options include specific criteria based
on the best information available.
EPA Letter ID: 673
Comment ID: 13988
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
C. 1. Microbial Toolbox Overview
(pages 47681-47715)
For each microbial toolbox component, EPA requests comment on: (1) Whether available data support
the proposed presumptive credits, including the design and implementation conditions under which the
credit would be awarded, (2) whether available data are consistent with the decision not to award
presumptive credit for roughing filters and raw water off-stream storage, and (3) whether additional data
are available on treatment effectiveness of toolbox components for reducing Cryptosporidium levels. EPA
will consider modifying today's proposal for microbial toolbox components based on new information
that may be provided. EPA particularly solicits comment on the performance of alternative filtration
technologies that are currently being used, as well as ones that systems are considering for use in the
future.
Jordan Valley Water supports EPAs use of the toolbox approach and the flexibility it gives water systems
to provide additional protection against Cryptosporidium.
Response: See Response lOOa.
EPA Letter ID: 678
Comment ID: 14657
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. It is important that the EPA bring the microbial toolbox requirements in line with Federal
Advisory Committee Act (FACA) discussions by explaining the overall concept of credit (not based
on strict log removal alone), and by enumerating the additional benefits of each toolbox item. The FACA
did not focus on strict log removal or Cryptosporidium alone, but rather on overall risk reduction from
other microbial contaminants and disinfection byproducts. That is why the discussion used the term -
credit-. In addition to data available on Cryptosporidium oocyst removal for a specific toolbox item, the
FACA also considered other benefits such as
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• Reducing peaks in occurrence of pathogens,
• Making other processes more stable or effective,
• Reducing other contaminants (i.e. total organic carbon, disinfection byproduct formation), etc. and
• Reducing other pathogens.
The FACA also encouraged the use of a variety of technologies that are viable alternatives to ultraviolet
(UV) disinfection in achieving Cryptosporidium removal. These technologies provide removal options
that are independent of the failure modes (such as lamp burnout or power loss) that UV disinfection faces.
The EPA-s focus in the proposed rule is on strict log removal. This leads the EPA to apply overly
conservative restrictions on the use of other technologies to comply with the regulation. Conservative
assumptions are made in discussing every toolbox component. The conservative assumptions are then
compounded leading to overly conservative endpoints. As a result of these conservative assumptions, the
potential risk of Cryptosporidium tends to be inflated while the potential treatment effectiveness tends to
be deflated. Furthermore, the additional benefits of individual technologies are mentioned but not taken
into consideration in determining credits. The approach used by the EPA does not treat these uncertainties
in a balanced manner. We recommend the EPA employ a balanced approach in the treatment of these
uncertainties. Additionally, considering that the FACA focused on multiple objectives (as outlined above)
and the concept of credit rather than strict (and overly conservative) log removal, we urge the EPA to
look at ways to provide greater flexibility through demonstration of performance rather than funneling
everything towards UV.
Response: See Response VIOa.EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR requirement and provide viable options other than UV disinfection for
most systems.
EPA Letter ID: 678
Comment ID: 14696
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 24. Sections 141.727(a) and (b) - It is not clear what alternatives a system would have in
order to meet the overall 5.5 log Cryptosporidium removal requirement, without the immediate need to
install a new treatment technology, if a system using conventional filtration treatment or direct filtration
treatment cannot meet the specific combined filter effluent or individual filter effluent turbidity
requirement in a particular month, and thus cannot claim the corresponding credits for Cryptosporidium
removal for that month. We request that EPA include a statement about available alternatives.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements. EPA notes the LT2ESWTR does not require a
5.5 log Cryptosporidium removal for all systems. Only systems in Bin 4 or systems choosing not to
perfrom source water monitoring are required to provide 5.5 log Cryptosporidium treatment. Systems in
Bin 3 and 4 must acheive at least 1 log of the additional Cryptosporidium treatment using bag filters,bank
filtration, cartridge filters,chlorine dioxide,membranes, ozone or UV or a combination of those
technologies.
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EPA Letter ID: 683
Comment ID: 14765
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
Comment: Microbial Toolbox: As recommended by the Stage 2 M- DBP Advisory Committee in the
Agreement in Principle, the LT2ESWTR proposal contains a list of treatment processes and management
practices for water systems to use in meeting additional Cryptosporidium treatment requirements under
the LT2ESWTR. The list, or the microbial toolbox, provides a variety of treatment technologies and
respective presumptive credits towards treatment process listed. Treatment plants will receive these
credits for toolbox components by demonstrating compliance with required design and implementation
criteria. Treatment credit greater than the presumptive credit may be awarded for a toolbox component
based on a site specific or technology-specific demonstration of performance.
The toolbox provides an important source of treatment alternatives and management practices that water
systems might select as the most appropriate and cost-effective treatment processes for their specific
conditions. However, it is important that the risk reduction benefits considered for each treatment
process not be limited to Cryptosporidium inactivation alone. Benefits of reduction of other microbial
contaminants and from DBFs must also be considered in determining treatment credit. FACA discussion
of the overall -credit- concept did not focus solely on Cryptosporidium removal, but considered other
benefits such as reducing peaks in the occurrence of pathogens, making processes more stable or
effective, reduction of other contaminants, and reduction of occurrence of other pathogens.
Response: See Response 710a.
EPA Letter ID: 703
Comment ID: 14785
Commenter: Rich Weirich, Plant Superintendent, Frenchtown Water Treatment
Commenter Category: Regulated Community (Utilities)
Comment: I have noticed that the rule leans heavily towards "UV" Treatment, I feel that there should be
some more notice to the treatment facilities that use ozone or another method of treatment to meet
compliance.
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems.
EPA Letter ID: 706
Comment ID: 14811
Commenter: John Spatz, Deputy Commissioner, City of Chicago Department of Water Management
Commenter Category: Regulated Community (Utilities)
Comment: 5. MICROBIAL TOOL BOX
UV
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The EPA should take in consideration that this was not to be a "UV Rule". UV only inactivates the
cryptosporidium protozoan.
Response: See response 710a. EPA believes that the toolbox options provide a broad range of alternatives
to meet LT2ESWTR treatment requirements and provide viable options other than UV disinfection for
most systems.
EPA Letter ID: 711
Comment ID: 16559
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 12. Sections 141.727(a) and (b) - If a system using conventional filtration treatment or direct
filtration treatment cannot meet the specific combined filter effluent or individual filter effluent turbidity
requirement in a particular month, and thus cannot claim the corresponding credits for Cryptosporidium
removal for that month, what alternatives would the system have in order to meet the overall 5.5 log
Cryptosporidium removal requirement?
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements. EPA notes the LT2ESWTR does not require a
5.5 log Cryptosporidium removal for all systems. Only systems in Bin 4 or systems choosing not to
perfrom source water monitoring are required to provide 5.5 log Cryptosporidium treatment. Systems in
Bin 3 and 4 must acheive at least 1 log of the additional Cryptosporidium treatment using bag filters,bank
filtration, cartridge filters,chlorine dioxide,membranes, ozone or UV or a combination of those
technologies.
8.3 Comment Code 720, Watershed Control Program
Summary of Issues
Public comments supported the concept of awarding credit towards Cryptosporidium treatment
requirements for an effective watershed control program. Commenters expressed concerns, however, with
specific criteria for awarding this credit, including annual watershed sanitary surveys, re-approval of
watershed control programs, standards for existing watershed control programs, and public availability of
documents related to the watershed control program. . Regarding the proposed requirement for annual
watershed sanitary surveys, commenters stated that this frequency is too high because activities to reduce
Cryptosporidium contamination in the watershed will often take many years to implement. These
commenters recommended that watershed sanitary surveys be performed every three to five years in
conjunction with PWSs sanitary surveys or longer. In contrast, other commenters supported annual
watershed sanitary surveys as being necessary to allow proper responses to new sources of contamination
that can occur quickly in watersheds. Commenters suggested such sources can occur through
development, new recreation programs, fires, unauthorized activities, and other factors.
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Several commenters felt that public outreach should not be a reason for relaxation of the sanitary survey
requirement while another commenter noted that public outreach demanded considerable resources and
could make compliance with the rule difficult.
Many commenters opposed the proposed requirement for PWSs to reapply for approval of their watershed
control programs after completing the second round of source water monitoring. The concern was that
this requirement would discourage PWSs from pursuing watershed control programs because they would
be uncertain about whether they would continue to receive treatment credit for their programs in the
future. As an alternative, commenters recommended that States monitor the progress of PWSs in
implementing watershed control programs through the watershed sanitary surveys and annual status
reports. A State could then deny treatment credit to a PWS if it failed to demonstrate adequate
commitment to its approved watershed control plan. Several commenters stated that PWSs with existing
watershed control programs should be eligible for Cryptosporidium treatment credit under the same
standards that apply to new programs.
With respect to a proposed requirement that the watershed control plan, annual status reports, and
watershed sanitary surveys be made available to the public, commenters stated that homeland security and
confidential business information concerns are associated with these documents. Homeland security
concerns apply to information on the location of treatment plant intakes and other structures. Confidential
business information concerns may apply to partnerships the PWS establishes with individuals and
businesses that represent sources of contamination in the watershed. Some commenters were concerned
that requiring PWSs to make this information publicly available would discourage partnerships to reduce
source water contamination.
Response to Comment Code 720
Public comments supported the concept of awarding credit towards Cryptosporidium treatment
requirements for an effective watershed control program. Commenters expressed concerns, however, with
specific criteria for awarding this credit, including annual watershed sanitary surveys, re-approval of
watershed control programs, standards for existing watershed control programs, and public availability of
documents related to the watershed control program.
Regarding the proposed requirement for annual watershed sanitary surveys, commenters stated that this
frequency is too high because activities to reduce Cryptosporidium contamination in the watershed will
often take many years to implement. These commenters recommended that watershed sanitary surveys be
performed every three to five years in conjunction with PWSs sanitary surveys or longer. In contrast,
other commenters supported annual watershed sanitary surveys as being necessary to allow proper
responses to new sources of contamination that can occur quickly in watersheds. Commenters suggested
such sources can occur through development, new recreation programs, fires, unauthorized activities, and
other factors.
Several commenters felt that public outreach should not be a reason for relaxation of the sanitary survey
requirement while another commenter noted that public outreach demanded considerable resources and
could make compliance with the rule difficult.
Many commenters opposed the proposed requirement for PWSs to reapply for approval of their watershed
control programs after completing the second round of source water monitoring. The concern was that
this requirement would discourage PWSs from pursuing watershed control programs because they would
be uncertain about whether they would continue to receive treatment credit for their programs in the
future. As an alternative, commenters recommended that States monitor the progress of PWSs in
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implementing watershed control programs through the watershed sanitary surveys and annual status
reports. A State could then deny treatment credit to a PWS if it failed to demonstrate adequate
commitment to its approved watershed control plan.
Several commenters stated that PWSs with existing watershed control programs should be eligible for
Cryptosporidium treatment credit under the same standards that apply to new programs.
With respect to a proposed requirement that the watershed control plan, annual status reports, and
watershed sanitary surveys be made available to the public, commenters stated that homeland security and
confidential business information concerns are associated with these documents. Homeland security
concerns apply to information on the location of treatment plant intakes and other structures. Confidential
business information concerns may apply to partnerships the PWS establishes with individuals and
businesses that represent sources of contamination in the watershed. Some commenters were concerned
that requiring PWSs to make this information publicly available would discourage partnerships to reduce
source water contamination.
Individual Comments on Code 720
EPA Letter ID: 417
Comment ID: 10526
Commenter: Kenneth Brown, Authority Manager, Stroudsburg Municipal Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: The Authority has completed the Phase III PFSW program, implemented Source Water
Protection programs, complete the SWAP program and participated in many studies on its source water.
Has all this time, money and effort been wasted or can it, will it be considered as part of this regulation?
Response: Given the highly site-specific nature of a watershed control program, including the feasibility
and effectiveness of control measures, EPA believes that systems should demonstrate their eligibility for
0.5 log Cryptosporidium credit through targeted programs that account for site-specific conditions. EPA
notes that the SWAP is a one time assesment which would provide valuable information for a watershed
control program but would not meet the requirements for ongoing surveillance and for control measures
that will be effective in mitigating sources of fecal contamination. Active source water protection
programs and ongoing investigations of source water would be important components of a watershed
control program.
EPA Letter ID: 468
Comment ID: 11054
Commenter: Michael L. McGlinchy, Public Utilities Bureau Manager, City of Akron Public Utilities
Bureau
Commenter Category: Regulated Community (Utilities)
Comment: Watershed Control Program Credit
Akron commends EPA for acknowledging that a well-planned watershed protection program can be an
effective barrier to Cryptosporidium. However, EPA has not clearly identified the other benefits, such as
reduction in disinfection byproduct precursors and suspended solids, protection against bacteria, viruses
and other pathogenic organisms, and protection from other chemical contaminants introduced to the water
Comment Response for LT2ESWTR 8-41 December 2005
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supply either intentionally or unintentionally. EPA should enumerate these additional benefits in the final
rule.
Response: See Response 720. The final LT2ESWTR preamble discusses the additional benefits of a
watershed control program.
EPA Letter ID: 506
Comment ID: 10742
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: o Watershed Protection Credit - CWD supports the intent of the FACA in including a
watershed protection credit in the toolbox. However, CWD is concerned that the way USEPA has
included watershed protection in the proposed rule will discourage its use. Specifically, CWD feels that
the requirement for annual watershed
Response: See Response 720.
EPA Letter ID: 512
Comment ID: 11516
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: b. The benefits of existing programs should not be expected to show up in monitoring for bin
placement because of 1) inadequacies in the analytical method (e.g. implementation of UV disinfection at
nearby waste water treatment facilities could reduce the presence of-viable and infectious-
Cryptosporidium in a system-s source water that would not be detected by present analytical methods that
merely count oocysts) and 2) benefits that can take many years to realize (e.g. A watershed grazing
management program, such as CCWD-s program at Los Vaqueros watershed that includes a combination
of physical (fenced watershed protection zones) and contractual controls, over a period of many years
leads to reduced risk of Cryptosporidium reaching source waters), c. The requirement for
Response: See Response 720. EPA notes that credit under this toolbox option is not based on
demonstration sampling for initial or continuing compliance.The Stage 2 M-DBP Advisory Committee
recommended a 0.5-log Cryptosporidium treatment credit for a watershed control program recognizing
that improvement in source water quality could likely never be measured given the available analytical
techniques.
EPA Letter ID: 556
Comment ID: 12064
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
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Comment:
It is important that EPA recognize that wastewater treatment facilities are currently examining ways to
avoid excessive chlorination of effluents to achieve whole effluent toxicity requirements under the Clean
Water Act. Water systems encouraging or negotiating the use of ultraviolet light disinfection as part of
their watershed protection program could have significant impacts on the presence of-viable and
infectious- Cryptosporidium in their source waters. Note that none of this improvement would be
detected by present analytical methods that merely count oocysts whether they are inactivated or not (UV
does not destroy the oocyst, it merely inactivates it).
Response: The Stage 2 M-DBP Advisory Committee recommended 0.5-log Cryptosporidium treatment
credit for a watershed control program recognizing that improvements in source water could likely never
be measured given the available analytical techniques. EPA notes that credit under this toolbox option is
not based on demonstration sampling for initial or continuing compliance. See Response 720.
EPA Letter ID: 585
Comment ID: 11973
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47685 [and §141.725(a)(4) on p. 47785]
The TCEQ concurs that an effective watershed control program can reduce the source water
Cryptosporidium levels. However, we recommend that sanitary surveys
Response: See Response lOOa.
EPA Letter ID: 617
Comment ID: 13255
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: standards that recognizes certain supplies to be at higher risk than others. We also are strong
supporters of EPA's recognition, through allocation of regulatory credit, that watershed protection is the
first step in assuring public health. We feel strongly that this provision must not be reduced to an
unattainable paper exercise but should provide meaningful incentive for utilities to invest resources in
their watersheds and for those who have made these investments, to provide a tangible regulatory return
for their efforts and resources. With this in mind we strongly encourage EPA to retain feasible
Response: See Response 720.
EPA Letter ID: 624
Comment ID: 13177
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
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Comment: 2. There is a disconnect between SDWA and CWA concerning Watershed Control.
Response: The LT2ESWTR establishes National Primary Drinking Water Standards under the Safe
Drinking Water Act for all public water systems using surface water and GWUDI. The purposes of the
LT2ESWTR are to protect public health from illnesses due to Cryptosporidium and other microbial
pathogens in drinking water and to address risk-risk tradeoffs with the control of disinfection-by-products
in public water systems. EPA agrees with the importance of limiting pathogen loading of surface waters,
particularly those used as drinking water sources. However, today's final rule does not directly address
ambient water quality upstream of each water intake. Rather, it addresses appropriate treatment levels for
Cryptosporidium by public water systems based on their source water quality, as EPA is authorized to do
under the Safe Drinking Water Act. EPA agrees that source water protection activities under the Clean
Water Act and the SDWA Source Water Assessment and Protection Program have a public health benefit
in reducing microbial pathogens in drinking water supplies. EPA encourages public water systems to
leverage other Federal, State and local programs in developing the elements of a watershed control
program to meet the requirements of the LT2ESTWR. The LT2ESWTR Toolbox Guidance Manual
describes the integration of other programs and regulations in a watershed control program.
EPA Letter ID: 624
Comment ID: 13188
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: Watershed Control Program (WCP):
1. GCWW believes that there is a critical flaw in the agency's proposed approach to the Watershed
Control Program. Specifically, we believe that the Watershed Control Program (WCP) is not integrated
with EPA's own Clean Water Act (CWA), a watershed pollution prevention and restoration program. In a
February 8,2003 memorandum, Assistant Administrator Tracy Mehan III states the following "I have
directed my staff to continue the CWMSDWA integration actions that have been a priority for the past
two years. The operating principle of these policy efforts is that, while public water systems are legally
accountable for the delivery of safe drinking water to their consumers, no water system should have to
provide more treatment than that which is necessary to address naturally occurring pollutant
concentrations, e.g., minerals leaching from rock formations, wildlife contamination unrelated to
anthropogenic activities. In addition, in an October 1, 2003 memorandum, the Assistant Administrator
made the following additional statements. "Protecting public health under the Clear Water Act is a critical
element of our mission. To protect a public water supply use, we must protect the ambient water quality
upstream of each water intake. Reliance solely on drinking water treatment, beyond that which is needed
to address naturally occurring pollutant concentrations imposes an unfair burden on communities to
address preventable problems caused by man made sources of pollution. Therefore, as I stated in my
February 8,2003 memorandum to the Regional Administrators, a core principle of source water protection
is to assure no public water system should have to provide more drinking water treatment other than that
which is necessary to address naturally occurring pollutant concentrations". It is obvious from the content
of these memoranda, as well as the efforts USEPA has been making over the past two years, that their
intent is for the CWA to be protective of drinking water.
Response: The LT2ESWTR establishes National Primary Drinking Water Standards under the Safe
Drinking Water Act for all public water systems using surface water and GWUDI. The purposes of the
LT2ESWTR are to protect public health from illnesses due to Cryptosporidium and other microbial
Comment Response for L T2ESWTR 8-44 December 2005
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pathogens in drinking water and to address risk-risk tradeoffs with the control of disinfection-by-products
in public water systems. EPA agrees with the importance of limiting pathogen loading of surface waters,
particularly those used as drinking water sources. However, today's final rule does not directly address
ambient water quality upstream of each water intake. Rather, it addresses appropriate treatment levels for
Cryptosporidium by public water systems based on their source water quality, as EPA is authorized to do
under the Safe Drinking Water Act. EPA agrees that source water protection activities under the Clean
Water Act and the SDWA Source Water Assessment and Protection Program have a public health benefit
in reducing microbial pathogens in drinking water supplies. EPA encourages public water systems to
leverage other Federal, State and local programs in developing the elements of a watershed control
program to meet the requirements of the LT2ESTWR. The LT2ESWTR Toolbox Guidance Manual
describes the integration of other programs and regulations in a watershed control program.
EPA Letter ID: 641
Comment ID: 13599
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47683 Requirements for Initial State Approval of Watershed Controls Programs
ASI agrees with specifications and States authority to approve, reject or conditionally approve said plans.
We agree with requirements to maintain state approval also.
Response: See response lOOa.
EPA Letter ID: 647
Comment ID: 12923
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Watershed Control Program
MDE generally supports inclusion of this tool, but recognizes that this tool will require significant effort
on the part of both the state and the water system. However, 0.5 log presumptive credit may not be
sufficient to represent
Response: See Response lOOaand Response 720.
EPA Letter ID: 673
Comment ID: 13989
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: C. 2. Watershed Control Program
(pages 47682-47685)
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Comments on Watershed Control Program
As proposed, the presumptive credit offered for implementation of a watershed control program is not a
viable one for most water systems who typically do not have control or jurisdiction over their watershed.
The watershed option will require States to develop specific elements to address how to determine they
effectiveness of the program in reducing the risk from Cryptosporidium. In addition, improvements in the
watershed will take years of effort before results could be measured.
Response: See Response 720.
EPA Letter ID: 677
Comment ID: 13954
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Comment: 3. Detailed requirements for approved watershed control programs (page47685). USEPA has
detailed requirements for the microbial toolbox options, including the watershed control program. The
City believes that this tool is a critical strategy to improve source water quality by minimizing overall
contamination and peaking. Under this option, the USEPA has identified that systems will need to obtain
initial state approval, conduct annual program status reports and annual watershed surveys. The credit for
this tool will need to be reapproved each six-year period. The City has concerns over most aspects of this
tool, including the initial state approval process, on-going re-approval process, and several detailed
program requirements.
Response: See Response 720.
EPA Letter ID: 678
Comment ID: 14685
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 19. Section 141.725 - The FACA encouraged watershed protection. It supported a credit for
watershed protection programs knowing that improvements in source water would be difficult, could
likely never be measured given the available analytical techniques, and would take many years of efforts.
Nevertheless, all FACA members including environmental and other advocacy groups, strongly supported
the credit based on the potential for long-term reductions in Cryptosporidium and also on the fact that
such efforts would serve to reduce other microbial pathogens and total organic carbon as well as
disinfection byproducts (see General Comment #2 above).
Response: See Response 720.
EPA Letter ID: 678
Comment ID: 14687
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Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 20. Section 141.725(a)(l) - The EPA has put much effort into the components of the rule, but
when put together the result is a heavy reliance on advanced treatment and a divergence away from
watershed protection. We believe prevention is as important as treatment in protecting our drinking water
sources from Cryptosporidium contamination. Furthermore, the requirement that existing
Response: EPA agrees that prevention is as important as treatment in protecting our drinking water
sources from Cryptosporidium contamination. The watershed toolbox option provides credit to meet bin
requirements as do other treatment options in the toolbox. See Response 720.
EPA Letter ID: 678
Comment ID: 14689
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The EPA should note that the benefits of existing watershed control programs may not
necessarily be realized prior to monitoring for bin placement because of the inadequacies of the analytical
method and the fact that benefits take many years to realize.
Response: The Stage 2 M-DBP Advisory Committee recommended 0.5-log Cryptosporidium treatment
credit for a watershed control program. The recommendation recognized that improvements in source
water would be difficult, could likely never be measured given the available analytical techniques, and
would take many years of effort. See Response 720.
8.3.1 Comment Code 721, Proposed credit
Individual Comments on Code 721
EPA Letter ID: 101
Comment ID: 10886
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 723 3. Reduced frequency for watershed survey
Comment: Watershed Control Programs
Systems should get a 1 log credit for Cryptosporidium inactivation and a reduction in the annual
watershed survey requirement for strong source water protection plans or for engaging the public through
outreach programs.
Response: The Stage 2 M-DBP Advisory Committee recommended a 0.5-log Cryptosporidium treatment
credit for a watershed control program. The recommendation recognized that improvements in source
water would be difficult, could likely never be measured given the available analytical techniques, and
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would take many years of effort. The commenter does not provide a basis or supporting information for
the treatment credit recommendation. See Response 720.
EPA Letter ID: 457
Comment ID: 11924
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 722 2. Program requirements
Comment: Watershed Control Program
We support inclusion of this tool and the 0.5 log presumptive credit. However, this tool requires
significant effort on the part of both the state and the water system, and may not be widely accepted or
used by the water systems.
Response: See Response lOOa.
EPA Letter ID: 491
Comment ID: 10666
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: 5. The requirements for watershed control program credits for filter systems are too onerous
to encourage watershed protection. Systems that wish to implement
Response: See Response 720.
EPA Letter ID: 496
Comment ID: 10703
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 2. Microbial Toolbox Key Issue 2: Watershed Protection Credit: Though improvements in
source water would be difficult, given the available analytical techniques, and would take many years of
effort, the EPA should encourage the Watershed Protection Credit. The credit based on the potential for
long reductions in Cryptosporidium, and on the fact that such efforts would serve to reduce other
microbial pathogens and TOC, and therefore disinfection by-products, creates support for the 0.5 log
credit. EPA has made the conditions for achieving and maintaining credit so arduous that few, if any,
systems will make use of it, even if they presently have a program established.
Comments for Microbial Toolbox key Issue 2 (Watershed Protection Credit): EPA should provide
watershed protection credit that will encourage, not discourage,its use. As presently structured, the credit
is not a practical one for water systems.
Comment Response for L T2ESWTR 8-48 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Response: See Response 720.
EPA Letter ID: 502
Comment ID: 10638
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: working together to protect our source water quality. Therefore, we strongly
support the 0.5-log credit for a watershed control program.
Response: See Response lOOa.
EPA Letter ID: 507
Comment ID: 11475
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 8. Watershed Control Program, IV.C.2., pg 47682.
The watershed control program requirements as outlined in the proposal tend to be very arduous and may
actually discourage utilities from developing such programs. For example, the requirements for an annual
watershed survey by a state certified party and the re-approval process every six years for only a 0.5 log
credit seems extremely burdensome. As it is, watershed control programs take many years to develop, are
costly and may include several different political subdivisions as FCWA has experienced administering
our Occoquan Watershed program. Results of such programs may not be apparent for many years. EPA
can be more reasonable in allowing a 0.5 log credit, especially to proactive utilities that currently have
watershed programs in place.
Response: See Response 720.
EPA Letter ID: 516
Comment ID: 11744
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 300 II. Filtered System Monitoring Requirements
(parameters, frequency, location)
Comment: P. 47655. EPA makes a point that there was greater variability in occurrences of
Cryptosporidium in flowing stream sources than in reservoir and lakes. Given this greater variability,
EPA should discuss why the proposed sampling frequency for binning purposes is the same for reservoirs
and lakes, and why the same log credit for watershed protection is given for systems on reservoirs and
lakes compared with flowing streams. By ignoring the fact that some watersheds are more stable than
others regarding the potential for episodic crypto events, such as the watersheds of unfiltered systems,
Comment Response for L T2ESWTR 8-49 December 2005
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EPA undervalues the benefits of robust watershed protection programs, such as those developed by
unfiltered systems, and overvalues the protections afforded by engineered solutions.
Response: Source water variability is one factor that influences the number of samples needed to
accurately classify plants in LT2ESWTR treatment bins. As variability increases, more samples are
needed to determine the mean Cryptosporidium level with high confidence. Statistical analysis from
studies performed in the ICR and ICRSS indicate that Cryptosporidium concentration values detected for
bin classification are independent of the source water type, i.e., lake/reservoir or flowing stream sources.
Statistical analyses also indicate that it is necessary for PWSs to collect at least 24 samples in order to
keep the likelihood of both false positives and false negatives at five percent or less. See the proposed
LT2ESWTR for additional details on this analysis (USEPA 2003a). Based on the results of this analysis,
EPA concluded that PWSs operating year-round should collect at least 24 samples when they monitor for
Cryptosporidium. This number of samples ensures a high likelihood of appropriate bin classification.
Today's rule does not allow bin classification based on fewer samples (except in the case of part-year
PWSs) as this would involve unacceptably high false positive or false negative rates and would, therefore,
be an inappropriate basis to determine Cryptosporidium treatment requirements. EPA does believe,
though, that PWSs should have the choice to collect more than 24 samples to further improve the
accuracy of bin classification, and today's rule allows this.
EPA Letter ID: 520
Comment ID: 11627
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Watershed Control Program
IEPA generally supports inclusion of this tool and the 0.5 log presumptive credit, but recognize that this
tool will require significant effort on the part of both the state and the water system.
Response: See Response lOOa.
EPA Letter ID: 556
Comment ID: 12062
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Basic Principles from the FACA Discussions: The concerns AMWA has with EPA-s
overall approach to credit, and its divergence from the FACA-s intentions,is well illustrated in the
Watershed Protection Credit requirements.
The FACA wanted to encourage watershed protection. Accordingly, the FACA supported a 0.5 log credit
for watershed protection programs knowing that improvements in source water would be difficult, could
likely never be measured given the available analytical techniques, and would take many years of effort.
Nevertheless, all FACA members including environmental and other advocacy groups strongly supported
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the credit based partially on the potential for long-term reductions in Cryptosporidium, but mainly based
on the overall benefits to ecosystems as well as human health. The FACA acknowledged that such efforts
would also serve to reduce other microbial pathogens and TOC and therefore reduce disinfection
byproducts.
Discussion: Despite the FACA-s clear desire to encourage watershed protection by awarding credit, EPA
has made the conditions for achieving and maintaining credit so onerous that few if any systems will
make use of it even if they presently have a program in place. Since EPA spent a considerable effort in
the proposal discussing resources that would be available for systems undertaking watershed programs,
AMWA believes that this was unintentional.
Recommendations: EPA should provide watershed protection credit that will encourage and not
discourage its use. As presently structured the credit is not a viable one for water systems.
Response: See Response 720.
EPA Letter ID: 556
Comment ID: 12063
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Systems that presently have watershed protection programs should be rewarded for
their proactive stance rather than penalized by increased requirements. The benefits of existing programs
should not be expected to show up in monitoring for bin placement because of the inadequacies of the
analytical method and the fact that benefits take many years to realize and may not necessarily be realized
prior to monitoring. Once again, EPA must keep in mind the concept of credit in this area rather than
implying through this requirement that the benefits are immediate and measurable. According to the
proposed Watershed Control Program (WCP) by EPA, existing WCP efforts are not given any credit
towards WCP approval. The WCP process as it is currently designed does not complement existing
programs but should. The progress made by these programs prior to the LT2ESWTR-required WCP
implementation should be considered and included in the initial watershed control plan.
EPA and States must be sensitive to forcing changes to an existing source water protection program as it
converts to a WCP. Flexibility must be provided to primacy authorities so that -one-size-fits-all-
programs do not negate years of prior groundwork, effort, relationships, and resources invested by a
system that could have made significant improvements if left unaltered. We recommend that source water
protection activities and implementation by the system prior to the initial WCP approval be included in
the evaluation of the WCP approval and that source water protection activities of significant value to the
WCP process already underway by the system not be altered or adjusted in order to -start from scratch-
in order to fit EPA-s -model- WCP approach.
Response: See Response 720.
EPA Letter ID: 595
Comment ID: 12589
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Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Watershed Control Program
Maine generally supports inclusion of this tool and the 0.5 log presumptive credit, but realizes that it will
create a great deal of additional work by both the state and the water system. The State should, however,
have flexibility in determining the areas of influence within the watershed actually impacting water
quality if applicable.
Response: See Response 720. Under the LT2ESWTR, PWSs identify the area of influence subject to
State approval.
EPA Letter ID: 620
Comment ID: 13301
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: alternatives to Cryptosporidium removal. Systems that have large surface water watersheds,
and have existing watershed improvement programs in place, should be allowed credit for such programs.
SPRWS already has programs in place which not only provide barriers for Cryptosporidium, but also
provide protection from taste and odor problems associated with algal blooms; protection from coliform
bacteria, nuisance chemicals such as phosphorus, nitrogen and sulfides, as well as buffers from chemical
spills and hazardous materials. Such programs are a significant benefit to the utility and it's customers and
should be encouraged.
Response: See Response 720.
EPA Letter ID: 620
Comment ID: 13306
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 3: Watershed Protection Credit
Comments: SPRWS recommends that existing and/or planned watershed control programs receive credit,
provided said programs are based on accepted engineering practices for removal of solids and other
contaminants. Practices such as sedimentation ponds, buffer strips and soil conservation methods should
be accepted. Such efforts help steer the water professional from the "magic bullet" approach (read UV) of
a given problem by encouraging stewardship and ingenuity with their resources.
Response: See Response 720.
Comment Response for L T2ESWTR 8-52 December 2005
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EPA Letter ID: 624
Comment ID: 13191
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 2.2.3 It is inappropriate to categorically exclude existing watershed programs from credit
towards the watershed control program. This is especially true of components of a program that may take
several years to realize their full value. Provisions should be included that allow for individual
components of existing programs to be evaluated and given their due "credit", as appropriate, in a
watershed control program.
Response: See Response 720.
EPA Letter ID: 629
Comment ID: 12829
Commenter: Melinda Rho, Manager of Regulatory Affairs and Consumer Protection, Los Angeles
Department of Water and Power
Commenter Category: Regulated Community (Utilities)
Comment: LADWP supports the 0.5 log treatment credit for watershed protection programs.
Response: See Response lOOa.
EPA Letter ID: 643
Comment ID: 12781
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Watershed Control Program
States generally support inclusion of this tool and the 0.5 log presumptive credit, but recognize that this
tool will require significant effort on the part of both the state and the water system.
Response: See Response lOOaand Response 720.
EPA Letter ID: 646
Comment ID: 13570
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: Watershed Protection Credit - As written the watershed protection credit is too Onerous to
achieve and maintain. Santa Fe obtains its source water from a watershed that is closed to the public and
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free of domestic grazing. The head waters are located in federal Wilderness Area. Santa Fe should not be
penalized with increased requirements when proactive protection measures are in place. FACA intended
the credit for systems with protective measures in place.
Response: See Response 720.
EPA Letter ID: 660
Comment ID: 14078
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: See below for specific comments of proposed toolbox options:
Watershed Control Program
If a utility is currently active in a source water protection program, they are penalized rather than
rewarded for their proactive approach under LT2ESWTR. Credit should be given to an existing watershed
protection program, which address the issues of microbial contaminants.
Response: See Response 720.
EPA Letter ID: 662
Comment ID: 14035
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Watershed Control Program
Effective watershed protection programs are long term efforts. Annual surveys would be useless, changes
and their impacts will take time to be realized. States should be able to award Watershed Control Program
toolbox credits based on the existence of a program and documented implementation. This should be a
Response: See Response 720.
EPA Letter ID: 667
Comment ID: 14016
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: 3. Watershed protection is a very valuable asset and should be given considerable credit to
encourage its use for the long term.
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Response: EPA appreciates the comment.The Stage 2 M-DBP Advisory Committee recommended 0.5-
log Cryptosporidium treatment credit for a watershed control program. The recommendation recognized
that improvements in source water would be difficult, could likely never be measured given the available
analytical techniques, and would take many years of effort.
EPA Letter ID: 678
Comment ID: 14686
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Contrary to the FACA-s clear desire to encourage watershed protection by awarding credit,
the EPA has made the conditions for achieving and maintaining credit so onerous that few, if any,
systems will make use of it even if they presently have a program in place. Thus, the credit as presently
proposed is not viable for water systems.
Response: See Response 720.
EPA Letter ID: 678
Comment ID: 14691
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We also recommend the EPA make the watershed credit less onerous and more attainable by
modifying the proposed requirement language appropriately and allowing systems the flexibility to obtain
greater credits if they can demonstrate greater than 0.5 log removal through watershed protection.
Response: The Stage 2 M-DBP Advisory Committee recommended 0.5-log Cryptosporidium treatment
credit for a watershed control program. The recommendation recognized that improvements in source
water could likely never be measured given the available analytical techniques. See Response 720.
EPA Letter ID: 711
Comment ID: 16544
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 4. EPA should re-evaluate the low credit given versus the weighty requirements currently
proposed for the watershed protection option. The 0.5 log credit given for this option will not promote its
use. This credit should be increased to at least 1 log. Refer to the appendix for more suggestions on the
verbiage for this toolbox option.
Response: The Stage 2 M-DBP Advisory Committee recommended 0.5-log Cryptosporidium treatment
credit for a watershed control program. The recommendation recognized that improvements in source
water would be difficult, could likely never be measured given the available analytical techniques, and
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would take many years of effort. The commenter does not provide a basis or supporting information for
the treatment credit recommendation. See Response 720.
EPA Letter ID: 711
Comment ID: 16557
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 10. Section 141.725(a)(l) - In protecting our drinking water source from Cryptosporidium
contamination, we believe prevention is important. However, considering the extensive resource and
effort requirements of the proposed Watershed Control Program and the resulting 0.5 log credit only,
systems may not find incentive to implement this toolbox option. To encourage systems to implement a
successful watershed control program and put more efforts on prevention rather than
removal/inactivation, EPA should allow 1 log credit or more instead of the currently proposed 0.5 log
credit for Cryptosporidium removal.
Response: The Stage 2 M-DBP Advisory Committee recommended 0.5-log Cryptosporidium treatment
credit for a watershed control program. The recommendation recognized that improvements in source
water would be difficult, could likely never be measured given the available analytical techniques, and
would take many years of effort. The commenter does not provide a basis or supporting information for
the treatment credit recommendation. See Response 720.
EPA Letter ID: 711
Comment ID: 16566
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: Comment: The watershed protection credit is very low (0.5 log) coupled with its onerous
requirements for the proposed Watershed Control Program make this option very unattractive for a utility
to implement. The watershed protection credit should be increased to 1 .O log to allow it to become a
realistic option. In addition, systems that currently have watershed protection programs should be
rewarded for their proactive stance rather than penalized by increased requirements.
Response: See Response 720.The Stage 2 M-DBP Advisory Committee recommended 0.5-log
Cryptosporidium treatment credit for a watershed control program. The recommendation recognized that
improvements in source water would be difficult, could likely never be measured given the available
analytical techniques, and would take many years of effort. The commenter does not provide a basis or
supporting information for the treatment credit recommendation.
8.3.2 Comment Code 722, Program requirements
Individual Comments on Code 722
Comment Response for L T2ESWTR 8-56 December 2005
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EPA Letter ID: 433
Comment ID: 10600
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Comment: Colorado Springs Utilities (PWSID # CO0121150) is disappointed that EPA has
made the conditions for achieving and maintaining watershed protection credit so onerous that few if any
systems will make use of it even if they presently have program in place. The requirement for an annual
watershed survey
Response: See Response 720.
EPA Letter ID: 457
Comment ID: 11924
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 721 1. Proposed credit
Comment: Watershed Control Program
We support inclusion of this tool and the 0.5 log presumptive credit. However, this tool requires
significant effort on the part of both the state and the water system, and may not be widely accepted or
used by the water systems.
Response: See Response lOOa.
EPA Letter ID: 460
Comment ID: 10995
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: 4. Microbial Toolbox - Watershed Protection Credit:
City-s position: Systems that currently have watershed protection programs should receive a credit.
Remove the excessive burdens associated with applying for and receiving credits for this toolbox option.
Drop the requirement for re-approval of the watershed protection credit every six years. Once established,
the program should be re-evaluated when the water provider-s operating permit is renewed. The
conditions for achieving credits under the proposed rule for watershed protection are onerous and overly
burdensome and would prevent most utilities from using them.
Response: See Response 720.
Comment Response for L T2ESWTR 8-5 7 December 2005
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EPA Letter ID: 468
Comment ID: 11052
Commenter: Michael L. McGlinchy, Public Utilities Bureau Manager, City of Akron Public Utilities
Bureau
Commenter Category: Regulated Community (Utilities)
Comment: 2. It is unreasonable for EPA to require utilities currently practicing effective watershed
protection to -amend and strengthen- their existing programs to receive the 0.5-log Cryptosporidium
removal credit. The 0.5 log removal credit should be applied due to existence of a current effective
program.
Response: See Response 720.
EPA Letter ID: 468
Comment ID: 11055
Commenter: Michael L. McGlinchy, Public Utilities Bureau Manager, City of Akron Public Utilities
Bureau
Commenter Category: Regulated Community (Utilities)
Comment: The current requirements to receive the 0.5-log Cryptosporidium removal credit for watershed
protection are onerous and punitive for those utilities such as Akron that have been proactive in
implementing watershed protection. It is unreasonable to require systems with an effective watershed
control program already in place to —amend and strengthen their programs to get the log removal
credit-
The City of Akron has protected its source waters, the Upper Cuyahoga River, since 1911 when
acquisition of property along the river and principal tributaries began. This program has since evolved to
include a much wider array of protection tools requiring administration, staff, supplies, equipment and
funding. What began as early action to acquire and protect environmentally sensitive lands, now includes
the implementation of best management practices on Akron-owned land, public education programs,
monitoring and reporting of pollution, organization and involvement with watershed-based stakeholder
groups and cooperation with other units of government, organizations and private landowners within the
watershed of the Upper Cuyahoga River.
Akron currently owns approximately 12% of the 207 square mile watershed and manages it to promote
natural land cover that includes mature forestland and wetlands. This type of land cover provides
protection of the natural resource base, filtration of airborne and waterborne pollutants, moderation of
stormwater runoff and continuity of river flow. Akron owns 36.3 miles of river frontage, equal to
approximately 31% of the 117.1 total river miles along the East Branch, West Branch and mainstem of
the Upper Cuyahoga River.
Akron-s Source Water Protection Program includes:
1. Land Acquisition - Akron acquires available property within the Upper Cuyahoga River watershed as
funds are available. Property offered for sale to Akron is prioritized for its potential benefit to Akron-s
water supply and is acquired by purchase or trade considering the current appraised value. Property within
the riparian corridor closest to Lake Rockwell is considered the highest priority.
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2. Best Management Practices - Akron utilizes common cultural and structural BMPs on its property to
maintain and improve upon water quality of the river and Akron-s reservoirs.
a. Tree planting of about 25,000 seedlings each year reforests land which is highly erodible or not
naturally regressing into forestland. Timber stand improvement on existing forestland accelerates the rate
of development of a mature forest canopy.
b. Sediment retention basins are constructed in waterways adjacent to Akron reservoirs to capture
sediment before it flows into the reservoirs. Accumulated sediment is periodically removed, spread on
nearby land and promptly revegetated.
c. Check dams are installed in waterways in order to reduce the velocity of instream flow, reducing and
eliminating stream scour and allowing sedimentation to occur in controlled locations from which the
sediment can later be removed.
d. Hazmat spill containment sites are established at strategic points to enable collection and removal of
hazardous materials from the river before it flows into Lake Rockwell.
e. Restriction of public access to environmentally sensitive and unsafe areas.
3. Public Education Programs - Akron staff promote awareness of the river-s water quality and Akron-s
use of the river through a public recreation program on large portions of Akron-s property, schools within
the watershed and Akron-s service area as well as through other agencies and organizations including
local park districts.
4. Watershed Monitoring - Akron Watershed Rangers monitor the entire 207 square mile watershed by
road and on the river for sources of possible contaminants. Upon identifying a source of contamination,
the landowner is made aware of the active contamination and referred to the local soil and water
conservation district for technical and financial assistance or the source is reported to a regulatory agency,
including the local health district and Ohio EPA.
5. Organization and Involvement with Watershed Groups - Akron was instrumental in organizing the
Upper Cuyahoga River Watershed Taskforce, a stakeholder group which meets bi-monthly to discuss
activities within the watershed and opportunities for members to form alliances for the benefit of the
river-s water quality. Members include public agencies, elected officials, private organizations and
private landowners.
a. The Taskforce annually hosts RiverScape, a public event for landowners within the watershed to learn
more about the river, its watershed, water quality, public programs to protect the river and how private
land management affects the river.
b. Taskforce committees have constructed several demonstration projects to promote innovative
conservation measures to promote water quality including a constructed wetland (CW) as an alternate for
conventional home sewage disposal systems (HSDS) and several rural road runoff improvement projects
to demonstrate means of improving road drainage while reducing maintenance and improving
downstream water quality in the river.
c. Taskforce members annually canoe a portion of the river to see it firsthand and gain a better
appreciation for the high quality of this unique natural resource.
6. Coordination with Other Units of Government, Organizations and Private Landowners - Akron staff
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regularly communicate with and participate in local emergency planning committees, county soil and
water conservation district planning meetings, township zoning commission meetings and with township
trustees at meetings or with special joint projects.
Akron firmly believes that watershed protection can be a valuable tool for enhancing raw water quality.
However, as it is written, the proposed rule and associated guidance are too prescriptive and discourage,
rather than encourage, utilities to develop a watershed protection program. Furthermore, it does not
reward utilities for having previously implemented an effective watershed protection program. Requiring
utilities to -amend and strengthen- their existing programs to receive the 0.5-log removal credit is
potentially punitive to utilities like Akron who have already done as much as they can do, and the
opportunities to -amend and strengthen- their existing program are too few and too costly to implement.
EPA should develop realistic expectations for watershed protection programs. The criteria are out-of-line
with the credit to be granted, and will serve as a disincentive, rather than incentive, to utilities considering
watershed protection. Annual reporting and watershed sanitary survey requirements are overly
burdensome and draw resources away from productive source water protection activities.
Response: See Response 720.
EPA Letter ID: 470
Comment ID: 11072
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: We believe that the proposed watershed control program credit and associated program
components are an important element to the multi-barrier approach for public health protection. We
believe that the states should have the flexibility
Response: See Response lOOa.
EPA Letter ID: 471
Comment ID: 11117
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 1. We are very supportive of the inclusion of watershed protection in the -toolbox-, but we
believe that the provisions as currently proposed discourage rather than encourage its use. WSSC has
been working for a number of years to develop and enhance source protection efforts within the two
watersheds of our drinking water sources, and we realize that the long-term protection afforded by source
protection is an important component of a multiple barrier approach. Unfortunately, our experience has
confirmed the conventional wisdom that these efforts require large amounts of time, effort, and
cooperation with stakeholders, which likely makes complying with the effective date of the rule
impractical or impossible. Furthermore, having recently completed extensive modeling efforts for our
source water assessments in conjunction with the State, we realize that there is very little site specific data
on both Cryptosporidium occurrence as well as the efficiency of agricultural/urban BMPs for controlling
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Cryptosporidium concentrations in raw waters. Thus, there is still much work to Washington Suburban
Sanitary Commission comments on proposed LT2ESWTR do in identifying specific sources for focusing
efforts in source protection. While the rule provisions and the guidance manual for the toolbox do not
specifically require demonstration of reductions in source water concentrations, they seem to imply such
and thus further relegate this important tool as impractical.
Response: See Response lOOaand Response 720.
EPA Letter ID: 471
Comment ID: 11118
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 2. Because of these limitations, we suggest that EPA more positively state the benefits of
source protection rather than viewing it strictly from a log-reduction perspective as well as provide
mechanisms for some type of credit where demonstration sampling cannot be achieved for initial
compliance either due to lack of information or the long-term nature of implementation. We also
suggest reconsideration of several other provisions to remove the barriers to watershed protection:
1) systems that presently have watershed protection programs should be rewarded for their proactive
stance rather than penalized by not getting any credit (other than an assumed credit from bin monitoring)
or by having increased requirements;
Response: See Response 720. EPA notes that credit under this toolbox option is not based on
demonstration sampling for initial or continuing compliance.
EPA Letter ID: 471
Comment ID: 11121
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 3. Watershed protection credits should also account for problems with current analytical
methods. Wastewater treatment facilities that are considering conversion to UV disinfection can
significantly impact the loading of viable Cryptosporidium to source waters and thus may be an important
BMP for water utilities to consider as part of their watershed protection efforts. However, since the
1622/1623 methods do not address viability, the impacts of such improvements would not be observed.
Response: See Response 720. EPA notes that credit under this toolbox option is not based on
demonstration sampling for initial or continuing compliance.The Stage 2 M-DBP Advisory Committee
recommended 0.5-log Cryptosporidium treatment credit for a watershed control program recognizing that
improvement in source water quality could likely never be measured given the available analytical
techniques.
Comment Response for L T2ESWTR 8-61 December 2005
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EPA Letter ID: 471
Comment ID: 11156
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 1. We are very supportive of the inclusion of watershed protection in the -toolbox-, but we
believe that the provisions as currently proposed discourage rather than encourage its use. WSSC has
been working for a number of years to develop and enhance source protection efforts within the two
watersheds of our drinking water sources, and we realize that the long-term protection afforded by
source protection is an important component of a multiple barrier approach. Unfortunately, our
experience has confirmed the conventional wisdom that these efforts require large amounts of time, effort,
and cooperation with stakeholders, which likely makes complying with the effective date of the rule
impractical or impossible. Furthermore, having recently completed extensive modeling efforts for our
source water assessments in conjunction with the State, we realize that there is very little site specific data
on both Cryptosporidium occurrence as well as the efficiency of agricultural/urban BMPs for controlling
Cryptosporidium concentrations in raw waters. Thus, there is still much work to Washington Suburban
Sanitary Commission comments on proposed LT2ESWTR do in identifying specific sources for focusing
efforts in source protection. While the rule provisions and the guidance manual for the toolbox do not
specifically require demonstration of reductions in source water concentrations, they seem to imply such
and thus further relegate this important tool as impractical.
Response: See Response lOOa. The Stage 2 M-DBP Advisory Committee recommended 0.5-log
Cryptosporidium treatment credit for a watershed control program. The recommendation recognized that
improvements in source water would be difficult, could likely never be measured given the available
analytical techniques, and would take many years of effort.
EPA Letter ID: 471
Comment ID: 11157
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 2. Because of these limitations, we suggest that EPA more positively state the benefits of
source protection rather than viewing it strictly from a log-reduction perspective as well as provide
mechanisms for some type of credit where demonstration sampling cannot be achieved for initial
compliance either due to lack of information or the long-term nature of implementation. We also
suggest reconsideration of several other provisions to remove the barriers to watershed protection:
1) systems that presently have watershed protection programs should be rewarded for their proactive
stance rather than penalized by not getting any credit (other than an assumed credit from bin monitoring)
or by having increased requirements;
Response: See Response 720. The preamble to the the LT2ESWTR discusses the benefits of source
protection.
EPA Letter ID: 483
Comment ID: 11266
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Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: - EPA should provide watershed protection credit that will encourage and not discourage its
use. Systems, such as ours, that presently have a watershed protection program should be rewarded for
their proactive stance rather than penalized by increased requirements.
Response: See response to Comment Code 720.
EPA Letter ID: 488
Comment ID: 11849
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4.4.1 Watershed Control Program
PWD believes that, as currently formulated, the Watershed Control Program (WCP) is not a viable
LT2ESWTR toolbox element. Key aspects of the WCP regulatory provisions and guidance are
inconsistent with the intent of the Agreement in Principle. We are extremely concerned that the draft
guidance creates disincentives for utilities with good potential for implementing source water protection
for regulatory credit, and that utilities currently engaged in source water protection will be penalized
rather than rewarded for their proactive effort.
In our view the Agency-s proposed approach includes the following critical flaws:
1. Unjustified requirements would interfere with the core mission of a source water protection program;
this interference escalates with every -re-approval cycle- (sanitary surveys, monitoring, etc.)
2. Existing watershed control programs and source water protection efforts are not credited
3. Lack of integration with Clean Water Act (CWA) watershed restoration programs including no
recognition of the time scale for CWA-related actions and no acknowledgement that substantive change
in a watershed through watershed restoration efforts can require more than a decade to translate into
measurable improvements in water quality
Response: See Response 720 and and Response 723. EPA disagrees that the requirements for the
watershed control tool imply monitoring requirements. The credit and requirements associated with this
option recognize that monitoring is unlikely to measure the successful implementation of this option.
EPA Letter ID: 488
Comment ID: 11851
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Existing Programs Need Fair Credit: Toolbox Guidance section 2.2.3 The guidance
indicates that existing WCP efforts do not count towards WCP approval under LT2ESWTR:
-Systems that already have a watershed control program in place are permitted to choose this option;
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however, they will have to amend and strengthen their programs to get the log removal credit. - To get
the additional credit, a system with an existing watershed control program could, for example, increase
public outreach efforts or toughen land use ordinances that affect water quality.-
Setting a higher bar for existing efforts than for new efforts is arbitrarily punitive toward established
programs. For this toolbox element to be a meaningful and realistic tool for LT2ESWTR compliance it is
imperative that the Agency wholly remove this distinction from guidance.
The Agency must recognize and acknowledge that the efforts and effects of existing source water
protection programs may not be evident or manifest at the time of initial source water monitoring and
WCP application but may require extended time periods (i.e., years or decades) to become observed.
There is no reason that progress made by such programs prior to LT2ESWTR be considered on any less
than an equal footing with new efforts spurred by the regulation. Primacy agencies should not be driven to
suggest changes to existing source water protection programs during evaluation for WCP credit under
LT2ESWTR solely for the sake of noting a change on paper. Such changes could counteract the
momentum obtained through years of groundwork, relationship-building, and resource investment by a
utility and its partners, and thus result in a net loss of benefits from the program.
Recommendation
The PWD recommends that source water protection activities and implementation efforts by utilities prior
to initial WCP approval be included in the program evaluation. Existing source water protection activities
relevant and of value to the WCP process should not be altered or adjusted in order to show something
new. Nor should these programs be directed to -start from scratch- in order to fit a -model- WCP
approach articulated in guidance or envisioned by a primacy agency.
Response: See Response 720.
EPA Letter ID: 496
Comment ID: 10704
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: Systems that currently have watershed protection programs should be rewarded for their
proactive stance rather than penalized by increased requirements. The benefits of existing programs
should not be expected to appear in monitoring for bin placement because of the inadequacies of the
analytical method and the fact that benefits take many years to realize, and may not necessarily be
realized prior to monitoring.
Response: See Response 720.
EPA Letter ID: 502
Comment ID: 10639
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
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Comment: 2. Systems that already have watershed protection programs should be rewarded for being
proactive rather than being penalized by increased requirements. It is not acceptable to exclude existing
watershed programs from the credit.
Response: See Response 720.
EPA Letter ID: 512
Comment ID: 11501
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Watershed Protection Credit - EPA must revise the requirements of the Watershed Control
Program to make it a viable toolbox element In drafting the proposed rule, EPA appears to have
inadvertently deviated from the FACA-s intentions to encourage watershed protection. The proposed
requirements for achieving and maintaining the watershed protection credit are so onerous that few, if
any, systems will make use of it even if they presently have a watershed protection program in place.
Watershed protection, although difficult to measure quantitatively, has the potential for long-term
reductions in not only Cryptosporidium, but other microbial contaminants and total organic carbon (thus
reducing the potential for disinfection byproduct formation). EPA should establish Best Management
Practices that constitute a baseline watershed protection program and provide examples for use in
developing watershed programs. Specific recommendations are included in Attachment 1.
Response: See Response 720.
EPA Letter ID: 512
Comment ID: 11515
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Watershed Protection Credit
a. In order for systems with existing watershed protection programs to earn credit, the proposed rule
requires that they -amend and strengthen- their existing program, regardless of what the programs
already comprise. Systems that presently have watershed protection programs should be rewarded for
their proactive stance rather than penalized by increased requirements. EPA should provide best
management practices that would constitute a baseline program and define what constitutes (-amend and
strengthen-).
Response: See Response 720.
EPA Letter ID: 520
Comment ID: 11628
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Comment Response for L T2ESWTR 8-65 December 2005
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Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: States should have flexibility in determining the "area of influence" for a watershed control
program. In many cases, the area of concern will be the entire watershed, but in some instances, the state
may determine a smaller area is appropriate.
Response: See Response 720. Under the LT2ESWTR, PWSs identify the area of influence subject to
State approval.
EPA Letter ID: 527
Comment ID: 10860
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Watershed Protection Credit: The problems with EPA-s overall approach to credit, and its
divergence from the FACA-s intentions is well illustrated in the Watershed Protection Credit
requirements.
The FACA wanted to encourage watershed protection. Accordingly, the FACA supported a 0.5-log credit
for watershed protection programs knowing that improvements in source water would be difficult, could
likely never be measured given the available analytical techniques, and would take many years of effort.
Nevertheless, all FACA members, including environmental and other advocacy groups, strongly
supported the credit based on the potential for long-term reductions in Cryptosporidium, and also on the
fact that such efforts would serve to reduce other microbial pathogens and TOC and therefore disinfection
byproducts.
Contrary to the FACA-s clear desire to encourage watershed protection by awarding credit, EPA has
made the conditions for achieving and maintaining credit so onerous that few, if any, systems will make
use of it even if they presently have a program in place.
EPA should provide watershed protection credit that will encourage and not discourage its use. As
presently structured, the credit is not a viable one for water systems. Systems that presently have
watershed protection programs should be rewarded for their proactive stance rather than penalized by
increased requirements. The benefits of existing programs should not be expected to show up in
monitoring for bin placement because of the inadequacies of the analytical method and the fact that
benefits take many years to realize and may not necessarily be realized prior to monitoring.
Response: See Response 720.
EPA Letter ID: 527
Comment ID: 10860
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
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Comment: Watershed Protection Credit: The problems with EPA-s overall approach to credit, and its
divergence from the FACA-s intentions is well illustrated in the Watershed Protection Credit
requirements.
The FACA wanted to encourage watershed protection. Accordingly, the FACA supported a 0.5-log credit
for watershed protection programs knowing that improvements in source water would be difficult, could
likely never be measured given the available analytical techniques, and would take many years of effort.
Nevertheless, all FACA members, including environmental and other advocacy groups, strongly
supported the credit based on the potential for long-term reductions in Cryptosporidium, and also on the
fact that such efforts would serve to reduce other microbial pathogens and TOC and therefore disinfection
byproducts.
Contrary to the FACA-s clear desire to encourage watershed protection by awarding credit, EPA has
made the conditions for achieving and maintaining credit so onerous that few, if any, systems will make
use of it even if they presently have a program in place.
EPA should provide watershed protection credit that will encourage and not discourage its use. As
presently structured, the credit is not a viable one for water systems. Systems that presently have
watershed protection programs should be rewarded for their proactive stance rather than penalized by
increased requirements. The benefits of existing programs should not be expected to show up in
monitoring for bin placement because of the inadequacies of the analytical method and the fact that
benefits take many years to realize and may not necessarily be realized prior to monitoring.
Response: See Response 720.
EPA Letter ID: 562
Comment ID: 12307
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.6 Watershed Control
As currently constructed, the Watershed Control Program (WCP) component of the LT2ESWTR is not a
viable toolbox element. The draft guidance creates disincentives through overly restrictive monitoring and
reporting requirements, rather than incentives for utilities to engage in source water protection activities.
Additionally, utilities currently engaged in source water protection are penalized by having to
demonstrate increased water quality improvement over and above current programs, rather than being
rewarded and recognized for their proactive effort.
AWWA believes that the Stage 2 M/DBP FACA intended to promote increased investment by drinking
water utilities in source water protection. In following through on this recommendation, the agency
should develop realistic expectations for watershed control programs. Several years may pass before
Response: See Response 720.
EPA Letter ID: 562
Comment ID: 12430
Comment Response for LT2ESWTR 8-67 December 2005
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.2.2 Watershed Control Program
AWWA believes that, as currently formulated, the Watershed Control Program (WCP) is not a viable
LT2ESWTR toolbox element. Key aspects of the WCP regulatory provisions and guidance are
inconsistent with the intent of the Agreement in Principle. We are extremely concerned that the draft
guidance creates disincentives for utilities with good potential for implementing source water protection
for regulatory credit, and that utilities currently engaged in source water protection are penalized rather
than rewarded for their proactive effort.
In our view, the agency-s proposed approach includes the following critical flaws:
1. Unjustified requirements would which interfere with the core mission of a source water protection
program and this interference escalates with every -re-approval cycle- (sanitary surveys, monitoring,
etc.)
2. Existing watershed control programs and source water protection efforts are not credited
2.3. Lack of integration with Clean Water Act (CWA) watershed restoration programs including no
failure to recognizeon of the time scale for CWA-related actions
3 .Existing watershed control programs and source water protection efforts are not credited
4. No acknowledgement it may take more than a decade to realize measurable improvements in water
quality after initiating watershed restoration efforts
5. Implication that reductions in Cryptosporidium oocyst levels at drinking water intakes are expected
within the six-year timeframe prior to a second round of defined monitoring
Our concerns and recommendations are discussed in more detail below:
Response: See Response 720.
EPA Letter ID: 562
Comment ID: 12432
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Existing Programs Need Fair Credit (Toolbox Guidance Manual §2.2.3 p.2-6)
The guidance indicates that existing WCP efforts do not count towards WCP
approval under LT2ESWTR:
-Systems that already have a watershed control program in place are permitted to choose this option;
however, they will have to amend and strengthen their programs to get the log removal credit. - To get
the additional credit, a system with an existing watershed control program could, for example, increase
public outreach efforts or toughen land use ordinances that affect water quality.-
Setting a higher bar for existing efforts and relative to new efforts is arbitrarily punitive toward
established programs. The agency should remove this distinction from guidance for this toolbox element
to become a meaningful and realistic tool for LT2ESWTR compliance.
The agency must recognize and acknowledge that the efforts and effects of existing source water
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protection programs may not be evident or manifest at the time of initial WCP application but may
require extended time periods (i.e., years or decades) to become observed. Progress made by such
programs prior to the LT2ESWTR should not be considered on any less than an equal footing with new
efforts spurred by the regulation. Primacy agencies should not be incited to suggest changes to existing
source water protection programs during evaluation for WCP credit under LT2ESWTR, solely for the
sake of noting a change on paper. Such changes could counteract years of groundwork, relationship-
building, and resource investment by a utility and its partners that could have yielded significant
improvements down the road if left unaltered.
The AWWA recommends that source water protection activities and implementation efforts by utilities
prior to initial WCP approval be included in the program evaluation. Existing source water protection
activities of significant value to the WCP process should not be altered or adjusted in order to show
something new. Nor should existing programs be directed to -start from scratch- in order to fit a -model-
WCP approach articulated in guidance or envisioned by a primacy agency.
Response: EPA agrees that well designed watershed control programs that focus on reducing levels of
Cryptosporidium contamination of water sources should be encouraged and that implementation of such
programs will likely reduce overall microbial risk. Given the highly site-specific nature of a watershed
control program, including the feasibility and effectiveness of control measures, EPA believes that
systems should demonstrate their eligibility for 0.5 log Cryptosporidium credit through targeted programs
that account for site-specific conditions. Further, EPA believes that States are in the best position to judge
whether a watershed control program is achieving or likely to achieve a substantial reduction of
Crytposoporidium in source water. EPA notes that both existing and new watershed control programs are
eligible for Cryptosporidium treatment credit under the same standards. EPA does not agree that State
review and approval of both new and existing programs under the same standards would negatively
impact exsiting programs or the State requested changes or additions to exsiting programs would
counteract the progress of such programs.
EPA Letter ID: 603
Comment ID: 12656
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47785) Section 141.725(a) -
Watershed control should be encouraged and this section is one way of encouraging it. However, the
watershed control program option does not include any monitoring requirements to quantify the
effectiveness of a watershed control plan. Please consider including a requirement for microbial
monitoring on at least a monthly basis for E. Coli or another indicator acceptable to the State to
demonstrate the watershed risk reduction commensurate with the log credit assigned.
Response: The Stage 2 M-DBP Advisory Committee recommended 0.5-log Cryptosporidium treatment
credit for a watershed control program recognizing that that improvements in source water could likely
never be measured given the available analytical techniques. EPA currently has no information to suggest
that monthly monitoring for E.Coli or another indicator would demonstrate a watershed risk reduction
commensurate with the log credit for the watershed tool.
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EPA Letter ID: 627
Comment ID: 12636
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: 4. Microbial Toolbox -Watershed Protection Credit:
City-s position: Systems that currently have watershed protection programs should receive a credit.
Remove the excessive burdens associated with applying for and receiving credits for this toolbox option.
Drop the requirement for re-approval of the watershed protection credit every six years. Once established,
the program should be re-evaluated when the water provider-s operating permit is renewed. The
conditions for achieving credits under the proposed rule for watershed protection are onerous and overly
burdensome and would prevent most utilities from using them.
Response: See Response 720.
EPA Letter ID: 628
Comment ID: 12846
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: 4. Watershed Control Program
a. Program requirements and the 0.5 log credit are incompatible. The SFPUC believes one of the FACA's
objectives is to encourage protection of water sources. The FACA supported a credit approach for
watershed protection programs knowing that improvements in source water would be difficult, could
likely never be measured given the available analytical techniques, and would take many years of efforts.
Nevertheless, all FACA members including environmental and other advocacy groups strongly supported
the credit based on the potential for long-term reductions in Cryptosporidium, and also on the fact that
such efforts would serve to reduce other microbial pathogens, total organic carbon, and disinfection
byproducts. Contrary to the FACA's desire to encourage watershed protection by awarding credit, the
EPA has made the conditions for achieving and maintaining credit so onerous hat few systems will make
use of it even if they presently have a program in place.
The EPA has put much effort into the components of the rule, but when put together the result is a heavy
reliance on advanced treatment and a divergence away from watershed protection. The proposed
watershed control program that imposes extensive resource expenditures but only grants a 0.5 log credit
does not encourage use of this toolbox component. The SFPUC has instituted an effective watershed
control program in protecting our sources of water supply. However, as presently proposed, the rule will
require the SFPUC to expend additional resources on its watershed protection programs to meet the
requirements for little if any significant improvements to obtain the 0.5 log credit. This would not only be
time consuming and unnecessary but is also a waste of the limited resources that the SFPUC could
otherwise use for program implementation and tracking. Thus, the SFPUC believes the proposed 0.5 log
credit and watershed control program are onerous and discouraging to water systems that have been
proactive and implementing an effective source water protection programs.
Response: The Stage 2 M-DBP Advisory Committee recommended 0.5-log Cryptosporidium treatment
credit for a watershed control program. The recommendation recognized that improvements in source
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water would be difficult, could likely never be measured given the available analytical techniques, and
would take many years of effort. See Response 720.
EPA Letter ID: 628
Comment ID: 12847
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: The EPA should note that the benefits of existing watershed control programs may not
necessarily be realized prior to monitoring for bin placement, as the benefits may take many years to
realize. Water systems with existing watershed control programs should be allowed to evaluate and
modify, if necessary, rather than re-formulate their programs. The SFPUC recommends the EPA make the
watershed credit less onerous and more attainable by modifying the proposed requirement language
Response: See Response 720.
EPA Letter ID: 629
Comment ID: 12828
Commenter: Melinda Rho, Manager of Regulatory Affairs and Consumer Protection, Los Angeles
Department of Water and Power
Commenter Category: Regulated Community (Utilities)
Comment: Microbial Tool Box -Watershed Protection
EPA requested comment on the proposed Microbial Tool Box. LADWP was hopeful that the Microbial
Tool Box would acknowledge and reward utilities that have or plan a proactive watershed management
program. However, the proposal has made the conditions for achieving and maintaining Watershed
Protection Credit more difficult than it should be.
Watershed protection programs should be encouraged. Accordingly, the Federal Advisory Committee
(FACA) supported a 0.5 log credit for watershed protection programs with the clear understanding that
improvements in source water would be difficult and would take of coordinated effort. Nevertheless, all
FACA members including environmental and other advocacy groups strongly supported this credit, based
on the potential for long term reductions in Cryptosporidium, and also on the fact that such efforts would
serve to reduce other microbial pathogens and TOC and therefore disinfection byproducts.
Response: See Response 720.
EPA Letter ID: 630
Comment ID: 13071
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
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Comment: The FACA wanted to encourage watershed protection. Accordingly, the FACA supported a
0.5 log credit for watershed protection programs knowing that improvements in source water would be
difficult, could likely never be measures given the available analytical techniques, and would take many
years of effort. Nevertheless, all FACA members including environmental and other advocacy gropus
strongly supported the credit based on the potential for long reductions in Cryptosporidium, and also on
the fact that such efforts would serve to reduce other microbial pathogens and TOC and therefore
disinfection byproducts.
Contrary to the FACA-s clear desire to encourage watershed protection by awarding credit, EPA has
made the conditions for achieving and maintaining credit so onerous that few if any systems will make
use of it even if they presently have a program in place.
It is recommended that EPA provide watershed protection credit that will encourage and not discourage
its use. As presently structured the credit is not a viable one for water systems. Additionally, consider the
following specific comments:
- Systems that presently have watershed protection programs should be rewarded for their proactive
stance rather than penalized by increased requirements. The benefits of existing programs should not be
expected to show up in monitoring for bin placement because of the inadequacies of the analytical method
and the fact that benefits take many years to realize and may not necessarily be realized prior to
monitoring.
Response: See Response 720.
EPA Letter ID: 630
Comment ID: 13072
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: - Wastewater treatment facilities are currently examining ways to avoid excessive
chlorination of effluents to achieve whole effluent toxicity requirements under the CWA. Water systems
encouraging or negotiating the use of ultraviolet light disinfection as part of their watershed protection
program could have significant impacts on the presence of-viable and infectious- Cryptosporidium in
their source waters. Note that none of this improvement would be detected by present analytical methods
that merely count oocysts whether they are able to cause disease or not. (UV does not destroy the oocyst,
it merely inactivates it).
Response: See Response lOOa.
EPA Letter ID: 637
Comment ID: 13078
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: District comment on the proposal to have States determine during Sanitary Survey that
significant changes have occurred in the watershed that could lead to increased contamination of the
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source water, the State may require systems to implement specific actions to address the contamination.
These actions include implementing options from the microbial toolbox.
Though it is appropriate for the State to evaluate changes in the watershed during Sanitary Surveys, it is
unwarranted to require the implementation of additional toolbox items based on perceived potential of an
increased contaminate. The state should have to produce evidence that an actual increase of hazard has
occurred with data before making the additional requirements of the water system.
Response: See Response 720.
EPA Letter ID: 637
Comment ID: 13094
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: The watershed option will require States to develop specific elements for a State-approved
program. This presents a concern as most water systems do not have control or jurisdiction over their
watershed. How will management by water systems be measured to determine the effectiveness of the
watershed control program? The current conditions for achieving and maintaining credit is so onerous that
it becomes unpractical for Systems to use this tool. Annual watershed surveys are unreasonable.
Compliance with the Source Protection Rule with a State approved Source Protection Plan should qualify
a system for this credit. The District has been participating in a very effective, State recognized, multi-
agency watershed protection group that documents an action plan annually for several decades. This long
term effort should be eligible for toolbox credit. The requirement for re-approval is also excessive as long
Response: See Response 720.
EPA Letter ID: 643
Comment ID: 12782
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States should have flexibility in determining the -area of influence- for a watershed control
program. In many cases, the area of concern will be the entire watershed, but in some instances, the state
may determine a smaller area is appropriate.
Response: See Response 720. Under the LT2ESWTR, PWSs identify the area of influence subject to
State approval.
EPA Letter ID: 647
Comment ID: 12924
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
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Comment: system. However, 0.5 log presumptive credit may not be sufficient to represent the
advantages of some watershed programs. In some states such New York, EPA has recognized that a
watershed control program can provide 2 or 3 log equivalent treatment. This has been demonstrated by
allowing unfiltered surface water systems. States should be allowed flexibility to designate a higher
credit than the 0.5 log presumptive credit when applicable.
Response: The Stage 2 M-DBP Advisory Committee recommended 0.5-log Cryptosporidium treatment
credit for a watershed control program. The recommendation recognized that improvements in source
water would be difficult, could likely never be measured given the available analytical techniques, and
would take many years of effort. EPA notes that under the Surface Water Treatment Rule(SWTR),
surface water systems may avoid filtration under specific conditions for water quality and watershed
control. Unfiltered systems must still meet the treatment technique requirements of the SWTR, 3 log
Giardia removal and/or inactivation and 4 log virus removal and/or inactivation. Under the LT2ESWTR,
unfiltered systems must provide at least 2 log Cryptosporidium inactivation.
EPA Letter ID: 647
Comment ID: 12925
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: States should have flexibility in determining the -area of influence- for a watershed control
program. In many cases, the area of concern will be the entire watershed, but in some instances, the state
may determine a smaller area is appropriate.
Response: See Response 720. Under the LT2ESWTR, PWSs identify the area of influence subject to
State approval.
EPA Letter ID: 654
Comment ID: 13124
Commenter: William Brant, Director, Miami-Dade Water and Sewer Department
Commenter Category: Regulated Community (Utilities)
Comment: toolbox. The MDWASD suggest that the Watershed Protection Credit proposed be modified
to reward systems that have an existing watershed protection program. The benefit of existing programs
should not be expected to show up in monitoring prior to bin placement. The credit should be granted if
systems show preventative measures with stringent enforcement.
Response: See Response 720.
EPA Letter ID: 677
Comment ID: 13955
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
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Comment: The USEPA is proposing that systems need to develop a watershed control program
that meets the requirements set forth in this regulation. Many systems, including the City, are currently
implementing source water protection programs and will be required to re-formulate these programs to
meet the guidelines set by USEPA. This would be time consuming, and not necessarily useful, as well as
a waste of funds which could otherwise be used for program implementation and tracking. The City
would like to encourage USEPA to allow for systems with existing programs to be evaluated and
modified if necessary, rather than reformulated. Also, we believe that it is inappropriate to require
systems to
Response: See Response 720.
EPA Letter ID: 678
Comment ID: 14688
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: contamination. Furthermore, the requirement that existing programs be strengthened or
augmented to gain the 0.5 log credit penalizes systems that have been proactive in watershed protection.
We believe this was most likely not the EPA-s intent. Many systems are currently implementing source
watershed protection programs. As presently proposed, the rule will require these systems to re-
formulate their watershed protection programs to meet the requirements and guidelines set by the EPA.
This would not only be time consuming and unnecessary, but also it will be a waste of the limited
resources that many systems could otherwise use for program implementation and tracking.
Response: See Response 720.
EPA Letter ID: 678
Comment ID: 14690
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We encourage the EPA to allow for systems with existing programs to be evaluated and
modified if necessary, rather than re-formulated.
Response: See Response 720.
8.3.3 Comment Code 723, Reduced frequency for watershed survey
Response to Code 723
A watershed sanitary survey is a comprehensive investigation and narrative report based on field
investigations and available data of a PWS watershed and would include an appraisal of sources of
contamination, watershed control and management practices, water treatment practices and
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recommendations for corrective actions. A watershed sanitary survey would be conducted by persons
with a background in public water supply and public health principles such as sanitary engineers and
environmental health specialists. A watershed sanitary survey would specifically include;
-A narrative description of the watershed including physical conditions such as topography, soils and
geology, vegetation, drainage patterns and water bodies as well as the hydrologic conditions in the
watershed.
-A review of water quality monitoring data as and an evaluation as the data relates to watershed control
and managements and water treatment practices.
-A description of activities in the watershed including land ownership and current and future land use as
well as an appraisal of the impacts to water quality and water treatment practices.
-A description of significant changes that have occurred since the last survey and an assessment of the
impact of those changes on source water quality and water treatment practices.
-A description of watershed control and management practices
-An appraisal of the system's ability to meet the treatment requirements based on the condition of the
watershed, an appraisal of watershed control and management practices and recommendations for
corrective actions.
For the purpose of the LT2ESWTR, a watershed sanitary survey would describe and evaluate progress in
meeting goals and implementing specific actions intended to reduce source water Cryptosporidium levels
and the status of existing control measures and any changes in potential sources of Cryptosporidium in
the watershed.
A Source Water Assessment would, as a minimum, include a delineation of the Source Water Assessment
Area, an inventory of Potential Sources of Contamination and a determination of the susceptibility of the
water supply to contamination. While a Source Water Assessment would include some of the information
found in a watershed sanitary, it would generally not include a description and evaluation of watershed
control and management practices, an appraisal of the systems ability to meet treatment requirements,
recommendations or an evaluation of progress in meeting goals and implementing actions related to
watershed control of Cryptosporidium. A watershed sanitary survey would generally be a much more
detailed evaluation requiring greater time and effort than that need to conduct a minimum SWA. Source
Water Assessments for surface water supplies would have value in completing the requirements for initial
State approval of a watershed control program and in completing the watershed sanitary survey.
While EPA believes that regular watershed sanitary surveys are necessary to identify new sources of
contamination and allow States to properly oversee watershed control programs, EPA agrees that
significant changes typically will not occur over one year. The final LT2ESWTR requires PWSs that
receive Cryptosporidium treatment credit for a watershed control program to undergo watershed sanitary
surveys every three to five years, rather than every year. These surveys will provide information to PWSs
and States regarding significant changes in the watershed that may warrant modification of the approved
watershed control plan. Further, they allow for an assessment of watershed control plan implementation.
This frequency is consistent with existing requirements for PWS sanitary surveys. Extending the
frequency further, as suggested by some commenters, does not allow for timely review of potential
contamination sources and opportunities for proactive responses by PWSs or for timely evaluations of
watershed control programs by States. To address commenter concerns that new sources of watershed
contamination can arise quickly, the final LT2ESTWR rule requires PWSs to identify any significant
changes that have occurred in their watersheds in their annual program status reports. States can then
require a watershed sanitary survey at an earlier date if significant changes have occurred since the
previous survey.
Individual Comments on Code 723
EPA Letter ID: 101
Comment ID: 10886
Comment Response for L T2ESWTR 8- 76 December 2005
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Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 721 1. Proposed credit
Comment: Watershed Control Programs
Systems should get a 1 log credit for cryptosporidium inactivation and a reduction in the annual
watershed survey requirement for strong source water protection plans or for engaging the public through
outreach programs.
Response: The Stage 2 M-DBP Advisory Committee recommended a 0.5-log Cryptosporidium treatment
credit for a watershed control program. The recommendation recognized that improvements in source
water would be difficult, could likely never be measured given the available analytical techniques, and
would take many years of effort. The commenter does not provide a basis or supporting information for
the treatment credit recommendation. See Response 720.
EPA Letter ID: 433
Comment ID: 10601
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: presently have program in place. The requirement for an annual watershed survey is excessive
and unreasonable given the scope and timeframes of watershed programs. We suggest that this credit to
tied to an established watershed program (e.g., SWAP) not tied to a program with people uninformed
about watersheds (e.g. sanitary surveys).
Response: See Response 723. EPA notes that the SWA is a one time assesment which would provide
valuable information for a watershed control program but would not meet the requirements for ongoing
surveillance and for control measures that will be effective in mitigating sources of fecal contamination.
EPA does not agree that persons performing sanitary surveys are uninformed of potential sources of fecal
contamiantion in watersheds and mitigation of those sources.
EPA Letter ID: 470
Comment ID: 11073
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: public health protection. We believe that the states should have the flexibility to reduce the
frequency of the annual watershed survey based upon alternative activities. We are unaware of any
specific scientific case studies or research
Response: See Response 723.
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EPA Letter ID: 471
Comment ID: 11119
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 2) the requirement for an annual watershed survey by a state certified party is a
discouragement to utilizing this tool. Such a provision is excessive and unreasonable given the scope and
timeframes of watershed programs; we suggest instead that any watershed surveys be performed in
conjunction with regular sanitary surveys; and
Response: See Response 723.
EPA Letter ID: 471
Comment ID: 11158
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 2) the requirement for an annual watershed survey by a state certified party is a
discouragement to utilizing this tool. Such a provision is excessive and unreasonable given the scope and
timeframes of watershed programs; we suggest instead that any watershed surveys be performed in
conjunction with regular sanitary surveys; and
Response: See Response 723.
EPA Letter ID: 483
Comment ID: 11264
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 745 5. Rule Language Edits
Comment: - A new term has been introduced i.e. -watershed sanitary survey- that is not defined. The
word sanitary should be deleted and any watershed survey should be performed in conjunction with
regular sanitary surveys. Persons conducting watershed surveys should not have to be approved by the
state. Approval of the plan is sufficient.
Response: The term watershed sanitary survey is used to distinguish the specifc requirements related to
the LT2ESTWR. A sanitary survey (defined in CFR 141.2) includes a review of facilities and equipment.
EPA believes the term watershed sanitary survey is commonly used and its meaning is generally well
understood.
EPA Letter ID: 485
Comment ID: 11291
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Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes that public outreach should be encouraged. However, the
watershed survey provides essential information to the water system, which is necessary to allow proper
response to proposed or new potentially contaminating activities. Watersheds can change quickly due to
development, new recreation programs, fires, unauthorized activities, etc. In order for the 0.5 log credit
for treatment to be maintained; control programs and Best Management Practices (BMPs) to minimize the
impact of contamination on the watershed must be addressed. Changes cannot be addressed without the
assessment provided by the watershed sanitary survey. However, if the watershed is completely
controlled by an agency that can confirm no changes have taken place in the watershed, consideration for
relaxation of the annual sanitary survey could be considered. The Department does not believe that public
outreach by itself is sufficient reason for relaxation of the annual survey requirement.
Response: See Response lOOa and Response 720.
EPA Letter ID: 488
Comment ID: 11852
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: §141.725a.4.ii Annual Watershed Sanitary Survey
The requirement to report results of an annual watershed sanitary survey conducted by persons approved
by the primacy agency imposes a substantial additional burden on utilities- resources without any
supported benefit. As such, it detracts from the viability of the WCP toolbox element and thereby opposes
the intent of the Agreement in Principle to encourage source water protection efforts. Though not stated
explicitly, in addition to fiscal and reporting burdens watershed sanitary surveys imply monitoring
requirements.
The proposal and guidance do not provide a rationale for additional watershed surveys on an annual or
any other frequency basis. The expectation for annual surveys contrasts sharply with the extended time
schedules EPA and States apply to stream assessments for Clean Water Act (CWA) impairments.
Furthermore, the Agency encourages primacy agencies to conduct CWA Section 305 watershed reviews
on a rolling schedule wherein individual watersheds are evaluated on a much longer timeline than the 3-
year schedule set in the CWA. This extended timeline is intended to ensure productive use of resources by
allowing adequate evaluation of a watershed when its review occurs and providing atimeframe over
which demonstrable change could be observed.
If the goal of the survey is to use water quality monitoring to detect improvements in water quality at the
watershed level an annual monitoring regime is not an effective use of resources. Annual Sanitary
Surveys and associated water quality monitoring are not only resource intensive, they are not likely to
detect improvements in water quality at the watershed level. Watershed restoration studies typically yield
significant discernable water quality improvements at the watershed level over decades after mitigation
activities have begun (in streams that aren-t first order). Implementing an annual watershed sanitary
survey is unlikely to provide additional value to the WCP approach and is sure to detract resources away
from key program activities. Current primacy agency efforts to implement watershed restoration and
develop Total Maximum Daily Loads (TMDLs) for contaminants such as nutrients and sediment take
Comment Response for L T2ESWTR 8- 79 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
many years to achieve results. These programs have regulatory authority and resources at their disposal
and are targeted at contaminants with good supporting field data and significant technical basis in
literature. To expect that a water utility-s WCP can address a much more complex contaminant
in a shorter period of time and without regulatory authority is unrealistic and contrary to the Agency-s
programmatic approach on watershed-based decision-making.
Recommendation
The PWD believes that in order for the LT2ESWTR WCP toolbox element to spur real improvements in
our nation-s source waters with efficient use of resources the Agency must acknowledge the long-term
nature of watershed protection efforts. The Agency must neither expect nor require observable reductions
of Cryptosporidium at affected water treatment plant intakes as proof of the benefit of these programs.
The PWD recommends that the agency either remove the WCP watershed sanitary survey provision from
the proposed rule and associated guidance or revise it to be commensurate with comparable watershed
programs under CWA authority. Employing comparable timeframes would provide synergy to facilitate
watershed-based efforts falling under the different regulatory programs and thereby promote needed
integration between SDWA and CWA statutes.
Response: See Response 723. EPA disagrees that the requirements for the watershed control tool imply
monitoring requirements. The credit and requirements associated with this option recognize that
monitoring is unlikely to measure the successful implementation of this option.
EPA Letter ID: 488
Comment ID: 11853
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: As noted above, the PWD recommends that EPA remove this requirement from the
LT2ESWTR. A watershed sanitary survey associated with a WCP toolbox credit would not be practical or
productive if conducted more frequently than once every 10 years. The primacy agency should be allowed
to reduce the frequency of annual watershed survey requirements based on local circumstances regardless
of whether the system is specifically engaged in public outreach.
This request for comment is complicated by the lack of definition for -public outreach.- Based on the
PWD-s experience, the relevant questions are: (1) On what frequencies would such surveys contribute to
the effectiveness of a WCP? And (2) at what frequencies can observable change be expected? Whether
the utility has held a public meeting, organized a stakeholder committee, or held watershed events at local
schools is not directly pertinent to these questions.
Response: See Response 723.
EPA Letter ID: 491
Comment ID: 10667
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR 8-80 December 2005
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Comment: too onerous to encourage watershed protection. Systems that wish to implement watershed
protection programs in addition to treatment should be encouraged. However, yearly watershed surveys
are too frequent given the scope and timeframes of watershed programs and would discourage systems
from pursuing this option. Instead, watershed surveys should coincide with regular sanitary surveys.
Response: See Response 723.
EPA Letter ID: 496
Comment ID: 10705
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: The EPA requirement for an annual watershed survey by a state-certified party is excessive
and unreasonable given the scope and time-frames of watershed programs. Any watershed surveys
should be performed in conjunction with regular sanitary surveys.
Response: See Response 723.
EPA Letter ID: 502
Comment ID: 10640
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: 3. The requirement for an annual watershed survey is excessive and unreasonable due to the
scope of the survey and time limitations restricting watershed programs. Also, is it necessary to have a re-
approval process for the watershed
Response: See Response 723.
EPA Letter ID: 506
Comment ID: 10743
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: its use. Specifically, CWD feels that the requirement for annual watershed surveys by a state
certified party is excessive and unreasonable given the scope and timeframes of watershed programs.
Watershed surveys should be handled in conjunction with the regular sanitary surveys. CWD is also
concerned that the
Response: See Response 723.
Comment Response for LT2ESWTR 8-81 December 2005
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EPA Letter ID: 512
Comment ID: 11517
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: reduced risk of Cryptosporidium reaching source waters), c. The requirement for
an annual watershed survey by a state certified party is excessive and unreasonable given the scope and
timeframes of watershed programs. Any watershed surveys should be performed in conjunction with
regular sanitary surveys, d. The requirement for reapproval of a watershed protection credit every six
years is onerous and should be dropped. Instead, the credit should remain in place as long as systems meet
the requirements of their watershed control program on a continuing basis.
Response: See Response 723.
EPA Letter ID: 520
Comment ID: 11629
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Although IEPA supports public outreach as a component of a watershed control program,
IEPA does not support reducing the frequency of the annual watershed survey requirement based solely
on a strong public outreach program. The watershed survey provides essential information to the water
system, which is necessary to allow proper response to proposed or new potentially contaminating
activities. Watersheds can change quickly due to development, new recreation programs, fires,
unauthorized activities, and other factors. In order for the 0.5 log credit for treatment to be maintained,
control programs and Best Management Practices (BMPs) to minimize the impact of contamination on
the watershed must be addressed. Changes cannot be addressed without the assessment provided by the
watershed sanitary survey. However, if the watershed is completely controlled by an agency that can
confirm no changes have taken place in the watershed, consideration for relaxation of the annual sanitary
survey could be considered.
Response: See Response lOOaand Response 723.
EPA Letter ID: 527
Comment ID: 10862
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The requirement for an annual watershed survey by a state certified party is excessive and
unreasonable given the scope and timeframes of watershed programs. Any watershed surveys should be
performed in conjunction with regular sanitary surveys.
Response: See Response 723.
Comment Response for L T2ESWTR 8-82 December 2005
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EPA Letter ID: 527
Comment ID: 10862
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The requirement for an annual watershed survey by a state certified party is excessive and
unreasonable given the scope and timeframes of watershed programs. Any watershed surveys should be
performed in conjunction with regular sanitary surveys.
Response: See Response 723.
EPA Letter ID: 556
Comment ID: 12065
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The requirement for an annual watershed survey by a state-certified party is excessive given
the scope and timeframes of watershed programs. Any watershed surveys should be performed in
conjunction with regular sanitary surveys. Annual reports should be sufficient between formal surveys.
Response: See Response 723.
EPA Letter ID: 562
Comment ID: 12433
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: §141.725(a)(4)(ii) Annual Watershed Sanitary Survey
The requirement to report results of an annual watershed sanitary survey conducted by persons approved
by the primacy agency imposes a substantial additional burden on utilities- resources without any
supported benefit. As such, the lack of benefit detracts from the viability of the WCP toolbox element and
thereby conflicts with the intent of the Agreement in Principle to encourage source water protection
efforts. Though not stated explicitly, in addition to fiscal and reporting burdens, watershed sanitary
surveys imply monitoring requirements.
Current primacy agency efforts to implement watershed restoration and develop Total Maximum Daily
Loads (TMDLs) for contaminants such as nutrients and sediment take at least a decade to achieve
measurable results. The TMDLs for these contaminants are supported with substantial field data and
significant technical basis in the literature. Through the CWA, such restoration programs have regulatory
authority and resources at their disposal. To expect that a water utility-s WCP can address a much more
complex contaminant in a shorter period of time and without regulatory authority is unrealistic and
contrary to the agency-s programmatic approach on watershed-based decision-making. The AWWA
believes that in order for the LT2ESWTR WCP toolbox element to spur real improvements in our nation-
s source waters with efficient use of resources the agency must acknowledge the long-term nature of
Comment Response for L T2ESWTR 8-83 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
watershed protection efforts. These efforts should be viewed on a decade-order rather than annual time
scale. The agency must neither expect nor require observable reductions of Cryptosporidium at affected
water treatment plant intakes as proof of the benefit of these programs.
The proposal and guidance do not provide a rationale for additional watershed surveys on an annual or
any other frequency basis. The expectation for annual surveys contrasts sharply with the extended time
schedules EPA and states apply to stream assessments for Clean Water Act (CWA) impairments.
Furthermore, the agency encourages primacy agencies to conduct CWA Section 305 watershed reviews
on a rolling schedule, wherein individual watersheds are evaluated on a much longer timeline than the
three-year schedule set in the CWA. This eExtended timelines under CWA areis intended to ensure
productive use of resources by allowing adequate evaluation of a watershed when its review occurs and
providing a timeframe over which demonstrable change could be observed.
If the goal of the survey is to use water quality monitoring to detect improvements in water quality at the
watershed level, an annual monitoring regime is not an effective use of resources. Watershed restoration
studies typically yield significant discernable water quality improvements at the watershed level over
decades after mitigation activities have begun (in streams that aren-t first order). Acquiring the necessary
background information to support a routine survey effort is a significant effort and has many practical
constraints. In most areas, state and federal agencies collect land-use information, discharger information,
agricultural and population census, as well as pertinent watershed characteristics. This information is not
updated on an annual cycle. Periodicity of such data collection efforts ranges from annual to decennial.
Implementing a watershed sanitary survey program at less than a 10-year frequency is unlikely to provide
additional value to the WCP approach and will likely detract resources away from key program activities
such as source tracking and identification, partnership development, and best management practice design
and implementation.
Current primacy agency efforts to implement watershed restoration and develop Total Maximum Daily
Loads (TMDLs) for contaminants such as nutrients and sediment take at least a decade to achieve
measurable results. The TMDLs for these contaminants are supported with substantial field data and
significant technical basis in the literature. Through the CWA, such restoration programs have regulatory
authority and resources at their disposal. To expect that a water utility-s WCP can address a much more
complex contaminant in a shorter period of time and without regulatory authority is unrealistic and
contrary to the agency-s programmatic approach on watershed-based decision-making. The AWWA
believes that in order for the LT2ESWTR WCP toolbox element to spur real improvements in our nation-
s source waters with efficient use of resources the agency must acknowledge the long-term nature of
watershed protection efforts. These efforts should be viewed on a decade-order rather than annual time
scale. The agency must neither expect nor require observable reductions of Cryptosporidium at affected
water treatment plant intakes as proof of the benefit of these programs.
The AWWA recommends that the agency either remove the WCP watershed sanitary survey provision
from the proposed rule and associated guidance or else revise it to be commensurate with comparable
watershed programs under CWA authority. Employing comparable timeframes will provide synergy to
facilitate watershed-based efforts falling under the different regulatory programs and thereby promote
needed integration between SDWA and CWA statutes.
Response: See Response 723 .EPA disagrees that the requirements for the watershed control tool imply
monitoring requirements. The credit and requirements associated with this option recognize that
monitoring is unlikely to measure the successful implementation of this option.
Comment Response for L T2ESWTR 8-84 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 562
Comment ID: 12434
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As noted above, the AWWA recommends that EPA strike this provision from the
LT2ESWTR. In no case should the frequency of a watershed sanitary survey associated with a WCP
toolbox credit be shorter than 10 years. The primacy agency should be allowed to reduce the frequency of
annual watershed survey requirements based on local circumstances regardless of whether the system is
specifically engaged in public outreach.
Response: See Response 723.
EPA Letter ID: 562
Comment ID: 12435
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: This request for comment is complicated by the lack of definition for -public outreach.-
Based on the AWWA-s experience, the relevant questions are: (1) On what frequencies would such
surveys contribute to the effectiveness of a WCP? And (2) at what frequencies can observable change be
expected? Whether the utility has held a public meeting, organized a stakeholder committee, or held
watershed events at local schools is not directly pertinent to these questions.
Response: See Response 723.
EPA Letter ID: 585
Comment ID: 11974
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: source water Cryptosporidium levels. However, we recommend that sanitary surveys of the
watershed be conducted on a three-year cycle rather than on an annual basis because it is unlikely that
conditions will change significantly on an annual basis. Since significant annual changes are unlikely,
reducing the frequency will lower implementation costs for both primacy agencies and public water
systems. This alternative approach would result in three contaminant source surveys; one within 2 years
after completing the first round of monitoring, a second about halfway between the first and second
rounds of monitoring, and a final survey to coincide with the second round of source water monitoring.
Response: See Response 723.
EPA Letter ID: 620
Comment ID: 13307
Comment Response for L T2ESWTR 8-85 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Annual watershed surveys are excessive, due to the slow moving nature of watershed
projects. Also, re-approval of a watershed protection credit every six
Response: See Response 723.
EPA Letter ID: 628
Comment ID: 12848
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: b. Reduce annual watershed survey frequency. The requirement for an annual watershed
survey by a state certified party is excessive and unreasonable given the scope and timeframes of
watershed programs. There are two major reasons for supporting a less frequent watershed sanitary
survey. First, most, if not all, water systems have limited resources for program investment. The SFPUC
believes it is better to spend those resources on actions and programs to prevent contamination rather than
doing detailed assessments every year. Second, many of the strategies that could be implemented to target
reduction of Cryptosporidium are long-term in nature and would not yield a measurable reduction of
loading on a yearly basis. An annual survey may not conclude much in terms of Cryptosporidium
reduction. Thus, the SFPUC recommend the watershed sanitary survey be comprehensive but reduced to a
frequency of every five years.
Response: See Response 723.
EPA Letter ID: 629
Comment ID: 12830
Commenter: Melinda Rho, Manager of Regulatory Affairs and Consumer Protection, Los Angeles
Department of Water and Power
Commenter Category: Regulated Community (Utilities)
Comment: However, LADWP believes that the requirement for an annual sanitary survey is excessive,
especially for extensive watersheds such as ours, which is approximately 4,000 square miles or 3,000,000
acres. Watershed sanitary surveys should be conducted as often as necessary to investigate significant
incidents or changes to the watershed, but at a minimum once every 5 years as specified in the current
regulations.
Response: See Response 723.
EPA Letter ID: 630
Comment ID: 13073
Comment Response for L T2ESWTR 8-86 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: - The requirement for an annual watershed survey by a state certified party is excessive and
unreasonable given the scope and timeframes of watershed programs. Any watershed surveys should be
performed in conjunction with regular sanitary surveys.
Response: See Response 723.
EPA Letter ID: 637
Comment ID: 13095
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: onerous that it becomes unpractical for Systems to use this tool. Annual watershed surveys
are unreasonable. Compliance with the Source Protection Rule
Response: See Response 723.
EPA Letter ID: 643
Comment ID: 12783
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Although states support public outreach as a component of a watershed control program,
states do not support reducing the frequency of the annual watershed survey requirement based solely on
a strong public outreach program. The watershed survey provides essential information to the water
system, which is necessary to allow proper response to proposed or new potentially contaminating
activities. Watersheds can change quickly due to development, new recreation programs, fires,
unauthorized activities, and other factors. In order for the 0.5 log credit for treatment to be maintained,
control programs and Best Management Practices (BMPs) to minimize the impact of contamination on
the watershed must be addressed. Changes cannot be addressed without the assessment provided by the
watershed sanitary survey. However, if the watershed is completely controlled by an agency that can
confirm no changes have taken place in the watershed, consideration for relaxation of the annual sanitary
survey could be considered.
Response: See Response lOOaand Response 720.
EPA Letter ID: 677
Comment ID: 13957
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Comment Response for L T2ESWTR 8-8 7 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Comment: The City recommends that the watershed sanitary survey requirement be reduced to a
frequency of every three to five years, similar to the requirements in the Interim Enhanced Surface Water
Treatment Rule. We believe that this is credible for two reasons. The first being that there are limited
dollars that each system can invest in programs. We believe it is better to spend those funds on actions
and programs to prevent contamination, rather than doing overall assessment on a continuous basis. Also,
many of the strategies which could be implemented to target reduction of Cryptosporidium are long-term
in nature and would not likely result in a measurable reduction of loading in less than three to five years.
Response: See Response 723.
EPA Letter ID: 678
Comment ID: 14692
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 21. Section 141.725(a)(4)(ii) - The requirement for an annual watershed survey by a state
certified party is excessive and unreasonable given the scope and timeframes of watershed programs.
There are two major reasons for supporting a less frequent watershed sanitary survey. First, most, if not
all, water systems have limited funds for program investment. We believe it is better to spend those funds
on actions and programs to prevent contamination, rather than doing overall assessment every year.
Second, many of the strategies that could be implemented to target reduction of Cryptosporidium are
long-term in nature and would not likely result in a measurable reduction of loading in less than three to
five years. An annual survey may not tell much in terms of Cryptosporidium reduction. Thus, we
recommend the watershed sanitary survey is reduced to a frequency of every three to five years, similar to
the requirements in the Interim Enhanced Surface Water Treatment Rule.
Response: See Response 723.
8.3.4 Comment Code 724, Data on methods to reduce
Cryptosporidium Contamination
Individual Comments on Code 724
EPA Letter ID: 470
Comment ID: 11074
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: activities. We are unaware of any specific scientific case studies or research in Vermont
relating to Cryptosporidium that assess the effectiveness of the watershed control program.
Response: See Response lOOa.
Comment Response for L T2ESWTR 8-88 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 485
Comment ID: 11292
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: EPA also request comments on whether the effectiveness of a watershed control program may
be difficult to assess because of uncertainty in the efficacy of control measures under site-specific
conditions. In order to provide constructive guidance, EPA welcomes reports on scientific case studies
and research that evaluated methods for reducing Cryptosporidium contamination of source waters.
Response: The Department has no information to provide at this time.
Response: See Response lOOa.
EPA Letter ID: 488
Comment ID: 11854
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: A number of studies indicate the effectiveness of various structural and non-structural best
management practices (BMPs) at reducing Cryptosporidium loadings to waterways. Most studies focus
on the effectiveness of riparian buffers or grass filter strips in agricultural areas in reducing loadings from
animal runoff. One recent study documented greater than 3-log reduction of oocysts by riparian buffers
(Atwill et al. 2002). New studies on enhanced removal of dissolved phosphorus by amending riparian
buffers with water treatment residuals may also indicate benefits for enhanced removal by filter buffers
beyond that documented by Atwill et al. (Dayton et al. 2003). Together, the American Water Works
Association Research Foundation (AwwaRF) and the Water Environment Research Foundation (WERF)
have six projects either completed or in progress to study source, fate, and transport of Cryptosporidium
and its variability in surface waters.
Studies focusing on wastewater show a 1 to 2-log reduction of Cryptosporidium loadings in sewage
effluent by conventional wastewater treatment. Wastewater plants with tertiary treatment or polishing
filters have observed up to 4.6 log reduction of Cryptosporidium oocysts (Corsi et al. 2003, Suwa and
Suzuki 2001, Suwa and Suzuki 2003, Rose et al. 1996). Additional publications focusing on urban
stormwater and wastewater also indicate that Cryptosporidium oocysts can be significantly reduced
through predation by other microbes such as free-living ciliates (i.e. Paramecium) in wetland treatment
systems (Stott et al. 2001). Wetland treatment systems, currently being implemented to address other
stormwater issues, could prove to be valuable tools for reducing Cryptosporidium oocysts in source
waters.
In addition to measurable reduction of total Cryptosporidium oocyst loadings it is important to recognize
the impact of WCPs on loadings of viable and infectious oocysts. Reducing these loadings will allow
water bodies used for both water supply and recreation to achieve simultaneous benefits and further
merge the goals of the CWA and SDWA. Reductions in Cryptosporidium viability or infectivity can be
obtained through sophisticated mechanical/structural controls such as ultraviolet disinfection of
wastewater discharges as well as through simpler techniques such as composting manure. Finstein (2004)
reviews the literature on inactivation of Cryptosporidium in animal manure. The data reviewed by
Finstein suggest the feasibility of passive small-scale calf manure composting as a highly effective
Comment Response for L T2ESWTR 8-89 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
method of Cryptosporidium oocyst inactivation.
To achieve CWA whole effluent toxicity limits wastewater treatment facilities are currently examining
ways to avoid effluent chlorination. Integration of ultraviolet disinfection into National Pollutant
Discharge Elimination System (NPDES) discharges upstream of drinking water intakes would lower
infectious oocyst loadings. A study by the Philadelphia Water Department plans to measure the
effectiveness of ultraviolet disinfection on the viability and infectivity of Cryptosporidium oocysts in
wastewater discharges upstream of regional drinking water intakes. Researchers from Johns Hopkins
University and the Maryland DEP have observed inactivated or dead Cryptosporidium oocysts in
wastewater from tertiary or ultraviolet treated discharges.
Though studies demonstrating the impacts of BMPs on Cryptosporidium oocysts are limited, there are
numerous studies using surrogate indicators. These data provide a basis in the literature for confidence
that, when properly implemented, BMPs can lead to meaningful reductions in the amount and infectivity
of Cryptosporidium oocysts in source water. These surrogate indicators can also be used to select and
pilot potentially suitable management practices to evaluate their effectiveness. For example, BMPs
effective at removing fine particles or bacteria should also reduce Cryptosporidium oocyst concentrations
in released water. Studies and reports sponsored by AwwaRF, WERF, EPA, and the Centers for
Watershed Protection demonstrate the effectiveness of vatious BMPs at reducing sediment and bacteria
loads to waterways. Inclusion of a compendium of this information in the WCP section of the
LT2ESWTR Toolbox Guidance Manual would provide a valuable resource for PWSs developing WCPs.
Response: EPA appreciates the information and will consider the information for inclusion in the
Toolbox Guidance Manual.
EPA Letter ID: 562
Comment ID: 12436
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: A number of studies currently ongoing and recently published indicate the effectiveness of
various best management practices (BMPs; structural and non-structural) at reducing Cryptosporidium
loadings to waterways. Appendix 3 provides a summary of some of the relevant published literature on
the effectiveness of BMPs. Most studies have focused on the effectiveness of riparian buffers or grass
filter strips in agricultural areas to reduce loadings from animal runoff. One recent study has documented
greater than 3-log reduction of oocysts by riparian buffers (Atwill et al. 2002). New studies on enhanced
removal of dissolved phosphorus by amending riparian buffers with water treatment residuals may also
indicate benefits for enhanced removal by filter buffers beyond that documented by Atwill et al. (Dayton
et al. 2003). Together, the American Water Works Association Research Foundation (AwwaRF) and the
Water Environment Research Foundation (WERF) have six projects either completed or in progress to
study source, fate, and transport of Cryptosporidium and its variability in surface waters.
Response: EPA appreciates the comment and information. EPA will consider this information for
LT2ESWTR guidance material.
Comment Response for LT2ESWTR 8-90 December 2005
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EPA Letter ID: 562
Comment ID: 12437
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Studies focusing on wastewater show a 1 to 2-log reduction of Cryptosporidium loadings in
sewage effluent by conventional wastewater treatment. Wastewater plants with tertiary treatment or
polishing filters have observed up to 4.6 log reduction of Cryptosporidium oocysts (WERF 99-HHE-2;
Suwa and Suzuki 2001; Suwa and Suzuki 2003; Rose 1996). Additional publications focusing on
urban storm water and wastewater also indicate that Cryptosporidium oocysts can be significantly
reduced through predation by other microbes such as free-living ciliates (i.e. Paramecium) in wetland
treatment systems (Stott et al. 2001). Wetland treatment systems, currently being implemented nationally
to address other storm water issues, could prove to be valuable watershed tools for reducing
Cryptosporidium oocysts in source waters.
In addition to measurable reduction of total Cryptosporidium oocyst loadings, the impact of WCPs on
loadings of viable and infectious oocysts is important. Reducing these loadings will allow water bodies
used for both water supply and recreation to achieve simultaneous benefits and further merge the goals
of the CWA and SDWA. Reductions in Cryptosporidium viability or infectivity can be obtained through
both sophisticated mechanical / structural controls such as ultraviolet disinfection of wastewater
discharges as well as through simpler techniques such as composting manure. Finstein (in press) reviews
the literature on inactivation of Cryptosporidium in animal manure. The data reviewed suggest the
feasibility of passive small-scale calf manure composting as a method to effectively inactivate all
Cryptosporidium oocysts.
Wastewater treatment facilities are currently examining ways to avoid effluent chlorination in order to
achieve CWA whole effluent toxicity limits. Integration of ultraviolet disinfection into National Pollutant
Discharge Elimination System (NPDES) discharges upstream of drinking water intakes would
dramatically reduce infectious oocyst loadings. A study currently in planning by the Philadelphia Water
Department aims to measure the effectiveness of ultraviolet disinfection on the viability and infectivity of
Cryptosporidium oocysts in wastewater discharges upstream of regional drinking water intakes. During
studies of wastewater discharges, researchers from Johns Hopkins University and the Maryland DEP
observed inactivated or dead Cryptosporidium oocysts in wastewater from tertiary or ultraviolet light
treated discharges. Results of this work, conducted in conjunction with the Interstate Potomac River
Basin Commission, were presented at USEPA headquarters in May 2003 and EPA representatives are
receiving project updates.
Response: EPA appreciates the information and will consider this information for inclusion in the
LT2ESWTR Toolbox Guidance Manual. EPA agrees that advanced waste water treatment processes and
manure management practices would have significant positive impacts in addressing fecal contamination
in watersheds.
EPA Letter ID: 562
Comment ID: 12438
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR 8-91 December 2005
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Comment: Though studies demonstrating the impacts of BMPs on Cryptosporidium oocysts are limited,
data for surrogate indicators are more plentiful. These data provide a basis in the literature for confidence
that, when properly implemented, BMPs can lead to meaningful reductions in the amount and infectivity
of Cryptosporidium oocysts in source water. These surrogate indicators can also be used to select and
pilot potentially suitable management practices to evaluate their effectiveness. For example, BMPs
effective at removing fine particles or bacteria should also reduce Cryptosporidium oocyst concentrations
in released water. There are numerous studies and reports sponsored by AwwaRF, WERF, EPA, and the
Centers for Watershed Protection demonstrating the effectiveness of numerous BMPs at reducing
sediment and bacteria loads to waterways. Inclusion of a compendium of this information in the WCP
section of the LT2ESWTR Toolbox Guidance Manual would provide a valuable resource for PWSs
developing WCPs.
Response: EPA appreciates the information. EPA agrees that BMPs can lead to meaningful reductions in
the amount and infectivity of Cryptosporidium oocysts in source water.
8.3.5 Comment Code 725, Data on delineating area of influence
Individual Comments on Code 725
EPA Letter ID: 470
Comment ID: 11075
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: In order for systems to delineate an -area of influence,- EPA must develop information on
the fate and transport of Cryptosporidium, including information on variations due to seasonal changes,
slope, and precipitation.
Response: See Response 720. EPA believes that fate and transport of Cryptosporidium and variations due
to seasonal changes, slope, and precipitation are watershed specific and must be addressed by the PWS
seeking credit under this option. EPA has included example watershed control program and common
contaminant sources in the LT2ESWTR Toolbox Guidance.
EPA Letter ID: 485
Comment ID: 11294
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes that the whole watershed should be considered. The
Department has a lot of experience reviewing watershed sanitary surveys. The surveys typically contain
many maps delineating the boundary of the whole watershed, maps indicating the topography, soils,
hydrogeology, natural vegetation, ownership, control practices, potential sources of contamination,
proposed future development, etc. The maps and description of these abovementioned items help assess
the potential level of contamination and measures in place to control these identified activities.
Comment Response for L T2ESWTR 8-92 December 2005
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Response: See Response lOOaand Response 720.
EPA Letter ID: 488
Comment ID: 11856
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: The area of influence component should be removed from the WCP program document
and guidance. Sensitive areas and priority sources will be identified in the vulnerability analysis. Areas
for the watershed sanitary surveys should be based upon the utility-s proposal and should be flexible
enough to accommodate changes on an as-needed basis.
The -area of influence- as defined in the WCP guidance represents all areas except where -no significant
probability of Cryptosporidium or fecal contamination affecting the drinking water intake- exists. This
definition is too broad and subject to interpretation. It assumes an area of vulnerability in which
Cryptosporidium oocysts quickly reach the intake with little attenuation, dilution, or inactivation (i.e., as
one proceeds upstream sources contribute less and less to observed occurrence at the water treatment
plant intake). Unfortunately there is no such absolute scale. Contributions from different sources are
variable and may fluctuate with season, precipitation, waste treatment facility capabilities, and stressors,
among other factors. The PWD recommends that the area of influence be described as an area defined by
the utility in cooperation with the primacy agency. As a utility-s WCP progresses this area should be
reevaluated based on new information about significant sources of greatest impact such as sourcetracking
studies, modeling, or watershed monitoring information.
Response: The "area of influence" in the watershed is intended to determine where potential and actual
source of Cryptosporidium occur in the watershed and where watershed control measures will be applied.
EPA Letter ID: 562
Comment ID: 12440
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The area of influence component should be removed from the WCP program document and
guidance. Sensitive areas and priority sources will be identified in the vulnerability analysis. Areas for the
watershed sanitary surveys should be based upon the utility-s proposal and should be flexible enough to
accommodate changes on an as-needed basis.
The -area of influence- as defined in the WCP guidance represents all areas except where -no significant
probability of Cryptosporidium or fecal contamination affecting the drinking water intake- exists. This
definition is too broad and subject to interpretation. It assumes an area of vulnerability in which
Cryptosporidium oocysts quickly reach the intake with little attenuation, dilution, or inactivation (i.e., as
one proceeds upstream sources contribute less and less to observed occurrence at the water treatment
plant intake). Cryptosporidium occurrence is not only a function of the distance between the source of
oocysts and the intake but also of the type of source and the amount of oocysts entering the water body.
AWWA recommends that the area of influence be described as an area defined by the utility in
cooperation with the primacy agency. As a utility-s WCP progresses, this area should be re-evaluated
Comment Response for L T2ESWTR 8-93 December 2005
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based on new information about significant sources of greatest impact, such as source-tracking studies,
modeling, or watershed monitoring information.
Response: The area of influence for the watershed control option is intended to define the area to be
evaluated in watershed sanitary surveys and the area to be included in watershed control measures and
management practices. The area of influence is not limited to an area of vulnerability in which
Cryptosporidium oocysts quickly reach the intake. Rather, the area of influence defines the area where
watershed control measures would be applied and where the effectiveness of those measures would be
evaluated. A PWS would indentify the area of influence and this would be subject to approval by the
State. Subsequent watershed sanitary surveys would appraise attenuation, dilution, or inactivation to the
extent possible and given the available analytical techniques this appraisal would qualitative rather than
quantitative. Subsequent watershed sanitary surveys would also appraise the effectiveness of watershed
control and management practices.
EPA Letter ID: 677
Comment ID: 13959
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Comment: With regard to defining an area of influence, the City believes that this will be specific to each
source water and that this should be coordinated with the primacy agency using the work conducted as
part of the source water assessment program. The City would also like to encourage USEPA to carefully
review the
Response: See Response lOOa.Under the LT2ESWTR, PWSs identify the area of influence
subject to State approval.
8.3.6 Comment Code 726, Confidentiality and watershed annual
reports
Individual Comments on Code 726
EPA Letter ID: 483
Comment ID: 11265
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: - Because of security concerns, watershed surveys should not be required to be made public
except at the discretion of the water system. States are in no position to make adequate decisions on this
point.
Response: See Response 720.
Comment Response for L T2ESWTR 8-94 December 2005
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EPA Letter ID: 485
Comment ID: 11293
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department agrees that there indeed may be confidential business information
(CBI) and Homeland Security concerns associated with making information on the watershed control
program available to the public. This CBI includes the location of intake structures, dams, and water
treatment facilities. One potential way to deal with CBI is to restrict dissemination of maps and locational
information to the public.
Response: See Response lOOaand Response 720.
EPA Letter ID: 488
Comment ID: 11855
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Much of the information referenced in the Agency-s guidance for WCP should remain
confidential. None of the reporting documents for the WCP, as currently described in guidance, are
suitable for public availability. In addition to the concerns outlined below, the effort necessary to generate
alternate versions of all WCP technical documents appropriate for sharing with the public would be better
put toward developing targeted communication products aligned with the objectives in the WCP Plan.
WCP technical documents are working papers that should be shielded as CBI because of the inherent role
of partnerships in WCP efforts. Few water utilities hold regulatory control over lands outside their
ownership and therefore partnerships are an essential tool in gaining the needed cooperation of neighbors.
Utility experience shows that forming partnerships with individuals, groups, businesses, and local
governments that represent sources of contamination requires describing how those individuals or entities
are impacting the water supply. From that common basis dialogue can be initiated and solutions
developed. This is a difficult process and could be easily inhibited or derailed by external entities wishing
to employ this information to serve other goals.
Partnerships are the cornerstone of the WCP. They are built on trust and cooperation. Stakeholder trust is
earned by providing a safe forum for discussion and negotiation that does not impose otherwise avoidable
risk to the parties concerned. Therefore, the PWD recommends that all WCP documents be considered
confidential by default. If a public document is required the utility should have an opportunity to develop
a separate non-sensitive version free of specific source-related information, focused on program goals,
status, and accomplishments.
Response: See Response 720.
Comment Response for L T2ESWTR 8-95 December 2005
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EPA Letter ID: 520
Comment ID: 11630
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA believes that there indeed may be confidential business information (CBI) and
Homeland Security concerns associated with making information on the watershed control program
available to the public. This CBI includes the location of intake structures, dams, and water treatment
facilities. One potential way to deal with CBI is to restrict dissemination of maps and locational
information to the public.
Response: See Response lOOaand Response 720.
EPA Letter ID: 562
Comment ID: 12439
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Some of the information referenced in the agency-s guidance for WCP would become
problematic if made publicly available. Some of the reporting documents for the WCP, as currently
described in guidance, may not be suitable for public availability for a variety of reasons. In addition to
the concerns outlined below, the effort necessary to generate alternate versions of all WCP technical
documents appropriate for sharing with the public would be better put toward developing communication
products aligned with the objectives in the WCP Plan.
Some WCP technical documents are working papers that should be shielded as CBI because of the
inherent role of partnerships in WCP efforts. Few water utilities hold regulatory control over lands outside
their ownership and therefore partnerships are an essential tool in gaining the needed cooperation of
neighbors. Utility experience shows that forming partnerships with individuals, groups, businesses, and
local governments that are sources of contaminants of concern requires describing how those individuals
or entities are impacting the water supply. From that common basis, dialogue and solutions are possible.
Developing partnerships is a difficult process and could be easily inhibited or derailed by external entities
wishing to employ this information to serve other goals.
Partnerships are the cornerstone of the WCP. They are built on trust and cooperation. Stakeholder trust is
earned by providing a safe forum for discussion and negotiation that does not impose otherwise avoidable
risk to the parties concerned. Therefore, the AWWA recommends that all WCP documents be considered
confidential by default. If a public document is required the utility should have an opportunity to develop
a separate, non-sensitive, version free of specific source-related information, focused on program goals,
status, and accomplishments.
Response: See Response 720.
EPA Letter ID: 595
Comment ID: 12590
Comment Response for L T2ESWTR 8-96 December 2005
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Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Maine believes that there may be security concerns over disseminating information regarding
specific locations of intakes, water treatment facilities, etc., of public water systems to the public. Perhaps
this particular information could be omitted from water reports to the public
Response: See Response 720.
EPA Letter ID: 643
Comment ID: 12784
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States believe that there indeed may be confidential business information (CBI) and
Homeland Security concerns associated with making information on the watershed control program
available to the public. This CBI includes the location of intake structures, dams, and water treatment
facilities. One potential way to deal with CBI is to restrict dissemination of maps and locational
information to the public.
Response: See Response lOOaand Response 720.
EPA Letter ID: 647
Comment ID: 12926
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: MDE believes that there may be confidential business information (CBI) and Homeland
Security concerns associated with making information on the watershed control program available to the
public. This CBI includes the location of intake structures, dams, and water treatment facilities. One
potential way to deal with CBI is to restrict dissemination of maps and locational information to
the public.
Response: See Response lOOaand Response 720.
EPA Letter ID: 677
Comment ID: 13958
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Comment: The City still supports the requirement for an annual program status report, which is intended
to note progress on program implementation and measure success as possible.
Comment Response for L T2ESWTR 8-9 7 December 2005
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Response: See Response lOOa.
8.3.7 Comment Code 727, Expiration of treatment credit after second
round of monitoring
Individual Comments on Code 727
EPA Letter ID: 434
Comment ID: 10603
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Comment: Colorado Springs Utilities (PWSID # CO0121150) would like the requirement for
re-approval of a watershed protection credit every six years to be eliminated. We recommend that the
credit be a continuing one for systems once initially approved and meeting the WCP requirements on a
continuing basis.
Response: See Response 720.
EPA Letter ID: 471
Comment ID: 11120
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 3) the requirement for re-approval of a watershed protection credit every six years is
inappropriate and makes it unlikely that a utility would count on this credit for long-term compliance. In
its place, we suggest that the credit be a continuing one for those systems that are initially approved and
meet the WCP requirements on a continuing basis.
Response: See Response 720.
EPA Letter ID: 471
Comment ID: 11159
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 3) the requirement for re-approval of a watershed protection credit every six years is
inappropriate and makes it unlikely that a utility would count on this credit for long-term compliance. In
its place, we suggest that the credit be a continuing one for those systems that are initially approved and
meet the WCP requirements on a continuing basis.
Response: See Response 720.
Comment Response for L T2ESWTR 8-98 December 2005
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EPA Letter ID: 483
Comment ID: 11267
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: - EPA should drop the requirement for re-approval of a watershed protection credit every six
years. The credit should be a continuing one for systems once initially approved and meeting the
watershed control requirements on a continuing basis.
Response: See Response 720.
EPA Letter ID: 488
Comment ID: 11850
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4. Implication that reductions in Cryptosporidium oocyst levels at drinking water intakes are
expected within the six-year timeframe prior to a second round of defined monitoring
Re-approval of a WCP every six years was not part of the Agreement in Principle. This requirement
places a greater burden on the WCP than on treatment-based toolbox items. As written, the six-year re-
approval process for the WCP creates an upward spiral of requirements for utilities engaged in source
water protection efforts. This conflicts with the Agency-s general approach to source water protection
which is based on steady incremental progress on a watershed basis.
In crafting the microbial toolbox the Stage 2 MDBP FACA expected that the WCP would be widely
utilized and thereby bring long-term and wide-reaching public health benefits (though not necessarily
immediately measurable) to the nation. However, because of the huge uncertainty associated with the re-
approval process outlined in the proposed guidance, even utilities at the forefront of watershed control in
the United States have indicated they could not plan to utilize this credit with confidence. The Agreement
in Principle with respect to WCP toolbox credit thus has not been met.
Recommendation
The PWD recommends that EPA eliminate the re-approval requirement from the regulation and remove
associated references from guidance. The WCP should be designed such that, once initially approved,
systems meeting the WCP requirements retain their approval status. Primacy agencies certainly need a
way to monitor utilities- progress under WCPs. This could be fulfilled by submission of an annual or
triannual report describing the utility-s ongoing WCP activities and programs. The primacy agency could
use such a reporting tool to determine whether a system is engaged in an active WCP program. The
reports would also provide a basis for discussion of the WCP plan during regular sanitary surveys. If a
utility failed to demonstrate adequate commitment to their WCP the primacy agency could deny them
eligibility for the 0.5 log toolbox credit until they obtained WCP re-approval. Examples of appropriate
report elements include:
- WCP milestones achieved in period
Comment Response for L T2ESWTR 8-99 December 2005
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- Metrics of pertinent activities during period (e.g. miles of stream bank
fenced, acres of buffer purchased, etc.)
- Summary of outreach activities conducted in period
- Program budget for period
- Summary of assigned personnel
Response: See Response 720.
EPA Letter ID: 496
Comment ID: 10706
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: EPA should eliminate the requirement for reapproval of a watershed protection credit every
six years. The credit should be a continuing one for systems once initially approved and meeting the WCP
requirements on a continuing basis.
Response: See Response 720.
EPA Letter ID: 502
Comment ID: 10641
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: programs. Also, is it necessary to have a re-approval process for the watershed protection
credit every six years? Once a system is approved and continues to meet the watershed control program
requirements, they should be awarded the 0.5-log credit and shouldn-t have to undergo a full re-
evaluation of the program. The uncertainty the -re-evaluation- process creates diminishes the
incentive for a system to spend their money and efforts on such a program. Undertaking this program for
a 0.5-log credit is not exactly an attractive option if the system then has to constantly worry if their
program will be approved every year.
Response: See Response 720.
EPA Letter ID: 506
Comment ID: 10744
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: conjunction with the regular sanitary surveys. CWD is also concerned that the requirement for
re-approval of a watershed protection credit every six years will discourage water systems from utilizing
this option in the toolbox. CWD recommends that the watershed protection credit be a continuing one as
long as the WCP requirements are met on a continuing basis.
Comment Response for LT2ESWTR 8-100 December 2005
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Response: See Response 720.
EPA Letter ID: 527
Comment ID: 10863
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additionally, EPA should drop the requirement for re-approval of a watershed protection
credit every six years. In its place, we recommend that the credit be a continuing one for systems once
initially approved and meeting the WCP requirements on a continuing basis.
Response: See Response 720.
EPA Letter ID: 527
Comment ID: 10863
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additionally, EPA should drop the requirement for re-approval of a watershed protection
credit every six years. In its place, we recommend that the credit be a continuing one for systems once
initially approved and meeting the WCP requirements on a continuing basis.
Response: See Response 720.
EPA Letter ID: 556
Comment ID: 12066
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additionally, EPA should drop the requirement for reapproval of a watershed protection
credit every six years. In its place, AMWA recommends that the credit be a continuing one for systems
once initially approved and meeting the WCP requirements on a continuing basis. A system failing to
meet the requirements of the WCP plan or program as determined by the primacy authority will be in
violation of the WCP program and not eligible for the 0.5 log removal credit until they have their program
reapproved by the State or choose to employ another toolbox option in lieu of the WCP. The installment
of a six-year re-approval process to the WCP creates an upward spiral of requirements. This is in direct
conflict with current EPA approaches to watershed protection, which are designed for steady and
incremental progress. As it currently stands even the systems with some of the best watershed control
programs would not consider the WCP option due to the uncertainty of reapproval every six years. In
many watersheds, excellent performance may be judged if it remains in place even in the face of
accelerating development. Encouraging WCP programs in such watersheds will help focus attention on
Comment Response for LT2ESWTR 8-101 December 2005
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ameliorating the potential negative impacts of uncontrolled development which is one of EPA-s
overarching goals.
Response: See Response 720.
EPA Letter ID: 562
Comment ID: 12308
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: expectations for watershed control programs. Several years may pass before noticeable
changes in water quality are realized. The agency should not impose administrative processes such as the
proposed -re-approval cycle- that draw resources away from productive source water protection
activities.
Response: See Response 720.
EPA Letter ID: 562
Comment ID: 12431
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: §141.730 Re-approval (FR 47791 Microbial Toolbox Reporting Requirements)
Re-approval of a WCP every six years was not part of the Agreement in Principle. This requirement
places a greater burden on the WCP than on treatment-based toolbox items. As written, the six-year re-
approval process for the WCP creates an upward spiral of requirements for utilities engaged in source
water protection efforts. This conflicts with the agency-s general approach to source water protection,
which is based on steady incremental progress on a watershed basis.
In crafting the microbial toolbox, the Stage 2 MDBP FACA expected that the WCP would be widely
utilized and thereby provide long-term and wide-reaching public health benefits (though not necessarily
immediately measurable) to the nation. However, because of the huge uncertainty associated with the six-
year re-approval process outlined in the proposed guidance, even utilities at the forefront of watershed
control in the United States have indicated they could not plan to utilize this credit with confidence. This
lack of confidence indicates that the intent of the Agreement in Principle with respect to WCP toolbox
credit has not been met.
The AWWA recommends that EPA eliminate the re-approval requirement from the regulation and
remove associated references from guidance (LT2ESWTR Toolbox Guidance Manual). The WCP should
be designed such that, once initially approved, systems meeting the WCP requirements retain their
approval status. Primacy agencies certainly need a way to monitor utilities- progress under WCPs. This
could be fulfilled by submission of an annual or triennial report describing the utility-s ongoing WCP
activities and programs. The primacy agency could use such a reporting tool to determine whether a
system is engaged in an active WCP program, given the size and resources of the utility. The reports
would also provide a basis for discussion of the WCP plan during regular sanitary surveys. If a utility
Comment Response for LT2ESWTR 8-102 December 2005
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failed to demonstrate adequate commitment to their WCP, the primacy agency could deny them eligibility
for the 0.5 log toolbox credit until they obtained WCP re-approval. Examples of appropriate report
elements include:
1. WCP milestones achieved in the reporting period,
2. Metrics of pertinent activities during that reporting period (e.g.
miles of stream bank fenced, acres of buffer purchased, etc.),
3. Summary of outreach activities conducted in that period,
4. Program budget, and
5. Summary of assigned personnel.
Response: See Response 720.
EPA Letter ID: 585
Comment ID: 11975
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: Since these system will be receiving a presumptive 0.5-log credit for Cryptosporidium
control, the TCEQ also recommends that these systems be required to complete a second round of source
water monitoring as proposed by EPA.
Response: See Response lOOa.
EPA Letter ID: 620
Comment ID: 13308
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: watershed projects. Also, re-approval of a watershed protection credit every six years should
be dropped. As long as a program meets the initial requirements, credit should be kept in perpetuity.
Response: See Response 720.
EPA Letter ID: 624
Comment ID: 13189
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 2. The LT2ESWTR proposal seems to imply that the reduction in Cryptospordium density
due to WCP will occur before the next round of sampling (6-years). The WCP takes time. The
implementation of the watershed management program will require multiple years of efforts.
Comment Response for LT2ESWTR 8-103 December 2005
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Additionally, longer timeframes would facilitate integration of the SDWA and CWA watershed control
efforts.
Response: See Response 720. The watershed control toolbox option does recognize that improvements in
source water will be difficult, will likely never be measured given the available analytical techniques, and
will take many years of effort.
EPA Letter ID: 624
Comment ID: 13193
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 2.3.3.3 Why is a "re-approval" of a watershed protection program necessary? This
requirement makes watershed control a less attractive alternative for a utility. It leaves the utility in a
constant state of uncertainty as to whether their credit will remain in force. Primacy agencies can still
periodically review watershed control programs and ensure that requirements are being met. There is
no need for a re-approval requirement.
Response: See Response 720.
EPA Letter ID: 628
Comment ID: 12849
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: c. Streamline implementation and avoid redundant reporting. The SFPUC requests
the implementation requirements for the watershed control program be streamlined and avoid redundant
reporting requirement. The proposed requirement of reapplication and re-approval of a watershed
protection credit every six years for all systems is not a sound use of limited utility and primacy agency
resources. The SFPUC recommends that the State have the flexibility to determine, based on the system-s
five-year sanitary survey results, whether or not the existing watershed control program is sufficient or
needs strengthening to maintain the existing removal credit. Re-approval should be automatic, provided
that all program requirements are met and that watershed sanitary survey shows an active program. The
SFPUC further recommends that reapplication be required only when the system has been reclassified
based on the second-round monitoring results. The proposed requirement of including a summary of
activities and issues identified during the previous approval period and a revised plan that addresses
activities for the next approval period in the re-application could be streamlined by addressing these in the
annual status reports and watershed sanitary surveys. Avoiding the request for repetitive information in
separate Sections could help reduce the reporting burden to water systems and the State primacy agency.
Response: See Response 720.
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EPA Letter ID: 630
Comment ID: 13074
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: - EPA should drop the requirement for re-approval of a watershed protection credit every six
years. In its place, recommend that the credit be a continuing one for systems once initially approved and
meeting the watershed protection credit requirements on a continuing basis.
Response: See Response 720.
EPA Letter ID: 637
Comment ID: 13096
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: for toolbox credit. The requirement for re-approval is also excessive as long as a system has
agreed in its plan to review and update the plan this should be a continuing credit.
Response: See Response 720.
EPA Letter ID: 662
Comment ID: 14036
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: on the existence of a program and documented implementation. This should be a continuously
approved credit as long as the terms of the program are maintained.
Response: See Response 720.
EPA Letter ID: 677
Comment ID: 13956
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Comment: reformulated. Also, we believe that it is inappropriate to require systems to reapply for
approval credit. Re-approval should be automatic, provided that all program requirements are met and
that watershed sanitary survey shows an active program.
Response: See Response 720.
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EPA Letter ID: 678
Comment ID: 14693
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 22. Section 141.725(a)(4)(iii) - The implementation requirements for the watershed control
program should be streamlined and avoid redundant reporting requirement. The proposed requirement of
reapplication and re-approval of a watershed protection credit every six years for all systems is
unnecessary. Instead, the State primacy agency should have the flexibility to determine, based on a
system-s sanitary survey results, whether or not the existing watershed control program is sufficient or
needs strengthening to maintain the existing removal credit. Re-approval should be automatic, provided
that all program requirements are met and that watershed sanitary survey shows an active program.
Reapplication should be required only when the system has been reclassified based on the second-round
monitoring results. Furthermore, the proposed requirement of including a summary of activities and
issues identified during the previous approval period and a revised plan that addresses activities for the
next approval period in the re-application could be streamlined by addressing these in the annual status
reports and watershed sanitary surveys. We recommend the EPA avoid asking repetitive information in
separate Sections, and help reduce reporting burdens to the systems and State primacy agency.
Response: See Response 720.
EPA Letter ID: 711
Comment ID: 16558
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 11. Section 141.725(a)(4)(iii)-We believe the proposed requirement of re-application for the
State review and re-approval of the watershed control program and for a continuation of the 0.5 log
removal credit for a subsequent approval period is unnecessary. The inclusion of a summary of activities
and issues identified during the previous approval period and a revised plan that addresses activities for
the next approval period in the re-application should have been addressed in the annual watershed control
program status reports andannual watershed sanitary surveys as required in Sections 141.725(a)(4)(i) and
(ii). We recommend EPA avoid asking repetitive information in separate Sections, and help reduce
reporting burdens to the systems and State primacy agency.
Response: See Response 720.
8.3.8 Comment Code 728, Rule Language Edits
Individual Comments on Code 728
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EPA Letter ID: 624
Comment ID: 13192
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 2.3.2.1 In the interest of clarity, a term other than "vulnerability" analysis should be used so
that this is not confused with the vulnerability analysis conducted by utilities as a result of terrorist
threats.
Response: The LT2ESWTR rule language has been modified from the proposal. The modified language
addresses the commenter's conern.
8.3.9 Comment Code 729, Guidance
Individual Comments on Code 729
EPA Letter ID: 624
Comment ID: 13190
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: Comments on Watershed Control Guidance Document:
General: The guidance leaves a lot of latitude for specific requirements to the states. Perhaps this is the
most appropriate approach, but from a utility's perspective, the USEPA guidance on watershed control is
of little use until the primacy agency determines their specific requirements. We cannot begin to
implement the WCP until the states have clarified their requirements.
Response: The guidance material for the watershed control toolbox option includes general information
for PWSs to use in developing and/or submitting watershed control plans and for States to use in
evaluating those plans. Watershed control plans are site specific and EPA believes PWSs are in the best
position to propose what is feasible and achievable on their watersheds and that States are in the best
position to evaluate plans. The LT2ESTWR requires systems to notify the State of the intent to apply for
watershed control credit two years prior to the compliance date and to submit a proposed plan at least one
year prior to compliance. These timelines are intended to allow PWSs and States to communicate
regarding site specific watershed control program requirements prior to approval and implementation.
EPA Letter ID: 624
Comment ID: 13194
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: No guidance is given on the methodology for determining the vulnerability of a system, how
these are to be categorized (e.g. low/medium/high), or what impact they will have on the approval or
requirements for a watershed control program. For example, if a system obtains a medium rating, are their
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requirements for a watershed control program less stringent than a system with a high rating? If this is the
intent, additional guidance should be given to the primacy agency on how these ratings should be used.
Response: See Response 720. LT2ESWTR treatment requirements are based on source water monitoring
results. Treament requirements and use of the watershed toolbox option are not based on a determination
of vulnerability. Identification of zone of influence for Crytpospordium or fecal contamination is a
requirement for the watershed tool. The zone of influence determination is subject to State approval.
8.4 Comment Code 740, Alternative Source/Intake/Intake
Management Strategy
Summary of Issues
Several commenters stated they were unsure if this option would be widely used due to the burden of
performing Cryptosporidium monitoring at both the current intake and the alternative source.
Commenters also recommended that PWSs first conduct source water assessments or watershed sanitary
surveys to evaluate intake management strategies to reduce Cryptosporidium levels in the plant influent.
Response to Code 740
EPA believes that PWSs who choose alternative source monitoring must also monitor their current intake
so that the State can determine the appropriate bin classification if the PWS does not subsequently modify
its intake. While few PWSs may choose to pursue alternative source monitoring, EPA believes this option
should be available for PWSs that elect to do so. EPA agrees that it is appropriate for PWSs to asess
contamination sources in the watershed when considering whether to relocate or change the operation of
their intakes. The Toolbox Guidance Manual provides information on conducting these assesments.
Individual Comments on Code 740
EPA Letter ID: 470
Comment ID: 11076
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: We believe that the intake management strategies by which systems could reduce the levels of
Cryptosporidium in the plant influent are appropriate and do not have any additional ones to add. We
believe that representative Cryptosporidium
Response: See Response lOOa.
EPA Letter ID: 520
Comment ID: 11631
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Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Alternative Source
IEPA does not object to this tool, but are unsure if this option will be widely used due to the burden of
performing Cryptosporidium monitoring at both the current intake as well as the alternative source.
Response: See Response 740.
EPA Letter ID: 538
Comment ID: 14098
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: The City of Wichita Falls thinks that some credit should be given for systems that have the
ability to manage their intakes and/or switch to alternative sources. Both practices demonstrate an ability
to protect the public health by not utilizing a -contaminated- water for the periods of time that they are
confirmed or suspected to be containing Cryptosporidium.
Response: See Response 740. EPA agrees that the practice the commenter refers to could reduce
Cryptosporidium levels in water entering the plant. However due to the system specific nature of these
practices, EPA believes that any reduction must be verified through monitoring.
EPA Letter ID: 562
Comment ID: 12442
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 750 D. Off-Stream Raw Water Storage
Comment: 4.2.3 Off-Stream Storage and Alternative Intake
AWWA agrees with the agency proposal that development and implementation of a we 11-constructed
monitoring plan to characterize oocyst occurrence at the alternative intake location and after off-steam
storage is the simplest mechanism for identifying the benefit of either of these toolbox components.
Response: See Response lOOa.
8.4.1 Comment Code 741, Proposed monitoring and reporting
requirements
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Individual Comments on Code 741
EPA Letter ID: 457
Comment ID: 11925
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Alternative Source
We do not object to this tool, but do not agree with the justification or the need to perform
Cryptosporidium monitoring at both the current intake as well as the alternative source.
Response: See Response 740.
EPA Letter ID: 538
Comment ID: 14099
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: The City of Wichita Falls believes that the proposed use of E. coli as an indicator would be of
benefit in this application. Just as the as the EPA has proposed for small systems to use as an indicator,
large systems could use E. coli to indicate an influx of fecal material that could potentially contain
Cryptosporidium. The system would then either manage its intakes to a level in the water column that did
not show the presence of E. coli, or switch to their alternative source. The City of Wichita Falls has both
of these capabilities and has used them with success on several occasions.
Response: EPA believes that monitoring for Cryptosporidium acheives the highest certainty that PWSs
will be classified in the correct Cryptosporidium treatment bin and provide the appropriate level of public
health protection. Since an alternative source/intake management strategy begins with classification to a
bin, EPA believes that source water monitoring for Cryptosporidium is appropriate as part of this toolbox
component.
EPA Letter ID: 643
Comment ID: 12785
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Alternative Source
States do not object to this tool, but are unsure if this option will be widely used due to the burden of
performing Cryptosporidium monitoring at both the current intake as well as the alternative source.
Response: See Response 740.
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EPA Letter ID: 647
Comment ID: 12927
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Alternative Source
MDE does not object to this tool, but us unsure if this option will be widely used due to the burden of
performing Cryptosporidium monitoring at both the current intake as well as the alternative source.
Response: See Response 740.
8.4.2 Comment Code 742, Intake management strategies
Individual Comments on Code 742
EPA Letter ID: 485
Comment ID: 11295
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: EPA requests comments on what are intake management strategies by which systems
could reduce levels of Cryptosporidium in the plant influent.
Response: The Department believes that systems should first conduct a thorough source water assessment
or watershed sanitary survey to obtain information that can be used to evaluate intake management
strategies to reduce Cryptosporidium levels in the plant influent. Systems might be able to eliminate or
control possible contaminating activities (PCAs) that were identified by the source water assessment. If
not, then systems might be able to change the location and/or depth of the intake to reduce the water
quality impacts associated with the PCAs. The Department concurs that concurrent Cryptosporidium
monitoring should be conducted to demonstrate that a different intake location or intake management
strategy will be effective in reducing oocyst levels in the plant
influent.
Response: EPA agrees that systems considering using the alternative source/intake management tool
should thoroughly evaluate alternative sources and intake management strategies prior to beginning
source water monitoring.
EPA Letter ID: 511
Comment ID: 11488
Commenter: Keith W. Cartnick, Director Water Quality Assurance, United Water New Jersey
Commenter Category: Regulated Community (Utilities)
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Comment: Topic #2: EPA requests comment on - what are intake management strategies by which
systems could reduce levels of Cryptosporidium in the plant influent. (Federal Register / Vol. 68, No. 154
/ Monday, August 11, 2003 / Proposed Rules, p. 47685)
Comment: Where practical, curtains (baffles) could provide additional detention time. Working towards
Cl water body designation may also help to improve source water quality.
Response: See Response lOOa. EPA agrees that increasing detention time in reservoirs and increased
source water protection could reduce source water Cryptosporidium levels.
EPA Letter ID: 520
Comment ID: 11632
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: With respect to EPA's specific requests for comments:
* IEPA believes that systems should first conduct a thorough source water assessment or watershed
sanitary survey to obtain information that can be used to evaluate intake management strategies to reduce
Cryptosporidium levels in the plant influent. Systems might be able to eliminate or control possible
contaminating activities that were identified by the source water assessment. If not, then systems might be
able to change the location and/or depth of the intake to reduce the water quality impacts associated with
the activities.
Response: EPA agrees that systems considering using the alternative source/intake management tool
should thoroughly evaluate alternative sources and intake management strategies prior to beginning
source water monitoring.
EPA Letter ID: 643
Comment ID: 12786
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: With respect to EPA-s specific requests for comments:* States believe that systems should
first conduct a thorough source water assessment or watershed sanitary survey to obtain information
that can be used to evaluate intake management strategies to reduce Cryptosporidium levels in the plant
influent. Systems might be able to eliminate or control possible contaminating activities that were
identified by the source water assessment. If not, then systems might be able to change the location and/or
depth of the intake to reduce the water quality impacts associated with the activities.
Response: EPA agrees that systems considering using the alternative source/intake management tool
should thoroughly evaluate alternative sources and intake management strategies prior to beginning
source water monitoring.
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EPA Letter ID: 647
Comment ID: 12928
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment:
With respect to EPA-s specific requests for comments:
- Systems should first conduct a thorough source water assessment or watershed sanitary survey to obtain
information that can be used to evaluate intake management strategies to reduce Cryptosporidium levels
in the plant influent. Systems might be able to eliminate or control possible contaminating activities that
were identified by the source water assessment. If not, then systems might be able to change the location
and/or depth of the intake to reduce the water quality impacts associated with the activities.
Response: EPA agrees that systems considering using the alternative source/intake management tool
should thoroughly evaluate alternative sources and intake management strategies prior to beginning
source water monitoring.
8.4.3 Comment Code 743, Representative monitoring prior to new
intake construction
Individual Comments on Code 743
EPA Letter ID: 470
Comment ID: 11077
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: have any additional ones to add. We believe that representative Cryptosporidium monitoring
to demonstrate a reduction in oocyst levels can be accomplished prior to implementation of a new intake
strategy. Furthermore, states should have the
Response: See Response lOOa.
EPA Letter ID: 485
Comment ID: 11296
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes that there may be situations where it is reasonable to
allow representative Cryptosporidium monitoring to demonstrate a reduction in oocyst levels prior to
implementation of a new intake strategy. It does not seem cost effective for a system to incur costs
associated with constructing a new intake before determining whether the strategy will reduce
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oocyst levels. If monitoring cannot be conducted before the modifications are complete, the utility should
be required to conduct the monitoring after the modifications are operable.
Response: The LT2ESWTR does requires monitoring prior to implementing a new intake strategy. The
results of monitoring must be submitted to the State along with supporting information documenting the
operating conditions under which the samples were collected. EPA agrees that in some cases this
monitoring could be conducted prior to actual construction if the system could document to the State that
the conditions under which the monitoring was conducted and the operating conditions of the new intake
were the same.
8.4.4 Comment Code 744, Application to plants with multiple sources
Individual Comments on Code 744
EPA Letter ID: 470
Comment ID: 11078
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: to implementation of a new intake strategy. Furthermore, states should have the flexibility to
decide how to manage this monitoring for plants that use multiple sources and for separate sources
entering a plant at different points.
Response: See Response lOOa. EPA notes that the LT2ESWTR rule requires that a system submit a
description of their sampling location(s) to the State at the same time of their sampling schedule.
EPA Letter ID: 485
Comment ID: 11297
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes that plants that use multiple sources, which enter a plant
through a common conduit, should be required to conduct Cryptosporidium monitoring of each source to
determine the Cryptosporidium levels of each source. (Note: see previous comments regarding analytical
detection limits and the precision and accuracy of the methods). Therefore, the system will know the
amount of Cryptosporidium loading to expect at the plant if the ratio of flows from the different sources
changes significantly. The Department also has the same position regarding plants that use separate
sources, which enter the plant at different points.
Response: See Response lOOa. The LT2ESWTR does require monitoring at each source unless sources
are combined prior to treatment. The use of multiple sources during monitoring must be consistent with
routine operational practice. Systems must also sumbit a description of their monitoring locations to the
State with their monitoring schedule.
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EPA Letter ID: 520
Comment ID: 11633
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: * IEPA generally believes that plants that use multiple sources, which enter a plant through a
common conduit, should be required to conduct Cryptosporidium monitoring of each source to determine
the Cryptosporidium levels of each source. Monitoring each source will allow the system to know the
amount ofCryptosporidium loading to expect at the plant if the ratio of flows from the different sources
changes significantly. This approach would also extend to plants that use separate sources that enter the
plant at different points.
Response: EPA appreciates the comment. The LT2ESWTR does require monitoring at each source
unless sources are combined prior to treatment. The use of multiple sources during monitoring must be
consistent with routine operational practice. Systems must also sumbit a description of their monitoring
locations to the State with their monitoring schedule.
EPA Letter ID: 538
Comment ID: 14100
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: Additionally, systems that blend 2 separate sources waters should be given some form of
credit due to the dilution that is provided, i.e. the overall loading ofCryptosporidium into the plant is
reduced. Reduction ofCryptosporidium or any contaminant is the purpose of a barrier, and dilution
demonstrates this reduction. If a system has 2 source waters and those are blended before they reach a
plant, the overall contaminant load that the plant has to treat is reduced. Therefore, systems that blend
their 2 source waters should be given credit for this ability.
Response: EPA is not aware of information upon which to base a "credit" for dilution and the situation
would be system specific. The LT2ESWTR allows systems with multiple sources that are combined prior
to treatment to collect samples from a sample tap where they are combined, to composite samples or to
seperately analyze samples and calculte a weighted average based on the fraction of each source
contributing to total plant flow.
8.4.5 Comment Code 745, Rule Language Edits
Individual Comments on Code 745
EPA Letter ID: 483
Comment ID: 11264
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
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MA
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 723 3. Reduced frequency for watershed survey
Comment: - A new term has been introduced i.e. -watershed sanitary survey- that is not defined. The
word sanitary should be deleted and any watershed survey should be performed in conjunction with
regular sanitary surveys. Persons conducting watershed surveys should not have to be approved by the
state. Approval of the plan is sufficient.
Response: The term watershed sanitary survey is used to distinguish the specifc requirements related to
the LT2ESTWR. A sanitary survey (defined in CFR 141.2) includes a review of facilities and equipment.
EPA believes the term watershed sanitary survey is commonly used and its meaning is generally well
understood.
8.5 Comment Codes 750, Off-Stream Raw Water Storage
Summary of Issues
While most commenters agreed with the proposal not to grant a presumptive credit other commenters
were concerned with the lack of a presumptive credit. Commenters noted that monitoring after off-stream
storage would reflect the removal achieved by these facilities. Some commenters felt that a presumptive
credit should be granted to new off- stream reservoirs (constructed after the effective date of the rule)
with verification of the credit through monitoring after the completion of the facility.
Response to Code 750
EPA believes that off-stream raw water storage can improve the microbial quality of water in a number of
ways. These include (1) reduced microbial and particulate loading to the plant due to settling in the
reservoir, (2) reduced viability of pathogens due to die-off, and (3) dampening of water quality and
hydraulic spikes.
EPA evaluated a number of studies that investigated the removal of Cryptosporidium and other
microorganisms and particles in raw water storage basins.
Overall these studies indicate that off-stream storage of raw water has the potential to effect significant
reductions in the concentration of viable Cryptosporidium oocysts, both through sedimentation and
degradation of oocysts (i.e., die-off). However, these data also illustrate the challenge in reliably
estimating the amount of removal that will occur in any particular storage reservoir. Removal and die-off
rates reported in these studies varied widely, and were observed to be influenced by factors like
temperature, contamination, hydraulic short circuiting, and biological activity. Because of this variability
and the relatively small amount of available data, it is difficult to extrapolate from these studies to
develop nationally applicable criteria for awarding removal credits to raw water storage. After a review of
the available literature, EPA is unable to determine criteria that provide reasonable assurance of achieving
a 0.5 or 1 log removal of oocysts.
Subsequent to the November 2001 pre-proposal draft, the Science Advisory Board (SAB) reviewed the
data that EPA had acquired to support Cryptosporidium treatment credits for off-stream raw water
storage. In written comments from a December 2001 meeting of the SAB Drinking Water Committee, the
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panel concluded that the available data were not adequate to demonstrate the treatment credits for off-
stream raw water storage described in the pre-proposal draft, and recommended that no presumptive
credits be given for this toolbox option. The panel did agree, though, that a utility should be able to take
advantage of off-stream raw water storage by sampling after the reservoir for appropriate bin placement.
EPA concurs with this finding by the SAB and the final LT2ESWTR rule is consistent with their
recommendation.
Individual Comments on Code 750
EPA Letter ID: 585
Comment ID: 11977
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: If the final rule includes presumptive removal credit for new off-stream raw water storage, the
TCEQ recommends that the system be required to conduct a second round of source water monitoring.
This second round of monitoring will be conducted downstream of the off-stream storage reservoir and
will assure that the facility is placed into the proper bin. The "efficacy-verification" approach being
recommended by the TCEQ is consistent with the approach that the EPA has proposed for new
presedimentation and bank filtration systems.
Response: See Response 750. EPA notes that the final LTESWTR does include requirements for
monitoring of new sources, which would inlcude new off-stream storage for the purpose of determining
Cryptosporidium treatment requirements.
EPA Letter ID: 562
Comment ID: 12442
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 740 C. Alternative Source/Intake/Intake Management
Strategy
Comment: 4.2.3 Off-Stream Storage and Alternative Intake
AWWA agrees with the agency proposal that development and implementation of a we 11-constructed
monitoring plan to characterize oocyst occurrence at the alternative intake location and after off-steam
storage is the simplest mechanism for identifying the benefit of either of these toolbox components.
Response: See Response lOOa.
8.5.1 Comment Codes 751, Decision not to grant credit based on
existing data
Individual Comments on Code 751
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EPA Letter ID: 101
Comment ID: 10887
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Off Stream Raw Water Storage
The available data are strong and support a presumptive 1 log cryptosporidium treatment credit for off-
stream raw water storage.
Response: See Response 750.
EPA Letter ID: 457
Comment ID: 11926
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Off-Stream Raw Water Storage
We support inclusion of this tool, but are concerned that the proposed rule does not include a presumptive
credit. We suggest a presumptive credit of 0.5 log.
Response: See Response lOOa. and Response 750.
EPA Letter ID: 485
Comment ID: 11298
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 343 3. Raw water off-stream storage
Comment: Response: The Department concurs with the finding and supports the LT2ESWTR
monitoring requirements for off stream raw water storage reservoirs. Monitoring at this site will allow the
utilities using off-stream storage to receive actual credit that may be greater or less than that previously
proposed. This monitoring should be in addition to the source water monitoring unless all source water is
passed through the off stream storage prior to treatment.
Response: See Response 343.
EPA Letter ID: 520
Comment ID: 11634
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
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Comment: Off-Stream Raw Water Storage
IEPA supports inclusion of this tool, but are concerned that the proposed rule does not include a
presumptive credit. Some states would support determining credit based on monitoring results while other
states suggest a modest presumptive credit (possibly 0.5 log). While the impact of existing off-stream
storage reservoirs can be evaluated based on the proposed sampling locations, similar evaluations for
proposed off-stream storage cannot be completed until after the facility is constructed. Systems that
construct off-stream storage could confirm the effectiveness of the reservoir through a second round of
source water monitoring conducted downstream of the off-stream storage. This "efficacy-verification" is
consistent with the approach that the EPA has proposed for new presedimentation and bank filtration
systems.
Response: See Response 750. EPA notes that the final LT2ESTWR does address sampling of new
sources, which would inlcude new off-stream storage.
EPA Letter ID: 562
Comment ID: 12418
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5. 0.5 log Cryptosporidium credit for 21-day off-stream raw water storage and 1.0 log for >60
day storage are indicated from currently available literature data. Log credit for off-stream storage is
appropriate not only because of Cryptosporidium removal, but also due to microbial antagonism
(predators and competitors) and natural die off. Monitoring after off-stream raw water storage will most
readily reflect this removal.
This analysis and these findings provide an important factual basis for the recommendations AWWA
offers in the following comments. AWWA-s review includes both research and data identified in the
LT2ESWTR proposal. AWWA believes the analysis in Appendix 1 and reflected in these comments more
correctly reflects the performance of some of these treatment technologies than the discussion provided in
the Federal Register notice and Microbial Toolbox Guidance. In addition to the literature and analysis
presented in Appendix 1 and Appendix 2, AWWA will also provide information and analysis with respect
to watershed control programs, bank filtration, ozone disinfection and UV disinfection.
4.2.1 Regulatory -Preference- vs. Agreement in Principle
Response: See Response 750. EPA notes that the final LTESWTR does include requirements for
monitoring of new sources, which would inlcude new off-stream storage for the purpose of determining
Cryptosporidium treatment requirements.
EPA Letter ID: 585
Comment ID: 11976
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
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Comment: p. 47685 [and §141.722(a) on p. 47784 to the extent that it omits presumptive
credit for offreservoir storage; and §141.726 on p. 47786]
The TCEQ does not concur with the proposal to exclude presumptive credit for water systems that install
off-stream raw water storage. While the impact of existing off-stream storage reservoirs can be evaluated
based on proposed sampling locations, similar evaluations for proposed off-stream storage cannot
be completed until after the facility is constructed. Based on the information presented in the proposal, it
appears that the number of viable oocysts can be reduced by off-stream storage, especially in
geographical areas with warmer water temperatures, higher biological activity, and higher suspended
solids concentrations.
In light of the data presented in the preamble and the fact that proposed off-stream storage reservoirs can
be designed and operated specifically to maximize particulate removal, the TCEQ recommends that the
EPA grant a 0.5-log presumptive Cryptosporidium removal credit for offstream raw water storage
constructed after the effective date of the LT2ESWTR.
Response: See Response 750. EPA notes that the final LTESWTR does include requirements for
monitoring of new source, which would inlcude new off-stream storage for the purpose of determining
Cryptosporidium treatment requirements.
EPA Letter ID: 643
Comment ID: 12788
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Off-Stream Raw Water Storage
States generally support inclusion of this tool, but are concerned that the proposed rule does not include a
presumptive credit. Some states would support determining credit based on monitoring results while other
states suggest a modest presumptive credit (possibly 0.5 log). While the impact of existing off-stream
storage reservoirs can be evaluated based on the proposed sampling locations, similar evaluations for
proposed off-stream storage cannot be completed until after the facility is constructed. Systems that
construct off-stream storage could confirm the effectiveness of the reservoir through a second round of
source water monitoring conducted downstream of the off-stream storage. This -efficacy-verification- is
consistent with the approach that the EPA has proposed for new presedimentation and bank filtration
systems.
Response: See Response 750. EPA notes that the final LTESWTR does include requirements for
monitoring of new sources, which would inlcude new off-stream storage for the purpose of determining
Cryptosporidium treatment requirements.
EPA Letter ID: 647
Comment ID: 12930
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment Response for LT2ESWTR 8-120 December 2005
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Comment: Off-Stream Raw Water Storage
MDE generally supports inclusion of this tool, but is concerned that the proposed rule does not include a
presumptive credit. Systems that construct off-stream storage could confirm the effectiveness of the
reservoir through a second round of source water monitoring conducted downstream of the off-stream
storage. This -efficacy-verification- is consistent with the approach that the EPA has proposed for new
presedimentation and bank filtration systems.
Response: See Response 750. EPA notes that the final LTESWTR does include requirements for
monitoring of new sources, which would inlcude new off-stream storage for the purpose of determining
Cryptosporidium treatment requirements.
EPA Letter ID: 668
Comment ID: 13901
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 8111. Decision not to award credit
Comment: - No credit should be provided for raw water storage (p 47687), or roughing filters (p. 47700-
01) because, as EPA has found, there is no evidence to support such credit. This is consistent with the
Agreement, which called upon EPA to review the science and verify the rough table in the agreement, and
to seek comment on all credits.
Response: See Response 810 and Response 750.
8.5.2 Comment Codes 752, Additional data on off-stream storage
Individual Comments on Code 752
EPA Letter ID: 470
Comment ID: 11079
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: The Vermont drinking water program does not have addition information on a presumptive
Cryptosporidium treatment credit for off-stream raw water storage.
Response: See Response lOOa.
8.5.3 Comment Codes 753, Addressing contamination due to algae,
birds, runoff, etc.
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Individual Comments on Code 753
EPA Letter ID: 470
Comment ID: 11080
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: We are supportive of the approach that is outlined in the proposed rule and believe that the
approach addresses algal growth, run-off, roosting birds, and other activities in the watershed.
Response: See Response lOOa.
EPA Letter ID: 485
Comment ID: 11299
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes that off-stream raw water storage reservoirs are surface
water sources vulnerable to all environmental contaminating activities and source water quality hazards
and therefore should be subject to all applicable ESWTR requirements. The Department also believes that
a Source Water Assessment of the off-stream storage facilities should identify the potential contaminating
activities that need to be mitigated as part of a -source water protection program- by utilities using the
source.
Response: See Response lOOaand Response 750.
8.5.4 Comment Codes 754, Rule Language Edits
Individual Comments on Code 754
EPA Letter ID: 678
Comment ID: 14713
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 9. For each microbial toolbox component, the EPA is requesting comment on whether
available data are consistent with the decision not to award presumptive credit for roughing filters and
raw water off-stream storage, and whether additional data are available on treatment effectiveness of
toolbox components for reducing Crypto levels. [47682, Cl]
Comment: The log reduction for Giardia in Bertolucci et al. 1998 should be 0.5, not 0.8 as shown in Table
IV-8. - Studies of Cryptosporidium and Giardia Removal from Off-Stream Raw Water Storage.
Response: See Response lOOa.
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8.6 Presedimentation Basin with Coagulant
8.6.1 Comment Code 761, Credit and criteria for awarding credit
Summary of Issues
All commenters supported the proposal to award presumptive credit for the use of a pre-sedimentation
basin with coagulation. Many commenters also supported the performance and monitoring requirements
for this option. A number of commenters felt that the turbidity performance requirement could not be met
by most plants due to normal periods of low source water turbidity. One commenter felt that basing the
turbidity performance based on an average of 12 months was inconsistent with performance standards for
other toolbox options Several commenters suggested returning to an overflow rate as a performance
standard while maintaining the requirements for continuous treatment of the entire flow operations and
coagulant addition while in operation.
Response to Code 761
EPA continues to believes that 0.5-log turbidity reduction is an appropriate performance indicator for 0.5-
log Cryptosporidium reduction in presedimentation processes. EPA has reviewed the additional data
submitted by commenters on the removal of turbidity and aerobic spores (as an indicator of
Cryptosporidium removal) in full-scale presedimentation basins. These data are consistent with data
reviewed for the proposal in showing that when turbidity removal was below 0.5-log, removal of aerobic
spores was also usually below 0.5-log. Conversely, when turbidity reduction exceeded 0.5-log, aerobic
spore removal was typically higher than 0.5-log. Consequently, while there is not a one-to-one
relationship between reduction in turbidity and reduction in aerobic spores, 0.5-log turbidity reduction is a
reasonable indicator of when Cryptosporidium removal is likely to be at least 0.5-log.
EPA recognizes, though, that 0.5-log turbidity reduction through presedimentation will not be feasible for
some PWSs when raw water turbidity is low. The final LT2ESWTR contains several provisions to
address this concern. First, PWSs can receive credit for presedimentation during any month the process
achieves 0.5-log turbidity removal. Thus, PWSs that cannot achieve 0.5-log turbidity reduction year-
round may receive credit for presedimentation in those months when they can meet this condition. The
LT2ESWTR rule also allows PWSs to receive presedimentation credit using State-approved performance
criteria other than turbidity reduction. If approved by the State, a PWS may receive credit for
presedimentation by demonstrating, for example, 0.5-log reduction in aerobic spores. Finally, if
presedimentation improves treatment plant performance by reducing and equalizing particle loading, a
PWS can receive additional treatment credit under today's rule for achieving lower filtered water
turbidity.
Individual Comments on Code 761
EPA Letter ID: 101
Comment ID: 10888
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
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Comment: Pre-sedimentation with Coagulant
A 1 log cryptosporidium removal credit should be awarded for pre-sedimentation.
Response: See Response lOOa.
EPA Letter ID: 457
Comment ID: 11927
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Pre-Sedimentation Basin with Coagulation
We support inclusion of this tool and the 0.5 log presumptive credit.
Response: See Response lOOa.
EPA Letter ID: 470
Comment ID: 11081
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: The Vermont drinking water program is in support of the proposed approach for awarding
credit to presedimentation.
Response: See Response lOOa.
EPA Letter ID: 472
Comment ID: 11138
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: P. 47691. c. Request for comment. EPA requests comment on the proposed criteria for
awarding credit to presedimentation. EPA would particularly appreciate comment on the following issues:
Whether the information cited in this proposal supports the proposed credit for presedimentation and the
operating conditions under which the credit will be awarded; Additional information that either supports
or suggest modifications to the proposed performance criteria and presumptive credit;
The COP expects the American Water Works Association to provide substantial comments with
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supporting documentation for this request for comment. Any decisions in this area must be approached
with documented sound science to support the final rule.
Response: See Response lOOa.
EPA Letter ID: 485
Comment ID: 11300
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department concurs with the proposed credit for pre-sedimentation as outlined
in the proposed rule. The Department believes that the data presented support this credit provided utilities
comply with the operational, monitoring and performance conditions stipulated in your proposal. The
Response: See Response lOOa.
EPA Letter ID: 520
Comment ID: 11635
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Pre-Sedimentation Basin with Coagulation
IEPA generally supports inclusion of this tool and the 0.5 log presumptive credit.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12419
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 6. Continuously operated pre-sedimentation basins are suitable for a
credit of at least 0.5 log.
This analysis and these findings provide an important factual basis for the recommendations AWWA
offers in the following comments. AWWA-s review includes both research and data identified in the
LT2ESWTR proposal. AWWA believes the analysis in Appendix 1 and reflected in these comments more
correctly reflects the performance of some of these treatment technologies than the discussion provided in
the Federal Register notice and Microbial Toolbox Guidance. In addition to the literature and analysis
presented in Appendix 1 and Appendix 2, AWWA will also provide information and analysis with respect
Comment Response for LT2ESWTR 8-125 December 2005
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to watershed control programs, bank filtration, ozone disinfection and UV disinfection.
4.2.1 Regulatory -Preference- vs. Agreement in Principle
Response: See Response 761. Based on available data, EPA believes that continuously operated pre-
sedimentation basins, with the continuous addition of a coagulant, are eligilbe for a 0.5 log
Cryptosporidium removal credit.
EPA Letter ID: 562
Comment ID: 12483
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As defined in §141.730 of the proposed LT2ESWTR, the pre-sedimentation default 0.5-log
credit is achieved through a clarifier or retention basin which is (1) continuously operated, (2) located
prior to point at which the entire water treatment plant flow reaches the -treatment plant-, (3) coagulant
is added when unit is operating, and (4) demonstration of 0.5-log turbidity reduction. While AWWA
agrees with the first three components of these criteria, the fourth is not routinely demonstrable and does
not reflect the overall benefits obtained through pre-sedimentation.
Conventional drinking water treatment processes are operated in such a way as to match treatment to
influent water challenge, in this instance, particle removal. While the coagulation-flocculation-
clarification-filtration process is robust, an important operational goal is process stability. Pre-
sedimentation is a useful tool in managing the initial particulate load reaching the primary treatment
process. Pre-sedimentation not only begins the solids removal process, it also helps to equalize water
quality reaching the primary treatment process. Moreover, when coagulant addition is occurring and the
treatment process is being actively managed to achieve clarification, solids removal achieved in pre-
sedimentation reduces the solids load on the primary clarification process in the water treatment plant.
The water treatment plant can operate the two processes in a complementary fashion so that the overall
treatment process is less dependent on the removal of the solids overflow during filtration.
Available data suggest that pre-sedimentation basins located prior to a point at which raw water flow
reaches the principal treatment train, and that are continuously operated using a coagulant (polymer, metal
salts, or recycled sludge), should receive a 0.5 credit at overflow rates up to 1.6 gpm/ft2.
The exact data that was used by the Science Advisory Board Drinking Water Committee when it drafted
its recommendations on pre-sedimentation credit is not completely clear. As defined in §141.730, pre-
sedimentation is functioning much like conventional clarification, except that pre-sedimentation is only
intended to meet pretreatment objectives, and consequently will often operate at higher overflow rates
than conventional clarification. Data are available in the peer-reviewed literature demonstrating 1-log and
greater Cryptosporidium removal with conventional clarification (Edzwald et al., 2000; Cornwell and
MacPhee, 2001; Cornwell, et al., 2001; Edzwald and Kelley, 1988; Plummer et al., 1995; Dugan et al.,
1999; Hall et al., 1994; Patania et al., 1995; and others). While the peer-reviewed literature (Appendix 7)
provides a sound foundation for this log credit, data collected and supplied with these comments from
four drinking water treatment plants operating pre-sedimentation processes likewise demonstrate
substantial removal of a surrogate organism, aerobic spores.
Comment Response for LT2ESWTR 8-126 December 2005
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Response: See Response 761.EPA recognizes that 0.5-log turbidity reduction through presedimentation
will not be feasible for some PWSs when raw water turbidity is low. The final LT2ESWTR rule contains
several provisions to address this concern. First, PWSs can receive credit for presedimentation during any
month the process achieves 0.5-log turbidity removal. Thus, PWSs that cannot achieve 0.5-log turbidity
reduction year-round may receive credit for presedimentation in those months when they can meet this
condition. The final LT2ESWTR rule also allows PWSs to receive presedimentation credit using State-
approved performance criteria other than turbidity reduction. If approved by the State, a PWS may
receive credit for presedimentation by demonstrating, for example, 0.5-log reduction in aerobic spores.
Finally, if presedimentation improves treatment plant performance by reducing and equalizing particle
loading, a PWS can receive additional treatment credit under the LT2ESTER for achieving lower filtered
water turbidity.
EPA Letter ID: 562
Comment ID: 12486
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA believes that the data included in the preamble, in combination with the information
provided in these comments, is adequate to support a 0.5 credit when pre-sedimentation is (1)
continuously operated, (2) located prior to point at which the entire water treatment plant flow reaches the
-treatment plant-, (3) coagulant is added when unit is operating, and (4) maintain overflow rates less than
or equal to 1.6 gpm/ft2.
Response: See Response 761.
EPA Letter ID: 585
Comment ID: 11978
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47687-91 [and §141.722(a)(3) on p. 47784, §141.726(a)(4) on p. 47786, and
§141.730(e)(3) on p. 47792; and §141.722(a)(6) & (7), §141.727(a) & (b)(l), and
several provisions of §141.730(e)]
The EPA has proposed a presumptive removal credit for presedimentation that is based on the cumulative
results of 12 monthly tests. While this approach seems consistent with the "annualized" Cryptosporidium
levels, it is inconsistent with the design/operations-based standards used for the other two pre-filtration
toolbox components. It is also inconsistent with the monthly performance standards for the toolbox
components involving treatment performance, additional filtration, and inactivation.
Since the presedimentation toolbox component requires the collection of daily data, the TCEQ
recommends that frequency of compliance determinations for this component be consistent with the
frequency of compliance determinations for other components that require daily (or more frequent)
monitoring.
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Response: See Response lOOa.EPA notes that presedimentation toolbox option does require daily
monitoring of performance with compliance based on the monthly mean of daily basin influent and
effluent measurements.
EPA Letter ID: 624
Comment ID: 13195
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: . Presedimentation: We feel that a 0.5-log turbidity removal at all times is unrealistic. During
summer months, and at other low-flow times, the turbidity levels in surface waters are normally low such
that it is impossible to mathematically demonstrate a 0.5-log turbidity removal during these times. Also,
addition of coagulants may add artificial turbidity to the source water during low turbidity periods and the
log removal may be mathematically negative. Figure 1, shows the comparison of turbidity and endospore
log removals across a lamella clarification unit process for GCWW's surface water treatment plant (2002).
As is evident from the figure, on an annual average basis at least 0.5 log removal is achieved using both
turbidity and endospores as microbial surrogates. Therefore, we recommend that EPA should proceed
with a default OS-log credit for presedimentation facilities that are continuously operated, treat the entire
flow, and continuously add coagulants. The overflow rate across the lamella plate settlers in Figure
1 during 2002 was as high as 0.9 gpm/ft2.
[SEE PAGE 5 OF PDF FOR FIGURE 1]
Response: See Response 761.
EPA Letter ID: 643
Comment ID: 12789
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Pre-Sedimentation Basin with Coagulation
States generally support inclusion of this tool and the 0.5 log presumptive credit.
Response: See Response lOOa.
EPA Letter ID: 647
Comment ID: 12931
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Pre-Sedimentation Basin with Coagulation
MDE generally supports inclusion of this tool and the 0.5 log presumptive credit. However, most
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presedimentation basins do not have chemical addition, and the basins are more accurately described as
raw water reservoirs. Please provide clarification on this matter in the guidance manual.
Response: See Response lOOa. Based on available data, EPA believes that continuous coagulant addition
is necessary for the removal credit allowed for this toolbox option.
EPA Letter ID: 678
Comment ID: 14694
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 23. Section 141.726(a)(4) - It is unclear on what basis the EPA requires the system to
demonstrate at least a monthly 0.5 log reduction of influent turbidity through the presedimentation
process in at least 11 of the 12 previous consecutive months in order to be eligible for 0.5 log
Cryptosporidium removal credit. Since there is no clear one-to-one relationship between the removal of
turbidity and Cryptosporidium, the requirement of 0.5 log turbidity removal in the presedimentation
process as a pre-qualifier for obtaining the 0.5 log credit for Cryptosporidium credit appears unwarranted.
If
Response: See Response 761.
8.6.1.1 Comment Code 762, Conditions that would affect
compliance with criteria
Response to Code 762
PWSs can receive credit for presedimentation during any month the process achieves 0.5-log turbidity
removal. Thus, PWSs that cannot achieve 0.5-log turbidity reduction year-round may receive credit for
presedimentation in those months when they can meet this condition. The LT2ESTWR also allows PWSs
to receive presedimentation credit using State-approved performance criteria other than turbidity
reduction. If approved by the State, a PWS may receive credit for presedimentation by demonstrating, for
example, 0.5-log reduction in aerobic spores. Finally, if presedimentation improves treatment plant
performance by reducing and equalizing particle loading, a PWS can receive additional treatment credit
under today's rule for achieving lower filtered water turbidity
Individual Comments on Code 762
EPA Letter ID: 534
Comment ID: 11999
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
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Comment: It is Kansas City, Missouri-s experience that river source water turbidities can vary
significantly. During periods of precipitation and runoff, the Missouri River at Kansas City exhibits
turbidities in the range of 1000 - 10,000 NTU, while the same river exhibits turbidities near 50 NTU
during periods of low flow and drought. If a water system is required to continuously add coagulant
regardless of source water turbidity, there could well be an increase in turbidity across the
presedimentation basin due to coagulant addition. Thus, the requirement for 0.5 log reduction of influent
turbidity for 11 of 12 consecutive months may be unattainable for presedimentation processes that add a
coagulant of lime and/or magnesium hydroxide to a river source water such as the Missouri even though
there is a 1 log plus removal of spores.
Response: PWSs that cannot achieve 0.5-log turbidity reduction year-round may receive credit for
presedimentation in those months when they can meet this condition. The LT2ESTWR rule also allows
PWSs to receive presedimentation credit using State-approved performance criteria other than turbidity
reduction. If approved by the State, a PWS may receive credit for presedimentation by demonstrating, for
example, 0.5-log reduction in aerobic spores. Finally, if presedimentation improves treatment plant
performance by reducing and equalizing particle loading, a PWS can receive additional treatment credit
under the LT2ESWTR rule for achieving lower filtered water turbidity.
EPA Letter ID: 562
Comment ID: 12488
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
Whether and under what conditions factors such as low-turbidity raw water, infrequent sludge removal,
and wind would make compliance with the 0.5-log turbidity removal requirement infeasible.
Response
If influent turbidity levels are low, then the solids load is not sufficient to support the required
demonstration. AWWA believes this practical limitation on the 0.5-log turbidity removal renders this rule
provision unsound. The agency should proceed with a default 0.5-log credit for pre-sedimentation that
does not include a turbidity removal criterion. Appropriate criteria are (1) continuously operated, (2)
located prior to point at which the entire water treatment plant flow reaches the -treatment plant-, (3)
coagulant is added when unit is operating, and (4) maintain overflow rates less than or equal to 1.6
gpm/ft2.
Response: See Response 762.
8.6.2 Comment Code 763, Additional data on presedimentation
Individual Comments on Code 763
EPA Letter ID: 562
Comment ID: 12484
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA solicits additional data supporting the pre-sedimentation credit.
Personnel at four drinking water plants operated by three U.S. utilities (in St. Louis, Mo.; Kansas City,
Mo.; and Cincinnati, Ohio) have independently collected data regarding the removal of Cryptosporidium
and spores (Bacillus subtilis and total aerobic spores) during operation of full-scale pre-sedimentation
basins. This data collection effort is an extension of the data collection effort cited in the LT2ESWTR
preamble. Cryptosporidium oocysts were rarely detected in raw water at these locations and,
consequently, calculating oocyst removal through these processes was not possible. Aerobic spores were
detected more readily in raw water than were Cryptosporidium, making it possible to calculate log
removal of spores at these three utilities. The observed spore removal rates clearly demonstrate that, with
coagulant addition, greater than the 0.5 log of removal can be routinely expected from such facilities.
Table 3. Summary of Spore Removal Data at Four Pre-Sedimentation Facilities
[SEE TABLE 3, P.51 IN PDF]
This same data collection effort also included turbidity data from Facilities B and C. Despite providing or
exceeding desired levels of spore removal, these facilities were not able to reliably demonstrate 0.5-log
turbidity removal on a monthly basis. In part, the level of influent turbidity limits demonstrating 0.5-log
turbidity removal. If influent turbidity levels are low, then the solids load is not sufficient to support the
required demonstration. AWWA believes this practical limitation on the 0.5-log turbidity removal renders
this rule provision unsound. Rather, the agency should proceed with a default 0.5-log credit for pre-
sedimentation that is (1) continuously operated, (2) located prior to point at which the entire water
treatment plant flow reaches the -treatment plant-, (3) coagulant is added when unit is operating, and (4)
maintain overflow rates less than or equal to 1.6 gpm/ft2.
Response: See Response 761. EPA recognizes that 0.5-log turbidity reduction through presedimentation
will not be feasible for some PWSs when raw water turbidity is low. The final LT2ESWTR contains
several provisions to address this concern. First, PWSs can receive credit for presedimentation during any
month the process achieves 0.5-log turbidity removal. Thus, PWSs that cannot achieve 0.5-log turbidity
reduction year-round may receive credit for presedimentation in those months when they can meet this
condition. The final LT2ESTWR also allows PWSs to receive presedimentation credit using State-
approved performance criteria other than turbidity reduction. If approved by the State, a PWS may
receive credit for presedimentation by demonstrating, for example, 0.5-log reduction in aerobic spores.
Finally, if presedimentation improves treatment plant performance by reducing and equalizing particle
loading, a PWS can receive additional treatment credit under today's rule for achieving lower filtered
water turbidity.
8.6.3 Comment Code 766, Credit for existing basins
Individual Comments on Code 766
EPA Letter ID: 390
Comment ID: 10493
Commenter: Jeff Taylor, Deputy Director, City of Houston Public Utilities Division
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Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 342 2. Presedimentation basins
Comment: a. Systems practicing presedimentation, as defined in the proposed rule, but required to
perform the Cryptosporidium sampling upstream of the basin, should be allowed credit for use of the
presedimentation basin. The presence of a disinfectant in the water entering the basin should have no
effect on the physical efficiency of the presedimentation process and failure to allow the system credit
could result in the decision to move the point of chlorination after the basin. Such a move could have a
deleterious effect on CT, DBP formation, or both.
If Cryptosporidium is not the controlling factor in the system's disinfection scheme, then they are
needlessly sacrificing the time factor in the CT calculation, forcing them to increase the concentration of
the disinfectant. If DBP formation becomes a problem, due to this change, the system will be forced
into a new method of disinfection, involving large capital expense, and lengthy construction times.
Response: See Response 342.
EPA Letter ID: 712
Comment ID: 16594
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Pre-sedimentation: Presumptive credit for pre-sedimentation should only be allowed for
systems that presently do not practice sedimentation. If a system adds an additional sedimentation stage,
they should have to demonstrate that overall they are achieving an additional 0.5 log removal. For
example, the system could operate their filter rate after implementing pre-sedimentation, and overall have
no improvement in log reductions.
Response: The commenter's reference to pre-sedimentation credit only for systems that presently do not
practice sedimentation is unclear. The LT2ESTWR defines pre-sedimentation as a process prior to
clarification (which would include sedimentation) and filtration. Systems that do not practice
sedimentation would be classified as direct, slow sand or an alternative filtration process and have
different removal requirements under the LT2ESTWR. The commenter's comments regarding filter rates
after implementing pre-sedimentation is also unlcear.
8.7 Comment Codes 770, Bank Filtration
Response to Code 770
Bank Filtration Value - EPA agrees that Bank Filtration (BF) is a valuable treatment technology for the
U.S. drinking water community. EPA agrees with the statement that BF will be more readily adopted by
primacy agencies if BF is included as part of today's Rule. EPA believes that more utilities will take
advantage of BF technology if the BF treatment efficiency is demonstrated at multiple sites using
scientifically appropriate methods. EPA recognizes and agrees with the many States that have commented
on the value of BF attenuating concentrations of all types of contaminants and the appropriate nature of
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the automatic credit provided in today's Rule.
Today's Rule - Bank filtration, as implemented in today's Rule, is predicated on automatic BF
Cryptosporidium removal credit without a site-specific demonstration of the treatment efficiency, if the
Rule criteria are met or exceeded. Today's Rule also provides for additional Cryptosporidium removal
credit beyond the amount automatically allowed, based on a site-specific demonstration that meets certain
scientifically-acceptable standards. Today's rule provides specific criteria that must be met to allow
automatic BF Cryptosporidium removal credit and provides for additional credit without specifying the
details for getting that additional credit using a site-specific demonstration. Because Cryptosporidium
removal is site-specific, guidance accompanying today's Rule will provide primacy agencies and utilities
with additional information, such as indicator selection (e.g. aerobic spores) to assist in designing,
managing and interpreting a site-specific demonstration of BF Cryptosporidium removal efficiency so
greater removal, beyond that automatically allowed, can be demonstrated. EPA intends to continue to
work with industry and the scientific community to better understand the removal processes, the changes
in those processes and the scientific procedures for demonstrating that the treatment efficiency is adequate
or suitable. As more information on surrogates, methods, theories, laboratory or field measurements
become available, EPA will update existing BF guidance. Today's Rule specifies that any site-specific
study for additional removal credit must include samples from the production well and from one or more
properly located monitoring (or pilot, observation and other small diameter) wells. Today's Rule requires
that monitoring wells be located along the shortest flow path between the surface water body and the
production well. EPA guidance will provide additional information, as suggested in comments, for the
proper location of monitoring wells. EPA agrees that flow path data are optimal for predicting BF
efficiency. In general short and direct flow paths have lesser Cryptosporidium removal efficiency.
However, flow path identification is very costly and difficult. In today's Rule, EPA uses horizontal
distance as an easily measured surrogate for flow path. EPA recognizes that newer drilling technology
may provide for inclined rather than horizontal and vertical wells. However, EPA believes that inclined
wells are not currently a significant technnology and can be highly variable in design and construction.
Thus, EPA will address inclined wells in guidance rather than in today's Rule. EPA agrees with the
comment that infiltration galleries and spring boxes are not eligible for BF removal credit.
Bank Filtration Efficiency - EPA disagrees with the statement that EPA maligns bank filtration and
provides overly strict operational criteria. EPA believes that BF removal efficiency is difficult to measure
because the removal processes are at work during subsurface passage of surface water to a PWS well. As
a result, the BF system is poorly understood and difficult to instrument for greater scientific
understanding. Continuously changing groundwater flux and flowpath direction will result in
continuously changing Cryptosporidium removal efficiency. As ground water flux increases and ground
water flowpath direction becomes shorter and more direct, removal efficiency can decrease below values
allowed under today's Rule. Repeated measurements at the well using robust parameters (including but
not restricted to temperature) are needed to measure removal in such a dynamic environment. Where such
measurements are inadequate, treatment efficiency claims are sometimes undocumented. EPA believes
that treatment efficiency must be demonstrated to be continuously effective under all types of ground
water flow conditions. EPA disagrees with the comment that the Wang et al (2001) data are
misinterpreted. EPA believes that Wang reports 3 log total removal, of which 2 log removal occurred in
the first two feet, where biological activity enhances removal. The commenter believes that the 3 log total
removal will occur even if the first two feet are removed. EPA believes that 3 log total removal is possible
over the lesser distance, as the commenter suggests, but the reported data do not support that value.
Filtration Theory - EPA disagrees with the statement that the river bed and the aquifer are subject to
filtration theory. Filtration theory is based on removal in slow sand or rapid sand filters where each
granule in the filter is similar in size, shape, packing, grain coat type and cover and particle composition.
The riverbed and aquifer are not engineered materials, with homogenous and isotropic properties. Rather,
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they are natural materials with highly variable particle sizes, shapes, packing, grain coats and
compositions. As such, they do not meet the minimum assumptions necessary to appropriately apply
filtration theory. However, EPA believes that filtration theory, as currently developed, is the best
available construct for making predictions about BF efficiency. Due to a lack of scientific data, EPA is
unable to compare the predictions made using current filtration theory, with field measurements of BF
efficiency.
Biofiltration - EPA disagrees with the statement that EPA overestimates the significance of the riverbed
or ground water-surface water interface as compared with the aquifer proper in evaluating the relative BF
efficiency. EPA believes that oxygen and nutrient-rich ground water at or near the ground water surface
promotes the growth of thin (centimeter-thick), biologically active zones that act to enhance BF
efficiency, similar to the activity of the schmutzdecke layer in a slow sand filter. As ground water moves
toward the well, it becomes more depleted in oxygen and nutrients, biologically activity declines and the
removal efficiency decreases. Thus, EPA gives greater significance to removal within the biologically
active zone as compared with removal within the aquifer.
Bank Filtration Scientific Literature - EPA has reviewed all the scientific literature, both primary and
secondary, that addresses BF efficiency and Cryptosporidium removal. EPA disagrees with the statement
that EPA has reviewed primarily secondary rather than the primary scientific literature. EPA disagrees
with the statement that no references were provided to support the automatic credit provisions of today's
Rule. EPA referenced published full scale controlled field measurements using aerobic and anaerobic
spore removal as Cryptosporidium surrogates in studies in Lousiville (Wang et al, 2001) and The
Netherlands (Havelaar et al, 1995, Medema et al, 2000, Schijven et al, 1998).
Bank Filtration in Europe - EPA believes that European BF systems are designed to maximize passage
through the biologically active layers. For example, many BF systems in Europe passage ground water
through the riverbed and then again through an infiltration basin to enhance removal at the ground water-
surface water interface. EPA believes that the European BF experience is valuable but not directly
applicable to today's Rule because the European BF design is considerably different.
Hydrogeologic Assessment - EPA recognizes that the hydrogeologic assessment required in today's Rule
for automatic Cryptosporidium-removal credit may not be used directly to obtain additional credit.
However, EPA believes that the hydrogeologic assessment, when used together with a site-specific
demonstration, will allow primacy agencies to grant additional credit, if the demonstration is scientifically
adequate and meets the criteria specified in today's Rule. The purpose of the hydrogeologic assessment is
to establish that the site merits automatic credit because some sites have little or no capability to remove
Cryptosporidium. When a site is determined to be suitable for automatic credit, all site data, including the
hydrogeologic assessment, as well as any data on biologically active zones, may be used to demonstrate
that additional credit is warranted. Because biologically active zones are zones of enhanced
Cryptosporidium removal, determining the character and the stability of those zones are important, but
perhaps not crucial, to demonstrating additional site-specific removal efficiency beyond that allowed by
automatic credit in today's Rule. EPA agrees that ground penetrating radar is an effective tool to identify
the depth to the bedrock/alluvial interface which is valuable but not critically important information
suitable for determining site specific BF potential efficiency prior to drilling a well. EPA guidance
discusses the value of ground penetrating radar in the hydrogeologic assessment. EPA agrees that
standard well pumping tests to determine sustained yield provides insight into particle size character in
the subsurface. Riverbed samples are also valuable for similar reasons. EPA guidance discusses the value
of pump tests and riverbed samples in evaluating BF efficiency. EPA agrees that ASTM methodology is
optimal for characterizing proper sieving procedures. EPA guidance will discuss the proper ASTM
methodology for sieving.
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100 Year Flood Plain Location - EPA disagrees with the comment that the starting point for BF
measurement should not be the boundary of the floodway or the 100 year flood plain. EPA recognizes
that there is no existing Safe Drinking Water Act (federal) requirement that wells should be located
outside of the floodway. EPA believes that the dynamic nature of the shoreline, even in locations where
flooding is controlled by reservoirs and other flood control structures, merits serious attention. Increased
flood discharge or surface water elevations have the capability to significantly alter the ground water flux
and ground water flow path direction, almost always allowing greater water volumes with faster flow
rates, and more direct flow paths to the well. At the same time, there is greater likelihood of scour or other
removal or suppression of biologically active zones. These two effects, in combination, suggests that BF
is most efficient when hydrologic conditions are unremarkable. When hydrologic conditions are unusual,
BF efficiency is less certain or predictable. Thus, EPA believes that automatic BF credit, under today's
Rule, should only be granted when flood conditions are not likely to short-circuit the BF Cryptosporidium
removal efficiency. EPA believes that such conditions are most likely to prevail when the setback
distance is measured from the flood way or 100 year flood plain boundary. EPA notes that it is not
unusual to have floods that exceed those specified boundaries. Thus, in today's Rule, EPA seeks only to
minimize the likelihood that poor Cryptosporidium removal might occur rather than seeking to eliminate
all risk of low Cryptosporidium removal efficiency. EPA believes that choosing criteria that eliminated all
risk would prevent most utilities from making use of this toolbox option in today's Rule.
Turbidity Monitoring - Turbidity monitoring is well established as a measure of treatment efficiency in
slow sand filtration and rapid sand filtration treatment plants. Repeated parameter measurement reflects
the highly variable nature of surface water quality and the need for very frequent evaluation of treatment
plant efficiency. Treatment plants are engineered to be highly efficient but frequent evaluation of the
efficiency is recognized as highly protective of public health. Wells that pump ground water under the
direct influence (GWUDI) of surface water will have less variability of surface water quality than the
surface water itself. However, there is a substantial likelihood that GWUDI quality will be highly variable
(albeit of lesser variability than surface water) if the source surface water is highly variable. Frequent
turbidity monitoring is a measure of ground water quality variability (whatever the cause) and EPA
believes that it is prudent to require turbidity monitoring in these GWUDI wells. Frequent turbidity
measurement is cost effective with instruments that continuously measure turbidity. EPA believes that the
instruments are sufficiently economical so that they are actually cheaper than repeat turbidity
measurements by hand. Thus, EPA believes that prudent public health protection and economics suggests
that continuous measurement of turbidity is most cost-effective and protective. Thus, continuous turbidity
monitoring, rather than monitoring every four hours or every day, is required under today's Rule. EPA
agrees with the comment that turbidity excursions above 1.0 NTU do not necessarily indicate pathogen
breakthrough. Well pumping can generate turbidity within the aquifer that is unrelated to the surface
water turbidity. Thus, EPA requires that Systems report significant monthly average excursions above 1
NTU and assess their BF treatment system together with the State.
Ground Water Dilution - Most GWUDI wells pump a continuously varying percentage of surface water
mixed in with ground water from the landward side of the well. The ground water may have a long
subsurface residence time indicative of "true" ground water or it may be surface water with a slightly
longer residence time than the surface water which took the fastest and most direct path to the well.
Determining the percentage of this ground water surface water mixture requires an expensive
combination of stable and radiogenic isotope measurements, temperature assays and sophisticated,
coupled, heat and fluid flow, three dimensional ground water flow models. In the absence of high quality,
site-specific data, EPA guidance suggests that all GWUDI well water be considered to be recent surface
water, rather than using inferior data, such as total dissolved solids values to determine the relative
proportions.
Aerobic spores - EPA agrees with the statement that aerobic spores are currently identified as an
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appropriate and conservative indicator of Cryptosporidium removal, both in treatment plants and BF
systems. However, research is continuing in this area and other indicators may, in the future be
determined to have equal or greater value as a Cryptosporidium indicator. In today's Rule, EPA identifies
aerobic spores as one suitable measure of BF efficiency. With the support of EPA, AWWARF is funding
research to evaluate the use of aerobic spores and other indicators to evaluate BF efficiency. This research
is intended to include laboratory and field data collection under all river discharge conditons, as suggested
by one commenter. EPA disagrees with comments that suggest that measurement of some large surrogate
organisms has relevance to Cryptosporidium removal. Commenters suggest that algae removal (other than
the smaller diatoms) is relevant. Algal particles are large (larger than Cryptosporidium) and so are
relatively immobile under subsurface conditions because they are removed from ground water by
straining. EPA believes that the algae removal is relatively uninformative, similar to information about
the removal offish during surface water transport through the subsurface. Both are so large, compared
with Cryptosporidium, that their removal values are not very informative.
Flood scour - EPA agrees with the comment that monthly sampling is poorly indicative of transient flood
scour. Today's Rule requires continuous turbidity measurement to provide the most detailed evaluation of
flood scour effects. Continued high turbidity when discharge is decreasing after a storm event in a
BFsystems is an indicator that the protective biologically active layer is not completely reformed and BF
efficiency is degraded. Biological activity is not immediately restablished after scour and scour deposits
do not immediately have optimal removal performance because biological activity regrows with time.
EPA agrees with the comment that flood scour can be relatively short-lived and, in some localities, may
have little effect on bank filtration efficiency. One comment states that scour does not significantly
degrade BF efficiency at the Bolton Well Field near Cincinnati. EPA agrees that the high quality data
from Cincinnati shows that, at that site, scour is short-lived and relatively insignificant. However, the
Bolton Well Field is located in a very deep, buried valley aquifer system. It is not clear that any of the
ground water pumped at the Bolton Field is indeed coming from surface water because the aquifer is very
deep and transmissive and can supply the well with little induced flow from surface water. In fact, the
primacy agency does not consider the Bolton well field to be GWUDI. Buried valley aquifers are atypical
in the US and more high quality data are needed from other GWUDI hydrogeologic settings to fully
evaluate the effects of flood scour on BF efficiency.
Bank Filtration Guidance - EPA thanks the commenters for the detailed exposition on bank filtration
technical issues (based largely on the unpublished PhD work of Steve Hubbs) addressed as comments on
the draft Bank Filtration Guidance document. Bank filtration research is concluding a very active period.
To the extent possible, the guidance document will be updated to include as much of the new research as
possible.
Individual Comments on Code 770
EPA Letter ID: 562
Comment ID: 12443
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.2.4 Bank Filtration
AWWA is deeply concerned that the proposed rule and guidance being provided to states substantially
maligns bank filtration (BF), when in fact, BF is a valuable technology for the U.S. drinking water
community. The general tone
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Response: See response to Comment Code 770, paragraph Bank Filtration Value and Bank Filtration
Efficiency.
EPA Letter ID: 562
Comment ID: 12446
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: including literature cited by the agency in the proposal preamble demonstrate that both the
river bed and the aquifer are subject to filtration theory and effectively remove contaminants following
processes typical of fate and transport in porous media. Available data from Louisville and Cincinnati on
Response: See response to Comment Code 770, paragraph Filtration Theory.
EPA Letter ID: 562
Comment ID: 12450
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Bank filtration: A Natural Process
Bank filtration is defined by the guidance manual as a surface water pretreatment process using the bed
and bank of a river and the adjacent aquifer as a natural filter and relying solely on the natural properties
of the surface water bed and aquifer, unmodified by engineering works or activity, except for the recovery
of ground water via a pumping well. This definition of bank filtration characterizes this process by
emphasizing natural properties and filtration capacity of the surface water-bed and aquifer. However,
throughout the Federal Register and guidance manual, significantly less importance and information is
given to the aquifer as far as its capability to achieve natural contaminant removal. Bank filtration
includes physical, chemical, and biological mechanisms impacting transport and removal of contaminants
in porous media. Some specific characteristics of certain zones, such as the riverbed surface or interface,
should not overshadow the main characteristics of the aquifer itself. The peer-reviewed literature,
including literature cited by the agency in the proposal preamble, demonstrate that both the river bed and
the aquifer are subject to filtration theory and effectively remove contaminants following processes
typical of fate and transport in porous media.
AWWA recommends that EPA try to better understand BF through a comprehensive review of the
primary literature rather than relying on secondary references cited in the proposal. Appendix 5 provides
an extended discussion of BF as a filtration process and contains a listing of a number of primary peer
reviewed articles that the agency should review and use as it improves its characterization of BF in the
finalizing LT2ESWTR.
Response: See response to Comment Code 770, paragraph Today's Rule, Biofiltration, Bank Filtration
Scientific Literature, and Bank Filtration Efficiency.
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EPA Letter ID: 562
Comment ID: 12456
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Response
The numerous benefits of bank filtration are recognized throughout Europe and are an important tool to
improve water quality from some of the most heavily populated and industrialized waterways in the
developed world. Currently, the United States has not adopted bank filtration as widely. The absence of
the routine state determinations as described by primacy agencies illustrates why EPA should clearly
contemplate BF in the LT2ESWTR. Currently, primacy agency action regarding Cryptosporidium is
guided by the IESWTR and LT1ESWTR. Neither of these rules specifically addresses bank filtration
either in the rule language or in subsequent guidance. Consequently, primacy agencies are unlikely to
develop protocols or practices that are not clearly reflected in the federal rule structure. While the
numerous benefits of bank filtration are recognized throughout Europe and are an important tool to
improve water quality from some of the most heavily populated and industrialized waterways in the
developed world. The United States has not adopted bank filtration as widely.
Response: See response to Comment Code 770, paragraph Today's Rule and Bank Filtration in Europe.
EPA Letter ID: 562
Comment ID: 12457
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: As was noted in the previous request for comment, currently primacy agency action regarding
Cryptosporidium is guided by the IESWTR and LT1ESWTR. Neither of these rules specifically addresses
bank filtration either in the rule language or in subsequent guidance. Consequently, primacy agencies are
unlikely to develop protocols or practices that are not clearly reflected in the federal rule structure. This
dampening of individual state initiative results from federal regulation and is delaying development of
bank filtration in the United States.
Response: See response to Comment Code 770, paragraph Today's Rule.
8.7.1 Comment Codes 771, Credits and criteria for awarding credit
Individual Comments on Code 771
EPA Letter ID: 420
Comment ID: 14091
Commenter: Eddie Partlow, General Manager, THE OLD HICKORY UTILITY DISTRICT
Commenter Category: Regulated Community (Development): Housing, FEEP, NAHB
Other EPA Comment Codes and Descriptions: 241 1. Conventional treatment; 791 1. Credit and
criteria for awarding credit
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Comment: Included in the Agreement in Principle is a hearty list of alternatives to installation of UV
disinfection. In the preamble to the LT2ESWTR the level of treatment that can be achieved through
routine operation of softening, riverbank filtration, and conventional treatment is underrated. Due to that
fact, the proposed rule and associated guidance include overly stringent operational criteria that will cause
utilities to make unnecessary significant investment in new treatment technologies.
Response: See Responses 240.a and 240.c.
EPA Letter ID: 457
Comment ID: 11929
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Bank Filtration
We support inclusion of this tool and the 0.5 log and 1.0 log presumptive credits.
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 467
Comment ID: 11039
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: LWC also has comments on the proposed Cryptosporidium credit for bank filtration. The
proposed credit is inadequate given the demonstrated bank filtration performances cited by EPA. In
addition, there is no logical or scientific reason that bank filtration is less effective than slow sand
filtration. Wang et al (2002) showed that bank filtration has a much lower filtration rate and a much
longer filter depth (flow path) as compared with slow sand. As a result, bank filtration is at least as
effective as slow sand filtration, if not more. LWC requests EPA increase the credit for bank filtration to
the level of slow sand filtration.
Response: See response to Comment Code 770, paragraph Today's Rule, Filtration Theory and Bank
Filtration Efficiency.
EPA Letter ID: 485
Comment ID: 11302
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
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Comment: Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Bank filtration. The proposed rule would allow for !/> to 1 log removal credit to systems using a source
(well, horizontal or vertical) drilled in unconsolidated aquifers, that meet a distance criteria (25 and 50
feet respectively) from the surface water source and have a daily maximum turbidity of less than 1 NTU.
Response: The Department supports the requirements as outlined. However we
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 513
Comment ID: 11530
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: 6. Bank filtration
We support the proposal for bank filtration as a tool in the microbial toolbox. However, we believe the
proposed treatment credits are overly conservative. Systems may be able to make site-specific arguments
for treatment credit in excess of 0.5 or 1.0 log. The State should have the flexibility to make decisions
about treatment credits based on individual circumstances.
Response: See response to Comment Code 770, paragraph Todya's Rule and Bank Filtration Efficiency.
EPA Letter ID: 520
Comment ID: 11637
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Bank Filtration
IEPA generally supports inclusion of this tool and the 0.5 log and 1.0 log presumptive credits.
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 537
Comment ID: 14107
Commenter: Anonymous537,, Lincoln Water System
Commenter Category: Regulated Community (Utilities)
Comment: Comment: EPA is being overly conservative in granting only 1.0 logs of removal/inactivation
credit when in-progress Riverbank Filtration studies by Lincoln Water System and completed studies by
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Greater Cincinnati Water Works (AWWA Journal, December 2003) indicate as much as 4 log removals
of Cryptosporidium, Giardia and Aerobic Spores.
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 556
Comment ID: 12069
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: addition to Cryptosporidium removal and kill (by antagonistic organisms). AMWA supports
the 0.5 and 1.0 toolbox credits proposed by EPA as well as qualification of bank filtration as an upper bin
technology (UBT). Available
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 562
Comment ID: 12309
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.7 Bank Filtration
AWWA agrees with the proposed rule provisions (§141.726) that allow 0.5 or 1.0-log Cryptosporidium
credit (§141.726(c)720(b)) or upper bin technology credit (§141.726720(c)) to utilities that propose to
install bank filtration wells. In addition to these requirements, the agency should also explicitly
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 562
Comment ID: 12310
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: wells. In addition to these requirements, the agency should also explicitly provide for
demonstration of additional log credit using a test well. An appropriate study should be adequate to obtain
more flexible design criteria, siting, and greater log credit assignment.
Response: See response to Comment Code 770, paragraph Today's Rule.
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EPA Letter ID: 562
Comment ID: 12448
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: by bank filtration. As proposed, the log credit values are highly conservative, and
appropriately designed pilot- or full-scale tests could demonstrate greater log removal credit on a site-
specific basis.
Therefore, new BF installations should be allowed to conduct a site-specific study to demonstrate greater
log-removal credit. The option to conduct a
Response: Response 770 - paragraph on today's rule
EPA Letter ID: 562
Comment ID: 12452
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: LT2ESWTR Compliance Requirements
In the LT2ESWTR compliance requirements, systems that propose to install bank filtration wells to meet
any additional treatment requirements imposed by the LT2ESWTRmay be eligible for 0.5 or 1.0-log
Cryptosporidium removal credit (§141.726(c)). In addition to these requirements, the agency should
explicitly provide for demonstration of additional credit using a test well. Such a test well should be
accompanied by information characterizing the aquifer material. Presentation of a data package
summarizing the results
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 562
Comment ID: 12460
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The objective of pilot testing where a permanent production well is not yet installed is to
demonstrate that a site will result in more than the given 0.5 to 1.0-log removal given by nature of the
default credit.
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 624
Comment ID: 13181
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Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 6. The proposed LT2 is requiring establishment of bin classification for "existing" riverbank
filtration systems at the wellhead, whereas new systems desiring to install riverbank filtration are required
to monitor the surface water for bin classification. This creates an inequitable situation for a new system
Response: Today's Rule has explicit sample locations required for systems with and without existing
bank filtration pre-treatment in order to determine bin placement. For a system without bank filtration
pre-treatment, systems must sample the source water. For a system with existing bank filtration pre-
treatment, systems must sample the well water after bank filtration. Bank filtration practices at the time of
sampling must be consistent with routine operations. Systems with existing bank filtration may not
receive automatic treatment credit. EPA disagrees that these sampling locations are inequitable for new
systems. A new system may receive automatic credit prior to drilling a well if all requirements in Today's
Rule are satisfied. Alternatively, a new system with a drilled well must sample at the well after bank
filtration treatment, as required in Today's Rule. EPA believes that it would be inequitable to allow new
systems to receive bank filtration removal credit twice; once for automatic bank filtration removal credit
and again because systems sampling at the well results in benefits from the subsurface passage to the well
that defines a bank filtration system.
EPA Letter ID: 624
Comment ID: 13215
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: River Bank Filtration:
1. Definition of additional "filtration" needed when determining location of source sampling (surface
water versus wellhead)
When determining the location for Crypto sampling (surface water or wellhead), the term "additional
filtration" needs to be clarified and belter defined. It is our understanding that the intent is that additional
filtration at a lime softening facility means operating at a high pH (to obtain metal ion precipitation), and
treat 100% of the ground water (e.g. no split-treatment). Filtration at lime softening plants without
coagulation and bypassing water is not acceptable for automatically receiving a full 3.0 log credit for
Crypto removal (See softening comments).
Response: See response to Letter ID 624, Comment ID 13181. Bin placement is determined by sampling
at the well prior to softening for existing bank filtration systems. EPA disagrees that the definition of
addtional filtration in Today's Rule needs clarification because all sampling is conducted prior to
additional treatment.
EPA Letter ID: 624
Comment ID: 13216
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR 8-143 December 2005
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Comment: 2. Sampling for bin classification at the surface water versus the well head
The proposed LT2 is requiring establishment of bin classification for "existing" riverbank filtration
systems at the wellhead, whereas new systems desiring to install riverbank filtration are required to
monitor the surface water for bin classification. This creates an inequitable situation for a new system. For
example, existing systems could potentially receive greater than two-log automatic credit. (See the
attached diagram.) Utility "A" operates a well inducing recharge from "Dirty River". Previously the well
was designated GWUDISW due to hydrology and MPA, and has installed a conventional surface water
treatment plant.
[SEE PAGE 11 OF PDF FOR GRAPHIC OF RIVERBANK FILTRATION]
Utility "A" monitors for Crypto during its required 2-year monthly sampling period and has no detects.
This places utility "A" in Bin 1 requiring no additional treatment. Utility "B" has been using the river as
its source and after monitoring has found that the river's Crypto RAA is >3.0 oocysts/L requiring 5.5 log
reduction. Since they too have a conventional treatment plant but can only receive 3.0 log credit for it,
Utility "B" has to provide 2.5 log additional reduction. If they opt to install RBF they will only receive 1.0
log credit and must install another treatment technology to obtain an additional 1.5
log.
In this example, simply by sampling at the wellhead, Utility "A" has been automatically given an
"unrecognized" 2.5-log credit. USEPA needs to be consistent and either allow sampling at the wellhead
for ALL RBF systems (preferred) or assign automatic credit for ALL RBF systems and allow for
additional credit through demonstration studies.
Response: See response to Letter ID 624, Comment ID 13181. See response to Comment Code 770,
paragraph Today's Rule.
EPA Letter ID: 624
Comment ID: 13220
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 4. Need for Demonstration Studies
The GCWW strongly recommends that the USEPA provide for additional credit through RBF
demonstration projects. Data published to date has shown that RBF
The 1 log maximum automatic credit does nothing to encourage RBF even when data shows that it can be
a very robust method for pathogen and organic compound removal.
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 643
Comment ID: 12791
Comment Response for LT2ESWTR 8-144 December 2005
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Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Bank Filtration
States generally support inclusion of this tool and the 0.5 log and 1.0 log presumptive credits.
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 647
Comment ID: 12933
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Bank Filtration
MDE generally supports inclusion of this tool and the 0.5 log and 1.0 log presumptive credits.
Response: See response to Comment Code 770, paragraph Today's Rule.
8.7.1.1 Comment Codes 772, Aquifer type/core characteristics
Individual Comments on Code 772
EPA Letter ID: 470
Comment ID: 11083
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: removing Cryptosporidium or surrogates. We believe that the use of other methods, such as
ground penetrating radar to determine site suitability for bank filtration credit is appropriate to
complement, but not to supplant, core drilling. Additionally, we do not have any additional knowledge on
bank filtration that EPA requests.
Response: See response to Comment Code 770, paragraph Today's Rule.
8.7.1.2 Comment Codes 773, Separation distance
Individual Comments on Code 773
Comment Response for LT2ESWTR 8-145 December 2005
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EPA Letter ID: 556
Comment ID: 12073
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: separate from the toolbox demonstration of performance item. AMWA further recommends
that EPA eliminate all criteria placed on bank filtration that is not absolutely necessary for its successful
implementation, such as the requirement that it not be located within the 100-year flood plain.
Response: See response to Comment Code 770, paragraph 100 year Flood Plain Location.
EPA Letter ID: 562
Comment ID: 12458
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
Any additional information related suitable separation distance(s) to be required between vertical or
horizontal wells and adjacent surface water.
Response
The proposed criteria require new BF wells seeking credit under LT2ESWTR to be located outside the
100-year flood plain. The agency should recognize that currently wellheads can be located within the 100-
year floodplain and are readily designed and permitted. At many potential sites, the proposed separation
will preclude construction of wells with adequate safe yields needed to justify investment in BF systems.
Consequently, the proposed criteria are not engineering safeguards but rather provisions designed to limit
the applicability of BF. Given the conservative approach employed in
Response: See response to Comment Code 770, paragraph Today's Rule and 100 year Flood Plain
Location.
8.7.1.3 Comment Codes 775, Turbidity monitoring
Individual Comments on Code 775
EPA Letter ID: 467
Comment ID: 11042
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: For the monitoring requirements, Turbidity is to be monitored from each well head every four
hours as stated in the document. It is too frequent. Data from Louisville Water Company as well as many
other water utilities that have well systems show that the turbidity from well head does not change
rapidly. Daily monitoring is sufficient to monitor the well water quality conditions.
Comment Response for LT2ESWTR 8-146 December 2005
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Response: See response to Comment Code 770, paragraph Turbidity Monitoring.
EPA Letter ID: 513
Comment ID: 11532
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: EPA has requested comment on the applicability of turbidity monitoring or other process
monitoring procedures to indicate the ongoing performance of bank filtration processes.
The City of Kearney performs continuous combined filter effluent monitoring to verify that the
performance of bank filtration is within acceptable limits (in compliance with IESWTR).
Response: See response to Comment Code 770, paragraph Turbidity Monitoring.
EPA Letter ID: 562
Comment ID: 12464
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: between the stream and the observation wells. Turbidity and spore data can be effective
measures of particle removal for estimating Cryptosporidium removal. Appendix 1 includes an example
demonstration of BF removal using
Response: See response to Comment Code 770, paragraph Turbidity Monitoring, Bank Filtration
Efficiency and Bank Filtration Scientific Literature.
EPA Letter ID: 562
Comment ID: 12467
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Response
Turbidity monitoring at bank filtration system wellheads or at the combined effluent from a group of bank
filtration system wells is an appropriate monitoring procedure to monitor the ongoing performance of
bank filtration processes. Turbidities from BF systems are typically lower than the 0.3 NTU required for
engineered rapid sand and 1.0 NTU for engineered slow sand filtration.
Response: See response to Comment Code 770, paragraph Turbidity Monitoring.
Comment Response for LT2ESWTR 8-147 December 2005
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EPA Letter ID: 624
Comment ID: 13224
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 5. Use of turbidity as a monitoring tool
The GCWW concurs with the use of turbidity as a monitoring tool at RBF sites. We recommend that
continuous monitors be placed on each wellhead. Wells could be taken offline if turbidity exceeds 1
NTU. We feel that RBF systems should be able to meet the same slow sand filtration limit or better.
However, it is important to point out that excursions above 1.0 NTU do not necessarily indicate break
through of pathogens. Excursions may be the result of inert aquifer material being stirred up or sediment
breaking off the screens. If these excursions last for more than several hours they should be investigated
and identified using microscopic particulate analysis (mpa).
Response: See response to Comment Code 770, paragraph Turbidity Monitoring.
8.7.2 Comment Codes 780, Indicator/surrogate measurements
suitable for predicting removal
Individual Comments on Code 780
EPA Letter ID: 562
Comment ID: 12465
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: between the stream and the observation wells. Turbidity and spore data can be effective
measures of particle removal for estimating Cryptosporidium removal. Appendix 1 includes an example
demonstration of BF removal using spore data. Usually the impact of groundwater dilution of the stream
infiltrate at the production well limits the use of this well for estimating long-term particle removal, as
transient conditions may persist for months. Thus, the monitoring well closest to the stream source must
be large enough to produce a sample volume adequate for the desired analysis.
Request for Comment
Information on the data and methods suitable for predicting Cryptosporidium removal based on the
available data from surrogate and indicator measurements in water collection devices.
Response
Data reported in the literature for pilot-scale microbial spiking studies indicate that Cryptosporidium is
typically removed more readily than aerobic spores during physical treatment process such as clarification
and filtration. Appendix 2 is a report prepared by EET for AWWA that summarizes the relevant literature
demonstrating this point. Work by Neiminski and Bellamy (2000) [previously referenced], as well as
other literature summarized in Appendix 2, demonstrates that aerobic spores are naturally occurring in
surface waters and are readily monitored using available analytical methods. Other characteristics of
aerobic spores include:
1. Can be detected at very low concentrations (
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
2. Are about the same size as Cryptosporidium,
3. Do not undergo regrowth, and
4. Are frequently found at levels high enough to demonstrate removal.
Given these attributes, which are appropriate for evaluating removal processes, and that aerobic spores are
a conservative measure of removal, AWWA recommends that the agency explicitly recognize aerobic
spores as a surrogate measure in removal studies under the LT2ESWTR including processes like BF.
Response: See response to Comment Code 770, paragraph Turbidity Monitoring, Bank Filtration
Efficiency, Bank Filtration Scientific Literature, Today's Rule, Aerobic Spores and Ground Water
Dilution.
EPA Letter ID: 624
Comment ID: 13217
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: Also, if there is a true concern over the occurrence of scour and its implied cause of pathogen
breakthrough, monthly sampling at the wellhead is not going to detect these conditions. Scour resulting
from storm-related high river velocities is generally infrequent and short-lived. Data from a
comprehensive Flowpath Study in southwestern Ohio (Cincinnati) have suggested that storm events
causing high-river stage and high velocity occur less than 1% of the time. Their impact is also less than 24
to 48 hours in length in duration.
Response: See response to Comment Code 770, paragraph Flood Scour.
EPA Letter ID: 624
Comment ID: 13218
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 3. The impact of scour on streambed removal at RBF sites
The USEPA has not provided any positive proof that scour of the streambed, during a high-stage event,
causes the breakthrough of pathogens at RBF sites. To date it has only been speculation on their part. The
GCWW has previously stated that scour maybe a concern (Gollnitz, 1999 as referenced in LT2), however
more recent research has found that scour has little impact. The GCWW will be submitting a paper for
peer review and publication in early 2004 demonstrating that the impact is minimal at the GCWW Bolton
Well Field. It is believed that even though there maybe scour, the underlying sediments are capable of
removal of pathogens. We agree that scour needs to be investigated on a site-by-site basis. On rivers of
concern we recommend looking at
Response: See response to Comment Code 770, paragraph Flood Scour.
Comment Response for LT2ESWTR 8-149 December 2005
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EPA Letter ID: 624
Comment ID: 13223
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: removal. Demonstration projects can be designed to look specifically at concerns over scour
as deemed necessary.
Response: See response to Comment Code 770, paragraph Flood Scour.
8.7.3 Comment Codes 781, Alternative methods for determining site
suitability
Individual Comments on Code 781
EPA Letter ID: 562
Comment ID: 12455
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
The use of other methods (e.g., geophysical methods such as ground penetrating radar) to complement or
supplant core drilling to determine site suitability for bank filtration credit
Response
Development of wells for drinking water supplies is not a new science. Numerous standards apply to
development of bank filtration facilities. Bank filtration is a simple technology that the agency should
promote, and not hamper by associating it with inordinately difficult to obtain or expensive data
acquisition systems or analysis.
Response: See response to Comment Code 770, paragraph Hydrogeologic Assessment, Bank Filtration
Value, Today's Rule, and Bank Filtration Efficiency.
EPA Letter ID: 562
Comment ID: 12461
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Most utilities complete pumping tests prior to final wellfield design to develop aquifer
characteristics of conductivity and specific storage. These values, along with particle size distributions of
the aquifer at various depths, will provide a great deal of insight into the capability of the aquifer to filter
particles. Riverbed particle size distributions are also helpful in characterizing the BF system.
Response: See response to Comment Code 770, paragraph Hydrogeologic Assessment.
Comment Response for LT2ESWTR 8-150 December 2005
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EPA Letter ID: 562
Comment ID: 12463
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Temperature can be an effective parameter to estimate the time of travel between the stream
and the observation wells. Turbidity and spore data can
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency and Ground Water
Dilution.
8.7.4 Comment Codes 782, Data on effectiveness of bank filtration at
existing sites
Individual Comments on Code 782
EPA Letter ID: 458
Comment ID: 10978
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Page 47695 - Bank Filtration log reduction credit - Within West Virginia, bank filtration
wells, either horizontal (ranney wells) or vertical depending upon the alluvial setting, generally indicate
that the water obtained is often of higher quality (removal of Cryptosporidium or other contaminants)
than the raw surface water obtained. An important aspect is that the removal of contaminants in surface
water is important because when the water is chlorinated these contaminants can be converted to harmful
chemicals referred to as disinfection byproducts (DBFs). Another concern for human health effects is
from emerging water quality issues/contaminants from industry, agriculture, medical treatment, and even
common household conveniences that may be transported from the surface water body through the sand
to the wells and not filtered from the water.
Response: See response to Comment Code 770, paragraph Bank Filtration Value and Bank Filtration
Efficiency.
EPA Letter ID: 467
Comment ID: 11038
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: Issue 3: Bank Filtration of LT2ESWTR
EPA requests comments on the performance of bank filtration in removing Cryptosporidium or surrogates
Comment Response for LT2ESWTR 8-151 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
in the proposed rule. One of the comments LWC has is that EPA staff misinterpreted some of the
available research results. For example, the proposed rule stated that -using aerobic spores, Wang et al
(2001) measured 1.0 log removal of aerobic spores over a 48 foot distance from a monitoring well
beneath a river to a horizontal well lateral.- This interpretation is completely wrong and misleading.
Wang et al (2001) study demonstrated that 2.0 log removal during first 2 feet of bank filtration and 3
logs during first 50 feet. If the first 2 feet is stripped, the remaining 48 feet will still be able to produce 3
logs removal as most of the removal occurred during the first few feet. This misinterpretation requires
correction.
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency.
EPA Letter ID: 470
Comment ID: 11082
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Vermont does not have any information on the performance of bank filtration in removing
Cryptosporidium or surrogates. We believe that the use of other
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency.
EPA Letter ID: 470
Comment ID: 11084
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: drilling. Additionally, we do not have any additional knowledge on bank filtration that EPA
requests.
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency.
EPA Letter ID: 562
Comment ID: 12445
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Available data in the peer-reviewed literature has shown that BF can achieve greater than 1-
log removal of multiple surrogates, including algae, diatoms, spores, and the two size ranges (cyst and
oocysts) of particle counts. Turbidities resulting from BF are typically lower than the 0.3 NTU required
for engineered rapid sand and 1.0 NTU for engineered slow sand filtration.
Comment Response for LT2ESWTR 8-152 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency, Today's Rule and
Turbidity Monitoring.
EPA Letter ID: 562
Comment ID: 12447
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: transport in porous media. Available data from Louisville and Cincinnati on the removal of
spores or colloids demonstrate more than 3.0 or 4.0-log removal by bank filtration. As proposed, the log
credit values are highly conservative,
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency and Today's Rule.
EPA Letter ID: 562
Comment ID: 12454
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Response
Available data in the peer-reviewed literature has shown that BF can achieve greater than 1-log removal
of multiple surrogates, including algae, diatoms, spores, and the two size ranges of particle counts (cyst
and oocysts).
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency and Today's Rule.
EPA Letter ID: 624
Comment ID: 13221
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: through RBF demonstration projects. Data published to date has shown that RBF can achieve
greater than Hog removal of multiple surrogates, including algae, diatoms, spores, and the two size ranges
(cyst and oocysts) of particle counts. Turbidities are typically lower than the 0.3 NTU required for
engineered rapid sand and 1.0 NTU for engineered slow sand filtration.
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency, Today's Rule,
Turbidity Monitoring and Aerobic Spores.
EPA Letter ID: 624
Comment ID: 13225
Comment Response for LT2ESWTR 8-153 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 6. Research needs
As part of the overall adoption of the LT2 the USEPA needs to provide additional funding for research
projects investigating the agencies two primary concerns - streambed scour and pathogen spiking studies.
In the recent past USEPA, through its STAR grant program, has funded numerous column and sand tank
model studies. Unfortunately, limited funds have been made available to full-scale studies. Column
studies are "nice" but are difficult to extrapolate to full-scale. The USEPA needs to fund several studies
looking at methodologies for measuring scour and particle removal during periods of scour and high
infiltration. In addition, the agency needs to encourage the development of a method for conducting
spiking of Giardia, Crypto or microspheres along with other surrogates at or near the streambed interface
at several RBF sites. These data will help build confidence in using surrogates to demonstrate removal.
Response: See response to Comment Code 770, paragraph Aerobic Spores.
8.7.5 Comment Codes 783, Data on GWUDI systems using bank
filtration alone
Individual Comments on Code 783
EPA Letter ID: 513
Comment ID: 11531
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: EPA has requested comment on the number of GWUDI systems in each State where bank
filtration has been utilized as the primary filtration barrier, and the method used by the State to determine
that each system was achieving 2 log removal of Cryptosporidium.
As stated above, the City of Kearney utilizes bank filtration as the primary filtration barrier. The State
awarded 2 log removal of Cryptosporidium based on the results of continuous combined filter effluent
monitoring (in compliance with the IESWTR turbidity limits of 95% of measurements < 0.3 NTU, never
to exceed 1 NTU).
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency and Today's Rule,
Value of Bank Filtration, and Turbidity Monitoring.
Comment Response for LT2ESWTR 8-154 December 2005
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8.7.6 Comment Codes 785, Procedures for making site-specific
decisions on bank filtration credit
Individual Comments on Code 785
EPA Letter ID: 556
Comment ID: 12070
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: data supports higher levels of removal than proposed. Water systems should be able to
undertake a demonstration of performance that would qualify them for higher credit. AMWA members
Louisville and Cincinnati have provided the Agency data on the removal of spores or colloids that
demonstrate more than 3.0 or 4.0-log removal by bank filtration.
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency and Today's Rule.
EPA Letter ID: 556
Comment ID: 12072
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Recommendation: AMWA recommends that water systems be allowed to make a
demonstration of higher log removals at their location. This demonstration should be based on test wells
at the future bank filtration location and be separate from the toolbox demonstration of performance item.
AMWA further
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency and Today's Rule.
EPA Letter ID: 562
Comment ID: 12449
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: by bank filtration. As proposed, the log credit values are highly conservative, and
appropriately designed pilot- or full-scale tests could demonstrate greater log removal credit on a site-
specific basis.
Therefore, new BF installations should be allowed to conduct a site-specific study to demonstrate greater
log-removal credit. The option to conduct a demonstration should be explicitly stated in the regulatory
language, preamble, and associated guidance manual. Such demonstration should not be limited to 0.5
or 1.0 log credit and should not be restricted by the distance measurements identified in §141.726(c). The
demonstration study should be based upon sound engineering practice appropriate to the construction of a
Comment Response for LT2ESWTR 8-155 December 2005
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BF facility (be it vertical, angled, or horizontal well system) with a reliable safe yield, appropriate water
quality, and reliably maintained operation.
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency, 100 year Flood
Plain Location and Today's Rule.
EPA Letter ID: 562
Comment ID: 12453
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: LT2ESWTR Compliance Requirements
In the LT2ESWTR compliance requirements, systems that propose to install bank filtration wells to meet
any additional treatment requirements imposed by the LT2ESWTRmay be eligible for 0.5 or 1.0-log
Cryptosporidium removal credit (§141.726(c)). In addition to these requirements, the agency should
explicitly provide for demonstration of additional credit using a test well. Such a test well should be
accompanied by information characterizing the aquifer material. Presentation of a data package
summarizing the results from such a study should be adequate to achieve substantial flexibility in
the:
1. Design of the collector system employed (i.e., type of collector, well depth, etc.),
2. Siting of the collection facility (i.e., location in the floodplain), as well as
3. Assignment of greater log removal credit.
AWWA is concerned that the current guidance on BF is incomplete with respect to the above issue of
pilot wells. We have several recommendations on BF testing protocols and procedures below, as well as
in Appendix 1. EPA should work with AWWA and other stakeholders to improve the guidance for bank
filtration and for studies employing test wells as proposed above.
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency, Today's Rule and
100 year Flood Plain Location.
EPA Letter ID: 562
Comment ID: 12459
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: limit the applicability of BF. Given the conservative approach employed in the BF default
credit criteria, the rule and guidance should clearly provide for the conduct of appropriate studies to
demonstrate as much as 5.5-log removal. Such demonstrations should be allowed using pilot well or full-
scale facilities. The opportunity to demonstrate performance at sites with less separation from the water
body than reflected in the default credits is essential.
Response: See response to Comment Code 770, paragraph Today's Rule.
Comment Response for LT2ESWTR 8-156 December 2005
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EPA Letter ID: 562
Comment ID: 12462
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: If additional demonstration of Cryptosporidium removal is desired, it may be feasible to
extend the pumping test with additional observation wells located along the shortest flowpath to the
stream. Given the aquifer characteristics, estimating the time of travel along this flowpath to the
observation wells and production well is possible. At the point in time where this flowpath is indicating
the influence of river water, water quality characteristics can be monitored to gain an indication of the
aquifer's ability to remove particles.
Response: See response to Comment Code 770, paragraph Today's Rule.
EPA Letter ID: 562
Comment ID: 12466
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: In finalizing the LT2ESWTR, EPA should not, however, foreclose the use of other analytical
methods to demonstrate removal. Some source waters do not contain enough naturally occurring aerobic
spores to demonstrate the levels of removal required by the LT2ESWTR. Consequently, the agency
should be open to considering demonstrations based on other types of surrogates such as turbidity,
particle counts, or another microbial indicator.
Response: See response to Comment Code 770, paragraph Bank Filtration Efficiency, Today's Rule,
Hydrogeologic Assessment, Ground Water Dilution and Aerobic Spores.
8.7.7 Comment Codes 786, Rule Language Edits
Individual Comments on Code 786
EPA Letter ID: 562
Comment ID: 12451
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Scouring
Based on the preamble language, scour is a significant issue for EPA. Scour and fill are two processes that
take place when flooding occurs and should not be analyzed separately, but as a combined natural
process. Through these scour and fill processes, some sediment is removed and some deposited on the
riverbed. In some cases, this process will lead to temporary exposure of the river-bed subsurface, but it
will also lead to new sediments being laid over the river-bed subsurface. In fact, scouring and fill should
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be described as a natural and automatic regeneration of the riverbed interface or riverbed. Scour and fill
are a pair of activities that together are beneficial to the BF process when a facility is appropriately sited,
allowing BF to achieve good water production both in terms of quality and quantity. Appendix 5 provides
an extended discussion of scour and fill phenomena and relate these processes to BF. EPA underestimates
the aquifer removal potential providd by the aquifer in the temporary absence of the interface as described
in Appendix 5.
Response: See response to Comment Code 770, paragraph Flood Scour.
8.7.8 Comment Codes 787, Guidance
Individual Comments on Code 787
EPA Letter ID: 467
Comment ID: 11041
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: The document also defines the characteristics of a bank filtration system that is eligible for
removal credit consideration. LWC assumes EPA wants to exclude certain type of design (e.g. infiltration
gallery and spring boxes). It is fine to do so. However, it is not appropriate to state that -Only horizontal
and vertical wells are eligible-. As we all know, there are more design types available as technologies
advance. For example, the inclined wells using directional drilling are no different from horizontal or
vertical wells for bank filtration. Therefore, it is recommended that EPA defines what unacceptable
designs are specifically, instead of defining what is acceptable.
Also, the horizontal distance of 25 feet and 50 feet (between the well location and the surface water
source) does not mean anything according LWC experience. It is the flow paths that matter the most for
removing the microbial contaminants. If there is a layer of clayey soil between the water source and
the well, the shortest flow path will be much longer than a straight line calculation. Therefore, it is
recommended that EPA modifies the language of-distance- to -flow path distance-.
Response: See response to Comment Code 770, paragraph Bank Filtration Guidance.
EPA Letter ID: 624
Comment ID: 13222
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: The GCWW has suggested guidance by providing a draft method for demonstrating effective
RBF. This guidance was provided at the Second International Conference on Riverbank Filtration in
Cincinnati in September 2003 as well as at the AWWA Water Quality Technology Conference held in
Philadelphia in November 2003. The guidance provides for evaluating RBF systems during periods of
high infiltration using multiple lines of evidence of particle removal. Demonstration projects can be
designed to look specifically at
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Response: See response to Comment Code 770, paragraph Bank Filtration Guidance.
8.8 Comment Codes 790, Lime Softening
Summary of Issues
In regard to the types of lime softening processes eligible for treatment credit, commenters recommended
that EPA better define two-stage softening. Commenters stated that two-stage softening involves two
separate reaction chambers with the addition of the softening chemical at the beginning of each chamber.
Some commenters recommended that eligibility for additional treatment credit should be based on the
level of softening precipitate formed or the settled water turbidity and not on whether a plant practices
single- or two-stage softening. Another commenter recommended that any plant designs with multiple,
continuously operated clarification processes in series should be eligible for additional treatment credit.
With respect to the amount of additional Cryptosporidium treatment credit for two-stage softening, most
commenters supported awarding 3.0-log treatment credit to single-stage lime softening, equivalent to a
conventional treatment plant, and an additional prescribed 0.5-log treatment credit for two-stage lime
softening. A few commenters requested that two-stage lime be granted an additional Cryptosporidium
treatment credit of 1.0-log, based on the level of aerobic spore removal measured across softening
clarifiers.
Commenters stated that achieving particle removal in lime softening is not dependent on a coagulant like
a metal salt or organic polymer. Some commenters recommended that coagulant be defined to include
softening chemicals like lime and magnesium hydroxide (a softening precipitate).
Response to Code 790
EPA has refined the definition of two-stage softening in the final LT2ESTWR rule, which requires that
softening processes employ chemical addition and hardness precipitation in two sequential stages to be
eligible for the prescribed additional treatment credit. EPA agrees with commenters that the level of
precipitate formation will influence the degree of Cryptosporidium removal. Available data, however,
indicate that two-stage softening will generally achieve more Cryptosporidium removal than single-stage
softening. Consequently, EPA believes that two-stage softening should be eligible for the additional
prescribed 0.5-log treatment credit. Plants with single-stage softening may receive additional treatment
credit under the LT2ESWTR through a demonstration of performance. Similarly, plants that employ
multiple clarification process other than softening in series may receive additional treatment credit either
as presedimentation or through a demonstration of performance.
EPA agrees with most commenters and the SAB that 0.5-log is an appropriate level of additional
prescribed Cryptosporidium treatment credit for two-stage softening. Where plants are able to
demonstrate a significantly higher level of removal of Cryptosporidium or an indicator like aerobic
spores, they may apply for additional treatment credit through a demonstration of performance.
EPA agrees with commenters that available data do not demonstrate the need for a traditional metal salt
or organic coagulant for effective particle removal in softening. Accordingly, the final LT2ESTWR does
not require the use of a coagulant as a condition for additional treatment credit in two-stage softening.
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Instead, each stage must involve chemical addition and hardness precipitation. EPA intends this
requirement to ensure that softening and associated particle removal occur in each stage if a plant is to
receive additional treatment credit for two-stage softening.
Individual Comments on Code 790
EPA Letter ID: 451
Comment ID: 14161
Commenter: Eric Abrams, Superintendent, McMinnville Water and Light
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 800 H. Combined Filter Performance; 930 P. Individual
Filter Performance; 950 Q. Other Demonstration of Performance
Comment: Comments #3: McMinnville Water and Light would like the EPA to consider re-evaluating
data already available with the objective of assigning sound, operationally achievable, treatment credit for
Cryptosporidium removal such as softening enhanced filtration and demonstrations of performance.
Response: EPA agrees with most commenters and the SAB that 0.5-log is an appropriate level of
additional prescribed Cryptosporidium treatment credit for two-stage softening. Where plants are able to
demonstrate a significantly higher level of removal of Cryptosporidium or an indicator such as aerobic
spores,they may apply for additional treatment credit through a demonstration of performance. See
Response 950.
8.8.1 Comment Codes 791, Credit and criteria for awarding credit
Individual Comments on Code 791
EPA Letter ID: 101
Comment ID: 10889
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Lime Filtration
Information in the proposed rule supports a 1 log credit for lime softening plants and additional 1 log
credit for two-stage softening.
Response: See Response 790. EPA believes the data only support the 0.5 log Cryptospordium removal
credit for two stage lime softening in the final LT2ESWTR. Systems may demonstrate higher
Cryptosporidium removals with the Demonstraion of Performance toolbox option.
EPA Letter ID: 420
Comment ID: 14091
Commenter: Eddie Partlow, General Manager, THE OLD HICKORY UTILITY DISTRICT
Commenter Category: Regulated Community (Development): Housing, FEEP, NAHB
Other EPA Comment Codes and Descriptions: 241 1. Conventional treatment; 771 1. Credits and
criteria for awarding credit
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Comment: Included in the Agreement in Principle is a hearty list of alternatives to installation of UV
disinfection. In the preamble to the LT2ESWTR the level of treatment that can be achieved through
routine operation of softening, riverbank filtration, and conventional treatment is underrated. Due to that
fact, the proposed rule and associated guidance include overly stringent operational criteria that will cause
utilities to make unnecessary significant investment in new treatment technologies.
Response: See Responses 240.a and 240.c.
EPA Letter ID: 457
Comment ID: 11928
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Lime Softening
We support inclusion of this tool and the 0.5 log presumptive credit.
Response: See Response lOOa.
EPA Letter ID: 470
Comment ID: 11085
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 801 1. Credit and criteria for awarding credit; 821 1.
Credit and criteria for awarding credit; 891 1. Credit and criteria for awarding credit; 9111. Credit and
criteria for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment
requirements
Response: See Response lOOa.
EPA Letter ID: 485
Comment ID: 11304
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department concurs with EPA-s proposal of granting an additional 0.5 log
credit for a two-stage softening plant that meets the associated criteria in the proposed rule based on the
studies presented by EPA. Two
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Response: See Response lOOa.
EPA Letter ID: 485
Comment ID: 11307
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: The Department does not have additional information to either support or suggest
modifications to the proposed criteria and credit.
Response: See Response lOOa.
EPA Letter ID: 502
Comment ID: 10637
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: Lime softening:
1. The City of Columbus supports the 3-log credit for single stage softening and an additional 0.5-log
credit for second stage softening. Our spore formation data, which we have collected since 1995, supports
that we can achieve at least an additional 0.5-log reduction of spores.
2. The scientific literature shows Cryptosporidium is typically removed more efficiently than aerobic
spores under the same conditions. Therefore, the relative removal of aerobic spores during physical
removal processes is a conservative estimator of Cryptosporidium removal during the process. It seems
reasonable that if a system can verify through spore reduction that they can achieve greater than 0.5-log
reduction that they should be granted the increased log reduction. Since 1995, one of our surface water
two-stage lime softening plants has consistently shown greater than 1.0-log spore reduction; therefore,
they could potentially be granted 1.0-log credit for their second stage softening - and we assert that this
should be the case.
[See table, page 3 of PDF]
Response: See Response lOOa.
EPA Letter ID: 520
Comment ID: 11636
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
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Comment: Lime Softening
IEPA generally supports inclusion of this tool and the 0.5 log presumptive credit.
Response: See Response lOOa.
EPA Letter ID: 534
Comment ID: 12002
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: As one of the water systems that provided the data supporting inclusion of 2-Stage lime
softening, Kansas City, Missouri clearly supports the additional 0.5 log credit for two-stage softening.
Kansas City encourages EPA to further
Response: See Response lOOa.
EPA Letter ID: 538
Comment ID: 14101
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: Comment Five:
The EPA is proposing the awarding of credit to systems that provide 2 stage softening, (page 47696).
The City of Wichita Falls disagrees with the EPA-s stance on this matter.
Third, the EPA indicates that two-stage softening plants have the potential for additional Cryptosporidium
removal because of additional sedimentation process. Yet, it states in the same paragraph that
contaminates coalesce with the precipitates which are then removed by settling and filtration. The City
of Wichita Falls believes that the removal occurs with the adsorption of Cryptosporidium into the
softening precipitate and not the settling process. Even if the softening precipitate, with the incorporated
Cryptosporidium, did not settle in the basin it has been destabilized and will be removed at the filtration
stage. Therefore, basing removal credit on additional settling is fundamentally incorrect. It should be
based on the level of precipitate formation, i.e. Magnesium removal and/or enhanced Calcium removal.
The EPA further bolsters this with their publication of Virus Removal in Lime Softening Plants (circa
1980), that states virus removal is accomplished by the -adsorption of the virus into the chemical
precipitate-. The process of incorporating Cryptosporidium into the chemical precipitate is fundamentally
the same.
Finally, the City of Columbus study the EPA is using for validation of this component of the LT2 should
be classified as a Single-Stage Softening plant because it adds the softening chemical in only one of the
clarifiers. If the EPA accepts the demonstrated removal of the Columbus plant as a basis for validating
the proposed credit established in the LT2, then the proposed credit should extend to Single-Stage
Softening plants because that is what the Columbus plant is utilizing. This further supports the City of
Wichita Falls- stance stated in the paragraph above, that it is not settling that removes the
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Cryptosporidiumbut rather the adsorption into the chemical precipitate.Therefore, the City of Wichita
Falls formally requests that the proposed log credit of 0.5 be extended to single-stage softening systems.
Response: EPA agrees with most commenters and the SAB that 0.5-log is an appropriate level of
additional prescribed Cryptosporidium treatment credit for two-stage softening. Where plants are able to
demonstrate a significantly higher level of removal of Cryptosporidium or an indicator like aerobic
spores, they may apply for additional treatment credit through a demonstration of performance.
EPA Letter ID: 561
Comment ID: 12233
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 7. Lime Softening
This Utility utilizes the lime softening for a turbid water supply with very high algae counts in the
summer. It is our experience that this process is very effective in turbidity and suspended solids removal,
with our settled turbidity constantly below 2 NTU. While we do not have supportive data on oocyst
removal efficiency, we do have sufficient data to support our experience with turbidity removal and are
supportive of at least a .5 log treatment credit for lime softening.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12420
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 7. Single-stage lime softening, i.e., a single clarification stage followed by conventional
filtration, is suitable for at least a 3.0 log baseline credit, identical to the credit assigned to other
combined clarification plus filtration technologies.
This analysis and these findings provide an important factual basis for the recommendations AWWA
offers in the following comments. AWWA-s review includes both research and data identified in the
LT2ESWTR proposal. AWWA believes the analysis in Appendix 1 and reflected in these comments more
correctly reflects the performance of some of these treatment technologies than the discussion provided in
the Federal Register notice and Microbial Toolbox Guidance. In addition to the literature and analysis
presented in Appendix 1 and Appendix 2, AWWA will also provide information and analysis with respect
to watershed control programs, bank filtration, ozone disinfection and UV disinfection.
4.2.1 Regulatory -Preference- vs. Agreement in Principle
Response: See Response lOOa.
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EPA Letter ID: 562
Comment ID: 12421
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 8. Two-stage lime softening (a second clarification stage added to single-stage softening) is
suitable for a total Cryptosporidium removal credit of at least 3.5 log, consistent with a 0.5 log
toolbox credit added for the second clarification stage.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12422
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 9. Two-stage lime softening preceded by a pre-sedimentation basin provides at least 4.0 log
Cryptosporidium removal, consistent with a 0.5 log credit for pre-sedimentation and a 0.5 log credit for
the second clarification stage.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12423
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 10. Log removals cited for lime softening are not dependent upon addition of a coagulant,
such as organic polymer or a metal salt
Response: See Response 790.
EPA Letter ID: 562
Comment ID: 12489
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA has appropriately and accurately summarized the available literature. Available data
indicate that a typical single-stage softening process routinely provides as much, or more, ryptosporidium
removal as traditional coagulation-clarification-filtration treatment processes. Consequently, drinking
water treatment plants that practice lime softening should achieve an average 3-log removal of
Cryptosporidium, as was assumed for other clarification and filtration treatment (-conventional-) plants
in the Bin Requirements Table of the Stage 2 M/DBP Agreement in Principle. When a secondary
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clarification step is included in a treatment process, such as with two-stage softening, available data
suggest that the second clarification step provides increased redundancy and stability to the treatment
train, plus an additional treatment barrier to the passage of protozoa into the potable water supply.
Consequently, an additional 0.5-log credit is appropriate for two-stage softening and other plant designs
that employ multiple, continuously operated, clarification processes in series.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12491
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The rule language also indicates that the coagulant may be excess lime or magnesium
hydroxide. This list of conditions is sound and appropriate assuming that the demonstration of
performance provisions of the proposal are workable in the final rule, so that utilities that only employ
single-stage softening are afforded an opportunity to demonstrate greater removals than the assumed 3-
log equivalent to conventional coagulation-flocculation-filtration. It would be helpful if the table in
§141.722 could be rewritten to parallel this text. The proposal text in the table calls for -coagulant
addition- only; alternative text might be -coagulant (i.e., alum, ferric chloride, lime, or magnesium
hydroxide, etc.).-
Response: EPA agrees that available data do not demonstrate the need for a traditional metal salt or
organic coagulant for effective particle removal in softening. The final LT2ESWTR does not require the
use of a coagulant as a condition for additional treatment credit in two-stage softening. Instead, each stage
must involve chemical addition and hardness precipitation.
EPA Letter ID: 562
Comment ID: 12492
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Response to Requests for Comment, 68 FR 47697 §IV(C)(7)(c)
The agency requests comment on the following issues concerning softening on page 47697 of the
proposed rule:
Request for Comment
Whether the information and analyses presented in this proposal supports an additional 0.5-log credit for
two-stage softening, and the associated criteria necessary for credit.
Response
EPA has appropriately and accurately summarized the available literature. Available data indicate that a
typical single-stage softening processes routinely provides as much or more Cryptosporidium removal as
traditional coagulation-clarification- filtration treatment processes. Consequently, drinking water
treatment plants that practice lime softening should achieve an average 3-log removal of
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Cryptosporidium, as was assumed for other clarification and filtration treatment (-conventional-) plants
in the Bin Requirements Table of the Stage 2 M/DBP Agreement in Principle. When a secondary
clarification step is included in a treatment process, such as with two-stage softening, available data
suggest that the second clarification step provides increased redundancy and stability to the treatment
train. It also provides an additional treatment barrier to the passage of protozoa into the potable water
supply. Consequently, an additional 0.5-log credit is appropriate for two-stage softening and other plant
designs that employ multiple, continuously operated, clarification processes in series.
Response: See Response lOOa.
EPA Letter ID: 620
Comment ID: 13305
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: The restriction of the lime softening credit to two-stage softening will also hurt SPRWS
ability to use the toolbox. Again, this seems to negate the progress some utilities have made in improving
their treatment operations in terms of settled water turbidity. The Partnership does not differentiate
between single stage and two stage softening, but the EPA has chosen to do so, to the detriment
of those who operate the former.
Response: Available data indicate that two-stage softening will generally achieve more Cryptosporidium
removal than single-stage softening. Consequently, EPA believes that two-stage softening should be
eligible for the additional prescribed 0.5-log treatment credit. Plants with single-stage softening may
receive additional treatment credit under the LT2ESTWR rule through a demonstration of performance.
EPA Letter ID: 624
Comment ID: 13212
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: Softening:
a. We support granting a 3-log credit for single stage softening and an additional 0.5-log credit for second
stage softening. The data would support these credits.
Response: See Response lOOa.
EPA Letter ID: 624
Comment ID: 13213
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
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Comment: b. Please clarify your coagulant definitions as applied to excess lime and magnesium
hydroxide. Does this imply that utilities using just lime are not eligible for credits?
Response: EPA has refined the definition of two-stage softening in today's final rule, which requires that
softening processes employ chemical addition and hardness precipitation in two sequential stages to be
eligible for the prescribed additional treatment credit.
EPA Letter ID: 624
Comment ID: 13214
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: c. The LT2 document states that lime-softening plants achieve a level of Crypto removal
equivalent to a conventional plant (i.e. 3.0 log). Clarification is needed as to the type of configuration
required to achieve this credit. It is our understanding that lime-softening plants must provide coagulation
either by excess lime (with precipitation of metal ions) or by adding an iron coagulant. Also, 100% of the
ground water must receive treatment (e.g. no split treatment for recarbonation).
Response: EPA has refined the definition of two-stage softening in the final LT2ESWTR, which requires
that softening processes employ chemical addition and hardness precipitation in two sequential stages to
be eligible for the prescribed additional treatment credit.
EPA Letter ID: 643
Comment ID: 12790
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Lime Softening
States generally support inclusion of this tool and the 0.5 log presumptive credit.
Response: See Response lOOa.
EPA Letter ID: 647
Comment ID: 12932
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Lime Softening
MDE generally supports inclusion of this tool and the 0.5 log presumptive credit.
Response: See Response lOOa.
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EPA Letter ID: 699
Comment ID: 14776
Commenter: David A. Visintainer, Water Comissioner, City of Saint Louis
Commenter Category: Regulated Community (Utilities)
Comment: 2. Section IV.C.7.C (page 47697) - We believe that aerobic spores are an extremely
conservative indicator for the removal of cryptosporidium oocysts in a treatment process or facility. This
was demonstrated, for example, in a comparison study of pilot plant lime softening removals of aerobic
spores and oocysts by Clarke, et al, in Austin, Texas. EPA has previously been provided the results of this
study. Based on the aerobic spore removal data submitted previously to EPA for ours and other lime
softening plants, as well as the high degree of conservatism entailed with the use of aerobic spore removal
as an indicator, we believe that two-stage lime softening plants should be granted a toolbox credit of 1
log.
Response: EPA agrees with most commenters and the SAB that 0.5-log is an appropriate level of
additional prescribed Cryptosporidium treatment credit for two-stage softening. Where plants are able to
demonstrate a significantly higher level of removal of Cryptosporidium or an indicator such as aerobic
spores, they may apply for additional treatment credit through a demonstration of performance.
8.8.2 Comment Codes 792, Additional data on lime softening
Individual Comments on Code 792
EPA Letter ID: 485
Comment ID: 11306
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: criteria in the proposed rule based on the studies presented by EPA. Two treatment plants
(Columbus Plant 1 and Columbus Plant 2) in the second studies (Dugan et al. 2001) are actually one-stage
lime softening plants with the first stage clarifier acting as a conventional clarifier (alum coagulation) and
the second stage clarifier for lime softening. They do not meet the typical definition for a two-stage
softening plant. The Department recommends modifying
Response: EPA appreciates the comment. EPA has refined the definition of two-stage softening in
today's final rule, which requires that softening processes employ chemical addition and hardness
precipitation in two sequential stages to be eligible for the prescribed additional treatment credit.
EPA Letter ID: 534
Comment ID: 12003
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
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Comment: log credit for two-stage softening. Kansas City encourages EPA to further investigate the
effects of high pH (i.e. pH> 11) on the viability/activity of Cryptosporidium.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12490
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA specifically asks for any new or additional information that would contribute to the
softening log removal credit. Several full-scale softening facilities have ongoing monitoring programs
whose data has been collected over the last year. Appendix 1 contains a summary of these data. Initial
findings from this data collection effort are reflected in a recently published article.
Addition of a Coagulant
Section 141.726(b) provides for a 0.5-log credit for two-stage lime softening
if:
1. A second clarification step is located between the primary
clarifier and filter(s), and
2. This second clarification step is operated continuously, and
3. Both clarifiers treat all of the plant flow, and
4. A coagulant is present in both clarifiers.
Response: EPA agrees with most commenters and the SAB that 0.5-log is an appropriate level of
additional prescribed Cryptosporidium treatment credit for two-stage softening. Where plants are able to
demonstrate a significantly higher level of removal of Cryptosporidium or an indicator like aerobic
spores, they may apply for additional treatment credit through a demonstration of performance.
EPA Letter ID: 699
Comment ID: 14777
Commenter: David A. Visintainer, Water Comissioner, City of Saint Louis
Commenter Category: Regulated Community (Utilities)
Comment: 2. Section IV.C.7.C (page 47697) - We believe that aerobic spores are an extremely
conservative indicator for the removal of Cryptosporidium oocysts in a treatment process or facility. This
was demonstrated, for example, in a comparison study of pilot plant lime softening removals of aerobic
spores and oocysts by Clarke, et al, in Austin, Texas. EPA has previously been provided the
Response: EPA agrees with most commenters and the SAB that 0.5-log is an appropriate level of
additional prescribed Cryptosporidium treatment credit for two-stage softening. Where plants are able to
demonstrate a significantly higher level of removal of Cryptosporidium or an indicator such as aerobic
spores, they may apply for additional treatment credit through a demonstration of performance.
Comment Response for LT2ESWTR 8-170 December 2005
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8.8.3 Comment Codes 793, Rule Language Edits
Individual Comments on Code 793
EPA Letter ID: 485
Comment ID: 11305
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: criteria in the proposed rule based on the studies presented by EPA. Two treatment plants
(Columbus Plant 1 and Columbus Plant 2) in the second studies (Dugan et al. 2001) are actually one-stage
lime softening plants with the first stage clarifier acting as a conventional clarifier (alum coagulation) and
the second stage clarifier for lime softening. They do not meet the typical definition for a two-stage
softening plant. The Department recommends modifying the term -two-stage lime softening- to -lime
softening process with multiple clarifiers- or other terms to avoid confusion.
Response: EPA appreciates the comment. EPA has refined the definition of two-stage softening in
today's final rule, which requires that softening processes employ chemical addition and hardness
precipitation in two sequential stages to be eligible for the prescribed additional treatment credit.
EPA Letter ID: 538
Comment ID: 14102
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: First, the definitions provided by the EPA for single-stage and two-stage softening are
incorrect. Single-Stage softening is where you only have one reaction chamber and one addition of the
softening chemical. Two-Stage Softening is where you have 2 separate reaction chambers and the
addition of the softening chemical at the beginning of each chamber. These definitions should be changed
to reflect thecorrect definition.
Response: EPA has refined the definition of two-stage softening in the final LT2ESWTR, which requires
that softening processes employ chemical addition and hardness precipitation in two sequential stages to
be eligible for the prescribed additional treatment credit
EPA Letter ID: 603
Comment ID: 12663
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47788) Section 141.730(e)-
In the table titled Microbial Toolbox Reporting Requirements, toolbox option (4) should read "Two- stage
lime softening" not "two-sage".
Response: See Response lOOa.
Comment Response for LT2ESWTR 8-171 December 2005
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8.9 Comment Codes 800, Combined Filter Performance
Comment Summary
Most commenters supported awarding 0.5-log additional Cryptosporidium treatment credit for PWSs that
achieve at least 95 percent of CFE turbidity measurements less than or equal to 0.15 NTU. A few
commenters, however, recommended that PWSs only receive additional treatment credit for
demonstrating this level of turbidity performance in each individual filter effluent (IFE), rather than the
CFE. In addition, one commenter stated that PWSs should be required to monitor CFE turbidity every 15
minutes, rather than every four hours as required under current regulations. One commenter summarized
additional studies that provide data on the improvement in Cryptosporidium removal efficiency at lower
filter effluent turbidity levels. According to this commenter, these studies demonstrate that lowering filter
effluent turbidity from 0.3 to 0.15 NTU translates to an improvement in Cryptosporidium removal of
more than 1.5-log, with individual studies showing a range of >0.7-log to >3-log based on median
removal.
Response to Code 800
EPA agrees with the recommendation of most commenters and has established additional
Cryptosporidium treatment credit based on meeting a 95th percentile turbidity level of 0.15 NTU in the
CFE. EPA recognizes, however, that achieving low turbidity in each IFE may represent a higher level of
performance than achieving low turbidity in the CFE. EPA has also established standards for additional
Cryptosporidium treatment credit based on low IFE turbidity in the final LT2ESWTR. EPA does not have
data indicating that PWSs should monitor the CFE turbidity at a higher frequency than every four hours,
as required under existing regulations. Consequently, EPA is not changing the frequency of required CFE
turbidity monitoring as a condition for PWSs to receive additional treatment credit under today's rule.
EPA finds that additional studies submitted by a commenter bolster the conclusion that PWSs operating
to meet 0.15 NTU in the filter effluent will achieve at least 0.5-log greater Cryptosporidium removal than
PWSs operating to meet 0.3 NTU. Thus, they support the additional 0.5-log Cryptosporidium treatment
credit under the final LT2ESTWR for PWSs meeting 0.15 NTU at the 95th percentile in the CFE.
Individual Comments on Code 800
EPA Letter ID: 441
Comment ID: 10777
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 930 P. Individual Filter Performance
Comment: Treatment performance toolbox options
Since 1988, DEP has worked closely with filtered surface water systems using special programs like
Filter Plant Performance Evaluations. In the mid-1990's, DEP became a regional partner in the
Partnership for Safe Water to encourage water suppliers to voluntarily optimize treatment, produce
turbidity levels that were better than the treatment technique requirements, and ultimately improve public
Comment Response for LT2ESWTR 8-172 December 2005
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health protection. DEP supports the turbidity performance incentives provided in LT2 as a means
of improving the removal of waterborne pathogens. National programs such as the Area Wide
Optimization Program (AWOP) have demonstrated the efficiency of training water supply operators and
optimizing existing facilities as a lower-cost alternative to protecting public health. AWOP has developed
a freeware program called "Optimization Assessment Software" that suppliers may wish to use when
implementing the toolbox option for the combined filter effluent and individual filter performance.
Overall, the treatment performance toolbox options will give suppliers additional flexibility to choose the
option that best suits their current treatmentscenarios.
Response: See Response lOOa, Response 800 and Response 930.
EPA Letter ID: 451
Comment ID: 14161
Commenter: Eric Abrams, Superintendent, McMinnville Water and Light
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 790 G. Lime Softening; 930 P. Individual Filter
Performance; 950 Q. Other Demonstration of Performance
Comment: Comments #3: McMinnville Water and Light would like the EPA to consider re-evaluating
data already available with the objective of assigning sound, operationally achievable, treatment credit for
Cryptosporidium removal such as softening enhanced filtration and demonstrations of performance.
Response: EPA agrees with most commenters and the SAB that 0.5-log is an appropriate level of
additional prescribed Cryptosporidium treatment credit for two-stage softening. Where plants are able to
demonstrate a significantly higher level of removal of Cryptosporidium or an indicator such as aerobic
spores,they may apply for additional treatment credit through a demonstration of performance. See
Response 950.
EPA Letter ID: 601
Comment ID: 13025
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 930 P. Individual Filter Performance
Comment: Combined Filter Performance and Individual Filter Performance
Utah supports the inclusion of combined and individual filter performance as a toolbox item and agrees
that systems should only receive credit for either the combined filter performance or the individual filter
performance and not both.
Response: See Response lOOaand Response 930.
Comment Response for LT2ESWTR 8-173 December 2005
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8.9.1 Comment Codes 801, Credit and criteria for awarding credit
Individual Comments on Code 801
EPA Letter ID: 101
Comment ID: 10892
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Combined Filter Performance
The studies cited in the proposed rule support awarding a 1 log credit removal for combined filter effluent
less than or equal to 0.2 NTU 95% of the time.
Response: See Response 800.
EPA Letter ID: 445
Comment ID: 10820
Commenter: James Fay, Chair, PSW Steering Committee, The Partnership for Safe Water
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: PSW believes that it is a benefit to have the data collection and calculation procedures
(metrics) used in the toolbox for filtration credit and the PSW Phase III and Phase IV data collection and
calculation procedures for filter performance mirror one another. (For these comments, the term "metric"
applies to the analytical protocol used to calculate a single value from a given database, and not a specific
number or goal). It is believed that this was EPA's intention when the proposed rule was drafted.
However, since that time, the PSW has modified its metric for individual filter performance based on
experience gained in the last several years.
The combined filter effluent treatment credit proposed in the toolbox matches exactly the metric currently
used by PSW: specifically, the 95th percentile of all data, taken at a minimum of 4 hours frequency, not
exceeding a target value (LT2ESWTR uses a limit of 0.15 NTU, PSW uses a goal of 0.10 NTU). The
target value is easily compiled, and is already in common use in the drinking water community. The PSW
suggests no changes to this element of the Proposed Rule.
Response: See Response lOOa and Response 800.
EPA Letter ID: 447
Comment ID: 10793
Commenter: Michael Barsotti, Water Quality Director, Camplain Water District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 931 1. Proposed credit and criteria for awarding credit
Comment: Champlain Water District, as a water supplier that has achieved the Partnership for Safe
Water -Excellence in Water Treatment- award for 5 years supports the comments submitted regarding
the toolbox credit for individual filter (IFE) performance by the Partnership for Safe Water. Champlain
Water District points out that we have been meeting the IFE metrics as recommended by the Partnership
Comment Response for LT2ESWTR 8-174 December 2005
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comments and found them realistic in requiring documentation of individual filter performance that
enhances filter particle removal from that achieved by focusing upon the combined filter effluent (CFE)
turbidity levels. Champlain Water District wishes to have entered into the public record the need to
control particle removal levels at levels closer to the 95th percentile from each filter as opposed to other
measures (either IFE or CFE) near the average or median. Any data submitted that discusses average,
medium or similar log removal data should be supplemented with data showing 95th percentile log
removal. It is important to have 95th percentile data to document whether a certain toolbox credit can
reliably remove cryptosporidium in the absence of UV treatment. It is CWD-s view that, if an individual
filter performance toolbox credit has the potential to substitute for UV treatment, then data supporting that
credit should use 95th percentile rather than medium or average log removal data.
Response: See Response lOOa, Response 800 and Response 930.
EPA Letter ID: 457
Comment ID: 11930
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Combined Filter Performance
We support inclusion of this tool and the 0.5 log presumptive credit.
Response: See Response lOOa.
EPA Letter ID: 470
Comment ID: 11085
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 791 1. Credit and criteria for awarding credit; 821 1.
Credit and criteria for awarding credit; 891 1. Credit and criteria for awarding credit; 9111. Credit and
criteria for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment requirements
Response: See Response lOOa.
EPA Letter ID: 485
Comment ID: 11308
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment Response for LT2ESWTR 8-175 December 2005
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Comment: Response: The EPA has required systems to collect CFE turbidity samples once every four
hours while requiring the collection of turbidity samples every fifteen minutes from individual filters. The
Department does not agree that data collected every four hours is sufficient basis for granting additional
Cryptosporidium removal credit. California water systems are required to monitor CFE every fifteen
minutes and we suggest that the EPA require the same. The Department also disagrees with the concept of
additional credit for CFE turbidity performance. The Department recommends only enhanced IFE
turbidity performance receive additional removal credit. See comments on IFE credit below.
Response: See Response lOOa and Response 800.
EPA Letter ID: 562
Comment ID: 12424
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 11. Available information indicates that achieving a 0.15-NTU combined filtered water
turbidity (CFE) achieves more than 1.5-log greater Cryptosporidium removal than a facility achieving
0.30 NTU in CFE.
This analysis and these findings provide an important factual basis for the recommendations AWWA
offers in the following comments. AWWA-s review includes both research and data identified in the
LT2ESWTR proposal. AWWA believes the analysis in Appendix 1 and reflected in these comments more
correctly reflects the performance of some of these treatment technologies than the discussion provided in
the Federal Register notice and Microbial Toolbox Guidance. In addition to the literature and analysis
presented in Appendix 1 and Appendix 2, AWWA will also provide information and analysis with respect
to watershed control programs, bank filtration, ozone disinfection and UV disinfection.
4.2.1 Regulatory -Preference- vs. Agreement in Principle
Response: See Response lOOa and Response 800.
EPA Letter ID: 562
Comment ID: 12469
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.2.5 Enhanced Filtration (CFE Credit)
Value of Conventional Treatment Compliant with IESWTR
The Stage 2 M/DBP FACA recommendations and the agency-s LT2ESWTR proposal credits for
additional Cryptosporidium reduction are premised on the assumption that existing direct filtration and
combined clarification-plus-filtration facilities complying with the IESWTR (or LTIESWTR) achieve at
least 2.5- and 3.0-log removal, respectively. In setting this baseline, the FACA members recognized that
many of these facilities achieve higher levels of Cryptosporidium removal.
Comment Response for LT2ESWTR 8-176 December 2005
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The microbial toolbox was intended to provide a wide selection of alternatives for plants to use to
demonstrate or establish Cryptosporidium protection capabilities. The proposed alternatives included
existing treatment technologies as well as some new technologies that might be added to plants to obtain
Cryptosporidium removal credit. The peer-reviewed literature includes data indicating that for some
treatment systems, compliance with the IESWTR may translate into 4.0-log, 5.0-log, or higher
Cryptosporidium protection potential, not just the 2.5- or 3.0-log default credit allowed for a conventional
filtration plant. One objective of the microbial toolbox is to provide realistically defined Cryptosporidium
protection credits so that a facility in compliance with the IESWTR that achieves more than 2.5- or 3.0-
log of protection can demonstrate or establish the higher treatment capability of the treatment plant.
Response: See Response lOOa and Response 800.
EPA Letter ID: 562
Comment ID: 12472
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 931 1. Proposed credit and criteria for awarding credit
Comment: As previously described, available experimental data in the peer review literature indicate that
existing facilities with clarification and filtration in compliance with the IESWTR can achieve 4.0, 4.5, or
higher log removal of Cryptosporidium. The 1.0, 1.5, or greater correction of the minimum 3.0 baseline
credit can be partially provided by the CFE and IFE credits. These credits both involve providing
additional Cryptosporidium protection credits when the filter effluent turbidity improves from 0.3 to
0.15 NTU. Existing literature contains evidence demonstrating that improvements in effluent turbidity
from 0.3 to 0.15 NTU translates to an improvement in Cryptosporidium removal of more than 1.5 log.
Response: EPA appreciates the comment and information. See Response 930 and Response 800.
EPA Letter ID: 562
Comment ID: 15049
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Alternatives for enhanced filtration credits, which seemed most appropriate, based upon
AWWA-s review of the available data, include the following:
1. Keep current CFE credit as currently defined (0.5 credit).
2. Keep current definition of CFE credit, but increase the credit from 0.5 to 1.0 credit.
3. Convert current CFE credit into a two-tiered credit. The current definition of the CFE credit will be
used as the first tier, and will continue to be allowed a 0.5 credit. The second tier would be an additional
0.5 credit, or a total of 1.0 credits, for facilities meeting CFE 97 percent <0.15 NTU. The IFE credit
would be eliminated.
Response: See Response 800 and Response 930.
Comment Response for LT2ESWTR 8-177 December 2005
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EPA Letter ID: 624
Comment ID: 13199
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 931 1. Proposed credit and criteria for awarding credit
Comment: 3. Combined Filter Effluent (CFE) and Individual Filter Effluent (IFE) Requirements:
GCWW recommends identifying 0.5-log removal separately for the IFE and CFE.
Response: See Response lOOa, Response 800 and Response 930.
EPA Letter ID: 635
Comment ID: 13115
Commenter: Robert A. Hollander, Compliance and Regulatory Affairs Administrator, City of Phoenix,
Water Services Department
Commenter Category: Regulated Community (Utilities)
Comment: Issue 3: Calibration Requirements for On-line Turbidimeters (Federal Register Page 47734)
"If a system chooses to use on-line units for monitoring, the system must validate the continuous
measurements for accuracy on a regular basis using a protocol approved by the State." Following the
turbidimeter manufacturer calibration recommendations and schedules is sufficient in determining
accuracy and should not require State approval.
Response: The commenter refers to turbidity instrument manufacturer calibration recommendations,
while the LT2ESWTR language refers to continuous monitoring instrument validation. Validation refers
to comparison between two instruments, in this case between a continuous monitoring instrument and a
bench top or single measurement instrument. EPA notes that State approval of the validation protocol for
turbidity instruments is consistent with the current requirements for all Subpart H systems (CFR 141.74)
EPA Letter ID: 637
Comment ID: 13097
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: Combined Filter Performance and Individual Filter Performance
District supports the inclusion of combined and individual filter performance as a toolbox item.
Membership in the Partnership for Safe Water should be
Response: See Response lOOa and Response 800.
Comment Response for LT2ESWTR 8-178 December 2005
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EPA Letter ID: 643
Comment ID: 12792
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Combined Filter Performance
States generally support inclusion of this tool and the 0.5 log presumptive credit. However, some states
prefer to only allow for additional removal credit if the individual filer performance criteria can be met
and would not allow credit for combined filter performance. The poor performance of an individual filter
could statically result in higher cyst concentrations in the combined effluent even when the combined
effluent turbidity is still in compliance with the combined effluent performance being proposed in this
section.
Response: See Response lOOa and Response 800.
EPA Letter ID: 643
Comment ID: 12793
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: One state suggested that water systems claiming the combined filter effluent credit should be
required to collect combined filter effluent turbidity samples once every fifteen minutes instead of once
every four hours as proposed.
Response: EPA appreciates the comment. See response to Comment Code 800.
EPA Letter ID: 647
Comment ID: 12934
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Combined Filter Performance
MDE generally supports inclusion of this tool and the 0.5 log presumptive credit.
Response: See Response lOOa.
EPA Letter ID: 660
Comment ID: 14079
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 931 1. Proposed credit and criteria for awarding credit
Comment Response for LT2ESWTR 8-179 December 2005
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Comment: Combined Filter Performance and Individual Filter Performance
CUWCD strongly supports filter performance as a criteria.
Response: See Response lOOa.
EPA Letter ID: 662
Comment ID: 14037
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 931 1. Proposed credit and criteria for awarding credit
Comment: Combined Filter Performance and Individual Filter Performance
Systems should receive credit for individual filter performance, or combined filter performance not both,
individual filter performance credit is preferred.
Response: See Response lOOa, Response 800 and Response 930.
EPA Letter ID: 673
Comment ID: 13990
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 931 1. Proposed credit and criteria for awarding credit
Comment: C. 8. Combined Filter Performance
(pages 47697-47700)
C. 16. Individual Filter Performance (pages 47716-
Comments on Combined Filter Performance and Individual Filter Performance
Jordan Valley Water supports including combined filter and individual filter performance as toolbox
items. Jordan Valley Water recommends that a presumptive credit of 0.5 be given for both the combined
filter and individual filter performance option, and then allowing water systems to claim the credit from
both options. Any water system meeting individual filter performance will automatically meet the
combined filter performance requirements. This will achieve the same result as the current proposal to
when the two options are used exclusively.
Response: See Response 100a,Response 800 and Response 930.
Comment Response for LT2ESWTR 8-180 December 2005
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8.9.2 Comment Codes 802, Additional data on filtration performance
Individual Comments on Code 802
EPA Letter ID: 562
Comment ID: 12470
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Data available during development of the IESWTR and LT1ESWTR indicated that combined
clarification-plus-filtration treatment, or filtration alone (i.e., direct filtration), achieved at least 2-log
Cryptosporidium removal. Studies published in the literature since then, coupled with a re-evaluation of
earlier data, indicate that conventional clarification-plus-filtration systems operating to meet IESWTR or
LTIESWTR requirements (turbidity ?0.3 NTU) achieve mean and median Cryptosporidium removals of
4 to 6 logs. These data are summarized in Table 2. True removal capabilities for these tests are likely to
be greater than indicated in Table 2 because filtered water Cryptosporidium concentrations were usually
below detection limits in these studies (see last column of table). Below-detection values limit the
demonstrated removal levels. Similarly, direct filtration studies typically demonstrated mean and median
Cryptosporidium removals exceeding 2.5-log.
Table 2. Impact of Achieving IESWTR Required Effluent turbidity (<0.3 NTU) on Log Removal of
Cryptosporidium During Treatment with Clarification Plus Filtration or Direct Filtration Alone
[SEE TABLE 2, P.42 IN PDF]
The agency-s summary of the available literature does not adequately reflect the conservatism underlying
the default log removal credits recommended by the negotiating committee. Toolbox credits for enhanced
filtration and demonstration of performance under the LT2ESWTR framework should provide credible
and feasible means for treatment plants to obtain the level of credit appropriate for their operational
performance when that performance exceeds the minimum baseline assumptions.
Response: EPA appreciates the comment and information. See Response 800.
EPA Letter ID: 562
Comment ID: 12471
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Improved Cryptosporidium Removal at Turbidity Below 0.15 NTU
EPA asks if available studies cited here support awarding 0.5-log credit for CFE < 0.15 NTU 95% of the
time. Data reported by Huck et al. (2002) (referenced in LT2ESWTR preamble) from separate pilot-scale
studies conducted in Ottawa and Southern California provide the most unambiguous demonstration
of the improvement in Cryptosporidium removal associated with reduction of filter effluent turbidity form
0.3 to 0.15 NTU. The information from the Ottawa and California studies reported by Huck et al. (2002)
are listed in Appendix 1. These data reflect log removal calculated for each pair of filter influent and
effluent samples reported from these studies. The Ottawa data demonstrated a >3 log improvement in the
median calculated log removal when filter effluent turbidity was <0.15 NTU versus when turbidity was
Comment Response for LT2ESWTR 8-181 December 2005
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between 0.15 and 0.3 NTU. Similar reduction in turbidity resulted in an improvement of 1.8 log for
median removal in the California studies.
Appendix 1 summarizes data for other full- and pilot-scale studies published in the literature. Most of the
other data cited in this table either has a limited number of results in one or both groups, or includes data
where the true difference in removal between the two groups can not be numerically established with the
filtered water detection limits used, given the low raw water occurrence. The few situations where a
comparison between <0.15 NTU versus between 0.15 and 0.3 NTU can be made indicate a difference in
log Cryptosporidium removal of >0.7-log to >3-log.
Response: See Response lOOa and Response 800.
8.9.3 Comment Codes 803, Turbidity monitoring accuracy at low
levels
Summary of Issues
In regard to the measurement of low level turbidity, some commenters raised concerns that turbidimeters
used by the US water supply industry do not agree when used to measure turbidity in the 0.01 to 0.5 NTU
range. Further, these differences are independent of the calibration method used and can be significant
when comparing instruments by different manufacturers. Other commenters stated that turbidimeters can
accurately reflect turbidity values less than 0.15 NTU if properly calibrated, and some commenters cited
the ASTM method development process to support this assessment. In addition, commenters suggested
that available guidance on turbidity measurement provides quality assurance measure that can reduce
analytical uncertainty.
Response to Code 803
EPA agrees with commenters that available methods and instruments are adequate to demonstrate
compliance with a 0.15 NTU turbidity level. In particular, EPA believes that monitoring low level
turbidity can be effective for demonstrating water quality improvements at individual plants, but also
recognizes that the performance of turbidimeters used at different plants may vary. Further, calibration
and maintenance of turbidity monitoring equipment is critical, and EPA has developed guidance on these
procedures.
Individual Comments on Code 803
EPA Letter ID: 425
Comment ID: 10891
Commenter: Kemon Papacosta, ASTM Member D19, ASTM
Commenter Category: Unknown
Comment: Upon review I would like to elaborate on my comments submitted previously, specifically,
the two studies cited as the premise for my comments. It is critical to validate the performance of a
turbidimeter at the proposed ultra low turbidity level 0.10 NTU and/or 0.15 NTU for finished drinking
water.
Comment Response for LT2ESWTR 8-182 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
A STUDY OF LOW-LEVEL TURBIDITY MEASUREMENTS
Sponsored by AWWA Research Foundation, published in 2001
I cite: Chapter 6, Summary and Conclusions, Paragraphs 2,3 & 4
Bench-Top and Portable Instruments
It was expected that for a given month, site, and calibration method the average turbidity readings would
vary in a random way with the instrument-mode. However, between the third or fourth month and the end
of the study the averages of the triplicate turbidity readings for each instrument-mode form two distinct
groups. The 7 instrument-modes with the higher average readings are labeled GroupA and the 5 with the
lower average readings are labeled Group B. Both groups include portable-type instruments with different
types of light sources.
The instrument-modes in Group A correspond to instruments that do not automatically set a
predetermined reading when a sample of low-particle (dilution) water is put in the instrument during the
calibration procedure. The instrument-modes in Group B correspond to the instruments that use the
calibration procedure to automatically set the low-particle reading at either zero or 0.02 NTU. In general,
when the turbidity of a sample was less than about 0.15 NTU on the Group A instruments, the Group B
instruments tended to give the reading (0.00 or 0.02 NTU) that they automatically assigned in the
calibration process to low-particle dilution water. The Group A instruments are all made by the same
manufacturer and Group B instruments are made by several manufacturers.
The difference between the mean turbidity for Groups A and B varies from about 0.1 to 0.3 NTU (about
20-30%) depending on the sample's source and the month and is essentially independent of the calibration
method.
The conclusion indicates two distinct types of turbidimeter performance due to the base point calibration
procedure. Group A, with a factory set, or non operator set point at 0.00 NTU or 0.02 NTU causing a
difference of 20% to 30% in the performance of the two groups of machines. This is consistent with the
ASTM round robin data.
It must, also, be noted that the difference was independent of the type of calibration standard used.
I am providing the study protocol and the reporting data from the ASTM study for Round Robin Data
Collection for turbidity below 5 NTU in static mode.
Test Study for Round Robin Data Collection Using Instruments for the "Standard Test Method for the
Determination of Turbidity Below 5 NTU in Static Mode"
Background:
When applicable, ASTM requires a full round robin test program (using 8-9 laboratories) be performed to
collect sufficient data for the precision and bias (P&B) statement of a new test method. In a typical round
robin, one facility will generate test samples and then send aliquots of the test samples to all participating
laboratories. Unfortunately, this practice has one inherent assumption: the samples and surrogates
governed by the test method and used in the study are stable for the duration of the round robin (shipping,
storage and use).
In reviewing our test method we feel that a standard round robin test program is not feasible. This is
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because low-level turbidity samples, and all turbidity samples in general, are known to be unstable. So,
we cannot expect the samples to maintain the same turbidity levels while being transferred from one
laboratory to the next under dubious storage conditions.
We utilized the following alternative: rather than send aliquots of samples from one laboratory to the
next, we will assemble instrumentation to a common location and perform analysis to a series of water
samples, unknown surrogate standards and verification standards that encompass the measurement range
of this method. In doing so, data collection can occur in a time frame that is practical to complete. This
will also allow samples to stand for the shortest time possible prior to analysis, which reduces the
possibility of changing due to the inherent nature of their instability.
Each instrument had a single operator assigned to it for the duration of the study. The instrument-operator
combination was treated as a separate location, even though all instruments and operators were located in
the same laboratory. Each operator was responsible for setup, calibration and verification of their assigned
instruments for the duration of the study. Samples were also prepared and measured by the operator on
their assigned instruments.
The ultimate goal of a round robin was to prove out the test method under review and to collect sufficient
data for the P & B statement of the test method. The plan was to collect and compile the test data from the
multiple "locations" to provide a P & B statement for the test method. The data in this program should
provide us with sufficient information to determine: 1) inter-instrument repeatability on the test samples,
2) instrument reproducibility on the test samples, and 3) inter-laboratory variability using the known
stable surrogates.
Study Protocol:
The purpose of this protocol was not to create a test method but to prescribe a set of guidelines for
generating uniform data to use for P & B data. The test method can be found in the Preliminary Draft 0.6
of the "Standard Test Method for the Determination of Turbidity Below 5 NTU in Static Mode." The
following paragraphs elaborate on how the study was set-up, calibration and verification of the
instruments, and finally, how samples were prepared and run in this study.
Instrument Set-Up and Calibration: Each manufacturers' representative as assigned to their respective
instruments. This generated a total of seven instrument-operator "locations" (excluding locations #1 and
#9 which were the process instruments run in static mode). The operator was responsible for first setting
up their instruments. This was followed by performing calibration using freshly prepared scratch formazin
standards.
NOTE: A laboratory chemist was assigned to prepare the scratch 4000 NTU formazin standard that was
prepared according to the strict preparation procedures outlined in the test method. From the scratch
standard, this chemist prepared all calibration standards that were used for calibration. The assignment of
one person to prepare all the calibration standards was necessary in order to allow for all instruments to be
calibrated in a relatively short period of time. Once the standards were prepared, they were given to each
operator. The operator then transferred the standards to sample cells, prepared the cells for measurement
and then performed the calibration on their assigned measurements. Overall, this allowed calibration to
occur as a parallel effort among the study participants and ultimately freed up time to perform sampling
measurements.
Sections 11.1 - 11.2 contains the detailed procedures required to set up their instrument(s) and perform
the instrument calibration using scratch formazin. (Sratch Formazin is defined as the reference turbidity
standard for this method: all other standards are referenced to Formazin. Since most instruments are
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designed for calibration with formazin, it is the best standard to use to calibrate the instruments for
performance testing in this study. SectionlO details the manufacturer of Formazin; a pre-made 4000 NTU
stock solution of Formazin may be used as the starting material for this test.) By calibrating with the same
formazin the study will eliminate any questions pertaining to the variability found in different calibration
standards and suppliers of formazin.
Instrument Calibration Verification: Each instrument operator was required to verify that their
instrument(s) were calibrated properly and are free from drift. Verification of the instrument calibration
and identification of any instrument drift will be performed using calibration verification standards
provided with the instruments (see section 11.3 of the draft test method for further information). The
verification will be performed at the beginning of the test (immediately after instrument calibration),
when the test is approximately half completed and at the end of the test. Any drift in the instrument
calibration will be noted for use in the data analysis.
Sample Measurement and Testing: Several samples were measured on each instrument. Samples included
surrogate real world water samples, StablCal (stabilized formazin) and SDVB samples of both known and
unknown values. Each sample was measured in triplicate at each of the locations. The data was then
recorded and transferred into an Excel(r) spreadsheet where the statistical formulas for generating the p &
B values could be applied. Originally, the goal was to obtain at least three samples in the test range of
interest (see section 1 on the scope of the test method). However, several additional samples were able to
be collected and run through these "locations" within the allotted timeto complete the study. The samples
that were run in the order are listed below:
_ Sample #1: Formazin A - Expected Value 0.90 NTU
_ Sample #2: Formazin B - Expected Value 0.625 NTU
_ Sample #3: Combined Filter Effluent - Expected Value 0.050
_ Sample #4: South Applies to Filters - Expected Value 0.270
_ Sample #5: SDVB Unknown A - Expected Value ??
_ Sample #6: StablCal Verification A - Expected Value 0.262 NTU
_ Sample #7: SDVB Unknown B- Expected Value ??
_ Sample #8: StablCal Verification B - Expected Value 0.262 NTU
_ Sample #9: South Applied to Filters #2 - Expected Value 1.00 NTU
_ Sample #10: SDVB Unknown C - Expected Value ??
_ Sample #11: Raw Water Delaware Intake
_ Sample #12: Raw Water Schuylkill
_ Sample #13: StablCal Verification C - Expected Value 4.01 NTU
_ Sample #14: Filtered Tap Water - Expected Value <0.10 NTU
Notes on sample analysis:
_ Each sample was collected into a single cleaned Nalgene(r) carboy that had been rinsed with reagent
water. The sample in this carboy was mixed by magnetic stirring during the entire dispensation process
into sample cells. Once a sample cell was filled with sample, the cell was immediately capped and given
to the operator for preparation and measurement at each location.
_ Samples 1-3 were completed on day 1. Samples 3-14 were completed on day 2.
_ SDVB samples were stable unknowns at the time these samples were run.
_ StablCal verification standards were of a defined value that was known at the time of measurement.
_ The verification standards, SDVB unknowns, and real-world water samples were all kept as part of the
P & B statistical package.
_ As for details for sample preparation and measurement, please refer to sections 7-8 and 12 of the draft
test method.
_ The dispensation of sample from the carboy randomly into sample cells was conducted by a designated
laboratory person. Using one person to perform this ask reduced the time required to perform this step,
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which insured that changes to the samples would be minimal.
Four examples are used from the reporting data to elaborate the need for a base point calibration and
verification of accuracy at 0.10 NTU and 0.15 NTU. Please see reporting data on the next page. The four
examples are highlighted in blue.
[SEE PAGE 8 OF .PDF FILE FOR TABLE]
1) Two materials are treated water and two are EPA approved standards.
2) In all cases there is a considerable increase in variance from within instrument repeatability and
between instrument reproducibility from a minimum of 33% to a maximum of 80%. The water samples
varied by 33% and 48%.
Why such a change in reproducibility between turbidimeters? The answer is in the calibration procedure.
Some instruments have their base point calibration set at the factory with no adjustment. Others use a 0.02
NTU base point. The next calibration point may be as high as 20.0 NTU. Clearly there must be a
standardization of the base point calibration in order for the proposed lowered turbidity values for treated
water of 0.10 NTU and 0.15 NTU to have relevance.
In my original comments, a base point value of 0.02 NTU should be set to standardize this value since it
is already being used by standards and instrument manufacturers. Also, Standard Methods 2130B.
Nepholometric Method under 3. Reagents defined dilution water having nominal value of 0.02 NTU after
following their preparation procedure.
The ASTM reporting data also supports the need for primary verification standards to verify the accuracy
of a calibrated turbidimeter at the 0.10 NTU and 0.15 NTU since the first calibration point after the
factory set base point or operator set base point may be several factors higher than the proposed reporting
values.
In my original comments, Formazin is mentioned as not an option for dilutions down to 0.15 NTU and
0.10 NTU with any degree of accuracy. The claim is based on data from the ASTM Standard Test Method
for the Determination of Turbidity Below 5 NTU in Static Mode. I was the task group Co-Chairman that
wrote the method. Under Reagents 9.2 Turbidity Standards:
A standard with a turbidity of 1.0 NTU is the lowest Formazin turbidity standard that should be produced
on the bench. Preparation of Formazin standards shall be performed by skilled laboratory personnel with
experience in quantitative analysis. Close adherence to the instructions within this section is required in
order to accurately prepare low-level turbidity standards.
*Note #1: The SDVB-APS 'B' true value is 0.20 NTU. I was the Director/General
Mgr. of the company that provided the standards for the tests.
*Note #2: It is stated in the text that the expected value is <0.10 NTU
The instructions are extensive, including:
1) Using the highest grade reagents (99+%)
2) Preparing ultra pure water (Filtration of Type III water)
3) Scrupulously cleaning glassware.
4) Seasoning glassware.
5) Using Class A, volumetric glassware
To summarize...the two independent studies reveal a built in error, at minimum of 20%, in the
performance of turbidimeters at ultra low turbidity values below 1.00 NTU. The error can be minimized
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by standardizing the base point calibration, operator set, at 0.02 NTU using a primary calibration standard
and verification of accuracy at 0.10 NTU and 0.15 NTU using primary calibration standards with the
same NTU values.
Response: See Response lOOa and Response 803.
EPA Letter ID: 454
Comment ID: 10952
Commenter: Richard D. Letterman,, Department of Civil and Environmental Engineering, Syracuse
University
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: Results published in an American Water Works Association Research Foundation study on
the low-level turbidity measurement and recently acquired supplemental data (see attached paper
draft)(see PDF) indicate that the turbidimeters used by the US water supply industry do not agree when
they are used to measure low-level values in the 0.01 to 0.5 NTU range. The turbidity values measured by
all the instruments of one prominent manufacturer are consistently higher than the readings obtained with
the instruments sold by competitors. For example, when the prominent manufacturer-s instruments read
0.4 NTU the instruments of various competitors cluster around 0.22 NTU. When the prominent
manufacturer-s instruments read an average value of 0.15 NTU the competing instruments read
approximately 0.02 NTU. These recent studies did not determine the specific reasons for these differences
but it is possible they are caused by differences in instrument design.
Response: See Response lOOa and Response 803.
EPA Letter ID: 454
Comment ID: 10954
Commenter: Richard D. Letterman,, Department of Civil and Environmental Engineering, Syracuse
University
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: The attached paper (see PDF) contains supporting data and has been submitted to the Journal
American Water Works Association for review. The AwwaRF report (Letterman, R. D., Johnson, C.
E.and Viswanathan, S. and Dwarakanathan, J. 2002. A Study of Low-Level Turbidity Measurements,
American Waterworks Association Research Foundation, Report 1P-2.5C-90890-6/02-CM, Denver, CO)
that was used to prepare this paper (see PDF) was peer-reviewed and has been available since 2002.
Response: EPA appreciates the comment and information. See Response 803.
EPA Letter ID: 472
Comment ID: 11139
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Comment Response for LT2ESWTR 8-187 December 2005
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Department
Commenter Category: Local Government
Comment: While on-line turbidimeters are robust instruments, when in use continuously for years it is
inevitable that bubbles, noise in SCADA electronics, and other factors will result in erroneous reported
values. Compliance algorithms should not be so stringent as to identify transient lapses in the
measurement and recording electronics to result in compliance violations.
Response: See Response 800 and Response 803. EPA believes the performance criteria in this toolbox
option adress instrument variablity.
EPA Letter ID: 485
Comment ID: 11309
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: The Department has conducted turbidity and particle counting studies in the past that have
shown turbidity values below 0.10 NTU can be distinguished. The Department believes turbidimeter
technology can accurately reflect turbidity values less than 0.15 NTU if proper calibration (primary and
secondary) is conducted.
Response: See Response lOOa and Response 803.
EPA Letter ID: 562
Comment ID: 12473
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Response As noted in the LT2ESWTR preamble, the method development process
undertaken by the American Society for Testing and Materials (ASTM) has produced a practice for on-
line instruments and a standard for static instruments measuring turbidity in the region of interest for both
the proposed CFE and IFE credits. The ASTM method development process was robust and data
generated through the practice and method development effort demonstrated that appropriate levels of
accuracy and precision can be maintained to support implementing regulatory requirements at 0.15 NTU.
While on-line turbidimeters are robust instruments, when in use continuously for years, bubbles, noise in
SCADA electronics, and other factors will inevitably result in erroneous reported values. Compliance
algorithms should not be so stringent as to identify transient lapses in the measurement and recording
electronics to result in compliance violations.
Response: See Response lOOa and Response 803.
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8.9.4 Comment Codes 804, Rule Language Edits
Individual Comments on Code 804
EPA Letter ID: 624
Comment ID: 13202
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: b. GCWW asks for clarification as to the differences between the Combined Filter Effluent
(CFE) and the finished water turbidity. EPA has used these terminologies interchangeably throughout the
document. CFE should be the primary filter effluent and finished water is what is entering the distribution
system prior to primary disinfectant addition. This could clarification could determine whether secondary
filtration needs additional credit.
Response: EPA appreciates the comment. The LT2ESTWR specifies combined filter effluents measured
as described in CFR 141.74(c).
8.9.5 Comment Codes 805, Guidance
Individual Comments on Code 805
EPA Letter ID: 389
Comment ID: 10486
Commenter: Kemon Papacosta, ASTM Member D19, ASTM
Commenter Category: Unknown
Comment: My comments are regarding LT2ESWTR Toolbox Guidance Manual, June 2003 Draft, EPA
815-D-03-009, Turbidity section 7.2.3.2 are based on two studies:
1. A Study of Low-Level Turbidity Measurements sponsored by AWWA Research Foundation, published
in 2001.
2. Test Study for Round Robin Data Collection Using Instruments for the Standard Test Method for the
Determination of Turbidity Below 5 NTU in Static Mode. The study is incorporated into the new ASTM
Standard Test Method for Determination of Turbidity Below 5 NTU in Static Mode.
Both of these studies showed a large variance between instruments below 0.30 NTU.
Section 7.2.3.2
Maintenance and Calibration
Base Point Calibration
Turbidimeter design should incorporate a base point, or zero point, calibration.
The turbidity base point value should be standardized at 0.02 NTU.
At a minimum the base point accuracy should be validated using a base point primary standard.
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Example
A slight variance in the bottom point turbidity setting equates to significant changes in turbidity values as
a percent of that value. For example:
Variance 0.03 NTU Change in the NTU value
1.00 compared to 1.033%
0.30 compared to 0.33 9%
0.10 compared to 0.13 30%
The 0.02 NTU primary standard is not unprecedented. It has been supplied to turbidimeter operators for
years by standards and Instrument manufacturers.
Verification Standards
The accuracy of the turbidimeter readings at the 0.15 NTU and/or 0.10 NTU should be validated using
primary verification standards that match those values. If secondary verification standards are used they
must be first checked for accuracy using primary validation standards. The verification procedure must be
done quarterly after the turbidimeter is calibrated.
Formazin
Dilution of Formazin down to 0.15 NTU and 0.10 NTU is not an option since it is impossible to
achieve these values with any degree of accuracy or consistency.
Response: See Response 803.
8.10 Comment Codes 810, Roughing Filters
Summary of Issues
The majority of commenters agreed that there was insufficient information regarding the efficacy of
roughing filters in removing Cryptosporidium and that removal credit was not appropriate although one
commenter felt the information supported a 1- log Cryptosporidium removal credit. Several commenters
felt that roughing filters should be included as a toolbox option, but that they should be subject to a
demonstration of performance or third party verification to determine the removal credit to be applied.
One commenter requested more information to distinguish roughing filters from simple screening.
Response to Code 810
The Stage 2 M-DBP Advisory Committee recommended a 0.5-log Cryptosporidium treatment credit for a
roughing filter with the stipulation that EPA identify the design and operational conditions under which
such credit is appropriate. After reviewing available data, however, EPA is unable to determine
conditions under which a roughing filter is likely to achieve at least 0.5-log removal of Cryptosporidium.
Roughing filters consist of coarse media like gravel and usually are not preceded by coagulation. They are
used to remove sediment and large particulate matter from raw water prior to the primary treatment
Comment Response for LT2ESWTR 8-190 December 2005
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processes. EPA has not identified studies indicating that roughing filters would be effective for removal
of Cryptosporidium and no additional information to supprt a Cryptosporidium treatment removal credit
was received with public comments.
Individual Comments on Code 810
EPA Letter ID: 601
Comment ID: 13026
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 8111. Decision not to award credit
Comment: Roughing Filter
Utah supports the inclusion of rouging filters as a technology for reducing turbidity and requiring States
to determine appropriate credit after reviewing demonstrated performance.
Response: See Response lOOa and Response 810.
8.10.1 Comment Codes 811, Decision not to award credit
Individual Comments on Code 811
EPA Letter ID: 101
Comment ID: 10893
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Roughing Filters
The information in the proposed rule support awarding a 1 log credit removal for Cryptosporidium by
roughing filters.
Response: See Response 810.
EPA Letter ID: 457
Comment ID: 11931
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Roughing Filter
We support inclusion of this tool; however, we recommend reliance on third party, vendors and
certifications such as ETV to ascertain the appropriate credit to apply.
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Response: See Response 810. EPA notes that under the demonstration of performance tool in today's
rule,third party or other verfication processes could be to demonstrate any Cryptosporidium removal by a
roughing filter or other unit process.
EPA Letter ID: 485
Comment ID: 11310
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department agrees that without sufficient documentation concerning the
efficacy of roughing filters and necessary assurances that the 0.5 log reduction can be achieved, this
should not be considered as a viable option at this time. Secondary filtration with proven technologies to
achieve the targeted
Response: See Response lOOa and Response 810.
EPA Letter ID: 520
Comment ID: 11640
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Roughing Filter
IEPA generally supports inclusion of this tool and the position that the technology needs to be proven in
order to receive any credit
Response: See Response lOOa and Response 810.
EPA Letter ID: 601
Comment ID: 13026
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 810 I. Roughing Filters
Comment: Roughing Filter
Utah supports the inclusion of rouging filters as a technology for reducing turbidity and requiring States
to determine appropriate credit after reviewing demonstrated performance.
Response: See Response lOOa and Response 810.
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EPA Letter ID: 637
Comment ID: 13099
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: Roughing Filter
District supports the inclusion of roughing filters as a technology for reducing turbidity and requiring
States to determine appropriate credit after reviewing demonstrated performance.
Response: See Response 810. EPA notes that under the demonstration of performance tool in today's
rule,third party or other verfication processes could be to demonstrate any Cryptosporidium removal by a
roughing filter or other unit process.
EPA Letter ID: 643
Comment ID: 12794
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Roughing Filter
States generally support inclusion of this tool and the position that the technology needs to be proven in
order to receive any credit. Some states indicated that they will rely on vendors and certifications such as
ETV to ascertain the appropriate credit to apply.
Response: See Response 810. EPA notes that under the demonstration of performance tool in today's
rule,third party or other verfication processes could be to demonstrate any Cryptosporidium removal by a
roughing filter or other unit process.
EPA Letter ID: 647
Comment ID: 12935
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment:
Roughing Filter
MDE supports inclusion of this tool and the position that the technology needs to be proven in order to
receive any credit. More information is needed to assist states in distinguishing between roughing filters
and screens.
Response: See Response 810.
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EPA Letter ID: 662
Comment ID: 14038
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Roughing Filter
Roughing filters, as a technology for reducing turbidity, should be designated appropriate credit after
reviewing demonstrated performance.
Response: See Response 810. EPA notes that under the demonstration of performance tool in today's
rule,third party or other verfication processes could be to demonstrate any Cryptosporidium removal by a
roughing filter or other unit process.
EPA Letter ID: 668
Comment ID: 13901
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 751 1. Decision not to grant credit based on existing
data
Comment: - No credit should be provided for raw water storage (p 47687), or roughing filters (p. 47700-
01) because, as EPA has found, there is no evidence to support such credit. This is consistent with the
Agreement, which called upon EPA to review the science and verify the rough table in the agreement, and
to seek comment on all credits.
Response: See Response 810 and Response 750.
8.11 Comment Codes 820, Slow Sand Filtration
Summary of Issues
Many commenters supported the proposed treatment credit. These commenters cited studies
demonstrating greater than 4-log Cryptosporidium removal by slow sand filtration and concluded that the
data justify a 2.5-log treatment credit for slow sand filtration added to a clarification and filtration
treatment train.
Several commenters, however, stated that this treatment credit is not justified due to the lack of data on
the performance of slow sand as a secondary filtration step. Available studies on slow sand filter
performance for Cryptosporidium removal have mostly been conducted on raw (i.e., unfiltered) water.
These commenters were concerned that if slow sand filtration is applied following a primary filtration
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process, the filter ripening period and other factors will be significantly affected. As a result, the slow
sand filtration may provide only limited removal over a long ripening period.
Response to Code 820
The Stage 2 M-DBP Advisory Committee recommended that slow sand filtration receive a 2.5 log or
greater Cryptosporidium treatment removal credit.
Based on available studies demonstrating greater than 4-log removal of Cryptosporidium through slow
sand filtration, the final LT2ESWTR awards a prescribed 3-log Cryptosporidium removal credit to slow
sand filtration as a primary filtration process. The effectiveness of slow sand as a secondary filtration
process is more uncertain. In general, EPA expects that the same microbial removal mechanisms will be
operative. However, due to the quality of treated water following a primary filtration process, filter
ripening and development of the biologically active layer in a secondary slow sand filter may be
inhibited. One study that evaluated Cryptosporidium removal by slow sand filtration alone and slow sand
filtration preceded by a rapid sand filter observed similar removal levels in the two treatment trains (Hall
etal. 1994).
EPA recognizes that little testing has been conducted on the performance of slow sand filtration
specifically as a second filtration stage in a treatment train. However, available data do not indicate that
slow sand filtration would be substantially less effective when used in this capacity. Slow sand filtration
is recommended only for higher quality source waters, and water quality following a primary filtration
process would be well within recommended design limits for slow sand filtration. Because of the
uncertainty regarding the performance of slow sand as a secondary filtration step and in consideration of
the Advisory Committee recommendation, the final LTESWTR establishes a 2.5-log additional
Cryptosporidium treatment credit for this application.
EPA agrees with commenters that filter ripening is critical to slow sand filtration achieving its full
performance level, and this process may require more time when slow sand filtration follows a primary
filtration process. However, this effect may be counterbalanced by very long filter run times between
cleaning the filter due to the high quality influent water. Consequently, EPA believes that 2.5-log
Cryptosporidium treatment credit for slow sand as a secondary filtration process is warranted.
Individual Comments on Code 820
EPA Letter ID: 485
Comment ID: 11312
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes more data is needed before there can be adequate
justification for awarding slow sand filtration additional removal credit as a secondary filtration step. The
Department is concerned that the slow sand filters may not perform as well on treated water as they have
been shown to do on raw water. The ripening period and other factors will be significantly affected by the
water source applied to the filters.
Response: See Response 820.
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8.11.1 Comment Codes 821, Credit and criteria for awarding credit
Individual Comments on Code 821
EPA Letter ID: 101
Comment ID: 10894
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Slow Sand Filtration
The available data suggest that a 3.0 log cryptosporidium removal credit for
slow sand filtration.
Response: See Response 820.
EPA Letter ID: 457
Comment ID: 11932
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Slow Sand Filter
We support inclusion of this tool and the 2.5 log presumptive credit.
Response: See Response lOOa.
EPA Letter ID: 470
Comment ID: 11085
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 791 1. Credit and criteria for awarding credit; 801 1.
Credit and criteria for awarding credit; 891 1. Credit and criteria for awarding credit; 9111. Credit and
criteria for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment requirements
Response: See Response lOOa.
EPA Letter ID: 520
Comment ID: 11641
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Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Slow Sand Filter
IEPA generally supports inclusion of this tool, but expressed concern with the 2.5 log presumptive credit.
There is a question whether slow sand filtration will be as effective in treating filter effluent as it is
treating raw water, noting that the ripening period and other factors will be significantly affected by the
water source applied to the filters.
Response: See Response 820.
EPA Letter ID: 548
Comment ID: 12164
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Metropolitan believes that awarding a 2.5 log credit to slow sand filtration applied as a
secondary filtration step for Cryptosporidium removal is not appropriate because the proposal was based
on the limited data of only one study. Hall et al. (1994), the basis for EPA-s proposal, showed that a
combined primary filtration process followed by slow sand filtration achieved greater than 3 log
Cryptosporidium removal in three of five experimental runs and 2.5 log removal in the other two runs,
while slow sand filtration alone achieved 3 log removal in four runs. The study did not determine whether
slow sand filtration applied as a secondary filtration step by itself achieved at least 2.5 log removal.
Response: See Response 820.
EPA Letter ID: 562
Comment ID: 12426
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 13. Slow sand filtration, when operated as outlined in the Surface Water Treatment Rule
(SWTR), is capable of achieving a 3.0-log baseline Cryptosporidium removal credit as a stand alone
system, or a >2.5-log credit as an add-on toolbox component.
This analysis and these findings provide an important factual basis for the recommendations AWWA
offers in the following comments. AWWA-s review includes both research and data identified in the
LT2ESWTR proposal. AWWA believes the analysis in Appendix 1 and reflected in these comments more
correctly reflects the performance of some of these treatment technologies than the discussion provided in
the Federal Register notice and Microbial Toolbox Guidance. In addition to the literature and analysis
presented in Appendix 1 and Appendix 2, AWWA will also provide information and analysis with respect
to watershed control programs, bank filtration, ozone disinfection and UV disinfection.
Comment Response for LT2ESWTR 8-197 December 2005
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4.2.1 Regulatory -Preference- vs. Agreement in Principle
Response: See Response 820.
EPA Letter ID: 643
Comment ID: 12795
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Slow Sand Filter
States generally supported inclusion of this tool, but expressed concern with the 2.5 log presumptive
credit. Some states questioned whether slow sand filtration will be as effective in treating filter effluent as
it is treating raw water, noting that the ripening period and other factors will be significantly affected by
the water source applied to the filters.
Response: See Response 820.
EPA Letter ID: 678
Comment ID: 14714
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 10. The Agency requests comment on whether the available data are adequate to support
awarding a 2.5 log Crypto removal credit for slow sand filtration applied as a secondary filtration step,
along with any additional information related to this application. [47702, Cl]
Comment: We believe that awarding a 2.5 log credit to slow sand filtration applied as a secondary
filtration step for Cryptosporidium removal is not appropriate because the proposal was based on the
limited data of only one study. Hall et al. (1994), the basis for the EPA-s proposal, showed that a
combined primary filtration process followed by slow sand filtration achieved greater than 3 log
Cryptosporidium removal in three of five experimental runs and 2.5 log removal in the other two runs,
while slow sand filtration alone achieved 3 log removal in four runs. The study did not determine whether
slow sand filtration applied as a secondary filtration step by itself achieved at least 2.5 log removal.
Response: See Response 820.
EPA Letter ID: 712
Comment ID: 16589
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment Response for LT2ESWTR 8-198 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Comment: 3. Issue: Presumptive Credit
Slow sand: EPA provided no data to justify the presumptive credit for secondary slow sand of 2.5 logs.
The data that was provided only indicated that rapid sand followed by slow sand filtration can produce
over 3-log reduction.
Response: See Response 820.
EPA Letter ID: 712
Comment ID: 16591
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 881 1. Credit and criteria for awarding credit
Comment: Since filter performance depends on the ripening, and secondary filters and secondary slow
sand filters may take much longer to ripen, there is a concern that they may provide limited log reductions
during a long ripening period. EPA should develop more data on secondary filtration and secondary slow
sandfiltration, or make its use require a demonstration of performance.
Response: See Response 880 and Response 820.
8.12 Comment Codes 830, Membrane Filtration
Response to Code 830
a. Today's final rule establishes criteria for awarding Cryptosporidium treatment credit to membrane
filtration processes. To receive removal credit, filters must meet the definition of a membrane filtration
process and undergo challenge testing to establish removal efficiency; PWSs must periodically verify
system integrity through direct integrity testing and perform continuous indirect integrity monitoring
during use. The removal credit awarded to a membrane process is based on the removal efficiency
demonstrated during challenge testing and the sensitivity of the direct integrity test.
b. Challenge testing establishes the maximum Cryptosporidium treatment credit a membrane filtration
process is eligible to receive, provided this value is less than or equal to the sensitivity of the direct
integrity test. Challenge testing for membranes is product-specific, and PWSs that install membranes that
have successfully undergone challenge testing are not required to repeat testing at their sites.
c. EPA acknowledges that there may be circumstances under which less frequent testing may provide
adequate public health protection, and has revised the rule to allow States to permit less frequent direct
integrity testing based on demonstrated process reliability, use of multiple barriers effective for
Cryptosporidium, or reliable process safeguards.
d. The final rule provides States with performance based criteria to allow for flexibility in choice of
technology. A system can use emerging or alternative technology as it becomes available so long as the
log removal is consistent with the requirements for awarding removal credit as stated in the Final Rule.
Comment Response for LT2ESWTR 8-199 December 2005
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e. EPA appreciates your comments in support of the flexibility of the Rule.
Individual Comments on Code 830
EPA Letter ID: 509
Comment ID: 11484
Commenter: Greg Parker,, Florida Department of Environmental Protection Drinking Water Program
Commenter Category: State/Tribe Government
Comment: 141.728 This section specifies testing requirements for membrane treatment to demonstrate
cryptosporidium removal rates. Consider clarifying the rule to reduce the demonstration requirements so
they are not based on a case by case evaluation but reflect experience data with specific membranes.
Response: See Response 830a - 830b.
EPA Letter ID: 601
Comment ID: 13027
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 831 1. Credit and criteria for awarding credit
Comment: Membrane Filtration
Utah supports inclusion of membranes as a tool, and the approach that gives States the responsibility to
determine appropriate credit based on demonstrated performance.
Response: See Responses 830a - 830e, 83 Ib and 83 Ig.
EPA Letter ID: 612
Comment ID: 13154
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: Membrane systems are relatively new, but unlike conventional filtration, membrane modules
typically have a shorter life span. Most membranes have a specified lifespan of 10 years and a few
systems are now approaching the end of this projected life. The Agency should conduct frequent searches
of pertinent membrane knowledge bases including those from the American Water Works Association
and the American Membrane Technology Association, and the North American Membrane Society. In
addition, a survey of current installed systems should be performed to better determine if membrane
integrity failure correlates to membrane age.
Response: EPA will consider this suggestion for future study.
Comment Response for LT2ESWTR 8-200 December 2005
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EPA Letter ID: 612
Comment ID: 13157
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment:
The majority of studies that support the framework of LT2 involve the use of micro-filtration and ultra-
filtration. Two other membrane filtration techniques that are emerging in the drinking water arena are
nano-filtration and reverse osmosis. The latter two technologies encompass significantly different
operational practices and test protocol. Both nano-filtration and reverse osmosis membranes have to take
exception to the pressure-based pressure tests that LT2 prescribes. LT2 does specify that marker-based
tests can be applied, but these tests are limited in scope and application. Marker-based tests have practical
limitations, especially when dealing with larger membrane racks.
Response: See Response 830d.
8.12.1 Comment Codes 831, Credit and criteria for awarding credit
Response to Code 831
a. Today's final rule establishes criteria for awarding Cryptosporidium treatment credit to membrane
filtration processes. To receive removal credit, filters must meet the definition of a membrane filtration
process and undergo challenge testing to establish removal efficiency; PWSs must periodically verify
system integrity through direct integrity testing and perform continuous indirect integrity monitoring
during use. The removal credit awarded to a membrane process is based on the removal efficiency
demonstrated during challenge testing and the sensitivity of the direct integrity test.
b. EPA appreciates your comments in support of the tools included which allow PWS's to meet the
treatment requirements. The Agency believes that this rule clarifies the process needed to comply with
these requirements, and provides States with the flexibility necessary to meet those requirements while
allowing for variations in technologies chosen and for consideration of the evolving nature of the
technologies.
c. Challenge testing establishes the maximum Cryptosporidium treatment credit a membrane filtration
process is eligible to receive, provided this value is less than or equal to the sensitivity of the direct
integrity test, as described later in this section. Challenge testing for membranes is product-specific, and
PWSs that install membranes that have successfully undergone challenge testing are not required to repeat
testing at their sites. Furthermore, if approved by the State, data from challenge testing conducted prior to
promulgation of today's rule may be considered in lieu of additional testing. However, the prior testing
must have been conducted in a manner that demonstrates a removal efficiency for Cryptosporidium
commensurate with the treatment credit awarded to the filter.
d. In order to receive Cryptosporidium treatment credit for a membrane filtration process, PWSs must
conduct direct integrity testing in a manner that demonstrates a removal efficiency equal to or greater than
the removal credit awarded to the membrane filtration process. The "frequency" of direct integrity testing
specifies how often the test is performed over an established time interval. Direct integrity tests available
Comment Response for LT2ESWTR 8-201 December 2005
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at the time of promulgation are applied periodically and must be conducted on each membrane unit at a
frequency of not less than once per day that the unit is in operation, unless the State determines that less
frequent testing is acceptable. This allows the requirement to evolve with the state of the technology and
with the State's program development. If continuous direct integrity test methods become available that
also meet the sensitivity and resolution criteria described earlier, such a continuous test may be used in
lieu of periodic testing.
e. An evaluation of available direct integrity tests indicates that pressure-based tests are widely applied
and sufficiently sensitive to provide verification of removal efficiencies in excess of 4-log. Marker-based
direct integrity tests are also available, and new direct integrity tests may be developed that present an
improvement over existing tests. Rather than specify a particular direct integrity test, today's final rule
defines performance criteria for direct integrity testing. These criteria are resolution, sensitivity, and
frequency, as previously described. EPA believes that this approach will provide flexibility for the
development and implementation of future innovations in direct integrity testing while ensuring that any
test applied to meet the requirements of this rule will achieve the required level of performance.
f The final rule requires that continuous indirect integrity monitoring include continuous filtrate turbidity
monitoring, however, the State may approve an alternative method and parameter. If the State approves
an alternate parameter for continuous indirect integrity monitoring, the State must approve a control limit
for that parameter. If the parameter exceeds the control limit for a period greater than 15 minutes, the
PWS must perform direct integrity testing on the associated membrane unit.
g. The performance based nature of the criteria for awarding Cryptosporidium removal credit will provide
for consistency in application of the rule across different membrane products. The methodology provided
in the Final Rule and MFGM for States to use in determining removal credit also provides a basis for
consistent application of the rule requirements. However, States may have requirements more stringent
than the LT2ESWTR.
h. Among other requirements as specified in the Final Rule, membrane challenge testing must be
conducted on either an identical full-scale module or a smaller-scale module identical in material and
similar in construction to the membrane modules the PWS will use. A module is the smallest component
of a membrane unit in which a specific membrane surface area is housed in a device with a filtrate outlet
structure.
i. The final rule does state that the feed concentration is measured during challenge testing (as opposed to
atheoretical concentration). For feed sampling location, section 3.12.3 of the MFGM indicates that the
feed sample tap should be at least 10 pipe diameters downstream of the challenge particulate injection
point and in-line mixers. Also, because the maximum log removal credit for membrane filtration
permitted under the LT2ESWTR is 5.5 log, the regulatory framework does take into account a buffer of
1.0 log by allowing for a maximum seeding concentration to enable the demonstration of 6.5 log removal.
j. Utilities have many options for meeting the requirements of the LT2ESWTR, only one of which is
membrane filtration. For example, it is unlikely that a small system would opt to utilize membrane
filtration for compliance if less expensive options are available. The revised rule language (and thus the
revised MFGM) does allow the States some discretion in permitting less frequent direct integrity testing if
it is supported by demonstrated process reliability, the use of multiple barriers effective for
Cryptosporidium, or reliable process safeguards.
Comment Response for LT2ESWTR 8-202 December 2005
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Individual Comments on Code 831
EPA Letter ID: 457
Comment ID: 11935
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Membranes
We support inclusion of this tool and the eligibility requirements for the membrane filtration process, but
have concerns with the process needed to determine appropriate credit to apply. We suggest EPA consider
a minimum 2 log presumptive credit for membranes and not require the performance of demonstration
studies at each and every facility. The performance of demonstration studies should be an -option- by the
water systems for earning higher credits.
Response: See Response 83 la - 83 Ic.
EPA Letter ID: 470
Comment ID: 11086
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 851 1. Credits and criteria for awarding credits; 881 1.
Credit and criteria for awarding credit; 9311. Proposed credit and criteria for awarding credit; 9511.
Proposed approach for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment requirements
Response: See Response lOOaand 83Ib.
EPA Letter ID: 485
Comment ID: 11313
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: 1. The membrane data work suggests using the 10th percentile of the average log removals
from 20 cartridges. We presume that the agency will not have any objections to California continuing to
rate membrane performance based on the 95th or 5th percentile for determining the credit. The manner in
which the USEPA is proposing to determine membrane credit is less stringent than our present state
approach because it rates membrane performance on the average or 50th percentile (assuming a normal or
Gaussian distribution of performance data) that 90 percent of the units tested can achieve. In the USEPA
approach, the minimum log removal credited an alternative filtration technology (AFT) is the average
removal that could be attained in at least 10 percent of the samples and does not account for changes in
performance due to operational changes resulting from the accumulation of solids on the membrane
technology (over time). However, California-s approach is to credit the membrane for performance based
Comment Response for LT2ESWTR 8-203 December 2005
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on minimum log removal a membrane could achieve at least 95% of the time based on AFT performance
across an operational cycle, i.e., between membrane cleanings (chemical clean in place).
If the variance associated with AFT performance under the USEPA guidance is small, the USEPA will
credit a membrane with a higher degree of log removal than under the California AFT testing program.
Since the membrane credit under the California AFT program grants removal credit based on
performance during the period of greatest vulnerability and since one cannot predict when the membranes
will receive their greatest challenge from the source waters, the manner in which California grants credit
is more conservative and should be viewed as being more stringent, as is allowed under the primacy
agreement. Hence, the state-s program and strategy for rating the membranes is assumed to be acceptable
to the USEPA, unless specifically directed otherwise.
Response: See Response 83 Ib and 83 Ig.
EPA Letter ID: 520
Comment ID: 11644
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Membranes
IEPA generally supports inclusion of this tool, but expressed concern with the process needed to
determine appropriate credit to apply. EPA, States, water systems, and vendors need to work together to
determine an acceptable approach or approaches that may allow for systems to avoid performing
demonstration studies at every facility.
Response: See Response 83 la - 83 Ic.
EPA Letter ID: 538
Comment ID: 14095
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: CS Title: Comment focusing on "system should be developed by the EPA to certify
membrane manufacturers on log removals for each of their membrane types"
submitted by J. Scott Taylor, Director of Public Works, City of Wichita Falls
Comment One:
The EPA states that it is unable to estimate an average log removal for other filtration technologies like
membranes and that it is going to leave it up to the individual States to determine log removal. (Page
47667)The City of Wichita Falls disagrees with this approach and believes that a system should be
developed by the EPA to certify membrane manufacturers on log removals for each of their membrane
types. This would be the same type of program that is utilized in the industry for water treatment
chemicalsand their certification with NSF (ANSI 60/61).
Comment Response for LT2ESWTR 8-204 December 2005
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Having 100 City-s across the nation certify the same membrane is an unnecessary cost to the consumers
of those 100 utilities and an acceptable alternative developed by the EPA.
Response: See Response 83 la - 83 Ic.
EPA Letter ID: 538
Comment ID: 14105
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: The EPA is proposing direct integrity testing of membranes every 24 hours, (page
47706). The City of Wichita Falls is not opposed to this level of testing due to the new nature of
membrane technology. However, as systems become more familiar with this technology and its reliability
is proven or disproved, the EPA should reevaluate the need for this level of testing in the near future.
Response: See Response 83 Id.
EPA Letter ID: 562
Comment ID: 12296
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.2 Notice of Data Availability
AWWA recommends that the agency publish a Notice of Data Availability (NODA)
that includes these subjects:
Response: EPA did not identify new information for the final LT2ESWTRthat required a Notice of Data
Availability. Consequently, the Agency did not issue one.
EPA Letter ID: 562
Comment ID: 12497
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.2.10 Membranes
In reviewing the microbial toolbox, AWWA is concerned that the agency is not holding all technologies
to equivalent compliance requirements. Compliance determinations should be consistent across different
treatment technologies. For example, membrane modules and racks are akin to UV reactor and banks,
which are not unlike ozone contactors. The compliance requirements for various treatment technologies
should be consistent in the application of safety factors employed for design, the allowable off-
specification water released downstream of the treatment, whether compliance is based on observations
per unit time or per unit volume, and the use of hourly, daily, monthly, or annual performance metrics.
The agency should review the membrane provisions with this consideration in mind.
Comment Response for LT2ESWTR 8-205 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Response: See Response 831c-831g.
EPA Letter ID: 601
Comment ID: 13027
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 830 K. Membrane Filtration
Comment: Membrane Filtration
Utah supports inclusion of membranes as a tool, and the approach that gives States the responsibility to
determine appropriate credit based on demonstrated performance.
Response: See Responses 830a - 830e, 83 Ib and 83 Ig.
EPA Letter ID: 603
Comment ID: 12657
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47787) Section 141.728 -
The requirement for State approval of log removal credit for alternative filtration technologies (bag,
cartridge, and membrane filters) is a resource burden both upon States and equipment manufacturers. The
EPA may want to consider taking on this responsibility so that there is a consistent application of this
section. Alternatively, the EPA could support the establishment of a national review committee of
regulatory personnel to review products submitted by manufactures in an effort to increases consistency
and simplify the approval process for manufacturers.
Response: See Response 83 Ib and 83 Ig.
EPA Letter ID: 603
Comment ID: 12659
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47788) Section 141.728(b)(2)(i)-
We recommend that challenge testing be performed only on full-scalemembrane modules. The use of
smaller-scale membrane modules may lead to confusion and technical disagreements between the
manufacturer and State.
Response: See Response 83 Ic and 83 Ih.
Comment Response for LT2ESWTR 8-206 December 2005
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EPA Letter ID: 603
Comment ID: 12669
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47681) Section IV. B. Options for Systems to Meet Cyptosporidium Treatment
Requirements
11. Membrane Filtration - In general, the membrane filtration challenge and integrity testing requirements
developed in this rule provide long awaited definition for this alternative filtration technology.
Response: See Response 83 Ib.
EPA Letter ID: 612
Comment ID: 13155
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment:
The Use of Turbidity as an Indirect Monitoring Tool: Turbidity is prescribed in LT2 as an indirect
method, and the level of regulation is set at 0.15 NTU. The basis for establishment of this value appears to
be a transition from the conventional filtration practices, in which the Agency may be assuming
equivalence between the two technologies (membranes and conventional filtration). In comparison to
conventional filtration systems, membranes are a different and new technology for the water industry with
different mechanisms and levels of integrity failure. Membrane filtration should have its own defined
set of prescribed performance criteria as it relates insuring the production of safe drinking water.
As currently proposed in LT2, an event resulting in a change in turbidity of 0.1 NTU on a large
membrane rack would have to be so substantial that a significant volume of feedwater would have to flow
un-restricted into the combined effluent of the rack. Since membranes systems can potentially serve as a
single treatment component for meeting the cryptosporidium removal requirement in LT2, the proposed
turbidity-monitoring requirement should be re-considered and lowered. Laser turbidity technology is
available and provides accurate measurement at the lowest turbidity levels (from 0.01 to 1.0 NTU range).
This technology can be a much more beneficial water quality monitoring parameter for membranes if the
newer turbidity technologies are used. The Agency should require the use of the newer laser-based
turbidity methods for such applications.
Response: See Response 83 If and 836e.
EPA Letter ID: 612
Comment ID: 13158
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment Response for LT2ESWTR 8-207 December 2005
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Comment: The Agency should also allow use of particle counting technologies for the continuous
monitoring of membrane systems, specifically when those systems are small or pilot scale-sized plants.
The approach for filtrate monitoring could be the same as proposed for the turbidity monitoring. The
Agency could use the same proposed approaches that are suggested with the turbidity monitoring
arameter to better detect the occurrence of a membrane integrity loss.
Response: See Response 83 If and 836e.
EPA Letter ID: 612
Comment ID: 13159
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: Summary:
In the drinking water industry, membranes are a rapidly expanding and emerging technology. The
magnitude of growth does not appear to be accurately recognized by the Agency. The referenced
literature in LT2 regarding membranes does not address the concerns associated with membrane integrity
near the end of a membrane's life.
When considering the prescribed regulations regarding integrity tests, there is virtually no emphasis on
the continuous monitoring of water quality as it exits a membrane module. As currently written, the
turbidity limit is set so high that even a substantial integrity loss could likely not elevate the turbidity
levels above the proposed 0.15 NTU level (CFR 47704). When considering that LT2 can allow the entire
log removal credit to come solely from this technology and the absence of effective continuous
monitoring regulations as currently written would likely result in a higher health risk in the case of
integrity failure. For example, with the frequency of the direct test proposed at once per 24 hours, a
catastrophic integrity loss theoretically could result in the direct introduction of untreated water into the
filtrate stream until the completion of the next direct test. Depending on the size of the membrane rack,
the proposed turbidity limit may or may not be exceeded. In this scenario, there is no fail-safe mechanism
that is provided.
There are many new technologies that are becoming available that can better monitor membrane integrity
more effectively. These include various particle counting technologies, laser turbidity procedures, and the
ability to multiplex many of these technologies in order to reduce or eliminate the effects of dilution on
detection sensitivity. The Agency should take an active role in insuring that fail-safe continuous
monitoring mechanisms are better applied to more rapidly identify membrane integrity losses.
Response: See Response 83 If and 836e.
EPA Letter ID: 637
Comment ID: 13100
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: Membrane Filtration
Comment Response for LT2ESWTR 8-208 December 2005
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District supports inclusion of membranes as a tool, and the approach to give States the responsibility to
determine appropriate credit based on demonstrated performance.
Response: See Response 83 la - 83 Ib.
EPA Letter ID: 641
Comment ID: 13601
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47703 (Challenge Testing, 2nd bullet on page)
Maximum Allowable feed concentration = 3.16 x 10EE6 x Filtrate Detection Limit)-. The challenge dose
should always be determined by collection and analysis of an influent sample, from a port as close as
possible to the treatment. The resulting concentration thereby incorporates any matrix interference, loss of
challenge organisms due to sampling, analytical inefficiency, etc. As stated above, this feed concentration
only allows demonstration 6.5 Log removal only if 100% recovery efficiency from the influent sample is
achieved. ASI recommends that EPA revise to allow a challenge dose of 0.5 to 1.0 log higher than the
desired log removal value.
4th bullet: LRV = Log (Cf) - Log (Cp) Cf, or Feed concentration, should be determined by sampling
influent water, not just theoretical feed concentration, to incorporate inefficiencies in sampling and
analysis. (See above also).
Response: See Response 83 li.
EPA Letter ID: 643
Comment ID: 12798
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Membranes
States generally support inclusion of this tool, but expressed concern with the process needed to
determine appropriate credit to apply and several states have indicated that they intend to submit specific
comments on this issue directly to EPA. States look forward to working with EPA, water systems, and
vendors to determine an acceptable approach or approaches that may allow for systems to avoid
performing demonstration studies at every facility.
Response: See Response 83 la - 83 Ic.
EPA Letter ID: 647
Comment ID: 12937
Comment Response for LT2ESWTR 8-209 December 2005
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Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Membranes
MDE supports inclusion of this tool, but is concerned with the process needed to determine the
appropriate credit to apply.
Response: See Response 83 la - 83 Ic.
EPA Letter ID: 662
Comment ID: 14039
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Membrane Filtration
Inclusion of membranes as a tool and the approach to give States the responsibility to determine
appropriate credit based on demonstrated performance is supported.
Response: See Response 83 la - 83 Ib.
EPA Letter ID: 673
Comment ID: 13992
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: C. 11. Membrane Filtration (pages 47702-47706)
Comments on Membrane Filtration
Jordan Valley Water supports inclusion of membranes as a tool, and the approach to give States the
responsibility to determine appropriate credit based on demonstrated performance.
Response: See Response 83 la - 83 Ib.
EPA Letter ID: 687
Comment ID: 14751
Commenter: David Pearson, General Manager, PCI Membrane Systems Inc.
Commenter Category: Manufacturer/Vendor
Comment Response for LT2ESWTR 8-210 December 2005
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Comment: Comment:
It is commonly understood that all membrane systems provide an excellent absolute barrier to pathogens
with log reduction in excess of log 6 expected when membranes are intact. All membrane configurations
are required to have a direct integrity test, [proposed §141.728(b)], to allow them to be granted a removal
credit. Proposed § 141.728(a) recognizes that it is not possible to have a direct integrity test for most bag
and cartridge filters and allows for the granting of removal credit to these devices.
For small systems, the additional cost of a conforming direct integrity test may be a significant additional
cost, whereas lower-cost approaches might provide sufficient back-up protection. Take the example of a
small community water system treating a high organic laden surface water with system capacity of 15 to
30 gpm and classified in one of the higher bins for cryptosporidium treatment under this rule. This
community might want to adopt a tubular or spiral nanofiltration membrane solution, in order to meet the
requirements of the disinfection by products rule. Such a system would be expected to easily meet in
excess of log 6 removal of cryptosporidium, however for the membrane system to be given any credit
whatsoever under the proposed rule a small system would have to include an additional, and most likely,
expensive direct integrity test of the membrane system.
The cost of a UV system for up to 15 gpm installed would come to under $2000. By comparison the cost
of a direct integrity test on a tubular or spiral membrane system of this capacity would be expected to be
significantly higher and require an additional level of system sophistication with instrumentation and
automated valves hat may be inappropriate for a small system. A manual direct integrity test might be
adopted, at much lower cost, to monitor for membrane/module failure on a monthly basis.
Installation of a secondary barrier using either a UV system or bag/cartridge filters provides insurance in
the unlikely event of loss of membrane integrity. The cost of these secondary barriers would be lower
than the cost of direct membrane integrity test equipment and would provide a safer and simpler to
operate water treatment process than a single membrane system with directintegrity test equipment. Yet in
these circumstances no credit would be given under the proposed rule to the membrane system despite the
rule giving credit to bag or cartridge filters. We request the EPA give consideration to the expense and
difficulty in designing direct integrity tests for some membrane configurations, particularly for small
community water systems, by allowing credit for membrane systems that do not have a direct integrity
test. Clearly a microbial challenge would need to be done prior to credit being given to such a system and
it would be reasonable to give credit lower than that given to a system with a direct integrity test.
Such an approach might enable small communities to adopt what might be considered a pragmatic and
safe alternative treatment train utilizing more than one technology for to meet the levels of
cryptosporidium treatment required under the rule, whilst also reaching goals for TTHM and HAA(5) set
under the D/DPB Rule.
Response: See Response 83 Ib, 831d-e, 83 Ig, and 83 Ij.
Comment Response for LT2ESWTR 8-211 December 2005
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8.12.2 Comment Codes 832, Additional data on membrane filtration
performance
Response to Code 832
The LT2ESWTR language for membrane filtration and associated guidance were not based primarily on
pilot studies or relatively small plants, as suggested in this comment. In addition, the regulatory
framework and MFGM have both been designed with an appropriate and significant degree of flexibility
that allows for future development and innovation.
In the August 11, 2003 proposed LT2ESWTR, EPA proposed to establish criteria for awarding credit to
membrane filtration processes for removal of Cryptosporidium (USEPA 2003g). The Agency based these
criteria on data demonstrating the Cryptosporidium removal efficiency of membrane filtration processes,
a critical evaluation of available integrity monitoring techniques, and study of State approaches to the
regulation of membrane filtration for pathogen removal. This information is summarized in the report
Low-Pressure Membrane Filtration for Pathogen Removal: Application, Implementation, and Regulatory
Issues (USEPA 200Ig).
As summarized in this report, a number of studies demonstrate the ability of membrane filtration
processes to remove pathogens, including Cryptosporidium, to below detection levels (USEPA 200Ig). In
some studies that used Cryptosporidium seeding, measured removal efficiencies were as high as 7-log
(Jacangelo, et al., 1997; Hagen, 1998; Kachalsky and Masterson, 1993). In other studies, removal
efficiencies ranged from 4.4- to 6.5-log and were only limited by the seeded concentration of
Cryptosporidium oocysts (Dwyer, et al. 1995, Jacangelo et al. 1989, Trussel, et al. 1998, NSF 2000a-g,
Olivieri 1989). Collectively, these results demonstrate that an integral membrane module (i.e., a
membrane module without any leaks or defects, with an exclusion characteristic smaller than
Cryptosporidium) is capable of removing this pathogen to below detection in the filtrate, independent of
the influent concentration.
Individual Comments on Code 832
EPA Letter ID: 612
Comment ID: 13152
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: The majority of the test and operational criteria that is written into LT2 was based on pilot
studies or on the operation of relatively small-sized plants (those that produce less than 1 MOD). Many of
the tests such as the direct integrity tests were derived on small systems. Do these same test and
operational practices translate to large-scale systems? Large-scale plants will often have a different set of
operational criteria than that, which are practices on small or pilot facilities. If so, is there data available
that confirms the extrapolation to large-scale systems? Recent presentations at the 2003 Water Quality
Technology Conference (Chung, et. al) discussed the difficulties of correlating scale-up from pilot to
large membrane racks with respect to operational and integrity protocols.
With the rapid growth of membrane systems that are designed for drinking water applications, this
technology is still in a state of emergence. This is particularly true when it comes to the larger systems
and large rack designs. At this time there are few if any studies that can confirm the extrapolation of the
proposed regulatory parameters from a pilot to large-scale system.
Comment Response for LT2ESWTR 8-212 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
The continual emergence of membranes is evidenced by the increased number of conferences and
symposiums that are dedicated to the operational aspects of membrane filtration. At this time, it would not
be appropriate for LT2 to be finalized and become inflexible in regards to membrane filtration. Hach
Company suggests that the Agency continue to perform frequent reviews of new practices and
technologies as they are applied to membrane filtration. It would not be in the best interest of all parties
(manufactures, supporting technologies, the drinking water treatment industry, the consumer, and the
regulatory authority) to pass a set of inflexible regulatory criteria until the operational practices
and guidelines for gauging performance are well understood through repetitive or similar confirmation
studies.
Response: See Response 832.
8.12.3 Comment Codes 833, Inclusion of membrane cartridge filters
that can be integrity tested
Response to Code 833
A cartridge filter device that fits the criteria described in the rule would constitute membrane filtration.
However, a sentence has been added to section 2.2.3 in the MFGM to reinforce that such devices that
operate as depth filters would not qualify as membrane cartridge filtration under the rule.
The regulatory rule addresses these concerns: If a cartridge filter does not meet the definition of a
membrane filtration device or cannot meet the criteria for sensitivity, resolution, and frequency, then it
would not be acceptable. However, those that do comply with these requirements would be considered
membrane filtration for the purposes of the rule. In terms of automation, utilities can always opt not to use
a particular device if direct integrity testing requires manual implementation; moreover, even if such
automated systems are not currently manufactured, systems could implement them as they become
available.
Individual Comments on Code 833
EPA Letter ID: 548
Comment ID: 12165
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: While the methodology of direct integrity testing for membrane cartridge filters is sound,
Metropolitan believes that membrane cartridge filters do not belong under Membrane Filtration (Sec. IV.
C.II), but rather under Bag and Cartridge Filtration (Sec. IV C.12). -Membrane cartridge filters- is a
misnomer in that there is no membrane at all, and the cartridge filters operate more like a depth filter in
that they have varying removal efficiencies of the source of a filtration cycle.
Response: See Response 833.
Comment Response for LT2ESWTR 8-213 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 603
Comment ID: 12670
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: As stated in this section, EPA is proposing to include membrane cartridge filters that can be
direct integrity tested under the definition of a membrane filtration process. The department disagrees
with this approach for a couple reasons. First, a membrane module consists of thousands of individual
fibers, with multiple modules in most systems. The failure of a single or even multiple fiber breaks fiber
is unlikely to compromise the ability of a membrane cartridge filter to compromise the log removal credit
awarded to a membrane filtration system. However, the corollary for membrane cartridge systems is not
true. A membrane cartridge system will contain less than a dozen cartridges in most cases and if one or
more membrane cartridge filters are compromised, there is not the degree of dilution from multiple intact
fibers as is the case with true membrane filters. Second, the direct integrity test for membrane cartridge
filters is not automated. A manual process is more labor intensive and unlikely to be implemented on a
daily basis on the very small, remote systems where membrane cartridge filters are likely to be installed.
In summary, membrane cartridge filters, although they maybe very effective at removing
Cryptosporidium, are unlikely to be able to meet the sensitivity,resolution, and frequency requirements of
membrane filtration systems.
Response: See Response 833.
8.12.4 Comment Code 834, Applicability of credit and criteria to
Giardia
Individual Comments on Code 834
EPA Letter ID: 548
Comment ID: 12166
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * The applicability of the proposed Cryptosporidium removal credits and performance criteria
to Giardia lamblia
Appropriate, though most likely too conservative.
Response: See Response 834.
Comment Response for LT2ESWTR 8-214 December 2005
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8.12.5 Comment Codes 835, Appropriate surrogates for challenge
testing
Individual Comments on Code 835
EPA Letter ID: 548
Comment ID: 12167
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * Appropriate surrogates, or the characteristics of appropriate surrogates, for use in challenge
testing - EPA requests data or information demonstrating the correlation between removal of a proposed
surrogate and removal of Cryptosporidium oocysts
Appropriate.
Response: See Response 835.
8.12.6 Comment Codes 836, Use of non-destructive performance
testing
Response to Code 836
a. EPA appreciates your comment. However, the Agency believes that continuous monitoring of each
membrane unit is necessary to ensure that a substantial integrity breach that may occur between direct
integrity test applications does not compromise filtrate quality.
b. Regarding the challenge test requirement, the State has the discretion to accept previously established
data on the challenge test performance of a membrane filter if that data was collected in a manner
consistent with the requirements established under the final rule. However, the prior testing must have
been conducted in a manner that demonstrates a removal efficiency for Cryptosporidium commensurate
with the treatment credit awarded to the filter.
c. In order to provide some measure of process performance between direct integrity testing events, PWSs
must perform continuous indirect integrity monitoring on each membrane unit. Continuous indirect
integrity monitoring is defined as monitoring some aspect of filtrate water quality that is indicative of the
removal of particulate matter at a frequency of at least once every 15 minutes. EPA appreciates your
comment in support of this testing interval for continuous indirect integrity monitoring.
d. As part of the challenge test, a quality control release value (QCRV) must be established for a non-
destructive performance test (e.g., bubble point test, diffusive airflow test, pressure/vacuum decay test)
that demonstrates the Cryptosporidium removal capability of the membrane module. The non-destructive
performance test must be applied to each membrane module a PWS uses in order to verify
Cryptosporidium removal capability. Membrane modules that do not meet the established QCRV are not
eligible for the Cryptosporidium removal credit demonstrated during challenge testing. EPA appreciates
your comment in support of the establishment of a QCRV for a non-destructive performance test.
Comment Response for LT2ESWTR 8-215 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
e. EPA appreciates your comment favoring on-line particle counters in place of turbidimetry as a method
for continuous indirect integrity monitoring. The requirement is not intended to establish a practical
relationship between turbidity (or other measure of filtrate water quality) and system integrity. Instead, it
is designed to provide some indication of a significant integrity problem between applications of direct
integrity testing. In addition, States do have the discretion to allow the use of particle counters as a
substitute for turbidimetry.
f The Agency thanks you for your suggestion to consider continuous indirect integrity testing on each
module. At this time there is not sufficient evidence to suggest that indirect methods are as sensitive to
integrity breaches as the direct methods. In addition, to monitor the filtrate of every module would likely
be prohibitively expensive, particularly if the combination of periodic direct testing and continuous
indirect monitoring will capably provide an adequate ongoing assessment of membrane integrity.
g. Regarding the establishment of an alternative turbidity control limit during a pilot phase of membrane
evaluation and process control limit: Piloting is not required under the LT2ESWTR, and thus the USEPA
cannot mandate a control limit that is linked to such testing. However, States would have the option of
requiring such an established link between piloting and a control limit for continuous indirect integrity
monitoring, provided the resulting control limit was more stringent than 0.15 NTU (in the case of
turbidity monitoring). This same rationale applies to the second suggested option regarding a statistical
method based on operating data collected under normal conditions.
h. Also, particle counters are permitted to be used as a continuous indirect integrity monitoring method
under the rule. Even for small systems, direct integrity test methods would still be more sensitive than
currently available indirect monitoring techniques. Moreover, the ability to conduct direct integrity tests is
a standard inclusion with almost all MF/UF systems, so EPA believes that implementing this testing does
not constitute an undue burden on small systems.
Individual Comments on Code 836
EPA Letter ID: 449
Comment ID: 10830
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: Based on our 5 years of experience operating a large scale microfiltration system, we feel that
membranes offer superior protection against parasites such as cryptosporidium. In fact, testing that was
conducted at our facility proved that the true performance of such systems cannot be measured by the use
of turbidimeters and particle counters. Therefore we feel that the proposal in section 141.728B(iii) that
each membrane unit have its own turbidimeter and particle counter is unnecessary. The tools provided by
the manufacturers of the systems are much better at tracking the systems integrity. The pressure decay
test (which at our facility is conducted every 8 hours) can help track down a breach of as little as 1 to 2
fibers. The sonic test is used to pinpoint the location of the fiber in the unit. These tools provide assurance
in the performance of the systems and have proved to be very reliable in locating problems. While we
understand that there is a need for parameters to operate these systems, we don-t feel that additional
testing such as challenge testing is necessary once the systems have a proven track record.
Response: See Response 836a - 836b.
Comment Response for LT2ESWTR 8-216 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 474
Comment ID: 11197
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: monitoring. We believe indirect integrity monitoring should be conducted on a 15-minute
interval. Based on this frequency, the frequency of direct integrity
Response: See Response 836c.
EPA Letter ID: 548
Comment ID: 12168
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * The use of a non-destructive performance test and associated quality control release values
for demonstrating the Cryptosporidium removal capability of membrane modules that are not directly
challenge tested
Appropriate.
Response: See Response 836d.
EPA Letter ID: 559
Comment ID: 12226
Commenter: Bill Pappathopoulos, Director, City of Two Rivers, Water & Light Utility
Commenter Category: Regulated Community (Utilities)
Comment: 11. Membrane Filtration - Continuous Indirect Integrity Monitoring
The discussion on this requirement suggests that continuous indirect integrity monitoring be required of
each membrane skid, such that continuous turbidity monitoring would be required of each membrane
filter system. After 11 months of pilot operation, our Utility is currently installing 5 membrane stages,
each provided with continuous on-line turbidity monitoring and we can assure you that there is no valid,
obvious or practical relationship between turbidity and system integrity. On-line particle counters would
offer a more valid and continuous monitoring process. The need, however, for on-line particle counting
of each membrane stage would not seem necessary especially if the combined effluent were continuously
monitored with the opportunity to isolate and monitor individual stages, when found necessary.
Response: See Response 836e.
Comment Response for LT2ESWTR 8-217 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 603
Comment ID: 12672
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Future developments may make it possible that continuous indirect integrity testing on each
module may be feasible, affordable, and sensitive enough to detect a single compromised fiber. EPA
should consider this potential for continuous indirect integrity monitoring on each filter module if there is
sufficient data to support such a monitoring approach when the rule is finalized.
Response: See Response 836f
EPA Letter ID: 612
Comment ID: 13156
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: Two options are suggested to better provide a more meaningful continuous monitoring
approach for the detection of membrane integrity loss (CFR 47706). First, would be to establish a
meaningful and appropriate turbidity control limit for membranes. The control value could be established
during the pilot phase of membrane evaluation under conditions that are confirmed to be integral. This
would establish a useful turbidity limit that would provide meaningful use for integrity loss in a timely
manor. The use of new and better turbidity monitoring technologies, which are specifically designed for
low-level monitoring should also be provided in the rule. The second option would be to develop a
process control limit that would be established under known integral operational conditions of the
membrane. For example, the establishment of an upper control limit (UCL) that is either two three
standard deviations above the pre-established turbidity value would serve as the UCL for that rack. In the
event that the filtrate turbidity exceeded this UCL, the rack would be taken offOline for further
investigation. Again, the use of newer and more sensitive turbidity monitoring technologies would
provide more accurate and meaningful continuous monitoring information.
The application of particle counting as an integrity monitoring tool: As previously mentioned, particle
counting is a very descriptive water quality parameter that can be applied continuously to membrane
effluent. This is a commonly utilized continuous monitoring technology by the membrane manufacturers
and is usually a continuous monitoring parameter in nearly all membrane pilot studies. For the smallest
membrane systems, particle counters can possess the sensitivity to detect integrity losses from a
continuous monitoring perspective. The LT2 rule does not recognize the availability of or the benefits of
this technology when its application is served to small membrane systems.
Response: See Response 836g.
Comment Response for LT2ESWTR 8-218 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
8.12.7 Comment Codes 837, Minimum direct integrity testing
frequency
Response to Code 837
a. EPA appreciates your comment in support of the 24 hour minimum frequency for direct integrity
testing of membranes.
b. In order to provide some measure of process performance between direct integrity testing events, PWSs
must perform continuous indirect integrity monitoring on each membrane unit. Continuous indirect
integrity monitoring is defined as monitoring some aspect of filtrate water quality that is indicative of the
removal of particulate matter at a frequency of at least once every 15 minutes. The Agency agrees that
this testing interval for continuous indirect integrity monitoring may in some cases reduce the need to
conduct the direct integrity test as frequently as the 24-hour minimum. The rule language and MFGM
have been modified to allow States some discretion for potentially reducing the frequency of direct
integrity testing if it is supported by demonstrated process reliability, the use of multiple barriers effective
for Cryptosporidium retention, or reliable process safeties.
c. EPA appreciates your comments requesting clarity on the conduct of direct integrity testing. The
MFGM explains the concept of resolution in section 4.2 and elaborates on how resolution is determined
for both pressure-based and marker-based direct integrity tests. Regarding the question of counting clock
time only during forward moving flow times, the Agency believes that operations such as backwashing
and chemical cleaning will not occur with sufficient frequency during normal operation to justify a more
complex system of defining operational time for the purpose of a more quantified definition of direct
integrity test frequency. The description of test frequency described in the rule language and elaborated
upon in the MFGM should not result in erroneous data. In any case, if backwashing and chemical
cleaning are accounted for in what might constitute normal operation, this will only result in a more
conservative frequency than by simply counting forward flow.
d. In considering the concepts of resolution and sensitivity, the MFGM does take into account operational
conditions where appropriate; because the determination of resolution and sensitivity is always applicable
to a site-specific full-scale system, scale-up considerations should not be a factor.
e. The Agency is not aware of widely accepted studies that suggest filtrate quality is dependent on either
feed pressure or transmembrane pressure (TMP). The maximum applied pressure is dictated by the
membrane manufacturers for their specific products. If it is true that over-pressurizaton during a pressure-
based direct integrity test could cause false positive results (which does not appear to be a widespread
performance issue; nor are applied test pressures typically very high), this would generate a conservative
result. Thus, the membrane manufacturers would have no motivation for prescribing an unusually high
test pressure.
Individual Comments on Code 837
EPA Letter ID: 474
Comment ID: 11198
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: EPA requested comments on the frequency for conducting direct integrity monitoring. We
believe indirect integrity monitoring should be conducted on a 15-minute interval. Based on this
Comment Response for LT2ESWTR 8-219 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
frequency, the frequency of direct integrity testing could be reduced from once a day to once per week.
As membrane plants become larger, it will likely become more difficult to conduct direct testing of
every module in the system on a daily basis. Weekly or less frequent direct integrity monitoring would
appear to be adequate so long as indirect integrity monitoring is conducted every 15 minutes.
Response: See Response 837b.
EPA Letter ID: 491
Comment ID: 10668
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: 6. The membrane integrity testing minimum frequency should allow greater
flexibility and reporting requirements should not become more stringent than what is currently proposed.
EPA has proposed integrity testing of membrane systems at least every 24 hours. While systems may test
more frequently during start-up to verify reliability, integrity testing more frequent than every 24 hours
during long-term operations would put an unnecessary burden on systems. Even daily testing can have an
impact on plant operations and production. Additional flexibility should be included in the LT2 rule to
allow integrity testing at minimum intervals less frequent than every 24 hours in the long-term for
systems that have consistent integrity test results that demonstrate the stability and reliability of the
membrane modules. Determinations for allowing reduced testing frequencies could be made by the
primacy agency based on a review of the integrity testing data. EPA has also proposed that monthly
Response: See Response 837a - 837b.
EPA Letter ID: 548
Comment ID: 12169
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * The appropriateness of the minimum direct integrity test frequency of once every 24 hours
Appropriate.
Response: See Response 837a.
EPA Letter ID: 585
Comment ID: 11979
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment Response for LT2ESWTR 8-220 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Comment: p. 47706 [and §141.728(b)(3)(vi) on p. 47788]
The TCEQ opposes a mandatory requirement for daily direct integrity tests for each membrane unit. The
preamble contains no data on membrane failure rates nor does it describe the impact that repeated
integrity testing has on membrane life. Consequently, it is unclear whether daily testing is a necessary
procedure to protect public health or a procedure that may result in premature membrane failure. Unless
the EPA has data suggesting that daily testing is necessary to prevent an elevated risk to public health, the
TCEQ recommends that the EPA require testing in accordance with the requirements of the primacy
agency. The recommendation to test on a daily basis can then be incorporated into guidance that primacy
agencies can use when developing and implementing their respective programs.
Response: See Response 837b.
EPA Letter ID: 603
Comment ID: 12671
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: The minimum direct integrity test of once per 24 hours is a reasonable standard and one that
has been adopted by many States, including Washington where indirect integrity testing is also employed.
The department supports this frequency of direct integrity testing.
Response: See Response 837a.
EPA Letter ID: 612
Comment ID: 13153
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: Direct Integrity Testing (CFR 47703) - LT2 mandates the requirement of conducting direct
integrity testing on membrane systems that will insure the integrity of the membrane rack. The direct test
must meet three criteria: sensitivity, resolution, and frequency. While sensitivity and frequency are
criteria that are well understood, resolution is a criterion that most users of the technology struggle to
understand. The Agency should provide within LT2, better examples on how to demonstrate compliance
with the resolution requirement.
LT2 should better define what is meant by frequency of measurement. Specifically, frequency is relative
to forward filtration flow only and not based on clock time. If this is not specified and if clock time is
used, erroneous monitoring data will result during operational events such as reverse flow, air scour, and
various membrane cleaning processes.
While resolution and sensitivity are both criteria that are derived through the use theoretical bubble point
calculations, have these tests been confirmed to be appropriate under different operational conditions as
well as for the scale-up to large membrane systems? These tests also prescribe a minimum pressure that
must be applied to achieve the theoretical resolution of the membrane. Can an additional pressure force
particles through membrane pores? LT2does not suggest an upper limit for the test practice. Without an
upper pressure limit, can additional pressurization of the system cause other intrinsic complications or
Comment Response for LT2ESWTR 8-221 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
cause other integrity losses within the membrane infrastructure. It has been demonstrated that over-
pressurization of the system could also result in performance complications including the generation of
false positive results. Additional prescriptive direction regarding the operation of integrity tests needs to
be placed into this rule or the rule needs to point specifically to the appropriate sections within the
membrane guidance manual for this direction.
Response: See Response 837c - 837e.
8.12.8 Comment Codes 838, Reporting frequency for not meeting
integrity criteria
Response to Code 838
EPA appreciates your comments in support of the reporting procedure that requires, for indirect integrity
testing, only those results that necessitate a direct integrity test.
Individual Comments on Code 838
EPA Letter ID: 491
Comment ID: 10669
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: flexibility and reporting requirements should not become more stringent than what is
currently proposed. EPA has proposed integrity testing of membrane review of the integrity testing data.
EPA has also proposed that monthly reporting would consist of a summary of direct integrity test results
above the control limit, as well as any indirect integrity testing (turbidity monitoring) results that trigger
direct integrity testing. Under this scenario, a plant would only have to report test results that are out-of-
range and would not have to list the results of each within-range test. ACWD supports this approach that
highlights only the data of concern.
Response: See Response 838.
EPA Letter ID: 548
Comment ID: 12170
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * The proposed minimum reporting frequency for direct integrity testing results above the
control limit and indirect integrity monitoring results that trigger direct integrity monitoring
Appropriate.
Response: See Response 838.
Comment Response for L T2ESWTR 8-222 December 2005
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8.12.9 Comment Codes 839, Rule Language Edits
Response to Code 839
The Agency appreciates your comment and has corrected the numbering of the paragraphs.
Individual Comments on Code 839
EPA Letter ID: 493
Comment ID: 11250
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment: 40 CFR 141.728(b)(3)(iii) refers to -... paragraph (b)(2)(iii)(A) or (b)(2)(iii)(B) of this
section...-. This is incorrect. Should read —... paragraph (b)(3)(iii)(A) or (b)(3)(iii)(B) of this section.
Response: See Response 839.
8.12.10 Comment Codes 840, Guidance
Response to Code 840
This comment addresses Guidance and not the LT2ESWTR, and EPA has considered it in finalizing the
Membrane Filtration Guidance Manual (MFGM). It is important to note that information contained in
guidance manuals (i.e., the SWTR, LT2ESWTR, or the MFGM) is only guidance for complying with the
respective rules with which they are associated, which are the law. The only specific requirements are
those cited in the rule language.
Although it is outside the scope of the MFGM to rescind previous regulations or advise a PWS or the
State to follow one regulation over another equally valid regulation under the law, it is appropriate for the
MFGM to provide some clarification on this subject. Thus, in Chapter 1 the MFGM clarifies that the
guidance offered by the Guidance Manual for Compliance with Filtration and Disinfection Requirements
for Public Water Systems Using Surface Water Sources (1990) is specific to Giardia and viruses, and thus
does not conflict with the Cryptosporidium regulatory framework for membrane filtration established
under the LT2ESWTR
Individual Comments on Code 840
EPA Letter ID: 485
Comment ID: 11314
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment Response for L T2ESWTR 8-223 December 2005
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Comment: 2. The Department recommends the USEPA rescind the section of its 1989 SWTR
Guidance manual (and any other guidance superseded by these guidance documents) granting reverse
osmosis (RO) membranes a 4-log virus removal credit without testing. Since the 1989 guidance manual is
still in use and will continue to be used, those sections that are no longer applicable should be clearly
identified for the states and regulated water utilities. The recommendation to rescind this portion of the
SWTR Guidance manual is based on the RO membrane performance from the San Diego water
purification project in which MS2 challenges showed less than 3 logs of removal when the membranes
are clean.
Response: See Response 840.
EPA Letter ID: 485
Comment ID: 11315
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: 3. The Department also seeks guidance on the regulation of desalination facilities. We would
presume that desalination facilities drawing from brackish groundwaters would be regulated as a
groundwater supply, with appropriate removal requirements based on a watershed sanitary survey.
Seawater desalination with beach wells would be handled in much the same way. In both cases a GWUDI
study will be conducted to determine if the source water should be treated as though it were a surface
supply.
In the case of seawater desalination associated with the cooling water from power plants or other surface
water intakes, the plants will be handled as if they were surface water treatment plants. Are there any
special hazards or practices associated with any of these high salinity source waters that need to be
addressed?
Response: See Response 840.
EPA Letter ID: 485
Comment ID: 11316
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Has the USEPA considered extending the LT2 to desalination facilities and have you given
any thoughts to additional water quality issues that might come from using marine or estuarine waters as
sources of supply (pfisteria, paralytic shellfish toxins, red tides, etc.)? The approach we are currently
taking is to permit desalination facilities as if they were a surface supply. Those desalination operations
using beach wells are handled like groundwater supplies, if there is no evidence that it is under the
influence of a surface water supply. We will continue this course of action unless we receive guidance to
the contrary.
Response: See Response 840.
Comment Response for L T2ESWTR 8-224 December 2005
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8.12.11 Comment Codes 841, Membrane Guidance Manual
(specific to the guidance manual)
Response to Code 841
These comments address Guidance and not the LT2ESWTR, and EPA has considered it in finalizing the
Membrane Filtration Guidance Manual (MFGM). It is important to note that information contained in
guidance manuals (i.e., the SWTR, LT2ESWTR, or the MFGM) is only guidance for complying with the
respective rules with which they are associated, which are the law. The only specific requirements are
those cited in the rule language.
Individual Comments on Code 841
EPA Letter ID: 101
Comment ID: 10912
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 970 R. Toolbox Guidance Manual (specific to the
guidance manual)
Comment: Use of Examples
NRWA encourages EPA to use examples throughout the guidance document. Relying on examples rather
than a range of numbers or figures provides maximum flexibility for communities to devise compliance
options unique to their circumstances.
Provide Small System Summary
The Agency should provide a five page summary of the entire guidance document and reference the
reader to specific sections for more details. This should not only be done for this document but also for all
the guidance documents related to these two rules. NRWA would be pleased to provide services for
EPA's contractor to write this summary.
Response: See Responses 970 and 841.
EPA Letter ID: 485
Comment ID: 11318
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: What differentiates nanofiltration from reverse osmosis?
Pg. 1-7 What are the criteria for determining the hole contributes a response from the test?
Pg. 1-8 What are the criteria for determining a control limit?
Pg. 3-4 Why can-t particle counting be used as a challenge particulate? Particle counting has been used to
-credit- alternative filtration technologies. How is the filtrate detection limit established? The statement
that begins with -This expression— only holds true if the filtrate detection limit is 1. This should be
stated for the reader to clarify the example.
Comment Response for L T2ESWTR 8-225 December 2005
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Pg. 3-11 What are the criteria for determining whether an LRV (log removal value) is significant or not,
i.e., what are the confidence level and minimum degrees of freedom?
Pg 3-23 The same issue, what are the criteria for establishing a detection limit in the filtrate?
Pg. 5-8 Since turbidity is such an integral part of monitoring these systems, shouldn-t the units be tested
and the testing results accepted through the advanced on-line monitoring ETV program? In fact shouldn-t
all on-line instrumentation be tested and accepted by the USEPA through the ETV program? If not, sense
the USEPA has accepted turbidimeters by method, should not the same approach be taken for particle
counters for the sake of consistency?
Pg. 5-9 allows the states to approve the use of particle counters for continuous indirect integrity
compliance monitoring. The citations listed in Section 5.3.1 entitled -Methods- appear to be calibration
methods, which are fine. However, what is missing is either a method detection limit or the criteria for
establishing a method detection limit. As noted on pg. 5-11 there is an advantage to using a statistical
approach to setting a control limit (CL) as the background noise will be filtered or blocked and one will
have confidence that the response indicates a problem. Therefore the criteria for establishing a detection
limit for the analytical instrumentation is critical. Such criteria should be uniform throughout the industry
and is therefore, properly established by the USEPA.
As noted elsewhere and on pg. 5-11 particle counters and turbidity may not provide an indication of an
integrity breach. However, as noted in the guidance manual, this is not critical unless the integrity breach
compromises the removal credit given the technology. As long as one is confident the performance
remains at or above the credited value, the barrier is sufficiently intact. This emphasizes the need to
establish detection limits for the analytical instrumentation.
Response: See Response 841.
8.13 Comment Codes 850, Bag and Cartridge Filtration
Response to Code 850
a. Thank you for these data on bag and cartridge filter performance. These results are consistent with the
range of results for bag and cartridge filters that EPA reviewed for the proposed LT2ESWTR and that
support today's final rule.
b. EPA believes that the required 1-log factor of safety for individual bag and cartridge filters is
appropriate to address variability in individual filter performance and in the absence of a direct integrity
test for these products. Challenge testing provides an estimate of the removal efficiency of a bag or
cartridge filter product line but does not involve testing every filter. Further, it does not fully capture the
variation in filter performance that will occur overtime during routine use. Parameters like turbidity and
pressure differential that may be monitored with these filters have not been shown to correlate well with
Cryptosporidium removal efficiency. Consequently, a safety factor is necessary to account for variation in
individual filter performance relative to challenge test results.
In today's final rule, EPA has reduced the factor of safety to 0.5-log for configurations consisting of two
or more filters in series. Series operation provides an intrinsic process safety and will dampen some of the
Comment Response for L T2ESWTR 8-226 December 2005
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variability in removal efficiency observed for individual filters.
For several other tools in the microbial toolbox, direct measurement of process performance is possible.
For example, every membrane can undergo direct integrity testing routinely to monitor removal
efficiency. Thus, an analogous safety factor is unnecessary.
c. As discussed in the preamble to today's final rule, the performance of bag and cartridge filters is
product specific and doesn't provide a basis for awarding a presumptive credit, as some commenters
suggested. Results from studies reviewed in the proposed LT2ESWTR indicated that both bag and
cartridge filters exhibit variable removal efficiency, ranging from 0.5- to 3.6-log. No correlation between
the pore size rating established by the manufacturer and the removal efficiency of the filter was apparent.
Additionally, available data did not indicate a strong relationship between process monitoring parameters
like turbidity reduction and Cryptosporidium removal efficiency. Due to this lack of correlation between
either design criteria or process monitoring and removal efficiency, today's rule requires challenge testing
of filters to establish Cryptosporidium treatment credit.
d. Expanded and clarified guidance on the process for conducting challenge tests to determine
Cryptosporidium removal efficiency for bag and cartridge filters has been included in the Toolbox
Guidance Manual. Further, today's rule specifies that in each challenge test, removal must be measured
during three periods over the filtration cycle, which correspond to start-up, mid-point, and terminal
pressure drop. The log removal value (LRV) for the filter is equal to the minimum LRV measured during
these three periods. EPA recognizes that this testing may not cover all operational scenarios that systems
will experience, such as start-stop operation. If a State determines that challenge test data for a particular
filter do not reflect operating practices for a given system, EPA recommends that the State request
additional challenge test data before approving the use of the filter by the system.
e. Under today's rule, PWSs may receive Cryptosporidium treatment credit of up to 2.0-log for an
individual bag or cartridge filter and up to 2.5-log for two or more bag or cartridge filters operated in
series. The assigned credit is equal to the removal efficiency established during challenge testing minus a
1.0-log factor of safety for an individual bag or cartridge filter or 0.5-log factor of safety for series
operation. Thus, the treatment credit may include a tenths decimal place (e.g., 1.5 log) as some
commenters recommended.
Individual Comments on Code 850
EPA Letter ID: 591
Comment ID: 12139
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: and these have been shown to achieve less than 2 log removal. In Ohio two microsphere
challenge studies for cartridge filters were conducted on the same system and both of the studies showed
less than 2 log removal in 95 percent of the data which is also consistent with the results from an En/
study using cartridge filters. Therefore, these small systems will be out of compliance with
Response: See Response 850.a.
Comment Response for L T2ESWTR 8-22 7 December 2005
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8.13.1 Comment Codes 851, Credits and criteria for awarding credits
EPA Letter ID: 470
Comment ID: 11086
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 831 1. Credit and criteria for awarding credit; 881 1.
Credit and criteria for awarding credit; 9311. Proposed credit and criteria for awarding credit; 9511.
Proposed approach for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment requirements
Response: See Response lOOaand 83Ib.
EPA Letter ID: 520
Comment ID: 11645
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Bag Filters and Cartridge Filters
IEPA generally supports inclusion of these tools, but do not necessarily support EPA's approach to
determining the presumptive credit for each technology. EPA is proposing a 1 log credit for bag filtration
if the system can demonstrate 2 log removal and a 2 log credit for cartridge filters if the system can
demonstrate 3 log removal. These are the only tools that require a system to demonstrate a higher level of
removal to receive the credit. There is concern that this may lead to systems not choosing these
technologies from the microbial tool box.
Response: See Response 850.b.
EPA Letter ID: 528
Comment ID: 12259
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: system is required to provide. We suggest that EPA provide a presumptive credit for
cartridge/bag filtration and provide state flexibility to provide additional credit based on demonstration of
performance.
Response: See Response 850.c.
Comment Response for L T2ESWTR 8-228 December 2005
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EPA Letter ID: 585
Comment ID: 11980
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47707-8 [and §141.728(a)(7)-(9) on p. 47787]
The TCEQ recommends that EPA clarify the process used to determine the removal efficiency of bag and
cartridge filters. The procedure requires these units to be challenged at three specified points during the
filtration cycle. However, the equation for log removal value (LRV) does not indicate which of the three
challenge events should be used to determine the removal efficiency of the filter. Since the LRV will
likely vary during the filter run, the EPA needs to clarify whether the LRV for a particular filter will be
based on the average, minimum, or maximum of the three distinct values or on a time-weighted average
of the measured LRVs.
Response: See Response 850.d.
EPA Letter ID: 585
Comment ID: 11983
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: If the rule does not allow for other than a 1-log removal credit for bag filters and a 2-log
removal credit for cartridge filters, the TCEQ recommends that the rule be revised to be 1.0 log and 2.0
log, respectively. Under the current proposal, a bag filter that achieved an actual 1.6-log removal of
Cryptosporidium would meet the 2-log challenge study criteria due to numerical rounding. The filter
would then be assigned a 1-log removal credit and have less than a 1.0-log factor of safety. In addition to
correcting this mathematical problem, the tenths decimal place for these two toolbox options (i.e., 0.1-
log) would be consistent with the number of decimal places used for the other toolbox options.
Response: See Response 850.e.
EPA Letter ID: 603
Comment ID: 12675
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Bag and Cartridges in Series - We recommend that a specific combination of bag and/or
cartridges be given log removal credit in a manner similar to that for single bag and cartridge filters. In
other words, if a bag and cartridge filter combination can continuously provide 4-log removal of
Cryptosporidium oocysts, the specific combination should be awarded 3-log removal credit.
Response: See Response 850.b.
Comment Response for L T2ESWTR 8-229 December 2005
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EPA Letter ID: 643
Comment ID: 15032
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Bag Filters and Cartridge Filters
States generally support inclusion of these tools, but do not necessarily support EPA-s approach to
determining the presumptive credit for each technology. EPA is proposing a 1 log credit for bag filtration
if the system can demonstrate 2 log removal and a 2 log credit for cartridge filters if the system can
demonstrate 3 log removal. These are the only tools that require a system to demonstrate a higher level of
removal to receive the credit. States are concerned that this may lead to systems not choosing these
technologies from the microbial tool box. Several states have indicated that they intend to submit specific
comments on this issue directly to EPA.
Response: See Response 850.b.
EPA Letter ID: 647
Comment ID: 12938
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Bag Filters and Cartridge Filters
MDE supports inclusion of these tools, but does not necessarily support EPA-s approach to determining
the presumptive credit for each technology. EPA is proposing a 1 log credit for bag filtration if the system
can demonstrate 2 log removal and a 2 log credit for cartridge filters if the system can demonstrate 3
log removal. These are the only tools that require a system to demonstrate a higher level of removal to
receive the credit. MDE is concerned that this may lead to systems not choosing these technologies from
the microbial tool box. These treatment systems will be utilized by very small non-community water
systems that require filtration. It is important that small systems have treatment options.
Response: See Response 850.b.
EPA Letter ID: 675
Comment ID: 13962
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: Section IV.C: Options for Systems to Meet Cryptosporidium Treatment
Requirements
The State of Minnesota is concerned about the filtration efficiency credit given to bag or cartridge
technologies. Minnesota Department of Health has 10 years of experience working with these fixed
barrier technologies and is very aware of the limits of the technology. Installation, operation, and
monitoring of the treatment system is based on protecting the public health from the contaminants of
Comment Response for L T2ESWTR 8-23 0 December 2005
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concern. We suggest EPA consider a state-defined filtration credit for these fixed barrier technologies.
To be accepted as a compliance technology, alternate filtration technologies undergo thorough testing to
determine filtration efficiency (credit) (NSF/ETV). By setting the filtration credit in rule at 1 log there is
no incentive to evaluate the filter beyond that point, or treatment technologies that demonstrate a greater
than 1 log inactivation will not be given full credit for their capabilities. It must be noted that if a public
water system selects to use convention filtration as their compliance filtration technology, it is accepted at
face value that with proper operation and maintenance the prescribed log credit will be achieved. There
have been no challenge studies that demonstrate the log credit assigned in the rule is proper, or that
additional safety factors have been assigned. We ask that there be consistency in how filtration credit is
determined and assigned in rule, whether this is a conventional filtration method, or alternate filtration
method.
If a safety factor is applied to bag and cartridge filters, then systems should be allowed to provide 2 log
removal or inactivation of Cryptosporidium with a combination of filtration and UV disinfection in order
to meet LT1 requirements. Having bag or cartridge filtration in front of UV disinfection will ensure that
particulates will not interfere with UV disinfection. Bag and cartridge filters are typically only allowed on
high quality source waters, and since two types of disinfection alone are adequate for Cryptosporidium
inactivation for unfiltered systems under LT2, it seems that a combination of filtration and disinfection
should be acceptable for filtered systems under LT1.
Response: See Responses 850.b, 850.c, and SOO.z.
8.13.1.1 Comment Codes 852, Use of 1 log safety factor
Individual Comments on Code 852
EPA Letter ID: 101
Comment ID: 10895
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Bag and Cartridge Filtration
Bag filters have been shown to achieve 3 log reduction of giardia, and 2 log reduction of Cryptosporidium.
Many states have already done on-site testing to
determine the effectiveness of bag filters on systems and are already in place. Systems must be able to
continue to use technologies, of which bag filters are only one, that are affordable to small systems. To
automatically assign a low log removal category to a technology prevents its use and stops industry from
trying to continue to improve the effectiveness of the treatment. The existing data supports an EPA
regulatory credit of a 2 log Cryptosporidium removal credit and a 3 log giardi removal credit for systems
using bag filters.
Further, the Agency should not be using precautionary assumptions to account for uncertainties. The
community will factor these uncertainties into the design, operation and maintenance of the bag filters.
Therefore it is unnecessary for any use of a 1 log factor or less of safety for awarding credit to bag and
cartridge filters. This is the technology that many small systems will rely on and EPA must not limit the
removal factor.
Comment Response for L T2ESWTR 8-231 December 2005
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Response: See Responses 850.b, 850.e, and SOO.y.
EPA Letter ID: 457
Comment ID: 11936
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Bag Filters and Cartridge Filters
We support inclusion of these tools, but do not necessarily support EPA-s approach to determining the
presumptive credit for each technology. EPA is proposing a 1 log credit for bag filtration if the system
can demonstrate 2 log removal and a 2 log credit for cartridge filters if the system can demonstrate 3
log removal. Instead of requiring a system to demonstrate a higher level of removal to receive a lower
credit, which may discourage systems not choosing these technologies, we suggest EPA to consider a
single presumptive credit of 1 log for these two technologies.
Response: See Responses 850.b and 850.c.
EPA Letter ID: 585
Comment ID: 11981
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47706-9 [and §141.722(a)(9)-(10) on p. 47784; and §141.728(a)(l) on p. 47787]
The TCEQ generally concurs with the incorporation of a 1-log safety factor when establishing the
removal credit for bag and cartridge filtration systems. Based on current technology, it is difficult, if not
impossible, to detect marginal failures with bag and cartridge filters. While it is impossible to determine
the degree to which these failures affect the efficacy of treatment, the TCEQ believes that a 1.0-log factor
of safety is a reasonable performance standard.
Response: See Response 850.b.
EPA Letter ID: 603
Comment ID: 12673
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: 12. Bag and Cartridge Filtration -Bag and cartridge filters are typically installed on sources
with very low turbidity and raw water fecal coliform concentrations. Lower quality source waters lead to
impractically rapid fouling of these filters. In many cases, the raw water fecal coliform concentrations
meet the unfiltered source raw water fecal coliform criteria. If a system can demonstrate that they
consistently and reliably have high quality source water, it is not clear that a 1-log safety factor is
appropriate for existing bag and cartridge filter system. The EPA has essentially credited unfiltered
Comment Response for L T2ESWTR 8-232 December 2005
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sources with 2-log Cryptosporidium control. It makes sense to extend this same logic to systems with bag
and cartridge filters where high quality source water can be demonstrated and not require an additional 1-
log safety factor.
Response: See Responses 850.b and 600.b.
EPA Letter ID: 675
Comment ID: 13963
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: If a bag or cartridge filter has undergone testing which tests filters from various lots as well as
at several stages of the filtration cycle, a safety factor of 0.5 log should be more than adequate to account
for variability in performance.
Response: See Response 850.b.
8.13.1.2 Comment Codes 853, Limiting log credit to 2 log (bag)
and 3 log (cartridge)
Individual Comments on Code 853
EPA Letter ID: 585
Comment ID: 11982
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: The TCEQ does not concur with the proposal to assign a fixed 1-log removal credit to bag
filters and a 2-log removal credit to cartridge filters that meet challenge study requirements. The
challenge study conditions specified in the proposed rule allow these filters to demonstrate up to 2.5-log
and 3.5-log removal, respectively. The proposal to limit the removal credit afforded to bag and cartridge
filters to 1-log and 2-log, respectively, could effectively provide as much as a 1.5-log safety factor to
these two technologies. Moreover, the proposal appears to eliminate any removal credit for bag filters and
cartridge filters that do not qualify for the 1-log and 2-log removal credit, respectively. Consequently, we
recommend that (after applying the 1.0-log safety factor) these bag and cartridge filters be given credit for
up to 1.5-log and 2.5-log removal credit, respectively.
Response: See Response 850.e and 850.b.
Comment Response for L T2ESWTR 8-233 December 2005
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8.13.2 Comment Codes 860, Additional data on bag and cartridge
filter performance
Individual Comments on Code 860
EPA Letter ID: 603
Comment ID: 12674
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: The EPA has requested comments on laboratory and field data as well as other sources of
information to help clarify pertinent questions on the effectiveness of bag and cartridge filtration for
Cryptosporidium removal. We understand that the some of the challenge testing, such as that conducted
by the EPA Office of Research and Development, will not be completed until after the comment period
has closed. As such, we recommend that the EPA review information received on this subject between
now and rule promulgation and write this section of the final rule in a manner that accommodates answers
to the question posed in this section.
Response: See Response lOO.a. EPA reviewed data on bag and cartridge filter challenge testing that EPA
Office of Research and Development conducted. These results were generally consistent with the results
of studies reviwed for the proposal, which are described in the preamble. Thus, the ORD results did not
change the regulatory requirements for bag and cartridge filters in the final LT2ESWTR, which are based
on studies reviewed for the proposal and public comment.
8.13.2.1 Comment Codes 861, Other challenge test
requirements
Individual Comments on Code 861
EPA Letter ID: 603
Comment ID: 12676
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Bag and Cartridge Filter Performance - Particle shedding during start-stop operation, which
has been observed by department staff as well as by the US Forest Service during challenge testing, is not
addressed by the challenge testing in the proposed rule. We recommend that the testing of bag and
cartridge filters include sampling of the finished water within 30 seconds after start-up of a rest period of
at least 6 hours, which is reflective of typical operations cycles. Start-stop operations should clarify the
filter-to-waste requirements, if any, for bag and cartridge filters.
Response: See Response 850.d.
Comment Response for L T2ESWTR 8-234 December 2005
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8.13.3 Comment Codes 871, Applicability of process monitoring to
verify integrity
Individual Comments on Code 871
EPA Letter ID: 675
Comment ID: 13964
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: If a particle counter or low range turbidimeter is used for indirect integrity monitoring of a
bag or cartridge filter, then full removal credit should be awarded to the filter.
Response: See Response 850.b.
8.13.4 Comment Codes 874, Rule Language Edits
Individual Comments on Code 874
EPA Letter ID: 493
Comment ID: 11248
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment: 40 CFR 141.728(a)(10) has the word -cartridge- misspelled. The word -addition-probably
should be -additional-.
Response: See Response 500.aa.
8.13.5 Comment Codes 875, Guidance
Individual Comments on Code 875
EPA Letter ID: 603
Comment ID: 12658
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47787) Section 141.728(a)(l)-
Bag and cartridge filters in series are currently being investigated as a means of providing 2-log removal
of Cryptosporidium oocysts. It appears that with the current language of this section a specific series of
bag and cartridge filters would need to demonstrate 3-log removal of oocysts to be eligible for 2-log
removal credit. However, it could be interpreted that demonstration of 4-log removal would be required
Comment Response for L T2ESWTR 8-235 December 2005
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for a series combination. Please provide language in this section to clarify this issue if data are available
to support such an approach. The multiple filter concept is supported by the rationale behind §141.728(c)
and§141.728(d).
Response: See Response 850.e.
8.14 Comment Code 880, Secondary Filtration
Summary of Issues
Public comment generally supported additional treatment credit for second-stage filtration. Commenters
raised specific concerns with EPA establishing design requirements for filtration, the sufficiency of data
to support prescribed treatment credit, and the expansion of this credit to include other filtration
technologies.
In the August 11, 2003 LT2ESWTR proposal, EPA requested comment on whether a minimum filter
depth should be required for PWSs to receive treatment credit for a second filtration stage. All
commenters opposed EPA setting regulatory design standards for filters on the basis that PWSs and States
need the flexibility to determine appropriate treatment designs.
Many commenters stated that available data support the prescribed 0.5-log Cryptosporidium treatment
credit for second-stage filtration. Some commenters provided additional data on the removal of aerobic
spores through GAC filters following conventional treatment that showed a mean reduction greater than
1-log. In contrast, other commenters were concerned about the lack of data to support increased removal
through a second filtration stage. These commenters recommended that treatment credit for second-stage
filtration should be awarded only on a site-specific basis through a demonstration of performance.
Several commenters recommended that EPA expand the second-stage filtration option to include
membranes, bag filters, and DE filtration.
Response to Code 880
EPA has concluded that available data are sufficient to support the prescribed 0.5-log treatment credit for
second-stage filtraton. Studies of granular media filtration demonstrate high levels of Cryptosporidium
and one study has shown greater than 1.0-log removal through secondary GAC filters. Secondary filters
can remove Cryptosporidium that pass through or detach from the primary filters. This added removal
will help to stabilize finished water quality by providing a barrier during periods of the filtration cycle
when the primary filters are not performing optimally.
EPA agrees with commenters that effective filter designs will vary depending on the application.
Consequently, EPA is not establishing filter design criteria in the final LT2ESWTR rule, but is requiring
that States approve designs for PWSs to receive treatment credit for second-stage filtration.
In response to commenters that recommended that EPA expand the second-stage filtration option to
include membranes, bag filters, and DE filtration, EPA notes that the final LT2ESWTR establishes
prescribed treatment credits specifically for bag and cartridge filters and membranes as microbial toolbox
options, and prescribed credit for DE filtration is addressed in bin placement. PWSs may also seek
Comment Response for LT2ESWTR 8-236 December 2005
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treatment credit for other filtration technologies through a demonstration of performance under today's
rule.
Individual Comments on Code 880
EPA Letter ID: 485
Comment ID: 11311
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: this time. Secondary filtration with proven technologies to achieve the targeted reduction
appears to be a viable approach provided appropriate supporting documentation is provided. However, as
proposed, this option is limited to rapid sand, dual media, GAC or other fine grain media following the
primary filtration step. The Department questions whether secondary filtration should be limited to the
options identified or expanded to include other recognized technologies such as membrane (e.g. micro,
nano, ultra) and bag filtration.
Response: See Response lOOa and Response 880.
EPA Letter ID: 712
Comment ID: 16592
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Dual sand filters: Dual sand filters should be addressed by EPA, including
obtaining actual log removal data.
Response: See Response lOOa and Response 880.
EPA Letter ID: 712
Comment ID: 16593
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: D.E. filtration: DE filtration does not depend on filter ripening and has been shown to be very
effective at removinghnactivating cryptosporidium, and should be considered a viable secondary filtration
step. EPA should evaluate allowing a presumptive credit for secondary DE filtration, The presumptive
credit could require a minimum DE precoat, body feed, and influent turbidity requirement.
Response: See Response lOOa and Response 880.
EPA Letter ID: 712
Comment ID: 16596
Comment Response for L T2ESWTR 8-23 7 December 2005
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Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Certain other treatment train combinations do not make sense and should be restricted, for
example, there is a concern with applying coagulated water to a slow sand filter used in secondary
filtration. It is not clear if, or how, presumptive credit would awarded to a proposed second stage
coagulation and filtration step after slow sand filtration.
Response: See Response 880. The secondary filtration process of the LT2ESWTR toolbox follows a
primary filtration process used for Subpart H (SWTR)compliance . In the commenter's example the slow
sand process is the primary filtration process and EPA has concluded that a primary slow sand filtration
process is capable of an average 3 log removal of Cryptosporidium.
8.14.1 Comment Code 881, Credit and criteria for awarding credit
Individual Comments on Code 881
EPA Letter ID: 101
Comment ID: 10896
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Secondary Filtration
A 1.0 cryptosporidium log removal credit should be awarded for secondary filtration. There should be no
minimum depth because every system will design
Response: See Response 880.
EPA Letter ID: 457
Comment ID: 11933
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Second Stage Filtration
We support inclusion of this tool and the 0.5 log presumptive credit; however, the states should have the
flexibility to determine appropriate treatment design parameters (instead of EPA specifying a minimum
depth for the secondary filters).
Response: See Response lOOa and Response 880.
Comment Response for L T2ESWTR 8-238 December 2005
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EPA Letter ID: 470
Comment ID: 11086
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 831 1. Credit and criteria for awarding credit; 851 1.
Credits and criteria for awarding credits; 931 1. Proposed credit and criteria for awarding credit; 951 1.
Proposed approach for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment requirements
Response: See Response lOOaand 83Ib.
EPA Letter ID: 485
Comment ID: 11320
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department believes that the concerns stated about the lack of data to support
increased removal credit for second stage filtration and the ability for increased removal resulting from a
second stage of filtration of particles that are not removed in the first stage are valid. We believe
additional removal credit should only be granted based on supporting data from the system requesting the
increased removal credit. We do not support granting 0.5 log cryptosporidium removal without more
specific supporting data. The Department would recommend that studies designed to evaluate a second
stage filtration process be designed to assess the entire treatment plant-s removal ability and not just the
secondary filtration process.
Response: See Response 880.
EPA Letter ID: 520
Comment ID: 11638
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Combined Filter Performance
IEPA generally supports inclusion of this tool and the 0.5 log presumptive credit. However, EPA should
consider allowing only for additional removal credit
Response: See Response lOOa and Response 880.
Comment Response for L T2ESWTR 8-239 December 2005
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EPA Letter ID: 520
Comment ID: 11642
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Second Stage Filtration
IEPA generally supports inclusion of this tool and the 0.5 log presumptive credit. States need flexibility to
determine appropriate treatment designs and
Response: See Response lOOa and Response 880.
EPA Letter ID: 561
Comment ID: 12234
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 13. Secondary Filtration
We are supportive of a .5 log credit for the application of a secondary filtration process. In our case that
process would consist of a deep bed (8-feet) of granular activated carbon (GAC) having an effective size
of greater than 1 mm for taste and odor reduction, BDOC reduction and SOC absorption. As such, the
proposed Rule is unclear as to the required media depth and effective size to be eligible for the credit.
Response: See Response lOOa and Response 880.
EPA Letter ID: 562
Comment ID: 12425
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 12. Two filtration stages operated in series are capable of providing more than 0.5-log
additional Cryptosporidium removal above the level capable of being achieved by either of these
filters acting alone.
This analysis and these findings provide an important factual basis for the recommendations AWWA
offers in the following comments. AWWA-s review includes both research and data identified in the
LT2ESWTR proposal. AWWA believes the analysis in Appendix 1 and reflected in these comments more
correctly reflects the performance of some of these treatment technologies than the discussion provided in
the Federal Register notice and Microbial Toolbox Guidance. In addition to the literature and analysis
presented in Appendix 1 and Appendix 2, AWWA will also provide information and analysis with respect
to watershed control programs, bank filtration, ozone disinfection and UV disinfection.
4.2.1 Regulatory -Preference- vs. Agreement in Principle
Comment Response for LT2ESWTR 8-240 December 2005
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Response: See Response 880.
EPA Letter ID: 585
Comment ID: 11984
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47709 [and §141.722(a)(12) on page 47784; and §141.728(c) on p. 47789]
The TCEQ concurs that second stage filtration may achieve additional Cryptosporidium control.
However, the efficacy of such treatment may be dependent on the design and operational characteristics
of the specific filter or combination of filters. However, we cannot concur with the proposal to grant
a 0.5-log presumptive credit to plants with second stage filtration. This proposal was based on the
performance at a single surface water treatment plant and no information was provided regarding the
design, operational, or performance characteristics of either the primary or secondary filters at that
facility. In addition, there is no indication that the results have been replicated during other studies. Until
data is available to demonstrate that these results can be achieved on a broad-scale basis at a variety of
plants, we recommend that this treatment approach be evaluated on a site-specific basis under the
provisions of 141.727(c)(l) that addresses the "demonstration of performance."
Response: See Response 880.
EPA Letter ID: 624
Comment ID: 13197
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment:
[SEE PAGE 7 OF PDF FOR FIGURE 2]
Secondary Filtration:
a. GCWW strongly supports giving at least 0.5-log credit for the secondary filtration process because that
it acts as an additional removal barrier and dampens turbidity fluctuations from the primary filtration
effluent thereby providing a uniform water quality in the finished water. As presented in Figure 2,
secondary filters at the GCWW's SWTP achieved an average of 1.06-log reduction of endospores. It
makes practical sense that the depth of the media should be at least 24-inches (generally accepted
engineering standards) as used for primary filtration processes.
Response: See Response lOOa and Response 880.
EPA Letter ID: 643
Comment ID: 12796
Comment Response for LT2ESWTR 8-241 December 2005
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Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Second Stage Filtration
States generally support inclusion of this tool and the 0.5 log presumptive credit. However, one state
suggested that instead of a presumptive credit, this treatment approach should be evaluated on a site-
specific -demonstration of performance- basis until data to demonstrate that results from a variety of
plants that support the credit are available.
Response: See Response lOOa and Response 880.
EPA Letter ID: 647
Comment ID: 12936
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Second Stage Filtration
MDE supports inclusion of this tool and the 0.5 log presumptive credit. States need flexibility to
determine appropriate treatment designs and therefore, MDE does not support EPA establishing a
minimum depth for secondary filters. The granular filtration process is a complex combination of physical
and hydraulic characteristics and, in some cases, biological activity.
Response: See Response lOOa and Response 880.
EPA Letter ID: 664
Comment ID: 14055
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment: 13. Secondary Filtration
We are supportive of a .5 log credit for the application of a secondary filtration process. In our case that
process would consist of a deep bed (8-
Response: See Response lOOa.
EPA Letter ID: 712
Comment ID: 16590
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment Response for L T2ESWTR 8-242 December 2005
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Comment: Secondary Filtration: EPA used only one study to determine the secondary filtration
presumptive credit. The secondary filter used in the study was a GAC filter used not for particulate
removal, but for DBF, and taste and odor control. Based on this one study, EPA determined that the
presumptive credit for secondary filtration should be 0.5 log removal. EPA should also evaluate
secondary rapid sand filtration using a filter aid. The use of a filter aid could greatly improve the
performance of a secondary filtration step.
Response: See Response 880.
EPA Letter ID: 712
Comment ID: 16591
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 821 1. Credit and criteria for awarding credit
Comment: Since filter performance depends on the ripening, and secondary filters and secondary slow
sand filters may take much longer to ripen, there is a concern that they may provide limited log reductions
during a long ripening period. EPA should develop more data on secondary filtration and secondary slow
sand filtration, or make its use require a demonstration of performance.
Response: See Response 880 and Response 820.
8.14.2 Comment Code 883, Minimum depth for secondary filter
Individual Comments on Code 883
EPA Letter ID: 101
Comment ID: 10897
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: filtration. There should be no minimum depth because every system will design and
implement what is appropriate for their circumstances. Systems should also
Response: See Response 880.
EPA Letter ID: 457
Comment ID: 11934
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment Response for L T2ESWTR 8-243 December 2005
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Comment: however, the states should have the flexibility to determine appropriate treatment design
parameters (instead of EPA specifying a minimum depth for the secondary filters).
Response: See Response lOOa and Response 880.
EPA Letter ID: 520
Comment ID: 11643
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: credit. States need flexibility to determine appropriate treatment designs and therefore do not
support EPA establishing a minimum depth for secondary filters. The granular filtration process is a
complex combination of physical and hydraulic characteristics and, in some cases, biological activity.
Response: See Response lOOa and Response 880.
EPA Letter ID: 585
Comment ID: 11985
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: The TCEQ also advises against establishing a minimum depth for secondary filters based
solely on the results at a single plant. The granular filtration process is a complex combination of physical
and hydraulic characteristics and, in some cases, biological activity. While it may be appropriate, and
even necessary, to establish these parameters, such decisions should be based on discussions between the
primacy agency and a particular water system. On the other hand, the TCEQ would welcome an EPA
guidance manual on the subject of filter design.
Response: See Response lOOa and Response 880.
EPA Letter ID: 643
Comment ID: 12797
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States need flexibility to determine appropriate treatment designs and therefore do not support
EPA establishing a minimum depth for secondary filters. The granular filtration process is a complex
combination of physical and hydraulic characteristics and, in some cases, biological activity.
Response: See Response 880.
Comment Response for L T2ESWTR 8-244 December 2005
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8.14.3 Comment Code 884, Credit for both second clarification stage
and lower finished water turbidity
Response to Code 884
Under the final LT2ESWTR, a system could receive credit for combined or individual filter performance
in the primary filtration process as well as the credit for a secondary filtration process. However, if the
system chose to take advantage of the prescribed credit, 0.5. log, the secondary filtraion process would
not eligible for any further additional credit based on a demonstration of performance. If a system chose
to use the demonstration of performance option for a secondary filtration process, it would recive the
removal credit demonstrated. EPA notes that the system would have to meet both the performance criteria
for the individual or combined turbidity in the primary filtration process and any performance or design
criteria the State determines is needed for the secondary filtration process.
Individual Comments on Code 884
EPA Letter ID: 101
Comment ID: 10898
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: and implement what is appropriate for their circumstances. Systems should also be allowed to
receive additional treatment credit for both a second clarification stage and lower finished water turbidity.
Response: See Response 884 and Response 880.
EPA Letter ID: 585
Comment ID: 11986
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: The EPA requested comment on whether a system should be allowed to claim additional
treatment credit for both a secondary clarification stage and lowered finished water turbidity levels. The
TCEQ believes that it is generally appropriate to allow additional treatment credit based on sequential
treatment processes such as second stage sedimentation and lower filtered water or finished water
turbidity levels. However, in the absence of a substantial body of data or a measurable change in some
appropriate surrogate, we have some reservations about allowing additional treatment credit based on the
sequential application of two essentially identical treatment processes.
Response: See Response 884.
EPA Letter ID: 624
Comment ID: 13179
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
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Comment: 4. GCWW strongly supports giving at least 0.5-log credit for the secondary filtration process
because that it acts as an additional removal barrier and dampens turbidity fluctuations from the primary
filtration effluent thereby providing a uniform water quality in the finished water. If a utility so desires,
the secondary filtration process could be used as the primary filtration process for compliance purposes as
long as the utility foregoes the 0.5-log credit for the second stage, and the effluent from the secondary
filters is used for CFE compliance.
Response: See Response 884.
EPA Letter ID: 624
Comment ID: 13203
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: c. If a utility so desires, the secondary filtration process could be used as the primary filtration
process for compliance purposes as long as the utility foregoes the 0.5-log credit for the second stage, and
the effluent from the secondary filters is used for CFE compliance. This would avoid double dipping for
secondary filters, which appears to be EPA's concern as it has requested specific comments on this issue.
Such an acceptance should be permitted if the second-stage filtration meets the design criteria such as
media depth, grain size, backwash rates and frequency, treatment of entire flow, etc.
Response: See Response 884.
EPA Letter ID: 712
Comment ID: 16595
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Second-stage filtration: Systems should not be allowed to receive credit for both secondary
filtration and filter performance of the second stage filtration. This would be double dipping. However, a
system should receive log reduction credit for filter performance of their primary filters when also
implementing secondary filtration.
Response: See Response 884.
8.14.4 Comment Code 886, Guidance
Individual Comments on Code 886
EPA Letter ID: 664
Comment ID: 14056
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment Response for L T2ESWTR 8-246 December 2005
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Comment: filtration process. In our case that process would consist of a deep bed (8-feet) of granular
activated carbon (GAC) having an effective size of greater than 1 mm for taste and odor reduction, BDOC
reduction and SOC absorption. As such, the proposed Rule is unclear as to the required media depth and
effective size to be eligible.
Response: See Response 880.
8.15 Comment Codes 890, Ozone and Chlorine Dioxide
Summary of Issues
Commenters stated concerns with the required criteria for achieving Cryptosporidium treatment credit,
including the conservatism EPA applied in developing the Ct tables, the ability of PWSs with different
types of source waters to use these disinfectants, and the range of conditions covered by the Ct tables.
Some commenters supported the proposed Ct tables, but others stated that the statistical approach used to
calculate the confidence bounds from which the Ct values are derived is overly conservative. These
commenters were concerned that this approach will increase capital and operating costs and lead to higher
byproduct levels.
Commenters were concerned that due to the relatively high ozone and chlorine dioxide doses necessary
for Cryptosporidium inactivation, some PWSs will be unable to use these disinfectants to achieve
required levels of Cryptosporidium treatment. In particular, using ozone for high Cryptosporidium
inactivation levels will be difficult in areas where cold water temperatures would necessitate especially
high doses or where high source water bromide levels would cause problems with bromate formation. The
use of chlorine dioxide for Cryptosporidium inactivation may be difficult due to chlorite formation.
Commenters recommended that EPA expand the range of conditions encompassed in the Ct tables.
Specifically, commenters asked that Ct tables include values for water temperatures above 25 oC and
supported this request by providing data showing temperature profiles for water sources with maximum
temperatures near 30oC. Commenters also requested Ct values for Cryptosporidium inactivation levels
below 0.5-log for PWSs that will use multiple disinfectants to meet the treatment requirements in today's
rule. In addition, commenters suggested that EPA provide equations that PWSs can use to interpolate
between the listed Ct values.
Commenters made recommendations for guidance on the use of ozone and chlorine dioxide to comply
with today's rule. These recommendations concern topics like monitoring disinfection reactors,
procedures for calculating disinfectant concentration and contact time, site specific studies, and
synergistic effects of multiple disinfectants.
Response to Code 890
EPA believes that the confidence bounds used for the ozone and chlorine dioxide CT tables in the final
LT2ESTWR are appropriate and necessary to ensure that PWSs achieve intended levels of
Cryptosporidium inactivation. They account only for uncertainty in the regression of inactivation data and
for variability in inactivation data that cannot be attributed to experimental error. This approach is
significantly less conservative than the approaches used in previous CT tables. EPA employed this less
conservative approach in recognition of the high disinfectant doses necessary for Cryptosporidium
Comment Response for L T2ESWTR 8-24 7 December 2005
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inactivation and concern with byproducts.
EPA recognizes that the use of ozone and chlorine dioxide to achieve Cryptosporidium inactivation will
depend on source water factors and will not be feasible for all PWSs. Due to the availability of UV, which
EPA has determined to be a feasible technology for Cryptosporidium inactivation by all PWS sizes, the
feasibility of today's rule does not depend on the widespread use of ozone or chlorine dioxide for
compliance. In assessing the impact of the LT2ESWTR rule on PWSs, EPA used ICR survey data to
estimate the fraction of PWSs that could use ozone or chlorine dioxide to achieve different levels of
Cryptosporidium inactivation without exceeding DBP MCLs. While EPA expects that some PWSs will
use these disinfectants, the microbial toolbox provides many other options for PWSs to comply with the
Cryptosporidium treatment requirements of the LT2ESTWR.
EPA has addressed recommendations regarding the CT table in the final LT2ESTWR. The CT tables for
ozone and chlorine dioxide include values for a water temperature of 30oC and for 0.25-log inactivation.
Footnotes to these tables contain equations that PWSs can use to calculate log inactivation credit for
conditions between those provided in the tables. PWSs may use these equations in their process control
systems.
EPA will address recommendations for guidance on the use of ozone and chlorine dioxide to comply with
the LT2ESWTR in the Toolbox Guidance Manual. These recommendations concern topics like
monitoring disinfection reactors, procedures for calculating disinfectant concentration and contact time,
site specific studies, and synergistic effects of multiple disinfectants.
Individual Comments on Code 890
EPA Letter ID: 101
Comment ID: 10899
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Ozone and Chlorine Dioxide
Ozone and chlorine dioxide should both be eligible for Cryptosporidium log removal credits.
Response: EPA agrees that the use of ozone and the use of chlorine dioxide can achieve Cryptosporidium
inactivation. As with other disinfectants,the level of inactivation achieved is dependent on the
concentration of disinfectant. That concentration is measured to determine the amount of inactivation
achieved.
EPA Letter ID: 488
Comment ID: 11858
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: The CT tables are prohibitive for cold waters needing 1 log of credit or more. It is unlikely
that a plant would go to the expense of installing ozone if additional treatment requirements would be
needed for either backup (in bin 2) or if the plant fell into bin 3 or 4. PWD conducted extensive pilot
studies to evaluate the feasibility of using intermediate ozone for Cryptosporidium inactivation and
concluded that ozone would be cost prohibitive. A cost analysis conducted based on the results of the
Comment Response for L T2ESWTR 8-248 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
studies estimated that it would cost nearly $50,000,000 to implement intermediate ozone at PWD-s three
treatment plants. This cost was based on CT requirements equivalent to 15-times the Giardia CT for 1 log,
which are lower than the currently proposed CT requirements. The estimate did not include construction
costs, nor did it account for the operation and maintenance costs that will be realized on an annual basis.
Taking the increased CT requirements, construction, and O&M into account, it is not unreasonable to
estimate the cost of installing ozone to exceed $100,000,000.
Response: See Response 890.
EPA Letter ID: 612
Comment ID: 13147
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: Ozonation-The application of ozonation generates concerns with residual bromate formation.
Second, effective disinfection requires a minimum dosage and contact time of ozone. These levels too are
impacted by external interferences including temperature, flow and turbidity.
Response: EPA recognizes that DBP formation concerns and source water quality may limit the ability of
some PWSs to use ozone to meet LT2ESWTR treatment requirements. EPA notes that there are other
toolbox options to meet treatment requirements that would not affect DBP formation and are less limited
by source water quality.
EPA Letter ID: 612
Comment ID: 13151
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Other EPA Comment Codes and Descriptions: 914 hi. Reactor monitoring
Comment: Summary:
Although LT2 provides these disinfection technologies as toolbox options, the rule falls short of requiring
continuous monitoring protocol that would insure the consistency and effectiveness of any these
technologies over time. Source water and the treatment train leading to the several of these disinfection
treatments can be varied throughout the year. Because of this, the application of certain on-line
monitoring technologies would provide assurance of consistent pathogenic kill rates over time
Response: See Response 910.f EPA believes that the requirements for ozone and chloramine disinfection
in today's final rule are the minimum necessary to ensure effective water treatment for public health
protection. Today's rule requires daily calculation of inactivation acheived (CT) at peak hourly conditions
to ensure that adequate inactivation levels are being maintained at all times. Today's rule requirements are
similar to the disinfection monitoring requirements of Subpart H. EPA agrees that continuous monitoring
of these technolgies would be provide additional reliability and believes that many plants will monitor
these processes continuously to ensure process reliability. However, EPA does not have a basis to require
continuous monitoring of these processes for compliance purposes.
Comment Response for L T2ESWTR 8-249 December 2005
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EPA Letter ID: 681
Comment ID: 14768
Commenter: Leah Rose, Staff Associate, American Chemistry Council
Commenter Category: Other: Other hard to categorize commenters
Comment: Rule). The Panel is gratified that EPA has worked with industry towards EPA-s proposing
Method 327 and that EPA was able to do so in time for inclusion in the Stage 2 DBP Rule. The Panel
would like to commend EPA for taking such an open approach in EPA-s development of the proposed
new method.
Response: See Response lOOa.
8.15.1 Comment Codes 891, Credit and criteria for awarding credit
Individual Comments on Code 891
EPA Letter ID: 457
Comment ID: 11937
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Ozone
We support inclusion of this tool and that credit would be based on log inactivation using the CT table.
Response: See Response lOOa.
EPA Letter ID: 470
Comment ID: 11085
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 791 1. Credit and criteria for awarding credit; 801 1.
Credit and criteria for awarding credit; 821 1. Credit and criteria for awarding credit; 9111. Credit and
criteria for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment requirements
Response: See Response lOOa.
EPA Letter ID: 472
Comment ID: 11166
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Comment Response for LT2ESWTR 8-250 December 2005
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Department
Commenter Category: Local Government
Comment: The COP utilizes ozone as a treatment process. Our six-stage ozone contactor sometimes has
a residual in stage two, but there is no residual of ozone as the treated water leaves stage six ozone
contactor. As proposed, the LT2ESWTR does not allow any credit for the first stage.
The CT table as proposed on page 47789 does not reflect a dosage level, only the measured concentration
levels. It seems dosage of chemical should be a factor in the inactivation of Cryptosporidium. Dosage
should be included in the CT table for ozone or a different CT table for each dosage. Say CT Tables for
ozone dosages of 0.25 mg/L, 0.5 mg/L, 0.75 mg/L-2.5 mg/L. Our maximum dosage in 18 months of
operation has been 1.2 mg/L.
Response: As with any inactivation/disinfection process, ozone CT is calculated based on contact time in
a disinfection segment and the disinfection concentration measured in that segment. If there is no
disinfection concentration measureable in a segment, CT credit is not appropriate. A CT calculation is
based on disinfection residual in a unit process. The applied dose at the beginning of a unit process is not
applicable to the CT concept since there has been no contact time at the point of application and therefore
no inactivation/disinfection.
EPA Letter ID: 472
Comment ID: 11167
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: On the ozone credit based on CT tables, the preamble states, -If the water temperature is
higher that 25°C, temperature should be set to 25°C for the log inactivation calculation.- Where is the
Agency supporting data for this stipulation? Surface water in the desert Southwest routinely achieves
30°C and in some cases 35°C. We recommend the CT table be modified to include water temperatures up
to 35°C. However, if the CT table is based on lowest seasonal water temperature, that should be stated.
The LT2ESWTR Toolbox Guidance Manual also is not clear if lowest water temperature is the
determining factor.
Response: See Response 890.
EPA Letter ID: 485
Comment ID: 11321
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Ozone and chlorine dioxide
Response: No response provided at this time.
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Response: No comment provided.
EPA Letter ID: 486
Comment ID: 14170
Commenter: Christopher R. Schulz, Drinking Water Practice Leader, CDM, Inc.
Commenter Category: Consultants: (where self-identified)
Comment: 11.2 Credits (Ozone)
16. The ozone CT tables should be expanded to include CT values from 0.1 to 3-log Crypto inactivation
and for water temperatures from 1 to 30 deg C. The research dataset on ozone inactivation of Crypto
supports development of an expanded table so utilities can receive credits below 0.5-log inactivation, if
they so desire.
Response: See Response 890.
EPA Letter ID: 488
Comment ID: 11860
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment:
Several levels of safety factors have been incorporated into the requirements for ozone implementation
such that the provision, taken as a whole, is overly conservative. The CT tables encompass a safety factor
through the use of upper confidence bounds on inactivation data. The conservative approaches used to
determine both ozone concentration and contact time each provide additional safety factors. The
determination of C (Table 11.3 in the guidance) is perhaps the most extreme case. The EPA has not
provided a rationale or analytical construct to explain how these various factors combine for an overall
acceptable margin of safety. Furthermore, utilities will always need to incorporate additional margins of
safety to ensure continuous compliance.
Response: See Response 890.
EPA Letter ID: 488
Comment ID: 11863
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4.4.4 Chlorine Dioxide
Credit for inactivation using chlorine dioxide requires daily raw and finished water chlorite and chlorine
dioxide monitoring in addition to distribution system chlorite monitoring three times per month. The CT
tables are conservative to account for the low reproducibility associated with chlorine dioxide residual
measurement.
Comments
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Difficulties associated with chlorine dioxide residual measurement (for example cleaning the glassware)
and the required frequency of both chlorine dioxide and chlorite measurement seriously limit chlorine
dioxide as a viable practical toolbox option. Requirements for distribution system chlorite monitoring are
reasonable and do not present an undue burden. The conservativeness of the CT tables together with the
chlorite MCL imply that implementation would be expensive, if not altogether precluded by chlorite
limits. It is recommended that the CT tables be reworked if and when the precision of residual
measurement methods improves.
The toolbox guidance manual cites chlorine dioxide as having 4 advantages and 11 disadvantages. This
certainly will discourage systems from adopting this option for regulatory compliance.
Response: EPA appreciates the comment. See response to Comment Code 890.
EPA Letter ID: 493
Comment ID: 11251
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment: 40 CFR 141.729 does not specify that the CT values for Cryptosporidium by chlorine dioxide
and ozone must be achieved at a point before or at the first customer?
Response: The LT2ESWTR requires monitoring in accordance with CFR 141.74, which requires
continuous monitoring of disinfectant residual prior to water entering the distribtuion system.
EPA Letter ID: 512
Comment ID: 11503
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Chlorine Dioxide
a. Chlorine dioxide CT values for lower logs (e.g. 0.1 log) Cryptosporidium inactivation should be
developed so that utilities with multiple disinfectants can claim partial credit.
Response: See Response 890.
EPA Letter ID: 520
Comment ID: 11646
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 892 i. Determination of CT , including confidence
bounds
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Comment: Ozone
IEPA generally supports inclusion of this tool and the requirement that credit would be based on log
inactivation using the CT table. There is concern with the CT table and the safety factor used.
Response: See Response 890.
EPA Letter ID: 522
Comment ID: 14142
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: EPA may also want to consider the merit of offering this approach as an alternate for
compliance for those unfiltered systems that use chemical disinfectants, but monitor continuously. It
would provide additional data to operators and primacy agencies on how plants actually operate over the
course of the days and month, and capture and regulate short periods of'off-spec' or under disinfected
water in periods other than the hour of maximum flow rate.
Response: See Response 600.g.
EPA Letter ID: 529
Comment ID: 13129
Commenter: Anonymous529,,
Commenter Category:
Other EPA Comment Codes and Descriptions: 896 5. Compliance with bromate and chlorite MCLs
Comment: 3. Re. Section IV C. 14. The proposed values for CT will be difficult and costly to achieve
given our background bromide concentration and MCLs for bromide. These should be relaxed or the
Bromate MCL raised to avoid a penalty for those who greatly benefit from the use of ozone.
Response: For developing earlier CT values, EPA has used bounds for confidence in prediction, which
account for both real variability and experimental error. EPA believes that this approach was appropriate
due to limited inactivation data and uncertainty in the sources of variability in the data. However, the high
doses of ozone and chlorine dioxide necessary to inactivate Cryptosporidium create an offsetting concern
with the formation of DBFs (e.g., bromate and chlorite). In consideration of this concern, EPA has
employed a less conservative method to calculate confidence bounds for the ozone and chlorine dioxide
CT values in the LT2ESWTR; specifically, EPA has attempted to exclude experimental error from the
confidence bounds. In order to estimate confidence bounds that exclude experimental error, EPA assessed
the relative contribution of experimental error to the variance observed in the Cryptosporidium
inactivation data sets. This assessment was done by comparing variance among data points with
consistent experimental conditions, which was attributed to experimental error, with the total variance in a
data set. By this analysis, EPA estimated that 87.5 and 62 percent of the variance in the Cryptosporidium
inactivation data for ozone and chlorine dioxide, respectively, could be ascribed to experimental error.
EPA then applied these estimates to the predictive equations using a modified form of a formula for
calculating a 90 percent confidence bound. EPA recognizes that DBP concerns may limit the ability of
Comment Response for L T2ESWTR 8-254 December 2005
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some PWSs to use ozone to meet LT2ESWTR treatment requirements. EPA notes that there are other
toolbox options to meet treatment requirements that would not affect DBF formation.
EPA Letter ID: 548
Comment ID: 12171
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Metropolitan believes that the proposed ozone CTs are difficult to achieve given (1) the low
temperature effect on CT requirement and (2) constraint imposed by bromate MCL. Because primacy
agency approval of plant designs are structured around worst-case design conditions, the ozone system
will be designed around low temperature conditions. Where the state requires the design to be based on 5°
C or less, ozone inactivation will be effectively limited to 1-log inactivation for most systems. In regions
of the U.S. where operating conditions are much warmer, then 1.5 to 2.0-log inactivation may be achieved
at an affordable (albeit, somewhat expensive) cost.
Response: See Response 890.
EPA Letter ID: 562
Comment ID: 12345
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Stage 2 DBPR. Consequently, the performance criteria for Cryptosporidium inactivation, in
combination with the bromate MCL, should allow a reasonable operating regime for drinking water
utilities, particularly where some utilities have proactively invested in ozone before or as a result of the
Stage 1DBPR/IESWTR.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12516
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: to its ability to inactivate Cryptosporidium. As currently proposed, the ozone CT
requirements are challenging, particularly in certain locales:
1. Coastal and arid regions where bromide levels are high in source waters with the potential for elevated
bromate formation (keeping in mind that bromide levels during the ICR were lower due to higher
than average rainfall); and
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2. Northern and eastern U.S. where cold temperature inactivation requirements make reliance on ozone
alone for high inactivation levels difficult.
While challenging, AWWA believes the proposed ozone provisions are substantially improved over the
stakeholder draft. AWWA is generally supportive of the ozone provisions. AWWA has a number of
detailed comments
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12519
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Conditions Encompassed in CT Table
Inactivation
The current CT tables are limited to a minimum of 0.5-log Cryptosporidium inactivation. Several utilities
that have to meet a minimum 0.5-log inactivation of Cryptosporidium may achieve required inactivation
levels using multiple disinfectants (e.g., ozone with chlorine dioxide). To allow this, the CT tables should
be extended to log inactivation levels below 0.5-log. The minimum log inactivation listed in the CT tables
should be 0.1-log, the likely minimum level a system would achieve with a single disinfectant. Utilizing
a minimum log inactivation in the CT table below 0.5-log is justified because the CT values listed in the
table were derived from mathematical models that were based on inactivation results staring from 0-
log. Therefore, excluding log inactivation values between 0 and 0.5-log is not justified.
Response: See Response 890.
EPA Letter ID: 562
Comment ID: 12528
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Using equations to calculate the log inactivation of Cryptosporidium down to 0.1 log should
be explicitly stated in §141.729. AWWA strongly recommends that EPA provide similar equations
expressing the log inactivation of Giardia lamblia cysts and viruses with chlorine dioxide.
Response: See Response 890. CT values for inactivation of Giardia and viruses by chlorine dioxide are
included in Part 141 CFR. Expansion of those CT tables was not proposed and is outside the requirements
of the LT2ESWTR.
EPA Letter ID: 628
Comment ID: 12852
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Comment Response for L T2ESWTR 8-256 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Commission
Commenter Category: Regulated Community (Utilities)
Comment: b. Avoid erratic citation of inactivation failures. The rule proposes that unfiltered systems
using chlorine dioxide or ozone and failing to achieve the Cryptosporidium log inactivation on more than
one day in the calendar month are in violation of the treatment technique requirement. This may be unfair
to the system if it happens to have two separate but back-to-back inactivation failures occurred before and
after mid-night and these failures are attributed to the same cause. The SFPUC recommends changing -
more than one day- to -more than one 24-hour period in the calendar month-. The proposed change
would avoid penalizing the system that may be investigating or in the process of remedying the initial
problem.
Response: The criteria for a treatment technique violation for failure to achieve the required
Cryptosporidium log inactivation for unfiltered systems in the LT2ESWTR is consistent with the
requirements for unfiltered systems under Subpart H. Those requirements are based on calendar days,
months and years. EPA believes that a calender day is a well defined and well understood concept and
does not result in erratic citation of inactivation failures. Basing compliance on a 24 hour period could
result in inconsistent determinations of inactivation failure unless the 24 hour period were defined by the
regulatory authority. Determining compliance with standards based on calendar months or years would
necessarily require defining the 24 compliance period as a calendar day.
EPA Letter ID: 628
Comment ID: 12858
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: Additionally, the SFPUC requests the EPA consider the merit of offering this approach as an
alternate for compliance for those unfiltered systems that use chemical disinfection, but monitor
continuously. It would provide additional data to operators and the State primacy agency on how plants
actually operate over the course of the days and month, and capture short periods of-off-spec- or under
disinfected water in periods other than the hour of maximum flow rate.
Response: See Response 600.g.
EPA Letter ID: 631
Comment ID: 13244
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: For example, ozonation followed by biologically active granular activated carbon is in design
for the City of Albuquerque water treatment plant process. According to the Toolbox Guidance Manual, -
Systems can receive between a 0.5 to 3.0 log Cryptosporidium inactivation credit with the addition of
ozone,— (page 11-2). The guidance manual also notes specific additional advantages of ozonation to
include reduction of total organic carbon, oxidation of iron, manganese, and sulfide, taste, odor, and color
control, reduction of disinfection by-product formation with chlorine disinfection, and the biological
Comment Response for L T2ESWTR 8-25 7 December 2005
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stability of biological filtration (pages 11-14 to 11-15). The guidance manual also acknowledges that
capital, operational, and maintenance costs of ozonation are relatively high when only benefits from
Cryptosporidium inactivation credits are considered. The City is willing to accept the set additional costs
given the increased benefits. The final regulations should allow that credit be given for these additional
benefits, as well.
Response: The LT2ESWTR establishes or extends treatment technique requirements in lieu of maximum
contaminant levels for Cryptosporidium. The advantages of ozonation in reduction of total organic carbon
and disinfection by-product formation or constiuents subject to secondary satndards would need to be
compared to other applicable treatment technique requirements, MCLs or SMCLs which are outside the
scope of the LT2ESWTR. EPA expects that PWSs would consider simultaneous complinace issues in
selecting options to comply with LT2ESWTR requirements.
EPA Letter ID: 643
Comment ID: 12799
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Ozone
States generally support inclusion of this tool and the requirement that credit would be based on log
inactivation using the CT table. Some states have
Response: See Response lOOa.
EPA Letter ID: 678
Comment ID: 14697
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 25. Section 141.729(c) -The table of CT Values for Cryptosporidium Inactivation By Ozone
should also be applicable to the situation in which the primary objective of using ozone in the treatment
process is for another purpose (such as taste & odor removal).
Response: See Response 890.
EPA Letter ID: 681
Comment ID: 14770
Commenter: Leah Rose, Staff Associate, American Chemistry Council
Commenter Category: Other: Other hard to categorize commenters
Comment: The initial specific issue for the Panel was to address chlorine dioxide residual measurements,
which are critical to ascertain accurate credits in disinfection applications. The importance of this issue
Comment Response for L T2ESWTR 8-258 December 2005
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was elevated by the added requirement of daily monitoring of the chlorite ion to comply with EPA-s
more recent risk assessment and risk management decision used to set the current Maximum Contaminant
Level Goal (MCLG) and Maximum Contaminant Level (MCL) for chlorite, along with the Maximum
Residual Disinfectant Level (MRDL) for chlorine dioxide in public water supplies.
Even after implementation of the Stage 1 DBF Rule, public water facilities have been asked to do more to
ensure public health protection with fewer resources. Among specific concerns was that small to mid-size
water utilities experiencing trihalomethane (THM) problems under the Stage 1 Rule were avoiding
chlorine dioxide as a disinfection alternative due to limitations of existing approved analytical methods.
Late Stage 1 Rule requirements for daily chlorite ion sampling and associated increases in cost made it
even more difficult for publicwater facilities to choose chlorine dioxide as a disinfection alternative.
Proposed Standard Method 327 goes a long way in providing an additional test method to the water
industry for daily monitoring of chlorine dioxide and its predominant disinfection byproduct, the chlorite
ion.
In keeping with the cooperative effort surrounding the development of this method, the Panel offers these
comments to refine the usefulness of this colorimetric analytical approach to monitoring chlorine dioxide.
Discussions with authors of the proposed method have led the Panel to believe that it is possible to obtain
specific and accurate measurements of chlorine dioxide alone (by using Lissamine Green B (LGB)
without the Horseradish Peroxidase (HRP) amplification step). This can be accomplished through:
A. Addition of specific chlorine dioxide sections to the proposed method (Scope, Application, Calibration
and Procedure);
B. Referenced Addendum to proposed Standard Method 327 (as a citable revised edition); or
C. A separate method (originally proposed as Standard Method 326).
Panel member companies are willing to provide composite and noted technical expertise from the field to
help EPA address these comments. While many positive comments have been received about the
development of Standard Method 327, industry, field and laboratory practitioners have raised some
questions that would point to a somewhat less-than-enthusiastic acceptance and lack of widespread
utilization among water plant laboratory or field personnel.
Following are general and technical comments on the proposed Standard Method
327.
1) The proposed new Method 327 does not reduce complexity nor simplify testing significantly from
Method 4500-Chlorine Dioxide E (amperometric titration method) for either chlorine dioxide or the
chlorite ion. The proposed method is still a method-by-difference, since it requires a nitrogen purge step
to separate out the chlorine dioxide from the chlorite ion. It appears to be more difficult than Method
4500-Chlorine Dioxide E, and likely beyond current capabilities of typical water plant operators.
Proposed Standard Method 327 has 10 steps, requires 16 pieces of equipment (including refrigeration),
careful preparation of 6 solutions using an analytical balance with gravimetric expertise, short shelf lives
and reagent product quality, storage and daily or weekly preparation and evaluation.
2) The quality control procedure is overly complex for most, if not all, water plant laboratories or utilities.
The proposed new method requires daily calibration, and the field utility of commercially available
standardized reagents for approved test methods has been overlooked.
3) The proposed method perpetuates a shortcoming of the existing method by utilizing the same
Comment Response for L T2ESWTR 8-259 December 2005
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assumptive conversion of any interfering chlorine by the addition of glycine.
4) The proposed new method requires acquisition of a field photometer and field-utility reagents to be
effective in the field or for use by a small utility.
5) EPA is proposing that the Minimum Reporting Level (MRL) be raised to 0.2 mg/L for the chlorite ion
contaminant, which is well above the Method Detection Limit (MDL) as is typically the practice for other
contaminants regulated in public drinking water. This MRL is equal to the Practical Quantitation Level
(PQL) for Method 4500-Chlorine Dioxide E, so using Method 4500- Chlorine Dioxide E and an
amperometric titrator will provide the same result.
6) The HRP Solution referenced in Section 7.2.5 as Sigma Part #P6782 is type 6A. The correct reagent is
Type II HRP is Sigma Part #P8250.
7) Chloroform as a biocide (actually only through membrane disruption) has been observed to shorten the
usable lifetime of the LGB/HRP reagent, which suggests use of an alternative microbiocide or membrane
solubilizer (e.g., trichloroethylene).
8) The LGB stock solution has a shelf lifetime of 2 months at 6 oC. A more viable solution for
commercialization and utility for water plant operators should be explored rather than the LGB/HRP
reagent.
9) The Chlorite Stock Standard Solution referenced in Sec. 7.3.1 of the proposed new method is not
catalogue #54106. The correct Absolute Standards solutions are #54109 and #54509.
Response: EPA notes that approval of the method suggested by the commenter was proposed in
"Guidelines Establishing Test Procedures for the Analysis of Pollutants Under the Clean Water Act;
National Primary Drinking Water Regulations; and National Secondary Drinking Water Regulations;
Analysis and Sampling Procedures; Proposed Rule" 18166 Federal Register / Vol. 69, No. 66 / Tuesday,
April 6, 2004 / Proposed Rules
EPA Letter ID: 681
Comment ID: 14771
Commenter: Leah Rose, Staff Associate, American Chemistry Council
Commenter Category: Other: Other hard to categorize commenters
Comment: Regulatory timing would not be overly impacted if Standard Method 327 were accepted with
adoption of the suggestions listed above. More importantly, it would at least give water utility managers
time to incorporate this new method into their own analytical facilities. If EPA does not incorporate these
minor, but important, changes at this time, the only logical alternative is to approach the Standards
Council at the American Water Works Association (AWWA) to bring this method and revisions into
subsequent editions of Standard Methods.
EPA-s fast track process has proven to be of exceptional utility in moving this new method forward. The
impressive outcome of this process is that the public drinking water industry and its ultimate consumers
have a new method developed under the sponsorship of EPA that offers an alternative to current testing
methods for daily monitoring of the chlorite ion and chlorine dioxide. This has been accomplished with
the support of the chemical industry and the input of professional standard-setting associations such as
Comment Response for L T2ESWTR 8-260 December 2005
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AWWA, the American Public Health Association, the American Society of Civil Engineers, and the
American Society for Testing and Materials.
Response: EPA notes that approval of the method suggested by the commenter was proposed in
"Guidelines Establishing Test Procedures for the Analysis of Pollutants Under the Clean Water Act;
National Primary Drinking Water Regulations; and National Secondary Drinking Water Regulations;
Analysis and Sampling Procedures; Proposed Rule" 18166 Federal Register / Vol. 69, No. 66 / Tuesday,
April 6, 2004 / Proposed Rules
EPA Letter ID: 683
Comment ID: 14766
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
Comment: For example, ozonation followed by biologically active granular activated carbon
is in design for the City of Albuquerque water treatment plant process. According to the Toolbox
Guidance Manual, -Systems can receive between a 0.5 to 3.0 log Cryptosporidium inactivation credit
with the addition of ozone, — (page 11-2). The guidance manual also notes specific additional advantages
of ozonation to include reduction of total organic carbon, oxidation of iron, manganese, and sulfide, taste,
odor, and color control, reduction of disinfection by-product formation with chlorine disinfection, and the
biological stability of biological filtration (pages 11-14 to 11-15). The guidance manual also
acknowledges that capital, operational, and maintenance costs of ozonation are relatively high when only
benefits from Cryptosporidium inactivation credits are considered. The City is willing to accept these
additional costs given the increased benefits. The final regulations should allow that credit be given for
these additional benefits, as well.
Response: The LT2ESWTR establishes or extends treatment technique requirements in lieu of maximum
contaminant levels for Cryptosporidium. The LT2ESWTR does not include requirements addressing
secondary standards, inorganic contaminants or disinfection by products. While the use of ozozne could
have positive benefits for these constituents EPA has no basis to add additional Cryptosporidium
treatment credits in the LT2ESWTR based on effects on these constituents.
8.15.1.1 Comment Codes 892, Determination of CT , including
confidence bounds
Individual Comments on Code 892
EPA Letter ID: 472
Comment ID: 11140
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
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Comment: COP believes any statistical analysis should be in the 90th-95th percentile confidence
interval.
Response: For developing earlier CT values, EPA has used bounds for confidence in prediction, which
account for both real variability and experimental error. EPA believes that this approach was appropriate
due to limited inactivation data and uncertainty in the sources of variability in the data. However, the high
doses of ozone and chlorine dioxide necessary to inactivate Cryptosporidium create an offsetting concern
with the formation of DBFs (e.g., bromate and chlorite). In consideration of this concern, EPA has
employed a less conservative method to calculate confidence bounds for the ozone and chlorine dioxide
CT values in today's rule; specifically, EPA has attempted to exclude experimental error from the
confidence bounds. In order to estimate confidence bounds that exclude experimental error, EPA assessed
the relative contribution of experimental error to the variance observed in the Cryptosporidium
inactivation data sets. This assessment was done by comparing variance among data points with
consistent experimental conditions, which was attributed to experimental error, with the total variance in a
data set. By this analysis, EPA estimated that 87.5 and 62 percent of the variance in the Cryptosporidium
inactivation data for ozone and chlorine dioxide, respectively, could be ascribed to experimental error.
EPA then applied these estimates to the predictive CT equations using a modified form of a formula for
calculating a 90 percent confidence bound .
EPA Letter ID: 512
Comment ID: 11502
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: a. The current CT values for ozone Cryptosporidium inactivation and virus inactivation
requirements are much higher compared to those for Giardia. These CT level requirements for
Cryptosporidium inactivation almost make it prohibitive for ozone to be used as a tool for
Cryptosporidium inactivation without significantly increasing the ozone dose. This will lead to increased
operation costs and increase the potential for bromate formation. CCWD believes the current CT table
was developed with an overly conservative safety factor. CCWD strongly agrees with AWWA-s and
ACWA-s comments on this issue.
Response: See Response 890.
EPA Letter ID: 520
Comment ID: 11646
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 891 1. Credit and criteria for awarding credit
Comment: Ozone
IEPA generally supports inclusion of this tool and the requirement that credit would be based on log
inactivation using the CT table. There is concern with the CT table and the safety factor used.
Comment Response for L T2ESWTR 8-262 December 2005
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Response: See Response 890.
EPA Letter ID: 522
Comment ID: 14150
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Excessive Conservatism in Application of Ozone: MWRA is aware of and appreciates the
progress made by EPA between the pre-proposal draft and this draft in realistically determining required
CT levels. We participated in the technical evaluations and review of alternative approaches conducted by
AWWA. While substantial progress has been made, MWRA still believes that the statistical approach
adds excessive conservatism to the calculation of the required CT for a given level of inactivation, raising
capital and operating costs, and increasing the levels of ozone byproducts unnecessarily.
Response: For developing earlier CT values, EPA has used bounds for confidence in prediction, which
account for both real variability and experimental error. EPA believes that this approach was appropriate
due to limited inactivation data and uncertainty in the sources of variability in the data. However, the high
doses of ozone and chlorine dioxide necessary to inactivate Cryptosporidium create an offsetting concern
with the formation of DBFs (e.g., bromate and chlorite). In consideration of this concern, EPA has
employed a less conservative method to calculate confidence bounds for the ozone and chlorine dioxide
CT values in the LT2ESTWR; specifically, EPA has attempted to exclude experimental error from the
confidence bounds. In order to estimate confidence bounds that exclude experimental error, EPA assessed
the relative contribution of experimental error to the variance observed in the Cryptosporidium
inactivation data sets. This assessment was done by comparing variance among data points with
consistent experimental conditions, which was attributed to experimental error, with the total variance in a
data set. By this analysis, EPA estimated that 87.5 and 62 percent of the variance in the Cryptosporidium
inactivation data for ozone and chlorine dioxide, respectively, could be ascribed to experimental error.
EPA then applied these estimates to the predictive equations developed using a modified form of a
formula for calculating a 90 percent confidence bound.
EPA Letter ID: 523
Comment ID: 11694
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Excessive Conservatism in Application of Ozone: The Unfiltered Systems Working Group
appreciates the progress made by EPA between the pre-proposal draft and this draft in realistically
determining required CT levels. We still believe that the statistical approach adds excessive conservatism
to the calculation of the required CT for a given level of inactivation, raising capital and operating costs,
and increasing the levels of ozone byproducts unnecessarily.
Response: See Response lOOa and Response 890.
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EPA Letter ID: 562
Comment ID: 12317
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.11 Ozone
AWWA believes that retention of ozone, as a viable technology was an essential component of the Stage
2 M/DBP Agreement in Principle. AWWA understands and supports the proposed contact-time (CT)
table as a balance between the best-available science and development of a CT table that affords a
consistent and simply applied safety factor to address outstanding policy concerns.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12518
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CT Table Methodology
AWWA recommends that the CT table for ozone and chlorine dioxide be based upon an upper percentile
confidence interval (e.g., 90th, 95th percentile) about a first order regression equation through the
available inactivation data. AWWA supports the proposed CT table as a balance between approach
seeking the best available science and development of a CT table that affords a consistent and simply
applied safety factor to address outstanding policy concerns.
EPA-s proposed approach provides a reasonably transparent methodology to appropriately partition
experimental / analytical variability (i.e., experimental method, between individual mice in experimental
protocols, ozone residual measurement, mice infectivity and excystation, true volume of sample fed to
each mouse) from variability in the underlying inactivation coefficient (K10) (i.e., variability in the
oocyst resistance to disinfection and effect of natural water matrix on the inactivation process). The
approach employed for ozone is also relevant to the second chemical disinfectant addressed by the
LT2ESWTR ~ chlorine dioxide. The agency should more clearly describe how the treatment of
variability should be addressed in site-specific studies.
Response: Based on linear regression, the CT tables consider uncertainty about the regression equation
and variability among applications (due to differences in treatment plants, source waters, and
microorganisms). EPA agrees with the commenter that this approach strikes a reasonable balance,
appropriately considering the different forms of variability (analytical and experimental) and uncertainty.
The CT tables in today's rule consider variability between applications and therefore provide confidence
that most plants will meet or exceed their target inactivation levels. EPA will consider the commenter's
recommendation regarding treatment of variability for site-specific studies of inactivation in revisions to
the LT2ESWTR Toolbox Guidance.
EPA Letter ID: 562
Comment ID: 12520
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Water Temperature
The current CT tables are limited to a maximum water temperature of 25 °C. Several systems treat waters
with temperatures exceeding 25 °C during the summer months. Figure 1 shows frequency distribution
profiles of water temperature for the Harwood-s Mill Reservoir used by the Newport News (Va.)
Water Works, and for the Colorado River water treated by the City of Phoenix, AZ. The data show that
water temperatures can reach 30 °C or higher. AWWA recommends that the CT table be extended to a
water temperature of 35 °C. The inactivation model used to develop the CT tables was based on a dataset
that included various data points at 30 °C and 37 °C. Therefore, the confidence in the calculated CT
values at the high temperatures should be as good as those at the low temperatures included in the current
CT tables.
Figure 1. Temperature Profiles from Newport News, Va., and Tampa Bay, Fla.
[SEE FIGURE 1, P.71 IN PDF]
Response: See Response 890.
EPA Letter ID: 562
Comment ID: 12526
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.2.13 Chlorine Dioxide
As noted above, AWWA believes that the CT table for ozone and chlorine dioxide should be based upon
an upper-percentile confidence interval (e.g., 90th, 95th percentile) about a first-order regression equation
through the available inactivation data. AWWA understands and supports the proposed CT table as a
balance between the best-available science and development of a CT table that affords a consistent and
simply applied safety factor to address outstanding policy concerns.
Response: See Response 890.
EPA Letter ID: 614
Comment ID: 12967
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: * Also, EPA needs to formulate CT Tables that reflect synergistic disinfection
through ozone-chloramine and ozone-free chlorine in the final rule.
Response: EPA did not propose CT tables for synergistic disinfection and the information was not
available for public review and comment as part of the LT2ESWTR proposal. EPA will consider the
information in revisions to the LT2ESWTR Toolbox Guidance. EPA notes that the final LT2ESWTR
Comment Response for L T2ESWTR 8-265 December 2005
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allows States to approve alternate chlorine dioxide or CT values based on a site specific study, which
would include synergistic effects of multiple disinfectants.
EPA Letter ID: 628
Comment ID: 12850
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: a. Avoid overly conservatism in consideration of ozone application for Cryptosporidium
removal. The SFPUC believes that the statistical approach used in calculation of the required CT for a
given level of inactivation adds excessive conservatism, which leads to an unnecessary increase in capital
and operational costs as well as the levels of ozone byproducts.
Response: See Response 890.
EPA Letter ID: 643
Comment ID: 12800
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: would be based on log inactivation using the CT table. Some states have expressed concern
with the CT table and the safety factor used.
Response: See Response lOOa and Response 890.
8.15.2 Comment Codes 893, Additional data on inactivation for CT
tables
Individual Comments on Code 893
EPA Letter ID: 562
Comment ID: 12319
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: calculations for ozone CT. EPA requested additional data to support the ozone CT table, and
these comments include an analysis of research reflecting synergistic disinfection. In addition to the CT
Tables in the proposal, EPA should present CT tables that reflect synergistic disinfection through ozone-
chloramine and ozone-free chlorine disinfection in the final rule.
Response: EPA appreciates the comment and information. EPA recognizes that the synergistic effects of
multiple disinfectants may increase disinfection efficacy. EPA did not propose CT tables for synergistic
Comment Response for L T2ESWTR 8-266 December 2005
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disinfection and the information was not available for public review and comment as part of the
LT2ESWTR proposal. EPA notes that the final LT2ESWTR allows States to approve alternate chlorine
dioxide or CT values based on a site specific study, which would include synergistic effects of multiple
disinfectants.EPA will consider this information for inclusion in LT2ESWTR guidance material.
EPA Letter ID: 562
Comment ID: 12525
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Synergistic Inactivation
Synergistic inactivation is defined as the enhancement of the inactivation efficiency of a disinfectant
against a certain microorganism by pre-exposing that microorganism to another disinfectant. This is
defined as -synergistic inactivation- because the combined effect of the two disinfectants in series
is greater than the added sum of their individual effects. Appendix 10 includes a memorandum prepared
for AWWA analyzing the available data on synergistic inactivation of Cryptosporidium with ozone and
chloramine, and recommending specific CT tables for the inactivation achieved by chloramine
application downstream of ozone. The analysis presented in Appendix 11 clearly shows that achieving
Cryptosporidium inactivation with chloramine is feasible downstream of ozone. Meeting target
Cryptosporidium inactivation requirements with synergistic inactivation of ozone and chloramines, or
ozone and chlorine, will greatly benefit water utilities, especially those limited in their ability to add
ozone due to potential bromate formation.
AWWA recommends that the agency give serious consideration to reflecting synergistic inactivation in
the LT2ESWTR with respect to ozone followed by chloramines and ozone followed by chlorine.
Incorporating synergistic inactivation into practice would be most easily achieved through inclusion of
CT tables, such as those included in Appendix 10 in the regulatory text, though application could be
accomplished through guidance provisions that clearly indicate that the agency endorses the concept.
Response: EPA appreciates the comment and information. EPA recognizes that the synergistic effects of
multiple disinfectants may increase disinfection efficacy. EPA did not propose CT tables for synergistic
disinfection and the information was not available for public review and comment as part of the
LT2ESWTR proposal. EPA notes that the final LT2ESWTR allows States to approve alternate chlorine
dioxide or CT values based on a site specific study, which would include synergistic effects of multiple
disinfectants.EPA will consider this information for inclusion in LT2ESWTR guidance material.
EPA Letter ID: 562
Comment ID: 12530
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
Any additional data that may be used to confirm or refine the proposed CT tables.
Response
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AWWA has submitted in the above discussion and in Appendix 10 an approach to expand the ozone CT
tables to address synergistic disinfection from ozone-chloramine application and the available data.
Response: EPA appreciates the comment and information. EPA recognizes that the synergistic effects of
multiple disinfectants may increase disinfection efficacy. EPA did not propose CT tables for synergistic
disinfection and the information was not available for public review and comment as part of the
LT2ESWTR proposal. EPA notes that the final LT2ESWTR allows States to approve alternate chlorine
dioxide or CT values based on a site specific study, which would include synergistic effects of multiple
disinfectants.EPA will consider this information for inclusion in LT2ESWTR guidance material.
8.15.3 Comment Codes 894, Site-specific determination of CT
Individual Comments on Code 894
EPA Letter ID: 472
Comment ID: 11168
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: The proposed LT2ESWTR does offer systems the option to conduct site specific inactivation
studies to determine CT requirements. However, the ADEQ recently shifted its policy to only adopt
Federal Rules by reference. This ADEQ policy change may negate this valuable option the Agency has
delegated to states. Due to ADEQ-s position they may not develop protocols or other information to
determine alternative CT values.
Response: Under the chlorine dioxide and ozone toolbox options, systems may demonstrate to the State
alternate CT values for Crytosporidium. The DOP option and the alternate CT values for chlorine dioxide
and ozone inactivation all require PWSs to obtain State approval. These options do not require States to
modify the standards for awarding disinfection credit to these technologies or to modify any Federal
Rules to approve a DOP credit or alternate CT value.
EPA Letter ID: 488
Comment ID: 11861
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Under the current proposal, utilities have the option of conducting a site-specific study to
generate a set of CT tables for their facility. However, the protocols for conducting such a study are so
intensive that they essentially eliminate this option. These protocols require the utility to measure the
actual inactivation achieved under a full range of temperatures, contact times and water quality conditions
representative of plant operating conditions. The measurement of cryptosporidium inactivation requires
laboratory skills, equipment, and financial resources that are well beyond even the most progressive
utility-s reach. Therefore this protocol is unlikely to provide a feasible compliance alternative for any
systems.
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Response: EPA recognizes that inactivation rates are sensitive to water quality and operational conditions
in the plant. Therefore, systems are given the option of performing a site specific inactivation study to
determince CT requiremnts. In the absense of a site specific study, systems would use the CT tables
included in today's rule. The CT tables included in today's rule are based on measurements of inactivation
acheived under specific temperature and water quality conditions. Systems using the CT tables would
measure disinfectant residual and contact time to determine CT achieved. For a site specific study, EPA
would expect the CT determination would be based on the same information. EPA recognizes that site
specific measurement of inactivation would require laboratory and financial resources however EPA does
believe it is appropriate to allow this option for systems. Systems would have to weigh the advantges of
developing site specifc CT requirements against the resources needed for a site specific study as well
against any disadvantge is using the CT tables included in today's rule. EPA notes that the protocols in the
Toolbox Guidance Manual are intended to assist systems and States. Today's rule requires States to
approve site specfic study protocol. EPA also notes that the CT tables in today's rule include an expanded
range of temperature and fractional log credit values.
EPA Letter ID: 562
Comment ID: 12524
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Site-Specific Studies
In promulgating the SWTR in 1989, EPA introduced the concept of site-specific studies. AWWA
supports the continuation of the application of this concept under the LT2ESWTR for Cryptosporidium
inactivation. Utilities will have significant opportunities to refine the application of ozone at their
facilities based on the above discussion of the ozone CT tables and methodologies to calculate ozone CT.
Such efforts will require significant resources and are not investments that every utility will be able to
undertake. However, when resources are available, so should the opportunity for site-specific studies.
Response: See Response lOOa and Response 890.
8.15.4 Comment Codes 896, Compliance with bromate and chlorite
MCLs
Individual Comments on Code 896
EPA Letter ID: 472
Comment ID: 11141
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: The COP utilizes ozone as a pretreatment process step. It has proved an excellent treatment
process combined with biological active filters in eliminating historic taste and odor challenges and
controlling disinfection byproduct formation. As drought conditions continue in the Southwest United
States, we have experienced an increase in bromide concentrations which contributes directly to bromate
Comment Response for L T2ESWTR 8-269 December 2005
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formation.
We are encouraged by recent research in the use of ammonia and lower pH levels in controlling bromate
formation with bromide impacted waters. However each of these supplemental methods to ozonation have
respective challenges such as TDS concerns with lower pH (our source water is over 800 mg/L TDS) and
additional disinfectant or larger contact basins if ammonia is used. As such, these supplemental methods
might not be applicable without extensive study or structural modifications.
COP believes the Agency has to carefully balance the level of conservatism in the analysis of CT tables
with the potential formation of bromate.
Response: See Response 890.
EPA Letter ID: 488
Comment ID: 11859
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: The prospect of a future lower MCL for bromate is a further disincentive for adopting ozone
as a treatment technology for LT2. PWD-s ozone pilot work included studies focused on evaluating
bromate formation under variable operating conditions. These tests showed that, with high influent
bromide concentrations, meeting a 5 (ig/L MCL would require process modifications and/or additional
chemical additions. Some promising options for low-level bromate control are in the experimental stage
and have not been proven full-scale (e.g. the chlorine-ammonia process) while others can be prohibitively
costly (acid addition for pH control). Thus, utilities with moderate to high source water bromide
concentrations may be unwilling to move forward with ozone given the potential for near-term regulatory
changes that could increase operating costs or even render their process out of compliance. The Agency
cannot expect ulities to make the capital expenditure necessary for ozone when the regulatory
implications are, by the Agency-s very admission, still under review. Finally, the issue of incremental
bromate contribution from hypochlorite stocks would place a further constriction on systems attempting
to meet a future lower MCL.
Response: See Response 890.
EPA Letter ID: 491
Comment ID: 10672
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: 9. Due to the seasonally high bromide in our source water, ACWD will have difficulty using
ozone to inactivate Cryptosporidium and meeting the bromate MCL concurrently. ACWD-s source water
bromide can range between 50 and 550 micrograms per liter. In 2002, a carbon dioxide feed system was
installed to control the pH of ozonation in order to minimize bromate formation in the ozone contactors.
Subsequently, testing was done at various ozonation pH values that included a characterization of the CTs
achieved along the entirety of the contactors (based on grab samples from each cell) and the resultant
bromate concentrations. Based on the results of these tests, it appears that ACWD will have difficulty
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achieving the CT values required for 0.5-log or greater Cryptosporidium inactivation, even with the
carbon dioxide system in use and taking advantage of credits throughout the entire length of each
contactor. ACWD is providing this information for consideration in response to EPA-s request for
comment on -the ability of systems to apply these [proposed] CT tables in consideration of the MCLs for
bromate and chlorite- in the LT2 rule.
Response: See Response lOOa and Response 890.
EPA Letter ID: 529
Comment ID: 13129
Commenter: Anonymous529,,
Commenter Category:
Other EPA Comment Codes and Descriptions: 891 1. Credit and criteria for awarding credit
Comment: 3. Re. Section IV C. 14. The proposed values for CT will be difficult and costly to achieve
given our background bromide concentration and MCLs for bromide. These should be relaxed or the
Bromate MCL raised to avoid a penalty for those who greatly benefit from the use of ozone.
Response: For developing earlier CT values, EPA has used bounds for confidence in prediction, which
account for both real variability and experimental error. EPA believes that this approach was appropriate
due to limited inactivation data and uncertainty in the sources of variability in the data. However, the high
doses of ozone and chlorine dioxide necessary to inactivate Cryptosporidium create an offsetting concern
with the formation of DBFs (e.g., bromate and chlorite). In consideration of this concern, EPA has
employed a less conservative method to calculate confidence bounds for the ozone and chlorine dioxide
CT values in the LT2ESWTR; specifically, EPA has attempted to exclude experimental error from the
confidence bounds. In order to estimate confidence bounds that exclude experimental error, EPA assessed
the relative contribution of experimental error to the variance observed in the Cryptosporidium
inactivation data sets. This assessment was done by comparing variance among data points with
consistent experimental conditions, which was attributed to experimental error, with the total variance in a
data set. By this analysis, EPA estimated that 87.5 and 62 percent of the variance in the Cryptosporidium
inactivation data for ozone and chlorine dioxide, respectively, could be ascribed to experimental error.
EPA then applied these estimates to the predictive equations using a modified form of a formula for
calculating a 90 percent confidence bound. EPA recognizes that DBP concerns may limit the ability of
some PWSs to use ozone to meet LT2ESWTR treatment requirements. EPA notes that there are other
toolbox options to meet treatment requirements that would not affect DBP formation.
EPA Letter ID: 548
Comment ID: 12172
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: As for bromate, the level of inactivation achievable for any particular source water will be a
function of bromide levels (in source water), pH of ozonation, ozone demand of the water, and whether
the utility is using sodium hypochlorite (and, if so, what grade [level of bromate contamination] of
hypochlorite is available). The pH of ozonation may be a significant factor where acidic pH levels are
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difficult to achieve in high-alkalinity waters, in part due to the NSF limit (50 mg/L on acid digestion.
Metropolitan is aware of water treatment facilities in southwestern U.S. that will be unable to achieve the
desired ozone CTs for 2-log Cryptosporidium inactivation and reliably comply with their internal
goals for bromate control.
Response: See Response 890.
EPA Letter ID: 562
Comment ID: 12517
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Balancing Inactivation and Bromate Formation
The Stage 2 M/DBP Agreement in Principle calls for retention of the current bromate MCL at 0.010
mg/L. This recommendation stemmed from the FACA-s view that ozone should be available as a
treatment technology for Cryptosporidium inactivation. The FACA recognized ozone as a valuable
disinfectant that is more effective for some microorganisms than chlorine and other more-frequently used
disinfectants. Also, the FACA recognized ozone was as an important oxidant to control taste and odor,
destroy organic contaminants, and enhance performance of other treatment processes such as coagulation-
flocculation-clarification processes. The FACA also considered the past or ongoing investment by a
number of drinking water utilities in ozone disinfection as a proactive step to address either disinfection
byproducts or Cryptosporidium. This recommendation is particularly significant given the agency-s
characterization of bromate health effects.
In the spirit of the FACA-s interest in retaining ozone as a viable technology in developing the ozone CT
requirements, the agency should recognize that increased inactivation requirements will increase bromate
formation, other things being equal (von Gunten and Oliveras, 1998, Song et al., 1997). As the Stage 2
M/DBP FACA realized, ozone doses necessary to inactivate Crytposporidium, even low-to-average
bromide levels can result in bromate levels near the Stage 1 MCL. Though bromate control strategies
exist, each of them has limitations (see e.g. Williams et al., 2003; Buffle et al., 2003):
1. pH control is effective, but can require costly chemical addition to first acidify and then buffer the
water post-ozonation;
2. A serious side effect of pH control in some waters can be a significant rise in TDS which represents a
water quality concern for both residential and commercial customers;
3. Ammonia addition can be effective for bromate control, though more so at high pH (in contrast to pH
control which employs low pHs);
4. Ammonia addition can result in a loss of disinfection credit due to the pH range employed,
necessitating the introduction of additional disinfectant or larger contact basins ; and
5. Application of the -ammonia process- for bromate control may not be feasible in moderate-to-high
TOC waters where the required initial chlorine addition step could yield unacceptable THM and/or HAA
concentrations. The effectiveness of this process has been well demonstrated in low TOC waters (Buffle
and Von Gunten 2003).
While these control strategies will work in some waters, engineering and/or cost issues constrain their
application. Consequently, the agency should carefully balance the level of conservatism reflected in the
analysis underlying the ozone CT tables with the potential formation of bromate.
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Response: See Response 890.
EPA Letter ID: 562
Comment ID: 12529
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
The ability of systems to apply these CT tables in consideration of the MCLs for bromate and chlorite.
Response
AWWA would characterize the proposed ozone CTs as difficult to achieve, given the requirement
regarding low-temperature effects on CT and constraints imposed by the bromate MCL. Because primacy
agency approval of plant designs is structured around worst-case design conditions, the ozone system will
be designed around low-temperature conditions. Where the state requires the design to be based on 5° C
or less, ozone inactivation is effectively limited to 1-log inactivation. In regions of the U.S. where water
temperatures are warmer, then 1.5 to 2.0-log inactivation can be achieved at an affordable cost.
With respect to bromate, the level of inactivation achievable for any particular source water will be a
function of source water bromide levels, whether or not the utility is using sodium hypochlorite (and if, so
what grade of hypochlorite is available). AWWA is aware of water treatment facilities in the
southwestern U.S. that will be unable to achieve the desired ozone CTs for 2-log Cryptosporidium
inactivation and reliably comply with their internal goals for bromate control.
Response: See Response 890.
8.15.5 Comment Codes 898, Guidance
Individual Comments on Code 898
EPA Letter ID: 523
Comment ID: 11676
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA may want to consider the merit of offering this approach as an alternate for compliance
for those unfiltered systems that use chemical disinfection, but monitor continuously. It would provide
additional data to operators and primacy agencies on how plants actually operate over the course of the
days and month, and capture short periods of'off-spec' or under disinfected water in periods other than
the hour of maximum flow rate.
Response: See Response lOOa.
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EPA Letter ID: 610
Comment ID: 12990
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: Our system has included the capacity to ozonate water for over twenty-five years. We believe
ozone to be an effective treatment of Cryptosporidium; however, the Guidance Manual does not list the
Ozone CT Table anywhere. The
Response: The ozone CT tables are included in the regulatory language, Code of Federal Regulations
Title 40 SubpartW 141.720.
EPA Letter ID: 614
Comment ID: 12966
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Ozone
* EPA needs to further define guidance regarding compliance calculations for Ozone CT (E.G.
Segregated Flow Analysis (S.F.A.), etc.)
Response: See Response lOOa.The LT2ESWTR Toolbox Guidance Manual will be revised to reflect the
final rule and EPA will consider public comments in the revision. A revised Toolbox Guidance will be
available for additional public comment.
EPA Letter ID: 628
Comment ID: 12851
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: Because of the higher ozone doses required to inactivate Cryptosporidium than Giardia, the
SFPUC requests the EPA further develop the concept of segregated flow analysis (SFA) to allow utilities
to better estimate and manage the application of ozone for CT. The EPA should explicitly indicate in the
Toolbox Guidance Manual that a system might demonstrate the SFA method to the State primacy agency
for use at its plant, and include an appendix to the manual that details the use of the SFA method.
Response: EPA appreciates the comment. The LT2ESWTR Toolbox Guidance Manual will be revised to
reflect the final rule and EPA will consider public comments in the revision. A revised Toolbox Guidance
will be available for additional public comment.
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8.16 Comment Codes 910, UV Light
Response to Code 910
a. Today's rule does not change the requirement established under the SWTR for systems to maintain a
chlorine disinfectant in the water entering the distribution system.
b. EPA is aware of the patent that Calgon Carbon Corp holds for UV inactivation of Cryptosporidium. In
estimating household costs for today's final rule, EPA included the licensing fee that Calgon has stated it
will charge for this use. As described in the LT2ESWTR Economic Analysis, after considering this
licensing fee, the Agency has concluded that UV disinfection remains a feasible technology for
compliance with Cryptosporidium treatment requirements under the LT2ESWTR. The Agency recognizes
the concerns that additional expenditures due to this licensing fee create for systems. However, EPA
played no role in helping Calgon Carbon to acquire this patent or to set the licensing fee. Currently, the
Agency is not involved in any activities to alter it.
c. The UV dose values for Cryptosporidium, Giardia, and virus inactivation in today's final rule apply
only to compliance with the LT2ESWTR.
d. As described in the LT2ESWTR Economic Analysis, EPA's analysis indicates that ozone is a feasible
technology in addition to UV for some unfiltered systems to comply with the Cryptosporidium
inactivation requirements of today's rule.
e. EPA recognizes that many systems and States lack significant experience with UV disinfection. To
address this situation, the Agency is providing a UV Disinfection Guidance Manual with today's final
rule. This guidance manual will help systems understand how to select, install, and operate UV reactors
and help states understand how to approve UV reactors for compliance with today's rule.
In developing this guidance manual, EPA has sought and received extensive input from technical experts
and other stakeholders. Specifically, EPA participated in several technical expert workshops on the
guidance manual that the American Water Works Association organized. These workshops included
participants from manufacturers, consultants, and governments. Prior to these workshops, participating
experts were given specific charge questions on which to provide feedback, though their feedback was not
limited to these questions. In addition, EPA has published this guidance manual, in whole or in part, for
stakeholder comment on three occasions: once prior to the LT2ESWTR proposal, once with the rule
proposal, and once after proposal. With each draft publication, EPA sought input on specific questions
and revised the draft based on comments received. EPA gratefully acknowledges the major role
stakeholders have played in helping the Agency to write an effective guidance manual for UV
disinfection.
EPA will provide guidance on the use of other technologies in the microbial toolbox through the
Microbial Toolbox Guidance Manual and the Membrane Filtration Guidance Manual.
f EPA believes that the requirements for UV disinfection in today's final rule are the minimum necessary
to ensure effective water treatment for public health protection. These requirements include (1) the doses
of UV light needed to achieve different levels of Cryptosporidium, Giardia, and virus inactivation, (2)
validation of any UV reactor to establish the operating conditions under which the reactor can deliver a
particular dose, and (3) reactor monitoring, which includes UV intensity as measured by a UV sensor,
flow rate, lamp status, and other parameters the State designates based on UV reactor operation. Today's
rule does not specify a monitoring frequency, but in most UV reactors, these parameters are monitored
Comment Response for L T2ESWTR 8-2 75 December 2005
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continuously.
If existing UV reactor certification programs, such as NSF, meet the requirements in today's rule, systems
may rely on these programs to select UV reactors that will qualify for treatment credit, as some
commenters suggested. However, because EPA does not manage these programs or set the standards they
use for certification, the Agency cannot automatically assign a particular level of treatment credit for a
certified UV reactor.
g. Today's final rule maintains the proposed LT2ESWTR doses of UV for up to 3-log Cryptosporidium
and Giardia, and 4-log virus inactivation. EPA believes that the analyses supporting these dose
requirements appropriately account for censored values (i.e., values in which the degree of inactivation is
reported as greater than a maximum measurable value) and tailing in the underlying data, which some
commenters noted as concerns. Qian et al. (2004) (Ultraviolet light inactivation of Cryptosporidium and
Giardia in drinking water: a Bayesian meta-analysis) describes how the analyses address these concerns.
In addition, EPA has added UV doses for 3.5- and 4-log inactivation of Cryptosporidium and Giardia.
Some systems could potentially need to achieve more than 3-log Cryptosporidium inactivation to comply
with today's rule, and available data support the determination of dose requirements at these treatment
levels. However, EPA has not extended the dose values beyond 4-log (some commenters recommended
extending the doses to 5-log inactivation) because no requirements established by EPA in today's rule or
previous rules would necessitate a higher level of inactivation. Although today's rule requires filtered
systems to provide up to 5.5-log Cryptosporidium treatment depending on bin classification, systems
must achieve at least 2-log of this treatment by removal (e.g., filtration), not inactivation, as required by
the IESWTR or LT1ESWTR.
UV dose requirements for virus inactivation are based on adenovirus because it is the most UV resistant
among waterborne pathogenic viruses for which data are available. The requirement for virus inactivation
established by the SWTR is intended to address all viruses that are a potential public health concern in
drinking water. As described in the proposal, EPA believes that adenovirus presents such a concern
because it is a common cause of GI illness, especially in children, is commonly found in waters
contaminated by human sewage, and is transmitted through the fecal-oral route. Further, the resistance of
adenovirus suggests that other pathogenic viruses for which UV dose-response data aren't available may
also be UV resistant. Thus, EPA believes that basing UV dose requirements for virus treatment on
adenovirus is appropriate for public health protection.
EPA has not been able to identify types of water bodies that would be susceptible to some pathogenic
viruses but not adenovirus and to establish alternative UV dose requirements for such waters, as some
commenters suggested. The Agency has not seen data indicating that such water bodies exist.
The UV dose requirements in today's rule were developed only for public water systems and apply only
to drinking water disinfection requirements established by the LT2ESWTR. EPA has not considered the
application of these UV dose levels to other uses, such as home treatment POU or POE devices, except
POE devices used by public water systems as an alternative to central treatment for primary disinfection.
EPA has accounted for the impact of all UV requirements in the Agency's analyses of costs and benefits
fortheLT2ESWTR
h. Thank you for commenting on EPA's UV Disinfection Guidance Manual.
As some commenters noted, the UV dose tables in the draft UV Disinfection Guidance Manual differed
from those in the proposed LT2ESWTR. This situation occurred due to the application of recommended
Comment Response for L T2ESWTR 8-2 76 December 2005
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safety factors to the dose requirements in the guidance manual. These safety factors accounted for reactor
hydraulics, errors in reactor monitoring, and other factors. The final version of this guidance manual
corrects this perceived discrepancy - recommended safety factors are applied during reactor validation
and not to the final UV dose requirement. Thus, the dose tables shown in the guidance document are the
same as those in today's final rule.
Further, in the final version of the guidance document, EPA has reviewed and modified the use of safety
factors from the draft version. The Agency has retained only those safety factor that are critical to
ensuring the UV reactor delivers the required dose for a given degree of pathogen inactivation. In
developing these recommended factors, the Agency considered their effect on operation and maintenance
costs, including power costs. For certain factors that were retained, such as the RED bias and
polychromatic bias, EPA has revised their calculation to be more site-specific and user-friendly. The use
of Tier 1 and Tier 2 validation protocols has been dropped due to commenters concerns that this approach
was difficult to implement and overly restrictive. EPA believes that with these revisions, the safety factors
applied to UV disinfection in the guidance manual are commensurate with those applied to other
disinfection technologies.
Lastly, EPA notes that the safety factors described in the guidance are not required and only reflect one
recommended approach. As the guidance manual acknowledges, other approaches may be effective.
Systems and States should determine whether alternative approaches are appropriate for particular plants
given expected design and operational strategies. EPA has accounted costs associated both with the
requirements for UV disinfection and with recommended procedures for meeting these requirements (e.g.,
UV reactor validation testing) in the economic analysis for today's rule.
i. EPA expects that States will maintain their roles in approving treatment changes for their systems under
today's rule. Today's rule requires States to approve significant changes to disinfection practices, which
would include the installation of UV disinfection, under the disinfection benchmarking and profiling
provisions.
j. EPA believes that the requirement in today's final rule for systems to achieve the required UV dose on
at least 95 percent of the water delivered to the public each month is appropriate. This requirement for
UV is approximately equivalent to the existing requirement from the SWTR for unfiltered systems to
achieve the required CT value for chemical disinfectants every day but any one day per month. As
described in the preamble, this treatment compliance requirement for UV is based on the percentage of
water treated because UV systems typically consist of multiple reactors with each monitored continuously
- a measurement of a daily CT value would not be practical or meaningful for UV systems.
EPA is applying this 95 percent compliance requirement to both filtered and unfiltered systems in today's
final rule in order to achieve uniform and consistent performance standards for Cryptosporidium
inactivation. Some commenters suggested that filtered systems should have a lower compliance standard,
such as 90 percent, because filtered systems have another Cryptosporidium barrier (i.e., filtration).
However, EPA believes that applying the same standard is appropriate because under today's rule, filtered
systems are required to implement UV only if their source water is higher risk (i.e., they fall into a higher
treatment bin due to higher levels of Cryptosporidium in their source water). Systems may use UV in
combination with chemical disinfectants to meet inactivation requirements established by today's final
rule.
EPA notes that this 95 percent compliance requirement for UV disinfection is not intended as a design
benchmark. EPA agrees with commenters that UV reactors should be designed to adequately disinfect all
water delivered to the public. However, if a reactor is operated outside of validated conditions, the 95
percent criterion establishes the point at which the system will incur a treatment technique violation.
Comment Response for LT2ESWTR 8-277 December 2005
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A few commenters suggested that the UV disinfection compliance requirement should be based on time,
rather than volume, and that it should be determined on a daily, rather than a monthly basis. EPA believes
that volume of water treated is the appropriate metric for determining compliance because it relates most
directly to public health protection. For example, if a system were running 20 UV reactors, the public
health risk would clearly be greater if all 20 failed to deliver the necessary dose over a given time than if
only one did. A volume-based standard properly accounts for this difference, while a time-based standard
would not. Today's rule is consistent with all existing treatment technique requirements for virus, Giardia,
and Cryptosporidium in determining compliance monthly. Thus, the treatment compliance standard for
UV is determined monthly, rather than daily. If a system is aware of conditions that might endanger
public health, the system can notify the public faster.
Some commenters suggested that when a UV reactor is operating outside the validated conditions for the
required UV dose (i.e., off-spec), but is still operating at some level (i.e., providing some disinfection),
systems should be able to receive some disinfection credit. EPA believes that if a UV reactor is not
delivering the required UV dose by operating within validated conditions, this is analogous to a system
practicing chemical disinfection that fails to achieve the required CT (but may still achieve some lesser
CT). Thus, any off-spec operating condition with UV reactors does not count towards the 95 percent of
delivered water that must be treated at the required UV dose every month.
k. EPA recognizes that computational fluid dynamic (CFD) models can be valuable tools for UV reactor
design. At this time, though, EPA does not believe that CFD can completely substitute for full-scale
testing for UV reactor validation. Rather, some full-scale testing is necessary to ensure that a model
accurately predicts reactor performance. Facilities exist to perform full scale testing for UV reactors that
are feasible for any system size.
Today's rule does allow States to approve alternative approaches to UV reactor validation testing. If a
State determines that a particular CFD model has been adequately tested, a State may approve the use of
the model for UV reactor validation. EPA has not prescribed any safety factor for CFD modeling in
today's final rule.
1. EPA does not currently certify facilities to conduct UV reactor validation testing or perform such
testing itself. Rather, the Agency has set standards that such testing must meet in today's rule and has
provided guidance on how to conduct the testing, including appropriate involvement of independent third
parties, in the UV Disinfection Guidance Manual. EPA expects that the actual testing will be conducted at
existing commercial facilities or new facilities that may be established.
As described in the preamble, EPA expects that most validation testing of UV reactors will be product-
specific, rather than site-specific. Thus, a UV reactor will be validated to deliver a given UV dose over a
specified range of operating conditions. Systems will purchase UV reactors that have been validated over
conditions corresponding to their needs and circumstances. EPA does not expect most systems to conduct
their own reactor validation testing.
m. EPA recognizes that inlet and outlet hydraulics affect UV reactor performance. Today's rule does not
require a particular hydraulic configuration for UV reactor validation testing. Rather, the LT2ESWTR
requires that when determining validated operating conditions, systems must account for inlet and outlet
piping or channel configurations of the UV reactor (in addition to other factors). The UV Disinfection
Guidance Manual describes different approaches for dealing with inlet and outlet hydraulics in reactor
testing. EPA believes that this will provide systems with flexibility while ensuring that this critical issue
is addressed.
Comment Response for L T2ESWTR 8-2 78 December 2005
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n. The UV Disinfection Guidance Manual provides recommendations on changes to UV reactors that
would warrant new reactor validation testing. In general, such changes include (1) anything that would
alter the hydraulics of the reactor (e.g., change in internal wetted geometry, different inlet or outlet
piping) and (2) a modification to the reactor monitoring system (e.g., UV sensor locations) that would
change the operating conditions corresponding to a given UV dose.
Individual Comments on Code 910
EPA Letter ID: 413
Comment ID: 10511
Commenter: Thomas C. Sliwoski, Director of Public Works, City of Staunton, Virginia
Commenter Category: Regulated Community (Utilities)
Comment: Issue 3 and 4 UV Disinfection and Utilization
The EPA should further study the practical use of ultra violet disinfection in regards to safety and real
time field research. Failure to keep some form of disinfection in the distribution system after UV
application would negate any reasonable efforts to maintain high quality drinking water at the tap. All
disinfection technology should be
Response: See Response 910.a.
EPA Letter ID: 502
Comment ID: 10636
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: 3. The City of Columbus vehemently objects to paying the patent fees for UV disinfection.
The excessive financial burden these fees will place on our utility, and in-turn our rate paying consumers,
make this technology markedly expensive. If we were to install UV technology at our surface water
treatment plants it will cost us up to $900,000 per year (based on water plant design capacity) just in the
licensing fees alone. This is an unjustifiably expensive monopoly engineered by Calgon, and the
Columbus Division of Water would appreciate the EPA-s assistance mediating a reasonable solution to it.
Response: See Response 910.b.
EPA Letter ID: 509
Comment ID: 11485
Commenter: Greg Parker,, Florida Department of Environmental Protection Drinking Water Program
Commenter Category: State/Tribe Government
Comment: 141.729 This section includes UV light, log credit values. They don-t appear in the Interim
Enhanced SWTR or the Long Term 1 ESWTR. Consider adding referencesto these rules so systems can
see how UV is supported for giardia and viruses.
Comment Response for L T2ESWTR 8-2 79 December 2005
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Response: See Response 910.c.
EPA Letter ID: 523
Comment ID: 11693
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We are also concerned with the Calgon's UV patent and its cost impact to unfiltered systems,
which, based on the proposed rule, will have to rely on the operation of UV to meet the Cryptosporidium
inactivation criterion. We believe it is inappropriate that the proposed rule's reliance on "UV only" causes
the unfiltered systems to pay a substantial patent fee annually to Calgon to meet the LT2 requirements.
Response: See Responses 910.b and 910.d.
EPA Letter ID: 591
Comment ID: 12138
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: the UV dose. Ohio EPA recommends that 40 CFR 141500 be amended to permit water
systems serving fewer than 10,000 to achieve compliance with the LTIESWTR requirements for
Cryptosporidium treatment through removal or inactivation. That section currently requires systems
serving a population of less than 10,000 to provide 2 log removal of Cryptosporidium. Ohio has some
small systems (transients, mobile home parks, etc.) that use a ground water under direct influence of
surface water source subject to the LTIESWTR requirements. At this time, we are unaware of any
feasible/practical treatment option small systems like these could provide to meet the 2 log removal
requirement. The only removal technology which we are aware of that would be practical are cartridge
filters and these have been shown to achieve less than 2 log removal. In Ohio two cartridge filters.
Therefore, these small systems will be out of compliance with the LTIESWTR rule when it becomes
effective on January 1, 2005 and at this time we have no guidance to give these systems on how to come
into compliance with the LTIESWTR Cryptosporidium removal requirement. Amending 40 CFR 141.500
at this time to permit Cryptosporidium treatment by inactivation would provide some small systems
viable treatment alternatives.
Response: See Response 500.z.
EPA Letter ID: 603
Comment ID: 12695
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Ultraviolet disinfection is still an evolving technology that is in its regulatory infancy in the
United States. Ultraviolet reactors also include the application of proprietary technology that is
manufacturer specific. In many cases, it will be difficult for States to individually maintain the regulatory
Comment Response for LT2ESWTR 8-280 December 2005
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expertise to address reactor monitoring and validation issues. The EPA should include substantial training
resources for states in its implementation of the LT2ESWTR.
Response: See Response 910.e.
EPA Letter ID: 612
Comment ID: 13150
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: 3. Continuous Monitoring Technologies for Alternative Pathogenic Inactivation
Processes:
LT2 provides within its toolbox of treatment options, several new alternatives for the inactivation of
pathogens. These include UV disinfection, Ozonation, and the use of Chlorine Dioxide. Each of these
technologies provides the benefits of cryptosporidium and virus inactivation, but many appear to lack the
supporting technologies for insuring consistent inactivation over time.
Discussion
UV Disinfection-The use of UV several disinfection technologies are provided in the LT2 toolbox.
However, the effectiveness of each of these technologies and / or the by-products of such can have an
impact on the quality of the water that exits the treatment toolbox option. For example, the effectiveness
of UV disinfection is based on the ability of the UV system to produce a minimum quantity of irradiation
energy, which can be influenced by a number of factors. For example, changes in flow, temperature, and
turbidity all can impact to the effectiveness of UV performance.
Response: See Response 910.e.
EPA Letter ID: 617
Comment ID: 13261
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: ensure that this technology remains feasible. It is very clear that the only solution to higher
bin classification will be the institution of UV treatment. During the FACA various approaches were
discussed regarding quality assurance of UV devices and installation with a focus towards retaining the
simplicity and cost effectiveness of the technology. The FACA was assured that a significant assumption
in adopting the essential elements of LT2 was that UV would be available, economical, and feasible for
the implementation of a rule which essentially depended on it. EPA must take into consideration that a
significant erosion of the economics for UV has occurred due to the patent on UV use for inactivation of
Crytosporidium granted to Calgon and which was not made aware to the FACA. It is entirely likely that
had the FACA been aware of this patent their deliberations and conclusions would have been
considerably different. As a result EPA has an even greater burden of responsibility to promulgate a UV
based regulation which does not place unnecessarily expensive requirements upon the implementation of
the technology.
Comment Response for LT2ESWTR 8-281 December 2005
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Response: See Response 910.b and lOO.t.
EPA Letter ID: 624
Comment ID: 13204
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: UV Disinfection
a. UV representation during AIP development by FACA: GCWW strongly opposes paying the patent
fees. Calgon representatives, who did not disclose their conflict of interest, participated in the FACA
process. In the LT2 proposal, EPA endorses that UV is an effective and affordable technology. With the
new patent fees, it places unnecessary financial burden on the utilities. For example, if GCWW
incorporates UV treatment, it will have to pay approximately $700,000 annually just towards licensing
fees.
Response: See Response 910.b and lOO.aa.
EPA Letter ID: 624
Comment ID: 13205
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: b. We encourage EPA to facilitate Primacy Agency approval of UV systems
so that all states have uniform approval criteria.
Response: See Response 910.e.
EPA Letter ID: 628
Comment ID: 12854
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: The SFPUC is also concerned with the Calgon-s UV patent and its cost impact on
the operation of large UV reactors. The SFPUC believes it is inappropriate for the EPA to promulgate a
rule, which as currently proposed is relying on UV only for achieving the highest inactivation of
Cryptosporidium, that will cause a system to pay a substantial patent fee annually to a third party to
comply with the regulatory requirements.
Response: See Response 910.d and 910.b and lOO.t.
Comment Response for L T2ESWTR 8-282 December 2005
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8.16.1 Comment Code 911, Credit and criteria for awarding credit
EPA Letter ID: 101
Comment ID: 10900
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Ultraviolet Light
Inactivation using ultraviolet light is the low cost technology for LT 2. Therefore, it is essential that the
requirements for UV maintain maximum flexibility. Something is wrong with the IT tables. The IT tables
in the
Response: See Responses 910.f and 910.h.
EPA Letter ID: 413
Comment ID: 10512
Commenter: Thomas C. Sliwoski, Director of Public Works, City of Staunton, Virginia
Commenter Category: Regulated Community (Utilities)
Comment: drinking water at the tap. All disinfection technology should be evaluated at the individual
plant site by their respective State Agencies.
Response: See Response 910.i.
EPA Letter ID: 415
Comment ID: 10520
Commenter: Miguel Arroyo, Water and Wastewater Treatment Manager, City of Fort Lauderdale Public
Services Department
Commenter Category: Regulated Community (Utilities)
Comment: * UV technology has come a long way in the last few years. However it does not seem like
these advances were taken into consideration on the rule making, due to the additional safety factors
imposed.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 419
Comment ID: 10504
Commenter: Billy Turner, President, Columbus Water Works
Commenter Category: Regulated Community (Utilities)
Comment Response for L T2ESWTR 8-283 December 2005
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Comment:
4) EPA should seriously reconsider the layers of safety factors and conservative assumptions that are
currently reflected in the UV guidance document and strive to restructure the Agency's expectations
in the context of a viable, operationally flexible disinfection strategy.
Response: See Response 910.h.
EPA Letter ID: 420
Comment ID: 14092
Commenter: Eddie Partlow, General Manager, THE OLD HICKORY UTILITY DISTRICT
Commenter Category: Regulated Community (Development): Housing, FEEP, NAHB
Comment: UV disinfection will be the low cost technology solution for many utilities that have to
provide additional treatment as a result of LT2ESWTR. As it is written, the UV guidance requires
significant safety factors (cumulatively almost a factor of 4 X ) both in the design and operation of UV
systems. EPA should reconsider the layers of safety factors and conservative assumptions that are
currently reflected in the UV guidance document. EPA's expectations should be in the form of a
viable, operationally flexible disinfection strategy.
Response: See Response 910.h.
EPA Letter ID: 451
Comment ID: 14162
Commenter: Eric Abrams, Superintendent, McMinnville Water and Light
Commenter Category: Regulated Community (Utilities)
Comment: Comment #4:Finally we would ask the EPA to reconsider the conservative assumptions and
layers of safety currently established in the UV Guidance Document and restructure its expectations
regarding viable, operationally flexible, disinfection strategy. McMinnville Water and Light would like to
thank the EPA for this opportunity to comment on the proposed LT2ESWTR.
Response: See Response 910.h.
EPA Letter ID: 453
Comment ID: 10948
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: 6. Concerning UV disinfection, the safety factors appear to be excessive. Also,
Response: See Response 910.h.
Comment Response for L T2ESWTR 8-284 December 2005
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EPA Letter ID: 457
Comment ID: 11938
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: UV
We support inclusion of this tool and that credit would be based on log inactivation using the IT table.
Response: See Response lOO.a.
EPA Letter ID: 470
Comment ID: 11085
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 791 1. Credit and criteria for awarding credit; 801 1.
Credit and criteria for awarding credit; 821 1. Credit and criteria for awarding credit; 891 1. Credit and
criteria for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment
requirements
Response: See Response lOOa.
EPA Letter ID: 471
Comment ID: 11113
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: UV Disinfection Criteria
1. We believe that the proposed rule-s approach to UV disinfection may be overly conservative due to the
compounded use of large safety factors which are outlined in the draft UV Guidance Manual. This is
evident from a comparison of the rule-s IT tables and the guidance manuals IT tables (e.g., for 2.0-log
credit for Giardia and Cryptosporidium, the rule requires ITs of 5.8 and 5.2 mJ/cm2, respectively,
whereas the guidance manual requires 21 and 20 mJ/cm2 to account for hydrodynamics, dose
distributions, and various inefficiencies). As we are in the preliminary design phase of retrofitting UV
disinfection at both of our water treatment plants, we are acutely aware of the significant additional
capital and operating costs associated with higher design and operating UV doses. We recommend that
EPA take a hard look at the safety factors that are being applied to UV use and insure that they are
reasonable and are not compounded leading to needlessly more expensive applications. Along these lines,
it is important to recognize that WSSC, along with many water systems, already builds in reasonable
safety factors in our facilities to insure that we continue to exceed the minimum compliance standards,
which is our standard approach to safeguarding public health.
Comment Response for L T2ESWTR 8-285 December 2005
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Response: See Response 910.h.
EPA Letter ID: 474
Comment ID: 11202
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: There appears to be a compounding of safety factors when the §141.729 table is translated to
the UV Guidance Manual, which, in turn, leads to overly conservative dosing to achieve inactivation. We
believe the values in the
Response: See Response 910.h.
EPA Letter ID: 479
Comment ID: 11222
Commenter: Brad Joyner, Superintendent, Town of Forest City WTP
Commenter Category: Local Government
Comment: The LT2ESWTR must reconsider the disinfection strategy through UV and recommend
alternative guidance based on the safety factors and feasible operational cost associated with the
technology.
Response: See Response 910.h.
EPA Letter ID: 483
Comment ID: 11269
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: - EPA should take a hard look at the safety factors that are being applied to UV use and
insure they are reasonable and are not compounded leading to needlessly more expensive applications.
Water systems will, of necessity (to insure compliance with validation requirements), build in their own
safety factors lessening the need for EPA to be too conservative.
Response: See Response 910.h.
EPA Letter ID: 486
Comment ID: 14166
Commenter: Christopher R. Schulz, Drinking Water Practice Leader, CDM, Inc.
Commenter Category: Consultants: (where self-identified)
Comment Response for L T2ESWTR 8-286 December 2005
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Comment: 141.729 Inactivation toolbox components
2. The CT calculations for chlorine dioxide and ozone must be determined each day during peak hourly
flow and reported monthly to state primacy agency. By comparison, UV disinfection systems must report
the percentage of water that was not treated within validated conditions for the UV reactor during the
month. In most treatment applications involving UV disinfection, UV will be used as part of an integrated
disinfection strategy whereby UV is used for achieving Crypto and Giardia inactivation credit and
chemical disinfectants (chlorine, chloramines, ozone or chlorine dioxide) are used for Giardia, virus
and possibly Crypto inactivation credit. There is no discussion in the Rule on how daily CT compliance
requirements for chemical disinfectants are reconciled with monthly reporting requirements for UV
disinfection, as would be the case when a facility takes credit for multiple disinfection segments through
the plant. We suggest that the monthly CT credits for UV disinfection be added to the daily CT credits for
chemical disinfectants in the monthly reporting forms to show compliance with daily log inactivation
requirements under the Rule.
Response: See Response 910.J.
EPA Letter ID: 496
Comment ID: 10698
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 1. UV Key Issue 1 Conservative Assumptions: Based on the proposal and the draft UV
Guidance Manual, the validation procedures will require doses more than three times higher than those
listed in the IT Tables in order to comply with the rule (i.e. for 2.0 log credit for Giardia and Crypto,
doses in rule are 5.8 and 5.2 mJ/cm2 respectively, and 21 and 20 mJ/cm2 in the guidance manual). This is
in addition to a safety factor of 2-3 inches in the IT Tables. Additionally, validation is to be applied to
"worst case" scenarios. Since the IT Table already includes a safety factor, care should be taken not to
compound those safety factors in Guidance.
Comments for UV Key Issue 1 (Conservative Assumptions): EPA should take a closer look at the safety
factors that are being applied to UV use and ensure that they are reasonable and are not compounded
which would lead to more expensive applications. In order to ensure compliance with validation
requirements, water systems will build in their own safety factors, thus eliminating the need for EPA to be
too conservative.
Response: See Response 910.h.
EPA Letter ID: 504
Comment ID: 11367
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: We find that factors of safety have been built into guidance in at least two layers. First, the IT
tables incorporate a factor of safety of 2 to 3. In addition, required validation procedures would require
use of dosing that is 4 to 5 times higher than indicated by the IT tables for a given condition. Further,
required validation procedures are to be conducted for worst-case conditions. We are concerned that the
Comment Response for L T2ESWTR 8-28 7 December 2005
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net result will be excessively conservative design that will add unnecessarily to the cost of UV isinfection.
We suggest that EPA reexamine the need for the degree of conservatism included in UV disinfection
guidance. Final guidance should acknowledge the application of a factor of safety in conventional
engineering design practice.
Response: See Response 910.h.
EPA Letter ID: 506
Comment ID: 10738
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: - UV Disinfection Criteria
o Conservative Assumptions - CWD requests that USEPA study the safety factors that are being applied
to UV and ensure that they are reasonable and are not compounded to a point that forces water systems to
more expensive applications. Since a water system will need to stay in compliance with the rule, they will
build their own safety factors into the specific installation, compounding the safety factors again. This
lessens the need for USEPA to build too many safety factors into the regulation.
Response: See Response 910.h.
EPA Letter ID: 507
Comment ID: 11469
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 5. Ultraviolet Light, IV.C.15., pg 47711.
FCWA recommends that EPA review the safety factors it has established for UV in that they are
reasonable and not unnecessarily compounded. We also encourage EPA
Response: See Response 910.h.
EPA Letter ID: 510
Comment ID: 16511
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: 1.2 Safety factor calculations in the UVDGM do not ensure safety
The calculations of safety factors rely on incorrect/unsafe assumptions.
Comment Response for L T2ESWTR 8-288 December 2005
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As stated earlier, the RED Bias calculation uses a default dose distribution which in itself is not
representative of drinking water systems, and is not the worst case dose distribution, thus compromising
public health.
The Polychromatic Bias quantifies an effect that has never been demonstrated to be significant, and uses
default reactor geometries in its calculation which also may not be worst case. Based on our research, we
believe that this is very small in magnitude. The calculations in the draft manual pre-suppose that UV
reactor monitoring is directly related to these polychromatic effects, and that the UV reactor control
system cannot correct for it. Within the draft manual, a default reactor is used in the calculations and may
not lead to results representative of what is actually occurring during operation with a real reactor. The
lamp spectra used in the calculations are not necessarily representative of actual spectra, and they should
be peer-reviewed. Overall, the theory of these calculations needs to be peer-reviewed and shown to be
representative. The UVDGM needs to specify how a spectrum must be validated to allow its use in the
calculations. The UVDGM must also allow for the determination of these factors through empirical
testing. In addition, if the effect can be calculated in a spreadsheet, then presumably a monitoring and
control system could calculate the effect and account for it on-line. This sort of control scheme exits, is
available, and is in use in drinking water systems in the United States. Thus the UVDGM should allow
for this type of monitoring and control strategy, which when properly validated, would remove any
potential Polychromatic Bias.
1.3 Equipment safety factors are inaccurately applied against microbiological targets.
Safety factors should be applied to equipment, not to microbiological targets. Confusion of these concepts
within the manual can lead to industry-wide confusion about moving targets and differences between
equipment.
The microbiological targets, in terms of log reductions required for specific epidemiologically significant
targets to be met should be explicitly stated. The equipment must then be shown to meet the required log
reductions of the pathogens. That is, targets for log reductions should be set for the various
pathogens, and the equipment must be shown to meet the log reduction targets required.
For example, Table 1.4 in the draft guidance manual specifies the microbiological dose required for 3 log
Cryptosporidium inactivation as 12 mJ/cm2, while Tables 4.1 and 4.2 specify that doses of 36 and 42
mJ/cm2 are required to achieve 3 log Cryptosporidium inactivation in LP and MP systems respectively.
These values of 36 and 42 mJ/cm2 are being wrongly interpreted as the microbiological dose
requirements, which is fundamentally incorrect because the true doses required for the logs of reduction
required are not technology dependent; it is the amount of equipment to achieve the target dose that
changes.
2.2 Separate equipment safety factors from site safety factors.
Equipment safety factor terms to be determined from the performance test results are the RED Bias (if
applicable, see below) and an Expanded Uncertainty term (different than currently defined in the draft
manual, see below).Site safety factor terms to be determined at the time of design by the engineer include
the Polychromatic Bias (if applicable), a term for installation hydraulics (see below), system fouling
effects, and a consideration of overall system safety.
Response: See Response 910.h and 910.e.
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EPA Letter ID: 510
Comment ID: 16513
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: 2.1 Be clear that the objective is to reach logs reduction of a specific
pathogen.
Use the terms dose, RED, and logs reduction with the clear understanding that what is fundamentally
required for protection of public health is logs reduction, and what is needed to ensure that public health
is maintained is monitoring of systems to ensure the right delivery of target design dose required to
produce the target logs reduction of the target pathogen.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 520
Comment ID: 11647
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Ultraviolet Disinfection
IEPA generally supports inclusion of this tool and the requirement that credit would be based on log
inactivation using the IT table. There is concern with the IT table and the safety factor used.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 522
Comment ID: 14129
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: documents. This is particularly obvious with UV: what the broad outline gives, the details
take away, with excess complexity and extreme layers of conservatism. We urge EPA to carefully sort
through the comments received, focusing on simplifying the final regulations, and reducing unnecessary
and costly requirements for overlapping safety and redundancy factors. Third,
Response: See Responses 910.f and 910.h.
EPA Letter ID: 522
Comment ID: 14140
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Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Compliance Determination for UV disinfection: For unfiltered systems using UV
disinfection to meet the required inactivation requirements, the draft regulations propose that compliance
with the standard be based on a 95th percentile. This is a commonsense approach to extending the
existing SWTR requirements for chemical disinfection in unfiltered systems to UV, and MWRA
supports this approach. In that it provides additional information on disinfection system performance,
particularly short periods of disruption, it improves on the current reporting system. It is protective of
public health, while avoiding the excesses of extraordinary redundancy.
Response: See Response 910.J.
EPA Letter ID: 522
Comment ID: 14146
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Excessive Conservatism in UV Guidance Manual: An important factor in the completion of
the FACA process resulting in consensus on the AIP was the recognition that inactivation of
Cryptosporidium using UV was possible at a low cost. Unfortunately, as developed in the UV
Disinfection Guidance manual, the multiple layers of redundant safety factors conspire to unnecessarily
raise the costs of compliance. MWRA's Wachusett Reservoir system serving
Response: See Response 910.h.
EPA Letter ID: 523
Comment ID: 11687
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Excessive Conservatism in UV Guidance Manual: An important reason that the FACA
process resulted in consensus on the AIP was the recognition that inactivation of Cryptosporidium using
ultraviolet light (UV) was possible at a low cost. Unfortunately, as developed in the UV Disinfection
Guidance manual, the multiple layers of redundant safety factors unnecessarily raise the costs of
compliance.
Response: See Response 910.h.
EPA Letter ID: 526
Comment ID: 11771
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Commenter: Nick Jackson,, Knoxville Utilities Board
Commenter Category: Local Government
Comment: 7. We feel the proposed guidelines for Ultraviolet Radiation (UV) implementation
as a means for achieving additional log removal of pathogens are unnecessarily conservative. While this
is a new technology, these guidelines in the their present form may cause utilities to not use UV where it
is often the best choice in retrofitting existing treatment plants economically to achieve higher
athogen removal requirements.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 527
Comment ID: 10855
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Conservative Assumptions: Based on the proposal and the draft UV Guidance Manual,
validation procedures will require doses more than three times higher than those listed in the UV dose
table to comply with the rule, (i.e., for 2.0 log credit for Giardia and Crypto doses in the rule are 5.8 and
5.2 mJ/cm2, respectively, and 21 and 20 mJ/cm2 in the guidance manual). This is on top of a
safety factor of 2 to 3 in the UV dose table. Additionally, validation is to be applied to -worst case-
conditions. Since the UV dose table already includes a safety factor, care should be taken in compounding
those safety factors in guidance. We recommend that EPA take a hard look at the safety factors that are
being applied to UV use and insure that they are reasonable and are not compounded leading to
needlessly more expensive applications. Water systems, to insure compliance with validation
requirements will, of necessity, build in their own safety factors lessening the need for EPA to be too
conservative.
EPA should retain the proposed UV dose table for Cryptosporidium and Giardia lamblia in the final rule.
The UV Disinfection Guidance Manual should be revised to reflect a single decision-making process that
ensures that when operating the applied UV dose will be reliably equal to or greater than the required
dose in the rule text. This process has to be articulated in a clear and simple way for ease of
implementation, and to ensure that the Agency-s actions do not impede the rapid advancement of UV
technology in drinking water treatment.
Extend UV Dose Table to Higher Log Inactivations: The UV dose table stops at 3.0 log inactivation and
does not provide values for 3.5, 4.0 or higher log inactivation for Giardia lamblia and Cryptosporidium.
The observed data from the research studies cited by the Agency included higher inactivations and
demonstrates that greater than 4 log inactivation is feasible.
EPA should complete the UV dose table in the rule to include doses required to receive up to and
including 4.0 log credit for Cryptosporidium and Giardia lamblia or higher if supported by the data.
Response: See Responses 910.f, 910.g, and 910.h.
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EPA Letter ID: 527
Comment ID: 10855
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Conservative Assumptions: Based on the proposal and the draft UV Guidance Manual,
validation procedures will require doses more than three times higher than those listed in the UV dose
table to comply with the rule, (i.e., for 2.0 log credit for Giardia and Crypto doses in the rule are 5.8 and
5.2 mJ/cm2, respectively, and 21 and 20 mJ/cm2 in the guidance manual). This is on top of a safety factor
of 2 to 3 in the UV dose table. Additionally, validation is to be applied to -worst case- conditions. Since
the UV dose table already includes a safety factor, care should be taken in compounding those safety
factors in guidance. We recommend that EPA take a hard look at the safety factors that are being applied
to UV use and insure that they are reasonable and are not compounded leading to needlessly more
expensive applications. Water systems, to insure compliance with validation requirements will, of
necessity, build in their own safety factors lessening the need for EPA to be too conservative.
EPA should retain the proposed UV dose table for Cryptosporidium and Giardia lamblia in the final rule.
The UV Disinfection Guidance Manual should be revised to reflect a single decision-making process that
ensures that when operating the applied UV dose will be reliably equal to or greater than the required
dose in the rule text. This process has to be articulated in a clear and simple way for ease of
implementation, and to ensure that the Agency-s actions do not impede the rapid advancement of UV
technology in drinking water treatment.
Extend UV Dose Table to Higher Log Inactivations: The UV dose table stops at 3.0 log inactivation and
does not provide values for 3.5, 4.0 or higher log inactivation for Giardia lamblia and Cryptosporidium.
The observed data from the research studies cited by the Agency included higher inactivations and
demonstrates that greater than 4 log inactivation is feasible.
EPA should complete the UV dose table in the rule to include doses required to receive up to and
including 4.0 log credit for Cryptosporidium and Giardia lamblia or higher if supported by the data.
Response: See Responses 910.f, 910.g, and 910.h.
EPA Letter ID: 556
Comment ID: 12039
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 710 A. Microbial Toolbox General Comments; 1832 2.
Adequacy of current capacity
Comment: punishment that far exceeds the crime. Other areas where the proposal would be improved by
referring to the intent of the FACA and AIP include: ensuring the availability of adequate laboratory
capacity; ensuring that the toolbox provides reasonable; achievable alternatives to UV disinfection; and
ensuring that safety factors and conservative assumptions do not needlessly add to the costs of
iimplementing UV.
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Response: See Responses 1830, 910.f, 910.h, and lOO.t.
EPA Letter ID: 556
Comment ID: 12074
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Background: Based on the proposal and the draft UV Guidance Manual, validation
procedures will require doses more than three times higher than those listed in the UV dose table to
comply with the rule (i.e., for 2.0 log credit for Giardia and Crypto doses in rule are 5.8 and 5.2 mJ/cm2,
respectively, and 21 and 20 mJ/cm2 in the guidance manual). This is on top of a safety factor of 2 to 3 in
the UV dose table. Additionally, validation is to be applied to -worst case- conditions. Since the UV dose
table already includes a safety factor, care should be taken in compounding those safety factors in
guidance.
Recommendations: AMWA recommends that EPA, in conjunction with experts in the field take a look at
the safety factors that are being applied to UV use and make certain they are reasonable and not
compounded, which will lead to unnecessarily more expensive applications. Water systems, to ensure
compliance with validation requirements will, of necessity, build in their own safety factors thereby
lessening the need for EPA to be too conservative.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 560
Comment ID: 14991
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comments on Draft Ultraviolet Disinfection Guidance Manual
Comment One - Off-Spec Limitation:
The Long-Term 2 Enhanced Surface Water Treatment Rule (LT2) requires that for unfiltered water
supplies, at least 95% of the monthly flow into a point of entry (POE) undergo UV disinfection within the
range of validated conditions. Two or 3-log Cryptosporidium inactivation credit is granted to unfiltered
water supplies, by virtue of having a validated UV disinfection system in place, even when as much as
5% of the monthly flow undergoes off-spec UV disinfection. Conceivably, 2 or 3-log Cryptosporidium
inactivation credit is granted even when as much as 5% of the monthly flow bypasses the UV disinfection
system.
The UVDGM addresses filtered water supplies very differently by suggesting that States define the off-
spec limits. Our concern is that some States may impose more stringent off-spec limits for filtered water
supplies than for unfiltered water supplies.
The other dissimilarity is in the math. While an unfiltered water supply is granted as much as 3-log
Cryptosporidium inactivation credit despite bypassing or experiencing off-spec UV disinfection for 5% of
the monthly flow, the UVDGM implies that inactivation credit for filtered water supplies is a function of
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the off-spec volume. The 4th paragraph on page 3-17 of the UVDGM states, -For example, if a 2-log
Cryptosporidium inactivation is desired, the UV reactors cannot be down while more than 1 percent of the
flow passes through them.- This implies a relationship such as: Off-spec volume (% of monthly
flow)Cryptosporidium inactivation credit 101120.13 Consequently, a filtered water supplier would have to
ensure that 99.9% of the monthly flow undergoes UV disinfection within validated conditions to achieve
3-log Cryptosporidium inactivation credit, which is much more stringent than the standard for unfiltered
water supplies. This is despite the additional treatment barriers and the relative quality of a filtered water
supply, which is at least equal to an unfiltered water supply with a filtration avoidance determination.
It is recommended that the LT2 and UVDGM define an off-spec standard such as 10% of the monthly
flow for filtered water supplies without deducting from the nominal Cryptosporidium inactivation credit.
Response: See Response 910.J.
EPA Letter ID: 562
Comment ID: 12289
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. EPA should reconsider the layers of safety factors and conservative assumptions that the
UV guidance document reflects to ensure that application of this technology is feasible for LT2ESWTR
compliance.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 562
Comment ID: 12314
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: drinking water treatment technology. Unfortunately, the redundant safety factors imposed in
the guidance, the difficulties in applying the Tier 1 and Tier 2 analyses, validation issues, and the off-
specification criteria set in the proposed rule represent significant obstacles to practical and efficient
application of UV.
Response: See Responses 910.f, 910.h, and 910.J.
EPA Letter ID: 562
Comment ID: 12500
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: or the resulting values in the UV dose table. The UV dose table has a built-in safety margin
because entries correspond to lower bounds of the -credible range- derived from inactivation study data.
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AWWA is seriously concerned that additional layers of safety factors related to design criteria and
redundancy requirements specified in guidance result in excessive conservativism in UV application
requirements. Furthermore, utilities will want to operate with a margin of safety relative to regulatory
requirements.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 562
Comment ID: 12501
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA encourages EPA to develop an approach to UV disinfection that is akin to the
approach that is employed for other disinfectants such as chlorine or ozone under the SWTR. The SWTR
rule specifies:
l.CT table, and
2. Basic compliance metric appropriate for identifying situations warranting state intervention and public
notice.
Additional direction was provided through guidance, namely:
1. Basic T10 calculation of contactor hydraulic residence time for calculation of time in the CT equation;
2. Approaches to integrating disinfectant contact time throughout the water treatment plant; and
3. Option for site-specific studies to address site-specific circumstances.
Individual states have expanded on this basic model within their primacy authority, but the national
framework set in 1989 is substantially the same nationwide. Individual utilities apply disinfectant per
utility-specific Standard Operating Procedures (SOPs) that include appropriate alarms and safety factors
to ensure CT is consistently and reliably achieved.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 562
Comment ID: 12505
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Excessive Safety Factors
In the final guidance manual, the agency must pay special attention to operation and maintenance (O&M)
costs, particularly power costs. Power costs are essentially proportional to UV dose. Use of excessive
safety factors will result in higher O&M costs for utilities. In addition, the ability to ramp the UV dose up
and down in response to water quality, flow rate, and reactor conditions is key to optimizing power usage.
Power consumption is a very real practical concern that has direct implications for the ongoing
affordability of UV operations. Eliminating operational flexibility is also a very real concern with the
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guidance manual. As a consequence, UV systems will have to be significantly over designed to allow
utilities to routinely operate with some margin for error with respect to regulatory requirements. As
violations and/or public notice requirements should only be applicable when there is a credible public
health concern, additional consideration should be given to the stringency of the proposed UV
Disinfection Guidance Manual.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 562
Comment ID: 12515
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA is genuinely concerned that, while the agency requests information about
many of the proven and well-understood technologies being considered for LT2ESWTR compliance, the
agency poses only a single question regarding the compliance technology the agency-s own EA suggests
will be the most frequently used by medium and large drinking water utilities. Response to Requests for
Comment, 68 FR 47713 §IV(C)(15)(c)The agency requests comment on the following issues concerning
softening on page 47697 of the proposed rule:
Request for Comment
The agency requests comment on whether the criteria described in this section for awarding treatment
credit for UV disinfection are appropriate, and whether additional criteria, or more specific criteria should
be included.
(68 FR 47713)
Response
AWWA has provided comment above on a number of issues that required attention in the UV
Disinfection Guidance Manual. These recommendations speak directly to the appropriateness of the
criteria for UV log-credit, in particular:
1. The UV dose table does not encompass an adequate range and should be extended to 5 log for
Cryptosporidium and Giardia lamblia;
2. Basing the UV dose table for viruses on adenovirus is suspect and requires substantiation and
reconsideration;
3. Potentially excessive safety factors are incorporated into the Tier 1 validation protocol;
4. Expectations for available data and resources required to achieve validation across the full range of a
water treatment plant-s operating conditions are inordinately and unjustifiably high;
5. The off-specification criteria are missing for filtered systems and should be set at an achievable level
(95% percentile within specification is too stringent); and
6. The proposed criteria will stifle technological improvements in UV.
Response: See Responses 910.g, 910.h, 910.f, and 910.J. EPA does not believe that the regulatory criteria
for UV in the LT2ESWTR will stifle technology improvements. The requirements specify only the doses
of UV light necessary for different levels of pathogen inactivation credit, reactor validation testing, and
reactor monitoring. These criteria are necessary and appropriate for any UV disinfection system. Further,
the rule allows States to approve alternative approaches to reactor validation. This provision recognizes
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that in the future, validation techniques may advance and systems should be able to use them with State
approval.
EPA Letter ID: 580
Comment ID: 12631
Commenter: Bruce Aptowicz, Chairman, Water Utility Council of the Pennsylvania American
Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. EPA should reconsider the layers of safety factors and conservative
assumptions that the UV guidance document reflects to ensure that application of
this technology is feasible for LT2ESWTR compliance.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 586
Comment ID: 12204
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: 6. Overly conservative safety factors for UV disinfection.
The UV guidance document included in the docket seems to impose excessive safety factors on UV
technology -almost a factor of 4, cumulatively. Since UV disinfection will be the treatment method of
choice for many systems to meet the new requirements of the LT2ESWTR, the additional cost of meeting
the design and operational criteria found in the guidance document may make the technology
cost-prohibitive.
We request that EPA closely examine the multiple lavers of safety factors, and the underlying
assumptions, found in the UV guidance document. It is important that treatment methods not only be
effective, but attainable as well.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 587
Comment ID: 12017
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: B) Basis of Compliance Determination -In the proposed rule under §141.721(c)(2)
and §141.730(e)(13) compliance is based upon a monthly volume of inadequately treated water. A time-
based method of compliance including daily triggers should be used. A monthly volume of treated water
basis is not consistent with the method of determining treatment effectiveness utilized for filtration plants
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or for chemical disinfection treatment as practiced under the Surface Water Treatment Rule. Focusing
solely on monthly compliance calculations is not consistent with current health concerns for acute
microbial contaminants.
Response: See Response 910.J.
EPA Letter ID: 587
Comment ID: 12024
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: 2. Basis of Compliance Determination - In the proposed rule under §141.721(c)(2)
and §141.730(e)(13) compliance is based upon a monthly volume of inadequately treated water. A
monthly volume of treated water basis is not consistent with the method of determining treatment
effectiveness utilized for filtration plants or for chemical disinfection treatment as practiced under the
Surface Water Treatment Rule. A failed UV Reactor does not provide any treatment. Consequently
the failed reactor acts essentially like a direct by-pass of the UV treatment barrier. A monthly volume
approach does not properly account for the by-pass nature of a failed UV reactor. In addition, a volume-
based approach would require additional calculations by the water system and by the state to determine
whether or not a TTV has occurred. I believe using time rather than volume will provide simpler and
clearer calculations of compliance, recognize the "by-pass" nature of a failed reactor, and be more
consistent with existing regulatory frameworks.
Second, there should be a means of calculating UV compliance on a daily basis. If a monthly volume
approach were to be enacted, a water system experiencing a complete UV failure on the first of the month
for an entire day, would not be able to determine if a TTV occurred until 29 days later. Consequently,
potential Public Notification for a primary microbial health parameter would happen a month later.
Focusing solely on monthly compliance calculations is not consistent with current health concerns for
acute microbial contaminants. It is not difficult to envision extreme discomfort explaining to a worried
parent or angry legislator that consuming two days of under-treated water does not represent a health
concern because the following 28 days the water was fully treated. I strongly recommend that both
monthly and daily compliance criteria for UV reactors be developed.
Response: See Response 910.J.
EPA Letter ID: 603
Comment ID: 12654
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47783) Section 141.721(c)(2)-
This section defines compliance with the W inactivation requirements on a monthly volume basis. In the
SWTR, there are daily and time based criteria for calculating compliance. For example, under the
IESWTR, for rapid sand filtration plants, the maximum allowable turbidity is 1NTU and lack of chlorine
residual of more than 4 hours constitutes a treatment technique violation. We strongly recommend the use
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of time rather than volume as the means of calculating compliance with the provision of a daily trigger to
support continuous operation of W reactors. The department position on these issues is further explained
in Attachment C.
Response: See Response 910.J.
EPA Letter ID: 603
Comment ID: 12691
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: 2. Basis of Compliance Determination -In the proposed rule under §141.721(c)(2)and
§141.730(e)(13) compliance is based upon a monthly volume of inadequately treated water. A monthly
volume of treated water basis is not consistent with the method of determining treatment effectiveness
utilized for filtration plants or for chemical disinfection treatment as practiced under the Surface Water
Treatment Rule. In addition, a volume-based approach would require additional calculations by the water
system and state to determine whether or not a TTV has occurred. We believe using time rather than
volume will provide simpler and clearer calculations of compliance and be more consistent with existing
regulatory frameworks.
Second, there should be a means of calculating UV compliance on a daily basis. If a monthly volume
approach were to be enacted, a water system experiencing a complete UV failure on the first of the month
for an entire day, would not be able to determine if a TTV occurred until 29 days later. Consequently,
potential Public Notification for a primary microbial health parameter would happen a month later.
Focusing solely on monthly compliance calculations is not consistent with current health concerns for
acute microbial contaminants. It is not difficult to envision extreme discomfort explaining to a worried
parent or angry legislator that consuming two days of under treated water does not represent a health
concern because the following 28 days the water was fully treated. We strongly recommend that there be
both monthly and daily compliance criteria for UV reactors.
Response: See Response 910.J.
EPA Letter ID: 617
Comment ID: 13260
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 4. EPA should reconsider the layers of safety factors and conservative assumptions that are
currently reflected in the UV guidance document to ensure that this technology remains feasible. It is very
clear that the only
Response: See Responses 910.f and 910.h.
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EPA Letter ID: 624
Comment ID: 13180
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 5. GCWW is very concerned that EPA has applied excessive safety factors (as high
as 4) on the application of UV doses in addition to conservatism built into the W dose table. Using
excessive safety factors has enormous cost implications on a utility, especially on energy costs.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 624
Comment ID: 13207
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: d. GCWW is very concerned that EPA has applied excessive safety factors (as high as 4) on
the application of UV doses in addition to conservatism built into the UV dose table. Using excessive
safety factors has enormous cost implications on a utility, especially on energy costs. GCWW has
conducted microbial inactivation studies using
mj/cm2 for both low and medium pressure lamps. If GCWW wants to use the Tier I approach and
medium pressure lamps, it will have to apply 42 mj/cm2 which is 14 times the dose necessary. This safety
factor would lead to over designing the facility costing significant amount of money without justified
public health benefit.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 628
Comment ID: 12855
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: Avoid excessive conservatism in accepting the UV technology. An important factor
in the completion of the FACA process resulting in consensus on the AIP was the recognition that
inactivation of Cryptosporidium using UV was possible at a low cost. Unfortunately, as developed in the
UV Disinfection Guidance Manual, the multiple layers of redundant safety factors conspire to
unnecessarily raise the costs of compliance. The SFPUC owns and operates one of the largest unfiltered
Response: See Responses 910.f and 910.h.
Comment Response for L T2ESWTR 8-3 01 December 2005
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EPA Letter ID: 630
Comment ID: 13066
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 1. UV Key Issue Conservative Assumptions: Based on the proposal and the draft UV
Guidance Manual, that validation procedures will require doses more than three times higher than those
listed in the IT Tables to comply with the rule, (i.e., for 2.0 log credit for Giardia and Crypto does in rule
are 5.8 and 5.2 mJ/cm2, respectively, and 2 1 and 20 mJ/cm2 in the guidance manual). This is on top of a
safety factor of 2 to 3 in the IT tables. There were also similar increases in the safety factors for viruses.
Additionally, validation is to be applied to -worst case- conditions. Since the IT Table already includes a
safety factor, care should be taken in compounding those safety factors in the Guidance.
EPA should take a hard look at the safety factors that are being applied to UV use and insure that they are
reasonable and are not compounded leading to needlessly more expensive applications. EPA is reminded
that water systems will insure compliance with validation requirements, out of necessity and build in
their own safety factors lessening the need for EPA to be too conservative.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 637
Comment ID: 13090
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: District comment on UV Disinfection Criteria
Even though there is a 2 to 3 safety factor built into the IT tables the Guidance Manual will result in at
least three times higher dosages than even the conservative IT tables. Water systems will of necessity
build in an additional safety factor to insure compliance. This should be recognized by EPA and care
taken not to continually compound safety factors at each phase. This places an unreasonable burden on
systems to install needlessly expensive applications.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 643
Comment ID: 12801
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Ultraviolet Disinfection
States generally support inclusion of this tool and the requirement that credit would be based on log
inactivation using the IT table. Some states have expressed concern with the IT table and the safety factor
used and have indicated that they intend to submit specific comments on this issue directly to EPA.
Comment Response for L T2ESWTR 8-3 02 December 2005
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Response: See Responses 910.f and 910.h.
EPA Letter ID: 647
Comment ID: 12939
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Ultraviolet Disinfection
MDE generally supports inclusion of this tool and the requirement that credit would be based on log
inactivation using the IT table. This is a technology that is expected to be used by small water systems.
EPA should make certain that this option is available.
Response: See Response lOO.a.
EPA Letter ID: 660
Comment ID: 14081
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: UV
The dosages between the regulatory language and the guidance manual are too different. The safety
factors applied in the guidance manual are too high.
Response: See Response 910.h.
EPA Letter ID: 666
Comment ID: 14021
Commenter: Wellington H. Jones, Engineer-Director, Frederick County Sanitation Authority
Commenter Category: Regulated Community (Utilities)
Comment: 3. The safety factor imposed for UV disinfection is too great. This technology appears to be
one of the most effective for Cryptosporidium removal. Imposing such a safety factor needlessly
increases the capital and operational cost of this technology.
result in wasting funds to remove Cryptosporidium that may not be present. The wasting of funds is
compounded when you don't recognize the potential of current treatment and you impose an exorbitant
safety factor. It is important to protect
Response: See Responses 910.f, 910.h, and 200.a.
Comment Response for L T2ESWTR 8-3 03 December 2005
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EPA Letter ID: 667
Comment ID: 14012
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: B.
1. Make sure UV applications are not so conservative that it would require unnecessary over kill.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 678
Comment ID: 14698
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 26. Section 141.729(d) - UV Dose Table. Based on the proposed rule and the draft UV
Guidance Manual, the validation procedures will require doses more than three times higher than those
listed in the UV Dose Table to comply with the rule (i.e., for 2.0 log credit for Cryptosporidium and
Giardia doses in the rule are 5.8 and 5.2 mJ/cm2, respectively, and 21 and 20 mJ/cm2 in the guidance
manual). This is on top of a safety factor of 2 to 3 in the UV Dose Table. Additionally, validation is to be
applied to -worst case- conditions. Since the UV Dose Table already includes a safety factor, we urge the
EPA to refrain from compounding arbitrary safety factors in establishing the validation testing
requirements in the UV Guidance. The EPA should take a hard look at the safety factors that are being
applied to the UV disinfection process and ensure that they are reasonable and are not compounded,
leading to needlessly more expensive applications. Water systems will build-in their own safety factors to
ensure conservative validation.
Response: See Responses 910.f and 910.h.
8.16.1.1 Comment Codes 912, UV dose tables Individual
Comments on Code 912
EPA Letter ID: 101
Comment ID: 10901
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: flexibility. Something is wrong with the IT tables. The IT tables in the validation chapter of
the guidance are higher than the IT tables in the proposed rule language. NRWA requests clarification on
this issue.
Response: See Response 910.h.
Comment Response for L T2ESWTR 8-3 04 December 2005
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EPA Letter ID: 470
Comment ID: 11087
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: UV disinfection is presented in the rule as a viable alternative to chlorine disinfection when
disinfection benchmarking indicates little flexibility in achieving giardia CT requirements through
changes in chlorination practice. However, virus inactivation requirements using UV have been
formulated based on the adenovirus which may require up to triple the capacity needed to adequately
handle giardia and cryptosporidium. This may seriously impact the incorporation of UV technology as a
viable option for reducing disinfection by-products. The rule and/or guidance needs to address this issue.
Criteria may need to be established to define types of water bodies, if these exist, that would be less
susceptible to supporting the adenovirus, and establish appropriate UV viral disinfection requirements for
systems served by these lower-risk sources.
Response: See Response 910.g.
EPA Letter ID: 474
Comment ID: 11201
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: The differences between the UV dose tables presented in §141.729 and in the UV Guidance
Manual lead to concern as to which will take regulatory precedence. There appears to be a compounding
of safety factors when the §141.729 table is translated to the UV Guidance Manual, which, in turn, leads
to overly conservative dosing to achieve inactivation. We believe the values in the §141.729 table should
be used in the final rule and that the Manual provide the criteria for reasonable use of safety factors and
the reduction equivalent dose.
Response: See Responses 910.g and 910.h.
EPA Letter ID: 485
Comment ID: 11323
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: 1. As water quality regulations become more complex, they impact other programs,
sometimes in unexpected ways. Has the USEPA thought about how the UV virus inactivation
requirements may impact the water treatment device certification program? According to -USEPA Guide
Standard and Protocol for Testing Microbiological Water Purifiers (Report of Task Force, Submitted
April 1986, Revised April 1987)- current devices must demonstrate they can achieve 4-logs of
virus inactivation (Poliovirus 1 and Rotavirus) with the dose requirement of 40 mJ/cm2. However, under
Comment Response for L T2ESWTR 8-3 05 December 2005
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the LT2 UV inactivation tables a 4-log virus inactivation will increase the dose requirement to about 5
times what it is now to 200 mJ/cm2, which will increase the UV reactor on a POE device 5 fold;
increasing the footprint and power costs of the system.
It is true the SDWA precludes the use of POU devices to meet a microbiological standard, but such a
requirement does not apply to POE devices, where UV might used as a component to treat water from a
constructed conveyance or small community water system (USEPA Region 9 supports the use of POE for
meeting federal microbiological water quality standards under the provisions of the Safe Drinking Water
Act [as amended in 1996]). A state might require that such a device might be tested against the USEPA
Guide Standard, which in itself is not a bad idea, but such a demand might preclude the application of UV
as part of a POE, based on the -It- tables presented in the guidance document.
Response: See Responses 910.g.
EPA Letter ID: 485
Comment ID: 11325
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: 3. Is the virus barrier being established for UV the same strength or does it supply an
equivalent degree of public health protection as the Ct tables for the other disinfectants? That is, aside
from comparing the degree of inactivation (i.e., 4 logs) would the resulting barrier result in an equivalent
level of viruses of concern in the final product. For example, the Ct table in the SWTR Guidance manual
was established for Hepatitis A virus. Will the inactivation tables for UV, based on adenovirus provide an
equivalent degree of public health protection as the Ct tables for the other disinfectants? While adenovirus
is difficult to inactivate with UV, is it easier to inactivate with chlorine than Hepatitis A? If not, shouldn-t
the chlorine Ct tables be revised to cover adenovirus inactivation? If the information is not available, what
information is available to ensure the public the different disinfectants provide an equal or greater degree
of protection against waterborne pathogens?
Response: See Response 910.g.
EPA Letter ID: 485
Comment ID: 11327
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: The UV disinfection also includes viruses and sets a -dose- requirement for viruses. Will this
dose table be applicable to the Groundwater Disinfection Rule? If not, then why not as it will create an
inconsistency in the quantity of UV needed to achieve similar log removals of microorganisms. If yes,
then the POE device certification program under the water treatment device certification requirements
needs to be changed as the dose requirements are about 5 times greater than current targets, which means
larger UV units on wellheads or treating well fields.
Response: See Response 910.g.
Comment Response for L T2ESWTR 8-3 06 December 2005
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EPA Letter ID: 496
Comment ID: 10699
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 2. UV Key Issue 2 Extend IT Tables to Higher Log Inactivations: The IT Table stops at 3.0
log activation and does not provide values for 3.5, 4.0, or higher log inactivation for Giardia and Crypto.
The observed data from research studies in the guidance manuals included higher inactivations and
demonstrated that greater than 4 log inactivations was feasible.
Comments for UV Key Issue 2 (Extend IT Tables to Higher Log Inactivations): EPA should complete the
inactivation credit table in the rule to include doses required to receive up to and including 4.0 log credit
for Giardia and Crypto (or higher, if supported by the data).
Response: See Response 910.g.
EPA Letter ID: 502
Comment ID: 10635
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: 2. Current regulations state that utilities using chemical disinfection must provide contact time
(CT) based on T10, which is the 90th percentile. It seems appropriate that systems using UV should meet
the same disinfection requirements on 100% of their finished water. Any requirement more stringent than
that is inconsistent and illogical.
Response: See Responses 910.f, 910.h, and 910.J.
EPA Letter ID: 506
Comment ID: 10739
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: o Extend IT Tables to Higher Log Inactivations - The IT table stops at 3.0 log inactivation for
Giardia and Cryptosporidium. CWD requests that USEPA complete the inactivation credit table in the
rule to include doses up to 4.0 log credit and higher if the data supports it.
Response: See Response 910.g.
EPA Letter ID: 507
Comment ID: 11470
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Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: that they are reasonable and not unnecessarily compounded. We also encourage EPA to
expand the IT Tables to include values for 3.5,4.0 and higher log inactivation for Cryptosporidium and
Giardia.
Response: See Response 910.g.
EPA Letter ID: 510
Comment ID: 16512
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: 1.7 The reference to adenovirus as a target design pathogen for UV may confuse
State regulators and UV practitioners who read the UVDGM.
The selection of adenovirus as the viral target pathogen is not based on demonstrated and accepted
epidemiological evidence, nor is the selection of adenovirus consistent with the cost-effective practical
applications of UV disinfection currently being implemented and envisioned by EPA. This is discussed
further in our comments to the LT2ESWTR and in Appendix I to this document.
Appendix 1
A discussion suggesting that adenovirus should not be the target design organism for disinfection by UV
Appendix 1: A discussion suggesting that the adenovirus should not be the target design organism for
disinfection by UV There has been a recent suggestion that adenovirus could be the target design
organism for UV disinfection; however, there are ample arguments why this should not be the case.
The traditional design dose of 40 mJ/cm2 has been selected for adequate inactivation of viruses such as
rotavirus - a significant UV-resistant viral pathogen. Rotavirus occurrence levels were selected as being
conservatively representative of virus occurrence in general and used by Stig Regli, Joan Rose, Charles
Haas and Charles Gerba in their -Modelling the risk from Giardia and viruses in drinking water-
(JAWWA 83, No. 11, 76-84, 1991) when examining public health protection using chlorination. In the
case of UV disinfection, rotavirus is also a UV-resistant virus (although rotavirus was not the most
resistant virus to chlorination). Disinfectant resistance was another criterion suggested by Regli et al for
selection of the target design organism. When selecting the target design organism, Regli et al also
indicated the appropriateness of the target being very significant clinically. Confusion about the target
virus for UV disinfection has arisen in a draft version of the US EPA UV Disinfection Guidance Manual
that has been laid open for public comment. Some of this confusion has been created simply by the
availability of doseresponse data on adenovirus from the laboratory of Charles Gerba indicating that
adenovirus is more resistant than rotavirus to UV (Q.S. Meng and C.P. Gerba, Comparative inactivation
of enteric adenoviruses, poliovirus and coliphages by ultraviolet irradiation, Water Research 30, No. 11,
2665-2668, 1996). Criteria, other than UV resistance, for selection of the target virus have not been
adequately considered. A recent review of UV disinfection dose-response data has placed even a higher
dose value for adenovirus in the literature (C.P. Gerba, N.Nwachuku and K.R. Riley, Disinfection
resistance of waterborne pathogens on the United States Environmental Protection Agency's
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Contaminant Candidate List (CCL), J of Water Supply: Research and Technology - AQUA 52, No. 2,
81- 94, 2003) based on work done on an AWWARF project by the Gerba laboratory. Whereas the first
paper cited a dose of approximately 120 mJ/cm2 for 4 logs inactivation, the newer data suggests a dose of
170 mJ/cm2 for 3 logs inactivation (extrapolated to 203 mJ/cm2 for 4 logs inactivation). The major
change in the results is explained by a change in methods to assay adenovirus. The AWWARF study
authors did add some cautionary notes when the AWWARF study went out for peer review with higher
doses. There are then several issues relevant to the selection of adenovirus as a target pathogen in the
GM:
- is drinking water borne adenovirus a pathogen of concern to public health?
- which dose is correct for adenovirus?
- was adenovirus reviewed as the target viral pathogen by the technical advisory group to the committee
that made recommendations to the EPA? Was the design dose reviewed? Was the use of a multiple
disinfectant strategy to address adenovirus discussed?
- if adenovirus were selected as the target design pathogen, would the current protocols using MS2 for
UV reactor validation still be appropriate?
- What might be the path forward for addressing adenoviruses?
UV Design Dose and Risk of Disease - elaboration
Selecting a design UV dose is not a trivial task, but one that should take into consideration the nature of
the source water, the treatment process, and the intended application as well as the nature of the
pathogens themselves.
It is a common practice when designing the UV dose for drinking water disinfection, to select the most
resistant pathogen of epidemiological significance, and identifying this pathogen includes a consideration
of the mode of transmission of the various pathogens, their frequency of occurrence, the exposure level to
the consumer, and the infectivity of the pathogens. Rotavirus is considered an extremely resistant virus of
epidemiological significance in drinking water, and a design dose of 40 mJ/cm2 will achieve typically 4
logs of inactivation. Unit operations that are upstream of the disinfection process will also help reduce the
virus levels in the produced water.
In reused wastewater, the upstream filtration process may be effective in removing many of the particles,
but the design disinfectant dose is usually selected to bring the number of surviving particles (microbial
aggregates) to an extremely low level by disinfection. In reuse projects using alum-assisted media
filtration, the particle size distribution is reshaped with a significant reduction in particle numbers in all
size ranges, and particles over 100 micrometers are absent. With this water quality, UV doses may
typically be in the range of 80 to 120 mJ/cm2 to produce less than 2.2 total coliform CFU/100 mL
(less than 0.02 total coliform CFU/mL). To the extent that viruses may be far fewer than the more
abundant coliforms (e.g. 1,000 PFU/lOOmL for viruses vs 1,000,000 CFU/lOOmL for total coliforms),
then the virus content in the produced water will be also reduced to low values depending upon the virus
and design dose. IF all the viruses were the resistant rotavirus, then a design dose of 120 mJ/cm2 would
result in approximately 12 logs of inactivation of rotavirus (i.e., 0.000000001 virus PFU/lOOmL). This
would require "consumption" of 108 litres of water to receive 1 rotavirus particle. Anecdotally, cross-
connections between potable water and reclaimed wastewater in apartment complexes have not led to
illness when the reclaimed wastewater was consumed by the apartment dwellers. When addressing
potable water, it is not anticipated that the same challenges in protecting public health would be
encountered as in reclaimed wastewater, and we would not anticipate a need to use such high doses to
protect public health as used for reclaimed wastewater. There is no published epidemiological evidence
that higher UV doses used to disinfect drinking water have a measurable impact on public health
protection.
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Adenovirus as an Alternative to Rotavirus as the Design Organism
Adenoviruses are more resistant than rotavirus, and until only recently, adenoviruses have not been
considered to be the appropriate target design organism for UV disinfection. This has been based on
several considerations brought out in the "Fact Sheets on Emerging Waterborne Pathogens: Final Report
to the Department of the Environment" (Report No. DWI 4248/1, Contract No. 10438-0, March 1997,
prepared by WRc and the Public Health Laboratory Service, Contract Manager: T.E. Irving, WRc pic,
Henley Road, Medmenham, Marlow, Buckinghamshire SL7 2HD, Telephone 01491 571 531).
1) The health effects of adenovirus are not generally considered life-threatening. The A-E sub-groups of
the 47 serotypes of human adenoviruses may cause upper respiratory infections, conjunctivitis, febrile
illness especially with sore throat and also glandular involvement. Asymptomatic infections occur
sometimes with long-term shedding of virus from the pharynx or gut. Adenovirus F serotypes cause
gastroenteritis in children, particularly those under one year old.
2) Infection routes are generally via the conjunctiva or the nasal mucosa (exposure to infected individuals
or inhalation of aerosols), and by the fecal-oral route in the case of children particularly.
3) Occurrence in water (sewage, rivers, lakes, groundwater, drinking water and recreational bathing
waters) reflects shedding of the virus in fecal material, but at the time of the report, there was no firm
clinical or epidemiological evidence that the bulk of respiratory illness in recreational water users has
been associated with adenovirus in recreational waters, although since 1979, there have been 3
documented cases of adenovirus outbreak resulting from swimming in recreational waters. There is no
evidence, according to the report, for spread of adenovirus F (the most severe form for young children) by
the water route.
4) Susceptibility to conventional treatment unit operations such as coagulationsedimentation, filtration
and disinfection can produce essentially virus-free waters. Adenoviruses are very susceptible to
inactivation by chlorine, and when chlorine is used as either the primary disinfectant or added
as a residual secondary disinfectant to protect the distribution lines following UV, then adenoviruses will
be well controlled. CT values for 99% adenovirus 40 inactivation have been suggested to be as low as
0.11 mg/L-min with chlorine, and up to 6.75 mg/L-min for 99.99% inactivation of adenovirus 12 (C.P.
Gerba, N. Nwachuku and K.R. Riley, Disinfection resistance of waterborne pathogens on the United
States Environmental Protection Agency's Contaminant Candidate List (CCL), J of Water Supply:
Research and Technology - AQUA 52, #2. 81-94,
2003).
It is worth noting that a risk assessment was also published by US researchers: (K.D. Crabtree, C.P.
Gerba, J.B. Rose and C.N. Haas, Waterborne Adenovirus: A Risk Assessment. Wat. Sci. Tech. 35, #11-
12, 1-6, 1997). The authors conclude with the following statement: -The limited data on their
(adenovirus) occurrence in water makes it difficult to determine the risks associated with
these viruses. Further investigations on their survivability in the environment and their susceptibility to
water treatment are also needed. More knowledge of these aspects of different adenovirus serotypes will
help in understanding the public health risks posed by these viruses-. These conclusions highlight the
need for additional research, but not the need for making adenovirus the target virus for UV disinfection.
Summary: In terms of public health, enteric adenovirus infections have not been recognized as a
significant source of illness and, as pointed out by CDC, all outbreaks were related to swimming pool
activities where fecal-oral route is strong (especially if the pool is inadequately disinfected). No drinking
waterborne outbreak or infection has ever been reported, suggesting that for whatever reason (infectious
dose, survival, susceptibility, immunity) the probability for reaching an epidemic level is never achieved.
This is somewhat confirmed by the fact that outbreaks occur mainly in children in day-care (high
viral doses subsequent to intimate contact with feces) and not in adults. Selecting adenoviruses as the
target organism could make some sense only if they were treated differently because the outcome of the
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infection in terms of public health appears minimal for the water route. A similar differential treatment
has been applied for parasites in drinking water: The required minimal log removal of Cryptosporidium is
only 2 logs while for Giardia it is 3 logs: this recognizes levels of risk and achievable goals. Significantly
higher goals are required when significantly higher pollution levels occur (there is no data suggesting this
to be the case for adenoviruses).
Now that adenoviruses have been shown to be more resistant to UV treatment, regulation is moving faster
that science. While recognizing some form of precautionary principle may exist, there has not been found
anywhere in the literature any indication that there is a risk requiring a significant and costly change in the
design of water treatment technologies.
What is the dose-response for Adenoviruses?
Although it is still unclear whether there is sufficient justification to make adenoviruses the design target
pathogen for UV disinfection, it is clear that the dose-response of the organism must be known to
determine what the design dose would have to be. The above reference (C.P. Gerba, N. Nwachuku and
K.R. Riley, Disinfection resistance of waterborne pathogens on the United States Environmental
Protection Agency's Contaminant Candidate List (CCL), J of Water Supply: Research and Technology -
AQUA 52, #2. 81-94, 2003) is a review article published after publication of the high-dose-obtaining
AWAARF report "Inactivation of Waterborne Emerging Pathogens by Selected Disinfectants"
by some of the same authors. The review paper did not mention the high doses experienced in the
AWWARF study. The details of the AWWARF study were subjected subsequently to peer-review and
published in 2003 (J.A. Thurston-Enriquez, C.N. Haas, J. Jacangelo, K. Riley, C.P. Gerba, Inactivation of
Feline Calicivirus and Adenovirus Type 40 by UV Radiation, Applied and Environmental Microbiology
69, #1, 577-582, 2003). The authors of this latter paper (the authors of the AWWARF study report) did
note that they received higher doses of UV with Adenovirus Type 40 than in earlier studies (Q.S. Meng
and C.P. Gerba, Comparative inactivation of enteric adenoviruses, polioviruses and coliphages by
ultraviolet irradiation, Water Research 30, 2665-2668, 1996) in which a dose of 124 mJ/cm2 was reported
for 4 logs inactivation. Extrapolation of the AWWARF data would have predicted a dose of 203 mJ/cm2
for 4 logs inactivation. The authors of the peer-reviewed paper have attempted to present a rationalization
of the different dose-responses obtained in the two different studies. The authors presented a suggestion
that the methods of preparing the viruses could influence the virus susceptibility to UV. The authors
acknowledged that: "The methods used in microbial preparation, water type, and experimental design can
produce significant differences in inactivation kinetics or do not reflect microbial inactivation during
water treatment". Trojan has observed that when making dose-response curves for bioassays using high
concentrations of viruses (e.g. MS2 bacteriophage), the dispersal of viruses can also be a problem,
especially when targeting high UV doses to obtain high levels of inactivation and when working in waters
with polyvalent cations that are not chelated with natural organic matter. The polyvalent cations can
contribute to virus clumping and/or dispersal problems. The clumped and non-dispersed virus problem is
usually manifest as a "tailing" in the dose-response curve just as seen in wastewater samples from the
particles that are in those water qualities. It is not clear from the figures presented in the peer-reviewed
paper by Thurston- Enriquez et al, 2003 whether their adenovirus inactivation data is without such tailing
at UV doses above about 100 mJ/cm2. Natural waters do not have the same high concentrations of viruses
that can be self-associated. The authors of the peer-reviewed paper (Thurston-Enriquez et al, 2003) have
appropriately cautioned: "Like those reported between this study and that of Meng and Gerba, variations
in the kinetics of inactivation between similar inactivation studies must be carefully examined, especially
if the results will be applied for regulatory purposes". The wise cautionary statement by the authors of the
peer-reviewed publication from the AWWARF study is important, especially if considering that the
change from a design dose of 124 to203 mJ/cm2 would imply an increase in equipment by a factor of
about 1.6 fold, an increase in equipment cost by about 1.6 fold and an increase in power consumption by
about 1.6 fold - and all for control of a virus that has not been demonstrated to be an epidemiologically-
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important target pathogen that is transmitted by water. Although selling an additional 1.6 fold amount of
equipment may appear appealing to UV manufacturers, the additional amount of money, if available,
might be better put into upgrades of other unit operations to ensure that the best possible multiple barrier
strategy is put into service. A low dose of chlorine added in flash mixing would provide adequate
protection against the adenoviruses and help in microbe control within the distribution lines. Chlorine
doses of less than 10 mg/L-min would be more than adequate if after UV disinfection at reasonable
rotavirus-targeting doses, adenoviruses were still considered to be a problem.
Was adenovirus as the target design virus and its design dose reviewed by the technical advisory group to
the panel making recommendations to EPA and an appropriate peer review undertaken?
There appears to be no record of a discussion with peer review having been undertaken to consider the
target virus and target design dose. The central focus of disinfection studies and costing of technologies
was for inactivation of Cryptosporidium. It is potentially beyond the scope of the UV Disinfection
Guidance Manual (UVDGM) to provide guidance on the choice of the target virus and the target design
dose for that virus without the appropriate open discussion of the cost-risks-benefits of the various options
available for the target design virus. Beyond the inappropriate target virus and dose recommendations for
UV alone, the UVDGM has not addressed the issue of a multiple disinfectant strategy that will almost
always be implemented with UV disinfection in municipal systems. Chlorine will commonly be used
within a treatment plant, but a chlorine residual will almost always be added as a residual after UV, or a
minimal chlorine dose could be used before conversion of chlorine to chloramine. These practical options
have not been presented as an alternative to use of high UV doses. It is questionable guidance if UV is
introduced to avoid high chlorine doses such as used for Giardia and Legionella when chlorine is the sole
disinfectant, and then UV is forced to be used at high doses for treatment of organisms such as adenovirus
that can be readily addressed with low doses of concurrently used chlorine.
Implications of adenovirus for use of MS2 as the challenge organism to validate UV reactors.
The non-ideality of reactors and the implications for organism-specific dose delivery has been well
described by Trojan Technologies (Petri, B.M.; Olson, D.A. -Bioassay Validation of Computational
Disinfection Models Used for UV Reactor Design and Scale-up-. Proceedings, Disinfection 2002: Health
and Safety Achieved Through Disinfection, Florida, 2002.
Chiu, K-P.; Buffle, M-O. -Effect of Lamp Spacing on UV Reactor Performance: Computational and
Experimental Investigations-. Proceedings, WEFTEC 2001, Atlanta, 2001.
Petri, B.M.; Olson, D.A. -Bioassay-validated Numerical Models for UV Reactor
Design and Scale-up-, First IUVA conference, Washington, D.C., June, 2001.
Wright, H.B. and Y.A. Lawryshyn. An assessment of the bioassay concept for UV reactor validation-.
WEF Specialty Conference on -Disinfection of Wastes in the New Millennium-. New Orleans, LA,
March 15-18, 2000.)
This non-ideality is recognized in the UVDGM; however, appears not to be
adequately addressed if adenovirus were to become the target pathogen and MS2 were the challenge
organism for validation. For a given log inactivation of adenovirus, the adenovirus UV dose must be
higher than the MS2 dose for the same log inactivation of MS2. Due to fluid dynamic behavior within the
UV reactor, for any non-ideal reactor that is being validated, the adenovirus dose under any operating
conditions will be higher than the MS2 dose under those same operating conditions. These two pieces of
information allow a prediction that when designing a reactor for delivery of an adenovirus dose to give a
target adenovirus reduction performance, that the result will be an underdesigned reactor if the MS2 dose
that gives the same target logs of MS2 reduction is used for design, and overdesigned by an
indeterminable amount if the target adenovirus dose for the required logs inactivation of adenovirus is
Comment Response for L T2ESWTR 8-312 December 2005
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designed by using the numerically equivalent MS2 dose. Only extrapolation using a validated
UVDosimeter algorithm such as that of Trojan-s, or multiple organism bioassay with an organism that is
more resistant than adenovirus and interpolation between the more resistant organism and MS2 dose will
be reliable in avoiding underdesign or overdesign. Overdesign will also result if the dose of the more
resistant organism that produces the target logs inactivation of adenovirus is used for design. It is clearly
not acceptable to extrapolate beyond a MS2 dose to an adenovirus dose in the absence of empirical data,
nor is it acceptable to levy a safety factor of indeterminable magnitude. This has not been acknowledged
in the UVDGM, nor has a more resistant organism than adenovirus been used or validated as an
appropriate challenge organism.
Path Forward for Addressing Adenoviruses
In order to avoid regulation getting ahead of science, the following suggestions are offered:
1) Adenoviruses should be placed in a separate -bin- until we know more of their occurrence and the
potential risk they pose to drinking water safety. 2) A 4-log inactivation of the other viruses can be
achieved using UV and thereby providing a very good safety factor for public health protection.
Depending upon which dose-response curve is eventually validated for adenoviruses, a UV design dose of
40 mJ/cm2 would provide between 0.8 and 2 logs inactivation of adenovirus. These levels of inactivation
might be adequate considering the current requirement is for 2 to 3 logs inactivation of Cryptosporidium
that poses a much higher demonstrated threat.
3) UV disinfection of municipal water will be used mainly on waters also treated with chlorine that
already provides public health protection against adenoviruses. When UV is added to municipal systems
(at the central treatment plant or at POU/POE residential applications within municipalities), the
adenovirus issue has been addressed by the chlorine used in the municipal treatment process. In rural or
cottage applications where UV or chlorine might be used alone, it is important to recognize that human
viruses are primarily of human origin and such human viruses are likely of relatively low occurrence
compared with human parasites that have both human and animal fecal origin. This would suggest that in
rural applications where a single disinfectant is used, that the choice of UV that can address the relatively
more health-impacting parasites might offer greater public health protection than chlorine that might
more readily inactivate resistant and less epidemiologically-significant viruses such as adenovirus, but is
unable to address the epidemiologically-significant parasites such as Cryptosporidium and can only
address Giardia at relatively high CT values.
1.3. Adenovirus, because it appears to have low epidemiological risk and is so easily taken care of with
the required chemical disinfection residuals in the finished water, should be parked on the sidelines in a
separate -bin- until its role as a pathogen of epidemiological significance for drinking water
disinfection by UV (and maybe other disinfectants) is clarified. A discussion of whether adenovirus is a
relevant pathogen as a target virus for UV disinfection is provided in an Appendix to the comments on the
UVDGM.
Adenovirus as a target of disinfection for UV disinfection is highly controversial, and the advocating of
adenovirus as the target for UV is perhaps getting regulation ahead of science. This entire issue is
addressed in an appendix to the comment on the UVDGM provided by Trojan Technologies Inc.
Response: See Response 910.g.
EPA Letter ID: 522
Comment ID: 14149
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Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: The MWRA urges EPA to use the UV dose table for Cryptosporidium and Giardia from the
proposed rule in the final rule. The UV Manual should be refocused on a more straightforward process to
ensure that the applied UV dose reliably equals or exceeds the required dose in the rule. Clarity and
simplicity will be needed if UV is expected to be the inactivation technology of choice for compliance
with the LT2.
Response: See Responses 910.g and 910.h.
EPA Letter ID: 523
Comment ID: 11691
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The Unfiltered Working Group urges EPA to use the UV dose table for Cryptosporidium and
Giardia from the proposed rule in the final rule. The UV Manual should be refocused on a more
straightforward process to ensure that the applied UV dose reliably equals or exceeds the required dose in
the rule.
Response: See Responses 910.g and 910.h.
EPA Letter ID: 548
Comment ID: 12173
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Instead of-applied- doses of UV, the rule should focus on -delivered- doses of UV light.
Table IV-21 does not include uncertainty and safety factors that need to be applied (these factors are
described in the UV disinfection guidance manual). Therefore, this table should have a note that these
values SHOULD NOT BE USED in designing or implementing UV light. These values need to be
multiplied against necessary, site-specific factors as provided in the guidance manual. This example is
comparable to the SWTR Ct required = CT x T10/T issues; however, it is not as intuitive for those
looking at the UV dose requirement table.
Response: See Responses 910.g and 910.h.
EPA Letter ID: 556
Comment ID: 12075
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Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should retain the proposed UV dose table for Cryptosporidium and Giardia lamblia in
the final rule. The UV Disinfection Guidance Manual should be
Response: See Responses 910.g and 910.h.
EPA Letter ID: 556
Comment ID: 12077
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. Extend UV Dose Table to Higher Log Inactivations:
Discussion: The UV Dose Table stops at 3.0 log inactivation and does not provide values for 3.5, 4.0 or
higher log inactivation for Giardia lamblia and Cryptosporidium. The observed data from research studies
in the guidance manuals included higher inactivations and demonstrate that greater than 4.0 log
inactivation is feasible.
Recommendation: EPA should complete the UV dose table in the rule to include doses required to receive
up to and including 4.0 log credit or higher for Cryptosporidium and Giardia lamblia if supported by the
data.
Response: See Response 910.g.
EPA Letter ID: 560
Comment ID: 14987
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Eight - Confusion of the UV Dose Tables: The UV dose table (Table IV-21) in
§141.729 is the regulatory requirement and the benchmark for compliance. As currently written the UV
Guidance Manual generates a substantially different UV dose table (Tier 1) that is a de facto regulatory
requirement that actually supercedes the UV dose table in §141.729. The dose table in the UV Guidance
Manual is substantially (three to four times) greater than the regulatory requirement doe to the safety
factors imposed through the guidance manual. This situation creates to significant concerns: 1. Confusion
is created by a UV dose table in regulation when compliancevalues are located in guidance;
2. The UV dose table in §141.729 reflects a factor of safety of 2 to 3 times the dose actually required to
cause the desired level of inactivation. The Guidance Manual adds another safety factor of 2 to 3+ times.
The net result is a dose requirement of 5 to 10 times what is actually required to achieve inactivation
of Cryptosporidium or Giardia lamblia.
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unnecessarily increase the cost of water treatment. EPA has not performed a
cost/benefit evaluation of these options to justify these excessive factors.
Response: See Responses 910.g and 910.h.
EPA Letter ID: 560
Comment ID: 14990
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Ten - Inconsistency in the UV Down Time and Out of Specification Guidelines:
The proposed regulation states that unfiltered water supplies are expected to provide inactivation using
UV to 95% of the water delivered each month. The lack of specific guidelines for filtered systems opens
the possibility that they may be held to a significantly higher reliability factor. Filtered systems need
surety in the final guidance manual on this reliability factor. The guidance manual discusses UPS and
back up power as necessary to ensure system reliability. American Water has been examining the issue of
power reliability and has concluded that there are a variety of ways to ensure reliability. American Water
has estimated that inclusion of a requirement for uninterruptible power supply (UPS) systems will
increase the cost of UV by 5 to 10% for each installation and does not feel it significantly increase the UV
reliability.
This reliability factor is substantially higher than the level of reliability required under the SWTR for
inactivation of Giardia lamblia or viruses using chlorine, chloramines, chlorine dioxide, or ozone. Under
current rules inactivation using a chemical disinfectant is driven by T10. In the case of ozone, CT is only
demonstrated once per day under peak flow. Therefore, make UV guidelines consistent with current
performance standards; EPA should use a 90th percentile value rather than a 95th percentile value for
filtered systems. The current expectations for chemical inactivation are difficult to reconcile with the
virtually continuous and instantaneous measurement of off-spec volume for UV systems. Similarly, the
off-spec performance standard for filtered systems measured on a monthly basis should be 90% (i.e., 90%
of finished water should be within specifications as described in guidance manual).
It also is inconsistent to set a performance standard for UV Cryptosporidium inactivation in a filtered
system that is as stringent or more stringent than the requirement for unfiltered systems. The presence of a
multi-barrier treatment approach should be acknowledged as credit in defining the regulatory performance
envelope for UV inactivation.
If EPA chooses to change the current performance standards for microbial inactivation, then the Agency
should justify this change with an appropriate risk assessment. This risk assessment should be applied
equally to both filtered and unfiltered systems. Finally, the cost/benefits for the 90%, 95%, and UPS
options should be performed and justified.
Response: See Response 910j.
EPA Letter ID: 562
Comment ID: 12315
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should retain the proposed UV dose table for Cryptosporidium and Giardia lamblia in
the final rule. The UV Disinfection Guidance Manual should be revised to focus on a single decision-
making process that ensures that operational UV doses are reliably equal to or greater than the required
dose in the rule text. This process has to be articulated in a clear and simple way for ease of
implementation, but this process cannot impede the rapid advancement of UV technology in drinking
water treatment.
Response: See Responses 910.g and 910.h.
EPA Letter ID: 562
Comment ID: 12499
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: UV Dose Table
The UV dose table in §141.729(d)(2) encompasses dose requirements for inactivation between 0.5-log
and 4.0-log inactivation of Cryptosporidium, Giardia lamblia, and virus. Developing these dose tables has
been challenging. Even with a large amount of data on UV inactivation, the available data are frequently
flawed with respect to several factors, including:
Censored Data - Censored data are data for which an analytical endpoint was not reached. With respect to
UV, the inactivation achieved during the experiment was greater than the upper limit that could be
demonstrated by the analytical method. For instance, where the upper limit was 2-log, and a result of >2-
log is given. Use of such data in any statistical analysis discounts the actual effect of UV, when in fact,
the value is a result of inadequate methodology.
Tailing - A drop in inactivation at higher disinfecting doses indicates incomplete delivery of the
disinfecting agent. Tailing is generally an artifact of the laboratory technique and under-estimates the
response of the organism to the disinfecting agent.
Peer review - Peer review either through publication or through review by a panel of unbiased experts is
an important milestone in the selection of data dose table development. Such scrutiny, even of well-
qualified researchers, may reveal concerns or modify conclusions of scientific studies.
Data that are censored, data that demonstrate tailing, and data that lack peer review are reflected in the
doses included in §141.729(d)(2). , These three factors consistently weight the analysis toward higher,
more conservative dose values. With respect to censored data, EPA employs Bayesian statistical analysis
as a means of compensating for censored data (i.e., I(Cijk)) in the analysis of Cryptosporidium and
Giardia lamblia. In using this Bayesian algorithm, EPA employs an analytical approach that would
provide a good estimate of the actual log inactivation assuming the true value were not much greater than
the censoring limit (i.e. the highest measurable value). However this assumption is unlikely to hold,
because these experiments employed very high doses due to the expectation that UV would not be an
effective disinfectant agent for protozoa. Consequently, the approach is a very conservative estimate of
the potential log inactivation because the statistical algorithm generates a conservative estimate of the
censored observations.
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Tailing is a function of the actual data available and the experimental design for the study that produced
the data. Appendix B of the UV Disinfection Guidance Manual that EPA-s analysis does not appear to
compensate for the tailing observed in the UV data at higher UV doses.AWWA does not contest the
Cryptosporidium and Giardia lamblia UV dose model or the resulting values in the UV dose table. The
UV dose table has a built-
Response: See Response 910.g.
EPA Letter ID: 562
Comment ID: 12502
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Extend UV Dose Table to 5.0-Log Inactivation EPA should continue the UV dose table for
Cryptosporidium, Giardia lamblia, and viruses to 5-log inactivation. Appendix B of the UV Disinfection
Guidance Manual indicates that the data used to model the range of inactivation represented in the current
dose table includes experimental data demonstrating greater than 5-log inactivation for Cryptosporidium
and viruses. Experimental data also demonstrates greater than 4.5-log inactivation of Giardia lamblia.
Moreover, the conservative nature of the statistical approach applied is clearly demonstrated graphically
in Figures B.4 - B.6 (Cryptosporidium, Giardia lamblia, and viruses respectively). The agency-s model
estimates a 5-log inactivation level would be almost four times the required 3-log UV dose for
Cryptosporidium. The percentage increase would be substantially smaller for viruses, but the levels of
inactivation required for the adenovirus model organism are a conservative indicator of inactivation
required and consistently involve very high UV
doses.
Response: See Response 910.g.
EPA Letter ID: 562
Comment ID: 12503
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Adenovirus as an Indicator
Under the LT2ESWTR, most surface water systems will consider UV disinfection for inactivation of
Cryptosporidium and Guardia lamblia, not viruses. The very high UV doses included in §141.729(d)(2)
for viruses make maintaining SWTR virus CT compliance with free chlorine a more economical and
practical solution. These doses will also be a critical part of the GWR implementation. Under the GWR,
groundwater systems that are required to disinfect will be required to provide 4-log virus reduction and
UV was identified in the proposed rule as a viable compliance technology. The use of adenovirus as a
conservative indicator of virus inactivation substantially increases the required UV dose over previous
estimates. Moreover, EPA-s LT2ESWTR preamble and the UV Disinfection Guidance Document do not
articulate:
1. How EPA arrived at its decision to employ adenovirus as a conservative indictor of virus inactivation
Comment Response for L T2ESWTR 8-318 December 2005
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byUV;
2. What other options the agency considered in selecting adenovirus; and
3. How the conservatism implicit in the use of adenovirus to identify UV inactivation requirements
compares to the use of other surrogates (e.g., Hepatitis A to set SWTR virus inactivation requirements).
AWWA encourages the agency to consider whether the occurrence of more UV-sensitive waterborne
viral pathogens, relative to the occurrence of adenovirus, should be taken into account in assigning dose
requirements for viruses. Adenovirus is principally a respiratory pathogen while other viruses like
rotavirus, hepatitis, and poliovirus are more likely to be waterborne. The latter organisms tend to require
20-40 mJ/cm2 for 4-log inactivation, an order of magnitude lower than the 186 mJ/cm2 UV dose table
requirement for adenovirus.
Response: See Response 910.g.
EPA Letter ID: 562
Comment ID: 12504
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Outstanding Issues with UV Dose Tables
The UV dose table in §141.729 is the regulatory requirement and the benchmark for compliance. As
currently written, the UV Guidance generates a substantially different UV dose table (Tier 1) that is a de
facto regulatory requirement over and above the UV dose table in §141.729. The dose table in the UV
Guidance Manual is substantially (three to four times) greater than the regulatory requirement due to the
safety factors imposed through guidance. This situation creates two significant concerns:
1. A UV dose table in regulation when compliance values are located in guidance creates confusion; and
2. The UV dose table in §141.729 reflects a factor of safety of two to three times the dose actually
required to cause the desired level of inactivation. The Guidance manual adds another safety factor
of two to three times. The net result is a dose requirement of four to nine times what is actually required
to achieve inactivation of Cryptosporidium or Giardia lamblia.
AWWA recommends that EPA finalize a UV dose table in the rule language similar to the dose table in
the proposed rule. This dose table should only reflect available collimated beam inactivation study data.
Achieving this dose is the objective for those PWSs employing UV disinfection. Guidance should entail a
single decision-making process that reflects key design parameters associated with reactor design and
installation. This process should parallel determination of dose and contact time for a chemical
disinfectant and should result in a site-specific -applied- UV dose necessary to ensure reliably achieving
the required UV dose in the rule. This process should address each of the uncertainties currently reflected
in the Tier 2 process. This decision-making process should be supported by a spreadsheet that allows the
selection of default values when installation-specific knowledge is not available. To the extent possible,
this process should separate considerations associated with the reactor from those particular to a given
installation. Such separation will allow the development of supporting data by UV manufacturers and
third party validation facilities.
Response: See Responses 910.g and 910.h.
Comment Response for L T2ESWTR 8-319 December 2005
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EPA Letter ID: 593
Comment ID: 11821
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: B. UV Disinfection Criteria
1. Extend IT Tables to Higher Log Inactivations: The IT Table stops at 3.0 log inactivation and does not
provide values for 3.5,4.0 or higher log inactivation for Giardia and Cryptosporidia. The observed data
from research studies in the guidance manuals included higher inactivation and demonstrated that greater
than 4 log inactivation was feasible. SAWS recommends that EPA complete the inactivation credit table
to include doses required to receive up to and including 4.0 log credit for Giardia and Cryptosporidia or
higher if supported by the data.
Response: See Response 910.g.
EPA Letter ID: 603
Comment ID: 12660
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47790) Section 141.729(d)-
We recommend that the UV dose table include doses required for up to 4-log inactivation of
Cryptosporidium and Giardia lamblia. Although 4-log inactivation is not required as part of the currently
proposed rule, future rules, regulatory changes or state specific requirements may necessitate greater than
3-log reduction.
Response: See Response 910.g.
EPA Letter ID: 603
Comment ID: 12677
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: 15. Ultraviolet Light - Comments are provided on the UV Disinfection Guidance Manual in
Attachment C. One concern not otherwise expressed is the concern that the W dose tables only go up to 3-
log inactivation for Giardia lamblia and Cryptosporidium. It appears that there is data to support 4-log UV
inactivation credit for these pathogens. Although the proposed rule, as currently written,does not require
4-log inactivation, 4 log inactivation doses should be identified.
Response: See Response 910.g.
Comment Response for LT2ESWTR 8-320 December 2005
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EPA Letter ID: 620
Comment ID: 13298
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 2: Extend IT Tables to Higher Log Inactivations
Comments: If data supports log removal beyond 3.0 log inactivation, such log removal should be included
in the tables.
Response: See Response 910.g.
EPA Letter ID: 624
Comment ID: 13206
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: c. USEPA should develop dose requirements for crypto/giardia/virus inactivation for up to
5.5-logs consistent with Bin-4 requirements. This dose development will help utilities that choose to use
UV alone for all required credits.
Response: See Response 910.g.
EPA Letter ID: 624
Comment ID: 13209
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: e. Why did EPA use Adenovirus as a conservative indicator of virus
inactivation? Hepatitis A was used for SWTR. Please clarify this disparity. Use of Adenovirus
inactivation doses is justified if this virus is specifically regulated and the surface water system does
not chlorinate.
Response: See Response 910.g.
EPA Letter ID: 624
Comment ID: 13210
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: f EPA should follow one dose table. UV dose tables are found in the
federal regulation, while compliance values are found in the Guidance Manual.
Comment Response for LT2ESWTR 8-321 December 2005
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Response: See Responses 910.g and 910.h.
EPA Letter ID: 624
Comment ID: 13211
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: g. Off-Spec Operation: Utilities which employ filtration avoidance criteria are
required to provide inactivation 95% of the time but conventional filtration plants are required to achieve
inactivation virtually 100% of time because of the UPS requirement. This is inconsistent. Under the
existing rules, CT (contact time) for chemical disinfectants is based on T10. Therefore, the current
performance standard is based on the 90%th percentile. A similar performance standard should be applied
to UV disinfection based on TOTAL Volume treated not on individual reactors or 100% performance.
Response: See Response 910.J.
EPA Letter ID: 630
Comment ID: 13067
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 2. UV Key Issue Extend IT Tables to Higher Log Inactivations: The IT Table stops
at 3.0 log inactivation and does not provide values for 3.5, 4.0 or higher log inactivation for Giardia and
Crypto. The observed data from research studies in the guidance manuals included higher inactivations
and demonstrated that greater than 4 log inactivation was feasible.
We suggest EPA complete the inactivation credit table in the rule to include doses required to receive up
to and including 4.0 log credit for Crypto and Giardia or higher if supported by the data.
Response: See Response 910.g.
EPA Letter ID: 637
Comment ID: 13091
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: The inactivation table needs to be extended beyond 3.0 log inactivation to at least a 4.0 l
inactivation.
Response: See Response 910.g.
Comment Response for L T2ESWTR 8-322 December 2005
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EPA Letter ID: 667
Comment ID: 14013
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: 2. Complete the inactivation credit table for UV to include doses required to receive up to and
including 4.0 log credit for Crypto and Giardia or higher if supported by data.
Response: See Response 910.g.
EPA Letter ID: 678
Comment ID: 14699
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additionally, the UV Dose in the proposed rule stops at 3.0 log inactivation and does not
provide values for 3.5, 4.0 or higher log inactivation for Cryptosporidium and Giardia. The UV Guidance
Manual includes observed data from research studies that demonstrate inactivation greater than 4 log was
feasible. We request the EPA complete the inactivation credit table in the rule by including doses required
to achieve higher log inactivation credits as supported by science.
Response: See Response 910.g.
8.16.1.2 Comment Codes 913, Reactor validation testing
Individual Comments on Code 913
EPA Letter ID: 101
Comment ID: 10902
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The regulation should exempt all water systems that treat less than 50 gallons per minute from
the validation requirements and rely on NSF approved UV technology as the validation test. Systems
installing NSF approved technology should automatically qualify for a 2.5 log removal credit for
cryptosporidium and Giardia lamblia. This will eliminate much confusion, burden, and cost on
small systems.
Response: See Response 910.f
EPA Letter ID: 101
Comment ID: 10903
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Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should not be specifying protocols and testing methods for approving treatment
technologies. This is exactly why the Environmental Treatment Verification program was set up by EPA
(even funded by EPA) through the NSF International, Inc. EPA must leave the testing and verification
activities to the experts in such areas. EPA's direct involvement will slow down the process, and confuse
the whole issue of what requirements treatment manufacturers are to follow in order to get their products
approved for use by small water systems. There is already protocols developed for nearly every tool in the
"tool box" so there is no need to re-do the whole process.
Response: See Response 910.f
EPA Letter ID: 474
Comment ID: 11203
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: The criteria for UV reactor validation testing require full scale testing at flows and conditions
representing -worst case- scenarios. Given that few systems have the capability of recreating these
conditions on-site, these validation tests are often relegated to the few validation facilities available in the
world today. Of these, the UV Validation Facility located in Portland, Oregon, is currently the only one
with the capacity to test reactors with capacities as large as 40 MOD. We are concerned that EPA-s
proposal to limit the use of Computational Fluid Dynamic (CFD) Modeling in reactor validation and
apply an additional safety factor for uncertainty of the model when it is used will result in under-utilizing
a very useful design tool. The key to improving theapplicability of CFD is a properly calibrated CFD
model, and we would highly recommend that EPA find a way to encourage rather than discourage
development of an approach that could play a significant role in the industry and provide an additional
means of validation for the larger units.
Response: See Response 910.k.
EPA Letter ID: 484
Comment ID: 10681
Commenter: Anonymous484,, Metro Nashville Water Services
Commenter Category: Regulated Community (Utilities)
Comment: UV Disinfection Criteria:
Unrealistic validation procedures requiring dosages levels at more than 3 times higher than those listed in
the IT tables.
Response: See Response 910.h.
Comment Response for L T2ESWTR 8-324 December 2005
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EPA Letter ID: 486
Comment ID: 14167
Commenter: Christopher R. Schulz, Drinking Water Practice Leader, CDM, Inc.
Commenter Category: Consultants: (where self-identified)
Comment: 3. The Rule should state that reactor validation testing must be performed by an EPA-certified
independent test facility not affiliated with any manufacturer of UV equipment. EPA should certify all
reactor validation test centers, including the test protocols used for validation testing. Validation testing
by equipment manufacturers presents a conflict of interest and should not be allowed under the Rule.
Response: See Response 910.1.
EPA Letter ID: 510
Comment ID: 16514
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: 2.3 Validation hydraulics: conduct equipment validation which is not
influenced by site geometries.
For equipment validation to be generic, transferable, and not confounded by site variations, performance
at a validation facility should be measured for a piece of equipment, not assuming a specific site layout. In
practice, a standard like 5 straight pipe lengths upstream of a reactor and 3 downstream of a reactor with
no valving or other flow modifiers in those sections should be specified to ensure consistency of testing
and ensure that measured performance is of the reactor, not of the arbitrary installation. Hydraulics do
change from site to site, and while site validation should be allowed, site by site validation is not
practical, not necessary, and could comprise the viability of the industry. Sites that offer installation
configurations that compromise the effectiveness of the equipment relative to the configuration under
which it was validated must install with factors of safety determined for the site, under the direction and
discretion of a qualified professional engineer.
Rationale: No one hydraulic configuration will result in worst-case performance for all UV reactors under
all operating conditions. As a consequence, validation performed under any specific configuration should
not alleviate the need for actual installations to assess on-site performance relative to validation
conditions.
For example, the European test configurations, which require testing with a 90° bend upstream of the
reactor, assume that this is representative of worst-case performance. As a demonstration of the
inaccuracy of this assumption, Figure 2 shows results from numerical simulation of a commercially-
available drinking water reactor for different upstream piping configurations. Performance of the
reactor installed with alternative piping arrangements has been plotted relative to the performance of the
reactor with a 90° upstream elbow. In Figure 2, it is demonstrated that different hydraulic installations can
exhibit varying degrees of improved or worsened performance. Furthermore, the actual differences in
performance are affected by operating conditions. In fact, it could equally be shown that the performance
of the reactor with the upstream elbow could be affected by the actual selection or orientation of the
elbow.
[SEE FIGURE 2, PAGE 10 IN PDF]
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Figure 2: Reactor Performance relative to a reactor with a 90° Elbow upstream. A 90 Elbow Upstream is
not the worst case: performance can be better or worse under different installation configurations.
It is, therefore, incumbent on the professional engineer to understand the operation of the reactors and to
design the installation of them accordingly. Since there is no configuration that guarantees conservatism,
there is no compelling argument to establish a complex hydraulic configuration as the norm during
validation. Doing so would only make the assessment of actual installations relative to validation
configurations more difficult. Consequently, it is recommended that the simple and pure form- straight
pipes upstream and downstream (suggest 5 upstream and 3 downstream without any perturbing features
like valves or flow meters) - become the standard, and that installation configurations be considered site
by site, with a professional engineer taking responsibility for the final design.
Response: See Response 910.m.
EPA Letter ID: 510
Comment ID: 16515
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: 2.5 Equipment Expanded Uncertainty: quantify this based on equipment
performance, not component performance
Expanded Uncertainty terms should only contain terms related to performance. Uncertainty related to
operating variables is inherently captured in performance variability.
Use the statistics of the validation equipment performance tests themselves to quantify the uncertainty in
the dose being delivered by the reactor, and use these numbers to determine the -validated dose- that the
reactor is said to have. Inherent in this -validated dose- is the equipment safety factor. This avoids the
need to make many assumptions about components in the reactor and puts the focus on what matters
most, the overall performance of all of the components operating together, which is the performance of
the reactor. The analyses of the reactor performance data could be prescribed in the guidance manual, and
could easily be automated in spreadsheets made to handle the data
for all tests.
Response: See Response 910.h.
EPA Letter ID: 510
Comment ID: 16516
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: 2.6 Do not allow an RED Bias calculation when the dose distribution is not
known.
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Without knowledge of the dose distribution, an RED Bias cannot be calculated, and the only techniques
that truly safeguard public health are:
i) to give credit for log reductions of target pathogens in terms of log reductions of challenge microbes
achieved during testing, when the challenge microbe is equally or more UV-resistant than the target
pathogen. For example, if a reactor provides a 4 log reduction of MS2, it is safe to assume that it will
achieve a 4 log reduction of Cryptospordium.
ii) to give credit for RED of target pathogens by using the numerically equivalent RED of challenge
microbes used during validation, when the challenge microbe is less UV-resistant than the target pathogen
iii) to interpolate the RED of the target pathogen or log reductions from validation with two organisms
that bracket the UV-resistance of the target pathogen
2.7 Allow RED Bias calculations when the validated dose distributions are known.
With knowledge of a validated dose distribution, allow the RED Bias calculation
to be used.
There are at least four ways to measure dose distributions (below). However, because a dose distribution
changes as operating variables change, -interpolating- dose distributions (the last option presented in the
list) is not practical. The other three methods, which validate a dose-distribution-calculating algorithm,
should allow the algorithm to be used on-line to determine the impacts of dose distributions during
operation. This technology exists, has been validated, is available, and is in use in drinking water UV
installations (Emerick et al., 2003, Ervin et al., 2003). Four approaches for determining a dose distribution
are:
i) multiple condition tests to validate calculated dose distributions
ii) multiple organism tests to validate calculated dose distributions
iii) actinometric microspheres to validate calculated dose distributions
iv) actinometric microspheres to determine dose distributions for given reactor tests
Response: See Response 910.h.
EPA Letter ID: 510
Comment ID: 16517
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: 2.8 The polychromatic bias term should be eliminated.
This term quantifies an unproven effect and is small in magnitude, so should be removed. If it remains,
the UVDGM should to specify how a spectrum must be validated to allow its use in the calculations. The
UVDGM should also allow for the determination of these factors through empirical testing. If the effect
can be calculated in a spreadsheet, then presumably a monitoring and control system could calculate the
effect and account for it on-line. This sort of control scheme exits, is available, and is in use in drinking
water systems in the United States. The UVDGM should allow for this type of monitoring and control
strategy, which when properly validated, would remove any Polychromatic Bias.2.9 Safety factors for the
site should be established by the engineer.Site safety factors must consider the whole water treatment
Comment Response for L T2ESWTR 8-32 7 December 2005
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plant configuration and operation, including such things as redundancy, reserve capacity, other
complementary technologies, the reactor installation configuration, site-specific hydraulics. Many of
these things are detailed in the draft guidance manual.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 510
Comment ID: 16518
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: Summary
In summary, proper empirical validation testing of UV reactors can be done without excessive
complication when the focus is on the whole reactor performance.
Relevant equipment must be tested to ensure that the required logs of reduction of pathogens (translated
into equipment dose) occur under the specified water quality and operating conditions. It must be
subsequently ensured that the equipment performs over its lifetime in a manner that is consistent with the
operational range over which the equipment was validated.
When this is done, the requirements in the five guiding principles outlined here have been met.
Response: See Responses 910.f and 910.h.
EPA Letter ID: 522
Comment ID: 14147
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: raise the costs of compliance. MWRA's Wachusett Reservoir system serving metro Boston is
the second largest unfiltered system in the US. We are concerned that the validation protocols developed
in the guidance manual be such that we can cost-effectively procure UV systems. For larger reactors,
computational fluid dynamics (CFD) modeling may be a cost-effective validation method. We urge EPA
to explicitly permit CFD analysis without site-specific flow testing in the regulation, with more specific
technical requirements to be developed and presented in guidance manuals as the science advances. Not
doing so may eliminate this option for the future.
The UV Disinfection Guidance Manual must explicitly allow use of CFD to predict UV inactivation for
reactors that are too large to subject to the physical validation test protocol currently described in the
Guidance Manual. The required quantities of test organisms, the large volumes of water needed, and the
disposal of contaminated water during testing, all present significantly different challenges for bioassay
tests of large reactors. In addition, the safety factor, if any, added due to the use of CFD must be
reasonable: the 20% increase in required dose described in the current version of the manual is absurdly
conservative.
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Response: See Response 910.k.
EPA Letter ID: 522
Comment ID: 14148
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: More information is needed as to whether and what future changes would require
revalidation. It is important to allow for incorporation of new UV and water treatment technology in the
future. Would future incorporation of new UV lamps/sensors require complete revalidation? Would
changes to other processes upstream of UV in a treatment facility require revalidation? If initially
validated as an unfiltered system, would future addition of filtration require revalidation? The regulation
and guidance manual must provide clear direction to implementing state primacy agencies on this topic.
Response: See Response 910.n.
EPA Letter ID: 523
Comment ID: 11688
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The water systems in the Unfiltered Working Group include some of the largest systems in
the US. We are concerned that the validation protocols developed in the Guidance be such that we can
cost-effectively procure UV systems. For larger reactors, computational fluid dynamic (CFD) modeling
may soon prove to be a cost-effective validation method, but as currently drafted the regulations appear to
exclude it. While feasible, the bioassay tests used to validate UV reactor performance are both impractical
and uneconomical at the flow rates that will be required for larger plants. The required quantities of test
organisms, the large volumes of water needed, and the disposal of contaminated water during testing, all
present significantly different challenges for large reactors. In addition, the safety factor, if any, added
due to the use of CFD must be reasonable: the 20% increase in required dose described in the current
version of the manual is absurdly conservative and without technical basis. We urge EPA to explicitly
permit CFD analysis without site-specific flow testing, following protocols to be developed in guidance at
a later date. This explicitly preserves the option, and encourages investment in improving the technique.
Response: See Response 910.k.
EPA Letter ID: 523
Comment ID: 11689
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The validation process is too cumbersome, unreliable, unpredictable, lengthy, complex, and
costly to be forced on each and every UV installation. It raises a considerable barrier to implementation of
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what should be a relatively predictable and easily installed technology. It would be more beneficial to the
industry and the public if the EPA focuses the validation process upon the manufacturers in all but the
most unusual installations. That way, the EPA could perform very rigorous validation tests up front,
allowing the manufacturers to use the results to improve the designs. The resulting pre-validated systems
could then be installed across the country with speed and certainty, allowing the public to enjoy their
benefits years earlier.
While we agree that CFD should be available as an option, it need not be the only costeffective validation
method. We think manufacturer pre-validation could basically replace any site-by-site validation when
flow rate and channel dimensions and characteristics are specified. In other words, a manufacturer
should be able to validate a modular system consisting of a given bank of bulbs when installed in a
smooth concrete channel of specified cross-sectional and longitudinal dimensions and operated in a
specified flow range. Utilities can then build the required number of such channels based on individual
situations, knowing that the UV supplier has already been validated for such an installation.
Response: See Responses 910.1 and 910.k.
EPA Letter ID: 523
Comment ID: 11690
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The collimated beam test is riddled with internal variability hazards, both biological and
physical. The variability of this test alone is enough to throw the entire validation process into question.
In addition, if every UV installation is required to repeat it, the variability between tests would likely be
statistically excessive. It should therefore be performed by the EPA once, up-front, with rigor and
applicability for all.
Response: See Response 910.1.
EPA Letter ID: 560
Comment ID: 14989
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Nine - Reduction Equivalent Dose:
The Reduction Equivalent Dose (RED) is a central component of the UV validation protocol and it
intrinsically results in a significant safety factor. American Water has many specific concerns with the
RED exist.
The polychromatic bias assumes that MP lamps are less effective than LP lamps. However, scientific data
shows that MP lamps are more effective than LP because UV wavelength other than UV250 - 280 impact
other cellular functions (Kalisvaart, Wat. Sci. Technol. 43(4): 191-197 2001 and others). Standard curves
have been created for challenge microorganisms. UV validation should validate the dose delivered by the
reactor and should not validate the -challenge microorganism kill- and convert it to a kill of the target
organism. The focus of validation should be on the reactor delivering the dose that meets or exceeds
Comment Response for L T2ESWTR 8-33 0 December 2005
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the existing standard curves for microorganisms, and not the mechanism of generating UV. American
Water recommends that EPA focus on the results (microbe inactivation), not the process, as this will stifle
innovation.
These comments lead us to question the scientific validity of the RED bias for biodosimetry. Because
Table IV-21 establishes the required UV doses for Giardia, Cryptosporidium, and virus inactivation, the
purpose of biodosimetry is only to determine if the UV reactor delivers the required UV dose. Comparing
the inactivation kinetics of the indicator (MS2) to the target organism (Cryptosporidium) is immaterial
because the required UV dose has already been established in Table IV-21. Thus the RED bias is both
redundant, and penalizes water utilities (through unnecessarily high UV costs) by requiring use of an
indicator (MS2) that is resistant to UV inactivation. American Water notes that the RED bias was not
included in the 2002 initial draft of the UV Guidance Manual, and contends that these concepts are not
generally accepted as sound science. American Water recommends that EPA conduct a thorough
scientificreview of the UV guidelines by the SAB.
Response: See Response 910.h.
EPA Letter ID: 562
Comment ID: 12507
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Reactor Validation
Three issues of concern are validation of reactors, the follow-up approval of validation by the primacy
agency, and the requirements for third-party validation. The guidance is based on low-pressure (LP)
lamps, viruses as challenge organisms, and use of a validation test facility. The guidance should, and does
allow validation at varying flow rates, UV transmittance (UVT), reactor/piping configuration, and lamp
characteristics. To simplify approval, primacy agencies should be strongly encouraged to accept results of
validation testing from a test facility, other operating sites, or using another EPA accepted protocol. The
question remains as to what qualifies as third-party validation given the realities of how validations are
being completed.
Response: See Response 910.1.
EPA Letter ID: 587
Comment ID: 12016
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: A) Develop a single, national validation review committee -I continue to be concerned with
the resources and expertise needed to implement UV disinfection at the state level and by medium and
small sized utilities. The EPA should develop a national regulatory review panel to review reactor
validation tests and assign log removal credit. The purpose of this panel would be to provide a thorough
and consistent review of reactor validation tests from individuals with a regulatory background that are
well versed in UV reactor validation issues. A multi-state review process should minimize the possibility
Comment Response for L T2ESWTR 8-331 December 2005
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that there will divergent interpretations of validation testing results from state to state. In addition, the
panel would decrease the implementation burden on the manufacturers to obtain individual state
approvals. The review committee should be chaired and funded by the EPA. This review committee could
be comprised of select state reviewers (such as California) with both technological and implementation
perspectives, similar EPA staff, and perhaps a university / research professor. Creation of such a review
committee should significantly improve consistency between states and decrease the overall
implementation burden on all parties involved.
Response: See Response 910.1.
EPA Letter ID: 587
Comment ID: 12020
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: Tier 2 Validation Approach -Specific Comments
The following comments were generated from using the draft UVDGM to review an actual validation
report submitted for a 180 MGD UV installation, which will employ reactors with medium pressure
lamps. The validation review was conducted with the intent of issuing inactivation credit for
Cryptosporidium and Giardia lamblia for the proposed UV reactors.
1. The Tier 2 approach presents significant problems to the primacy agency in that the approach can
generate a different safety factor (and thus a different dose requirement) for each of the individual
validation runs that comprise a reactor validation test. In other words, the Tier 2 approach can generate an
infinite number of regulatory dose requirements -"Tier Infinity". Under this approach, two different
utilities using sources in the same watershed, and using the same reactor could have different regulatory
dose requirements. Our experience has identified the following issues associated with the Tier 2
approach:
a. The choice of input parameters for the Tier 2 Validation Protocol Calculator Tool is very subjective.
This subjectivity, resulting in different regulatory dose values (an appealable action), increases the
vulnerability of a State to legal challenges.
b. The Tier 2 approach requires significant time and labor to review. Due to the complexities involved,
the reviewer(s) must be highly trained further increasing State costs to implement. Because of the unique
characteristic of each Tier 2 validation, costs associated with each review cannot be distributed over
future reviews. Potential "power savings" may actually be transferred to the State agency in the form of
increased program costs.
c. Experts in the field have disagreed with the input parameters even for the same validation effort. For
example: What level of aged or fouling factor should be used in the calculator tool? The use of default
values as appropriate in a given application is difficult to verify.
d. The presence of multiple regulatory doses increases the difficulty of State compliance monitoring and
increases the likelihood of missing reporting and compliance violations. The department believes that the
presence of multiple regulatory doses will increase State costs associated with monitoring and tracking
system compliance.
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e. The presence of multiple different dose requirements will be difficult and time consuming to explain to
1) the general public; 2) the legislature; 3) utilities and 4) the media.
f If a Public Notification (PN) requirement is triggered by a Treatment Technique Violation (TTV), we
believe that the presence of multiple regulatory doses under a Tier 2 approach will create 1) an incentive
for a utility to challenge the dose requirement in question (picture an adjacent utility operating under a
lower dose requirement), and 2) will create public confusion on what the dose means.
Response: See Response 910.h.
EPA Letter ID: 587
Comment ID: 12021
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: 2. Every increased option available in the regulations has a very big impact on the resources
needed by the State to effectively implement the program in a sustained manner. The development of a
validation program more closely modeled on the German standard (DVGW W294) would be simpler to
implement at less cost and with less margin for error.
3. If a Tier 2 approach is needed to satisfy industry concerns, development of a second 'tighter' set of
validation criteria should be pursued. The creation of a single Tier 2 Dose would be "infinitely" better. (A
single dose requirement is preferred).
Response: See Response 910.h.
EPA Letter ID: 603
Comment ID: 12640
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: 2. The Washington State Department of Health has significant concerns with the
Tier 2 reactor validation approach outlined in the draft Ultraviolet Disinfection Guidance Manual. The
complexity and ambiguity of the Tier 2 validation approach will make it difficult to implement.
Response: See Response 910.h.
EPA Letter ID: 603
Comment ID: 12681
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
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Comment: Develop a single, national validation review committee - The department continues to be
extremely concerned with the resources and expertise needed to implement W disinfection at the state
level, It is strongly recommended that the EPA develop a national regulatory review panel to review
reactor validation tests and assign log removal credit. The purpose of this panel would be to provide a
thorough and consistent review of reactor validation tests from individuals with a regulatory background
that are well versed in UV reactor validation issues. A multi-state review process should minimize the
possibility that there will divergent interpretations of validation testing results from state to state. In
addition, the panel would decrease the implementation burden on the manufacturers to obtain individual
state approvals. The review committee should be chaired and funded by the EPA. This review committee
could be comprised of select state reviewers (such as California) with both technological and
implementation perspectives, similar EPA staff, and perhaps a university / research professor. Creation of
such a review committee should significantly improve consistency between states and decrease the
overall implementation burden on all parties involved.
Response: See Response 910.1.
EPA Letter ID: 603
Comment ID: 12687
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Tier 2 Validation Approach -Specific Comments
Department staff developed the following comments after using the draft UVDGM to review an actual
validation report submitted for a 180 MGD W installation, which will employ reactors with medium
pressure lamps. The department conducted the review with the intent of issuing inactivation credit for
Cryptosporidium and Giardia lamblia for the proposed UV reactors.
1. The department opposes the Tier 2 validation approach as presented. The Tier 2 approach presents
significant problems to the primacy agency in that the approach can generate a different safety factor (and
thus a different dose requirement) for each of the individual validation runs that comprise a reactor
validation test. In other words, the Tier 2 approach can generate an infinite number of regulatory dose
requirements-'Tier Infinity". Under this approach, two different utilities using sources in the same
watershed, and using the same reactor could have different regulatory dose requirements. Our experience
has identified the following issues associated with the Tier 2 approach:
a. The choice of input parameters for the Tier 2 Validation Protocol Calculator Tool is very subjective.
This subjectivity, resulting in different regulatory dose values (an appeal able action), increases the
vulnerability of a State to legal challenges.
b. The Tier 2 approach requires significant time and labor to review. Due to the complexities involved,
the reviewer(s) must be highly trained further increasing State costs to implement. Because of the unique
characteristic of each Tier 2 validation, costs associated with each review cannot be distributed over
future reviews. Potential "power savings" may actually be transferred to the State agency in the form of
increased program costs.
c. Experts in the field have disagreed with the input parameters even for the same validation effort. For
example: What level of aged or fouling factor should be used in the calculator tool? The use of default
values as appropriate in a given application is difficult to verify.
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d. The presence of multiple regulatory doses increases the difficulty of State compliance monitoring and
increases the likelihood of missing reporting and compliance violations. The department believes that the
presence of multiple regulatory doses will increase State costs associated with monitoring and tracking
system compliance.
e. The presence of multiple different dose requirements will be difficult and time consuming to explain to
1) the general public; 2) the legislature; 3) utilities and 4) the media.
f If a Public Notification (F") requirement is triggered by a Treatment Technique Violation (TTV), we
believe that the presence of multiple regulatory doses under a Tier 2 approach will create 1) an incentive
for a utility to challenge the dose requirement in question (picture an adjacent utility operating under a
lower dose requirement), and 2) will create public confusion on what the dose means.
Response: See Response 910.h.
EPA Letter ID: 603
Comment ID: 12688
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Every increased option available in the regulations has a very big impact on the resources
needed by the State to effectively implement the program in a sustained manner. The development of a
validation program more closely modeled on the German standard (DVGW W294) would be simpler to
implement at less cost and with less margin for error.
If a Tier 2 approach is needed to satisfy industry concerns, development of a second 'tighter' set of
validation criteria should be pursued. The creation of a single Tier 2 Dose would be "infinitely" better. (A
single dose requirement is preferred).
Response: See Response 910.h.
EPA Letter ID: 603
Comment ID: 12694
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: The department supports a UV implementation approach using a single dose standard for
target pathogen inactivation, with safety factors applied separately for the validated reactor and site
specific conditions. A single approach for applying safety factors to the reactor based upon validation
results should be implemented in the UVDGM.
A set of default safety factors should be developed to simplify implementation. The default values could
be based on a sensitivity analysis of the impacts of different parameters (i.e., UVT for different lamp to
sensor distances) for set ranges. A table that lists these default parameters should help primacy agency
and utility implementation efforts.
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Response: See Response 910.h.
EPA Letter ID: 628
Comment ID: 12853
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: 6. UV Disinfection Requirements
a. Proposed ultraviolet (UV) validation requirements are cumbersome, cost-ineffective, and unnecessary
complex. The validation process as described in the proposed rule and UV Guidance Manual is too
cumbersome, unpredictable, lengthy, complex, and costly, as every UV installation has to conduct the in-
situ validation. The bioassay tests used to validate UV reactor performance are both impractical and
uneconomical at the flow rates that will be required for larger plants. The required quantities of test
organisms, the large volumes of water needed, and the disposal of contaminated water during testing, all
present significantly different challenges for large reactors. Additionally, the collimated beam test is
riddled with internal variability hazards, both biological and physical. The variability of this test alone is
enough to throw the entire validation process into question. Further, if every UV installation were
required to repeat it, the variability between tests would likely be statistically excessive. Such a site-by-
site validation process places a considerable barrier to implementation of what should be a relatively
predictable and easily installed technology. The SFPUC is also concerned that the validation protocols
developed in the Guidance Manual will lead to a costly UV installation.
The SFPUC believes it is more cost-effective without adversely affecting the public health protection if
the EPA would focus the validation process on the manufacturers and their equipment in all but the most
unusual installations. With such a pre-validation approach, the EPA could perform very rigorous
validation tests up front, allowing the manufacturers to use the results to improve the designs. That way,
the resulting pre-validated systems could then be installed across the country with speed and certainty,
allowing the public to enjoy their benefits years earlier.
Thus, the SFPUC recommends the EPA consider modular pre-validations instead of the proposed site-by-
site validations. The modular pre-validation procedure requires a manufacturer to validate a modular
system consisting of a given bank of bulbs in a section of smooth concrete channel or pipeline of
specified cross-sectional and longitudinal dimensions and inlet and outlet conditions, and operated in a
specified flow range. Utilities can then build the required number of modules based on individual
situations, knowing that the UV supplier has already been validated for such an installation.
Response: See Responses 910.f, 910.L and 910.1.
EPA Letter ID: 678
Comment ID: 14700
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 27. Section 141.729(d)(2) - The rule states -Systems may apply this table [UV Dose Table
for Cryptosporidium, Giardia Lamblia, and Virus Inactivation Credit] to UV reactors with other lamp
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types through reactor validation testing-.-. Does this mean that systems using UV reactors with low-
pressure mercury-vapor lamps of a wavelength of 254 nm can claim the log removal credit without going
through the reactor validation testing? We request that EPA provide clarification on this issue.
Response: See Response 910.f
EPA Letter ID: 678
Comment ID: 14701
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 28. Sections 141.721(c)(2) and 141.729(d)(3)- The proposed rule requires unfiltered systems
that use UV light to provide Cryptosporidium disinfection in at least 95 percent of the water delivered to
the public every month. There is no similar provision for filtered systems. A similar 95th percentile
allowance should be provided for filtered systems in the rule. The EPA should provide a clear definition
of the off-spec limitations and include a provision in the rule to allow the filtered systems to meet
validation conditions in 95 percent of the water delivered. In the vast majority of cases, falling outside
validation conditions will only be cutting into the built-in safety factors, and will therefore not be
impacting the desired level of health protection.
Response: See Response 910.J.
EPA Letter ID: 678
Comment ID: 14724
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. Section 4 of the Manual. Given the difficulty, uncertainty, cost, and inaccuracies inherent
in performing and measuring microbiological response in the field, particularly for smaller community
utilities, we feel that it would be more efficient for the entire industry to focus the validation requirements
on the manufacturers of the systems. Essentially, this would expand the Tier 1 category to include almost
all prefabricated -black box- closed channel reactors when orientation, flow rate and UVT ranges
are specified, and even open channel units when channel dimensions, wall roughness, and UV albedo are
also specified. The advantages of this approach include:
* The EPA can require a single more rigorous and accurate validation process for the manufacturers, the
results of which can benefit many utilities and consumers across the nation
* Utilities will have far more predictable budgeting, scheduling, and design frameworks
* Communities will save time and money
* Manufacturers will have belter marketing predictability
Response: See Response 910.1.
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8.16.1.3 Comment Codes 914, Reactor monitoring
Individual Comments on Code 914
EPA Letter ID: 587
Comment ID: 12018
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: C) Required monitoring parameter -As defined in §141.729 (d)(3)(i), the requirement for
measurement of UV intensity sensors and flow rate for each reactor as reportable parameters should be
maintained within the regulations. The monitoring parameters are essential to defining the operating
conditions under which a reactor was validated. The dose control approach involves the use of algorithms
to calculate the reduction equivalent dose (RED) under a certain set of conditions. While the simplicity of
the output is easy to understand, the manufacturer can adjust the algorithms. Flow rate, UV intensity, and
UV transmittance are directly measured parameters that should be monitored and reported to the state.
Response: See Response 910.f
EPA Letter ID: 587
Comment ID: 12023
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: 1. UV Intensity - UV intensity is a critical parameter and should be required for all UV
installations regardless of the control strategy employed. UV intensity should be included in the
'Parameters Monitored' column for the Calculated Dose control strategy in Table 5.5 of the UVDGM.
Response: See Response 910.f
EPA Letter ID: 603
Comment ID: 12642
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: The Washington State Department of Health also has significant concern with the calculation
of Ultraviolet reactor compliance on a monthly volume basis. We strongly recommend monitoring and
reporting on a time basis with a daily monitoring trigger to support continuous operation of Ultraviolet
reactors. The
Response: See Response 910.J.
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EPA Letter ID: 603
Comment ID: 12662
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47793) Section 141.730(e)(13)-
Similarto §141.721(~)(2), this section defines compliance with the UV inactivation requirements on a
monthly volume basis. The department strongly recommends the use of time rather than volume as the
means of calculating compliance with the provision of a daily trigger to support continuous operation
of UV reactors.
Response: See Response 910.J.
EPA Letter ID: 603
Comment ID: 12685
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Required monitoring parameter -As defined in 5141.729 (d)(3)(i), please continue to include
the requirement for measurement of UV intensity sensors and flow rate for each reactor as reportable
parameters. The monitoring parameters are essential to defining the operating conditions under which a
reactor was validated. The dose control approach involves the use of algorithms to calculate the reduction
equivalent dose (RED) under a certain set of conditions. While the simplicity of the output is easy to
understand, the manufacturer can adjust the algorithms. Flow rate, UV intensity, and UV transmittance
are directly measured parameters that should be monitored and reported to the state.
Response: See Response 910.f
EPA Letter ID: 603
Comment ID: 12686
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Validation Protocols
Our most significant concern with the draft UVDGM is the validation approaches outlined in Chapter 4.
The defined parameters of the Tier 1 approach are preferred over the uncertainty and ambiguity of the
Tier 2 approach. The flexibility of the Tier 2 approach results in an indefinite set of safety factors and is
opposed by the department for the following reasons:
- State Resources -The validation of UV reactors is a complex process. As such, the review of a Tier 2
reactor validation report is expected to consume staff time, not only to review the validation report, but
also to develop and maintain the expertise necessary to review the validation, especially a validation
without defined boundaries.
- Consistency -Without defined uncertainties, the Tier 2 approach may result in inconsistent regulatory
approaches between States and within a State over the years as personnel responsible for review change.
- Ambiguity -The Tier 2 approach results in different safety factors depending upon the uncertainty and
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microbial response of the selected reactor challenge test. The results are arguable, at best, resulting in
uncertainty in the required Reactor Equivalent Dose (RED) for inactivation of the target pathogen.
- Enforceability -It is impossible to regulate the reactor performance at a utility if the RED is arguable.
Drinking water regulations are based upon enforceable parameters such as maximum contaminant levels,
turbidity standards, and inactivation ratios. The ambiguity of a Tier 2 RED makes taking clear
enforcement actions, when required, problematic.
Response: See Response 910.h.
EPA Letter ID: 603
Comment ID: 12690
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: 1. UV Intensity -UV intensity is a critical parameter and should be required for all UV
installations regardless of the control strategy employed. W intensity should be included in the
'Parameters Monitored' column for the Calculated Dose control strategy in Table 5.5 of the WDGM.
Response: See Response 910.f
EPA Letter ID: 612
Comment ID: 13151
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Other EPA Comment Codes and Descriptions: 890 N. Ozone and Chlorine Dioxide
Comment: Summary:
Although LT2 provides these disinfection technologies as toolbox options, the rule falls short of requiring
continuous monitoring protocol that would insure the consistency and effectiveness of any these
technologies over time. Source water and the treatment train leading to the several of these disinfection
treatments can be varied throughout the year. Because of this, the application of certain on-line
monitoring technologies would provide assurance of consistent pathogenic kill rates over time
Response: See Response 910.f EPA believes that the requirements for ozone and chloramine disinfection
in today's final rule are the minimum necessary to ensure effective water treatment for public health
protection. Today's rule requires daily calculation of inactivation acheived (CT) at peak hourly conditions
to ensure that adequate inactivation levels are being maintained at all times. Today's rule requirements are
similar to the disinfection monitoring requirements of Subpart H. EPA agrees that continuous monitoring
of these technolgies would be provide additional reliability and believes that many plants will monitor
these processes continuously to ensure process reliability. However, EPA does not have a basis to require
continuous monitoring of these processes for compliance purposes.
EPA Letter ID: 628
Comment ID: 12859
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Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: The EPA should consider some accommodation of operational realities in that an unfiltered
water system is allowed to calculate 95th percentile performance using actual radiation and flow rate
measurements. This would allow unfiltered water systems to gain disinfection credit for measurable
disinfection effect whether or not it is defined as -in-spec.-
Response: See Response 910.J.
EPA Letter ID: 678
Comment ID: 14725
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Given the site-specific and time-sensitive nature of UVT, lamp age, and lamp fouling
variation, we feel it would be more protective of human health to require the utility to perform more
intensive monitoring during an extended start-up period of 12 months. The extended start-up period
monitoring should be less intensive for small systems, but should still span 12 months to accommodate
seasonal variations.
Response: See Response 910.f
8.16.1.4 Comment Codes 916, Compliance determination for
filtered systems
Individual Comments on Code 916
EPA Letter ID: 453
Comment ID: 10949
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: 6. Concerning UV disinfection, the safety factors appear to be excessive. Also, when UV
reactors are not operating within validation conditions, filtered systems should be given the same
flexibility as unfiltered systems. This will provide the desired level of health protection.
Response: See Responses 910.f, 910.h, and 910.J.
EPA Letter ID: 471
Comment ID: 11115
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
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Comment: the States; and 2) given that there is a 95th percentile off-spec allowance for unfiltered
systems (which have less barriers against Cryptosporidium), that the specific provision for meeting
validation conditions be for 90 (ninety) percent of the water delivered for filtered water supplies. This
provision is critical
Response: See Response 910.J.
EPA Letter ID: 471
Comment ID: 11154
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: the States; and 2) given that there is a 95th percentile off-spec allowance for unfiltered
systems (which have less barriers against Cryptosporidium), that the specific provision for meeting
validation conditions be for 90 (ninety) percent of the water delivered for filtered water supplies. This
provision is critical
Response: See Response 910.J.
EPA Letter ID: 474
Comment ID: 11200
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: been left to the State or primacy agency for determination. We believe filtered and unfiltered
systems should be held to the same performance standard, measured monthly, particularly when both are
subject to the same events and conditions that can lead to water that could be considered -off
specification-. We concur
Response: See Response 910.J.
EPA Letter ID: 496
Comment ID: 10700
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 3. UV Key Issue 3 Off-Spec Limitation and Reporting: Off-spec simply means that water is
delivered when UV reactors are not operating within validation conditions. Unfiltered systems are
specifically allowed off-spec conditions. They must monitor each UV reactor while in use and must
record periods when any reactor operates outside of validated conditions. The disinfection treatment must
ensure at least 99 % (or 99.9 % when required) inactivation of Cryptosporidium in at least 95 % of the
water delivered to the public every month. There is no similar provision for filtered systems. A similar
95th percentile minimum allowance should be provided for in the proposal. Since filtered systems already
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have a significant barrier against Crypto established, a 90th percentile minimum allowance would be
more appropriate.
provide a clearer definition of the off-spec limitations and a specific provision for meeting validation
conditions in 90 % of the water delivered for filtered water supplies. This is crucial for the design and
operation of a UV system and for utilities to
Response: See Response 910.J.
EPA Letter ID: 512
Comment ID: 11505
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: b. EPA should recognize multiple barriers of protection when setting inactivation
requirements. Under the proposed regulation, it appears unfiltered water systems using UV for
Cryptosporidium inactivation must provide this inactivation to 95% of the water delivered each month;
while filtered water systems need to meet a more stringent reliability factor that is specified in the
guidance manual. This is inconsistent with the Surface Water Treatment Rule-s philosophy of multi-
barrier protection. The relative risks associated with unfiltered systems whose only barrier is UV versus
filtered systems that have the additional barrier of filtration are not commensurate. EPA should
implement inactivation requirements for filtered and unfiltered systems that are consistent. At a
minimum, filtered systems should not be held to a higher inactivation standard than unfiltered systems.
Response: See Response 910.J.
EPA Letter ID: 527
Comment ID: 10856
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Off-Specification Limitation and Reporting: Off-Specification simply means that water is
delivered when UV reactors are not operating within validated conditions. Unfiltered systems are
specifically allowed off-specification conditions. They must monitor each UV reactor while in use and
must record periods when any reactor operates outside of validated conditions. The disinfection treatment
must ensure at least 99 percent (or 99.9 percent if required) inactivation of Cryptosporidium in at least 95
percent of the water delivered to the public every month. The proposal does not have a similar provision
for filtered systems. A similar 95th percentile allowance, at a minimum, should be provided for in the
proposal.
Response: See Response 910.J.
EPA Letter ID: 527
Comment ID: 10856
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Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Off-Specification Limitation and Reporting: Off-Specification simply means that water is
delivered when UV reactors are not operating within validated conditions. Unfiltered systems are
specifically allowed off-specification conditions. They must monitor each UV reactor while in use and
must record periods when any reactor operates outside of validated conditions. The disinfection treatment
must ensure at least 99 percent (or 99.9 percent if required) inactivation of Cryptosporidium in at least 95
percent of the water delivered to the public every month. The proposal does not have a similar provision
for filtered systems. A similar 95th percentile allowance, at a minimum, should be provided for in the
proposal.
Response: See Response 910.J.
EPA Letter ID: 556
Comment ID: 12079
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: least 95 percent of the water delivered to the public every month. There is no similar
provision for filtered systems. A similar 95th percentile allowance at minimum should be provided for in
the proposal.
Response: See Response 910.J.
EPA Letter ID: 562
Comment ID: 12508
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Off-Specification Water
The proposed LT2ESWTR states that unfiltered water supplies using UV are expected to provide
inactivation to 95% of the water delivered each month. A similar provision is absent for filtered systems.
The draft guidance manual alludes to filtered systems being expected to meet a significantly higher,
but undefined, reliability factor. The allusion to this higher, but undefined, reliability factor should be
eliminated to minimize confusion. Filtered systems need more explicit details in the final guidance
manual on this reliability factor. This factor would apply when power supply is lost for a short period, as
well as to any -off spec- water resulting from lamp fouling, reduced UVT, etc.
The proposed requirements for design of UV systems are extremely conservative. The 95% off-spec
criteria for unfiltered systems is not gauged to failure to meet the delivered UV dose but to failure to meet
validated conditions that reflect numerous safety factors which together increase the required dose three-
to four-fold. AWWA recommends that an off-spec performance standard for filtered systems measured on
a monthly basis should be 90% (i.e., 90% of finished water should be within specifications as described in
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guidance manual). EPA should evaluate setting the unfiltered off-spec criteria at the same level as is
employed for filtered systems.
Response: See Response 910.J.
EPA Letter ID: 630
Comment ID: 13068
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 3. UV Key Issue Off-Spec Limitation and Reporting: Off-Spec simply means that water is
delivered when UV reactors are not operating within validation conditions. Unfiltered systems are
specifically allowed off-spec conditions. They must monitor each UV reactor while in use and must
record periods when any reactor operates outside of validated conditions. The disinfection treatment
must ensure at least 99 percent (or 99.9 percent if required) inactivation of Cryptosporidium in at least 95
percent of the water delivered to the public every month. There is no similar provision for filtered
systems. A similar 95th percentile allowance at minimum should be provided for in the proposal. Since
filtered systems already have a significant barrier against Crypto in place, a 90th percentile allowance
would be more appropriate. It is also imperative that
Response: See Response 910.J.
EPA Letter ID: 637
Comment ID: 13092
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: Unfiltered systems are allowed an -off-spec- limitation of 95%. This means that the UV
system must provide a 99% inactivation to 95% of the water delivered to the public. Filtered systems
should be given at least the same limitation. In fact, due to the additional treatment barrier, it would be
more appropriate to allow a filtered water system a lower -off-spec- limitation. These off-spec variances
where the UV systems falls outside of validation conditions will cut into the built-in safety factors (not to
mention the ones mentioned above) and will therefore not impact the desired level of health protection.
Response: See Response 910.J.
EPA Letter ID: 678
Comment ID: 14723
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. We understand the value of regulatory simplicity as manifested in the operational
requirement for 95% of delivered water to be -in specification-. However, public health risk benefits
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would more accurately be measured via a general disinfection calculation analogous to CT. Therefore, a
utility should have the option of using it-s specific dose-response curve to calculate overall cumulative
disinfection for the month to meet a regulatory goal. This would allow a UV system the flexibility to vary
certain operational criteria and still get disinfection credit when slightly out of specification.
Response: See Response 910.J.
8.16.1.5 Comment Codes 917, Off-spec operation
Individual Comments on Code 917
EPA Letter ID: 388
Comment ID: 10480
Commenter: Andreas Kolch,, WEDECO AG
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment:
3.1.3, 3-9 Defining Design Parameters
The off spec list seems not to be clear: If not all lamps are off, is there a possibility that the reactor is not
off spec, because it would be still possible to operate in a validated range? We think that this can not be
the case. In consequence the term "all UV lamps in all UV reactors are off..." is irritating. Single lamp
failures can occur and should contribute to an off spec status even if all control signals would indicate an
operation within a validated range.
Response: See Response 910.J.
EPA Letter ID: 471
Comment ID: 11114
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 2. Another important UV issue that we have concerns about are the -off-spec- provisions. As
a filtered water supply, we are very concerned that the off-spec provisions are not clearly defined and left
to the discretion of the State. In particular, our plants may have issues with power quality that may
significantly affect our ability to meet an overly stringent off-spec requirement. As such, we would like to
suggest the following: 1) that EPA provide a clearer definition of the off-spec limitations in the rule and
implementation guidance as a model for the States; and 2) given that there is a 95th percentile off-spec
allowance for
Response: See Response 910.J.
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EPA Letter ID: 471
Comment ID: 11116
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: of the water delivered for filtered water supplies. This provision is critical for the reasonable
design, operation, and compliance of a UV system, and in the vast majority of cases, falling outside
validation conditions will only be cutting into the built-in safety factors, and will therefore not be
impacting the desired level of health protection.
Response: See Response 910.J.
EPA Letter ID: 471
Comment ID: 11155
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: of the water delivered for filtered water supplies. This provision is critical for the reasonable
design, operation, and compliance of a UV system, and in the vast majority of cases, falling outside
validation conditions will only be cutting into the built-in safety factors, and will therefore not be
impacting the desired level of health protection.
Response: See Response 910j.
EPA Letter ID: 474
Comment ID: 11199
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: The EPA has proposed a standard of compliance with inactivation requirements, for unfiltered
systems using UV for disinfection, at the 95th percentile. A compliance percentile for filtered systems has
not been set by the EPA, but has been left to the State or primacy agency for determination. We believe
filtered
that can lead to water that could be considered -off specification-. We concurwith the use of the 95th
percentile inactivation compliance specification and believe that this will provide an appropriate level of
public health protection.
Response: See Response 910j.
EPA Letter ID: 480
Comment ID: 11232
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Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: Subpart (c)(2) requires that unfiltered systems using UV disinfection for inactivation of
Cryptosporidium must achieve the required log inactivation in at least 95% of the water served each
month.
The current proposed LT2 draft requires that at least 95% of the flow, totalized monthly, meet the
specified requirements of the UV validation. Water that doesn-t meet identified operating conditions,
whether due to a single lamp failure, or complete reactor failure, is counted in this total. We support this
approach.
An alternative proposal has been offered for unfiltered system compliance: In that proposal, all reactors in
a system must operate within their specified limits at least 95% of the time the system treats water,
irrespective of flow or whether the entire system (i.e. all reactors), a single reactor, or a single lamp out
causes the out-of-spec performance. We do not agree with this approach. Depending on the number of
reactors employed, even if a single reactor is completely out of service, substantial treatment may remain.
The following figure illustrates this point.
[SEE GRAPH ON PAGE 4 OF PDF]
This chart illustrates, particularly with the number of reactors the vast majority of systems will operate
(<10), that there is a tremendous difference in delivered treatment between a reactor that is completely
off-line (but passing water) and one that may be out of specification, and the timebased compliance
approach is blind to this difference.
It is important to reiterate that the intent of this utility is to operate the system within specification at all
times. However, it is recognized that minor upsets occur, whether by mechanical failure or operator error,
and they are generally contained rapidly.
We continue to believe that the flow based approach as proposed is appropriate, and can be readily
monitored by the utility and regulatory agencies. EPA should evaluate options for differentiating off-line
reactors from off-spec reactors.
Response: See Response 910.J.
EPA Letter ID: 483
Comment ID: 11270
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: - Off-Spec limitation and reporting - Unfiltered systems are specifically allowed offspec
conditions. The disinfection treatment must ensure at least 99 percent inactivation of Cryptosporidium in
at least 95 percent of the water delivered to the public every month. There is no similar provision for
filtered systems. A similar 95th percentile allowance at minimum should be provided for in the proposal
for filtered systems. Since filtered systems already have a significant barrier against Crypto in place, a
90th percentile allowance would be more appropriate.
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Response: See Response 910.J.
EPA Letter ID: 496
Comment ID: 10701
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: Comments for Key Issue 3 (Off-Spec Limitation and Reporting): EPA should provide a
clearer definition of the off-spec limitations and a specific provision for supplies. This is crucial for the
design and operation of a UV system and for utilities to maintain compliance with the regulation. In the
majority of cases, falling outside the validation conditions will only be cutting into the built-in safety
factors, and therefore will not be influencing the desired level of health protection.
Response: See Response 910.J.
EPA Letter ID: 502
Comment ID: 10634
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: UV Disinfection:
1.1. Off-spec limitations and reporting: Please provide a clearer definition of offspec operation. We
would like clarification on whether -off-spec- means the system is off and not providing any disinfection,
or does it mean that a system is not operating within the validated specifications? We feel it is important
tointerject that substantial consideration be given to the fact that even if a system is not operating within
certain validated conditions, that does not mean that adequate disinfection is not being provided. This is
especially true when there are built in safety factors in place.
Response: See Response 910.J.
EPA Letter ID: 506
Comment ID: 10740
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: o Off-Spec Limitation and Reporting - CWD recommends that USEPA provide a clearer
definition of the off-spec limitations and a specific provision for meeting validation conditions in 90% of
the water delivered, for filtered water supplies. CWD feels that this is important for the design and
operation of UV systems and for utilities to maintain compliance with the regulation. In almost all cases,
these off-spec conditions would be cutting into the built-in safety factors and therefore not compromising
public health protection.
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Response: See Response 910.J.
EPA Letter ID: 516
Comment ID: 11736
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 6) U.V. DISINFECTION: OFF-SPECIFICATION REQUIREMENTS
The Rule states that —disinfection treatment- must ensure at least 99 percent inactivation of
Cryptosporidium in at least 95 percent of the water delivered to the public every month. Systems are
required to report periods when UV reactors operate outside of validated conditions on a monthly basis-
(LT2ESWTRIV.B. 1).- This has the same intent as previously regulated disinfection requirements (i.e.
one day per month out of compliance), but this requirement for UV disinfection will be difficult to
monitor and enforce without further details. AWWA-s comments (see Preliminary Draft of Formal
Comments of the AWWA on the LT2ESWTR, 12/8/2003; p 51 line 31 and following 3 paragraphs)
correctly state the inconsistencies with the LT2ESWTR and the previous rules and with the difficulty
of determining the severity of the -off-specification- violation. Separating off-specification from down
time (e.g. treatment failure due to a power interruption or lamp failure) will aid in defining the
equirements of what constitutes offspecification treatment. Leaving the rule as it is currently
worded will allow for different States to enforce this requirement in significantly different ways and has
the potential of requiring overly stringent requirements to ensure satisfactory treatment is achieved to
meet the regulation, rather than the goal of ensuring satisfactory treatment to protect public health.
The analysis that AWWA has made comparing the requirements of providing 95% of treated water to be
within validated specifications to the 90% required for chemical disinfection (i.e. tlO) is erroneous. The
comparison of the 95% on-spec treatment should be made to the one day per month out of compliance for
CT (or approximately 97% compliance). The tlO for CT compliance relates to a distribution of dose for
chemical disinfection (i.e. at least 90% of the water will achieve the required CT), which is analogous to
the dose distribution in a UV reactor. Properly designing fortlO in order to achieve CT compliance is
done by assuming a conservative baffling factor for a clearwell. In UV disinfection, the dose distribution
is accounted for in the validation testing by assuming a conservative dose distribution factor in
developing the safety factors. That being so, the requirements for CT compliance of all but one day per
month are in truth more restrictive than the 95% requirement for UV disinfection.
Response: See Response 910.J.
EPA Letter ID: 522
Comment ID: 14141
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: EPA may want to consider separating "off-spec" from down time (i.e. lamp off). There is
clearly a difference in the health risk of having no UV irradiation from that of providing 98 percent as
much as is required. As most systems will have multiple reactors, having a single reactor at slightly less
that full capacity, and others above their required capacity, may still yield an average above the minimum.
Comment Response for LT2ESWTR 8-350 December 2005
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MWRA urges EPA to draft the final rule and guidance to provide clarity on this topic. MWRA is not
supportive of the suggested alternative approach that suggests that each and very reactor must meet the
95% standard independently. The intent is to ensure that the water leaving the plant is within
specification.
Response: See Response 910.J.
EPA Letter ID: 523
Comment ID: 11674
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Compliance Determination for UV disinfection: For unfiltered systems using UV disinfection
to meet the required inactivation requirements, the draft regulations propose that compliance with the
standard be based on a 95th percentile of water delivered to the public. We fully support this
commonsense approach to extending the existing SWTR requirements for chemical disinfectants
to UV. It is protective of public health, while avoiding the excesses of extraordinary redundancy.
Response: See Response 910.J.
EPA Letter ID: 523
Comment ID: 11675
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should consider some accommodation of operational realities so that an unfiltered water
system is allowed to calculate 95th percentile performance using actual radiation and flowrate
measurements. This would allow unfiltered water systems to gain some disinfection credit for measurable
disinfection effect even when it is defined as "off-spec" by some small amount.
Response: See Response 910.J.
EPA Letter ID: 527
Comment ID: 10857
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should provide a clearer definition of the off-specification limitations and a specific
provision for meeting validation conditions in 95 percent of the water delivered for filtered water
supplies. This is critical for the design and operation of a UV system, and for utilities to maintain
compliance with the regulation. EPA should keep in mind that in the vast majority of cases, falling
outside validation conditions will only be cutting into the built-in safety factors, and will therefore not be
Comment Response for LT2ESWTR 8-351 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
impacting the desired level of health protection. Likewise, compliance metrics should be equally fair to
systems regardless of the number of UV reactors in operation.
Response: See Response 910.J.
EPA Letter ID: 527
Comment ID: 10857
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should provide a clearer definition of the off-specification limitations and a specific
provision for meeting validation conditions in 95 percent of the water delivered for filtered water
supplies. This is critical for the design and operation of a UV system, and for utilities to maintain
compliance with the regulation. EPA should keep in mind that in the vast majority of cases, falling
outside validation conditions will only be cutting into the built-in safety factors, and will therefore not be
impacting the desired level of health protection. Likewise, compliance metrics should be equally fair to
systems regardless of the number of UV reactors in operation.
Response: See Response 910.J.
EPA Letter ID: 548
Comment ID: 12174
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment:
How will the EPA consider a UV system that is operating below validated conditions? If a sensor drops
below a validated condition, does it necessitate reporting to the primacy agency or only corrective action?
To what degree of deviation from validated conditions necessitates reporting? This needs to be clarified.
Response: See Response 910.J.
EPA Letter ID: 548
Comment ID: 12175
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Under subsection -Reactor Validation Testing,- after the first sentence of the paragraph -
Today-s proposal requires testing of full-scale UV reactors— a sentence should be inserted that states -
However, the State may allow for an alternative basis for validating UV reactors.- This type of statement
Comment Response for L T2ESWTR 8-352 December 2005
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would be a proper reminder for the States, and is consistent with other sections of this Rule and the
proposed UV Disinfection Guidance Manual.
Response: See Response lOO.a and 910.k.
EPA Letter ID: 556
Comment ID: 12080
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Recommendation: EPA should provide a clearer definition of the off-specification limitations
and a specific provision for meeting validation conditions in 95 percent of the water delivered for filtered
water supplies. This is critical for the design and operation of a UV system, and for utilities to maintain
compliance with the regulation. EPA should keep in mind that in the vast majority of cases, falling
outside validation conditions will only be cutting into the built-in safety factors and will therefore not be
impacting the desired level of health protection. Likewise, compliance metrics should be equally fair to
systems regardless of the number of UV reactors in operation.
Response: See Response 910.J.
EPA Letter ID: 560
Comment ID: 14992
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: The UVDGM addresses filtered water supplies very differently by suggesting that States
define the off-spec limits. Our concern is that some States may impose more stringent off-spec limits for
filtered water supplies than for unfiltered water supplies.
It is recommended that the LT2 and UVDGM define an off-spec standard such as 10% of the monthly
flow for filtered water supplies without deducting from the nominal Cryptosporidium inactivation credit.
Response: See Response 910.J.
EPA Letter ID: 560
Comment ID: 14993
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Two - Off-Spec versus Downtime:
The draft UVDGM treats off-spec and downtime as the same condition. In terms of protecting public
health, an off-spec episode that encroaches on the RED safety factors is better than actual downtime of a
Comment Response for L T2ESWTR 8-353 December 2005
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UV disinfection system. Therefore, the USEPA should consider setting mutually exclusive limits for off-
spec and downtime.
Response: See Response 910.J.
EPA Letter ID: 562
Comment ID: 12316
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should clarify the off-specification requirement for filtered systems under LT2ESWTR.
AWWA believes that off-specification time should be distinct from -down time-. The guidance should
differentiate from when a reactor is providing treatment but may not be reaching the required UV dose
versus when a UV reactor is not providing any treatment at all. Likewise, compliance metrics should be
equally fair to systems regardless of the number of UV reactors in operation.
Response: See Response 910.J.
EPA Letter ID: 562
Comment ID: 12509
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Because monitoring of UV systems will be virtually continuous and accomplished at the
individual reactor level rather than for the entire treatment train, off-spec requirements should be
determined based on volume (i.e., volume treated) and not time (i.e., hours of operation). Current
federal requirements for monitoring and reporting of chemical disinfection are based on hours of
operation, so this last recommendation is a departure from previous rule structures. Current rules for
ozone are, however, a useful model for bridging this gap between UV and chemical disinfection.
Previous federal regulations provide good models for UV regulatory requirements. In particular,
regulation of ozone specifies a single measurement each day under peak flow for determination of
compliance with CT. Individual states specify different mechanisms for ensuring that this observation is
appropriately captured. For UV, federal regulations can specify a similar daily compliance observation
that would determine compliance with the MCL. Federal guidance could address off-spec level goals
and tracking in the context of operational monitoring and reporting to the state, much like individual filter
monitoring and reporting.
Response: See Response 910.J.
EPA Letter ID: 562
Comment ID: 12510
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for L T2ESWTR 8-354 December 2005
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Comment: The guidance manual does not differentiate between off-spec water and down time. These
two operating conditions are significantly different and the guidance manual should address these
differences. Down time would be defined as when the entire UV system is not operating, while off-spec
would be defined as when the system is operating but not meeting the required UV dose. Off-spec
operation will still provide some level of inactivation and likely a high level due to the multiple safety
factors. The guidance manual should provide methods of calculating both types of operating scenarios
and build both types into the compliance calculations.
Response: See Response 910.J.
EPA Letter ID: 587
Comment ID: 12025
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: 3. Compliance Calculations ("off spec" vs. "downtime") - Operation of a reactor outside of
the validated range and other forms of reactor non-treatment or under treatment should be considered
equivalent (equal to zero log inactivation) for determining compliance. During the UVGM workgroup
meeting significant 'discussion centered on the issue of "off-spec" operation with several participants
advocating for some "partial" credit to be given for reactors that had lamps powered but were operating
outside the validated range (i.e. low flows, low UVT, low power settings). This position seems to
undercut the very basis of the whole validation efforts. Unless specific log inactivation credit
can be assigned to the reactor under the operating conditions in question, then the level of treatment is
unknown, and the reactor must be given zero treatment credit. Manufacturer representatives and research
experts agree that the level of treatment provided by UV reactors is not known and cannot be assumed for
conditions outside of the validated range. (If the level of inactivation is known for the operating
conditions, then the reactor is not "off-spec" and this is not an issue)!
Response: See Response 910.J.
EPA Letter ID: 603
Comment ID: 12692
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: 3. Compliance Calculations -Operation of a reactor outside of the validated range and other
forms of reactor failure should be considered equivalent when it comes to determining compliance. While
it could be said that a system employing chlorine with an inactivation ratio of less than l.O is still
achieving some disinfection, failure to achieve this level of inactivation is a treatment technique violation.
Unless specific log inactivation credit can be assigned to the reactor under the operating conditions in
questions, then the reactor must be given zero treatment credit. Manufacturer representatives and research
experts agree that the level of treatment provided by UV reactors is not known and cannot be assumed for
conditions outside of the validated range.
Response: See Response 910.J.
Comment Response for L T2ESWTR 8-355 December 2005
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EPA Letter ID: 620
Comment ID: 13299
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 3: Off-Spec Limitation and Reporting
Comments: EPA should provide a clearer definition of off-spec limitations. Filtered systems should be
allowed criteria of 90 percent within specification. If proper safety factors are built in to the UV system,
minor deviations from specification should not compromise final water quality.
Response: See Response 910.J.
EPA Letter ID: 628
Comment ID: 12857
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: Accommodate operational realities in compliance determination. For unfiltered systems using
UV disinfection to meet the required inactivation requirements, the rule proposes that compliance with
the standard be based on a 95th percentile. The SFPUC commends the EPA for using a commonsense
approach, which is protective of public health and avoids the excesses of extraordinary redundancy.
Nevertheless, the EPA should allow for more credit if unfiltered systems can demonstrate compliance
with the standard based on a 99th percentile.
Response: See Response 910.J.
EPA Letter ID: 630
Comment ID: 13069
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 90th percentile allowance would be more appropriate. It is also imperative that appropriate
consideration be given to systems that are able to maintain the required removal inactivation credits when
their UV reactors are operating off-spec or are offline.
It is recommend that EPA provide a clearer definition of the off-spec limitations and a specific provision
for meeting validation conditions in 90 percent of the water delivered for filtered water supplies, This is
critical for the design and operation of a UV system, and for utilities to maintain compliance with the
regulation. EPA is reminded that, in the vast majority of cases, falling outside validation conditions will
only be cutting into the built-in safety factors, and will therefore not be impacting the desired level of
health protection.
Comment Response for LT2ESWTR 8-356 December 2005
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Response: See Response 910.J.
EPA Letter ID: 667
Comment ID: 14014
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: 3. Filtered water supplies should not have to meet the same UV off-speclimitaion as unfiltered
systems since they already have a Crypto removal factor.
Response: See Response 910.J.
EPA Letter ID: 678
Comment ID: 14702
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: provided for filtered systems in the rule. The EPA should provide a clear definition of the off-
spec limitations and include a provision in the rule to allow the filtered systems to meet validation
conditions in 95 percent of the water delivered. In the vast
Response: See Response 910.J.
8.16.2 Comment Codes 920, Additional data on UV disinfection
Individual Comments on Code 920
EPA Letter ID: 560
Comment ID: 14988
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: American Water has conducted detailed inactivation studies of Cryptosporidium parvum
using accurate cell culture techniques (Bukhari et al. 2003). These studies have shown 4-log reduction of
Cryptosporidium infectivity at a dose of 4 mJ-cm-2. As outlined below, the excessive safety factors are
both unfounded and unnecessarily increase the cost of water treatment. EPA has not performed a
Response: See Responses 910.f and 910.h.
Comment Response for L T2ESWTR 8-35 7 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 624
Comment ID: 13208
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: energy costs. GCWW has conducted microbial inactivation studies using collimated beam
analysis. As presented in Figure 3, greater than 31og inactivation of Cryptosporidium was achieved at
dose of approximately 3 mj/cm2 for both low and medium pressure lamps. If GCWW wants to use the
[SEE PAGE 9 OF PDF FOR FIGURE 3]
Response: See Responses 910.f and 910.h.
8.16.3 Comment Code 921, Rule Language Edits
Individual Comments on Code 921
EPA Letter ID: 548
Comment ID: 12175
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Under subsection -Reactor Validation Testing,- after the first sentence of
the paragraph -Today-s proposal requires testing of full-scale UV reactors—
a sentence should be inserted that states -However, the State may allow for
an alternative basis for validating UV reactors.- This type of statement
would be a proper reminder for the States, and is consistent with other
sections of this Rule and the proposed UV Disinfection Guidance Manual.
Response: See Response lOO.a and 910.k.
8.16.4 Comment Codes 922, Guidance
Response to Code 922
Thank you for these comments on EPA's UV Disinfection Guidance Manual. EPA has considered these
comments in revising this guidance document. These comments do not address regulatory requirements in
the proposed or final LT2ESWTR.
Individual Comments on Code 922
Comment Response for L T2ESWTR 8-358 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 100
Comment ID: 10797
Commenter: Kemon Papacosta, ASTM Member D19, ASTM
Commenter Category: Unknown
Comment: I suggest additional information be added to 2.4.7 UVT monitor section, to include a further
explanation of the instrument design and a drawing eliminating possible confusion over the choice of an
acceptable UVT monitor to use for the EPA method.
2.4.7
Add to second paragraph...
In general, commercial on-line UVT monitors calculate UVT by measuring the UV intensity at one or
various distances from a lamp. Two examples of such monitors are displayed in Figure 2.17. In the first
monitor a stream of water passes through a cavity containing a LP lamp with three UV intensity sensors
located at various distances from the lamp. The difference in sensor readings is used to calculate UVT.
The second monitor measures at a fixed path length from the lamp (2.2 cm). This measurement is then
calculated and displayed as the transmittance at 1 cm. Lamp variation is compensated for with a reference
detector that is not in the sample path.
[See attachment for graphic (p. 3 of .pdf file)]
Response: Response 922.
EPA Letter ID: 101
Comment ID: 10913
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Use of Examples
NRWA encourages EPA to use examples throughout the guidance document. Relying on examples rather
than a range of numbers or figures provides maximum flexibility for communities to devise compliance
options unique to their circumstances.
Provide Small System Summary
The Agency should provide a five page summary of the entire guidance document and reference the
reader to specific sections for more details. This should not only be done for this document but also for all
the guidance documents related to these two rules. NRWA would be pleased to provide services for
EPA's contractor to write this summary.
Remove Rank Orders
In general, EPA should not be ranking technology or providing specific advice on how a treatment
technology would be optimally operated, designed or located in a treatment plant. Rather, the Agency
should be providing the pros and cons of each, enabling the community to decide what is best tailored for
their needs. The Agency should strive for providing the most options and maximum flexibility
for communities to decide what best meets their needs.
Specifically EPA should remove the rankings that recommend specific locations for placing UV
Comment Response for L T2ESWTR 8-359 December 2005
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treatment. In addition the statement referencing the "preferred" method should be removed. In section
3.1.2.1 the guidance states that "of the three options described, the combined filter installation is generally
preferred when conditions permit." Simply listing the pros and cons of each option will suffice.
In another location (Section 3.1.2.3) the guidance states that, "UV installations downstream of the clear
well are not recommended because of the increased potential for adverse pressure conditions within the
UV reactor and the increased reliability and size considerations." Again, simply listing these as cons will
suffice. EPA may be concerned of a broken treatment unit releasing contaminants into treated water but
with proper precautions these types of concerns can be completely overcome. Again, these should be
decisions made by the community.
Response: Response 922.
EPA Letter ID: 388
Comment ID: 10479
Commenter: Andreas Kolch,, WEDECO AG
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: 2.2.1, 2-2 Nature of UV-Light
The acceptable UV light range is referred to be 200 and 300 run. To be in consistence with German and
Austrian Standards, it should be 240-300 nm instead.
Table 2.1, 2-15 Mercury Vapor Lamps Characteristics
Which sources contributed to this table? Is this according to manufacturers data?
2.4.4, 2-17 Lamp Sleeves
Which sources contributed to the given dimensions in this chapter. We think, that this should be not
specified at it would be used from engineering companies.
2.4.4, 2-18 Lamp Sleeves
What is the source of the statement regarding the "microscopic fractures"? Would it not be more
appropriate to speak about "scaling" instead of "fouling"?
2.4.9, 2-22 Monitoring UV Disinfection Performance
The calculated UV dose approach should be questioned as this is virtually not possible to be determined
through the listed parameters and may cause severe misunderstandings with the operators.
2.5.2, 2-25 Byproducts from UV Disinfection
Recent research from Austria about mutagenic effects in the spectral emission range of medium pressure
lamps is missing in the list.
4.3.1, 4-7 Inlet and Outlet Hydraulics
What is the source of the 20% safety factor in conjunction with CFD predictions?
4.6.1, 4-17 UV Intensity Sensors
The spectral response from sensors should peak between 250 and 280 nm. Does this makes sense if the
Comment Response for LT2ESWTR 8-360 December 2005
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germicidal range is defined from 200 to 300 nm (s. 2.2.1)?
General
The following figures should be replaced more general schemes or the draft should show more examples
of different technological solutions for sensors, wipers, etc. Psychologically engineers, operators will tend
to take the examples given in the draft as the best solution, although the reasons for taken a certain picture
may be different, e.g. there was no other picture available:
Figure 2.10 UV Disinfection Schematic (Severn Trent)
Figure 2.11 Closed and Open Channel Reactors (Trojan)
Figure 2.15 Wiping System (Calgon Carbon)
Figure 2.16 Sensor (Severn Trent)
Figure 2.17 UV Transmittance Monitor (Severn Trent)
Figure A.20 Interior UV Intensity Sensor (Severn Trent and WEDECO)
Figure A. 23 UV Transmittance Monitor (Severn Trent)
Response: Response 922.
EPA Letter ID: 421
Comment ID: 10789
Commenter: David A. Poole,, David A. Poole Consultants, Ltd.
Commenter Category: Consultants: (where self-identified)
Comment: the broad subject of "Presentation ". I frankly don't see the hand of a conscientious Editor who
has gone through looking for flaws, conflicts, lack of clarity and repetition. And there is no reason why
there should be; after all this is a "Draft "; open to such comments as mine.
These presentation problems I view in the context of general recommendations for Report Writing. There
are dozens of books on Report Writing, supplemented by many dozens and dozens of seminars, training
sessions and the like. Many organizations publish their own internal Report Guidelines.
The common recommendation in most of these documents is "Clarity! Clarity! Clarity!"
One seminar I attended had the following statement (in a handout) on a test for Clarity. "Does the text
flow from beginning to end? Or is the reader forced, consciously or subconsciously, to retrace the lines,
reconsidering the sense of the text; mumbling: 'How was that again?'"
In this Report Writing material, Lack of Clarity (LoC) is variously described as'bafflegab', 'Haigspeak',
and also related to a marginal editing note, "Awk " (abbreviation of "awkward" I suppose) further defined
as: "Take this sentence to the shop for repair!"
I believe that there are some LoC problems in the Draft Manual and I have made some relevant
observations in my review comments.
Several other recommendations fall out of published material on Report Writing such as: "say something
once clearly, and don't try to repeat it: 'in other words '"
Examples of such repetition are noted in AA]-Table 3.4 vs. Appendix C -and may also be seen in the
following:
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- Section 3 'Planning and Design' has a number of pages discussing "Potential Locations" for the point of
UV reactor installation
- Appendix K Preliminary Engineering has a number of pages discussing "Potential Locations" for the
point of UV reactor installation
And it appears that Section 3 and Appendix K are written - understandably by different authors. There are
general differences and major differences in presentation. I wonder why Appendix K is an Appendix and
is not integrated with the Design Section?
Another example of repetition is:
- Section 4 is "Overview of Validation Testing "(21 Pages)
- Appendix C is "Validation of UV Reactors "(76 Pages)
- Appendix F is "Background to the UV Reactor Validation Protocol "(45 Pages)
There is a lot of uncoordinated overlap. Also I have to wonder how an "Overview", presumably intended
as some kind of summary, can consume 28% of the master document. One reason is straight duplication.
-Figure C. 4 is identical to Figure 4. 4 (except for a totally different figure title!)
-Both Appendix C and Appendix F contain a number of "examples" with numerical data. All useful, but 11
different and divided between the 2 Appendices.
I suggest that the Manual will be a lot more useable with some fairly ruthless editing.
Yours very truly,
David A. Poole M. Eng. P. Eng.
Life Member AWWA.
Comments AA]
Hvdraulic Configuration at the Facilitv Relative to Validation Configuration.
The following is extracted (scanned) from page 3-23 Chapter 3 of the Manual.
a], b], etc. are added for identification of the distinct paragraphs in the Table 3.4, in the discussions.
3.1.4.3 Equipment Validation Issues
The LT2ESWTR requires that UV reactors be validated (40 CFR 14 1. 729(d)). A utility's approach to
UV reactor validation will affect the UV installation design. The issues to consider are the hydraulic
parameters for validation and whether equipment will be validated on-site or off-site.
This section describes how these issues affect the design and installation footprint estimation. Chapter 4
provides an overview of validation, and Appendix C details UV reactor validation guidelines in detail.
Validation Hydraulics
The inlet and outlet hydraulics of the UV reactor can significantly affect dose delivery; therefore, the
following validation and corresponding installation strategies are recommended in the validation protocol
(section C.3.1.5)and are presented in Table 3.4.
Table 3.4 Summary of Recommended Hydraulic Configurations for Validation and Installation [see . pdf
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file for graphic, p. 3]
Option 1
Validation
The inlet and outlet configuration is the same as the installation for 10 diameters upstream and 5
diameters downstream of the W reactor, a]
UV Installation
The inlet and outlet configuration is the same as when the UV reactor was validated for 10 diameters
upstream and 5 diameters downstream of the UVreactor. b]
Option 2
The UV reactor is validated with a go-degree bend directly upstream of the UV reactor. The UV reactor is
defined to include a specific amount of straight pipe upstream or downstream of the UV reactor as
pecified by the UV manufacturer, c]
The UV reactor should be installed with a minimum of 5 pipe diameters of straight piping between the
UV reactor and any upstream hydraulic configuration. {This approach is not acceptable if the upstream
filling is an expansion or if the upstream valve will be used for flow control. A valve that will be
exclusively used for open/close service (e. g. . isolation)is acceptable. } d]
Option 3
The velocity at the validation facility is measured at evenly spaced points through a given cross section of
the flow upstream and downstream of the UV reactor e]
Velocity at the installation is measured at evenly spaced points through a given cross section of the flow
upstream and downstream and is within 20 percent of the theoretical velocity determined during
validation fj
Option 1 is most applicable when unique piping configurations are needed or if the inlet and outlet
conditions validated in Option 1 cannot be achieved because of site constraints. For example, Option 1
may be the only validation option for an individual filter effluent location, which probably does not have
5 diameters of straight pipe before the UV reactors (Option 2). because of existing site constraints.
The validation and installation of a particular UV reactor should meet one of these options. Option 2
provides more general applicability for validation and installation of UV reactors. For example, the inlet
and outlet piping configuration for installations in a new building could be designed based on how
the procured UV reactor was validated. Option 3 also provides flexibility but may have the practical
limitation of measuring the velocity through a cross section at the installation.
Off-site Versus On-site Validation
Manufacturers will likely validate UV reactors over a wide range of flowrates and water quality (e.g.,
IJVT)conditions at off-site testing facilities. The inlet and outlet hydraulic conditions during validation
will probably be selected so the UV reactors can be installed in most WTPs. . .
First note the LoC in the 2 paragraphs following and describing the Table. The lead-in sentence to the
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second paragraph applies to all the options and also this paragraph includes comments on Option 2 and
Option 3 merged.
What the reader needs is a logical presentation, say: The validation and installation of a particular W
reactor should meet one of the 3 Options noted in Table 3.4 above.
Comments on these Options:
Option 1 blah blah blah
Option 2 blah blah
Option 3 blah blah blah
Note too the invalid assumption (I have commented on this elsewhere) that: "Option 1 may be the only
validation option for an individual filter effluent location, which probably does not have 5 diameters of
straight pipe before the UV reactors (Option 2). because of existing site constraints "
An individual filter effluent location for a UV reactor does not necessarily mean an existing situation.
Turning to the text within the table, note the Lack of Clarity (LoC)in some of the wording. In particular c]
is a tester.
The UV reactor is validated with a 90-degree bend directly upstream of the W reactor (OK)
The W reactor is defined (by?) to include a specific amount (what can that mean under validation?
Reactor to "include"?) of straight pipe upstream or downstream of the UV reactor as specified
(specified?) by the W manufacturer
This c]and other portions of the Table 3.4~the whole of Option 3~cause major problems of
comprehension in the minds of the readers. As this section of the Manual notes a reference to Appendix C
(". . . the following validation and corresponding installation strategies are recommended in the validation
protocol (section C.3.1.5) and are presented in Table 3.4.") let's go there to see if that Appendix clarifies
any issues.
What we find is that Appendix C covers the same/similar options (called now "approaches ") described in
Table 3.4 (but not numbered Option 1, etc) using roughly the same amount of words but in cases
significantly different words, and also showing conflicts in wording. In table 3.4 the 3 given options are
split into two columns (validation and site configurations)which causes more comprehension problems
than does Appendix C which manages to describe the 3 options in one paragraph for each option.
In some cases—notably c]~the Appendix wording does provide considerable clarification of Table 3.4,
but in other cases no clarification.
A significant difference is that Appendix C allows using a "combination" of the 3 options which is not
mentioned in Table 3.4, although how to implement a 'combination' is a mystery unto itself.
The following is a verbatim extract from Appendix C, followed on the next page By a side-by-side
comparison, Option by Option, with discussion and comments.
Appendix C. Validation of UV Reactors C.3.1.5 UV Reactor Inlet and Outlet Conditions
As stated previously, the inlet and outlet structures to the UV reactor during validation should result in
equal or worse dose delivery than with the reactor installed at the WTP. EPA recommends using any one
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or combination of the following approaches:
-Inlet and outlet conditions used at the WTP match those used during validation for at least 10 pipe
diameters upstream and 5 pipe diameters downstream of the reactor.
-UV reactor is validated either with a 90-degree bend immediately upstream of the reactor inlet or a with
90-degree bend followed by a length of straight pipe immediately upstream of the reactor inlet. The
reactor is installed at the WTP with a length of straight pipe immediately upstream of the reactor equal to
5 pipe diameters plus any length used after the 90 degree bend during validation. To avoid jetting effects,
piping upstream of the straight pipe length should not have expansions for at least 10 pipe
diameters and any valves located in that length of pipe should always be fully open during operation of
the reactor. With this approach, it is assumed that the 90-degree bend immediately upstream of the reactor
inlet provides worse hydraulics than the installation. This approach assumes that the reactor design has
not been optimized for the 90-degree bend inlet.
-Velocity of the water measured at evenly-spaced points through a given cross section of the flow
upstream and downstream of the reactor is within 20 percent of the theoretical velocity with both the
validation test stand and the installation. The theoretical velocity is defined as the flowrate divided by the
cross-sectional area.
Text with Table 3.4 says "meet one option"; 'combination'not mentioned.
Comparison of Options Combining Table 3.4 and Appendix C [see p. 7 of. pdf file for graphic]
Table 3.4 Summary of Recommended Hydraulic Configurations for Validation and Installation and
Appendix C. Validation of UV Reactors
Option 1
Validation
The inlet and outlet configuration is the same as the installation for 10 diameters upstream and 5
diameters downstream of the UV reactor a]
UV Installation
The inlet and outlet configuration is the same as when the UV reactor was validated for 10 diameters
upstream and 5 diameters downstream of the UV reactor.b]
Appendix C. Validation
Inlet and outlet conditions used at the WTP match those used during validation for at least 10 pipe
diameters upstream and 5 pipe diameters downstream of the reactor, x]
a)The intent of a] is unclear as to 'chicken or egg'. It could be taken to mean that the validation is
completed after the installation, to validate that actual, or intended, configuration. Although possible, it is
difficult to believe that such a sequence would ever occur; that is, a number of manufacturers being asked
to validate a specific unique configuration just so presumably they can compete for procurement on that
project with a validated unit. The Appendix x] is unambiguous and logical; first know the validation
configuration and then match the installation to that.
b)The major drawback to the use of this Option is its absolute rigidity. The designer must choose his
installation configuration to be the SAME as (must MATCH) that of the known validation. First the
Designer may be contemplating using a number of alternative reactors all of which may have different
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validation configurations. Lets assume then that after the procurement process the preliminary design
configuration should be amended to conform to the validation configuration of the selected reactor. But
what if the validation configuration of the selected reactor is difficult, unsuitable or impossible for
the design configuration to achieve? Must the designer discard the selected reactor because he cannot
duplicate exactly (the SAME) the validation configuration of that reactor?
c) The wording of this Option does not allow the designer any judgment on "better" than validation
hydraulics. For example (real world case) in a filter gallery 3 diameters of straight pipe can be achieved
upstream of a reactor that was validated with a 90 degree bend immediately upstream. The 3 diameters
should logically provide better hydraulics than the bend but the designer may not use that configuration
since it would not be the SAME-he has to put a 90 degree bendimmediately upstream, to qualify as
SAME!
d) The downstream configuration spawns more problems of "sameness". If an installation configuration
has a tee, say 4 diameters downstream of the reactor then it will not qualify under this option unless the
validation of the reactor to be installed also has a tee 4 diameters downstream! The reason for the 5
diameters downstream requirement is unclear. A number of manufacturers have said that they are not
really concerned with downstream hydraulics, and also Option 2 has zero downstream requirements.
e) Overall the SAME configuration is nearly impossible to comply with. For example, look at a bank of
parallel reactors which the designer wishes to use with inlet flow-splitting weirs (Page 3-33 of the
Manual) How will he find a reactor that has been validated with a valve and a weir upstream? Without
that (even ignoring the downstream conditions)the installation cannot qualify as SAME.
f) Perhaps the irony of this Option 1 is that it is noted as: ". . . most applicable when unique piping
configurations are needed or if the inlet and outlet conditions validated in Option 1 (may be typo? Option
2 intended?) cannot be achieved because of site constraints. For example, Option 1 may be the only
validation option for an individual filter effluent location, which probably does not have 5 diameters of
straight pipe before the UV reactors (Option 2). because of existing site constraints. "
Option 1 is hardly suitable for "unique piping configurations" unless the Designer can find a reactor
whose validation configuration had the SAME uniqueness as the installation. Although seemingly
intended to address the unique situations, the use of Option 1 is between 'problematical' and 'impossible'
for virtually all situations.
Option 2 [see p. 9 of .pdf file for graphic]
The UV reactor is validated with a 90 degree bend directly upstream of the UV reactor. The UV reactor is
defined to include a specific amount of straight pipe upstream or downstream of the UV reactor as
pecified by the UV manufacturer c]
The UV reactor should be installed with a minimum of 5 pipe diameters of straight piping between the
UV reactor and any upstream hydraulic configuration. 1} l}This approach is not acceptable if the
upstream fitting is an expansion or if the upstream valve will be used for flow control. A valve that will
be exclusively used for open close service (e.g. isolation)is acceptable, d]
UV reactor is validated either with a 90-degree bend immediately upstream of the reactor inlet or a with
go-degree bend followed by a length of straight pipe immediately upstream of the reactor inlet. The
reactor is installed at the WTP with a length of straight pipe immediately upstream of the reactor equal to
5 pipe diameters plus any length used after the 90-degree bend during validation. To avoid jetting effects,
piping upstream of the straight pipe length should not have expansions for at least 10 pipe diameters and
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any valves located in that length of pipe should always be fully open during operation of the reactor. With
this approach, it is assumed that the 90 degree bend immediately upstream of the reactor inlet provides
worse hydraulics than the installation. This approach assumes that the reactor design has not been
optimized for the 90-degree bend inlet, y]
a) Appendix C, y] clarifies the LoC wording of c]to a large extent, albeit with a conflict, c] states "straight
pipe upstream or downstream", while y] ignores the downstream configuration (as does d])
b) The statement in y]:"With this approach, it is assumed that the 90-degree\bend immediately upstream
of the reactor inlet provides worse hydraulics than the installation. This approach assumes that the reactor
design has not been optimized for the 90-degree bend inlet." is not clearly understood. Since the
installation is required to have 5 diameters of straight pipe upstream of the reactor even when the
validation was made with the bend immediately upstream of the reactor, the reason for stating an
"assumption" of "worse hydraulics"is unclear.
Why the reactor is assumed not to be optimized for the 90 degree bend is unclear. Many manufacturers
are validating and optimizing their reactors with a 90 degree bend immediately upstream.
c)The contingency length of 5 diameters makes this Option onerous and presents practical difficulties.
Assume a bank of parallel 1200 mm/48" UV reactors between an inlet manifold and outlet manifold.
Assume that two UV reactors being considered have validation with (in one case)a bend immediately
upstream and in the other case with 5 diameters of straight pipe upstream.
The relative installations required under this Option would be:
Case l:upstream straight piping 6. 0 m/20 ft.
Case 2:upstream straight piping 12. 0 m 740 ft
Does EPA consider that these kinds of installations represent reasonable expectations/requirements? This
especially as many manufacturers are validating their units with an 90° bend immediately upstream, with
the thought that their equipment would be used in retrofits in tight areas. The additional 5 diameters for
"contingency" hydraulics can nullify that approach completely in many real life situations. What is the
point of a validation with a 90-degree bend immediately upstream of the reactor if the actual installation
can not be configured to take advantage of this, but is required automatically to have an added
contingency length of 5 diameters of straight pipe?
Option 3 [see p. 10 of .pdf file for graphic]
The velocity at the validation facility is measured at evenly spaced points through a given cross section of
the flow upstream and downstream of the UV reactor e]
Velocity at the installation is measured at evenly spaced points through a given cross section of the flow
upstream and downstream and is within 20 percent of the theoretical velocity determined during
validation fj
Velocity of the water measured at evenly-spaced points through a given cross section of the flow
upstream and downstream of the reactor is within 20 percent of the theoretical velocity with both the
validation rest stand and the installation. The theoretical velocity is defined as the flowrate divided by the
cross-sectional area, z]
a) What is a "given" cross section? Who 'gave' (determined) this?
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
b) What means "at evenly spaced points through a given cross section". A cross section is a plane. Must
velocity be measured at points across the whole plane? Commonly velocities are measured at points
along a diameter to give the velocity profile and hence the average velocity (say by insert pitometer tube,
or insert wand style, magnetic flow meter). How many points are required? Are say, just 2 "evenly
spaced" points OK?
c) In f] "theoretical velocity" could be challenged~in the absence of a definition~for logic since surely
some actual velocity would have been determined during validation by field measurements? However,
z]does provide a definition which really confuses the issue. "The theoretical velocity is defined as the
flowrate divided by the cross-sectional area." It is unclear how this differs from the normal pipe
hydraulics of Q=AV . And there of course, the V is the average velocity of the flow Q. Neither Q nor A
requires measurement of a number of points through the cross section. For example Q may be determined
with a flow meter of good accuracy well upstream of the UV installation. Is "theoretical velocity" as
defined not really "average actual velocity"? How do we get from the measured velocity at the x number
of measurement points to the flowrate? Average them? Multiply the average by the cross-sectional area?
d) In the absence of any definition "within 20 percent of the theoretical velocity" is a "given" i. e. will
always be achieved, since the average velocity by flow meter (or even by a profile along a diameter)is
virtually certain to be within 20% on a V=Q/A basis. The intent of this Option is not readily discernable
since the target is stated to be just within 20%of the velocity in the overall cross section??
Let me step back and make a wild guess about possible reasons, logic, thinking ....
Assume the overall idea is to match the field installation to the validation in Some way so that the
Designer can reasonably assume that the proposed installation will hydraulically perform similarly to the
validation set-up. In other words the designer can take the validation data for a UV reactor and say
with some confidence:
"... because I match the validation hydraulics in "this" way, I can reasonably assume that the
performance validation data is applicable to my installation
So one way that I can match the validation hydraulics is to mimic in my installation the degree of
turbulence and erratic flow lines and velocity variations present in the validation set-up. To achieve this
mimicry I must first find out what the "original" was. Yep! The validation did determine some type of
velocity profile by "qwqwqw "(That is, in this speculative case. Don't see that the measurement of
velocities upstream and downstream over the cross section is mandatory in a validation) So what if
I run similar (or identical) flow measurements in the full scale installation? And if the field profile is
within 20%of the velocity at all points in the validation profile, then I should be OK? Yes? Maybe? What
if most points match nearly perfectly but a couple of points are off by 23%?
Now I have no idea if that line of thought is even close to the intent, but I can say with some certainty that
this option 3 should be rewritten to state (without LoC) exactly what the intent and required procedures
are. And this should be written clearly in just one place, to avoid taxing the reader/user with the
duplication and conflicts between Table 3.4 and Appendix C
e)The 2nd. paragraph of text accompanying table 3.4 notes: "Option 3 also provides flexibility, but may
have the practical limitation of measuring the velocity through a cross section at the installation"
However, it is doubtful if this Option 3 gives much "flexibility" at all and it is not that "limitation to
measurement of velocities "on site is the supreme headache for the Designer, but rather the potential
venture into an area of gross uncertainty.
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
With this option a reactor has to be selected and installed based on faith that later field measurements of
velocity will allow the validation data for that reactor to be applied the actual installation.
And a few general wrap-up comments
Note, the statement in the Manual: "The inlet and outlet hydraulic conditions during validation will
probably be selected so the UV reactors can be installed in most WTPs ..." That is true and the strategy
of the manufacturers is obvious: validation is expensive and time consuming so we had better validate
with poor hydraulic conditions so that the designer has a wide choice as to how to configure the piping in
the designed facility to accommodate OUR reactor. The draft Manual does not enable a designer to avail
himself of the poor hydraulic conditions used in the validation, so the intentions of the manufacturers are
nullified.
Overall note some of the fuzzy choices available to a designer
If validation was made with a 90° bend immediately upstream then: -must use that 90 °bend immediately
upstream; no straight pipe may be used even if feasible. (Option 1) and must use "same" downstream
configuration for 5 diameters.
-must not use that 90° bend immediately upstream but must use a length of straight pipe (Option 2)and
can ignore all of downstream conditions
-and the Designer will be terrified to attempt Option 3 because of the massive uncertainty of only being
able to determine that the reactor installed is validated, until after site velocity measurements are made.
A random thought. . . what is a 90° bend? There will be hydraulic differences between short and long
radius; smooth and segmented; bends. No mention is made of these differences.
This issue-how can I make a design hydraulically compatible with the way the reactor was validated~is
of key importance to every Designer. From my analysis I believe that the issue deserves a fresh look by
EPA.
Comments BB] Selection of the point of UV application within the process train To come
Response: Response 922.
EPA Letter ID: 422
Comment ID: 10791
Commenter: Alexander Cabaj,, Institut Fur Medizinische Physik Und Biostatistik,
Veterinarmedizinische Universitat
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: Comments concerning the Ultraviolet Disinfection Guidance Manual:
Page IX, germicidal effectiveness
"This value is usually approximated by the relative absorbance of DNA at each wavelength,..."
The DNA-curve corresponds very badly to real microbicidal curves, it should not be used.
Comment Response for LT2ESWTR 8-369 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Low Pressure (LP) Lamp
The international unit of pressure is the Pascal (Pa), Torr should not be used, it is an old unit. The same
holds for Medium Pressure (MP) Lamp.
Page XI
"Reduction Equivalent Dose (RED)-a calculated dose " should be replaced by a measured dose because
the RED is measured in usingmicroorganisms
Page XII
4th line from below: "In" should be replaced by "If.
Page XIII
e "exponent of the" should be deleted
Page XIV
replace hertz by Hertz
replace joule by Joule
replace kW-hr by kWh
Page XV
replace Osterreichisches Normungsinstitut (Austrian Standards Institute) by Osterreichische Norm
(Austrian Standard)
Page XVI
replace watt by Watt
Page 1-7
Table 1.4: no unit of dose is given
Page 2-3
line 8,10,13: use Pa instead of Ton-
Page 2-5
UV absorbance
The mathematical definition of absorbance should be given: [See .pdf file for equations]
Page A-4
Use Pa instead of Torr (twice)
General remark: many topics in Appendix A were already treated earlier. As the complete document is
very long there would be a possibility to shorten it.
Page A-17
Equation A. 12
If e is used instead of 10 as basis, the constants k254 and d254 are different in these two cases. I think the
basis 10 is more convenient to use and is used more than e in this connex. Equation A. 12 should read:
[see .pdf file for equation]
where
k-eff and d-eff are effective values, D is the unweighted dose The sum term should be deleted.
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Page A-19
For the definition of the RED a reference to Cabaj et al. (1996) (see page F-44) would be useful and the
connected definition formula for the RED also should be given.
Page A-22
Equation A.20 should read:
[see .pdf file for equation]
Page B-16
Table B.2: the unit of the dose should be given.
Page C-5
The ONORM M 5873-2 for medium pressure lamps has been published and should be mentioned here.
Response: Response 922.
EPA Letter ID: 474
Comment ID: 11204
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: Current UV disinfection technology uses mercury in the reactor lamps as the source for the
ultraviolet radiation. While risk of exposure is minimal in the event of breakage, even in multiple failures,
there is, nonetheless, the public perception of extreme risk in any release into drinking water. The
solutions offered in the Guidance Manual, i.e. quick closing valves, downstream containment, etc., aren-t
ideal. To suggest so is misleading. A belter approach would be to emphasize safe handling; spill
prevention and response planning in the Manual, and provide a public acknowledgement of exposure risk.
Response: This comment addresses EPA guidance and not regulatory requirements in the LT2ESWTR.
EPA has considered this comment in developing the final UV Disinfection Guidance Manual.
EPA Letter ID: 485
Comment ID: 11322
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: Overall, the guidance document is extensive. It provides the reader with a great
deal of information on UV disinfection, covering the fundamentals and principles well. However, the
focus of the guidance manual should be on theapplication of UV with intended audience being the state
regulators and utilities, whom the USEPA is counting on to implement this disinfection strategy. While
the background provided in the guidance is good, there are several areas of application that need
additional work or supplemental material.
While there is general support for the overall approach, basing validation and assignment of RED and the
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use of a statistical analysis of the data to improve and aid data interpretation, there are areas of the
document that need further clarification and guidance from the agency. The Department offers the
following comments in an effort to bolster the utility of the guidance manual to the states and utilities that
would use it.
Response: Response 922.
EPA Letter ID: 485
Comment ID: 11324
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: 2. The UV guidance provides a range of collimated beam dose response curves for B. subtilis
and MS2 phage. The guidance provides methods for growing these cultures, harvesting, and using them
for bioassays. What the guidance lacks is a clear definition or standard as to what constitutes an
acceptable dose response curve for either of these organisms from a collimated beam test? The suggested
boundaries are not clearly defined and as stated in the guidance manual is too wide to be acceptable (if the
tolerance suggested is accepted, the potential for sizing differences between systems will create an uneven
playing field for UV manufacturers and may also leave some water systems with UV systems nadequately
sized for the flows.) Without such a standard, there can and will be a high degree of variability between
bioassay results, which will subsequently impact the RED. This will also lead to confusion and variability
in the water and UV industry as to what constitutes an acceptable UV system and what constitutes an
adequate design between UV systems. One objective is to attain comparability between manufacturers.
Granted there will be some variability between microbial cultures, that is just the inherent nature of
biological materials. However, not to define an acceptable performance standard dose response curve,
such as was done in the NWRI/AWWARF UV Disinfection guidelines, has the potential for creating
major problems in the interpretation and implementation of UV as a disinfection technology.
The Department already knows there is variability in the dose response curve for any microorganism.
This variability does not appear to be accounted for in the error analysis outlined in the guidance manual,
which accounts for the variability in the pilot study results, but not the collimated beam test. Hence,
the dose response curve that is used as a reference could vary markedly between manufacturers, or
manufacturers could conduct tests that would show equipment performance in the best light.
The Department has seen problems with seed microorganisms that would have resulted in much better
performance being credited to the UV system based on a bioassay conducted using an organism that was
more susceptible to UV than the intended target. Unfortunately the seeding was conducted assuming the
correct organism was seeded in the reactors. If it had not been for the standard curves the problem might
not have been investigated.
The Department has also found radiometer calibration to be a problem. Dose response curves are strongly
influenced by the calibration of the radiometers. An improper radiometer can result in a significant error
in the RED, again, which is not necessarily compensated for by the uncertainty analysis outlined in the
UV Guidance manual. Maybe USEPA should consider working with the US Bureau of Standards to
tighten up their radiometer calibration or acceptability
criteria.
Comment Response for L T2ESWTR 8-3 72 December 2005
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The Department suggests that the USEPA set standards for the dose response curve and radiometer
calibration to ensure uniformity in the production of UV reactor bioassays to aid the states in their
evaluation of UV technologies. Such a strategy might be implemented through the Small Water
Treatment Systems segment of your ETV program.
The ETV program may be the other venue in which some comparability between test results may be
attained.
Response: Response 922.
EPA Letter ID: 485
Comment ID: 11326
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: 4. Flow measurement for the pilot systems is covered in Appendix C and Section 3.3.1.2,
what about criteria for flow meter calibration; also how frequently should the calibration be done and
checked?
5. Should not axial dispersion be considered in the design section? In-line reactors may appear to behave
like plug flow reactors, but with axial dispersion their performance will deviate from the ideal. Short-
circuiting will impact performance and depending on the degree of axial dispersion and the rate of
inactivation the target organisms will be inactivated to different degrees. How does one assess whether or
not all the individual microbiological water quality objectives are met? Should the hydraulic
characteristics of the reactor be determined, like they were for the other chemical disinfectants?
Pg 4-5 of the guidance manual requires utilities installing a prevalidated UV reactor to ensure the
validation conditions are appropriate for their plant operations, but no guidance is given to the states to
identify those critical conditions and appropriate values. The factor controlling reactor design may
change based on scaling or other site-specific factors. Like the tlO/T correction factors given in the
SWTR Guidance Manual, similar guidance should be provided for the UV reactors.
Pg 4-8: The RED requirements in the USEPA guidance are based on MS2 phage. Since the agency
includes B. subtilis dose response information and allows its use, shouldn-tthe agency provide a similar
set of RED requirements based on B. subtilis? We would presume the RED for B. subtilis be different
because the dose response is different from MS2?
Pg 4-9: The challenge organisms are to be prepared in accordance with a peerreviewed method. It is
critical for the USEPA to define these standards. This should be a standard method or the method should
produce a microorganism that responds to UV radiation in a manner described by a standard dose
response curve. What constitutes an adequate peer review? There should be no flexibility in QA/QC!
Pg 4-11: The guidance calls for sample collection, but provides no criteria for determining when or how
sampling should be determined to be representative of the reactor contents.
Pg 4-12: The guidance manual uses the term statistically different, but fails to define what criteria should
be used for determining the level of difference. The confidence level and degree of difference desired are
required in order to define what is going to be statistically different.
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Pg 4-13: The guidance suggests different means of curve fitting. Only one method of curve fitting should
be allowed for each possible seed organism and the curve should not be forced through zero. While it is
true that no UV exposure should not yield any inactivation, the regression line should reflect the inherent
variability or uncertainty in the performance of the UV reactor. Between zero and a minimum UV dose
the organism response is not reliable because degree of inactivation is lost in the variance of the analytical
response of the assay.
Pg 4-21: The document ends rather abruptly, was something left out?
Pg C-26: In the example, it would be helpful if at least one of the bullets was worked out in detail so the
reader could see how the numbers were derived. What are the criteria for establishing steady-state in the
system?
Pg C-27: The criteria for the trip control states the numbers should be the same at the 90 percent
confidence level, but does not provide a number of samples or limit. The 90 percent confidence level is
fine, but incomplete. The limit of the difference between the values that would be acceptable or the
number of samples also needs to be specified.
Pg C-28: Can the regression coefficients be at the 95% confidence level and the confidence interval for
the regression line be 80%?
Pg C-29: What were the coefficients used to derive the values in the lower table?
Pg C-38: Under the flow measurement section there is a requirement for precision, i.e., 5 percent at 80
percent confidence level, but there is no requirement for accuracy. The precision requirement is correctly
stated, but a requirement for accuracy is equally important. Inaccurate flow measurements may result in
operation outside the appropriate flow range.
Pg C-49: The readers might be interested in knowing the 1.28 coefficient in equation C. 14 comes from a
statistical table where n= ? and ? = 0.20.
Pg N-l 1 contains a statement that the utility should contact their primacy agency for a list of local
recycling agencies. While they can do this, they might not necessarily get a response. Recycling is
typically handled through a resource agency, like Cal EPA. However, the primacy agency may not be in a
resource agency, but in a health agency and may not have direct access to such information. In addition,
many recycling programs are local and better advice might come from the local county or city recycling
agency. Perhaps the statement could be expanded to give the reader a fuller range of potential sources of
information, not just assuming the primacy agency has the knowledge to address the issue.
Response: Response 922.
EPA Letter ID: 486
Comment ID: 14168
Commenter: Christopher R. Schulz, Drinking Water Practice Leader, CDM, Inc.
Commenter Category: Consultants: (where self-identified)
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Comment: UV Disinfection Guidance Manual
3.1.4.3 Equipment Validation Issues
4. Include a table on the advantages and disadvantages of onsite vs. offsite validation. Clearly, the
industry trend will be to use offsite validation testing, since the equipment manufactures will cover theses
costs for their various reactor designs, and it reduces the risk of reactor failure by completing offsite
testing prior to installation. Use of CFD modeling for predicting impacts of technology or operational
changes (e.g., new lamps with different spectral outputs, changes in reactor design flows, changes in
instrument setpoints, etc.) for operating UV facilities should be considered by EPA and state primacy
agencies to avoid the need for additional offsite validation testing after a system is operational. One
approach would be to develop a calibrated CFD model for a given reactor design based on validation
testing results and use the calibrated model for predictive validation testing of any future changes to the
reactor design conditions.
3.3.3.3 UV Intensity and Calculated Dose
5. This section recommends continuous monitoring of UV intensity sensor output to determine adequate
dose delivery. However, the main purpose of UV intensity sensors is to monitor the reduction in lamp
output overtime and to compare these measurements against validated UV intensity setpoints. Since the
degradation of lamp spectral emissions occurs only gradually (typically over a period of 6 to 12 months
depending on whether MP or LPHO lamps are used), continuous UV intensity measurements are not
necessary for routine disinfection monitoring. In fact, continuous exposure of the UV sensor to UV light
can lead to premature failure of sensor cutoff filters, increased measurement uncertainty, and inaccurate
dose delivery measurements. Therefore, the UVDGM should include a balanced discussion of the
advantages and disadvantages of continuous and intermittent UV intensity monitoring, including impacts
on UV sensor performance. Note that new types of actinometry-based UV intensity sensors are currently
under development that would be operated intermittently (say every 4 hours) to improve the reliability of
UV intensity sensor measurements. Photocell sensors operated intermittently with shutters (to avoid
excessive UV exposure) would also help to improve the reliability of sensor measurements.
3.3.4.2 Backup Power Supply
6. There are significant differences in the susceptibility of lamp ballasts to power quality fluctuations. For
example, Calgon Carbon claims that its magneticballasts can operate at a voltage surge of plus 15 percent
and voltage dip ofminus 30 percent, whereas electronic ballasts supplied by WEDECO and Trojan
can only handle voltage swings of plus/minus 10 percent. Therefore, the UVDGM should discuss field
test procedures for confirming claims of manufacturers with respect to power quality, which could be
performed by the Contractor during start-up of a UV system (e.g., forced power surges and dips
to individual UV reactor power supply cabinets). This would allow design engineers to make confident
decisions on whether back-up power supplies are required, and put the burden on the manufacturer to
back-up power quality claims during start-up.
4.2.3 Third-Party Oversight
7. Reactor validation testing is the most critical requirement in the LT2ESWTRto demonstrate that UV
reactors will achieve dose delivery requirements. Third party oversight by certified test facilities is
essential to ensure defensible validation testing results. We therefore recommend that the third party
oversight recommendation in the UVDGM be included as a requirement in the LT2ESWTR.
Furthermore, EPA should establish a program to certify all third party test centers and the test protocols
used for validating UV reactors for drinking water disinfection applications.
4.3.2.2 Control Strategies
8. Three dose delivery control strategies are listed in this section and further explained in Appendix C.
For any control strategy, UV intensity measurements are required to calculate delivered UV dose. Most
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UV reactor designs include multiple UV intensity sensors, either one sensor per lamp (MP systems) or
one sensor per row of lamps (LPHO systems). To ensure that UV dose delivery measurements are
monitored conservatively by the vender-supplied UV dose control program, the UVDGM should require
that only the UV intensity measurement for the weakest lamp in the reactor be used for these calculations.
For reactors with one sensor per lamp, the programmable logic controller (PLC) for the reactor should
automatically select the sensor with the lowest reading and use this measurement for calculating the
delivered UV dose for the entire reactor. For reactors with only one sensor per row of lamps, periodic
monitoring of all lamps should be practiced to ensure that the weakest lamp is monitored for UV dose
calculations.
4.5.4 Determining Inactivation Credit
9. The Tier 1 reduction equivalent dose (RED) targets are 15-18 percent higher for medium pressure (MP)
reactors than for low-pressure high-output (LPHO) reactors due to the application of a polychromatic bias
safety factor for MP lamps. This difference is significant and unfairly penalizes MP reactor designs.
Since Tier 1 criteria will likely be specified by engineering consultants and required by state regulatory
agencies for most projects, this bias needs to be corrected to maintain a competitive bid situation on
projects and avoid any claims by equipment suppliers of MP reactors. Accordingly, we suggest that a
default polychromatic bias factor of 1.0 be used for both LPHO and MP reactors and that all venders be
required to submit documentation (e.g., lamp aging data showing spectral shifts) to support use of this
factor (or a different factor) in assigning the delivered UV dose at end-of-lamp life for a particular reactor
design. This will allow use of a single RED target table for both types of reactors, which will avoid
confusion and potential protests by UV equipment suppliers.
4.6.1 UV Intensity Sensors
10. The Tier 1 Criteria for UV intensity sensors are too restrictive and cannot be met using standard UV
reactor designs supplied by several major UV equipment venders. Specifically, the restrictive criteria
include:
- Location of UV sensor
- UV sensor spectral response
- NIST traceable measurements for duty and reference sensors
Until consensus-based industry standards are established for UV sensor performance specifications, these
criteria should be relaxed or eliminated to allow all major UV equipment venders to bid on projects using
Tier 1 criteria. Following completion of the ongoing AWWARF Project 2977 (Development of
Performance Guidelines for UV Sensors), which will establish industry standards for sensor performance,
more specific criteria on UV sensor design requirements can be incorporated into future federal and state
regulations.
11. The Tier 1 Criteria calls for a higher number of UV sensors for MP reactors (one sensor per lamp)
compared to LPHO reactors (one sensor per bank of lamps). This unfairly penalizes MP systems and
further increases sensor monitoring and calibration requirements for MP reactors. The Tier 1 criteria
should therefore include the option for allowing MP and LPHO systems to monitor the weakest lamp in a
bank of lamps and to use this measurement for calculating the delivered UV dose, as discussed under
Comment 8. This would provide equipment suppliers with flexibility to develop different sensor
configurations based on meeting this requirement, and possibly reduce the number of duty sensors
required per reactor. However, UV reactors should be designed with the capability to periodically monitor
the irradiance output of all lamps in a reactor, regardless of the type of reactor, to demonstrate that the
weakest lamp is always monitored for calculating delivered dose. This can be accomplished by providing
sensor wells for each lamp in MP reactors (for periodic monitoring by a reference sensor) and use of a -
UV sensor stick- for LPHO reactors (the latter is currently under development by WEDECO).
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5.3.2.2 UV Intensity Sensors
12. This section states that the reference sensor specification should exactly match that of the duty sensor
so that the calibration of the duty sensors can be accurately verified. Matching duty and reference sensor
specifications is desirable if a photocell-type duty sensors are used, but is not required if an actinometry-
based reference sensor is used. Research completed by Veolia Water has demonstrated a strong
correlation between photocell and actinometry sensors for monitoring polychromatic emissions from MP
lamps. Given the advantages of actinometry-based reference sensors for verifying the calibration of
photocell sensors (i.e., no instrument drift, excellent repeatability, ease of use), the use of this type of
sensor for verifying the calibration of a photocell duty sensor should be discussed as an option in the
UVDGM.
13. This section discusses a step-by-step procedure for checking the calibration of on-line duty UV
intensity sensors using a calibrated reference sensor of the same type. This section should conclude with a
brief discussion of other types of sensor calibration techniques currently under development by the UV
industryincluding actinometry based reference sensors (Schulz, et.al. 2002) and use of aNIST-traceable
lamp for calibration of duty sensors (Severn-Trent Services, unpublished communication).
5.4.1 Monitoring and Recording Frequency for Compliance Parameters 14. Table 5.5 lists the parameters
to be monitored to determine off-specification events. As discussed under Comment 8, the UV intensity
of the weakest lamp in a reactor should be monitored and recorded to determine UV dose delivery and
off-specification performance periods. UV intensity measurement of other lamps (with higher emission
outputs) do not need to be recorded or reported to the state primacy agency. This approach will provide a
conservative measurement of UV dose delivery and simplify monitoring, control and reporting
procedures.
Response: Response 922.
EPA Letter ID: 489
Comment ID: 11177
Commenter: Ludwig Dinkloh,, WEDECO AG Water Technology
Commenter Category: Manufacturer/Vendor
Comment:
General comments had been provided by Andreas Kolch (see IUVA News Volume 5/ No. 4). The
following are more specific reg. the actual contents of the Draft UV Disinfection Guidance Manual.
[SEE TABLE IN PDF]
Response: Response 922.
EPA Letter ID: 494
Comment ID: 11179
Commenter: Keith Bircher,, Calgon Carbon Corporation
Commenter Category: Manufacturer/Vendor
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Comment: Comment:
[SEE PDF]
Response: Response 922.
EPA Letter ID: 510
Comment ID: 11825
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: The UVDGM is a significant document that supports introduction to the USA of technology
to treat drinking water with ultraviolet light. This technology has been in use internationally for some
time, and is starting to be implemented in the USA now. That significant expertise has gone into
preparation of this comprehensive draft manual is clear. The UVDGM is a credit to the EPA and the
authors and contributors to the manual.
Further questions regarding this submission may be addressed to my attention.
Linda Gowman, Ph.D., P.Eng.
Overview ... 4
1. Weaknesses of the UVDGM ... 4
1.1 We are concerned about safety: there are cases when the Tierl/Tier2 approach, which uses a default
dose distribution in the implementation of an RED bias, is not safe and would compromise public health.
These instances cannot be identified using the procedures currently outlined in the manual ... 4
1.2 Safety factor calculations in the UVDGM do not ensure safety ... 6
1.3 Equipment safety factors are inaccurately applied against microbiological targets ... 6
1.4 It is not possible to complete the safety factor calculations currently prescribed in the draft manual. . .
7
1.5 Some prescribed safety factors - the Expanded Uncertainty terms - are not calculated correctly ... 7
1.6 The concept of a Tierl/Tier2 approach is problematic ... 7
1.7 The reference to adenovirus as a target design pathogen for UV may confuse State regulators and UV
practitioners who read the UVDGM ... 8
1.8 The UVDGM is not universally applicable to all UV technologies ... 8
2. Recommendations to Overcome Weaknesses of the UVDGM ... 8
ELIMINATE THE TIER 1 AND TIER 2 SYSTEM INSTEAD: ... 8
2.1 Be clear that the objective is to reach logs reduction of a specific pathogen ... 8
2.2 Separate equipment safety factors from site safety factors ... 9
2.3 Validation hydraulics: conduct equipment validation which is not influenced by site geometries ... 9
2.4 Site hydraulics: site-specific installation geometries are the responsibility of a professional engineer . .
. 11
2.5 Equipment Expanded Uncertainty: quantify this based on equipment performance, not component
performance ... 11
2.6 Do not allow an RED Bias calculation when the dose distribution is not known. ... 11
2.7 Allow RED Bias calculations when the validated dose distributions are known ... 12
2.8 The polychromatic bias term should be eliminated ... 12
2.9 Safety factors for the site should be established by the engineer 13
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ACCEPT INNOVATIONS ... 13
SUMMARY ... 13
REFERENCES ... 14
Appendix 1: A discussion suggesting that adenovirus should not be the target design organism for
disinfection by UV ... 16
Appendix 2: Detailed Suggestions for Changes ... 25
Appendix 3: A High Level Protocol for the Validation of UV Disinfection Equipment... 33
Appendix 4: Validation Alternatives for the USEPA UVDGM ... 37
Appendix 5: Comments in response to the LT2ESWTR ... 61
Thank you for giving us the opportunity to provide comments on EPA 815-D-03- 0076, June 2003 Draft,
USEPA Ultraviolet Disinfection Guidance Manual.
In this document we outline issues that we feel are weaknesses of the draft manual, and propose solutions.
Further details to the principal arguments and specific comments of other substantive and clerical matters
are attached in Appendices.
Overview
We have undertaken what we believe is a thorough review of the USEPA UVDGM and base our
comments on the assumption that the draft manual is based on the following guiding principles:
1. The primary principle is to protect public health.
2. UV reactors should be empirically tested to guarantee performance
3. Testing of UV reactors should result in universal validation; i.e., reactor safety factors with no site-
specific variables should be determinable during validation
4. Protocols should support and not hinder innovation and technology evolution
5. Guidance should be easy to understand and not overly complex, to promote technology acceptance and
responsible implementation
Based on the above guiding principles, we identify weaknesses in the UVDGM within Section 1 and
advocate changes and alternatives within Section 2. The appendices provide further detail.
1. Weaknesses of the UVDGM
We feel that the following issues should be considered thoroughly.
1.1 We are concerned about safety: there are cases when the Tierl/Tier2 approach, which uses a default
dose distribution in the implementation of an RED bias, is not safe and would compromise public health.
These instances cannot be identified using the procedures currently outlined in the manual.
The default dose distribution in the UVDGM was taken from work on an open channel wastewater system
(ref: Chui et al) that is quite different and therefore of unknown relationship to a drinking water system
that is pressurized and downstream of a 90° bend of the recommended testing setup in the UVDGM).
The default dose distribution is an unknown characterization of any given reactor during operation: dose
distributions will be different for every reactor model, for different installation hydraulics, and for any
changes in operating variables (flow rate, UVT, power setting).
Because dose distributions are a function of reactor design, hydraulics, and operating variables, the
default dose distribution cannot be taken to be worst case and the protection of public health is not
guaranteed.
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Without knowledge of the dose distribution, a RED Bias cannot be calculated. Furthermore, the default
dose distribution is not the worst-case: dose distributions for an existing drinking water reactor that are
worse than the default are shown in Figure la. Figure Ib shows the associated RED bias that would be
calculated for given challenge microbes using the commercial reactor dose distribution of Figure la and
the UVDGM default dose distribution. Using the default would result in a smaller RED Bias value than
truly exists, leading to unsafe undersizing.
[SEE FIGURES la AND Ib, PAGE 5 IN PDF]
Figures la and Ib. Figure la shows the dose distribution of a commercially available reactor whose dose
distribution is worse than the default distribution in the draft guidance manual. Figure Ib shows that use
of the dose distribution in Figure la predicts a RED Bias value that would result in aggressive sizing
relative to the proposed default in the draft guidance manual: hence this sizing would not be safe.
We believe that it is not possible in principle to produce a dose distribution -for all time and all cases-
that guarantees that public safety is protected. The argument that -reactors with dose distributions worse
than the default in the draft manual would not be sold because they would not be competitive- is neither
accurate nor compelling.
1.2 Safety factor calculations in the UVDGM do not ensure safety
The calculations of safety factors rely on incorrect/unsafe assumptions.
As stated earlier, the RED Bias calculation uses a default dose distribution which in itself is not
representative of drinking water systems, and is not the worst case dose distribution, thus compromising
public health.
The Polychromatic Bias quantifies an effect that has never been demonstrated to be significant, and uses
default reactor geometries in its calculation which also may not be worst case. Based on our research, we
believe that this is very small in magnitude. The calculations in the draft manual pre-suppose that UV
reactor monitoring is directly related to these polychromatic effects, and that the UV reactor control
system cannot correct for it. Within the draft manual, a default reactor is used in the calculations and may
not lead to results representative of what is actually occurring during operation with a real reactor. The
lamp spectra used in the calculations are not necessarily representative of actual spectra, and they should
be peer-reviewed. Overall, the theory of these calculations needs to be peer-reviewed and shown to be
representative. The UVDGM needs to specify how a spectrum must be validated to allow its use in the
calculations. The UVDGM must also allow for the determination of these factors through empirical
testing. In addition, if the effect can be calculated in a spreadsheet, then presumably a monitoring and
control system could calculate the effect and account for it on-line. This sort of control scheme exits, is
available, and is in use in drinking water systems in the United States. Thus the UVDGM should allow
for this type of monitoring and control strategy, which when properly validated, would remove any
potential Polychromatic Bias.
1.3 Equipment safety factors are inaccurately applied against microbiological targets.
Safety factors should be applied to equipment, not to microbiological targets. Confusion of these concepts
within the manual can lead to industry-wide confusion about moving targets and differences between
equipment.
The microbiological targets, in terms of log reductions required for specific epidemiologically significant
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targets to be met should be explicitly stated. The equipment must then be shown to meet the required log
reductions of the pathogens. That is, targets for log reductions should be set for the various pathogens,
and the equipment must be shown to meet the log reduction targets required.
For example, Table 1.4 in the draft guidance manual specifies the microbiological dose required for 3 log
Cryptosporidium inactivation as 12 mJ/cm2, while Tables 4.1 and 4.2 specify that doses of 36 and 42
mJ/cm2 are required to achieve 3 log Cryptosporidium inactivation in LP and MP systems respectively.
These values of 36 and 42 mJ/cm2 are being wrongly interpreted as the microbiological dose
requirements, which is fundamentally incorrect because the true doses required for the logs of reduction
required are not technology dependent; it is the amount of equipment to achieve the target dose that
changes.
1.4 It is not possible to complete the safety factor calculations currently prescribed in the draft manual.
Instructions for calculations in the current version of the manual requires inputs which can only be
obtained from future installations. The calculations required during universal validation should only
include terms that quantify uncertainty around reactor performance, so that a safety factor can be
calculated for a reactor. Site specific factors should only be addressed at the time of system design for a
particular site.
1.5 Some prescribed safety factors - the Expanded Uncertainty terms - are not calculated correctly.
The Expanded Uncertainty includes terms that do not belong in the universal validation of a reactor,
namely, measures of uncertainties of operating variables. In general, uncertainty must be quantified on the
measured variable (disinfection performance), not on the operating variables (flow, UVT, etc.). This
shortcoming arises because the definition of-uncertainty- needs to be clarified with respect to either -
accuracy- or -precision-. Accuracy refers to how close a measure is to the true value, while precision
refers to how repeatable a measurement is. In the case of operating variables, precision will be inherently
accounted for in the response variable (if flow rate wavers, log reductions will vary, and the scatter in log
reductions will account for the flow rate precision). Accuracy is difficult to account for with operating
variables other than by calibration against a standard or taking the value from a calibration certificate. An
uncertainty calculated at an 80% confidence limit, as specified for operating variables, is meaningless for
attempting to quantify accuracy, and is difficult to interpret when attempting to quantify precision.
1.6 The concept of a Tierl/Tier2 approach is problematic.
The approach makes significant assumptions of current reactor and component design. There are
significant inherent assumptions about what a reactor looks like and how it works. If Tier 1 is embraced,
its prescriptiveness will likely be a barrier to innovation and technology will likely stagnate. If Tier 2 is
embraced, Tier 1 will be by-passed and the guidance will quickly be out of date. However, the Tier 2
approach is so complex that it is forcing Tier 1 compliance, which is a very likely hindrance to
innovation.
1.7 The reference to adenovirus as a target design pathogen for UV may confuse State regulators and UV
practitioners who read the UVDGM.
The selection of adenovirus as the viral target pathogen is not based on demonstrated and accepted
epidemiological evidence, nor is the selection of adenovirus consistent with the cost-effective practical
applications of UV disinfection currently being implemented and envisioned by EPA. This is discussed
further in our comments to the LT2ESWTR and in Appendix I to this document.
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1.8 The UVDGM is not universally applicable to all UV technologies.
The guidance manual, in its implementation, assumes that lamps will be medium pressure or low
pressure. It assumes much about what sensor technology is. It assumes that there is one sensor per
medium pressure lamp, and not so for low-pressure lamps. In short, the manual assumes equipment
configurations as they currently exist in the market. In so doing, it immediately promotes a significant
barrier to entry for different UV technologies needing validation.
2. Recommendations to Overcome Weaknesses of the UVDGM
The above weaknesses can be eliminated with the following proposed approach, which would meet the
five guiding principles presented above.
Eliminate the Tier 1 and Tier 2 system. Instead:
Undertake an empirical validation of a reactor installed with straight pipes upstream and downstream of
the reactor, tested over the relevant operating conditions. Analyze the uncertainty in the data coming from
these tests to provide the right level of safety on the performance of the reactor. The validation is for the
equipment, not the site. Site specific issues must be addressed by the responsible engineer and
documented in an engineer-s site-specific design report. In particular:
2.1 Be clear that the objective is to reach logs reduction of a specific pathogen.
Use the terms dose, RED, and logs reduction with the clear understanding that what is fundamentally
required for protection of public health is logs reduction, and what is needed to ensure that public health
is maintained is monitoring of systems to ensure the right delivery of target design dose required to
produce the target logs reduction of the target pathogen.
2.2 Separate equipment safety factors from site safety factors.
Equipment safety factor terms to be determined from the performance test results are the RED Bias (if
applicable, see below) and an Expanded Uncertainty term (different than currently defined in the draft
manual, see below).Site safety factor terms to be determined at the time of design by the engineer include
the Polychromatic Bias (if applicable), a term for installation hydraulics (see below), system fouling
effects, and a consideration of overall system safety.
2.3 Validation hydraulics: conduct equipment validation which is not influenced by site geometries.
For equipment validation to be generic, transferable, and not confounded by site variations, performance
at a validation facility should be measured for a piece of equipment, not assuming a specific site layout. In
practice, a standard like 5 straight pipe lengths upstream of a reactor and 3 downstream of a reactor with
no valving or other flow modifiers in those sections should be specified to ensure consistency of testing
and ensure that measured performance is of the reactor, not of the arbitrary installation. Hydraulics do
change from site to site, and while site validation should be allowed, site by site validation is not
practical, not necessary, and could comprise the viability of the industry. Sites that offer installation
configurations that compromise the effectiveness of the equipment relative to the configuration under
which it was validated must install with factors of safety determined for the site, under the direction and
discretion of a qualified professional engineer.
Rationale: No one hydraulic configuration will result in worst-case performance for all UV reactors under
all operating conditions. As a consequence, validation performed under any specific configuration should
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not alleviate the need for actual installations to assess on-site performance relative to validation
conditions.
For example, the European test configurations, which require testing with a 90° bend upstream of the
reactor, assume that this is representative of worst-case performance. As a demonstration of the
inaccuracy of this assumption, Figure 2 shows results from numerical simulation of a commercially-
available drinking water reactor for different upstream piping configurations. Performance of the
reactor installed with alternative piping arrangements has been plotted relative to the performance of the
reactor with a 90° upstream elbow. In Figure 2, it is demonstrated that different hydraulic installations can
exhibit varying degrees of improved or worsened performance. Furthermore, the actual differences in
performance are affected by operating conditions. In fact, it could equally be shown that the performance
of the reactor with the upstream elbow could be affected by the actual selection or orientation of the
elbow.
[SEE FIGURE 2, PAGE 10 IN PDF]
Figure 2: Reactor Performance relative to a reactor with a 90° Elbow upstream. A 90 Elbow Upstream is
not the worst case: performance can be better or worse under different installation configurations.
It is, therefore, incumbent on the professional engineer to understand the operation of the reactors and to
design the installation of them accordingly. Since there is no configuration that guarantees conservatism,
there is no compelling argument to establish a complex hydraulic configuration as the norm during
validation. Doing so would only make the assessment of actual installations relative to validation
configurations more difficult. Consequently, it is recommended that the simple and pure form- straight
pipes upstream and downstream (suggest 5 upstream and 3 downstream without any perturbing features
like valves or flow meters) - become the standard, and that installation configurations be considered site
by site, with a professional engineer taking responsibility for the final design.
2.4 Site hydraulics: site-specific installation geometries are the responsibility of a professional engineer.
It is recommended that the professional engineer determining the installation configuration use
appropriate engineering tools and practice to model fluid flow conditions relevant to the reactor to ensure
appropriateness of final installation design.
Site velocity testing could be conducted, or models such as validated Computational Fluid Dynamics
(CFD) models could be used.
Numerous examples of the use of CFD to demonstrate regulatory compliance can be provided. One
example was published by Ronald Graves and Kelly Thomas of Westinghouse Safety Management
Solutions (WSMS). In this case, CFD was used during licensing of a nuclear waste processing unit to
demonstrate that a significant volume of benzene above the lower flammability limit was not produced in
a liquid-filled tank. (Ref: Graves, Ronald; Thomas, Kelly. Computer Simulation Demonstrates Mixing
Speed in Vapor Space to Regulatory Authorities, Fluent Journal Article JA114. 2000.) In another example
related to air quality, it has been well established that highly non-linear numerical models have been
used to assess long range transport of pollutants and their impacts for regulatory compliance under the
Clean Air Act (EPA, 40 CFR Part 51, Revision to the Guideline on Air Quality Models: Adoption of a
Preferred Long Range Transport Model and Other Revisions; Final Rule).
2.5 Equipment Expanded Uncertainty: quantify this based on equipment performance, not component
performance
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Expanded Uncertainty terms should only contain terms related to performance. Uncertainty related to
operating variables is inherently captured in performance variability.
Use the statistics of the validation equipment performance tests themselves to quantify the uncertainty in
the dose being delivered by the reactor, and use these numbers to determine the -validated dose- that the
reactor is said to have. Inherent in this -validated dose- is the equipment safety factor. This avoids the
need to make many assumptions about components in the reactor and puts the focus on what matters
most, the overall performance of all of the components operating together, which is the performance of
the reactor. The analyses of the reactor performance data could be prescribed in the guidance manual, and
could easily be automated in spreadsheets made to handle the data
for all tests.
2.6 Do not allow an RED Bias calculation when the dose distribution is not known.
Without knowledge of the dose distribution, an RED Bias cannot be calculated, and the only techniques
that truly safeguard public health are:
i) to give credit for log reductions of target pathogens in terms of log reductions of challenge microbes
achieved during testing, when the challenge microbe is equally or more UV-resistant than the target
pathogen. For example, if a reactor provides a 4 log reduction of MS2, it is safe to assume that it will
achieve a 4 log reduction of Cryptospordium.
ii) to give credit for RED of target pathogens by using the numerically equivalent RED of challenge
microbes used during validation, when the challenge microbe is less UV-resistant than the target pathogen
iii) to interpolate the RED of the target pathogen or log reductions from validation with two organisms
that bracket the UV-resistance of the target pathogen
2.7 Allow RED Bias calculations when the validated dose distributions are known. With knowledge of a
validated dose distribution, allow the RED Bias calculation to be used.
There are at least four ways to measure dose distributions (below). However, because a dose distribution
changes as operating variables change, -interpolating- dose distributions (the last option presented in the
list) is not practical. The other three methods, which validate a dose-distribution-calculating algorithm,
should allow the algorithm to be used on-line to determine the impacts of dose distributions during
operation. This technology exists, has been validated, is available, and is in use in drinking water UV
installations (Emerick et al., 2003, Ervin et al., 2003). Four approaches for determining a dose distribution
are:
i) multiple condition tests to validate calculated dose distributions
ii) multiple organism tests to validate calculated dose distributions
iii) actinometric microspheres to validate calculated dose distributions
iv) actinometric microspheres to determine dose distributions for given reactor tests
2.8 The polychromatic bias term should be eliminated.
This term quantifies an unproven effect and is small in magnitude, so should be removed. If it remains,
the UVDGM should to specify how a spectrum must be validated to allow its use in the calculations. The
UVDGM should also allow for the determination of these factors through empirical testing. If the effect
can be calculated in a spreadsheet, then presumably a monitoring and control system could calculate the
effect and account for it on-line. This sort of control scheme exits, is available, and is in use in drinking
water systems in the United States. The UVDGM should allow for this type of monitoring and control
strategy, which when properly validated, would remove any Polychromatic Bias.
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2.9 Safety factors for the site should be established by the engineer. Site safety factors must consider the
whole water treatment plant configuration and operation, including such things as redundancy, reserve
capacity, other complementary technologies, the reactor installation configuration, site-specific
hydraulics. Many of these things are detailed in the draft guidance manual.
The system/site safety factors should be detailed in a professional engineer-s report.
Accept Innovations
Allow testing on innovations to be in compliance with the guidelines when the intent of the testing is met.
Where technologies are different in their configuration to those prescribed in detail in this manual,
making implementation of the testing prescribed impossible, testing should be considered adequate if it
meets the intent of each section. For this to occur, the rationale for the testing detailed in each section
needs to be stated. A system containing pulsed lamps, for example, would need to be shown to function
over its stated operating range by empirical validation testing of the relevant parameters prescribed,
meeting the rationale stated.
Summary
In summary, proper empirical validation testing of UV reactors can be done without excessive
complication when the focus is on the whole reactor performance.
Relevant equipment must be tested to ensure that the required logs of reduction of pathogens (translated
into equipment dose) occur under the specified water quality and operating conditions. It must be
subsequently ensured that the equipment performs over its lifetime in a manner that is consistent with the
operational range over which the equipment was validated.
When this is done, the requirements in the five guiding principles outlined here have been met.
References
Chiu, K.-P., D.A. Lyn, P. Savoye, and E.R Blatchley. 1999. Effect of UV system modifications on
disinfection performance. Journal of Environmental Engineering 125(5):459-469.
Emerick, R.W., Enloe, J.P., and Schegg, L.C. (2003). -Bioassay and dose monitoring performance of a
UV disinfection system for the North Tahoe Public Utility District-. In the proceedings of the Water
Quality Technology Conference, Philadelphia, PA, Nov. 2-3, 2003.
EPA, 40 CFR Part 51, Revision to the Guideline on Air Quality Models: Adoption of a Preferred Long
Range Transport Model and Other Revisions; Final Rule.Ervin, K.K., Petri, B., and Trussler, S. (2003). -
Full-scale bioassay and on-line dose monitoring validation of a UV disinfection system-. In the
proceedings of the Water Quality Technology Conference, Philadelphia, PA, Nov. 2-3, 2003.
Graves, Ronald; Thomas, Kelly. Computer Simulation Demonstrates Mixing Speed in Vapor Space to
Regulatory Authorities, Fluent Journal Article JA114. 2000
Appendix 1
A discussion suggesting that adenovirus should not be the target design organism for disinfection by UV
Appendix 1: A discussion suggesting that the adenovirus should not be the target design organism for
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disinfection by UVThere has been a recent suggestion that adenovirus could be the target design
organism for UV disinfection; however, there are ample arguments why this should not be the case.
The traditional design dose of 40 mJ/cm2 has been selected for adequate inactivation of viruses such as
rotavirus - a significant UV-resistant viral pathogen. Rotavirus occurrence levels were selected as being
conservatively representative of virus occurrence in general and used by Stig Regli, Joan Rose, Charles
Haas and Charles Gerba in their -Modelling the risk from Giardia and viruses in drinking water-
(JAWWA 83, No. 11, 76-84, 1991) when examining public health protection using chlorination. In the
case of UV disinfection, rotavirus is also a UV-resistant virus (although rotavirus was not the most
resistant virus to chlorination). Disinfectant resistance was another criterion suggested by Regli et al for
selection of the target design organism. When selecting the target design organism, Regli et al also
indicated the appropriateness of the target being very significant clinically. Confusion about the target
virus for UV disinfection has arisen in a draft version of the US EPA UV Disinfection Guidance Manual
that has been laid open for public comment. Some of this confusion has been created simply by the
availability of doseresponse data on adenovirus from the laboratory of Charles Gerba indicating that
adenovirus is more resistant than rotavirus to UV (Q.S. Meng and C.P. Gerba, Comparative inactivation
of enteric adenoviruses, poliovirus and coliphages by ultraviolet irradiation, Water Research 30, No. 11,
2665-2668, 1996). Criteria, other than UV resistance, for selection of the target virus have not been
adequately considered. A recent review of UV disinfection dose-response data has placed even a higher
dose value for adenovirus in the literature (C.P. Gerba, N.Nwachuku and K.R. Riley, Disinfection
resistance of waterborne pathogens on the United States Environmental Protection Agency's Contaminant
Candidate List (CCL), J of Water Supply: Research and Technology - AQUA 52, No. 2, 81- 94, 2003)
based on work done on an AWWARF project by the Gerba laboratory. Whereas the first paper cited a
dose of approximately 120 mJ/cm2 for 4 logs inactivation, the newer data suggests a dose of 170 mJ/cm2
for 3 logs inactivation (extrapolated to 203 mJ/cm2 for 4 logs inactivation). The major change in the
results is explained by a change in methods to assay adenovirus. The AWWARF study authors did add
some cautionary notes when the AWWARF study went out for peer review with higher doses. There are
then several issues relevant to the selection of adenovirus as a target pathogen in the GM:
- is drinking water borne adenovirus a pathogen of concern to public health?
- which dose is correct for adenovirus?
- was adenovirus reviewed as the target viral pathogen by the technical advisory group to the committee
that made recommendations to the EPA? Was the design dose reviewed? Was the use of a multiple
disinfectant strategy to address adenovirus discussed?
- if adenovirus were selected as the target design pathogen, would the current protocols using MS2 for
UV reactor validation still be appropriate?
- What might be the path forward for addressing adenoviruses?
UV Design Dose and Risk of Disease - elaboration
Selecting a design UV dose is not a trivial task, but one that should take into consideration the nature of
the source water, the treatment process, and the intended application as well as the nature of the
pathogens themselves.
It is a common practice when designing the UV dose for drinking water disinfection, to select the most
resistant pathogen of epidemiological significance, and identifying this pathogen includes a consideration
of the mode of transmission of the various pathogens, their frequency of occurrence, the exposure level to
the consumer, and the infectivity of the pathogens. Rotavirus is considered an extremely resistant virus of
epidemiological significance in drinking water, and a design dose of 40 mJ/cm2 will achieve typically 4
logs of inactivation. Unit operations that are upstream of the disinfection process will also help reduce the
virus levels in the produced water.
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In reused wastewater, the upstream filtration process may be effective in removing many of the particles,
but the design disinfectant dose is usually selected to bring the number of surviving particles (microbial
aggregates) to an extremely low level by disinfection. In reuse projects using alum-assisted media
filtration, the particle size distribution is reshaped with a significant reduction in particle numbers in all
size ranges, and particles over 100 micrometers are absent. With this water quality, UV doses may
typically be in the range of 80 to 120 mJ/cm2 to produce less than 2.2 total coliform CFU/100 mL
(less than 0.02 total coliform CFU/mL). To the extent that viruses may be far fewer than the more
abundant coliforms (e.g. 1,000 PFU/lOOmL for viruses vs 1,000,000 CFU/lOOmL for total coliforms),
then the virus content in the produced water will be also reduced to low values depending upon the virus
and design dose. IF all the viruses were the resistant rotavirus, then a design dose of 120 mJ/cm2 would
result in approximately 12 logs of inactivation of rotavirus (i.e., 0.000000001 virus PFU/lOOmL). This
would require "consumption" of 108 litres of water to receive 1 rotavirus particle. Anecdotally, cross-
connections between potable water and reclaimed wastewater in apartment complexes have not led to
illness when the reclaimed wastewater was consumed by the apartment dwellers. When addressing
potable water, it is not anticipated that the same challenges in protecting public health would be
encountered as in reclaimed wastewater, and we would not anticipate a need to use such high doses to
protect public health as used for reclaimed wastewater. There is no published epidemiological evidence
that higher UV doses used to disinfect drinking water have a measurable impact on public health
protection.
Adenovirus as an Alternative to Rotavirus as the Design Organism
Adenoviruses are more resistant than rotavirus, and until only recently, adenoviruses have not been
considered to be the appropriate target design organism for UV disinfection. This has been based on
several considerations brought out in the "Fact Sheets on Emerging Waterborne Pathogens: Final Report
to the Department of the Environment" (Report No. DWI 4248/1, Contract No. 10438-0, March 1997,
prepared by WRc and the Public Health Laboratory Service, Contract Manager: T.E. Irving, WRc pic,
Henley Road, Medmenham, Marlow, Buckinghamshire SL7 2HD, Telephone 01491 571 531).
1) The health effects of adenovirus are not generally considered life-threatening. The A-E sub-groups of
the 47 serotypes of human adenoviruses may cause upper respiratory infections, conjunctivitis, febrile
illness especially with sore throat and also glandular involvement. Asymptomatic infections occur
sometimes with long-term shedding of virus from the pharynx or gut. Adenovirus F serotypes cause
gastroenteritis in children, particularly those under one year old.
2) Infection routes are generally via the conjunctiva or the nasal mucosa (exposure to infected individuals
or inhalation of aerosols), and by the fecal-oral route in the case of children particularly.
3) Occurrence in water (sewage, rivers, lakes, groundwater, drinking water and recreational bathing
waters) reflects shedding of the virus in fecal material, but at the time of the report, there was no firm
clinical or epidemiological evidence that the bulk of respiratory illness in recreational water users has
been associated with adenovirus in recreational waters, although since 1979, there have been 3
documented cases of adenovirus outbreak resulting from swimming in recreational waters. There is no
evidence, according to the report, for spread of adenovirus F (the most severe form for young children) by
the water route.
4) Susceptibility to conventional treatment unit operations such as coagulationsedimentation, filtration
and disinfection can produce essentially virus-free waters. Adenoviruses are very susceptible to
inactivation by chlorine, and when chlorine is used as either the primary disinfectant or added
as a residual secondary disinfectant to protect the distribution lines following UV, then adenoviruses will
be well controlled. CT values for 99% adenovirus 40 inactivation have been suggested to be as low as
0.11 mg/L-min with chlorine, and up to 6.75 mg/L-min for 99.99% inactivation of adenovirus 12 (C.P.
Gerba, N. Nwachuku and K.R. Riley, Disinfection resistance of waterborne pathogens on the United
States Environmental Protection Agency's Contaminant Candidate List (CCL), J of Water Supply:
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Research and Technology - AQUA 52, #2. 81-94, 2003).
It is worth noting that a risk assessment was also published by US researchers: (K.D. Crabtree, C.P.
Gerba, J.B. Rose and C.N. Haas, Waterborne Adenovirus: A Risk Assessment. Wat. Sci. Tech. 35, #11-
12, 1-6, 1997). The authors conclude with the following statement: -The limited data on their
(adenovirus) occurrence in water makes it difficult to determine the risks associated with these viruses.
Further investigations on their survivability in the environment and their susceptibility to water treatment
are also needed. More knowledge of these aspects of different adenovirus serotypes will help in
understanding the public health risks posed by these viruses-. These conclusions highlight the need for
additional research, but not the need for making adenovirus the target virus for UV disinfection.
Summary: In terms of public health, enteric adenovirus infections have not been recognized as a
significant source of illness and, as pointed out by CDC, all outbreaks were related to swimming pool
activities where fecal-oral route is strong (especially if the pool is inadequately disinfected). No drinking
waterborne outbreak or infection has ever been reported, suggesting that for whatever reason (infectious
dose, survival, susceptibility, immunity) the probability for reaching an epidemic level is never achieved.
This is somewhat confirmed by the fact that outbreaks occur mainly in children in day-care (high viral
doses subsequent to intimate contact with feces) and not in adults. Selecting adenoviruses as the target
organism could make some sense only if they were treated differently because the outcome of the
infection in terms of public health appears minimal for the water route. A similar differential treatment
has been applied for parasites in drinking water: The required minimal log removal of Cryptosporidium is
only 2 logs while for Giardia it is 3 logs: this recognizes levels of risk and achievable goals. Significantly
higher goals are required when significantly higher pollution levels occur (there is no data suggesting this
to be the case for adenoviruses).
Now that adenoviruses have been shown to be more resistant to UV treatment, regulation is moving faster
that science. While recognizing some form of precautionary principle may exist, there has not been found
anywhere in the literature any indication that there is a risk requiring a significant and costly change in the
design of water treatment technologies. What is the dose-response for Adenoviruses?
Although it is still unclear whether there is sufficient justification to make adenoviruses the design target
pathogen for UV disinfection, it is clear that the dose-response of the organism must be known to
determine what the design dose would have to be. The above reference (C.P. Gerba, N. Nwachuku and
K.R. Riley, Disinfection resistance of waterborne pathogens on the United States Environmental
Protection Agency's Contaminant Candidate List (CCL), J of Water Supply: Research and Technology -
AQUA 52, #2. 81-94, 2003) is a review article published after publication of the high-dose-obtaining
AWAARF report "Inactivation of Waterborne Emerging Pathogens by Selected Disinfectants" by some of
the same authors. The review paper did not mention the high doses experienced in the AWWARF study.
The details of the AWWARF study were subjected subsequently to peer-review and published in 2003
(J.A. Thurston-Enriquez, C.N. Haas, J. Jacangelo, K. Riley, C.P. Gerba, Inactivation of Feline Calicivirus
and Adenovirus Type 40 by UV Radiation, Applied and Environmental Microbiology 69, #1, 577-582,
2003). The authors of this latter paper (the authors of the AWWARF study report) did note that they
received higher doses of UV with Adenovirus Type 40 than in earlier studies (Q.S. Meng and C.P. Gerba,
Comparative inactivation of enteric adenoviruses, polioviruses and coliphages by ultraviolet irradiation,
Water Research 30, 2665-2668, 1996) in which a dose of 124 mJ/cm2 was reported for 4 logs
inactivation. Extrapolation of the AWWARF data would have predicted a dose of 203 mJ/cm2 for 4 logs
inactivation. The authors of the peer-reviewed paper have attempted to present a rationalization of the
different dose-responses obtained in the two different studies. The authors presented a suggestion that the
methods of preparing the viruses could influence the virus susceptibility to UV. The authors
acknowledged that: "The methods used in microbial preparation, water type, and experimental design can
produce significant differences in inactivation kinetics or do not reflect microbial inactivation during
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water treatment". Trojan has observed that when making dose-response curves for bioassays using high
concentrations of viruses (e.g. MS2 bacteriophage), the dispersal of viruses can also be a problem,
especially when targeting high UV doses to obtain high levels of inactivation and when working in waters
with polyvalent cations that are not chelated with natural organic matter. The polyvalent cations can
contribute to virus clumping and/or dispersal problems. The clumped and non-dispersed virus problem is
usually manifest as a "tailing" in the dose-response curve just as seen in wastewater samples from the
particles that are in those water qualities. It is not clear from the figures presented in the peer-reviewed
paper by Thurston- Enriquez et al, 2003 whether their adenovirus inactivation data is without such tailing
at UV doses above about 100 mJ/cm2. Natural waters do not have the same high concentrations of
viruses that can be self-associated. The authors of the peer-reviewed paper (Thurston-Enriquez et al,
2003) have appropriately cautioned: "Like those reported between this study and that of Meng and Gerba,
variations in the kinetics of inactivation between similar inactivation studies must be carefully examined,
especially if the results will be applied for regulatory purposes". The wise cautionary statement by the
authors of the peer-reviewed publication from the AWWARF study is important, especially if considering
that the change from a design dose of 124 to203 mJ/cm2 would imply an increase in equipment by a
factor of about 1.6 fold, an increase in equipment cost by about 1.6 fold and an increase in power
consumption by about 1.6 fold - and all for control of a virus that has not been demonstrated to be an
epidemiologically-important target pathogen that is transmitted by water. Although selling an additional
1.6 fold amount of equipment may appear appealing to UV manufacturers, the additional amount of
money, if available, might be better put into upgrades of other unit operations to ensure that the best
possible multiple barrier strategy is put into service. A low dose of chlorine added in flash mixing would
provide adequate protection against the adenoviruses and help in microbe control within the distribution
lines. Chlorine doses of less than 10 mg/L-min would be more than adequate if after UV disinfection at
reasonable rotavirus-targeting doses, adenoviruses were still considered to be a problem.
Was adenovirus as the target design virus and its design dose reviewed by the technical advisory group to
the panel making recommendations to EPA and an appropriate peer review undertaken?
There appears to be no record of a discussion with peer review having been undertaken to consider the
target virus and target design dose. The central focus of disinfection studies and costing of technologies
was for inactivation of Cryptosporidium. It is potentially beyond the scope of the UV Disinfection
Guidance Manual (UVDGM) to provide guidance on the choice of the target virus and the target design
dose for that virus without the appropriate open discussion of the cost-risks-benefits of the various options
available for the target design virus. Beyond the inappropriate target virus and dose recommendations for
UV alone, the UVDGM has not addressed the issue of a multiple disinfectant strategy that will almost
always be implemented with UV disinfection in municipal systems. Chlorine will commonly be used
within a treatment plant, but a chlorine residual will almost always be added as a residual after UV, or a
minimal chlorine dose could be used before conversion of chlorine to chloramine. These practical options
have not been presented as an alternative to use of high UV doses. It is questionable guidance if UV is
introduced to avoid high chlorine doses such as used for Giardia and Legionella when chlorine is the sole
disinfectant, and then UV is forced to be used at high doses for treatment of organisms such as adenovirus
that can be readily addressed with low doses of concurrently used chlorine.
Implications of adenovirus for use of MS2 as the challenge organism to validate UV reactors.
The non-ideality of reactors and the implications for organism-specific dose delivery has been well
described by Trojan Technologies (Petri, B.M.; Olson, D.A. -Bioassay Validation of Computational
Disinfection Models Used for UV Reactor Design and Scale-up-. Proceedings, Disinfection 2002: Health
and Safety Achieved Through Disinfection, Florida, 2002.
Chiu, K-P.; Buffle, M-O. -Effect of Lamp Spacing on UV Reactor Performance: Computational and
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Experimental Investigations-. Proceedings, WEFTEC 2001, Atlanta, 2001.
Petri, B.M.; Olson, D.A. -Bioassay-validated Numerical Models for UV Reactor
Design and Scale-up-, First IUVA conference, Washington, B.C., June, 2001.
Wright, H.B. and Y.A. Lawryshyn. An assessment of the bioassay concept for UV
reactor validation-. WEF Specialty Conference on -Disinfection of Wastes in the New Millennium-.
New Orleans, LA, March 15-18, 2000.)
This non-ideality is recognized in the UVDGM; however, appears not to be adequately addressed if
adenovirus were to become the target pathogen and MS2 were the challenge organism for validation. For
a given log inactivation of adenovirus, the adenovirus UV dose must be higher than the MS2 dose for the
same log inactivation of MS2. Due to fluid dynamic behavior within the UV reactor, for any non-ideal
reactor that is being validated, the adenovirus dose under any operating conditions will be higher than the
MS2 dose under those same operating conditions. These two pieces of information allow a prediction
that when designing a reactor for delivery of an adenovirus dose to give a target adenovirus reduction
performance, that the result will be an underdesigned reactor if the MS2 dose that gives the same target
logs of MS2 reduction is used for design, and overdesigned by an indeterminable amount if the target
adenovirus dose for the required logs inactivation of adenovirus is designed by using the numerically
equivalent MS2 dose. Only extrapolation using a validated UVDosimeter algorithm such as that of
Trojan-s, or multiple organism bioassay with an organism that is more resistant than adenovirus and
interpolation between the more resistant organism and MS2 dose will be reliable in avoiding underdesign
or overdesign. Overdesign will also result if the dose of the more resistant organism that produces the
target logs inactivation of adenovirus is used for design. It is clearly not acceptable to extrapolate
beyond a MS2 dose to an adenovirus dose in the absence of empirical data, nor is it acceptable to levy a
safety factor of indeterminable magnitude. This has not been acknowledged in the UVDGM, nor has a
more resistant organism than adenovirus been used or validated as an appropriate challenge organism.
Path Forward for Addressing Adenoviruses
In order to avoid regulation getting ahead of science, the following suggestions
are offered:
1) Adenoviruses should be placed in a separate -bin- until we know more of their occurrence and the
potential risk they pose to drinking water safety.
2) A 4-log inactivation of the other viruses can be achieved using UV and thereby providing a very good
safety factor for public health protection. Depending upon which dose-response curve is eventually
validated for adenoviruses, a UV design dose of 40 mJ/cm2 would provide between 0.8 and 2 logs
inactivation of adenovirus. These levels of inactivation might be adequate considering the current
requirement is for 2 to 3 logs inactivation of Cryptosporidium that poses a much higher demonstrated
threat.
3) UV disinfection of municipal water will be used mainly on waters also treated with chlorine that
already provides public health protection against adenoviruses. When UV is added to municipal systems
(at the central treatment plant or at POU/POE residential applications within municipalities), the
adenovirus issue has been addressed by the chlorine used in the municipal treatment process. In rural or
cottage applications where UV or chlorine might be used alone, it is important to recognize that human
viruses are primarily of human origin and such human viruses are likely of relatively low occurrence
compared with human parasites that have both human and animal fecal origin. This would suggest that in
rural applications where a single disinfectant is used, that the choice of UV that can address the relatively
more health-impacting parasites might offer greater public health protection than chlorine that might more
readily inactivate resistant and less epidemiologically-significant viruses such as adenovirus, but is unable
to address the epidemiologically-significant parasites such as Cryptosporidium and can only address
Giardia at relatively high CT values.
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Appendix 2
Detailed Suggestions for Changes
Appendix 2: Detailed Suggestions for Changes
Key issues:
1. Validation requirements by LT2ESWTR
Section 4.1 reviews the LT2ESWTR UV Disinfection Requirements. UV validation related requirements
are -Validation testing must determine a set of operating conditions that can be monitored by a utility to
ensure that the UV dose required for a given pathogen inactivation credit is delivered —, -Validation
operating conditions must include, at a minimum, the following: UV intensity (as measured by a UV
intensity sensor)—. GM must explain specifically how compliance conditions are established based on
validation. Misinterpretation of compliance conditions will result in unnecessary confusion, and
significant difficulties in implementing the UV technology. For example, misinterpretation
of the requirement of establishing sensor set-point for compliance is inconsistent with GM-s UV control
and monitoring strategies which in addition to the sensor set-point method, also includes UV intensity/set-
point and calculated dose methods. For reactors that use the calculated dose monitoring/control method, a
requirement for setting an UV intensity range as part of the reactor validation condition is not justified
and should not be required. Emerick et al (2003)* demonstrated that with such a reactor it was not
appropriate to establish an intensity sensor set point for dose delivery during reactor validation. The
calculated dose method was validated to provide safe dose delivery. Therefore, we strongly recommend
GM provide specific guidance on compliance conditions of reactor validation which cover all current
technologies and future innovation. Please also refer to our submission of the LT2ESWTR comments.
* Emerick, R.W., Enlow, J.P., and Schegg, L.C. (2003). -Bioassay and dose monitoring performance of a
UV disinfection system for the North Tahoe Public Utility District-. In the Proceedings of the Water
Quality Technology Conference, Philadelphia, PA, Nov. 2-3, 2003.
2. Number of sensors
Sensor monitoring requirement for MP vs. LP/LPHO systems is not consistent. Fundamentally, the
requirement should be based on dose delivery and dose monitoring regardless of the lamp technology. In
the current draft of GM, Tier 1 requires one sensor per lamp for MP, and one sensor per bank for
LP/LPHO. This specification favors the LP/LPHO lamp systems, and does not provide equivalent
monitoring. In order for equivalence, the LP/LPHO requirement can be 1 sensor per x kW of disinfection
or for example 10% of lamps be monitored for UV and all lamps be monitored for failure (short circuit or
open circuit). Otherwise the LP/LPHO systems can have failures and compromised disinfection safety
goes un-noticed. Perhaps both LP and MP should require 10% UV monitoring plus 100%
failure monitoring. In the main body of text, Tier 2 requirement is not specified. Only in Appendix F.3.5,
discussion was made on the requirement for the case of the number of sensors less than the number of the
lamp. The suggestion to EPA is that remove the 2-Tier structure, and propose the same requirement for
MP and LP/LPHO.
3. Information on lamps
Information on lamps is scattered throughout the document: 2.4.2, A 1.1 and A3.1. Two appendix
sections, A 1.1 and A3.1 could be combined, or section A3.1 deleted. (A3.1.2 does not add to the
document, since most of the information is contained elsewhere. It appears to be a difficult compilation of
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information from the 20-year old Roger Phillips book on lamps.)
Appendix A3.1.2 makes misleading statements about maximum pinch temperatures and
lamp efficiency. It provides an -optimum- design for LP lamps. This should be deleted, as some
customers and consultants may try to demand an -optimum- lamp. The best lamp for a particular system
is a compromise and will rarely match this description.
A3.1.2 states that 60% efficiency is achieved with this optimum LP lamp. This is highly unlikely in any
disinfection system, and is misleading for users. It also contradicts the statement of efficiency given in
section 2.4.2 table 2.1. Table 2.1 is more accurate, though even this is optimistic. UV efficiency of lamps
in disinfection systems is overwhelmed by the effects of reactor hydraulic efficiency.
A3.1.2 also provides misleading information on MP lamp efficiency based only on measurements of
wavelengths greater than 248nm!
Figure A16A is a repetition of graph 2.12 contained in section 2. It does not show the real output at e.g.
313 and 365nm.
A3.1.6 suggests that only soft-glass LP lamps suffer from mercury reacting with the lamp wall. This is
not true. Mercury will also react with quartz LP lamp walls, reducing UV output substantially.
A3.2 attributes the discovery of reverse impedance to Persson and Kuusisto in 1998. This characteristic
has been known for many decades.
Table A4 states that electronic ballasts are more prone to electrode sputtering than are magnetic ballasts.
This is not true. In fact, section A.3.2.5 contradicts Table A4 by stating that electronic ballasts with high
frequency reduce electrode deterioration, which is related to sputtering.
Section 2.4.2, UV Lamps: Figure 2.12 is not accurate for LP or LPHO lamps. There should be some
additional output at other wavelengths (e.g. 313, 365) on the scale shown.
Section 5.4. Lamp cycles are recorded, but the effect of cycling on maintenance is not known or required.
Section 5.6.5 states that LP & LPHO can be up to full output with 15 seconds of power application. This
is not typically true. If the interruption allows the lamp to cool to ~20C, it could be -120 seconds to reach
90% output. This depends very much on system design.
Section 5.7.3 Threshold limit values for UV are not actually set by the ACGIH. They adopt the values
established by Britain's "National Radiological Protection Board" which contains identical information to
that used by the International Commission on Non-Ionizing Radiation Protection (ICNIRP).
Figure A19 is presented as the transmittance of quartz. Since reflectance was just discussed, it should be
clearly stated that this figure includes the effects of reflection at two quartz/air interfaces, and the
absorption of a particular thickness of quartz. Otherwise, the reader may believe this is a curve of
absorption only.
4. Cleaning Systems
Current GM, Section 2.4.5 treats online physical/chemical cleaning (OPCC) systems as a subset of the
online mechanical cleaning (OMC) systems. OPCC removes fouling on sleeves both chemically and
mechanically. Due to its distinct cleaning mechanism and performance, GM should differentiate these
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two, and list three categories equally, i.e., off-line chemical cleaning (OCC), OMC and OPCC.
Among the three technologies, OPCC is the least sensitive to water quality and other factors associated
with fouling, and can provide the most consistent and reliable high degree of cleaning. The cleaning
performance should be considered in the UV reactor sizing. For example, a fouling factor is required
for sizing by California-s NWRI guideline for drinking water and wastewater reuse applications.
Distinctiveness, benefit and applicability of OPCC should be allowed to obtain performance credits such
as reduced safety factors related to sleeve fouling.
The table below provides our comments by the sections in the GM.
[SEE TABLE, PAGES 26-31 IN PDF]
Appendix 3:
Trojan Technology Inc.-s Internal High Level Validation Protocol and Rationale
Appendix 3: A High Level Protocol for the Validation of UV Disinfection Equipment
The primary principle that should govern disinfection applications is to protect public health. Public
health is protected through disinfection by:
- Setting adequate log reduction targets of microbial pathogens or indicators
- Providing equipment that delivers those log reductions
UV radiation inactivates microbes. Different microbes have varying degrees of UV-resistance, but in
general, as UV dose increases the level of inactivation for any microbe increases. The UV-resistances of
many microbes have been determined, demonstrating that UV is an effective disinfectant. UV reactors
irradiate microbes in the water passing through them. A hypothetical reactor that is perfectly efficient,
would deliver the same dose to each microbe passing through it. However, due to hydraulic regimes and
non-uniform light distributions in real reactors (UV light is attenuated exponentially as distance
from a light source increases), microbes traveling through a reactor follow different stream lines and are
exposed to different UV intensities, resulting in a distribution of doses delivered to the microbes.
To ensure the protection of public health with UV disinfection equipment, one must ensure that the
equipment will perform. However, because of the complexities that lead to dose distributions for every
reactor, calculations of UV reactor performance are inaccurate. Thus, UV reactors must be validated by
empirically demonstrating disinfection.
In addition, dose distributions in real reactors make it difficult to extrapolate an overall inactivation result
with microbes of a given UV-
resistance to microbes of different UV-resistance. Thus, to test a reactor: - Demonstrate inactivation
through the reactor using the target microbe, or using a surrogate with the same UV-resistance as the
target.
- Determine the range of conditions where the reactor will deliver at least the required log reductions.
Often the testing cannot be done with the target microbe, and a surrogate may not exist that has the same
UV-sensitivity. As an alternative testing method:
- Demonstrate inactivation through the reactor using a challenge microbe with greater UV-resistance than
the target.
- Determine the range of conditions where the reactor will deliver the same number of log reductions of
the challenge microbe as is required of the target microbe.
- Because of the dose distribution in reactors, differences in performance between two microbes with
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different sensitivity cannot be predicted. Disinfection credit can only be given in terms of the
demonstrated log reductions. Because the challenge organism has greater UV-resistance,
at least the equivalent number of log reductions of the less UV-resistant target organism is guaranteed.
- However, more energy is required to achieve the same level of inactivation for the challenge microbe
than the target microbe. Thus, there is an incentive to test the reactor with a microbe that is as similar in
resistance to the target as possible.
To better resolve the performance of a UV reactor for a target microbe of a given UV-resistance:
- Demonstrate inactivation through the reactor using two challenge microbes with UV-resistances that
bracket the UV-resistance of the target.
- For each test, plot the inactivation achieved versus the inactivation constant for each of the challenge
microbes. Interpolate the inactivation of the target microbe based on its inactivation constant.
- Determine the range of conditions where the reactor will deliver at least the required log reductions of
the target.
Predicting UV reactor performance is difficult due to the dose distribution that every reactor has.
However, with a known (and validated) dose distribution, the performance of the UV reactor can be
determined for microbes with any UVresistance. To determine reactor performance from a known dose
distribution:
- Calculate the overall log inactivation achieved for a test by applying the inactivation kinetics to the dose
distribution.
- Determine the range of conditions where the reactor will deliver at least the required log reductions of
the target.
Dose distributions can be determined (and validated) in a number of ways:
- Measure the dose delivered to a population of actinometric microspheres passed through the reactor at
given operating conditions. Quantify individual doses and tabulate to generate a frequency-dose
distribution.
- Calculate the dose distribution using models of fluid flow, light irradiation, and inactivation kinetics,
and validate the calculation algorithm by:
- Measuring the dose distribution with actinometric microspheres
- Comparing actual inactivation with a challenge microbe to calculated inactivation. Dose distributions
will change with changes of operating conditions (flow rate, power level, UVT); if actual and calculated
results agree over a range of operating conditions, the dose distribution calculation is validated.
- Comparing actual inactivation with two or more challenge microbes to calculated inactivation. Because
of the dose distribution, overall inactivation will be different for microbes with different UV- resistance at
the same operating conditions; if actual and calculated results agree for different microbes, the dose
distribution calculation is validated.
- Future experimental innovations may allow for other methods of validating dose distributions.
In all validation tests, performance must be linked to monitoring results, so that the monitoring results can
be used during operation as a guarantee of performance. Monitoring schemes include:
- Intensity sensor set point methods
- Intensity sensor and UVT monitor set point methods
- Dose calculation methods
Uncertainty in testing must be quantified and applied against the reactor in the form of an equipment
safety factor. The safety factor should be used to discount the credited inactivation of the reactor in each
test. Uncertainty in testing arises from:
- Variability in the inactivation result. Quantify using error propagation formulas: the root of the sum of
squared errors of inlet and outlet counts, with errors determined as the xx% confidence interval.
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- Variability in test conditions. Any variability in flow, power, or transmittance is inherently manifested
in the inactivation variability, quantified above.
- Accuracy of the instruments quantifying test conditions (flow meter, UVT meter, intensity sensors).
Accuracy of instruments can be specified as required to be below a certain limit; or the accuracies can be
added to the safety factors by using error propagation formulas.
When validated UV reactors are specified for installation in water treatment plants, a number of other
safety factors must be determined and applied to the design. These include:
- A polychromatic bias correction (for polychromatic systems). Inactivation achieved during testing and
inactivation achieved during installation can be different due to different lamp spectra (aging), sleeve
spectra (fouling), and water spectra. However, the dose or intensity monitoring system will also be
different. If the monitoring system tracks the difference in dose delivery, there is no bias and no
correction is necessary. If the monitoring system does not track the difference in dose delivery, a bias
correction is required. The bias term is applied against the inactivation performance demonstrated during
testing. The polychromatic bias can be determined:
- By calculation (as per USEPA)
- By empirical testing, comparing results from validation to results obtained with the different
polychromatic spectra.
- A hydraulic bias correction (for all reactors). Inactivation achieved during testing and inactivation
achieved during installation can be different due to different upstream and downstream hydraulics. The
bias term is applied against the inactivation performance demonstrated during testing. The hydraulic bias
can be determined:
- By calculation using validated models of fluid flow, light irradiation, and inactivation kinetics (see
above for validation methods).
- By empirical testing, comparing results from validation tests to results obtained with different hydraulic
conditions.
- By empirical testing, of actinometric results during validation tests and in tests with different hydraulic
conditions.
Appendix 4: Validation Alternatives for the USEPA UVDGM
Appendix 4
Validation Alternatives for the USEPA UVDGM
(presented December 8-9, 2003, Washington)
[SEE PRESENTATION, PAGES 38-59 IN PDF]
Appendix 5
Comments in response to the LT2ESWTR
Comments in response to the LT2ESWTR Appendix 5:
Comments in response to the LT2ESWTR (as embodied in the Federal Register Vol 68, No. 154,
Monday, August 11, 2003)
Submitted by Trojan Technologies Inc.
Please note that the comments regarding LT2ESWTR are consistent with those presented in our
comments on the EPA-s UV Disinfection Guidance Manual, June 2003 draft (UVDGM). It might be
Comment Response for L T2ESWTR 8-395 December 2005
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helpful to cross-reference this submissions with our comments in response to the UVDGM (and included
with this document).
SUMMARY
1. We would suggest that treatment of Cryptosporidium is best obtained with a holistic approach. A non-
holistic approach within LT2ESWTR to use disinfectants that can treat Cryptosporidium could result in
misunderstanding and therefore possible misguidance to the States. The result of that would be a
narrowing of perspective that would lead to solutions that are not as cost-effective and possibly even not
optimized technically for the protection of public health.
Consistent with what we believe is a more system-wide, holistic approach, we offer the following
recommendations for consideration.
1.1. More realistic holistic examples of using short-lived disinfectants for treatment of Cryptosporidium
should be considered within the LT2ESWTR.
1.2. It should be acknowledged that the target design virus for UV system design could very reasonable
be a function of the second disinfectant that is used along with the UV: the target for UV need not be
adenovirus to protect public health in systems with chemical disinfection residuals.
1.3. Adenovirus, because it appears to have low epidemiological risk and is so easily taken care of with
the required chemical disinfection residuals in the finished water, should be parked on the sidelines in a
separate -bin- until its role as a pathogen of epidemiological significance for drinking water disinfection
by UV (and maybe other disinfectants) is clarified. A discussion of whether adenovirus is a relevant
pathogen as a target virus for UV disinfection is provided in an Appendix to the comments on the
UVDGM.
1.4. We suggest that the Rule cite logs of reduction of pathogens, not UV doses, as logs of reduction are
the fundamental requirement to protect health. While the rule should require logs of reduction, doses
could be placed in guidance (UVDGM) to allow easier use of new scientific information over the lifetime
of the rule. If doses must be in the rule, then the rule would have broader and longer term currency if the
UV doses (or CT values for other disinfectants) were provided for the wider range of viruses that are
potential target design viruses for UV (or other disinfectants) depending upon the multiple disinfectant
strategies possible, and those doses were clearly labeled as the dose unique to each particular virus.
Hence, we suggest inclusion of a more exhaustive table of epidemiologically significant water-borne
viruses if UV doses are discussed in the rule.
1.5. The use of short-lived disinfectants such as ozone or UV inherently create the use of multiple
disinfectant strategies. The use of these technologies can be optimized by considering that different
viruses could be the targets of different disinfectants in the strategy. We suggest that regulations should
cease to refer to the generic -virus- unless the regulation specifies only logs reduction. If dose is to be
discussed in regulation, then a number of potential target viruses should be specified along with their
virus-specific dose to achieve the desired logs reduction. This would facilitate focus on the logs of
reduction and eliminate the possible effect of biasing implementation to too much of one technology or
another, rather than facilitating the optimization of all of it together.
1.6. It would be helpful if the complete array of target viruses for virus profiling were specified and
reviewed for applicability to multiple disinfectant strategies. Without this, we feel there is considerable
weakness in the rule.
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DETAILS
The focus on using short-lived disinfectants such as ozone and UV as enabling technologies for
Cryptosporidium treatment when the oocysts are not removed by membranes (FR pg 47659, middle
column, first paragraph) implies that a second disinfectant (at least as a residual, but also with an in-plant
CT) will be most often used in municipal systems along with these disinfectants. In fact, the use
of two disinfectants is specifically stated as a requirement for unfiltered systems (FR pg 47679, third
column, third paragraph). Unfortunately, the LT2ESWTR provides an example (FR pg 47679, third
column, third paragraph) of using UV only for Cryptosporidium and some Giardia treatment, with the
second disinfectant being chlorine for control of Giardia and viruses.
The above example in the LT2ESWTR could color the State perception of how to use UV, and has quite
possibly impacted how the UVDGM was written, even by experienced engineers who understand that the
above example would seem inconsistent with an optimized use of the two disinfectants to protect public
health:
a) by having UV inactivate Cryptosporidium and Giardia, both of which are similarly UVsensitive,
whereas Giardia requires high chlorine doses that impact on chlorinated disinfection byproduct formation,
b) by having UV inactivate Legionella that like Giardia is chlorine resistant and requiring high CTs,
c) by using UV doses that inactivate the full range of bacterial pathogens and viral pathogens with UV
resistances up to and including rotavirus, thus providing better redundancy should there be a failure of the
chlorination system, and
d) by using chlorine to ensure that chlorine-sensitive, but UV-resistant viruses are inactivated as can be
accomplished at a lower CT than needed for Giardia, and hence result in lower chlorinated disinfection
byproduct formation.
The attached figure generated by Trojan Technologies Inc. illustrates how a modest dose of UV that is
compatible with current practice (40 mJ/cm2), when combined with a chlorine CT of approximately 10
mg-min/L (that is about 1/30 of what is needed for control of Giardia in cold waters), will provide a 4-log
control of the indicated pathogens and minimize the production of chlorinated byproducts. The chlorine
CT can be controlled by conversion of the chlorine to chloramine that is the better biofilm control agent in
the distribution lines. Although the example is with chlorine as the second disinfectant following UV,
similar strategies with other disinfectants can be devised to achieve the same endpoint of minimizing the
production of chlorinated byproducts without compromising on the inactivation of target pathogens. The
common use of chlorine now would likely lead to a simple transition to the UV-chlorine dual disinfectant
strategy with chlorine reduction being a subsequent stage that might require additional research, but could
be implemented anytime after the UV-chlorine dual disinfectant strategy was implemented as an
extension of the multiple barrier strategy of public health protection.
[SEE FIGURE, P.63 IN PDF]
The inclusion (FRpg 47712, table) of UV doses for UV-resistant adenovirus as the only representative of
-viruses- is also a distraction to the States and to the authors of the UVDGM for addressing the multiple
disinfectant strategy that will almost axiomatically be implemented when a short-lived disinfectant is
used. As seen in the above figure and from published data cited in the UVDGM, the UV dose for
achieving any target reduction of adenovirus is substantially higher (by at least 3 fold) than what is
needed for rotavirus; however, when using a dual disinfectant strategy of UV-chlorine, there is no need to
use the high UV doses needed for adenovirus when this virus is so sensitive to low CT values with
chlorine. The dual disinfectant strategy will substantially reduce the amount of UV equipment needed to
achieve the lower UV dose and save on both capital and operating cost for UV and bring the cost of
adding UV technology more in line with the values determined by EPA during its background due
Comment Response for L T2ESWTR 8-39 7 December 2005
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diligence research prior to publishing the LT2ESWTR.
The inclusion (FR pg 47712, table) of UV doses for only adenovirus suggests that adenovirus is a target
design virus for all applications of UV, but as indicated above, this is not necessarily true in a multiple
disinfectant strategy. Dose requirements for other viruses should be included or preferably doses should
be eliminated completely from the rule, and only logs of inactivation specified. From a general
perspective, as we move into multiple disinfectant strategies, the use of-virus- in regulations should be
avoided whenever dose to achieve the target logs inactivation is also going to be discussed. The target
design virus changes with different strategies, and different doses for different viruses must be
determined. Doses, if necessarily discussed, should be captured within the UVDGM to allow for the
upgrading and evolution of scientific knowledge that can be used legally when the original information
appeared as guidance, but is more problematically used when the original information appears as
regulation. Additionally, the LT2ESWTR does not have the space to address the nuances of UV dose
generated in an ideal collimated beam apparatus compared with UV dose validated for a real reactor that
has water quality, optical, hydraulic and microbial kinetics impacts on the delivered dose, and to avoid
potential misuse of UV doses that might appear in regulation, it is best to eliminate any reference to dose
within regulation, but to specify logs reduction and direct practitioners to the UVDGM to learn how to
translate logs reduction into a UV system design dose.
The LT2ESWTR advocates Giardia and virus profiling either as a periodic monitoring program for some
treatment plants, or as a benchmarking exercise prior to process changes (FR pg 47715, third column,
third paragraph). It should be recognized that the resistant viruses for chlorine are not necessarily
resistant for other disinfectants, and that the target design virus for either of two disinfectants in a two-
disinfectant strategy could be different from what is actually the target with chlorine alone (for example,
many of the target viruses for chlorine regulations are relatively sensitive to UV at conventional design
doses of 40 mJ/cm2 and are therefore not the target design virus for UV). Simple reference to a long-
established virus-profiling method that can be used after chlorination may not provide the EPA with the
level of insight sought for virus profile changes following changes in process or even routine changes in
viral profile as a function of water quality, operating conditions, etc. The complete array of target viruses
to be monitored should be defined both for the purpose of optimizing multiple disinfectant strategies, and
for ensuring that the correct viruses are monitored during the profiling exercise. Additional research may
be needed to better define the virus profiling protocols for multiple disinfectant strategies. The procedures
for profiling (FR pg 47717) may need to be reviewed for use with UV disinfection technologies that are
not equipped to monitor the actual dose being delivered, but only to respond to a sub-target design dose
with an alarm or other appropriate response. No CT equivalent would exist for these technologies (only a
knowledge that the dose was greater than the specified target design value).
Adenovirus as a target of disinfection for UV disinfection is highly controversial, and the advocating of
adenovirus as the target for UV is perhaps getting regulation ahead of science. This entire issue is
addressed in an appendix to the comment on the UVDGM provided by Trojan Technologies Inc.
2. The LT2ESWTR has correctly emphasized the need for UV reactor and monitor/controller validation
to ensure that the UV system will deliver a target design dose to achieve the target level of pathogen
inactivation over the full range of operating and water quality conditions. However, the rule has not the
capacity to describe all the various technology options available and validation protocols to address all the
various reactor, monitoring and controlling technology options. Consequentially, the rule omits mention
of some existing technology options already commercially available and could unintentionally
exclude those technology options from consideration by end users. To overcome these issues we
recommend that:2.1. The rule should be restricted to requiring that UV technologies be validated and that
the monitoring/controlling technologies be also validated. 2.2. The rule should defer totally to the
UVDGM for details of technology validation, and not attempt a precis within the rule. If details must be
Comment Response for L T2ESWTR 8-398 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
provided, then the rule should be expanded to include reference to calculated dose methods as well as
intensity-based methods for monitoring/controlling of dose. The validation methods for each should not
be confused.
DETAILS
The rule attempts in several places (FR pg 47712, first column, beginning with last paragraph; FR pg
47712, second column, last paragraph beginning with sentence -At a minimum systems must monitor-..-;
FR pg 47713, first column, beginning in the last paragraph with the sentence -Consequently, it is more
reliable to evaluate reactor performance-.-) to capture the essence of validation logic and requirements,
but has presented a picture that is incomplete with respect to current practice. For example, UV
disinfection technologies exist that monitor/control on the basis of calculated dose and not on intensity as
a surrogate for dose. For reactors that use these calculated dose monitoring/controlling technologies, a
requirement for setting an UV intensity range as part of the reactor validation condition is not justified.
Emerick et al (2003) demonstrated that with such a reactor it was not appropriate to establish an intensity
sensor set point for dose delivery during reactor validation. These calculated dose monitoring/controlling
technologies are not referenced in the rule, and the rule could be used as a selection tool to bias the end
users from selection of calculated dose-based technologies already validated and in use, but not included
within the rule-s precis of validation. We do not believe that this is not the intention of the rule, and any
misuse or confusion resulting from the rule could be avoided by the rule deferring to the UVDGM for the
details of validation logic and requirements. This is already done, and it is necessary only to remove the
precis on validation requirements (the above cited paragraphs) from the rule.
The rule-s reference to validation under -worst case- conditions is flawed since there is no worst case
hydraulic condition that can be readily defined or known a priori (see Trojan Technologies- comments on
the UVDGM). Additionally, the above-cited paragraphs in the rule create confusion as to what would be
suitable operating parameters to monitor for validation of UV technologies that use dose-based vs
intensity-based approaches to monitoring/control. The embodiment within regulation of technology
details rather than focusing on the objectives of technology will create a barrier to technology evolution.
These errors and biases are also reasons for avoiding a precis of validation within the rule, and deferring
to the UVDGM for validation details.
Note, however, that the rationale for validation is an appropriate and essential content for the rule. If it is
necessary to provide a precis of validation requirements within the rule, then the rule should be expanded
to include reference to the calculated dose method for monitoring/control as well as the UV intensity
method. The rewording of the rule should be reviewed by manufacturers who provide both types of
monitoring/controlling technologies to ensure technical correctness and completeness. However, we feel
that the addition of this elaboration on validation might be over-extending the objectives of the rule and
not providing the detailed explanations that can be provided better and more completely within the
UVDGM.
REFERENCE
Emerick, R.W., Enlow, J.P., and Schegg, L.C. (2003). -Bioassay and dose monitoring performance of a
UV disinfection system for the North Tahoe Public Utility District-. In the Proceedings of the Water
Quality Technology Conference, Philadelphia, PA, Nov. 2-3, 2003.
Response: Response 922.
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 512
Comment ID: 11504
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Ultaviolet Disinfection
a. EPA should provide general guidelines in the UV Disinfection Guidance Manual that accompanies the
proposed LT2 ESWTR, rather than over-specifying restrictive design criteria that do not allow utilities the
flexibility to adapt treatment to their local conditions. Water quality conditions, treatment process trains,
and treatment challenges differ widely across the nation. EPA should structure the Guidance Manual in a
way that provides information that assists water utilities in considering this technology and addresses
basic factors that should be evaluated in the design of UV system, without being overly prescriptive. This
would allow greater flexibility for primary agencies with the best knowledge about their water quality and
treatment conditions to implement this technology in an effective manner.
Response: Response 922.
EPA Letter ID: 515
Comment ID: 11536
Commenter: Matthew Valade,, Hazen and Sawyer/Camp Dresser & McKee
Commenter Category: Consultants: (where self-identified)
Comment: opportunity to provide comments on the UV Disinfection Guidance Manual. We feel that the
recent draft of the UVDGM is a significant improvement over the Preliminary Draft and that the
comments received by EPA for that draft were effectively implemented. We commend the EPA and the
contract team on the significant effort and resulting improvements in the document.
Although the Draft UVDGM is a significant improvement over the earlier draft, there are several topics
that are still of concern. The most significant topic of concern is that of the UV reactor validation, as the
crux of effectively implementing UV disinfection for water treatment is the validation. The current
validation requirements, as presented in the Draft UVDGM, are overly complex and difficult to
understand. Simplification of the methodology and procedures presented in the Guidance Manual will
greatly benefit the industry by making the presenting the validation requirements in a more transparent
manner.
Additionally, greater usage of summary tables and examples in the Guidance Manual will allow for
greater transfer of information to the general users of the document. Highlighting significant information
in tabular form will allow users to easily understand the important topics in each section, with greater
detail remaining in the text of the document. Dificult topics, such as the validation fundamental, need
additional examples to explain the topics.
The Joint Venture has provided detailed comments of ht eUVDGM in the enclosed documents [See pdf in
EPA Letter 516]. If you require further explanation of
Response: Response 922.
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 516
Comment ID: 11737
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 7. U.V. GUIDANCE MANUAL
The methodology outlined in UVDGM is based on conservative assumptions of UV unit performance and
ensures that the reduction equivalent dose (RED) will still be conservative (as compared to dose). The
requirements for the Tier 1 approach are overly stringent and will be a challenge for most utilities to meet.
In addition, when compared to Tier 2, there does not appear to be a great deal of difference between the
two approaches. The mandatory validation procedures in the manual should be simplified and made more
understandable. The validation method should be changed from the reduction equivalent dose (which is a
UV dose with safety factors included), to one that is based on the UV dose and individual safety factors
that can be evaluated separately rather than being lumped together. Developing individual safety factors
will allow utilities that do extensive testing to have more flexibility in determining dose. A -tiered-
approach can be created using criteria dictating whether default safety factors are used or whether a utility
will need to develop specific safety factors for a UV reactor. Additional comments concerning the UV
Guidance Manual, prepared by DEP-s consultants, the Joint Venture of Hazen and Sawyer and COM are
provided as Attachment l[See pdfj.
Response: Response 922.
EPA Letter ID: 516
Comment ID: 11755
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Part Ill-Additional Comments on UV Guidance Manual
[See PDF; Excel file with data also provided]]
Response: Response 922.
EPA Letter ID: 523
Comment ID: 11692
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Clarity and simplicity will be needed if UV is expected to be the inactivation technology of
choice for compliance with the LT2.
Response: Response 922.
Comment Response for LT2ESWTR 8-401 December 2005
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EPA Letter ID: 530
Comment ID: 11994
Commenter: Bruno Ferrari,, Ondeo Degremont, Inc.
Commenter Category: Manufacturer/Vendor
Comment: CS Title: Comments focusing on "June 2003 Draft of the Ultraviolet Disinfection Guidance"
submitted by Ondeo Degremont, (ODI)
Company/Group/Association Name: Ondeo Degremont, Inc.
Comment:
[See pdf- comments on UVDGM]
Response: Response 922.
EPA Letter ID: 531
Comment ID: 11995
Commenter: Paul Swaim,, CH2MHill
Commenter Category: Consultants: (where self-identified)
Comment: CS Title: Comment focusing on "comments related to viruses and the use of adenovirus as a
regulatory basis merit consideration by EPA, as do the comments on off-spec water and CFD modeling"
submitted by Paul Swaim, CH2M HILL
Company/Group/Association Name: CH2M HILL
Comment: See attachment.
[See pdf]
Response: Response 922.
EPA Letter ID: 548
Comment ID: 12153
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: 4. Complexity of the Ultraviolet Disinfection Guidance Manual. The organization and
statistical analysis included in the UV manual are both complex and unclear. The manual appears to need
a great deal of work.
Response: Response 922.
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 548
Comment ID: 12191
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Comments on the Draft Microbial Laboratory Guidance Manual and its Appendices
for the Proposed Long Term 2 Enhanced Surface Water Treatment Rule Metropolitan Water District of
Southern California
General Comments:
1. The manual and its appendices refer to the required storage and shipping temperature for microbial
samples in various ways, including -<10°C and not frozen-, -between 0°C and 10°C-, —received at
>10°C or frozen-must be rejected-, -less than 10°C-, -1-4°C-, and -2-8°C-. It is best to be consistent
throughout the documents regardless of the analysis in order to maintain the integrity of the samples and
avoid confusion among the utilities and the laboratories analyzing the samples. If samples at 0°C and
10°C are unacceptable, the sample temperature must be specified as ->0°C and <10°C-.
2. EPA evaluated several studies that showed that the samples may be analyzed after 24 hours of transit
and storage without significant differences in E. coli concentrations. Based on these holding time studies,
EPA is proposing that the holding time for microbial samples be extended to 24 hours. It is suggested that
methods other than these must retain the 8-hour holding time for source water samples:
mFC -> NA-MUG
Colilert QuantiTray 2000
Colilert
mEndo -> NA-MUG
mTEC
Specific Comments:
1. Microbial Laboratory Guidance Manual, June 2003 Drafta. Section 2.2 Sample Temperature
Monitoring, 3rd line, p. 8
-Cryptosporidum and E. coli samples for LT2 -analyzed the same day- must be maintained below 10°C
to reduce biological activity during transport and must be refrigerated upon arrival at the laboratory (if not
analyzed right away).- (Insert bolded portion)
b. Section 2.2, 2nd paragraph, p. 9: There are two points that need clarification in this paragraph that
refers to: 1) Cryptosporidium samples that must be received -at <10°C and not frozen-; and 2) -samples
that were not collected the same day they were received, and are received at >10°C or frozen- must be
rejected. The first question is if samples that are at 10°C are acceptable or not - if they are, then it should
be clearly stated, e.g. -samples should be stored and transported at <10°C and not frozen-; if not, it
should say that samples at >10°C or frozen are not acceptable. The other QC requirement mentioned is
the rejection of samples that were not collected on the same day they were received. Both versions (April
2001 and June 2003) of EPA Methods 1622/1623 clearly identify the holding time for Cryptosporidium
samples as 96 hours from initiation of sample collection or filtration to elution. Therefore, as long as the
samples are kept at <10°C or <10°C, whichever is finalized, samples that are still within the holding time
of 96 hours, with enough time for the laboratory to schedule and perform elution, should still be
acceptable. Perhaps it should be specified also that systems should have prior arrangement with the
laboratory and should send the laboratory advance notification if samples are to arrive at the laboratory
within 24 or 48 hours of the end of the holding time.
c. Section 4.2.1.1, 1st paragraph, p. 47 (refer to General Comments #2)
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d. Section 3.9.2, 1st paragraph, p. 38
-Slides should be stored in a humid chamber in the dark at 0°C to 10°C-. Unless the freezing point of the
mounting medium, i.e., DABCO-glycerol or elvanol, is lower than 0°C, this statement should be modified
in order to prevent the slide (and the sample in it) from freezing. When mounting with elvanol, slides
must be stored in a dry box at 4-8 oC because elvanol will not set in a humid chamber.
e. Section 4.2.1.1, 2nd paragraph, p. 47
Samples for E. coli analysis must be kept between 0°C and 10°C during transport and not be allowed to
freeze. With the phrase -not allowed to freeze-, samples at 0°C are eliminated. However, it should be
clarified if this means ->0°C and <10°C- or ->0°C and
< 10°C-
f Section 4.2.1.3, p. 47
-To test sterility of newly prepared media-.incubate one plate, tube or bottle per each media batch-.-.
(Bolded phrase is added and crossed word deleted.)
g. Section 4.2.3.1, Incubation Time and Temperature, Table 4-5, p. 50
For mENDO~>NA-MUG and Les-ENDO~>NA-MUG, the table indicates an incubation time of 22-26
hours at 35 C+ 0.5°C.
Incubation time should be 22-24 hours for ENDO media samples because the sheen on coliform colonies
can fade between 24 to 26 hours.
h. Section 4.2.3.3, last sentence, p. 50
Standard Methods (SM, 20th ed.) recommends inserting - a sterile rinse water sample after filtration of 10
samples to check for possible cross-contamination or contaminated rinse water-. Metropolitan-s practice
for drinking water samples for many years has been to filter a maximum of 10 samples in a series, sterile
rinse water samples at the start and end of a series, rinses in between samples and changing the filtration
funnel for the next series, instead of ending a series -when 30 minutes or more elapse between sample
filtrations-. For non-potable water samples, e.g., source water or wastewater, SM recommends
decontamination of the filtration unit after each sample or an -additional buffer rinse of the filter unit
after the filter is removed to prevent carryover between samples-. Since source waters are expected to
have higher numbers of noncoliform and coliform bacteria, Metropolitan also recommends either
decontamination of the filtration unit or changing the filtration unit after each sample to prevent cross-
contamination between samples. In addition, filtration of sterile rinse water samples at the start and end of
the source water sample is recommended. Sterile disposable filtration units are commercially available
and may be used in lieu of glass filtration units.
i. Section 4.3.1, p. 51 (refer to I.e. above)
j. Section 4.4, Sample Volume and Dilution Guidance, p. 51, versus Section 4.4.3, Sample Volume and
Dilution Guidance for Multiple-Tube Methods, p. 52
Directions on the number of dilution needed are conflicting. In 4.4, -For MTF methods, the PWS will be
initially required to analyze five sample volumes of 10, 1.0, 0.1, 0.01 and 0.001 mL.- In 4.4.3, -Initially,
the PWS will be required to analyze four sample volumes (10.0, 1.0, 0.1, and 0.01 mL).- Which is
correct?
k. Section 4.5.3.2 Determination of E. coli Concentrations Using Multiple Tube Methods: p. 60 and 61.
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The guidelines for determining MPN values provided are confusing and may result in vastly different
results among analysts, particularly with variations similar to examples B and D. Additional examples or
ultimately a much more extensive MPN chart with four or five dilutions are needed.
2. Appendix C: EPA Method 1623 for Cryptosporidium and Giardia
(comments may also apply to Appendix B: EPA Method for Cryptosporidium)
a. Section 7.8, p. 10
Elvanol is not mentioned as a choice of mounting medium for slide preparation. Metropolitan has had
great success with this mounting medium. In the ICR method, sealing the cover slip with fingernail polish
was relatively easy due primarily to its smaller size (relative to the slide). In method 1623, sealing the
larger cover slip with fingernail polish becomes quite difficult because it is almost as wide as the well
slide. In addition, the accompanying precipitate that forms when DABCO-glycerol comes in contact
with the fingernail polish can interfere with the microscopic observation. If used properly, elvanol is
vastly superior to DABCO-glycerol as a mounting medium. While there may be some difficulty with
preparing elvanol in the laboratory, it is commercially available from Waterborne Inc. Metropolitan
strongly recommends that elvanol be considered as an option for mounting slides.
b. Section 7.10.3, p. 10
The required storage temperature for oocyst and cyst suspensions is at 0°C to 10°C and not allowed to
freeze. However, 0°C is freezing temperature for water that is the diluent for the Tween-20 or other
solutions used for the oocyst and cyst suspensions. Unless the solution does not freeze at 0°C,
the requirement must be changed to ->0°C and <10°C-.
c. Sections 8.1.2.2 to 8.1.3, p. 11 (refer to l.a. above)
d. Section 8.1.4.4, p. 12
Since stick-on temperature strips are not as precise as the other options, perhaps its use should be
eliminated. Incorrect temperature readings may cause a sample to be rejected by the laboratory, resulting
in wasted material, time and effort in collecting the sample.
e. Section 8.5, p. 13 (refer to 2.b. above)
f Section 11.3.5.12, p. 32
Slides must be stored -in the dark at 0°C to 8°C <10°C and not frozen-. Perhaps the intention here was to
cross out 8°C, but that still leaves the 0°C that is a freezing temperature, unless the mounting medium
does not freeze at this temperature and the integrity of the cysts and oocysts is kept. Requirements must
be modified accordingly.
g. Section 11.3.6.19, p. 33
Slides must be stored -in the dark at 0°C to <8°C (but not frozen)-. Temperature requirements must be
consistent - perhaps the intention here was to cross out 8°C instead of 0°C and replace it with 10°C.
Please refer to 2.f above.
h. Section 21.0, Table 4, p. 57
The asterisk after -Mean recovery- should be replaced with -1, 2-.
i. Section 22.0, p. 65
-Principle analyst- should be changed to -Principal analyst-.
3. Appendix D: Cryptosporidium Sample Results Acceptability Checklist for the
LT2 Rule
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a. General Requirement No. 1
Temperature requirement must be clarified and must be consistent throughout the documents - change -
between 0°C and 8°C- to the appropriate temperature range.
b. MS Sample Requirements
The two choices for sorting spiking suspensions (by flow cytometry or manually) should be included in
the checklist.
4. Appendix E: Cryptosporidium Laboratory QA Program Applicationa. Last paragraph
Notification of status of application must include estimated target period, e.g. within one month, two
months, etc.
b. Part 3, Principal Analyst and Analyst
Metropolitan recommends adding the following information (or modifying existing information):
No. of samples for protozoan analysis using IFA microscopy
Length of continuous bench experience with Cryptosporidium and IFA microscopy
Length of experience using EPA Methods 1622/1623
-Time in current position- does not assure EPA that the person has been doing the same analysis during
the whole period.
5. Appendix F: Cryptosporidium Laboratory QA Program Audit Checklist
a. Part A, 1.1.4, p. 5
The heterotrophic plate count must be written as -<500 CFU/mL-. (Bolded abbreviation should be
added)
b. Part A, 3.3, p. 7
The -Recommendation- that -current Method 1622/1623 bench sheets used to record sample processing
data- must be changed to -Requirement- to make the records consistent throughout the public water
systems.
c. PartB, 18.8 and 14.12, p. 13
DAPI and finished slides are stored -in the dark at 0°C to 8°C-. Again, the temperature requirement for
storage of solutions and finished slides must be consistent throughout the documents. Unless neither
DAPI nor the mounting medium (elvanol, not Evenol) would freeze at 0°C, the range above must be
changed.
d. PartB, 15.5, p. 14
The -Recommendation- that the mercury bulb be used less than the maximum hours recommended by
the manufacturer must be changed to -Requirement- because insufficient light could influence the
visibility of the cysts and oocysts, and therefore, affect quantification.
6. Appendix I: Standard Methods 9223B: Colilert®
a. 1.5, p. 1
-Colilert® is not for intended for use with marine waters.- (Delete first -for-.)
b. 4.1, last line, p. 1
Delete extra -may be-.
c. 8.1.1, 2nd paragraph, p. 2
Insert -and greater than 0°C- or -and not frozen- after -less than 10°C-.
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d. 8.1.2, last sentence, p. 2
-For non-potable water for compliance, do not exceed 6 hours holding time (including travel time) and
process within 2 hours.- (Insert bolded phrase to distinguish travel time or transport time from time the
sample is kept in the refrigerator).
However, the holding time for non-potable water samples may be extended to 24 hours using particular
methods including Colilert, as shown by the holding time studies that EPA has recently evaluated. The
24-hour holding time is being proposed under the LT2ESWTR.
e. 11.1.12, 1st line
Change -fluorescent- to -fluorescence-.
f 15.0, Verification Procedure, p. 4
Indicates -Not Applicable-
Standard Methods 20th Ed. has a verification procedure in section 9020B indicating that 10% of the
positive samples be verified. It is recommended that this be included in the procedure.
g. Refer to Appendix J, 11.1.14, p. 3
Metropolitan-s experience with Colilert® shows that samples may turn positive for total coliforms and E.
coli before 24 hours. Therefore, as in Colilert®-18, such results must be considered valid. Furthermore,
the Colilert® package insert form IDEXX also states that lack of yellow color in an inoculated Colilert®
sample that is incubated over 28 hours is a valid negative test. We recommend that EPA consider these
results for Colilert® valid.
7. Appendix J: Standard Methods 9223B: Colilert®-18
a. 8.1.1, 2nd line, p. 2
The temperature of the samples should be specified as -less than 10°C and greater than 0°C- (or not
frozen)
b. 8.1.2, last sentence, p. 2 (refer to 6.c. above for comment)
c. 11.1.14, p. 3
-Colilert®-18 results are definitive at 18-22 hours. In addition, positives for both total coliforms and E.
coli observed before 18 hours and negatives observed after 22 hours are also valid.- Metropolitan has the
same experience with this method as well as with the 24-hour Colilert® (refer to 6.g. above).
8. Appendix K: Standard Methods mEndo/LES-Endo NA-MUG and mFC NA-MUG
a. 2.a., last paragraph, 6th line, p. 3
Change -4 to 5 m- to -4 to 5 mm-.
9. Appendix L: EPA Method 1103.1
a. 6.23, p. 3
Water bath should be maintained at 44.5 + 0.2°C, instead of + 0.5°C (refer to
11.9, p. 8).
b. 8.1.1, 1st line and 8.1.2, p. 7
In this method, samples are kept at 1-4°C during transit that should not be longer than 6 hours between
collection and analysis. EPA has evaluated studies that showed that E. coli concentrations did not change
significantly in samples transported and stored for 24 hours below 10°C without freezing (p. 47734 of the
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proposed LT2ESWTR). These studies included mTEC as one of the methods used. In light of these
studies, increasing the holding time to 24 hours at <10°C without freezing for methods evaluated may be
appropriate, particularly since some systems have to transport their samples from the source to the
laboratory that will analyze them.
10. Appendix N: EPA Method 1604
a. 7.7.2, last line, p. 6
The method specifies 4°C as the storage temperature for the MI agar plates. It may be more realistic to
consider and include a range, e.g. 1-4°C, for storage temperature for media.
b. 8.2.1, 1st sentence, p. 6
The method specifies 1-4°C as the transit and storage temperature. Under the LT2ESWTR, EPA proposes
that microbial samples be kept at <10°C without freezing so that would include samples for E. coli
analysis as well.
c. 8.2.2, p. 6
Refer to 9.b. above. The holding time studies evaluated by EPA did not include the MI agar method
(Method 1604) as one of the analytical methods used. Without any evidence that the integrity of the
sample in retained after 24 hours when Method 1604 is used, it is best to remain within the recommended
holding time of 8 hours for source water when using this method.
d. This procedure does not have a verification section, but including verification is recommended.
11. Appendix O: m-ColiBlue24® Broth
a. 8.3, p. 4
As in Appendix N, 8.2.2, the holding time studies evaluated by EPA did not include the m-ColiBlue®
Broth as one of the analytical methods used. Therefore, it is suggested that the holding time of samples
remain at 8 hours when using this method.
b. 11.1.2, last sentence, p. 5
It is best to incubate plates with media-saturated pads grid-side up and not inverted to prevent the pad and
membrane filter from falling, resulting in loss of the sample.
c. 16.10, p. 8
Delete extra-1-before 1992.
d. This procedure does not have a verification section, but including
verification is recommended.
12. Appendix Q: E. coli Most Probable Number Sample Results Acceptability Checklist for the LT2 Rule
a. No. 1 and No. 2
Specify temperature for transport and storage as ->0°C and <10°C- or ->0°C
and <10°C, whichever is approved.
b. No. 2 and No. 7
LTB and EC-MUG were not among the methods used in the holding studies evaluated by EPA.
Therefore, it is suggested that the holding time for samples analyzed with LTB and EC-MUG remain at 8
hours between collection and analysis.
13. Appendix R: E. coli Membrane Filtration Sample Results Acceptability
Checklist for the LT2 Rule
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a. mEndo ~>NA-MUG and LES Endo --> NA-MUG should have an incubation period of 22 to 24 hours
instead of 24 + 2 hr. The sheen appearance on the colony can fade between 24 to 26 hours.
b. No. 1 and No. 2 (refer to 12.a. above)
c. No. 2 and No. 7 (refer to General Comments 2.)
Response: Response 922.
EPA Letter ID: 548
Comment ID: 12192
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Comments on the Draft Ultraviolet Disinfection Guidance Manual and its Appendices for the
Proposed Long Term 2 Enhanced Surface Water Treatment Rule Metropolitan Water District of Southern
California
General Comments:
1. Overall, the workability of the guidance manual is highly complex. It would be very challenging for
utility staff to pick up this manual and properly use it as UV guidance because of the following reasons:
(a) important information on specific topics is spread throughout the entire document (multiple report
chapters and appendices); (b) many individual topics (e.g., validation) are described as highly complex
issues that do not have sufficient examples that can walk someone through the process; and (c) there are
many verbose topics of little or no guidance value for utilities that will be searching for guidance in how
to meet regulations while operating UV disinfection.
2. Statistics are both too complex and poorly explained. In many places, you must be more of an expert in
statistics in order to understand how to properly use the equations given.
3. There is a poor, overall structure to the manual. It appears unorganized-adding to its complexity. There
needs to be more of an apparent organized feel to the manual. For example, to understand all necessary
issues of validation, one must read through most the entire guidance manual. This would be better
handled if there were a map (appendix?) of how to follow guidance on specific topics.
4. Guidance on reporting requirements/maintaining compliance needs to be revised to be more practical
for utility personnel.
5. Compliance requirements for non-filtered and filtered systems are not equivalent for off-spec
excursions (see comments below). This is not appropriate.
Specific Comments:
Chapter 1: Introduction
1. Delete section 1.3 - it is redundant and not necessary for guidance. However, keep a brief description
and guidance of how to interpret Table 1.4. This new text, with Table 1.4, should be an outline of how to
move through the manual, how to interpret the dose table, and how to find complete information on all the
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
different topics in the manual (without guessing where all the information can be found, which is what is
currently needed).
Chapter 2: Overview of UV Disinfection
1. The document would be best served if sections 2.1 through all of section 2.3 were moved into an
appendix as they only provide supplemental information.
2. Figure 2.10 should say -Example of UV Disinfection—.
3. Tables 2.1 and 2.2 should both say -Example Mercury Vapor-.-.
4. The y-axis in Figure 2.13 should say -Lamp output relative to maximum output in range per each data
set-.
5. Page 2-18, 1st paragraph, 1st sentence should say -Lamp sleeves can fracture and foul, and their
transmittance may decrease as they age.-
6. Page 2-18, 2nd paragraph, 2nd sentence should say -The UV reactor manufacturer may control
internal-.- & 4th sentence should say -Some compounds that may contribute to fouling are discussed-.-
7. Page 2-18, 2nd paragraph, last sentence: -solarization- is discussed, but it is not defined in the front -
please define this in the beginning of the manual for the reader.
8. Figure 2.15 should say -Examples of (a) Mechanical Wiper Systems—.
9. Regarding section 2.4.6, you may want to describe more reference sensor possibilities - such as is used
in the following paper: Mofidi, A.A.; Coffey, B.M.; Chou, C.I.; Mehta, H.M.; & Green, J.F. (2001)
-Demonstration-Scale Evaluation of UV Irradiation for Treatment of Surface Water,- Proc., AWWA
Ann. Conf., Wash., D.C. June 17-21, 2001.
10. Figure 2.1.6 should say -Example of a UV Intensity—.
11. An example of vagueness is illustrated on p. 2-22, under the 2nd approach to monitoring (i.e., 2. UV
Intensity and UVT Setpoint Approach). In the first paragraph, it states that —the UV sensor is placed
close to the lamp—, but it does not define what -close- is. This is misleading and confusing for the
reader.
12. Midpoint on p. 2-22 it states that dose monitoring recommendations are discussed in section 5.4.2 - it
is difficult for the reader to understand how to best use the manual when there is this shuffling through
the manual to understand different topics. Please re-organize the manual so that topics can be best
grouped together-or a better map is given to the reader so that these little -snippets- of hidden discussion
for different topics can be more easily located.
13. Due to the nature of validation (measurement of UV absorbance/transmittance is required), and the
need in reporting, does not that make the 1st setpoint approach (UV intensity only) something that
will not work from a reporting standpoint? This first approach should be removed & all systems should be
required to monitor for UV absorbance/transmittance.
14. Section 2.5, 1st paragraph, 1st sentence, change to -There are constituents in the water that may affect
the performance of UV disinfection.-
15. Section 2.5.1, 4th paragraph on p. 2-23 starting with -Fouling rate kinetics—. This paragraph
references section A.4.1.4 for how to use the LSI or CCPP - this appendix does not provide information
on how to use these indices.
16. Table 2.3 should say -Example of Water Quality Data—
17. Section 2.5.2, 2nd paragraph. Research has shown that the use of UV (at high doses) can increase
THM and HAA formation potential of water by 5 to 10 percent. Please see the following reference:
Mofidi, A.A.; Baribeau, H.; Green, J.F.; De Leon, R.; & Wolfe, R.L. (1998) -Disinfection Using High
Intensity Pulsed-Ultraviolet Irradiation,- Proceedings, AWWA WQTC, San Diego, Calif. Nov. 1-5, 1998.
Chapter 3: Planning and Design Aspects for UV Disinfection - the following title may be more
appropriate: -Planning and Design Aspects for Filtered Water UV Installations-
1. The -topics- that are discussed should not be introduced as questions - there should be more specific
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topics listed (on page 3-1). For example, use the following as the list for page 3-1:
a. UV installation goals 3.1.1
b. List of installation options 3.1.2
c. Off-specification issues and effects of water and power quality
3.1.3
d. Effect of UV reactor type on design UV technology 3.1.4
e. Validation options 3.1.4.3
f Operational strategies (this was not itemized onp.3-l)3.1.5
g. Evaluating hydraulics and footprint 3.1.6
h. Evaluating costs and benefits 3.1.7
i. Procurement options 3.2
j. Hydraulic/flow measurement requirements 3.3.1
k. Operation/monitoring strategy 3.3.2
1. Process instrumentation and controls issues 3.3.3
m. Electric power issues 3.3.4
n. Site layout issues 3.3.5
o. Equipment specification issues 3.3.6
p. Drawings and specifications issues 3.3.7
q. Reporting requirements 3.4
Having said the above, items -i-, -o-, and -p- do not need to be included in this body of text as they are
not important guidance issues. They should either be deleted completely, or moved into an appendix.
2. Figure 3.1 should say -Example Flowchart for-.-
3. The Giardia repair statement at the top of page 3-5 should be referenced.
4. The end of the paragraph at the top of page 3-5 should be changed to -Therefore, microbial repair of
bacteria may not affect UV installation design where secondary, residual disinfection is practiced.-
5. The 2nd paragraph on p 3-5 that starts with -To a degree— should be deleted. There is no useful
guidance there.
6. Section 3.1.2: The first paragraph that starts with -It is strongly recommended—should be deleted.
This guidance is for installation of UV downstream of filtration and other locations should not be
discussed.
7. Section 3.1.3: 4th paragraph w/ bullets that starts -The UV reactors— should be changed to -The UV
reactors may be off-specification-.-
8. Section 3.1.3.1: 2nd paragraph: instead of saying 1 NTU or less, it should say much less than 1, or even
less than 0.5 (we-re talking filtered water here-).
9. Section 3.1.3.1: 3rd paragraph: change to -Prior to UV implementation, water quality data should be
collected-.-
10. For Table 3.5, the authors should show a table of raw data & how to calculate the data presented in the
figure (some will not know how to do this).
11. Should the guidance be based on UV transmittance or UV absorbance? The actual measure that is
done by the utility/consultant would be UV absorbance, correct? Because of this, the guidance should be
changed to talk about UVA, not UVT.
12. Page 3-14, -Lamp Fouling/Aging Factor-, 2nd paragraph, 1st sentence should say -Reduction in
lamp output or shifts in spectral output may result in a reduction in UV dose.-
13. What aging factor should be used? How can this be determined? There is no guidance for this.
14. Page 3-15, -Impacts of Upstream Treatment Processes— The paper described above by Mofidi et al.
has a good deal of information describing how upstream processes affect UV disinfection performance.
This should be referenced or discussed. The reference is as follows: Mofidi, A.A.; Coffey, B.M.; Chou,
C.I.; Mehta, H.M.; & Green, J.F. (2001)
-Demonstration-Scale Evaluation of UV Irradiation for Treatment of Surface Water,- Proc., AWWA
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Ann. Conf., Wash., B.C. June 17-21, 2001.15. Section 3.1.3.3. The last paragraph on page 3-17 should be
deleted. Off-spec operation cannot be tied to log inactivation performance. 16. Table 3.2 should say -
Possible Start and Restart—17. Delete the last paragraph on page 3-19 starting with -The most suitable-
.-. This is not necessary to state and may lead to confusion or over-guidance by States.
18. For the 2nd paragraph on page 3-20, Change the opening sentence to -Where economically feasible
(though not mandatory), utilities may desire to have a complete WTP-wide assessment-
19. For the last paragraph on p. 3-21 where it states, -This is discussed in greater detail in section 3.1.7.-
- there really isn-t any greater detail there. This should be deleted.
20. Off-site versus on-site validation starting on page 3-23 is too verbose. Most of this text (through page
3-27) could be removed without any detriment to the manual.
21. Section 3.1.7, 1st paragraph, 1st sentence, change to -The amount of analysis necessary to determine
the appropriate post-filtration location for a UV installation is site-specific.-
22. Section 3.2 is not needed in this document - this should either be deleted or moved to an appendix.
23. All -secondary recommendations- in section 3.3 are confusing because the comments are very vague.
Much of this section-s text should be deleted. Is this mandatory information? Validation work will be the
ultimate -clarifier- for these topics and so it seems that this section is redundant and confusing. Much of
the text presented does not necessarily help - it is basically telling the reader that you need a consultant if
you do not know how to do what is presented.
24. Section 3.3.5 should be renamed -Example UV Disinfection Layouts.-
25. Tables 3.9 and 3.10 should be renamed as -Example- instead of-Recommended.-
26. In section 3.4.1, remove the 1st sentence -The State may require that a pre-design report be submitted
that summarizes the decision logic used to identify, evaluate, and select UV disinfection.- This
information provides additional requirements on planning and design that many States may use in good
will, but may significantly slow down design work. Of course, utilities should be guided to work with
States, but setting -requirements- of this nature may be prohibitive to the progress of design/construction.
27. Same as comment #26, comments in sections 3.4.2, 3.4.3, and 3.4.4 recommending that pre-design
report, drawings and specs, validation reports, and as-builts be approved by the State is an overly-
burdening recommendation. This text should be removed.
Chapter 4: Overview of Validation Testing
1. Third-party oversight (Section 4.2.3) should be done by a registered professional engineer (an
independent consultant or engineer hired by the utility or design engineer). Oversight by this engineer-
knowledgeable in validation testing and UV operations-will provide insight for the utility/design
consultant on how to handle all of the areas that are ambiguously discussed in the guidance manual.
Therefore, much of the vague recommendations in the guidance manual can be removed without worry.
2. Section 4.3.2.2 on control strategies: Validation conditions are supposed to be met by the utility during
operations in order to show compliance. In other words, validation conditions will need to show UV
intensity sensor measurements, flow rate, and UVT. Therefore, strategy # 1 is invalid or a mute point
because UVT needs to be known in order to match up with validation conditions. Therefore, based on
this, there are only two valid strategies, -UV intensity/UVT setpoint- and -Calculated dose.-
3. Section 4.3.2.4 on lamp aging: Is the guidance mandating re-validation with aged lamps? The
recommendations are confusing and need to be clarified.
4. Figure 4.3 should be renamed as -Example Biodosimetry Test Components.-
5. The first paragraph in section 4.5.1 starting with -Dose-response curves should initially be generated-
.- should be completely deleted. This is information that the 3rd party engineer would know best to
handle.
6. Section 4.5.1.2, subsection 3: It is unclear why different confidence levels are specified (95 and 80
percent) and why the reference to section C.4.9.7 is made - this is confusing.
7. Section 4.6.1: It is unclear where uncertainty numbers for the reference sensor and the duty sensor will
come from. In addition, how do you get uncertainty for a UV spectrophotometer for the UVA
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measurements? Should this refer to the instrument error?
8. Section 4.6.2: Is this information practically available?
9. Section 4.6.3: Where do you get flow meter uncertainty?
10. Section 4.6.4: How do you calculate collimated beam measurement uncertainty of+/- 15 percent at an
80 percent confidence?
Chapter 5: Start-Up and Operation of UV Installations
1. This section provides a great deal of information on different aspects of the UV reactor that needs to be
operated/maintained. However, there is a lack of information as to how operators will need to respond to
changes in operations. The decision trees are helpful (Figures 5.4, 5.5), but hidden in the chapter and
challenging to read through. It is recommended that a more simplistic, straightforward approach be
outlined at the beginning of the chapter.
2. Change title of Table 5.6 to -Recommended Monitoring Parameters and Recording Frequencies.-
3. Change title of Table 5.7 to -Additional Monitoring Parameters and Recording Frequencies- and delete
the turbidity requirements (this should already be monitored by the plants).
4. For Figures 5.4 and 5.5, what is off-spec operation? If operation is off spec, is the UV system in
violation, or is it a performance situation that needs to be corrected? Guidance on how to respond to
changes in operation needs to allow operators to change operation before the UV system enters
into violation.
Appendix A: Fundamentals of UV Disinfection
On page A-56, it mentions using LSI to estimate fouling potential. However, it does not give guidance on
how to do this. Because this is a guidance manual, there should be an example of how to do this.
Appendix B: Derivation of UV Dose-Response Requirements
The Mofidi et al. 1999 reference is incorrect. It should be Mofidi et al. 2001 and the full reference should
be given as follows: Mofidi, A.A.; Baribeau, H.; Rochelle, P.A.; De Leon, R.; Coffey, B.M.; & Green,
J.F. (2001)
-Disinfection of Cryptosporidium parvum with Polychromatic UV Light,- Journal
AWWA 93:6:95-109.
Appendix C: Validation of UV Reactors
1. It is hard to understand if this is exactly what needs to be followed while validating UV reactors, or is it
this appendix plus what is stated in the bulk of the UVDGM text? There is information that is placed in
both places that is independent of the other.
2. For C.4.9.7 (p C-27), what UVT is recommended for testing (unadjusted)? Moreover, it states that -A
one-liter influent sample should be sufficient for measuring the challenge microorganism UV dose-
response—why can a separate sample be not made from the titer to get a ~>105/mL result for
the collimated-beam dose-response? I would think that it would work either way.
3. Regarding the -Fitting Dose-Response Data- on p. C-28, the non-linear curve fit guidance for dose-
response kinetics of MS-2 should be deleted. The dose response of MS-2 is linear, and this has been
proven in the literature.
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4. Provide guidance in how to get the P-statistic values given in the examples. This is unclear.
5. Much of the example is hard to follow and difficult to understand.
6. The UVDGM should keep with 80 percent or 95 percent Cl-s-it jumps around between the two and is
confusing.
7. Uncertainty assumptions are confusing - how are the uncertainty values determined? Provide guidance.
Appendix F: Background to the UV Reactor Validation Protocol
Figure F.I should be renamed -Theoretical Worst-Case Dose Distribution Estimated to be Delivered by a
UV Reactor -
Appendix G: Issues for Unfiltered Systems
This section should be deleted.
Appendix H: Issues for Ground Water Systems
This section should be deleted.
Appendix L: Regulatory Timeline
Figure L. 1 should have the years in the table changed to year 1, year 2, year 3, etc- instead of giving
actual years.
Appendix M: Compliance Forms
These forms need to be changed significantly due to comments made above (change from volume-based
monitoring, etc.)
Appendix N: UV Lamp Breakage Issues
This section should provide clear guidance on what to do if a lamp breaks and what to report to the States
if this happens while delivering water.
Appendix O: Case Studies
There is a 2001 AWWA Annual Conference paper that would provide a great deal of insight into how
changes in water quality, etc. affect changes in UV system operation. This paper would be a good -case
study-, even though it is a description of demonstration-scale testing at Metropolitan Water District
of Southern California. Please consider including this -case study- in Appendix O. The reference for the
paper is as follows: Mofidi, A.A.; Coffey, B.M.; Chou, C.I.; Mehta, H.M.; & Green, J.F. (2001) -
Demonstration-Scale Evaluation of UV Irradiation for Treatment of Surface Water,- Proceedings,
AWWA Annual Conference, Washington, D.C. June 17-21, 2001.
Response: Response 922.
Comment Response for LT2ESWTR 8-414 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 556
Comment ID: 12076
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: lamblia in the final rule. The UV Disinfection Guidance Manual should be revised to focus on
a single decision-making process that ensures that operating the applied UV doses will result in a dose
that is reliably equal to or greater than the required dose in the rule text.
This process has to be articulated in a clear and simple way for ease of implementation, but this process
cannot impede the rapid advancement of UV technology in drinking water treatment. AMWA appreciates
the efforts of the Agency to encourage and ensure stakeholder involvement in the development of the
necessary guidance manuals and believes that a reasonable process can be developed in conjunction with
the UV stakeholder group.
Response: Response 922.
EPA Letter ID: 560
Comment ID: 14995
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: [SEE pdf for comments 3 -6 and other comments on UVDGM]
Response: Response 922.
EPA Letter ID: 562
Comment ID: 12313
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.10 Ultraviolet Light
Inactivation using ultraviolet light (UV) is the low-cost compliance technology for the LT2ESWTR. The
UV Disinfection Guidance Manual must ensure that UV is a usable technology. AWWA believes that the
UV Disinfection Guidance Manual represents an important step forward in advancing UV as a
Response: Response 922.
EPA Letter ID: 562
Comment ID: 12498
Comment Response for LT2ESWTR 8-415 December 2005
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: (§5.3). AWWA believes that UV Disinfection Guidance Manual needs to be much
clearer in order to meet the proposed regulatory requirements on a national scale. AWWA-s main
concerns are outlined below.
Generic Application of UV Disinfection Guidance
The purpose of the UV Disinfection Guidance Manual as envisioned by the Stage 2 M/DBP FACA was to
facilitate implementation of UV on a national scale. The FACA discussed several principles:
1. Identifying information needed to ensure that utilities could obtain apples-to-apples comparisons
among different reactor designs;
2. Facilitating primacy agency approval of UV systems;
3. Educating the -average- drinking water system design engineer who is not as familiar with designing
UV systems as clarification systems, filters, membranes, etc.; and
4. Informing water treatment plant operators about operational issues related to UV systems.
While the draft guidance manual has made significant progress toward three of these four objectives, the
draft may not facilitate primacy agency approval of UV systems, at least, not with any sense of national
consistency. In promulgating the LT2ESWTR and Stage 2 DBPR, the agency is assuming that UV
will be a readily available treatment technology throughout the United States. At present, the draft UV
Disinfection Guidance Manual is presenting UV disinfection in a manner that may not lead primacy
agencies to form technically sound policies on UV that will allow its practical and timely adoption by the
drinking water utility community. The requirements may not result in consistent implementation among
the various primacy agencies. In particular, EPA should encourage primacy agencies to:
1. Accept results of validation testing per guidance manual or other EPA accepted protocol, and
2. Use the ranges of validations and supporting CFD analysis to approve reactors and -dose- for
individual water treatment plants within the parameters tested without additional testing by the utility.
UV System Design
EPA is engaged in preparing three regulatory actions that will increase the installation of UV at individual
drinking water utilities (i.e., the LT2ESWTR, the Stage 2 DBPR, and the Groundwater Rule [GWR]). The
UV Disinfection Guidance Manual provides information that assists these utilities in considering UV
disinfection, but EPA needs to ensure that its guidance does not potentially impose a national design -
straight jacket.- For example, the heavily structured validation process in Germany has allowed UV
implementation, but UV manufacturers and consultants indicate that such an approach severely limits
innovation in reactor design and operation.
EPA has a considerable reservoir of UV expertise at its disposal, but information is limited about the site-
specific circumstances for retrofits or greenfield designs at the hundreds of individual water treatment
facilities that will install UV to comply with the LT2ESWTR. Therefore, the agency-s guidance should
be limited to the factors that should be considered in the design of an UV system and the provision of
practical examples. EPA should not be engaged in setting a de facto national design standard. For
example, the draft guidance manual recommends hydraulic conditions of straight pipe for 10 pipe
diameters upstream and 5 pipe diameters downstream. This many not be possible for validation and
installation in existing, tight filter galleries. As another example, the draft guidance manual strongly
discourages post-clearwell UV installations. While post-clearwell installations present significant
challenges, installation of UV between the filters and the clearwell may be inappropriate or infeasible in
Comment Response for LT2ESWTR 8-416 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
certain circumstances. If EPA severely discourages post-clearwell installation in its guidance, during
actual permitting by primacy agencies, this -advice- will become a de facto prohibition.
Response: Response 922.
EPA Letter ID: 562
Comment ID: 12506
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Tier 1 Requirements
The Tier 1 requirements are, as AWWA understands them, intended to provide a streamlined approach to
approval of a UV reactor. Safety factors are introduced that, in combination, result in a conservative
estimate of delivered UV dose that is well in excess of primacy agency expectations for design
conservatism. While AWWA questions the level of conservatism imposed through the Tier 1
requirements, another practical point EPA should be aware of is that the information needed to comply
with the Tier 1 requirements is not generally available. Some examples include variability in lamp output
and uncertainty in accuracy of some types of flow meters. Requiring data not generally available from
manufacturers ~ as it is not important to the actual design of the equipment or compliance with standards
bodies ~ illustrates an overly complex level of evaluation that is beyond what is needed to ensure
LT2ESWTR compliance.
AWWA, through CH2M Hill, conducted an example Tier 1 analysis of an existing low-pressure lamp UV
installation. The report from that comparison is attached in Appendix 8. In summary, this review found
that current Tier 1 criteria are in excess or different from standard engineering practice in several respects.
The following Tier 1 criteria that were not met in this analysis included: sensor location; NIST traceable
sensor standard and sensor uncertainty; lamp variability; and confidence intervals on dose. The review
also identified a number of other validation requirements included in guidance that are unclear with
respect to compliance expectations. Examples include evaluation of lamp and sleeve aging, adherence to
QA/QC sample enumeration, inclusion of low-UVT/high-power and high-UVT/low-power test points,
and UV intensity sensor evaluation. We discuss specific modifications to the Tier 1 protocol
recommended in the review in the Appendix.
The agency should remove the Tier 1 appraisal from the final guidance document per the previous
recommendation. The Tier 1 appraisal currently provides a useful starting point for the development of
default assumptions included in the single decision-making process described above.
Response: Response 922.
EPA Letter ID: 562
Comment ID: 12511
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The guidance manual discusses uninterrupted power supplies (UPS) and back up
power as necessary to ensure system reliability. AWWA believes dual power feeds and/or back up power
Comment Response for LT2ESWTR 8-417 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
supply are important to ensure reliability. UPS is estimated to increase the cost of UV by 5% to 10% for
each installation. An ongoing AwwaRF project is specifically addressing power supply issues
surrounding UV disinfection. This project will be completed prior to the promulgation of the final
LT2ESWTR and EPA should incorporate it into the inal guidance manual.
Maintaining -Validated Conditions- Over Time
Over the life of the UV system, ongoing operations and maintenance of the UV system will necessarily
lead to changes in the components in the UV reactor and monitoring system. Changes will stem from
equipment design life, component failure, planned obsolescence in manufacturer inventory, and
technological advances. Such changes will range from changing lamps and sensors to updating
monitoring software and even replacing reactors. Some activities in this spectrum clearly do not warrant
re validation.
Changing reactors would clearly necessitate interaction with the primacy agency and presentation of
information about the new reactor. However, the replacement of lamps, sensors, software, and other
routine maintenance activities associated with UV operation should not automatically trigger revalidation
and interaction with the primacy agencies. In these instances, the utility has an obligation to review the
specifications for the relevant component of the UV system, comparing those specifications to those of
the replacement component. Where the replacement component is compatible and equal to or superior to
the initial validated system component specifications, then the use of an alternate component (even
components by a different manufacturer) is appropriate. Maintenance records should be kept to document
this type of comparison and such records should be available for the primacy agency to review, if it so
chooses, during its regular sanitary survey inspection.
Response: Response 922.
EPA Letter ID: 562
Comment ID: 12514
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Lamp Breakage
System isolation and quick valve closing are not practical solutions to lamp breakage due to water
hammer and mechanical / hydraulic limitations. Breakage will result in small amounts of mercury release
into water systems before automatic or manual systems can isolate the problem. In endorsing and
encouraging UV as a disinfectant technology for drinking water, EPA must address this issue. The agency
should:
1. Openly disclose the mercury exposure risk tradeoff and demonstrate that under realistic scenarios it
presents a de minimus risk; and
2. Clearly articulate in the UV Disinfection Guidance Manual that the development of a site-specific
mercury spill response plan that employs practical and prudent steps to minimize mercury releases is
sufficient to reduce any risk associated with mercury to a de minimus level.
Response: Response 922.
Comment Response for LT2ESWTR 8-418 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 587
Comment ID: 12015
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: The draft Ultraviolet Disinfection Guidance Manual (UVDGM) is a substantial document.
The authors should be commended for the thorough and detailed analysis of the issues and complexity
that surround this technology. The manual is well written and comprehensive. The focus of my review
was on those issues that are expected to most significantly impact State implementation of ultraviolet
(UV) disinfection, specifically monitoring and validation that will impact the inactivation credit assigned.
General Comments
Response: Response 922.
EPA Letter ID: 587
Comment ID: 12019
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: D) Validation Protocols
The most significant concern with the draft UVDGM is the validation approaches outlined in Chapter 4.
The defined parameters of the Tier 1 approach are preferred over the uncertainty and ambiguity of the
Tier 2 approach. The extreme flexibility of the Tier 2 approach results in an almost infinite set of dose
requirements. This "Tier Infinity" approach is a significant concern.
Response: Response 922.
EPA Letter ID: 587
Comment ID: 12022
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: 4. Tier 2 default values in the calculator tool need to be clearly defined and labeled for the
user. Users of the tool will likely use the default values without a true knowledge of the implications of
their use. The department questions whether it would be more appropriate to remove default values
altogether. If the user is unable to get actual lamp output data, etc., they probably should not be using the
tool for a Tier 2 calculation.
5. We have not been able to substantiate UVDGM statements that the spectral output of a medium
pressure lamp shifts with age. We have received data from two different manufacturers showing that the
medium pressure lamps do not exhibit a spectral shift.
Comment Response for LT2ESWTR 8-419 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
6. If an unfiltered sensor is used with a medium pressure lamp for a validation effort, and no spectral shift
occurs (or aged lamps are used in the validation), why is this an issue? If it is not an issue, the use of an
unfiltered sensor should be included in the Tier 1 approach.
7. The allowance of dose-based control algorithms presents problems for primacy agency ongoing
tracking. A change in a single line of control algorithm code could impact the validated conditions -yet
the State has little ability to verify algorithm codes, much less to even know what changes are occurring.
8. Please include information of statistical parameters in an appendix with at-test table. It would be
helpful to have all the necessary statistical parameters for UV reactor validation included in one location.
UV Reactor Monitoring, Reporting, and Compliance Calculations -Specific CommentsThe creation of
appropriate and effective W monitoring and reporting requirements has been a significant issue
surrounding efforts toward implementing W treatment in Washington State. In partnership with the EPA,
the Department of Health developed daily and monthly W monitoring requirements as defined in a joint
Memorandum of Agreement (MO A). Daily and monthly reporting has significant implications for the
utility and for the primacy agency.
Response: Response 922.
EPA Letter ID: 587
Comment ID: 12026
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: 4. Standardize Monitoring Components - Although there are some requirements for UV duty
and reference intensity sensors in the Tier Ivalidation approach, the requirements are not as stringent as
those in the NWRI and DVGW W294 standards. The UV intensity standards should be more explicit and
there should be similar quality control standards cited or developed for UVT monitors.
5. Continuous Monitoring - In Table 5.6 of the UVDGM, it is recommended that key monitoring
parameters be recorded every four hours. A four hour recording and reporting frequency is not
appropriate for this technology. W disinfection is a sophisticated treatment process that relies on
continuous monitoring for ensuring effective pathogen inactivation. The recording and reporting
requirements should reflect the sophistication of the treatment system. Key parameters should be recorded
every minute with the most critical value (Le. lowest value for UV intensity) reported on a daily basis for
each flow rate. A verification that the lowest value was above the minimum required (e.g. operated
within validated conditions) should be required for each day. If the system was outside of the validated
conditions, then the duration of the "off-spec" operation should be determined and reported.
6. UV Reactor Start-up - The department is evaluating how to require reporting and recording of
treatment parameters during UV lamp warm-up periods. Filter-to-waste or the use of treated water during
lamp warm-up are viable design options. Section 3.3.3.1 and Section 5.2.3.1 of the UVDGM should more
strongly discourage the discharge of inadequately treated water to the distribution system. There are a
number of design alternatives, such as re-circulation systems and the use of treated water during start-up
that would eliminate the discharge of inadequately treated water. We do not envision allowing designs
Comment Response for LT2ESWTR 8-420 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
that allow inadequately treated water to be delivered to the clearwell or distribution system as a routine
operational practice.
7. UV Intensity Sensors - Please continue to include the requirement for measurement of UV intensity
sensors as a reportable parameter. The on-line intensity sensor requirement is essential to defining the
operating conditions under which a reactor is validated. The dose control approach involves the use
of algorithms to calculate the reduction equivalent dose (RED) under a certain set of conditions. While
the simplicity of the output is easy to understand, the manufacturer can adjust the algorithms. Flow rate,
UV intensity, and W transmittance are directly measured parameters that should be included on the
monitoring form.
Other Minor Comments on the UV Disinfection Guidance Manual
The analysis of validation conditions involves significant statistical analysis. Please consider including an
appendix that summarizes statistical analysis applicable to UV reactor validation including examples for
calculation of statistical significance and at-testtable.
(Pg. C-26) Section C.4.9.5 -
The first paragraph in this section of this paragraph recommends at least three influent and effluent
samples be collected for each test condition, while the Tier Ivalidation criteria require five influent and
effluent samples be collected for each test condition. The recommended number of samples should be
modified reference made to the five samples required under Tier 1
(Pg. C-38) Section C.4.10.1-
The proposed protocols lack adequate biological QNQC parameters and procedures. It is recommended
that the NWRI collimated beam dose response quality control parameters for MS2 coliphage and Bacillus
subtilus be included in any validation approach.
(Pg. 1-3) Section 1.5 -
Please note that not all conventional low pressure reactors need three phase power. Smaller reactors run
on 120/240V single phase power, which is typically what is available in remote locations.
Other Comments
During the Workgroup discussions regarding the Draft UVGM, held in Washington D.C. on December 8-
10, 2003, the idea of an UV implementation approach using a single dose standard for target pathogen
inactivation, with safety factors applied separately for the validated reactor and site specific conditions
was proposed. This approach should be easier to implement and explain than the current Tier 1 / Tier
Infinity approach proposed. A single approach for applying safety factors to the reactor based upon
validation results should be implemented in the UVDGM.
A set of default safety factors should be developed to simplify implementation. The default values could
be based on a sensitivity analysis of the impacts of different parameters (i.e., UVT for different lamp to
sensor distances) for set ranges. A table that lists these default parameters should help primacy agency
and utility implementation efforts.
Response: Response 922.
Comment Response for LT2ESWTR 8-421 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 603
Comment ID: 12641
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Please consider a tightened Tier luncertainty criteria for lower applied doses in lieu of the
complexity and ambiguity of the Tier 2 validation approach. Detailed comments are provided in
Attachment C.
Response: Response 922.
EPA Letter ID: 603
Comment ID: 12689
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Tier 2 default values in the calculator tool need to be clearly defined and labeled for the user.
Users of the tool will likely use the default values without a true knowledge of the implications of their
use. The department questions whether it would be more appropriate to remove default values altogether.
If the user is unable to get actual lamp output data, etc., they probably should not be using the tool for a
Tier 2 calculation.
We have not been able to substantiate UVDGM statements that the spectral output of a medium pressure
lamp shifts with age. We have received data from two different manufacturers showing that the medium
pressure lamps do not exhibit a spectral shift.
If an unfiltered sensor is used with a medium pressure lamp for a validation effort, and no spectral shift
occurs (or aged lamps are used in the validation), why is this an issue? If it is not an issue, the use of an
unfiltered sensor should be included in the Tier 1 approach.
The allowance of dose-based control algorithms presents problems for primacy agency ongoing tracking.
A change in a single line of control algorithm code could impact the validated conditions- yet the State
has little ability to verify algorithm codes, much less to even know what changes are occurring.
Please include information of statistical parameters in an appendix with a t-test table. It would be helpful
to have all the necessary statistical parameters for W reactor validation included in one location.
UV Reactor Monitoring, Reporting, and Compliance Calculations The department has been grappling
with UV monitoring and reporting requirements in response to a specific UV installation project currently
under development and is preparing to issue inactivation credit for the UV facility. In partnership with the
EPA, we have developed daily and monthly UV monitoring requirements as defined in a joint
Memorandum of Agreement (MO A). Daily and monthly reporting have significant implications for the
utility and for the primacy agency.
Response: Response 922.
Comment Response for L T2ESWTR 8-422 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 603
Comment ID: 12693
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: 4. Standardize Monitoring Components -Although there are some requirements forW
duty and reference intensity sensors in the Tier 1 validation approach, the requirements are not as
stringent as those in the NWRI and DVGW W294 standards. The W intensity standards should be more
explicit and there should be similar quality control standards cited or developed for W T monitors.
5. Continuous Monitoring -In Table 5.6 of the UVDGM, it is recommended that key monitoring
parameters be recorded every four hours. We believe that a four hour recording and reporting frequency is
not appropriate for this technology. W disinfection is a sophisticated treatment process that relies on
continuous monitoring for ensuring effective pathogen inactivation. The recording and reporting
requirements should reflect the sophistication of the treatment system. Key parameters should be recorded
every minute with the most critical value (i.e. lowest value for UV intensity) reported on a daily basis for
each flow rate. A verification that the lowest value was above the minimum required (e.g. operated within
validated conditions) should be required for each day. If the system was outside of the validated
conditions, then the duration of the off spec operation should be determined and reported.
6. UV Reactor Start-up - The department is evaluating how to require reporting and recording of
treatment parameters during UV lamp warm-up periods. Filter-to-waste or the use of treated water during
lamp warm-up are viable design options. Section 3.3.3.1 and Section 5.2.3.1 of the UVDGM should more
strongly discourage the discharge of inadequately treated water to the distribution system. There are a
number of design alternatives, such as recirculation systems and the use of treated water during start-up
that would eliminate the discharge of inadequately treated water. We do not envision allowing designs
that allow inadequately treated water to be delivered to the clearwell or distribution system as a routine
operational practice.
Please continue to include the requirement for measurement of UV intensity sensors as a reportable
parameter. The on-line intensity sensor requirement is essential to defining the operating conditions under
which a reactor is validated. The dose control approach involves the use of algorithms to calculate the
reduction equivalent dose (RED) under a certain set of conditions. While the simplicity of the output is
easy to understand, the algorithms can be adjusted by the manufacturer. Flow rate, UV intensity, and UV
transmittance are directly measured parameters that should be included on the monitoring form.
Other Minor Comments on the UV Disinfection Guidance Manual
The analysis of validation conditions involves significant statistical analysis. Please consider including an
appendix that summarizes statistical analysis applicable to W reactor validation including examples for
calculation of statistical significance and at-testtable.
(Pg. C-26) Section C.4.9.5 -
The first paragraph in this section of this paragraph recommends at least three influent and effluent
samples be collected for each test condition, while the Tier 1 validation criteria require five influent and
effluent samples be collected for each test condition. The recommended number of samples should be
modified reference made to the five samples required under Tier 1.
(Pg. C-38) Section C.4.10.1-
The proposed protocols lack adequate biological QNQC parameters and procedures. It is recommended
that the NWRI collimated beam dose response quality control parameters for MS-2 coliphage and
Bacillus subtilus be included in any validation approach.
Comment Response for L T2ESWTR 8-423 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
(Pg. 1-3) Section 1.5-
Please note that not all conventional low pressure reactors need three phase power. Smaller reactors run
on 120/240V single phase power, which is typically what is available in remote locations.
Response: Response 922.
EPA Letter ID: 628
Comment ID: 12856
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: systems, which may require the procurement and installation of large UV reactors. For larger
reactors, CFD modeling may be an alternative cost-effective validation method. The EPA should consider
the use of CFD analysis as an additional alternative to the required site-specific flow testing.
Response: Response 922.
EPA Letter ID: 678
Comment ID: 14722
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: IV. Comments on UV Disinfection Guidance Manual
1. The sections on UV scientific background and system design and operation are informative and useful.
However, the manual is quite lengthy, and it would be helpful to have those sections broken out of the
regulation itself into a separate users manual. That would greatly unclutter the substance of the
regulations.
Response: Response 922.
EPA Letter ID: 678
Comment ID: 14726
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. Appendix E of the Manual. The accuracy of the collimated beam procedure may be
compromised by the presence and turbulence of the stirbar, which could exacerbate clustering, and the
refraction and differential depth caused by the possible cyclone created by stirring. For this and other
technical and economic reasons, we feel that the EPA should perform or sponsor highly rigorous
collimated beam tests, which would be published for use by all utilities and manufacturers.
Comment Response for L T2ESWTR 8-424 December 2005
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Response: Response 922.
8.16.5 Comment Codes 923, Guidance on UV
Individual Comments on Code 923
EPA Letter ID: 101
Comment ID: 16536
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Ultraviolet Light Draft Guidance Document
Small System Standards, Validation and Testing
The guidance document should encourage regulatory agencies (including county and city boards) to allow
all water systems that treat less than 50 gallons per minute to rely on NSF approved UV technology. This
will eliminate much confusion, burden, and cost on small systems.
Response: Response 922.
EPA Letter ID: 562
Comment ID: 15050
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: New UV Technology Acceptance
The UV Disinfection Guidance Manual is written based on low-pressure UV lamps and physical testing
experience at the Portland UV Test Facility operated by Carollo Engineers. Austria, Germany, and New
York State also operate testing facilities. Individual manufacturers have in-house testing facilities as
well. NSF is also revising its protocols to support validation of UV reactors for LT2ESWTR application.
Reactors will be validated and installed throughout the country. The UV Disinfection Guidance Manual
needs to provide a level playing field (i.e., data from any facility performing validation tests that conform
with the guidance manual should be accepted) for all of these facilities to validate UV reactors and
provide clear expectations for validation studies so that utilities obtain information that is usable,
meaningful, and comparable. The guidance manual also needs to maximize the potential for primacy
agencies to accept validation work performed in other states or countries.
The draft guidance does not presently provide a level playing field across available UV technologies. The
draft guidance penalizes medium-pressure UV lamp systems due to handling of polychromatic bias.
Polychromatic systems are required to have a 20% higher dose than monochromatic systems. The
proposed approach to polychromatic bias in Section 4 and Appendix C of the guidance does not reflect
the full impact of polychromatic spectra on Cryptosporidium oocysts. Consequently, the draft guidance
requires greater UV dosage from UV systems that employ medium pressure lamps than from systems
that employ low-pressure lamps.
The manual needs to recognize that UV disinfection is a rapidly evolving technology. Developments are
Comment Response for L T2ESWTR 8-425 December 2005
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under way on almost every aspect of UV, including technology that would:
1. Increase the efficiency of UV delivery,
2. Remove UV lamps from the water flow, and
3. Provide alternatives to mercury vapor lamps.
The draft guidance does not provide a realistic validation pathway for emerging technologies and thereby
inhibits innovation that might provide important solutions to design and risk management issues that the
current UV guidance is seeking to address.
Response: Response 922.
EPA Letter ID: 562
Comment ID: 15051
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Computational Fluid Dynamic Modeling
The draft UV Disinfection Guidance Manual suggests computational fluid dynamic modeling (CFD) as a
method to analyze alternative piping configurations. This is an appropriate but limited recommendation.
The guidance manual should encourage primacy agencies to accept the use of CFD models to approve
reactors and -dose- for WTP that fit within the range of parameters tested during reactor validation and /
or supplemental testing.
The draft guidance also includes disincentives to use CFD ~ a very powerful design tool ~ in addition to
placing roadblocks to the development of new UV technologies. The guidance assigns a minimum 20%
increase in UV dose due to uncertainty in CFD estimates. The proposed criteria significantly increases
the testing required to validate a UV reactor by implying a limited role for CFD and penalizing the use of
CFD in a recognized application. Use of CFD models to interpolate, and possibly, extrapolate observed
inactivation to flow, dose, and transmissivity conditions not specifically tested is essential to developing
efficient and operationally robust UV system designs. The expense of reactor validations and the site-
specific nature of some design factors make reliance solely on values observed in validation tests
impractical.
The use of CFD in the design of UV reactors is already a standard industry practice. The draft guidance
would in effect penalize utilities that employ reactors designed using state of the art design tools. CFD has
a clear role in validating variations in flow rates and piping layouts from the tested condition, after CFD
has been shown to match the test condition. Any model generates an estimate reflecting the input
parameters and some model estimates are more accurate than others. Therefore, model estimates are
typically bounded by measures of statistical confidence. Which statistical measure is appropriate and the
stringency imposed on a particular estimated value depends on the model and its application. The
selection of a fixed percentage buffer on any CFD estimate is arbitrary and unsound.
The UV Disinfection Guidance Manual should promote the general acceptance of CFD to predict UV
inactivation for reactors that are too large for a rigorous physical validation test protocol. Bioassay tests
used to validate UV reactor performance at high flow rates (i.e., greater than 20 MGD) associated with
testing very large reactors are both impractical and uneconomical. The logistical and practical difficulties
Comment Response for L T2ESWTR 8-426 December 2005
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associated with handling adequate quantities of test organisms and delivering sufficiently large volumes
of water under controlled conditions to the test reactor essentially require the acceptance of CFD results.
Response: Response 922.
EPA Letter ID: 562
Comment ID: 15053
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA believes the guidance documents should use appropriate language to clearly state
that guidance is guidance, i.e. the incorporated recommendations are not mandatory, and that Tthe
preamble and guidance documents should reflect a balanced view of treatment alternatives as well as
the premises underlying the rule and compliance alternatives. Given the substantial bulk of the guidance
manuals, the agency must be careful to avoid imposing regulatory requirements beyond rule provisions
through guidance, a prospect that is not legally sound.*
Response: This comment addresses EPA guidance and not regulatory requirements in the LT2ESWTR.
EPA has considered this comment in developing the final guidance documents for the rule.
EPA Letter ID: 562
Comment ID: 15054
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: *Barrick Goldstrike Mines Inc. v. Browner, 215 F. 3d 45, DC Cir. 2000,
Appalachian Power Company v.
Environmental Protection Agency, 200 WL 336911, D.C. Cir. 2000
Response: Response 922.
8.17 Comment Codes 930, Individual Filter Performance
Summary of Issues
Several commenters stated that PWSs could not consistently achieve the proposed individual filter
effluent turbidity criterion of 95 percent of daily maximum measurements less than or equal to 0.1 NTU.
Commenters provided data on turbidity levels in PWSs to support this assertion and indicated that the
Partnership modified this criterion in the Phase V individual filter performance goals because PWSs could
not meet it.
A few commenters suggested that as an alternative to establishing numerical criteria for individual filter
performance, today's rule should award additional treatment credit for PWSs that successfully participate
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in a peer review program. In addition to the Partnership, commenters listed the Area Wide Optimization
Program and the Texas Optimization Program as examples of programs that will provide for
comprehensive improvements in treatment performance.
Commenters supported the proposal that systems not be eligible for credit under both the combined filter
effluent (CFE) and individual filter effluent (IFE) performance tool box options. Several commenters
requested that the turbidity performance standard be the same (0.15 NTU) to ensure consistent
implementation . One commenter suggested the turbidity performance standard should be expressed as
0.10 NTU to eliminate rounding issues in compliance determinations.
Another significant issue raised by commenters is the need for a review process for deviations from the
criteria for individual filter performance due to circumstances that cannot be prevented through plant
optimization. An example given by several commenters is a filter that malfunctions and is taken out of
service, but that may have exceeded the individual filter performance turbidity criteria for a short period
when the filter was operating.
Several commenters also felt that the proposed criteria excluding the 15 minute periods after filter
backwash was too difficult to meet in larger plants or plants without filter-to-waste capability. These
commenters felt the exclusion period should be extended or that this performance criteria should be
eliminated from the final rule. In contrast, the Science Advisory Board recommended that PWSs receive
0.5-log, rather than 1.0-log, additional Cryptosporidium treatment credit for achieving individual filter
effluent turbidity below 0.15 NTU at the 95th percentile.
Response to Code 930
The LT2ESWTR proposal included a 1.0-log Cryptosporidium treatment credit for PWSs that met the
individual filter performance goals of Phase V of the Partnership for Safe Water (Partnership), 95 percent
of daily maximum values below 0.1, with no values above 0.3 NTU. The Partnership modified the Phase
V goals for individual filter performance in 2003. The revised goal is filtered water turbidity less than
0.10 NTU at least 95 percent of the time based on values recorded at 15 minute time intervals. Thus,
where the earlier goal was based on daily maximum values for each filter, the revised goal is based on all
values for each filter-a less stringent approach. The Partnership made this modification after finding that
none of the water treatment plants that had been evaluated could consistently meet the 0.1 NTU goal
using daily maximum values and, further, that this goal was biased against plants with more filters.
In the final LT2ESWTR, EPA has adjusted the criteria from the proposal for PWSs to receive additional
treatment credit based on individual filter effluent turbidity. These adjustments are in response to the
changes the Partnership made to Phase V individual filter performance goals. Under the final
LT2ESWTR, PWSs receive 1.0-log additional Cryptosporidium treatment credit if effluent turbidity from
each filter is less than or equal to 0.15 NTU at least 95 percent of the time and never exceeds 0.3 NTU in
two consecutive measurements taken 15 minutes apart. EPA expects that PWSs will operate at less than
0.1 NTU in order to comply with a regulatory limit of 0.15 NTU. Consequently, EPA regards these
criteria as comparable to the revised Partnership Phase V standards for individual filter performance.
In response to commenter recommendations, the final LT2ESWTR rule requires additional individual
filter performance criteria to support 1.0-log total additional treatment credit. Specifically, today's rule
incorporates the Partnership Phase V performance goal that individual filter effluent turbidity never
exceed 0.3 NTU in two consecutive measurements taken 15 minutes apart. EPA believes that these
criteria, in conjunction with the expectation that controlling effluent turbidity at all filters individually
rather than just the combined filter effluent will generally result in lower microbial risk, justify 1.0-log
additional treatment credit.
EPA does not support awarding a higher level of additional treatment credit for a more stringent
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combined filter effluent turbidity criterion, beyond the 0.5-log credit available under combined filter
performance. The purpose of the individual filter performance toolbox option is to recognize the higher
pathogen removal PWSs will likely achieve by maintaining very low effluent turbidity for each individual
filter.
In response to commenter concerns regarding deviations from the individual filter performance criteria
that cannot be prevented by plant optimization, the final LT2ESWTR gives States authority to determine
whether to issue a treatment technique violation for PWSs that exceed individual filter performance
limits. This authority applies in the case where a PWS receives credit for individual filter performance to
meet the treatment requirements of the LT2ESTWR and fails to achieve the criteria to receive this credit
during a month. If the State determines that this failure was due to unusual and short-term circumstances
that could not reasonably be prevented through treatment optimization, the State may choose not to issue
a treatment technique violation, which the PWS otherwise will incur. Because this authority should be
applied only to unusual plant circumstances, a State cannot make this determination if a PWS has
experienced more than two such failures in any calendar year.
EPA is granting States this authority because PWSs that consistently meet the criteria for individual filter
performance treatment credit may occasionally experience short-term deviations from these criteria due to
circumstances largely beyond the PWS's control. An example of such a circumstance may be
malfunctioning equipment that a PWS quickly removes from service, but that nevertheless prevents the
PWS from fully meeting individual filter performance criteria in a particular month. EPA believes that
States should only apply this authority in cases where PWSs have consistently achieved the criteria for
individual filter performance treatment credit in previous months.
The approach in the final LT2ESWTR for valuing individual filter performance treatment credit differs
from the approach in the proposal. EPA's intent in both the proposal and final rule is to award an
additional 1.0-log Cryptosporidium treatment credit to PWSs that meet the criteria for individual filter
performance. In the proposal, however, PWSs could receive 1.0-log additional treatment credit
specifically for meeting the individual filter performance criteria, but were then not eligible to receive any
treatment credit under the combined filter performance option. In the final LT2ESWTR, PWSs receive
0.5-log credit for the individual filter performance option and also receive an additional 0.5-log treatment
credit for the combined filter performance option resulting in 1.0-log total additional credit. EPA has
made this modification so that if a PWS fails in an attempt to achieve individual filter performance credit,
the PWS is clearly still eligible to received combined filter performance credit.
EPA agrees with commenters that participation in peer review programs is beneficial for PWSs and that
such programs may assist PWSs in meeting the filtration performance criteria in the final LT2ESTWR for
additional Cryptosporidium treatment credit. EPA does not believe, however, that participation in a peer
review program alone is an appropriate basis for awarding additional treatment credit. Rather, to ensure
national consistency in standards for compliance with treatment requirements, EPA has concluded that
additional treatment credit should be based on PWSs meeting numerical criteria for enhanced treatment
performance.
Individual Comments on Code 930
EPA Letter ID: 441
Comment ID: 10777
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
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Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 800 H. Combined Filter Performance
Comment: Treatment performance toolbox options
Since 1988, DEP has worked closely with filtered surface water systems using special programs like
Filter Plant Performance Evaluations. In the mid-1990's, DEP became a regional partner in the
Partnership for Safe Water to encourage water suppliers to voluntarily optimize treatment, produce
turbidity levels that were better than the treatment technique requirements, and ultimately improve public
health protection. DEP supports the turbidity performance incentives provided in LT2 as a means
of improving the removal of waterborne pathogens. National programs such as the Area Wide
Optimization Program (AWOP) have demonstrated the efficiency of training water supply operators and
optimizing existing facilities as a lower-cost alternative to protecting public health. AWOP has developed
a freeware program called "Optimization Assessment Software" that suppliers may wish to use when
implementing the toolbox option for the combined filter effluent and individual filter performance.
Overall, the treatment performance toolbox options will give suppliers additional flexibility to choose the
option that best suits their current treatment scenarios.
Response: See Response lOOa, Response 800 and Response 930.
EPA Letter ID: 451
Comment ID: 14161
Commenter: Eric Abrams, Superintendent, McMinnville Water and Light
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 790 G. Lime Softening; 800 H. Combined Filter
Performance; 950 Q. Other Demonstration of Performance
Comment: Comments #3: McMinnville Water and Light would like the EPA to consider re-
evaluating data already available with the objective of assigning sound, operationally achievable,
treatment credit for Cryptosporidium removal such as softening enhanced filtration and demonstrations of
performance.
Response: EPA agrees with most commenters and the SAB that 0.5-log is an appropriate level of
additional prescribed Cryptosporidium treatment credit for two-stage softening. Where plants are able to
demonstrate a significantly higher level of removal of Cryptosporidium or an indicator such as aerobic
spores,they may apply for additional treatment credit through a demonstration of performance. See
Response 950.
EPA Letter ID: 468
Comment ID: 11053
Commenter: Michael L. McGlinchy, Public Utilities Bureau Manager, City of Akron Public Utilities
Bureau
Commenter Category: Regulated Community (Utilities)
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Comment: 3. It is preferred that the proposed credits for individual filter performance and combined
filter performance remain separate, since combining them into one toolbox option may prevent utilities,
like Akron, from receiving any Cryptosporidium removal credit for enhanced filtration.
Response: See Response 930.
EPA Letter ID: 468
Comment ID: 11056
Commenter: Michael L. McGlinchy, Public Utilities Bureau Manager, City of Akron Public Utilities
Bureau
Commenter Category: Regulated Community (Utilities)
Comment: Enhanced Filter Performance Credits
The rule proposes two microbial toolbox options for enhanced filter performance:
1. 0.5-log credit for combined filter effluent (CFE) turbidity less than 0.15 NTU in 95% of monthly
samples.
2. 1.0-log credit for individual filter effluent (IFE) turbidity less than 0.1 NTU in 95% of maximum daily
values for each filter and no consecutive readings greater than 0.3 NTU.
Systems that demonstrate compliance with the IFE criteria and claim the 1.0-log removal credit are not
eligible for the CFE credit.
Akron is already doing more than is required by state and federal drinking water regulations. In addition
to the turbidity requirements of the IESWTR, we have established a CFE goal of 0.05 NTU measured as
an annual average. While there are months where we would meet the IFE criteria in the proposed rule,
there are also months (generally the cold weather months) where it would be difficult for us to meet the
IFE criteria. If the IFE and CFE criteria were combined, we may not be eligible to receive any removal
credit.
We believe there are a number of utilities that may successfully meet the CFE requirements, but might
have difficulty meeting the IFE requirements. For these reasons, Akron supports keeping the combined
and individual filter performance credits separate, i.e., do not require both IFE and CFE goals to be met to
receive removal credit.
Response: See Response 930.
EPA Letter ID: 485
Comment ID: 11328
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department evaluated the data presented in the CFE section, which showed an
additional 0.5 log removal of Cryptosporidium based on pilot and bench top studies with turbidity of less
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than 0.1 NTU. The studies presented did not reveal an additional 1.0 log removal credit of
Cryptosporidium and the EPA did not present any additional studies in the IFE section. The Department
disagrees with the 1.0 log removal credit for the listed performance. The Department suggests a 0.5 log
removal credit of Cryptosporidium only if the IFE can meet the listed criteria.
The Department does not recommend granting an additional 1.0 log removal credit based on lower
turbidity of the IFE or the CFE. The Department does not agree with the concept of providing additional
removal credit of 1.0 log for any turbidity criteria. Water systems have argued in the past that lower
turbidity values leaving their treatment plants can equate to justification for using lower disinfection
inactivation. This potential increase in the amount of removal credit will allow systems to ask for
additional removal credit and could result in requests to achieve their Giardia and Cryptosporidium
regulatory reduction requirements by removal only. The Department strongly suggests to the EPA and all
water systems that a minimum amount of inactivation (!/> log giardia or 2 log virus, whichever is greater)
be utilized at all times to improve the overall reliability of the treatment process and to account for
variation in individual unit treatment process performance. Removal alone cannot be relied upon.
Response: See Response 930.
EPA Letter ID: 591
Comment ID: 12142
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: 15. §141.727(b)(l), (Page 47787)
This section of the proposed rule indicates the individual filter effluent turbidity (IFE) standard of 0.1
NTU must be met after a 15 minute period following return to service from a filter backwash. The 15
minute time period is too short as atypical filter takes longer than 15 minutes to ripen. Figure 10-9
of the Guidance Manual for Compliance with the Interim Enhanced Surface Water Treatment Rule:
Turbidity provisions shows a typical filter run. The turbidity of the typical filter run is shown to be the
highest at 30 minutes following a backwash. We recommend requiring the IFE standard be met after a 30
minute period following return to service from a filter backwash.
Response: See Response 930. EPA notes that under IESWTR and LT1 individual filter performance
requirements are based on 15 minute readings.
EPA Letter ID: 592
Comment ID: 12099
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Turbidity criteria
# Allowable turbidity criteria for individual filter performance should be established in hundredths (1.5
NTU) since the equipment used reports in hundredths. Rounding up is confusing and unnecessary because
any licensed operator, qualified to perform turbidity testing, is already using hundredths to assess filter
performance.
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Response: See Response 930.
EPA Letter ID: 601
Comment ID: 13025
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 800 H. Combined Filter Performance
Comment: Combined Filter Performance and Individual Filter Performance
Utah supports the inclusion of combined and individual filter performance as a toolbox item and agrees
that systems should only receive credit for either the combined filter performance or the individual filter
performance and not both.
Response: See Response lOOaand Response 930.
8.17.1 Comment Codes 931, Proposed credit and criteria for
awarding credit
Individual Comments on Code 931
EPA Letter ID: 390
Comment ID: 10494
Commenter: Jeff Taylor, Deputy Director, City of Houston Public Utilities Division
Commenter Category: Regulated Community (Utilities)
Comment: b.Systems meeting a 0.1 NTU 95% of the time for individual filters should be given the full
1.0 log removal credit. As this could result in a tremendously large reporting burden, particularly for large
plants, we believe that compliance should be determined by achieving Phase IV status from the
Partnership For Safe Water. A current certification of achievement from the Partnership would be
inspected as a part of the annual sanitary survey, performed by the Primacy Agency. Any system would
be required to notify the Primacy Agency immediately upon failure to maintain current Phase IV status.
Response: See Response 930.
EPA Letter ID: 445
Comment ID: 10821
Commenter: James Fay, Chair, PSW Steering Committee, The Partnership for Safe Water
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: PSW believes that it is a benefit to have the data collection and calculation procedures
(metrics) used in the toolbox for filtration credit and the PSW Phase III and Phase IV data collection and
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calculation procedures for filter performance mirror one another. (For these comments, the term "metric"
applies to the analytical protocol used to calculate a single value from a given database, and not a specific
number or goal). It is believed that this was EPA's intention when the proposed rule was drafted.
However, since that time, the PSW has modified its metric for individual filter performance based on
experience gained in the last several years.
The metric for individual filter performance now included in the proposed LT2ESWTR toolbox differs
significantly from the current Partnership for Safe Water metric. PSW changed this metric in favor of a
more robust statistic that allowed for greater evaluation of individual filter performance. The differences
in the current PSW metric and the proposed LT2ESWTR metric are described below:
1. Proposed Individual Filter Metric in the LT2ESWTR
The metric for individual filter performance proposed in the toolbox matches the metric used by PSW 2
years ago: specifically, the 95 th percentile of the single maximum daily filter turbidity reading of all
filters, measured at a minimum frequency of 15 minutes. This yields a database of 365 points each year
per plant, and EPA proposed a goal of 0.1 NTU for this metric. PSW found that this metric, while easy to
compile, was exceedingly stringent, and that none of thewater treatment plants (WTP) evaluated could
consistently meet this criterion. Further, a WTP with 20 filters essentially was held to a standard 10 times
more stringent than a WTP with 2 filters. Thus, this metric was both unattainable and biased towards
plants with fewer filters.
2. Current Individual Filter Metric Used by the Partnership for Safe Water PSW thus developed and has
implanted into its optimization system another metric for individual filter performance that addressed
these issues. This metric requires the compilation and analysis of all data from an individual filter for
a month, measured at a minimum frequency of 15 minutes. These data are analyzed for frequency
distribution, with a goal of 95% of all data being at or below 0.10 NTU. This metric is most easily
compiled and analyzed by database spreadsheets, which are considered a necessity for thorough review of
such large databases.
PSW has successfully demonstrated the effectiveness of these calculation procedures, and has used these
methods as the basis for the most recent Phase IV award. The benefits of this metric include:
- The database used is the same as required under the LT2ESWTR.
- The metric is robust and versatile: the target is very easily identified, and the database can be easily
manipulated to yield additional data (90th to 99.9th percentiles).
- This metric eliminates the need to make special provisions for the initial portion of the filter run often
associated with increased turbidity. All data are considered in this metric.
- Many PSW plants are now developing individual filter effluent data to provide this metric, and 8 plants
have initiated the process for Phase IV certification.
- The metric requires development of data analysis capabilities consistent with a higher level of WTP
performance.
It is recommended that EPA adopt the same metric (data collection and calculation procedures) utilized
by PSW in Phase IV of its treatment optimization program for the toolbox credit for individual filter
performance. Specifically, EPA should base this toolbox credit on a percentile of all monthly data taken
for a filter based on a minimum 15-minute frequency, for each filter in the treatment plant.
EPA also requested input regarding the specific value for the filtration treatment credits. PSW feels that it
is appropriate for the regulatory limit for individual filter performance compliance credit to be set higher
than the goal established in the PSW program. The 0.10 NTU goal established by PSW is extremely
stringent, noting that only a few treatment plants are currently capable of operating consistently within
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this very low goal. The regulatory value should be set at a level obtainable by well-operated treatment
plants focusing on optimization of individual filters.
Recognizing the need to consider deviations from the stated PSW goals, a review process was established
to evaluate instances where data from an otherwise compliant plant fell outside the goal. Through this
review process, PSW allows for deviations from this goal recognizing that conditions may exist resulting
in data falling outside of the goal limits, while the objectives of the program are still being met. If EPA
sets a specific IFE limit, it should likewise recognize the need for a review process to consider data that
exceeds the regulatory limit. It has been our experience through the Partnership's Program Effectiveness
Assessment Committee review process that such deviations can occur without a significant deterioration
in water quality.
An example is a filter that malfunctions (faulty flow rate control valve) early in the month and is taken
off-line for repair. Such a filter might produce water quality above the goal for the first few minutes of a
run, during the first days of the month. While only one or two readings might exceed the target, because
the total number of 15-minute readings is small for the month, a violation of the criteria may exist. This
type of occurrence is certainly possible for utilities with many filters operating over a course of many
years, and should not result in the loss of credit for this toolbox item. This example represents
an actual situation where the actions taken were prudent and in the best interest of water quality, but
forced the utility to fall outside of the statedgoal limits. Water quality objectives, however, were met and
were within the spirit and intent of the PSW program.
It is reasonable to expect that similar examples of plant conditions and management decisions will arise
beyond our ability to anticipate them. PSW thus recommends that for any IFE goal established, EPA
recognize and provide consideration for deviations from the established limits. This is reasonable,
noting the number of readings taken for each filter, the number of filters in each utility, and the need to
make decisions in the best interest of water quality. A flexible review process is an important element of
the PSW program, and an appropriate review process should be incorporated into the IFE toolbox
credit. This review process should clearly recognize the objectives of the IFE credit (public health), and
allow for consideration of deviations resulting from sound management decisions that do not threaten the
stated objective. This review process should also recognize that a utility with many filters will have
a higher probability of exceeding the regulatory limit than will a utility with fewer filters, as a violation
from any one of the filters results in the credit being lost.
Response: See Response 930.
EPA Letter ID: 447
Comment ID: 10793
Commenter: Michael Barsotti, Water Quality Director, Camplain Water District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 801 1. Credit and criteria for awarding credit
Comment: Champlain Water District, as a water supplier that has achieved the Partnership for Safe
Water -Excellence in Water Treatment- award for 5 years supports the comments submitted regarding
the toolbox credit for individual filter (IFE) performance by the Partnership for Safe Water. Champlain
Water District points out that we have been meeting the IFE metrics as recommended by the Partnership
comments and found them realistic in requiring documentation of individual filter performance that
enhances filter particle removal from that achieved by focusing upon the combined filter effluent (CFE)
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turbidity levels. Champlain Water District wishes to have entered into the public record the need to
control particle removal levels at levels closer to the 95th percentile from each filter as opposed to other
measures (either IFE or CFE) near the average or median. Any data submitted that discusses average,
medium or similar log removal data should be supplemented with data showing 95th percentile log
removal. It is important to have 95th percentile data to document whether a certain toolbox credit can
reliably remove cryptosporidium in the absence of UV treatment. It is CWD-s view that, if an individual
filter performance toolbox credit has the potential to substitute for UV treatment, then data supporting that
credit should use 95th percentile rather than medium or average log removal data.
Response: See Response lOOa, Response 800 and Response 930.
EPA Letter ID: 449
Comment ID: 10828
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: Section 141.727 refers to the proposed rules involving individual filter effluent turbidity. We
support the idea of EPA considering the use of low filtered water turbidity data as a tool to exempt plants
from extensive testing. It is well documented that there is a direct correlation between finished water
turbidity and the chances of cryptosporidium entering a water system.
Response: See Response lOOa. EPA notes that the Individual Filter Performance Tool allows system to
meet their Cryptosporidium treatment requirements based on bin placement but does not exempt systems
from the source water monitoring requirements of the LT2ESWTR or performance monitoring
requirements under this rule.
EPA Letter ID: 457
Comment ID: 11939
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Individual Filter Performance
We support inclusion of this tool and the 1 log presumptive credit. We also support only allowing one of
the filter performance credits per system (either the combined filter performance credit or the individual
filter performance credit).
Response: See Response lOOaand Response 930.
EPA Letter ID: 467
Comment ID: 11044
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
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Comment: The second issue is associated with the criteria for awarding credits to individual filter
performance. The wording of-daily maximum- is an extremely difficult criterion which no utilities will
be able to meet. From practical point of view, this is an unattainable standard. For example, if a utility has
a filter that has two daily maximum turbidity readings above 0.1 NTU during the month on a different day
(which is not unusual in very well run plant), then, the utility will not get the credit because it will fail the
95% goal. Therefore, LWC strongly opposes this criterion and request the wording of-daily maximum-
be removed from the final rule. The rule should require 95% of all measures taken to be less than 0.1 ntu.
If a utility measures filter effluent turbidity every 15 minutes as is the practice at a number of utilities, the
rule would be more meaningful and effective.
Response: See Response 930.
EPA Letter ID: 467
Comment ID: 11045
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 934 4. Existing peer review programs eligible for credit
Comment: In addition, LWC has concerns with the implementation of the IFE credits. The guidance
manual did not address the issue of handling partial compliance of the turbidity criteria. There are two
questions remaining to be addressed: a) what if a utility meets the goal in one month and violates in
another month? b) what if a utility has 95% of the filters meet the IFE goal on monthly basis? To avoid
the implementation difficulties associated with IFE credits, LWC proposes either of the following:
Response: See Response 930.
EPA Letter ID: 467
Comment ID: 11046
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: 1. Eliminate the IFE credit language and revise the CFE credit language. For example, revise
the CFE language to -0.5 logs of additional Cryptosporidium removal credit for plants with CFE are less
than or equal to 0.15 NTU in at least 95% of the measurements- and -1.0 logs of additional
ryptosporidium removal credit for plants with CFE are less than or equal to 0.09 NTU in at least 95% of
the measurements".
Response: See Response 930.
EPA Letter ID: 470
Comment ID: 11086
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
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Other EPA Comment Codes and Descriptions: 831 1. Credit and criteria for awarding credit; 851 1.
Credits and criteria for awarding credits; 8811. Credit and criteria for awarding credit; 951 1. Proposed
approach for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment requirements
Response: See Response lOOaand 83Ib.
EPA Letter ID: 483
Comment ID: 11268
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: - Under individual filter performance, the 15 minute period following start up after backwash
is too arbitrary. Systems without filter to waste capability are at a disadvantage. The 15 minutes should be
expanded to one (1) hour.
Response: See Response 930.
EPA Letter ID: 486
Comment ID: 14165
Commenter: Christopher R. Schulz, Drinking Water Practice Leader, CDM, Inc.
Commenter Category: Consultants: (where self-identified)
Comment: 1. The IFE 1-log credit requires individual effluent turbidity less than 0.15 NTU in 95 percent
of daily maximum samples each month. Assuming 15-minute sampling intervals for individual filters, this
means that the highest turbidity value in 96 samples taken per day must be used and that only one daily
maximum value per month can be above 0.15 NTU in order to qualify for this filtration credit. We believe
that this requirement is excessively restrictive and cannot be consistently met by water facilities that have
achieved optimal filtration performance and want to take this additional credit. Instead, we suggest that 1-
log credit be allowed if individual effluent turbidity is less than 0.15 NTU in 95 percent of samples taken
per month based on 15-minute or 4-hour sampling intervals, similar to what is required for the 0.5-log
combined filter effluent (CFE) credit. Note that the TGM (Section 7.2.2.2) discusses this approach, which
conflicts with the LT2ESWTR. Recognizing that filtration is the most critical treatment barrier against the
passage of waterborne pathogens into the finished water, EPA should establish an achievable target for
utilities that have taken steps to optimize individual filtration performance.
Response: See Response 930.
EPA Letter ID: 488
Comment ID: 11865
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Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: The proposed IFE provision has a number of critical shortcomings. It is much
more stringent than the PfSW requirements, it may discourage best filter management practices, and it
does not balance performance across different filters properly.
The PfSW Phase IV requirements involve limits on the 95th percentile of turbidity readings (excluding
15-minute period following backwash) for each filter over the course of amonth. Thus, in athirty-day
month up to 144 (less the number of post-backwash periods) fifteen-minute readings at each filter can
exceed 0.1 NTU and the >0.1 readings may occur on one or more days in the month. In contrast,
application of the 95th percentile measure to individual filter daily maximum turbidity values the
proposed IFE requirement means that each filter is only permitted one day a month with any reading
above 0.1 NTU (5% x 30 days =1.5 days). Thus, as few as two individual filter readings above 0.1 NTU,
occurring on different days, could lead to a violation. This cannot be compared to the PfSW Phase IV
requirements which allow up to 144 such readings. Furthermore, the provision is very imbalanced in that
it allows multiple filters to operate for an entire day above 0.1 NTU while it prohibits any single filter
from experiencing even a single blip above 0.1 NTU on more than one day. The proposed criteria are so
restrictive that this toolbox item is going to be attainable for few, if any, plants. At PWD filter-to-waste
operation would be required, at a minimum, to meet these criteria. In its effort to estimate the viability of
toolbox elements Environmental Engineering & Technology has found no plants that can meet these
proposed IFE requirements.
Response: See Response 930.
EPA Letter ID: 488
Comment ID: 11867
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Use of 24-hour Time Period for Individual Filter Data Evaluation is Flawed
Daily evaluation of individual filter data does not reflect actual filter operations. At some water treatment
facilities 40 to 70-hour filter runs are common while at others filter runs may be closer to 12 hours. Thus,
the -maximum daily- tubidity value may represent a fraction of a filter run, a single filter run, or a set of
two or more filter runs. It would be very unfortunate if filtration plants were motivated by a desire to
conform filter operations into some pattern that coincides with this arbitrary 24-hour constraint rather than
strive to operate their filters according to the best management practice appropriate to their sytstem.
Response: See Response 930.
EPA Letter ID: 488
Comment ID: 11868
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
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Comment: The 15-Minute Post Backwash Period
The PfSW Phase IV guidelines and the EPA proposed rule both describe the post backwash period as the
15-minute period following the opening of the filter effluent valve after a backwash. During this 15-
minute period, the filter effluent turbidity may be above 0.1 NTU but not above 0.3 NTU. This restrictive
approach does not consider the principles of good filter operation, restricts flexibility in operations, and
favors high-rate filter plants.
Small and large treatment plants must be considered distinctly with respect to IFE standards. EPA has
conducted most of their studies in small plants with short ripening periods of less than the 15-minute
interval allowed between turbidity measurements. The filter ripening period is the time when
contaminants are most likely to pass through filters. In contrast, large plants with larger filter beds, and
thus longer filter ripening periods, cannot avoid taking turbidity reading during the ripening period if it
exceeds 15-minutes. Moreover, best filter management practices for these systems involve slowly
ramping up flow rates onto filters after return to service. Though it does not achieve steady state within 15
minutes, this kind of ramping practice has been shown to lower turbidity levels overall. In contrast, a filter
returned rapidly to service (without ramping) might stabilize within 15 minutes but is more likely to allow
substantially higher turbidity spikes to pass through within the short ripening time period (when
measurements are exempt). Thus the proposed IFE provision favors small plants and moreover may serve
as a discouragement to best practices.
The goal of the PfSW and the EPA should be to minimize the time individual filter turbidity is above 0.1
NTU after backwash and also to minimize the peak turbidity during this time frame. A filter flow rate
must be substantial to flush the post backwash remnants from the filter media and above the filter,
through the filter effluent, within 15 minutes after the effluent valve opens. High rate filters, with deep
bed designs, are more likely to follow this practice. The partnership criteria were developed based largely
on understanding of smaller filter plants using high-rate filters. Filter plants may be able to operate this
way but the higher flow rates required will lead to higher turbidity, albeit occurring within the first fifteen
mintes, than a ramped or stepped flow rate. If an ineffective backwash, non-optimized pretreatment, or a
filter underdrain failure occurs, the higher flow rate will lead to greater breakthrough and less opportunity
for the operator to respond.
A ramped or stepped flow rate, a tool recommended by EPA and the PfSW for optimizing filter effluent
performance, cannot be utilized effectively with the 15-minute restriction because the post backwash peak
turbidity will likely occur beyond 15 minutes after the filter effluent opens. The PfSW-s adoption of
the 15-minute restriction conflicts with this goal. In this respect, the EPA should be wary of following the
PfSW approach. As an example, for the Belmont Water Treatment Plant in Philadelphia, a ramped flow
rate is utilized to minimize the post backwash turbidity peak. This peak routinely occurs at 40 to 45
minutes after the effluent valve opens. Throughout the year, most post backwash turbidity peaks do not
rise above 0.1 NTU. However, when they do, they occur at the 40 to 45 minute period. The Belmont
Water Treatment Plant cannot meet the requirement to be below 0.1 NTU within 15 minutes of opening
the effluent valve, as implied by the PfSW Phase IV and the EPA proposed rule IFE criteria. However,
current filter operational practices at the Belmont plant do have the desired result of minimizing the peak
turbidity level passing through the filter during the overall filter run. The fact that this peak might occur
later rather than sooner in the run has no detrimental consequence with respect to provision of safe water.
Restricting the post backwash turbidity peak to within 15 minutes of the opening of the filter effluent alve
is inflexible, ignores the potential for further optimization, and favors high rate filtration. We recommend
that the EPA revise its approach to excluding the 15-minute post backwash period and the underlying
assumption that peak turbidity levels should be expected to occur within this time window. The proposed
rule should be modified to achieve the goal of having the post backwash turbidity peak return to under 0.1
Comment Response for LT2ESWTR 8-440 December 2005
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NTU within 15 minutes of the peak occurrence. This approach would not promote the unintended
consequence of motivating plants to operate outside of best filter management guidelines.
Response: See Response 930. The Stage 2 M-DBP Advisory Committee recommended 1.0-log treatment
credit for PWSs that successfully participate in a peer review program and identified Phase V of the
Partnership for Safe Water as a program where such credit would be appropriate. EPA does not have
information suggesting that larger plant size is a factor in meeting performance standards or peer review.
EPA notes that for plants, such as the example given, that cannot meet the performance requirements of
this option due to physical, operational or other constraints, the Demonstration of Performance option, as
well non treatment options, are available to meet bin treatment requirements.
EPA Letter ID: 520
Comment ID: 11639
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: if the individual filer performance criteria can be met and would not allow credit for
combined filter performance. The poor performance of an individual filter could statically result in higher
cyst concentrations in the combined effluent even when the combined effluent turbidity is still in
compliance with the combined effluent performance being proposed in this section.
Response: See Response 930.
EPA Letter ID: 520
Comment ID: 11648
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Individual Filter Performance
IEPA generally supports inclusion of this tool and the 1 log presumptive credit. IEPA supports only
allowing one of the filter performance credits per system (either the combined filter performance credit or
the individual filter performance credit).
Response: See Response lOOaand Response 930.
EPA Letter ID: 534
Comment ID: 12001
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
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Comment: Kansas City welcomes the proposed rule-s recognition of the validity of the Partnership
standard and sees no reason to change the proposed criterion.
Response: See Response lOOaand Response 930.
EPA Letter ID: 556
Comment ID: 12068
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The LT2ESWTR should support and be an incentive to participate in such programs which
set challenging operating goals and pursue comprehensive performance valuation-like programs.
However, few appropriate programs exist and these are not uniformly available to all utilities.
One solution to this dilemma is to incorporate a stringent but achievable IFE or CFE credit in the
Microbial Toolbox. Based on knowledge of the Partnership for Safe Water, AMWA believes that the
proposed IFE standard is so stringent that it cannot be practically achieved on an ongoing basis even by
highly optimized plants.
Recommendation: AMWA recommends that EPA finalize as an alternative that plants maintaining CFE
turbidity at < 0.15 NTU 97 percent of the time as measured on a monthly basis be awarded credit. This
algorithm accomplishes the same end as the IFE while being easier to implement for both systems and
primacy authorities.
Response: See Response 930.
EPA Letter ID: 562
Comment ID: 12311
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.8 Revision of Enhanced Filter Performance Criteria
The proposed rule defines the Combined Filter Effluent (CFE) credit as a 0.5-log credit and the Individual
Filter Effluent (IFE) credit as a 1.0-log credit that cannot be used in combination with the CFE credit. The
net maximum is 1.0-log credit. The same net effect can be achieved more simply by defining the two
credits as separate 0.5-log credits that can be combined, thereby still resulting in a maximum 1.0-log
credit. The proposal of an IFE credit began with the Stage 2 M/DBP FACA-s inclusion of-Peer review
program (e.g., PSW Phase IV)- in the microbial toolbox. AWWA continues to believe that utilities that
participate in peer review programs should receive credit as proposed by the FACA. However, few
appropriate programs exist and those are not uniformly available to all utilities. One other A solution to
this dilemma is to eliminate the proposed IFE credit and replace it with a modified CFE credit. A rigorous
CFE credit is detailed later in these comments appropriate for a second 0.5-log credit beyond the current
0.5 CFE credit.
Response: See Response 930.
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EPA Letter ID: 562
Comment ID: 12472
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 801 1. Credit and criteria for awarding credit
Comment: As previously described, available experimental data in the peer review literature indicate that
existing facilities with clarification and filtration in compliance with the IESWTR can achieve 4.0, 4.5, or
higher log removal of Cryptosporidium. The 1.0, 1.5, or greater correction of the minimum 3.0 baseline
credit can be partially provided by the CFE and IFE credits. These credits both involve providing
additional Cryptosporidium protection credits when the filter effluent turbidity improves from 0.3 to 0.15
NTU. Existing literature contains evidence demonstrating that improvements in effluent turbidity from
0.3 to 0.15 NTU translates to an improvement in Cryptosporidium removal of more than 1.5 log.
Response: EPA appreciates the comment and information. See Response 930 and Response 800.
EPA Letter ID: 562
Comment ID: 12477
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The IFE credit as currently defined in the proposal is too restrictive and inappropriate for
facilities attempting to achieve this credit and that are well operated facilities deserving of the defined
credit. The current IFE credit includes two provisions. One provision requires 95 percent of the daily
maximum observations to be <0.15 NTU each month. The daily maximum is the largest of the 96
turbidity readings collected at 15-minute intervals from midnight to midnight at a single filter. The second
provision disallows the credit if any filter during a month has two consecutive 15-minute readings >0.349
NTU. Even considered separately, these provisions are unrealistically restrictive and cannot be achieved
consistently by facilities where the 1.0-log credit is appropriate.
Response: See Response 930. EPA notes the performance criteria are consistent with Partnership for Safe
Water.
EPA Letter ID: 562
Comment ID: 12480
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additive Credit is Easier to Implement
The current rule defines the CFE credit as a 0.5-log credit and the IFE credit as a 1.0-log credit that
cannot be used in combination with the CFE credit. The net maximum credit is 1.0-log credit. The same
net effect can be achieved more simply by defining the two credits as separate 0.5-log credits that can be
combined, thereby still resulting in a maximum 1.0-log credit. This revision would substantially improve
the current definition, which is confusing.
Comment Response for L T2ESWTR 8-443 December 2005
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Section 141.727 indicates -Systems may not claim credit under this paragraph [combined filter
performance] and paragraph (b) [Individual filter performance] in the same month.- With this construct,
EPA is implicitly recognizing that a water treatment plant may meet its LT2ESWTR log-credit
requirements one month by complying with IFE criteria and then, when failing to make IFE, by
complying with CFE. A more transparent approach to these two criteria would be assignment of
independent 0.5-log credits to each performance target. This approach would be more straightforward
both in terms of implementation and interpretation.
Response: See Response 930.
EPA Letter ID: 585
Comment ID: 11987
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47713 [and §141.722(a)(7) on page 47784; and §141.727(b) on p. 47786]
The TCEQ agrees that plants that meet the performance goals of the Partnership for Safe Water should
receive an additional 1.0-log removal credit for Crypto. However, the performance standard for individual
filters contained in the proposed rule are inconsistent and incompatible with the Phase IV performance
goals of the Partnership. The Phase IV goals for individual filter effluent turbidity levels specify that
(excluding the readings collected 15 minutes following the start-up of a backwashed filter) at least 95% of
all 15-minute readings from each filter be 0.10 NTU or less. The EPA has proposed a performance
standard that says that at least 95% of maximum daily readings for each filter must be 0.1 NTU or less.
Let's assume that you have a particular filter that operates 20 hours per day under "normal" operating
conditions, is not idle, and the 15-minute post-backwash reading has been excluded. The proposed rule
specifies that individual filter effluent turbidity readings must be collected at 15-minute intervals.
There will be 80 discrete 15-minute readings collected from that filter. A plant can meet the Phase IV
performance criteria for that day as long as no more than 4 of those 80 readings (i.e., 80 * 0.05 = 4) are
above 0.10 NTU. Therefore, for a 30 day month, the plant will meet Phase IV goals as long as no more
than 120 of the 2,400 readings, i.e., 5%, are above 0.10 NTU.
Now assume that you have that same filter operating under identical conditions. Although there will still
be 2,400 discrete 15-minute readings, there will be only 30 maximum daily values. Therefore, the filter
would violate the proposed EPA criteria if only 2 of those maximum daily readings were above 0.1 NTU
(i.e., 30 * 0.05 = 1.5). Assuming that those two readings occurred on separate days, this would equate to a
99.92% compliance with the Partnership goal instead of the 95% performance target that they adopted.
Furthermore, assuming that every reading for a single day was above 0.1 NTU goal, the proposed rule
will allow a maximum of 80 readings to be above 0.10 NTU (because the 81st reading would occur on
another day) which equates to a 96.7% compliance rate with the Partnership's Phase IV goal.
The EPA's proposed standard will be much more difficult to meet than the Phase IV performance goal set
by the members of the Partnership for Safe Water. Furthermore, the TCEQ believes that this disparity
violates the provisions of the Stage 2 M-DBP Agreement in Principle that was developed by the Stage 2
M/DBP FACA Committee members. Consequently, the TCEQ recommends that EPA revise the toolbox
item on individual filter effluent turbidity so that it is more consistent with the Phase IV provisions of the
Partnership for Safe Water.
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Response: See Response 930.
EPA Letter ID: 603
Comment ID: 12678
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: 16. Individual Filter Performance - The individual filter effluent criterion should be listed as
0.10 NTU to avoid possible implementation issues associated with rounding as well as be consistent with
the intent of the Partnership for Safe Water standards.
Response: See Response 930.
EPA Letter ID: 620
Comment ID: 13304
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Comments: Log removal credits for some of the toolbox options appear too small. For
example, the individual filter performance option is only Hog. Meeting the performance goals of this
option are strenuous and require a first rate plant operation. This performance is the same as the AWWA
Partnership for Safe Water phase IV individual filter criteria. Many utilities have used the Partnership as
the benchmark for achieving compliance to upcoming EPA rules by operating their plants at high
performance levels. Now it may be that such benchmarks are inadequate.
Response: See Response 930.
EPA Letter ID: 624
Comment ID: 13199
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 801 1. Credit and criteria for awarding credit
Comment: 3. Combined Filter Effluent (CFE) and Individual Filter Effluent (IFE)
Requirements:
GCWW recommends identifying 0.5-log removal separately for the IFE and CFE.
Response: See Response lOOa, Response 800 and Response 930.
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EPA Letter ID: 635
Comment ID: 13114
Commenter: Robert A. Hollander, Compliance and Regulatory Affairs Administrator, City of Phoenix,
Water Services Department
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 935 5. Use of 0.15 NTU rather than 0.1 NTU
Comment: Issue 2: Presumptive Credit for Filter Effluent Turbidity (Federal Register Page
47714)
"The individual filter effluent turbidity criterion of 0.1 NTU is proposed because it is consistent with
Phase IV Partnership standards, as based on CCP goals. However, with allowable rounding, turbidity
levels less than 0.15 NTU are in compliance with a standard of 0.1. Consequently, EPA requests
comment on whether 0.15 NTU should be the standard for individual filter performance credit, as this
would be consistent with the standard of 0.15 NTU that is proposed for combined filter performance
credit in section IV.C.8."
Section IV.C.8, Federal Register page 47698, states in reference to combined filter effluent turbidity, "-
EPA expects plants relying on compliance with a 0.15 NTU standard will consistently operate below 0.1
NTU-" Based on this statement, the fact that combined filter effluent turbidity is dependent on individual
filter effluent turbidity, and the allowable rounding; it seems appropriate to allow an additional 1 log
treatment credit for plants that meet either a combined or individual filter effluent turbidity criterion of
less than 0.15 NTU.
Response: EPA does not agree that a 1 log credit is appropriate for plants that meet the turbidity
performance standard based on combined filter effluent measurements. Studies reviewed by EPA indicate
that PWSs complying with a combined filter effluent turbidity standard of 0.15 NTU will achieve at least
0.5-log greater Cryptosporidium removal than PWSs complying with the existing 0.3 NTU standard.
Based on this finding, EPA concluded that an additional 0.5-log Cryptosporidium treatment credit is
appropriate for PWSs using conventional or direct filtration that meet a 95th percentile CFE turbidity
standard of 0.15 NTU.
EPA Letter ID: 637
Comment ID: 13098
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: Combined Filter Performance and Individual Filter Performance
District supports the inclusion of combined and individual filter performance as a toolbox item.
Membership in the Partnership for Safe Water should be considered demonstration of enhanced
performance as originally agreed upon.
Response: See Response lOOaand Response 930.
EPA Letter ID: 643
Comment ID: 12802
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Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Individual Filter Performance
Most states support inclusion of this tool and the 1 log presumptive credit, although at least one state
suggests that the credit should be reduced to 0.5 log. States support only allowing one of the filter
performance credits per system (either the combined filter performance credit or the individual filter
performance credit).
Response: See Response lOOaand Response 930.
EPA Letter ID: 643
Comment ID: 12803
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: One state indicated that the performance standards for individual filters contained in the
proposed rule are inconsistent and incompatible with the Phase IV performance goals of the Partnership
for Safe Water. The Phase IV goals for individual filter effluent turbidity levels specify that (excluding
the readings collected 15 minutes following the start-up of a backwashed filter) at least 95% of all 15-
minute readings from each filter must be 0.10 NTU or less. EPA has proposed a performance standard
that says that at least 95% of maximum daily readings for each filter must be 0.1 NTU or less.
Response: See response to Comment Code 930.
EPA Letter ID: 647
Comment ID: 12940
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Individual Filter Performance
MDE supports inclusion of this tool and the 1 log presumptive credit. MDE supports only allowing one of
the filter performance credits per system (either the combined filter performance credit or the individual
filter performance credit).
Response: EPA appreciates the comment. See response to Comment Code 930.
EPA Letter ID: 660
Comment ID: 14079
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Comment Response for L T2ESWTR 8-44 7 December 2005
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Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 801 1. Credit and criteria for awarding credit
Comment: Combined Filter Performance and Individual Filter Performance
CUWCD strongly supports filter performance as a criteria.
Response: See Response lOOa.
EPA Letter ID: 662
Comment ID: 14037
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 801 1. Credit and criteria for awarding credit
Comment: Combined Filter Performance and Individual Filter Performance
Systems should receive credit for individual filter performance, or combined filter performance not both,
individual filter performance credit is preferred.
Response: See Response lOOa, Response 800 and Response 930.
EPA Letter ID: 668
Comment ID: 13902
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - EPA should stick with the 0.1 NTU per filter, and the peer review requirement, as proposed
in the Agreement. The proposal to weaken this portion of the agreement is not justified by any data, and
would pose unreasonable public health risks, (p. 47713-14)
Response: See Response 930.
EPA Letter ID: 673
Comment ID: 13990
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 801 1. Credit and criteria for awarding credit
Comment: C. 8. Combined Filter Performance
(pages 47697-47700)
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
C. 16. Individual Filter Performance (pages 47716-
Comments on Combined Filter Performance and Individual Filter Performance
Jordan Valley Water supports including combined filter and individual filter performance as toolbox
items. Jordan Valley Water recommends that a presumptive credit of 0.5 be given for both the combined
filter and individual filter performance option, and then allowing water systems to claim the credit from
both options. Any water system meeting individual filter performance will automatically meet the
combined filter performance requirements. This will achieve the same result as the current proposal to
when the two options are used exclusively.
Response: See Response 100a,Response 800 and Response 930.
EPA Letter ID: 699
Comment ID: 14778
Commenter: David A. Visintainer, Water Comissioner, City of Saint Louis
Commenter Category: Regulated Community (Utilities)
Comment: 3. CFE and IFE Credits - As defined in the proposed Rule, CFE is 0.5 log and the
IFE is 1.0 log. These cannot be used in combination. We believe that a better approach would be to grant
the CFE and IFE 0.5 log credit each with a total maximum combined credit of 1.0 log.
Additionally, the IFE credit determination as proposed in the Rule is unreasonably restrictive and
unworkable. As currently proposed, 95 per cent of the daily max turbidity readings for each individual
filter must be less than 0.15 NTU each month. Also, no two consecutive 15-minute individual filter
readings can exceed 0.349 NTU in any given month. These proposed criteria make this credit virtually
unachievable on a consistent basis and will, therefore, be of little applicability in the water industry.
Therefore, we recommend that EPA consider alternative approaches to that proposed.
Response: See Response 930.
8.17.2 Comment Codes 933, Different or additional criteria for
awarding credit
Individual Comments on Code 933
EPA Letter ID: 101
Comment ID: 10904
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Individual Filter Performance
NRWA supports the EPA proposed 1.0 log removal credit when individual filters have a turbidity of less
than 0.1 NTU in 95% of daily measurements excluding backwashes. However, NRWA would encourage
the EPA to increase the maximum measured level to 0.8 NTU in two consecutive measurements taken 15
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minutes apart. This will allow systems time to fix filters that are not optimized or take them off-line to
evaluate plant performance. On rare occasions the plant can be disturbed and by raising the value from
0.3 NTU to 0.8 NTU, the system is more likely to maintain compliance and have enough flexibility to fix
the problem before it spikes.
Response: See Response 930. The LT2ESTWR incorporates the Partnership for Safe Water Phase V
performance goal that individual filter effluent turbidity never exceed 0.3 NTU. EPA believes that these
criteria, in conjunction with the expectation that controlling effluent turbidity at all filters individually,
rather than just the combined filter effluent, will generally result in lower microbial risk, justify the
treatment credit.
EPA Letter ID: 458
Comment ID: 10979
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Page 47700 - Combined Filter Effluent log reduction credit & Page 47714 - Individual Filter
Effluent log reduction credit - If another toolbox option is chosen, the system, for many of the options,
just has to verify that all of the flow went through an additional treatment unit(s) each month for
verification . For CFE/IFE systems currently submit CFE data to the primacy agency, and IFE is
spot checked during sanitary surveys by the primacy agency for accuracy. If there is a failure in many of
the other options, there is no means of double checking the accuracy of the PWS verification statement.
This option has the highest probability of a treatment technique being issued due to the required record
retention and review by the primacy agency. The belief is that the proposed regulations will indirectly
discourage the higher turbidity standards, which should be encouraged. Additionally, there will be
additional cost on the primacy agency to review and/or develop a means to monitor compliance if the
individual filter effluent option is chosen by a public water system.
Response: See Response 930.
EPA Letter ID: 467
Comment ID: 11043
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: The first issue is associated with turbidity measurement (data quality). Although the Guidance
Manual has recommendations for maintaining on-line turbidimeter maintenance, it does not provide any
language for eliminating artificial turbidity spikes due to electronic signal error. As we all know, there are
always artificial turbidity spikes no matter how well the turbidimeters are maintained. Utilities need the
language in the final rule stating that these artificial readings can be eliminated from the monthly
turbidity report.
Response: See Response to Code 930.
Comment Response for LT2ESWTR 8-450 December 2005
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EPA Letter ID: 488
Comment ID: 11866
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: The use of the daily maximum for calculating the 95 % should be eliminated. Four
alternatives worth considering are:
1. Monthly IFE: Base 95th percentile on all recorded values at each filter in each month, excluding the 15
minute period following backwashes
2. Filter Run IFE: Base 95th percentile on all recorded values in each filter run in each month, excluding
the 15 minute period following backwashes (this scenario might require a lower percentile than the 95th,
to be feasible)
3. Combined IFE: Base 95th percentile on all recorded values at all filters in each month, excluding the 15
minute period following backwashes (under this scenario it would be possible to go to a higher percentile
such as 97.)
4. Enhanced CFE: Dispense with use of IFE data and instead provide an additional 0.5-log credit for
achieving a higher percentile of CFE turbidity readings <0.1 NTU in a month (e.g. 97% or 98%)
Response: See Response 930.
EPA Letter ID: 488
Comment ID: 11871
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: The rule does not allow for any margin of error and does not explain how filters that are taken
out of service upon exceeding 0.1 will be handled. Will the value contributing to the filter being taken out
of service be considered a daily maximum for the purposes of compliance? What happens if the filter is
taken out of service early in the month so that only one maximum daily value triggers the 5% of daily
max exceedance? Not even the most well-run facilities can ensure that filters will never fail or have a bad
run requiring removal from service. Explicit language is needed to address these issues. An example of
such language is: -a filter taken off-line for poor performance will not contribute to the compliance
calculation provided that the filter is taken offline within 30 minutes of the first value exceeding 0.1-.
Response: See Response 930.
EPA Letter ID: 503
Comment ID: 10627
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR 8-451 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Comment: Issue No. 6 - Individual Filter Effluent Credit
Provisions for turbidimeter failure should be explicitly cited in the Final Rule. If a turbidimeters fails and
it is not possible to get 15 minute turbidity readings during that time, utilities should still be eligible for
the credit provided that grab samples are taken at reasonable intervals and the turbidimeter is fixed in a
reasonable amount of time, much like the filter turbidity monitoring requirements of IESWTR.
Response: See Response 930.
EPA Letter ID: 562
Comment ID: 12475
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: credits for state approved peer-review programs. AWWA proposes that an alternative 0.5-log
credit be available for utilities where recognized programs are not available, and for utilities that do not
choose to participate in such voluntary peer review programs. The proposed numeric criterion is
achieving 0.15 NTU or less in 97 percent or more of observations taken at the CFE based on 15-minute
observations and computed on a monthly basis.
Response: See Response 930.
EPA Letter ID: 562
Comment ID: 12478
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Several alternatives to the current IFE credit are evaluated in Appendix 1. Several alternatives
considered provide improvement but remain too restrictive. For example, replacing the daily maximum
(i.e., maximum of 96 daily 15-minute readings) with all 15-minute data (i.e., all 96 daily data points) as
the basis for the 95th percentile limit still renders the credit achievable for water treatment plants where
the performance credit correction is appropriate.
Alternatives for enhanced filtration credits, which seemed most appropriate, based upon AWWA-s
review of the available data, include the following:
1. Keep current CFE credit as currently defined (0.5 credit).
2. Keep current definition of CFE credit, but increase the credit from 0.5 to 1.0 credit.
3. Convert current CFE credit into a two-tiered credit. The current definition of the CFE credit will be
used as the first tier, and will continue to be allowed a 0.5 credit. The second tier would be an additional
0.5 credit, or a total of 1.0 credits, for facilities meeting CFE 97 percent <0.15 NTU. The IFE credit
would be eliminated.
Increasing the CFE to a 97-percent compliance level is a strict requirement, supportable by the literature
described earlier that indicates a <0.15 NTU filtered turbidity shows >1.0 long improvement in
Cryptosporidium removal. At a 95-percent compliance level, a plant can operate between 0.15 NTU and
1.0 NTU for 36 hours during a month. That time is reduced to 20 hours, or almost in half, by increasing
Comment Response for L T2ESWTR 8-452 December 2005
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the compliance level to 97 percent. This additional credit is consistent with the literature and with EPA-s
goal of having systems produce more consistent water at a lower turbidity. This CFE regulatory provision
is consistent with current regulations that utilities and states are familiar with implementing. In addition,
AWWA believes that the IESWTR reporting provisions for IFE are suitable to address any potential
problems with individual filters.
Alternative 3, which is based on CFE rather than IFE criteria, offers the added benefit of greater equity
when applied across the breadth of plant sizes and designs. IFE criteria by definition place a greater
burden on plants that have more filters because of their design or because of their size. This differential
can be substantial. As a consequence, the likelihood of failing to comply with the criteria rises with the
number of filters in operation. The CFE based alternative does offer significant advantage in minimizing
reporting and data management burdens for states.
Response: See Response 930.
EPA Letter ID: 624
Comment ID: 13200
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: Consistent with the IESWTR, the compliance with IFE should be based on 15-minute
readings rather than DAILY MAX readings. In addition, GCWW recommends e 0.15 NTU
Response: See Response 930.
8.17.3 Comment Codes 934, Existing peer review programs eligible
for credit
Individual Comments on Code 934
EPA Letter ID: 467
Comment ID: 11045
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 931 1. Proposed credit and criteria for awarding credit
Comment: In addition, LWC has concerns with the implementation of the IFE credits. The guidance
manual did not address the issue of handling partial compliance of the turbidity criteria. There are two
questions remaining to be addressed: a) what if a utility meets the goal in one month and violates in
another month? b) what if a utility has 95% of the filters meet the IFE goal on monthly basis? To avoid
the implementation difficulties associated with IFE credits, LWC proposes either of the following:
Response: See Response 930.
Comment Response for L T2ESWTR 8-453 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 467
Comment ID: 11047
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: or
2. Adopt Partnership for Safe Water program for the IFE credit.
Response: See Response 930.
EPA Letter ID: 485
Comment ID: 11329
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: The Department does not have additional information concerning peer review programs that
can be evaluated.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12474
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.2.6 Peer Review (IFE) Credit
EPA requests comment in the Federal Register preamble on whether peer-review programs exist and if
different or additional performance measures should be required to meet the 1.0-log additional credit. As
described below, the microbial toolbox in the Stage 2 M/DBP Agreement in Principle includes a 1.0-
log credit for peer review programs. The Agreement in Principle specifically cites the Partnership for Safe
Water (PSW) Phase IV as an example. At the time of the Agreement in Principle, PSW Phase IV program
could be described as:
1. Having aggressive numeric goals that serve as objectives for water treatment plants to seek to achieve,
2. Engaging peers or technical consultants to review data, reports, and inspect applicant facilities,
3. Committing to continuous improvement management strategy, and
4. Employing the Composite Correction Program (CCP) process.
The PSW Phase IV program did (and does) not rigidly require participants to achieve fixed numeric
criteria. This distinction is critical when compared to traditional regulatory frameworks. PWS-s numeric
criteria are goals against which compliance is measured given local water quality and operational
constraints. The goal of PSW participation is not to meet numeric targets but to undertake the
management and operational changes that will enhance performance of the drinking water facility. Gross
departures from the numeric goals or repeated failure to achieve the goals cause a utility to be denied
approval for Phase IV of the PSW but the primary purpose of the numeric criteria are as goals. The PSW
Comment Response for L T2ESWTR 8-454 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
and similar programs aim to raise the overall performance of their participants. These programs are not
geared toward identifying violations or requiring strict adherence to numeric criteria. This wholly
different outlook on reporting and recordkeeping is a factor that must be reconciled with traditional
regulatory approaches if the enhanced filtration element of the microbial toolbox is to be appropriately
developed in the final LT2ESWTR.
The FACA Agreement in Principle included a 1.0-log credit for peer-review programs, such as Phase IV
review under the PSW. The original intention of the peer-review credit was to reward utilities that have
already undergone such peer-review processes as Phase IV of the PSW, and to also encourage other
utilities to undergo these same activities in the future. The recognized benefits of the peer-review process
include independent review and feedback from outside parties involved in the process. Perhaps a more
important benefit is the activities and improvements to infrastructure and operational practices initiated
internally by the utilities themselves to reach their goals. The benefits of a peer-review process such as
Phase IV of the PSW, and one of the main justifications for the associated 1.0-log credit, was the depth
and breadth of consequences from activities associated with meeting the Phase IV goals. These
improvements would directly increase microbial protection and improve filtered water quality, but would
also involve comprehensive improvements throughout the entire process (watershed through filtration).
Therefore, the 1.0-log credit was partially for comprehensive improvements in treatment performance, not
just for an increase in microbial protection. Information provided by the PSW indicates that utilities that
are involved with this process do improve treatment operations, including filter performance. For
example, all plants that have achieved PSW Phase III status have improved 95th percentile CFE
values, and most have reduced the frequency, duration, and magnitude of turbidity spikes.
However, since the PSW has dropped on-site, third-party peer review from the Phase IV requirements,
EPA believed, perhaps rightly, that PSW Phase IV should not be directly reflected in the proposed
LT2ESWTR, and did not include the peer-review credit as an option. EPA replaced it with an IFE
credit based on a one of the numeric goals of Phase IV of the PSW (a criteria that PSW has since
abandoned).
The IFE credit proposed by EPA, though numerically similar to the criteria formerly used by the PSW,
does not included an essential ingredient in the Phase IV PSW process, the third party peer review. In the
PSW process, expert review allows award of Phase IV status to water treatment plants that do not
necessarily achieve the numeric IFE goal. Conversely, meeting the numeric IFE goal does not guarantee
award of Phase IV status.
Analysis conducted for AWWA indicated that the IFE credit proposed in the LT2ESWTR is not
achievable at U.S. utilities, even at well-operated facilities such as those in PSW. This assessment is
described in some detail in Appendix 1. This analysis has led AWWA to return to the Stage 2 M/DBP
FACA-s intent when it endorsed establishing a credit for peer-review programs. While most agree that
PSW should not become a regulatory program, participation in PSW and other similar peer-review
programs offer an important mechanism to enhance treatment performance beyond levels typical of
the average IESWTR compliant facility. EPA-s Composite Correction Program (CCP) is the underlying
methodology for PSW and the principle source of the PSW-s original numeric targets. The CCP program
is at the heart of the PSW program, but PSW is not the only program to employ the CCP program.
Individual state programs and EPA-s own Area-Wide Optimization Program (AWOP) are based on the
CCP process.
AWWA endorses the microbial toolbox credit for successful participation in peer review programs. The
proposed peer-review credit would provide 0.5-log credits for state approved peer-review programs.
AWWA proposes that an
Comment Response for L T2ESWTR 8-455 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Response: See Response 930. EPA does not believe that participation in a peer review program alone is
an appropriate basis for awarding additional treatment credit. As the commenter notes the Partnership for
Safe Water peer review program no longer exists and EPA has not indentified a similar nationwide
program. Therefor EPA believes that numerical criteria are needed to ensure national consistency in
standards for compliance with treatment requirements.
EPA Letter ID: 562
Comment ID: 12476
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Peer Review Programs Do Exist
In the fall of 2000, the PSW modified the peer-review component from its Phase IV program. Therefore
this program is substantially different from the peer-review component of the toolbox as outlined in the
Agreement in Principle. In 2003, the PSW modified the Phase IV individual filter turbidity goal to 0.10
NTU 95 % of the time for each operating filter, calculated monthly and based on all 15-minute readings
during filter runs. Standard arithmetic rounding rules apply. Currently, two facilities in the United States
meet Phase IV PSW goals and have been recognized as complying with this and other applicable criteria.
AWWA is not aware of a similar independent national model having the same characteristics as the PSW
Phase IV program.
A number of more localized programs are similar to the PSW Phase IV (circa. 2000). These programs
entail each of the program characteristics described above though specific numeric goals are more apt to
parallel the CCP program than the PSW. Two programs that have been frequently cited as models are
the Texas Optimization Program and the Area Wide Optimization Program (AWOP) that has been used
extensively in Kentucky. The Texas Optimization Program is based on individual filter turbidity limits.
The AWOP program is substantially based on the CCP program drafted by the EPA drinking water
program. The SDWA primacy agency operates both programs. Both are voluntary and rely primarily on
peer-to-peer communication to assist participants in achieving improved operations. Based on Kentucky-
s success in improving operations at drinking water utilities that were encountering operational or
management challenges, EPA is encouraging EPA Regions to promote the AWOP concept nationwide.
A Suitable Numeric Standard is Needed
The PSW eliminated the peer-review component from Phase IV, the program under the EPA AWOP
initiative is not nationally applied, and only a few states sponsor peer-review programs. Consequently, a
microbial toolbox component based solely on approval through an appropriate peer-review program is not
equally available to all utilities. Therefore, EPA should supplement the peer-review log-credit with a
separate but equal numeric criteria reflected explicitly in the LT2ESWTR and associated LT2ESWTR
guidance.
Response: See Response 930. EPA does not believe that participation in a peer review program alone is
an appropriate basis for awarding additional treatment credit. EPA has not indentified a nationwide
program for peer review. Therefor EPA believes that numerical criteria are needed to ensure national
consistency in standards for compliance with treatment requirements.
Comment Response for L T2ESWTR 8-456 December 2005
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EPA Letter ID: 562
Comment ID: 12481
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: answered on a program-specific basis. The state primacy agency must not necessarily be
directly involved in a peer-review program or for primacy agency to -manage- such a program. Primacy
agencies do operate such programs, such as Texas- program that is modeled after the PSW and the
Composite Correction Program (CCP). A peer-review program can function just like any other
independent standards group (i.e., ISO, Standard Methods, ASTM, ASCE, ASM, etc.) outside the
umbrella of regulatory supervision. Congress encouraged integration of non-governmental standard
bodies through such statutes as the National Technology Transfer and Advancement Act.
The relevant primacy agencies must recognize that participation in the program meets the agency-s
expectations regarding obtaining credit under LT2ESWTR. Consequently, a primacy agency should
clearly state the metrics by which it judges such peer-review programs in the context of LT2ESWTR.
Such metrics might include:
1. A written set of performance standards or goals,
2. Integration of the goals and objectives and similar processes to the CCP,
3. An independent or multi-stakeholder managing board,
4. Preparation of an annual report containing metrics of performance for participating utilities,
5. Preparation of a quarterly or annual report of participating utilities,
6. The preparation of a formal written report summarizing peer review findings on applicant-s acceptance
into program,
7. Written reports that document any approved deviation from the program-s performance standards or
goals,
8. Minimum expectations for data management, and
9. An internal or third party audit of both the peer-review organization-s finances and review process.
Primacy agencies electing to develop an internal -peer-review- program should seriously consider
applying the metrics above to their own programs. With or without such performance metrics, operating
or managing a peer-review program will be taxing on primacy organizations. Recognizing third-party
organizations to provide this service is a good example of how agencies can outsource well-defined,
special-purpose programs.
Response: See Response 930. EPA has not identified any nationwide programs that include the criteria
suggested and EPA does not believe that participation in a peer review program alone is an appropriate
basis for awarding additional treatment credit.
EPA Letter ID: 614
Comment ID: 12965
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: * Finally, we believe that utilities that participate in the "Partnership For Safe Water" should
receive credit under the Individual Filter Effluent mechanism.
Comment Response for L T2ESWTR 8-45 7 December 2005
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Response: EPA does not believe that participation in a peer review program alone is an appropriate basis
for awarding additional treatment credit. EPA has not indentified a nationwide program for peer review.
Therefore EPA believes that numerical criteria are needed to ensure national consistency in standards for
compliance with treatment requirements.
EPA Letter ID: 660
Comment ID: 14080
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: CUWCD does support giving additional credit for completion of the Phase IV Partnership for
Safe Water Program.
Response: See Response lOOaand Response 930.
EPA Letter ID: 673
Comment ID: 13991
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: Jordan Valley Water does not support giving additional credit for completion of a peer review
as part of the Phase IV Partnership for Safe Water.
Response: See Response lOOaand Response 930.
8.17.4 Comment Codes 935, Use of 0.15 NTU rather than 0.1 NTU
Individual Comments on Code 935
EPA Letter ID: 472
Comment ID: 11170
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: - The individual filter effluent turbidity criterion of 0.1 NTU is proposed because it is
consistent with Phase IV Partnership standards, as based on CCP goals. However, with allowable
rounding, turbidity levels less than 0.15 NTU are in compliance with a standard of 0.1. Consequently,
EPA requests comment on whether 0.15 NTU should be the standard for individual filter performance
credit, as this would be consistent with the standard of 0.15 NTU that is proposed for combined filter
performance credit in section IV.C.8.
Comment Response for L T2ESWTR 8-458 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Yes, it would cause less confusion if both IFE and CFE turbidities were evaluated at the same numeric
standard.
Response: See Response lOOaand Response 930.
EPA Letter ID: 511
Comment ID: 11489
Commenter: Keith W. Cartnick, Director Water Quality Assurance, United Water New Jersey
Commenter Category: Regulated Community (Utilities)
Comment: Comment: Allowing 0.15 NTU to be the standard for individual filter performance credit
would essentially mean that 0.149 NTU complies with a specified criterion of 0.1 NTU. I believe that this
is an accurate assessment, which is consistent with other turbidity compliance requirements. For example,
the IESWTR criterion of 0.3 NTU for CFE means that 0.349 NTU is in compliance with this
specification. In addition, the turbidity Performance Evaluation data of a 0.15 NTU standard, which is
summarized in Table IV-16 of the above referenced document (p. 47699), indicates that this is a
conservative specification even if a compliance level of 0.10 NTU was desired. (This statement is based
on the mean values obtained from the various instruments and associated standard deviations.)
Response: See Response 930.
EPA Letter ID: 527
Comment ID: 10864
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Revision of Enhanced Filter Performance Criteria
The proposal of an IFE credit began with the Stage 2 M/DBP FACA-s inclusion of-Peer review program
(e.g., Partnership Phase IV)- in the microbial toolbox. Today, fostering peer review programs like the
Partnership for Safe Water, Area Wide Optimization Programs, and efforts within individual states
remain important. The LT2ESWTR should support and be an incentive to participate in such programs
which set challenging operating goals and pursue comprehensive performance evaluation-like programs.
However, few appropriate programs exist and these are not uniformly available to all utilities. One
solution to this dilemma is to incorporate a stringent but achievable IFE or CFE credit in the microbial
toolbox. Based on our analysis, the proposed IFE standard is so stringent as to not be practically
achievable, even by highly optimized plants. However, alternatives such as maintaining CFE turbidity at
< 0.15 NTU 97 percent of the time as measured on a monthly basis would be an example of an achievable
yet robust option.
Response: See Response 930.
EPA Letter ID: 527
Comment ID: 10864
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
Comment Response for L T2ESWTR 8-459 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Revision of Enhanced Filter Performance Criteria
The proposal of an IFE credit began with the Stage 2 M/DBP FACA-s inclusion of-Peer review program
(e.g., Partnership Phase IV)- in the microbial toolbox. Today, fostering peer review programs like the
Partnership for Safe Water, Area Wide Optimization Programs, and efforts within individual states
remain important. The LT2ESWTR should support and be an incentive to participate in such programs
which set challenging operating goals and pursue comprehensive performance evaluation-like programs.
However, few appropriate programs exist and these are not uniformly available to all utilities. One
solution to this dilemma is to incorporate a stringent but achievable IFE or CFE credit in the microbial
toolbox. Based on our analysis, the proposed IFE standard is so stringent as to not be practically
achievable, even by highly optimized plants. However, alternatives such as maintaining CFE turbidity at
< 0.15 NTU 97 percent of the time as measured on a monthly basis would be an example of an achievable
yet robust option.
Response: See Response 930.
EPA Letter ID: 548
Comment ID: 12176
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: It seems appropriate to change the -0.1 NTU- proposal to -less than 0.15
NTU.-
Guidelines appear to be appropriate.
Response: See Response lOOa.
EPA Letter ID: 562
Comment ID: 12482
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
Whether 0.15 NTU should be the standard for individual filter performance credit, as this would be
consistent with the standard of 0.15 NTU that is proposed for combined filter performance credit in
section IV.C.8.
Response
If the agency were to pursue an individual filter performance criterion in the absence of a peer-review
program, an approach for which AWWA has proposed a credible and fairer alternative, then 0.15 NTU is
Comment Response for L T2ESWTR 8-460 December 2005
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more appropriate than 0.10 NTU (see above discussion and Appendix 1) regarding demonstrated
removals achieve when filtration achieves 0.15 NTU.
Response: See Response 930.
EPA Letter ID: 624
Comment ID: 13201
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: in less than 95% of the samples based on 15-minute readings be used as the compliance
number rather than <0.1NTU. This avoids rounding, which will be consistent with CFE requirements and
current IESWTR. Rounding issues lead to confusion with the proposed CFE determination. Also, it is the
intent of the SDWA Amendments of 1996 to have simplified regulatory language. The rounding issues
are not discussed for CFE or finished water in the proposed regulations as well as the current IESWTR. In
addition, the current Interim Enhanced Surface Water Treatment rule requires a WTP to monitor CFE
continuously, and the compliance is based on 15-minute interval readings. This would have compliance
based on 2,880 reading per month not 180 (4-hours readings) as proposed in the LT2ESWTR.
Response: See Response 930.
EPA Letter ID: 635
Comment ID: 13114
Commenter: Robert A. Hollander, Compliance and Regulatory Affairs Administrator, City of Phoenix,
Water Services Department
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 931 1. Proposed credit and criteria for awarding credit
Comment: Issue 2: Presumptive Credit for Filter Effluent Turbidity (Federal Register Page 47714)
"The individual filter effluent turbidity criterion of 0.1 NTU is proposed because it is consistent with
Phase IV Partnership standards, as based on CCP goals. However, with allowable rounding, turbidity
levels less than 0.15 NTU are in compliance with a standard of 0.1. Consequently, EPA requests
comment on whether 0.15 NTU should be the standard for individual filter performance credit, as this
would be consistent with the standard of 0.15 NTU that is proposed for combined filter performance
credit in section IV.C.8."
Section IV.C.8, Federal Register page 47698, states in reference to combined filter effluent turbidity, "-
EPA expects plants relying on compliance with a 0.15 NTU standard will consistently operate below 0.1
NTU-" Based on this statement, the fact that combined filter effluent turbidity is dependent on
individual filter effluent turbidity, and the allowable rounding; it seems appropriate to allow an additional
1 log treatment credit for plants that meet either a combined or individual filter effluent turbidity criterion
of less than 0.15 NTU.
Response: EPA does not agree that a 1 log credit is appropriate for plants that meet the turbidity
performance standard based on combined filter effluent measurements. Studies reviewed by EPA indicate
that PWSs complying with a combined filter effluent turbidity standard of 0.15 NTU will achieve at least
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0.5-log greater Cryptosporidium removal than PWSs complying with the existing 0.3 NTU standard.
Based on this finding, EPA concluded that an additional 0.5-log Cryptosporidium treatment credit is
appropriate for PWSs using conventional or direct filtration that meet a 95th percentile CFE turbidity
standard of 0.15 NTU.
8.18 Comment Codes 950, Other Demonstration of Performance
Summary of Issues
Commenters generally supported inclusion of the demonstration of performance option to award site-
specific treatment credit to PWSs. Commenters stated that many well-run surface water treatment plants
achieve significantly greater Cryptosporidium removal than the prescribed treatment credit, and
demonstration of performance testing is needed to award an appropriate level of credit in such cases. Two
aspects of this option that received significant public comment are the provision for States to award less
than the prescribed treatment credit if indicated by testing results and the need for guidance on
demonstration of performance testing. These comments and EPA's responses are summarized as follows.
Several commenters recommended that EPA eliminate the provision that allows States to award less than
the prescribed treatment credit based on demonstration of performance testing. These commenters stated
that pilot- and full-scale testing is conservative and challenging to implement and that for past regulations,
States generally have not awarded lower treatment credit based on a site-specific study. If this provision
remains in the regulation, commenters suggested that EPA provide criteria addressing how it should be
applied. Such criteria should recognize the conservative nature of testing with surrogates for
Cryptosporidium removal and the potential for misleading or flawed testing results.
Many commenters stated that EPA should provide thorough guidance on demonstration of performance
testing. Topics for this guidance suggested by commenters include approaches to demonstrating treatment
credit, minimum duration of testing, the use of safety factors, and periodic reconfirmation of testing
results. Some commenters recommended that guidance address both full-scale testing with surrogates like
aerobic spores and pilot-scale testing with Cryptosporidium or surrogates. Other commenters
recommended that testing should be limited to full-scale processes and that testing with pilot-scale
representations of full-scale equipment should be discouraged.
Many commenters felt that the EPA should include more specific criteria for a demonstration of
performance and felt that the guidance provided was limited. Other commenters felt that the criteria
proposed in both regulation and guidance was too demanding and application of this tool would be very
limited. One commenter felt that pilot- scale demonstrations were adequate for a demonstration of
performance while another felt that this tool should only be applied to operating unit processes or
treatment trains. Another commenter suggested that uniform criteria would be difficult to establish and
that this issue, and the limited history of this entire approach, could be addressed through case- by-case
review by a review panel.
Most commenters also felt that demonstration of performance studies should be site-specific and the
results should not be extended to other processes or treatment trains.
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Response to Code 950
The option for demonstration of performance testing in today's rule reflects a recommendation by the
Stage 2 M-DBP Advisory Committee. Specifically, the Committee stated that the LT2ESWTR should
allow site-specific testing both to establish Cryptosporidium treatment credit above the prescribed credit
for microbial toolbox processes and to demonstrate Cryptosporidium removal for technologies not listed
in the microbial toolbox. Demonstration of performance testing will be specific to a particular site and
will depend on the treatment processes being tested, water quality, plant infrastructure, PWS resources,
and other factors. Consequently, the final LT2ESTWR rule does not establish specific protocols for
demonstration of performance testing but gives States the authority to approve testing protocols
developed by PWSs and to determine what level of Cryptosporidium treatment credit is appropriate. The
Toolbox Guidance Manual provides information for PWSs and States regarding conducting
demonstration of performance testing, including analytical methods for measuring aerobic and anaerobic
spores.
In general, demonstration of performance testing should encompass the full range of expected operating
conditions and should conservatively assess the degree of Cryptosporidium removal that a treatment
process can reliably achieve. Directly quantifying the removal of Cryptosporidium typically is not
feasible in full-scale testing due to limitations in source water concentrations and analytical method
performance. Consequently, demonstration of performance testing that is conducted at full-scale may
involve the use of surrogates, such as aerobic spores, that have been shown to correlate with the removal
of Cryptosporidium. PWSs and States may also consider the use of pilot-scale studies in conjunction with
full-scale studies for demonstration of performance testing.
As a condition of approving a demonstration of performance credit, the State may designate treatment
performance criteria the PWS must meet on an ongoing basis to remain eligible for the credit. For
example, if a PWS conducts a demonstration of performance study while operating with very low filtered
water turbidity, the State may establish as a condition of approving treatment credit based on the study
that the PWS must continue operating at the low filtered water turbidity. EPA believes this condition is
appropriate because, in this example, if the PWS were to begin operating at a higher filtered water
turbidity level, the demonstration of performance study results might no longer represent the PWSs actual
performance.
EPA believes that States should have the discretion to award either more or less treatment credit than the
prescribed credit on a case-by-case basis where a State has site-specific information that an alternative
credit is appropriate. The final LT2ESWTR rule allows this. EPA recognizes, however, that
demonstration of performance testing should be designed to provide a conservative estimate of treatment
efficiency and, as such, is not generally intended to reduce the level of treatment credit a PWS receives.
Further, results from demonstration of performance testing should be rigorously evaluated for flaws and
bias prior to being used to support either a higher or lower treatment credit. EPA notes that the final
LT2ESWTR does not require States to award either more or less credit. States may require, or systems
may provide voluntarily, additional data or analyses to supplement or support a request for treatment
credit under this toolbox option. The Toolbox Guidance Manual identifies criteria for States to consider in
awarding higher or lower treatment credit.
In the Toolbox Guidance Manual, EPA provides information on procedures for demonstration of
performance testing that addresses issues raised by commenters. These issues include surrogates for full-
scale testing, potential roles for pilot-scale testing in conjunction with full-scale testing, minimum
duration of testing to capture the full range of operating conditions, the analysis of data from testing to
establish treatment credit, and routine monitoring to verify that the conditions under which demonstration
of performance credit is awarded are maintained during routine operation. EPA believes that this
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guidance will assist PWSs and States with implementing demonstration of performance testing
appropriately.
Individual Comments on Code 950
EPA Letter ID: 101
Comment ID: 10905
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Other Demonstration of Performance
In all cases, national standards are not appropriate for the local conditions and circumstances that may be
encountered in rural and small America. EPA should fully embrace and allow full flexibility for systems
to demonstrate that treatment is performing better than an arbitrarily set standard log removal credit.
Response: Treatment credits for the toolbox options in the LT2ESWTR are based on EPA's review of the
data and studies available and applicable to a particular toolbox option and recommendations from EPA's
Science Advisory Board and the Stage 2M-DBP Advisory Commitee. EPA agrees that in some cases a
treatment plant or unit treatment process may be capable of higher Cryptosporidium removals. The DOP
option allows systems to demonstrate these removals.
EPA Letter ID: 449
Comment ID: 10829
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: We also approve of the additional log reduction credit that may be offered to well operated
plants. Many treatment facilities are producing water with a much higher log reduction than they are
being given credit for. One example of this is the operation of our microfiltration plant. Our primacy
agency now gives us 4 log reduction credit for the operation of this facility, and after 5 years of operation
we are confident that the true log reduction is consistently higher than 4 logs. We feel that once new
technologies have a proven track record they should be offered reduced monitoring requirements. Perhaps
the best way to do this is to monitor systems on a case by case basis.
Response: See Response lOOaand Response 950.
EPA Letter ID: 451
Comment ID: 14161
Commenter: Eric Abrams, Superintendent, McMinnville Water and Light
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 790 G. Lime Softening; 800 H. Combined Filter
Performance; 930 P. Individual Filter Performance
Comment: Comments #3: McMinnville Water and Light would like the EPA to consider re-evaluating
data already available with the objective of assigning sound, operationally achievable, treatment credit for
Cryptosporidium removal such as softening enhanced filtration and demonstrations of performance.
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Response: EPA agrees with most commenters and the SAB that 0.5-log is an appropriate level of
additional prescribed Cryptosporidium treatment credit for two-stage softening. Where plants are able to
demonstrate a significantly higher level of removal of Cryptosporidium or an indicator such as aerobic
spores,they may apply for additional treatment credit through a demonstration of performance. See
Response 950.
EPA Letter ID: 457
Comment ID: 11940
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Demonstration of Performance
We support the flexibility to award credit to a unit process or a treatment train based on demonstration of
performance.
Response: See Response lOOaand Response 950.
EPA Letter ID: 472
Comment ID: 11171
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: The Agency specifically excluded chlorine dioxide, ozone, and UV from DOP analysis since
you are giving states the authority to —modify the standards for awarding disinfection credit to these
technologies.- However, ADEQ has stated they have no intention of modifying any Federal Rules. For
the states like Arizona that eliminate these options, they should be allowed the overall aspect of DOP for
all treatment processes. At the local stakeholder level, we might be able to persuade ADEQ to accept one
state-developed program with the LT2ESWTRrather than several individual programs.
Response: The DOP option excludes chlorine dioxide, ozone, and UV from DOP analysis credit because
States may approve alternate CT values for Crytosporidium under the chlorine dioxide and ozone toolbox
options and States may approve alternate approachs to UV reactor validation under the UV inactivation
option. The DOP option, the alternate CT values for chlorine dioxide and ozone inactivation and
alternative approaches to UV reactor validation all require PWSs to obtain State approval. The States
approval approach is to be included in its primacy application. These options do not require States to
modify the standards for awarding disinfection credit to these technologies or to modify any Federal
Rules to approve a DOP credit, alternate CT value or alternate UV validation approach.
EPA Letter ID: 513
Comment ID: 11533
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Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: 17. Other Demonstration of Performance
We support the proposal to allow systems to demonstrate that a plant, or a unit process within a plant,
should receive a higher Cryptosporidium treatment credit than is presumptively awarded under LT2. This
component of the toolbox recognizes that optimal operation of a plant or unit process can achieve higher
pathogen removal than would be presumptively awarded, and systems should be able to claim the
additional credit.
Response: See Response lOOaand Response 950.
EPA Letter ID: 586
Comment ID: 12203
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: in EPA's microbial toolbox. A treatment system should also be allowed to demonstrate
performance of its existing technology if it believes that EPA's categorical treatment credits are
inaccurate.
Response: Treatment credits for the toolbox options in the LT2ESWTR are based on EPA's review of the
data and studies available and applicable to a particular toolbox option and recommendations from EPA's
Science Advisory Board and the Stage 2M-DBP Advisory Commitee. EPA agrees that in some cases a
treatment plant or unit treatment process may be capable of higher Cryptosporidium removals. The DOP
option allows systems to demonstrate these removals.
EPA Letter ID: 637
Comment ID: 13101
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 955 5. Credit for unit processes
Comment: Other Demonstration of Performances
District encourages EPA to allow States the option to grant higher levels of Cryptosporidium credit to
water systems that can demonstrate that a plant or a unit process can achieve efficiency greater than the
presumptive credit specified in the LT2ESWTR
Response: See Response lOOaand Response 950.
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8.18.1 Comment Codes 951, Proposed approach for awarding credit
Individual Comments on Code 951
EPA Letter ID: 470
Comment ID: 11086
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 831 1. Credit and criteria for awarding credit; 851 1.
Credits and criteria for awarding credits; 8811. Credit and criteria for awarding credit; 931 1. Proposed
credit and criteria for awarding credit
Comment: Vermont is, in general, supportive of the remaining tools to meet the treatment requirements
Response: See Response lOOaand 83Ib.
EPA Letter ID: 485
Comment ID: 11330
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department supports the proposal to allow states to assign additional removal
credit and suggests that EPA develop a guidance document for such studies which addresses such factors
as:
- Qualification necessary for conducting such studies
- Maximum additional credit allowed
- Minimum duration of study
- Safety factors to be applied
- Required periodic reconfirmation of the assigned credit.
The Department believes that all additional credit assigned should be site specific and not awarded across
the board to different sources and treatment plants as the physical and chemical reactions involved in the
removal process are unique to each site.
Response: See Response lOOa .
EPA Letter ID: 488
Comment ID: 11864
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: The guidance is very laborious and discouraging and it is doubtful that any system would
want to attempt this type of demonstration after reviewing the requirements. There is limited guidance on
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what the state is supposed to approve (Cryptosporidium or suitable surrogate for monitoring).
The Agency needs to look to the scientific community for development of appropriate protocols. It would
be naive to pretend that we could establish uniform criteria for a demonstration study. The best approach
given the newness of this topic would be to establish a review panel on a case-by-case basis. Such an
approach would encourage research and development in this area for the long-term goal of improved
public safety for everyone.
Response: EPA appreciates the information and will consider the information in the revisions to the
LT2ESWTR guidance material.
EPA Letter ID: 512
Comment ID: 11500
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Demonstration of Performance - EPA should encourage and facilitate the use of DOP
Demonstration of Performance (DOP) is one of the toolbox alternatives that will probably have the most
widespread use by utilities. Many utilities will be able to use existing facilities to meet pathogen removal
requirements, balance Disinfection By-Product (DBP) formation, and maximize the benefits of previous
investments made in treatment technologies. Also, through on-going DOP monitoring, utilities will be
encouraged to enhance existing multiple-barrier treatment strategies. Encouraging improved performance,
and rewarding facilities that already achieve a suitably high level of performance, meets LT2ESWTR
objectives and promotes well-designed and well-managed drinking water treatment facilities. As the DOP
provisions are currently described they do not appear to properly credit the Cryptosporidium protection
potential of existing utilities nor provide flexibility to allow utilities to gain proper credit for the
synergistic effect from the application of existing treatment processes in various combinations.
Response: See Response 950. The DOP option allows sytems to demonstrate Cryptosporidium removal
credit for a unit process or plant beyond the credit allowed in the rule and toolbox options. The credits in
the rule and toolbox options are based on the best information available. EPA does not a have a basis for
additional credits for plant or unit processes. EPA does recognize that plants or unit processes may
provide Cryptosporidium removal beyond the credits allowed under the LT2ESWTR and has included the
DOP option to allow systems to demonstrate that additional Cryptosporidium removal is occuring. EPA
recognizes that the synergistic effects of multiple disinfectants may increase disinfection efficacy. EPA
did not propose CT tables for synergistic disinfection and the information regarding synergistic
disinfection was not available for public review and comment as part of the LT2ESWTR proposal. EPA
notes that the final LT2ESWTR allows States to approve alternate chlorine dioxide or CT values based on
a site specific study, which would include synergistic effects of multiple disinfectants.
EPA Letter ID: 512
Comment ID: 11513
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
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Comment: Demonstration of Performance
a. EPA should encourage and facilitate DOP as a means for utilities to potentially gain credit for existing
synergistic processes in their treatment trains (for Cryptosporidium removal and DBP reduction) that
would not otherwise be given for individual processes. For example, an existing treatment plant such
as CCWD-s Bollman WTP that incorporates flocculation, sedimentation, ozonation, multimedia filtration
with GAC, and chloramination may be achieving far more Cryptosporidium removal as a whole and
forming lower DBP levels than would be given credit for under current proposed credits for individual
processes. In fact, CCWD is heading a regional research project funded by EPA and AWWARF to
study the synergies of multiple disinfectants and Total Organic Carbon (TOC) removal processes for
treatment of San Francisco Bay Delta water. Findings of this research may encourage utilities, especially
those treating waters with elevated bromide and TOC levels, to seek DOP credits for existing treatment
trains.
b. As the DOP provisions are currently described they do not appear to properly credit Cryptosporidium
protection potential of existing utilities nor provide flexibility to allow utilities to gain proper credit for
existing synergistic treatment processes. Instead, the actions encouraged by the rule appear to favor
the use of high cost, technology intensive treatment. For example, treatment facilities that are in
compliance with the IESWTR (turbidity <0.3 NTU), including both of CCWD-s treatment facilities, have
shown that a conventional clarification plus filtration system produces a mean and median
Cryptosporidium removal of 4 to 6 log, typically >4- log. This does not mean that the automatic
3.0- log credit for a single clarification and filtration process should be increased to an automatic credit of
4.0- log or higher, but many existing, well-run surface water treatment plants will likely be able to
provide 4.0- log or greater Cryptosporidium removal and should be given credit if they are able to
demonstrate performance.
Response: See Response 950. The DOP option allows sytems to demonstrate Cryptosporidium removal
credit for a unit process or plant beyond the credit allowed in the rule and toolbox options. The credits in
the rule and toolbox options are based on the best information available. EPA does not a have a basis for
additional credits for plant or unit processes. EPA does recognize that plants or unit processes may
provide Cryptosporidium removal beyond the credits allowed under the LT2ESWTR and has included the
DOP option to allow systems to demonstrate that additional Cryptosporidium removal is occuring. EPA
recognizes that the synergistic effects of multiple disinfectants may increase disinfection efficacy. EPA
did not propose CT tables for synergistic disinfection and the information regarding synergistic
disinfection was not available for public review and comment as part of the LT2ESWTR proposal. EPA
notes that the final LT2ESWTR allows States to approve alternate chlorine dioxide or CT values based on
a site specific study, which would include synergistic effects of multiple disinfectants.
EPA Letter ID: 512
Comment ID: 11514
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: c. In addition, the rule specifies that States should develop site specific DOP testing protocols.
While it seems to make sense for site-specific performance verification to be administered by the states,
EPA should provide guidance that allows states to easily adopt DOP programs. If all responsibility is left
to the states, adoption of DOP protocols may be difficult and might not be implemented soon enough.
Response: See Response 950.
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EPA Letter ID: 520
Comment ID: 11649
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Demonstration of Performance
IEPA appreciates having the flexibility to award credit to a unit process or a treatment train based on
demonstration of performance. IEPA would appreciate EPA providing as much guidance as possible on
various approaches to demonstrating the additional credit. However, IEPA believes that all additional
credit assigned should be site specific and not awarded across the board to different sources and treatment
plants as the physical and chemical reactions involved in the removal process are unique to each site.
Response: See Response lOOaand Response 950.
EPA Letter ID: 548
Comment ID: 12179
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Regarding the stipulation that the State may down-rate a plant or unit process if demonstrated
Cryptosporidium removal is lower than presumptive credits: Is the text describing site-specific testing
(tests on filters at plant -A- do not affect similar-type filters at plant -B-) or unit-specific testing (plant -
B- filters down rated if similar filters at plant -A- show low Crypto removal)? The requirement should
indicate the first option (results at -A- don-t affect -B-).
Response: See Response 950. DOP credits are plant specific or specific to an individual unit process at a
specific plant. In the commenter's example, tests on filters at plant A do not affect similar type filters at
plant B and plant B filters are not affected by DOP results from similar filters at plant A.
EPA Letter ID: 562
Comment ID: 12312
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.9 Demonstration of Performance
AWWA believes that the Demonstration of Performance (DOP) provisions as written are inconsistent
with good engineering practices for drinking water treatment plant design. A full year of testing is
inconsistent with typical pilot-scale testing of two weeks for each quarter or two weeks during
challenging raw water quality conditions. Moreover, these provisions do not encourage or facilitate
utilities using DOP. Pilot-scale and full-scale testing is routinely used to demonstrate treatment efficacy
and treatment system modifications to primacy agencies. AWWA believes that the penalty provision
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imposed by the DOP guidance when lower than expected removals are observed should be removed. The
agency should significantly modify the proposed guidance to follow good engineering practices for water
plant design. A number of specific recommendations are provided in the comments, including
endorsement of aerobic spores as an indicator of Cryptosporidium removal in full and pilot scale studies.
Response: There a number of studies that have shown aerobic spores are a conservative indicator of
removal by sedimentation and filtration and also are a conservative indicator of riverbank filtration
efficiency. Because the type of demonstration of performance testing that will be appropriate for a given
facility will depend on site specific conditions, the LT2ESWTR does not include specfic criteria for
testing or indicators. EPA will provide additional information to assist States and PWSs in applying the
DOP option.EPA will consider these comments in revisions to the guidance materials.
EPA Letter ID: 562
Comment ID: 12417
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. No indicators have yet been identified that accurately reflect occurrence of
Cryptosporidium in either raw or finished water.
4. Numerous pilot and spiking studies indicate that total aerobic spores, as well as Bacillus subtilis spores
(a subset of total aerobic spores), are a reliable conservative indicator of Cryptosporidium removal using
clarification and filtration technologies typically employed for drinking water treatment, as long as water
is properly coagulated.
This analysis and these findings provide an important factual basis for the recommendations AWWA
offers in the following comments. AWWA-s review includes both research and data identified in the
LT2ESWTR proposal. AWWA believes the analysis in Appendix 1 and reflected in these comments more
correctly reflects the performance of some of these treatment technologies than the discussion provided in
the Federal Register notice and Microbial Toolbox Guidance. In addition to the literature and analysis
presented in Appendix 1 and Appendix 2, AWWA will also provide information and analysis with respect
to watershed control programs, bank filtration, ozone disinfection and UV disinfection.
4.2.1 Regulatory -Preference- vs. Agreement in Principle
Response: There a number of studies that have shown aerobic spores are a conservative indicator of
removal by sedimentation and filtration and also are a conservative indicator of riverbank filtration
efficiency. Because the type of demonstration of performance testing the will be appropriate for a given
facility will depend on site specific conditions, the LT2ESWTR does not include specific criteria for
testing or indicators. EPA will provide additional information to assist States and PWSs in applying the
DOP option.
EPA Letter ID: 562
Comment ID: 12494
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
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Comment: Full-Scale Studies Using Aerobic Spores
Full-scale studies using aerobic spores are an appropriate test strategy for determining removal credit
through DOP. A full-scale test should entail one year of weekly, full-scale aerobic spore monitoring data
because:
1. Aerobic spore removal is a conservative indicator of Cryptosporidium removal;
2. Approved analytical methods are available for aerobic spores using equipment, materials, and
procedures that are familiar and available to drinking water microbial laboratories;
3. Using larger samples volumes lowers the finished water detection limits for spores and this will
increase the ability to mathematically demonstrate higher credits (lower detection limits can
underestimate true treatment capability of system);
4. Use of mean to calculate the numerical value of the DOP credit will either result in gross
miscalculation of the true spore removal (can be over- or under-estimated) or will require complicated
statistical methods to identify and correct data outliers and account for censored (BDL) data. Use of
median spore concentration data avoid these problems, and will result in a suitable and simpler approach
to establishing the numerical value of the DOP credit;5. Low raw water spore occurrence can inhibit
ability to mathematically demonstrate true treatment capability of systems being evaluated and will limit
the ability of some plants to use a full-scale DOP study to obtain approval for additional credit;
6. Facilities using at least one year of weekly full-scale spore monitoring data can demonstrate 4.0-log or
greater spore removal, and hence are capable of achieving at least the same level or higher of
Cryptosporidium removal; and
7. Collecting spore samples more than once per week is not necessary to establish the DOP credit (though
facilities may voluntarily choose to collect samples more often).
Response: EPA appreciates the information and will consider the information in the revisions to the
LT2ESWTR guidance material.
EPA Letter ID: 562
Comment ID: 12495
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Pilot-Scale Studies
A DOP pilot-scale challenge study would involve measuring removal of spiked Cryptosporidium or
appropriate surrogate in a minimum 2 to 5 gpm pilot facility mimicking the full-scale treatment plant.
Source water for the pilot facility should be provided from the location representative of where the
Cryptosporidium bin assignment samples are/were collected. Although explicit guidance on pilot studies
is not available from USEPA, the following would be reasonable for most facilities:
1. Challenge studies should be conducted on a frequency and duration discussed with and approved by the
primacy agency. The procurement of sufficient volumes of spores or Cryptosporidium to spike
influent water for long periods of pilot operation is problematic and may not be possible. Rather than
requiring extensive piloting duration, pilot protocol schedules should take into account operating
conditions such as spring runoff turbidity increases and cold water impacts to ensure that pilot results
provide a robust representation of treatment challenge conditions. In some cases, a two-week challenge
study may be sufficient, while in other cases, two weeks per quarter may be needed;
2. The study should be preceded by two weeks of side-by-side studies comparing performance of full-
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scale facility to pilot plant operated under identical conditions (it must be shown that full-scale
performance equals or exceeds pilot-scale performance through the final filtration stage);
3. Monitoring of raw, spiked, and finished water grab samples to include turbidity, particle counts, and
Cryptosporidium (or other microbial indicator);
4. On-line, continuous turbidity monitoring of individual filter and combined filter effluent is
recommended. On-line continuous particle count monitoring may be included for evaluating operations
of the pilot facility, but this monitoring should not be a requirement or condition for the credit;
5. Pilot-study protocol to be negotiated with and approved by the primacy agency;
6. Objectives of testing should be to establish performance under routine or typical conditions (not -
worst-case- scenarios - see later discussion), with -typical- performance established by monitoring
removal of Cryptosporidium (or approved surrogate) in combined filter effluent (not in individual filters -
see discussion below); and
7. DOP credit established in pilot studies will be applicable to full-scale plant at full-scale flow rates
consistent with unit process loading rates used in pilot-scale unit processes (flocculation, clarification,
filtration) during DOP evaluation, unless otherwise negotiated with the state.
This proposal departs significantly from Chapter 12 of the draft Microbial Toolbox Guidance Manual,
which outlines an approach that is much more extensive than is routinely applied in approval of drinking
water treatment plant design and modification. For example, Chapter 12 reflects 52 weeks of testing
(Table 12.3, page 12-13 of draft Microbial Toolbox Guidance Manual), a requirement that is 12 - 25
times more extensive than currently required for other similar applications of special study testing.
The objective of testing should be to represent performance under routine or typical conditions, not
necessarily the -worst-case- conditions emphasized in the draft guidance manual. This is consistent with
the goal and framework of the LT2ESWTR, which is intended to address endemic risk of ryptosporidiosis
associated with average source water Cryptosporidium challenges, assuming performance consistent with
IESWTR (or LT1) requirements. In addition, -typical- treatment performance is reflected by measuring
removal performance between raw (plus spike) through combined filter effluent, not between raw
water and individual pilot filters. This is consistent with the requirements for the DOP credit using spores
and with Section 12.5.2.1 of the guidance manual. However, Table 12.3 of the guidance manual
introduces confusion on this point by implying that sampling must be conducted at individual filter
effluents.
The DOP credit established in pilot studies should be applicable to the full-scale plant at full-scale flow
rates consistent with unit process loading rates used in pilot-scale unit processes (flocculation,
clarification, filtration) during the DOP evaluation, unless otherwise negotiated with the primacy agency.
For example, a pilot study achieves >4.5-log removal of Cryptosporidium, using the primacy agency
approved protocol, when pilot filters were operated at 8 gpm/sf In this example, the full-scale plant
should be certified for a total credit of at least 4.5-log, not the 3.0-log automatic credit, as long as the full-
scale plant filtration rate is <8 gpm/sf. This does not mean the primacy agency is required to certify the
full-scale plant for filtration rates up to 8 gpm/sf. However, it does mean that as long as the primacy
agency establishes the maximum filtration rate for the plant anywhere below 8 gpm/sf (e.g., 4.5 gpm/sf),
the primacy agency can not award a credit lower than 4.5-log.
Appendix 1 includes a complete description of a pilot and full-scale DOP study. Also, once established,
the DOP credit should be retained as long as
Response: EPA appreciates the information and will consider the information in the revisions to the
LT2ESWTR guidance material.
Comment Response for L T2ESWTR 8-4 73 December 2005
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EPA Letter ID: 562
Comment ID: 12496
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: study. Also, once established, the DOP credit should be retained as long as the facility
maintains compliance with the IESWTR and there are no major changes made to the treatment processes.
Response: Using the DOP option, a utility may demonstrate a higher log removal credit than those
allowed under the LT2ESWTR for a plant or individual process. That higher log removal credit would be
demonstrated to the State under a given set of operating conditions and plant performance and, as with log
removal credits under SWTR IESWTR,LT1ESTWR or other toolbox options under LT2ESTWR, would
not be applicable under all conditions and performance levels. Compliance with IESWTR requirements
may not represent the operating conditions and performance levels under which DOP removal was
achieved. If the plant or process is not operating under the conditions under which the DOP credit was
achieved then it may no longer be in compliance with the treatment technique requirements of the
LT2ESTWR and removal credits may no longer be appropriate.
EPA Letter ID: 595
Comment ID: 12592
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: guidance from EPA on the issue. Maine would agree with the idea that the credit
should be awarded on a case-by-case basis.
Response: See Response lOOaand Response 950.
EPA Letter ID: 614
Comment ID: 12963
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: aerobic spores as an alternative to turbidity removal. Also, the penalty 'provision imposed by
the DOP guidance, when lower than expected removals are observed, should be removed as it will
completely discourage these studies.
Response: See Response 950. EPA will consider these comments in revisions to the guidance materials.
EPA Letter ID: 643
Comment ID: 12804
Comment Response for L T2ESWTR 8-4 74 December 2005
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Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Demonstration of Performance
States appreciate having the flexibility to award credit to a unit process or a treatment train based on
demonstration of performance. States would appreciate EPA providing as much guidance as possible on
various approaches to demonstrating the additional credit. However, states believe that all additional
credit assigned should be site specific and not awarded across the board to different sources and treatment
plants as the physical and chemical reactions involved in the removal process are unique to each site.
Response: See Response lOOaand Response 950.
EPA Letter ID: 647
Comment ID: 12941
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Demonstration of Performance
MDE would appreciate EPA providing as much guidance as possible on various approaches to
demonstrating the additional credit. However, all additional credit assigned should be site specific and not
awarded across the board to different sources and treatment plants as the physical and chemical reactions
involved in the removal process are unique to each site.
Response: See Response lOOaand Response 950.
EPA Letter ID: 673
Comment ID: 13993
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: C. 17. Other Demonstrations of Performance
Comments on Other Demonstration of Performances
Jordan Valley Water encourages EPA to allow States the option to grant higher levels of Cryptosporidium
credit to water systems that can demonstrate that a plant or a unit process can achieve efficiency greater
than the presumptive credit specified in the LT2ESWTR
Response: See Response lOOaand Response 950.
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8.18.2 Comment Codes 952, Approaches that should be considered
or excluded
Individual Comments on Code 952
EPA Letter ID: 548
Comment ID: 12178
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Testing should be limited to the actual full-scale processes used (i.e., pilot-scale
representations of full-scale equipment should be discouraged), or a proven equivalent.
Response: See Response lOOaand Response 950.
EPA Letter ID: 562
Comment ID: 12493
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Penalizes Facilities Attempting DOP Studies
A provision in the rule proposal (section IV. C. 17) and in Chapter 12 of the Microbial Toolbox Guidance
Manual allows states the discretion to penalize facilities that conduct a DOP study and end up
mathematically demonstrating a total credit that is less than the automatic credits allowed by T2ESWTR.
For example, a state can choose to award a 3.3-log credit to a facility that qualifies for 3.5-log automatic
credit if the utility was only able to mathematically demonstrate 3.3-log removal in a DOP spore study or
pilot study. Inclusion of this penalty will deter facilities that may have benefited from using the credit
from even trying for the credit.
AWWA believes that this DOP penalty provision is misguided and inconsistent with the practice and
science of drinking water treatment plant design. Pilot-scale and full-scale testing is routinely used to
demonstrate treatment systems and treatment system modifications to primacy agencies. Because of
the conservative nature of these study designs and the implementation challenges which any individual
pilot or full-scale study may encounter, primacy agencies do not as a matter of practice impose lower
removal credit under the SWTR as a result of a site-specific study. Drinking water utilities, their
consultants, and primacy agencies generally accept that full-scale treatment plants perform better than
pilot plants. AWWA believes this provision should be removed entirely from the proposal and associated
guidance.
In the event that the agency imposes this penalty provision within the DOP guidance, this provision
should be accompanied by a set of qualifying tests so that individual utilities are not penalized by poorly
designed or operated tests. Test results would need to withstand scrutiny with respect to:
1. The conservative nature posed by the selected surrogate vs. Cryptosporidium oocysts,
2. Demonstration of adequate surrogate in the influent water,
3. Demonstration that the laboratory analysis was not flawed,
Comment Response for L T2ESWTR 8-4 76 December 2005
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4. Demonstration that the pilot test was operated correctly and within the appropriate testing regime, and
5. The better performance achieved by full-scale treatment plants.
Response: See Response 950.
EPA Letter ID: 601
Comment ID: 13028
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Other Demonstration of Performances
Utah encourages EPA to allow States the option to grant higher levels of Cryptosporidium credit to water
systems that can demonstrate that a plant or a unit process can achieve efficiency greater than the
presumptive credit specified in the LT2ESWTR, especially when more technical data becomes available.
Response: See Response lOOaand Response 950.
EPA Letter ID: 614
Comment ID: 12962
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: * Specifically, in terms of DOP, we would like to see particle counting and
aerobic spores as an alternative to turbidity removal. Also, the penalty '
Response: There a number of studies that have shown aerobic spores are a conservative indicator of
removal by sedimentation and filtration and also are a conservative indicator of riverbank filtration
efficiency. Because the type of demonstration of performance testing that will be appropriate for a given
facility will depend on site specific conditions, the LT2ESWTR does not include specfic criteria for
testing or indicators. EPA will provide additional information to assist States and PWSs in applying the
DOP option.
EPA Letter ID: 662
Comment ID: 14040
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Other Demonstration of Performances
All credits should be based on performance. If a plant can demonstrate a higher levels of Cryptosporidium
Comment Response for LT2ESWTR 8-477 December 2005
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removal credit to water systems should be granted even if it exceeds the presumptive credit specified in
the LT2ESWTR
Response: See Response lOOaand Response 950.
8.18.3 Comment Codes 953, Minimum elements for testing
Individual Comments on Code 953
EPA Letter ID: 591
Comment ID: 12129
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Ohio EPA believes the states should determine what will be an acceptable demonstration study, however,
guidance should be available for what constitutes an acceptable method for demonstrating log removal
through an entire treatment plant or a partial treatment process. One issue we would like to have
addressed in guidance is whether particle counting is appropriate for showing log removal through the
treatment plant or a partial treatment process.
Response: See Response 950.
8.18.4 Comment Codes 954, Safety factor
Individual Comments on Code 954
EPA Letter ID: 591
Comment ID: 12131
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Ohio EPA does not believe that a factor of safety should be applied to alternative treatment technologies,
but recommends that the same approach used for conventional treatment systems be applied to alternative
treatment technology demonstration studies. For example, conventional surface water treatment systems
are granted 3 log removal based on their average removal performance. Similarity, alternative treatment
technologies should be granted credit based on their average removal performance shown in the
demonstration study. In addition, the alternative treatment technology should show at least 2
log removal in 95 percent of the data to meet the 2 log removal requirement of the IESWTR/LT1 since
the conventional plants have been shown to remove a minimum of 2 log removal when complying with
the turbidity requirements of the IESWTR/LT1.
Response: See Response lOOaand Response 950.
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8.18.5 Comment Codes 955, Credit for unit processes
Individual Responses to Code 955
EPA Letter ID: 548
Comment ID: 12152
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: 2. Demonstration of performance. Metropolitan suggests that the demonstration of
performance be limited to the ability of testing (1) unit processes that are operating within their design
values, or (2) a combination of properly operating unit processes when they must be operated (i.e., rapid
mixing, flocculation, and sedimentation) for proper, overall plant performance.
Response: See Response lOOaand Response 950.
EPA Letter ID: 548
Comment ID: 12177
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Limit the demonstration of performance to the ability of testing (1) unit processes that are
operating within their design values, or (2) a combination of properly operating unit processes when they
must be operated together (i.e., rapid mixing, flocculation, and sedimentation) for proper, overall
plant performance. Overall, plant performance must be understood as not negatively affected.
Response: See Response lOOaand Response 950.
EPA Letter ID: 591
Comment ID: 12132
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Under the proposed rule systems that demonstrate a performance credit may not also receive a
presumptive credit for something that was included in the demonstration study. For example, if a system
demonstrates a performance credit while operating under conditions of lower finished turbidity the plant
may not also receive additional presumptive credit for lower finished turbidity. What if a system shows x
log removal and the finished water turbidity during that study happens to be 0.1 NTU? Does that mean a
system will be required to operate at 0.1 NTU on a normal basis to receive that credit? Does that mean
alternative technologies or systems that conduct a demonstration study on conventional treatment may be
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required to meet different finished water turbidity standards based on the results of their study? We need
clarification on this in a guidance manual if the turbidity standard currently required by rule will not be
changed. If a new turbidity standard is to be required based on a demonstration study, we recommend that
this requirement be stated in the rule to enable states to make it an enforceable standard.
Response: Under the DOP option, States may set monitoring and treatment performance criteria to verify
that the conditions under which the demonstration of performance credit was approved are maintained
during routine operation. DOP Cryptosporidium removal credit would be demonstrated to the State under
a given set of operating conditions and plant performance and, as with log removal credits under SWTR
IESWTR,LT1ESTWR or other toolbox options under LT2ESTWR, would not be applicable under all
conditions and performance levels. If the plant or process is not operating under the conditions under
which the DOP credit was achieved then it may no longer be in compliance with the treatment technique
requirements of the LT2ESTWR and removal credits may no longer be appropriate.
EPA Letter ID: 624
Comment ID: 13178
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 3. EPA should not discourage utilities from performing a Demonstration of Performance
(DOP) by indicating that EPA will give only the credit demonstrated. A utility could actually lose credit
by performing a DOP.
Response: See Response 950.
EPA Letter ID: 624
Comment ID: 13198
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: [SEE PAGE 7 OF PDF FOR FIGURE 2]
b. Demonstration Of Performance POP): EPA should not discourage utilities from performing a DOP by
indicating that EPA will give only the crelt demonstrated. A utility could actually lose credit by
performing a DOP. EPA needs to realize that a lower log removal may be caused by low surrogate
concentrations in the source water, and it is not possible to mathematically to demonstrate greater
than 3-log reduction as presented in Figure 2.
Response: See Response 950.
EPA Letter ID: 637
Comment ID: 13101
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Comment Response for LT2ESWTR 8-480 December 2005
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Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 950 Q. Other Demonstration of Performance
Comment: Other Demonstration of Performances
District encourages EPA to allow States the option to grant higher levels of Cryptosporidium credit to
water systems that can demonstrate that a plant or a unit process can achieve efficiency greater than the
presumptive credit specified in the LT2ESWTR
Response: See Response lOOaand Response 950.
8.18.6 Comment Codes 957, Guidance
Individual Comments on Code 957
EPA Letter ID: 591
Comment ID: 12133
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: also receive additional presumptive credit for lower finished turbidity. What if a system
shows x log removal and the finished water turbidity during that study happens to be 0.1 NTU? Does that
mean a system will be required to operate at 0.1 NTU on a normal basis to receive that credit? Does that
mean alternative technologies or systems that conduct a demonstration study on conventional treatment
may be required to meet different finished water turbidity standards based on the results of their study?
We need clarification on this in a guidance manual if the turbidity standard currently required by rule will
not be changed.
Response: Under the DOP option, States may set monitoring and treatment performance criteria to verify
that the conditions under which the demonstration of performance credit was approved are maintained
during routine operation. DOP log removal credit would be demonstrated to the State under a given set of
operating conditions and plant performance and, as with log removal credits under SWTR
IESWTR,LT1ESTWR or other toolbox options under LT2ESTWR, would not be applicable under all
conditions and performance levels. If the plant or process is not operating under the conditions under
which the DOP credit was achieved then it may no longer be in compliance with the treatment technique
requirements of the LT2ESTWR and removal credits may no longer be appropriate.
EPA Letter ID: 595
Comment ID: 12591
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Demonstration of Performance
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Maine believes this option should be available, but would appreciate some guidance from EPA on the
issue. Maine would agree with the idea that the credit
Response: See Response lOOaand Response 950.
8.19 Comment Code 970, Toolbox Guidance Manual (specific to the
guidance manual)
Response to Code 970
EPA appreciates the comments and information provided regarding the LT2ESWTR Toolbox Guidance
Manual. EPA will consider the comments and information in revising the document. EPA intends to issue
a revised Draft Toolbox Guidance Manual for comment.
Individual Comments on Code 970
EPA Letter ID: 101
Comment ID: 10912
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 841 11. Membrane Guidance Manual (specific to the
guidance manual)
Comment: Use of Examples
NRWA encourages EPA to use examples throughout the guidance document. Relying on examples rather
than a range of numbers or figures provides maximum flexibility for communities to devise compliance
options unique to their circumstances.
Provide Small System Summary
The Agency should provide a five page summary of the entire guidance document and reference the
reader to specific sections for more details. This should not only be done for this document but also for all
the guidance documents related to these two rules. NRWA would be pleased to provide services for
EPA's contractor to write this summary.
Response: See Responses 970 and 841.
EPA Letter ID: 467
Comment ID: 11040
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: Issue 4: LT2ESWTR Guidance Manual for Bank Filtration
In the introduction section of the guidance manual (Chapter 4), the document states: -In optimal locations
and under optimal conditions, bank filtration is suitable for accomplishing Cryptosporidium removal to
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partially meet the requirements of— This statement is very inaccurate. Many studies have demonstrated
that with appropriate design, the bank filtration process is very effective in removing microorganisms
and is able to completely meet the LT2ESWTR requirements (Schijven and Hassanizadeh 2000; Medema
et. al, 2000; Wang et. al. 2002). These study results should be fully reflected in the document.
The guidance manual differentiates bank filtration from other engineered recharge/recovery systems.
However, the wording in the document is a little confusing as bank filtration is also an engineered process
because it relies on the design and construction of water collection devices (wells). The document should
be modified to exclude specific designs that EPA does not want to consider. An exclusion of-engineering
work- in general will just add confusions to the document.
Response: See Response 970.
EPA Letter ID: 485
Comment ID: 11319
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: Response: The Department has used the same approach in approving bag and cartridge
treatment systems as that was used for approving membranes and our concerns and questions concerning
the bag and cartridge technologies are the same as those expressed in the response concerning membranes
outlined above.
Response: EPA notes that State requirements must be at least as stringent as those in the final T2SWTR.
A State membrane approval process that is more stringent than the LT2ESWTR requirements would meet
that standard.
EPA Letter ID: 486
Comment ID: 14169
Commenter: Christopher R. Schulz, Drinking Water Practice Leader, COM, Inc.
Commenter Category: Consultants: (where self-identified)
Comment: Toolbox Guidance Manual
7.2.2.2 Individual Filter Effluent
15. The description of monitoring frequency and compliance calculation requirements for the IFE option
conflicts with Section 7.3.2 (Individual FilterPerformance) and LT2ESWTR requirements, as discussed in
Comment 1.
Response: See Response 970.
EPA Letter ID: 486
Comment ID: 14171
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Commenter: Christopher R. Schulz, Drinking Water Practice Leader, CDM, Inc.
Commenter Category: Consultants: (where self-identified)
Comment: 17. Equations that interpolate between the discrete values in the CT table should be included
in the TGM for Crypto inactivation so these can be used in lieu of tabular values to facilitate
programming of PLC-based control systems for ozone disinfection systems.
11.3 CT Determination (Ozone)
16. Most CDM ozone design projects require tracer studies or CFD modeling of ozone contactors to be
performed by the general contractor or owner. These results are used to define appropriate baffle factors
which are programmed into the CT calculation control logic of the ozone system. There should be a
sufficient database in the ozone industry to develop conservative T10/HRT default values based on
different types of contactor geometries and baffle layouts (over-and-undervs. serpentine baffles) for
inclusion in the final version of the TGM. This information could be easily obtained through a survey
of operating ozone systems.
17. This section presents three methods for calculating CT: (1) T10, (2) continuous-stirred tank reactor
(CSTR) and (3) Extended-CSTR. This list should also include two additional methods, which are
supported by research and experience, and widely used in automated CT control systems for ozone
systems in the United States: (1) log integration method, and (2) geometric mean method. Both of these
methods rely on tracer studies or CFD modeling of the ozone contactor at design flow to determine a T10
value for the effective disinfection contact time, but differ in terms of how -C-is calculated. Accordingly,
they could be discussed in the TGM as sub-methods related of the T10 method, as follows:
- T10 method, as currently defined in TGM: Divide T10 proportionally by volume among the contactor
chambers; calculate -C- for each chamber based on ozone residual measurements at outlet of each
chamber. Use -Cout- for co-current diffusion chambers and reaction chambers and Cout/2 for counter-
current diffusion chambers. Sum the CT values for each chamber to determine the total log inactivation
credit for the contactor. This is the most conservative method and will result in the highest applied ozone
dose to meet a given CT target.
- Log integration method: Divide T10 proportionally by volume among the contactor chambers; calculate
-C- for each chamber based on ozone residual measurements at inlets and outlets of diffusion and
reaction chambers. Use -Cin- and -Cout- measurements, HRT or T50 values, and the first-order decay
rate equation to calculate -C- for each active chamber (i.e., chambers with detectable outlet ozone
residual). Sum the CT values for each chamber to determine the total log inactivation credit for the
contactor. This approach will result in higher -C- values and a lower applied ozone dose to meet a given
CT target.
- Geometric mean method: Divide T10 proportionally by volume among the contactor chambers;
calculate -C- for each chamber based on ozone residual measurements at inlets and outlets of diffusion
and reaction chambers. Use -Cin- and -Cout- measurements and the geometric mean equation [C= (C
initial x C final) 1/2] to calculate -C- for each active chamber (i.e., chambers with a detectable outlet
ozone residual). Sum the CT values for each chamber to determine the total log inactivation credit for the
contactor. This approach will result in higher -C- values and a lower applied ozone dose to meet a given
CT target.
11.3.1 Measuring C for T10 and CSTR Methods
18. Include additional methods for calculating -C-, as discussed under Comment 17.
11.321T10 Method
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19. Include an example CT calculation for the log integration and geometric mean sub-methods, as
discussed under Comment 17.
20. The example CT calculation states that the T10 allocation by proportional volume to individual
contactor chambers cannot be done when nondetectable ozone residual concentrations are measured in
more than 50 percent of the chambers. There is no justification provided for this restrictive requirement,
and it cannot be practically applied to full-scale operating ozone systems for the following reason. The
ozone contacting system must be designed for the worst-case condition of peak flow and maximum ozone
decay rate, but must operate under widely varying flows (typically 2-5 fold over a year) and ozone decay
rates (typically 5 to 10-fold over a year depending on seasonal water temperature and water quality
fluctuations). These variations cannot be handled entirely through the use of multiple parallel contactor
trains. Typically, during cold water periods (low ozone decay rates), an ozone residual will be carried
through all or most of the contactor volume with a minimum number of contactor trains in service. During
warm water periods (high ozone decay rates), an ozone residual will be carried through only the first third
or half of the contactor with a maximum number of contactor trains in service (to meet peak flow
requirements and plant hydraulic grade line constraints). If there is a concern about the validity of
proportioning the T10 value to individual chambers at low flows, this could be handled by conducting
tracer studies with sampling at midpoint and outlet of ozone contactor, or using CFD modeling to predict
T10 values for individual chambers.
Appendix B Ozone CT Methods
B.2 Selection of Methods for Calculating Inactivation Credit
21. The extended-CSTR method calculates -C- based on a predicted ozone concentration profile in the
contactor using three measurement points. The contact time is based on the hydraulic detention time
(HDT) and an assumption of completely mixed flow. Since tracer studies have been performed on most
ozone disinfection contactors in the United States, this method, as currently written, will not be of use to
most water utilities for CT compliance monitoring. Therefore, this method should be replaced or
supplemented by the -modified log integration method-, relying on the same method for calculating -C-,
but using T10, proportioned to individual contact chambers by volume, for calculatingdisinfection contact
time.
B.3 Ozone Contactor Configurations
22. Include a contactor configuration with horizontal and vertical ozone pipeline dissolution systems.
These systems will provide stable initial ozone residual at the inlet to the baffled contactor, thereby
increasing the volume of the contactor available for CT credit.
B.4.3.2 Calculating Log Inactivation across an Extended-CSTR Zone
23. This section presents an equation for calculating Cx (or Cout) at the outlet of Chamber X in an
extended-CSTR zone. A second first-order rate equation should also be presented to calculate Caverage
for each chamber based on calculated values for the decay rate constant k*, Cin and Cx, as described in
this section. This value is used in the modified log integration method to calculate CT values, and will
result in a lower applied ozone dose than the current method to meet a given CT target.
24. Equation 11-1 does not apply if a T10 value has been determined from a tracer study of the ozone
contactor. Again, this section should be rewritten to include discussion of a -modified log integration
method as discussed under Comment 21.
B.4.3.2.1 Determining the Value of k*
25. A potential source of error in the Extended-CSTR method is the assumption that the extended-CSTR
zone of the contactor can be modeled as an -equal-volume CSTR in series- reactor. In full-scale
operating ozone contactors, flow streaming, recirculation zones, and hydraulic flow short-circuiting may
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lead to significant departures from the idealized CSTR model and result in errors in calculating the decay
rate constant k* as a function of the HDT, as discussed under Comment 26.
26. Use of three sample measurement points to calculate two individual k*values and an average k* value
is a conservative approach to avoid falsek* values due to sample or analytical error. However, use of
HDT valuesto predict the contact time between sample points may not be accurate for all contactor
configurations, and could lead to larger error values in the comparison of individual k* values. In fact, the
generous error rangeof 80 to 120 percent of the average k* value, is probably necessary due to localized
contactor hydraulics in the vicinity of the sample taps, which influence the actual contact time between
sample points. To address thisproblem, CDM, Black and Veatch and possibly other consulting firms,
have used ozone residual sample pipe loops outside the contactor to improve the accuracy of contact time
measurements and k* calculations. Therefore, alternative methods of measuring the k* value should be
discussed in the TGM to reduce inherent errors associated with the current method. For example, external
sample pipe loops can be designed to take a sample from the extended-CSTR zone and to measure the
ozone residual at three points along the pipe loop to perform thesame types of calculations as discussed in
this section, but with improved contact time measurements and lower k* error values.
B.4.3.2.2 Determining the Value of Cin
27. If tracer study data is available for the ozone contactor, the T 50 value should be used in lieu of HDT
to calculate the Cin value for the modified log integration method.
B.4.4 Example of Extended-CSTR Application
28. Include an example of the modified log integration method, which combines elements of the T10 and
Extended-CSTR method, as discussed in Comment 21.
Response: See Response 970.
EPA Letter ID: 488
Comment ID: 11848
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: In addition to the stringent requirements proposed in the regulation, the tone of the guidance
tends to be excessively prescriptive. This will intimidate utilities away from some toolbox elements that
might otherwise have proved viable. The Watershed Control Program (WCP) is an example of a toolbox
element that has the potential to be a beneficial practice and a viable tool for many utilities, but will likely
be overlooked because of the tone and requirements of guidance.
Response: See Response 970.
EPA Letter ID: 488
Comment ID: 11862
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment Response for L T2ESWTR 8-486 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Comment: The EPA needs to provide clarification about compliance implications of ozone residual and
contact time measurement requirements. For instance, if the proper measurements are not obtained for
one or two days in a month does this translate to a violation?
Response: The compliance requirements for ozone residual and contact time measurements are contained
in the LT2ESTWR rule langauge and in Subpart H of Part 141 CFR.
EPA Letter ID: 488
Comment ID: 11870
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: The draft guidance includes conflicting statements about the IFE toolbox criteria:
Section 7.2.1: IFE turbidity must be less than 0.1 NTU in at least 95 % of the maximum daily values
recorded at each filter in each month, excluding the 15 minute period following return to service from a
filter backwash
Section 7.2.2: IFE turbidity must be measured every 15 minutes (excluding the 15 minute period
following return to service from a filter backwash.) and 95 percent of the measurements form each month
must be less than or equal to 0.1 NTU
Response: See Response 970.
EPA Letter ID: 522
Comment ID: 14151
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Because of the higher ozone doses required to inactivate Cryptosporidium compared to
Giardia, particularly in the colder water temperatures that several of our systems experience, it is
important to further develop the SWTR concept of segregated flow analysis (SFA) to allow utilities to
better estimate and manage the application of ozone for CT. SFA is not currently in the Guidance Manual:
we urge that the Guidance Manual explicitly indicate that a system may demonstrate the SFA method to
the Primacy Agency for use at its plant, include an appendix to the Guidance Manual that details the use
of the SFA method.
Response: See Response 970.
EPA Letter ID: 523
Comment ID: 11695
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for L T2ESWTR 8-48 7 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Comment: Because of the higher ozone doses required to inactivate Cryptosporidium than Giardia,
particularly in the colder water temperatures that several of our systems experience, it is important to
further develop the SWTR concept of "segregated flow analysis" to allow utilities to better estimate and
manage the application of ozone for CT. SFA is not currently in the Guidance Manual: we urge that the
Guidance Manual explicitly indicate that a system may demonstrate the SFA method to the Primacy
Agency for use at its plant, include an appendix to the Guidance Manual that details the use of the SFA
method.
Response: See Response 970.
EPA Letter ID: 538
Comment ID: 14103
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: Second, EPA states that -Calcium is removed in single-stage softening and that Two-Stage
softening is used to remove Magnesium and greater levels of Calcium-. This is incorrect. It is possible to
remove Magnesium in Single-Stage Softening because softening is a chemical process that is governed
primarily on the Alkalinity & pH, not physical processes like stages. Any reference to Magnesium being
removed only by Two-Stage Softening should be removed from the rule and correctly stated as being
dependent on Alkalinity and pH.
Response: See Response 970.
EPA Letter ID: 556
Comment ID: 12071
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additionally, there is a problem with the content and tone of the Bank Filtration Guidance. As
written, it serves to make bank filtration unattractive rather than promote the technology.
AMWA also recommends EPA revise the guidance manual to present bank filtration in its proper context,
i.e., as a technology that when properly installed is an efficient, cost effective, -easy to operate-
technology that provides multiple benefits in addition to Cryptosporidium removal and kill (by
antagonistic organisms). EPA should incorporate examples of utilities with successful bank filtration
performance in the guidance.
Response: See Response 970.
EPA Letter ID: 562
Comment ID: 12318
Comment Response for L T2ESWTR 8-488 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA recommends that the agency take additional steps to clearly present these
CT requirements, and further refine draft guidance regarding compliance calculations for ozone CT. EPA
requested additional data to support the ozone
Response: See Response 970.
EPA Letter ID: 562
Comment ID: 12441
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.2.3Detailed Comments on Watershed Control Program Guidance Appendix 4 contains
additional specific comments on the guidance provided regarding watershed control program credit. The
comments in the appendix parallel the comments offered above. AWWA recommends the agency revise
the draft guidance to reflect the above comments as well as those specifically directed to the guidance
manual.
Response: See Response 970.
EPA Letter ID: 562
Comment ID: 12444
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: valuable technology for the U.S. drinking water community. The general tone of the guidance
does not encourage utilities to explore or invest in BF when the numerous advantages to bank filtration
range from improved water quality to enhanced security.
Response: See Response 970.
EPA Letter ID: 562
Comment ID: 12468
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.2.3Detailed Comments on Bank Filtration Guidance
Appendix 6 contains additional specific comments on the guidance provided regarding BF. The
comments in the appendix parallel the comments offered above and address additional detailed issues.
AWWA recommends the agency revise the draft guidance to reflect the above comments as well as those
specifically directed to the guidance manual.
Comment Response for L T2ESWTR 8-489 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Response: See Response 970.
EPA Letter ID: 562
Comment ID: 12521
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additional Information Needed in CT Table
The Guidance manual currently includes an equation to calculate the klO values for the inactivation of
Cryptosporidium, with ozone as a function of water temperature:
[SEEP.71INPDF]
This equation is important for water utilities because it can be incorporated into the plant-s computer-
control system. AWWA offers the following comments related to this equation:
[SEEP.71INPDF]
1. In addition to the possibility of having to meet the inactivation requirements for Cryptosporidium, a
plant is required to meet the inactivation requirements for Giardia and virus. Similar equations
are needed for Giardia and virus. We propose the following equations for expressing the values of klO for
the inactivation of Giardia and virus with ozone:
[SEEP. 71 IN PDF]
These equations were derived by fitting the klO values as derived from the SWTR CT tables.
2. The equations are currently listed in Chapter 11 of the Toolbox Guidance Manual. These are not visible
enough for primacy agencies and utilities to use. AWWA recommends that these equations be moved to
the same page where the CT tables are listed in the preamble and placed directly in the regulatory
language. They can be listed in a separate table or in a footnote to the ozone CT table. However, we
suggest modifying the equations to directly calculate the log inactivation values as a function of
temperature and CT. The purpose of this change is only to simplify the understanding and application of
these equations in plant control systems. The modified equations become as follows:
[SEE TABLE, P.72 IN PDF]
The regulatory language should state that the equations can be used to calculate the log inactivation of
each microorganism down to 0.1-log, especially for Cryptosporidium inactivation with ozone.
Response: See Response 970.
EPA Letter ID: 562
Comment ID: 12522
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR 8-490 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
Comment: Calculation of Compliance
Monitoring Period
Section §141.729(a) states that log inactivation is to be reported once per day during peak-flow hours.
However, the Microbial Toolbox Guidance Manual recommends that hourly sampling be done if a utility
does not know the hour of peak flow. The guidance manual requirement appears to be more stringent
than the rule. Regardless, the hourly sampling requirement is unnecessary and will greatly increase the
reporting burden on systems. Since several reporting requirements have a four-hour reporting period,
EPA should revise the hourly requirement to a four-hour reporting period if a system cannot identify the
hour of peak flow.
Response: See Response 970.
EPA Letter ID: 562
Comment ID: 12523
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Conservatism in -C- Value
Table 11.3 in the Toolbox Guidance Manual recommends the use of Cout as the characteristic
concentration, C*, in reactive-flow chambers when using the T10 method. Considering that T10 is a
conservative estimate of the true contact time through the chamber, and CT values are based on upper
confidence limits, no additional conservatism is needed in the -C- value. AWWA recommends that
the rule allow the use of the geometric mean (or log mean) of the influent and effluent ozone
concentrations in reactive chambers:
[SEE P.72 IN PDF]
Rationale for CriterionPage 11-8 of the current Toolbox Guidance Manual states
that the T10 method —cannot be used if the chambers with final concentrations of zero (non-
detectable) are 50 percent or greater than the entire volume of the chambers.- The rationale for this
criterion is not indicated, and the document does not specify what a system should do if its ozone
contactor operation falls within this criterion on a certain day. This requirement is an unnecessary
complication not supported by scientific data. Figure 2 shows tracer testing results from and over-under
contactor in Florida. The tracer tests were conducted at two flows: 15 and 33 MGD, and samples were
collected from Tap 3 and Tap 8 along the contactor. Although Tap 3 is about one third the distance to Tap
8, the T10/HRT values at both taps are virtually identical. The rationale is that the flow pattern develops
through the first few chambers of the contactor and does not necessarily change through the rest of the
contactor. A plug flow contactor with a 10-minute contact time has the same flow pattern as a plug flow
contactor with a 20-minute contact time. With T10/HRT ratios in ozone contactors in excess of 0.6, ozone
contactors experience similar behavior.
The practical problem with the current limitation is the addition of an unnecessary layer of complexity to
the operation of an ozone system. The uncertainty factors used in the calculation of T10, C, and the log-
inactivation value provide adequate safety factors. This additional burden is unwarranted.
Applying Multiple Compliance Algorithms
The Toolbox Guidance Manual indicates that a system can use either the T10 or the CSTR method in
Comment Response for LT2ESWTR 8-491 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
calculating the log-inactivation credit through ozone contactors, but systems —should select one method
to be used and use that method consistently-. However, a system must meet several QA/QC criteria for
every calculation of the log-inactivation credit. If a system fails a criterion on one day, it must be allowed
to utilize the other method to calculate the log inactivation for the day. For example, if the ozone residual
dissipates to below detection within less than 50% of the contactor, the guidance manual says that the T10
method cannot be used. In that situation, the system should be allowed to use the CSTR method to
calculate the log inactivation. The guidance manual should explicitly state that a system may use the other
method on specific occasions, when its pre-selected method is not applicable. Regardless of the reason for
switching calculation methods, a system should be allowed to utilize any approved methodology on any
day regardless of what it used on the previous day since there is no relationship between any two
onsecutive inactivation compliance reporting events.
Figure 2. Tracer Testing Results from an Over-Under Ozone Contactor in Florida
[SEE FIGURE 2, P.74]
Using Average k* Value
The Extended-CSTR method uses a calculated ozone decay coefficient, k*, to calculate the log
inactivation across an ozone contactor. The k* value is calculated as the average of two calculated k*
values using three ozone residual measurements. However, the method includes a QC criterion of a
maximum variance of 20% between the two individual calculated k* values and the average value. The
current guidance manual states that if this QC criterion is not met, the average k* value cannot be used,
and a system will need to re-sample the contactor and calculate a new k* value. Considering that
inactivation is to be met 100% of the time, the rejection of the data based on this QC criterion and the
requirement to resample is a high-risk requirement that many systems cannot take. AWWA recommends
that USEPA change this requirement so that a system that fails the 20% QC criterion on k* can either
resample and recalculate the k* value until it meets the QC criterion, or use the higher of the two k*
values. Appendix 9 contains a memorandum documenting the need for an approach to k* in greater detail,
providing datasets illustrating the issues involved, and proposing an alternative calculation when QC
criterion is not met.
Determining the klO Value
In determining the klO value for the inactivation of Cryptosporidium with ozone, EPA staff determined
the uncertainty factorto be applied to the regression line of Ln(KlO) vs. water temperature. The approach
includes a rigorous statistical analysis to determine the relevant 90% confidence in the klO value.
Appendix A to the current Toolbox Guidance Manual includes a description of disinfection testing that a
system may conduct to develop site-specific CT values. However, the document does not indicate how to
calculate the uncertainty factorto apply to the regression line of Ln(klO) vs. temperature. The statistical
approach used in the development of the current CT table is recommended for use by individual systems
for the development of site-specific CT tables. The approach includes the following steps:
Step 1 - Collect -n- number of pairs of CT and log-inactivation values at various temperatures
Step 2 - Divide each log-inactivation value by its corresponding CT value. This will provide a specific
klO value at a specific temperature
Step 3 - Plot all the Ln(klO) values vs. water temperature. In this plot, -Y- is the Ln(klO) value and -X-
is the temperature
Step 4 - Utilize Equations 1 & 2 to calculate the upper (YU) and lower (YL) 90% confidence limits on
the Ln(klO) values. The only unknown in Equation 1 is the factor -f- which represents the fraction of the
scatter that is attributed to variability in the microorganism itself and in the impact of the water matrix
on the inactivation efficiency. In the development of the CT tables included in the rule, the value of-f-
was determined to be 0.125. The value of-f- for the site-specific inactivation data collected by a utility
Comment Response for L T2ESWTR 8-492 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
can be determined by conducting a specific statistical analysis of the site-specific data gathered.
[SEE EQUATIONS, P.76 IN PDF]
Segregated Flow Analysis
The ozone Cryptosporidium CT tables developed by EPA for LT2ESWTR are substantially higher than
those required for virus or Giardia lamblia inactivation. Substantial cost consequences and potential
health concerns (i.e., bromate formation) are associated with overly conservative application of ozone to
achieve CT. Therefore, the further development of the Surface Water Treatment Rule concept of-
segregated flow analysis- is critical to allow utilities to better estimate and manage the application of
ozone for CT.
The Segmented (or Segregated) Flow Analysis (SFA) method for calculating log-inactivation through
ozone contactors was considered by USEPA but was not included in the guidance manual because of
concerns over accuracies of the method. Appropriate testing methods exist which a water system may
conduct to evaluate the accuracy of the SFA method. AWWA recommends that the Guidance manual
explicitly indicate that a system may conduct a study to demonstrate the SFA method to the state for use
at its plant.
In addition, even if the state approves the application of the SFA method after a demonstration study, the
description of the method application is not currently included in the guidance manual. AWWA
recommends that the USEPA include an appendix to the guidance manual that details the application of
the SFA method. In this manner, a state can utilize this appendix to approve the application of the SFA
method after a system adequately demonstrates its accuracy. Appendix 10 provides a model approach to
such a model guidance document.
Response: See Response 970.
EPA Letter ID: 562
Comment ID: 12527
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Transfer of Ozone CT Approach to Chlorine Dioxide While the guidance manual currently
includes equations to calculate the klO value for the inactivation of Cryptosporidium, no such equation is
provided for chlorine dioxide. The inclusion of such equations for the inactivation of Cryptosporidium,
Giardia, and virus with chlorine dioxide would be very helpful to utilities. Such equations are easily
developed using the same approach used to develop the equations for ozone. Based on a similar approach,
the following equation is proposed for the inactivation of Cryptosporidium with chlorine dioxide:
Log Inactivation = 70.001506 x (1.09116)Temp] x CT
Using equations to calculate the log inactivation of Cryptosporidium down to 0.1 log should be explicitly
stated in §141.729. AWWA strongly recommends that EPA provide similar equations expressing the log
inactivation of Giardia lamblia cysts and viruses with chlorine dioxide.
Response: See Response 970.
Comment Response for L T2ESWTR 8-493 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
EPA Letter ID: 612
Comment ID: 13149
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: 2. Particle Counting:
One of the themes of LT2 is that the risk of cryptosporidium occurrence is reduced through the removal
of particles in the same size range as this pathogen. Many studies have been conducted using this
technology to correlate the removal of particles that would exit a filtration system within a specific size
range as a conservative surrogate to the pathogens such as Giardia and Cryptosporidium. (CFR47661,
McTigue, etal. (1998).
However, there is no suggestion or encouragement in LT2 for the utilization of sensitive descriptive
continuous monitoring technologies such as particle counters to monitor the performance of different
treatment and filtration processes, nor to confirm the passage of particles in the same size range as
those pathogens of concern stated in LT2.
Discussion:
Particle counters have become common water quality monitoring tools for filtration performance in the
drinking water industry. Further, particle counters are key monitoring technologies for the demonstration
of LRV in membrane challenge studies and in the monitoring of membrane filtrate in small-scale plants.
Many water utilities have become heavily vested in particle counting technology monitoring and use them
for process optimization and filter effluent monitoring. However, with the lack of encouragement from a
regulatory standpoint, many plants cannot consider the use of this technology.
Several studies have been conducted which demonstrate how particle counters can be used to monitor
filtration processes and many of these papers indicate the technology as a viable alternate or
complementary monitoring technique when compared to current regulatory accepted turbidity methods
(namely 180.1 and Standard Methods 2130B). The partnership for safe drinking water advocates the
benefits of using particle counters for gauging filter performance.
It should be noted that there is a typographical error associated to the discussion of the McTigue et al.
(1998) reference (CFR47661). In the paragraph that contains this reference, discussion of "median
removals particle greater than 2 mm" should have the units microns (um).
Summary:
Hach Company encourages the Agency to promote the known benefits of particle counters for drinking
water monitoring and application. The technology provides sensitivity and descriptive water quality
characteristics related to particle distributions that are unique regarding this technology. Many utilities
have spent the time and the effort to install and apply this technology for both filtration optimization and
effluent monitoring and they should be rewarded if they can demonstrate that these instruments can
ultimately help to reduce pathogen intrusion into the effluent through detection of particle spikes. These
instruments are capable of establishing stringent performance criteria (e.g. log removal credit) across
particulate removal systems such as conventional filters and membranes.
Particle counting is a technology that is highly sensitive to changes in the particulate load within the
effluent stream. Though the technology is often perceived as complex and difficult to apply, there are a
large number of utilities that have overcome these issues and have developed this technology into highly
Comment Response for L T2ESWTR 8-494 December 2005
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ChapterS: Options for Meeting Treatment Requirements Comment Codes 700-970
sensitive analytical tools for effluent monitoring. Those utilities that choose to install, learn, and utilize
this type of technology, and can demonstrate how the technology can provide an advantage in the
detection of pathogen intrusion into the effluent should be recognized. The awarding of a specific level
log removal credit for such efforts should be performed to those utilities who have taken these extra steps
to reduce the risk or microbial intrusion into their effluent waters.
Response: See Response 970.
EPA Letter ID: 643
Comment ID: 12823
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Guidance Documents
States have reviewed the guidances prepared in support of the LT2ESWTR and are submitting comments
directly to EPA-s responsible program office. States also recommend that EPA modify guidances based
on changes made to the final rule in response to comments received.
Response: See Response 970.
Comment Response for L T2ESWTR 8-495 December 2005
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9. Disinfection Benchmarks: Comment Codes 1000-1020
9.1 Comment Code 1000, Disinfection Benchmarks
Response to Code 1000
1000.1
EPA agrees with commenters who suggested that disinfection profiling should not be required for every
system and should only be required for systems that are planning a change in disinfection practice. In the
final rule, EPA has significantly modified the applicability requirements for disinfection profiling. PWSs
are only required to develop a disinfection profile if they propose to make a significant change in
disinfection practice after completing the first round of source water monitoring. EPA has made this
change from the proposal because under the LT2ESWTR and Stage 2 DBPR, most PWSs will not be
required to make significant changes to their disinfection practice. Consequently, most PWSs will not
need a disinfection profile. EPA believes that disinfection profiling requirements should be targeted to
those PWSs that will make significant disinfection changes. This change will significantly reduce the
burden on systems and States.
1000.2
One commenter suggested that disinfection profiling should not be required for small systems. Others
commented that profiling and benchmarking are not necessary because they are addressed adequately in
the Interim Enhanced Surface Water Treatment Rule (IESWTR) and the Long Term 1 Enhanced Surface
Water Treatment Rule (LT1ESWTR). EPA disagrees with these comments. A goal in the development of
rules to control microbial pathogens and disinfection byproducts (DBPs) is the balancing risks between
these two classes of contaminants. EPA established disinfection profiling and benchmarking under the
IESWTR and LT1ESWTR, based on a recommendation by the Stage 1 M-DBP Advisory Committee, to
ensure that PWSs maintained adequate protection against pathogens as they reduced risk from DBPs.
EPA is extending profiling and benchmarking requirements to the LT2ESWTR for the same objective.
Some PWSs will make significant changes in their current disinfection practice to meet TTHM and
HAAS requirements under the Stage 2 DBPR and to provide additional treatment for Cryptosporidium
under the LT2ESWTR. To ensure that these PWSs maintain disinfection that is effective against a broad
spectrum of microbial pathogens, EPA believes that PWSs and States should evaluate the effects of
significant changes in disinfection practice on current microbial treatment levels, regardless of the size of
the system. Disinfection profiling and benchmarking serves as a tool for making such evaluations.
1000.3
EPA disagrees with those who questioned the need for disinfection benchmark requirement for viruses for
sources that already have a disinfection profile for Giardia lamblia because they believe that current
disinfection practices aimed at inactivating Giardia lamblia typically result in inactivation ratios for
viruses that are much greater than needed. EPA believes that profiling for both target pathogens is
appropriate because the types of treatment changes that PWSs will make to comply with the Stage 2
DBPR or LT2ESWTR could lead to a significant change in the inactivation level for one pathogen but not
the other. For example, a PWS that switches from chlorine to UV light to meet Giardia lamblia
inactivation requirements is likely to maintain a high level of treatment for this pathogen. The level of
treatment for viruses, however, may be significantly reduced. In general, viruses are much more sensitive
Comment Response for LT2ESWTR 9-1 December 2005
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
to chlorine than Giardia but are more resistant to UV. The situation for a PWS switching to microfiltration
is similar. Consequently, EPA believes that States and PWSs should consider whether such a decrease in
virus treatment will occur when evaluating proposed treatment changes. Moreover, developing a virus
disinfection profile does not require the collection of operational data beyond that necessary to develop a
Giardia lamblia disinfection profile. Therefore, today's rule allows PWSs to use previously developed
Giardia lamblia disinfection profiles and allows the operational data that underlie the Giardia lamblia
profile to be used for a virus disinfection profile.
1000.4
EPA agrees with the commenters who suggested that states be provided the flexibility to provide waivers
or determine the appropriate time for different systems to perform profiling monitoring. EPA has
eliminated the scheduling requirements for development of the disinfection profile in order to provide
more flexibility to PWSs and States. Today's rule only requires that PWSs notify States prior to making a
significant change in their disinfection practice and that this notification include the disinfection profiles
and benchmarks, along with an analysis of how the proposed change will affect the current benchmarks.
1000.5
EPA has used the word "average" in place of "mean" in todays final rule to be consistent with the
IESWTR and LT1ESWTR. EPA notes that "average" has the same mathematical definition as "mean" so
this change in wording does not represent a change in requirements.
1000.6
All States with primacy currently have approved procedures for calculating Giardia CT values. These
procedures are based on the Giardia CT tables established by the SWTR and approaches for interpolating
between CT table values, including the use of regression equations. Today's rule requirements for
disinfection profiling do not modify, withdraw, or expand existing approved procedures for calculating
Giardia CT values. Rather, the rule relies on existing approved procedures. Given the long standing
approved procedures for calculating Giardia CT values, all of which must be based on a uniform set of
CT tables in the SWTR, EPA has not identified a technical basis to establish a uniform set of regression
equations as the commenter recommends.
1000.7
EPA is developing implementation guidance for the LT2ESWTR that addresses the disinfection profiling
and benchmarking requirements of the rule
Individual Comments on Code 1000
EPA Letter ID: 101
Comment ID: 10906
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Disinfection Benchmarks for Giardi lamblia and Viruses
Small systems (serving <10,000) that are meeting the requirements of the LT 2 Rule should not be subject
to the Giardia and virus disinfection benchmarking requirements. This activity is an extra requirement
Comment Response for the LT2ESWTR 9-2 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
based on an unnecessary precautionary principle. Small systems do not have the resources or time to
implement this requirement - their focus will be maintaining compliance with the other requirements in
this rule to increase public health protection.
Response: See response 1000.1
EPA Letter ID: 441
Comment ID: 10776
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Requirements when making a significant change in disinfection practice
The Interim and Long Term 1 Enhanced Surface Water Treatment Rules specify that the disinfection
benchmark shall consist of the lowest monthly average. However, the benchmark for the proposed LT2 is
the lowest monthly mean. To reduce confusion, EPA should use the same benchmark definition specified
in the previous two rules.
Response: See response 1000.5
EPA Letter ID: 457
Comment ID: 11900
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Disinfection Profiling/Benchmarking
We do not oppose the disinfection profiling provisions of the proposed rule, but request flexibility to
determine the appropriate time for different systems to perform profiling monitoring. This can be
addressed as a special primacy requirement in the final rule.
Response: See response 1000.4
EPA Letter ID: 457
Comment ID: 11941
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Section IV.D Disinfection Benchmarks for Giardia lamblia and Viruses (pages
47715-47718)
Comment Response for the LT2ESWTR 9-3 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
We do not oppose the disinfection profiling provisions of the proposed rule, but request flexibility to
determine the appropriate time for different systems to perform profiling monitoring.
Response: See response 1000.4
EPA Letter ID: 458
Comment ID: 10980
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Page 47718 - Profile/Benchmark should only be required for viruses if a disinfection change
is proposed (CFR 141.713(c)(2)). The reasoning for a mandatory development is missing from the
preamble, particularly if the acceptable data to develop a benchmark/profile already exists under the
-grandfather- provisions listed in the proposed rule.
Response: See response 1000.1
EPA Letter ID: 475
Comment ID: 11212
Commenter: Edmund G. Archuleta, General Manager, El Paso Water Utilities
Commenter Category: Regulated Community (Utilities)
Comment: The Disinfection Profiling requirement of the proposed rule would also require us to sample
our plants for Giardia and viruses weekly for 12 consecutive months. Again, our plants operate
consecutively for only 4 to 8 months of the year.
Response: The final rule requires that systems that operate for fewer than 12 mnoths per year must
monitor weekly during the period of operation.
EPA Letter ID: 480
Comment ID: 11230
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: The need to balance microbial protection and disinfection byproduct formation is well
established and important. The mandatory development of disinfection profiles in a prescriptive manner,
and on a prescriptive schedule for a subset of public water systems is difficult for many utilities to
understand, and difficult for primacy agencies to implement. This diverts resources from other important
and pressing work. As well, it may present a very incomplete picture of the system-s microbial
protection, and the trade-offs of a specific treatment revision. The requirement is a snapshot, collected
between the months of 24 and 36 (after rule promulgation), and doesn-t necessarily consider other issues
that could have a significant impact on disinfection (changes in other chemical treatment, like pH
Comment Response for the LT2ESWTR 9-4 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
adjustment, or changes in source water characteristics).
It is appropriate to require consultation with the primacy agency prior to making a change in disinfection
practice, however it is unnecessary to prescribe the creation of a profile that may or may not have
relevancy to the issues at hand when that consultation occurs. It would be far better to require the
consultation (many States already require this), and provide in Guidance the relevant considerations a
State and utility should address. This utilizes resources more efficiently, reduces regulatory uncertainty,
and, at least in a small way, simplifies this rule.
Response: See responses 1000.1 and 1000.2. The requirement for systems to notify the State before
implementing any significant change in disinfection practice will initiate the suggested consultation with
the State.
EPA Letter ID: 497
Comment ID: 10657
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Disinfection Profiling/Benchmarking
The MDEQ objects to the -disinfection profiling and benchmarking- requirements in the proposed
LT2ESWTR. We believe these requirements have already been addressed more than adequately in the
Interim Enhanced Surface Water Treatment Rule (IESWTR) and the Long Term 1 Enhanced Surface
Water Treatment Rule(LTIESWTR). The requirement in the proposed LT2ESWTR would mandate that
allcommunity systems profile. The benefit of profiling is limited at best and assumes erroneously that
states need the information it provides to make disinfection decisions. There is no reason to require
disinfection profiling unless the established benchmark has an associated regulatory requirement. Absent
that, the Giardia and virus removal/inactivation requirements in the surface water treatment rule,
IESWTR, and LTIESWTR are the only absolute standards that the EPA can expect to be uniformly
enforced.
Response: See responses 1000.1 and 1000.2
EPA Letter ID: 509
Comment ID: 11483
Commenter: Greg Parker,, Florida Department of Environmental Protection Drinking Water Program
Commenter Category: State/Tribe Government
Comment: 141.729 Many states are automating their systems Benchmarking and Profiling by
incorporating their Monthly Operation Reports into a spreadsheet. Regression equations are used to select
log removal values rather than interpolation from a table. Consider including regression equations in the
rule for uniformity of results.
Response: See response 1000.6
Comment Response for the LT2ESWTR 9-5 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
EPA Letter ID: 520
Comment ID: 11598
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Disinfection Profiling/Benchmarking
IEPA disagrees with the disinfection benchmark requirement for viruses for sources that already have a
disinfection profile for Giardia lamblia. Current disinfection practices aimed at inactivating Giardia
lamblia typically result in inactivation ratios for viruses that are much greater than needed. Unnecessarily
focusing water system attention on virus inactivation ratios may lead to greater confusion than true public
health protection and could lead some water systems to inappropriately reduce their chlorine dose
believing their dose to be higher than necessary. Additionally, IEPA will need to focus resources on
reviewing viral disinfection profiles instead of undertaking other activities that could directly increase
public health protection.
Response: See response 1000.1
EPA Letter ID: 520
Comment ID: 11650
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Section IV.D Disinfection Benchmarks for Giardia lamblia and Viruses (pages
47715-47718)
IEPA disagrees with the disinfection benchmark requirement for viruses for sources that already have a
disinfection profile for Giardia lamblia. Current disinfection practices aimed at inactivating Giardia
lamblia typically result in inactivation ratios for viruses that are much greater than needed. Unnecessarily
focusing water system attention on virus inactivation ratios may lead to greater confusion than true public
health protection and could lead some water systems to inappropriately reduce their chlorine dose
believing their dose to be higher than necessary. Additionally, IEPA will need to focus resources on
reviewing viral disinfection profiles instead of undertaking other activities that could directly increase
public health protection.
Response: See response 1000.1. (Comment is a repeat of 520-11598)
EPA Letter ID: 528
Comment ID: 12264
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 9-6 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
Comment: Disinfection Profiling/Benchmarking
We oppose the disinfection profiling provisions of the proposed rule, and request flexibility to determine
the appropriate time for different systems to perform profiling monitoring.
Response: See responses 1000.1 and 1000.2
EPA Letter ID: 536
Comment ID: 11805
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Disinfection Profiling/Benchmarking
Colorado disagrees with the disinfection benchmark requirement for viruses for sources that already have
a disinfection profile for Giardia lamblia. Current disinfection practices aimed at inactivating Giardia
lamblia typically result in inactivation ratios for viruses that are much greater than needed. Unnecessarily
focusing water system attention on virus inactivation ratios may lead to greater confusion than true public
health protection and could lead some water systems to inappropriately reduce their chlorine dose
believing their dose to be higher than necessary. Additionally, state staff will need to focus resources on
reviewing viral disinfection profiles instead of undertaking other activities that could directly increase
public health protection.
Response: See response 1000.1
EPA Letter ID: 559
Comment ID: 12227
Commenter: Bill Pappathopoulos, Director, City of Two Rivers, Water & Light Utility
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.D. - Disinfection Bench Marks for Giardia Lamblia & Viruses
The requirements under this proposal would seem to duplicate and expand the current burdensome CT
calculations required to demonstrate compliance with Giardia and viruses inactivation requirements. This
requirement would especially seem burdensome where the system is not proposing changes to its
disinfection practices. This proposed Rule was suggested not to function as a regulatory standard, only as
another tool to assess microbial risk. We would not want to see disinfection profiling and benchmarking
required of all system, especially where plant compliance with LT 2 ESWTR and Stage 2 DBPR is
consistent.
Response: See response 1000.1
EPA Letter ID: 561
Comment ID: 12235
Comment Response for the L T2ESWTR 9- 7 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.D. - Disinfection Bench Marks for Giardia Lamblia & Viruses
The requirements under this proposal would seem to duplicate and expand the current burdensome CT
calculations required to demonstrate compliance with Giardia and virus inactivation requirements. This
requirement would especially seem burdensome where the system is not proposing changes to its
disinfection practices. This proposed Rule was suggested not to function as a regulatory standard, only as
another tool to assess microbial risk. We would not want to see disinfection profiling and benchmarking
required of all system, especially where plant compliance with LT 2 ESWTR and Stage 2 DBPR is
consistent.
Response: See response 1000.1
EPA Letter ID: 562
Comment ID: 12558
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: formation and disinfection. In the lESWTRthe disinfection profiling and benchmarking
provisions were explicitly written to address risk balancing during the implementation of the Stage 1
DBPR and IESWTR and LT1ESWTR. Extending this concept to LT2ESWTR is sound.
Response: See Response lOOa.
EPA Letter ID: 591
Comment ID: 12134
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Ohio EPA does not believe that requiring virus profiling for systems using chlorine provides any useful
data and we request that this be deleted from the rule. Its an implementation burden on the state and
system and doesn't seem to be meaningful.
The IESWTR and LTIESWTR allowed systems to demonstrate relatively low levels of D/DBPs to waive
the requirement for developing a disinfection profile and benchmark. The new rule will now require some
of these systems to conduct a profile regardless of their D/DBP levels and will require other systems to
again demonstrate low levels of D/DBPS to waive the disinfection profiling requirements for Giardia
lamblia inactivation. The reason given is that some systems may change treatment to comply with the
LT2ESWTR. If systems met the waiver provision of the previous rules, they should not be required to
perform a profile based on new criteria.
Response: See response 1000.3
Comment Response for the LT2ESWTR 9-8 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
EPA Letter ID: 595
Comment ID: 12593
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Section IV.D Disinfection Benchmarks for Giardia lamblia and Viruses pages
47715-47718)
Maine believes that current practices of Giardia lamblia inactivation generally results in higher than
necessary inactivation ratios. Therefore, the requirement for systems to create an additional disinfection
benchmark for viruses seems nonsensical.
Response: See response 1000.3
EPA Letter ID: 601
Comment ID: 13029
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on the proposed provisions of the inactivation profiling
and benchmark requirement.
Utah recommends that States be allowed to grant waivers for disinfection profiling similar to the waivers
outlined in the IESWTR and LT1ESWTR. This reduces the burden for systems that do not have to make
significant changes to meet the Stage 2 D/DBPR and therefore will not compromise adequate inactivation
of Giardia and viruses.
In addition, Utah recommends that States be granted flexibility in determining the appropriate time for
water systems to perform profile monitoring, if needed.
Response: See responses 1000.1 and 1000.4
EPA Letter ID: 603
Comment ID: 12653
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47782) Section 141.713(b)(c)(2)-
Currently, all systems in this state that serve less than 10,000 people have disinfection profiles for Giardia
lamblia. However, none have developed virus profiles and none should be required to do so unless they
make a change in disinfection practices. The development of a virus profile without a change in
disinfection practice may give a water system a false sense that it has exceedingly high inactivation ratios.
Comment Response for the LT2ESWTR 9-9 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
Development of virus disinfection profiles should be limited to those systems that have not completed a
disinfection profile for Giardia lamblia or plan to install UV disinfection.
Response: See response 1000.3
EPA Letter ID: 603
Comment ID: 12679
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47715) Section 1V.D. Disinfection Benchmarks for Giardia lamblia and
Viruses
The department disagrees with the disinfection benchmark requirement for viruses for sources that
already have a disinfection profile for Giardia lamblia. The requirement for disinfection profiling should
be required prior to switching disinfectants, but not universally. The universal implementation of
disinfection profiles will distract State staff from higher priority implementation activities.
Chlorine, which is the primary disinfectant used by nearly all of the Subpart H systems in this state, is
very effective at inactivating viruses compared to Giardia lamblia. For example, with a direct filtration
plant operating at apH of 7.0,0.5C, and chlorine residual of 0.6 m a, 1-log inactivation of Giardia
lamblia would require a CT of 56 versus a CT of 6 for 2-log inactivation of viruses. In other words, an
inactivation ratio of 1.1 for Giardia lamblia would result in an inactivation ratio of greater than 10 for
viruses. Unnecessarily focusing water system attention on virus inactivation ratios may lead to greater
confusion than public health protection and could lead some water systems to inappropriately reduce their
chlorine dose believing their dose to be higher than necessary.
Response: See responses 1000.1 and 1000.3
EPA Letter ID: 609
Comment ID: 14123
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Disinfection Profiling/Benchmarking
The MDEQ objects to the "disinfection profiling and benchmarking" requirements in the proposed
LT2ESWTR. We believe these requirements have already been addressed more than adequately in the
Interim Enhanced Surface Water Treatment Rule (IESWTR) and the Long Term 1 Enhanced Surface
Water Treatment Rule (LTIESWTR). The requirement in the proposed LT2ESWTR would mandate that
all community systems profile. The benefit of profiling is limited at best and assumes erroneously that
states need the information it provides to make disinfection decisions. There is no reason to require
disinfection profiling unless the established benchmark has an associated regulatory requirement. Absent
that, the Giardia and virus removal inactivation requirements in the surface water treatment rule,
IESWTR, and LTIESWTR are the only absolute standards that the USEPA can expect to be uniformly
enforced.
Comment Response for the LT2ESWTR 9-10 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
Response: See responses 1000.1 and 1000.2 (REPEAT of comment 497-10657)
EPA Letter ID: 637
Comment ID: 13102
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on the proposed provisions of the inactivation profiling
and benchmark requirement.
District recommends that States be allowed to grant waivers for disinfection profiling similar to the
waivers outlined in the IESWTR and LT1ESWTR. This reduces the burden for systems that do not have
to make significant changes to meet the Stage 2 D/DBPR and, therefore, will not compromise adequate
inactivation of Giardia and viruses.
Response: See responses 1000.1 and 1000.4
EPA Letter ID: 643
Comment ID: 12750
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Disinfection Profiling/Benchmarking
Some states disagree with the disinfection benchmark requirement for viruses for sources that already
have a disinfection profile for Giardia lamblia. Current disinfection practices aimed at inactivating
Giardia lamblia typically result in inactivation ratios for viruses that are much greater than needed.
Unnecessarily focusing water system attention on virus inactivation ratios may lead to greater confusion
than true public health protection and could lead some water systems to inappropriately reduce their
chlorine dose believing their dose to be higher than necessary. Additionally, states will need to focus
resources on reviewing viral disinfection profiles instead of undertaking other activities that could directly
increase public health protection.
Response: See response 1000.1
EPA Letter ID: 643
Comment ID: 12805
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section IV.D Disinfection Benchmarks for Giardia lamblia and Viruses (pages
47715-47718)
Some states disagree with the disinfection benchmark requirement for viruses for sources that already
have a disinfection profile for Giardia lamblia. Current disinfection practices aimed at inactivating
Comment Response for the LT2ESWTR 9-11 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
Giardia lamblia typically result in inactivation ratios for viruses that are much greater than needed.
Unnecessarily focusing water system attention on virus inactivation ratios may lead to greater confusion
than true public health protection and could lead some water systems to inappropriately reduce their
chlorine dose believing their dose to be higher than necessary. Additionally, states will need to focus
resources on reviewing viral disinfection profiles instead of undertaking other activities that could directly
increase public health protection.
Response: See response 1000.1 (REPEAT of 643-12750)
EPA Letter ID: 647
Comment ID: 12903
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Disinfection Profiling/Benchmarking
MDE disagrees with the disinfection benchmark requirement for viruses for sources that already have a
disinfection profile for Giardia lamblia. Current disinfection practices aimed at inactivating Giardia
lamblia typically result in inactivation ratios for viruses that are much greater than needed. Unnecessarily
focusing water system attention on virus inactivation ratios may lead to greater confusion than true public
health protection and could lead some water systems to inappropriately reduce their chlorine dose
believing their dose to be higher than necessary. Additionally, states will need to focus resources
on reviewing viral disinfection profiles instead of undertaking other activities that could directly increase
public health protection.
Response: See response 1000.1
EPA Letter ID: 647
Comment ID: 12942
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Section IV.D Disinfection Benchmarks for Giardia lamblia and Viruses (pages
47715-47718)
MDE disagrees with the disinfection benchmark requirement for viruses for sources that already have a
disinfection profile for Giardia lamblia. Current disinfection practices aimed at inactivating Giardia
lamblia typically result in inactivation ratios for viruses that are much greater than needed. Unnecessarily
focusing water system attention on virus inactivation ratios may lead to greater confusion than true public
health protection and could lead some water systems to inappropriately reduce their chlorine dose
believing their dose to be higher than necessary. Additionally, states will need to focus resources on
reviewing viral disinfection profiles instead of undertaking other activities that could directly increase
public health protection.
Response: See response 1000.1 (REPEAT of 647-12903)
Comment Response for the LT2ESWTR 9-12 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
EPA Letter ID: 662
Comment ID: 14041
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
D. Disinfection Benchmarks for Giardia lamblia and Viruses
3. Request for Comments (pages 47715-47718)
EPA requests comment on the proposed provisions of the inactivation profiling and benchmark
requirement.
Waivers from this requirement should be available.
State should also have the flexibility to determine the timing of the profiling.
Response: See response 1000.4
EPA Letter ID: 664
Comment ID: 14057
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.D. - DISINFECTION BENCH MARKS FOR GIARDIA LAMBLIA &
VIRUSES
The requirements under this proposal would seem to duplicate and expand the current burdensome CT
calculations required to demonstrate compliance with Giardia and viruses inactivation requirements. This
requirement would especially seem burdensome where the system is not proposing changes to its
disinfection practices. This proposed Rule was suggested not to function as a regulatory standard, only as
another tool to assess microbial risk. We would not want to see disinfection profiling and benchmarking
required of all system, especially where plant compliance with LT 2 ESWTR and Stage 2 DBPR is
consistent.
Response: See response 1000.1
EPA Letter ID: 668
Comment ID: 13887
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 1100 VII. Uncovered Finished Water Reservoirs
Comment Response for the LT2ESWTR 9-13 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
Comment: Moreover, we support the requirements for Disinfection Profiling and Benchmarking, and for
covering or treating water from uncovered finished water reservoirs as included in the Agreement.
Response: See Response 100.a
EPA Letter ID: 673
Comment ID: 13994
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
D. Disinfection Benchmarks for Giardia lamblia and Viruses
3. Request for Comments (pages 47715-47718)
EPA requests comment on the proposed provisions of the inactivation profiling and benchmark
requirement.
Jordan Valley Water recommends that States be allowed to grant waivers for disinfection profiling similar
to the waivers outlined in the IESWTR and LT1ESWTR. This reduces the burden for systems that do not
have to make significant changes to meet the Stage 2 D/DBPR and therefore will not risk adequate
inactivation of Giardia and viruses.
Response: See responses 1000.1 and 1000.4
EPA Letter ID: 673
Comment ID: 13995
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: In addition, Jordan Valley Water recommends that States be granted flexibility
in determining the appropriate time for water systems to perform profile monitoring.
Response: See response 1000.4
EPA Letter ID: 678
Comment ID: 14682
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 16. Section 141.713 (c)(l) - The sentence stating -systems using existing operational data
may develop disinfection profiles for a period of up to three years- is not clear. It is our impression
Comment Response for the LT2ESWTR 9-14 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
that systems are required to only develop a disinfection profile for a 12-month period. We request that
EPA clarify this statement.
Response: The final rule has been clarified to state that systems that have at least one year of existing
data may use the data to develop disinfection profiles, and they may at their option develop profiles using
up to three years of existing data.
EPA Letter ID: 678
Comment ID: 14683
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 17. Section 141.713 (d) - It is not clear what would happen if a system has developed
disinfection profiles for both Giardia and virus for all the treatment plants but the profiles were never
submitted to the State. Could the system still use those profiles? We request that EPA clarify this
provision.
Response: Systems may use disinfection profiles developed under § 141.172 or § § 141.530 through
141.536 in lieu of developing a new profile if the system has neither made a significant change to its
treatment practices nor changed sources since the profile was developed.
EPA Letter ID: 711
Comment ID: 16555
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 8. 141.71 3 (c)(l) -What does -systems using existing operational data may develop
disinfection profiles for a period of up to three years- mean? Are we not required to develop a
disinfection profile for only a 12 month period?
Response: The final rule has been clarified to state that systems that have at least one year of existing
data may use the data to develop disinfection profiles, and they may at their option develop profiles using
up to three years of existing data.
EPA Letter ID: 711
Comment ID: 16556
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 9. 141.71 3 (d) - What happens if a system has developed disinfection profiles for both
Giardia and virus for all the treatment plants but the profiles were never submitted to the State? Could the
system still use those profiles? Our profiles were developed from 1999 to 2000 or 2000 to 2001 plant
data.
Comment Response for the LT2ESWTR 9-15 January 2006
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Chapter 9: Disinfection Benchmarks Comment Codes 1000-1020
Response: Systems may use disinfection profiles developed under § 141.172 or § § 141.530 through
141.536 in lieu of developing a new profile if the system has neither made a significant change to its
treatment practices nor changed sources since the profile was developed.
9.2 Comment Code 1020, Guidance
Individual Comments on Code 1020
EPA Letter ID: 591
Comment ID: 12140
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: 13. Preamble Section IV. D. (Page 47717)
EPA indicates that it may produce an addendum to the Disinfection Profiling and Benchmarking
Guidance Manual (USEPA 1999d) to reflect changes in the profiling and benchmarking requirements
necessary to comply with LT2ESWTR. Ohio EPA requests that this additional guidance be provided.
Response: See response 1000.7
Comment Response for the LT2ESWTR 9-16 January 2006
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10. Uncovered Finished Water Reservoirs: Comment Codes
1100-1170
10.1 Comment Code 1100, Uncovered Finished Water Reservoirs
Response to Code 1100
1100.1
EPA disagrees with comments that suggest that no treatment or covering should be required for
uncovered finished water storage facilities if there is no documented problem or because of the costs
involved. EPA is concerned about the likely water quality degradation in open reservoirs as documented
in numerous studies and described in the preamble. Examples of such degradation include increases in
algal cells, coliform bacteria, heterotrophic plate count bacteria, turbidity, particulates, disinfection
byproducts, metals, taste and odor, insect larvae, Giardia, Cryptosporidium and nitrate. Contamination of
open reservoirs occurs through surface water runoff, bird and animal wastes, human activity, algal
growth, insects and fish, and airborne deposition. The final rule will increase public health protection by
reducing or eliminating the health effects related to this contamination. EPA understands that costs are
associated with the requirements regarding uncovered finished water storage facilities and has accounted
for these costs in the Economic Analysis for the LT2ESWTR. The Agency believes that the substantial
costs of either covering uncovered finished water storage facilities, building alternative storage, or
providing treatment are appropriate in consideration of the significant risks created by uncovered finished
water storage.
1100.2.
EPA does not agree with comments that support a risk mitigation plan or performance measures as
alternatives to covering a reservoir or treating the discharge because EPA does not believe that a risk
mitigation plan or performance measures would provide equivalent public health protection.
Consequently, a risk mitigation plan would not meet the statutory provision for a treatment technique to
prevent adverse health effects from pathogens like Giardia and Cryptosporidium to the extent feasible
(SDWA section 1412(b)(7)(A)). As described in the preamble, control measures can provide a degree of
protection against some sources of contamination of open reservoirs (e.g., bird deterrent wires, security
fences with setback distances). However, all PWSs are significantly constrained in the degree to which
they can implement such measures with existing open reservoirs due to factors like the size of the
reservoir, the location of the reservoir (e.g., within residential communities or parks), and the existing
infrastructure. For example, many open finished water reservoirs are impacted by runoff, despite the fact
that this has been prohibited for many years under existing regulations. EPA has concluded that
implementing control measures that would be highly effective against all sources of contamination of
open reservoirs would not be feasible for PWSs.
Similarly, monitoring for the chemical and biological pathogens that could contaminate open storage
reservoirs to protect public health is not technologically or economcially feasible. As described in the
preamble, pathogens like Cryptosporidium and Giardia present public health concerns when present at
levels as low as 1 per 10,00 liters. For public water systems to show that these pathgens are not
contaminating open reservoirs at levels of concern, they would have to regularly monitor hundreds of
thousands of liters of water. With current technologies, monitoring this volume of water is not feasible.
Comment Response for L T2ESWTR 10-1 Januray 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
1100.3
EPA disagrees with commenters who suggest that 4-log inactivation for viruses alone is sufficient for
those systems that treat the effluent of uncovered finished water reservoirs rather than cover them. As
described in the preamble, studies have demonstrated the potential for contamination of open reservoirs
by Giardia and Cryptosporidium, and treatment for viruses alone would be ineffective against these
pathogens. EPA believes that requiring treatment for viruses, Giardia, and Cryptosporidium in uncovered
finished water reservoirs is consistent with SDWA section 1412(b)(7)(A), which authorizes the use of a
treatment technique to prevent adverse health effects to the extent feasible if measuring the contaminant is
not feasible. Monitoring for these pathogens at the very low levels that would cause public health concern
and at the frequency necessary to detect contamination events is not feasible with available analytical
methods.
Individual Comments on Code 1100
EPA Letter ID: 456
Comment ID: 10960
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 620 B. Cryptosporidium Treatment Requirements
Comment: The Friends of the Reservoirs of Portland, OR, disagree with the proposed requirement that
unfiltered source water systems and systems with uncovered finished storage should build additional
treatment, no matter how pure its water is. The EPA should not require massive expenditures without a
clearly defined benefit to be gained.
Response: See Responses 600.b and 1100.1.
EPA Letter ID: 456
Comment ID: 10964
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: The EPA should impose performance standards only. The proposed Rule recognizes this
principle for filtering water systems. The principle should be expanded to include nonfiltering systems
and systems with open finished storage. The Rule should not impose a mitigation, especially a hugely
expensive one, where there is no documented problem or likelihood of a problem. There have been no
reported cases of cryptosporidiosis or other water-borne illness caused by caused by water from Portland-
s unfiltered source, the Bull Run, or from water from Portland-s uncovered finished water reservoirs. (1)
Communities whose source water is protected from sewage, and who have no history of drinking water
related illness, should be able to continue to provide clean water without additional treatment as long as
they are able to document that they meet performance standards.
With regard to open finished water reservoirs, we maintain that here, too, there should be a stated
standard which a community may meet to avoid a requirement to cover, treat, or build some other
expensive intervention. The term "log 4 virus inactivation" does not account for systems with no
Comment Response for the L T2ESWTR 10-2 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
measurable virus burden. A System should be able to perform monitoring to document that virus levels
meet some stated maximum allowable level, and if it can, no further intervention would be required.
Response: See responses 1100.1, 1100.2 and 1100.3.
EPA Letter ID: 456
Comment ID: 10966
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: We are confident that the unfiltered Bull Run source water, and water in our uncovered open
reservoirs at Mt Tabor Park and Washington Park, can meet any reasonable performance standards with a
minimum of low-tech investment. The EPA must make this pathway available.
Response: See response 1100.2.
EPA Letter ID: 470
Comment ID: 11088
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: We support the concept that uncovered finished water storage facilities may pose an
additional health risk and that this risk should be addressed in the Rule. Since Vermont does not have any
uncovered finished water storage facilities, we defer to the Association of State Drinking Water
Administrators- comments.
Response: See Response 100.a
EPA Letter ID: 474
Comment ID: 11190
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 600 IV. Unfiltered Systems Monitoring and Treatment
Requirements
Comment: As an unfiltered system with uncovered finish water reservoirs, the proposed rule would have
profound impacts on the Portland water systems and on the rates our customers pay for water service.
We estimate, for example, that the cost of treatment improvements for Cryptosporidium for the Bull Run
source (250 MOD capacity) would range from a low of about $55 million(l) for ultraviolet light
disinfection improvements to a high of about $202 million for a direct filtration or membrane filtration
plant.
Comment Response for the L T2ESWTR 10-3 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
(1) Costs presented for Bull Run treatment are in 2001 dollars as developed for the use by the Citizens
Panel on Bull Run Treatment
Response: See Response lOO.c and 1100.1.
EPA Letter ID: 520
Comment ID: 11596
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Uncovered Finished Water Storage Facilities
IEPA supports the concept that uncovered finished water reservoirs may pose an additional risk to public
health and that this risk should be addressed. The proposed options of covering the facility, providing
treatment, or implementing a state-approved risk mitigation plan are appropriate, but there are concerns
with the level of state resources needed to implement the last option.
Response: See Response lOO.aand 1110.3.
EPA Letter ID: 520
Comment ID: 11651
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Section IV.E Additional Treatment Technique Requirements for Systems with
Uncovered Finished Water Storage Facilities (pages 47718-47719)
IEPA supports the concept that uncovered finished water reservoirs may pose an additional risk to public
health and that this risk should be addressed. The proposed options of covering the facility, providing
treatment, or implementing a state-approved risk mitigation plan are appropriate. IEPA also suggests
Response: See Response 100.a
EPA Letter ID: 536
Comment ID: 11804
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment Response for the L T2ESWTR 10-4 January 2006
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Comment: Uncovered Finished Water Storage Facilities
Colorado supports the concept that uncovered finished water reservoirs may pose an additional risk to
public health and that this risk should be addressed.
Response: See Response 100.a
EPA Letter ID: 608
Comment ID: 13131
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 620 B. Cryptosporidium Treatment Requirements
Comment: The Friends of the Reservoirs of Portland, OR, disagree with the proposed requirement that
unfiltered source water systems and systems with uncovered finished storage should build additional
treatment, no matter how pure its water is. The EPA should not require massive expenditures without a
clearly defined benefit to be gained.
The EPA should impose performance standards only. The proposed Rule recognizes this principle for
filtering water systems. The principle should be expanded to include nonfiltering systems and systems
with open fished storage. The Rule should not impose a mitigation, especially a hugely expensive one,
where there is no documented problem or likelihood of a problem. There have been no reported cases of
cryptosporidiosis or other water-borne illness caused by caused by water from Portland's unfiltered
source, the Bull Run, or from water from Portland's uncovered finished water reservoirs. (1) Communities
whose source water is protected from sewage, and who have no history of drinking water related illness,
should be able to continue to provide clean water without additional treatment as long as they are able to
document that they meet performance standards.
(1) Report and Recommendations of the Bull Run Treatment Panel, p. 13.
http://www.bullrun.ci.portland.or.us/PUBINV/ADDITIONAL/OPT_RecFinal_Full.pdf
Response: See Responses 600.b, 600.c, 100.1, SOO.b, 600.d, and 1100.1.
EPA Letter ID: 608
Comment ID: 13133
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 620 B. Cryptosporidium Treatment Requirements
Comment: The Friends of the Reservoirs propose that the EPA formally recognize the Hazard Analysis
Critical Control Point (HACCP) program as the framework for documenting that source water, water in
storage, and water throughout the distribution ystem continues to meet performance standards. This
program was developed in the 1960's by the Pillsbury Corporation in an effort to provide quality-assured
food for NASA. The goal is to establish a series of check points during processing. This program is
currently in effect with the FDA and the USDA (seafood and juice processing) and is being adopted by
the food processing industry in Canada. Under this program, multiple check points from the source
Comment Response for the L T2ESWTR 10-5 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
and throughout the distribution system would undergo continuous monitoring. (2) This program actually
creates the possibility of cleaner, safer water than the interventions imposed by the LT2SWTR.
We are confident that the unfiltered Bull Run source water, and water in our uncovered open reservoirs at
Mt Tabor Park and Washington Park, can meet any reasonable performance standards with a minimum of
low-tech investment. The EPA must make this pathway available.
(2) "Summary of Bull Run Water Treatment Findings: Phase One, an Independent Review-2003" by Scott
Fernandez, M.Sc., a member of the Portland Utilities Review Board.
Response: See Response 600.c, 600.e, 600.d, and 1100.2.
EPA Letter ID: 608
Comment ID: 15036
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: With regard to open finished water reservoirs, we maintain that here, too, there should be a
stated standard which a community may meet to avoid a requirement to cover, treat, or build some other
expensive intervention. The term "log 4 virus inactivation" does not account for systems with no
easurable virus burden. A System should be able to perform monitoring to document that virus levels
meet some stated maximum allowable level, and if it can, no further intervention would be required.
Response: See responses 1100.2 and 1100.3.
EPA Letter ID: 643
Comment ID: 12749
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Uncovered Finished Water Storage Facilities
States support the concept that uncovered finished water reservoirs may pose an additional risk to public
health and that this risk should be addressed. The proposed options of covering the facility, providing
treatment, or implementing a state-approved risk mitigation plan are appropriate, but some states have
concerns with the level of state resources needed to implement the last option.
Response: See Response lOO.aand 1110.3.
EPA Letter ID: 643
Comment ID: 12806
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the L T2ESWTR 10-6 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
Comment: Section IV.E Additional Treatment Technique Requirements for Systems with
Uncovered Finished Water Storage Facilities (pages 47718-47719)
States support the concept that uncovered finished water reservoirs may pose an additional risk to public
health and that this risk should be addressed. The proposed options of covering the facility, providing
treatment, or implementing a state-approved risk mitigation plan are appropriate, but some states have
concerns with the level of state resources needed to implement the last option.
Response: See Responses lOO.aand 1110.3.
EPA Letter ID: 668
Comment ID: 13887
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Other EPA Comment Codes and Descriptions: 1000 VI. Disinfection Benchmarks
Comment: Moreover, we support the requirements for Disinfection Profiling and Benchmarking, and for
covering or treating water from uncovered finished water reservoirs as included in the Agreement.
Response: See Response 100.a
10.2 Comment Code 1110, Risk Mitigation or Treatment Instead of
Covering
Response to Code 1110
In the proposed LT2 rule, EPA requested comment on whether it is appropriate to allow systems with
uncovered finished water storage facilities to implement a risk management plan or treat the effluent to
inactivate viruses instead of covering the facility.
1110.1
Several commenters recommended that EPA require all finished water reservoirs to be covered. These
commenters stated that making an uncovered reservoir equal in quality to a covered reservoir is not
possible - open reservoirs will always be contaminated by fecal material from birds and small mammals,
as well as increased DBFs due to algae and other aquatic organisms, airborne contaminants, and sediment
stirred up by wind.
EPA disagrees with the opinion that the rule must require that all existing finished water reservoirs to be
covered to adequately protect public health. With today's final rule, EPA expects that many PWSs will
cover or eliminate uncovered finished water reservoirs. For reservoirs where covering is not feasible, EPA
believes that treating the water for Giardia, Cryptosporidium, and viruses will provide protection against
the range of pathogens likely to contaminate the reservoir. The treatment option represents a balanced
approach, recognizing the risks associated with uncovered finished water storage and the substantial costs
of either covering them or building alternative storage. Regarding potential DBP formation, the Stage 2
Comment Response for the L T2ESWTR 10-7 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
DBF rule will provide for a holistic assessment and treatment of DBF levels throughout the distribution
system, including finished water reservoirs.
1110.2
Commenters were also concerned that uncovered reservoirs are a major vulnerability for PWS security
(i.e., intentional contamination). In response to the September 11, 2001 terrorism, water systems have
conducted vulnerability assessments and taken additional steps to improve security at their facilities,
including reservoirs, as required under the SDWA.
1110.3
Today's rule does not allow PWSs to implement a risk mitigation plan as an alternative to covering a
reservoir or treating the discharge because EPA does not believe that a risk mitigation plan would provide
equivalent public health protection. Consequently, a risk mitigation plan would not meet the statutory
provision for a treatment technique to prevent adverse health effects from pathogens like Giardia and
Cryptosporidium to the extent feasible (SDWA section 1412(b)(7)(A)).
Open reservoirs are subject to contamination from many sources, including runoff, birds, animals,
humans, algae, insects, and airborne deposition. Control measures can provide a degree of protection
against some of these sources (e.g., bird deterrent wires, security fences with setback distances). All
PWSs are significantly constrained, however, in the degree to which they can implement such measures
with existing open reservoirs due to factors like the size of the reservoir, the location of the reservoir (e.g.,
within residential communities or parks), and the existing infrastructure. For example, many open
finished water reservoirs are impacted by runoff, despite the fact that this has been prohibited for many
years under existing regulations (USEPA 1999e). EPA has concluded that implementing control measures
that would be highly effective against all sources of contamination of open reservoirs would not be
feasible for PWSs. Accordingly, today's rule does not allow this option.
Individual Comments on Code 1110
EPA Letter ID: 387
Comment ID: 10476
Commenter: Anonymous387,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: the watershed control program is not working!! (2) All uncovered finished water reservoirs
should be required by be covered. There should be no exceptions. (3)
Response: See Response 1110.1.
EPA Letter ID: 395
Comment ID: 10532
Commenter: Anonymous395,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: I was astonished to learn that there are nearly 150 uncovered finished water reservoirs in
existence as of the publication of LT2. When you compare that there are probably millions of covered
Comment Response for the L T2ESWTR 10-8 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
finished water reservoirs it is absolutely ludicrous to maintain an environmental loophole for these
systems with option 2 and 3. Here you are proposing that these public water systems spend a lot of money
testing for Cryptosporidium. The samples are taken from the lake or river that is supplying the water to be
treated. Yet, after the water is cleaned up to where it is safe to drink, it is stored in another lake where it
is subject to all kinds of contamination before being delivered to the water system customers. This makes
no sense at all ! Why have you allowed water systems to store finished water in uncovered reservoirs for
all these years??? The only option that should be allowed for these systems is to cover—period.
Give them more time if needed, but close the loophole.
Response: See Response 1110.1.
EPA Letter ID: 397
Comment ID: 10533
Commenter: Ron Kailey, Laboratory Supervisor, Cheyenne Board of Public Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Covered Reservoirs Vs Uncovered I have been in the Environmental Lab industry for 22
years, 19 in Wastewater Treatment and 3 in Water Treatment. I cannot believe the EPA allows any city in
the US to still have ?Uncovered Reservoirs? this has to be the biggest hole for source water contaminants
and system security. All Cities in the US should be required to cover their reservoirs. Large and small
systems must ensure the citizens that wild life, as well as terrorist, cannot access their surface waters.
Thanks Ron Kailey Lab
Response: See Responses 1110.1 and 1110.2.
EPA Letter ID: 402
Comment ID: 13675
Commenter: Anonymous402,,
Commenter Category: Regulated Community (Utilities)
Comment: When I first heard that uncovered finished water reservoirs existed anywhere in the United
States I was absolutely shocked!! Close this massive environmental loophole- the only option should be
coverthem period! Considering that there are some 161,000 systems in America serving some 290
million people and if you make a conservative guess that there are at least 2 covered finished water
reservoirs per system than that's 322,000 finished water reservoirs compared to 150 uncovered finished
water reservoirs. That should speak for itself. It is impossible to make an uncovered finished water
reservoir equal in quality to a covered finished water reservoir where the only access to
the atmosphere is a downturned vent with a fine screen on it Water is a magnet for life you may not find
dead animals like in some breached covered reservoirs and that is because the beavers, muskrats, etc
swim through it leaving their crypto. It is impossible to keep birds off of uncovered finished water
reservoirs and they leave their crypto. When I did a little research on uncovered reservoirs I found they
contained fish lots offish. I don't have gross contamination of fecal matter from animals swimming
through, birds or fish swimming in my COVERED FINISHED WATER RESERVOIRS! There is no way
that option 3 a mitigation plan could make equal a covered and uncovered finished water reservoir with
gross contamination let alone finer water quality concerns. Consider aglae growth. Uncovered finished
water reservoirs are open to sunlight which will promote aglae growth, which will increase TTHMs. With
Comment Response for the L T2ESWTR 10-9 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
all the critters swimming through an uncovered finished water reservoir option 2 four logs of virus
inactivation would not make covered and uncovered reservoirs equal ~ everyone knows crypto can't be
destroyed by chlorine. Close this huge environmental loophole all finished res. need to be covered
Response: See Response 1110.1 and 1110.3.
EPA Letter ID: 403
Comment ID: 10529
Commenter: Anonymous403,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: I would like to second the comment made that the environmental loophole of uncovered
finished water reservoirs needs to be closed. In a study by LeChevallier (AWWA Journal 1997,
September), showed that cysts and oocysts in the inlet and outlet were statistically significant, the median
difference between inlet and outlet effluent crypotsporidium concentrations was nearly sevenfold. The
article states "Source water for these reservoirs is highly treated, so it is possible to observe small
increases in oocyst concentration from nonpoint sources of contamination" and further states "Any
contamination of the water supply poses a risk of water borne cryptosporidiosis". So, the 4 logs of virus
inactivation would not inactivate crypto, the only option should be to cover these reservoirs. The article
states that possible sources of contamination to uncovered finished water reservoirs include: Airborne
contaminants (industrail pollutants and autombile emmisions,dust particulate matter); Contaminants
transported by surface water runoff (some of these uncovered finished water reservoirs are lakes with
significant runoff areas); Trihalomethane and other disinfection by-product formation caused by growth
and decomposition of algae and other aquatic organisms as a result of sunlight, nutrient loadings, and
other environmental conditions; microbial contamination from animal or bird droppings; contamination
caused as a result of ambient weather conditions (wind currents stir up sediments from the side,
downpours, snowmelt). So, it not possible by any honest consideration of equality between
covered and uncovered reservoirs that a mitigation plan can in any way be equal to a covered finished
water reservoir. The most compelling reason to close this environmental loophole is security of the
system is not possible in systems with uncovered finished water. This last reason alone should suffice to
close this loophole.
Response: See Response 1110.1 and 1110.3.
EPA Letter ID: 405
Comment ID: 10530
Commenter: Anonymous405,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: The second and third options for uncovered finished water reservoirs (UFWR) need to be
eliminated the only option allowed here must be to cover UFWR and bring them up to industry standard.
This decision needs to be made on the weight of comman sense evidence. Indeed, I would be surprised to
find waterborne disease outbreaks associated with UFWR now or in the future. What we have here
clearly, is an epidemiologic issue (low level of disease in a community). Toxicologists and others
involved in epidemiological studies are keenly aware of the difficulty of showing what the cause is of
increased low level of disease in a community especially in large cities which UFWR seem to be
Comment Response for the LT2ESWTR 10-10 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
concentrated in. Therefore, the weight of common sense evidence is more than enough to suffice to
require all UFWR to be covered. This coupled with the fact that UFWR cannot be secured from the ill
intentions of a few. Given the millions of persons these UFWR serve, it would seem reasonable to give
them additional time to make these improvements. What I would like to emphasis very strongly is, the
way the regulation is written now the E.P.A. is perpetuating a clear public health issue whereas the
regulation should simply say "all existing UFWR must be covered by such-and-such a date". The weight
of evidence in the preamble supports this comman sense conclusion.
Response: See Response 1110.1 and 1110.3.
EPA Letter ID: 408
Comment ID: 10545
Commenter: Craig Barsness, Chief Plant Operator, Shoshone Municipal Pipeline
Commenter Category: Regulated Community (Utilities)
Comment: 2) I can't believe that the EPA is allowing finished water to be stored in uncovered reservoirs
and under the LT2 will continue to do so. Two concerns should prohibit this practice. The first is
contamination of the finished water and the second is security/vulnerability. All finished water reservoirs
should be covered with no exceptions.
Response: See Response 1110.1 and 1110.2.
EPA Letter ID: 436
Comment ID: 10607
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Comment: Colorado Springs Utilities (PWSID # CO0121150) and Fountain Valley Authority
(PWSID # COO 121300) are appalled that EPA has irresponsibly proposed the continued use uncovered
finished water reservoirs. This is not good science and does not protect public health. It is common sense
that all finished water reservoirs MUST be covered!
Response: See Response 1110.1.
EPA Letter ID: 474
Comment ID: 11205
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: Comment - Uncovered Finished Water Storage Facilities
The Portland Water Bureau acknowledges that the options presented for dealing with uncovered finished
water reservoirs are the realistic solutions for dealing with potential microbial contamination for such
Comment Response for the LT2ESWTR 10-11 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
facilities, although we note the options provide different levels of benefit in addressing security issues that
have been of growing concern over the last several years.
Response: See Responses lOO.a, 1110.2 and 1110.3.
EPA Letter ID: 516
Comment ID: 11738
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Part II-Other Comments
Reservoir Covers:
DEP supports the EPA-s proposal to allow existing finished water storage facilities to remain uncovered
under the conditions specified. The proposed rule recognizes the substantial costs that may be associated
with covering reservoirs or providing storage (though we believe significantly underestimated these
costs), and has offered reasonable alternatives.
Response: See Response lOO.a.
EPA Letter ID: 560
Comment ID: 14985
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Seven - Inadequate Treatment Requirements for Uncovered Reservoirs:
American Water Believes that EPA has not adequately addressed the issue of microbial and chemical
risks in uncovered open finished reservoirs based on the available science. Of the three options provided,
American Water believes that all open finished water reservoirs should be covered or treated as unfiltered
water sources. Towards this end, providing only 4-log virus inactivation or a open finished water
reservoirs. Given the security risks posed by open finished reservoirs, American Water strongly
recommends that EPA require either coverage or proper protozoan treatment for these facilities.
Response: See Response 1110.1 and 1110.2.
EPA Letter ID: 562
Comment ID: 12559
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
Is it appropriate to allow systems with uncovered finished water storage facilities to implement a risk
management plan or treat the effluent to inactivate viruses instead of covering the facility? (68 FR 47719)
Comment Response for the LT2ESWTR 10-12 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
Response
AWWA is a signatory to the Stage 2 M/DBP Agreement in Principle as is EPA. The Agreement in
Principle specifies that either covering the reservoirs or the implementation of a risk management plan per
the approval of the primacy agency are adequate remedies if treatment of the uncovered reservoir effluent
is not provided. AWWA supports the Agreement in Principle including this provision.
Response: See Responses lOO.aand 1110.3.
EPA Letter ID: 641
Comment ID: 13602
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Other EPA Comment Codes and Descriptions: 1150 E. Changing Definition of Uncovered Finished
Water Reservoirs
Comment: Pg 47719 RFC - Uncovered Finished Water Storage Reservoirs - ASI believes that, ideally,
finished water storage reservoirs should be covered without exception, and that uncovered reservoirs
should be reclassified as -Filtered Water Storage Reservoirs.- ASI agrees that PWSs should be required
to
Response: EPA disagrees. Storage facilities may contain finished water that has not undergone treatment
by filtration, and it would not be appropriate to limit the definition to "Filtered Water Storage
Reservoirs". Also, see Response 1110.1.
10.3 Comment Code 1120, Requiring Inactivation of Cryptosporidium
and Giardia
Response to Code 1120
1120.1
EPA requested comment on whether systems should be required to inactivate Cryptosporidium and
Giardia lamblia if they treat the effluent of a finished water storage facility instead of covering it, since
these protozoa have been found to increase in uncovered storage facilities.
Many commenters supported requiring treatment for Giardia and Cryptosporidium for PWSs that treat the
reservoir discharge. Commenters stated that reservoirs should either be covered or treated as unfiltered
sources (meaning 3-log Giardia, 2-log Cryptosporidium, and 4-log virus treatment). The LeChevallier et
al. (1997) study was cited as demonstrating increases in Giardia and Cryptosporidium in uncovered
finished water reservoirs, and commenters noted that treatment for viruses would not be effective against
these protozoa. EPA agrees with these comments and today's rule requires treatment for Giardia and
Cryptosporidium, as well as viruses, by PWSs that do not cover their reservoirs.
Individual Comments on Code 1120
Comment Response for the LT2ESWTR 10-13 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
EPA Letter ID: 488
Comment ID: 11872
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Yes, the treatment should address Giardia and Cryptosporidium unless the utility can
demonstrate control or prevention by other means.
Response: See Response 1120.1.
EPA Letter ID: 560
Comment ID: 14986
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Giardia or Cryptosporidium. As noted in the preamble, increases in cysts and oocysts have
been reported in open finished water reservoirs (LeChevallier et al. 1997). American Water believes that
available technology (such as UV treatment) should be applied to open finished water reservoirs (those
not covered) to minimize all microbial risk, not just those for viruses. In fact, EPA failed to cite research
where viruses were identified as risks in open finished reservoirs. LeChevallier et al. (1997) did not detect
either malespecific or somatic bacteriophage in either inlet or outlet samples of six open finished water
reservoirs. Given the security risks posed by open finished
Response: See Response 1120.1.
EPA Letter ID: 562
Comment ID: 12560
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
If systems treat the effluent of a finished water storage facility instead of covering it, should systems be
required to inactivate Cryptosporidium and Giardia lamblia, since these protozoa have been found to
increase in uncovered storage facilities? (68 FR 47719)
Response
Under the Stage 2 M/DBP Agreement in Principle, a risk management plan approved by the primacy
agency is an adequate remedy for an uncovered reservoir. If treatment strategies are included in such a
risk management plan for a particular uncovered reservoir, it should address the range of microbes for
which treatment is necessary. The primacy agency can specify treatment for Cryptosporidium, Giardia
lamblia, and / or viruses, if needed, depending on site-specific circumstances and the adequacy of other
aspects of the risk management plan.
Response: See Response 1120.1 and 1110.3.
Comment Response for the LT2ESWTR 10-14 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
EPA Letter ID: 641
Comment ID: 13603
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: -Filtered Water Storage Reservoirs.- ASI agrees that PWSs should be required to disinfect
UFWSR water - for both viruses and protozoa - before distribution. Failing this, Uncovered FW Storage
Reservoirs should at least be required to implement a management plan, which should include regular
(infectious) virus monitoring. Viral monitoring should include, but not be limited to, adenovirus,
astrovirus, Coxsackie virus, enteroviruses, and rotavirus. Protozoa monitoring (for infectious Giardia and
Crypto.) should be considered also, but may be limited by the lack of available, inexpensive infectivity
assessment. A phased approach, with protozoa enumeration above a certain concentration triggering
infectivity determination, could be considered.
Response: See Response 1120.1 and 1110.3.
EPA Letter ID: 668
Comment ID: 13903
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - Uncovered finished water reservoirs should be required to inactivate Crypto and Giardia,
since these protozoa have been found to increase in uncovered storage facilities, (p. 47719)
Response: See Response 1120.1.
10.4 Comment Code 1130, Data on Contamination of Uncovered
Reservoirs
Individual Comments on Code 1130
EPA Letter ID: 562
Comment ID: 12561
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
Additional information on contamination or health risks that may be associated with uncovered finished
water storage facilities. (68 FR 47719)
Response
EPA should review the docket of the IESWTR, and records of subsequent stakeholder interaction on
Comment Response for the LT2ESWTR 10-15 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
guidance for uncovered reservoirs. These records provide a robust description of the issues relevant to
uncovered finished water storage facilities.
Response: EPA considered the information provided in developing the IESWTR, in addition to other
information provided by studies such as LeChevallier et al. 1997, AWWA Committee 1983, Silverman et
al. 1983 and Pluntze 1974, in assessing the issues and risks relevant to uncovered finished water facilities
to determine the requirements for this rule.
10.5 Comment Code 1140, Data on Weather, Effect on Corrosion
Control
Individual Comments on Code 1140
EPA Letter ID: 474
Comment ID: 11207
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: EPA has also requested information related to impacts of open finished water reservoirs on
corrosion control treatment. Portland has some system specific information based on our use of a single
chemical, sodium hydroxide, to adjust Bull Run water-s pH for corrosion control. During an October
2002 workshop, a technical advisory committee consisting of several experts in the field of corrosion
control, including EPA-s in-house expert, advised that pH levels at or above 8.0, an action under
discussion to improve compliance with the Lead and Copper Rule, would be unstable across open
reservoirs. They were concerned about the potential adverse affects of wide pH level fluctuations in the
distribution system on both control of lead from plumbing and red water from unlined cast iron and
galvanized pipes. We have reviewed pH data across our existing open reservoirs. At pH 7.5 - 7.8, no
significant change in pH was noted.
Response: Thank you for the information you provided relative to the stability of the water related to pH
and corrosion control across your finished water reservoirs.
10.6 Comment Code 1150, Changing Definition of Uncovered
Finished Water Reservoirs
Response to Code 1150
1150.1
In the proposed rule, EPA requested comment on whether the definition of an uncovered finished water
storage facility should be revised to specifically include systems that apply a treatment such as corrosion
control to water stored in an uncovered reservoir after the water has undergone filtration, where required,
and primary disinfection. EPA agrees with commenters who suggested that the definition needs
refinement to allow for necessary small openings to the atmosphere such as screened vents and overflows.
Comment Response for the LT2ESWTR 10-16 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
EPA also agrees with commenters who suggest that the definition be revised to reflect the common
practice of corrosion control treatment that is common at uncovered finished water storage facilities.
Therefore, in the final rule the definition is revised to read as follows: Uncovered finished water storage
facility is a tank, reservoir, or other facility used to store water that will undergo no further treatment to
reduce microbial pathogens except residual disinfection and is directly open to the atmosphere.
Individual Comments on Code 1150
EPA Letter ID: 458
Comment ID: 10981
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Page 47719 - Definition of uncovered finished water storage tank needs refinement, due to
the words -open to the atmosphere-. A typical above ground water storage facility will have an air vent,
typically screened , with a protective hood that prevents insects, rainfall, and large particulate matter
from entering the storage facility, however, due to the nature of the air vent, it must be open to the
atmosphere. Similarly, overflow lines would fit a similar scenario. Adding the word -directly- (directly
open to the atmosphere) may correct this interpretation problem.
Response: See Response 1150.1.
EPA Letter ID: 516
Comment ID: 11739
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: DEP does, however feel that a certain clarification is appropriate, regarding the definition of
an Uncovered Reservoir. According to LT2ESWTR, the definition of an uncovered finished storage water
facility in 40 CFR 141.2 is a tank, reservoir, or other facility used to store water that will undergo no
further treatment except residual disinfection and is open to the atmosphere (p.47719). Many water
utilities provide post filtration treatment to uncovered finished water storage facilities, such as pH
adjustment for corrosion control. Such corrosion control treatment does not represent treatment to remove
contaminants (e.g. filtration) or provide primary disinfection. Therefore, an uncovered reservoir still
meets the definition of-facilities where water is stored after it has already undergone all filtration and
primary disinfection to satisfy microbial treatment technique requirements for Giardia lamblia,
Cryptosporidium, and most viruses,- if corrosion control is added after storage. Further, it is in the best
interest of public health and infrastructure maintenance for systems to provide corrosion control at the
optimal location to provide these benefits. The optimal location for corrosion control is immediately
downstream of Hillview Reservoir in the New York City drinking water system. Consequently, DEP
suggests that EPA clarify its definition of an uncovered finished water storage facility
to allow corrosion control treatment following storage.
Response: See Response 1150.1.
Comment Response for the LT2ESWTR 10-17 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
EPA Letter ID: 520
Comment ID: 11652
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: a state-approved risk mitigation plan are appropriate. IEPA also suggests clarifying that "open
to air" does not include vents and overflows of covered storage reservoirs.
Response: See Response 1150.1.
EPA Letter ID: 595
Comment ID: 12594
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Section IV.E Additional Treatment Technique Requirements for Systems with
Uncovered Finished Water Storage Facilities (pages 47718-47719)
Maine requests that EPA define and/or clarify in exact terms what constitutes an -uncovered finished
water storage facility-.
Response: See Response 1150.1.
EPA Letter ID: 641
Comment ID: 13602
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Other EPA Comment Codes and Descriptions: 1110 A. Risk Mitigation or Treatment Instead of
Covering
Comment: Pg 47719 RFC - Uncovered Finished Water Storage Reservoirs - ASI believes that, ideally,
finished water storage reservoirs should be covered without exception, and that uncovered reservoirs
should be reclassified as -Filtered Water Storage Reservoirs.- ASI agrees that PWSs should be required
to
Response: EPA disagrees. Storage facilities may contain finished water that has not undergone treatment
by filtration, and it would not be appropriate to limit the definition to "Filtered Water Storage
Reservoirs". Also, see Response 1110.1.
EPA Letter ID: 643
Comment ID: 12807
Comment Response for the LT2ESWTR 10-18 January 2006
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Chapter 10: Uncovered Finished Water Reservoirs Comment Codes 1100-1170
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: With respect to the definition of an uncovered finished water storage facility in 40 CFR 141.2,
states suggest modifying the definition to specifically include systems that apply a treatment such as
corrosion control to water stored in an uncovered reservoir after the water has undergone filtration,
where required, and primary disinfection. States also suggest clarifying that -open to air- does not
include vents and overflows of covered storage reservoirs.
Response: See Response 1150.1.
EPA Letter ID: 668
Comment ID: 13904
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - EPA should expand the definition of uncovered finished water reservoirs to include systems
that apply a treatment like corrosion control to water stored in an uncovered reservoir after filtration
and/or disinfection, (p. 47719)
Response: See Response 1150.1.
10.7 Comment Code 1170, Guidance
Individual Comments on Code 1170
EPA Letter ID: 704
Comment ID: 14788
Commenter: Steven G. Gould, Chairman, New York State American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. Section 141.724. Uncovered Storage.
Guidance is necessary from USEPA for systems to establish an acceptable uncovered reservoir risk
mitigation plan in lieu of reservoir covering or required treatment.
Response: The final rule does not allow for risk mitigation plans for uncovered finished water storage
facilities and therefore no guidance is needed for establishing the plans.
Comment Response for the LT2ESWTR 10-19 January 2006
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Public Comment and
Response Document
for the Long Term 2
Enhanced Surface Water
Treatment Rule
Volume III: Chapters 11-22
-------
TABLE OF CONTENTS
11. COMPLIANCE SCHEDULES: COMMENT CODES 1200-1250 11-1
11.1 COMMENTCODE 1200, COMPLIANCE SCHEDULES 11-1
11.2 COMMENT CODE 1210, A. LARGE SYSTEM MONITORING AND TREATMENT 11-30
11.3 COMMENTCODE 1220, SMALL SYSTEM MONITORING AND TREATMENT 11-45
11.3.1 Comment Code 1221, Lag Between Large and Small System Monitoring 11-47
11.4 COMMENTCODE 1230, SCHEDULE FOR CONSECUTIVE SYSTEMS, STAGE2DBPR 11-53
11.5 COMMENTCODE 1240, UNCOVERED FINISHED WATER RESERVOIRS 11-54
11.6 COMMENTCODE 1250, RULE LANGUAGE EDITS 11-55
12. PUBLIC NOTIFICATION: COMMENT CODES 1300-1340 12-1
12.1 COMMENTCODE 1300, PUBLIC NOTIFICATION 12-1
12.2 COMMENTCODE 1310, TIER 2 NOTICE FOR TREATMENT VIOLATIONS 12-6
12.3 COMMENTCODE 1320, HEALTH EFFECTS LANGUAGE 12-14
12.4 COMMENT CODE 1340, GUIDANCE 12-18
13. VARIANCES AND EXEMPTIONS : COMMENT CODES 1400-1420 13-1
13.1 COMMENTCODE 1400, VARIANCES AND EXEMPTIONS 13-1
13.2 COMMENTCODE 1410, PROPOSAL NOT TO PERMIT VARIANCES 13-7
13.2.1 Comment Code 1411, Unfiltered systems 13-12
13.3 COMMENTCODE 1420, PROPOSAL NOT TO PERMIT EXEMPTIONS 13-14
14. REPORTING REQUIREMENTS: COMMENT CODES 1500-1530 14-1
14.1 COMMENTCODE 1500, REPORTING REQUIREMENTS 14-1
14.2 COMMENT CODE 1510, MONTHLY REPORTING ON COMPLIANCE WITH TOOLBOX REQUIREMENTS 14-6
14.2.1 Comment Code 1511, Alternative Requiring Systems to keep Records Onsite 14-13
14.2.2 Comment Code 1522, Bin classification 14-15
14.3 COMMENTCODE 1530, RULE LANGUAGE EDITS 14-16
15. COMMENT CODE 1600: RECORDKEEPING REQUIREMENTS 15-1
15.1 COMMENTCODE 1600, XII. RECORDKEEPING REQUIREMENTS 15-1
16. ANALYTICAL METHODS: COMMENT CODES 1700-1760 16-1
16.1 COMMENTCODE 1700, XIII. ANALYTICAL METHODS 16-1
16.2 COMMENTCODES 1710, CRYPTOSPORIDIUM 16-2
16.2.1 Comment Code 1711, Minimum sample volume, packed pellet volume, number of filters 16-4
16.2.2 Comment Code 1712, Use of different versions of Method 1622/1623, performance-based approaches,
and alternate test procedures 16-10
16.2.3 Comment Code 1713, Matrix spike recoveries, poor recoveries, data adjustment 16-14
16.1.3.1 Comment Code 1714, Frequency of matrix spike analyses 16-16
16.2.4 Reporting total oocysts 16-21
16.2.4.1 Comment Code 1716, Adjustment for empty or non-infectious oocysts 16-21
16.2.5 Comment Code 1717, Subjectivity of microscopy, third-party review of slides 16-24
16.2.6 Comment Code 1719, Approach to matrix spike samples when sampling above 10L 16-26
16.2.7 Comment Code 1720, Other comments on use of Method 1623 16-28
16.2.8 Comment Code 1721, Rule Language Edits 16-37
16.2.9 Comment Code 1722, Guidance 16-38
16.2.10 Comment Code 1723, Specific to LT2 Microbial Sampling Guidance Manual 16-40
16.2.11 Comment Code 1724, Method 1622 or 1623 June 2003 draft 16-49
16.3 E.COLI 16-93
16.3.1 Comment Code 1731, Proposed methods 16-93
16.3.2 Comment Code 1732, Additional methods 16-96
Comment Response for LT2ESWTR i December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
16.3.3 Comment Code 1733, Extension of holding time 16-97
16.3.4 Comment Code 1734, Data on cost and availability of overnight delivery in rural areas 16-107
16 A COMMENT CODE 1750, TURBIDITY 16-108
16.4.1 Comment Code 1751, Proposed methods 16-113
16.4.2 Comment Code 1752, Additional methods 16-117
16.5 COMMENT CODE 1760, EXTENSION OF HOLDING TIME FOR OTHER PARAMETERS 16-119
17. LABORATORY APPROVAL AND CAPACITY: COMMENT CODES 1810-1870 17-1
17.1 COMMENT CODE 1810, CRYPTOSPORIDIUM LABORATORY APPROVAL 17-1
17.1.1 Comment Code 1811, Process and criteria for laboratory Approval 77-3
17.1.1.1 Comment Code 1812, Analyst experience criteria 17-5
17.1.2 Comment Code 1820, State programs to approve laboratories 17-10
17.1.2.1 Comment Code 1821, How to demonstrate equivalence 17-12
to federal program 17-12
17.1.3 Laboratory disapproval process 17-13
17.2 CRYPTOSPORIDIUM LABORATORY CAPACITY 17-14
17.2.1 Need for EPA estimate 77-77
17.2.2 Comment Code 1832, Adequacy of current capacity 17-34
17.2.2.1 Need to delay or modify rule implementation schedule 17-56
17.2.3 Comment Code 1834, Approaches to increase capacity 17-69
17.3 COMMENT CODE 1840, E.COLI LABORATORY APPROVAL 17-70
17.4 COMMENT CODE 1850, TURBIDITY ANALYST APPROVAL 17-73
17.5 COMMENT CODE 1870, GUIDANCE 17-74
18. SANITARY SURVEY REQUIREMENTS FOR SYSTEMS WHERE EPA HAS PRIMACY:
COMMENT CODE 1900 18-1
18.1 COMMENT CODE 1900, XV. SANITARY SURVEY REQUIREMENTS FOR SYSTEMS WHERE EPA HAS
PRIMACY 18-1
19. STATE IMPLEMENTATION: COMMENT CODES 2000-2090 19-1
19.1 COMMENT CODE 2000, STATE IMPLEMENTATION 19-1
19.2 COMMENT CODES 2010, SPECIAL STATE PRIMACY REQUIREMENTS 19-2
19.2.1 Comment Codes 2030, Assessing changes in watershed as part of sanitary survey process 19-5
19.2.2 Comment Codes 2040, Determining adequacy of risk mitigation plans for uncovered finished
water reservoirs 19-6
19.3 COMMENT CODE 2090, INTERIM PRIMACY 19-7
20. ECONOMIC ANALYSIS: COMMENT CODES 2200-2280 20-1
20.1 COMMENT CODE 2200, ECONOMIC ANALYSIS 20-1
20.2 COMMENT CODE 2220, RISK ASSESSMENT 20-21
20.2.1 Comment Code 2221, Dose-response (including infectivity and morbidity) 20-22
20.2.2 Comment Code 2222, Drinking water consumption (including averting behavior) 20-29
20.2.3 Comment Code 2223, Comparison with epidemiological data 20-33
20.2.4 Comment Code 2224, Sensitive subpopulations 20-44
20.2.5 Comment Code 2225, Uncertainty 20-45
20.2.6 Comment Code 2226, Cases of illness compared to IESWTR or LT1ESWTR estimates 20-47
20.3 COMMENT CODE 2230, BENEFITS 20-50
20.3.1 Comment Code 2231, Valuation of Non-fatal Cryptosporidiosis 20-57
20.3.2 Comment Code 2232, Valuation of Mortality 20-53
20.3.3 Comment Code 2234, Nonquantifiable benefits 20-55
20.4 COMMENT CODE 2240, COSTS 20-56
20.4.1 Comment Code 2250, Water System Costs 20-57
20.4.1.1 Comment Code 2251, Monitoring 20-59
20.4.1.2 Comment Code 2252, Treatment 20-63
20.4.1.2.1 Comment Code 2253, Incorporation of toolbox technologies 20-65
20.4.1.3 Comment Code 2254, Uncovered finished water reservoirs 20-66
Comment Response for the LT2ESWTR ii December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
20.4.2 Comment Code 2255, Household costs 20-67
20.4.3 Comment Code 2256, State costs 20-68
20.5 COMMENT CODE 2280, BENEFIT/COST DETERMINATION 20-74
21. STATUTORY AND EXECUTIVE ORDER REVIEWS: COMMENT CODES 2300-2420 21-1
21.1 COMMENT CODE 2300, STATUTORY AND EXECUTIVE ORDER REVIEWS 21-1
21.2 COMMENT CODE 2350, EXECUTIVE ORDER 13132: FEDERALISM 21-2
21.3 COMMENT CODE 2360, EXECUTIVE ORDER 13175: CONSULTATION WITH INDIAN TRIBAL
GOVERNMENTS 21-3
21.4 COMMENT CODE 2400, EXECUTIVE ORDER 12898: ENVIRONMENTAL JUSTICE 21-4
21.5 COMMENT CODE 2410, CONSULTATIONS WITH THE SCIENCE ADVISORY BOARD, NATIONAL DRINKING
WATER ADVISORY COUNCIL, AND THE SECRETARY OF HEALTH AND HUMAN SERVICES 21-4
21.6 COMMENT CODE 2420, PLAIN LANGUAGE 21-5
22. REFERENCES: COMMENT CODE 2510-2511 22-1
22.1 COMMENT CODE 2510, AMENDMENTS TO SWTR, IESWTR, OR LT1ESWTR 22-1
22.2 COMMENT CODE 2511, AMENDMENTS TO PUBLIC NOTIFICATION RULE 22-7
Comment Response for the LT2ESWTR in December 2005
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11. Compliance Schedules: Comment Codes 1200-1250
11.1 Comment Code 1200, Compliance Schedules
Response to Code 1200
a. EPA recognizes that small systems face particular challenges in complying with drinking water
regulations due to lower monetary and staffing resources. Today's rule establishes the same treatment
technique requirements for small systems in order to achieve equitable public health protection for all
systems. However, the LT2ESWTR contains provisions to reduce the burden on small systems. For
source water monitoring, small filtered systems initially monitor only for E. coli, which is much less
costly to analyze than Cryptosporidium. These systems only monitor for Cryptosporidium if E. coli
concentrations exceed specified trigger values. Further, small systems begin monitoring later in the
implementation schedule than large systems, which will give small systems more time to understand the
requirements of the rule, prepare budgets, learn how to collect samples, establish contracts with
laboratories, and other compliance activities.
b. EPA's goals for the compliance schedule in today's final rule are to provide additional public health
protection to higher risk systems as soon as is feasible and to give systems the time necessary to prepare
to implement the rule. Because systems must conduct significant source water monitoring to determine
additional treatment requirements, systems must begin monitoring prior to three years following rule
promulgation. EPA believes that smaller systems will require more time than larger systems to prepare for
monitoring due to having more limited resources and experience. Therefore, the monitoring under today's
rule is staggered, with smaller systems starting later than larger systems. Further, this staggering will
facilitate implementation by States. The overall implementation timeframe in today's final rule and the
approach of staggering large and small system monitoring reflect consensus recommendations from the
M-DBP Advisory Committee.
Under today's rule, systems have three years following bin classification to provide additional treatment
when required. States may allow systems making capital improvements up to an additional two years to
comply with additional treatment requirements.
SDWA section 1412(b)(10) states that a drinking water regulation shall take effect 3 years from the
promulgation date unless the Administrator determines that an earlier date is practicable. Today's rule
requires systems to begin monitoring prior to 3 years from the promulgation date. Based on EPA's
assessment and recommendations of the Advisory Committee, EPA has determined that these monitoring
start dates are practicable and appropriate.
c. In today's final rule, EPA has pushed back the compliance schedule relative to the proposal by 6
months for systems serving 50,000 to 99,999 people (begin monitoring at 12 months after rule
promulgation) and by 18 months for systems serving 10,000 to 49,999 people (begin monitoring at 24
months following rule promulgation). As described in the preamble, EPA believes that this revised
schedule will give these systems sufficient time to prepare for monitoring, such as identifying appropriate
sampling locations and procedures and establishing contracts with labs. Systems serving at least 100,000
people must begin monitoring 6 months after rule promulgation, as proposed. However, most of these
systems have already conducted source water Cryptosporidium monitoring under the ICR. Consequently,
they should not require as much time to prepare to monitor under today's rule.
Comment Response for LT2ESWTR 11-1 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Cryptosporidium monitoring by systems serving fewer than 10,000 people is scheduled to begin at 48
months after rule promulgation, as proposed. This point is when monitoring by larger systems concludes.
EPA does not agree with comments to further delay the start of small system monitoring. Such a delay
would push back the date when systems with higher risk sources would implement additional treatment to
protect public health. The current schedule gives small systems years to prepare for monitoring (2.5 yrs
for E. coli and 4 yrs for Cryptosporidium). This schedule provides sufficient time for small systems to
understand monitoring requirements and for EPA and States to assist small systems with preparing for
monitoring. Moreover, having small system Cryptosporidium monitoring begin at the time that large
system monitoring ends will facilitate laboratories maintaining Cryptosporidium analytical capacity.
EPA agrees that States can play a valuable role in working with systems and EPA to implement today's
rule; implementation agreements between EPA and primacy States with respect to new drinking water
rules are often used prior to State adoption of the rule; thus, early implementation does nto need to disrupt
existing State regulatory oversight of their water systems. The revised compliance schedule in today's
final rule will facilitate States assisting systems with initiating monitoring. By pushing back and further
staggering monitoring start-dates for most systems, the schedule both gives States more time to work with
most systems and decreases the number of systems that will begin monitoring at any one time (EPA
anticipates that systems will require the most assistance near the time when they initiate monitoring).
Further, EPA has developed detailed guidance with today's rule to instruct systems on identifying the
correct sampling location and other activities needed to initiate monitoring. Where States are unable to
assume implementation responsibility for today's rule, EPA will oversee implementation.
d. Today's rule allows small systems that conduct Cryptosporidium monitoring to sample once per month
for two years or twice per month for one year. However, all small systems must comply with any
additional treatment requirements under the same scheduling requirements in order to avoid delaying
public health protection for higher risk systems.
e. Wholesale systems must comply with the requirements of today's rule based on the population of the
largest system in the combined distribution system. Thus, a small system that treats surface water and
sells it to a large system must comply with the LT2ESWTR requirements that apply to the large system,
including the compliance schedule. This approach is appropriate because the staggered implementation
schedule and other requirements in today's rule that apply to small systems were developed with the
consideration that the resources of small systems are more limited. However, a small system that sells
water to a large system will generally have resources commensurate with the large system because the
small system indirectly receives income from the large system's consumer base. Thus, the small system
should have the capacity to comply with today's rule on the schedule applicable to the large system.
f Today's rule establishes requirements for monitoring locations and frequencies to ensure that
monitoring results meet the goals of today's rule for bin classification and associated public health
protection.
g. EPA recognizes the concern with ensuring that capacity at Cryptosporidium laboratories will be
sufficient. Through EPA's laboratory approval program, the Agency has evaluated capacity at
Cryptosporidium laboratories. Based on information provided by laboratories, EPA believes that current
capacity at Cryptosporidium laboratories will be sufficient for the monitoring that PWSs serving at least
100,000 people will begin six months after the rule is effective. EPA expects that commercial laboratories
will increase capacity as needed to serve the demand of smaller PWSs that begin monitoring later.
Approximately six months are required to train Cryptosporidium analysts. Consequently, the staggered
compliance schedule should allow time for laboratories to hire and train staff as necessary. In addition,
with the compliance schedule in today's final rule, no break exists between the time that large PWSs end
Comment Response for the LT2ESWTR 11-2 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
and small PWSs begin Cryptosporidium monitoring. Thus, EPA has eliminated this potential disincentive
to laboratories investing in capacity.
However, EPA will continue to monitor laboratory capacity and the ability of PWSs to contract with
laboratories to meet their monitoring requirements under the LT2ESWTR. The Agency will assist with
implementation of the rule to help maximize the use of available laboratory capacity by PWSs. If
evidence emerges during implementation of the rule that PWSs are experiencing problems with
insufficient laboratory capacity, the Agency will undertake appropriate action at that time. EPA believes
that laboratory capacity for E. coli analyses under today's rule will be sufficient. Many laboratories are
approved for the E. coli methods required by today's rule. Further, the nature of these methods will allow
these laboratories to increase capacity readily as needed.
h. EPA believes that systems should provide sampling schedules not later than 3 months prior to the
required monitoring start date. This time frame is sufficient for primacy agencies to identify systems that
are not complying with the rule (e.g., have not submitted a sampling schedule or have not established a
correct schedule) and take appropriate follow-up steps to ensure all systems begin monitoring as required.
Further, submission of the sampling location description at the same time allows the primacy agency to
review the descriptions and ensure systems are collecting samples at the right location.
i. Today's final rule specifies that if the bin classification for a filtered system (or the mean
Cryptosporidium level for an unfiltered system) changes following the second round of source water
monitoring so that additional treatment is required, the system must meet this treatment requirement on a
schedule the State approves. EPA believes that this approach provides flexibility for the State to
determine an appropriate timeframe for the system to implement additional public health protection.
j. Today's rule requires systems to submit monitoring results for grandfathering to EPA or the State,
along with required supporting documentation, no later than two months after the system is required to
begin monitoring. This timing will allow a system to continue collecting data for grandfathering until the
month the system is required to begin monitoring under today's rule, plus an additional two months for
sample analysis and compilation of the data for submission. Under this schedule, the largest systems (>
100,000) must report results for grandfathering not later than 8 months after rule promulgation. Reporting
deadlines for smaller systems are delayed in proportion to the implementation schedule (e.g., 14 months
for systems serving 50,000 to 99,999).
k. Small filtered systems that exceed the E. coli trigger level must initiate Cryptosporidium monitoring
not later than 6 months after the scheduled completion of E. coli monitoring. EPA believes that this
timeframe is sufficient for small systems to evaluate their E. coli data (to determine if Cryptosporidium
monitoring is required), arrange for an approved laboratory to analyze their Cryptosporidium samples,
and set up a sampling schedule.
EPA recognizes that some small systems would like additional time to prepare for Cryptosporidium
monitoring. The Agency does not believe that further delaying the initiation of Cryptosporidium
monitoring by small systems would be appropriate. Pushing back the monitoring start date further would
create additional delays in public health protection for high-risk systems. This would also create a time
gap between the end of large system monitoring and the start of small system Cryptosporidium
monitoring, which would adversely impact laboratory capacity. Rather, EPA recommends that small
systems consider their historical source water data and evaluate E. coli monitoring results on an ongoing
basis during monitoring. If historical and ongoing monitoring results indicate that a small system may be
required to conduct Cryptosporidium monitoring, the system can begin preparing for it prior to the end of
E. coli monitoring.
Comment Response for the LT2ESWTR 11-3 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
1. As described in the preamble to the proposed rule, EPA believes that national occurrence data from the
ICR and ICR Supplemental Surveys provide an appropriate basis for the E. coli trigger concentrations in
the LT2ESWTR. These data show that filtered systems with mean E. coli levels below the trigger
concentrations are less likely to have Cryptosporidium levels requiring additional treatment. Considering
the greater burden that Cryptosporidium monitoring places on small systems, EPA concluded that these
data support exempting small filtered systems with E. coli levels below the trigger concentrations from
monitoring for Cryptosporidium. This conclusion reflects a consensus recommendation from the
Advisory Committee.
Because available data sets are limited, however, some large system data collected under the LT2ESWTR
will be used to confirm or refine the E. coli trigger concentrations. EPA does not believe, though, that the
start of small system monitoring should be further delayed due to this large system data evaluation, as
some commenters suggested. EPA will receive large system monitoring data on a monthly basis,
beginning six months after rule promulgation. By the time small systems begin E. coli monitoring under
today's rule, EPA will have received 2 years worth of large system monitoring data, which will comprise
tens of thousands of sample results. These data will be sufficient for EPA to determine whether the E. coli
trigger levels should be modified and, if so, issue guidance to States. Under today's rule, States can
approve alternatives to the E. coli trigger values without EPA modifying the regulation.
m. As recommended by the Advisory Committee, the LT2ESWTR maintains simultaneous compliance
with the Stage 2 DBPR with respect to Stage 2 DBP MCLs and LT2ESWTR treatment technique
requirements.
n. Today's rule specifies that within 36 months following rule promulgation, systems with uncovered
finished water reservoirs must cover or treat the reservoir or be on a State-approved schedule to do so.
EPA recognizes that three years after rule promulgation may not be sufficient time for a system to install
replacement tanks or covers for a large reservoir. Consequently, today's rule allows systems to meet these
requirements on a State-approved schedule, which may be longer than 3 years.
o. In today's final rule, EPA has modified the presentation of compliance dates and other requirements
from the proposal to make them easier for systems and States to follow.
p. Today's rule follows the approach of the previous M-DBP rules and establishes a defined compliance
schedule for monitoring, treatment, and reporting activities. The rule does not allow States the flexibility
to set their own compliance schedules. The one exception is that States may allow a two-year extension in
compliance with additional treatment requirements for systems making capital improvements. EPA
believes that a uniform national compliance schedule for today's rule is necessary. This will help systems
to clearly understand when they must take different compliance steps and, accordingly, to prepare and
budget for those steps. It will allow Cryptosporidium laboratories to anticipate the sample analysis
demand that will exist and increase capacity to meet that demand. And it will allow the public to know
when their water system may be required to implement additional treatment for public health protection.
Individual Comments on Code 1200
EPA Letter ID: 101
Comment ID: 10923
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 11-4 December 2005
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Comment: NRWA believes that flexibility should be built into the implementation and enforcement of
MCLs to account for the wide variation in system sizes and characteristics. (Koorse 2003)
- The flexibility to adjust regulatory limits and enforcement is essential if small systems are to receive
equitable treatment in the regulatory environment and Fensterheim (2003) has shown that this flexibility
exists in the SDWA and has been used by EPA.
Response: See Response 1200.a.
EPA Letter ID: 441
Comment ID: 10780
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: General requirements
DEP interprets SEC. 108. Effective Date for Regulations, of the 1996 amendments to the federal Safe
Drinking Water Act to provide an effective date of 3 years after the date on which the regulation is
promulgated. LT2's compliance requirements for disinfection profiling and Cryptosporidium monitoring
occur within 24 months following publication of the final rule. DEP believes these requirements are
critical but require a substantial amount of preparation and training for water suppliers and regulators.
Due to their complexity, these activities are not practicable within the established time frame. DEP
believes public health protection will be improved if EPA delays these early LT2 requirements for 3 years
following promulgation to allow water suppliers and State regulatory agencies to adequately prepare for
the monitoring, implementation, treatment and compliance requirements.
Response: See Response 1200.b.
EPA Letter ID: 457
Comment ID: 11889
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: In order to protect public health, monitoring must occur at appropriate locations at appropriate
frequencies. This includes microbial monitoring to determine appropriate treatment under the
LT2ESWTR, disinfection byproducts monitoring to determine appropriate monitoring locations under the
Stage 2 DBPR, and routine compliance monitoring. Failure to monitor at both the appropriate location
and frequency may lead to treatment decisions that are not appropriate or disinfection byproducts
monitoring locations that are not representative of the water being delivered to the public. Ultimately, this
may lead to the need to repeat the monitoring at other locations/frequencies at additional cost.
We believe that the Drinking Water Program in the primacy state is the appropriate agency to determine
appropriate monitoring locations and frequencies. Through the years, during the implementation of the
SDWA, we have established a very close relationship with the public water systems in our state. We
Comment Response for the LT2ESWTR 11-5 December 2005
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believe that this relationship will allow the states and the water systems to work together to determine rule
applicability, appropriate monitoring requirements, and whether a waiver from monitoring should be
granted, especially for water systems with intricate distribution systems.
We prefer that the LT2ESWTR and Stage 2 DBPR limit any deadlines for water system and enforcement
activities within the first two years following rule promulgation. The primacy agencies need this time to
work with the water systems to identify appropriate monitoring locations; develop appropriate schedules
for microbial and DBF monitoring; prepare state rules for adoption; update data management systems;
and prepare for rule implementation.
Although we do not agree with the EPA-s early implementation requirement immediately following rule
promulgation, we have expressed our willingness to assist USEPA Region 4, in determining appropriate
monitoring locations and frequencies under the proposed implementation schedule, as the current state
resources allow.
LT2ESWTR Implementation Schedule
We recommend staggering the schedule for microbial monitoring out by 18 months. This would apply to
all deadlines for large system Cryptosporidium monitoring and small system indicator and/or
Cryptosporidium monitoring. This will give the states adequate time to work with the water systems to
assess their current levels of treatment (e.g., whether the system provides 5.5 log of treatment for
Cryptosporidium) as well as the opportunity to assist large systems in developing an acceptable
Cryptosporidium monitoring plan (including both monitoring location(s) and a sampling schedule).
Additional time is needed, because, in most cases, we will directly work with each water system to ensure
the proposed monitoring location for the system is appropriate. Additionally, staggering implementation
out by 18 months may allow for certification of additional commercial laboratories for Cryptosporidium
analysis.
Although this will delay compliance with any new treatment requirements by 18 months, we do not
believe that the overall public health protection will be compromised since the water systems will be
better informed about the regulations and more likely to be performing monitoring at appropriate
locations at appropriate frequencies. This will also give water systems reasonable time to budget for
Cryptosporidium sampling and contract with a laboratory for the analysis.
To reduce the economic burden on the states and the small systems, EPA should allow small systems to
follow the 24-month, one Cryptosporidium sample per month sampling strategy that is available to large
systems. This is our preferred approach. This approach will greatly reduce the financial strain on small
systems and the states by spreading the sampling cost out over a two-year period instead of compressing
the entire cost into a single 12-month period.
Response: See Responses 1200.b, 1200.C, and 1200.d.
EPA Letter ID: 457
Comment ID: 11920
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 11-6 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Comment: In order to address these issues, we suggest that EPA revise the currently proposed
LT2ESWTR implementation schedule and offer more flexibility to the states in determining the most
appropriate monitoring strategy on a case-by-case basis.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 457
Comment ID: 11942
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: We recommend staggering the schedule for microbial monitoring out by 18 months. This
would apply to all deadlines for large system Cryptosporidium monitoring and small system indicator
and/or Cryptosporidium monitoring. The 18-month phase in will help the states to have adequate time to
assess water systems- current levels of treatment (whether the system provides 5.5 log of treatment for
Cryptosporidium). It will also allow the states the opportunity to assist large systems in the development
of their Cryptosporidium monitoring plans and sampling schedules. Additionally, staggering
implementation by 18 months may allow for certification of additional commercial laboratories for
Cryptosporidium analysis. Furthermore, it will also give water systems reasonable time to budget for
Cryptosporidium sampling and contract with a laboratory for the analysis.
Although compliance with any new treatment requirements will be delayed by 18 months, we believe that
the overall public health protection will be improved in quality and effectiveness of required monitoring
by the water systems. They will be better informed about the regulations and will properly monitor at
correct locations and at appropriate frequencies.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 457
Comment ID: 11944
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: In regard to EPA-s request for comment on implementation timing in a scenario where a
small system treats surface water and sells it to a large system, we suggest that these types of situations be
addressed by the state, on a case-by-case basis.
response: See Response 1200.e.
EPA Letter ID: 466
Comment ID: 11009
Comment Response for the LT2ESWTR 11-7 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: ND understands the need to provide timely public health protection and recognizes that the
proposed schedule is designed to bring systems into compliance with the new requirements on an
accelerated basis. However, we believe that public health will be better protected by taking additional
time at the outset of the rules in order to ensure that monitoring locations and frequencies are appropriate
and therefore recommend changes from the proposed implementation schedule that we believe will
ultimately lead to better public health protection. Additional concerns about the LT2ESWTR follow.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 466
Comment ID: 11011
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: We believe that, as the state drinking water program, we are the appropriate regulator to
determine appropriate monitoring locations and frequencies. The drinking water program staff has
established a solid relationship with the systems in ND that will allow us to work together to determine
rule applicability, appropriate monitoring requirements, and waiver options. Our preference is that the
LT2ESWTR limit any deadlines for water system activity within the first two years following rule
promulgation. We need this time to work with the systems to identify appropriate monitoring locations
and develop appropriate schedules. In addition, ND will use this delay to prepare our state rules, update
data systems, and undertake other implementation-related activities.
Response: See Responses 1200.b, 1200.C, and 1200.f
EPA Letter ID: 470
Comment ID: 11062
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: We have concerns over the implementation schedule. We have discussed these concerns
below and are also in support of the proposed revisions presented in the comments submitted by the
Association of State Drinking Water Administrators. We are in support of the need to implement this rule
and Stage 2 Disinfection and Disinfection Byproducts Rule concurrently.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 497
Comment ID: 10644
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 11-8 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Comment: We strongly object to early implementation that requires water supplies to begin
compliance monitoring prior to state involvement and regulatory oversight. We have objected to this
method of rule-making in previous comments to the EPA. The
accelerated timeline forces states to devote resources to rule implementation at the same time we are
adopting our own rules.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 499
Comment ID: 10715
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: of imposition, burden, and cost on the regulated entities. Any and all opportunities to delay
these requirements to the fullest extent possible should be undertaken to allow primacy agencies and
regulated entities alike to -catch up- to, and recover from, the extraordinary requirements which have
been enacted by Congress and promulgated by EPA within just the last 10 years.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 504
Comment ID: 11344
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 710 A. Microbial Toolbox General Comments
Comment: 1. We believe that EPA should make an explicit and direct comparison between its predicted
benefits (numbers of cryptosporidiosis cases likely to be avoided by implementation of the proposed rule)
and available epidemiologic data on the occurrence of cryptosporidiosis. If the result is a lower estimate
of benefits then we believe EPA should reconsider other elements of the rule, in particular, the need for
early implementation and the justification for conservative valuation of treatment credits for toolbox
components.
Response: See Responses 1200.b, lOO.t, and 500.b.
EPA Letter ID: 504
Comment ID: 11356
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: The implementation schedule proposed by EPA in 40CFR 141.701, .703, .707, and .708
includes accelerated and hasty completion of activities that are critical to rule compliance and that will
determine the extent of capital and operational changes to be required of individual utilities.
Comment Response for the LT2ESWTR 11-9 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
The proposed schedule of-early implementation- forces utilities to adapt to the new and unfamiliar
processes and to make critical decisions without access to normal and established regulatory consultation
with state primacy agencies.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 513
Comment ID: 11521
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: We prefer that any deadlines for water system activities within the first two years following
rule promulgation be delayed. The Safe Drinking Water Act (Section 10) states that the effective date of a
national primary drinking water regulation shall be the date that is 3 years after the date of promulgation,
unless the Administrator determines that an earlier date is feasible. Requiring systems to conduct
monitoring that would start for large systems 30 months prior to the effective date of a regulation is an
unreasonable acceleration of activities. Systems will not have time to prepare adequate sampling plans
and budget for sample collection and analysis costs. We do not believe that early implementation
activities of this magnitude are reasonable.
The 2 years after promulgation are necessary for systems to develop microbial monitoring plans with
appropriate sampling locations and frequencies in consultation with the State. We believe public health
will be better served by taking the time before microbial monitoring commences to be sure that the
microbial monitoring is done correctly. All potential benefits of the proposed rule hinge on microbial
monitoring being done correctly, so accuracy should be the goal instead of speed.
In addition to allowing more time for development of sampling plans, this delay would allow more time
for additional laboratories to become certified for the analysis of Cryptosporidium, and for data
management software to be developed and tested.
Response: See Responses 1200.b, 1200.c, and 1200.g.
EPA Letter ID: 513
Comment ID: 11534
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: Section IV. F. Compliance Schedules
As stated above in -General Comments on LT2,- Nebraska requests that any deadlines for water system
activities within the first two years following rule promulgation be delayed. The additional time will be
necessary to ensure that monitoring locations and frequencies are appropriate, and that systems have time
to budget for costs associated with sampling. Ultimately this extra planning will provide better public
health protection, thus achieving the goal of the proposed rule.
Response: See Responses 1200.b and 1200.C.
Comment Response for the LT2ESWTR 11-10 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 516
Comment ID: 11710
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: drinking water suppliers. In summary, we find significant problems with the cost, risk, and
benefit analyses which are presented by EPA as justification for the proposed regulations; and in addition,
we find troublesome certain
Response: See Response lOO.r.
EPA Letter ID: 520
Comment ID: 11554
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: However, IEPA is concerned with the implementation schedule included in the proposed
rules. States appreciate the need to provide timely public health protection and recognize that the
proposed schedule is designed to bring systems into compliance with the new requirements on an
accelerated basis. However, IEPA believes that public health will be better protected by taking additional
time at the outset of the rules in order to ensure that monitoring locations and frequencies are appropriate
and therefore recommend changes from the proposed implementation schedule that we believe will
ultimately lead to better public health protection, monitoring. However, IEPA does have concerns with
the proposed implementation schedule. These concerns are discussed in greater detail later in this
Attachment.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 520
Comment ID: 11561
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: To truly protect public health, monitoring must occur at appropriate locations at appropriate
frequencies. This includes microbial monitoring to determine appropriate treatment under the
LT2ESWTR and routine compliance monitoring. Failure to monitor at both the appropriate location and
frequency may lead to treatment decisions that are not appropriate. Ultimately, such deficiencies may lead
to the need to repeat the monitoring at other locations/frequencies at additional cost (which can take funds
away from other public health protection activities).
IEPA also believes that the state drinking water program is the appropriate regulator to determine
appropriate monitoring locations and frequencies. Through implementation of the SDWA, we have
established a solid relationship with its water systems. This relationship will allow states and water
Comment Response for the LT2ESWTR 11-11 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
systems to work together to determine rule applicability, appropriate monitoring requirements, and
whether a waiver from monitoring should be granted, especially for complex rules that affect water
systems with advanced treatment trains and/or intricate distribution systems.
The IEPA preference is that the LT2ESWTR limit any deadlines for water system
activity as well as enforceable activities within the first two years following rule promulgation. States and
water systems need this time to work together to identify appropriate monitoring locations and develop
appropriate schedules for microbial monitoring. Additionally, IEPA will use this time to prepare state
rules, update our data systems, and undertake other implementation-related activities.
Response: See Responses 1200.b, 1200.C, and 1200.f
EPA Letter ID: 520
Comment ID: 11562
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA recognizes the need for simultaneous compliance with the LT2ESWTR and the Stage 2
DBPR. The lEPA-preferred approaches described below are designed to allow systems to have the
necessary information to make informed decisions on both rules at the same time.
IEPA appreciates EPA's recognition throughout the proposed rules' preambles that some states may not be
able to participate in implementation activities immediately following rule promulgation. Although some
states have indicated that they may be willing to assist EPA in determining appropriate monitoring
locations and frequencies under the proposed implementation schedule, other states have indicated that
they may not be able to be a major participant in implementation activities immediately following rule
promulgation. In this case, EPA will initially need to provide oversight for implementing the
LT2ESWTR. States, on an individual basis, will need to work with their EPA Regional Office (and
possibly EPA Headquarters) to determine exactly how implementation will be handled in each state,
including whether the state anticipates being able to prepare and submit its primacy revision application
within two years of rule promulgation (and therefore assume interim primacy) or if a request for an
extension might be likely (in which case EPA may need to assume the lead for implementation for a
longer period).
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 520
Comment ID: 11563
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA is concerned that the proposed implementation schedule for the LT2ESWTR may be
too aggressive to the point that it will be extremely difficult to implement. Our concerns include: early
implementation; identification and approval of monitoring plans; large system ability to prepare for and
execute monitoring; follow-up activity for large systems; small system activities; laboratory capacity; and
coordination between large system and small system monitoring. Each of these concerns is discussed
below.
Comment Response for the LT2ESWTR 11-12 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Early Implementation Activities
We continue to be concerned with EPA's practice of including early implementation activities in new
regulations. In accordance with the SDWA, States have at least 2 years to adopt new rules and up to 4
years to receive primacy for new rules, including LT2. EPA should not be promulgating regulations that
require States to undertake any activities before States are ready to adopt the new rules, properly train
staff, modify our database to track compliance, and inform systems of new requirements. Under the
current proposal, large PWSs (serving > 10,000 people) must submit crypto sampling plans to EPA within
3 months after rule promulgation, begin source water monitoring 3 months later, submit the source water
data to EPA, and EPA will make bin assignments based on PWS' submittals. Small systems (serving <
10,000 people) will be required to submit source water data to the State. It is our understanding that EPA
will be undertaking all early implementation activities associated with large systems under LT2 prior to
the State adopting these rules. EPA should either eliminate the early implementation requirements for
small systems or commit to also implementing LT2 requirements for small systems until such time that
the State has adopted this new regulation.
Response: See Responses 1200.b, 1200.c, and 1200.g.
EPA Letter ID: 520
Comment ID: 11588
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: The need for IEPA and water systems to work together to address deviations from
monitoring plans and missed samples is another example of the need to delay microbial monitoring by 18
months. Without such a delay, many water systems would need to work with their EPA Region to address
these issues if their state does not yet have primacy.
Response: See Response 1200.c.
EPA Letter ID: 520
Comment ID: 11614
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 340 D. Sampling Location
Comment: With respect to the specific issues on which EPA requested comment, IEPA believes that
EPA should provide flexibility to address these concerns on a case-by-case basis. The need to address
these issues is another example of why EPA should modify the LT2ESWTR implementation schedule to
better ensure state participation.
Response: See Responses 340(B), 365, 1200.C, and 1200.f.
Comment Response for the LT2ESWTR 11-13 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 521
Comment ID: 11759
Commenter: Leslie Rush,, Dalton Utilities
Commenter Category: Regulated Community (Utilities)
Comment: We believe that adequate time must be allowed for the development of a microbial
monitoring program and recommend a longer implementation schedule to include an additional 18 to 24
months.
Response: See Response 1200.c.
EPA Letter ID: 528
Comment ID: 12241
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: However, we are concerned with the implementation schedule included in the proposed rule.
We understand the need to provide timely public health protection and recognize that the proposed
schedule is designed to bring systems into compliance with the new requirements on an accelerated basis.
However, public health may be better protected by taking additional time at the outset of the rules in order
to ensure that monitoring locations and frequencies are appropriate and therefore recommend changes
from the proposed implementation schedule that might ultimately lead to better public health protection.
Arkansas- suggested changes include a delay in microbial monitoring. The issue we are concerned with
are discussed in detail on the attachment.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 528
Comment ID: 12242
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Arkansas is concerned that the proposed implementation schedule for the LT2ESWTR may
be too aggressive to the point that it will be extremely difficult to implement. Our concerns include:
identification and approval of monitoring plans; laboratory capacity; large system Cryptosporidium
results being reported directly to EPA; small system activities; and coordination between large system and
small system monitoring. Each of these concerns is discussed below.
Response: See Responses 1200.b, 1200.C, and 1200.f.
EPA Letter ID: 528
Comment ID: 12253
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 11-14 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Comment: We are concerned that strictly adhering to the compliance date in the proposed rule (8.5 years
after rule promulgation) could result in a large number of systems being required to monitor for
Cryptosporidium at the same time. In addition to potential lack of adequate laboratory capacity to support
analysis for a larger number of systems, in addition to oversight issues based on resource limitations. The
time needed for states to approve monitoring locations and the system to then perform the monitoring
may not be adequate to allow the system to the time needed to develop a Cryptosporidium monitoring
schedule, budget for Cryptosporidium monitoring, and begin monitoring, if such monitoring is necessary
based on the indicator monitoring results.
Response: See Responses 1200.b and 1200.C and 1200.g.
EPA Letter ID: 536
Comment ID: 11775
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Colorado is very concerned that the state implementation costs associated with this rule are
not adequately addressed. While the accuracy of state implementation costs may not significantly affect
the overall cost/benefit analysis of the proposed rule, it has significant negative impact on the ability of
our program to justify and secure adequate resources to implement the new rule if the costs articulated in
the EPA rulemaking are inaccurately low. Our ability to evaluate state implementation costs based on
EPA-s analysis was significantly compromised by the overly complex and unexplained analysis
contained in the Federal Register and supporting appendices. We are concerned that the implementation
costs for state primacy agencies may be significantly underestimated and are frustrated that we were
unable in a reasonable time period to use the EPA analytical results to estimate Colorado resources
necessary to implement this rule over the coming 5-10 years.
Response: See Response lOO.r.
EPA Letter ID: 536
Comment ID: 11777
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Through implementation of the SDWA, Colorado has established a solid relationship with its
water systems. This relationship allows us to work together with water systems to determine rule
applicability, appropriate monitoring requirements, and whether a waiver from monitoring should be
granted, especially for complex rules that affect water systems with advanced treatment trains and/or
intricate distribution systems.
It is Colorado-s preference that the LT2ESWTR limit any deadlines for water system activity as well as
enforceable activities within the first two years following rule promulgation. Colorado and its water
systems need this time to work together. Additionally, Colorado will use this time to prepare state rules,
update state data systems, and undertake other implementation-related activities.
Comment Response for the LT2ESWTR 11-15 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Colorado is concerned that the proposed implementation schedule for the LT2ESWTR may be too
aggressive to the point that it will be extremely difficult to implement. Aspects of this concern include:
identification and approval of monitoring plans; large system ability to prepare for and execute
monitoring; follow-up activity for large systems; small system activities; laboratory capacity; and
coordination between large system and small system monitoring. Each of these aspects is discussed
below.
Response: See Responses 1200.b, 1200.C, and 1200.f.
EPA Letter ID: 536
Comment ID: 11798
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: The need for Colorado and its public water systems to work together to address deviations
from monitoring plans and missed samples is another example of the need to delay microbial monitoring
by 18 months. Without such a delay, many water systems would need to work with the EPA to address
these issues, a practice that compromises the basic structure of state primacy.
Response: See Response 1200.c.
EPA Letter ID: 537
Comment ID: 14108
Commenter: Anonymous537,, Lincoln Water System
Commenter Category: Regulated Community (Utilities)
Comment: Due to the wide range of variability in water systems (not only on a National scale but within
States) it is imperative that EPA ,as in past rules, allow the States sufficient time to gain primacy for this
rule.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 556
Comment ID: 12037
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The proposed implementation of the rule, however, is extremely complex and demanding, not
only for water systems but for primacy agencies and EPA alike. AMWA believes that changes should be
made to facilitate implementation of the rule, keeping in mind that the vast majority of systems are not
expected to have significant problems with Cryptosporidium occurrence.
Response: See Responses 1200.b and 1200.C.
Comment Response for the LT2ESWTR 11-16 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 556
Comment ID: 12047
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additionally, it is possible that laboratory capacity will prove inadequate for timely execution
of the rule after the rules are finalized even though EPA determined prior to finalizing the rule that
adequate laboratory capacity would be available. It is therefore necessary that both rules contain specific
provisions that allow for changes in compliance schedules based on available capacity. Such a provision
is required to meet the commitment by the Agency referenced above.
Response: See Responses 1200.f and lOO.r.
EPA Letter ID: 562
Comment ID: 12305
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.4 Implementation Schedule
The Stage 2 FACA constructed a very aggressive implementation schedule for the LT2ESWTR. As EPA
lays out specifics of implementation, the practicality of the schedule reflected in the Agreement in
Principle has become more questionable. AWWA believes that implementation would be best
accomplished through state primacy agencies, rather than developing a new process through EPA Regions
that are less familiar with the utilities. Primacy agency review and approval are needed for the evaluation
of pre-existing data for bin determination, and for the defined sampling plan and schedule. Accordingly,
AWWA recommends that the rule provide that delays in completing primacy agency review not impact a
system-s total compliance timeframe of three years, plus an additional two years if needed for capital
improvements.
Response: See Response 1200.c.
EPA Letter ID: 585
Comment ID: 11988
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47719-22 [and §141.703(a)(l)-(4) on page 47778]
The TCEQ opposes the adoption of any implementation schedule which effectively precludes the
participation of the primacy agencies in any meaningful way. The proposed rule commences large system
monitoring six months after promulgation. As EPA notes in the preamble, this implementation schedule
does not provide sufficient time for the states to develop the necessary regulatory provisions to
implement this component of the rule.
Comment Response for the LT2ESWTR 11-17 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 588
Comment ID: 12091
Commenter: Lance Nielson, Manager, Idaho Drinking Water Program, Department of Environmental
Quality
Commenter Category: State/Tribe Government
Comment: 1) Early implementation schedules should be rolled back. Although we support the
compromise schedule proposed in the ASDWA comments, we would be happier still if EPA would honor
the schedule provided in the Safe Drinking Water Act. States need the two-year window following rule
promulgation to study the language and prepare a primacy package. Early implementation may require
EPA to deal directly
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 592
Comment ID: 12096
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Compliance dates The greatest economic burden of this proposed rule is in the timing. 1993
was the final date for compliance with the Surface Water Treatment Rule. Most Maine water utilities had
to borrow money, (mostly 20 year bonds), to build new treatment facilities to comply with the standards
of the Surface Water Treatment Rule. With the proposed LT2 rules we will be asked to return to our
customers and explain that the changes instituted in 1993were inadequate and we need more money to
retrofit or build new treatment facilities -and we need that money before we have finished paying for the
old projects. The final compliance date for this rule cannot be earlier than 2013, and should be pushed
back to 2016. We must have time to pay off our existing debts before embarking on questionable and
expensive modfications and treatment.
Response: See Response 1200.b and lOO.c.
EPA Letter ID: 595
Comment ID: 12575
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: available treatment options may require more capital spending. When EPA determines the
effective dates, we hope that EPA will consider balancing costs to benefits to allow implementation dates
to follow bond pay offs so that the consumers will not be unduly burdened with high rates if even for a
short period of time. The monitoring costs for LT2 could be a per household cost of $30 to
Response: See Response 1200.b.
Comment Response for the LT2ESWTR 11-18 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 601
Comment ID: 13006
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah prefers that the LT2ESWTR limit any deadlines for water system activity within the first
two years following rule promulgation. Utah and our water systems need this time to work together to
identify appropriate monitoring locations and develop appropriate schedules for microbial monitoring.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 601
Comment ID: 13033
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah recognizes that this will delay compliance with any new treatment requirements by 18
months, but strongly believe that public health protection will ultimately be increased since the delay will
ensure that water systems, that are subject to monitoring under the rule, monitor at appropriate locations
at appropriate frequencies.
Response: See Response 1200.c.
EPA Letter ID: 601
Comment ID: 13034
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah prefers that the LT2ESWTR limit any deadlines for water system activity within the first
two years following rule promulgation. Utah and our water systems need this time to work together to
identify appropriate monitoring locations and develop appropriate schedules for microbial monitoring.
Response: See Response 1200.c.
EPA Letter ID: 609
Comment ID: 14111
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 11-19 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Comment: We strongly object to early implementation that requires water supplies to begin compliance
monitoring prior to state involvement and regulatory oversight. We have objected to this method of
rulemaking in previous comments to the USEPA. The accelerated time line forces states to devote
resources to rule implementation at the same time we are adopting our own rules.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 609
Comment ID: 14113
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: The USEPA proposes to assume responsibility for large system monitoring and reporting
under the LT2ESWTR. The USEPA will not be prepared to guide our water suppliers through this early
monitoring and to review results. Specifically, compliance dates for monitoring should be moved back an
additional 18 months from the proposed 6 months after rule promulgation.
Response: See Response 1200.c.
EPA Letter ID: 634
Comment ID: 13276
Commenter: Michael A. Neher, Environmental Services Manager, City of Henderson
Commenter Category: Local Government
Comment: Finally, the City is concerned that these regulations could be implemented before states are
able to attain primacy. It is very important to the City that Nevada has primacy at the time the rules
become effective. The Nevada drinking water program would become fractured and less effective when
only a portion of the program is under state authority. We recommend that EPA work with the states to
develop a feasible implementation schedule that includes state primacy, particularly for Nevada.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 637
Comment ID: 13105
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: District recommends that an additional time of 12 to 18 months be granted for
implementation of the rule. This would allow water systems sufficient time to assess current levels of
treatment as well as time to evaluate toolbox options. Please see District comments on compliance
schedule. Initial reporting to EPA then transferring compliance reporting to States is inappropriate and
will place undo burden on water systems.
Response: See Response 1200.c.
Comment Response for the LT2ESWTR 11-20 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 641
Comment ID: 13581
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Other EPA Comment Codes and Descriptions: 1833 i. Need to delay or modify rule implementation
schedule
Comment: that have already confirmed schedules with the lab. (b) Also, requiring sampling schedules
within 3 months may not be feasible. For example, if purchasing policies require PWSs to wait for
promulgation to put out a RFQ, then they write the RFQ, put it out to bid (typically 30 days later), and
then award the bid (rarely done in less than 30 days). This will result in the laboratories being under
tremendous pressure to generate responses to RFQs (conceivably, 100s or 1000s will arrive
approximately 30 days after promulgation) and the PWSs will have to award the bid and set up the
schedule very quickly, (c) Lastly, since
Response: See Responses 1200.c and 1830.
EPA Letter ID: 641
Comment ID: 13582
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: have to award the bid and set up the schedule very quickly, (c) Lastly, since there is no
requirement for EPA to -approve- sample collection schedules, and therefore no need for a built-in
response time,- the proposed 3 month period should be extended.
Response: See Response 1200.h.
EPA Letter ID: 641
Comment ID: 13629
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: that have already confirmed schedules with the lab. (b) Also, requiring sampling schedules
within 3 months may not be feasible. For example, if purchasing policies require PWSs to wait for
promulgation to put out a RFQ, then they write the RFQ, put it out to bid (typically 30 days later), then
award the bid (rarely done in less than 30 days). This will result in the laboratories being under
tremendous pressure to generate responses to RFQs (conceivably, 100s or 1000s will arrive
approximately 30 days after promulgation) and the PWSs will have to award the bid and set up the
schedule very quickly, (c) Lastly, since there is no requirement for EPA to -approve- sample collection
schedules, and therefore no need for a built-in -response time,- the proposed 3 month period should be
extended.
Comment Response for the LT2ESWTR 11-21 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Response: See Response 1200.h.
EPA Letter ID: 643
Comment ID: 12701
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: However, states are concerned with the implementation schedule included in the proposed
rules. States appreciate the need to provide timely public health protection and recognize that the
proposed schedule is designed to bring systems into compliance with the new requirements on an
accelerated basis. However, states believe that public health will be better protected by taking additional
time at the outset of the rules in order to ensure that monitoring locations and frequencies are appropriate
and therefore recommend changes from the proposed implementation schedule that states believe will
ultimately lead to better public health protection. ASDWA-s suggested changes include a delay in
microbial monitoring and incorporating the Initial Distribution System Evaluation concept into the initial
round of monitoring for Stage 2B MCL compliance.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 643
Comment ID: 12707
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: monitoring. States do have concerns with the proposed implementation schedule. These
concerns are discussed in greater detail later in this Attachment.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 643
Comment ID: 12709
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: To truly protect public health, monitoring must occur at appropriate locations at appropriate
frequencies. This includes microbial monitoring to determine appropriate treatment under the
LT2ESWTR, DBF monitoring to determine appropriate monitoring locations under the Stage 2 DBPR,
and routine compliance onitoring. Failure to monitor at both the appropriate location and frequency may
lead to treatment decisions that are not appropriate or DBF monitoring locations that are not
representative of the water being delivered to the public. Ultimately, such deficiencies may lead to the
need to repeat the monitoring at other locations/frequencies at additional cost (which can take funds away
from other public health protection activities).
States also believe that the state drinking water program is the appropriate regulator to determine
Comment Response for the LT2ESWTR 11-22 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
appropriate monitoring locations and frequencies. Through implementation of the SDWA, each state has
established a solid relationship with its water systems. This relationship will allow states and water
systems to work together to determine rule applicability, appropriate monitoring requirements, and
whether a waiver from monitoring should be granted, especially for complex rules that affect water
systems with advanced treatment trains and/or intricate distribution systems.
The states- preference is that the LT2ESWTR and Stage 2 DBPR limit any deadlines for water system
activity as well as enforceable activities during the first two years following rule promulgation. States and
water systems need this time to work together to identify appropriate monitoring locations and develop
appropriate schedules for microbial and DBF monitoring. Additionally, states use this time to prepare
state rules, update state data systems, and undertake other implementation-related activities.
States recognize the need for simultaneous compliance with the LT2ESWTR and the Stage 2 DBPR. The
state-preferred approaches described below are designed to allow systems to have the necessary
information to make informed decisions on both rules at the same time.
States appreciate EPA-s recognition throughout the proposed rules- preambles that some states may not
be able to participate in implementation activities immediately following rule promulgation. Although
some states have indicated that they may be willing to assist EPA in determining appropriate monitoring
locations and frequencies under the proposed implementation schedule, other states have indicated that
they may not be able to be a major participant in implementation activities immediately following rule
promulgation. In this case, EPA will initially need to provide oversight for implementing the LT2ESWTR
and the Stage 2 DBPR. States, on an individual basis, will need to work with their EPA Regional Office
(and possibly EPA Headquarters) to determine exactly how implementation will be handled in each state,
including whether the state anticipates being able to prepare and submit its primacy revision application
within two years of rule promulgation (and therefore assume interim primacy) or if a request for an
extension might be likely (in which case EPA may need to assume the lead for implementation for a
longer period).
LT2ESWTR Implementation Schedule
State Concerns
States are concerned that the proposed implementation schedule for the LT2ESWTR may be too
aggressive to the point that it will be extremely difficult to implement. State concerns include:
identification and approval of monitoring plans; laboratory capacity; large system ability to prepare for
and execute monitoring; follow-up activity for large systems; large system Cryptosporidium results being
reported directly to EPA; small system activities; and coordination between large system and small
system monitoring. Each of these concerns is discussed below.
Response: See Responses 1200.b, 1200.C, 1200.f, and 1200.g.
EPA Letter ID: 643
Comment ID: 12721
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Further, EPA would also have to determine the impact a delay in large system monitoring
would have on small system microbial monitoring as well as simultaneous compliance with the Stage 2
Comment Response for the LT2ESWTR 11-23 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
DBPR. EPA must ensure that any changes to monitoring schedules do not result in an unacceptably large
number of systems being required to monitor for Cryptosporidium at the same time. In addition to
potential lack of adequate laboratory capacity to support analysis for a larger number of systems, some
states may face oversight issues based on resource limitations.
Response: See Responses 1200.c and 1200.g.
EPA Letter ID: 643
Comment ID: 12739
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The need for states and water systems to work together to address deviations from monitoring
plans and missed samples is another example of the need to delay microbial monitoring by 18 months.
Without such a delay, many water systems would need to work with their EPA Region to address these
issues if their state does not yet have primacy.
Response: See Response 1200.c.
EPA Letter ID: 643
Comment ID: 12768
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
With respect to the specific issues on which EPA requested comment, states believe that EPA should
provide states with flexibility to address these concerns on a case-by-case basis. The need to address these
issues is another example of why EPA should modify the LT2ESWTR implementation schedule to better
ensure state participation.
Response: See Response 1200.c.
EPA Letter ID: 647
Comment ID: 12866
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: We are concerned about the implementation schedules included in the proposed rules. There
is a need to provide timely public health protection. However, we believe that public health will be better
protected by taking additional time at the outset of the rules in order to ensure that monitoring locations
and frequencies are appropriate and therefore recommend changes from the proposed implementation
schedule that will ultimately lead to better public health protection. MDE suggests a delay in microbial
monitoring for small water
Response: See Responses 1200.b and 1200.C.
Comment Response for the LT2ESWTR 11-24 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 647
Comment ID: 12872
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: monitoring. States do have concerns with the proposed implementation schedule. These
concerns are discussed in greater detail later in this Attachment.
Response: See Response 1200.b.
EPA Letter ID: 647
Comment ID: 12874
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: To truly protect public health, monitoring must occur at appropriate locations at appropriate
frequencies. This includes microbial monitoring to determine appropriate treatment under the
LT2ESWTR, DBF monitoring to determine appropriate monitoring locations under the Stage 2 DBPR,
and routine compliance monitoring. Failure to monitor at both the appropriate location and frequency may
lead to treatment decisions that are not appropriate or DBP monitoring locations that are not
representative of the water being delivered to the public. Ultimately, such deficiencies may lead to the
need to repeat the monitoring at other locations/frequencies at additional cost (which can take funds away
from other public health protection activities).
The state drinking water program is the appropriate regulator to determine appropriate monitoring
locations and frequencies. Through implementation of the SDWA, each state has established a solid
relationship with its water systems. This relationship will allow states and water systems to work together
to determine rule applicability, appropriate monitoring requirements, and whether a waiver from
monitoring should be granted, especially for complex rules that affect water systems with advanced
treatment trains and/or intricate distribution systems.
MDE-s preference is that the LT2ESWTR and Stage 2 DBPR limit any deadlines for water system
activity as well as enforceable activities within the first two years following rule promulgation. States and
water systems need this time to work together to identify appropriate monitoring locations and develop
appropriate schedules for microbial and DBP monitoring. Additionally, states use this time to prepare
state rules, update state data systems, and undertake other implementation-related activities.
There is a need for simultaneous compliance with the LT2ESWTR and the Stage 2 DBPR. The state-
preferred approaches described below are designed to allow systems to have the necessary information to
make informed decisions on both rules at the same time.
MDE-s Concerns
The proposed implementation schedule for the LT2ESWTR may be too aggressive to the point that it will
be extremely difficult to implement.
Comment Response for the LT2ESWTR 11-25 December 2005
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Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 647
Comment ID: 12897
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: The need for states and water systems to work together to address deviations from monitoring
plans and missed samples is another example of why a delay in microbial monitoring by 18 months
should be considered. Without such a delay, many water systems would need to work with their EPA
Region to address these issues if their state does not yet have primacy.
Response: See Response 1200.c.
EPA Letter ID: 647
Comment ID: 12915
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: With respect to the specific issues on which EPA requested comment, EPA should provide
states with flexibility to address these concerns on a case-by-case basis. The need to address these issues
is another example of why EPA should modify the LT2ESWTR implementation schedule to better ensure
state participation.
Response: See Response 1200.c.
EPA Letter ID: 660
Comment ID: 14083
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: reporting. Compliance for all systems should be delayed until the States achieve primacy
(with the exception of those not meeting a reasonable deadline). This reduces the burden on water
systems to make the transition from reporting to EPA, and then to States at a later date.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 660
Comment ID: 14084
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 11-26 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
J. System Reporting and Record keeping Requirements (pages 47724-47731)
EPA requests comment on the reporting and recordkeeping requirements proposed for LT2ESWTR.
CUWCD recommends that an additional time of 12 to 18 months be granted for implementation of the
rule. This would allow water systems sufficient time to assess current levels of treatment as well as time
to evaluate toolbox options.
Response: See Response 1200.c.
EPA Letter ID: 662
Comment ID: 14043
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: capacity issues as well as the reporting software issues. State primacy is also a concern. EPA
should aim for State-s to be the primacy agency on initiation of this rule since they are most familiar with
the systems and all the potential local ramifications of tool box issues.
Response: See Response 1200.c.
EPA Letter ID: 664
Comment ID: 14058
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.F. - COMPLIANCE SCHEDULE
Under the proposed Rule, for those systems serving more than 10,000 people, a sampling schedule would
have to be submitted within 3 months of promulgation of the Rule with source water monitoring to begin
within 6 months. Who would we submit our sampling schedule and plan to and who would review and
approve it? There will be many questions from individual systems that will need to be addressed. Without
sufficient time allotted to provide each State the opportunity to have Administrative Rules developed and
staff trained in these issues, the burden would fall to the regional EPA who will not be sufficiently staffed
or knowledgeable of the specific issues at each plant site. We would suggest that a more reasonable
schedule dates be allotted for compliance for each requirement to ensure that the existing State-s
regulatory staff has implemented the necessary rules and training to ensure compliance by the systems.
Response: See Response 1200.c.
EPA Letter ID: 673
Comment ID: 13997
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 11-27 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Comment: the deadline for sampling and reporting. Compliance for all systems should be delayed until
the States achieve primacy (with the exception of States not meeting a reasonable deadline). This reduces
the burden placed on water systems that must report to EPA, and then to repeat the process for States at a
later date.
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 673
Comment ID: 14000
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
J. System Reporting and Recordkeeping Requirements (pages 47724-47731)
EPA requests comment on the reporting and recordkeeping requirements proposed for LT2ESWTR.
Jordan Valley Water recommends that an additional time of 12 to 18 months be granted for
implementation of the rule. This would allow water systems sufficient time to assess current levels of
treatment as well as time to evaluate toolbox options.
Response: See Response 1200.c.
EPA Letter ID: 675
Comment ID: 13969
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: In total, these implementation modifications would greatly simplify states- and EPA-s
monitoring and compliance requirements, laboratory arrangements, and budgeting. State rule preparation,
data system modification, monitoring location identification, and other implementation activities would
also be possible during that time. The proposed extensive gaps between Cryptosporidium sampling
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 675
Comment ID: 13972
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: The State of Minnesota recognizes that the recommended implementation changes would
delay compliance with new treatment requirements for some systems, but believes that public health
protection will ultimately be increased. These specific delays will ensure that water systems that are
Comment Response for the LT2ESWTR 11-28 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
subject to monitoring under the rule monitor at appropriate locations at appropriate frequencies. State
involvement in identifying microbial sampling locations and establishing sampling schedules is important
to ensure that the data collected is useful in determining appropriate treatment requirements. Moreover,
we recommend states and water systems work together to address deviations from monitoring plans and
missed samples. Without such a delay, many water systems will be required to work directly with their
EPA Region to address these issues. The Minnesota Department of Health does not intend to participate
in any early implementation activities. EPA would need to undertake any follow-up activities directly.
The regulation gives a public system a defined window of time to achieve compliance with the rules. The
rule should be flexible to account for the differences in states compliance and enforcement programs. This
is comparable to the Lead and Copper Rule, where numerous milestones were established to document
corrosion control implementation progress. The result being the focus becomes the mandated reporting,
not compliance. As co-regulators we understand our responsibilities for successful implementation of
LT1 and LT2, and the Agency needs to trust the states that this is going to happen. Each state is
responsible for informing the region how they plan to implement the provisions of the SWDA in their
program plan. The EPA regional offices are responsible for monitoring and evaluating these
implementation activities for individual state programs. If a state is failing to meet what is specified in
their plan, this can be addressed informally through the program audit process, and not through prescribed
milestones or benchmarks to satisfy congressional reporting requirements.
Response: See Responses 1200.b, 1200.c, and 1200.p.
EPA Letter ID: 678
Comment ID: 14668
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: established by the State primacy agency. The compliance schedule should also be modified to
incorporate review and approval of the LT2 monitoring plan by the State primacy agency prior to
initiation of the required monitoring. Additionally, the EPA should allow
Response: See Responses 1200.h.
EPA Letter ID: 678
Comment ID: 14680
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: required to do so after the second round. We recommend the final rule include a provision
that will allow some time extension for a system that might be required to install additional treatment
after the second round of monitoring as it did for a system that is required to install additional treatment
after the first round of monitoring.
Response: See Response 1200.i.
Comment Response for the LT2ESWTR 11-29 December 2005
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EPA Letter ID: 704
Comment ID: 14787
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1. Section 141.703. Sampling Schedules.
Systems serving greater than 10,000 persons must submit a sample plan within three (3) months of rule
promulgation. Considering the limited number of labs that are available for cryptosporidium analysis, we
believe three months does not allow sufficient time for development of the plan. A longer period is
needed for plan development to allow laboratories to come up to speed and to allow the systems to -
practice- sample prior to establishing the plan.
Response: See Responses 1200.c and 1200.h.
EPA Letter ID: 704
Comment ID: 14792
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section 3.4. EPA suggests a complete practice sample before -official- data sampling begins.
It is going to be extremely difficult to contract with a lab, set the sample schedule, and handle all the
associated issues (e.g. learning the LT2 data system). Now they are -recommending- a practice run too in
this 6-month period. Possibly more time is needed to put the entire sample plan together as this window is
very narrow.
Response: See Responses 1200.c and 1200.h.
11.2 Comment Code 1210, A. Large System Monitoring and
Treatment
Individual Comments on Code 1210
EPA Letter ID: 439
Comment ID: 10759
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: historic Cryptosporidium data would then be negated for these systems. The
compliance schedule should be modified to allow the primacy agency (i.e. State of Colorado) to review
and approve the LT2ESWTR monitoring plan.
Response: See Response 1200.h.
Comment Response for the LT2ESWTR 11-30 December 2005
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EPA Letter ID: 441
Comment ID: 10767
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Compliance requirements table
For large water suppliers, the LT2 requires the installation of treatment, if necessary, and compliance with
the treatment technique no later than 72 months following promulgation. Small system requirements are
similar, but the compliance period is 102 months following promulgation. Unfortunately, a small
percentage of water suppliers in the country are already involved in constructing new treatment processes,
regardless of LT2's status. A supplier that completes major construction now and incurs debt may be
financially unable to initiate another major construction project for many years. EPA should grant
additional time to install treatment and comply with the treatment technique if the supplier initiated major
construction after the LT2 proposed rule date of August 11, 2003.
Response: See Response 1200.b.
EPA Letter ID: 466
Comment ID: 11018
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: We support the staggered three phase Cryptosporidium monitoring. This would allow for
additional time for the smaller large systems (systems under 30,000) to prepare for monitoring and it
would also minimize early implementation activities. Once sampling is in place, having large systems
sample for two years would allow for an ample number of samples to be collected and seasonal
variability.
Response: See Responses 1200.c and SOO.p.
EPA Letter ID: 470
Comment ID: 11089
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Based upon our concerns relating to lab capacity, early implementation issues, and data
analysis, Vermont recommends the following approach for implementing the LT2ESWTR:
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 470
Comment ID: 11091
Comment Response for the LT2ESWTR 11-31 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: EPA should delay Cryptosporidium monitoring for large systems by 18 months to allow for
state-water system interaction to determine appropriate monitoring locations. Such a delay would result in
an equivalent delay in large system compliance (compliance would be achieved 7.5 years after rule
promulgation instead of 6 years as proposed).
Response: See Response 1200.c.
EPA Letter ID: 476
Comment ID: 10675
Commenter: Anonymous476,, Department of Defense
Commenter Category: Other: Other hard to categorize commenters
Comment: 2. Provide Additional Time for Compliance When Capital Improvements are Needed.
Requirement. As proposed, the LT2ESWTR would require large water systems to comply with
Cryptosporidium treatment requirements within four and a half years after monthly monitoring
requirements are complete. Small water systems are required to comply with Cryptosporidium treatment
requirements within four years after monthly monitoring requirements are complete. EPA does stipulate
that States may grant up to an additional two years for systems making capital improvements
Comment. Due to the protracted nature of the Federal budgeting and funding process, four to four and a
half years may be insufficient time for systems to comply where capital improvements for treatment or
other modifications of the water supply system are required.
Discussion. Budgeting for military construction (MILCON) funds requires submission of a request
presenting the problem and options, along with an initial estimate. Once this request is approved through
the budget process, funds for design are provided. After design, another request is required for funding to
implement the project. Projects in excess of $500,000 require congressional approval. Even projects given
high priority cannot progress to the stage of having construction funding in hand in less than three years,
and it is not unusual for the process to take longer. Once construction funding and design are in hand,
further time is necessary to award the contract for construction and perform the construction work.
If a State does not grant additional time for systems making capital improvements, then systems will have
only four and a half years, maximum, to comply with treatment requirements. Unfortunately, even four
and a half years, although it may appear generous, may be insufficient time to complete capital
improvements.
Recommendation. If capital improvements to the water supply system are required for compliance, extend
the compliance date to seven years after monitoring requirements are complete.
Response: See Response 1200.b.
Comment Response for the LT2ESWTR 11-32 December 2005
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EPA Letter ID: 497
Comment ID: 10647
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Large public water supply systems (>10,000 pop.) will be required to submit monitoring
plans for samples collected from source water for Cryptosporidium, E. coli, and turbidity three months
after rule promulgation. Monitoring must then commence six months later. We believe this is insufficient
time for a water system to coordinate sampling schedules for Cryptosporidium with certified laboratories.
In addition, surface water treatment plants have historically used total coliform to measure relative
pollution in source water. Quantification using E. coli or fecal coliform will require time for laboratories
to establish procedures or purchase additional equipment. The EPA should delay source water monitoring
for large supplies by an additional 18 months.
Response: See Responses 1200.C, 1200.g, and 1200.h.
EPA Letter ID: 499
Comment ID: 10719
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: 2. KDHE supports a six month delay in the Cryptosporidium monitoring requirements for
systems with populations between 10,000 and 100,000. Such a delay will provide these systems
additional opportunity to contract with acceptable laboratories while affording the presently limited
number of certified laboratories additional time to prepare for additional workloads.
3. KDHE supports additional time being added to the end of large system Cryptosporidium monitoring
and the beginning of small system Cryptosporidium monitoring. This delay will afford both EPA and the
primacy agencies additional opportunity to evaluate any unforeseen problems which have resulted from
the monitoring process before implementation to the large number of small systems which will initiate
monitoring.
Response: See Response 1200.c.
EPA Letter ID: 504
Comment ID: 11359
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: Following reevaluation of the benefits estimate suggested under item 2 (above), we suggest
that EPA reconsider the implementation schedule in order to (1) to permit state primacy agencies to
become meaningfully involved in this critical stage of the rule, and (2) reduce the likelihood of errors and
improve the quality.
Comment Response for the LT2ESWTR 11-33 December 2005
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Response: See Response 1200.c.
EPA Letter ID: 513
Comment ID: 11520
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "Requiring systems to conduct monitoring that would start
for large systems 30 months prior to the effective date of a regulation is an unreasonable acceleration of
activities" submitted by Richard
Response: See Response 1200.b.
EPA Letter ID: 520
Comment ID: 11573
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: - Stagger Cryptosporidium monitoring for large systems over three phases:
[SEE PAGE 6 OF PDF FILE FOR TABLE]
As an alternative, EPA should consider a two-phase stagger with monitoring beginning for very large
systems two years after rule promulgation and for large systems three years after rule promulgation (exact
breakpoints would need to be determined based on the number of systems in each category). Although
this would increase laboratory demand, the schedule would allow IEPA and water systems additional time
to prepare for monitoring and would minimize early implementation activities.
IEPA recognizes that this will delay compliance with any new treatment requirements for some systems,
but as indicated previously, IEPA strongly believes that public health protection will ultimately be
increased since the delay will ensure that water systems that are subject to monitoring under the rule
monitor at appropriate locations at appropriate frequencies.
Response: See Response 1200.c.
EPA Letter ID: 528
Comment ID: 12251
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: - EPA should delay Cryptosporidium monitoring for large systems by 18 months to allow for
state-water system interaction to determine appropriate monitoring locations. This delay would also
provide states time to develop data systems for large system Cryptosporidium results and allow for
traditional water system-to-
Comment Response for the LT2ESWTR 11-34 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
state reporting instead of requiring direct reporting to EPA (which could result in savings to laboratories
since laboratories have established reporting mechanisms to the state and development of a new reporting
mechanism to EPA could require additional programming). The State could then share Cryptosporidium
results with EPA as needed. Such a delay would result in an equivalent delay in large system compliance
(compliance would be achieved 7.5 years after rule promulgation instead of 6 years as proposed).
Response: See Response 1200.c.
EPA Letter ID: 528
Comment ID: 12252
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: - If adequate laboratory capacity is not available to support large system Cryptosporidium
monitoring under EPA-s proposed approach, this approach would be to delay implementation as
described in the previous bullet. However, we would support a staggered approach for large system
Cryptosporidium monitoring. Such an approach for large systems that would be consistent with the
timeframes in the proposed rule would be: [See pdf for table]
System size Cryptosporidium Monitoring
Date of Bin
Determination Compliance Date
>25,000 2 years of monitoring beginning 1 year after rule promulgation
3.5 years after rule promulgation
6.5 years after rule promulgation
<25,000 2 years of monitoring beginning 3 years after rule promulgation
5.5 years after rule promulgation
8.5 years after rule promulgation
Response: See Responses 1200.b, 1200.c, and 1200.g.
EPA Letter ID: 533
Comment ID: 12212
Commenter: Edward Urheim,,
Commenter Category: Consultants: (where self-identified)
Comment: I do not agree with EPA-s proposed early implementation requirement immediately
following rule promulgation. The proposed start of source monitoring under the
LT2ESWTR should be no sooner than 24 months after the final rule is promulgated.
Rule implementation and compliance schedules should also be delayed an Equivalent period. This delay
is needed to allow the primacy agencies time to work with and train the water systems to identify
appropriate monitoring locations; develop appropriate schedules for microbial monitoring; prepare state
rules for adoption; update data management systems; and prepare for rule implementation. I believe that
the State Primacy Agency in each State is the
Response: See Responses 1200.b and 1200.C.
Comment Response for the LT2ESWTR 11-35 December 2005
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EPA Letter ID: 533
Comment ID: 12214
Commenter: Edward Urheim,,
Commenter Category: Consultants: (where self-identified)
Comment: this important rule, resulting in better public health protection. I also
believe that delaying the start of implementation of this regulation these few months will help EPA and
States work together resulting in better over-all rule implementation and compliance.
Response: See Response 1200.c.
EPA Letter ID: 556
Comment ID: 12048
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: It is important to note that the agreement does not prohibit such actions as further staging of
the rule by system size so that the rule may be undertaken in a reasonable manner in the face of partial
laboratory capacity availability. Such staging may have additional benefits of easing primacy agency
implementation issues by allowing time for states to attain primacy before medium and smaller systems
(which make up the majority of systems but serve a minor portion of the population) need to take action.
In fact, AMWA strongly recommends that EPA begin thinking now about how rule implementation might
be most effectively undertaken should laboratory capacity prove to be insufficient.
Response: See Responses 1200.c and 1200.g.
EPA Letter ID: 559
Comment ID: 12228
Commenter: Bill Pappathopoulos, Director, City of Two Rivers, Water & Light Utility
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.F. - Compliance Schedule
Under the proposed Rule, for those systems serving more than 10,000 people, a sampling schedule would
have to be submitted within 3 months of promulgation of the Rule with source water monitoring to begin
within 6 months. Who would we submit our sampling schedule and plan to and who would review and
approve it? There will be many questions from individual systems that will need to be addressed. Without
sufficient time allotted to provide each State the opportunity to have Administrative Rules developed and
staff trained in these issues, the burden would fall to the regional EPA who will not be sufficiently staffed
or knowledgeable of the specific issues at each plant site. We would suggest that a more reasonable
schedule dates be allotted for compliance for each requirement to ensure that the existing State-s
regulatory staff has implemented the necessary rules and training to ensure compliance by the systems.
Response: See Response 1200.c.
Comment Response for the LT2ESWTR 11-36 December 2005
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EPA Letter ID: 560
Comment ID: 14978
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Three - Implementation Schedule:
The tight time line between submission of the sampling schedule to EPA for approval and the beginning
of monitoring is of concern, as it requires EPA to review and approve thousands of sampling plans (and
allow time for modification if necessary) within a 3-month period. It is suggested that the Rule be revised
to require monitoring to begin 3 months after EPA approves the sampling schedule.
Response: See Responses 1200.h and 1200.C.
EPA Letter ID: 561
Comment ID: 12236
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.F. - Compliance Schedule
Under the proposed Rule, for those systems serving more than 10,000 people, a sampling schedule would
have to be submitted within 3 months of promulgation of the Rule with source water monitoring to begin
within 6 months. Who would we submit our sampling schedule and plan to and who would review and
approve it? There will be many questions from individual systems that will need to be addressed. Without
sufficient time allotted to provide each State the opportunity to have Administrative Rules developed and
staff trained in these issues, the burden would fall to the regional EPA who will not be sufficiently staffed
or knowledgeable of the specific issues at each plant site. We would
suggest that a more reasonable schedule dates be allotted for compliance for each requirement to ensure
that the existing State-s regulatory staff has implemented the necessary rules and training to ensure
compliance by the systems.
Response: See Response 1200.c.
EPA Letter ID: 585
Comment ID: 11957
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: p. 47665-6 [and §141.703(a) on p. 47778]
The TCEQ does not concur with the monitoring schedule summarized in Table IV-1. For large systems,
the proposed schedule does not allow primacy agencies sufficient time to develop an implementation plan
for Cryptosporidium monitoring , does not provide public water systems sufficient time to effectively
budget for significant costs associated with Cryptosporidium monitoring, limits the time available to build
laboratory capacity and analyst expertise, and extends the lag time between the initial Cyptosporidium
monitoring periods for large and small systems. For small systems, the proposed bi-weekly, 12-month
Comment Response for the LT2ESWTR 11-3 7 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Response: See Responses 1200.b, 1200.c, and 1200.g.
EPA Letter ID: 585
Comment ID: 11989
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: As noted previously, the TCEQ does not concur with the sampling schedule contained in the
proposed rule for a variety of other reasons as well. These reasons include:
1) Large systems are not allowed a reasonable time to budget for addition sampling and analytical costs.
While these costs may be a minor logistical issue for very large systems, they could pose a significant
problem for systems serving fewer than 50,000 people unless the rule happens to be promulgated just
before the system begins budgeting for the fiscal year when sampling occurs. Since many budgeting
processes last 3-6 months, it is likely that this implementation schedule will pose an administrative and
economic hardship beyond the simple issue of cost. For example, the proposed rule will effectively
require water system administrators to propose and adopt budgets for a rule that has not yet been
promulgated; in some jurisdictions, this type of activity may be prohibited.
2) Depending upon the content of the final rule, it may not be possible for large systems to prepare a
complete monitoring plan within 90 days of rule promulgation. Although this effective date may be
reasonable if there are no major revisions resulting from public comment, the schedule presumes that
systems are familiar with the content of the proposed rule and have begun preparing their plans prior to
rule promulgation.
3) The EPA will only have 90 days to review the proposed sampling locations and monitoring plans for
all large systems. Based on our experience as a primacy agency, this aggressive schedule will impose
appreciable, and perhaps insurmountable, logistical challenges for the EPA. For example, our experience
suggests that the initial compliance rate for new reporting requirements will likely not exceed 90% for the
first reporting period; the non-compliance rate for this rule is likely to be higher because EPA will be
asking systems to begin certain implementation activities prior to rule adoption. Consequently, there
are likely to be numerous systems that miss the deadline for submitting their plan and this will impact on
EPA's ability to complete its review in time for the system to commence monitoring six months after
promulgation.
Response: See Responses 1200.c and 1200.h.
EPA Letter ID: 585
Comment ID: 11992
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: The TCEQ recommends that the implementation schedule for large systems be delayed by 18
months to allow both water systems and primacy agencies to institute the necessary infrastructure to
effectively implement the monitoring program for large systems. Furthermore, the TCEQ recommends
that the
Comment Response for the LT2ESWTR 11-38 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Response: See Response 1200.c.
EPA Letter ID: 591
Comment ID: 12119
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Ohio EPA believes the early implementation requirements for water systems serving 10,000
or more persons are burdensome and unrealistic. We recommend that at least twelve months be provided
for large systems to submit an initial source water monitoring plan and eighteen months to begin
monitoring. For systems wishing to use previously collected data, at least twelve months should be
provided to submit the data with supporting documentation to U.S. EPA for approval. Other compliance
deadlines should be adjusted accordingly.
Response: See Responses 1200.C, 1200.h, and 1200.J.
EPA Letter ID: 591
Comment ID: 12120
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Ohio EPA believes the early implementation requirements for water systems serving 10,000
or more persons are burdensome and unrealistic. We recommend that at least twelve months be provided
for large systems to submit an initial source water monitoring plan and eighteen months to begin
monitoring. For systems wishing to use previously collected data, at least twelve months should be
provided to submit the data with supporting documentation to U.S. EPA for approval. Other compliance
deadlines should be adjusted accordingly.
Response: See Responses 1200.C, 1200.h, and 1200.J.
EPA Letter ID: 601
Comment ID: 13015
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 371 1. Reporting large system results directly to EPA
and role of States
Comment: This need for states and water systems to work together to address deviations from
monitoring plans and missed samples is another example of the need to delay microbial monitoring by 18
months. Without such a delay, many Utah water
Response: See Responses 371(C) and 1200.c.
Comment Response for the LT2ESWTR 11-39 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 601
Comment ID: 13030
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Comments on compliance schedule.
The requirement that large systems must submit a sampling schedule to EPA within 3 months after
promulgation of the LT2ESWTR seems unreasonable when compared to compliance for the Stage 2
D/DBPR. Utah recommends delaying the schedule for microbial monitoring by 18 months. This would
apply to all deadlines for both large system Cryptosporidium monitoring and small system indicator and
Cryptosporidium monitoring. Utah is suggesting this delay to allow states ample time to work with water
systems to assess current levels of treatment (e.g., whether the system provides 5.5 log of treatment for
Cryptosporidium) as well as assisting large systems in developing an acceptable Cryptosporidium
monitoring plan (including both monitoring location(s) and a sampling schedule).
Response: See Responses 1200.c and 1200.h.
EPA Letter ID: 609
Comment ID: 14114
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Large public water supply systems (populations >10,000) will be required to submit
monitoring plans for samples collected from source water for Cryptosporidium, E. coli, and turbidity
three months after rule promulgation. Monitoring must then commence six months later. We believe this
is insufficient time for a water system to coordinate sampling schedules for Cryptosporidium with
certified laboratories. In addition, surface water treatment plants have historically used total coliform to
measure relative pollution in source water. Quantification using E. coli or fecal coliform will require time
for laboratories to establish procedures or purchase additional equipment. The USEPA should delay
source water monitoring for large supplies by an additional 18 months.
Response: See Responses 1200.C, 1200.g, and 1200.h.
EPA Letter ID: 609
Comment ID: 14118
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Laboratory Issues
We have concern with the current laboratory capacity for Cryptosporidium monitoring. The MDEQ's
Environmental Laboratory, for one, is considering seeking certification for Cryptosporidium analysis.
However, large water systems are forced to make monitoring location and sampling date commitments to
the USEPA three months after rule promulgation. Implementation decisions this soon may not allow time
Comment Response for the LT2ESWTR 11-40 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
for laboratories seeking certification to meet the large water system monitoring requirements. Again, the
USEPA should delay source water monitoring for large supplies an additional 18 months to allow
laboratories and surface water plants time to coordinate sampling protocols. As an alternative, the USEPA
Response: See Responses 1200.g and 1200.h.
EPA Letter ID: 637
Comment ID: 13103
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: District comments on compliance schedule.
The requirement that large systems must submit a sampling schedule to EPA within 3 months after
promulgation of the LT2ESWTR is unreasonable. The deadline for sampling and reporting should be
extended until the primacy agencies can achieve primacy. This reduces the burden on water systems to
make the transition from reporting to EPA then to States at a later date. Utah recently went through an
experience with this transition and it is an unreasonable excessive burden to place on systems. It also
presented an additional burden on the system to bring EPA personnel to an appropriate understanding of
the system. This knowledge already exists with the State. This is a wasteful use of system resources to be
forced to deal with EPA on a temporary basis.
Response: See Responses 1200.c and 1200.h.
EPA Letter ID: 643
Comment ID: 12720
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: * The state-preferred approach would be that EPA delay Cryptosporidium monitoring for
large systems by 18 months (beyond the proposed timeframe) to allow for state-water system interaction
to determine appropriate monitoring locations and ensure adequate laboratory capacity is available. This
delay would also provide states time to develop data systems for large system Cryptosporidium results
and allow for traditional water system-to-state reporting instead of requiring direct reporting to EPA
(which could result in savings to laboratories since many laboratories have established reporting
mechanisms to the state and development of a new reporting mechanism to EPA could require additional
programming). States could then share Cryptosporidium results with EPA as needed. Such a delay would
result in an equivalent delay in large system compliance (compliance would be achieved 7.5 years after
rule promulgation instead of 6 years as proposed).
Response: See Responses 1200.c and 1200.h.
EPA Letter ID: 643
Comment ID: 12723
Comment Response for the LT2ESWTR 11-41 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: * Many states believe that adequate laboratory capacity to support large system
Cryptosporidium monitoring six months after rule promulgation will not be available. Although the state-
preferred approach (an 18-month delay as described in the previous bullet) would likely address this
issue, some states have indicated that they would support a staggered approach for large system
Cryptosporidium monitoring (possibly in two or three stages) to address a lack of adequate laboratory
capacity. However, as explained under the state-preferred approach in the previous bullet, EPA would
need to ensure that changing to a staggered approach does not result in an unacceptably large number of
systems being required to monitor for Cryptosporidium at the same time.
While states recognize that the number of systems in each size category would directly impact the
breakpoints, one staggered approach would be:
[SEE TABLE, P. 12 (OF 42) IN PDF]
This staggered approach would extend the deadline for large system compliance beyond the proposed
deadline of 6 years, but ultimately bring all large surface water systems into compliance by the latest
compliance deadline in the proposed rule (the 8.5 year deadline for small surface water systems that are
required to perform Cryptosporidium monitoring).
Some states expressed concern that a staggered approach could be problematic from a data management
standpoint and urge EPA to consider this aspect if a staggered approach is considered.
Response: See Responses 1200.c and 1200.h.
EPA Letter ID: 647
Comment ID: 12882
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 365 2. Submitting monitoring plan (date and location)
Comment: Based on the foregoing discussion, MDE recommends the following approach for
implementing the LT2ESWTR:
- Require systems to submit a microbial monitoring plan three months before monitoring is required to
begin.
- Stagger Cryptosporidium monitoring for large systems over three phases:
[SEE TABLE, P. 9 (OF 32) IN PDF]
Response: See Responses 365, 1200.h, and 1200.C.
EPA Letter ID: 660
Comment ID: 14082
Comment Response for the LT2ESWTR 11-42 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
F. Compliance Schedules
(pages 47719-47722)
Compliance Schedule
The requirement that large systems must submit a sampling schedule to EPA within three months after
promulgation of the LT2ESWTR seems rushed. Because of potential problems with Cryptosporidium
laboratory capacity, it may take much longer than three months for a utility to get a contract with a
laboratory. Consideration should be given to extending the deadline for sampling and reporting.
Compliance for all systems should be delayed until the States
Response: See Responses 1200.c and 1200.h.
EPA Letter ID: 662
Comment ID: 14042
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
F. Compliance Schedules
(pages 47719-47722)
EPA requests comments on compliance schedule.
The requirement that large systems must submit a sampling schedule to EPA within 3 months after
promulgation of the LT2ESWTR totally ignores the laboratory capacity issues as well as the reporting
software issues. State primacy is also
Response: See Responses 1200.C, 1200.h, and 1200.g.
EPA Letter ID: 673
Comment ID: 13996
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
F. Compliance Schedules
(pages 47719-47722)
Comment Response for the LT2ESWTR 11-43 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Jordan Valley Water comments on the proposed compliance schedule.
The requirement that large systems must submit a sampling schedule to EPA within 3 months after
promulgation of the LT2ESWTR seems unreasonable when compared to compliance for the Stage 2
D/DBPR. Consideration should be given to extending the deadline for sampling and reporting.
Compliance for all systems should be
Response: See Responses 1200.c and 1200.h.
EPA Letter ID: 675
Comment ID: 13966
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: Section IV.F: Compliance Schedules
The State of Minnesota suggests EPA modify the implementation schedules included in the proposed
rules. EPA should limit or eliminate any LT2ESWTR and Stage 2 DBPR deadlines for water system
activity and states- enforceable activities within the first two years following rule promulgation.
We recommend that EPA modify requirements of microbial monitoring at both large and small water
systems. The State of Minnesota recommends a staged approach similar to that developed by ASDWA,
which would stagger Cryptosporidium monitoring for large systems over three phases. We also
recommend EPA modify
Response: See Responses 1200.b and 1200.C.
EPA Letter ID: 688
Comment ID: 14735
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Preamble Pg 47666
Sampling Schedule (14.70(a)(l)) - Large systems must submit a sampling schedule
within three months after promulgation of the rule. This may not be enough time to develop a sample
schedule for a large system. Arrangements will need to be made with a laboratory to do this work and
there will probably be only a limited number of labs capable of providing service. In Missouri-s case, the
state will be required by law to provide this service and organizing the schedules of our systems will be
difficult in 3 months. Six months would be the preferred time period to allow adequate time to plan the
monitoring.
Response: See Responses 1200.c and 1200.h.
Comment Response for the LT2ESWTR 11-44 December 2005
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11.3 Comment Code 1220, Small System Monitoring and Treatment
Individual Comments on Code 1220
EPA Letter ID: 466
Comment ID: 11016
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: ND supports the use of E. coli as an indicator for small system monitoring. We are concerned
that the final rule needs to address adequate timing for these systems to budget for Cryptosporidium
monitoring and contract with a laboratory for analysis. The proposed six month window for this activity is
inadequate. Small systems in ND that need to monitor for Cryptosporidium will need at least one year to
secure funding. ND agrees small systems should be allowed the option of monitoring for
Cryptosporidium instead of monitoring for the indicator
bacteria E. coli.
Response: See Response 1200.k.
EPA Letter ID: 528
Comment ID: 12247
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Small System Activities
We support the use of indicator monitoring for small systems, and are concerned that the final rule needs
to include adequate timing for small systems to prepare. The six-month window included in the proposed
rule may not be adequate. Some systems that must monitor for Cryptosporidium will most likely need
more time.
Response: See Response 1200.k.
EPA Letter ID: 585
Comment ID: 11958
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: small systems. For small systems, the proposed bi-weekly, 12-month Cryptosporidium
monitoring schedule accelerates sampling costs for systems that are least capable of affording it and
increases the number of erroneously low bin classifications when compared to the monthly, 24-month
sampling schedule being implemented for large systems.
Response: See Response 1200.d.
Comment Response for the LT2ESWTR 11-45 December 2005
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EPA Letter ID: 585
Comment ID: 11993
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: program for large systems. Furthermore, the TCEQ recommends that the implementation
schedule for small systems be adjusted so that the initial round of required Cryptosporidium monitoring
begin three months after the end of the initial round of large system monitoring and to allow small
systems to utilize a 24-month Cryptosporidium monitoring cycle.
Response: See Responses 1200.d and 1200.C.
EPA Letter ID: 601
Comment ID: 13031
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: microbial monitoring by 18 months. This would apply to all deadlines for both large system
Cryptosporidium monitoring and small system indicator and Cryptosporidium monitoring. Utah is
suggesting this delay to allow states ample
Response: See Responses 1200.c and 1200.k.
EPA Letter ID: 647
Comment ID: 12867
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: health protection. MDE suggests a delay in microbial monitoring for small water systems, and
coordination of Initial Distribution System Evaluation concept and compliance monitoring.
Response: See Responses 1200.c and 1200.k.
EPA Letter ID: 675
Comment ID: 13968
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: Section IV.F: Compliance Schedules
The State of Minnesota suggests EPA modify the implementation schedules included in the proposed
rules. EPA should limit or eliminate any LT2ESWTR and Stage 2 DBPR deadlines for water system
activity and states- enforceable activities within the first two years following rule promulgation.
Comment Response for the LT2ESWTR 11-46 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
We recommend that EPA modify requirements of microbial monitoring at both large and small water
systems. The State of Minnesota recommends a staged approach
monitoring for Cryptosporidium monitoring. Also, the six-month window for indicator monitoring at
small systems is not adequate. The Minnesota Department of Health and its Laboratory request
reasonable time to budget for Cryptosporidium sampling and, if necessary, to contract with another
laboratory for analysis.
Response: See Responses 1200.C, 1200.L and 1200.b.
EPA Letter ID: 688
Comment ID: 14741
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Page 47722 (141.701(e))
The time periods associated with bin assignment and compliance with additional
treatment requirements for small systems are the same as those proposed for large systems. The small
systems will definitely need more time to install treatment after their bin assignment. It is unlikely that a
small system will have any previous Cryptosporidium data due to the high cost of monitoring. Therefore
they will have no indication of their possible treatment needs until the required monitoring is completed.
This prevents them from planning ahead and getting an earlier start on treatment plant modifications or
other actions. Small systems also have a more difficult time obtaining funding for system improvements
and will need additional time to acquire grants or loans to finance improvement projects. We would
suggest that small systems have a total of five years after the completion of Cryptosporidium monitoring
before treatment technique requirements would be enforced. This would be done by adding 18 months to
the time period for installing treatment or other measures.
Response: See Response 1200.b.
11.3.1 Comment Code 1221, Lag Between Large and Small System
Monitoring
Individual Comments on Code 1221
EPA Letter ID: 444
Comment ID: 10814
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment: a. EPA should allow adequate time from the end of the monitoring period for Crypto and E
Coli for large systems and the initiation of small system monitoring for E Coli to draw valid conclusions
about the relationship of E Coli and Crypto. The states will need substantial technical background, based
on the full 24 months of large system monitoring results, to evaluate the need for alternate trigger values.
Comment Response for the LT2ESWTR 11-47 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Response: See Response lOO.u and 1200.1.
EPA Letter ID: 458
Comment ID: 10982
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Page 47722 - monitoring time table between large systems and small systems - It appears
that there will be approximately 12 months from the completion of the large system testing to the
completion of the small system testing. Is this adequate time for EPA to assess the data collected and
modify the regulations via the Federal Register? EPA would be in a better position to determine if the
time is adequate. The twelve month time period is based on the assumption that laboratory analysis
methods would not change, and no small system begins sampling early. It may be in the best interest of
not setting standards for the smaller systems in the initial rules, in order to allow adequate time to
evaluate e-coli cutoff values, laboratory methods, etc. and modify the required dates at a later time, if this
is acceptable within the federal timetables and guidelines.
Response: See Response 1200.1.
EPA Letter ID: 485
Comment ID: 11331
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Response: While EPA proposes that they will be analyzing data during the LWS sampling period to try
and determine trigger values that would require SWS to conduct Cryptosporidium sampling following
their one year of E. Coli monitoring,
the Department believes that a one year separation between the time the LWS
complete monitoring and the SWS start their E. coli monitoring would be beneficial. This would give
EPA additional time to try and confirm the E. coli/Cryptosporidium relationship. This could result in
reducing the number of SWS that will be required to monitor for Cryptosporidium, thereby resulting in
saving significant costs for SWS.
Response: See Response 1200.1.
EPA Letter ID: 520
Comment ID: 11570
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA is also concerned that extensive gaps between Cryptosporidium sampling at large and
small systems may undermine maintaining analyst proficiency and assuring adequate laboratory capacity.
Comment Response for the LT2ESWTR 11-48 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
IEPA believes that evenly spreading Cryptosporidium monitoring over the implementation schedule will
support proficiency and capacity.
Response: See Response 1200.c.
EPA Letter ID: 528
Comment ID: 12245
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Extensive gaps between Cryptosporidium sampling at large and small systems may
undermine maintaining analyst proficiency and assuring adequate laboratory capacity. It will also place a
burden on our implementation of the rule. Spreading Cryptosporidium monitoring evenly over the
implementation schedule will support proficiency and capacity.
Response: See Response 1200.c.
EPA Letter ID: 536
Comment ID: 11784
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Colorado is also concerned that extensive gaps between Cryptosporidium sampling at large
and small systems may undermine maintaining analyst proficiency and assuring adequate laboratory
capacity. Colorado believes that evenly spreading Cryptosporidium monitoring over the implementation
schedule will support proficiency and capacity.
Response: See Response 1200.c.
EPA Letter ID: 548
Comment ID: 12180
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: The proposed compliance schedule does not leave any time for EPA or the States to review
the results of the source water monitoring data of large systems and make possible changes to the E. coli
levels that will trigger monitoring of Cryptosporidium by small systems. Metropolitan believes that
a time window of three to six months between the end of large system monitoring and the beginning of
small system monitoring may be adequate to conduct this evaluation.
Response: See Response 1200.1.
Comment Response for the LT2ESWTR 11-49 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 585
Comment ID: 11990
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: 4) There is an 18-month window between the Cryptosporidium sampling at large and small
systems that should be avoided in order to maintain analyst proficiency and assure adequate laboratory
capacity.
Response: See Response 1200.c.
EPA Letter ID: 586
Comment ID: 12194
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 330 C. Use of E. coli as trigger for Crypto monitoring
Comment: We would first like to say that we appreciate the extended compliance timeframe and phased
monitoring approach proposed for small treatment systems. Using
Response: See Response lOOa.
EPA Letter ID: 591
Comment ID: 12135
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment U.S. EPA is proposing to delay small system E. coli monitoring until results are
obtained from large system Cryptosporidium monitoring. After the large system Cryptosporidium results
are available, U.S. EPA may then refine the levels of E. coli which will trigger Cryptosporidium
monitoring for the small systems. If the timeline of the rule is changed to allow 18 months for
implementation in accordance with the early implementation comment from ASDWA, Ohio EPA
recommends requiring the small systems to monitor for E. coli concurrently with the large systems so the
data will be available for use once a decision is made on the appropriate trigger level. The extra year
gained by having the small systems monitor early could be added to the time allowed for these systems to
install additional treatment if necessary. This may help more systems comply with the LT2ESWTR rule.
Ohio EPA recommends that the trigger levels for E. coli for streams, lakes, and GWUDIs should not be
determined until all of the large system E. coli and Cryptosporidium data is collected and analyzed. As
stated in the General
Response: See Responses 1200.c and 1200.1.
Comment Response for the LT2ESWTR 11-50 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 603
Comment ID: 12680
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47719) Section IV. F. Compliance Schedules
As noted in the proposed rule, the implementation schedule does not leave any time between the
completion of large system monitoring and the start of small system monitoring. It is recommended that a
6 months break between large and small system monitoring be included in the final rule to allow
adjustments to the E. coli thresholds as appropriate and for State to understand that impacts on large
systems before proceeding with monitoring for small systems.
Response: See Response 1200.1.
EPA Letter ID: 641
Comment ID: 13605
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47722 RFC - (Compliance Schedules) Time Window Between Large and Small Systems
- The proposed window of between large and small systems is appropriate and should be maintained.
Extending the window would allow additional data re alternative triggers, but would results in a
disjointed rule, potentially jeopardizing uninterrupted laboratory service.
Response: See Response 1200.c.
EPA Letter ID: 643
Comment ID: 12712
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States are also concerned that extensive gaps between Cryptosporidium sampling at large and
small systems may undermine maintaining analyst proficiency and assuring adequate laboratory capacity.
States believe that evenly spreading Cryptosporidium monitoring over the implementation schedule will
support proficiency and capacity.
Response: See Response 1200.c.
EPA Letter ID: 645
Comment ID: 13559
Commenter: Kathy Moriarty, Water Quality Manager, Bangor Water District
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 11-51 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Comment: F. Compliance Schedules [pp. 47719-47722]
Request for
Comment: Time window between large and small system
Monitoring
Suggested Comments:
It has not yet been determined if there is a direct correlation between the presence of E. coli and
Cryptosporidium in a water source. Large systems will be monitoring for both. Time is needed to collect
and interpret this data to see if there is a correlation before small systems start their monitoring period
collecting E. coli data. Additional time should be allowed at the end of a large system monitoring period
for Cryptosporidium and E. coli in order to show that there is in fact a correlation. Thousands of small
systems will be spending scant resources monitoring for a pathogen that may be useless in determining
Cryptosporidium presence.
Response: See Response 1200.1.
EPA Letter ID: 675
Comment ID: 13970
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: during that time. The proposed extensive gaps between Cryptosporidium sampling at large
and small systems may undermine maintaining analyst proficiency and risk inadequate laboratory
capacity. Spreading Cryptosporidium monitoring over the implementation schedule will support
proficiency and capacity. Furthermore, properly staged microbial monitoring will fulfill EPA-s goal of
evaluating initial large system monitoring results in order to determine the need for refinements to the
E.coli trigger levels.
Response: See Responses 1200.c and 1200.1.
EPA Letter ID: 678
Comment ID: 14715
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 11. The EPA requests comment on whether an additional time window between the end of
large system monitoring and the beginning of small system monitoring is appropriate and, if so, how long
such a window should be. [47722, C2]
Comment: The proposed compliance schedule does not leave enough time for the EPA or the States to
review the results of the source water monitoring data of large systems and make possible changes to the
E. coli levels that will trigger monitoring of Cryptosporidium by small systems. A time window of three
to six months between the end of large system monitoring and the beginning of small system monitoring
may be adequate to conduct this evaluation.
Response: See Response 1200.1.
Comment Response for the LT2ESWTR 11-52 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
EPA Letter ID: 688
Comment ID: 14742
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Time Window Between Large and Small System Monitoring (141.701(e))
There needs to be adequate time for EPA to evaluate the results of large system
Cryptosporidium and E. coli monitoring before small systems are required to start monitoring. We feel at
least 6 months should be allowed even though that means small system monitoring, bin classification and
treatment might be delayed. All this special monitoring will be difficult for small systems and EPA needs
to be sure that the monitoring scheme being set up in the rule for small systems is adequate before they
start to monitor. The worst case would be wasting small system effort on an inadequate monitoring plan
that would have to be redone later with the resulting waste of limited resources.
Response: See Response 1200.1.
11.4 Comment Code 1230, Schedule for Consecutive Systems, Stage
2DBPR
Individual Comments on Code 1230
EPA Letter ID: 458
Comment ID: 10983
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Implementation schedule for consecutive systems - This should be consistent between both
rules. The recommendation is to make it clear in the rules that the population for a system is based on the
combined distribution system population when determining monitoring requirements.
Response: See Response 1200.e.
EPA Letter ID: 472
Comment ID: 11180
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: -Implementation Schedule for Consecutive Systems
Small systems that supply water to a larger system should comply on the large system schedule.
Comment Response for the LT2ESWTR 11-53 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
Response: See Response 1200.e.
EPA Letter ID: 485
Comment ID: 11332
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Response: Since the impact of the LT2ESWTR monitoring requirements on SWS
will be significant, the Department suggests that some incentive be offered to the SWS meeting the above
criteria to encourage them to achieve compliance early. Perhaps, some assistance could be provided by
the involved LWS to help the SWS in their sampling effort. Without such assistance, there would be little
incentive for the SWS to make an effort to conduct the early sampling. Unless some assistance is
provided, the Department would not recommend that the SWS be required to conduct early pathogen
monitoring or make treatment change based on the same schedule as the LWS.
Response: See Response 1200.e.
EPA Letter ID: 562
Comment ID: 12340
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3.2.3 Simultaneous Compliance with Stage 2 DBPR
As proposed, the rule schedule reflects simultaneous compliance with the Stage 2 DBPR. AWWA
believes that this pairing is critical to the risk-risk balance between DBP and microbial contaminant
control. AWWA supports the agency-s continued pairing of requirements during initial monitoring and
assessment provisions (i.e., source water monitoring and initial distribution system assessment) and final
compliance with MCLs and treatment technique requirements.
Response: See Response 1200.m.
11.5 Comment Code 1240, Uncovered Finished Water Reservoirs
Individual Comments on Code 1240
EPA Letter ID: 704
Comment ID: 14801
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 6. Section 141.701.h. Compliance date for uncovered finished water reservoirs.
The rule requires that facilities using uncovered reservoirs comply with the uncovered reservoir
requirements within 36 months of rule promulgation. Three years may not be sufficient for design and
Comment Response for the LT2ESWTR 11-54 December 2005
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Chapter 11: Compliance Schedules Comment Codes 1200-1250
construction time for replacement tanks or covers, particularly for large reservoirs. A two year extension
can be requested per Section IV. F. b. We believe that the compliance period for complying with
uncovered finished water storage requirements should be extended to five years to allow ample time for
compliance.
Response: See Response 1200.n.
11.6 Comment Code 1250, Rule Language Edits
Individual Comments on Code 1250
EPA Letter ID: 504
Comment ID: 11357
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: Not only will utilities be adding requirements of the LT2 rule to their existing activities, but
they will be further challenged with the concurrent implementation of the S2DBP rule. The critical IDSE
component of that rule must be completed on a schedule that demands development of sampling plan,
submittal, approval, and implementation within the 6-month period following promulgation simultaneous
with the LT2 rule.
Utilities will be faced with the problem of managing constructive regulatory interchange under significant
time pressure with unfamiliar federal agency staff having little or no prior knowledge or experience with
the systems and facilities for which they will be asked to make critical decisions. The EPA Regional
Office staff (presumably) will be faced with a one-time exceptional workload imposed by the need to
provide meaningful review and approval of the sampling plan required for LT2 BIN monitoring and
concurrently the IDSE sampling plans. These will be submitted within 3-months of the date of
simultaneous LT2 and S2 promulgation. Utilities must begin LT2 BIN monitoring within 3-months of
plan submittal. It is almost inconceivable that EPA will be equipped to respond in a manner approaching
what would be provided were state primacy agencies formally authorized. An EPA alternative under such
circumstances would be to use contract assistance. Such personnel would be further removed from normal
primacy agency interaction with utilities. Such recourse would be unacceptable.
Response: See Response 1200.c.
EPA Letter ID: 603
Comment ID: 12646
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47777) Section 141.701(e)-
Compliance Requirements Table -
It may be possible for those systems that read only this table for compliance deadlines to miss the
sampling schedule requirements. Therefore, we recommend that the sampling schedule requirements
under §141.703(a) be included in this table and §141.703(a) be modified appropriately.
Response: See Response 1200.o.
Comment Response for the LT2ESWTR 11-55 December 2005
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12. Public Notification : Comment Codes 1300-1340
12.1 Comment Code 1300, Public Notification
Response to Code 1300
a. Today's rule does not modify existing regulations for reporting monitoring results in Consumer
Confidence Reports. EPA regularly updates guidance for CCR reporting to address new regulations. As
necessary, EPA will update CCR guidance to address requirements established under the LT2ESWTR.
b. Under today's rule, systems achieve Cryptosporidium treatment credit for microbial toolbox options on
a monthly basis by meeting the design, operational, and/or performance criteria specified in the rule.
Today's rule states that a treatment technique violation occurs during any month when a system fails to
achieve treatment credit through microbial toolbox options that is at least equal to the required treatment
level (i.e., bin treatment requirement). This violation requires a Tier 2 public notice. The violation
consequences apply until the system meets the required treatment level. The rule allows systems to use
different toolbox technologies in different months to meet the required treatment level. EPA does not
agree with commenters who suggested that compliance for Bin 2 should be treated more leniently than for
Bins 3 and 4. While the total treatment requirement for Bin 2 is lower than for higher bins, EPA regards
the prescribed level of treatment for systems in this bin as the minimum necessary for protection of public
health. Consequently, today's rule requires systems to meet the treatment requirements of their bin
classification every month.
c. EPA agrees with commenters that the purpose of public notice is to inform the public about the
performance of their water system in meeting applicable regulations to provide safe water. Violations that
may result in serious risks to public health from short-term exposure are addressed by Tier 1 public notice
requirements, which today's rule does not establish. Tier 2 and 3 public notice requirements address risks
to public health that may occur over a longer period through failure of water systems to meet required
treatment and monitoring standards.
Today's rule establishes Tier 2 public notice requirements for violating treatment technique requirements,
as well as failing to report bin classification or at least 3 Cryptosporidium samples, and Tier 3 PN
requirements for remaining monitoring and reporting violations. EPA does not believe that a Tier 1 notice
is necessary for violations of the treatment technique requirements of today's rule. These requirements are
designed to reduce annual risks from Cryptosporidium and other pathogens to consumers. The Agency
does not consider such a violation to present an acute health risk to most consumers (i.e., a violation of
the LT2ESWTR would not by itself indicate an outbreak risk). This approach is consistent with existing
regulations. However, under existing public notice regulations (40 CFRpart 141 subpart Q), States have
the authority to elevate the tier of a public notice for a particular violation either in their regulations or on
a case-by-case basis.
Today's rule is not establishing new health effects language. EPA believes that existing health effects
language appropriately characterizes the risks from microbial pathogens like Cryptosporidium that the
LT2ESWTR addresses.
Today's rule does not give States the authority to reduce the Tier of a public notice. Specifically, States
cannot decide that a Tier 3 notice or no public notice is appropriate for a treatment technique violation.
Comment Response for LT2ESWTR 12-1 January 2006
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Chapter 12: Public Notification Comment Codes 1300-1340
EPA believes that treatment technique requirements relate directly to public health protection and,
therefore, the public should be informed under a Tier 2 notice schedule when the water system violates a
treatment technique requirement. This will serve to inform the public of potential risks in a timely
manner. Not only is this approach consistent with existing regulations, it maintains national consistency
with respect to regulatory stringency.
d. Consistent with existing regulations, failure by a water system to comply with any applicable
monitoring or treatment technique requirement of today's rule triggers public notice requirements.
However, in the case cited by one commenter, if a system is unable to report a sampling schedule
electronically, today's rule specifies that the system may use an alternative approach for submitting the
sampling schedule that EPA approves.
Individual Comments on Code 1300
EPA Letter ID: 441
Comment ID: 10779
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Consumer Confidence Report (CCR) requirements
EPA needs to specify how systems should report source water
Cryptosporidium monitoring results in their CCR.
Response: See Response 1300.a.
EPA Letter ID: 499
Comment ID: 10725
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1310 A. Tier 2 Notice for Treatment Violations
Comment: 9. KDHE supports the public-s right to know about the quality of its water and the risks
posed by violations of drinking water standards. KDHE concurs that the Public Notification Rule and the
Consumer Confidence Report Rule are the appropriate vehicles to provide this information, and that the
proposed Tier 2 and Tier 3 violations are consistent with the tiers established in the Public Notification
Rule. KDHE also supports EPA-s determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11602
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Comment Response for the L T2ESWTR 12-2 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Public Right-to-Know
IEPA supports the public's right to know about the quality of its water and the risks posed by violations of
drinking water standards. IEPA concurs that the Public Notification Rule and the Consumer Confidence
Report Rule are the appropriate vehicles to provide this information and that the proposed Tier 2
Response: See Response 100.a.
EPA Letter ID: 520
Comment ID: 11653
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA supports the public's right to know about the quality of its water and the risks posed by
violations of drinking water standards. IEPA concurs that the Public Notification Rule and the Consumer
Confidence Report Rule are the appropriate vehicles to provide this information and that the proposed
Tier 2
Response: See Response lOO.a.
EPA Letter ID: 536
Comment ID: 11806
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Public Right-to-Know
Colorado supports the public-s right to know about the quality of its water and the risks posed by
violations of drinking water standards. We concur that the Public Notification Rule and the Consumer
Confidence Report Rule are the appropriate vehicles to provide this information and that the proposed
Tier 2 and Tier 3 violations are consistent with the Tiers established in the Public Notification Rule.
Colorado also supports EPA-s determination that no new health effects language for microbial
contaminants is needed.
Response: See Response lOO.a.
EPA Letter ID: 562
Comment ID: 12531
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the L T2ESWTR 12-3 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
Comment: 4.2.15 Microbial Toolbox- Maintaining Compliance
The LT2ESWTR and associated guidance manuals have not directly or completely addressed important
issues regarding requirements for maintaining a microbial toolbox credit, once awarded, nor the
consequences of not being able to meet one of the requirements for a specific credit for a short time
period (i.e., one month). The regulatory consequences of violation of the requirements for a microbial
toolbox credit probably will entail a Tier 2 (30-day) notice. The final rule preamble and guidance should
address the following questions:
1. How to identify or define when a violation occurs, and 2. Once a violation occurs, how long should
consequences apply.
In order to ensure compliance many utilities will identify log credits greater than that actually required by
the LT2ESWTR. Therefore, if one toolbox component does not perform adequately, and the associated
log credit is not achieved, there is an extra 0.5- to 1.0-log credit -in reserve.- An example utility on a
New England lake needs to achieve 2-log credit to comply with the LT2ESWTR. This utility employs
ozone, but may have difficult meeting CT in the coldest parts of the winter. The utility might employ the
CFE and WCP tools to ensure a -reserve- of 0.5- to 1.0-log credits. The compliance algorithm for the
LT2ESWTR should allow utilities to employ such proactive management techniques to ensure ongoing
compliance.
Response: See Response ISOO.b.
EPA Letter ID: 595
Comment ID: 12595
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Section IV.G Public Notice Requirements (pages 47722-47723)
Maine supports EPA on this particular matter.
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12754
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Public Right-to-Know
States support the public-s right to know about the quality of its water and the risks posed by violations of
drinking water standards. States concur that the Public Notification Rule and the Consumer Confidence
Report Rule are the appropriate vehicles to provide this information and that the proposed Tier 2 and Tier
3 violations are consistent with the Tiers established in the Public Notification Rule. States also support
EPA-s determination that no new health
Comment Response for the L T2ESWTR 12-4 December 2005
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Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12808
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States support the public-s right to know about the quality of its water and the risks posed by
violations of drinking water standards. States concur that the Public Notification Rule and the Consumer
Confidence Report Rule are the appropriate vehicles to provide this information and that the proposed
Tier 2 and Tier 3 violations are consistent with the Tiers established in the Public Notification Rule.
States also support EPA-s determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 647
Comment ID: 12943
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Section IV.G Public Notice Requirements (pages 47722-47723)
MDE supports the public-s right to know about the quality of its water and the risks posed by violations
of drinking water standards. MDE concurs that the Public Notification Rule and the Consumer
Confidence Report Rule are the appropriate vehicles to provide this information and that the proposed
Tier 2 and Tier 3 violations are consistent with the Tiers established in the Public Notification Rule. MDE
also supports EPA-s determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 647
Comment ID: 12949
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Public Right-to-Know
MDE supports the public-s right to know about the quality of its water and the risks posed by violations
of drinking water standards. MDE concurs that the Public Notification Rule and the Consumer
Confidence Report Rule are the appropriate vehicles to provide this information and that the proposed
Tier 2 and Tier 3 violations are consistent with the Tiers established in the Public Notification Rule. New
health effects language for microbial contaminants is needed.
Response: See Response lOO.a.
Comment Response for the L T2ESWTR 12-5 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
EPA Letter ID: 688
Comment ID: 14743
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Page 47723 - Public Notice Requirements
Missouri feels the proposed public notice requirements are reasonable and appropriate.
Response: See Response lOO.a.
12.2 Comment Code 1310, Tier 2 Notice for Treatment Violations
Individual Comments on Code 1310
EPA Letter ID: 457
Comment ID: 11903
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Public Right-to-Know
We support the public-s right to know about the quality of its water and the risks posed by violations of
drinking water standards. We concur that the Public Notification Rule and the Consumer Confidence
Report Rule are the appropriate vehicles to provide this information and that the proposed Tier 2 and Tier
3 violations are consistent with the Tiers established in the Public Notification Rule. We also support
EPA-s determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 457
Comment ID: 11945
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Section IV.G Public Notice Requirements (pages 47722-47723)
We support the public-s right to know about the quality of its water and the risks posed by violations of
drinking water standards. We concur that the Public Notification Rule and the Consumer Confidence
Report Rule are the appropriate vehicles to provide this information and that the proposed Tier 2 and Tier
Comment Response for the LT2ESWTR 12-6 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
3 violations are consistent with the Tiers established in the Public Notification Rule. We also support
EPA-s determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 470
Comment ID: 11094
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Public Notice Requirements pp. 47722-47723
Vermont agrees that a Tier 2 public notice and the proposed health effects language are appropriate.
Response: See Response lOO.a.
EPA Letter ID: 472
Comment ID: 11181
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: The COP agrees that Tier 2 public notice is appropriate for violations in this area. The health
effects language as developed under the IESWTR is appropriate.
Response: See Response lOO.a.
EPA Letter ID: 485
Comment ID: 11333
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Response: Regarding Public Notice Requirements, the Department urges USEPA to
give states the authority to determine the appropriate level of public notice to be distributed to insure that
public health is protected. Tier 2 public notices should NEVER be used as a punitive measure—the
function of public notices is to provide health-related information to the public so that they may make
informed decisions regarding drinking the water, i.e., notices are intended to address the public "right-to-
know" .
In some cases of treatment technique violations, the specific details of the water system and situation may
clearly demonstrate that public health is not at risk and the distribution of a Tier 2 notice could confuse
the public. Public health protection is not well-served when notices are issued that do not directly serve to
protect public health, because such notices tend to undermine the overall credibility of public notices in
Comment Response for the LT2ESWTR 12-7 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
general. The local regulatory agency is best equipped to evaluate a water system's treatment technique
violation to determine how best to protect public health.
Response: See Response 1300.c.
EPA Letter ID: 488
Comment ID: 11857
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4.4.2 Combined Filter Performance The Combined Filter Effluent 0.5 log credit requires that
95% of CFE turbidity measurements (maximum 4 hour readings), on a monthly basis, remain at or below
0.15NTU.
Comments Should a very extreme weather event or other anomaly cause this limit to be exceeded in a
single month (in the 0.15-0.3 NTU range) it is questionable whether triggered public notifications would
be appropriate. Given the lack of a demonstrated health threat associated with an intermittent violation of
the applicable LT2 toolbox item(s), a Tier 1 violation would be wholly inappropriate. The assumptions
underlying the risk evaluation conducted for this rulemaking involve huge uncertainties including lack of
any demonstrated endemic cryptosporidiosis risk. Public notices creating the appearance of an acute
health risk that has not been established would be counterproductive. The EPA needs to make this very
clear to Primacy agencies including clarification of the very different objectives behind the LT2 and
IESWTR (or LT1R).
Response: See Responses 1300.b and 1300.C.
EPA Letter ID: 488
Comment ID: 11874
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Given the lack of a demonstrated health threat associated with an intermittent violation of the
applicable LT2 toolbox item(s) a Tier 1 violation would be wholly inappropriate. The assumptions
underlying the risk evaluation conducted for this rulemaking involve huge uncertainties including lack of
any data showing the presence of endemic cryptosporidiosis. Thus, public notices creating the appearance
of an acute health risk would be inappropriate, couterproductive, and potentially harmful. The EPA needs
to make this very clear to Primacy agencies including clarification of the very different objectives behind
the LT2 and IESWTR (or LT1R).
Response: See Response 1300.c.
EPA Letter ID: 493
Comment ID: 11242
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment Response for the L T2ESWTR 12-8 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
Comment: 40 CFR 141.700 states that -Failure to comply with any requirement of this subpart is a
violation and requires public notification.- Is this really true? Is it really necessary to require public
notification for any violation of the subpart? I would think that public notification should be limited to
monitoring, analytical, MCLs, MRDLs, treatment technique violations, variances, exemptions, or any
special public notices required as per the public notification requirements specified under 40 CFR
141.201(a). For example, if a system fails to submit its sampling schedule to EPA electronically as per 40
CFR 141.703(a)(l), will the PWS be then required to issue public notice of such violation?
Response: See Response 1300.d.
EPA Letter ID: 499
Comment ID: 10725
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1300 IX. Public Notification
Comment: 9. KDHE supports the public-s right to know about the quality of its water and the risks
posed by violations of drinking water standards. KDHE concurs that the Public Notification Rule and the
Consumer Confidence Report Rule are the appropriate vehicles to provide this information, and that the
proposed Tier 2 and Tier 3 violations are consistent with the tiers established in the Public Notification
Rule. KDHE also supports EPA-s determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11603
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: appropriate vehicles to provide this information and that the proposed Tier 2 and Tier 3
violations are consistent with the Tiers established in the Public Notification Rule. IEPA also supports
EPA's determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11654
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment Response for the L T2ESWTR 12-9 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
Comment: appropriate vehicles to provide this information and that the proposed Tier 2 and Tier 3
violations are consistent with the Tiers established in the Public Notification Rule. IEPA also supports
EPA's determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 548
Comment ID: 12181
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Metropolitan agrees with EPA in requiring a Tier 2 public notice for violations of additional
treatment requirements for Cryptosporidium and a Tier 3 public notice for violations of monitoring and
testing requirements under the LT2ESWTR. Metropolitan believes that the health effects language
Response: See Response 1300.c.
EPA Letter ID: 560
Comment ID: 14994
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Violations
The proposed LT2 requires a Tier 2 Public Notice for violations, and 40 CFR 141 allows primacy
agencies to elevate such a violation to a Tier 1 Public Notice. This enforcement action is reasonable for
utilities that flout the law and do not implement UV disinfection (or an LT2 toolbox alternative) to
provide additional Cryptosporidium inactivation if warranted by the source water monitoring results.
However, it is not a reasonable enforcement action for utilities that implement UV disinfection but
temporarily exceed the off-spec limit. A public notice or Boil Water advisory does not serve the public
health, especially when:
- All other aspects of a surface water treatment plant continue to operate in
accordance with the original SWTR and the LT1ESWTR
- The off-spec condition merely encroaches on the safety factors of the RED
Comment Three - UV Disinfection System Location:
Response: See Responses 1300.c and 910.J.
EPA Letter ID: 562
Comment ID: 12532
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 12-10 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
Comment: 4.3 Public Notice Provisions
EPA has correctly characterized violations of the additional treatment requirements for Cryptosporidium
under the LT2ESWTR as subject to Tier 2 public notice requirements. The PNR language was changed to
accommodate the provisions of the IESWTR with respect to Cryptosporidium. No additional changes are
needed at this time.
Response: See Response lOO.a.
EPA Letter ID: 591
Comment ID: 12136
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: Comment
Ohio EPA agrees this should be a Tier 2 violation.
Response: See Response lOO.a.
EPA Letter ID: 601
Comment ID: 13035
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on whether the violations for additional treatment requirements for
Cryptosporidium under the LT2ESWTR should require a Tier 2 public notice and whether the proposed
health effects language is appropriate.
Utah agrees that the Consumer Confidence Report is an appropriate method to provide the public with
information. Utah also agrees that the proposed Tier 2 public notice for violations of additional treatment
requirements and Tier 3 public notice for monitoring violations are reasonable. It is also recommended
Response: See Responses 100.a and 1300.C.
EPA Letter ID: 637
Comment ID: 13104
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on whether the violations for additional treatment requirements for
Cryptosporidium under the LT2ESWTR should require a Tier 2 public notice and whether the proposed
health effects language is appropriate.
Public Notification requirements should be kept to a reasonable lever. An example of an inappropriate
level of public notification would be to require a system who was relying on credit from the watershed
Comment Response for the LT2ESWTR 12-11 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
control program in the toolbox to send out a notice to the public of the health hazards of Crypo just
because a committee that was an integral component of their watershed protection plan dissolved. There
is no additional health risk from this event and unnecessarily inflaming the public is unwarranted. The
level of public notification should be left up to the discretion of the primacy agency.
Response: See Responses ISOO.b and ISOO.c.
EPA Letter ID: 643
Comment ID: 12755
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: and the risks posed by violations of drinking water standards. States concur that the Public
Notification Rule and the Consumer Confidence Report Rule are the appropriate vehicles to provide this
information and that the proposed Tier 2 and Tier 3 violations are consistent with the Tiers established in
the Public Notification Rule. States also support EPA-s determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12809
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: and the risks posed by violations of drinking water standards. States concur that the Public
Notification Rule and the Consumer Confidence Report Rule are the appropriate vehicles to provide this
information and that the proposed Tier 2 and Tier 3 violations are consistent with the Tiers established in
the Public Notification Rule. States also support EPA-s determination that no new health
Response: See Response lOO.a.
EPA Letter ID: 647
Comment ID: 12944
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: risks posed by violations of drinking water standards. MDE concurs that the Public
Notification Rule and the Consumer Confidence Report Rule are the appropriate vehicles to provide this
information and that the proposed Tier 2 and Tier 3 violations are consistent with the Tiers established in
the Public Notification Rule. MDE also supports EPA-s determination that no new health
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 12-12 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
EPA Letter ID: 647
Comment ID: 12950
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: risks posed by violations of drinking water standards. MDE concurs that the Public
Notification Rule and the Consumer Confidence Report Rule are the appropriate vehicles to provide this
information and that the proposed Tier 2 and Tier 3 violations are consistent with the Tiers established in
the Public Notification Rule. New health effects language for microbial contaminants is
Response: See Response lOO.a.
EPA Letter ID: 662
Comment ID: 14044
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
G. Public Notice Requirements (pages 47722-47723)
EPA requests comment on whether the violations for additional treatment requirements for
Cryptosporidium under the LT2ESWTR should require a Tier 2 public notice and whether the proposed
health effects language is appropriate.
Any treatment violations should be addressed in the Consumer Confidence Reports. Tier 2 public notices
are appropriate.
Response: See Response 1300.c.
EPA Letter ID: 668
Comment ID: 13891
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: Public Notice Should be Tier 1 for Acute Threats, Such as Failure of Inactivation
A violation of the substantive requirements of the LT2ESWTR (such as a failure to inactivate Crypto in a
high risk system) certainly should be a Tier 1 Public Notice, since it poses obvious and immediate public
health risks, such as a Crypto outbreak (p. 47723-24)
Response: See Response 1300.c.
Comment Response for the LT2ESWTR 12-13 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
EPA Letter ID: 668
Comment ID: 13905
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: - A violation of the substantive requirements of the LT2ESWTR (such as a failure to
inactivate Crypto in a high risk system) certainly should be a Tier 1 Public Notice, since it poses obvious
and immediate public health risks, such as a Crypto outbreak (p. 47723-24)
Response: See Response 1300.c.
EPA Letter ID: 673
Comment ID: 13998
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
G. Public Notice Requirements (pages 47722-47723)
EPA requests comment on whether the violations for additional treatment requirements for
Cryptosporidium under the LT2ESWTR should require a Tier 2 public notice and whether the proposed
health effects language is appropriate.
Jordan Valley Water agrees that the Consumer Confidence Report is an appropriate method to provide the
public with information.
Jordan Valley Water agrees that the proposed Tier 2 public notice for violations of additional treatment
requirements and Tier 3 public notice for monitoring violations are reasonable.
Response: See Response lOO.a.
12.3 Comment Code 1320, Health Effects Language
Individual Comments on Code 1320
EPA Letter ID: 457
Comment ID: 11904
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Notification Rule. We also support EPA-s determination that no new health effects language
for microbial contaminants is needed.
Comment Response for the LT2ESWTR 12-14 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
Response: See Response lOO.a.
EPA Letter ID: 457
Comment ID: 11946
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Notification Rule. We also support EPA-s determination that no new health effects language
for microbial contaminants is needed.
Response: See Response lOO.a.
EPA Letter ID: 499
Comment ID: 10726
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: Notification Rule. KDHE also supports EPA-s determination that no new health effects
language for microbial contaminants is needed.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11604
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Notification Rule. IEPA also supports EPA's determination that no new health effects
language for microbial contaminants is needed.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11655
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Notification Rule. IEPA also supports EPA's determination that no new health effects
language for microbial contaminants is needed.
Comment Response for the LT2ESWTR 12-15 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
Response: See Response lOO.a.
EPA Letter ID: 528
Comment ID: 12265
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Public Right-to-Know
We also support EPA-s determination that no new health effects language for microbial contaminants is
needed.
Response: See Response lOO.a.
EPA Letter ID: 548
Comment ID: 12182
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: under the LT2ESWTR. Metropolitan believes that the health effects language is appropriate
for the protection of public health and consumer right-to-know provisions of the 1996 SDWA
Amendments.
Response: See Response lOO.a.
EPA Letter ID: 601
Comment ID: 13036
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: public notice for monitoring violations are reasonable. It is also recommended that no new
health effects language is needed at this time.
Response: See Response lOO.a.
EPA Letter ID: 618
Comment ID: 13251
Commenter: Craig Bryant, Director, Chesterfield County Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 12-16 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
Comment: 2. Presentation of Health Effects Data
When presenting health effects data, the EPA should add perspective to the data presented to prevent
undue alarm or concern among those reviewing the information. There are numerous examples of
substances or practices in use today that make secant reductions in human disease and death rates through
alleviation of various disease agents or threats while in turn presenting their own unique health related
issues far less significant than ones they eliminate. Examples of these might be medicines, herbicides and
pesticides and quite possibly conventional water treatment.
Health effects data should be presented with appropriate emphasis and perspective relative to
significance.
Response: See Response 1300.c.
EPA Letter ID: 643
Comment ID: 12756
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Notification Rule. States also support EPA-s determination that no new health effects
language for microbial contaminants is needed.
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12810
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Notification Rule. States also support EPA-s determination that no new health effects
language for microbial contaminants is needed.
Response: See Response lOO.a.
EPA Letter ID: 647
Comment ID: 12945
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Notification Rule. MDE also supports EPA-s determination that no new health effects
language for microbial contaminants is needed.
Response: See Response lOO.a.
Comment Response for the LT2ESWTR 12-17 December 2005
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Chapter 12: Public Notification Comment Codes 1300-1340
EPA Letter ID: 647
Comment ID: 12951
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Notification Rule. New health effects language for microbial contaminants is needed.
Response: See Response 1300.c.
EPA Letter ID: 673
Comment ID: 13999
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: Jordan Valley Water recommends that no new health effects language is needed at this time.
Response: See Response lOO.a.
12.4 Comment Code 1340, Guidance
Individual Comments on Code 1340
EPA Letter ID: 488
Comment ID: 11873
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4.6 Maintaining Toolbox Compliance The LT2ESWTR and associated guidance manuals
have not directly or completely addressed important issues with respect to requirements for maintaining a
microbial toolbox credit, once awarded, and consequences of not being able to meet one of the
requirements for a specific credit for a short time period (i.e., one month). The regulatory consequences of
violation of the requirements for a microbial toolbox credit probably will entail a Tier 2 (30-day) notice.
The question, however, becomes how to identify or define when a violation occurs, and once it occurs,
how long should consequences apply. Obviously this is an enormous concern for utilities as they face
decisions about toolbox choices and the level of redundancy that will be needed to reliably ensure
continuous compliance. We support comments put forth on this issue by the AWWA.
Response: Response 1300.b.
Comment Response for the LT2ESWTR 12-18 December 2005
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13. Variances and Exemptions : Comment Codes 1400-1420
13.1 Comment Code 1400, Variances and Exemptions
Response to Code 1400
a. SDWA section 1416(a) specifies that a State may grant an exemption from a treatment technique
requirement only if the exemption will not result in an unreasonable risk to health. As described in the
proposed LT2ESWTR, EPA believes that granting an exemption to the Cryptosporidium treatment
requirements of the LT2ESWTR would result in an unreasonable risk to public health. Cryptosporidium
causes acute health effects, which may be severe in sensitive subpopulations like infants, the elderly, and
the immunocompromised. The treatment requirements of the LT2ESWTR are targeted to higher risk
systems, and EPA believes that the level of treatment required under the rule is the minimum necessary to
protect public health. Consequently, EPA has concluded that exemptions to the LT2ESWTR should not
be allowed.
Some commenters suggested that water systems should be allowed to operate under an exemption to the
LT2ESWTR and avoid an unreasonable risk to public health by taking steps to protect sensitive
subpopulations (e.g., providing bottled water). EPA does not believe that such an approach is likely to be
practical or effective. A water system would not have the information or resources to identify all sensitive
individuals (some sensitive persons will be unaware of their own immune status) and to ensure that all
such individuals do not directly consume tap water.
b. SDWA section 1415 specifies two provisions under which general variances to treatment technique
requirements may be granted:
(1) A State that has primacy may grant a variance to a PWS from any requirement to use a specified
treatment technique for a contaminant if the PWS demonstrates to the satisfaction of the State that the
treatment technique is not necessary to protect public health because of the nature of the PWS's raw water
source. EPA may prescribe monitoring and other requirements as conditions of the variance (section
(2) EPA may grant a variance from any treatment technique requirement upon a showing by any person
that an alternative treatment technique not included in such requirement is at least as efficient in lowering
the level of the contaminant (section 1415(a)(3)).
EPA does not believe that the first variance provision is applicable to filtered PWSs under today's rule.
Filtered PWSs are required to implement additional treatment under the LT2ESWTR only when source
water monitoring demonstrates higher levels of Cryptosporidium contamination. Thus, this treatment
technique requirement accounts for the nature of the PWS's raw water source. Unfiltered PWS treatment
requirements also account for the nature of a PWS's raw water source with respect to whether 2- or 3-log
Cryptosporidium inactivation is required.
In theory, the first variance provision could be applied to the requirement that all unfiltered PWSs provide
at least 2-log Cryptosporidium inactivation. If an unfiltered PWS could show a raw water
Cryptosporidium level 3-log lower than the Bin 1 cutoff for filtered PWSs (i.e., below 0.075
oocysts/1,000 L), this could demonstrate that no treatment for Cryptosporidium is necessary. The
unfiltered PWS would already be achieving public health protection against Cryptosporidium equivalent
Comment Response for LT2ESWTR 13-1 January 2006
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
to filtered PWSs due to the nature of the raw water source.
In practice, EPA has not identified an approach that is economically or technologically feasible for a PWS
to demonstrate such a low level of Cryptosporidium to support granting a variance. This is due to the
extremely large volume and number of samples that would be necessary to make such a demonstration
with confidence. However, unfiltered PWSs may choose to pursue the development and implementation
of monitoring programs to apply for a variance from Cryptosporidium inactivation requirements based on
the nature of the raw water source. A sufficient monitoring program may be feasible in site-specific
circumstances or with the use of innovative approaches.
The second provision for granting a variance is not applicable to the LT2ESWTR because the rule
provides broad flexibility in how PWSs achieve the required level of Cryptosporidium reduction through
the microbial toolbox. Moreover, the microbial toolbox contains an option for Demonstration of
Performance, under which States can award treatment credit based on the demonstrated efficiency of a
treatment process in reducing Cryptosporidium levels. Thus, there is no need for this type of variance
under the LT2ESWTR.
SDWA section 1415(e) describes small PWS variances, but these cannot be granted for a treatment
technique for a microbial contaminant. Hence, small PWS variances are not allowed for the LT2ESWTR.
c. Today's rule does not withdraw or modify any existing criteria for avoiding filtration under 40 CFR
141.71. Accordingly, unfiltered systems must continue to comply with all existing filtration avoidance
criteria. EPA believes these criteria help to ensure that watershed protection provides a microbial barrier
in those systems that do not filter. EPA did not propose any modifications to the existing filtration
avoidance criteria and received no new information in public comment on the proposed rule that would
warrant such modifications.
Further, today's rule does not establish any new criteria for filtration avoidance. In the proposed
LT2ESWTR, EPA indicated that compliance with DBP standards under the Stage 2 DBPR would be
incorporated into the criteria for filtration avoidance. However, EPA has not done this in today's final rule
in order to give States more flexibility in working with unfiltered systems to comply with the Stage 2
DBPR. Thus, Stage 2 DBPR provisions will not impact filtration avoidance status of unfiltered supplies.
Individual Comments on Code 1400
EPA Letter ID: 101
Comment ID: 10924
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: NRWA believes that USEPA should proceed to define defensible URTH levels and
implement the variance provisions of Sec. 1415 and the exemption provisions of Sec. 1416 consistent
with the intent of the SDWA.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 101
Comment ID: 10925
Comment Response for the LT2ESWTR 13-2 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: NRWA supports the State's right to determine implementation, variances, exemptions and
compliance with drinking water rules.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 101
Comment ID: 10927
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Rationale: A wide variety of regulatory concerns are covered by these policies.
Key arguments driving these policies are:
- What constitutes an "acceptable risk" is an important consideration in regulatory decision making
(Cohen 2001), but because of differences in risk perceptions, competing risks and agency policies,
assessing risks against a single acceptable limit is not appropriate. Rather flexibility should be
provided to account for differences in risk perceptions and abilities to pay for risk avoidance.
- The concept of thresholds in dose response to contaminants is a major factor in development of
contaminant limits, but Bull (2001) points out that trying to prove or disprove the existence of such
thresholds for many contaminants is not an appropriate use of resources, because of the extremely large
animal populations required.
- Currently, variance and exemptions for water systems may only be issued upon a finding that an
unreasonable risk to health (URTH) will not occur if the variance or exemption is implemented. By intent,
the SDWA defines URTH levels as protective of public health. USEPA has had difficulty in establishing
appropriate URTH levels and this has been a barrier to the proper implementation of SDWA Sec. 1415
and 1416. NRWA is currently funding a white paper effort to examine the issues associated with URTH
and how such values might be established.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 488
Comment ID: 11875
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4.8 Variances and Exemptions PWD supports the AWWA-s position that the primacy
agencies should be given the flexibility to provide variances or exemptions from the monitoring and
treatment requirements under the LT2ESWTR. Sections 1415 and 1416 of the SDWA clearly vest those
states that have primary enforcement responsibility with the initial determination as to whether variances
or exemptions should be granted. This initial discretion, however, is carefully circumscribed by the Act in
that numerous conditions must be met before a state can exercise its authority. For example, in the case of
an exemption, there must be proven, among other things, that compelling factors exist, that expeditious
compliance schedules are in place, that no unreasonable risk to public health exists, etc. Further
Comment Response for the LT2ESWTR 13-3 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
restraining the state-s discretion are public hearing provisions as well as EPA-s ultimate veto power.
The SDWA, therefore, sets up a structure where states have the initial duty, responsibility and authority to
grant variances and exemptions and may only do so under certain very limited and controlled
circumstances. This ensures that federal standards may only be deviated from in unusual circumstances
and then only for limited periods of time.
Such a structure makes perfect sense. No regulation, no matter how carefully or well conceived, can
anticipate every possible unique factual situation that could arise. Every regulation needs some flexibility,
albeit carefully controlled flexibility, to allow for the myriad of unique situations that can arise.
The LT2ESWTR, as proposed, removes this very valuable and necessary flexibility found in the SDWA.
On the variance side it makes the legal conclusion that the conditions for the granting of a variance can
not be established since both source water and alternative treatment techniques are already accounted for
under the rule. Regarding exemptions, it draws the scientific conclusion that granting an exemption would
result in an unreasonable risk to health.
It would be fair to say that these conclusions are subject to debate. For example, if a PWS has high
concentrations of crypto in its source water, yet at the same time has robust public health and
epidemiological evidence showing no historic outbreaks of cryptosporidiosis from drinking water, can it
be fairly said that granting an exemption in this case would provide an unreasonable risk to health?
The real issue here is not whether the EPA-s rationales supporting the elimination of variances and
exemptions are right or wrong. Rather, it is whether it-s appropriate for EPA to make such broad
sweeping conclusions on a national basis as opposed to states looking carefully at individual factual
circumstances and then drawing conclusions subject to EPA oversight?
The SDWA recognized that these type of findings and conclusions are best left with the states to
determine under the carefully prescribed conditions set forth in the Act. EPA is, of course, still free to
exercise its discretion on a case by case basis. This tailored approach, as envisioned by the SDWA, is far
more flexible and practical than the rule as proposed which eliminates all flexibility and consideration of
unique circumstances by the states. We, therefore, believe, that exemptions and variances should be
allowed within the LT2ESWTR.
Response: See Responses 1400. a and 1400.b.
EPA Letter ID: 516
Comment ID: 11708
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 5) Provide a variance or exemption allowance Variances and exemptions should not be
prohibited under LT2 or under the earlier surface water treatment rule.
Response: See Responses 1400.a and 1400.b.
Comment Response for the LT2ESWTR 13-4 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
EPA Letter ID: 516
Comment ID: 11732
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: In addition, DEP feels that the characterization of cryptosporidiosis as causing "acute health
effects, which may be severe in sensitive subpopulations and include the risk of mortality" is not a
balanced and fair description. Specifically, as is stated in EPA's analysis, most cases of cryptosporidiosis
result in mild gastrointestinal symptoms (in fact EPA considers that most people who become ill do not
consider themselves sufficiently ill to seek any sort of medical treatment, and thus they are not detectable
under even the most sensitive health surveillance systems). It is interesting to note that one of the reasons
that it is so difficult to assess whether drinking water results in gastrointestinal illness is that there is such
a high baseline of GI illness in the population from all causes (travel, food, person-to-person contact,
etc.), yet GI illness does not appear to be one of the top concerns of the public health community. Also,
while DEP fully acknowledges the potentially severe consequences of cryptosporidium exposure for
sensitive populations (DEP has aided the NYC Department of Health and Mental Hygiene over the years
to educate its HIV/AIDS population on this topic), it is conceivable that, in certain circumstances, or at
least for certain restricted periods of time, that a more reasonable/economical alternative means of
protecting the sensitive subpopulation may be available than compliance with the specific LT2 treatment
requirement in question. For example, if a system is having difficulty achieving the required crypto log
inactivation for a period and rectification of the problem will unavoidably take some time, a reasonable
solution might be for that system to operate under a variance or exemption temporarily, and that
provisions for bottled water could be made to serve persons in sensitive subpopulations (and this
population appears to be those with advanced AIDS). While this solution may sound unusual, it might be
determined to be the most appropriate and reasonable one, and fully protective of public health. Also, it is
important to consider that any monies spent by a municipality for projects such as water treatment plant
construction or operation, means money that is taken away from other critical needs, like HIV/AIDS
education, and other public health programs. Again, all we are saying is that there should be some
flexibility for alternative compliance strategies, where warranted, as long as public health is adequately
protected.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 516
Comment ID: 11733
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Though NYC is committed to installing treatment to meet the 2 log cryptosporidium
inactivation requirements of the proposed LT2 rule, NYC does have some concerns with regard to
consistent compliance with the LT2, and specifically with the Filtration Avoidance Criteria of the 1989
Surface Water Treatment Rule which are carried forth under the proposed LT2. As described in our
comment #1 above, DEP has major concerns with regard to the continued strict adherence to the 1989
SWTR Filtration Avoidance Criteria, which is currently proposed under LT2. While it is our firm belief
that the 1989 Filtration Avoidance Criteria should be deleted or modified as discussed in #1 above, in the
very unfortunate case that this goal can not be achieved, there should, at a minimum, be the possible
allowance for a variance or exemption for certain types of minor violations. While DEP has consistently
met all of the Avoidance Criteria since the SWTR became effective, and DEP intends to continue to meet
these criteria, DEP feels that some flexibility and/or discretion should be permitted under these rules. By
Comment Response for the LT2ESWTR 13-5 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
2007, NYC will have invested over $1 Billion on watershed protection for SWTR compliance, and under
LT2 will be investing an estimated $600 Million for UV treatment. Given these huge financial
commitments, there must be some provision for a minor and/or temporary exceedance of one of the
Filtration Avoidance Criteria (e.g., a minor exceedance of the raw water turbidity standard, or an
exceedance of the DBF regulations), so that such an exceedance does not automatically and unavoidably
trigger filtration.
Response: See Responses 1400.a, 1400.b, 1400.C, and2510.a.
EPA Letter ID: 516
Comment ID: 11734
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: As EPA is fully aware, there is a difficult task now before the drinking water industry ~ that
is to reduce both microbial risk and disinfection byproduct risk, in addition to meeting other NPDW
Regulations, while insuring system reliability and security, and while at the same time, keeping drinking
water rates at a reasonable level, such that obtaining water from the local municipal supply does not a
present an undue financial burden for customers. Meeting all of these objectives can be a difficult
balancing act, therefore it is essential that provisions be made for flexibility and application of discretion.
This brings us to another example of a NYC concern, involving the balancing of DBP risks and system
reliability, and relating to the City's Third Water Tunnel project. This tunnel is being constructed at the
cost of approximately $6 Billion, and the purpose is to improve infrastructure reliability. Analysis has
recently indicated that, at least during the period of project completion, NYC may experience DBP levels
above the recently proposed levels (under the D/DBP2 rule) in certain areas. The somewhat elevated DBP
levels would result from increased water age, which would occur until the new tunnel is fully completed,
projected for the year 2020, at which time one of the other tunnels to be taken out of service and the water
aging problem will be reduced. DEP is concerned that under the rules as proposed, a DBP violation
resulting from this tunnel construction project would count as a violation of the 1989 SWTR Filtration
Avoidance Criteria, and thus would automatically trigger filtration. DEP believes it is consistent with the
intent of the SDWA to allow primacy agencies to grant exemptions for systems that experience MCL
compliance problems as a result of efforts to improve system reliability, depending on the magnitude and
frequency of exceedances of the DBP rule, the ability of the System to come into compliance via
operational changes and other means, and the long-term projections for water quality (after the
infrastructure improvements have been realized).
In summary, DEP is not asking for a variance from the log removal requirement for unfiltered systems,
only that there be the option of variances and exemptions, under limited circumstances, and at the
discretion of the primacy agency.
Response: See Responses 1400.b, 1400.c, and 1400.a.
Comment Response for the LT2ESWTR 13-6 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
13.2 Comment Code 1410, Proposal Not to Permit Variances
Individual Comments on Code 1410
EPA Letter ID: 101
Comment ID: 10908
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Variance and Exemptions
EPA should embrace the variance provision for unfiltered systems. Systems with strong source water
protection plans and other measures in place to protect against cryptosporidium contamination should be
granted a variance for providing comparable public health protection without additional inactivation. EPA
has assumed that this is not technologically or economically feasible because they believe that an
extremely large number of samples would be necessary to make this determination. This directly opposes
the Safe Drinking Water Act which specifically instructs EPA to issue variances. EPA recognizes in the
proposed rule that a variance is possible but the approach outlined in the proposed rule, does not even
allow the option. EPA must allow this variance provision to be an option for systems and allow them to
make the decision whether it is in their best interest ("economically or technically") to adopt the variance
- This is what the Act requires.
Response: See Response 1400.b.
EPA Letter ID: 457
Comment ID: 11901
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Variances and Exemptions
We concur that variances and exemptions should not be allowed under the LT2ESWTR for the reasons
listed. We do not like to use variance provisions of the SDWA because of the potential public perception
that a standard different than the one Federally promulgated is acceptable and defensible. We also do not
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 470
Comment ID: 11095
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1420 B. Proposal Not to Permit Exemptions
Comment Response for the LT2ESWTR 13-7 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
Comment: Variances and Exemptions pp. 47726-47724
Vermont is in support of not granting variances and exemptions to the requirements of this rule.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 485
Comment ID: 11334
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Response: The Department agrees with EPA-s decision regarding the non-
eligibility
for variances for systems of any size associated with the LT2ESWTR.
Exemption
EPA has previously established the criteria for granting an exemption to any
treatment technique included in the SDWA. One of the criteria is for a finding that the issuance of the
exemption will not result in an unreasonable risk to health. EPA believes that granting an exemption to
the Cryptosporidium treatment requirements of the LT2ESWTR would result in an unreasonable risk to
health. Cryptosporidium causes acute health effects, which may be severe in sensitive subpopulations and
include risk of mortality.
Response: See Response 1400.a.
EPA Letter ID: 492
Comment ID: 11239
Commenter: Anonymous492,, City of Walla Walla Public Works/Water Division
Commenter Category: Regulated Community (Utilities)
Comment: any potential small reduction in risk. Some allowance should be made for communities where
the risk of upstream contamination is limited, to elect to negotiate, on a case by case basis, an exception to
the rule until such time as monitoring or an increase in incidence or an increase in risk indicates that
further protection is necessary.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 516
Comment ID: 11729
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 4) VARIANCES AND EXEMPTIONS
Variances and exemptions are important tools permitted under the Safe Drinking Water Act to allow for
Comment Response for the LT2ESWTR 13-8 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
flexibility and Primacy Agency discretion, under limited circumstances. However, EPA proposes under
the LT2ESWT Rule to exclude variances and exemptions. DEP feels strongly that variances and
exemptions should be permitted under the LT2 rule (and as well, under the 1989 Surface Water Treatment
Rule). Note that DEP is NOT asking for a variance or exemption from the basic cryptosporidium
inactivation requirement specified in LT2 for unfiltered systems, however DEP is suggesting that there
may be certain circumstances, for filtered and unfiltered systems, that a variance or exemption would be
appropriate, and that granting of such would not present an undue risk to public health. EPA's stated
reasons for exclusion of variances and exemptions under LT2, and DEP's argument against these reasons,
are provided below.
EPA lists one condition under which a primacy State may grant a variance from a specified treatment
technique to be a situation where the system demonstrates that the treatment technique is not necessary to
protect public health because of the nature of the system's raw water source. (In such case, EPA may
prescribe monitoring and other requirements as conditions of the variance.) EPA states its belief that this
reason for a variance is not applicable here because the LT2ESWTR cryptosporidium treatment technique
requirements account for the degree of source water contamination. This is true, however, this does not
take into account the fact that it is quite possible that a water system may develop scientific data, beyond
oocyst concentrations, which could assure public health protection at a treatment level lower than
specified by the rule. For example, it could potentially be determined that in a given watershed, all (or
most) of the oocysts detected are non-viable (e.g., due to environmental degradation), or that the vast
majority of oocysts are of a species that is not infectious to humans. Therefore DEP feels that the variance
option is appropriate, and should be made available.
Response: See Response 1400.b.
EPA Letter ID: 520
Comment ID: 11599
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Variances and Exemptions
IEPA concurs that variances and exemptions should not be allowed under the
LT2ESWTR for the reasons listed. IEPA has never used the variance provisions of the SDWA because of
the potential public perception that a different standard than the one Federally promulgated is acceptable
and defensible. IEPA has never used exemptions and prefer to use other mechanisms, such as Consent
Orders, in instances where water systems cannot achieve compliance in the required timeframe.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 520
Comment ID: 11656
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 13-9 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
Comment: Section IV.H Variances and Exemptions (page 47723-47724)
IEPA concurs that variances and exemptions should not be allowed under the
LT2ESWTR for the reasons listed. IEPA has never used the variance provisions of the SDWA because of
the potential public perception that a different standard than the one Federally promulgated is acceptable
and defensible. IEPA does not use exemptions and prefers to use other mechanisms, such as Consent
Orders, in instances where water systems cannot achieve compliance in the required timeframe.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 562
Comment ID: 12533
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 1420 B. Proposal Not to Permit Exemptions
Comment: 4.4 Variance and Exemptions
Variance and exemption avenues are included in most SWTR rules, but the proposed LT2ESWTR
forecloses the potential to apply for either. Given the agency-s handling of the microbial toolbox, the
microbial toolbox will likely not be an adequate substitute for including the variance and exemption
reports. The situation is even more acute for unfiltered supplies that have few alternatives in the microbial
toolbox. Primacy agencies should be given the flexibility to provide variances or exemptions from
monitoring and treatment requirements under the LT2ESWTR. A practical application of these provisions
might be oversight of unfiltered systems that are compliant under the LT2ESWTR but experience an
excursion under the SWTR. This issue also raises the issue of simultaneous compliance discussed by the
FACA. Ongoing compliance with DBP levels is a condition for filtration avoidance, so the possibility
exist that Stage 2 DBPR provisions, rather than the LT2ESWTR provisions, would impact Filtration
Avoidance status of unfiltered supplies. AWWA recommends that the agency extend relevant provisions
of the SWTR to the LT2ESWTR.
Response: See Responses 1400.a, 1400.b, and 1400.c.
EPA Letter ID: 595
Comment ID: 12596
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1420 B. Proposal Not to Permit Exemptions
Comment: Section IV.H Variances and Exemptions (page 47723-47724)
Maine concurs that variances and exemptions should not be allowed under the LT2ESWTR. The public
perceives any allowances outside the rule to be unfair or biased; therefore, variances and exemptions are
rarely used. When necessary, particularly in cases where a water system cannot attain compliance within
the timeframe specified by the primacy agency, Consent Orders are generally preferred.
Response: See Responses 1400.a and 1400.b.
Comment Response for the LT2ESWTR 13-10 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
EPA Letter ID: 643
Comment ID: 12751
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Variances and Exemptions
States concur that variances and exemptions should not be allowed under the LT2ESWTR for the reasons
listed. States have rarely, if ever, used the variance provisions of the SDWA because of the potential
public perception that a different standard than the one Federally promulgated is acceptable and
defensible. States generally do not use exemptions and prefer to use other
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 643
Comment ID: 12811
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section IV.H Variances and Exemptions (page 47723-47724)
States concur that variances and exemptions should not be allowed under the LT2ESWTR for the reasons
listed. States have rarely, if ever, used the variance provisions of the SDWA because of the potential
public perception that a different standard than the one Federally promulgated is acceptable and
defensible. States generally do not use exemptions and prefer to use other
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 647
Comment ID: 12904
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Variances and Exemptions
Variances and exemptions should not be allowed under the LT2ESWTR for the reasons listed. MDE
generally does not use exemptions and prefers to use other
Response: See Responses 1400.a and 1400.b.
Comment Response for the LT2ESWTR 13-11 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
13.2.1 Comment Code 1411, Unfiltered systems
Individual Comments on Code 1411
EPA Letter ID: 394
Comment ID: 10556
Commenter: Marian Rose, President, Croton Watershed Clean Water Coalition Inc.
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: The Croton Watershed Clean Water Coalition, Inc. (CWCWC) disagrees that granting an
exemption in cases where raw water Cryptosporidium levels are 3-log lower than the cutoff for bin 1 risk
category would result in an unreasonable risk to health ".
EPA's argument appears to be twofold. The first is that the technology does not exist to measure these
extremely low levels of Cryptosporidium without taking an unrealistically large number of samples. The
second is that such a procedure, if it were carried out, would be extremely expensive. In other words, EPA
's admission of its inability to measure such low concentrations is its only reason for advocating that these
should be reduced to 1/100 (2-log) of whatever unmeasurable value they may have. EPA does not offer
any argument based on science as to why the reduction should be 2-log rather than 1.5-log,or even 1-
log.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 516
Comment ID: 11731
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: EPA asks for comments in particular on the exclusion of the variance option in the case of
unfiltered systems. NYC opposes this exclusion particularly, and strongly requests that EPA modify this
exclusion. EPA indicates the theoretical possibility that an unfiltered system would determine its oocyst
levels to be considerably lower than those levels on which EPA based its LT2 analysis; however, EPA
then states that data that would be of relevance could not reasonably be obtained (due to economic or
technologic limitations). DEP disagrees with this analysis for the following reasons. First of all, though it
may be unlikely that a system could collect data indicating that its Cryptosporidium concentrations are
two or three logs below the values EPA used for the LT2 analysis, it may be feasible for a water system to
collect data indicating that its oocyst concentrations are one log lower, and thus only 1 log of inactivation
may be needed to achieve EPA's public health goal. (NYC's data at this time would not support such a
treatment reduction, however it is conceivable data from some other unfiltered systems might.) In
addition, there is the possibility, as described above, of data other than oocyst concentration (i.e., species
identification, oocyst viability analysis) which could provide assurance of adequate public health
protection, and thus a variance may be warranted.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 520
Comment ID: 11659
Comment Response for the LT2ESWTR 13-12 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA appreciates EPA's inclusion of discussion on the possible circumstances under which a
variance might be appropriate for unfiltered systems. IEPA supports EPA's determination that it is not
currently economically or technologically feasible for an unfiltered system to demonstrate raw water
Cryptosporidium levels that are 3 log lower than the cutoff for bin 1 for filtered systems and, thus, that it
is providing comparable public health protection without additional inactivation.
Response: See Response 1400.b.
EPA Letter ID: 562
Comment ID: 12534
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: treatment requirements under the LT2ESWTR. A practical application of these provisions
might be oversight of unfiltered systems that are compliant under the LT2ESWTR but experience an
excursion under the SWTR. This issue also
Response: See Response 1400.c and 2510.a.
EPA Letter ID: 643
Comment ID: 12814
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States appreciate EPA-s inclusion of discussion on the possible circumstances under which a
variance might be appropriate for unfiltered systems. States support EPA-s determination that it is not
currently economically or technologically feasible for an unfiltered system to demonstrate raw water
Cryptosporidium levels that are 3 log lower than the cutoff for bin 1 for filtered systems and, thus, that it
is providing comparable public health protection without additional inactivation.
Response: See Response 1400.b.
EPA Letter ID: 645
Comment ID: 13560
Commenter: Kathy Moriarty, Water Quality Manager, Bangor Water District
Commenter Category: Regulated Community (Utilities)
Comment: H. Variances and Exemptions [pp. 47726-47724]
Request for
Comment: Variances and Exemptions
Comment Response for the LT2ESWTR 13-13 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
Suggested Comments:
The decision if it is economically feasible for an unfiltered system to demonstrate that its water source
provides comparable protection without additional inactivation, must be a utility decision. The utility
should decide if spending money for more monitoring is desired versus the expenditure of millions of
dollars for unneeded additional treatment. EPA-s role should be to set the criteria that must be met and
not make financial decisions for the utility. EPA should propose to allow unfiltered systems to
demonstrate raw water
Cryptosporidium levels low enough to avoid inactivation requirements. The Bangor Water District-s
source of supply is an unfiltered surface water. It has a highly protected watershed. Ninety-eight percent
of the watershed is owned or controlled by the District. There is no boating, swimming, or fishing
allowed. All access roads to the source are gated and locked. The watershed is forested containing no
grazing animals. The District monitored Cryptosporidium monthly for 5 years in the raw and finished
water and never detected a confirmed oocyst. Highly protected and pristine sources may never detect
Cryptosporidium. If that were the case, millions of dollars would be spent on inactivating
Cryptosporidium that does not exist. The financial resources that would be spent to solve this non-existent
problem would better serve public health by being spent on upgrading distribution systems or other more
immediate needs that the water utilities are facing. Waiver criteria should be established and made
available for those utilities that can show that Cryptosporidium is not an issue with their source.
Response: See Response 1400.b.
13.3 Comment Code 1420, Proposal Not to Permit Exemptions
Individual Comments on Code 1420
EPA Letter ID: 457
Comment ID: 11902
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: than the one Federally promulgated is acceptable and defensible. We also do not use
exemptions, and prefer to use other mechanisms, such as Consent Orders, in instances where water
systems cannot achieve compliance in the required timeframe.
Response: See Response 1400.a.
EPA Letter ID: 457
Comment ID: 11947
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: We also support EPA-s determination that granting an exemption to the Cryptosporidium
treatment requirements of the LT2ESWTR would result in an unreasonable health risk due to the acute
Comment Response for the LT2ESWTR 13-14 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
health effects, which may be severe in sensitive subpopulations and include risk of mortality.
Response: See Response 1400.a.
EPA Letter ID: 470
Comment ID: 11095
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1410 A. Proposal Not to Permit Variances
Comment: Variances and Exemptions pp. 47726-47724
Vermont is in support of not granting variances and exemptions to the requirements of this rule.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 485
Comment ID: 11335
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Response: The Department agrees with EPA-s position regarding the non-
eligibility for exemptions for systems of any size associated with the LT2ESWTR.
Response: See Response 1400.a.
EPA Letter ID: 516
Comment ID: 11730
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 4) VARIANCES AND EXEMPTIONS
Variances and exemptions are important tools permitted under the Safe Drinking Water Act to allow for
flexibility and Primacy Agency discretion, under limited circumstances. However, EPA proposes under
the LT2ESWT Rule to exclude variances and exemptions. DEP feels strongly that variances and
exemptions should be permitted under the LT2 rule (and as well, under the 1989 Surface Water Treatment
Rule). Note that DEP is NOT asking for a variance or exemption from the basic cryptosporidium
inactivation requirement specified in LT2 for unfiltered systems, however DEP is suggesting that there
may be certain circumstances, for filtered and unfiltered systems, that a variance or exemption would be
appropriate, and that granting of such would not present an undue risk to public health. EPA's stated
reasons for exclusion of variances and exemptions under LT2, and DEP's argument against these reasons,
are provided below.
- With regard to exemptions, EPA states its belief that "granting an exemption to the Cryptosporidium
treatment requirements of the LT2ESWTR would result in an unreasonable risk to
health....Cryptosporidium causes acute health effects, which may be severe in sensitive subpopulations
and include risk of mortality." While DEP shares EPA's commitment to public health protection, DEP
Comment Response for the LT2ESWTR 13-15 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
takes issue with these statements. First of all, it is possible, as described above, that further scientific
examination could, in some cases, reveal that public health is not at risk to the degree suggested by oocyst
presence (e.g., if oocysts are not viable or not infectious). Secondly, there is still a significant degree of
uncertainty about whether current oocyst levels in typical US drinking waters are resulting in any
endemic illness, and if so, at what level (see our discussion of "Overestimation of Risk" above, including
the discussion of the findings of the Melbourne study and the Davenport study, where no reduction in GI
illness was observed in the groups that received enhanced drinking water treatment).
Response: See Response 1400.a and 100.r and 600.b.
EPA Letter ID: 520
Comment ID: 11600
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA concurs that variances and exemptions should not be allowed under the
LT2ESWTR for the reasons listed. IEPA has never used the variance provisions of
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 520
Comment ID: 11601
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: than the one Federally promulgated is acceptable and defensible. IEPA has never used
exemptions and prefer to use other mechanisms, such as Consent Orders, in instances where water
systems cannot achieve compliance in the required timeframe.
Response: See Response 1400.a.
EPA Letter ID: 520
Comment ID: 11657
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA concurs that variances and exemptions should not be allowed under the
LT2ESWTR for the reasons listed. IEPA has never used the variance provisions of
Response: See Responses 1400.a and 1400.b.
Comment Response for the LT2ESWTR 13-16 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
EPA Letter ID: 520
Comment ID: 11658
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: use exemptions and prefers to use other mechanisms, such as Consent Orders, in instances
where water systems cannot achieve compliance in the required timeframe.
Response: See Response 1400.a.
EPA Letter ID: 520
Comment ID: 11660
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA also supports EPA's determination that granting an exemption to the
Cryptosporidium treatment requirements of the LT2ESWTR would result in an unreasonable health risk
due to the acute health effects, which may be severe in sensitive subpopulations and include risk of
mortality.
Response: See Response 1400.a.
EPA Letter ID: 562
Comment ID: 12533
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 1410 A. Proposal Not to Permit Variances
Comment: 4.4 Variance and Exemptions
Variance and exemption avenues are included in most SWTR rules, but the proposed LT2ESWTR
forecloses the potential to apply for either. Given the agency-s handling of the microbial toolbox, the
microbial toolbox will likely not be an adequate substitute for including the variance and exemption
reports. The situation is even more acute for unfiltered supplies that have few alternatives in the microbial
toolbox. Primacy agencies should be given the flexibility to provide variances or exemptions from
monitoring and treatment requirements under the LT2ESWTR. A practical application of these provisions
might be oversight of unfiltered systems that are compliant under the LT2ESWTR but experience an
excursion under the SWTR. This issue also raises the issue of simultaneous compliance discussed by the
FACA. Ongoing compliance with DBP levels is a condition for filtration avoidance, so the possibility
exist that Stage 2 DBPR provisions, rather than the LT2ESWTR provisions, would impact Filtration
Avoidance status of unfiltered supplies. AWWA recommends that the agency extend relevant provisions
of the SWTR to the LT2ESWTR.
Response: See Responses 1400.a, 1400.b, and 1400.c.
Comment Response for the LT2ESWTR 13-17 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
EPA Letter ID: 595
Comment ID: 12596
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1410 A. Proposal Not to Permit Variances
Comment: Section IV.H Variances and Exemptions (page 47723-47724)
Maine concurs that variances and exemptions should not be allowed under the LT2ESWTR. The public
perceives any allowances outside the rule to be unfair or biased; therefore, variances and exemptions are
rarely used. When necessary, particularly in cases where a water system cannot attain compliance within
the timeframe specified by the primacy agency, Consent Orders are generally preferred.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 643
Comment ID: 12752
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States concur that variances and exemptions should not be allowed under the LT2ESWTR for
the reasons listed. States have rarely, if ever, used the
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 643
Comment ID: 12753
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: defensible. States generally do not use exemptions and prefer to use other mechanisms, such
as Consent Orders, in instances where water systems cannot achieve compliance in the required
timeframe.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 643
Comment ID: 12812
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States concur that variances and exemptions should not be allowed under the LT2ESWTR for
the reasons listed. States have rarely, if ever, used the
Comment Response for the LT2ESWTR 13-18 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 643
Comment ID: 12813
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: defensible. States generally do not use exemptions and prefer to use other mechanisms, such
as Consent Orders, in instances where water systems cannot achieve compliance in the required
timeframe.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 643
Comment ID: 12815
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States also support EPA-s determination that granting an exemption to the Cryptosporidium
treatment requirements of the LT2ESWTR would result in an unreasonable health risk due to the acute
health effects, which may be severe in sensitive subpopulations and include risk of mortality.
Response: See Response 1400.a.
EPA Letter ID: 647
Comment ID: 12905
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Variances and Exemptions
Variances and exemptions should not be allowed under the LT2ESWTR for the reasons listed. MDE
generally does not use exemptions and prefers to use other mechanisms, such as Consent Orders, in
instances where water systems cannot achieve compliance in the required timeframe.
Response: See Responses 1400.a and 1400.b.
EPA Letter ID: 688
Comment ID: 14744
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 13-19 December 2005
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Chapter 13: Variances and Exemptions Comment Codes 1400-1420
Comment: Page 47723 - Variances and Exemptions
This section of the preamble states that granting an exemption would result in an unreasonable risk to
health. This contradicts a statement in the first paragraph in the middle column of page 47722 that small
systems could be given extra time -through granting exemptions.- There is a need to allow small water
systems more time to provide needed treatment. In many cases the treatment techniques required will be
difficult for small system operators to master as well as expensive. The additional time recommended in
our comment from page 47722 would be adequate if exemptions are not allowed. Otherwise we would
recommend the option of exemptions be open to systems with the State having the responsibility to
determine when the health risk is too great.
Response: See Response 1400.a.
EPA Letter ID: 704
Comment ID: 14799
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5. Limited exemptions are provided under the rule.
The exemption avenue has been afforded to most rules developed by USEPA and should be extended to
the LT2ESWTR. States should be given the flexibility to provide exemptions from monitoring and
treatment requirements where it is known that source water quality is high and watershed protection is
strong. With the
Response: See Responses 1400.a and 1400.b.
Comment Response for the LT2ESWTR 13-20 December 2005
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14. Reporting Requirements: Comment Codes 1500-1530
14.1 Comment Code 1500, Reporting Requirements
Response to Code 1500
a. EPA agrees that the reporting and recordkeeping requirements for systems and States should be the
minimum necessary to ensure appropriate regulatory oversight for public health protection. The Agency
has reviewed the reporting and recordkeeping requirements in today's final rule in areas like source water
monitoring and microbial toolbox compliance to ensure that they meet this standard.
b. EPA recognizes the resource burden that the reporting requirements in today's rule place on systems
and States and has accounted for this burden in the Economic Analysis for the LT2ESWTR. As described
in this document, EPA believes that this burden is justified in consideration of the public health benefits
that today's rule will achieve. Further, EPA has taken steps to reduce this burden. The Agency has
developed a data system to allow electronic reporting of source water monitoring results. Systems serving
at least 10,000 people will report monitoring results directly to EPA using this system, and States may
review monitoring results for their systems on-line. Updates to State Drinking Water Information System
(SDWIS) modules will facilitate reporting and recordkeeping in areas like bin classification and toolbox
compliance.
c. EPA will ensure that the data systems the Agency must develop to support LT2ESWTR reporting and
recordkeeping requirements are ready when needed for implementation of the rule. For example, the LT2
data system for electronic reporting and review of source water monitoring results will be completed and
fully tested when the LT2ESWTR becomes effective.
d. State reporting requirements are distinct from system requirements. Today's final rule explicitly lists
the information that States must report to EPA in 40 CFR 142.15. This information includes filtered
system bin classification, unfiltered system mean Cryptosporidium level (whether above 0.01 oocysts/L),
and any change in treatment requirements for systems due to watershed assessment during sanitary
surveys. States do not have to report modifications that systems make to treatment processes to EPA.
e. In today's final rule, 40 CFR 141.721(f) lists the information that systems must report to achieve
treatment credit for microbial toolbox options. In general, this information comprises only what is
necessary to demonstrate compliance with the required design and operational criteria for treatment credit
for each option.
Also, today's rule allows States to approve self-certification by systems rather than monthly reporting of
operational data for compliance with toolbox options. If a State approved this approach, a system would
keep toolbox-related operational records (e.g., disinfection CT values) on site for State review. Each
month, the system would report to the State that it had met the operational criteria required for treatment
credit, and would only report operational data if it failed to achieve compliance. EPA agrees with the
many commenters who recommended that the rule should allow this approach.
Today's rule presents system recordkeeping requirements for toolbox options in 40 CFR 141.722.
Systems must keep the results of required monitoring associated with microbial toolbox options for 3
years.
Comment Response for LT2ESWTR 14-1 December 2006
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
f Today's rule requires reporting of source water monitoring results no later than 10 days after the end of
the first month following the month when the sample is collected. This means that if a system took a
sample on the last day of a month, the system would typically have 40 or 41 days (assuming a 30 or 31
day month following the sampling month) to report the monitoring result. EPA's experience with source
water monitoring programs for Cryptosporidium indicates that this is sufficient time for laboratories to
conduct the analysis and systems to review the results.
g. Today's rule requires systems to keep source-water monitoring results until 3 years after bin
classification (or determination of the mean Cryptosporidium level for unfiltered systems) for the
particular round of monitoring. This recordkeeping requirement applies to systems, not laboratories.
Regardless of whether a system contracts with a laboratory or another party to maintain records, the
responsibility to meet regulatory recordkeeping requirements rests with the system. Systems must ensure
that laboratories comply with the quality control requirements of required methods when they analyze
samples and report results under today's rule. However, systems are not required to archive the
laboratories' quality control records. EPA will review these when approved laboratories are audited.
Individual Comments on Code 1500
EPA Letter ID: 457
Comment ID: 11906
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: We support EPA-s efforts to streamline reporting and recordkeeping requirements, but we are
concerned about the amount of data required for submittal. EPA must continue to closely monitor the
reporting and recordkeeping requirements for both water systems and states and ensure that there is an
appropriate business need for the data to be reported and/or stored. We do not believe that EPA really
needs all of the data generated by the systems or the states to perform its work.
Response: See Response 1500.a.
EPA Letter ID: 485
Comment ID: 11336
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Response: The Department is concerned about the significant resource needs
associated with the review of the data proposed to be reported to the State as well as very concerned about
the need for substantial enhancements to the database management system in place to enable reporting of
the required data elements. We recommend that EPA work with the States to develop uniform monitoring
and reporting requirements to verify compliance with the LT2ESWTR.
Response: See Responses 1500.a and 1500.b.
EPA Letter ID: 520
Comment ID: 11606
Comment Response for the L T2ESWTR 14-2 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1600 XII. Recordkeeping Requirements
Comment: IEPA supports EPA's efforts to streamline reporting and recordkeeping requirements. One of
the driving forces behind the data management requirements in a proposed rule is the amount of data
needed at the water system, state, and Federal levels. EPA must continue to closely monitor the reporting
and recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored.
Water systems need a broad range of data to perform their everyday work, but we only need a subset of
that data to perform their everyday work, and EPA needs yet a smaller subset of that data to do their
everyday work.
Response: See Response 1500.a.
EPA Letter ID: 528
Comment ID: 12267
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1600 XII. Recordkeeping Requirements
Comment: We support EPA-s efforts to streamline reporting and recordkeeping requirements. One of the
driving forces behind the data management requirements in a proposed rule is the amount of data needed
at the water system, state, and Federal levels. EPA must continue to closely monitor the reporting and
recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored. Water systems need a broad range of data to
perform their everyday work, but states only need a subset of that data to perform their everyday work,
and EPA needs yet a smaller subset of that data to do their everyday work.
Response: See Response 1500.a.
EPA Letter ID: 536
Comment ID: 11808
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1600 XII. Recordkeeping Requirements
Comment: Colorado supports EPA-s efforts to streamline reporting and record keeping requirements.
One of the driving forces behind the data management requirements in a proposed rule is the amount of
data needed at the water system, state, and Federal levels. EPA must continue to closely monitor the
reporting and record keeping requirements for both water systems and states and ensure that there is an
appropriate business need for the data to be reported and/or stored. Water systems need a broad range of
data to perform their everyday work, but states only need a subset of that data to perform their everyday
work, and EPA needs yet a smaller subset of that data to do their everyday work.
Comment Response for the L T2ESWTR 14-3 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
Response: See Response 1500.a.
EPA Letter ID: 595
Comment ID: 12597
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1600 XII. Recordkeeping Requirements
Comment: Section IV.J System Reporting and Recordkeeping Requirements (page 47724-47731)
Maine is concerned that the data systems necessary to perform duties associated with this rule will not be
fully developed prior to the date of required recordkeeping.
Response: See Response 1500.c.
EPA Letter ID: 601
Comment ID: 13038
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1600 XII. Recordkeeping Requirements
Comment: EPA requests comment on the reporting and recordkeeping requirements proposed for
LT2ESWTR.
Utah supports EPA-s efforts to streamline reporting and recordkeeping requirements. One of the driving
forces behind the data management requirements in a proposed rule is the amount of data needed at the
water system, state, and Federal levels. EPA must continue to closely monitor the reporting and
recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored. Water systems need a broad range of data to
perform their everyday work, but states only need a subset of that data to perform their everyday work,
and EPA needs yet a smaller subset of that data to do their everyday work.
Response: See Response 1500.a.
EPA Letter ID: 641
Comment ID: 13606
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Other EPA Comment Codes and Descriptions: 1600 XII. Recordkeeping Requirements
Comment Response for the LT2ESWTR 14-4 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
Comment: Pg 47731, 4. RFC (Reporting and Record keeping) We believe the record keeping and
reporting requirements for Crypto (grandfathered data and compliance period data), as currently described
in the Proposed Rule, are adequate and should be maintained.
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12758
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 1600 XII. Recordkeeping Requirements
Comment: States support EPA-s efforts to streamline reporting and recordkeeping requirements. One of
the driving forces behind the data management requirements in a proposed rule is the amount of data
needed at the water system, state, and Federal levels. EPA must continue to closely monitor the reporting
and recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored. Water systems need a broad range of data to
perform their everyday work, but states only need a subset of that data to perform their everyday work,
and EPA needs yet a smaller subset of that data to do their everyday work.
Response: See Response 1500.a.
EPA Letter ID: 647
Comment ID: 12907
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1600 XII. Recordkeeping Requirements
Comment: MDE supports EPA-s efforts to streamline reporting and recordkeeping requirements. One of
the driving forces behind the data management requirements in a proposed rule is the amount of data
needed at the water system, state, and Federal levels. EPA must continue to closely monitor the reporting
and recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored. Water systems need a broad range of data to
perform their everyday work, but states only need a subset of that data to perform their everyday work,
and EPA needs yet a smaller subset of that data to do their everyday work.
Response: See Response 1500.a.
EPA Letter ID: 712
Comment ID: 16583
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: 2. Issue: Reporting Requirements
Comment Response for the L T2ESWTR 14-5 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
The reporting requirements outlined in Table N-34 should be clarified. It is unclear which data must be
reported to EPA after it is reported to the State. Section N.J.4 implies that monthly toolbox data need not
be transmitted to EPA, but no mention is made of data collected only once or at a lesser frequency.
Response: See Response 1500.d.
EPA Letter ID: 712
Comment ID: 16586
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Section IV.C Microbial Toolbox Overview, should clarify the documentation of and awarding
of credits for log removal. The retention and reporting of this documentation should be clarified.
Response: See Response 1500.e.
EPA Letter ID: 712
Comment ID: 16588
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Section V.N.3, records and record keeping needs to be clarified. Should modifications to
treatment processes or techniques be required to be reported to EPA? The current reporting structures,
SDWIS/State and SDWISFED, do not allow for this information to be stored by the State or transmitted
to EPA.
Section V.N.3 should be expanded to identify the specific data to be reported to EPA.
Response: See Response 1500.d.
14.2 Comment Code 1510, Monthly Reporting on Compliance with
Toolbox Requirements
Individual Comments on Code 1510
EPA Letter ID: 101
Comment ID: 10909
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: System Reporting and Recordkeeping
EPA has added another layer of burden to systems by requiring them to report monthly. This requirement
is not only unnecessary but it is not a good use of resources - systems can use their time much more
effectively by concentrating on running the system optimally rather than spending time generating
Comment Response for the LT2ESWTR 14-6 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
unnecessary paperwork that could not possibly be reviewed by EPA or the State Primacy Agency
in a timely and efficient manner. The only thing necessary for systems to report are violations of a
standard. The Agency must rely on the system to self-police and audit there own performance.
Response: See Response 1500.a.
EPA Letter ID: 457
Comment ID: 11908
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: We are also concerned with the level of reporting required as systems implement various
toolbox options. We believe that the level of reporting in this area should be up to the states. The EPA
could present this reporting need to the states as a way of guidance.
Response: See Response 1500.e.
EPA Letter ID: 466
Comment ID: 11025
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: of problems encountered in the ICR and UCMR. We are also concerned with the level of
reporting required as systems implement various toolbox options.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 470
Comment ID: 11096
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: System Reporting and Recordkeeping Requirements pp. 47724-47731
Vermont is proposing that an alternative reporting and recordkeeping requirement be provided for in the
rule. We believe that the system should report annually to the state instead of monthly or simply
maintaining the records for on-site review by the state.
Response: See Response 1500.a.
Comment Response for the LT2ESWTR 14-7 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
EPA Letter ID: 472
Comment ID: 11182
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: P. 47731.4. Request for Comment EPA requests comment on the reporting and
recordkeeping requirements proposed for the LT2ESWTR. Specifically, the Agency requests comment on
the proposed requirement that systems report monthly on the use of microbial toolbox components to
demonstrate compliance with their Cryptosporidium treatment requirements. An alternative may be for
systems to keep records on site for State review instead of reporting the data.
The COP believes without an analysis of laboratory capacity it is difficult to comment. Our routine
contract laboratory turnaround time for results is two to four weeks. If we collect two samples per month
as we anticipate from the first two weeks of the month, we could have reporting challenges in meeting the
deadline of the tenth of the following month. Should laboratory capacity become an issue, four weeks or
more could become the norm in obtaining results.
Response: See Response 1500.f
EPA Letter ID: 476
Comment ID: 10676
Commenter: Anonymous476,, Department of Defense
Commenter Category: Other: Other hard to categorize commenters
Comment: 3. Remove Reporting Requirements for the Use of Microbial Toolbox Components
Requirement. As proposed, the LT2ESWTR requires systems to report monthly on the use of microbial
toolbox components to demonstrate compliance with their Cryptosporidum treatment requirements.
Comment. Submitting monthly reports regarding the use of microbial toolbox components to EPA places
an unnecessary paperwork burden on system operators.
Discussion. States visit systems periodically, and it makes more sense for water systems to keep records
on site for State review rather than submit monthly reports to EPA. The proposed LT2ESWTR does not
explain how EPA will use the data submitted on a monthly basis. Unless EPA has a reason for requiring
monthly data submissions, the requirement places an unnecessary regulatory burden on system operators.
Recommendation. Water systems should retain records on site for State review rather than reporting the
data to EPA.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 485
Comment ID: 11337
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment Response for the L T2ESWTR 14-8 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
Comment: Furthermore, we believe that it is unnecessary to receive all of the data elements monthly to
ascertain compliance with the provisions of the rule. Although monthly data tracking is important for
some water quality parameters, this is not necessary for all data that will need to be documented and
recorded. State staff will be evaluating treatment plants and their operations on an on-going basis. The
installation of the new treatment processes and their operation will be closely tracked through our existing
approval procedures. There is no need to require a lot of data elements to be submitted on a monthly basis
other than to require a certification by a responsible party that the approved toolbox components were
operated the entire month in conformance with the plant-s approved operations plan.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 488
Comment ID: 11869
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Additional Comments
IESWTRIFE reporting in Pennsylvania is done by exception reporting not compliance reporting. The
State only issues a directive if a plant has two months of problems with the same filter.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 520
Comment ID: 11608
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA is also concerned with the level of reporting required as systems implement various
toolbox options. Specific comments and suggestions for reducing this reporting burden are included in
comments below.
Response: See Response 1500.a.
EPA Letter ID: 520
Comment ID: 11661
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Section IV.J System Reporting and Recordkeeping Requirements (page 47724-47731)
IEPA is concerned that the proposed reporting requirements for the various toolbox options will result in
the need for substantial enhancements to state database management systems. Specifically, IEPA is
Comment Response for the L T2ESWTR 14-9 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
concerned that the level of data EPA is suggesting that systems report to states is beyond the data that
states need to perform their everyday work.
IEPA agrees that a water system needs to track applicable water quality parameters in order to ensure that
the toolbox option is being properly implemented, but do not agree that states need to receive this
information. IEPA staff will be evaluating treatment plants and their operations on an on-going basis. The
installation of the new treatment processes and their operation will be closely tracked through our existing
approval procedures. IEPA prefers an approach under which the system certifies that the approved
toolbox components were operated the entire month in conformance with the plant's approved operations
plan rather than requiring systems to report numerous data elements.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 528
Comment ID: 12268
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: States are also concerned with the level of reporting required as systems implement various
toolbox options.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 536
Comment ID: 11810
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Colorado is also concerned with the level of reporting required as systems implement various
toolbox options.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 548
Comment ID: 12183
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Metropolitan believes that monthly reporting on the use of microbial toolbox components is a
more effective way of communicating compliance with LT2ESWTR and supports an ongoing review and
evaluation by the State.
Response: See Responses 1500.a and 1500.e.
Comment Response for the LT2ESWTR 14-10 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
EPA Letter ID: 595
Comment ID: 12598
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Maine agrees that a water system should keep track of necessary water quality information in
order to make sure that the appropriate microbial toolbox is being utilized. However, the data does not
need to be sent to the state on a monthly basis. Rather, the data should be stored at the water system and
be
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 601
Comment ID: 13040
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Utah is also concerned with the level of reporting required as systems implement various
toolbox options
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 643
Comment ID: 12760
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States are also concerned with the level of reporting required as systems implement various
toolbox options. Specific comments and suggestions for reducing this reporting burden are included in
Attachment 2.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 643
Comment ID: 12816
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section IV.J System Reporting and Recordkeeping Requirements (page 47724-47731)
States are concerned that the proposed reporting requirements for the various toolbox options will result
Comment Response for the LT2ESWTR 14-11 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
in the need for substantial enhancements to state database management systems. Specifically, states are
concerned that the level of data EPA is suggesting that systems report to states is beyond the data that
states need to perform their everyday work.
States agree that a water system needs to track applicable water quality parameters in order to ensure that
the toolbox option is being properly implemented, but do not agree that states need to receive this
information. State staff will be evaluating treatment plants and their operations on an on-
going basis. The installation of the new treatment processes and their operation will be closely tracked
through our existing approval procedures. States prefer an approach under which the system certifies that
the approved toolbox components were operated the entire month in conformance with the plant-s
approved operations plan rather than requiring systems to report numerous data elements.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 647
Comment ID: 12909
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: to problems encountered in ICR and UCMR reporting. MDE is also concerned with the level
of reporting required as systems implement various toolbox options.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 647
Comment ID: 12946
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Section IV.J System Reporting and Recordkeeping Requirements (page 47724-47731)
MDE is concerned that the proposed reporting requirements for the various toolbox options will result in
the need for substantial enhancements to state database management systems. The level of data EPA is
suggesting that systems report to states is beyond the data that states need to perform their everyday work.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 662
Comment ID: 14045
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
Comment Response for the LT2ESWTR 14-12 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
J. System Reporting and Recordkeeping Requirements (pages 47724-47731)
EPA requests comment on the reporting and recordkeeping requirements proposed for LT2ESWTR.
Monthly reporting of the use of microbial toolbox components is excessive and would not be productive.
Records of the use of the toolbox components should be kept for State review as deemed necessary, or
during sanitary surveys.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 712
Comment ID: 16584
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Each of the individual tools from the Microbial Toolbox that are unit processes should be
classified as such and made consistent with those that are or will be contained in SDWIS/State. Individual
tools that are performance or program-based should be specifically identified as such and the means for
recording and requirements for reporting on these separate tools needs to be specified. If the reporting
requirements are to be greater, then all additional data elements should be specifically identified along
with the reported frequency.
Response: See Responses 1500.a and 1500.e.
14.2.1 Comment Code 1511, Alternative Requiring Systems to
keep Records Onsite
Individual Comments on 1511
EPA Letter ID: 444
Comment ID: 10816
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment: a. EPA proposes that systems report monthly on the use of toolbox components to
demonstrate compliance with Crypto treatment requirements. NH prefers that
systems keep records on site for periodic state review instead of reporting the
data.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 511
Comment ID: 11490
Commenter: Keith W. Cartnick, Director Water Quality Assurance, United Water New Jersey
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 14-13 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
Comment:
Comment: An option could be to require monthly reporting to the State only if there was an exceedance
or problem in the system. This would be consistent with reporting requirements of the IESWTR, where
reporting of individual filter turbidities is required only if the specified limit of 1.0 NTU or 0.5 NTU for
two readings 15 minutes apart is exceeded. This requirement would be in addition to the requirement for
systems to keep records on site for State review.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 595
Comment ID: 12599
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: monthly basis. Rather, the data should be stored at the water system and be available for
review by the primacy agency at any time.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 629
Comment ID: 12832
Commenter: Melinda Rho, Manager of Regulatory Affairs and Consumer Protection, Los Angeles
Department of Water and Power
Commenter Category: Regulated Community (Utilities)
Comment: LADWP supports the alternative to keep records on site for State review. Additional ongoing
reporting, reviewing, and evaluation would be an added burden on both utilities and the States and would
not lead to more effective compliance.
Response: See Responses 1500.a and 1500.e.
EPA Letter ID: 647
Comment ID: 12952
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: MDE agrees that a water system needs to track applicable water quality parameters in order to
ensure that the toolbox option is being properly implemented, but does not agree that states need to
receive this information. State staff will be evaluating treatment plants and their operations on an on-
going basis. The installation of the new treatment processes and their operation will be closely tracked
through our existing approval procedures. MDE prefers an approach under which the system certifies that
the approved toolbox components were operated the entire month in conformance with the plant-s
approved operations plan rather than requiring systems to report numerous data elements.
Response: See Responses 1500.a and 1500.e.
Comment Response for the LT2ESWTR 14-14 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
EPA Letter ID: 688
Comment ID: 14745
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Page 47731 - Request For Comment (Reporting Requirements 141.730(e))
Missouri feels that systems should keep the most detailed records available for review by department staff
during sanitary surveys but only report summary or compliance status information to the department
monthly. This is to reduce the reporting burden on systems and also to reduce the volume of paper the
state has to handle. This is especially true for the reporting requirements for chlorine dioxide and ozone.
Here, daily CT values would have to be reported based on the rule proposal. It would be sufficient for the
system to report once a month whether all CT values were sufficient to maintain adequate log
inactivation. This could be verified during sanitary surveys or by special data reviews if other indicators
alerted the department to a problem. In a real world regulatory
situation, especially in light of resource reductions in most states, the more detailed and voluminous the
paper reporting, the less likely it is that true violations will be identified. A more limited and targeted
reporting scheme may actually be more protective of the drinking water quality.
Response: See Responses 1500.a and 1500.e.
14.2.2 Comment Code 1522, Bin classification
Individual Comments on Code 1522
EPA Letter ID: 485
Comment ID: 11287
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Response: The Department believes that all bin classifications, once determined by the EPA, should be
reviewed and approved by the state.
Response: Response 500.1
EPA Letter ID: 513
Comment ID: 11526
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: Determination of LT2ESTWR Bin Classification
EPA has requested comment on whether bin classification should formally be made or reviewed by
States.
We believe bin classification should be made by the State. This will reduce the likelihood of
misunderstanding about treatment requirements based on monitoring results, and should accelerate
Comment Response for the LT2ESWTR 14-15 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
compliance with the proposed rule. This would be consistent with the State-s authority to determine
whether sources are ground water under the direct influence of surface water.
Response: See Response SOO.t.
EPA Letter ID: 520
Comment ID: 11619
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Determination of LT2ESWTR bin classification
As indicated above, IEPA believes that bin determinations need to be approved by the regulating agency.
This will avoid any confusion as to the level of treatment each surface water system is required to
provide.
Response: See Response SOO.t.
EPA Letter ID: 538
Comment ID: 14097
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment: The City of Wichita Falls supports formally stating a systems bin classification. Allowing the
States a review period would substantially slow down the process of complying with the regulation and
further complicate its implementation.
Response: See Response SOO.t.
14.3 Comment Code 1530, Rule Language Edits
Individual Comments on Code 1530
EPA Letter ID: 603
Comment ID: 12661
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47791) Section 141.730(e)-
Please consider rearranging the Microbial Toolbox Reporting Requirements table so that the toolbox
options are presented in the same order as in the table for toolbox options in § 141.722on page 47784. It
would be useful if the table includes the toolbox options for which there are no reporting requirements
and indicates such.
Comment Response for the LT2ESWTR 14-16 December 2005
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Chapter 14: Reporting Requirements Comment Codes 1500-1530
Response: See Response lOO.a.
EPA Letter ID: 603
Comment ID: 12664
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47788) Section 141.730(f)-
In Table 1, "Cryptosporidium" is misspelled.
Response: See Response 500.aa.
Comment Response for the LT2ESWTR 14-17 December 2005
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15. Comment Code 1600: Recordkeeping Requirements
15.1 Comment Code 1600, XII. Recordkeeping Requirements
Individual Comments on Code 1600
EPA Letter ID: 520
Comment ID: 11606
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1500 XI. Reporting Requirements
Comment: IEPA supports EPA's efforts to streamline reporting and recordkeeping requirements. One of
the driving forces behind the data management requirements in a proposed rule is the amount of data
needed at the water system, state, and Federal levels. EPA must continue to closely monitor the reporting
and recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored.
Water systems need a broad range of data to perform their everyday work, but we only need a subset of
that data to perform their everyday work, and EPA needs yet a smaller subset of that data to do their
everyday work.
Response: See Response 1500.a.
EPA Letter ID: 528
Comment ID: 12267
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1500 XI. Reporting Requirements
Comment: We support EPA-s efforts to streamline reporting and recordkeeping requirements. One of the
driving forces behind the data management requirements in a proposed rule is the amount of data needed
at the water system, state, and Federal levels. EPA must continue to closely monitor the reporting and
recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored. Water systems need a broad range of data to
perform their everyday work, but states only need a subset of that data to perform their everyday work,
and EPA needs yet a smaller subset of that data to do their everyday work.
Response: See Response 1500.a.
EPA Letter ID: 536
Comment ID: 11808
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
Comment Response for LT2ESWTR 15-1 December 2005
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Chapter 15: Recordkeeping Requirements Comment Code 1600
and Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1500 XI. Reporting Requirements
Comment: Colorado supports EPA-s efforts to streamline reporting and record keeping requirements.
One of the driving forces behind the data management requirements in a proposed rule is the amount of
data needed at the water system, state, and Federal levels. EPA must continue to closely monitor the
reporting and record keeping requirements for both water systems and states and ensure that there is an
appropriate business need for the data to be reported and/or stored. Water systems need a broad range of
data to perform their everyday work, but states only need a subset of that data to perform their everyday
work, and EPA needs yet a smaller subset of that data to do their everyday work.
Response: See Response 1500.a.
EPA Letter ID: 595
Comment ID: 12597
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1500 XI. Reporting Requirements
Comment: Section IV.J System Reporting and Recordkeeping Requirements (page 47724-47731)
Maine is concerned that the data systems necessary to perform duties associated with this rule will not be
fully developed prior to the date of required recordkeeping.
Response: See Response 1500.c.
EPA Letter ID: 601
Comment ID: 13038
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1500 XI. Reporting Requirements
Comment: EPA requests comment on the reporting and recordkeeping requirements proposed for
LT2ESWTR.
Utah supports EPA-s efforts to streamline reporting and recordkeeping requirements. One of the driving
forces behind the data management requirements in a proposed rule is the amount of data needed at the
water system, state, and Federal levels. EPA must continue to closely monitor the reporting and
recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored. Water systems need a broad range of data to
perform their everyday work, but states only need a subset of that data to perform their everyday work,
and EPA needs yet a smaller subset of that data to do their everyday work.
Response: See Response 1500.a.
Comment Response for the L T2ESWTR 15-2 December 2005
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Chapter 15: Recordkeeping Requirements Comment Code 1600
EPA Letter ID: 641
Comment ID: 13606
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Other EPA Comment Codes and Descriptions: 1500 XI. Reporting Requirements
Comment: Pg 47731, 4. RFC (Reporting and Record keeping) We believe the record keeping and
reporting requirements for Crypto (grandfathered data and compliance period data), as currently described
in the Proposed Rule, are adequate and should be maintained.
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12758
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 1500 XI. Reporting Requirements
Comment: States support EPA-s efforts to streamline reporting and recordkeeping requirements. One of
the driving forces behind the data management requirements in a proposed rule is the amount of data
needed at the water system, state, and Federal levels. EPA must continue to closely monitor the reporting
and recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored. Water systems need a broad range of data to
perform their everyday work, but states only need a subset of that data to perform their everyday work,
and EPA needs yet a smaller subset of that data to do their everyday work.
Response: See Response 1500.a.
EPA Letter ID: 647
Comment ID: 12907
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1500 XI. Reporting Requirements
Comment: MDE supports EPA-s efforts to streamline reporting and recordkeeping requirements. One of
the driving forces behind the data management requirements in a proposed rule is the amount of data
needed at the water system, state, and Federal levels. EPA must continue to closely monitor the reporting
and recordkeeping requirements for both water systems and states and ensure that there is an appropriate
business need for the data to be reported and/or stored. Water systems need a broad range of data to
perform their everyday work, but states only need a subset of that data to perform their everyday work,
and EPA needs yet a smaller subset of that data to do their everyday work.
Response: See Response 1500.a.
Comment Response for the L T2ESWTR 15-3 December 2005
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Chapter 15: Recordkeeping Requirements Comment Code 1600
EPA Letter ID: 704
Comment ID: 14794
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section 3.9. Archiving Quality Control (QC) records.
Archiving Quality Control (QC) records associated with samples from a PWS is the
responsibility of the PWS, not the analytical laboratory unless the PWS designates the responsibility to
the contract lab. The archiving period continues through 36 months after the 2nd Round of
Cryptosporidium samples, i.e. nine (9) years after rule promulgation. PWS should have a documentation
indication that if archiving authority is designated to the contract lab stating the labs intention to archive
data for that entire period of time. Labs are
most likely not going to distribute raw QC data to their clients. Rather, by releasing data to the PWS, they
acknowledge that all QC criteria have been met.
Response: See Response ISOO.g.
Comment Response for the L T2ESWTR 15-4 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
16. Analytical Methods: Comment Codes 1700-1760
16.1 Comment Code 1700, XIII. Analytical Methods
Summary of Issues
One comment suggested that EPA incorporate a pathway to qualify emerging technologies. The other
comment expressed concerns regarding the techniques and their accuracy, the cost of sample collection
and the effect of climate conditions on Cryptosporidium concentrations.
Response to Comments on Code 1700
Emerging Technologies
EPA believes the pathway to qualify emerging technologies exists with the Alternative Test Procedures
program. The EPA agrees that prior to a second round of monitoring, the Agency should evaluate the
results of the first round of monitoring, along with whatever new information is available on
Cryptosporidium analytical methods, risk, and other relevant issues.
General concerns
EPA believes that the accuracy of the methods, the cost of sample collection for small systems, and the
possible effect of climate conditions on the variability of Cryptosporidium levels are incorporated into the
rule. Subsequent to promulgating the IESWTR, EPA developed improved Cryptosporidium methods,
EPA Method 1622/1623, to achieve higher recovery rates and lower inter- and intra-laboratory variability
than previous methods. Methods 1622 and 1623 incorporate improvements in the concentration,
separation, staining, and microscope examination procedures. During the ICRSS, which required the use
of Method 1622 or 1623, a spiking study demonstrated a mean Cryptosporidium recovery of 43 percent
(Connell et al. 2000). Thus, mean Cryptosporidium recovery with Methods 1622 and 1623 was more than
3.5 times higher compared to the ICR Method performance in the earlier spiking study. In addition, the
relative variation in recovery from sample to sample was lower with Methods 1622 and 1623. In addition,
as stated in the Lab QA Program, EPA is providing accurate flow cytometry counted proficiency samples
as well as requiring the use of flow cytometry counted oocysts for method quality control during
LT2ESWTR. This provides an accurate check on the quality of data being produced.
EPA believes that the effect of climate conditions has been included in the required monitoring. The
Agency considered the trade-off between monitoring over a long period to better capture temporal
fluctuations and the desire to prescribe additional treatment quickly to PWSs with higher
Cryptosporidium levels. Today's rule requires large PWSs to evaluate their source water Cryptosporidium
levels using two years of monitoring. This will account for some degree of yearly variability, without
significantly delaying additional public health protection where needed.
Cryptosporidium monitoring places a relatively greater economic burden on small PWSs, and EPA will
have additional E. coli and Cryptosporidium data from large PWS monitoring prior to the initiation of
small PWS monitoring. Based on these considerations and the available data on E. coli as an indicator of
sources with lower Cryptosporidium levels, the Advisory Committee recommended that small filtered
PWSs initially monitor for E. coli for one year as a screening analysis. This will help decrease the
economic burden on small PWSs.
Comment Response for the L T2ESWTR 16-1 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Individual Comments on Code 1700
EPA Letter ID: 456
Comment ID: 10967
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: We also request that the EPA incorporate into the Rule a pathway to qualify emerging
technologies for water testing, in lieu of old-fashioned expensive wet-
lab techniques.
Response: See Response 1700.
EPA Letter ID: 647
Comment ID: 12865
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 320 B. Small System Monitoring Requirements; 530 C.
Procedures for Calculating Bin Classification
Comment: we have significant concerns about the laboratory techniques and accuracy, cost of sample
collection for small water systems, and the effect of climate conditions on the variability of
Cryptosporidium levels. MDE also supports the
Response: See Response 320(A) regarding small system sampling costs. (Also see Responses 500.o,
500.p, lOO.c, lOO.i, and 1700 for other comments).
16.2 Comment Codes 1710, Cryptosporidium
Summary of Issues
One commenter stated that no comments could be made because the agency lacked experience with the
proposed methods. Comments requested that EPA use caution when basing treatment requirements on
data from the methods and that methodology that is faster, easier, cheaper and more precise should be
incorporated as it is developed. Another comment agreed with the development of QA/QC procedures for
the methods.
Response to Code 1710
EPA appreciates the fact that an agency inexperienced with Methods 1622/1623 chose not to comment.
EPA believes that the methods are appropriate for bin classification but that improved methods may be
incorporated as they are developed. Subsequent to promulgating the IESWTR, EPA developed improved
Cryptosporidium methods, EPA Method 1622/1623, to achieve higher recovery rates and lower inter- and
intra-laboratory variability than previous methods. Methods 1622 and 1623 incorporate improvements in
the concentration, separation, staining, and microscope examination procedures. During the ICRSS,
Comment Response for the L T2ESWTR 16-2 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
which required the use of Method 1622 or 1623, a spiking study demonstrated a mean Cryptosporidium
recovery of 43 percent (Connell et al. 2000). Thus, mean Cryptosporidium recovery with Methods 1622
and 1623 was more than 3.5 times higher compared to the ICR Method performance in the earlier spiking
study. In addition, the relative variation in recovery from sample to sample was lower with Methods 1622
and 1623. EPA expects that PWSs will achieve comparable performance with these methods during
source water monitoring under today's rule. With the minimum sample volume and QC requirements in
today's rule, this level of performance will be sufficient to assign PWSs to Cryptosporidium treatment
bins and realize the public health goals intended by EPA and the Advisory Committee for the
LT2ESWTR. Prior to a second round of monitoring, the Agency will evaluate the results of the first round
of monitoring, along with whatever new information is available on Cryptosporidium analytical methods,
risk, and other relevant issues. The Stage 2 M-DBP Advisory Committee recommended that EPA initiate
a stakeholder process several years prior to the second round of monitoring to review new information
and today's rule requires this. If EPA determines that there should be changes to the requirements for a
second round of monitoring in today's rule, the Agency will issue a new rule establishing those changes.
EPA agrees that the required methods reflect the development in QA/QC procedures. Today's rule
requires the use of methods 1622 or 1623 because they are the best available methods that have
undergone full validation testing. The proposed LT2ESWTR required the use of April 2001 versions of
Methods 1622 or 1623 and requested comment on approving revised versions of these methods in the
final rule (USEPA 2003a). The revised methods were included in the proposal as draft June 2003
versions. The revisions in these versions included increased flexibility in some QC requirements,
clarification of certain method procedures, an increase in the allowable sample storage temperature to
10°C, the addition of several approved analysis modifications, and other refinements.
Individual Comments on Code 1710
EPA Letter ID: 497
Comment ID: 10653
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: With regards to the draft Analytical Methods request for comment, the MDEQ laboratory has
no comments concerning Cryptosporidium due to its lack of experience with this analysis. With regards
to E. coli testing of source water,
Response: See Response 1710.
EPA Letter ID: 526
Comment ID: 11769
Commenter: Nick Jackson,, Knoxville Utilities Board
Commenter Category: Local Government
Comment: 5. Despite having been used for years, the current analytical methods for detecting
Cryptosporidium and Giardia are slow, cumbersome, expensive and include considerable opportunity for
error. Until the development of faster, more accurate analytical techniques up to and including online
instrumentation (verifiable by laboratory or benchtop methods) EPA should exercise considerable caution
in basing treatment requirements upon existing methods.
Comment Response for the L T2ESWTR 16-3 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Response: See Response 1710.
EPA Letter ID: 562
Comment ID: 12373
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5. Development of QA/QC procedures for Cryptosporidium sampling.
EPA has reflected each of these components in the proposed rule. AWWA continues to believe that each
of these five recommendations is sound and appropriate for the LT2ESWTR. AWWA is concerned about
the specifics of EPA-s implementation of these general recommendations.
Response: See Response 1710.
EPA Letter ID: 592
Comment ID: 12103
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: margin of accuracy, at best 50%. Provisions must be incorporated into this rule to allow for
cheaper, more precise testing for Cryptosporidium or for a correlated pathogen, surrogate or other
chemical parameter when and if they are established. It is appreciated that we will be allowed to
grandfather testing
Response: See Response 1710.
16.2.1 Comment Code 1711, Minimum sample volume, packed pellet
volume, number of filters
Summary of Issues
Commenters agreed that the methods are appropriate for use including the minimum sample volume
requirements. Other comments disagreed with the minimum sample requirements because the
requirements yield a high detection limit and result in higher costs for utilities with turbid waters. Another
comment expressed concern regarding the laboratories ability to subsample properly. Commenters also
requested clarification of the required volume analyzed for samples when 10 L was collected and >10 L
was collected. Clarification regarding QC for multiple sample volumes and scheduling of multiple
volume samples was also requested.
Pellet size and filter usage
EPA agrees with the comments that the rule requirements to analyze 10 L, or at least 2 mL packed pellet,
or as much sample volume as can be filtered by two filters are appropriate for all systems. If a sample is
very turbid, it may generate a large packed pellet volume upon centrifugation (a packed pellet refers to the
Comment Response for the LT2ESWTR 16-4 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
concentrated sample after centriftigation has been performed in EPA Methods 1622 and 1623). Samples
resulting in large packed pellets must have the sample concentrate aliquoted into multiple "subsamples"
for independent processing through IMS, staining, and examination as required by the method.
Subsampling procedures and protocols are part of the technical audit checklist through the Lab QA
Program. PWSs are not required to analyze more than 2 mL of packed pellet volume per sample. PWSs
unable to process a 10 L sample must analyze as much sample volume as can be filtered by two approved
filters, up to a packed pellet volume of at least 2 mL.
Limit of detection
The EPA disagrees that the method limit of detection is not appropriate for bin classification. The mean
Cryptosporidium recovery with Methods 1622 and 1623 was more than 3.5 times higher compared to the
ICR Method performance. As stated in the preamble, EPA concluded that a monitoring program using
Methods 1622 or 1623 can be effective in characterizing PWSs source water Cryptosporidium levels for
purposes of determining the need for additional treatment requirements. EPA agrees that PWSs should
have the choice to collect more than 24 samples to increase the total volume analyzed and further improve
the accuracy of bin classification, and today's rule allows this. As stated in the Source Water Monitoring
Guidance Manual for LT2ESWTR, systems may analyze volumes larger than 10 L, and larger volumes
analyzed should increase analytical sensitivity (detection limit) and representativeness, provided method
performance is acceptable. The required minimum volume analyzed applies to every sample.
Laboratory QC and Sample Volume
Today's rule requires the use of the revised versions of Methods 1622 and 1623 including the required
QC samples. A laboratory that processes different sample volumes should demonstrate ongoing
acceptable performance at both extremes of the volume spectrum by performing one OPR and method
blank at a volume consistent with the highest sample volume submitted by clients (e.g. 50 L) and
performing a second OPR and method blank at a volume consistent with the lowest sample volume
submitted by clients (but not less than 10 L). Labs analyzing multiple sample volumes, should
demonstrate acceptable performance in a manner representative of the sample volumes they process i.e. at
the same percentage as volumes in field samples submitted to the laboratory. Frequency of OPR's with
different volumes should be consistent with the frequency of samples with different volumes.
Laboratories should work with their PWS clients to attempt to schedule clients with different sample
volume sizes for different periods during the week, so the field samples can be batched with QC samples
of comparable volume. EPA encourages systems to analyze similar sample volumes throughout the
monitoring period. However, data sets including different samples volumes will be accepted, provided the
system analyzes the minimum sample volume requirements noted above.
Individual Comments on Code 1711
EPA Letter ID: 472
Comment ID: 11183
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Other EPA Comment Codes and Descriptions: 1731 1. Proposed methods
Comment: P. 47732. c. Request for comment. EPA requests comment on the proposed method
requirements for Cryptosporidium analysis, including the following specific issues:
Comment Response for the L T2ESWTR 16-5 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
- Minimum Sample Volume It is the intent of EPA that LT2ESWTR sampling provide
representative annual mean source water concentrations. If systems were unable to analyze an entire
sample volume during certain periods of the year due to elevated turbidity or other water quality factors,
this could result in systems analyzing different volumes in different samples. Today-s proposal requires
systems to analyze at least 10 L of sample or the maximum amount of sample that can be filtered through
two filters, up to a packed pellet volume of 2 mL.
- EPA requests comment on whether these requirements are appropriate for systems with source waters
that are difficult to filter or that generate a large packed pellet volume. Alternatively, systems could be
required to filter and analyze at least 10 L of sample with no exceptions.
See p. 47732 third column for proposed changes in EPA Methods 1622 and 1623 and if they should be
promulgated?
Seep. 47733 bottom for allowing 24-hour holding time for e-coli samples.
P. 47734. c. Request for comment. EPA requests comment on whether the E. coli methods proposed for
approval under the LT2ESWTR are appropriate, and whether there are additional methods not proposed
that should be considered. Comments concerning method approval should be accompanied by supporting
data where possible.
The COP believes these methods are appropriate.
Response: See Responses 1711 and 1731.
EPA Letter ID: 504
Comment ID: 11363
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: 7. Analytical Methodology
The method specified for use in conducting required BIN monitoring has one virtually fatal flaw and two
specific limitations that could be altered to produce data that would more effectively serve objectives of
the proposed rule. The fatal flaw is that the limit of detection for the method as described by EPA is
typically 0.25 oocysts/L. The obvious problem due to this is that concentrations below the limit of
detection cannot be measured. It is only the (uneven) statistical distribution of oocysts at low
concentration, therefore chance alone, that would contribute to positive oocyst findings at concentrations
less than 0.25 oocysts/L. The significance of this to the universe of utilities subject to this regulation is
immense. The EPA estimate of plants for which concentrations fall in this range is somewhere in the
range of 70% to 90% of all surface water plants. All plants expected to be in BIN 1 and a large proportion
of plants expected to be in BIN 2 would be affected. Utilities in the upper end of the BIN 1 range must
take a most critical view of the prospect that chance alone will determine the BIN to which their plants
will be assigned.
This fatal flaw and the first correctable limitation is the method-s limit of detection as described above.
Analysis of larger samples is the most direct way (and the only way without altering fundamental aspects
of the method) of improving resolution of analytical results at low concentration. Given that the
consequence of an inappropriately established BIN is relatively expensive, it is in a utility-s best interest
Comment Response for the LT2ESWTR 16-6 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
to invest more in improved monitoring that would be provided by analysis of larger samples to assure
accurate results.
Response: See Response 1711.
EPA Letter ID: 514
Comment ID: 11538
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: Minimum Sample Volume: The requirement to analyze the maximum amount
of sample that can be filtered through two filters, up to a packed pellet volume of 2 mL, is appropriate for
systems with turbid source waters. Otherwise, this analysis could become cost-prohibitive especially
during run-off events in the spring and fall.
Response: See Response 1711.
EPA Letter ID: 548
Comment ID: 12184
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Metropolitan believes that a minimum sample volume of 10 L is appropriate for analysis of
Cryptosporidium. However, it is in the utilities- best interest to sample and analyze as large a volume as
possible in order to get a better representation of the source water and lower detection limit. Additionally,
collecting a 10-L sample over a longer period of time (e.g. collecting the sample within a 24-hr period, for
example, at certain intervals) may provide a better sample representation.
Metropolitan is also aware that this does not address systems with source waters that have high turbidities
and are therefore difficult to filter. In such cases, Metropolitan agrees that the maximum amount of
sample (less than 10 L) that can be filtered through two filters, up to a packed pellet volume of 2 mL, may
be analyzed.
Response: See Response 1711.
EPA Letter ID: 562
Comment ID: 12394
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the L T2ESWTR 16-7 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Comment: 2. Minimum sub-sampling analysis requirements.*
rule provisions.* AWWA also recommends that the minimum sub-sampling analysis be modified to
reflect that the laboratory followed prevailing good laboratory practice regarding sub-sampling at the time
of the sample-s handling. As proposed, matrix spike samples are an excellent practice, but their use will
not substantively affect acceptance of LT2ESWTR samples (i.e., failure to process matrix spike is an
issue but the sample will not be used to inform the use of the actual monitoring samples).
Response: See Response 1711.
EPA Letter ID: 562
Comment ID: 12398
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
* Source Water Monitoring Guidance Manual for Public Water Systems for the Long Term 2 Enhanced
Surface
Water Treatment Rule, Section 2.1, p. 8.
Response: Not a comment (reference to a guidance manual), no response required.
EPA Letter ID: 641
Comment ID: 13588
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Also, ASI recommends further clarification regarding large pellets by adding: -For maximum
sensitivity, EPA recommends analyzing the entire pellet, however, only the minimum volumes are
required to be analyzed. Therefore, for example, if a 50L sample yields a 2 mL pellet, only the equivalent
of 10L (0.4mL pellet) must be analyzed.-
Response: See Response 1711.
EPA Letter ID: 641
Comment ID: 13607
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: K. Analytical Methods 1. Crypto
Method Requirements - The -volume analyzed- information should be restated. See below for more
information.
Response: See Response 1711.
Comment Response for the L T2ESWTR 16-8 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
EPA Letter ID: 641
Comment ID: 13609
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47732 RFC (Crypto Method)
Minimum Sample Volume - ASI supports the proposed minimum sample volume requirements, however,
we recommend that these requirements be clarified and standardized throughout the Rule.
Response: See Response 1711.
EPA Letter ID: 641
Comment ID: 13611
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Also, ASI recommends further clarification regarding large pellets by adding: -For maximum
sensitivity, EPA recommends analyzing the entire pellet, however, only the minimum volumes are
required to be analyzed. Therefore, for example, if a SOL sample yields a 2 mL pellet, only the equivalent
of 10L (0.4mL pellet) must be analyzed.-
Response: See Response 1711.
EPA Letter ID: 664
Comment ID: 14059
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.K. - ANALYTICAL METHODS FOR CRYPTOSPORIDIUM
The minimum sample volume for analysis is 10 L, or up to a 2 ML sample size for filtered material. With
a source water such as Lake Winnebago, which can be difficult to filter and also can generate a large
filtered volume; this Rule provides for a sampling procedure which results in nearly a doubling in
sampling and analytical cost under Method 1623. For a small utility, the sampling burden will be
significant. According to the Wisconsin State Lab of Hygiene, which is certified for this analytical
procedure, the analysis cost will nearly double from $350/sample to $700/sample.
Response: See Response 1711.
EPA Letter ID: 704
Comment ID: 14793
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section 3.3.15.2. Labs are supposed to perform QC samples with sample volumes equivalent
to the client samples they process in that batch.
Comment Response for the L T2ESWTR 16-9 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Different clients will sample different volumes and to try to group sample schedules according to volumes
sampled will be very burdensome. Labs must have the flexibility to work with their clients to schedule
sampling events according to the client-s needs and the best fit in the lab routine, not based on client-s
sample volumes. Also, what if a client with multiple sources chooses to send different volumes for each
source. EPA recommends that they should sample at different times to fit with the lab QC protocols, a
notion that is very impractical.
Response: See Response 1711.
EPA Letter ID: 707
Comment ID: 14818
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: pg. 47732
c. Request for Comment
1. Minimum Sample Volume (parag. #6)
Comment: Exception should be made for systems with elevated turbidity levels in
their source water. Systems which have high turbidity in source waters should
not be required to process more than two filters to obtain their 2 mL packed pellet volume under the LT2.
If the laboratory has to process more than one filter the cost will increase for the system. Some
laboratories are presently charging a fee for the IMS/FITC/DAPI procedure plus the cost of each filter
(i.e., $395.00 for IMS procedure + $85.00 for each filter used). The cost would increase for the system by
$45-$85 per filter depending on the filter used by the laboratory.
Response: See Response 1711.
16.2.2 Comment Code 1712, Use of different versions of Method
1622/1623, performance-based approaches, and alternate test
procedures
Summary of Issues
Comments were received expressing concern over when the June 2003 version of Method 1622/1623
should begin being used. A commenter also expressed concern over whether a lab approved using
previous methods will have to be approved for the June 2003 method. Other comments approved of the
use of the June 2003 version because of its many detailed clarifications and method improvements.
Commentary expressed concern that older versions of the method may not be acceptable but should be
acceptable especially for grandfathered data. Comments also stated that the methods are performance-
based and using proper validation procedures will result in valid data. Other comments supported the
additional recommendations for minimizing carry-over debris onto microscope slides, the flexibility in
Matrix Spike (MS) scheduling, and the completion of Initial Precision Recovery (IPR).
Comment Response for the LT2ESWTR 16-10 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Response to Code 1712
Method versions
The latest revisions of the methods will be promulgated with the rule. Today's rule requires the use of the
revised versions of Methods 1622 and 1623. A laboratory may be approved through the Laboratory
Quality Assurance (Lab QA) program using the 1999, 2001, or 2003 version of the methods until the
revised method is promulgated. Cryptosporidium analysis for source water monitoring under today's rule
must be conducted using either Method 1623: Cryptosporidium and Giardia in Water by
Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA-815-R-05-002, or
Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2005, United States Environmental
Protection Agency, EPA-815-R-05-001.
Grandfathered data
As described in the preamble, PWSs may grandfather data generated with earlier approved versions of
these methods (i.e., 1999 or 2001 versions). The rule states that the following methods may be used prior
to promulgation:
• Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA, 2005, United States
Environmental Protection Agency, EPA-815-R-05-002.
• Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2005, United States Environmental
Protection Agency, EPA-815-R-05-001.
• Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA, 2001, United States
Environmental Protection Agency, EPA-821-R-01-025.
• Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2001, United States Environmental
Protection Agency, EPA-821-R-01-026.
• Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA, 1999, United States
Environmental Protection Agency, EPA-821-R-99-006.
• Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 1999, United States Environmental
Protection Agency, EPA-821-R-99-001.
Today's rule requires the use of Methods 1622 or 1623 because they are the best available methods that
have undergone full validation testing. In addition, Methods 1622 and 1623 incorporate improvements in
the concentration, separation, staining, and microscope examination procedures. During the ICRSS,
which required the use of Method 1622 or 1623, a spiking study demonstrated a mean Cryptosporidium
recovery of 43 percent (Connell et al. 2000). Thus, mean Cryptosporidium recovery with Methods 1622
and 1623 was more than 3.5 times higher compared to the ICR Method performance in the earlier spiking
study.
Approval comments
The EPA agrees with the suggestion that the new Method be approved and that the improvements be
incorporated into the updated version of the Method.
Individual Comments on Code 1712
EPA Letter ID: 411
Comment ID: 10560
Comment Response for the LT2ESWTR 16-11 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Commenter: Devon Cole,, Utah Department of Health Laboratory
Commenter Category: State/Tribe Government
Comment: When should the June 2003 versions of Method 1622/1623 begin to be used? Will
Response: See Response 1712.
EPA Letter ID: 548
Comment ID: 12185
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: * Approval of updated versions of EPA Methods 1622 and 1623 - EPA is requesting
comment on whether these revised versions should be approved for monitoring under the LT2ESWTR,
rather than the April 2001 versions proposed in today-s rule.
Metropolitan believes that the revised versions of EPA Methods 1622 and 1623 enhance the efficiency
and QC aspects of the methods and therefore should be approved for monitoring under the LT2ESWTR.
However, Metropolitan also recognizes the fact that the April 2001 versions are also adequate and have
been used to monitor source waters nationwide for many years with good results. Metropolitan suggests
that both versions of the methods be approved for monitoring and leave the choice to the system or the
laboratory analyzing the samples. Furthermore, systems that may apply for approval of randfathered data
have been using the April 2001 versions and may want to continue monitoring using the same versions
for data continuity.
Response: Today's rule approves the revised versions of EPA Methods 1622 and 1623. EPA belives that
for new monitoring performed under the rule, these versions of the methods, rather than earlier versions,
should be used because they provide improved efficiency and quality control. However, systems may
grandfather data collected using earlier approved versions of the methods, including the April 2001
versions.
EPA Letter ID: 562
Comment ID: 12303
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: modifying hold times, will facilitate monitoring under the LT2ESWTR. The agency should
continue to recognize that EPA Method 1622/1623 is a performance-based method. Therefore, using
appropriate validation procedures, modification of the method is appropriate and the resulting data is
valid under the LT2ESWTR. In defining performance of EPA Method 1622/1623
Response: See Response 1712.
Comment Response for the LT2ESWTR 16-12 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
EPA Letter ID: 641
Comment ID: 13670
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Comments on the Laboratory Guidance Manual for LT2 (June 2003)
3.1.2 Revised Crypto. Method
1. Increased flexibility in MS scheduling and in completion of IPRs a. ASI supports these changes. 2.
Additional recommendations for minimizing carry-over debris onto microscope slides a. ASI supports
including these recommendations.
Response: See Response 1712.
EPA Letter ID: 678
Comment ID: 14716
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 12. The EPA requests comment on the proposed method requirements for Crypto analysis,
including the approval of updated versions of EPA Methods 1622 and 1623, and whether these revised
versions should be approved for monitoring under the LT2 Rule, rather than the April 2001 versions
proposed intoday-s rule. [47732, C3]
Comment: The revised versions of EPA Methods 1622 and 1623 enhance the efficiency and QC aspects
of the methods and therefore should be approved for monitoring under the LT2 Rule. However, the April
2001 version is also adequate and has been used to monitor source waters nationwide for many years with
good results. Both versions of the methods should be approved for monitoring and the EPA should leave
the choice to the system or the laboratory analyzing the samples. Furthermore, systems that may apply for
approval of grandfathered data have been using the April 2001 versions and may want to continue
monitoring using the same versions for data continuity.
Response: See Response 1712.
EPA Letter ID: 688
Comment ID: 14746
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Page 47734 - Approval of Updated Versions of EPA Methods 1622 & 1623 (141.705(a))
EPA should approve the latest Cryptosporidium method revisions in the final
LT2ESWTR as long as previous versions of the methods will still be accepted for
grandfathering of historical sample results.
Response: See Response 1712.
Comment Response for the LT2ESWTR 16-13 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
EPA Letter ID: 711
Comment ID: 16567
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 7. EPA requests comment on the proposed method requirements for Crypto analysis,
including the following specific issues:
- Approval of updated versions of EPA Methods 1622 and 1623 - [47732, C3]
Comment: We believe the latest method (June 2003 Draft) should be used for LT2.
monitoring. It contains many detailed clarifications and method improvements regarding the topics (1-1
0). [below found 47732, C3, and 47733, Cl -C2]
Response: See Response 1712.
16.2.3 Comment Code 1713, Matrix spike recoveries, poor recoveries,
data adjustment
Summary of Issues
Comments expressed concern regarding the ability of laboratories to recover Cryptosporidium oocysts
from matrices decreasing the number of false positives. Another comment suggested the approval of BTF
ColorSeed™ for use in QC samples.
Response to Code 1713
Ability of laboratories to recover Cryptosporidium
EPA disagrees with the concerns expressed regarding the ability of laboratories to recover
Cryptosporidium. Subsequent to promulgating the IESWTR, EPA developed an improved
Cryptosporidium method, EPA Method 1622 (and later, 1623), to achieve higher recovery rates and lower
inter- and intra-laboratory variability than previous methods. Methods 1622 and 1623 incorporate
improvements in the concentration, separation, staining, and microscope examination procedures. During
the ICRSS, which required the use of Method 1622 or 1623, a spiking study demonstrated a mean
Cryptosporidium recovery of 43 percent (Cornell et al. 2000). Thus, mean Cryptosporidium recovery
with Methods 1622 and 1623 was more than 3.5 times higher compared to the ICR Method performance
in the earlier spiking study. In addition, the relative variation in recovery from sample to sample was
lower with Methods 1622 and 1623.
EPA agrees that measures should be in place to ensure quality data and reduce the number of false
positive and false negatives. Given the potentially significant implications for PWSs and drinking water
consumers of microbial monitoring under the LT2ESWTR, laboratory analyses for Cryptosporidium
should be accurate and reliable within the limits of approved methods. Therefore, today's final rule
requires PWSs to use laboratories that have been approved to conduct analyses by EPA or the State.
Laboratories seeking approval under the EPA Lab QA Program for Cryptosporidium analysis must
submit an interest application to EPA, successfully analyze a set of initial performance testing samples,
and undergo an on-site evaluation. Laboratories that pass the quality assurance evaluation are approved
for Cryptosporidium analysis under the LT2ESWTR. To maintain approval, laboratories must
successfully analyze a set of three ongoing proficiency testing samples approximately every four months.
Comment Response for the LT2ESWTR 16-14 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Methods 1622/1623 have specific requirements for analysts, QA/QC samples, and ongoing analyst
verification. EPA has concluded that the analyst criteria included in Methods 1622 and 1623 are
reasonable for ensuring that analysts have the experience to evaluate source water samples under today's
rule. The Method requires laboratories to perform initial precision and recovery samples, ongoing
precision and recovery samples, matrix spikes, and verification of analyst performance in addition to the
ongoing proficiency testing completed through the Laboratory QA Program.
Approval of BTF ColorSeed™
At this time, BTF ColorSeed™ is not approved for use in Method 1622/1623. However, BTF is
conducting an Alternative Test Procedure (ATP) in conjunction with EPA, to validate the use of
ColorSeed™ in Method 1622/1623.
Individual Comments on Code 1713
EPA Letter ID: 423
Comment ID: 10573
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: Public water systems are mandated by the proposed rules to place blind faith in the analytical
results provided them by certified laboratories. Analytical results should not be considered valid unless
the laboratory demonstrates it recovers known spiked concentrations of cryptosporidium from the sample
matrix of each system's source water. Experts have testified that some less experienced analysts report
iron bacteria, algae or other organisms as cryptosporidium.
Some analysts may not even recognize cryptosporidium at all. Analytical error can lead to both false
positive and negative results. PWSs should have ready access to standard concentrations of
cryptosporidium oocysts to spike each sample set in order to determine if the laboratory made an
accurate estimate of the organisms present.
Response: See Response 1713.
EPA Letter ID: 442
Comment ID: 10786
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: 40CFR141.705 Analytical Methods
Public water systems are mandated by the proposed rules to place blind faith in the analytical results
provided them by certified laboratories. Analytical results should not be considered valid unless the
laboratory demonstrates it recovers known spiked concentrations of cryptosporidium from the sample
matrix of each system's source water. Experts have testified that some less experienced analysts report
iron bacteria, algae or other organisms as cryptosporidium.
Comment Response for the LT2ESWTR 16-15 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Some analysts may not even recognize cryptosporidium at all. Analytical error can lead to both false
positive and negative results. PWSs should have ready access to standard concentrations of
cryptosporidium oocysts to spike each sample set in order to determine if the laboratory made an
accurate estimate of the organisms present.
Response: See Response 1713.
EPA Letter ID: 466
Comment ID: 11014
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: be a financial concern to systems in ND. Not only are the number of laboratories limited but
their capabilities may force a system to add unnecessary and costly treatment options. Thus far,
laboratories have been limited in their ability to recover spiked concentrations of Cryptosporidium
samples. Algae, iron bacteria or other organisms have falsely been reported as Cryptosporidium.
Response: See Response 1713.
EPA Letter ID: 614
Comment ID: 12969
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Laboratory Capacity/Issues
* Suggest approval of BTF ColorSeed for spiking QC Samples.
Response: See Response 1713.
16.1.3.1 Comment Code 1714, Frequency of matrix spike
analyses
Summary of Issues
Comments expressed concern that the frequency of the ongoing precision and recovery (OPR) samples
restricted lab capacity. One comment agreed with the required frequency of matrix spike (MS) samples;
however, two comments suggested matrix spikes were not performed frequently enough. It was also
suggested that the MS requirement be deleted for both grandfathered data and required monitoring. One
comment suggested a language clarification regarding the frequency of matrix spikes for PWSs sampling
more than once per month.
Response to Code 1714
Comment Response for the LT2ESWTR 16-16 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
OPR frequency
EPA disagrees that the frequency of OPR samples should be changed from 1 per 20 samples or 1 per
week as stated in Method 1622/1623 to 1 per day. Systems must analyze for Cryptosporidium using
Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA, 2005, United States
Environmental Protection Agency, EPA-815-R-05-002 or Method 1622: Cryptosporidium in Water by
Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA-815-R-05-001. The
revisions in these versions include increased flexibility in some QC requirements, clarification of certain
method procedures, an increase in the allowable sample storage temperature to 10°C, the addition of
several approved analysis modifications, and other refinements. Today's rule requires the use of methods
1622 or 1623 because they are the best available methods that have undergone full validation testing.
EPA believes that the frequency of one OPR test per 20 samples is appropriate for identifying and
correcting problems. For example, if an OPR test is performed once per day for a laboratory that
processes 60 samples per day, a problem that occurs at sample 10 will be continued through the next 50
samples. If an OPR test is performed once per 20 samples, a problem that occurs at sample 10 would only
affect 10 additional samples. Consequently, EPA is maintaining the current QC criteria in Methods 1622
and 1623.
Matrix spike frequency
EPA disagrees that the matrix spike frequency should be less frequent than 1 every 20 samples or deleted.
As required by Method 1622 and 1623, PWSs must have 1 MS sample analyzed for each 20 source water
samples. This applies to both required monitoring and grandfathered data. These methods were used
during the ICRSS, where MS samples indicated a mean recovery and relative standard deviation of 43
and 47 percent, respectively (Connell et al. 2000). EPA expects that PWSs will achieve comparable
performance with these methods during source water monitoring under today's rule. With the minimum
sample volume and QC requirements in today's rule, this level of performance will be sufficient to assign
PWSs to Cryptosporidium treatment bins and realize the public health goals intended by EPA and the
Advisory Committee for the LT2ESWTR. As suggested in the Microbial Laboratory Guidance Manual
for the LT2ESWTR, MS samples may be analyzed more frequently than one every 20 field samples to
better characterize method performance in the matrix.
The requirement that "at least 12 months must elapse between the first and last MS samples" only applies
to PWSs sampling on a monthly basis not to those PWSs that sample more frequently.
Individual Comments on Code 1714
EPA Letter ID: 437
Comment ID: 10612
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: General Comment: Quality control is of major importance in the execution of the
Method 1623.
However, the performance of an excessive and unnecessary number of quality control samples will
impact the total capacity of the samples that can be processed by a commercial laboratory such as ours.
Comment Response for the LT2ESWTR 16-17 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
The requirement for a set of OPR samples (positive and negative controls) for every 20 samples will be an
onerous burden on high capacity laboratories. Our laboratory expects to perform OPR samples daily,
however, during the LT2 sampling period there will very likely be days when more than 20 samples will
be delivered. Upon receipt of the 21 st sample a technician will be required to stop working on client
samples and begin processing a second OPR sample for that day. Given that samples are typically
delivered each morning, more than one set of OPR samples may be run simultaneously. The scientific
basis for the "once in every 20 th sample" rule is unclear and seems to be an arbitrarily set limit that holds
little to no significant meaning for this particular method. Therefore, not only will there be OPR samples
generated unnecessarily, there will be fewer technicians (overall) available to work on client samples.
Since the EPA is concerned about laboratory capacity this is one area that can be modified to help to
improve laboratory throughput without any significant impact on data quality. Please re-word this
requirement to, "...once in every 20 th sample or a maximum of oneOPR set per day".
Response: See Response 1714.
EPA Letter ID: 449
Comment ID: 10831
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: In section IV.K. 1 EPA is requesting comment on increasing the frequency of MS (matrix
spike) samples. Based on our experience, we feel that the current rules involving matrix spike samples are
acceptable and that no additional testing is necessary. In response to the wording in section IV.K.2 we
feel that the current
Response: See Response 1714.
EPA Letter ID: 504
Comment ID: 11364
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: The second limitation is the lack of specific measurement of recovery efficiency for each
water sample. Assessment of IMS-based Cryptosporidium analysis has shown that recovery efficiency is
dependent on sample turbidity. Method 1622/23 requires only that recovery efficiency be measured for
each batch or every 20 samples. Since this is only a general QC check and not taken into account in
determining the measured concentration it might seem that it is unimportant to analysis results. However,
samples of higher turbidity will almost certainly have concentrations underestimated relative to those of
lower turbidity.
We suggest that EPA consider modifications to analytical requirements as suggested above that should
assist in improving data fundamental to meeting rule objectives.
Response: See Response 1714.
Comment Response for the LT2ESWTR 16-18 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
EPA Letter ID: 516
Comment ID: 11747
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: p. 47731. DEP believes that EPA should re-evaluate the requirement for matrix spiking under
Method 1623 that systems must have only 1 matrix spike for each 20 source water samples. Specifically,
DEP believes that it would be prudent to require 1 matrix spike per sampling event per source water, if
the samples are collected for the purposes of binning or log removal requirements. Considering the
criticality to which these data will be used and the low cost of matrix spiking in relation to the overall cost
of the decision (rule compliance), a spiking frequency of 1 per 20 would result in only two matrix spikes
for a given source water over a 24 month sampling period. For the last several years, DEP has performed
analyzed matrix spikes at a frequency of once per week, at our source water keypoints. Matrix spike
duplicates are analyzed at a rate of once per month. Through this extensive QA effort, on at least one
occasion, we identified a transient recovery problem that appeared to be related to the algal assemblages
in the source water. We would be glad to share that data with EPA, upon request. Therefore, DEP
believes that the proposed protocol of one matrix spike per 20 is inadequate for the purposes of binning.
There should be one matrix spike per separate source water per month.
Response: See Response 1714.
EPA Letter ID: 562
Comment ID: 12393
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: gaps in a preexisting sample data set. EPA-s Source Water Monitoring Guidance Manual for
Public Water Systems for the LT2ESWTR provides a useful summary of the agency-s expectations for
preexisting data. Two additional data quality expectations enumerated in this guidance are unnecessary
when reviewing preexisting data:
1. Analysis of a matrix spike at least every 20 monitoring samples, and
AWWA agrees with proposed guidance that a matrix spike sample that fails QA/QC need not be re-
sampled. Moreover, AWWA recommends that the matrix spike sample requirement be struck from the
guidance. This requirement is
Response: See Response 1714.
EPA Letter ID: 641
Comment ID: 13619
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 3.2.7 - Paragraph 3 "-at least 12 months must elapse between the first and last MS
sample-"
Comment Response for the LT2ESWTR 16-19 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
ASI recommends revising to include that for PWSs sampling more than once per month, the 1 MS per 20
samples must still be observed.
Response: See Response 1714.
EPA Letter ID: 641
Comment ID: 13639
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Checklist for Submitting GF Data - Please see comments under PWS Guidance Manual,
Appendix B MS sample results - ASI recommends revising to include that for PWSs sampling more than
once per month, the 1 MS per 20 samples must still be observed.
Response: See Responses 389 and 1714.
EPA Letter ID: 641
Comment ID: 13672
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 2. -One OPR must be analyzed each week or every 20 field and MS samples, whichever is
more frequent.- a. ASI recommends that this requirement should be revised to include -Laboratories that
process (from elution through IMS) more than 20 samples on a single calendar day, may consider these
samples as a single batch and perform a single OPR and blank for this batch.- b. A laboratory may
receive 100+ samples per week , with the majority of the samples arriving towards the end of the week.
Forcing large laboratories to halt operations after 20 sample blocks to complete another OPR, or to
artificially create divisions within the lab for OPR batches and sample allocation, or otherwise restrict
capacity to meet this criterion does not serve the Rule. c. To reiterate, ASI recommends to analyze one
OPR to cover the samples processed during a single day, regardless of the number of samples received
and processed. This would provide a check on reagents, stains, procedures, equipment, etc., while not
unduly impacting capacity, i. Further, ASI proposes that laboratories be allowed to begin processing OPR
samples for any given batch prior to completion of the preceding batch(es), in order to allow response
time in the event of a QC failure, ii. We are not proposing this revision be taken to its extreme, for
example, we do not recommend that laboratories be allowed to batch all OPR samples for the week on
Monday d. ASI envisions the current -1 in 20- OPR requirement as the single largest barrier to laboratory
capacity. Based on current workload expectations, the 1 in 20 requirement would require ASI to process
up to 2 to 4 OPRs in a typical work day. This would require completing each OPR prior to initiating the
next batch of 20 samples so as to not jeopardize sample data integrity (and resampling) in the event of a
QC failure and, therefore, would cause very significant delays in initiation of sample batches, which could
compromise protocol hold times, etc.
Response: See Response 1714.
Comment Response for the LT2ESWTR 16-20 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
16.2.4 Reporting total oocysts
16.2.4.1 Comment Code 1716, Adjustment for empty or non-
infectious oocysts
Summary of Issues
One comment stated agreement with the definition of an oocyst to report and with not including method
recovery in the calculation of the final concentration of oocysts. Another comment disagreed with EPA's
approach toward estimating the risk for some systems especially those that achieve higher recoveries and
have lower rates of infectious oocysts. This comment pointed out that unfiltered systems typically do not
have sewage influence and have a detention time of months or years. The comment suggested including
data on different Cryptosporidium genotypes in the risk model and suggested recovery and degree of
infectiousness do not off-set for every system. Another comment noted that the methods used will not
detect the improvements (UV disinfection addition) being completed at wastewater facilities.
Response to Code 1716
Adjustment for empty or non-infectious oocysts
EPA agrees with the definition of a reportable oocyst according to today's rule. PWSs must report total
Cryptosporidium oocysts as detected by FITC as determined by the color (apple green or alternative stain
color approved for the laboratory under the Lab QA Program), size (4-6 micrometers) and shape (round to
oval). This total includes all of the oocysts identified as described here, less any atypical organisms
identified by FITC, DIC, or DAPI (e.g., possessing spikes, stalks, appendages, pores, one or two large
nuclei filling the cell, red fluorescing chloroplasts, crystals, spores, etc.).
EPA concurs with the recommendation that monitoring results should not be adjusted to account for
either recovery or the fraction of oocysts which are infectious which cannot be determined by methods
1622/1623. Two considerations that relate to characterizing Cryptosporidium monitoring results to
determine treatment requirements are (1) fewer than 100 percent of oocysts in a sample are recovered and
counted by the analyst and (2) not all the oocysts measured with Methods 1622 or 1623 are capable of
causing infection. These two factors are offsetting, in that oocyst counts not adjusted for recovery tend to
underestimate the true concentration, while the total oocyst count typically overestimates the infectious
concentration that presents a health risk. EPA has analyzed all of the available infectivity data using an
expanded range of models. Substantial uncertainty about the infectivity parameter remains in several
areas. These include the variability in host susceptibility, response at very low oocyst doses typical of
drinking water ingestion, and the relative occurrence of different Cryptosporidium isolates in the
environment. Nevertheless, the available infectivity data suggest the risk associated with a given
concentration of Cryptosporidium is most likely higher than EPA had estimated for the Interim Enhanced
Surface Water Treatment Rule (IESWTR). This finding supports the need for increased treatment for
Cryptosporidium as required under the LT2ESWTR. PWSs are classified in treatment bins using the total
number of Cryptosporidium oocysts counted, without further adjustment. The LT2ESWTR treatment bins
in today's rule are constructed to reflect this approach.
Because the methods do not determine infectious vs noninfectious oocysts, EPA agrees that the
monitoring will not detect improvements (UV disinfection) potentially made by wastewater treatment
facilities. Again, the risk analyses considered the lack of infectivity knowledge from the monitoring and
this risk analysis supports the treatment bin classifications as discussed above.
Comment Response for the LT2ESWTR 16-21 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
EPA disagrees that this risk-based approach is not applicable to all systems specifically unfiltered
systems. Only the ICR provided data to evaluate Cryptosporidium occurrence in unfiltered PWS sources.
The median Cryptosporidium level among unfiltered PWS sources was 0.0079 oocysts/L. This level is
approximately 10 times lower than the median level for filtered PWS sources. When the Cryptosporidium
removal that filtered PWSs achieve is taken into account, these occurrence data suggest that unfiltered
PWSs typically have higher concentrations of Cryptosporidium in their treated water than filtered PWSs.
EPA has estimated that conventional filtration plants commonly remove around 99.9 percent (3-log) of
the Cryptosporidium present in the source water.
Most unfiltered PWSs, however, provide no treatment for Cryptosporidium. If an unfiltered PWS had a
source water Cryptosporidium level 10 times lower than a filtered PWS and the filtered PWS achieved 3-
log Cryptosporidium removal, then the Cryptosporidium level in the treated water of the unfiltered PWS
would be 100 times higher than in the filtered PWS. These results suggest that to achieve public health
protection equivalent to that provided by filtered PWSs, unfiltered PWSs must take additional steps.
Therefore, EPA continues to believe that all unfiltered PWSs should provide treatment for
Cryptosporidium to protect public health. Monitoring has shown that unfiltered PWS sources are
contaminated with Cryptosporidium, and no source is likely to be entirely free of Cryptosporidium due to
the ubiquity of Cryptosporidium in both human and many animal populations. Studies have established
that Cryptosporidium from animals can infect humans. EPA does not regard the absence of
cryptosporidiosis cases attributed to drinking water in a particular community as evidence that no
treatment for Cryptosporidium is needed.
Individual Comments on Code 1716
EPA Letter ID: 390
Comment ID: 10491
Commenter: Jeff Taylor, Deputy Director, City of Houston Public Utilities Division
Commenter Category: Regulated Community (Utilities)
Comment: 1. We agree that only individual confirmed (not presumed) oocysts should be counted for bin
determination purposes with no calculation of total concentration based on method recovery
determinations. EPA is correct in offsetting the likely infectivity of the observed spore concentration with
the numerical adjustment obtained by applying a recovery factor.
Response: See Response 1716.
EPA Letter ID: 516
Comment ID: 11740
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: is derived from the work of LeChevallier. DEP believes that EPA-s approach biases the
analysis towards overestimating the risks for some systems which get greater recoveries of oocysts, and
lower rates of infectious oocysts. For example, DEP achieves an average recovery of approximately
50+%. LeChevallier, too, demonstrated much higher recoveries than 40% were achievable in the six
watersheds that were studied in the paper cited by EPA. Further, EPA-s assignment of a narrowly defined
triangular distribution (Mode of 40%) for the percentage of oocysts that are infectious suggests that all
Comment Response for the L T2ESWTR 16-22 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
watersheds are alike with regard to the type and degree of infectiousness of the oocysts. EPA could have
calculated a lower bound, using the LeChevallier data indicating that, for example, the relatively pristine
watershed in Oregon had a percentage of infectious oocysts that was closer to 20%. By their nature, the
source waters of unfiltered supplies are significantly more likely to have a higher fraction of older, more
degraded, and non-infectious oocysts. While for the purpose of the binning procedure in the proposed
rule, the unfiltered systems agreed with the simplifying approach to treat all enumerated oocysts as if they
were the same, they are not. Many filtered systems have direct discharges of sewage treatment effluent to
their sources, in some cases in large volumes and in close proximity to their intakes, presenting an
opportunity for fresh, human infectious oocysts to arrive quickly at their treatment plants. This is not the
case for unfiltered systems. The detention time in most unfiltered systems is substantial: not hours or days
from pollutant source to intake, but months or years. The physical nature of these systems serves to allow
for natural degradation, reducing the potential of any given enumerated oocyst to be infectious. And
certainly, watershed characteristics, vulnerability to point sources of human fecal material (e.g.
wastewater treatment plants and CSOs), and potential sensitivity to environmental degradation such as
travel time from the watershed to the distribution system, should have been considered by EPA as part of
the modeling exercise and sensitivity analysis and as to whether recovery and infectiousness are
offsetting.
Additionally, EPA should factor in, at least for risk modeling purposes data on the different types of
crypto genotypes that might be found in different watersheds. For example, DEPDEP has worked in
collaboration with the CDC and applied a PCR-RFLP technique based on the small sub-unit rRNA gene
to storm water samples collected in two sub-basins of the DEP watershed (Ashokan Brook and Malcolm
Brook). Of the 59 PCR positive samples from storm water, 54 (91.5%) were linked to either known or
unknown animal sources. The exceptions were three samples collected from Malcolm Brook within a two
week period, where genotypes were discovered from non-human animal sources along with a few typed
as C. hominus, suggesting a human source. Malcolm Brook storms were monitored for the next year;
however, C. hominus was not recovered again. Several genotypes were discovered in both watersheds
including: W4 (cervid) genotype from deer, W7 (muskrat) genotype, Wl 1 (snake) genotype and Wl
genotype from an unknown animal source (probably rodents). Several Cryptosporidium genotypes were
commonly seen in Ashokan Brook: a type from birds, two types from opossum, and some from unknown
animals; however, these were not seen in Malcolm Brook. Likewise, there were a few types recovered
from Malcolm Brook that were not seen at Ashokan Brook - fox, rodent, and an unknown animal source.
In summary, DEP believes that EPA has not made a case that recovery and degree of infectiousness are
off-setting for all systems, and with the implied conclusion that all watersheds are alike. As part of an
uncertainty analysis, EPA should look at the sub-set of systems that are unfiltered to determine whether
there are differences in filtered and unfiltered systems (such as recovery and infectiousness) that should
be accounted for in determining relative risks between filtered and unfiltered systems, and the need for
additional treatment.
p. 47645. EPA indicates that it is not proposing any changes to the MCLG for cryptosporidium at this
time. At a minimum, EPA should restate the MCLG to be zero oocysts that are infective in humans.
While at this time, the testing methods are not adequate to distinguish the degree of infectivity of each
oocyst, such methods may be available in the future.
Response: See Response 1716.
EPA Letter ID: 527
Comment ID: 10861
Comment Response for the L T2ESWTR 16-23 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should recognize that wastewater treatment facilities are currently examining ways to
avoid excessive chlorination of effluents to achieve whole effluent toxicity requirements under the Clean
Water Act. Water systems encouraging or negotiating the use of ultraviolet light disinfection as part of
their watershed protection program could have significant impacts on the presence of-viable and
infectious- Cryptosporidium in their source waters. Note that none of this improvement would be
detected by present analytical methods that merely count oocysts, whether they are inactivated or not (UV
does not destroy the oocyst, it merely inactivates it).
Response: See Response 1716.
EPA Letter ID: 527
Comment ID: 10861
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should recognize that wastewater treatment facilities are currently examining ways to
avoid excessive chlorination of effluents to achieve whole effluent toxicity requirements under the Clean
Water Act. Water systems encouraging or negotiating the use of ultraviolet light disinfection as part of
their watershed protection program could have significant impacts on the presence of-viable and
infectious- Cryptosporidium in their source waters. Note that none of this improvement would be
detected by present analytical methods that merely count oocysts, whether they are inactivated or not (UV
does not destroy the oocyst, it merely inactivates it).
Response: See Response 1716.
16.2.5 Comment Code 1717, Subjectivity of microscopy, third-
party review of slides
Summary of Issues
The comments expressed concern that the analyst verification requirements as stated in Methods
1622/1623 were excessive and would increase an analyst's time at the microscope and reduce lab capacity
for client samples. The comments suggested changes to the analyst verification procedure by deleting the
DAPI positive/negative determination for an entire slide, deleting or decreasing the number of oocysts
described by all analysts on DIG, and decreasing the frequency of the analyst verification requirement.
Response to Code 1717
Analyst verification
According to the rule, systems must analyze for Cryptosporidium using Method 1623: Cryptosporidium
and Giardia in Water by Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA-
Comment Response for the L T2ESWTR 16-24 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
815-R-05-002 or Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2005, United States
Environmental Protection Agency, EPA-815-R-05-001. Verification of analyst performance is a required
QC component of both methods. These components will be promulgated with the rule. The purpose of the
analyst verification is to encourage comparison and discussion among analysts to refine the consistency of
characterizations between analysts. EPA disagrees that monthly verification of analyst performance is too
frequent. Higher concentrations of organisms have been recommended in the December 2005 versions of
the methods to expedite analytical time to find organisms for characterization. The 2005 version requires
examination of only 10 oocysts for DAPI characterization by all analysts.
Individual Comments on Code 1717
EPA Letter ID: 514
Comment ID: 11541
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: 2) Verification of analyst performance
a. 10.6.2. The requirement that each analyst must determine the number (of oocysts) that are DAPI
positive and DAPI negative should be removed. The DAPI stain fades after each reading so results could
(and are) different when different analysts read the same slide. We see no value with this exercise and
adds time to the analysis. DAPI (as well as DIC) characterization is already done on 3 cysts and oocysts
each day of reading. It is redundant to require it again. We agree that each analyst should determine the
total number of oocysts (by FA) and be within 10%. We also recommend removing the monthly
requirement for each analyst to characterize 10 oocysts (both DAPI and DIC). This type of verification is
more suited to initial demonstration of capability for new analysts than to verify the capabilities of already
trained analysts. It also adds an additional hour to analysis time which is not necessary.
Response: See Response 1717.
EPA Letter ID: 516
Comment ID: 11753
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Section 10.6.3 indicates a QC minimum of a monthly group analysis of a prepared slide to
show analyst comparability. Counting the slide and comparing the number of organisms and the DAPI
results between all analysts is a good idea, and DEP has this as part of current routine QC.
However, for the entire group of analysts to do the above, and now in addition, take turns looking at 10
individual organisms one by one to characterize the DIC interpretation is quite excessive and time
consuming, especially every month. Both the proposed number of examinations, and the frequency of this
group exercise are beyond what is necessary to ensure analyst comparability. DEP recommends reducing
the DIC characterization by the group of analysts to only 3 organisms a month, or, decreasing the
frequency of this QC to quarterly.
Response: See Response 1717.
Comment Response for the L T2ESWTR 16-25 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
16.2.6 Comment Code 1719, Approach to matrix spike samples
when sampling above 10 L
Summary of Issues
Commenters agreed with the proposed matrix spike sample collection protocol for samples greater than
10L. Commenters recommended that it be included in the method along with a notation that matrix spike
recoveries may be different due to the volume collected, spiked, and filtered. A commenter expresses
concern that if a SOL MS can now be collected as 40L filtered in the field, followed by 10L spiked in the
lab and run through the same filter; then the OPR samples for that same batch should also be analyzed in
the same fashion. Another comment endorsed the collection of MS using split sampling or sequentially
and no resampling for MSs that do not pass criteria.
Response to Code 1719
Matrix spike sample collection greater than 10 L
EPA agrees with the protocol for spiking samples >10 L as stated in the rule: if the volume of the MS
sample is greater than 10 L, the system may filter all but 10 L of the MS sample in the field, and ship the
filtered sample and the remaining 10 L of source water to the laboratory. In this case, the laboratory must
spike the remaining 10 L of water and filter it through the filter used to collect the balance of the sample
in the field.
EPA disagrees that a notation regarding matrix spike recoveries needs to be included. As stated in the
Source Water Monitoring Guidance Manual for LT2ESWTR, PWSs may collect MS samples by splitting
their sample stream and collecting the monitoring sample volume and MS sample volume simultaneously
or collecting the MS sample immediately before or after the monitoring sample. MS sample results will
not be used to adjust Cryptosporidium recoveries at any individual source water; but MS results would be
used collectively to assess overall recovery and variability for EPA Method 1622/1623 in source water.
No resampling is necessary for MS samples that do not meet Method 1622/1623 recovery guidelines.
LT2 samples are associated with QC samples through a "QC batch." A QC batch consists of an OPR and
method blank and a maximum of 20 field and MS samples that are eluted, concentrated, and purified in
the same week as the OPR and method blank samples using the same reagents (i.e., eluting solution). A
laboratory that processes different sample volumes should demonstrate ongoing acceptable performance
at both extremes of the volume spectrum by performing one OPR and method blank at a volume
consistent with the highest sample volume submitted by clients (e.g. 50 L) and performing a second OPR
and method blank at a volume consistent with the lowest sample volume submitted by clients (but not less
than 10 L). Labs analyzing multiple sample volumes, should demonstrate acceptable performance in a
manner representative of the sample volumes they process i.e. at the same percentage as volumes in field
samples submitted to the laboratory. Frequency of OPR's with different volumes should be consistent
with the frequency of samples with different volumes. Laboratories should work with their PWS clients to
attempt to schedule clients with different sample volume sizes for different periods during the week, so
the field samples can be batched with QC samples of comparable volume. EPA encourages systems to
analyze similar sample volumes throughout the monitoring period. However, data sets including different
samples volumes will be accepted, provided the system analyzes the minimum sample volume
requirements noted above.
Comment Response for the L T2ESWTR 16-26 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Individual Comments on Code 1719
EPA Letter ID: 516
Comment ID: 11748
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Comments on Cryptosporidium Sampling and Analysis Procedures
- Comments on Preamble Section IV.K.l.b.
DEP concurs with the proposed alternate matrix spike sample collection for samples greater than 10 liters
(i.e. field filtering 40L and spiking 10L in the laboratory) and it should be included in Method 1623 (6/03,
USEPA 2003k). However, DEP also recommends that a notation be included here, as well as within
Method 1623, in order to notify laboratories to what extent this will/may change laboratory matrix spike
percent recoveries since spiking 10L is different than spiking SOL. (DEP recalls that during the study the
HV filter mean MS recovery for a SOL spike was 56 %, whereas the mean MS recovery for the 10L
spikes was 72%.).
Response: See Response 1719.
EPA Letter ID: 516
Comment ID: 11749
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Since there are differences in recovery between spiking 10L and spiking SOL, DEP is
wondering if EPA has considered changing the OPR spiking method to 40L + 10L as well to match MS
samples in the same batch? If a SOL MS can now be collected as 40L filtered in the field, followed by 10L
spiked in the lab and run through the same filter; then shouldn't the OPR samples for that same batch also
be analyzed in the same fashion (40L DI filtered, then 10L spiked and filtered through the same filter)?
The OPR is often referred to as the recovery attainable without matrix interference. Therefore, at times,
the MS recovery is compared to the OPR recovery. For example, when an OPR recovery is 60% and the
matrix recovery is 40%, it is generally considered that the matrix studied interfered with recovery by
about 20%. If the OPR is performed spiking SOL, but the MS is performed spiking 10L then differences
between the recovery of an MS and an OPR may be more related to spiking different volumes rather than
being a measure of matrix interference.
Some utilities will be collecting 10L, others SOL. There are noted recovery differences between these
volumes especially in difficult matrices. Is it being considered that two utilities with similar water quality
could generate different results solely based on the volume they choose to collect for the LT2?
Response: See Response 1719.
EPA Letter ID: 641
Comment ID: 13608
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment Response for the L T2ESWTR 16-2 7 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Comment: Matrix Spike Samples - ASI agrees that PWSs should be allowed to field filter all but 10L of
the MS sample, and ship 10L in bulk for lab spiking.
Response: See Response 1719.
EPA Letter ID: 641
Comment ID: 13631
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 6.4.2.1 ASI agrees that for MS samples >10L, PWSs should be allowed to field filter
all but 10L of the MS sample (and submit the remaining 10L as a bulk sample for spiking). Shipping
larger volumes to the lab for spiking and filtering is very expensive and unnecessary.
Response: See Response 1719.
16.2.7 Comment Code 1720, Other comments on use of Method
1623
Summary of Issues
Many comments agreed with the use of Method 1622/1623 and the improvements made; however, two
comments expressed concern with its use for monitoring because of low recoveries and cost. Many
comments agreed with changing the receipt and storage temperature from 8° to 10°C. One commenter
agreed with using any standard technique that was able to be calibrated to ascertain the receipt
temperature. Another comment suggested making the temperature and time limits less restrictive. One
comment disagreed with the requirement of purchased HC1 and NaOH; another comment agreed with the
requirement. Other comments disagreed with the flexibility in the MS sampling timing stating that it
needs to be a requirement to complete a MS the first time source water is sampled. It was suggested that
EPA add a requirement to record pressure at time of collection, add the sampling protocols, add a plan of
action to follow in case of QC failures, add guidance regarding the required QC for additional rinses, the
use of methanol, and clarify that shipping should occur overnight.
Response to Code 1720
General comments supporting changes to the methods including holding time and temperature
requirements
The final rule reflects comments supporting the use of Method 1622/1623 and the changes and
improvements to the methods and associated documents including the clarification and incorporation of
temperature requirements and holding times.
Low recovery rates in Methods 1622 and 1623 and utility expense
EPA disagrees that the low recovery rates of Methods 1622 and 1623 do not justify the PWSs expense to
meet the treatment requirements. Today's rule requires the use of Methods 1622 or 1623 because they are
the best available methods that have undergone full validation testing. These methods were used during
Comment Response for the L T2ESWTR 16-28 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
the ICRSS, where MS samples indicated a mean recovery and relative standard deviation of 43 and 47
percent, respectively (Connell et al. 2000). EPA expects that PWSs will achieve comparable performance
with these methods during source water monitoring under today's rule. With the minimum sample
volume and QC requirements in today's rule, this level of performance will be sufficient to assign PWSs
to Cryptosporidium treatment bins and realize the public health goals intended by EPA and the Advisory
Committee for the LT2ESWTR.
Secondly, to defray the costs associated with complying with the rule requirements, smaller utilities
serving less than 10,000 individuals are permitted to monitor E. coli concentrations as an alternate trigger
organism. This monitoring is much less expensive than Cryptosporidium monitoring, and should help
smaller utilities to comply with the requirements in a cost-effective manner.
Temperature and holding times
EPA agrees that the acceptable temperature range for receipt of samples should be changed to allow for
sample temperature to exceed 10°C; however, storage should be maintained between 1°C and 10°C
whenever the samples are not in transit. The QC criteria have been modified to allow for C and not
frozen. Laboratories must reject LT2Ereceipt of samples at <20 Cryptosporidium samples that are
received at >C (unless they are analyzedE20 the same day they are collected). In these cases, the PWS
must re-collect and re-ship the sample. An increase in the range of acceptable temperatures for sample
receipt was based on recent publication of research investigating the infectivity of oocysts stored at 20°C.
No evidence of significant degradation of the oocysts was noted for samples exposed to 20°C for <2 days.
EPA disagrees that holding times are too restrictive and the time allotted for shipping could be
misinterpreted. Method 1622/1623 states that processing should be completed as soon as possible;
however, the laboratory is permitted to split up the sample processing steps after filtration, application of
the purified sample onto the slide, or staining. These holding times allow some flexibility in processing
for the laboratory. As long as holding times are met (i.e., elution must be initiated within 96 hours of
sample collection or filtration), the time at which samples must be shipped is flexible. Section 8.1.2 of the
June 2003 version of Method 1623 clearly states the requirements for shipping samples: Samples should
be chilled to reduce biological activity, and preserve the state of source water samples between collection
and analysis. Sample analyzed by an off-site laboratory should be shipped via overnight service on the
day they are collected.
Necessity of additional rinses for OPR sample
EPA agrees that an OPR sample is needed in the case that additional rinses are being used on field
samples to reduce carry-over of debris. OPRs with additional rinses should be processed at the same
percentage that additional rinses are used on field samples. MS samples should be processed using the
same method variation as the associated field sample to demonstrate ongoing acceptable laboratory
performance.
Necessity of the methanol fixation step
EPA agrees that the use of the methanol fixation step is required only when stated as per the
manufacturer's instructions. Method 1623 states in Section 14.2 that slide staining is per manufacturer's
instructions.
Mandatory purchasing of HC1 and NaOH at laboratories
EPA disagrees that purchasing of HC1 and NaOH should be recommended as opposed to mandatory. This
change was incorporated in the revised 2005 version of the method as compared to the original
Comment Response for the L T2ESWTR 16-29 December 2005
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recommendation in the April 2001 method. The pH adjustment [at whatever step] is extremely critical so
EPA believes the best way to insure accurate normality of these solutions is to purchase them
commercially.
Timing of matrix spike sample analysis
EPA disagrees that it should be a requirement that matrix spike samples collected during the first
sampling event to assess method performance. It may not be possible to analyze an MS sample during the
first sampling event due to laboratory sample processing burden or other reasons. In this case, the first
MS sample should be analyzed as soon as possible to identify potential method performance issues with
the matrix.
Additional recommendations
With respect to the recommendation that pressure be recorded for all LT2 samples, according to the
Source Water Monitoring Guidance Manual for LT2ESWTR, the pressure is monitored and reduced if
necessary. Pressure is not one of the required primary data points as stated in 40 CFR part 141.706(e)(l)-
(2); therefore, it is not required for the PWS to record. Detailed sampling protocols are included in the
Source Water Monitoring Guidance Manual for LT2ESWTR. EPA disagrees that a specific plan of action
for QC failures is not available. The Microbial Laboratory Guidance Manual for LT2ESWTR gives
guidance to laboratories regarding failed QC and required replacement samples.
This document is available to both laboratories and PWSs. As stated in Section 3.1.1 of the Microbial
Laboratory Guidance Manual for LT2ESWTR, laboratories should have a protocol in place to divert
samples to another approved laboratory in the event that their approval status changes. PWSs are also
recommended to secure contracts with both a primary and secondary analytical laboratory during LT2
required monitoring. A PWS may choose to use the secondary analytical laboratory in the event the
primary laboratory approval status changes.
Individual Comments on Code 1720
EPA Letter ID: 411
Comment ID: 10562
Commenter: Devon Cole,, Utah Department of Health Laboratory
Commenter Category: State/Tribe Government
Comment:
Addition of the requirement to examine 10 oocyts and 10 cysts using DIC to the analyst verification
procedure increases the amount of time needed for microscopy analysis. This may limit the number of
samples that can read in the 4 hr/day microscope time constraint.
Response: See Responses 1717 and 1720.
EPA Letter ID: 411
Comment ID: 10565
Commenter: Devon Cole,, Utah Department of Health Laboratory
Commenter Category: State/Tribe Government
Comment Response for the L T2ESWTR 16-3 0 December 2005
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Comment:
June 2003 versions of Method 1622/1623 provide for additional rinses to minimize carry-over of debris at
MPC-1 and MPC-M steps. When performing additional rinses, does the OPR sample also need additional
rinses to ensure the sample batch is not affected?
Response: See Response 1720.
EPA Letter ID: 411
Comment ID: 10566
Commenter: Devon Cole,, Utah Department of Health Laboratory
Commenter Category: State/Tribe Government
Comment:
June 2003 versions of Method 1622/1623 discontinue the methanol fixation step in lieu of following
manufacturer's instructions for the staining procedure. If methanol fixation is not included in the staining
procedure, should it not still be completed?
Response: See Response 1720.
EPA Letter ID: 437
Comment ID: 10611
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: We encourage US EPA to increase the holding temperature of the samples from 8 o C to 10 o
C. Our experience has shown that, even when samples are packed appropriately (especially during the
summer months), the sample temperature can not be maintained at or below 8 o C if not pre-chilled.
Samples (especially 10 L grab samples) must be pre-chilled to well below shipping temperature prior
to packaging and shipment. However, in some cases there may not enough time to take the sample at a
remote location, chill the sample adequately, pack the sample on ice and ship it so that it arrives to the
laboratory in time and under the current 8 o C upper limit. We believe that 10 o C is a more consistently
attainable goal for the bulk samples.
We support all of the changes to Method 1622/23 proposed in this section with the exception of:2. ...
requiring (rather than recommending) that laboratories purchase HC1 and
NaOH . We believe that this should remain a recommendation.
Response: See Response 1720.
EPA Letter ID: 440
Comment ID: 10800
Commenter: Gary Hum, Director of Source & Treatment, Central Arkansas Water
Commenter Category: Regulated Community (Utilities)
Comment Response for the L T2ESWTR 16-31 December 2005
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Other EPA Comment Codes and Descriptions: 361 1. 5-day sampling window and allowable
exceptions; 381 1. Sample acceptance criteria (frequency, volume, analytical method)
Comment: 1. Cryptosporidium monitoring for bin placement: The source water
monitoring requirements should allow increased flexibility for sample
collection and data quality. More latitude should be allowed in regards to
the available sampling period window, the sample temperature requirements,
missing data, and acceptance of grandfathered data.
Response: See Responses 360(A) and 381(A) and (B).
EPA Letter ID: 449
Comment ID: 10827
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: Another concern that we have is the effectiveness of the current methods used to test for
cryptosporidium. In section 141.705, it states that utilities must use method 1622 or 1623 when
performing cryptosporidium testing. It is our understanding that both of these methods have about a 40%
recovery rate. This seems to be a very ineffective method to justify the cost that utilities would have to
spend on testing and ultimately spend to upgrade their facilities to meet the new requirements.
Response: See Response 1720.
EPA Letter ID: 504
Comment ID: 11362
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: 6. Analytical Flexibility
Analytical requirements are rigid and out of proportion with the relatively small effect on results that
could result from departing from prescribed limits. For example, acceptability of an analytical result is
judged according to strict control of temperature and time limits. Published data are only general
supportive of an adverse effect on analytical results derived from samples maintained at 15° C, rather than
10° C. Similarly, little hard data support the rigid time limits imposed on sample processing. We
recommend that EPA reconsider some of the more restrictive criteria such as temperature and processing
time and provide more flexibility to reduce the likelihood of rejecting an analytical result.
Response: See Response 1720.
EPA Letter ID: 514
Comment ID: 11539
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Comment Response for the L T2ESWTR 16-32 December 2005
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Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: June 2003 version: The use of the updated version (dated June 2003) is necessary and easier
for laboratories to address LT2 rule monitoring requirements, especially the change in sample storage and
shipping temperatures to -<10° C, and not frozen.- Facilities have difficulty shipping samples to our
laboratory in the summer months, even after following the shipping suggestions in the Guidance
document. The June 2003 draft revisions of EPA Methods 1622 and 1623 should be approved for
monitoring under the LT2ESWTR, rather than the April 2001 version with the following exceptions:
Response: See Response 1720.
EPA Letter ID: 516
Comment ID: 11750
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: DEP is finding that there may be reduced recovery when samples are collected at higher
pressures, even if the sample is collected within the 60psi recommended by the filter manufacturer. DEP
feels strongly that recording sample collection pressure is critical in data analysis and thinks it would be
very beneficial for EPA to require, at a minimum, that utilities record the pressure during sample
collection if not even perhaps limit collection pressure. If pressure is recorded now for the LT2 samples (a
minor task), then additional valuable information may be culled from the LT2 effort at a later date if
collection pressure is confirmed to have an effect on recovery.
Response: See Response 1720.
EPA Letter ID: 516
Comment ID: 11752
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: - Comments on Method 1623 (USEPA 2003k):
DEP highly recommends that EPA include a detailed procedure for field sample collection, for samples to
be analyzed using Method 1623, within the final version of Method 1623. Including sample collection
procedures in the method has been done in previous Cryptosporidium (and Giardia) enumeration
Methods: 1) The Information Collection Rule (ICR) Microbial Laboratory Manual (EPA/600/R-
95/178 April 1996) and 2) Standard Methods for the Examination of Water and Wastewater, 19th Edition
(American Public Health Association, Washington D.C., 1995).
Currently, Method 1623, Section 8 - Sample Collection, does not provide enough information to properly
collect a sample - it refers elsewhere for more detail. DEP feels it is beneficial to include complete sample
collection and analysis procedure in one related document. Right now, the detailed procedure for sample
collection for Method 1623 is in the appendices of a separate document - Appendix E and F of The
Source Water Monitoring Guidance Manual for Public Water Systems for the Long Term 2 Enhanced
Surface Water Treatment Rule (LT2 Rule). These examples provided for sample collection may best be
documented within the method, rather than just part of the LT2 source water monitoring.
Comment Response for the L T2ESWTR 16-33 December 2005
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Additionally, it should be emphasized that these example procedures for field collection, are in fact
examples, and that there is flexibility; albeit minimal, for alternate collection methods to accommodate
multiple study objectives and locations. An example of an alternate sampling apparatus is presented
below [See pdf for figure].
Response: See Responses 471 and 1724.
EPA Letter ID: 562
Comment ID: 12302
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA has taken important steps to make improvements to EPA Method 1622 / 1623. A
number of these improvements, such as qualifying additional filters and modifying hold times, will
facilitate monitoring under the LT2ESWTR. The
Response: See Response 1720.
EPA Letter ID: 562
Comment ID: 12372
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. Monitoring to employ EPA Method 1622 or EPA Method 1623, and
EPA has reflected each of these components in the proposed rule. AWWA continues to believe that each
of these five recommendations is sound and appropriate for the LT2ESWTR. AWWA is concerned about
the specifics of EPA-s implementation of these general recommendations.
Response: See Response 1720.
EPA Letter ID: 562
Comment ID: 12406
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Holding Times and Temperature
EPA has, through recent method revisions to EPA Method 1622/1623, revised holding times and
proposed revision of required holding period temperatures. The revised holding times are important
changes to facilitate processing LT2ESWTR monitoring samples. Likewise, the proposed revision of the
8?C holding temperature to 10?C is an important modification that will facilitate sample management
without significantly affecting method performance. AWWA encourages the agency to continue to
explore sample holding temperature, as at present there is not any specific data that suggests that higher
temperatures would be detrimental to enumeration of presumptive oocysts under LT2ESWTR.
Comment Response for the L T2ESWTR 16-34 December 2005
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Response: See Response 1720.
EPA Letter ID: 592
Comment ID: 12102
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Cryptosporidium testing methodology
Furthermore, almost all of the rules proposed in LT2 hinge on the most current existing testing
methodology for Cryptosporidium, which has a questionable margin of accuracy, at best 50%. Provisions
must be incorporated into this rule
Response: See Response 1720.
EPA Letter ID: 641
Comment ID: 13632
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Section 6.4.5 Monitoring Sample Temperature ASI agrees with the proposed LT2
requirement that samples processed not on the day of collection must be received at the laboratory at
<10°C and not frozen. Increasing the upper limit of acceptable temperature from 8° C to 10°C will
decrease the number of rejected samples in the hot summer months.
Response: See Response 1720.
EPA Letter ID: 641
Comment ID: 13634
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: ASI agrees that the laboratroy should be able to use any standard method that incorporates
daily calibration to determine sample temperature upon receipt, not just those methods/products listed in
herein.
Response: See Response 1720.
EPA Letter ID: 641
Comment ID: 13640
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment Response for the L T2ESWTR 16-35 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Comment: Sample temperature requirements - ASI supports the <10°C and not frozen sample
temperature criteria. Please see comments above the PWS Guidance Manual section (Section 6.4.5
Monitoring Sample Temperature).
Response: See Response 1720.
EPA Letter ID: 707
Comment ID: 14819
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: pg. 47731
K. Analytical methods
1. Cryptosporidium
Matrix Spike Samples: states that systems must have one (1) matrix spike (MS) sample analyzed for each
20 source water samples. (Parag. #5, line 1-2)
Comment: Matrix spike samples should be processed for the each system with their initial unspiked
sample to determine method performance if there are any
interfering factors (algal cells, etc.) which may be present in the systems source water and that may cause
problems with the IMS procedure and misinterpretation of the slide. The laboratory should be required to
process the initial MS when the initial source water is collected instead of performing the MS at their own
prerogative after the first initial sample.
c. (1) Increased flexibility in matrix spike samples ....
Comment: The matrix spike sample would give the laboratory needed information
of the PWS source water and any interfering factors for Method 1622/1623.
Therefore, it is recommended that the laboratory be required to process the Matrix spike during the first
sampling event for the new PWS.
Response: See Response 1720.
EPA Letter ID: 707
Comment ID: 14820
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: c. (2) Requirement for laboratories to purchase HCL and NaOH ....
Comment: Agree with requirement. Very important step in the IMS bead separation. Normality specific
reagents should be required for IMS completion.
Response: See Response 1720.
EPA Letter ID: 711
Comment ID: 16568
Comment Response for the LT2ESWTR 16-36 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: (4) Clarification in the method of the actions to take in the event of QC failures
Comment: This is very important. EPA should provide a detailed plan of action for utilities that will not
be analyzing their own samples. The plan of action should be flexible with regard to resampling.
Response: See Response 1720.
EPA Letter ID: 711
Comment ID: 16569
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: (5) Changes to the sample storage and shipping temperature to -less than 10°C and not
frozen-, and additional guidance on sample storage and shipping procedures
Comment: The storage and shipping temperature of-less than 1 O°C and not frozen- should be
consistently used throughout the LT2ESWTR documents, including the Microbial Laboratory Manual
and its accompanying appendices.
Response: See Response 1720.
16.2.8 Comment Code 1721, Rule Language Edits
Summary of Issues
Commenters approved of the language in the June 2003 Microbial Laboratory Guidance Manual for
LT2ESWTR. The commenter also recommended that the language in the June 2003, Section 3.1.3, page
11, should be used in the proposed rule in Section 141.704(a)(l). A commenter expressed concern over
the clarification of the word "frozen".
Response to Code 1721
Standardizing Language
EPA agrees that the language in the June 2003 version of the guidance manual, Section 3.1.3, page 11, is
clear regarding sample volume requirements. It will be reviewed and potentially used throughout the
Microbial Laboratory Guidance Manual for LT2ESWTR. The rule in 40 CFRpart 141.704(a)(l) states
the requirements as follows: systems must analyze at least a 10 L sample or a packed pellet volume of at
least 2 mL as generated by the methods listed in paragraph (a) of this section. Systems unable to process a
10 L sample must analyze as much sample volume as can be filtered by two filters approved by EPA for
the methods listed in paragraph (a) of this section, up to a packed pellet volume of at least 2 mL.
Language Clarification
The rule requires that samples be kept between 1° C and 10° C and not allowed to freeze.
What is meant by frozen
Comment Response for the L T2ESWTR 16-3 7 December 2005
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Samples must be refrigerated between 1° C and 10° C so that freezing cannot occur.
Individual Comments on Code 1721
EPA Letter ID: 641
Comment ID: 13587
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47669, Bullet #2 - -For each sample, the laboratory analyzed at least 10L— this language
should be standardized throughout the Rule. The June 2003 Lab Guidance Manual is exemplary in
clarifying this requirement (Section 3.1.3, Page 11) and this format should be used throughout. For
example, in the proposed rule, Section 141.705(a)(l) should be similarly revised.
Response: See Response 1721.
EPA Letter ID: 641
Comment ID: 13610
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: The June 2003 Lab Guidance Manual is exemplary in clarifying this requirement (Section
3.1.3, Page 11) and this format should be used throughout. For example, in the proposed rule, Section
141.705(a)(l) should be similarly revised.
Response: See Response 1721.
EPA Letter ID: 641
Comment ID: 13633
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: EPA may want to clarify "frozen" - does the presence of any small amount of ice render the
sample unacceptable ?
Response: See Response 1721.
16.2.9 Comment Code 1722, Guidance
Summary of Issues
The only comment in this group recommends that QA/QC need not be re-sampled. Secondly, the
commenter suggests removing the matrix spike (MS) sample requirement from the guidance as it is stated
in the analytical method but not utilized by the LT2 rule provisions.
Comment Response for the L T2ESWTR 16-38 December 2005
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Response to Code 1722
Necessity of resampling QA/QC
EPA disagrees that QA/QC samples need not be reanalyzed in the event of a QC failure. In order to
determine whether a problem during analysis has been rectified, it is necessary to reanalyze method
blanks and OPR samples before proceeding with field sample analyses. Field samples associated with
failed QC samples must be recollected. The June 2003 version of Method 1623 states that in the case of
contamination of method blanks, laboratories should perform the following procedure: Analysis of
additional samples is halted until the source of contamination is eliminated, the method blank test is
performed again, and no evidence of contamination is detected. The following is stated in the case that the
OPR sample fails: Any sample in a batch associated with an unacceptable OPR sample is unacceptable.
Analysis of additional samples is halted until the analytical system is brought under control. Troubleshoot
the problem using the procedures at Section 9.7.5, of the June 2003 version of Method 1623, as a guide.
After assessing the issue, perform another OPR test and verify that Cryptosporidium and Giardia
recoveries meet the acceptance criteria.
Inclusion of matrix spike sample requirement in the Guidance document
EPA disagrees that the matrix spike sample requirement should be removed from the rule and the
guidance documents because, contrary to the statement made by the commenter, it is utilized in
LT2ESWTR provisions. According to the LT2ESWTR, utilities are required to use Methods 1622 or
1623 for analysis of Cryptosporidium which require the use of matrix spikes per every 20 field samples.
The rule states the following: Cryptosporidium analysis for source water monitoring under today's rule
must be conducted using either Method 1623: Cryptosporidium and Giardia in Water by
Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA-815-R-05-002, or
Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2005, United States Environmental
Protection Agency, EPA-815-R-05-001. As required by Method 1622/1623, PWSs must have 1 matrix
spike sample analyzed for each 20 source water samples. The volume of the MS sample must be within
ten percent of the volume of the unspiked sample that is collected at the same time, and the samples must
be collected by splitting the sample stream or collecting the samples sequentially. The MS sample and the
associated unspiked sample must be analyzed by the same procedure. MS samples must be spiked and
filtered in the laboratory.
Because matrix spikes are required by the rule, there is no reason to remove instruction about matrix
spikes from the Microbial Laboratory Guidance Manual for LT2ESWTR. Methods 1622/1623 were used
during the ICRSS, where MS samples indicated a mean recovery and relative standard deviation of 43
and 47 percent, respectively (Connell et al. 2000). EPA expects that PWSs will achieve comparable
performance with these methods during source water monitoring under today's rule. With the minimum
sample volume and QC requirements in today's rule, this level of performance will be sufficient to assign
PWSs to Cryptosporidium treatment bins and realize the public health goals intended by EPA and the
Advisory Committee for the LT2ESWTR.
Individual Comments on Code 1722
EPA Letter ID: 562
Comment ID: 12395
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the L T2ESWTR 16-39 December 2005
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Comment: QA/QC need not be re-sampled. Moreover, AWWA recommends that the matrix spike
sample requirement be struck from the guidance. This requirement is already reflected in the analytical
method but not utilized by the LT2ESWTR rule provisions.* AWWA also recommends that the minimum
sub-sampling
Response: See Response 1722.
EPA Letter ID: 562
Comment ID: 12399
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: *Guidance on Generation and Submission of Grandfathered Cryptosporidium Data for Bin
Classification Under theLong Term 2 Enhanced Surface Water Treatment Rule, April 2003, p. 6.
Response: Not a comment (a reference to a guidance document). No response required.
16.2.10 Comment Code 1723, Specific to LT2 Microbial Sampling
Guidance Manual
Summary of Issues
Comments suggested clarifications and changes regarding the sample receipt temperature (actual
temperature and consistency throughout the document), slide storage, target time period for notification of
laboratory application, organism characterization requirements for field and QC slides, required QC for
method modifications, analyst criteria, sterility checks, incubator temperature for different methods,
filtration unit decontamination protocol, dilutions used for MTF methods, MPN value determination,
interpretation of Colilert®, holding times, verification procedures, and holding times for media. Other
comments suggested changes to the Sample Results Acceptability Checklist and various typographical
errors. Another comment suggested that EPA fund research to determine the effects of temperature and
volume on recovery.
Response to Code 1723
Entire Manual
The guidance manual is provided to help implement the LT2ESWTR. The guidance document does not,
however, substitute for the LT2ESWTR or any of the analytical methods approved for use under the rule.
The material presented within the guidance manual is intended solely for guidance and does not alter any
regulatory or analytical method requirements not altered by the LT2ESWTR itself.
EPA understands the concerns of the commenters and will be reviewing and revising the guidance manual
to accurately reflect today's rule. Specific changes, as described in the comments, will be addressed and
the guidance manual will be revised if these comments are found to be valid and they provide help in
implementing the LT2ESWTR. EPA thanks the commenters for reviewing the manual and appreciates the
Comment Response for the LT2ESWTR 16-40 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
feedback, allowing this document to fulfill its purpose.
EPA agrees with the sample receipt temperature clarification. The temperature for storage and transit of
all samples (i.e., Cryptosporidium and E. coli) is between 1°C and 10°C but not frozen. E. coli samples
must be received <10°C and Cryptosporidium samples must be received <20°C. Systems must analyze for
Cryptosporidium using Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA, 2005,
United States Environmental Protection Agency, EPA-815-R-05-002 or Method 1622: Cryptosporidium
in Water by Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA-815-R-05-
001. These revised methods include an increase in the allowable sample storage temperature between 1°C
and 10°C. For E. coli, systems must maintain samples between 0°C and 10°C during storage and transit to
the laboratory. The temperature change dictated a change in all the appropriate appendices of the manual
including the Sample Results Acceptability Checklist. The MS spiking suspension requirement listed on
the former checklist was not revised; as stated in the preamble, laboratories must use flow cytometer-
counted spiking suspensions for spiked QC samples. EPA agreed with the editorial changes and
typographical errors reported by commenters.
Section 3: Guidance for Cryptosporidium Laboratories
Laboratories performing Cryptosporidum analyses for the LT2 rule may use Section 3 of the Microbial
Laboratory Guidance Manual for LT2ESWTRto clarify implementation of the rule and use of the
methods. EPA will consider clarification of the following in the guidance manual: temperature criteria for
samples received the same day they were collected, slide storage procedure dependant on mounting
medium used, requirement of flow-cytometer counted spiking suspensions, and formatting changes to
Audit Checklist. EPA will consider clarifying the QC requirements for various method modifications.
EPA will also consider the suggested changes to the Lab QA Program application: including the target
time period for notification of laboratory application and additions to the Principal Analyst and Analyst
section of the QA Program application.
Under today's rule, PWSs must report total Cryptosporidium oocysts as detected by FITC as determined
by the color (apple green or alternative stain color approved for the laboratory under the Lab QA Program
described in section IV.K), size (4-6 micrometers) and shape (round to oval). This total includes all of the
oocysts identified as described here, less any atypical organisms identified by FITC, DIC, or DAPI (e.g.,
possessing spikes, stalks, appendages, pores, one or two large nuclei filling the cell, red fluorescing
chloroplasts, crystals, spores, etc.). Section 15.2.2 of Methods 1622/1623 explains the examination
procedure for field samples. As stated in Section 15.2.1 an analyst characterizes and records three oocysts
from the positive staining control slide before beginning field sample examination. Three oocysts from
the OPR slide are also characterized and recorded.
EPA disagrees that the current Method 1622/1623 benchsheets are a requirement. Section 3.5 of the
Microbial Laboratory Guidance Manual for LT2ESWTR lists the recordable data which is required and
recommended. EPA does not agree that using the mercury bulb following manufacturer's instructions
should change from a recommendation to a requirement.
EPA appreciates the suggested research project and will take the topics under consideration.
Section 4: Guidance for E. coli Laboratories
EPA disagrees with the comments expressing concern that incubating mEndo plates longer than 24 hours
may result in fading of the sheen. Although this may be a concern for drinking water (potable) samples it
is not for other matrices including ambient (source) waters. EPA also disagrees with the comment that
suggested Colilert® positive results prior to 24 hours and negative results after 28 hours should be
considered valid. EPA believes that the incubation time, 24-28 hours, provided by the manufacturer is
Comment Response for the LT2ESWTR 16-41 December 2005
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appropriate. Similarly, a comment suggested Colilert®18 positive results prior to 18 hours and negative
results after 22 hours should be considered valid. EPA believes that the incubation time, 18-22 hours,
provided by the manufacturer is appropriate.
In response to the comment expressing concern that higher concentrations of bacteria found in source
waters could cause cross-contamination from one sample to the next if the filtration unit is not
decontaminated or changed between samples: EPA agrees that this could be a concern and a cautionary
statement will be included in the lab guidance manual to ensure laboratories are aware of the potential for
cross-contamination.
EPA agrees that for MTF, five dilutions should be analyzed initially. The appropriate section in the
manual will be corrected to indicate 5 dilutions throughout. EPA also agrees that the guidelines for
determining MPN values may be confusing for some laboratories; however, laboratories that will be using
the MPN technique are required to be certified for the technique and should be familiar with this process.
In addition, the LT2 database will allow laboratories to enter primary data, number of positive tubes for
all five dilutions, and then the database will choose the appropriate tube series and calculate MPN/100
mL.
For mColiBlue plates, EPA does not agree that the plates should not be inverted during the incubation
period.
Appendices N, O, and Q: Holding time
EPA believes the time from sample collection to initiation of analysis (i.e., the holding time) for source
water E. coli samples may not exceed 30 hours for all approved E. coli methods. However, if the State
determines on a case-by-case basis that analyzing an E. coli sample within 30 hours is not feasible, the
State may approve the holding of an E. coli sample for up to 48 hours between collection and initiation of
analysis. E. coli samples held between 30 to 48 hours must be analyzed by the Colilert® reagent version
of Standard Method 9223B as listed in 40 CFR 136.3.
Appendices N and O: Verification
Comments expressed concern that Method 1604 and mColiBlue24 do not include method-specific
verification procedures. Laboratories should follow guidance provided in the Certification manual for
verification of E. coli colonies.
Individual Comments on Code 1723
EPA Letter ID: 628
Comment ID: 15043
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: 7. Laboratory Issues a. Method procedures need clarification and reconsideration. The
laboratory guidance manual proposes in Section 11.4.3.1 that -Use Anti-Foam A and 20 ml RO-. This
changes the manufacture directions (specially BTF uses a 0.05% Tween 80 solution instead of Antifoam
A). Tween 80 is more readily available whereas there has been some variation in the Antifoam A that is
available. The SFPUC also has concern over the use of 20ml of RO water. The tube that the SFPUC is
rinsing only holds about lOmls of liquid (Easy Seed). The manufacturer only requests that 3 ml of RO be
Comment Response for the L T2ESWTR 16-42 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
used in the 2nd and 3rd rinses. The SFPUC requests the EPA to reconsider the proposed requirement and
revise them to be consistent with the manufacturer-s direction.
b. Suggest cleaning frequency to be specified. The proposed cleaning method in Section 10.4 of the
laboratory guidance manual does not include a frequency requirement. The SFPUC believes it may be
more complete to suggest or recommend a cleaning frequency such as annually. Another option might be
that these items should be covered with each service appointment or that if any problems arise when
viewing a slide, an overall cleaning be done as part of the troubleshooting process.
c. The EPA proposes in Section 10.6.2 of the laboratory guidance manual that, in addition to the
requirement of counting the total number of oocysts and cysts and the number that are DAPI positive and
DAPI negative on the entire slide, each analyst should count the number of nuclei using DAPI and DIG
for 10 oocysts and 10 cysts. If numbers don-t match, this will not be recorded but will be discussed. Does
this replace the previous DAPI verification procedure? Or is this done in addition to what was already
written? The SFPUC suggests that the total count using FA remain for oocysts and cysts and the total
DAPI count be dropped and replaced with (what the EPA is suggesting now) the DAPI and DIC nucleic
enumeration of 10 oocysts and 10 cysts. The SFPUC further requests the EPA develop a standard
worksheet to help water systems document this information.
Response: See Response 1724.
EPA Letter ID: 678
Comment ID: 15045
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 13. The EPA requests comment on the proposed changes to the sample storage and shipping
temperature to -less than 10°C and not frozen-, and additional guidance on sample storage and shipping
procedures.
Comment: The storage and shipping temperature of-less than 10°C and not frozen- should be
consistently used throughout the LT2 Rule documents, including the Microbial Laboratory Manual and its
accompanying appendices. See General Comment #1 on the Microbial Laboratory Manual below.
Response: See Response 1723.
EPA Letter ID: 678
Comment ID: 15046
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: V. Comments on Draft Microbial Laboratory Manual for the LT2 Rule
A. General Comments
1. The manual and its appendices refer to the required storage and shipping temperature for microbial
samples in various ways, including -<10°C and not frozen-, -between 0°C and 10°C-, —received at
>10°C or frozen-must be rejected-, -less than 10°C-, -1-4°C-, and -2-8°C-. It is best to be consistent
Comment Response for the L T2ESWTR 16-43 December 2005
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throughout the documents regardless of the analysis in order to maintain the integrity of the samples and
avoid confusion among the utilities and the laboratories analyzing the samples. If samples at 0°C and
10°C are unacceptable, the sample temperature must be specified as ->0°C and <10°C-.
Response: See Response 1723.
EPA Letter ID: 678
Comment ID: 15047
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: B. Specific Comments
1. Microbial Laboratory Guidance Manual, June 2003 Draft
a. Section 2.2 (Sample Temperature Monitoring), 3rd line, p. 8 - suggest the insertion of the bolded and
underlined portion as follows:
-Cryptosporidium and E. coli samples for [LT2 Rule] -analyzed the same day- must be maintained
below 10°C to reduce biological activity during transport and must be refrigerated upon arrival at the
laboratory (if not analyzed right away).-
b. Section 2.2, 2nd paragraph, p. 9:
There are two points that need clarification in this paragraph that refers to: 1) Cryptosporidium samples
that must be received -at <10°C and not frozen-; and 2) -samples that were not collected the same day
they were received, and are received at >10°C or frozen- must be rejected.
The first question is whether or not samples kept at 10°C are acceptable or not? If they are, then the rule
should clearly state as much, e.g. -samples should be stored and transported at lower than or equal to
10°C and not frozen-; otherwise, it should say that samples at 10°C or higher or frozen are not acceptable.
The other QC requirement mentioned is the rejection of samples that were not collected on the same day
they were received. Both the April 2001 version and June 2003 draft of EPA Methods 1622/1623 clearly
identify the holding time for Cryptosporidium samples as 96 hours from initiation of sample collection or
filtration to elution. Therefore, samples that are kept at <10°C or <10°C (whichever is finalized), not
frozen, and are still within the holding time of 96 hours, with enough time for the laboratory to schedule
and perform elution, should still be acceptable. Perhaps it should be specified also that systems must have
prior arrangement with the laboratory or must send the laboratory advance notification if samples are to
arrive at the laboratory within 24 or 48 hours of the end of the holding time.
c. Section 4.2.1.1, 1st paragraph, p. 47 (refer to General Comment #2 on Draft Microbial Laboratory
Manual for the LT2 Rule)
d. Section 3.9.2, 1st paragraph, p. 38
-Slides should be stored in a humid chamber in the dark at 0°C to 10°C-. This statement should be
modified in order to prevent the slide (and the sample in it) from freezing, e.g. -at >0°C to 10°C-, unless
the freezing point of the mounting medium, i.e., DABCO/glycerol or elvanol, is lower than 0°C. When
mounting with elvanol, slides must be stored in a dry box at 4-8°C because elvanol will not set in a humid
chamber.
e. Section 4.2.1.1, 2nd paragraph, p. 47
Samples for E. coli analysis must be kept between 0°C and 10°C during transport and not be allowed to
freeze. With the phrase -not allowed to freeze-, samples at 0°C are eliminated.
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Chapter 16: Analytical Methods Comment Codes 1700-1760
However, it should be clarified if this means ->0°C and <10°C- or ->0°C and < 10°C-.
f Section 4.2.1.3, p. 47 - Suggest modifying the sentence by adding the bolded and underlined phrase and
deleting the crossed word as follows:
-To test sterility of newly prepared media-.incubate one plate, tube or bottle per each media batch-.-.
g. Section 4.2.3.1, Incubation Time and Temperature, Table 4-5, p. 50: For mENDOaNA-MUG and Les-
ENDOaNA-MUG, the table indicates an incubation time of 22-26 hours at 35 C+ 0.5°C.
Incubation time should be 22-24 hours for ENDO media samples because the sheen on coliform colonies
can fade between 24 to 26 hours.
h. Section 4.2.3.3, last sentence, p. 50
Standard Methods (SM, 20th ed.) recommends inserting - a sterile rinse water sample after filtration of 10
samples to check for possible cross-contamination or contaminated rinse water-. Some utilities- practice
for drinking water samples has been to filter a maximum of 10 samples in a series, sterile rinse water
samples at the start and end of a series, rinses in between samples, and changing the filtration funnel for
the next series, instead of ending a series -when 30 minutes or more elapse between sample filtrations-.
For non-potable water samples, e.g., source water or wastewater, SM recommends decontamination of the
filtration unit after each sample or an -additional buffer rinse of the filter unit after the filter is removed to
prevent carryover between samples-. Since source waters are expected to have higher numbers of non-
coliform and coliform bacteria, we believe either decontamination of the filtration unit or changing the
filtration unit after each sample to prevent cross-contamination between samples. In addition, filtration of
sterile rinse water samples at the start and end of the source water sample is recommended. Sterile
disposable filtration units are commercially available and may be used in lieu of glass filtration units.
i. Section 4.3.1, p. 51 (refer to I.e. above)
j. Section 4.4, Sample Volume and Dilution Guidance, p. 51, versus Section 4.4.3, Sample Volume and
Dilution Guidance for Multiple-Tube Methods, p. 52
Directions on the number of dilution needed are conflicting. In 4.4, -For MTF methods, the PWS will be
initially required to analyze five sample volumes of 10, 1.0, 0.1, 0.01 and 0.001 mL.- In 4.4.3, -Initially,
the PWS will be required to analyze four sample volumes (10.0, 1.0, 0.1, and 0.01 mL).- Which is
correct?
k. Section 4.5.3.2 Determination of E. coli Concentrations Using Multiple Tube Methods: p. 60 and 61.
The guidelines for determining MPN values provided are confusing and may result in vastly different
results among analysts, particularly with variations similar to examples B and D. Additional examples or
ultimately a much more extensive MPN chart with four or five dilutions are needed.
Response: See Response 1723.
EPA Letter ID: 678
Comment ID: 15048
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the L T2ESWTR 16-45 December 2005
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Comment: 3. Appendix D: Cryptosporidium Sample Results Acceptability Checklist for the LT2 Rule
a. General Requirement No. 1
Temperature requirement must be clarified and must be consistent throughout the documents - change -
between 0°C and 8°C- to the appropriate temperature range.
b. MS Sample Requirements
The two choices for sorting spiking suspensions (by flow cytometry or manually) should be included in
the checklist.
4. Appendix E: Cryptosporidium Laboratory QA Program Application
a. Last paragraph
Notification of status of application must include estimated target period, e.g. within one month, two
months, etc.
b. Part 3, Principal Analyst and Analyst
We recommend adding the following information for completeness (or modify existing information):
* No. of samples for protozoan analysis using IFA microscopy
* Length of continuous bench experience with Cryptosporidium and IFA microscopy
* Length of experience using EPA Methods 1622/1623
Additionally, the required -Time in current position- does not assure the EPA that the person has been
doing the same analysis during the whole period.
5. Appendix F: Cryptosporidium Laboratory QA Program Audit Checklist
a. Part A, 1.1.4, p. 5
The heterotrophic plate count must be written as -<500 CFU/mL-. ((Bolded abbreviation should be
added)
b. Part A, 3.3, p. 7
The -Recommendation- that -current Method 1622/1623 bench sheets used to record sample processing
data- must be changed to -Requirement- to make the records consistent throughout the public water
systems.
c. PartB, 18.8 and 14.12, p. 13
DAPI and finished slides are stored at -in the dark at 0°C to 8°C-. Again, the temperature requirement for
storage of solutions and finished slides must be consistent throughout the documents. Unless neither
DAPI nor the mounting medium (elvanol, not Evenol) would freeze at 0°C, the range above must be
changed.
d. PartB, 15.5, p. 14
The -Recommendation- that the mercury bulb be used less than the maximum hours recommended by
the manufacturer must be changed to -Requirement- because insufficient light could influence the
visibility of the cysts and oocysts, and therefore, affect quantification.
6. Appendix I: Standard Methods 9223B: Colilert®
a. Section 1.5, p. 1
-Colilert® is not for intended for use with marine waters.- (Delete first -for-.)
b. Section 4.1, last line, p. 1
Delete extra -may be-.
Comment Response for the LT2ESWTR 16-46 December 2005
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c. Section 8.1.1, 2nd paragraph, p. 2
Insert -and greater than 0°C- or -and not frozen- after -less than 10°C-.
d. Section 8.1.2, last sentence, p. 2
-For non-potable water for compliance, do not exceed 6 hours holding time (including travel time) and
process within 2 hours.- (Insert bolded phrase to distinguish travel time or transport time from time the
sample is kept in the refrigerator).
However, the holding time for non-potable water samples may be extended to 24 hours using particular
methods including Colilert, as shown by the holding time studies that the EPA has recently evaluated.
The 24-hour holding time is being proposed under the LT2 Rule.
e. Section 11.1.12, 1st line
Change -fluorescent- to -fluorescence-.
f Section 15.0, Verification Procedure, p. 4
Indicates -Not Applicable-
Standard Methods 20th Ed. has a verification procedure in section 9020B indicating that 10% of the
positive samples be verified. It is recommended that this be included in the procedure.
g. Refer to Appendix J, 11.1.14, p. 3
Some of our experience with Colilert® shows that samples may turn positive for total coliforms and E.
coli before 24 hours. Therefore, as in Colilert®-18, such results must be considered valid. Furthermore,
the Colilert® package insert from IDEXX also states that lack of yellow color in an inoculated Colilert®
sample that is incubated over 28 hours is a valid negative test. We recommend that the EPA consider
these results for Colilert® valid.
7. Appendix J: Standard Methods 9223B: Colilert®-18
a. Section 8.1.1, 2nd line, p. 2
The temperature of the samples should be specified as -less than 10°C and greater than 0°C- (or not
frozen).
b. Section 8.1.2, last sentence, p. 2 (refer to 6.c. above for comment)
c. Section 11.1.14, p. 3
-Colilert®-18 results are definitive at 18-22 hours. In addition, positives for both total coliform and E.
coli observed before 18 hours and negatives observed after 22 hours are also valid.- Some utilities have
the same experience with this method as well as with the 24-hour Colilert® (refer to 6.f above).
8. Appendix K: Standard Methods mEndo/LES-Endo NA-MUG and mFC NA-MUG
a. Section 2.a., last paragraph, 6th line, p. 3
Change -4 to 5 m- to -4 to 5 mm-.
9. Appendix L: EPA Method 1103.1
a. Section 6.23, p. 3
Water bath should be maintained at 44.5 + 0.2°C, instead of + 0.5°C (refer to 11.9, p. 8).
b. Sections 8.1.1, 1st line and 8.1.2, p. 7
In this method, samples are kept at 1-4°C during transit that should not be longer than 6 hours between
collection and analysis. The EPA has evaluated studies that showed that E. coli concentrations did not
Comment Response for the L T2ESWTR 16-4 7 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
change significantly in samples transported and stored for 24 hours below 10°C without freezing (p.
47734 of the proposed LT2 Rule). These studies included mTEC as one of the methods used. In light of
these studies, increasing the holding time to 24 hours at <10°C without freezing for methods evaluated
may be appropriate, particularly since some systems need more time (>6 hours) to transport their samples
from the source to the laboratory that will analyze them.
10. Appendix N: EPA Method 1604
a. Section 7.7.2, last line, p. 6
The method specifies 4°C as the storage temperature for the MI agar plates. It may be more realistic to
consider and include a range, e.g. 1-4°C, for storage temperature for media.
b. Section 8.2.1, 1st sentence, p. 6
The method specifies 1-4°C as the transit and storage temperature. Under the LT2 Rule, the EPA proposes
that microbial samples be kept at <10°C without freezing so that would include samples for E. coli
analysis as well.
c. Section 8.2.2, p. 6
Refer to 9.b. above. The holding time studies evaluated by the EPA did not include the MI agar method
(Method 1604) as one of the analytical methods used. Without any evidence that the integrity of the
sample is retained after 24 hours when Method 1604 is used, it is best to remain within the recommended
holding time of 8 hours for source water when using this method.
d. This procedure does not have a verification section, but including verification is recommended.
11. Appendix O: m-ColiBlue24® Broth
a. Section 8.3, p. 4
As in Appendix N, 8.2.2, the holding time studies evaluated by the EPA did not include the m-ColiBlue®
Broth as one of the analytical methods used. Therefore, it is suggested that the holding time of samples
remain at 8 hours when using this method.
b. Section 11.1.2, last sentence, p. 5
It is best to incubate plates with media-saturated pads grid-side up and not inverted to prevent the pad and
membrane filter from falling, resulting in loss of the sample.
c. Section 16.10, p. 8
Delete extra-1-before 1992.
d. This procedure does not have a verification section, but including verification is recommended.
12. Appendix Q: E. coli Most Probable Number Sample Results Acceptability Checklist for the LT2 Rule
a. No. 1 and No. 2
Specify temperature for transport and storage as ->0°C and <10°C- or ->0°C and <10°C, whichever is
approved.
b. No. 2 and No. 7
LTB and EC-MUG were not among the methods used in the holding studies evaluated by the EPA.
Therefore, it is suggested that the holding time for samples analyzed with LTB and EC-MUG remain at 8
hours between collection and analysis.
13. Appendix R: E. coli Membrane Filtration Sample Results Acceptability Checklist for the LT2 Rule
a. mEndo ~>NA-MUG and LES Endo --> NA-MUG should have an incubation period of 22 to 24 hours
Comment Response for the L T2ESWTR 16-48 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
instead of 24 + 2 hr. The sheen appearance on the colony can fade between 24 to 26 hours.
b. No. 1 and No. 2 (refer to 12.a. above)
c. No. 2 and No. 7 (refer to General Comments 2.)
Response: See Response 1723.
16.2.11 Comment Code 1724, Method 1622 or 1623 June 2003 draft
Summary of Issues
Comments requested changes/clarifications to Methods 1622/1623 regarding the following topics:
editorial changes, sampling diagram, sampling procedures, sampling protocol using the Filta-Max® filter,
procedure using Filta-Max® filters, sample collection pressure, recording of volume filtered, use of
temperature strips, increased sample receipt acceptance temperature, number of organisms used for
spiking, spiking protocol, expiration date of the elution buffer, wrist shaker speed, expiration date of
DAPI stock, working DAPI concentration, additional mounting mediums, frequency of microscope
cleaning, length of time that an OPR/MB are valid, frequency of OPR/MB, analyst verification procedure,
and analyst criteria and experience. A comment also agreed with the changes incorporated into the 2003
version of the methods and agreed that the 2003 version should be used for LT2ESWTR. Comments were
also received that suggest trainees be allowed to analyze LT2ESWTR samples under direct supervision of
an experienced analyst.
Response to Code 1724
Changes/clarifications already incorporated
EPA appreciates the notification regarding the editorial and spelling changes and will revise the methods
accordingly. Under today's rule, Cryptosporidium analysis for source water monitoring must be
conducted using either Method 1622: Cryptosporidium in Water by Filtration/IMS/FA (EPA 815-R-05-
001, USEPA 2004f) or Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA (EPA
815-R-05-002, USEPA 2004g). These two methods include the revisions incorporated into the 2003
version of each method. The sampling diagram is updated to include the two most widely used filters.
More sampling diagrams and sampling protocols are available in the Source Water Monitoring Guidance
Manual for LT2ESWTR. The correct pressure for each filter is included in the protocols. As stated in
today's rule, for samples in which at least 10 L are filtered and all of the sample volume is analyzed, only
the sample volume filtered and the number of oocysts counted must be reported. The sample volume
filtered in liters is reported to the nearest % L. The revisions in the 2003 versions included storage
between 1°C and 10°C . The filters that have been approved by EPA for nationwide use with Methods
1622 and 1623 are the Pall Gelman Envirochek™ and Envirochek™ HV filters, and the IDEXX Filta-
Max® foam filter. The recommendation that all references to the Envirochek™ filter also include the
reference to the Envirochek™ F£V filters will be applied where appropriate. It was recommended that the
concentration for the working DAPI solution and the concentration and use of antifoam and rinse
procedure used with spiking suspensions refer to manufacturer's instructions. EPA agrees that these
procedures may be conducted according to manufacturer's instructions and may be adopted by a
laboratory as a method modification using a Tier 1 validation. According to the Lab QA Program
checklist, the proper shaker speed used during elution of the Envirochek™ and Envirochek™ HV filters
Comment Response for the L T2ESWTR 16-49 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
is a method procedure and may be determined by each lab by following the Tier 1 modification
procedures. Section 8.1.4 of the Methods 1622/1623 lists options for monitoring sample receipt
temperature from which the laboratory and/or PWS may choose depending on individual specifications.
Other options exist and may be investigated by the laboratory and/or PWS. The microscopy cleaning
frequency is listed in Section 10.4.8 of the Method.
Changes/clarifications under consideration
EPA understands the concerns of the commenters and will be reviewing and revising the methods to
accurately implement today's rule. Specific changes, as described in the comments, will be addressed and
the method will be revised if these comments are found to be valid. EPA thanks the commenters for
reviewing the method and appreciates the feedback.
Under consideration are changing the expiration date of stock DAPI and including a week expiration for
the elution buffer. Commenters recommended various changes to the analyst verification procedure which
are also under consideration. BTF EasySeed™ has been approved for routine QC use with Method
1622/1623. Because the individual organism concentration may fall slightly below 100 organisms, EPA
will consider clarifying the limits of the spiking concentration for IPR/OPR/MS samples. Clarification
was requested regarding the OPR/MB set performed each week. If the OPR/MB is performed on a
Thursday, the commenter asked if the week extends into the next calendar week. EPA is considering
clarifying this issue. EPA will consider adding additional reagents, such as Elvanol mounting medium, to
the method or the Microbial Laboratory Guidance Manual for LT2ESWTR. Mounting medium is a
method procedure and may be changed at a laboratory following the Tier 1 modifications as stated in the
methods.
Analyst Criteria and OPR frequency
EPA believes the proposed requirements are reasonable for ensuring that analysts have the experience to
evaluate source water samples under the LT2ESWTR. These requirements were established because the
Cryptosporidium analyses required in the rule entail the use of manual procedures that rely heavily on
analyst skill and examination steps that require expertise and experience for accuracy. EPA believes that
reducing the analyst requirements will reduce the reliability of Cryptosporidium monitoring data under
the rule. Approximately 6 months are required to train Cryptosporidium analysts on Method 1622/1623
procedures and microscopy, and the staggered compliance schedule allows laboratories time to continue
to train personnel while monitoring is occurring but before the peak number of analyses is reached. No
break exists between large system and small system monitoring eliminating the potential disincentive to
laboratories investing in capacity. As stated in the Microbial Laboratory Guidance Manual For the Long
Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR Rule), training prior to analyzing samples
for LT2ESWTR includes review of laboratory SOPs, observation of an experienced analyst, performance
of the method while being observed by an experienced analyst, and acceptable performance of a set of
IPR samples using blind spikes. After initial training is successfully completed, quality control samples
and non-LT2ESWTR samples analyzed using the same method may also be used by the trainee to gain
experience. When the required experience and number of samples are successfully completed,
documentation supporting the completion is sent to the EPA and the trainee status is changed to analyst or
technician.
Today's rule requires the use of Methods 1622 or 1623 because they are the best available methods that
have undergone full validation testing. EPA believes that the frequency of one OPR test per 20 samples is
appropriate for identifying and correcting problems. For example, if an OPR test is performed once per
day for a laboratory that processes 60 samples per day, a problem that occurs at sample 10 will be
continued through the next 50 samples. If an OPR test is performed once per 20 samples, a problem that
Comment Response for the LT2ESWTR 16-50 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
occurs at sample 10 would only affect 10 additional samples. Consequently, EPA is maintaining the
current QC criteria in Methods 1622 and 1623.
Trainee Analysis
EPA agrees that trainees should analyze LT2ESWTR samples under direct supervision of an experienced
analyst but only after sufficient experience and training with non-LT2 samples.
Individual Comments on Code 1724
EPA Letter ID: 540
Comment ID: 12088
Commenter: Manja Blazer, Government Affairs and Market Development Manager, IDEXX
Laboratories
Commenter Category: Independent Laboratories
Comment: Method 1623: Cryptosporidium and Giardia in water by Filtration/IMS/FA. June
2003. Draft for comment.
- The comments list below have been added to a Word document (track
changes) (downloaded .pdf file)
- For the purpose of this document additions to the text are underlined and
deletions are in red colored text.
1. In all instances where Filta-Max(tm) is written this now needs to be Filta-Max(r)
2. 12.3.1.1.3
Note: The maximum operating pressure of 8 bar (120) psi should not be exceeded, refer to manufacturers
instructions.
3. 12.3.1.2
Place filter module into the filter housing bolt head down
4. 12.3.1.3
Verify that the filter housing is installed so that the end closest to the screw top cap lid is the inlet.
5. 12.3.2.2.1
(b) take the assembled concentrator tube out of the jaws
(d) pour the excess liquid into the assembled concentrator tube
(d) firmly in place. Or, alternatively, if a Filta-Max(r) Quick Connect kit is being used to aid attachment
of the assembled concentrator and elution
tube, refer to manufacturers instructions.
(i) Detach the assembled concentrator tube
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1. 13.3.2.2.2
(a) add an additional 600ml of PBST to the assembled concentrator tube
2. 12.3.3.2.1
(b) begin stirring and open the tap increase the vacuum using the hand pump
3. 12.3.3.2.3
(b) Rinse the sides of the concentrator tube and the magnetic stirrer with PBST
4. 12.3.3.2.4
Place a new membrane in the concentrator tube base smooth side up
IMPORTANT
In addition to the above comments please note that on Page 61 of the June 2003 draft there is a Diagram
titled "Figure 3. Laboratory Filtration System".
This is not relevant to the IDEXX Filta-Max(r) system.
The ordering of the equipment for pushing a sample through the Filta- Max(r) housing and filter is as
follows:
Sample Pump Flow Controller (only necessary if the pump is not controllable) Filta-Max(r) Housing
Drain
The pump is always placed upstream from the housing inlet (which is always the lid).
LT2R Methods Manual Comments Made By IDEXX submitted January 8, 2004
Appendix G comments made in track changes (coloured red text)
Section
1.1.1
1.1.2
1.2
1.5.4
2.2.1.2
2.2.1.4
2.2.1.6
2.2.1.9
2.2.2.1
2.3.1.2
2.3.2.1
3.2.2.4
3.2.3
3.2.3.1
[SEE PDF FOR APPENDIX G]
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Appendix C comments made in track changes (coloured red text)
Section
1.0
2.1.8
2.1.16
2.2.2
2.2.7 + note
2.2.12
2.2.14
[SEE PDF FOR APPENDIX C]
[Edits to Method 1623 submitted as red text in pdf. Only sections with edits were included in database.
Red text noted with double brackets -[[ ]]-.]
Method 1623: Cryptosporidium and
Giardia in Water by Filtration/IMS/FA
June 2003
Draft for Comment
Office of Water (4607)
EPA815-R-03-XXX
http://www.epa.gov/microbes/
June 2003
Printed on Recycled Paper
Disclaimer
This method has been reviewed by the U.S. EPA Office of Water and approved for publication. Mention
of trade names or commercial products does not constitute endorsement or recommendation for use.
Questions regarding this method or its application should be addressed to:
[[Laboratory Quality Assurance Program for the Analysis of Cryptosporidium in Water Coordinator
Office of Ground Water and Drinking Water Technical Support Center
U.S. EPA Office of Water
26 West Martin Luther King Drive
Cincinnati, OH 45268-1320
William A. Telliard
U.S. EPA Office of Water
Analytical Methods Staff
Mail Code 4303
Washington, DC 20460
Email: telliard.william@epa.gov]]
[[Method Development and Validation]]
EPA initiated an effort in 1996 to identify new and innovative technologies for protozoan monitoring and
analysis. After evaluating potential alternatives to the then-current method through literature searches,
discussions with research and commercial laboratories, and meetings with experts in the field, the
Engineering and Analysis Division within the Office of Science and Technology within EPA's Office of
Water developed draft Method 1622 for Cryptosporidium detection in December 1996.
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This Cryptosporidium-only method was validated through an interlaboratory study in August 1998, and
was revised as a final, valid method for detecting Cryptosporidium in water in January 1999.
Although development of an acceptable immunomagnetic separation system for Giardia lagged behind
development of an acceptable system for Cryptosporidium, an acceptable system was identified in
October 1998, and EPA validated a method for simultaneous detection of Cryptosporidium and Giardia in
February 1999 and developed quality control (QC) acceptance criteria for the method based on this
validation study. To avoid confusion with Method 1622, which already had been validated and was in use
both domestically and internationally as a stand-alone Cryptosporidium-only detection method, EPA
designated the new combined procedure EPA Method 1623. The interlaboratory validated versions of
Method 1622 (January 1999; EPA-821-R-99-001) and Method 1623 (April 1999; EPA-821-R-99-006)
were used to analyze approximately 3,000 field and QC samples during the Information Collection Rule
Supplemental Surveys (ICRSS) between March 1999 and February 2000. Method 1622 was used to
analyze samples from March 1999 to mid-July 1999; Method 1623 was used from mid-July 1999 to
February 2000. [[The April 2001 revision of both methods include updated QC acceptance criteria based
on analysis of the QC samples analyzed during the ICRSS.
Changes in the April 2001 Versions of the Methods
Both methods were revised in April 2001, after completion of the ICRSS and multiple meetings with
researchers and experienced laboratory staff to discuss potential method updates.
Changes incorporated in the April 2001 revisions of the methods (EPA-821-R-
01-025 and EPA-821-R-01-026) included the following:
C Nationwide approval of modified versions of the methods using the following
components:
(a) Whatman Nuclepore CrypTest(tm) filter
(b) IDEXX Filta-Max(tm) filter
(c) Waterborne Aqua-Glo(tm) G/C Direct FL antibody stain
(d) Waterborne Crypt-a-Glo(tm) and Giardi-a-Glo(tm) antibody stains
C Clarified sample acceptance criteria
C Modified capsule filter elution procedure
C Modified concentrate aspiration procedure]]
iii
[[C Modified IMS acid dissociation procedure
C Updated QC acceptance criteria for IPR and OPR tests
C Addition of a troubleshooting section for QC failures
C Modified holding times
C Inclusion of flow cytometry-sorted spiking suspensions
Changes in the June 2003 Versions of the Methods
Both methods were revised again in June 2003 to support proposal of EPA's Long Term 2 Enhanced
Surface Water Treatment Rule. Changes incorporated into the December 2002 versions include:
- Nationwide approval of a modified version of the methods using the Pall Gelman Envirochek(tm) HV
filter
- Removal of Whatman Nuclepore CrypTest(tm) filter from the methods as a result of discontinuation of
the product by the manufacturer
- Nationwide approval of the use of BTF EasySeed(tm) irradiated oocysts and cysts for use in routine
Comment Response for the L T2ESWTR 16-54 December 2005
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quality control (QC) samples
- Minor clarifications and corrections
- Rejection criteria for sample condition upon receipt
- Guidance on measuring sample temperatures
- Clarification of QC sample requirements and use of QC sample results
- Guidance on minimizing carry-over debris onto microscope slides after IMS
Performance-Based Method Concept and Modifications Approved for Nationwide
Use]]
EPA Method 1623 is a performance-based method applicable to the determination of Cryptosporidium
and Giardia in aqueous matrices. EPA Method 1623 requires filtration, immunomagnetic separation of the
oocysts and cysts from the material captured, [[and enumeration of the target organisms based on the
results of immunofluorescence assay, 4',6-diamidino-2-phenylindole (DAPI) staining results, and
differential interference contrast microscopy.]]
Since the interlaboratory validation of EPA Method 1623, interlaboratory Validation studies have been
performed to demonstrate the equivalency of modified versions of the method using the following
components:
- Whatman Nuclepore CryptTest(tm) filter [[(no longer available)]]
- IDEXX Filta-Max(tm) filter
[[- Pall Gelman Envirochek(tm) HV filter]]
- Waterborne Aqua-Glo(tm) G/C Direct FL antibody stain
- Waterborne Crypt-a-Glo(tm) and Giardi-a-Glo(tm) antibody stains
[[- BTF EasySeed(tm) irradiated oocysts and cysts for use in routine QC samples]]
iv
The validation studies for these modified versions of the method met EPA's
performance-based measurement system Tier 2 validation for nationwide use (see Section 9.1.2 for
details), and have been accepted by EPA as equivalent in performance to the original version of the
method validated by EPA. The equipment and reagents used in these modified versions of the method are
noted in Sections 6 and 7 of the method; [[the procedures for using these equipment and reagent options
are available from the manufacturers.]]
Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA
1.1 This method is for determination of the identity and concentration of Cryptosporidium (CAS Registry
number 137259-50-8) and Giardia (CAS Registry number 137259-49-5) in water by [[filtration
concentration,]] immunomagnetic separation (IMS), and immunofluorescence assay (FA) microscopy.
Cryptosporidium and Giardia may be confirmed using 4',6-diamidino-2-phenylindole (DAPI) staining and
differential interference contrast (DIG) microscopy. The method has been validated in surface water, but
may be used in other waters, provided the laboratory demonstrates that the method's performance
acceptance criteria are met.
1.4 This method is for use only by persons experienced in the determination of Cryptosporidium and
Giardia by filtration, IMS, and FA. Experienced persons are defined in Section 22.2 as analysts [[(and
principal analysts, in applicable programs)]]. Laboratories unfamiliar with analyses of environmental
samples by the techniques in this method should gain experience using water filtration techniques, IMS,
fluorescent antibody staining with monoclonal antibodies, and microscopic examination of biological
particulates using bright-field and DIG microscopy.
2.0 Summary of Method
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2.1 A water sample is filtered and the oocysts, cysts, and extraneous materials are retained on the filter.
Although EPA has only validated the method using laboratory filtration of bulk water samples shipped
from the field, field-filtration also [[can may]] be used.
2.3.2 Qualitative analysis is performed by scanning each slide well for objects that meet the size, shape,
and fluorescence characteristics of Cryptosporidium oocysts or Giardia cysts. [[Potential oocysts or cysts
are confirmed through DAPI staining characteristics and DIC microscopy. Oocysts and cysts are
identified when the size, shape, color, and morphology agree with specified criteria and examples in a
photographic library.]]
3.0 Definitions
3.1 Cryptosporidium is [[defined as]] a protozoan parasite potentially found in water and other media.
The six species of Cryptosporidium and their potential hosts are C. parvum (mammals, including
humans); C. baileyi and C. meleagridis (birds); C. muris (rodents); C. serpentis (reptiles); and C. nasorum
(fish). [[Cryptosporidium is defined in this method as those determined by brilliant apple green
fluorescence under UV light, size (4 to 6 (im), and shape (round to oval), excluding atypical organisms
specifically identified as other microbial organisms by FITC and DIC (for example, those possessing
spikes, stalks, appendages, pores, one or two large nuclei filling the cell, red fluorescing chloroplasts,
crystals, spores, etc.).]]
3.2 Giardia is a protozoan parasite potentially found in water and other media. The two species of Giardia
and their potential hosts are G. intestinalis (humans) and G. muris (mice). [[Giardia is defined in this
method as those determined by brilliant apple green fluorescence under UV light, size (8 to 18 (im long
by 5 to 15 (im wide), and shape (oval), excluding atypical organisms specifically identified as other
microbial organisms by FITC and DIC (for example, those possessing spikes, stalks, appendages, pores,
one or two large nuclei filling the cell, red fluorescing chloroplasts, crystals, spores, etc.).]]
4.0 Contamination, Interferences, and Organism Degradation
4.1 Turbidity caused by inorganic and organic debris can interfere with the concentration, separation, and
examination of the sample for Cryptosporidium oocysts and Giardia cysts. In addition to naturally-
occurring debris, such as clays and algae, chemicals, such as iron and alum coagulants and polymers [[,
may be]] added to finished waters during the treatment process[[, which ]]may result in
additional interference.
4.2 Organisms and debris that autofluoresce or demonstrate non-specific fluorescence, such as algal and
yeast cells, when examined by epifluorescent microscopy, may interfere with the detection of oocysts and
cysts and contribute to false positives by immunofluorescence assay (FA) [[(Reference 20.1)]].
[[4.4 Interferences co-extracted from samples will vary considerably from source to source, depending on
the water being sampled. Experience suggests that high levels of algae, bacteria, and other protozoa can
interfere in the identification of oocysts and cysts (Reference 20.1).]]
4.[[4]] Freezing samples, filters, eluates, concentrates, or slides may interfere with the detection and/or
identification of oocysts and cysts.
4.[[5]] All equipment should be cleaned according to manufacturers' instructions. Disposable supplies
should be used wherever possible.
5.0 Safety
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5.5 Centers for Disease Control (CDC) regulations (42 CFR 72) prohibit interstate shipment of more than
4 L of solution known to contain infectious materials [[(see
http://www.cdc.gov/od/ohs/biosfty/shipregs.htm for details)]]. State regulations may contain similar
regulations for intrastate commerce. Unless the sample is known or suspected to contain
Cryptosporidium, Giardia, or other infectious agents (e.g., during an outbreak), samples should be
shipped as noninfectious and should not be marked as infectious. If a sample is known or suspected to be
infectious, and the sample must be shipped to a laboratory by a transportation means affected by CDC or
state regulations, the sample should be shipped in accordance with these regulations.
6.0 Equipment and Supplies
6.2.2 [[Original]] Envirochek(tm) sampling capsule [[or Envirochek(tm) HV sampling capsule]]
equipment requirements (for use with the procedure described in Section 12.2). The version[[s]] of the
method using [[this filter was these filters were]] validated using 10-L [[and 50-L]] sample volumes[[,
respectively]]. Alternate sample volumes may be used, provided the laboratory demonstrates acceptable
performance on initial and ongoing spiked reagent water and source water samples (Section 9.1.2).
[[6.2.2.1.1]] Envirochek(tm), Pall Gelman Laboratory, Ann Arbor, MI, product no. 12110 [[(individual
filter) and or product no. 12107 (box of 25 filters) (www.pall.com/gelman or (800) 521-1520 ext. 2)
6.2.2.1.2 Envirochek(tm) HV, Pall Gelman Laboratory, Ann Arbor, MI, product no. 12099 (individual
filter) or product no. 12098 (box of 25 filters) (www.pall.com/gelman or (800) 521-1520 ext. 2)]]
[[6.2.3 CrypTest(tm) capsule filter equipment requirements. Follow the manufacturer's instructions when
using this filtration option. The version of the method using this filter was validated using 10-L sample
volumes; alternate sample volumes may be used, provided the laboratory demonstrates acceptable
performance on initial and ongoing spiked reagent water and matrix samples (Section 9.1.2).
6.2.3.1 Capsule filter-CrypTest(tm), Whatman Inc, Clifton, NJ, product no.
610064
6.2.3.2 Cartridge housing-Ametek 5-in. clear polycarbonate, Whatman cat. no.
71503, or equivalent
6.2.3.3 Ultrasonic bath-VWR Model 75T#21811-808, or equivalent
6.2.3.4 Laboratory tubing-Tygon formula R-3603, or equivalent]]
6.2.[[3]] Filta-Max(tm) foam filter equipment requirements [[(for use with the procedure described in
Section 12.3)]]. The version of the method using this filter was validated using 50-L sample volumes;
alternate sample volumes may be used, provided the laboratory demonstrates acceptable performance on
initial and ongoing spiked reagent water and matrix samples (Section 9.1.2).
6.2.[[3]]. 1 Foam filter-Filta-Max(tm), IDEXX, Westbrook, ME. Filter module and membrane: product
code FMC 10601; filter membranes (100 pack), product code FMC 10800
6.2.[[3]].2 Filter processing equipment-Filta-Max starter kit, IDEXX, Westbrook, ME, cat. no. FMC
11002. Includes all equipment required to run and process Filta-Max filter modules (manual wash station
(FMC 10102) including plunger head (FMC 12001), elution tubing set (FMC 10301), vacuum set (FMC
10401), filter housing (FMC 10501), and magnetic stirrer (FMC 10901).
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6.3.3 Centrifugal pump-[[Grainger, Springfield, VA, cat. no. 2P613 Simer, model number, M40,]] or
equivalent.
6.10.3 Nonfluorescing immersion oil[[-Type FF, Cargille cat. no. 16212, or equivalent]]
7.0 Reagents and Standards
7.4 Reagents for eluting filters
[[NOTE: Laboratories should store prepared eluting solution for no more than 1 week or when noticeably
turbid, whichever comes sooner.]]
7.4.1.3 0.5 M EDTA, 2 Na, pH 8.0-Dissolve 186.1 g ethylenediamine tetraacetic acid, disodium salt
dihydrate (Fisher cat. no. S311) in 800 mL [[of reagent water]] and adjust pH to 8.0 with 6.0 N HC1 or
NaOH. Dilute to a final volume of 1000 mL with reagent water and adjust to pH 8.0 with 1.0 N HC1 or
NaOH.
[[7.4.2 Reagents for eluting CrypTest(tm) capsule filters (Section 6.2.3). To 900 mL of reagent water add
8.0 g NaCl, 0.2 g KH2PO4, 2.9 g Na2HPO4 (12H2O) 0.2 g KC1, 0.2 g sodium lauryl sulfate (SDS), 0.2
mL Tween 80, and 0.02 mL Antifoam A (Sigma Chemical Co. - cat. no. A5758, or equivalent). Adjust
volume to 1 L with reagent water and adjust pH to 7.4 with 1 N NaOH or HC1.]]
7.4.[[2]] Reagents for eluting Filta-Max(tm) foam filters (Section 6.2.[[3]])
7.4.[[2]]. 1 Phosphate buffered saline (PBS), pH 7.4-Sigma Chemical Co. cat. no.
P-3813, or equivalent. Alternately, prepare PBS by adding the following
to 1 L of reagent water: 8 g NaCl; 0.2 g KC1; 1.15 gNa2HPO4, anhydrous; and 0.2 g KH2PO4.
7.4.[[2]].2 Tween 20-Sigma Chemical Co. cat. no. P-7949, or equivalent
7.4.[[2]].3 High-vacuum grease-BDH/Merck. cat. no. 636082B, or equivalent
7.4.[[2]].4 Preparation of PBST elution buffer. [[Add 100 (iL of Tween 20 to prepared PBS (Section
7.4.3.1 7.4.2.1). Alternatively,]] add the contents of one [[sachet packet]] of PBS to 1.0 L of reagent
water. Dissolve by stirring for 30 minutes. Add 100 (iL of Tween 20. Mix by stirring for 5 minutes.
7.6.3 Crypt-a-Glo(tm) and Giardi-a-Glo(tm), Waterborne cat. nos. A400FLR and A300FLR, respectively,
New Orleans, LA, or equivalent NOTE: If a laboratory will use multiple types of labeling reagents, the
laboratory must demonstrate acceptable performance through an initial precision and recovery test
(Section 9.4) for each type, and must perform positive and negative staining controls for each batch of
slides stained using each product. However, the laboratory is not required to analyze additional ongoing
precision and recovery samples or method blank samples for each type. [[The performance of each
labeling reagent used also should be monitored in each source water type.]]
7.6.4 Diluent for labeling reagents-Phosphate buffered saline (PBS) [[(Section 7.4.1)., Ph 7.4-Sigma
Chemical Co. cat. no. P-3813, or equivalent. Alternately, prepare PBS by adding the following to 1 L of
reagent water: 8 g NaCl; 0.2 g KC1; 1.15 g Na2HPO4, anhydrous; and 0.2 g KH2PO4. Filter-sterilize
(Section 6.19) or autoclave. Discard if growth is detected or after 6 months, whichever comes first.]]
7.7 4',6-diamidino-2-phenylindole (DAPI) stain-Sigma Chemical Co. cat. no. [[D9542]], or equivalent
7.7.2 Staining solution (1/5000 dilution in PBS [Section 7.6.4])-Add 10 (iL of 2 mg/mL DAPI stock
Comment Response for the L T2ESWTR 16-58 December 2005
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solution to 50 mL of PBS. Prepare daily. Store at 0°C to 8°C in the dark except when staining. Do not
allow to freeze. The solution concentration may be increased [[up to 1 (ig/mL]] if fading/diffusion of
DAPI staining is encountered, but the staining solution must be tested first on expendable environmental
samples to confirm that staining intensity is appropriate.
7.10.1 Enumerated spiking suspensions prepared by flow cytometer-not heat-
fixed or formalin fixed[[: Wisconsin State Laboratory of Hygiene Flow Cytometry Unit or equivalent.
7.10.1.1 Live, flow cytometer-sorted oocysts and cysts-Wisconsin State Laboratory of Hygiene Flow
Cytometry Unit ([608] 224-6260), or equivalent
7.10.1.2 Irradiated, flow cytometer-sorted oocysts and cysts-flow cytometer-sorted oocysts and cysts-BTF
EasySeed(tm)
(www.biotechnologyfrontiers.com), or equivalent]]
[[7.10.3]] Storage procedure-Store oocyst and cyst suspensions at 0°C to [[810]]°C, until ready to use; do
not allow to freeze
8.0 Sample Collection and Storage
[[8.1 Sample collection, shipment, and receipt
8.1.1 Sample collection.]] Samples are collected as bulk samples and shipped to the laboratory for
processing through the entire method, or are filtered in the field and shipped to the laboratory for
processing from elution (Section 12.2.6) onward.
[[8.1.2 Sample shipment. Ambient water samples are dynamic environments and, depending on sample
constituents and environmental conditions, Cryptosporidium oocysts or Giardia cysts present in a sample
can degrade, potentially biasing analytical results. Samples that are not analyzed the same day they are
collected should be chilled to reduce biological activity, and preserve the state of source water samples
between collection and analysis.]] Samples [[must analyzed by an off-site laboratory should]] be shipped
via overnight service on the day they are collected. [[Overnight service may not be necessary if the
samples are maintained below 10°C (but not frozen) and holding times are met.]]
[[8.1.2.1 If samples are collected early in the day,]] chill samples as much as possible between collection
and shipment by storing in a refrigerator or
pre-icing the sample in a cooler. If the sample is pre-iced before shipping, replace with fresh ice
immediately before shipment.
[[8.1.2.2 If samples are collected later in the day, these samples may be held overnight in a refrigerator.
This should be considered for bulk water
samples that will be shipped off-site, as this minimizes the potential for
water samples collected during the summer to melt the ice in which they
are packed and arrive at the laboratory at >10°C.
8.1.2.3]] Samples should be shipped at [[0°C to < 10°C 8°C and not frozen]], unless the time required to
chill the sample to [[8°C 10°C]] would prevent the sample from being shipped overnight for receipt at the
laboratory the day
after collection. Samples must not be allowed to freeze.
[[8.1.2.4 Public water systems shipping samples to off-site laboratories for analysis should include in the
shipping container a means for monitoring the temperature of the sample during shipping to verify that
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the sample
did not freeze or exceed 10°C. Suggested approaches for monitoring sample temperature during shipping
are discussed in Section 8.1.4.
8.1.3 Sample receipt. Upon receipt, the laboratory must record the temperature. Samples that were not
collected the same day they were received, and that are received at >10°C or frozen, or samples that the
laboratory has determined exceeded >10°C or froze during shipment, must be rejected. After receipt,
samples must be stored at the laboratory at <10°C, and not frozen, until processed. Results from samples
shipped overnight to the laboratory and received at >8°C should be qualified by the laboratory..
8.1.4 Suggestions on measuring sample temperature. Given the importance of maintaining sample
temperatures for Cryptosporidium and Giardia determination, laboratories performing analyses using this
method must establish acceptance criteria for receipt of samples transported to their laboratory. Several
options are available to measure sample temperature upon receipt at the laboratory and, in some cases,
during shipment:
8.1.4.1 Temperature sample. One option, for filtered samples only (not for 10-L bulk samples), is for the
sampler to fill a small, inexpensive sample bottle with water and pack this "temperature sample" next to
the filtered sample. The temperature of this extra sample volume is measured upon receipt to estimate the
temperature of the filter. Temperature sample bottles are not appropriate for use with bulk samples
because of the potential effect that the difference in sample volume may have in temperature equilibration
in the sample cooler. Example product: Cole Farmer cat. no. U-06252-20.]]
8.1.4.2 [[Thermometer vial. A similar option is to use a thermometer that is securely housed in a liquid-
filled vial. Unlike temperature samples, the laboratory does not need to perform an additional step to
monitor the temperature of the vial upon receipt, but instead just needs to read the thermometer. Example
product: Eagle-Picher Sentry Temperature Vial 3TR-40CS-F or 3TR-40CS.
8.1.4.3 iButton. Another option for measuring the sample temperature during shipment and upon receipt
is a Thermocron(r) iButton. An iButton is a small, waterproof device that contains a computer chip that
can be programmed to record temperature at different time intervals. The information is then downloaded
from the iButton onto a computer. The iButton should be placed in a temperature sample (Section
8.1.4.1), rather than placed loose in the cooler. Information on Thermocron(r) iButtons is available from
http://www.ibutton.com/. Distributors include http://www.pointsix.com/, http://www.rdsdistributing.com,
and http://www.scigiene.com/.
8.1.4.4 Stick-on temperature strips. Another option is for the laboratory to apply a stick-on temperature
strip to the outside of the sample container upon receipt at the laboratory. This option does not measure
temperature as precisely as the other options, but still mitigates the risk of sample contamination while
providing an indication of sample temperature to verify that the sample temperature is acceptable.
Example product: Cole Farmer cat. no. U-90316-00.
8.1.4.5 Infrared thermometers. A final option is to measure the temperature of the surface of the sample
container or filter using an infrared thermometer. The thermometer is pointed at the sample, and measures
the temperature without coming in contact with the sample volume. Example product: Cole Farmer cat.
no. EW-39641-00. As with other laboratory equipment, all temperature measurement devices must Be
calibrated routinely to ensure accurate measurements. See the EPA Manual for The Certification of
Laboratories Analyzing Drinking Water (Reference 20.6) for More information.]]
8.2 Sample holding times. [[Samples must be processed or examined within each of the holding times
specified in Sections 8.2.1 - 8.2.4.]] Sample processing should be completed as soon as possible by the
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laboratory. The laboratory should complete sample filtration, elution, concentration, purification, and
staining the day the sample is received wherever possible. However, the laboratory is permitted to split up
the sample processing steps if processing a sample completely in one day is not possible. If this is
necessary, sample processing can be halted after filtration, application of the purified sample onto the
slide, or staining. Table 1, in Section 21.0 provides a breakdown of the holding times for each set of steps.
Sections 8.2.1 through 8.2.4 provide descriptions of these holding times.
8.5 Spiking suspension enumeration holding times. Flow-cytometer-sorted spiking suspensions (Sections
7.10.1 and 11.2) used for spiked quality control (QC) samples (Section 9) must be used within the
expiration date noted on the suspension. [[Laboratories should use flow-cytometer- sorted spiking
suspensions containing live organisms within two weeks of preparation at the flow cytometry
laboratory.]] Manually enumerated spiking suspensions must be used within 24 hours of enumeration of
the spiking suspension if the hemacytometer chamber technique is used (Section 11.3.4); or within 24
hours of application of the spiking suspension to the slides if the well slide or membrane filter
enumeration technique is used (Sections 11.3.5 and 11.3.6). [[Oocyst and cyst suspensions must be stored
at 0°C to 10°C, until ready to use; do not allow to freeze]]
9.0 Quality Control
9.1.2 In recognition of advances that are occurring in analytical technology, the laboratory is permitted to
modify certain method procedures to improve recovery or lower the costs of measurements, provided that
all required quality control (QC) tests are performed and all QC acceptance criteria are met. Method
procedures that can be modified include front-end techniques, such as filtration or immunomagnetic
separation (IMS). The laboratory is not permitted to use an alternate determinative technique to replace
immunofluorescence assay in this method (the use of different determinative techniques are considered to
be different methods, rather than modified version of this method).
However, the laboratory is permitted to modify the immunofluorescence assay
procedure, provided that all required QC tests are performed (Section 9.1.2.1) and all QC acceptance
criteria are met (see guidance on the use of multiple labeling reagents in Section 7.6).
[[NOTE: Method modifications should be considered only to improve method performance, reduce cost,
or reduce sample processing time. Method modifications that reduce cost or sample processing time, but
that result in poorer method performance should not be used.]]
9.1.2.1.1 Method modifications at a single laboratory. Each time a modification is made to this method
for use in single laboratory, the laboratory must, [[at a minimum,]] validate the modification according to
Tier 1 of EPA's performance-based measurement system (PBMS) (Table 2 [[and Reference 20.8]]) to
demonstrate that the modification produces results equivalent or superior to results produced by this
method as written. Briefly, each time a modification is made to this method, the laboratory is required to
demonstrate acceptable modified method performance through the IPRtest (Section 9.4). IPR results
must meet the QC acceptance criteria in Tables 3 and 4 in Section 21.0, and should be comparable to
previous results using the unmodified procedure. Although not required, the laboratory also should
perform a matrix spike/matrix spike duplicate (MS/MSD) test to demonstrate the performance of the
modified method in at least one real-world matrix before analyzing field samples using the modified
method. The laboratory is required to perform MS samples using the modified method at the frequency
noted in Section 9.1.8. [[If the modified method involves changes that cannot be adequately evaluated
through these tests, additional tests may be required to demonstrate acceptability.]]
9.1.2.1.2 Method modifications for nationwide approval. If the laboratory or a manufacturer seeks EPA
approval of a method modification for nationwide use, the laboratory or manufacturer must, [[at a
minimum,]] validate the modification according to Tier 2 of EPA's PBMS (Table 2 [[and Reference
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20.8]]). Briefly, at least three laboratories must perform IPR tests (Section 9.4) and MS/MSD
(Section 9.5) tests using the modified method, and all tests must meet the QC acceptance criteria specified
in Tables 3 and 4 in Section 21.0. Upon nationwide approval, laboratories electing to use the modified
method still must demonstrate acceptable performance in their own laboratory according to the
requirements in
9.1.2.1.2 Method modifications for nationwide approval. If the laboratory or a manufacturer seeks EPA
approval of a method modification for nationwide use, the laboratory or manufacturer must, [[at a
minimum,]] validate the modification according to Tier 2 of EPA's PBMS (Table 2 [[and Reference
20.8]]). Briefly, at least three laboratories must perform IPR tests (Section 9.4) and MS/MSD
(Section 9.5) tests using the modified method, and all tests must meet the QC acceptance criteria specified
in Tables 3 and 4 in Section 21.0. Upon nationwide approval, laboratories electing to use the modified
method still must demonstrate acceptable performance in their own laboratory according to the
requirements inSection 9.1.2.1.1. [[If the modified method involves changes that cannot be adequately
evaluated through these tests, additional tests may be required to demonstrate acceptability.]]
Section 9.1.2.1.1. [[If the modified method involves changes that cannot be adequately evaluated through
these tests, additional tests may be required to demonstrate acceptability.]]
9.1.8 [[The laboratory shall analyze MS samples (Section 9.5.1) at aminimum frequency of 1 MS sample
per 20 field samples and at least 12 months must elapse between the first and last MS sample. The
laboratory should analyze an MS sample when samples are first received from a PWS for which the
laboratory has never before analyzed samples to identify potential method performance issues with the
matrix (Section 9.5.1; Tables 3 and 4). If an MS sample cannot be analyzed on the first sampling event,
the first MS sample should be analyzed as soon as possible to identify potential method performance
issues with the matrix.]]
9.2.1 Micropipettes must be sent to the manufacturer for calibration annually. Alternately, a qualified
independent technician specializing in micropipette calibration can be used[[, or the calibration can be
performed by the laboratory, provided the laboratory maintains a detailed procedure that can be evaluated
by an independent auditor.]] Documentation on the precision of the recalibrated micropipette must be
obtained from the manufacturer or technician.
9.4.1.1 [[The laboratory is permitted to analyze the four spiked reagent samples on the same day or on as
many as four different days (provided that the spiked reagent samples are analyzed consecutively), and
also may use different analysts and/or reagent lots for each sample (however, the procedures used for all
analyses must be identical). Laboratories should note that the variability of four measurements performed
on multiple days or using multiple analysts or reagent lots may be greater than the variability of
measurements performed on the same day with the same analysts and reagent lots. As a result, the
laboratory is at a greater risk of generating unacceptably variable IPR results if the test is performed
across multiple days, analysts, and /or reagent lots.]]
[[9.4.1.3 The set of four]] IPR [[tests samples]] must be accompanied by analysis of [[a an acceptable]]
method blank (Section 9.6).
9.4.3 Compare the RSD and the mean with the corresponding limits for initial precision and recovery in
Tables 3 and 4 in Section 21.0. If the RSD and the mean meet the acceptance criteria, system performance
is acceptable and analysis of blanks and samples may begin. If the RSD or the mean falls outside the
range for recovery, system performance is unacceptable. In this event, [[trouble-shoot the problem by
starting at the end of the method (see guidance in Section 7.9.5 9.7.5),]] correct the problem and repeat
the test (Section 9.4.1).
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9.5.1 Matrix spike-The laboratory shall spike and analyze a separate field sample aliquot to determine the
effect of the matrix on the method's oocyst and cyst recovery. [[The MS and field sample must be
collected from the same sampling location as split samples or as samples sequentially collected
immediately after one another. The MS sample volume analyzed must be within 10% of the field sample
volume]]. The MS shall be analyzed according to the frequency in Section 9.1.8.
9.5.1.1 Analyze an unspiked field sample according to the procedures in Sections 12.0 to 15.0. Using the
spiking procedure in Section 11.4 and enumerated spiking suspensions (Section 7.10.1 or Section 11.3),
spike, filter, elute, concentrate, separate (purify), stain, and examine a second field sample aliquot with [[a
similar the]] number of organisms [[as that]] used in the IPR or OPR tests (Sections 9.4 and 9.7).
9.5.1.4 As part of the QA program for the laboratory, method precision for samples should be assessed
and records maintained. After the analysis of five samples [[for which the spike recovery for each
organism passes the tests in Section 9.5.1.3]], the laboratory should calculate the average percent recovery
(P) and the standard deviation of the percent recovery (sr). Express the precision assessment as a percent
recovery interval from P ! 2 sr to P + 2 sr for each matrix. For example, if P = 80% and sr = 30%, the
accuracy interval is expressed as 20% to 140%. The precision assessment should be updated regularly
across all MS samples and stratified by MS samples for each source
9.6 Method blank (negative control sample, laboratory blank): Reagent water blanks are analyzed to
demonstrate freedom from contamination. Analyze the blank immediately [[prior to after]] analysis of the
IPR test (Section 9.4) and OPR test (Section 9.7) and prior to analysis of samples for the week to
demonstrate freedom from contamination
9.6.2.1 [[If Cryptosporidium oocysts, Giardia cysts, or potentially interfering organisms or materials that
may be misidentified as oocysts or cysts are not found in the method blank, the method blank test is
acceptable and analysis of samples may proceed Any method blank in which oocysts or
cysts are not detected is assumed to be uncontaminated and may be reported.
9.6.2.2 ]]If Cryptosporidium oocysts[[, or]] Giardia cysts [[(as defined in Section 3)]] or any potentially
interfering organism or materials [[that may be misidentified as oocysts or cysts]] are found in the method
blank[[, the
method blank test is unacceptable. Any field sample in a batch associated with an unacceptable method
blank a contaminated blank that shows the presence of one or more oocysts or cysts]] is assumed to be
contaminated and should be recollected [[, if possible]]. Analysis of additional samples is halted until the
source of contamination is eliminated, [[the method blank test is performed again, and no evidence of
contamination is detected]].
9.7 Ongoing precision and recovery (OPR; positive control sample; laboratory control sample):
Using the spiking procedure in Section 11.4 and enumerated spiking suspensions (Section 7.10.1 or
Section 11.3), filter, elute, concentrate, separate (purify), stain, and examine at least one reagent water
sample spiked with 100 to 500 oocysts and 100 to 500 cysts each week to verify all performance criteria.
The laboratory must analyze one OPR sample for every 20 samples if more than 20 samples are analyzed
in a week. If multiple method variations are used, separate OPR samples must be prepared for each
method variation. Adjustment and/or recalibration of the analytical system shall be performed until all
performance criteria are met. Only after all performance criteria are met [[may should]] samples be
analyzed.
9.7.1.1 Using 200X to 400X magnification, more than 50% of the oocysts or cysts must appear
undamaged and morphologically intact; otherwise, [[the organisms in the spiking suspension may be of
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unacceptable quality or]] the analytical process is may be damaging the organisms. [[Examine the
spiking suspension organisms directly (by centrifuging, if possible, to concentrate the organisms in a
volume that can be applied directly to a slide). If the organisms appear undamaged and morphologically
intact under DIG,]] determine the step or reagent that is causing damage to the organisms. Correct the
problem and repeat the OPR test.
[[9.7.4 Actions
9.7.4.1]] If the recoveries [[for Cryptosporidium and Giardia]] meet the acceptance criteria, system
performance is acceptable and analysis of [[blanks and]] samples may proceed.
[[9.7.4.2]] If[[, however,]] the recovery for [[Cryptosporidium or Giardia]] falls outside of the criteria
range given, system performance is unacceptable. [[Any sample in a batch associated with an
unacceptable OPR sample is unacceptable. Analysis of additional samples is halted until the analytical
system is brought under control. In this event, there may be a problem with the microscope or with the
filtration or separation systems.]]
Troubleshoot the problem using the procedures at Section 9.7.5 as a guide. After assessing the issue[[,
perform another OPR test and verify that Cryptosporidium and Giardia recoveries meet the acceptance
criteria. All samples must be associated with an OPR that passes the criteria in Section 21.0. Samples that
are not associated with an acceptable OPR must be flagged accordingly.]]
[[9.7.5.1 Quality of spiked organisms. Examine the spiking suspension organisms directly (by
centrifuging, if possible, to concentrate the organisms in a volume that can be applied directly to a slide).
If the organisms appear damaged under DIC, obtain fresh spiking materials. If the organisms appear
undamaged and morphologically intact, determined whether the problem is associated with the
microscope system or antibody stain (Section 9.7.5.2).
9.7.5.2]] Microscope system and antibody stain: To determine if the failure of the OPR test is due to
changes in the microscope or problems with the
antibody stain, re-examine the positive staining control (Section 15.2.1),
check Kohler illumination, and check the fluorescence of the fluoresceinlabeled
monoclonal antibodies (Mabs) and 4',6-diamidino-2-phenylindole (DAPI). If results are unacceptable, re-
examine the previously-prepared positive staining control to determine whether the problem is associated
with the microscope or the antibody stain.
[[9.7.5.3]] Separation (purification) system: To determine if the failure of the OPR test is attributable to
the separation system, check system performance by spiking a 10-mL volume of reagent water with 100 -
500 oocysts and cysts and processing the sample through the IMS, staining, and examination procedures
in Sections 13.3 through 15.0. [[Recoveries should be greater than 70%.]]
[[9.7.5.4]] Filtration/elution/concentration system: If the failure of the OPR test is attributable to the
filtration/elution/concentration system, check system performance by processing spiked reagent water
according to the procedures in Section 12.2 through 13.2.2.1 [[13.2.2]], and filter, stain, and examine the
sample concentrate according to Section 11.3.6.
10.0 Microscope Calibration and Analyst Verification
10.3.5.7 Follow the procedure below for each objective. Record the information as shown in the example
below and keep the information available at the microscope.
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Item no.
Objective
power Description
No. of ocular micrometer spaces
No. of stage micrometer mm(l)
(im/ocular
micrometer
space2
1 10XN.A.3=
2 20X N.A.=
3 40X N.A.=
4 100XN.A.=
(1)100[[0]] (im/mm
2(Stage micrometer length in mm x (1000 (im/mm)) + no. ocular micrometer
spaces 3N.A. refers to numerical aperature. The numerical aperature value is engraved on the barrel of the
objective.
10.3.6.5 The aperture diaphragm of the condenser [[should is]] now [[be]] adjusted to make it compatible
with the total numerical aperture of the optical system. This is done by removing an ocular, looking into
the tube at the rear focal plane of the objective, and stopping down the aperture diaphragm iris leaves
until they are visible just inside the rear plane of the objective.
[[10.4 Microscope cleaning procedure
10.4.1 Use canned air to remove dust from the lenses, filters, and microscope body.
10.4.2 Use a Kimwipe-dampened with a microscope cleaning solution (MCS) (consisting of 2 parts 90%
isoproponal and 1 part acetone) to wipe down all surfaces of the microscope body. Dry off with a clean,
dry Kim wipe.
10.4.3 Protocol for cleaning oculars and condenser
10.4.3.1 Use a new, clean Q-tip dampened with MCS to clean each lense. Start at the center of the lens
and spiral the Q-tip outward using little to no
pressure. Rotate the Q-tip head while spiraling to ensure a clean surface
is always contacting the lens.
10.4.3.2 Repeat the procedure using a new, dry Q-tip.
10.4.3.3 Repeat Sections 10.4.3.1 and 10.4.3.2.
10.4.3.4 Remove the ocular and repeat the cleaning procedure on the bottom lens of the ocular.
10.4.4 Protocol for cleaning objective lenses
10.4.4.1 Wipe 100X oil objective with lense paper to remove the bulk of the oil from the objective.
10.4.4.2 Hold a new Q-tip dampened with MCS at a 45° angle on the objective
and twirl.
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10.4.4.3 Repeat Sections 10.4.4.2 with anew, dry Q-tip.
10.4.4.4 Repeat Sections 10.4.4.2 and 10.4.4.3.
10.4.4.5 Clean all objectives whether they are used or not.
10.4.5 Protocol for cleaning light source lens and filters
10.4.5.1 Using a Kim wipe dampened with microscope cleaning solution, wipe off the surface of each lens
and filter.
10.4.5.2 Repeat the procedure using a dry Kimwipe.
10.4.5.3 Repeat Sections 10.4.5.1 and 10.4.5.2.
10.4.6 Protocol for cleaning microscope stage
10.4.6.1 Using a Kimwipe dampened with microscope cleaning solution, wipe off the stage and stage clip.
Be sure to clean off any residual immersion oil or fingernail polish. Remove the stage clip if necessary to
ensure that it is thoroughly cleaned.
10.4.7 Use 409 and a paper towel to clean the bench top surrounding the microscope.
10.4.8 Frequency
10.4.8.1 Perform Sections 10.4.2, 10.4.3, 10.4.4, 10.4.5 and 10.4.7 after each microscope session.
10.4.8.2 Perform complete cleaning each week.]]
10. [[5]] Protozoa libraries: Each laboratory is encouraged to develop libraries of photographs and
drawings for identification of protozoa.
10.[[5]].1 Take color photographs of Cryptosporidium oocysts and Giardia cysts by FA[[, and]] 4',6-
diamidino-2-phenylindole (DAPI)[[, and DIC]] that the analysts (Section 22.2) determine are accurate
(Section 15.2).
10.[[5]].2 Similarly, take color photographs of interfering organisms and materials by FA[[, and]] DAPI[[,
and DIC]] that the analysts believe are not Cryptosporidium oocysts or Giardia cysts. Quantify the size,
shape, microscope settings, and other characteristics that can be used to differentiate oocysts and cysts
from interfering debris and that will result in [[accurate positive]] identification [[of DAPI positive or
negative organisms]].
10.[[6]] Verification of [[analyst]] performance: Until standard reference materials, such as National
Institute of Standards and Technology standard reference materials, are available that contain a reliable
number of DAPI positive or negative oocysts and cysts, this method shall rely upon the ability of the
analyst for identification and enumeration of oocysts and cysts.
10.[[6]]. 1 At least monthly when microscopic examinations are being performed, the laboratory shall
prepare a slide containing 40 to 100 oocysts and 40 to 100 cysts. More than 50% of the oocysts and cysts
must be DAPI positive [[and undamaged under DIC]].
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10.[[6]].2 Each analyst shall determine the total number of oocysts and cysts and the number that are
DAPI positive and DAPI negative [[for the entire slide. For 10 oocysts and 10 cysts, each analyst shall
determine using the slide prepared in Section 10.5.1. the number of nuclei by DAPI and the DIG category
(empty, containing amorphous structures, or containing identifiable internal structures) of each.
10.6.3 Requirements for laboratories with multiple analysts
10.6.3.1]] The total number and the number of DAPI positive [[or and DAPI]] negative oocysts and cysts
determined by each analyst (Section 10.5.2.) must be within ±10% of each other. If the number is not
within this range, the analysts must identify the source of any variability between analysts'
examination criteria, prepare anew slide, and repeat the performance verification (Sections 10.5.1 to
10.5.2). [[Differences in the number of nuclei by DAPI and in DIC categorizations among analysts must
be discussed and resolved, and these resolutions must be documented.
10.6.3.2]] Document the date, name(s) of analyst(s), number of total, DAPI positive or negative oocysts
and cysts determined by the analyst(s), whether the test was passed/failed and the results of attempts
before the test was passed.
[[10.6.3.3]] Only after an analyst has passed the criteria in Section 10.[[6]].3, may oocysts and cysts in
QC samples and field samples be identified and enumerated.
[[10.6.4 Laboratories with only one analyst should maintain a protozoa library (Section 10.5) and
compare the results of the examinations performed in Sections 10.6.1 and 10.6.2 to photographs of
oocysts and cysts and interfering organisms to verify that examination results are consistent with these
references. These laboratories also should perform repetitive counts of a single verification slide for FITC
and DAPI. These laboratories should also coordinate with other laboratories to share slides and compare
counts.]]
11.0 Oocyst and Cyst Suspension Enumeration and Spiking
11.1 This method requires routine analysis of spiked QC samples to demonstrate acceptable initial and
ongoing laboratory and method performance (initial precision and recovery samples [Section 9.4], matrix
spike and matrix spike duplicate samples [Section 9.5], and ongoing precision and recovery samples
[Section 9.7]). The organisms used for these samples must be enumerated to calculate recoveries and
precision. EPA recommends that flow cytometry be used for this enumeration, rather than manual
techniques. Flow cytometer-sorted spikes generally are characterized by a relative standard deviation of
#2.5%, versus greater variability for manual enumeration techniques (Reference 20.[[8]]). Guidance on
preparing spiking suspensions using a flow cytometer is provided in Section 11.2. Manual enumeration
procedures are provided in Section 11.3. The procedure for spiking bulk samples in the laboratory is
provided in Section 11.4.
11.2.6 Holding time criteria. Flow-cytometer-sorted spiking suspensions (Sections 7.10.1 and 11.2) used
for spiked quality control (QC) samples (Section 9) must be used within the expiration date noted on the
suspension. [[The holding time specified by the flow cytometry laboratory should be determined based on
a holding time study. Laboratories should use flow-cytometer-sorted spiking suspensions containing live
organisms within two weeks of preparation at the flow cytometry laboratory.]]
11.3 Manual enumeration procedures. Two sets of manual enumerations are required per organism before
purified Cryptosporidium oocyst and Giardia cyst stock suspensions (Sections 7.9.2.1 and 7.9.2.2
[[Section 7.10.2]]) received from suppliers can be used to spike samples in the laboratory. First, the stock
suspension must be diluted and enumerated (Section 11.3.3) to yield a suspension at the appropriate
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oocyst or cyst concentration for spiking (spiking suspension). Then, 10 aliquots of spiking suspension
must be enumerated to calculate a mean spike dose. Spiking suspensions can be enumerated using
hemacytometer chamber counting (Section 11.3.4), well slide counting (Section 11.3.5), ormembrane
filter counting (Section 11.3.6).
11.3.3.5 Move the chamber so the ruled area is centered underneath [[it the objective]]
11.3.3.9 Use the following formula to determine the number of organisms per mL of suspension: number
of 10 dilution number of organisms counted factor 1[[000]] mm2 organisms
x x x = number of mm2
1 mm 1 1 |iL[[mL]] |iL[[mL]] counted.
11.3.3.12 Based on the hemacytometer counts, the stock suspension should be diluted to a final
concentration of between [[8000 and 12,000 organisms per mL]] (8[[0]] to 12[[0]] organisms per [[10]]
(iL); however, ranges as great as [[5000 to 15,000 organisms per mL Q]5[[0]] to 15[[0]] organisms per
[[10]](iL[[)]]canbeused.
NOTE: If the diluted stock suspensions (the spiking suspensions) will be enumerated using
hemacytometer chamber counts (Section 11.3.4) or membrane filter counts (Section 11.3.6), then the
stock suspensions should be diluted with 0.01% Tween-20. If the spiking suspensions will be enumerated
using well slide counts (Section 11.3.3 [[11.3.5]]), then the stock suspensions should be diluted in reagent
water.
To calculate the volume (in (iL) of stock suspension required per mL of reagent water (or reagent
water/Tween-20, 0.01%), use the following formula: required number of organisms [[x 1000 :L]] volume
of stock suspension (|iL) required = number of organisms/ (i[[m]]L of stock suspension
If the volume is less than 10 (iL, an additional dilution of the stock suspension is recommended before
proceeding.
To calculate the dilution factor needed to achieve the required number of organisms per 10 (iL, use the
following formula:
number of organisms required x 10:L
total volume (:L) = predicted number of organisms per 10:L (80 to 120)
To calculate the volume of reagent water (or reagent water/Tween-20, 0.01%) needed, use the following
formula: reagent water volume (:L) = total volume (:L) - stock suspension volume required (:L)
11.3.5.1 [[Prepare well slides for sample screening and label the slides. Remove well slides from cold
storage and lay the slides on a flat surface for 15 minutes to allow them to warm to room temperature]]
[[11.3.5.7 Apply 50-(iL of absolute methanol to each well containing the dried sample and allow to air-
dry for 3 to 5 minutes.]]
11.3.5.[[7]] Follow the manufacturer's instructions (Section 7.6) in applying the stain to the slide.
11.3.5.[[8]] Place the slides in a humid chamber in the dark and incubate [[according to manufacturer's
directions, at room temperature for approximately 30 minutes.]] The humid chamber consists of a tightly
sealed plastic container containing damp paper towels on top of which the slides are placed.
11.3.5.[[9]] Apply one drop of wash buffer (prepared according to the manufacturer's instructions
[Section 7.6]) to each well. Tilt each slide on a clean paper towel, long edge down. Gently aspirate the
excess detection reagent from below the well using a clean Pasteur pipette or absorb with a paper towel or
other absorbent material. Avoid disturbing the sample.
NOTE: If using the Merifluor stain (Section 7.6.1), do not allow slides to dry completely.
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11.3.5.[[10]] Add mounting medium (Section 7.8) to each well.
11.3.5. [[11]] Apply a cover slip. Use a tissue to remove excess mounting fluid from the edges of the
coverslip. Seal the edges of the coverslip onto the slide using clear nail polish.
11.3.5.[[12]] Record the date and time that staining was completed. If slides will not be read immediately,
store in a humid chamber in the dark at 0°C to 8°C
< 10°C and not frozen until ready for examination.
11.3.5.[[13]] After examination of the 10 wells, calculate the mean, standard deviation, and RSD of the 10
replicates. Record the counts and the calculations on a spiking suspension enumeration form. The relative
standard deviation (RSD) of the calculated mean spike dose must be #16% for Cryptosporidium and
#19% for Giardia before proceeding. If the RSD is unacceptable, or the mean number is outside the
expected range, add additional oocysts from stock suspension or dilute the contents of the beaker
appropriately with reagent water. Repeat the process to confirm counts.
11.3.6.3 Filter-sterilize (Section 6.19) approximately 10 mL of PBS pH 7.2
(Section 7. 9. 4 [[7.6.4]]). Dilute detection reagent (Section 7.7) as per manufacturer's instructions using
sterile PBS. Multiply the anticipated number of filters to be stained by 100 mL to calculate total volume
of stain required. Divide the total volume required by 5 to obtain the microliters of antibody necessary.
Subtract the volume of antibody from the total stain volume to obtain the required microliters of sterile
PBS to add to the antibody.
11.3.6.19 Record the date and time that staining was completed. If slides will not be read immediately,
store sealed slides in a closed container in the dark at [[0°C to <]] 8°C (but not frozen) until ready for
examination.
11.4.1 Arrange a bottom-dispensing container to feed the filter [[or insert the influent end of the tube
connected to the filter through the top of a carboy to allow siphoning of the sample.]]
11.4.2 For initial precision and recovery (Section 9.4) and ongoing precision and recovery (Section 9.7)
samples, fill the container with [[10 L of reagent water or]] a volume of reagent water equal to the volume
of the field samples analyzed in the analytical batch. For matrix spike samples (Section 9.5), fill the
container with the field sample to be spiked. Continuously mix the sample (using a stir bar and stir plate
for smaller-volume samples and alternate means for larger-volume samples).
11.4.3 [[Follow the procedures in Section 11.4.3.1 for flow cytometer-
enumerated suspensions and the procedures in Section 11.4.3.2 for manually enumerated suspensions.
Vortex the spiking suspension(s) (Section 11.2 or Section 11.3) for a minimum of 2 minutes.]]
11.4.3.1.6
Add 400 (iL of Antifoam A to 100 mL of reagent water, and mix well to emulsify.
Add 500 (iL of the diluted antifoam to the tube containing the spiking suspension and vortex for [[30
seconds 2 minutes]].
[[11.4.3.2.1]]
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Vortex the spiking suspension(s) (Section 11.2 or Section 11.3) for a minimum of 30 seconds.]]
11.4.6 When the water level approaches the discharge port of the carboy, tilt the container so that it is
completely emptied. At that time, turn off the pump and add sufficient reagent water to the container to
rinse. Swirl the contents to rinse down the sides. [[Additional rinses may be performed.]]
12.0 Sample Filtration and Elution
12.1 A water sample is filtered according to the procedures in Section 12.2 [[or Section 12.3.]] Alternate
procedures may be used if the laboratory first demonstrates that the alternate procedure provides
equivalent or superior performance per Section 9.1.2.
NOTE: Sample elution must be initiated within 96 hours of sample collection (if shipped to the laboratory
as a bulk sample) or filtration (if filtered in the field).
12.2 Capsule filtration (adapted from Reference 20.[[9]]). This procedure was validated using 10-L
sample volumes [[(for the original Envirochek(tm) filter) and 50-L sample volumes (for the
Envirochek(tm) HV filter)]]. Alternate sample volumes may be used, provided the laboratory
demonstrates acceptable performance on initial and ongoing spiked reagent water and source
water samples (Section 9.1.2).
NOTE: The filtration procedures specified in Section 12.2.1 - 12.2.5.3 are specific to laboratory filtration
of a bulk sample, and reflect the procedures used during the interlaboratory validation of this method
(Reference 20. [[10]]). These procedures may require modification if samples will be filtered in the field.
12.2.4.1 [[Mix the sample well by shaking and]] connect the sampling system to the field carboy of
sample water, or transfer the sample water to the laboratory carboy used in Section 12.2.1.1. If the sample
will be filtered from a field carboy, a spigot (Section 6.2.1) can be used with the carboy
to facilitate sample filtration.
12.2.4.3 Allow the carboy discharge tube and capsule to fill with sample water [[by gravity]]. Vent
residual air using the bleed valve/vent port, gently shaking or tapping the capsule, if necessary. Turn on
the pump to start water flowing through the filter. Verify that the flow rate is 2 L/min.
12.2.4.4 After all of the sample has passed through the filter, turn off the pump. Allow the pressure to
decrease until flow stops. (If the sample was filtered in the field, and excess sample remains in the filter
[[capsule]] upon receipt in the laboratory, pull the remaining sample volume through the filter before
eluting the filter [Section 12.2.6].)
12.2.5.2 Based on the water level in the graduated container [[and 1/2-L hash marks]] or meter reading,
record the volume filtered on the bench sheet to the nearest quarter liter. Discard the contents of the
graduated container.
12.2.6.2.1 Record the elution date and time on the bench sheet. Using a ring stand or other means, clamp
each capsule in a vertical position with the inlet end up. [[Remove the inlet cap and allow the liquid level
to stabilize.]]
12.2.6.2.2 Pour elution buffer through the inlet fitting. [[Remove the inlet cap and allow the liquid level to
stabilize.]] Sufficient elution buffer must be added to cover the pleated white membrane with buffer
solution. Replace the inlet cap [[and clamp the cap in place.]]
[[12.3 Sample filtration using the Filta-Max(tm) foam filter. This procedure was validated using 50-L
sample volumes. Alternate sample volumes may be used, provided the laboratory demonstrates acceptable
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performance on initial and ongoing spiked reagent water and source water samples (Section 9.1.2).
NOTE: The filtration procedures specified in Sections 12.3.1.2 - 12.3.1.6.3 are specific to laboratory
filtration of a bulk sample. These procedures may require modification if samples will be filtered in the
field.
12.3.1 Filtration
12.3.1.1 Flow rate adjustment
12.3.1.1.1 Connect the sampling system, minus the filter housing,
to a carboy filled with reagent water.
12.3.1.1.2 Place the peristaltic pump upstream of the filter housing.
12.3.1.1.3 Turn on the pump and adjust the flow rate to 1 to 4 L per
minute.
NOTE: A head pressure of 0.5 bar (7.5 psi) is required to create flow through the filter, and the
recommended pressure of 5 bar (75 psi) should produce the flow rate of 3 to 4 L per minute. The
maximum operating pressure of 8 bar (120 psi) should not be exceeded, refer to manufacturers
instructions
12.3.1.1.4 Allow 2 to 10 L of reagent water to flush the system. Adjust the pump speed as necessary
during this period. Turn off the pump when the flow rate has been adjusted.
12.3.1.2 Place filter module into the filter housing bolt head down and secure lid, hand tighten housings,
apply gentle pressure to create the seal between the module and the 'O' rings in the base and the lid of the
housing. Excessive tightening is not necessary, and may shorten the life of the 'O' rings. Tools may be
used to tighten housing to the alignment marks (refer to manufacturer's instructions). 'O' rings should be
lightly greased before use (refer to manufacturer's instructions).
12.3.1.3 Install the filter housing in the line, securing the inlet and outlet ends with the appropriate
clamps/fittings. Verify that the filter housing is installed so that the end closest to the screw lid is the inlet
and the opposite end is the outlet.
12.3.1.4 Record the sample number, sample turbidity (if not provided with the field sample), and the
name of the analyst filtering the sample on a bench sheet.
12.3.1.5 Filtration
12.3.1.5.1 Connect the sampling system to the field carboy of sample water, or transfer the sample water
to the laboratory carboy used in Section 12.3.1.1.1. If the sample will be filtered from a field carboy, a
spigot can be used with the carboy to facilitate sample filtration.
NOTE: If the bulk field sample is transferred to a laboratory carboy, the laboratory carboy must be
cleaned and disinfected before it is used with another
field sample.
12.3.1.5.2 Place the drain end of the sampling system tubing into an empty graduated container with a
capacity greater than or equal to the volume to be filtered. This container will be used to determine the
sample volume filtered. Alternately, connect a flow meter downstream of the
filter, and record the initial meter reading.
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12.3.1.5.3 Allow the carboy discharge tube and filter housing to fill with sample water. Turn on the pump
to start water flowing through the filter. Verify that the flow rate is between 1 and 4 L per min.
12.3.1.5.4 After all of the sample has passed through the filter, turn off the pump. Allow the pressure to
decrease until flow stops.
12.3.1.6 Disassembly
12.3.1.6.1 Disconnect the inlet end of the filter housing assembly while maintaining the level of the inlet
fitting above the level of the outlet fitting to prevent backwashing and the loss of oocysts and cysts from
the filter. Restart the pump and allow as much water to drain as possible. Turn off the pump.
12.3.1.6.2 Based on the water level in the graduated container or the meter reading, record the volume
filtered on a bench sheet to the nearest quarter liter.
12.3.1.6.3 Loosen the outlet fitting, the filter housing should be sealed with rubber plugs.
NOTE: Filters should be prevented from drying out, as this can impair their ability to expand when
decompressed.
12.3.2Elution
12.3.2.1 The filter is eluted to wash the oocysts from the filter. This can be accomplished using the Filta-
Max(tm) wash station, which moves a plunger up and down a tube containing the filter and eluting
solution (Section 12.3.2.2), or a stomacher, which uses paddles to agitate the stomacher bag containing
the foam filter in the eluting solution (Section 12.3.2.3). If the Filta-MaxTM automatic wash station is
used please see the manufacturer's operator's guide for instructions on its use.
12.3.2.2 Filta-Max(tm) wash station elution procedure
12.3.2.2.1 First wash
(a) Detach the removable plunger head using the tool provided, and remove the splash guard.
(b) Place the filter membrane flat in the concentrator base with the rough side up. Locate the concentrator
base in the jaws of the wash station and screw on the concentrator tube (the longer of the two tubes),
creating a tight seal at the membrane. Take the assembled concentrator tube out of the jaws and place on
the bench.
(c) Replace the splash guard and temporarily secure it at least 15 cm above the end of the rack. Secure the
plunger head with the tool provided ensuring that the lever is fully locked down.
(d) Remove the filter module from the filter housing or transportation container. Pour excess liquid into
the assembled concentrator tube, then rinse the housing or container with PBST and add the rinse to the
concentrator tube. Screw the filter module onto the base of the plunger. Locate the elution tube base in
the jaws of the wash station and screw the elution tube (the shorter of the two tubes) firmly in place. Or
alternatively if a Filta-Max(r) Quick Connect kit is being used to aid attachment of the assembled
concentrator and elution tube, refer to the manufacturers instructions.
(e) Pull the plunger down until the filter module sits at the bottom of the elution tube; the locking pin (at
the top left of the wash station) should "click" to lock the plunger in position.
(f) Remove the filter module bolt by turning the adapted alien key (provided) in a clockwise direction
(as seen from above). Attach the steel tube to the elution tube base.
(g) Add 600 mL of PBST to the assembled concentrator. If more than 50 mL of liquid has been
recovered from the shipped filter module, reduce the volume of PBST accordingly. Screw the
concentrator tube onto the base beneath the elution tube. Release the locking pin.
NOTE: Gentle pressure on the lever, coupled with a pulling action on the locking pin should enable the
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pin to be easily released.
(h) Wash the foam disks by moving the plunger up and down 20 times. Gentle movements of the plunger
are recommended to avoid generating excess foam.
NOTE: The plunger has an upper movement limit during the wash process to prevent it popping out of
the top of the chamber.
(i) Detach the assembled concentrator tube and hold it such that the stainless steel tube is just above the
level of the liquid. Purge the remaining liquid from the elution tube by moving the plunger up and down 5
times, then lock the plunger in place. To prevent drips, place the plug provided in the end of the steel
tube.
(j)Prior to the second wash the eluate from the first wash can be concentrated using the Filta-Max(tm)
apparatus according to Section 12.3.3.2.1 or the eluate can be decanted into a 2-L pooling beaker and
set aside.
13.3.2.2.2 Second wash
(a) Add an additional 600 mL of PBST to the assembled concentrator tube, remove the plug from the end
of the steel tube and screw the concentrator tube back onto the elution module base. Release the
locking pin.
(b) Wash the foam disks by moving the plunger up and down 10 times. Gentle movements of the plunger
are recommended to avoid generating excess foam.
(c) The eluate can be concentrated using the Filta- Max(tm) apparatus according to Section 12.3.3.2.2 or
the eluate can be decanted into the 2-L pooling beaker containing the eluate from the first wash and
concentrated using centrifugation, as described in Section 12.3.3.3.
12.3.2.3 Stomacher elution procedure
12.3.2.3.1 First wash
(a) Place the filter module in the stomacher bag then use the alien key to remove the bolt from the filter
module, allowing the rings to expand. Remove the end caps from the stomacher bag and rinse with
PBST into the stomacher bag.
12.3.2.3.2
12.3.3 Concentration
(b) Add 600 mL of PBST to stomacher bag containing the filter pads. Place bag in stomacher and wash
for 5 minutes on a normal setting.
(c) Remove the bag from the stomacher and decant the eluate into a 2-L pooling beaker.
Second wash
(a) Add a second 600-mL aliquot of PBST to the stomacher bag. Place bag in stomacher and wash for
5 minutes on a normal setting. Remove the bag from the stomacher and decant the eluate from the
stomacher bag into the 2-L pooling beaker. Wring the stomacher bag by hand to remove eluate from
the foam filter and add to the pooling beaker. Remove the foam filter from the bag and using a
squirt bottle, rinse the stomacher bag with reagent water and add the rinse to the pooling beaker.
(b) Proceed to concentration (Section 12.3.3).
12.3.3.1 The eluate can be concentrated using the Filta-Max(tm) concentrator apparatus, which pulls most
of the eluate through a membrane filter leaving the oocysts concentrated in a small volume of the
remaining eluting solution (Section 12.3..2), or by directly centrifuging all of the eluting solution used to
wash the filter (Section 12.3.2.3).
12.3.3.2 The Filta-Max(tm) concentrator procedure
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12.3.3.2.1 Concentration of first wash
(a) If the stomacher was used to elute the sample (Section 12.3.2.3), transfer 600 mL of eluate from
the pooling beaker to the concentrator tube. Otherwise proceed to Step (b).
(b) Stand the concentrator tube on a magnetic stirring plate and attach the lid (with magnetic stirrer bar).
Connect the waste bottle trap and hand or electric vacuum pump to the valve on the concentrator base.
Begin stirring and open the tap. Increase the vacuum using the pump.
NOTE: The force of the vacuum should not exceed 30 cmHg.
(c) Allow the liquid to drain until it is approximately level with the middle of the stirrer bar then close the
valve. Remove the magnetic stirrer, and rinse it with PBST or distilled water to recover all oocysts.
Decant the concentrate into a 50-mL tube, then rinse the sides of the concentration tube and add the
rinsate to the 50-mL tube.
12.3.3.2.2 Concentration of second wash
(a) If the stomacher was used to elute the sample (Section 12.3.2.3), transfer the remaining 600 mL of
eluate from the pooling beaker to the concentrator tube. Otherwise proceed to Step (b).
12.3.3.2.3
(b) Add the concentrate, in the 50-mL tube, retained from the first concentration (Section 12.3.3.2.1 (c))
to the 600 mL of eluate from the second wash, then repeat concentration steps from Sections 12.3.3.2.1
(b) and 12.3.3.2.1 (c). The final sample can be poured into the same 50-mL tube used to retain the
first concentrate. Rinse the sides of the concentrator tube and the magnetic stirrer with PBST and add the
rinse to the 50-mL tube.
(c) Remove the magnetic stirrer. Insert the empty concentrator module into the jaws of the wash
station and twist off the concentrator tube.
(d) Transfer the membrane from the concentrator base to the bag provided using membrane forceps.
Membrane elution. The membrane can be washed manually or using a stomacher:
- Manual wash. Add 5 mL of PBST to the bag containing the membrane. Rub the surface of the
membrane through the bag until the membrane appears clean. Using a pipette, transfer the eluate to
a 50-mL tube. Repeat the membrane wash with another 5 mL of PBST and transfer the eluate to the
50-mL tube. (Optional: Perform a third wash using another 5 mL of PBST, by hand-kneading an
additional minute or placing the bag on a flat-headed vortexer and vortexing for one minute. Transfer the
eluate to the 50-mL tube.)
NOTE: Mark the bag with an "X" to note which side of the membrane has the oocysts to encourage the
hand-kneading to focus on the appropriate side of the membrane.
- Stomacher wash. Add 5 mL of PBST to the bag containing the membrane. Place the bag containing
the membrane into a small stomacher and stomach for 3 minutes. Using a pipette transfer the eluate to a
50-mL tube. Repeat the wash two times using the stomacher and 5-mL aliquots of PBST. (Optional:
Perform a fourth wash using another 5 mL of PBST, by hand-kneading an additional minute or placing
the bag on a flat-headed vortexer and vortexing for one minute. Transfer the eluate to the 50-mL tube.)
12.3.3.2.4 If the membrane filter clogs before concentration is complete, there are two possible options
for completion of concentration. One option is replacing the membrane as often as necessary. Filter
membranes may be placed smooth side up during the second concentration step. Another option is
concentrating the remaining eluate using centrifugation. Both options are provided below.
- Using multiple membranes. Disassemble the concentrator tube and pour any remaining eluate
back into the pooling beaker. Remove the membrane using membrane forceps, placing it in the bag
provided. Place a new membrane in the concentrator
- base smooth side up, reassemble, return the eluate to the concentrator tube, rinse the pooling beaker and
add rinse to the eluate, and continue the concentration. Replace the membrane as often as necessary.
Centrifuging remaining volume. Decant the remaining eluate into a 2-L pooling beaker. Rinse
the sides of the concentrator tube and add to the pooling beaker. Remove the filter membrane and
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place it in the bag provided. Wash the membrane as described in Section 12.3.3.2.3, then concentrate the
sample as described in Section 12.3.3.3.1.
12.3.3.3 If the Filta-Max(tm) concentrator is not used for sample concentration, or if the membrane filter
clogs before sample concentration is complete, then the procedures described in Section 12.3.3.3.1 should
be used to concentrate the sample. If less than 50 mL of concentrate has been generated, the sample can
be further concentrated, as described in Section 12.3.3.3.2, to reduce the volume of sample to be
processed through IMS.
NOTE: The volume must not be reduced to less than 5 mL above the packed pellet. The maximum
amount of pellet that should be processed through IMS is 0.5 mL. If the packed pellet is greater than 0.5
mL then the pellet may be subsampled as described in Section 13.2.4.
12.3.3.3.1 Centrifugation of greater than 50 mL of eluate
(a) Decant the eluate from the 2-L pooling beaker into 250-mL conical centrifuge tubes. Make sure that
the centrifuge tubes are balanced.
(b) Centrifuge the 250-mL centrifuge tubes containing the eluate at 1500 x G for 15 minutes. Allow the
centrifuge to coast to a stop.
(c) Using a Pasteur pipette, carefully aspirate off the supernatant to 5 mL above the pellet. If the sample is
reagent water (e.g. initial or ongoing precision and recovery sample) extra care must be taken to avoid
aspirating oocysts and cysts during this step.
(d) Vortex each 250-mL tube vigorously until pellet is completely resuspended. Swirl the centrifuge tube
gently to reduce any foaming after vortexing. Combine the contents of each 250-mL centrifuge
tube into a 50-mL centrifuge tube. Rinse each of the 250-mL centrifuge tubes with PBST and add the
rinse to the 50-mL tube.
(e) Proceed to Section 12.3.3.3.2.
12.3.3.3.2 Centrifugation of less than 50 mL of eluate
(a) Centrifuge the 50-mL centrifuge tube containing the combined concentrate at 1500 x G for 15
minutes. Allow the centrifuge to coast to a stop. Record the initial pellet volume (volume of solids) and
the date and time that concentration was completed on a bench sheet.
(b) Proceed to Section 13.0 for concentration and separation (purification).
12.3.4 Maintenance and cleaning
12.3.4.1 Maintenance of O-rings
12.3.4.1.1 Check all rubber O-rings for wear or deterioration prior to each use and replace as necessary.
12.3.4.1.2 Lubricate the plunger head O-ring inside and out with silicon before each use.
12.3.4.1.3 Lubricate all other O-rings (concentrator tube set, filter housing) regularly in order to preserve
their condition.
12.3.4.2 Cleaning
12.3.4.2.1 All components of the Filta-MaxTM system can be cleaned using warm water and laboratory
detergent. After washing, rinse all components with oocyst and cyst free reagent water and dry them. All
O-rings should be re-lubricated. Alternatively a mild (40°C) dishwasher cycle without bleach or rinse aid
can be used.
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12.3.4.2.2 To wash the detachable plunger head slide the locking pin out and wash the plunger head and
locking pin in warm water and laboratory detergent. Rinse the plunger head and locking pin with oocyst
and cyst free reagent water and dry. Lightly lubricate the locking pin and reassemble the plunger head.]]
13.0 Sample Concentration and Separation (Purification)
13.2.4 If the packed pellet volume is > 0.5 mL, the concentrate [[needs to must]] be separated into
multiple subsamples (a subsample is equivalent to no greater than 0.5 mL of packed pellet material, the
recommended maximum amount of particulate material to process through the subsequent purification
and examination steps in the method). Use the following formula to determine the total volume required
in the centrifuge tube before separating the concentrate into two or more subsamples:
pellet volume
total volume (mL) required = x 5 mL
0.5mL
(For example, if the packed pellet volume is 1.2 mL, the total volume required is 12 mL.) Add reagent
water to the centrifuge tube to bring the total volume to the level calculated above. [[Vortex the tube
vigorously for 10 to 15 seconds to completely resuspend the pellet. Record the resuspended pellet volume
on the bench sheet.]]
13.2.4.1.3 Process subsamples through IMS. [[Vortex the tube vigorously for 10 to 15 seconds to
completely resuspend the pellet. Record the resuspended pellet volume on the bench sheet.]] Proceed
[[immediately]] to Section 13.3, and transfer aliquots of the resuspended concentrate equivalent to the
volume in the previous step to multiple, flat-sided sample tubes in Section 13.3.2.1. Process the
sample as multiple, independent subsamples from Section 13.3 onward, including the preparation and
examination of separate slides for each aliquot. Record the volume of resuspended concentrate transferred
to IMS on the bench sheet (this will be equal to the volume recorded in Section 13.2.4). Also record the
number of subsamples processed independently through the method on the bench sheet.
13.2.4.2 Analysis of partial sample. If not all of the concentrate will be examined, [[vortex the tube
vigorously for 10 to 15 seconds to completely resuspend the pellet. Record the resuspended pellet volume
on the bench sheet.]] Proceed [[immediately]] to Section 13.3, and transfer one or more 5-mL aliquots of
the resuspended concentrate to one or more flat-sided sample tubes in Section 13.3.2.1. Record the
volume of resuspended concentrate transferred to IMS on the bench sheet. To determine the volume
analyzed, calculate the percent of the concentrate examined using the following formula: total volume of
resuspended concentrate transferred to IMS percent examined = x 100% total volume of resuspended
concentrate in Section 13.2.4 Then multiply the volume filtered (Section 12.2.5.2) by this percentage
to determine the volume analyzed.
13.3 IMS procedure (adapted from Reference 20.![[!]])
NOTE: The IMS procedure should be performed on a bench top with all materials at room temperature,
ranging from 15°C to 25°C.
13.3.2.1 Use a graduated, 10-mL pipette that has been pre-rinsed with elution buffer to transfer the water
sample concentrate from Section 13.2 to the flat-sided tube(s) containing the SL-buffer[[s]]. If all of the
concentrate is used, rinse the centrifuge tube twice with reagent water and add the rinsate to the flat-sided
tube containing the concentrate (or to the tube containing the first subsample, if multiple subsamples will
be processed). Each of the two rinses should be half the volume needed to bring the volume in the flat-
sided sample tube to 10 mL [[(including the buffers added in Sections 13.3.1.2 and 13.3.1.3).]] (For
example, [[if the tube contained 1 mL of SL-buffer-A and 1 mL of SL-buffer-B,]] and 5 mL of
sample was transferred after resuspension of the pellet, [[for a total of 7 mL,]] the centrifuge tube would
be rinsed twice with [[1.5 mL]] of reagent water to bring the total volume in the flat-sided tube to 10 mL.)
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Visually inspect the centrifuge tube after completing the transfer to ensure that no concentrate remains. If
multiple subsamples will be processed, bring the volume in the remaining flat-sided tubes to 10 mL with
reagent water. Label the flat-sided tube(s) with the sample number (and subsample letters).
13.3.2. 10 Ensure that the tilting action is continued throughout this period to prevent binding of low-
mass, magnetic or magnetizable material. If the sample in the MPC-1 is allowed to stand motionless for
more than 10 seconds, [[remove the flat-sided tube from the MPC-1, shake the tube to resuspend all
material, replace the sample tube in the MPC-1 and]] repeat Section 13.3.2.9 before continuing to Section
13.3.2.11.
13.3.2.11 Return the MPC-1 to the upright position, sample tube vertical, with cap at top. Immediately
remove the cap and, keeping the flat side of the tube on top, pour off all of the supernatant from the tube
held in the MPC-1 into a suitable container. Do not shake the tube and do not remove the tube from MPC-
1 during this step. [[Allow more supernatant to settle; aspirate additional supernatant with pipette.]]
13.3.2.12 Remove the sample tube from the MPC-1 and resuspend the sample in [[1-mL 0.5 mL]] IX SL-
buffer-A (prepared from 10X SL-buffer-A stock- supplied). Mix very gently to resuspend all material in
the tube.
Do not vortex.
13.3.2.13 Quantitatively transfer (transfer followed by two rinses) all the liquid from the sample tube to a
labeled, 1.5-mL microcentrifuge tube. Use [[1 mL 0.5 mL of IX SL-buffer-A to perform the first rinse
and]] 0.5 mL of reagent water [[for the second rinse. Liberally rinse down the sides of the Leighton tube
before transferring and transfer the rinsate to the microcentrifuge tube.]] Allow the flat-sided sample tube
to sit for a minimum of 1 minute after transfer of the second rinse volume, then use a pipette to collect
any residual volume that drips down to the bottom of the tube to ensure that as much sample volume is
recovered as possible. Ensure that all of the liquid and beads are transferred.
13.3.3.2 Add 50 (iL of 0. 1 N HC1, then vortex at the highest setting for approximately 50 seconds.
NOTE: The laboratory [[should must]] use 0.1-N standards purchased directly from a vendor, rather than
adjusting the normality in-house.
13.3.3.8 Add 5 (iL of 1.0 N NaOH to the sample wells of two well slides (add 10 (iL to the sample well of
one well slide if the volume from the two required dissociations will be added to the same slide).
NOTE: The laboratory [[should must]] use 1.0-N standards purchased directly from a vendor rather than
adjusting the normality in-house.
13.3.3.10 Do not discard the beads or microcentrifuge tube after transferring the volume from the first
acid dissociation to the well slide. Perform the steps in Sections 13.3.3.1 through 13.3.3.9 a second time.
The volume from the second dissociation can be added to the slide containing the volume from the first
dissociation, or can be applied to a second slide.
NOTE: [[If one slide is used, exert extra care when using The wells on]] Dynal Spot-On slides [[are likely
to be too small to accommodate the volumes from both dissociations.]]
13.3.3. 12 Air-dry the sample on the well slide(s). Because temperature and humidity var[[yies]] from
laboratory to laboratory, no minimum time is specified. However, the laboratory must take care to ensure
that the sample has dried completely before staining to prevent losses during the rinse steps. A slide
warmer set at 35°C to 42°C also can be used.
[[13.3.4 Tips for minimizing carry-over of debris onto microscope slides after IMS
- Make sure the resuspended pellet is fully homogenized before placing the tube in the MPC-1 or MPC-
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M to avoid trapping "clumps" or a dirty layer between the beads and the side of the tube.
- When using the MFC-1 magnet, make sure that the tube is snugged flat against the magnet. Push the
tube flat if necessary. Sometimes the magnet is not flush with the outside of the holder and, therefore, the
attraction between the beads and the magnet is not as strong as it should be. However, it can be difficult to
determine this if you do not have more than one MPC-1 to make comparisons.
-After the supernatant has been poured off at Section 13.3.2.11, leave the tube in the MPC-1 and allow
time for any supernatant remaining in the tube to settle down to the bottom. Then aspirate the settled
supernatant and associated particles from the bottom of the tube. The same can be done at Section
13.3.2.16 with the microcentrifuge tube.
-An additional rinse can also be performed at Section 13.3.2.11. After the supernatant has been poured
off and any settled material is aspirated off the bottom, leave the tube in the MPC-1 and add an additional
10 mL of reagent water or PBS to the tube and repeat Sections 13.3.2.9 and 13.3.2.11. Although labs have
reported successfully using this technique to reduce carryover, because the attraction between the MPC-1
and the beads is not as great as the attraction between the MPC-M and the beads, the chances would be
greater for loss of cysts and oocysts doing the rinse at this step instead of at Section 13.3.2.16.
- After the supernatant has been aspirated from the tube at Section 13.3.2.16, add 0.1 mL of PB S, remove
the tube from the MPC-M, and resuspend. Repeat Sections 13.3.2.15 and 13.3.2.16.
- Use a slide with the largest diameter well available to spread out the sample as much as possible.]]
14.0 Sample Staining
14.1.3 Air-dry the control slides (see Section 13.3.3.12 for guidance).
[[NOTE: If the laboratory has a large batch of slides that will be examined over several days, and is
concerned that a single positive control may fade, due to multiple examinations, the laboratory should
prepare multiple control slides with the batch of field slides and alternate between the positive controls
when performing the positive control check.
14.2 Apply 50-(iL of absolute methanol to each well containing the dried sample and allow to air-dry for
3 to 5 minutes.]]
14.2 Follow manufacturer's instructions in applying stain to slides.
14.[[3]] Place the slides in a humid chamber in the dark and incubate at room temperature for
approximately 30 minutes. The humid chamber consists of a tightly sealed plastic container containing
damp paper towels on top of which the slides are placed.
[[14.4 Remove slides from humid chamber and allow condensation to evaporate, if present.]]
14. [[5]] Apply one drop of wash buffer (prepared according to the manufacturer's instructions [Section
7.6]) to each well. Tilt each slide on a clean paper towel, long edge down. Gently aspirate the excess
detection reagent from below the well using a clean Pasteur pipette or absorb with paper towel or other
absorbent material placed at edge of slide. Avoid disturbing the sample.
[[NOTE: If using the Merifluor stain (Section 7.6.1), do not allow slides to dry completely.]]
14.[[6]] Apply 50 (iL of 4',6-diamidino-2-phenylindole (DAPI) staining solution (Section 7.7.2) to each
well. Allow to stand at room temperature for a minimum of 1 minute. (The solution concentration may be
increased up to 1 (ig/mL if fading/diffusion of DAPI staining is encountered, but the staining solution
must be tested first on expendable environmental samples to confirm that staining intensity is
appropriate.)
14. [[7]] Apply one drop of wash buffer (prepared according to the manufacturer's instructions [Section
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Chapter 16: Analytical Methods Comment Codes 1700-1760
7.6]) to each well. Tilt each slide on a clean paper towel, long edge down. Gently aspirate the excess
DAPI staining solution from below the well using a clean Pasteur pipette or absorb with
paper towel or other absorbent material placed at edge of slide. Avoid disturbing the sample.
NOTE: If using the Merifluor stain (Section 7.6.1), do not allow slides to dry completely.
14.[[8]] Add mounting medium (Section 7.8) to each well.
14.[[9]] Apply a cover slip. Use a tissue to remove excess mounting fluid from the edges of the coverslip.
Seal the edges of the coverslip onto the slide using clear nail polish.
14.[[10]] Record the date and time that staining was completed on the bench sheet. If slides will not be
read immediately, store in a humid chamber in the dark at [[0°C to <]] 8°C [[(but not frozen)]] until ready
for examination.
15.0 Examination
NOTE: Although immunofluorescence assay (FA) and 4',6-diamidino-2-
phenylindole (DAPI) and differential interference contrast (DIG) microscopy examination [[and
confirmation]] should be performed immediately after staining is complete, laboratories have up to 7 days
from completion of sample staining to complete the examination and confirmation of samples. However,
if fading/diffusion of FITC or DAPI staining is noticed, the laboratory must reduce this holding time. In
addition the laboratory may adjust the concentration of the DAPI staining solution (Sections 7.7.2) so that
fading/diffusion does not occur.
15.2 Examination using immunofluorescence assay (FA), 4',6-diamidino-2-
phenylindole (DAPI) staining characteristics, and differential interference contrast (DIG) microscopy. The
minimum magnification requirements for each type of examination are noted below.
NOTE: All [[shape characterization]] and [[size]] measurements must be determined using 1000X
magnification and reported to the nearest 0.5 (im.
Record examination results for Cryptosporidium oocysts on a Cryptosporidium [[report examination
results]] form; record examination results for Giardia cysts on a Giardia [[report examination results]]
form. All oocysts and cysts that meet the criteria specified in Sections 15.2.2 and 15.2.3, less atypical
organisms specifically identified as non-target organisms by DIC or DAPI (e.g. possessing spikes, stalks,
appendages, pores, one or two large nuclei filling the cell, red fluorescing chloroplasts, crystals, spores,
etc), must be reported.
15.2.1 Positive and negative staining control. [[Positive and negative staining controls must be
acceptable.]]
15.2.1.1 Each analyst must characterize a minimum of three Cryptosporidium oocysts and three Giardia
cysts on the positive staining control slide before examining field sample slides. This characterization
must be performed by each analyst during each microscope examination session. FITC examination must
be conducted at a minimum of 200X total magnification, DAPI examination must be conducted at a
minimum of 400X, and DIC examination [[and size measurements]] must be conducted at a minimum of
1000X. Size, shape, and DIC and DAPI characteristics of the three Cryptosporidium oocysts and Giardia
cysts must be recorded by the analyst on a microscope log. The analyst also must indicate on each sample
[[report examination results]] form whether the positive staining control was acceptable.
15.2.1.2 Examine the negative staining control to confirm that it does not contain any oocysts or cysts
(Section 14.1). Indicate on each sample [[report examination results]] form whether the negative staining
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Chapter 16: Analytical Methods Comment Codes 1700-1760
control was acceptable.
15.2.2.1 FITC examination (the analyst must use a minimum of 200X total magnification). Use
epifluorescence to scan the entire well for applegreen fluorescence of oocyst and cyst shapes. When
brilliant apple-green fluorescing ovoid or spherical objects 4 to 6 (im in diameter are observed
with brightly highlighted edges, increase magnification to 400X and switch the microscope to the UV
filter block for DAPI (Section 15.2.2.2), then to DIG (Section 15.2.2.3) [[at 1000X]].
15.2.2.3 DIC examination (the analyst must use a minimum of 1000X total magnification [[[oil
immersion lens]]]). Using DIC, look for external or internal morphological characteristics atypical of
Cryptosporidium oocysts (e.g., spikes, stalks, appendages, pores, one or two large nuclei filling the cell,
red fluorescing chloroplasts, crystals, spores, etc.) (adapted from Reference20.7). If atypical structures are
not observed, then categorize each apple-green fluorescing object as:
(a) An empty Cryptosporidium oocyst
(b) A Cryptosporidium oocyst with amorphous structure
(c) A Cryptosporidium oocyst with internal structure (one to four sporozoites/oocyst)
Using 1000X total magnification, record the shape, measurements (to the nearest 0.5 (im), and number of
sporozoites (if applicable) for each apple-green fluorescing object meeting the size and shape
characteristics.
Although not a defining characteristic, surface oocyst folds may be observed in some specimens.
NOTE: All measurements must be made at 1000X magnification.
15.2.3.1 FITC examination (the analyst must use a minimum of 200X total magnification). When brilliant
apple-green fluorescing round to [[oval ovoid]] objects (8 - 18 (im long by 5 - 15 (im wide) are observed,
increase magnification to 400X and switch the microscope to the UV filter block for DAPI (Section
15.2.3.2) then to DIC (Section 15.2.3.3) [[at 1000X]].
15.2.4 Record the date and time that sample examination was completed on the [[report examination
results]] form.
[[15.2.6 Record analyst name]]
17.0 Method Performance
17.1 Method acceptance criteria are shown in Tables 3 and 4 in Section 21.0. The initial and ongoing
precision and recovery criteria are based on the results of spiked reagent water samples analyzed during
the Information Collection Rule Supplemental Surveys (Reference 20.[[8]]). The matrix spike
and matrix spike duplicate criteria are based on spiked source water data generated during the
interlaboratory validation study of Method 1623 involving 11 laboratories and 11 raw surface water
matrices across the U.S. (Reference 20.1[[0]]).
18.0 Pollution Prevention
18.2 Solutions and reagents should be prepared in volumes consistent with laboratory use to minimize the
volume of expired materials [[that need to be discarded to be disposed]].
20.0 References
[[20.6 USEPA. Manual for the Certification of Laboratories Analyzing Drinking Water: Criteria and
Procedures; Quality Assurance; Fourth Edition, EPA 815-B-97-001, Office of Ground Water and
Drinking Water, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati,
Comment Response for the LT2ESWTR 16-80 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
OH 45268 (1997).]]
[[20.8 USEPA. EPA Guide to Method Flexibility and Approval of EPA Water Methods, EPA 821-D-96-
004. Office of Water, Engineering and Analysis Division, Washington, DC 20460 (1996).]]
0.[[8]] Cornell, K., C.C. Rodgers, H.L. Shank-Givens, J Scheller, M.L Pope, and K. Miller, 2000.
Building a Better Protozoa Data Set. Journal AWWA, 92:10:30.
20.[[9]] "Envirochek(tm) Sampling Capsule," PN 32915, German Sciences, 600 South Wagner Road,
Ann Arbor, MI 48103-9019 (1996).
20.[[10]] USEPA. Results of the Interlaboratory Method Validation Study for Determination of
Cryptosporidium and Giardia Using USEPA Method 1623, EPA-
821-R-01-028. Office of Water, Office of Science and Technology, Engineering and Analysis Division,
Washington, DC (2001).
20.[[11]] "Dynabeads(r) GC-Combo," Dynal Microbiology R&D, P.O. Box 8146 Dep., 0212 Oslo,
Norway (September 1998, Revision no. 01).
20.[[12]] USEPA. Implementation and Results of the Information Collection Rule Supplemental Surveys.
EPA-815-R-01-003. Office of Water, Office of Ground Water and Drinking Water, Standards and Risk
Management Division, Washington, DC (2001).
20. [[13]] Connell, K., J. Scheller, K. Miller, and C.C. Rodgers, 2000. Performance of Methods 1622 and
1623 in the ICR Supplemental Surveys. Proceedings, American Water Works Association Water Quality
Technology Conference, November 5-9, 2000, Salt Lake City, UT.
21.0 Tables and Figures
Table 1. Method Holding Times (See Section 8.2 for details)
Sample Processing Step Maximum Allowable Time between Breaks
[[(Samples should be processed as soon as possible)]]
22.0 Glossary of Definitions and Purposes
22.2 Definitions, acronyms, and abbreviations (in alphabetical order)
Analyst-[[The analyst should have at least 2 years of college in microbiology or equivalent or closely
related field. The analyst also should have a minimum of 6 months of continuous bench experience with
Cryptosporidium and IFA microscopy. The analyst should have a minimum of 3 months experience using
EPA Method 1622 and/or EPA Method 1623 and should have successfully analyzed a minimum of 50
samples using EPA Method 1622 and/or EPA Method 1623. The analyst must have at least 2 years of
college lecture and laboratory course work in microbiology or a closely related field. The analyst also
must have at least 6 months of continuous bench experience with environmental protozoa detection
techniques and IFA microscopy, and must have successfully analyzed at least 50 water and/or wastewater
samples for Cryptosporidium and Giardia. Six months of additional experience in the above areas may be
substituted for two years of college.]]
[[Principle analyst-The principle analyst (may not be applicable to all monitoring programs) should have
a BS/BA in microbiology or closely related field and a minimum of 1 year of continuous bench
experience with Cryptosporidium and IFA microscopy. The principle analyst also should have a
minimum of 6 months experience using EPA Method 1622 and/or EPA Method 1623 and should have
analyzed a minimum of 100 samples using EPA Method 1622
Comment Response for the LT2ESWTR 16-81 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
and/or EPA Method 1623.]]
[SEE PDF FOR APPENDIX C]
[SEE PDF FOR APPENDIX G]
Response: See Response 1724.
EPA Letter ID: 548
Comment ID: 12186
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Changes to the methods include the following:
(5) Changes to the sample storage and shipping temperature to -less than 10°C and not frozen-, and
additional guidance on sample storage and shipping procedures
Metropolitan suggests that the sample storage and shipping temperature of-less than 10°C and not
frozen- be consistently used throughout the LT2ESWTR documents, including the Microbial Laboratory
Manual and its accompanying appendices.
(7) Addition of an approved method modification using the Pall Gelman Envirochek HV filter
Metropolitan has been approved to use the Pall Gelman Envirochek HV filters since May 2001. The HV
filers are vastly superior to the Envirochek Standard filter. Metropolitan-s data show a 20-25% increase
in Cryptosporidium recovery with much improved precision.
(9) Addition of BTF EasySeed- irradiated oocysts and cysts as acceptable materials for spiking routine
QC samples
Metropolitan has been using BTF EasySeed for weekly OPR samples exclusively since the product has
been approved. It significantly reduces labor and improves precision.
14. Section IV.K.2. Analytical Methods: E. coli (p. 47733-47734)
* EPA requests comment on whether the E. coli methods proposed for approval under the LT2ESWTR
are appropriate, and whether there are additional methods not proposed that should be considered.
Comments concerning method approval should be accompanied by supporting data where possible.
Please refer also to accompanying comments on the Microbial Laboratory Guidance Manual.
* EPA also requests comment on the proposal to extend the holding time for E. coli source water sample
analyses to 24 hours, including any data or other information that would support, modify, or repudiate
such an extension.
Metropolitan believes that the holding time for E. coli source water samples may be extended to 24 hours
only for those analytical methods evaluated in the holding time studies noted in the proposed rule, i.e.,
mFC to NA-MUG, Colilert Quanti-Tray 2000, Colilert, mEndo to NA-MUG, and mTEC agar. None
Comment Response for the L T2ESWTR 16-82 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
of the studies evaluated used LTB to EC-MUG, modified mTEC agar, MI medium and m-ColiBlue24
broth, to show that sample integrity is likewise kept using these methods. Therefore, the holding time for
samples analyzed with these methods must remain at 8 hours until further studies are undertaken to
evaluate longer holding times.
* Should EPA increase the source water E. coli holding time to 30 or 48 hours for samples evaluated by
ONPG-MUG, and retain a 24-hour holding time for samples evaluated by other methods?
EPA reviewed only one study that showed that -most E. coli samples analyzed using ONPG-MUG-
incurred no significant degradation after a 30 to 48 hour holding time-. Metropolitan believes that more
studies should be conducted and should show that there is indeed no significant difference in the
integrity of the samples before the holding time can be substantially extended to 30 or 48 hours.
15. Section IV.K.3. Analytical Methods: Turbidity (p. 47734)
* EPA requests comment on whether the turbidity methods proposed today for the LT2ESWTR should be
approved, and whether there are additional methods not proposed that should be approved.
Response: See Response 1724.
EPA Letter ID: 641
Comment ID: 13612
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Approval of Updated Versions of 1622/3 - ASI strongly agrees that the June 2003 version of
Method 1622/3 should be approved for use under LT2, rather than the April 2001 version. Data collected
using the earlier versions should still be acceptable for LT2 grandfathering purposes.
Specifically, the changes noted below are paramount to laboratory operations and must be incorporated.
(1) Increased flexibility in MS scheduling is critical to laboratory workload scheduling. (5) Changing the
sample storage conditions to -less than 10 degrees C and not frozen- will significantly decrease the
number of rejected samples, facilitating rule compliance. (7) The Envirochek HV filter should be
approved for LT2, as proposed. (9) BTF EasySeed should also be approved for use in routine LT2 QC
samples, as proposed.
Lastly, addressing all these changes in a single updated version of the method is vastly preferable and a
more effective means of communication than regulatory updates.
Response: See Response 1724.
EPA Letter ID: 641
Comment ID: 13665
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment Response for the L T2ESWTR 16-83 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Comment: Comments on Method 1623 (June 2003 version)
1. Section 7.7.1 Reagents and Standards For DAPI stock solution, the method states: -Discard unused
solution when positive staining control fails.-
Comment: Waiting until a positive staining control fails is not very favorable. An acceptable duration of
use should be established. ASI recommends that DAPI working stock be kept no longer than 2 weeks.
Response: See Response 1724.
EPA Letter ID: 641
Comment ID: 13666
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 2. Section 10.6 Analyst Verification Section States: 1. -Prepare slide with 40-100 of each
organism.- 2. Each analyst determines: a. Total number of organisms on slide that are DAPI positive or
negative, b. Characterize 10 of each organism using DAPI and DIC.
Comment: The intent is to compare results between analysts, which can be done readily for the
enumeration portion. However, if each analyst selects 10 (oo)cysts at random, the result cannot be
meaningfully compared. In order to compare results of all analysts labs would be required to have all
analysts perform characterizations on the same set of organisms. To do so, analysts would have to
characterize one organism at a time, each analyst taking a turn at the scope until all analysts have
completed the characterization, before moving to the next organism. This is unacceptable in a large
laboratory with multiple analysts for two reasons. (1) Characterization of organisms often decreases the
stain intensity. Consequently, with numerous analysts, the image quality may deteriorate substantially
between the first and last analyst. (2) Furthermore, having all analysts waiting a turn at the scope is
extremely inefficient and impractical in a commercial laboratory setting. ASI recommends that this
requirement be changed to a recommendation, and that comparison of the total number of oocysts and
number of the DAPI positive and DAPI negative oocyst be sufficient.
Response: See Response 1724.
EPA Letter ID: 641
Comment ID: 13667
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 3. Section 12.2 Capsule Filtration (Sample Filtration and Elution) Section 12.2.5.2
Section states: —record the volume filtered to the nearest 1/4L—
Comment: The sample collection instructions in the Lab Guidance Manual (Section 3.33, Pg 11)
indicates — the requirement of 10L (rather than 10.OL or 10.00L) accommodates the potential; for
imprecisely filled containers or filters. Sample volumes should be rounded to the nearest whole liter to
determine compliance (e.g., 9.5L would be rounded to 10L and would meet the requirements).-
- ASI recommends that this be revised to read -record to the nearest whole liter.-
Response: See Response 1724.
Comment Response for the L T2ESWTR 16-84 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
EPA Letter ID: 641
Comment ID: 13668
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 12.2.6.1.2 Sample Filtration and Elution Section States: 1.-Prepare sufficient elution buffer so
that all samples to be eluted on that day can be eluted with the same batch of buffer.-
Comment: EPA-s wording implies that new elution solution needs to be prepared each day. Point of fact -
none of the ingredients have short hold times, and the June 2003 version of Method 1623 indicates that
elution solution may be held for 1 week or until turbid. Further, it does not serve a purpose to standardize
the elution solution unless it is associated with an OPR batch (which is not required). ASI recommends
the above EPA wording should be deleted, revised to a recommendation, or revised to clearly incorporate
the one week shelf life of the elution solution.
Response: See Response 1724.
EPA Letter ID: 641
Comment ID: 13669
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 4. Section 7.7.2 D.A.P.I Stock Recipe Section 11.4.3.1 Spiking Procedure Section 14.0
Sample Staining
Comment: Each of the above sections has statements or instructions that may not be applicable,
depending on what products the laboratory uses, are not necessarily true. For example, according to the
method, the recipe for our DAPI stock solution is 10(iL of DAPI into 50mL PBS. However, BTF-s
instructions for Easy Stain call for 50(iL DAPI into 50mL PBS.
The instructions for the above sections can be completely different depending on what stain you are
using, or what spike suspension is used. In procedures where the manufactures instructions could be
different, ASI recommends that the method should state -see manufacturers instructions- or the method
should include instructions for each approved stain or spiking suspension.
Response: See Response 1724.
EPA Letter ID: 641
Comment ID: 13671
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 3.3.4 OPR Test 1. -The OPR- entails analysis of a reagent water sample spiked with 100 to
500 oocysts— a. Commercially available preparations, such as EasySeed, often note <100 oocysts per
vial (for example, 99±0.5). Therefore, ASI recommends revising the dose to 90 - 500 oocysts.
Comment Response for the L T2ESWTR 16-85 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Response: See Response 1724.
EPA Letter ID: 641
Comment ID: 13673
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 3.6 Record Keeping
1. FITC, DAPI and DIG info for all Oocysts detected, a. DAPI and DIG confirmations of each oocyst
could be extremely difficult to do with accuracy if the sample has a very high concentration of oocysts
(for example, if there are multiple oocysts per field, switching to and from DAPI and DIG and reliably
mapping each oocyst is very difficult and time consuming). While ASI understands the importance of
these data and organism confirmation, we suggest EPA consider establishing a maximum number of
oocysts that require confirmation for each sample, b. There appears to be a contradiction from 3.6 and
3.3.10 on number of organisms to characterize. 3.6 seems to refer to positive stain control and 3.3.10
seems to indicate analysis verification.
Response: See Responses 1723 and 1724.
EPA Letter ID: 641
Comment ID: 13674
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: 3.3.10 Ongoing Analyst Verification 1. -For laboratories with multiple analysts, each analyst
shall determine the total number of oocysts and cysts and the number that are DAPI positive and DAPI
negative for the entire slide.- a. This is a reasonable requirement, albeit tedious for laboratories that
process numerous slides and routinely compare (oo)cyst counts. 2. —For 10 oocyst and cysts, each
analyst shall determine the number of nuclei by DAPI and the DIG category of each-. Differences in the
number of nuclei by DAPI and the DIG categorizations among analysts must be discussed and resolved,
and these resolutions must be documented.- a. This is illogical. Suppose the analysts select a different 10
(oo)cysts - how can their results be compared? b. The only way to compare is to have analysts line up and
each view the same (oo)cyst in turn, noting its DAPI and DIG condition, and then proceed to the next
(oo)cyst. However, this would cause fading of the stain, and would be unlikely to produce useful
comparisons, especially in a large laboratory with multiple analysts.
Response: If laboratories routinely compare oocyst counts as suggested in the comment, then this
requirement will mainly involve documentation of those comparisons. As suggested the analysts may line
up and each view the same oocyst in turn, noting DAPI and DI C condition. It is especially important in
large laboratories with multiple analysts to encourage comparison and discussion among analysts to
continually refine the consistency of characterizations between analysts. DAPI should be compared 1st
and each analyst will need to view the oocyst quickly and close the light shutter immediately after
viewing to avoid fading of the DAPI stain. DIG will not fade and may be observed after all analysts have
completed DAPI comparison.
Comment Response for the L T2ESWTR 16-86 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
EPA Letter ID: 651
Comment ID: 12956
Commenter: Rhonda Sherman, Laboratory Director, CH Diagnostic & Consulting Services, Inc.
Commenter Category: Manufacturer/Vendor
Comment: Section 8.0: Sample Collection and Storage
8.1.1 Increasing the sample receipt acceptance temperature from <8°C to <10°C is appropriate and
possibly could be extended to an upper limit of 15°C.
1. Does there exist data to prove that Cryptosporidium recovery decreases if the receipt temperature upper
limit is >10°C? Given that many lakes and reservoirs possess temperatures in excess of 10°C throughout
the majority of the year, thus, subjecting any ambient oocysts to >10°C temperatures, the question is
begged as to whether artificially cooling the sample to <10°C post-collection makes any appreciable
difference with respect to maintaining oocyst integrity. If so, what empirical studies can be cited in
support of the claim? Suggestion: If a Matrix Spike is performed at the higher temperature and the percent
recovery meets required criteria, then sample receipt of >10°C would be acceptable for that particular
location.
Section 9: Quality Control
9.1.7 Weekly Method Blank and OPR set.
1. During weeks in which a second OPR/MB set is required (i.e. >20 field samples are being processed),
does the time frame of this second OPR/MB set extend into the following calendar week? More precisely,
if the second Method Blank/OPR set is performed on Thursday, is it valid through the following Thursday
(seven days later)? If the second OPR/MB set is valid for seven days, then QC requirements are met for
any additional field samples received the following week.
2. In light of the projected sample load generated by LT2, the frequency of performing an OPR/MB set
could possibly be a daily occurrence.
2.1. Options:
2.1.1. Increase the number of field samples, from 20 to 25, that can be processed with an associated
MB/OPR set.
2.1.2. Do not dictate an exact number of field samples that can associate with an OPR/MB set; instead,
specify that an OPR/MB set must be performed on Mondays and Thursdays or when a new batch of
eluting solution is made. By having a processing laboratory perform OPR/MB sets based on appointed
times rather than number of samples, logistical, scheduling and space issues are minimized.
2.1.3. Frequency of OPR could be based on the volume of reagents prepared in house or purchased. A
total of fifty samples (field and QC) could be processed under a single OPR based upon the
predetermined volumes of the Dynal bead and Merifluor staining kits. The associated eluting solution
volume could be prepared to accommodate fifty field samples. Method Blank samples performed at
regular intervals (every 20 - 25 field samples) would check for contamination.
Section 10: Microscope Calibration and Analyst Verification
10.6 Verification of analyst performance:
1. 10.6.1: Change target number of oocysts/cysts from "40 to 100" to "40 to 200".
2. 10.6.2: Change the number of described cysts/oocysts using DAPI from "the entire slide" to "5"
cysts/oocysts.
3. 10.6.2: Change the number of described cysts/oocysts using DIC/DAPI from "10" to "5" cysts/oocysts.
Section 22.0 Glossary of Definitions and Purposes - Analyst
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Chapter 16: Analytical Methods Comment Codes 1700-1760
1. In lieu of requiring an analyst to have six months bench experience before working with LT2 samples,
allow:
1.1. A three-month "hands-on" bench period during which the analyst will demonstrate proficiency
working with MB, OPR and Method 1623 noncompliant samples.
1.1.1. During this three month experience, the analyst must perform a minimum of five MB/OPR sets,
which meet the minimum Method 1623 criteria as well as the individual laboratory criteria for mean,
standard deviation and precision.
2. Alternatively, allow the trainee to work with LT2 samples while under the direct supervision of a LT2
approved analyst during the six-month continuous bench experience.
Comments based on "Source Water Monitoring Guidance Manual for Public Water
Systems for the Long Term 2 Enhanced Surface Water Treatment Rule (LT2 Rule)"
Section 2: Grandfathering Cryptosporidium Data
1. Allow "flagging" and acceptance of data when field or matrix spike sample receipt temperatures are
>10°C
1.1. Alternatively, for samples that do not meet the temperature requirement, allow the utility to perform
an additional matrix spike on the source water at the higher temperature.
1.1.1. Compare the results with the matrix spike conducted at < 10°C, and, if it meets MS/MSD criteria,
allow the data to be accepted.
2. Allow "flagging" and acceptance of data when field or matrix spike sample receipt volume examined
>8 L but <9.5 L
3. Allow "flagging" and acceptance of data when field and matrix spike samples are >10% difference in
volume
3.1. Increase acceptable volume difference between field and matrix spike samples to 20%.
3.1.1. This allows a volume range from 8 and 10 L; 40 and 50 L.
4. If "flagging" data is not an option, then allow unacceptable individual data points to be replaced with
substitute data points that are collected at the end of the monitoring period.
4.1. Alternatively, substitute the non-acceptable sample with a sample collected the same month as
original sample but during the current year. e.g. July 2002 sample receipt was >10°C, delete this data
point and replace with a sampling episode collected from July 2004.
Section 6: Collecting and Shipping Source Water Samples
6.2 Sample Collection Location:
On occasion multiple water treatment plants use the same source water? Does each WTP have to analyze
the same water?
From p. 47677 of the Federal Register Section IV.A.2.d.
1. Basis for accepting previously collected data: "...giving credit for data collected by proactive
utilities....allowing utilities to improve their data set for bin determination by considering more than 2
years of data..."
1.1. Suggestion: In order to support the above statement, allow more flexibility in accepting grandfathered
data than the acceptance criteria outlined during the required monitoring period.
Comments for "Microbial Laboratory Guidance Manual for the Long term 2
Enhanced Surface Water Treatment Rule (LT2 Rule)"
Comment Response for the L T2ESWTR 16-88 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Section 2: General Microbial Laboratory Quality Assurance
2.2 Sample temperature monitoring
This section 2.2 contradicts section 3.3.12 with reference to temperature of field samples collected and
received on the same day at >10°C. Do these samples need to be processed the same day?
Section 3: Guidance for Cryptosporidium Laboratories
3.3.6 Quality Control Batches
Last sentence is vague "....with the field and MS samples eluted, concentrated, and purified, in the same
time period". What is meant by "the same time period"? Does this mean the "time period" is one week
(seven days), thus, overlapping calendar weeks?
3.3.14.3 Using multiple method variations
Paragraphs within this section are contradictory.
Clarification requested for IRP, IPX, OPR and OPT samples for additional rinses as well as multiple
membranes use as part of the FiltaMax concentration step.
General Comments
Lab Capacity issues
1. In lieu of all utilities > 10,000 beginning monitoring six months after promulgation, allow for the
staggered start dates, for instance, a six-month separation period.
1.1. A staggered start would:
1.1.1. mitigate of laboratory burden;
1.1.2. allow the laboratory to increase capacity gradually, thus allowing time for training new analysts;
1.1.3. afford utilities and laboratories time to work through logistics.
1.2. Various possibilities exist including:
1.2.1. Partitioning the utilities into groups, e.g. half, third, quarter, whereby each group would begin at
their designated staggered start date. 1.2.1.1. For instance, half of the utilities could begin six-months
after promulgation and the remaining half would start 1 year after promulgation
1.2.1.2. Or, one third of the utilities could begin 6-months after promulgation, the second third begin 12-
months after promulgation, and the last third 18-months after promulgation.
2. Provide laboratory equipment support in the form of used laboratory equipment.
2.1. e.g. old BL2 hoods.
Sampling Episodes
1. Why is it acceptable to allow a water treatment plant to be closed for a period of time and thus have
missing data points? Water treatment plants close for maintenance, weather conditions, annual closures,
etc., and therefore will not have an uninterrupted data set of 24. This establishes two issues:
1.1. How will the generated monthly average of Cryptosporidium oocysts per liter for WTP with an
incomplete data set be statistically comparable with other WTP having a complete 24-month data set.
1.2. If plant closures are acceptable and missing data points are not penalized, then data points collected
during the Grandfathering period that do not meet criteria should also be considered as "missing" and not
be penalized.
2. There is a difference between seasonality closures and operational closures. Certain WTPs will operate
one week and then be shut down the next week. Suggestion: WTPs are held responsible to sample only
when the WTP is online with the goal of collecting a complete data set. To achieve this, allow variability
in sampling dates.
2.1. Suggestion: Allow a minimum of 12 data points for average. Or calculate the average crypto
concentration for as many data points as accumulated over the 24 month monitoring period.
2.2. Suggestion: If a WTP is scheduled to operate for a specified time period, then perhaps collect 2
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samples/month.
2.3. Suggestion: Sample collection occurs the first available date each month, which implies potential
variation in sample collection frequency.
2.4. Regardless of the approach, the WTP will document why sampling did not occur and return to
scheduled dates as soon as possible.
3. Possible Experiments
3.1. Fund a research project to determine the effect of temperature on
Cryptosporidium recovery.
3.2. What data supports the claim that recovery of Cryptosporidium oocysts is
statistically different at 8 L vs. 10 L; 40L vs. SOL?
Response: See Responses 340, 381, 389, 1720, 1723, 1724, and 1830/1831/1832/1833/1834.
EPA Letter ID: 652
Comment ID: 12954
Commenter: Brad Eldred, President, Analytical Services, Inc.
Commenter Category: Manufacturer/Vendor
Comment: Sections 6.2.2.2.1 and 12.2.6.2.3:
The EPA specified wrist-action shaker has a maximum speed of 750 rpm. Section 12.2.6.2.3. references a
target speed of 900 rpm. This is an obvious conflict.
In addition, the approved Envirochek HV capsule filter was validated at a speed of 600 rpm. This is
another obvious conflict with the target of 900 rpm specified in the method.
ASI recommends that EPA revise the 900 rpm speed specified for Method 1623 (and Method 1622 as
applicable) downward to the 600 - 700 rpm rate to incorporate the physical capability of the specified
equipment as well as to be consistent with the agitation speed at which the Envirochek HV was validated.
Response: See Response 1724.
EPA Letter ID: 652
Comment ID: 12954
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Sections 6.2.2.2.1 and 12.2.6.2.3:
The EPA specified wrist-action shaker has a maximum speed of 750 rpm. Section 12.2.6.2.3. references a
target speed of 900 rpm. This is an obvious conflict.
In addition, the approved Envirochek HV capsule filter was validated at a speed of 600 rpm. This is
another obvious conflict with the target of 900 rpm specified in the method.
ASI recommends that EPA revise the 900 rpm speed specified for Method 1623 (and Method 1622 as
Comment Response for the LT2ESWTR 16-90 December 2005
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applicable) downward to the 600 - 700 rpm rate to incorporate the physical capability of the specified
equipment as well as to be consistent with the agitation speed at which the Envirochek HV was validated.
Response: See Response 1724.
EPA Letter ID: 673
Comment ID: 14005
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: EPA Method 1622 /1623 for Cryptosporidium (June 2003 draft for comment)
8.0 Sample Collection and Storage
2.2 Sample Temperature Monitoring
Jordan Valley Water comments on changing the storage temperature from 8°C to 10°C.
Jordan Valley Water supports the change from 8°C to 10°C as a more practical receiving temperature for
shipping Cryptosporidium samples. This change will help systems meet the requirement of the method,
without negatively impacting sample recovery.
Response: See Response 1724.
EPA Letter ID: 678
Comment ID: 14730
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. Appendix C: EPA Method 1623 for Cryptosporidium and Giardia (comments may also
apply to Appendix B: EPA Method for Cryptosporidium)
a. Section 7.8, p. 10
Elvanol is not mentioned as a choice of mounting medium for slide preparation. Some utilities have had
great success with this mounting medium. In the ICR method, sealing the cover slip with fingernail polish
was relatively easy due primarily to its smaller size (relative to the slide). In Method 1623, sealing the
larger cover slip with fingernail polish becomes quite difficult because it is almost as wide as the well
slide. In addition, the accompanying precipitate that forms when DABCO-glycerol comes in contact with
the fingernail polish can interfere with the microscopic observation. If used properly, elvanol is vastly
superior to DABCO-glycerol as a mounting medium. While there may be some difficulty with preparing
elvanol in the laboratory, it is commercially available from Waterborne Inc. We strongly recommend that
elvanol be considered as an option for mounting slides.
b. Section 7.10.3, p. 10
The required storage temperature for oocyst and cyst suspensions is at 0°C to 10°C and not allowed to
freeze. However, 0°C is freezing temperature for water that is the diluent for the Tween-20 or other
solutions used for the oocyst and cyst suspensions. Unless the solution does not freeze at 0°C, the
requirement must be changed to ->0°C and <10°C-.
c. Sections 8.1.2.2 to 8.1.3, p. 11 (refer to l.a. above)
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d. Section 8.1.4.4, p. 12
Since stick-on temperature strips are not as precise as the other options, perhaps its use should be
eliminated. Incorrect temperature readings may cause a sample to be rejected by the laboratory, resulting
in wasted material, time and effort in collecting the sample.
e. Section 8.5, p. 13 (refer to 2.b. above)
f Section 10.4, p. 25. The draft Manual does not specify a minimum or optimum microscope cleaning
frequency. We recommend specifying either a cleaning frequency, such as annually, for consistency
purpose, or a set of conditions under which an overall cleaning be done as part of the troubleshooting
process.
g. Section 10.6.2, p. 26.
In addition to the requirement of counting the total number of oocysts and cysts and the number that are
DAPI positive and DAPI negative on the entire slide, the EPA proposes to require, for 10 oocysts and 10
cysts, each analyst should count the number of nuclei using DAPI and DIC. If numbers don-t match, this
will not be recorded but will be discussed. Does this replace the previous DAPI verification procedure?
Or is this done in addition to what was already written? We suggest that the total count using FA remain
for oocysts and cysts and the total DAPI count be dropped and replaced with (what the EPA is suggesting
now) the DAPI and DIC nucleic enumeration of 10 oocysts and 10 cysts. Is there a suggested worksheet
to document this?
h. Section 11.3.5.12, p. 32
Slides must be stored -in the dark at 0°C to 8°C <10°C and not frozen-. Perhaps the intention here was to
cross out -8°C-, but that still leaves the 0°C, which is a freezing temperature, unless the mounting
medium does not freeze at this temperature and the integrity of the cysts and oocysts is kept.
Requirements must be modified accordingly.
i. Section 11.3.6.19, p. 33
Slides must be stored -in the dark at 0°C to <8°C (but not frozen)-. Temperature requirements must be
consistent - perhaps the intention here was to cross out -8°C- instead of-0°C to- and replace it with -
10°C-. Please refer to 2.h. above.
j. Section 11.4.3.1, p. 34.
Use Anti-Foam A and 20 ml reagent water. This changes the manufacturer-s directions that recommend,
specifically for BTF, the use of a 0.05% Tween 80 solution instead of Antifoam A. Tween 80 is more
readily available while there has been some variation in the Antifoam A that is available. We are
concerned with the use of 20 ml of reagent water. The tube that is being rinsed only holds about 10 ml of
liquid (Easy Seed). The manufacturer requests that only 3 ml of reagent water be used in the 2nd and 3rd
rinses.
k. Section 21.0, Table 4, p. 57
The asterisk after -Mean recovery- should be replaced with -1,2-.
1. Section 22.0, p. 65
-Principle analyst- should be changed to -Principal analyst-.
Response: See Response 1724.
Comment Response for the L T2ESWTR 16-92 December 2005
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EPA Letter ID: 686
Comment ID: 14754
Commenter: Rick Jones,, Pall Life Sciences
Commenter Category: Manufacturer/Vendor
Comment: Comments for "Example for Field-Filtering Samples for Crytosporidium Analysis Using Pall
Life Sciences Envirochek or Envirochek F£V Filters"
2.1.4
The Envirochek filter is rated to 30 PSID and the Envirochek F£V filter is rated to 60 PSID. Insure
regulator is not needed unless the source pressure exceeds these values. Use of a pressure regulator
upstream of the filter when not necessary will require extra cleaning for the regulator between samples.
This is not necessary if using the Envirochek F£V filter in systems with less the 60 PSIG
When referencing the Envirochek filter, you need to reference both the Envirochek and the Envirochek
F£V filters since both are options in every case. There are multiple places where only the Envirochek is
mentioned in a generic form. A note in the beginning stating that "Unless otherwise noted, the mention of
Envirochek capsule indicates either Envirochek or Envirochek F£V can be used.", would suffice.
Figure 1. page 2.
The description states the for systems greater the 20 psig a pressure regulator is need. This is not the case
as mentioned in my first note.
Comments for "Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA June 2003
Draft for Comment"
12.2.6.2.2
First line reads: "Pour elution buffer through he inlet fitting. Remove the inlet cap and allow the liquid to
stabilize. ..." Should read: "Remove the inlet cap and pour elution buffer through the inlet fitting and
allow the liquid level to stabilize."
12.2.6.2.3
Indicates to set the shaker to maximum speed (approximately 900 rpms). This was never validated and
some shakers cannot survive well at this speed. The shaking speed used for validation was 600 rpms.
Response: See Response 1724.
16.3 E. coli
16.3.1 Comment Code 1731, Proposed methods
Summary of Issues
Comments agreed that the proposed E. coli methods were appropriate and no additional methods should
be added. One comment supported the change of sample temperature acceptance criteria from 8°C to
10°C.
Comment Response for the L T2ESWTR 16-93 December 2005
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Response to Code 1731
Proposed E. coli methods EPA has reviewed all comments on this topic and appreciates the commenters'
attention to this issue, as well as their support.
Individual Comments on Code 1731
EPA Letter ID: 449
Comment ID: 10832
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: necessary. In response to the wording in section IV.K.2 we feel that the current methods for e-
coli testing are acceptable and that additional methods need not be considered. Also in that section, since
there was no degradation found in
Response: See Response 1731.
EPA Letter ID: 464
Comment ID: 11003
Commenter: Dr. Susan Boutrous, President, Environmental Associates Ltd.
Commenter Category: Independent Laboratories
Comment: Section 8.1.3 Change of sample temperature acceptance criteria from 8C to 10 C.
We agree with the change since it would cause rejection of fewer samples without compromising quality.
Response: See Response 1731.
EPA Letter ID: 472
Comment ID: 11183
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Other EPA Comment Codes and Descriptions: 1711 1. Minimum sample volume, packed pellet
volume, number of filters
Comment: P. 47732. c. Request for comment. EPA requests comment on the proposed method
requirements for Cryptosporidium analysis, including the following specific issues:
- Minimum Sample Volume It is the intent of EPA that LT2ESWTR sampling provide
representative annual mean source water concentrations. If systems were unable to analyze an entire
sample volume during certain periods of the year due to elevated turbidity or other water quality factors,
this could result in systems analyzing different volumes in different samples. Today-s proposal requires
systems to analyze at least 10 L of sample or the maximum amount of sample that can be filtered through
two filters, up to a packed pellet volume of 2 mL.
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- EPA requests comment on whether these requirements are appropriate for systems with source waters
that are difficult to filter or that generate a large packed pellet volume. Alternatively, systems could be
required to filter and analyze at least 10 L of sample with no exceptions.
See p. 47732 third column for proposed changes in EPA Methods 1622 and 1623 and if they should be
promulgated?
Seep. 47733 bottom for allowing 24-hour holding time for e-coli samples.
P. 47734. c. Request for comment. EPA requests comment on whether the E. coli methods proposed for
approval under the LT2ESWTR are appropriate, and whether there are additional methods not proposed
that should be considered. Comments concerning method approval should be accompanied by supporting
data where possible.
The COP believes these methods are appropriate.
Response: See Responses 1711 and 1731.
EPA Letter ID: 704
Comment ID: 14798
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section 4.2.1.1.
E. coli samples will require four dilutions at first, then three dilutions once a normal range of values is
determined for the source water. However, this means that for E. coli three (3) analyses will be performed
for each sample event, which translates into three times the cost for a utility.
Response: EPA acknowledges that because the sample must be diluted to obtain quantitative E. coli
results, this may result in additional laboratory charges. However, utilities are encouraged to establish a
contract with a laboratory for all LT2 analyses, and in doing so, establish costs for all analyses upfront.
EPA Letter ID: 707
Comment ID: 14826
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: (EPA 1604), mColiBlue24 or Colilert (ONPG-MUG SM 9223B). Our experience
with mEndo media and NA/MUG (SM 9223B/G) was unsatisfactory when working
with source water, since fluorescence on NA/MUG was difficult to interpret due to high numbers of false
positives from the presence of Pseudomonas. The state of Kentucky would not recommend permitting
laboratories to use this option to
enumerate E. coli under the LT2.
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Response: EPA agrees that some waters will have background flora which may interfere with the ability
to accurately enumerate E. coli despite additional dilutions. In these situations, laboratories are advised to
employ an alternate approved method.
EPA Letter ID: 711
Comment ID: 16570
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 8. EPA requests comment on whether the E. coli methods proposed for approval under the
LT2 are appropriate, and whether there are additional methods not proposed that should be considered.
Comments concerning method approval should be accompanied by supporting data where possible.
[47734, C2]
Comment: We believe the proposed E. coli methods are sufficient. - EPA also
Response: See Response 1731.
16.3.2 Comment Code 1732, Additional methods
Summary of Issues
Comment requested that the list of approved E. coli methods be revised to include Coliscan®.
Additional E. coli methods
EPA agrees that Coliscan® is an acceptable version of MI medium under the Total coliform rule (TCR)
and Surface water treatment rule (SWTR). However, EPA does not agree that it should be approved under
LT2ESWTR. EPA believes that the source water E. coli analyses that PWSs will conduct under
LT2ESWTR are similar to the ambient water analyses for which EPA approved E. coli methods under
"Guidelines Establishing Test Procedures for the Analysis of Pollutants; Analytical Methods for
Biological Pollutants in Ambient Water". Coliscan® was not approved under "Guidelines Establishing
Test Procedures for the Analysis of Pollutants; Analytical Methods for Biological Pollutants in Ambient
Water" because there was insufficient data to support the approval of Coliscan® in ambient water.
The membrane filtration methods, that do not include a transfer step, approved for analyses under
LT2ESWTR include modified mTEC, MI medium, and m-ColiBlue24® broth.
Individual Comments on Code 1732
EPA Letter ID: 707
Comment ID: 14821
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: pg. 47733
2. (a) E. coli
Methods Summarized in Table IV-37.
Comment: Under Membrane Filtration (MF) Technique, a request to include Coliscan as an approved
Comment Response for the L T2ESWTR 16-96 December 2005
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method for E. coli enumeration. For laboratories that still utilize the MF method the use of Coliscan
(Micrology Labs. Coliscan media is similar to MI medium but uses different substrates to distinguish
between total coliforms and E. coli colonies. Coliscan is considered an acceptable version of MI medium
[EPA Method 16041 when used in accordance with the requirements with EPA Method 1604. As such,
Coliscan, is not included in the CFR, but can be used wherever MI Medium [EPA Method 16041 is
approved for analysis) would cut down on the extra step of taking filters from mFC to "MUG for
confirmation of E. coli.
In Kentucky, 75% of the laboratories perform membrane filtration (mEndo to NA/MUG) for drinking
water compliance samples, with 25% performing Colilert. Therefore, those laboratories that are certified
for membrane filtration would only have to be certified for the mFC method or Coliscan to complete this
requirement. Those laboratories performing Colilert MPN would already be certified to perform E. coli
under the LTF2EW§TR, while those labs using Colilert PA format would have to purchase a sealer and
trays for the Colilert 2000.
Response: See Response 1732.
16.3.3 Comment Code 1733, Extension of holding time
Summary of Issues
All comments supported extending the holding time for some of the methods. However, three comments
requested that the holding time only be extended for the methods evaluated in Pope et al. (2003). Twelve
comments supported the extension of the holding time to 24 hours for all methods. Five comments
supported the holding time for ONPG-MUG be extended beyond 24 hours (30-48). In addition, three
comments supported extending the holding time for all methods to 48 hours. One comment requested that
holding times be consistent to minimize confusion.
Response to Code 1733
Holding time
EPA agrees that the holding time for surface water samples analyzed for E. coli should be extended
beyond 8 hours. For LT2ESWTR, EPA is establishing a holding time of 30 hours for all approved E. coli
methods. After reviewing public comment on this issue, and reassessing the studies described in the
proposed rule, EPA has concluded that a 30 hour holding time limit for E. coli samples is appropriate and
consistent with the data quality objectives of LT2ESWTR source water monitoring. Further, EPA
believes that meeting a 30 hour holding time is feasible for most PWSs that must ship E. coli samples to
an off-site laboratory for analysis. However, if the State determines on a case-by-case basis that analyzing
an E. coli sample within 30 hours is not feasible, the State may approve holding an E. coli sample for up
to 48 hours between collection and initiation of analysis. E. coli reagent™samples held between 30 to 48
hours must be analyzed by the Colilert version of Standard Method 9223B as listed in 40 CFR part 136.3
Individual Comments on Code 1733
EPA Letter ID: 437
Comment ID: 10614
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
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Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: We fully support the increase in holding time to 24 hours for E. Coli samples.
Response: See Response 1733.
EPA Letter ID: 449
Comment ID: 10833
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: be considered. Also in that section, since there was no degradation found in samples tested by
ONPG-MUG that were held for up to 30 hours, the holding time on such samples should be increased. All
other methods should continue a 24 hour holding time. In response to section IV.K.3, we feel that the
current approved
Response: See Response 1733.
EPA Letter ID: 457
Comment ID: 11948
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: We recommend that EPA consider extending the holding time for E.coli source water sample
analyses for those analytical methods evaluated and note so in this section. This would give an alternative
for the delivery of samples from public water systems located in remote rural areas.
Response: See Response 1733.
EPA Letter ID: 458
Comment ID: 10984
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: Page 47734 - Source water e-coli laboratory procedure - the information in this area indicates
that the holding time is going to be increased from 8 hours to 24 hours. This is not reflected in the
proposed language of the rule. The holding time and temperature requirement will require the PWS to
either hand deliver themselves or hire an overnight delivery service to deliver the samples to certified
laboratories, at a cost that will exceed the laboratory analysis fee.
Response: See Response 1733.
Comment Response for the L T2ESWTR 16-98 December 2005
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EPA Letter ID: 464
Comment ID: 11004
Commenter: Dr. Susan Boutrous, President, Environmental Associates Ltd.
Commenter Category: Independent Laboratories
Comment: E coli hold time.
It is a definite improvement to lengthen the hold time for E. coli to 24 hours. Thirty hours is even better.
The extended hold time will greatly increase flexibility for utilities to select laboratories to perform the
analysis. The laboratory processing the Method 1623 samples can now analyze the E. coli sample.
Response: See Response 1733.
EPA Letter ID: 470
Comment ID: 11097
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Analytical Methods pp.47731-47734
Vermont encourages that E. coli holding time should be consistent so that water systems do not become
confused with varying requirements of monitoring.
Response: See Response 1733.
EPA Letter ID: 472
Comment ID: 11184
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: - EPA also requests comment on the proposal to extend the holding time for E. coli source
water sample analyses to 24 hours, including any data or other information that would support, modify, or
repudiate such an extension. Should EPA limit the extended holding time to only those E. coli analytical
methods that were evaluated in the holding time studies noted in this section? The results in Pope et al.
(2003) indicate that most E. coli samples analyzed
using ONPG-MUG (see methods in Table IV- 37) incurred no significant degradation after a 30 to 48
hour holding time. As a result, should EPA increase the source water E. coli holding time to 30 or 48
hours for samples evaluated by ONPGMUG, and retain a 24-hour holding time for samples analyzed by
other methods?
The COP supports extending the holding time for all E. coli methods to 24-30 hours.
Comment Response for the L T2ESWTR 16-99 December 2005
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Response: See Response 1733.
EPA Letter ID: 497
Comment ID: 10654
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: experience with this analysis. With regards to E. coli testing of source water, the MDEQ
laboratory agrees with the EPA that the holding time should be extended to 24 hours. In addition, the
EPA should not limit the extended holding time to only the analytical methods evaluated. Evaluation was
based on the degradation of the E. coli bacteria, not on the method used. For approved E. coli methods,
there should be no difference in the time it takes the bacteria to degrade.
Response: See Response 1733.
EPA Letter ID: 514
Comment ID: 11542
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: E.coli Holding Time: The holding time for E.coli should be extended to 24 hours
based on the EPA data presented in this document (Pope et al. 2003) and our in-
house laboratory observations with the mFC/NA+MUG method for both fecal coliform and E.coli
analyses. Based on Phase 3 data where many different methods were used with no significant difference
after 24 hours, the extended holding time should be applied to all E.coli methods listed.
Response: See Response 1733.
EPA Letter ID: 540
Comment ID: 12086
Commenter: Manja Blazer, Government Affairs and Market Development Manager, IDEXX
Laboratories
Commenter Category: Independent Laboratories
Comment: IDEXX urges USEPA to allow a method-specific holding time of 48 hours for E.coli samples
analyzed by ONPG-MUG. It is not feasible for water systems to meet an 8hour holding time for E.coli
when samples cannot be analyzed onsite. Small systems will need to ship their samples to a certified
laboratory. In or close to metropolitan areas, it should be feasible to meet a 24 hour holding time by using
overnight delivery services. However, in rural areas, it will not be feasible to meet a 24 hour holding time
because overnight delivery service is not as available. This is also true for a 30 hour holding time, which
some small water systems simply will not be able to meet easily. In remote areas it could take a single
working day to get the sample to the overnight delivery service, and then another working day for the
Comment Response for the LT2ESWTR 16-100 December 2005
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delivery service to deliver the sample to the laboratory. Therefore, USEPA should allow an extended
holding time of 48 hours for samples evaluated by ONPG-MUG.
Response: See Response 1733.
EPA Letter ID: 560
Comment ID: 14984
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comment Six - E. coli Holding Times:
American Water agrees with EPA on extending the holding times for E. coli to 24 h or longer. It is not
realistic to expect that all medium sized plants will process E. coli samples on site. The American Water
System is not planning on developing the capability to analyze E. coli samples at all treatment plants. The
provision for shipment of E. coli samples to regional laboratories is needed. EPA needs to provide
appropriate QC samples so that laboratories can demonstrate the performance with a 24 h (or longer)-
holding time. Based on the data reported by Pope et al. (2003), American Water recommends that the
hold time for the Colilert method be extended to 36 hours.
Response: See Response 1733.
EPA Letter ID: 562
Comment ID: 12407
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: E.coli Method Holding Times
AWWA agrees that the holding time study conducted by EPA, Wisconsin State Laboratory of Hygiene
and a number of other participants as reported in Pope et al, 2003, provides sufficient information to
support longer holding times for E.coli source water samples. EPA proposes a holding time of 24 hours
for all considered E. coli methods. AWWA believes that the 24-hour hold time is appropriate for all of the
methods considered in Pope et al. AWWA would further recommend that the hold time for at least the
Colilert® method (if not a broader selection of E. coli methods) be extended to 36 hours per the
demonstration of performance in Pope et al. AWWA does not endorse Colilert® itself or its
manufacturer, but the study indicates that a longer hold time is possible with Colilert® and there will be
utilities for which the 36-hour hold time will greatly facilitate sample delivery to a certified compliance
laboratory. The additional hold time also will provide utilities in more remote locations some buffer
against the need to repeatedly resample due to vagaries of express package delivery.
Response: See Response 1733.
EPA Letter ID: 586
Comment ID: 12198
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 16-101 December 2005
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Comment: 2. 24-hour holding time for E. Coli samples.
Under 141.705(b)(l), the time from E. coli sample collection to initiation of analysis may not exceed 24
hours.
In remote parts of Alaska, it is often difficult to get samples to a certified laboratory within a 24-hour
period. The State of Alaska, under 18 AAC 80.350, allows a 48-hour period between collection and
analysis of total coliform bacteria samples for remote systems based on distance from certified
laboratories, lack of roads, and lack of regularly scheduled airline flights.
Considering the potential ramifications of an incomplete monitoring program as discussed under (1)
above, a provision needs to be included in the regulations to allow more than 24 hours between sample
collection and analysis for remote water systems.
Response: See Response 1733.
EPA Letter ID: 592
Comment ID: 12100
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Holding time for samples
The EPA must also increase the allowable holding time for source water E. coli sampling to more than 24
hours. Holding time should be 48 hours for any approved method. It has already been proven that there is
no significant difference in E. coli density between 0 and 48 hours holding time, regardless of method.
Extending holding time to 48 hours would allow small utilities to ship overnight rather than having to
spend the whole day delivering samples to a laboratory hundreds of miles away.
Response: See Response 1733.
EPA Letter ID: 601
Comment ID: 13041
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on the proposal to extend the holding time for E. coli source water
sample analyses to 24 hours.
Utah supports EPA-s conclusion that E. coli samples can be held for up to 24 hours prior to analysis
without compromising the data quality objectives of LT2ESWTR E. coli monitoring.
Response: See Response 1733.
EPA Letter ID: 609
Comment ID: 14120
Comment Response for the L T2ESWTR 16-102 December 2005
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Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: lack of experience with this analysis. With regards to E. coli testing of source water, the
MDEQ's Environmental Laboratory agrees with the USEPA that the holding time should be extended to
24 hours. In addition, the USEPA should not
Response: See Response 1733.
EPA Letter ID: 637
Comment ID: 13107
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on the proposal to extend the holding time for E. coli source water
sample analyses to 24 hours.
District supports EPA-s conclusion that the holding time prior to analysis for E. coli samples can be
increased without compromising the data quality objectives of LT2ESWTR E. coli monitoring.
Response: See Response 1733.
EPA Letter ID: 641
Comment ID: 13613
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47734 RFC (E coli) - Extend holding time - Agree, holding times for E. coli should be
extended to 24 hours, for those analytical methods that were evaluated. Further, holding time for ONPG-
MUG should be extended to 48 hours.
Response: See Response 1733.
EPA Letter ID: 645
Comment ID: 13561
Commenter: Kathy Moriarty, Water Quality Manager, Bangor Water District
Commenter Category: Regulated Community (Utilities)
Comment: K. Analytical Methods [pp. 47731-47734]
Request for
Comment: E. coli
Suggested Comments:
EPA should increase the source water E. coli holding time to 48 hours for analysis by any approved
Comment Response for the L T2ESWTR 16-103 December 2005
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method. Pope et al - Applied and Environmental Microbiology Oct. 2003 clearly show that there are no
significant differences in
E. coli densities between time 0 and 48-hour holding time, regardless of method.
Extending holding times to 48 hours would allow small utilities to ship samples
overnight rather than having to spend a whole day delivering samples to a central laboratory miles away.
Currently under the SWTR, unfiltered systems with an exemption to filter are
required to test for fecal coliform or total coliform in the raw water. The SWTR
does not allow for the testing of E. coli in lieu of fecal coliform. The fecal coliform test requires an 8 hour
holding time. The testing for fecal with the 8 hour holding time is highly restrictive. E. coli is allowed to
be tested in lieu of fecal coliform for the Total Coliform Rule and is recognize as an indicator of water
quality in the LT2. The SWTR is not open for comment, however the LT2 is an integral part of the
SWTR. Utilities should be able to test for E. coli in lieu of fecal coliforms as described in the SWTR with
a 48 hour holding time. This change of the SWTR should be allowed through the final rule of the LT2.
Response: See Response 1733.
EPA Letter ID: 660
Comment ID: 14085
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
K. 2. E. coli
(page 47733-47734)
EPA requests comment on the proposal to extend the holding time for E. coli source water sample
analyses to 24 hours.
CUWCD supports that E. coli samples can be held for up to 24 hours prior to analysis without
compromising the data quality objectives of LT2ESWTR E. coli monitoring.
Response: See Response 1733.
EPA Letter ID: 673
Comment ID: 14001
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
K. 2. E. coli
(page 47733-47734)
EPA requests comment on the proposal to extend the holding time for E. coli source water sample
analyses to 24 hours.
Comment Response for the L T2ESWTR 16-104 December 2005
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Jordan Valley Water supports EPA-s conclusion that E. coli samples can be held for up to 24 hours prior
to analysis without compromising the data quality objectives of LT2ESWTR E. coli monitoring.
Response: See Response 1733.
EPA Letter ID: 678
Comment ID: 14718
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 14. The EPA also requests comment on the proposal to extend the holding time for E. coli
source water sample analyses to 24 hours, including any data or other information that would support,
modify, or repudiate such an extension. [47734, C2]
Comment: The holding time for E. coli source water samples may be extended to 24 hours only for those
analytical methods evaluated in the holding time studies noted in the proposed rule. None of the studies
evaluated used LTB to EC-MUG, modified mTEC agar, MI medium and m-ColiBlue24 broth, to show
that sample integrity is likewise kept using these methods. Therefore, the holding time for samples
analyzed with these methods should remain at 8 hours.
Response: See Response 1733.
EPA Letter ID: 678
Comment ID: 14719
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 15. The EPA requests comment on the alternative that would allow the source water E. coli
holding time be increased to 30 or 48 hours for samples evaluated by ONPG-MUG, and retain a 24-hour
holding time for samples evaluated by other methods.
Comment: The EPA reviewed only one study that showed that -most E. coli samples analyzed using
ONPG-MUG-incurred no significant degradation after a 30 to 48 hour holding time-. We believe that
more studies should be conducted and should show that there is indeed no significant difference in the
integrity of the samples before the holding time can be substantially extended to 30 or 48 hours.
Response: See Response 1733.
EPA Letter ID: 678
Comment ID: 14728
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the L T2ESWTR 16-105 December 2005
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Comment: 2. The EPA evaluated several studies that showed that the samples may be analyzed after 24
hours of transit and storage without significant differences in E. coli concentrations. Based on these
holding time studies, the EPA is proposing that the holding time for microbial samples be extended to 24
hours. It is suggested that methods other than the following must retain the 8-hour holding time for source
water samples:
mFC -> NA-MUG
Colilert Quanti-Tray 2000
Colilert
mEndo -> NA-MUG
mTEC
Response: See Response 1733.
EPA Letter ID: 688
Comment ID: 14747
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Page 47733 - E. coli
EPA is proposing a holding time of 24 hours for E. coli samples. In Missouri, most water systems will use
a centralized state laboratory for E. coli analysis. Even the 30-hour holding time allowed under the Total
Coliform Rule is difficult to meet. Many rejected samples could be expected with a 24 hour holding time
which will create monitoring violations and reduce the number of E. coli results available for determining
source water quality. Missouri recommends using the same 30-hour holding time as is used under the
Total Coliform Rule. We do not feel that the quality of the results is significantly reduced with the extra
six hours holding time, especially for samples analyzed using the ONPG-MUG method.
Response: See Response 1733.
EPA Letter ID: 707
Comment ID: 14822
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: Holding time of 24 hours for E. coli (parag. #7)
Comment: Agree with this recommendation. Our laboratory performed an ATP study using 720
secondary sewage effluent samples from 12 different geographic sites in the USA. Dilutions prepared and
held for 24-30 hours exhibited no significant difference in E. coli counts on mFC.
Extended holding time for ONPG-MUG to 30-48 hours
Comment: Recommend that a set holding time of 30 hours be set for all methods.
The PWS would be responsible for transporting samples to laboratory by a set time, not a set method. The
PWS is already accustomed to the 30 hour hold time for drinking water compliance samples and this
would be less of a problem getting the samples to the laboratory on time.
Comment Response for the L T2ESWTR 16-106 December 2005
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Response: See Response 1733.
EPA Letter ID: 711
Comment ID: 16571
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: requests comment on the proposal to extend the holding time for E. coli source
water sample analyses to 24 hours, including any data or other information that would support, modify, or
repudiate such an extension. [47734, C2]
Comment: The holding time for E. coli source water samples may be extended to 24
hours only for those analytical methods evaluated in the holding time studies noted in the proposed rule.
None of the studies evaluated used LTB to EC-MUG, modified mTEC agar, MI medium and m-
ColiBlue24 broth, to show that sample integrity is likewise kept using these methods. Therefore, the
holding time for samples analyzed with these methods must remain at 8 hours. EPA needs to do more
testing for methods other than Colilert before increasing the holding time from 8 hours to 24 hours.
Response: See Response 1733.
16.3.4 Comment Code 1734, Data on cost and availability of
overnight delivery in rural areas
Response to Code 1734
Shipping for systems in rural areas
EPA understands the concerns of systems in rural areas and recommends using a guaranteed overnight
shipping service to ensure that the samples will be shipped immediately to the laboratory for analysis and
in compliance with sample temperature requirements. Despite their concerns, the two commenters on this
subject noted their ability to arrange overnight shippin. In the final rule, EPA has expanded the justifiable
reasons for collecting a replacement samples to include documented shipping problems such as the loss of
or damage to the sample.
For additional information, see the Source Water Monitoring Guidance Manual for Public Water Systems
under the Long Term 2 Enhanced Surface Water Treatment Rule. This document provides guidance on
sampling location, procedures for collecting and shipping samples, contracting with laboratories, and
related topics to assist PWSs in complying with LT2ESWTR monitoring requirements. PWSs are advised
to work with the laboratory and the shipper to coordinate shipping requirements.
Individual Comments on Code 1734
EPA Letter ID: 472
Comment ID: 11185
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment Response for the L T2ESWTR 16-107 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Comment: - EPA also requests comment on the cost and availability of overnight delivery services for E.
coli samples, especially in rural areas.
Shipping of environmental samples overnight will continue to be a challenge. The two commercial
laboratories the COP uses include the cost of shipping in their analytical service pricing. Thus we do not
experience shipping fees directly.
Response: See Response 1734.
EPA Letter ID: 514
Comment ID: 11543
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: Cost and Availability of Overnight Service: The cost for facilities shipping an
E.coli surface water sample to our laboratory would be approximately $4-6 utilizing UPS ground service
which guarantees overnight delivery anywhere in the state without paying -overnight- prices. In the
winter, facilities may need to utilize USPS overnight mail service to avoid frozen samples which may cost
$12-15. There should not be a problem with overnight delivery service availability for those Iowa
supplies that will be submitting samples. Our facilities are familiar with this requirement for their
wastewater samples.
Response: See Response 1734.
16.4 Comment Code 1750, Turbidity
Summary of Issues
Comments were received concerning the measurement of turbidity under the LT2ESWTR. One
commenter believed that EPA was ignoring recent technological advances which would allow utilities to
measure their turbidities at much lower levels more reliably. This commenter believed that utilities that
could demonstrate turbidity levels >0.05 NTU with 95% confidence should be granted additional log
removal credit. One commenter believed EPA should clearly state that turbidity testing should be
concurrent with E. coli testing using one of the allowed methods.
Response to Code 1750
New advances allowing lower turbidity measurements
The Stage 2 M-DBP Advisory Committee recommended an additional 0.5-log Cryptosporidium treatment
credit for PWSs that achieve a CFE turbidity less than or equal to 0.15 NTU in at least 95 percent of
measurements per month (USEPA 2000a). This 95th percentile turbidity standard is one half the level
required under existing regulations for PWSs using conventional or direct filtration, as stated earlier. The
August 11, 2003 proposal included this treatment credit for PWSs using conventional or direct filtration
Comment Response for the L T2ESWTR 16-108 December 2005
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(USEPA 2003), and EPA is establishing it in today's final rule with no changes from the proposal. The
following discussion summarizes the basis for this treatment credit.
In the proposal, EPA analyzed the improvement in Cryptosporidium removal that conventional and direct
filtration plants realize when operating at lower effluent turbidity levels. For this analysis, EPA estimated
that PWSs complying with the existing 95th percentile CFE turbidity standard of 0.3 NTU will typically
operate with filter effluent turbidity between 0.1-0.2 NTU; PWSs complying with a CFE standard of 0.15
NTU were estimated to operate with filter effluent turbidity less than 0.1 NTU. Accordingly, EPA
compared Cryptosporidium removal efficiencies when effluent turbidity was below 0.1 NTU with those
when effluent turbidity was in the range of 0.1-0.2 NTU.
Studies by Patania et al. (1995), Emelko et al. (1999), and Dugan et al. (2001) observed the average
removal of Cryptosporidium to be 0.5- to 1.2-log greater when filter effluent turbidity was less than 0.1
NTU in comparison to removal with effluent turbidity between 0.1-0.2 NTU. These studies, therefore,
indicate that PWSs complying with a filter effluent turbidity standard of 0.15 NTU will achieve at least
0.5-log greater Cryptosporidium removal than PWSs complying with the existing 0.3 NTU standard.
Based on this finding, EPA concluded that an additional 0.5-log Cryptosporidium treatment credit is
appropriate for PWSs using conventional or direct filtration that meet a 95th percentile CFE turbidity
standard of 0.15 NTU.
EPA has reviewed studies of low level turbidity measurements, as well as standard test methods for
measurement of turbidity below 5 NTU. After reviewing this information, EPA concluded that currently
available monitoring equipment can reliably measure turbidity at levels of 0.15 NTU and lower.
However, EPA agrees that rigorous calibration and maintenance of turbidity monitoring equipment is
necessary for PWSs pursuing the low filtered water turbidity performance options in the microbial
toolbox. EPA has developed guidance on proper calibration, operation, and maintenance of turbidimeters
(USEPA 1999).
A method for laser nephelometry is currently approved under 40 CFR 141.74. All approved methods for
turbidity monitoring found in 40 CFR 141.74 are acceptable for compliance monitoring requirements of
today's rule. If other turbidity methods are approved and added to 40 CFR 141.74 in the future, these
methods would acceptable for compliance monitoring under the LT2ESWTR.
Simultaneous turbidity/E. coli sampling
EPA believes the fact that turbidity and E. coli sampling are concurrent and must be conducted using one
of the approved methods, is clearly stated in the rule and does not require further emphasis.
Individual Comments on Code 1750
EPA Letter ID: 548
Comment ID: 12188
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: 16. Section IV.L. Laboratory Approval (p. 47735)
? Turbidity analyses must be conducted by a person approved by the State for analysis of turbidity in
drinking water under 40 CFR 141.74.
Comment Response for the L T2ESWTR 16-109 December 2005
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Metropolitan requests clarification on what constitutes a party approved by the State to measure turbidity.
Several hundred persons at Metropolitan analyze turbidity in addition to laboratory analysts, including
operators, electronic technicians, maintenance mechanics, maintenance workers, and pumping plant
personnel.
Response: See Response 1850.
EPA Letter ID: 612
Comment ID: 13148
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: LT2 has within its microbiological toolbox of options; several treatment technologies require
the monitoring of turbidity. In addition, two of the toolbox technologies directly relate to lower filtered
turbidity and lower combined effluent turbidity. Several studies (Patania et al (1999), Huck et al (2000),
and Emelko et al (2000)) also convey information that there is a correlation between lower
cryptosporidium levels and lower filtered water turbidity (CFR 47660 -47661). In fact, the Emelko et al.
reference demonstrated the benefit of monitoring for very small increases in filtered turbidity as a
precursor to enhanced cryptosporidium removal (CFR 47698). However, in other parts throughout LT2,
turbidity is often referred to as a gross water quality measurement and without sensitivity. Therefore only
the most conservative approaches relevant to the application of this water quality parameter should be
considered.
Discussion:
Turbidity is one of the primary water quality benchmarks for filtration performance and overall water
treatment plant (WTP) performance. However, USEPA has failed to recognize the advancements in
turbidity measurement that have occurred over the last 40 years and specifically those advancements that
have occurred within the past 5 years. These advancements now provide better and more accurate low-
level turbidity measurements than ever before.
The two-benchmark methods for turbidity are USEPA 180.1 and Standard Methods 2130B. Both of these
methods that have remained relatively unchanged with respect to optical design criteria over the last
several decades. The resistance by the EPA to provide an efficient mechanism for the integration and use
of new technologies related to this water quality parameter has prevented its technological advancement.
In addition, those newer technologies that are implemented into the regulatory monitoring arena and are
benchmarked against the older reference technology and thereby assumed to be no better in performance.
This is exhibited by the resolution of reporting criteria for turbidity values.
An example that the Agency regards all turbidity methods essentially equivalent regardless of the
technology involved the October 2002 approval of Hach Method 10133, the FilterTrak Laser turbidity
method. To gain Agency approval of Hach Method 10133, a demonstration of benchmark performance
against the currently approved EPA methods was required using the alternative test procedure (ATP)
process. This demonstration insured that the technology does not take a step backward, but it also
generates the perception within the Agency that the methods provide no additional benefit with respect to
measurement performance and reliability.
Comment Response for the L T2ESWTR 16-110 December 2005
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The laser turbidity technology provided in Hach Method 10133 does provide a significant advancement
over other pre-approved technologies. Laser turbidity has been demonstrated to be more sensitive to
changes in turbidity (higher sensitivity), have lower stray light (due to better control over the incident
light source and optics), and is more sensitive to lower levels and smaller sizes of particles when
compared to older turbidity measurement designs. This is primarily due to significant overlap between a
short wavelength incident light source and the detector response spectrum. In fact, where methods 180.1,
and 2130B provide a reporting resolution of 0.05 NTU, Method 10133 provides a lower reporting
resolution of 10 mNTU, (0.01 NTU). With better reporting resolution, newer turbidity monitoring
technologies, such as laser-based turbidimeters, have demonstrated that they are capable of detecting finer
turbidity changes, having greater measurement stability and in performing more accurate measurements.
The newer turbidimeter technologies have also been demonstrated on pilot studies that they may also
provide the advantages of filtration event prediction and in the qualifying of a particle event that was not
possible with historical turbidity methods. Several papers have been published that demonstrate the
advantages of using new turbidity-monitoring technologies. Copies of these papers can be found in the
Hach Literature Paper "Introduction to Laser Nephelometry: An Alternative to Conventional Particulate
Analysis Methods," 3rd Ed (2003), Hach Company, Loveland CO.
In addition to the advancement of turbidity monitoring technology, the supportive technology with
respect to calibration standards, verification standards and secondary verification standards have also
advanced. For example, the USEPA WS041 Study (CFR 47699) involved the use of new low-level
turbidity standards. Three of the samples were provided by the manufacturers, in a ready-
to-use format. This was the first study that actually used stable low-level turbidity standards that were
previously unavailable. The WS041 results were very favorable and provided demonstration that low-
level monitoring can be achieved and validated.
Summary: Hach Company strongly recommends that agency recognize those newer and improved
turbidity-monitoring technologies and provide guidance and encouragement of these new technologies for
low-level turbidity monitoring. (CFR 47434.) The agency must also provide better detail into the
methodologies related to performing accurate low-level turbidity measurements. These technological and
analytical method advancements raise the benchmark for performance in turbidity monitoring. These new
technologies benefit the water utilities in that the newer designs reduce the positive error bias on low-
level measurements, have fail-safe software features and support methods which reduce systematic and
mechanical errors associated with these measurements, which have typically been the biggest setback in
low-level turbidity measurement.
The new turbidity technologies such as those found in the laser turbidity methods will provide a more
accurate and better assessment of filtration performance and a heightened sensitivity that would assist in
detecting pre-
cursors to filtration breakthrough. This is essential to reduce the increase of cryptosporidium pathogen
passage through filters. Further, these technologies provide the ability to accurately discern critical
changes in the filtered effluent and resolution in turbidity measurement values. The need for accuracy and
resolution is critical for many utilities that would choose to meet the stricter turbidity levels that are
offered in the microbial toolbox requirements of the LT2 rule.
The Agency's rational for the lower turbidity levels in filter effluent, was based upon those referenced
studies in which lower filtered turbidity levels correlate to reduced cryptosporidium levels in the filtered
effluent stream. For those utilities that provide the cost, time, and effort to implement the more sensitive
turbidity monitoring technologies and optimize their filtration processes to achieve the lowest of turbidity
levels should be given the benefit of additional log removal credit. For example, utilities that demonstrate
that they can achieve turbidity levels below 0.050 NTU 95% of the time using those turbidimeter
Comment Response for the L T2ESWTR 16-111 December 2005
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technologies with the appropriate accuracy and resolution to confirm this performance would provide the
greatest risk reduction in pathogen cyst removal.
Hach Company also offers the opportunity to the EPA to partner with those manufacturers of new
turbidity technologies to provide a meaningful set of turbidity data that is acquired under true process
conditions that accurately reflect those from drinking water utilities. This study would be similar to the
Letterman, et al, 2001 study (CFR47434), in the instrument setup and analysis but would be performed at
various utilities where measurements could be performed over a long period of time (days vs minutes in
the Letterman study). This study should be conducted using those appropriate low-level monitoring
technologies and the proper analytical support methods (relative to instrument setup, maintenance,
calibration and verification) that were developed in parallel. This will ultimately provide the most
accurate and representative data set for the demonstration of low-level performance.
Being the recognized world leader in turbidity analysis and technology, Hach Company is willing to
partner with the Agency and in facilitating a critical review and education regarding the advancements in
turbidity monitoring technology and in the design and participation of any on-line low-level turbidity
study.
Response: See Response 1750.
EPA Letter ID: 704
Comment ID: 14797
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section 4.2.1.1.
Turbidities must be collected at the same time as E. coli samples are collected by one of the approved
methods described in the LT2 rule. Utility managers must be made aware of this provision up front.
Response: See Response 1750.
EPA Letter ID: 711
Comment ID: 16547
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 2. Section 141.706(c) - Measurements of turbidity must be made by a party approved by the
State. It is unclear whether or not this requirement also applies to the party who collects samples and
measures the turbidity in the field. Our interpretation of this requirement is that anyone who works in a
lab that is State certified is approved by the State to conduct turbidity measurements. This section needs
clarification since as stated, it can have widely varying interpretations.
Response: See Response 1850.
Comment Response for the L T2ESWTR 16-112 December 2005
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16.4.1 Comment Code 1751, Proposed methods
Summary of Issues
Comments were received concerning the proposed methods for measuring turbidity under the
LT2ESWTR. One commenter requested that the LT2ESWTR specifically address turbidity measurements
in plants that practice lime softening. All of the remaining comments supported the turbidity methods the
EPA has approved for this rule.
Response to Code 1751
Turbidity measurements in plants that practice lime softening
EPA notes that additional treatment credit for combined filter effluent turbidity is based on measurements
collected under 40 CFRpart 141.173 or 40 CFRpart 141.551 (the IESWTR or LT1ESWTR). These
regulations allow PWSs that use lime softening to acidify samples prior to analysis in order to address the
effects of lime softening on turbidity measurements. In regard to LT2ESWTR treatment credit based on
individual filter effluent turbidity, EPA agrees with commenters that acidifying samples while measuring
turbidity every 15 minutes at each individual filter, as the LT2ESTWR requires, is not feasible. However,
PWSs that practice lime softening could use the demonstration of performance toolbox option to
demonstrate that a plant is achieving removal efficiencies equivalent to the additional credit allowed for
individual filter performance.
Support of approved methods
In agreement with supportive comments, EPA has maintained in the final rule the requirement for PWSs
to use the analytical methods that have been previously approved by EPA for analysis of turbidity in
drinking water as listed in 40 CFR Par 141.74.
Individual Comments on Code 1751
EPA Letter ID: 449
Comment ID: 10834
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: holding time. In response to section IV.K.3, we feel that the current approved methods for
turbidity measurement in the LT2ESWTR are good and should remain as the approved methods.
Response: See Response 1751.
EPA Letter ID: 548
Comment ID: 12187
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment Response for the L T2ESWTR 16-113 December 2005
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Comment: Metropolitan has experience with three out of the four analytical methods. The majority of
these comments relate to the two nephelometric methods, Standard Method 21 SOB and EPA Method
180.1, since this methodology is utilized by all of Metropolitan-s laboratories. Metropolitan has found
these two methods provide very specific guidelines in some areas, but that they are general in others, and
discrepancies exist between the two. Metropolitan suggests that method variations and amendments
having separate approval be noted. Metropolitan has found the California Department of Health Services-
Turbidity Monitoring Guidelines (attached) [see pdfj to provide clarification in many of these problem
areas. Following are examples:
Detector: Both methods specify the primary detector be at 90o to the incident light beam. The USEPA
approved Hach-s ratio Method 8195 in December 1997 as meeting the design criteria of Method 180.1.
This amendment should be included. Method 180.1 still requires dilution of samples with turbidity
greater than 40 NTU. It is Metropolitan-s experience that instruments in the ratio mode can be calibrated
and accurately measure to 4000 or 10000 NTU, depending on the model. CDHS has revised their
guideline to incorporate this revision.
Primary Standards: There are three acceptable calibration standards recognized in USEPA Method 180.1,
and two variations in 2130B. There is a fourth approved by the USEPA in April 1998, StablCal stabilized
formazin, which is in Hach FilterTrak Method 10133. The CDHS guideline specifically includes it as a
primary calibration standard and Metropolitan has been using it very successfully.
Calibration frequency and criteria for re-calibration: Methods 2130B and 180.1 do not adequately address
this important protocol, or defer to manufacturer-s operating instructions, which do not address it either.
It is very specifically addressed in the CDHS guidelines that Metropolitan complies with.
Dilution water: Method 2130B specifies dilution water of 0.02 NTU; 180.1 requires -a lower turbidity
than unfiltered distilled water-. The CDHS regulation is 0.05 NTU or less. Turbidity of 0.02 NTU is at
the very lowest limit of the measurable range and, in Metropolitan-s experience, may not be accurately
measured.
Holding time: Method 180.1 allows storage at 4oC for 48 hours; Method 2130B and CDHS guidelines
prefer immediate analysis with no refrigeration. At Metropolitan-s very low turbidity levels of less than
0.1 NTU, precise field measurement would be difficult due to the unreliable nature of handheld
instruments and the lack of portability of bench top instruments.
Low turbidity analysis: Both methods propose sample and cell handling techniques appropriate for
Metropolitan-s range of interest which is at 0.1 NTU and less. CDHS provides more specific guidelines,
including a procedure for degassing, allowing the sample to sit for a few minutes or application of
vacuum. Metropolitan also uses sonication for such an analysis
Great Lakes Instruments Method 2 is used at several of Metropolitan-s facilities in on-line process
instruments. The photo detector is more stable and has less drift than the nephlometric methods using
incandescent lamp. There are no standardized procedures in GLI Method 2 for maintenance of the
cube used in secondary verification checks. CDHS provides some general guidelines for the technician.
Metropolitan is not currently using the fourth method, Hach FilterTrak Method 10133, so no comment
will be provided on theory or application.
Response: See Response 1724.
Comment Response for the L T2ESWTR 16-114 December 2005
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EPA Letter ID: 601
Comment ID: 13042
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: EPA requests comment on whether the turbidity methods proposed should be approved
Utah supports EPA-s recommendation to require systems to use the analytical methods that have been
previously approved by EPA for analysis of turbidity in drinking water as listed in 40 CFR Par 141.74.
Response: See Response 1751.
EPA Letter ID: 637
Comment ID: 13108
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: EPA requests comment on whether the turbidity methods proposed should be approved.
District supports EPA-s recommendation to require systems to use the analytical methods that have been
previously approved by EPA for analysis of turbidity in drinking water as listed in 40 CFR Par 141.74.
Response: See Response 1751.
EPA Letter ID: 654
Comment ID: 13119
Commenter: William Brant, Director, Miami-Dade Water and Sewer Department
Commenter Category: Regulated Community (Utilities)
Comment: The MDWASD requests that the EPA clarify the turbidity standards that will apply in the
LT2. The proposed rule does not specifically define what the required turbidity standards are for Public
Water Systems (PWS). The MDWASD contacted the Safe Drinking Water Hotline regarding this issue.
According to the operator at the hotline, the turbidity standards that will apply in the LT2 are the same
standards and limits as those in the Interim Enhanced Surface Water Treatment Rule (IESWTR). The
IESWTR states turbidity limits as well as provisions or plants that practice lime softening to acidify the
samples prior to taking turbidity measurements. The following is a quote from the Federal Register
Volume 63, Number 241:
The IESWTR allows acidification of samples for the combined filter effluent at a lime softening plants. In
addition, EPA is allowing systems that use lime softening to apply to States for alternative exceedance
reporting levels for individual filters if they can demonstrate that higher turbidity levels in individual
filters are due to lime carryover and not due to degraded filter performance.
The MDWASD also raised the question about the provisions for acidification of samples from lime
Comment Response for the L T2ESWTR 16-115 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
softening systems prior to turbidity measurements in the LT2 stakeholder meeting held on October 9,
2003. The answer provided by the presenter was the same as that of the hotline operator stated above,
which is that the turbidity standards and provisions established in the IESWTR will be carried over to the
LT2.
Public water systems (PWS) that use a lime softening/filtration process, for treating pristine ground water,
are somewhat unique in that the process generates significant quantities of turbidity that result from
precipitated calcium carbonate. The majority of the precipitated calcium carbonate settles in the softeners
or is removed in the filters, however a small percentage may pass through even a well operated filter and
thereby contribute to elevated levels of turbidity on the filtered water. The EPA already recognized the
potential for this turbidity induced by the softening process, to interfere with the determination of
turbidity measurements and therefore, established provisions in the IESWTR that allows States to permit
utilities to acidify turbidity samples for combined filter effluent of lime softening plants. The process
established in the IESWTR is sustained in the National Primary Water Standards (NPWS) under
§141.173, which states that for conventional filtration or direct filtration, a system that uses lime
softening may acidify representative samples prior to analysis using a protocol approved by the State.
Acidification of the sample eliminates the interference of softening induced turbidity by dissolving any
calcium carbonate particles present in filtered water.
MDWASD would like to reiterate the comments that were submitted to the EPA during the development
of the IESWTR, requesting that the acidification provision be included. MDWASD believes that the same
arguments are still valid and that the acidification provisions should again be included in the LT2. The
MDWASD respectfully requests that the EPA specifically and explicitly include the turbidity limits and
provisions as stated in the IESWTR in the LT2. The MDWASD believes that by doing this, the EPA will
clear up the confusion and concern of many PWS. The MDWASD has done an extensive study on the
acidification process in order to propose a protocol for the State of Florida. The MDWASD is more than
willing to provide copies of this study for EPA-s review.
Response: See Response 1751.
EPA Letter ID: 662
Comment ID: 14047
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
K. 3. Turbidity
(page 47734)
EPA requests comment on whether the turbidity methods proposed should be approved.
Methods previously approved by EPA for analysis of turbidity in drinking water as listed in 40 CFR Par
141.74, should be approved.
VII. Statutory and Executive Order Reviews
Response: See Response 1751.
Comment Response for the L T2ESWTR 16-116 December 2005
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EPA Letter ID: 673
Comment ID: 14002
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
K. 3. Turbidity
(page 47734)
EPA requests comment on whether the turbidity methods proposed should be approved.
Jordan Valley Water supports EPA-s recommendation to require systems to use the analytical methods
that have been previously approved by EPA for analysis of turbidity in drinking water as listed in 40 CFR
Par 141.74.
Response: See Response 1751.
EPA Letter ID: 711
Comment ID: 16572
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 9. EPA requests comment on whether the turbidity methods proposed today for the LT2
should be approved, and whether there are additional methods not proposed that should be approved.
[47734, C3]
Comment: We believe the turbidity methods proposed in LT2 are sufficient.
Response: See Response 1751.
16.4.2 Comment Code 1752, Additional methods
Summary of Issues
Comments were received concerning additional methods for monitoring turbidity under the LT2ESWTR.
One commenter suggested that EPA allow laser nephelometry as an approved method for measuring
turbidity. One commenter expressed the opinion that EPA should use a third party testing organization to
ensure that different turbidity measurement devices can produce similar results.
Response to Code 1752
New turbidity measuring technology
A method for laser nephelometry EPA is currently currently approved under 40 CFR 141.74. All
Comment Response for the L T2ESWTR 16-117 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
approved methods for turbidity monitoring found in 40 CFR 141.74 are acceptable for compliance
monitoring requirements of today's rule. If other turbidity methods are approved and added to 40 CFR
141.74 in the future, these methods would acceptable for compliance monitoring under the LT2ESWTR.
Third party testing to ensure instrument agreement
EPA has reviewed studies of low level turbidity measurements, as well as standard test methods for
measurement of turbidity below 5 NTU. After reviewing this information, EPA concluded that currently
available monitoring equipment can reliably measure turbidity at levels of 0.15 NTU and lower, and
therefore third party testing and certification is not needed to assure accurate, repeatable results. However,
EPA agrees that rigorous calibration and maintenance of turbidity monitoring equipment is necessary for
PWSs pursuing the low filtered water turbidity performance options in the microbial toolbox. EPA has
developed guidance on proper calibration, operation, and maintenance of turbidimeters (USEPA 1999).
Individual Comments on Code 1752
EPA Letter ID: 390
Comment ID: 10495
Commenter: Jeff Taylor, Deputy Director, City of Houston Public Utilities Division
Commenter Category: Regulated Community (Utilities)
Comment: c. We did not see the use of Laser nephelometry in the approved methodology for turbidity
measurement. We understand that EPA has recently approved this method, and it is certainly superior to
traditional light scattering methods, currently in use, for measurement of very low levels of turbidity.
Response: See Response 1752.
EPA Letter ID: 454
Comment ID: 10953
Commenter: Richard D. Letterman,, Department of Civil and Environmental Engineering, Syracuse
University
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: I believe that promulgation of the LT2ESWTR should include a USEPA supported effort to
obtain better agreement between the instruments used to determine compliance. This can be done through
the voluntary standards system. Perhaps a third party testing organization (e.g., NSF International) is
needed to determine and certify if instruments meet the standards and are in effective agreement.
Response: See Response 1752.
Comment Response for the L T2ESWTR 16-118 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
16.5 Comment Code 1760, Extension of holding time for other
parameters
Summary of Issues
One comment requested the extension of holding times for fecal coliform analysis for raw water under the
SWTR (to meet filtration avoidance criteria) to 24 hours. Another comment suggested that for all
approved E. coli methods, the holding time should be the same because there will be no difference in time
for the bacteria to degrade.
Response to Code 1760
E. coli holding time
Today's rule does not withdraw or modify any existing criteria or approved methodology for compliance
under 40 CFR 141.71. Today's rule does not establish any new criteria for filtration avoidance; unfiltered
PWSs must continue to comply with all existing filtration avoidance criteria. EPA believes these criteria
help to ensure that watershed protection provides a microbial barrier in those PWSs that do not filter.
After reassessing the studies described in the proposed rule, EPA has concluded that a 30 hour holding
time limit for samples being analyzed for E. coli under LT2 is appropriate and consistent with the data
quality objectives of this rule. Further, EPA believes that meeting a 30 hour holding time is feasible for
most PWSs that must ship E. coli samples to an off-site laboratory for analysis. This longer holding time,
however, does not apply to E. coli monitoring conducted under other regulations and programs.
Individual Comments on Code 1760
EPA Letter ID: 462
Comment ID: 10551
Commenter: Anonymous392,
Commenter Category: Regulated Community (Utilities)
Comment: The proposed LT2 rule allows a 24 hour holding time for the E coli analyses of raw water.
Can EPA modify the SWTR holding time for fecal analysis of raw water (for meeting filtration avoidance
criteria), which is currently 8 hours, to also allow 24 hours, if the sample is kept cool? It is not fair to
make unfiltered systems try to get raw water samples to a lab within 8 hours, especially in rural areas
where labs are far away and weather conditions can be bad. Please modify the test requirements in
Subpart H to allow at least 24 hours for the raw water fecal analysis, for meeting filtration avoidance
criteria.
Response: See Response 1760.
EPA Letter ID: 609
Comment ID: 14121
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment Response for the L T2ESWTR 16-119 December 2005
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Chapter 16: Analytical Methods Comment Codes 1700-1760
Comment: limit the extended holding time to only the analytical methods evaluated. Evaluation was
based on the degradation of the E. coli bacteria, not on the method used. For approved E. coli methods,
there should be no difference in the time it takes the bacteria to degrade.
Response: See Response 1760.
Comment Response for the LT2ESWTR 16-120 December 2005
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17. Laboratory Approval and Capacity: Comment Codes
1810-1870
17.1 Comment Code 1810, Cryptosporidium Laboratory Approval
Summary of Issues
Many comments requested further information regarding the Laboratory QA Program currently
administered by the EPA. These requests and comments included the request that EPA continue to
administer the Lab QA Program for Cryptosporidium, that EPA evaluate any State QA program for
equivalency, that EPA set clear certification standards, and requested EPA to provide training for auditors
at the State level. These comments expressed concern that the States will not have the resources to
administer an equivalent Lab QA Program due to the specific nature of the analysis. Other commenters
suggested that EPA considered utility labs incapable of performing the analyses and expressed concern
that the state of Kentucky expects to have only two approved labs within their state.
Response to Code 1810
Laboratory QA Program
Given the time necessary for EPA to approve a sufficient number of laboratories to assure adequate
capacity for LT2ESWTR monitoring, EPA began laboratory evaluation under the Laboratory Quality
Assurance Evaluation Program for Analysis of Cryptosporidium under the Safe Drinking Water Act (Lab
QA Program) prior to promulgation of the rule in order to accommodate such an implementation
schedule. EPA's Lab QA Program is a voluntary program open to laboratories analyzing
Cryptosporidium in water using EPA Method 1622 and EPA Method 1623. The program is open to both
utility and commercial laboratories. To increase the likelihood that laboratories analyzing water samples
for Cryptosporidium generate reliable data, EPA has established the following process for evaluating
laboratory performance and quality assurance practices: application, performance testing, and an on-site
evaluation. The application process includes a self audit checklist which clearly states the requirements
necessary for production of quality data. A list of laboratories that are approved under this program is
available on the Internet at http://www.epa.gov/safewater/lt2/cla_fmal.html.
Continuation of Laboratory QA Program
EPA intends to maintain the Lab QA Program for Cryptosporidium, but States are allowed to certify
Cryptosporidium laboratories by setting up an equivalent program. States do not currently approve
laboratories for Cryptosporidium. If a State adopts an equivalent approval process under a State
laboratory certification program, then PWSs may use laboratories approved by the State. EPA believes it
would be an undue burden on the states to set up a Cryptosporidium certification program for a finite
period of time to address the LT2ESWTR Rule. States are not required to guarantee a specific number of
laboratories because samples may be shipped to any approved lab. No comments were received
suggesting any other elements to include in a State QA program. Therefore, an equivalent program would
consist of the same elements as the EPA Lab QA Program currently in place including successful analysis
of initial and on-going blind proficiency testing samples, on-site technical and data audit by a qualified
and experienced auditor, and use of the audit checklist. EPA does not plan to provide training for State
Comment Response for LT2ESWTR 17-1 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
auditors for the evaluation of Cryptosporidium analysis.
Water treatment plant in-house analysis
EPA does not restrict water treatment plants with their own laboratories from conducting
Cryptosporidium analysis, and many such laboratories have achieved pending approval under the EPA
Laboratory QA Program. Unlike simple analytical procedures for turbidity, chlorine and C1O2, approved
methods 1622 and 1623 for Cryptosporidium analysis are complicated methods, requiring trained analysts
with extensive experience and knowledge of the methods and equipment. Through the Laboratory QA
Program, laboratories and analysts demonstrate the ability to achieve quality results while benefitting
from EPA guidance on methods and procedures. EPA also requires lab certification or aproval for
monitoring requirements other than simple analyses like turbidity or chlorine residual. Therefore,
treatment plant laboratories must be approved through the EPA Laboratory QA program to meet
analytical requirements under the LT2 rule.
Individual Comments on Code 1810
EPA Letter ID: 398
Comment ID: 10536
Commenter: Ron Kailey, Laboratory Supervisor, Cheyenne Board of Public Utilities
Commenter Category: Regulated Community (Utilities)
Comment: EPA needs to allow Water Treatment Plants to run their own compliance monitoring just as it
allows Wastewater too do the same. As more regulations are being forced upon the WTP, they need to
have the flexibility to report their own internal numbers. They need to give water treatment plants the
option of performing some of the analyses in house. EPA allows the wastewater to do many of the
compliance tests in-house but not on the water end. If it's a question of "Drinking water Vs operator
integrity" then how come plants are allowed to report their own Turbidity, Chlorine, CLO2 and a few
other parameters that EPA cannot control? We need the ability to do our own in-house testing without the
cost of becoming certified. We would be happy to perform "Performance testing", allow Lab audits and
even submit blind sample data to the EPA. It is time that the EPA realizes the WTP people are
professionals and can do the required testing to the same ability as the contract lab. Problems with
contract labs:
- They cannot always get the reports back in time for required reporting. - No Certified labs close to the
WTP (Wyoming communities). - Shipping problems will effect and skew the contract lab results. - The
contract labs will not show the care that the In-house labs will. - If there is a problem the In-house lab can
address it right away. - The In-House lab can and will monitor more instances of the parameter if they do
not have the external cost. - WTP personnel need to know that qualified people performed the results.
- Just because a lab is certified does not mean the results are good.
Response: See Response 1810.
EPA Letter ID: 643
Comment ID: 12817
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the L T2ESWTR 17-2 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
Comment: Laboratory Approval (pages 47734-47736)
Given the specialized nature of the work and desire to avoid duplication and confusion in the laboratory
certification process, states recommend that the EPA maintain a national laboratory certification program
for Cryptosporidium through the initial and follow-up rounds of Cryptosporidium analysis.
Response: See Response 1810.
EPA Letter ID: 647
Comment ID: 12947
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Laboratory Approval (pages 47734-47736)
Given the specialized nature of the work and desire to avoid duplication and confusion in the laboratory
certification process, states recommend that the EPA maintain a national laboratory certification program
for Cryptosporidium through the initial and follow-up rounds of Cryptosporidium analysis.
Response: See Response 1810.
EPA Letter ID: 707
Comment ID: 14829
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: At this time, Kentucky does not anticipate more than two laboratories seeking
Cryptosporidium certification (Louisville Water Company has recently received
certification, but is not interested in performing Cryptosporidium analysis
for other systems).
Response: See Response 1810.
17.1.1 Comment Code 1811, Process and criteria for laboratory
Approval
Response to Code 1811
See individual responses below.
Individual Comments on Code
EPA Letter ID: 411
Comment ID: 10561
Comment Response for the L T2ESWTR 17-3 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
Commenter: Devon Cole,, Utah Department of Health Laboratory
Commenter Category: State/Tribe Government
Comment: When should the June 2003 versions of Method 1622/1623 begin to be used? Will method
changes require recertification for laboratories already approved using previous method versions?
Response: See Response 1712.
EPA Letter ID: 534
Comment ID: 12008
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: Considering the complexity and uncertainty of the laboratory methods on which
this rule is based, Kansas City welcomes clear laboratory certification standards.
Response: See Responses 1712 and 1810.
EPA Letter ID: 592
Comment ID: 12098
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Licensing labs for turbidity The proposed rule also requires that all monitoring for turbidity
be performed in a licensed laboratory. Most of Maine-s smaller water systems do not have the resources
to establish licensed laboratories and there are no licensed laboratories close by in Northern rural Maine.
There must be provisions in this rule for the State to -approve- licensed operators asqualified to perform
turbidity testing.
Response: See Response 1850.
EPA Letter ID: 595
Comment ID: 12600
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Laboratory Approval (pages 47734-47736)
Maine believes that the EPA should maintain a national laboratory certification program for
Cryptosporidium through the initial and follow-up rounds of Cryptosporidium analysis.
Comment Response for the L T2ESWTR 17-4 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
17.1.1.1 Comment Code 1812, Analyst experience criteria
Summary of Issues
Commenters expressed concern that the Cryptosporidium analysis requirements for analyst and technician
may be too restrictive; the restrictive requirements may impact lab capacity and analytical costs. Some
commenters requested a decrease in the number of samples and the time required for an analyst.
Commenters also requested clarification regarding the samples processed during the time period in which
an analyst gains experience. One commenter requested that the requirements remain as written or increase
to ensure quality data for the utilities. One commenter requested that an additional six months experience
not substitute for 2 years of college. One commenter suggested cooperation between labs especially as a
backup for microscopic examination. Comments were also received that suggest trainees be allowed to
analyze LT2ESWTR samples under direct supervision of an experienced analyst.
Response to Code 1812
Analyst Experience Criteria
EPA does not agree that the requirements as currently stated are too restrictive and will negatively impact
lab capacity or analytical costs. EPA believes the proposed requirements are reasonable for ensuring that
analysts have the experience to evaluate source water samples under the LT2ESWTR. These requirements
were established because the Cryptosporidium analyses required in the rule entail the use of manual
procedures that rely heavily on analyst skill and examination steps that require expertise and experience
for accuracy. EPA believes that reducing the analyst requirements will reduce the reliability of
Cryptosporidium monitoring data under the rule. The requirements for an analyst include at least 2 years
of college in microbiology or equivalent or a closely related field, a minimum of 6 months of continuous
bench experience with Cryptosporidium and IFA microscopy, a minimum of 3 months of experience
using Method 1622/1623, and successful analysis of a minimum of 50 samples using Method 1622/1623.
The requirements for a technician include 3 months of experience with specific procedures performed and
successful analysis of a minimum of 50 samples using Method 1622/1623. No minimum educational
requirements or previous experience with protozoan detection are required for a technician. These
requirements have not been altered. Approximately 6 months are required to train Cryptosporidium
analysts on Method 1622/1623 procedures and microscopy, and the staggered compliance schedule
allows laboratories time to continue to train personnel while monitoring is occurring but before the peak
number of analyses is reached. No break exists between large system and small system monitoring
eliminating the potential disincentive to laboratories investing in capacity.
EPA disagrees that 6 months additional experience of continuous bench experience with Cryptosporidium
and IFA microscopy may be substituted for 2 year of college lecture and laboratory course work. This
option was deleted from the April 2001 version of Method 1622/1623 during the revisions for latest
version.
As stated in the "Microbial Laboratory Guidance Manual For the Long Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR Rule)" for the rule, training prior to analyzing samples for LT2ESWTR
includes review of laboratory SOPs, observation of an experienced analyst, performance of the method
while being observed by an experienced analyst, and acceptable performance of a set of IPR samples
using blind spikes. After initial training is successfully completed, quality control samples and non-
LT2ESWTR samples analyzed using the same method may also be used by the trainee to gain experience.
When the required experience and number of samples are successfully completed, documentation
Comment Response for the L T2ESWTR 17-5 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
supporting the completion is sent to the EPA and the trainee status is changed to analyst or technician.
Cooperation between laboratories
EPA agrees with the comment suggesting interaction between laboratories to discuss slide examination
and encourages the cooperation. At this time EPA is investigating and developing protocols to assist
laboratories in this potential interaction. In addition, EPA is pursuing options to support the laboratories
in staff training for both initial and ongoing training including a series of on-line training modules.
Trainee Analysis
EPA agrees that trainees should analyze LT2ESWTR samples under direct supervision of an experienced
analyst but only after sufficient experience and training with non-LT2 samples.
Individual Comments on Code 1812
EPA Letter ID: 437
Comment ID: 10616
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: In order to improve the Laboratory Approval process the EPA needs to better define the
training requirements for the Laboratory Technician by Method 1623. As written (section 3.2.2), only
"experienced" technicians can work on LT2 samples. Given the current language it would be impractical
to train new laboratory technicians during the period when LT2 is enforced. On what samples would
technicians gain their 3 month experience if they could not work on LT2 samples? Please modify the
wording so that a new technician can be directly supervised on LT2 samples by an experienced technician
or analyst while in training and have the work signed-off by the trainee AND the experienced worker.
There will be turn-over in laboratory staff during the projected time period of LT2. If EPA does not
change this requirement, then it will not be feasible, nor perhaps possible, for laboratories to train/replace
technicians once LT2 has begun.
Response: See Response 1812.
EPA Letter ID: 449
Comment ID: 10835
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: In section IV.L there is discussion about substituting 6 months of experience working with
the approved cryptosporidium testing methods for the 2 years of college training that is now required. It is
our feeling that this should not be approved. We understand that there may be a shortage of qualified
technicians to perform testing if the new rules are implemented now, but because of the importance of
such testing results, it is imperative that the chemists performing the tests be qualified. If EPA were to
wait 2 years until the states have primacy to implement some of the new rules it would allow time for
more chemists to be trained.
Comment Response for the L T2ESWTR 17-6 December 2005
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Response: See Response 1812.
EPA Letter ID: 463
Comment ID: 10997
Commenter: Anonymous462,, Washington Aqueduct
Commenter Category: Regulated Community (Utilities)
Comment: Analyst experience requirement for Cryptosporidium analysis is too restrictive. It would
require labs to pay analysts to analyze samples that could not be used for compliance in order to acquire
experience. It would be difficult to maintain adequate staffing with required experience. Only a small
number of labs would be able to meet the proposed experience requirements. The cost associated with
training analysts would be passed on to the customer. In addition, the small numbers of labs able to meet
the requirements would create a market where costs to analyze samples could become prohibitive for the
customer. A better requirement would be that each analyst be required to pass annual or even biannual
proficiency samples.
Response: See Response 1812.
EPA Letter ID: 514
Comment ID: 11547
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: 4. Request for comment
Analyst Experience Criteria: For Cryptosporidium testing analyst experience requirements are necessary.
We suggest that the requirements be reduced if
training is performed by an already approved Method 1623 analyst (e.g. minimum 25 samples if the
person was an analyst approved to conduct-.ICR Protozoan Method OR was trained by a Method 1623
approved analyst). This would help shorten the training time for analysts without sacrificing the training
experience needed. We currently have this situation in our laboratory and the new analyst that was trained
by an approved analyst is ready to perform samples on his own after processing only 20-25 samples.
Response: See Response 1812.
EPA Letter ID: 548
Comment ID: 12189
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Metropolitan believes that the criteria for analyst experience in the Lab QA program are
appropriate because in general, it takes that much experience to be able to adequately analyze
Comment Response for the L T2ESWTR 17-7 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
Cryptosporidium using EPA Method 1622 and/or 1623. Metropolitan also recognizes the fact that some
analysts may learn the methods/techniques faster than others and may not need as much experience
with actual samples as stated in the Lab QA Program. However, increased training and experience for
such analysts could only result in better and more efficient performance and would therefore be of
advantage to the laboratory and the utilities it serves.
Response: See Response 1812.
EPA Letter ID: 641
Comment ID: 13614
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Pg 47735 RFC - Analyst Experience Criteria - ASI has some concerns regarding the
personnel qualifications, with regard to hiring new staff for LT2.
As outlined in the Laboratory Guidance Manual (Section 3.2.2), the Principal Analyst criteria, including -
Education,—Experience- and -Number of samples,- are fine. Similarly, the -Education- and -Number
of samples- criteria for Analysts and Technicians are fine and should be maintained to help ensure data
quality. However, the -experience- criteria for analysts and technicians should be eliminated. ASI
recommends that (a) detailed training records should be kept and the Principal Analysts should sign off on
each Trainee after completion of the 50 samples; (b) that if any of the 50 samples used for training are
LT2 samples, they must be processed by the Trainee under direct observation of an Analyst or Principal
Analyst; and (c) that laboratories should be evaluated based on initial audit criteria (equipment,
procedures, personnel, etc.) and on Proficiency Testing results.
Our concern is that while EPA-s proposed experience criteria seem benign and desirable, they may prove
too restrictive to allow laboratories to maintain or increase capacity if necessary, and therefore be
counterproductive to the overall rule. For example, new Technician with some laboratory background,
does not require 3 months of training before s/he is qualified to filter/concentrate/elute samples, or
perform IMS for that matter. Similarly, depending upon the Analyst and the training expertise available in
the laboratory, it may not require 6 months experience with Crypto, and IFA and also 3 months with 1623
to develop proficiency. If EPA feels -Experience- criteria are necessary for Analysts and/or Technicians,
we recommend 1 month for analysts (Crypto/IFA and 1623) and 2 weeks for Technicians, as long as the -
Education- and Number of Samples- criteria detailed above are also prerequisite. \
Response: See Response 1812.
EPA Letter ID: 678
Comment ID: 14720
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 16. The EPA requests comment on the laboratory approval requirements proposed today,
[47735, C3, 47736, Cl-2] Minimum qualifications for Cryptosporidium analysts
Comment: We recognize the fact that some analysts may learn the methods/techniques faster than others
and may not need as much experience with actual samples as stated in the Lab QA Program. However,
Comment Response for the L T2ESWTR 17-8 December 2005
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increased training and experience for such analysts could only result in better and more efficient
performance and would therefore be of advantage to the laboratory and the utilities it serves.
Response: See Response 1812.
EPA Letter ID: 688
Comment ID: 14748
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: Page 47735 Analyst Experience Criteria
Missouri is concerned that overly restrictive lab analyst criteria may have a negative impact on lab
capacity and also analytical costs. That could ultimately disrupt implementation of the entire LT2ESWTR
if the problem became widespread. While analyst experience is a critical factor in achieving good
recovery for the Cryptosporidium methods, the criteria used needs to be reasonable. The analytical
methods themselves provide adequate criteria. This could be backed up by proficiency testing if necessary
to alleviate any concern about unqualified analysts jeopardizing the integrity of the sample results.
Response: See Response 1812.
EPA Letter ID: 707
Comment ID: 14827
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: 4. Request for Comment on laboratory approval requirements
Comment: Analyst experience under the LT2ESWTR for performance of the IMS procedure should be
three months and the completion of 25 samples instead of 50 IMS samples presently recommended.
Samples included during the six months training should include different source water matrix spike
samples which will provide a variety of different sample types demonstrating possible interfering
factors with the IMS method. Method 1622/1623 IMS procedure should be easy for the already trained
microbiology analyst to comprehend and master the technique. However, more extensive training should
be required for protozoan microscopic detection. Even though Method 1622/1623 has made slide
observation somewhat easier than the ICR method slides, an individual must have more training on the
microscope for protozoan detection due to interfering factors that may occur. The analyst should have six
months microscopy training using the IFA method in protozoan detection prior to being allowed to sign
off on Cryptosporidium results.
It is not recommended to reduce or eliminate the analyst bench experience in processing samples using
IMS or microscopic detection using IFA by the passing of a set of proficiency samples.
A principal analyst/supervisor would be in charge of training analyst in their laboratory and should have
the background required to instruct Method 1622/1623 techniques and microscopy. As written, the
criteria for principal analyst/supervisor is acceptable.
One possible solution to the problem of maintaining analyst trained in Method 1622/1623 and microscopy
Comment Response for the L T2ESWTR 17-9 December 2005
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would request that certified laboratories have a link between each other that would allow them to send
slides to the another laboratory for confirmation of results in cases where the laboratory may lose their
primary analyst, but still have an analyst to perform the IMS procedure. Due to the lack of certified
laboratories in the nation at this time, some type of link between laboratories would assist in the assurance
that samples will be completed under the LT2ESWTR. Analyst trained to complete the IMS procedure
should not present the most problem; however, analyst performing microscopic evaluations of the slides,
would most likely cause laboratories difficulty in completing Cryptosporidium analysis.
Response: See Response 1812.
17.1.2 Comment Code 1820, State programs to approve laboratories
Individual Comments on Code 1820
EPA Letter ID: 520
Comment ID: 11662
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Laboratory Approval (pages 47734-47736)
Given the specialized nature of the work and desire to avoid duplication and confusion in the laboratory
certification process, IEPA recommends that the EPA maintain a national laboratory certification program
for Cryptosporidium through the initial and follow-up rounds of Cryptosporidium analysis.
Response: See Response 1810.
EPA Letter ID: 548
Comment ID: 12190
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: Metropolitan believes that EPA should evaluate State approval program for Cryptosporidium
to determine if they are equivalent to the Lab QA Program.
Response: See Response 1810.
EPA Letter ID: 595
Comment ID: 12602
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 17-10 December 2005
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Comment: State Implementation pages 47737-47738)
The state is concerned about the special primacy requirement for states to approve laboratories to analyze
for Cryptosporidium. This would prove to be very costly and difficult for the state as well as the
laboratories. Each state would develop it-s own procedure requiring the laboratories to deal with 50
different agencies. The state believes that the most efficient approval method will be for one agency
(EPA) to approve the laboratories for Cryptosporidium.
Response: See Response 1810.
EPA Letter ID: 603
Comment ID: 12824
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47735) Section IV. L. Laboratory Approval
Cyptosporidium analysis is highly specialized work. Currently, there are only a limited number of
laboratories qualified to do the analysis, and the vast majority, if not all, of Cryptosporidium analysis for
water systems in Washington State will be done by out of state laboratories. In the past, department staff
and water systems have had difficulties coordinating laboratory capacity for microscopic particulate
analyses (MPAs) let alone developing a certification program for MPAs. It is not efficient for the state to
develop a Lab QA program for out-of-state labs and have the QA program repeated by 48 other States.
Given the specialized nature of the work and desire to avoid duplication and confusion in the laboratory
certification process, the department recommends that the EPA maintain a national laboratory
certification program for Cryptosporidium through the initial and follow-up rounds of
Cryptosporidium analysis.
Response: See Response 1810.
EPA Letter ID: 641
Comment ID: 13615
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: State Programs to Approve Labs For Crypto Analysis - The proposed rule should be changed
to require all laboratories to be approved by the EPA Lab Approval Program (and for that lab approval to
apply for the first round of LT2 for both the large and small utilities) and NOT include an -equivalent
state program- option, as these are not available at this time. For future rounds of Crypto monitoring,
equivalent state programs may be developed, but each of these programs should be evaluated by the EPA
to determine whether they are at least equivalent to the EPA Lab Approval program. Further, no State
programs (whether now or in the future) should be allowed to supercede the EPA Lab Approval program.
Lastly, all State approval programs should be required to include reciprocity with other states (since they
will be EPA approved and will be replacing the EPA approval, which applies to all states). Certification
programs, especially those involving laboratory audits and proficiency testing, are quite expensive.
Without reciprocity, laboratories would need to pursue certification in multiple states for there to be
adequate laboratory capacity in the future, which would be a financial hardship (and might compromise
contracts already in place).
Comment Response for the LT2ESWTR 17-11 December 2005
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Response: See Response 1810.
EPA Letter ID: 711
Comment ID: 16573
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 10. Laboratory Approval [47735, Cl -C3]
- For Crypto analyses under the LT2, EPA proposes to approve laboratories that have passed a quality
assurance evaluation under EPA-s Laboratory Quality Assurance Evaluation Program (Lab QA Program)
for Analysis of Crypto in Water (described in 67 FR 9731, March 4, 2002) (USEPA 2002). If States adopt
an equivalent approval process under State laboratory certification programs, then systems can use
laboratories approved by the State.
Comment: We agree with the proposal that if States adopt an equivalent approval
process under State laboratory certification programs, then systems can use laboratories approved by the
State for Crypto analysis.
Response: See Response 1810.
17.1.2.1 Comment Code 1821, How to demonstrate equivalence
to federal program
Individual Comments on Code 1821
EPA Letter ID: 437
Comment ID: 10617
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: Page 47735. IV. L. Laboratory Approval. State Programs to Approve Laboratories
for Cryptosporidium Analysis.
EPA must evaluate State Approval programs to determine if they are equivalent to the Lab QA Program.
Response: See Response 1810.
EPA Letter ID: 514
Comment ID: 11548
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment Response for the LT2ESWTR 17-12 December 2005
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Comment: State Approval Programs: EPA should most definitely evaluate State Approval programs to
determine if they are equivalent to the current Lab QA Program.
The elements listed in this document that would constitute an equivalent State approval program for
Cryptosporidium analyses are very satisfactory and have worked well to produce an excellent Lab QA
Program for these analyses. In regard to the expectation that States will adopt the approval program for
Cryptosporidium is not realistic. Most States would not have the resources (both technical and financial)
to adopt such a program. We believe the Lab QA Program for the highly specialized Cryptosporidium
analyses should remain under the auspices of EPA during the duration of the LT2ESWTR.
Response: See Response 1810.
EPA Letter ID: 678
Comment ID: 14721
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 17. The EPA requests comment on State laboratory approval process minimum criteria
Comment: The EPA should evaluate State approval program for Cryptosporidium to determine if they are
equivalent to the Lab QA Program.
Response: See Response 1810.
EPA Letter ID: 711
Comment ID: 16576
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 11. EPA requests comment on the laboratory approval requirements proposed today, [47735,
C3, 47736, Cl-2]
- Minimum qualifications for Crypto analysts
- State laboratory approval process minimum criteria
Comment: EPA should evaluate State approval program for Cryptosporidium to
determine if they are equivalent to the Lab QA Program.
Response: See Response 1810.
17.1.3 Laboratory disapproval process
Summary of Issues
Comments were received regarding the status of a laboratory's certification if they fail an ongoing
proficiency testing (OPT) test, receipt of additional OPT samples if that occurs, and when those OPT
Comment Response for the LT2ESWTR 17-13 December 2005
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samples will be received.
Response to Code 1822
Ongoing Proficiency Testing
EPA has stated the procedure that will be followed if a laboratory fails an OPT test in the LT2ESWTR
Microbial Laboratory Guidance Manual. If a laboratory fails to meet the precision or recovery criteria for
a set of OPT samples, the laboratory will be shipped a second set of samples. The laboratory's status
changes to "conditional" but they are still permitted to analyze samples under LT2ESWTR. If the
laboratory's next set of OPT data are acceptable, the laboratory will be returned to "approved" status. If a
laboratory fails the second set of OPT samples (two sets of OPTs in a row), the laboratory will be
disapproved for analysis of LT2ESWTR samples and must get additional training. The laboratory must
consult with EPA regarding the level and type of training required, and must submit to EPA proof of this
training upon completion. If the laboratory's training is acceptable, the laboratory must repeat the Initial
Proficiency Test (IPT) test before being re-approved.
Individual Comments on Code 1822
EPA Letter ID: 614
Comment ID: 12972
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: * A few questions that arise about approved laboratories are: What happens to a laboratory's
certification if they should fail an ongoing proficiency-testing (OPT) sample? Will they be given another
set of, samples to analyze? Will they need to wait 4 months for the next set to be sent before they can
analyze samples and produce acceptable data?
Response: See Response 1822.
17.2 Cryptosporidium Laboratory Capacity
Summary of Issues
The majority of these comments state concern for the fact that there will not be sufficient State or
commercial laboratory capacity available to handle the number of samples that must be analyzed per
month once the rule comes into effect (approx. 2,000 samples/month). Similarly, many commenters stated
that they are not confident that the data management software will be able to effectively handle the large
amount of data reporting that will occur during this time. The commenters referenced the FACA
agreement (Agreement in Principle) which states that the compliance schedule for LT2ESWTR will be
tied to the availability of sufficient analytical capability for Cryptosporidium at approved laboratories and
the availability of data management software. If either is unavailable, implementation of the LT2ESWTR
compliance schedules ought to be delayed. Some of the commenters recommended that EPA implement a
staggered approach for utilities to ease the number of samples per month that laboratories will have to
analyze; only one comment disagreed with a staggered approach. One commenter stated that from a
business perspective, laboratories would probably rather go to the expense of hiring personnel and
gearing up for sample analysis if the period of sampling was spread over six years rather than two years.
Comment Response for the LT2ESWTR 17-14 December 2005
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Several commenters were concerned that the short implementation period would not allow for sufficient
training of laboratory personnel which could result in poor data reporting abilities.
Response to Code 1830
Determination and availability of Lab capacity upon implementation of the rule
Many commenters were concerned that the capacity at Cryptosporidium analytical laboratories would not
be sufficient for the proposed implementation schedule. Commenters noted that the proposed rule
schedule had a break of 18 months between the end of large PWS Cryptosporidium monitoring and the
start of small PWS Cryptosporidium monitoring and thought that this break would discourage laboratories
from making investments to improve capacity. Other commenters stated that excess laboratory capacity
exists and that upon indication that a final rule is imminent, commercial laboratories will hire staff to
handle the expected number of samples. Laboratories will, however, need time to train analysts. EPA
recognizes the concern with ensuring that capacity at Cryptosporidium laboratories will be sufficient.
Through EPA's laboratory approval program (described in section IV.K), the Agency has evaluated
capacity at Cryptosporidium laboratories. Based on information provided by laboratories, EPA believes
that current capacity at Cryptosporidium laboratories will be sufficient for the monitoring that PWSs
serving at least 100,000 people will begin six months after the rule is effective. EPA expects that
commercial laboratories will increase capacity as needed to serve the demand of smaller PWSs that begin
monitoring later. Approximately six months are required to train Cryptosporidium analysts.
Consequently, the staggered compliance schedule should allow time for laboratories to hire and train staff
as necessary. In addition, with the compliance schedule in today's final rule, no break exists between the
time that large PWSs end and small PWSs begin Cryptosporidium monitoring. Thus, EPA has eliminated
this potential disincentive to laboratories investing in capacity. Based on this information, EPA does not
believe that a formal published determination of lab capacity is needed.
However, EPA will continue to monitor laboratory capacity and the ability of PWSs to contract with
laboratories to meet their monitoring requirements under the LT2ESWTR. The Agency will assist with
implementation of the rule to help maximize the use of available laboratory capacity by PWSs. If
evidence emerges during implementation of the rule that PWSs are experiencing problems with
insufficient laboratory capacity, the Agency will undertake appropriate action at that time.
Problems with data reporting and submitting large data sets electronically
EPA disagrees that the electronic data reporting for the larger utilities will be problematic and unreliable.
EPA has ensured that the LT2ESWTR data system has been fully tested and deployed prior to finalizing
the rule. During development of the data system, EPA has involved stakeholders in a joint requirements
workgroup, which has made recommendations for data system characteristics and has participated in data
system testing. EPA has developed guidance and other training materials for PWSs, States, and
laboratories on how to use the data system and will provide technical assistance on an ongoing basis to
data system users. EPA believes these steps will help to avoid problems that stakeholders experienced
with data systems for earlier rules.
Time required for laboratories to hire and train personnel to perform Cryptosporidium analysis
EPA disagrees that there will not be sufficient time for State and commercial laboratories to hire and train
personnel to perform Cryptosporidium analysis. The staggered schedule for compliance based on the size
of the utility will allow for more time for laboratories to prepare for sample analysis. Today's rule
eliminates the break between the time when large utilities finish monitoring and small utilities begin
monitoring for Cryptosporidium. The rule states the following with respect to time for analyst hiring and
Comment Response for the LT2ESWTR 17-15 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
training: EPA believes that Cryptosporidium laboratory capacity will be sufficient to support the
compliance schedule in today's final rule. Through EPA's laboratory approval program (described in
section IV.K), EPA evaluates capacity at Cryptosporidium laboratories. Current capacity at
Cryptosporidium laboratories will be sufficient for the monitoring that PWSs serving at least 100,000
people will begin six months after rule promulgation. Currently, 37 labs are pending approval and 21 have
stated that the laboratory will take LT2 samples from utilities. EPA expects that commercial laboratories
will increase capacity as needed to serve the demand of smaller PWSs that begin monitoring later.
Approximately six months are required to train Cryptosporidium analysts. Consequently, the staggered
compliance schedule will allow time for laboratories to hire and train staff as necessary. In addition, with
the compliance schedule in today's final rule, no break exists between the time that large PWSs end and
small PWSs begin Cryptosporidium monitoring. Thus, EPA has eliminated this potential disincentive to
laboratories investing in capacity. Figure IV.K-1 of the preamble shows projected demand for
Cryptosporidium sample analysis by PWSs during LT2ESWTR source water monitoring. The projections
in Figure IV.K-1 are based on the number of PWSs in different size categories (corresponding to the
staggered implementation schedule) that treat surface water or GWUDI, along with estimates of the
percentage of PWSs that will sample for Cryptosporidium once or twice per month (USEPA 2004h).
Suggestion of staggered approach to monitoring based on utility size
EPA appreciates comments that suggested a staggered approach to monitoring based on utility size in
order for laboratories to gradually build up capacity for Cryptosporidium sample analysis. EPA also
appreciates the suggestion to grandfather data which is acceptable as stated in the rule.
Samples per analyst per week
Estimates as to how many samples may be effectively run per analyst per week have been received from a
few labs. The range of estimates is from 10 to 30 samples per analyst per week. EPA has used 15 samples
per analyst per week as a reasonable estimate.
Individual Comments on Code 1830
EPA Letter ID: 527
Comment ID: 10845
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We are pleased the agency has made a commitment to this provision in the proposed rule:
The Agency is monitoring sample analysis capacity at approved laboratories
through the Lab QA Program, and does not plan to implement LT2ESWTR
monitoring until the Agency determines that there is adequate laboratory
capacity. (68 FR 47735).
In past rules, required new databases or modified data management systems were not in place or
experienced serious problems prior to rule promulgation. Examples include both the Information
Collection Rule and the Unregulated Contaminants Monitoring Rule.
Based on our past experiences, we feel very strongly that adequate laboratory capacity and availability of
data management software is fundamental to successful implementation of the rule, and we are very
Comment Response for the LT2ESWTR 17-16 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
concerned that the total capacity needed may not be in place when needed. Utility and commercial
laboratories that process EPA Method 1622 /1623 indicate that it is unreasonable to develop additional
capacity for a short duration of time.
Response: See Response 1830.
EPA Letter ID: 527
Comment ID: 10845
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We are pleased the agency has made a commitment to this provision in the proposed rule:
The Agency is monitoring sample analysis capacity at approved laboratories
through the Lab QA Program, and does not plan to implement LT2ESWTR
monitoring until the Agency determines that there is adequate laboratory
capacity. (68 FR 47735).
In past rules, required new databases or modified data management systems were not in place or
experienced serious problems prior to rule promulgation. Examples include both the Information
Collection Rule and the Unregulated Contaminants Monitoring Rule.
Based on our past experiences, we feel very strongly that adequate laboratory capacity and availability of
data management software is fundamental to successful implementation of the rule, and we are very
concerned that the total capacity needed may not be in place when needed. Utility and commercial
laboratories that process EPA Method 1622 /1623 indicate that it is unreasonable to develop additional
capacity for a short duration of time.
Response: See Response 1830.
17.2.1 Need for EPA estimate
Response to Code 1831
See Response 1830.
Individual Comments on Code 1831
EPA Letter ID: 411
Comment ID: 10563
Commenter: Devon Cole,, Utah Department of Health Laboratory
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 17-17 December 2005
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Comment:
Specific holding times are listed for each stage of sample analysis, cumulatively extending sample
analysis over a 14 day period. Does EPA have any guidelines/estimates as to how many samples may be
effectively run per analyst per week? At this time, our weekly capacity is about 12 samples per analyst
per week.
Response: See Response 1830.
EPA Letter ID: 419
Comment ID: 10502
Commenter: Billy Turner, President, Columbus Water Works
Commenter Category: Regulated Community (Utilities)
Comment:
2) EPA should have included an assessment of laboratory capacity in the supporting documentation and
preamble discussion for the LTT2ESWTR. Having failed to do so, EPA is obligated under the Agreement
in Principal to publish in the Federal Register a formal finding with supporting documentation that there
is adequate laboratory capacity prior to promulgation of LT2ESWTR. This finding should contain
information and analysis that substantiates the Agency's view regarding available laboratory capacity; and
the Agency's finding should itself be subject to notice and comment prior to the promulgation of
LT2ESWTR.
Response: See Response 1830.
EPA Letter ID: 420
Comment ID: 14090
Commenter: Eddie Partlow, General Manager, THE OLD HICKORY UTILITY DISTRICT
Commenter Category: Regulated Community (Development): Housing, FEEP, NAHB
Comment: An assessment of laboratory capacity should have been included in the supporting
documentation and preamble discussion for the LT2ESWTR. Since EPA did not do this, EPA should be
required under the Agreement in Principle to publish in the Federal Register a formal finding with
supporting documentation that there is adequate laboratory capacity prior to promulgation of
LT2ESWTR. This finding should contain information and analysis that substantiates EPA's view
regarding available laboratory capacity and EPA should be subject to notice and comment prior to the
promulgation of LT2ESWTR.
There should be a meaningful discussion of available laboratory capacity to support the LT2ESWTR
Cryptosporidium monitoring. This capacity was identified in the Stage 2 M/DBP Agreement in Principle
as a pre-requisite to implementing the LT2ESWTR (65 FR 83017).
Response: See Response 1830.
Comment Response for the LT2ESWTR 17-18 December 2005
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EPA Letter ID: 430
Comment ID: 10594
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: be out-sourcing many samples to a contract lab. Water utilities must not be held responsible
for meeting impossible schedules and falling into noncompliance if analytical capacity or data
management software is unavailable. Hence, prior to issuing final rules, EPA should publish a formal
determination in the Federal Register open for comments that laboratory capacity and data management
software are available. If unavailable, the final rules should be delayed or modified to
Response: See Response 1830.
EPA Letter ID: 439
Comment ID: 10748
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: The EPA should conform to requirements outlined in the Agreement in Principle
to ensure that water systems do not fall into non-compliance (water systems should not be held
responsible if there are an insufficient number of contract laboratories available to provide timely,
efficient Cryptosporidium analyses and it would be very difficult for every water system to meet a
mandated sampling schedule for these few laboratories.) The final rule should be delayed until
lab capacity has been demonstrated and until all data management software has been proven to be
functional. EPA should have a database for the submitted results that has been beta-tested and is in-place
prior to rule implementation.
Response: See Response 1830.
EPA Letter ID: 440
Comment ID: 10802
Commenter: Gary Hum, Director of Source & Treatment, Central Arkansas Water
Commenter Category: Regulated Community (Utilities)
Comment: 3. Laboratory availability: An assessment should be made to determine
that there are sufficient laboratories available to perform the required
cryptosporidium monitoring required of the utilities. The assessment should
also be subject to notice and comment prior to promulgation of LT2ESWTR.
Response: See Response 1830.
EPA Letter ID: 451
Comment ID: 14160
Commenter: Eric Abrams, Superintendent, McMinnville Water and Light
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 17-19 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
Comment: Comment #2: As stated above we use outside labs to perform most of our required testing.
Adequate laboratory capacity is critical to us especially if issues mentioned in comment #1 stay as
proposed. McMinnville Water and Light would like the EPA to consider making a finding that
substantiates that there is adequate laboratory capacity which should be subject to notice and comment
prior to promulgation of the LT2ESWTR.
Response: See Response 1830.
EPA Letter ID: 453
Comment ID: 10947
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: Assuring adequate laboratory capacity is a pre-requisite to implementation according to the
Agreement in Principle.
Response: See Response 1830.
EPA Letter ID: 461
Comment ID: 10989
Commenter: Greg Merrigan, Chair, South Dakota Section of the American Waterworks Association
(SDAWWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Laboratory Capacity - EPA has not included an assessment of the available laboratory
capacity to meet the requirements of the LT2ESWTR. EPA should, prior to the promulgation of the
LT2ESWTR, assess the availability of labs to perform the samples that will be generated and publish this
information. EPA should take into account that some systems may request analysis of additional samples,
other than those required, for their own information (such as finished water). They may also request
analysis of Giardia at the same time.
If there fails to be adequate laboratory capacity there may be some systems that are caught in the Failure
To Complete Monitoring requirement and thus be forced to meet the treatment requirements of bin 4.
Response: See Response 1830.
EPA Letter ID: 471
Comment ID: 11108
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: unavailable. To insure that this issue is not ignored, we suggest that the EPA, prior to issuing
the final rule, publish a formal determination in the Federal Register open for comments that laboratory
capacity and data management software are available. If unavailable, the final rules should be delayed or
Comment Response for the LT2ESWTR 17-20 December 2005
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modified to appropriately stretch out time frames so that the available capacity is sufficient. Additionally,
both final rules should specifically provide for
Response: See Response 1830.
EPA Letter ID: 471
Comment ID: 11165
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: unavailable. To insure that this issue is not ignored, we suggest that the EPA, prior to issuing
the final rule, publish a formal determination in the Federal Register open for comments that laboratory
capacity and data management software are available. If unavailable, the final rules should be delayed or
modified to appropriately stretch out time frames so that the available capacity is sufficient. Additionally,
both final rules should specifically provide for
Response: See Response 1830.
EPA Letter ID: 472
Comment ID: 11144
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: 2. Concern: The August 11 proposal fails to provide any significant discussion of available
laboratory capacity. Laboratory capacity is essential to support the LT2ESWTR required
Cryptosporidium monitoring. Laboratory capacity was identified in the Stage 2 M/DBP Agreement in
Principle as a pre-requisite to implementing the LT2ESWTR (65 FR 83017).
Remedy: EPA should have included an assessment of laboratory capacity in the preamble for the
LT2ESWTR. Since EPA failed to provide this assessment, EPA is duty-bound under the Agreement in
Principal to publish in the Federal Register supporting documentation of adequate laboratory capacity
prior to promulgation of LT2ESWTR. This assessment should substantiate the Agency-s position
regarding available laboratory capacity. The Agency-s assessment should be subject to notice and
comment prior to the promulgation of LT2ESWTR.
Response: See Response 1830.
EPA Letter ID: 479
Comment ID: 11221
Commenter: Brad Joyner, Superintendent, Town of Forest City WTP
Commenter Category: Local Government
Comment: The proposed laboratory capacity to support the LT2ESWTR Cryptosporidium monitoring
needs to be more specific. The EPA needs to insure the assessment of laboratory capacity is available
Comment Response for the LT2ESWTR 17-21 December 2005
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prior to promulgation and provide documented information to support the capacity. The LT2ESWTR also
needs to identify more data findings in regards to treatment techniques used for removal of
Cryptosporidium and credit the performance therein accordingly.
Response: See Responses 710(a) and 1830.
EPA Letter ID: 483
Comment ID: 11259
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment: - In regards to PWS compliance with the monitoring and reporting requirements, EPA should
conform to requirements of the Agreement in Principle so that water systems are not held responsible for
meeting impossible schedules and falling into noncompliance if analytical capacity or data management
software is unavailable. EPA should, prior to issuing final rules, publish a formal determination in the
Federal Register open for comments that laboratory capacity and data management software are available.
If unavailable, the final rules should be delayed or modified to appropriately stretch out time frames so
that the capacity available is sufficient. EPA should have a database that has been
Response: See Response 1830..
EPA Letter ID: 496
Comment ID: 10688
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: To ensure that this issue is not ignored, EPA should, prior to issuing final rules, publish a
formal determination in the Federal Register open for comments that laboratory capacity and data
management software are available. If unavailable,
Response: See Response 1830.
EPA Letter ID: 504
Comment ID: 11346
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: 2. EPA is obligated under the Agreement in Principle to publish in the Federal Register a
formal finding with supporting documentation to demonstrate adequate laboratory capacity for the
required Cryptosporidium and E. coli monitoring prior to promulgation of LT2ESWTR. The Agency-s
demonstration of available laboratory capacity must be subject to public notice and comment through a
Notice of Data Availability (NODA) prior to the promulgation of LT2ESWTR.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-22 December 2005
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EPA Letter ID: 504
Comment ID: 11355
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: approved laboratory (40CFR 141.706). In the M/DBP AIP, EPA is committed to verify that
adequate lab capacity is available to permit implementation of the rule (AIP § 2,1 la (FR 65(251):83015).
However, to the best of our knowledge, no mechanism for assurance of lab capacity availability has been
provided in the rule.
EPA must, as a prerequisite to implementation of LT2, demonstrate through a Notice of Data Availability
(NODA) that the existing certified labs available at the time of rule implementation are capable of
performing the required number of analyses within the limited time provided in the regulation.
Response: See Response 1830.
EPA Letter ID: 506
Comment ID: 10728
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: The Cleveland Division of Water (CWD) is concerned that commercial laboratories will not
wish to invest in additional personnel and training for a relatively short period of monitoring time with a
five year gap before the next round. USEPA should perform a survey of approved laboratories and their
capacities and compare it to the projected number of samples anticipated from water systems to determine
if there really is sufficient laboratory capacity. A notice in the Federal Register notifying the regulated
community of the findings of the survey should then be issued, prior to the scheduled start of monitoring.
If laboratory
Response: See Response 1830.
EPA Letter ID: 507
Comment ID: 11463
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: capacity capable of performing monthly Cryptosporidium analyses. We would suggest that
before the final rule is issued, EPA ascertain that commercial laboratory capabilities are available and can
meet the demands of this rule. If
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-23 December 2005
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EPA Letter ID: 513
Comment ID: 11523
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: Prior to publication of the final rule, EPA should publish in the Federal Register a
determination that laboratory capacity exists and data management software capable of handling the
demands of the new rule has been developed and adequately tested. This would be consistent with the
requirements of the Stage 2 M-DBP Agreement in Principle (Federal Register, December 29, 2000).
Response: See Response 1830.
EPA Letter ID: 520
Comment ID: 11593
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1833 i. Need to delay or modify rule implementation
schedule
Comment: Cryptosporidium at the same time. EPA must ensure that adequate laboratory capacity is
available or delay implementation of the rule in accordance with the
FACA Agreement in Principle.
Response: See Response 1830.
EPA Letter ID: 527
Comment ID: 10846
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We recommend that EPA make a formal determination whether or not sufficient
capacity exists through a NODA at least six months before the rules are to be finalized. Additionally,
based on experience with the ICR and in keeping with
Response: See Response 1830.
EPA Letter ID: 527
Comment ID: 10846
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the L T2ESWTR 17-24 December 2005
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Comment: We recommend that EPA make a formal determination whether or not sufficient
capacity exists through aNODA at least six months before the rules are to be finalized. Additionally,
based on experience with the ICR and in keeping with
Response: See Response 1830.
EPA Letter ID: 534
Comment ID: 12011
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Other EPA Comment Codes and Descriptions: 372 2. Electronic data reporting and review system
Comment: this mean -grandfathered- data is invalid? Due to the timeframes, the number of
water systems affected, and the potential for significant capital investment, it is imperative that EPA
ensures the laboratory and data management capabilities are in place so that water systems have a
reasonable potential to comply.
Response: See Responses 371(C) and 1830.
EPA Letter ID: 536
Comment ID: 11800
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Cryptosporidium at the same time. EPA must ensure that adequate laboratory capacity is
available or delay implementation of the rule in accordance with the FACA Agreement in Principle.
Further, we were unable to determine if the state
Response: See Response 1830.
EPA Letter ID: 540
Comment ID: 12085
Commenter: Manja Blazer, Government Affairs and Market Development Manager, IDEXX
Laboratories
Commenter Category: Independent Laboratories
Comment: IDEXX urges USEPA to take the steps necessary to ensure that laboratory capacity will exist
to meet these analytical demands. The above monitoring requirements are essential for the success of this
regulation, which should include follow-up monitoring as mentioned above. Clearly, there will be a surge
in demand for Cryptosporidium analysis during the years of compliance monitoring, and then the
analytical market is expected to decline (unless follow-up monitoring is required). It is unclear whether
laboratories will gear up to provide services for Cryptosporidium testing when the market demand is only
expected to last 1 or 2 years.
Comment Response for the L T2ESWTR 17-25 December 2005
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Response: See Response 1830.
EPA Letter ID: 556
Comment ID: 12046
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: B. Monitoring
1. Laboratory Capacity
Basic Principle from the FACA Discussions: Monitoring is central to the undertaking of the rule. If
adequate laboratory capacity is not available to undertake monitoring, the implementation schedule for
the rule will be delayed until capacity is adequate.
Discussion: Because monitoring is central to the rule, AMWA feels very strongly that laboratory capacity
must be available prior to rule implementation. The Information Collection Rule (ICR) was a similar,
albeit much smaller, effort to gather data. The ICR involved sampling by approximately 300 water
systems. The problems associated with monitoring were significant and involved schedule delays,
database problems, laboratory errors, missed samples, disallowed samples and laboratory capacity issues.
AMWA expects the proposed monitoring undertaking will experience similar or greater problems because
of the size and complexity of the undertaking. That is why AMWA stressed the need for a -Laboratory
Capacity- provision within the Agreement in Principle.
Commercial and utility laboratories that process EPA Method 1622/1623 indicate that it is unreasonable
to develop additional capacity for a short duration of additional monitoring. Therefore, this is a very real
question that must be addressed.
Recommendation: Laboratory capacity is so central to the agreement and ultimate success of the rule that
it calls for special consideration. AMWA recommends that at least six months prior to finalizing the
LT2ESWTR and accompanying Stage 2 DBPR, EPA issue a NODA outlining available laboratory
capacity. The reason for considering both rules is because of simultaneous compliance. At that time the
Agency will know how many laboratories they have approved and should be able to survey those
laboratories to determine whether or not adequate capacity is available. If capacity is not available, the
monitoring schedule should be delayed as specified in the agreement.
Response: See Response 1830.
EPA Letter ID: 560
Comment ID: 14976
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: implementation. Failure to provide an estimate of laboratory capacity is a failure to fulfill the
Agency-s responsibility as outlined in the Agreement in Principle. American Water believes that it is
essential that the Agency provide an open and transparent process to evaluate the laboratory capacity to
support the LT2 prior to promulgation of the final rule.
Comment Response for the L T2ESWTR 17-26 December 2005
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Toward this end, American Water has attached a report on the time required for Cryptosporidium
analysis, based on its monitoring of 33 water systems using Method 1623 (American Water intends to
submit these data for grandfathering). The process used to determine the time required for sample analysis
can be used by the Agency to determine the number of analysts required to perform the projected
workload generated by the LT2 Cryptosporidium monitoring. Based on the data provided, American
Water believes that a reasonable workload is 10 samples per analyst, per week. EPA needs to determine a
reasonable workload, per analyst, per week, to assess exactly how many people will be needed to
guarantee -sufficient analytical capacity at approved laboratories.- The assessment should allow for
reasonable expectations for vacations, sickness, personnel turnover, and other downtime.
Failure to accurately assess the workload will result in problems with the implementation of the
monitoring schedule, water utility non-compliance, doubts about data quality, and ultimately delays in
implementation of the Rules. The implementation of the Information Collection Rule was delayed and
once ongoing, plagued by data quality issues. Both issues resulted in part from a lack of adequate skilled
laboratory capacity. The ICR required systems serving more than 100,000 persons to provide data
(n=330), however, LT2 will require more than 2,362 PWS greater than 10,000 population served to
monitor within 6 months of final rule promulgation, and another 12,202 PWSs to start monitoring E. coli
within 3 years of promulgation. Currently there are 19 approved protozoan method laboratories.
EPA needs to develop a Notice of Data Availability prior to promulgation of the final rule that includes
the analysis of laboratory capacity and specifically, the capacity of the laboratory analysts.
Response: See Response 1830.
EPA Letter ID: 562
Comment ID: 12287
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. EPA is obligated under the Agreement in Principle to publish in the Federal Register a
formal finding with supporting documentation to demonstrate adequate laboratory capacity for the
required Crytosporidium and E. coli monitoring prior to promulgation of LT2ESWTR. The agency-s
demonstration of available laboratory capacity must be subject to public notice and comment through a
Notice of Data Availability (NODA) prior to the promulgation of LT2ESWTR.
Response: See Response 1830.
EPA Letter ID: 562
Comment ID: 12294
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. The proposal briefly mentions laboratory capacity but does not include a demonstration of
adequate laboratory capacity for the required Crytosporidium and E. coli monitoring; and
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-2 7 December 2005
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EPA Letter ID: 562
Comment ID: 12298
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1. An assessment of laboratory capacity,
2. A capacity development plan or a plan to extend the sampling period to accommodate the limited
capacity, if the agency deems there is inadequate laboratory capacity,
3. Provision of an adequate period of time for utilities to prepare the sampling plan, and an adequate
period for the primacy agency (EPA regional offices or state primacy agencies) to review and approve the
plan,
4. A description of the status and adequacy of the data management system, and
Response: See Response 1830.
EPA Letter ID: 562
Comment ID: 12346
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The proposed rule does not discuss substantively discuss anywhere in the text the availability
of commercial laboratory capacity to implement the LT2ESWTR monitoring. Documentation of this
capacity is particularly important given the dependence of both the LT2ESWTR and Stage 2 DBPR
implementation timelines on the availability of adequate commercial laboratory capacity to support rule
implementation.
While EPA acknowledges laboratory capacity as an important issue, the agency fFails to provide an
estimate of laboratory capacity. The agency must ensure that adequate laboratory capacity exists; failure
to do so is a breach of the Agreement in Principle and as such, is not in keeping with the Administrative
Procedures Act-Federal Advisory Committee Act, under which the Stage 2 M/DBP FACA was organized.
AWWA believes that the agency must provide a robust appraisal of laboratory capacity to support
LT2ESWTR prior to promulgation of the final rule. Moreover, AWWA believes that the agency-s
estimate, methodology, and analysis that substantiate that estimate should be made available for public
comment through a Notice of Data Availability (NODA) prior to the promulgation of LT2ESWTR. As is
clearly stated in the Agreement in Principle, EPA-s laboratory capacity estimate should reflect both
Cryptosporidium oocyst and E. coli sampling.
The agency-s duty to develop a robust estimate of laboratory capacity is not only a requirement of the
Agreement in Principle, but it is also a sound recommendation for any rule where implementation of
compliance requirements is tied to monitoring provisions. Recent experience with the Information
Collection Rule provides a relevant example of how unforeseen implementation problems resulted in
prolonged delays in the data availability.* However, the ICR only applied to 297 utilities (population >
100,000) whereas the LT2ESWTR will require more than 1,3212,362 PWS (population >10,000) to
collect and report Cryptosporidium and E. coli monitoring data, and another 12,2028,322 PWSs to start
monitoring E. coli within 3 years of promulgation.**
Comment Response for the L T2ESWTR 17-28 December 2005
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Response: See Response 1830.
EPA Letter ID: 562
Comment ID: 12347
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: *61 FR 24353, May 16, 1996
Response: See Response 1830.
EPA Letter ID: 562
Comment ID: 12348
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Currently, 19 laboratories are approved for the protozoan method. Of those 19 laboratories,
only 7 are commercial labs. Another way to look at capacity is, if every PWS only had one water
treatment plant (an underestimate) six months into the rule implementation, each of the commercial
laboratories would have to process almost approximately half as many samples per month as were
processed each month by all of the laboratories that supported the ICR. Neither utilities nor EPA want to
see this monitoring component fail and having adequate laboratory capacity is essential to preventing
such a failure.
Response: See Response 1830.
EPA Letter ID: 562
Comment ID: 12349
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3.4 Notice of Data Availability
AWWA recommends that the agency publish a Notice of Data Availability (NODA) that includes these
subjects:
1. An assessment of laboratory capacity,
2. A capacity development plan or a plan to extend the sampling period to accommodate the limited
capacity, if the agency deems there is adequate laboratory capacity,
3. Provision of an adequate period of time for utilities to prepare the sampling plan, and an adequate
period for the primacy agency (EPA regional offices or state primacy agencies) to review and approve the
plan,
4. A description of the status and adequacy of the data management system, and
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-29 December 2005
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EPA Letter ID: 562
Comment ID: 12352
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: **2000 Community Water System Survey, Table 1, SDWIS, Surface Water Systems (Surface
Water Systems)
Response: Not a comment. This is a source footnote relating to a separate comment.
EPA Letter ID: 562
Comment ID: 12356
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 710 A. Microbial Toolbox General Comments
Comment: Cryptosporidium oocyst monitoring / reporting. While a number of outstanding issues still
remain, two specific issues from the stakeholder draft remain a fundamental concern. The two issues are:
(1) the absence of an assessment of laboratory capacity and (2) the agency-s failure to craft a fair and
implementable microbial toolbox.
3.5.3 UV Representatives
AWWA remains concerned that some representatives to the Stage 2 M/DBP FACA process, with clear
financial interests in a single technology (ultraviolet light), participated in the FACA as advocates of this
single technology. More importantly, an alternate representative participated in the FACA process
without disclosing that his company was simultaneously undertaking an
Response: See Response 710a. EPA believes that the toolbox options provide a broad range of
alternatives to meet LT2ESWTR treatment requirements and provide viable options other than UV
disinfection for most systems. Also see response 1830 regarding lab capacity.
EPA Letter ID: 562
Comment ID: 12360
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: the LT2ESWTR provisions are being developed. If the agency proceeds to promulgate the
final rule as proposed, AWWA believes that such action is contrary to law, arbitrary and capricious, and
an abuse of discretion for the following reasons:
2. The agency will violate the Administrative Procedures Act (APA) if the agency does not ensure
adequate laboratory capacity for Cryptosporidium and E. coli monitoring as required by the Agreement in
Principle.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-3 0 December 2005
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EPA Letter ID: 580
Comment ID: 12629
Commenter: Bruce Aptowicz, Chairman, Water Utility Council of the Pennsylvania American
Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. EPA is obligated under the Agreement in Principle to publish in the Federal Re~stera
formal finding with supporting documentation to demonstrate adequate laboratory capacity for the
required Cytosporidium and E. coli monitoring prior to promulgation of LT2ESWTR. The agency-s
demonstration of available laboratory capacity must be subject to public notice and comment through a
Notice of Data Availability (NODA) prior to the promulgation of LT2ESWTR.
Response: See Response 1830.
EPA Letter ID: 586
Comment ID: 12200
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: demand. It is our understanding that the need for an evaluation of laboratory capacity was
identified in the Stage 2 DDBP Agreement in Principal (65 FR 83017).
EPA is obligated to publish a formal finding of adequate laboratory capacity, with supporting
documentation, in the Federal Register prior to promulgation of the LT2ESWTR.
Response: See Response 1830.
EPA Letter ID: 589
Comment ID: 13053
Commenter: Lawrence Libeu, President, The Western Coalition of Arid States
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Issue 1: Lab Capacity and Data Management It is important that the EPA follow obligations
under the Agreement in Principal and publishes in the Federal Register supporting documentation that
adequate laboratory capacity exits prior to fmalization of the LT2ESWTR. This supporting
documentation must be open for public comment. Both the LT2ESTWR and Stage 2 Disinfection should
provide a means of delaying implementation if it is shown that laboratory capacity is insufficient for
systems to complete monitoring requirements. It is also imperative that EPA has an operational database
in place prior to rule promulgation. This database must be beta-tested prior to rule implementation.
Response: See Response 1830.
EPA Letter ID: 590
Comment ID: 12031
Commenter: Steve Robbins, General Manager-Chief Engineer, Coachella Valley Water District
Commenter Category: Regulated Community (Utilities)
Comment Response for the L T2ESWTR 17-31 December 2005
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Comment: The Stage 2 Microbial Disinfection By-product (Stage 2 M/DBP) Federal Advisory
Committee (Stage 2 M/DBP FACA) recognized the considerable uncertainties in the available
information and reflected those uncertainties in a limited but proactive set of recommendations. EPA has,
to a great extent, also recognized those uncertainties. However, there is a major aspect of the LT2ESWTR
proposal that gives great concern because it is inconsistent with the Stage 2 M/DBP Agreement in
Principle. That aspect is laboratory capacity.
1. Laboratory capacity to support the Cryptosporidium and E. coli monitoring provisions of § 141.701 of
the proposal has not been adequately taken into account.
2. This District believes that EPA should conduct a full assessment of laboratory capacity and publish a
Notice of Data Availability, allowing a reasonable opportunity for public comment, prior to promulgating
LT2ESWTR. This action need not delay rule promulgation; but it is essential that EPA not promulgate a
rule with expectations for implementation that cannot be reasonably achieved simply because of a
fundamental issue like laboratory capacity.
Response: See Response 1830.
EPA Letter ID: 625
Comment ID: 13136
Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Before the rule is implemented, USEPA should ensure that sufficient laboratory capacity is
available as well as provide validation that these providers generate quality data. As stated by others,
there is little impetus for a private laboratory to develop additional capacity for a short-term monitoring
program. Therefore, USEPA, by subsidy, if necessary, should ensure analytical capacity and quality is
available. Software used in this program should be beta-
Response: See Response 1830.
EPA Letter ID: 630
Comment ID: 13057
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: At present EPA appears to assume that these new monitoring requirements will be met by an
expanded capacity by private laboratories as well as utility laboratories. However, it is unreasonable to
assume that will be a significant increase in the monitoring capacity of either private or utility laboratories
given the extensive costs and the short duration of the intensive monitoring requirements. In the past,
databases for data management were not in place or had problems prior to rule promulgation (e.g., the
ICR and UCMR databases - there were no clear explanation of required data elements leading to
significant compliance problems).
2. Monitoring Key Issue Analytical Capacity: It is important that EPA conform to requirements of the
Agreement in Principle so that water systems are not held responsible for meeting impossible schedules
and falling into noncompliance if analytical capacity or data management software is unavailable. To
insure that this issue is not ignored, EPA should, prior to issuing final rules, publish a formal
determination in the Federal Register open for comments that laboratory capacity and data management
Comment Response for the L T2ESWTR 17-32 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
software are available. If unavailable, the final rules should be delayed or modified to appropriately
stretch out time frames so that the capacity available is sufficient. Additionally, both final rules should
specifically provide for delaying implementation if capacity proves insufficient, or data management
software fails after the rules become effective. Additionally, EPA should have a database that has been
beta-tested, is in-place, and operational prior to rule implementation.
Response: See Response 1830.
EPA Letter ID: 643
Comment ID: 12746
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Cryptosporidium at the same time. EPA must ensure that adequate laboratory capacity is
available or delay implementation of the rule in accordance with the FACA Agreement in Principle.
Response: See Response 1830.
EPA Letter ID: 647
Comment ID: 12900
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: EPA must ensure that adequate laboratory capacity is available or delay implementation of
the rule in accordance with the FACA Agreement in Principle. In addition, the poor accuracy at the test
method for raw water samples is also a concern.
Response: See Response 1830.
EPA Letter ID: 653
Comment ID: 14065
Commenter: Tim Stefanich, Environmental Engineer, Sioux Falls Water Purification, City of Sioux Falls
Commenter Category: Local Government
Comment: Laboratory Capacity - EPA has not included an assessment of the available laboratory
capacity to meet the requirements of the LT2ESWTR. EPA should, prior to the promulgation of the
LT2ESWTR, assess the availability of labs to perform the samples that will be generated and publish this
information. EPA should take into account that some systems may request analysis of additional samples,
other than those required, for their own information (such as finished water). They may also request
analysis of Giardia at the same time.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-33 December 2005
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EPA Letter ID: 678
Comment ID: 14664
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: rule implementation. Prior to issuing the final rule, the EPA should publish for comment a
formal determination in the Federal Register that sufficient laboratory capacity and data management
software are available.
Response: See Response 1830.
17.2.2 Comment Code 1832, Adequacy of current capacity
Response to Code 1832
See Response 1830.
Individual Comments on Code 1830
EPA Letter ID: 387
Comment ID: 10546
Commenter: Anonymous387,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: The costs for monitoring for Crypto, and the issues of lab capacity, are very concerning
There are many states without labs able to do Methods 1623, and the
Response: See Response 1830.
EPA Letter ID: 408
Comment ID: 10543
Commenter: Craig Barsness, Chief Plant Operator, Shoshone Municipal Pipeline
Commenter Category: Regulated Community (Utilities)
Comment: 1) The system I work for serves approximately 22,000. We will be required to conduct
monthly monitoring of the source water for cryptosporidium. There are no labs in Wyoming certified for
method 1622 or 1623 .We currently use CH diagnostics in Love land, Colorado for our annual MPA's
(including giardia and crypto) but they are extremely busy, and we can't always schedule them when we
want. How will the limited numbers of labs be able to handle the increased sampling? I am also
concerned with the cost of these tests. At $500/sample and 24 samples, it will cost us $12,000 over two
years (not including overnight shipping).This is excessive. We must also submit a sampling schedule, in
advance, for the entire two years and collect each sample within two days of the scheduled sample date. It
is safe to say that considering how busy the labs will be, this requirement is ridiculous.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-34 December 2005
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EPA Letter ID: 413
Comment ID: 10510
Commenter: Thomas C. Sliwoski, Director of Public Works, City of Staunton, Virginia
Commenter Category: Regulated Community (Utilities)
Comment: Issue 2 Available Lab capacity
Approval pending status of EPA Methods 1622 and 1623 is dependant upon promulgation of
LT2ESWTR. The EPA Website lists only 17 laboratories having applications for approval for
Cryptosporidium counts. Since this law affects every water plant in the United States, logic would dictate
a severe shortage of approved laboratories. This should be resolved prior to final promulgation.
Response: See Response 1830.
EPA Letter ID: 414
Comment ID: 10515
Commenter: John Amodeo, General Manager and Chief Engineer, Vista Irrigation District
Commenter Category: Regulated Community (Utilities)
Comment: 1. We have already been testing for Cryptosporidium for years, but labs that can do this type
of testing are not in grand supply. I am concerned with the extra testing that my agency will have to
perform, and those agencies that will now need to undertake testing, there will not be enough qualified
labs to perform the test in a timely manner. We have had difficulties already, and it will only be worse.
Response: See Response 1830.
EPA Letter ID: 417
Comment ID: 10524
Commenter: Kenneth Brown, Authority Manager, Stroudsburg Municipal Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: There is also a "grave" concern that there is currently a lack of available laboratories to
support the monitoring requirements which will potentially increase the cost in testing to the utilities and
perhaps errors in laboratory results or reporting. EPA should make sure this is "in place" prior to the
requirements.
Response: See Response 1830.
EPA Letter ID: 430
Comment ID: 10593
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
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Comment:
Comment: Colorado Springs Utilities (PWSID # CO0121150) is concerned about laboratory capacity to
perform cryptosporidium analyses. Although Colorado Springs Utilities is a large utility, due to cost-
effectiveness, we do not perform these analyses in-house. With four surface water treatment plants of its
own as well as a fifth for another system, Colorado Springs Utilities will be out-sourcing many samples to
a contract lab. Water utilities must not be
Response: See Response 1830.
EPA Letter ID: 437
Comment ID: 10609
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: General Comment - Laboratory Capacity
BioVir Laboratories considers itself to be a high capacity laboratory with respect to Method 1622/23
testing of drinking water samples. It is our firm belief that excess industry capacity currently exists and
that, upon indication that promulgation of a Final Rule is imminent, commercial testing laboratories
can hire and train additional staff to handle the approximately 2,000 samples expected to be generated
monthly. We have provided capacity information to the EPA as part of the ongoing discussion regarding
this issue and feel that this information adequately supports our belief.
Response: See Response 1830.
EPA Letter ID: 441
Comment ID: 10772
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: * DEP is concerned about the overall number of Cryptosporidium-approved laboratories and
their location in or near Pennsylvania. In addition, the routine Cryptosporidium sampling and the quality
assurance spiking of samples could exceed laboratory capacity. If the availability of approved laboratories
is insufficient for a specific period, then the monitoring and compliance schedules for LT2 should be
delayed by an equivalent period.
Response: See Response 1830.
EPA Letter ID: 457
Comment ID: 11887
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 17-36 December 2005
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Comment: Although many other states may have concerns with laboratory capacity for Cryptosporidium,
we do not expect it to be a concern in Georgia. We plan to build up our state laboratory capacity to
perform the required microbial monitoring for all the public systems affected by this rule. We are aware
that
Response: See Response 1830.
EPA Letter ID: 457
Comment ID: 11898
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Laboratory Issues
We support other states- concerns that lack of adequate laboratory capacity for Cryptosporidium
monitoring is a major concern. EPA must ensure that adequate laboratory capacity is available or delay
the implementation of the rule in accordance with the FACA Agreement in Principle.
Response: See Response 1830.
EPA Letter ID: 464
Comment ID: 11000
Commenter: Dr. Susan Boutrous, President, Environmental Associates Ltd.
Commenter Category: Independent Laboratories
Comment: Laboratory Capacity
The question of laboratory capacity has been brought up repeatedly as an industry concern. However,
based on our experience we have calculated that relatively few laboratories should be able to process the
sample load for the LT2. In a laboratory that processes only a few Cryptosporidium samples in a week,
one person may take the samples through all of the analytical steps. As a laboratory processing multiple
samples weekly, our work pattern is different, and there is an economy of scale. The tasks required for
analysis of Method 1622/1623 for Cryptosporidium can be viewed as a skill / work hour pyramid
consisting of three levels.
Top: Analyst / Sr. Analyst microscopy
Middle: Technician / Sr. Technician IMS steps
Base: Technician /Clerk Sample receipt/ handling coolers/ concentration / elution
The base of the pyramid has the lowest skill requirements and greatest man-hours. It requires several
hours to handle multiple samples received in a single day, but the amount of training required of staff is
significantly less than for the upper two levels of work. The tasks at the base level include sample receipt,
cleaning and return of coolers as well as the analytical tasks of concentration or elution of samples. The
middle level tasks process the sample through the immunomagnetic magnetic separation (IMS) steps, but
these steps can be batch processed by a technician in sets of twelve in 2-3 hours. The top skill level is the
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analyst / microscopist. Method 1623 slides can be read in significantly less time than ICR method slides
and a skilled analyst can read four to five negative slides in an hour with more time required for more
complex backgrounds and positive slides. Working four hours a day, a microscopist can read 16-20
negative slides in a day and 80 to 100 slides per week. By taking the number of Method 1623 samples in
our log book for November 2003 vs. the number of hours on the payroll minus time spent on other
activities, I calculated that 147 samples took 236 hours to complete or 1.6 hours per sample. One staff
person -equivalent- could process 25 samples per 40 hour week or 100 per month. If the total number of
LT2 samples were 2000 per month then a total of 20 people would be needed.
Staff Training
There are some laboratory staffing issues regarding the time required to train staff that could be eased,
specifically the six-month training time currently written into the rule. I would also like a definition of the
term -analyst-. It does not take six months to train someone to complete the tasks at the bottom of the
pyramid, and the IMS steps can be mastered in one to two weeks, not months if the person has good lab
skills and manual dexterity. Training for microscopy also does not take six months if the individual has
experience with light microscopy and knowledge of algae and protozoa. As a performance based method,
the training requirements should be based on ability not length of time performing a task. I would also
suggest that EPA address the issues of different skill levels of technician and analyst with regard to
training qualifications. Laboratories frequently experience a significant turnover of staff particularly at the
less skilled levels and a faster training cycle is desirable.
Utility Readiness
I think utility readiness is a greater concern than laboratory capacity for the smooth implementation of the
LT2. Our current client profile is at least 8:1 -utilities over 100,000- to -utilities between 10,000 and
100,000. The ratio of larger to smaller utilities for the rule is probably more like 1:5. Based on our
experience many smaller utilities have little experience with this type of sampling. The rule has
complexities relating to the number of filters, subsamples, and sampling frequency that need to be
understood. It is important for a utility to take at least a few samples in advance of the rule so that they
can be confident that they understand the requirements.
Response: See Response 1830.
EPA Letter ID: 466
Comment ID: 11010
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: ND has serious concerns with laboratory capacity for Cryptosporidium. These concerns
include the overall number of approved laboratories, the geographic distribution of the approved
laboratories, and the potential spiking of the number of Cryptosporidium samples that will need to be
analyzed in a short time frame if many systems are required to monitor for Cryptosporidium at the same
time.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-38 December 2005
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EPA Letter ID: 466
Comment ID: 11013
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: In order to execute their monitoring, large systems must budget for and contract with a
laboratory that is capable of handling their Cryptosporidium samples. Because of the limited number of
approved laboratories, at this time, this could be a financial concern to systems in ND. Not only are the
number of laboratories limited but their capabilities may force a system to add unnecessary and costly
treatment options. Thus far, laboratories have been limited in their ability to recover spiked concentrations
of Cryptosporidium samples. Algae, iron bacteria or other organisms have falsely been reported as
Cryptosporidium.
Response: See Response 1830.
EPA Letter ID: 470
Comment ID: 11098
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Vermont has concerns about lab capacity issues. In particular, we are concerned with the
number of labs who are approved for Cryptosporidium analyses and the potential spiking of the number
of Cryptosporidium samples that need to be analyzed in a short time frame if many systems are required
to monitor for Cryptosporidium at the same time. We encourage EPA to consider providing funding to
state labs to support the start- up costs and training needs to implement this rule and to evenly spread the
Cryptosporidium monitoring over the implementation schedule will help to relieve these problems.
Response: See Response 1830.
EPA Letter ID: 471
Comment ID: 11107
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 1. We have concerns that the Environmental Protection Agency (EPA) may be overlooking
the realities of laboratory capacity and compliance monitoring databases, both of which are critical to the
compliance efforts of utilities. For example, WSSC, like many other utilities, is not planning to invest in
the capability to perform Cryptosporidium analyses in-house, and therefore, we are entirely dependent
upon existing environmental laboratories to provide this service. There is a fair amount of uncertainty
whether these labs will have suitable capacity Washington Suburban Sanitary Commission comments on
proposed LT2ESWTR to meet the needs of the many utilities that will simultaneously be undertaking the
relatively short term monthly (or more frequent) monitoring. The EPA must conform to requirements of
the Agreement in Principle so that water systems are not held responsible for meeting impossible
schedules and falling into noncompliance if analytical capacity or data management software is
unavailable. To insure that this issue is not ignored, we suggest that the EPA,
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Response: See Response 1830.
EPA Letter ID: 471
Comment ID: 11164
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: 1. We have concerns that the Environmental Protection Agency (EPA) may be overlooking
the realities of laboratory capacity and compliance monitoring databases, both of which are critical to the
compliance efforts of utilities. For example, WSSC, like many other utilities, is not planning to invest in
the capability to perform Cryptosporidium analyses in-house, and therefore, we are entirely dependent
upon existing environmental laboratories to provide this service. There is a fair amount of uncertainty
whether these labs will have suitable capacity Washington Suburban Sanitary Commission comments on
proposed LT2ESWTR to meet the needs of the many utilities that will simultaneously be undertaking the
relatively short term monthly (or more frequent) monitoring. The EPA must conform to requirements of
the Agreement in Principle so that water systems are not held responsible for meeting impossible
schedules and falling into noncompliance if analytical capacity or data management software is
unavailable. To insure that this issue is not ignored, we suggest that the EPA,
Response: See Response 1830.
EPA Letter ID: 497
Comment ID: 10651
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Laboratory Issues
We have concern with the current laboratory capacity for Cryptosporidium monitoring. The MDEQ
drinking water laboratory, for one, is considering seeking
Response: See Response 1830.
EPA Letter ID: 505
Comment ID: 11173
Commenter: Darron Busch, Administrator, Department of Environment and Natural Resources,
Drinking Water Program
Commenter Category:
Comment: - We have concerns with laboratory capacity for Cryptosporidium analysis. These concerns
include the number of approved laboratories nationally, the geographic distribution of the approved
laboratories, and the capacity of the approved laboratories should it turn out that a large number of
samples have to be analyzed in a short period of time.
Response: See Response 1830.
Comment Response for the LT2ESWTR 17-40 December 2005
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EPA Letter ID: 506
Comment ID: 10733
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: requirements. A great deal of CWD-s concern on this issue stems from our doubts about
sufficient laboratory capacity, as previously mentioned. With a potentially larger volume of samples than
the lab is prepared to handle, there is the greater potential for mistakes. CWD previously received a
violation when a commercial laboratory failed to report some of our data to our State primacy
agency. It was bad enough to receive a violation for the laboratory-s mistake
and to be required to notify the public, but in this case it would be far worse.
Response: See Response 1830.
EPA Letter ID: 507
Comment ID: 11462
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 1. Source Water Monitoring Large Systems, IV.A.l.b., pg 47665
Most water systems, both large and small, do not analyze for Cryptosporidium and are reliant on
commercial laboratories for this time-consuming and expensive analysis. A concern is that there will not
be sufficient commercial laboratory capacity capable of performing monthly Cryptosporidium analyses.
We would
Response: See Response 1830.
EPA Letter ID: 512
Comment ID: 11497
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: Lab Capacity - Compliance schedules must be tied to availability of sufficient lab capacity. A
well-constructed and implemented sampling plan will be non-productive if the laboratory base is not there
to support the field effort. Currently, sufficient analytical capacity simply does not exist to handle the
impending sample load and will take time to develop. The combination of inadequate lab capacity
coupled with the proposed highest risk bin placement for even minor noncompliance with the monitoring
requirement has the potential for wasteful resource allocation, and non-productive actions that will do
little to improve on true public health risks.
CCWD runs its own laboratory and also uses contract laboratories for some work including
Cryptosporidium analyses. It is CCWD-s experience that it takes time for the lab industry to respond to
increased demands caused by new regulations. Since the entire weight of this rule rests on the ability of
utilities to complete their monitoring on time, EPA should adjust the implementation timeline to allow
Comment Response for the LT2ESWTR 17-41 December 2005
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sufficient lab capacity to develop and should consider additional staging of the rule by system size as a
means of implementing the rule given limitations in lab capacity.
Response: See Response 1830.
EPA Letter ID: 513
Comment ID: 11522
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: Nebraska is very concerned about whether there is adequate laboratory capacity and data
management software to manage the samples that will be generated during microbial monitoring.
Difficulties have been encountered in the past with data management software that proved to be
inadequate (e.g., the ICR and UCMR databases). The Nebraska Health and Human Services Laboratory is
not on the list of laboratories with approval pending for the analysis of Cryptosporidium under the
SDWA. Therefore we would contract with a laboratory that has earned provisional approval for analysis
of Cryptosporidium samples collected by systems in Nebraska. If a contract cannot be established, or if
the contract lab cannot analyze samples within approved holding times, the water systems will be
penalized and possibly obliged to meet treatment requirements for Bin 4. We are very concerned about
these potential, dire consequences of inadequate laboratory capacity.
Response: See Response 1830.
EPA Letter ID: 520
Comment ID: 11569
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Laboratory Capacity
IEPA does have concerns with laboratory capacity for Cryptosporidium including the overall number of
approved laboratories, the geographic distribution of the approved laboratories, and the potential spiking
of the number of Cryptosporidium samples that need to be analyzed in a short timeframe if many systems
are required to monitor for Cryptosporidium at the same time. The FACA recognized this concern and
included the following language in the Agreement in Principle under Section 2.11 .a:
If the availability of adequate laboratory capacity or data management software for microbial monitoring
under LT2ESWTR for large or medium systems is delayed then monitoring, implementation, and
compliance schedules for both the LT2ESWTR and Stage 2 DBPR described under 2.11 .c will be delayed
by an equivalent period.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-42 December 2005
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EPA Letter ID: 520
Comment ID: 11592
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Laboratory Issues
As indicated previously, IEPA has concerns with laboratory capacity for
Cryptosporidium. These concerns include the overall number of approved laboratories, the geographic
distribution of the approved laboratories, and the potential spiking of the number of Cryptosporidium
samples that need to be analyzed in a short timeframe if many systems are required to monitor for
Cryptosporidium at the same time. EPA must ensure that adequate laboratory
Response: See Response 1830.
EPA Letter ID: 521
Comment ID: 11757
Commenter: Leslie Rush,, Dalton Utilities
Commenter Category: Regulated Community (Utilities)
Comment: We are concerned with the availability of reasonably priced laboratory services for testing for
Cryptosporidium.
Response: See Response 1830.
EPA Letter ID: 524
Comment ID: 12208
Commenter: Gary Larimore, Executive Director, Kentucky Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Laboratory Availability and Costs
KRWA agrees with the comments from the Kentucky Division of Water. EPA should not minimize the
importance of having an adequate number of certified laboratories available before testing begins for
Cryptosporidium under the Long Term 2 Enhanced Surface Water Treatment Rule. Currently, there are
only a few laboratories that are certified to test for Cryptosporidium in the United States. Coupled with
the fact that the cost of monitoring for Cryptosporidium is approximately $400 per sample and that the
testing accuracy for Cryptosporidium is suspect - producing a high number of false positives, this should
be enough to suggest that EPA proceed with caution. The rule, as proposed, is cost-
prohibitive for public water systems.
Response: See Response 1830.
EPA Letter ID: 526
Comment ID: 11765
Comment Response for the L T2ESWTR 17-43 December 2005
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Commenter: Nick Jackson,, Knoxville Utilities Board
Commenter Category: Local Government
Comment: 1. KUB has considerable experience with the Methods 1622 and 1623, analyses for
Cryptosporidium and Giardia, having been one of the few utility laboratories in the state of Tennessee to
implement the methods back in the early 1990s. We are not, however, certified by the Tennessee
epartment of Environment and Conservation to perform these methods, so the issue of outside laboratory
availability is very important to us. Having performed the method many times ourselves, we realize how
time consuming, costly and labor-intensive the testing is to perform. Thus, many outside laboratories may
not consider it to be a profitable venture for a two year period. The regulations appear to state KUB or
any other utility would automatically be noncompliant if sampling requirements were not met due to
untimely sample analyses even if samples were collected on time. EPA should take steps to assure the
adequacy of laboratory services before implementing the proposal to avoid noncompliances due to
insufficient lab capacity and increased costs due to limited certified services.
Response: See Response 1830.
EPA Letter ID: 528
Comment ID: 12244
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Laboratory Capacity
Arkansas is considering obtaining certification for Cryptosporidium analysis as a result of this rule and
for other public health concerns. This would be a savings to the State and our water systems. To do so
plenty of lead time will be required. If monitoring commences according to the proposed schedule, to
fulfill our commitments we will likely have to contract laboratory analysis. This will be costly and time
consuming.
In general, we have concerns with laboratory capacity for Cryptosporidium including the overall number
of approved laboratories, the geographic distribution of the approved laboratories, and the potential
spiking of the number of Cryptosporidium samples that need to be analyzed in a short timeframe if many
systems are required to monitor for Cryptosporidium at the same time. The FACA recognized this
concern and included the following language in the
Agreement in Principle under Section 2.11 .a:
Response: See Response 1830.
EPA Letter ID: 536
Comment ID: 11783
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Laboratory Capacity
Colorado has concerns with laboratory capacity for Cryptosporidium including the overall number of
Comment Response for the L T2ESWTR 17-44 December 2005
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approved laboratories, the geographic distribution of the approved laboratories, and the potential spiking
of the number of Cryptosporidium samples that need to be analyzed in a short timeframe if many systems
are required to monitor for Cryptosporidium at the same time. The FACA recognized this concern and
included the following language in the Agreement in Principle under Section 2.11 .a:
If the availability of adequate laboratory capacity or data management software for microbial monitoring
under LT2ESWTR for large or medium systems is delayed then monitoring, implementation, and
compliance schedules for both the LT2ESWTR and Stage 2 DBPR described under 2.11 .c will be delayed
by an equivalent period.
Response: See Response 1830.
EPA Letter ID: 536
Comment ID: 11799
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Laboratory Issues
As indicated previously, Colorado has concerns with laboratory capacity for Cryptosporidium. These
concerns include the overall number of approved laboratories, the geographic distribution of the approved
laboratories, and the potential spiking of the number of Cryptosporidium samples that need to be analyzed
in a short timeframe if many systems are required to monitor for Cryptosporidium at the same time. EPA
must ensure that adequate laboratory
Response: See Response 1830.
EPA Letter ID: 554
Comment ID: 12221
Commenter: Wayne Price, Water Plant Superintendent, Broad River Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: Issue 2: Adequate numbers of regional laboratories should be available for Crytosporidium
and E. coli testing prior to implementaion of the LT2ESWTR.
Comment: There should be a list of EPA approved laboratories convenient to all water systems prior to
implementing the LT2ESWTR.
Response: See Response 1830.
EPA Letter ID: 556
Comment ID: 12039
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
Comment Response for the L T2ESWTR 17-45 December 2005
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(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 710 A. Microbial Toolbox General Comments; 9111.
Credit and criteria for awarding credit
Comment: punishment that far exceeds the crime. Other areas where the proposal would be improved by
referring to the intent of the FACA and AIP include: ensuring the availability of adequate laboratory
capacity; ensuring that the toolbox provides reasonable; achievable alternatives to UV disinfection; and
ensuring that safety factors and conservative assumptions do not needlessly add to the costs of
implementing UV.
Response: See Responses 1830, 910.f, 910.h, and lOO.t.
EPA Letter ID: 560
Comment ID: 14975
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: Comments on LT2
Comment One - Laboratory Capacity; Conformity with the FACA Agreement in
Principle:
Adequate documentation of laboratory capacity was not addressed in the preamble of the proposed LT2.
Section 2.11.a. of the Agreement in Principle specifics that: "Compliance schedules for the LT2ESWTR
will be tied to the availability of sufficient analytical capacity at approved laboratories for all large and
medium affected systems to initiate Cryptosporidium and E. coli monitoring - ."
There is no substantive discussion of the availability of laboratory capacity to implement the
LT2rulemaking. This information is particularly important given the dependence of both the LT2 and
Stage 2 DBPR implementation timelines on the availability of adequate laboratory capacity to support the
LT2 rule implementation. Failure to provide an estimate of laboratory capacity is a
Response: See Response 1830.
EPA Letter ID: 586
Comment ID: 12199
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: 3. Ability of laboratories to perform Cryptosporidium analysis.
Within six months of promulgation of the LT2ESWTR, certified laboratories will be inundated with
Cryptosporidium samples.
There is little discussion of the capability of laboratories to meet this new demand. It is our understanding
that the need for an evaluation of laboratory capacity was identified in the Stage 2 DDBP Agreement in
Principal (65 FR 83017).
EPA is obligated to publish a formal finding of adequate laboratory capacity, with supporting
documentation, in the Federal Register prior to promulgation of the LT2ESWTR.
Comment Response for the L T2ESWTR 17-46 December 2005
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Response: See Response 1830.
EPA Letter ID: 593
Comment ID: 11816
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 372 2. Electronic data reporting and review system
Comment: 2. Monitoring Lab Capacity: EPA appears to be taking the position that if the agency requires
monitoring, then monitoring capability will be expanded to meet market demand. SAWS- believes that it
is unreasonable to develop additional capacity for a short duration of time. In the past, databases for data
management were not in place or had problems prior to rule promulgation (e.g., the Information
Collection Rule and the Unregulated Contaminant Monitoring Rule databases are examples that lead to
significant compliance problems). SAWS recommends the following: EPA conform to requirements of
the Agreement in Principle so that water systems are not held responsible for meeting impossible
schedules and falling into non-compliance if analytical capacity or data management system is
unavailable. EPA publishes a formal determination in the Federal Register open for comments that
laboratory capacity and database management software are available. Develop a database that has been
beta-tested, is in-place, and operational prior to rule implementation.
Response: See Responses 371(A) and 1830.
EPA Letter ID: 601
Comment ID: 13043
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Laboratory Issues
Utah does have concern with laboratory capacity for Cryptosporidium. This concern includes the overall
number of approved laboratories, the geographic distribution of the approved laboratories, and the
potential spiking of the number of Cryptosporidium samples that need to be analyzed in a short timeframe
if many systems are required to monitor for Cryptosporidium at the same time. Utah currently has one
laboratory (the state primacy lab) certified to perform this monitoring. Currently in Utah with very few
systems sampling, samples are routinely shipped out of state which presents problems with proper
packaging to prevent freezing and additional costs to ensure that the samples arrive within the holding
times. EPA must ensure that adequate laboratory capacity is available or delay implementation of the rule
in accordance with the FACA Agreement in Principle.
Response: See Response 1830.
EPA Letter ID: 603
Comment ID: 12682
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Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 322 2. Cryptosporidium monitoring frequency and
duration
Comment: The currently limited laboratory capacity is a concern. Not so much for the large systems,
many of which are currently collecting data in preparation for grandfathering, but for the small systems
that will be required to collect 24 samples over 12 months, which roughly corresponds to $9,600. We
recommend that EPA allow small water systems to decrease the number of samples that they collect over
one year and/or extend the collection period to two years to decrease impact on small water systems and
laboratories during this part of rule implementation.
Response: See Response 320(C).
EPA Letter ID: 607
Comment ID: 12979
Commenter: Cam Ferguson, Manager of Water Resources, Greenville Water System
Commenter Category: Regulated Community (Utilities)
Comment: 2) There is a concern there may not be enough laboratory capacity to process a large number
of samples. There also may not be enough trained microscopists. Errors by inexperienced and
insufficiently trained analysts could force a utility into a lower bin unnecessarily. A sufficient number of
highly trained analysts must be assured.
Response: See Response 1830.
EPA Letter ID: 610
Comment ID: 12987
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: Will there be enough laboratories that will gear up for a national testing program that lasts for
a 24-month period? EPA is obligated under the Agreement in Principle to publish in the Federal Register
a formal funding with supporting documentation to demonstrate adequate laboratory capacity for the
Cryptosporidium and E. Coli monitoring prior to promulgation of LT2ESWTR. Even
Response: See Response 1830.
EPA Letter ID: 614
Comment ID: 12970
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment Response for the L T2ESWTR 17-48 December 2005
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Comment: * Laboratory capacity could potentially be an issue if there is not an increase in the number of
approved laboratories. The rule somewhat addresses this issue by stating "The Agency is monitoring
sample analysis capacity at approved laboratories through the Lab QA Program, and does not plan to
implement LT2ESWTR monitoring until the Agency determines that there is adequate laboratory
capacity." EPA should, prior to issuing final rules, publish a formal determination in the Federal Register
open for comments that laboratory capacity and data management software are available. If unavailable,
the final rules
Response: See Response 1830.
EPA Letter ID: 617
Comment ID: 13258
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 2. EPA is obligated under the Agreement in Principle to publish in. the Federal Register a
formal finding with supporting documentation to demonstrate adequate laboratory capacity for the
required Crytosporidium and E. coli monitoring prior to promulgation of LT2ESWTR. This lab issue is of
essential importance to the success of the bin classification concept and a utility's ability to achieve
regular consecutive monthly samples as indicated in #1 above. Implementing this rule without assurance
of adequate lab capacity and with the monitoring penalty as currently stated essentially defeats the bin
classification program as conceived by the FACA.
Response: See Response 1830.
EPA Letter ID: 618
Comment ID: 13246
Commenter: Craig Bryant, Director, Chesterfield County Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: The number of laboratories qualified to perform EPA approved method testing is limited.
Market adjustments in the industry in response to these regulations may or may not occur. Additionally.
sample holding conditions for contract lab
Response: See Response 1830.
EPA Letter ID: 620
Comment ID: 13283
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: 2. We are not convinced that there is adequate laboratory capacity to process the amount of
samples to be collected. The EPA should conform to the Agreement in Principle in that utilities should
not, be responsible for falling into non-compliance due to delays caused by inadequate capacity.
Comment Response for the L T2ESWTR 17-49 December 2005
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Response: See Response 1830.
EPA Letter ID: 620
Comment ID: 13286
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 1: Lab Capacity
Comments: EPA should publish evidence that adequate laboratory capacity exists for the amount of
samples to be collected. Costs associated with sampling and
Response: See Response 1830.
EPA Letter ID: 624
Comment ID: 13183
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: 1. Analytical Capability: The FACA Agreement in Principle (AIP) states that the regulatory
compliance schedule will be tied to the availability of sufficient analytical capacity at the approved
laboratories. EPA needs to ensure the adequacy of laboratory capacity and amend the compliance
schedule, if necessary, so that utilities will have a smooth transition from monitoring to compliance. A
well-planned and thoughtful compliance
Response: See Response 1830.
EPA Letter ID: 630
Comment ID: 13064
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: 6. Monitoring Key Issue 5 Laboratory Costs: In the costs and technology document, EPA has
estimated the average lab cost per Crypto sample is $530, (minimum $389 and maximum $713). We are
concerned about the increase in lab costs due to monitoring and the additional training or hiring for what
will only be lab requirements for temporary monitoring for this and the DBP rule. Many large labs and
utilities are not keen to invest or do the hiring for what they see as a temporary requirement adding to the
laboratory capacity problems. (See Lab Capacity, Issue #1 above)
Response: See Response 1830.
EPA Letter ID: 631
Comment ID: 13241
Comment Response for the LT2ESWTR 17-50 December 2005
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Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: Laboratory capacity is a concern for New Mexico water systems. The Environmental
Microbiology Supervisor of the New Mexico EPA certified drinking water laboratory has stated that the
lab does not intend to address Cryptosporidium analyses at this time and not until the methods are clearly
defined, if then. Further, as additional training or hiring for what will be lab requirements for temporary
monitoring for only three (3) water systems state-wide, it will not likely be cost effective for the
laboratory to become certified for Cryptosporidium analysis. Therefore, water systems in New Mexico
must submit samples to out-to-state laboratories. Likewise, no certification program for Cryptosporidium
analysis is planned for the City-s Water Quality Laboratory.
Response: See Response 1830.
EPA Letter ID: 641
Comment ID: 13616
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: Nationwide Laboratory Capacity
The proposed Rule does not specifically request comments regarding nationwide laboratory capacity, but
there has been discussion on the topic. ASI has investigated lab capacity by tracking our own processing
times for samples, efficiencies gained by scheduling, etc., and by discussing capacity with other major
laboratories. We are convinced that more than adequate capacity will exist with in the current timeframe
of the propose Rule (promulgation in June 05, implementation by Jan 06).
To summarize the lab capacity issue, if there are approx. 2500 samples per month during the LT2
compliance period (which may be a conservatively high figure, given grandfathering), and if the six
largest labs all increase capacity to an average of 400 samples per month, that accounts for 2400 samples
per month. The remaining smaller labs and utilities that are analyzing their own samples, etc., will easily
fill the gap. At ASI, we expect to exceed this capacity of 400 samples per month substantially, and have
comments elsewhere in this document to provide maximum sample processing efficiency.
Response: See Response 1830.
EPA Letter ID: 643
Comment ID: 12711
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Laboratory Capacity
States have concerns with laboratory capacity for Cryptosporidium including the overall number of
approved laboratories, the geographic distribution of the approved laboratories, and the potential spiking
of the number of Cryptosporidium samples that need to be analyzed in a short timeframe if many systems
are required to monitor for Cryptosporidium at the same time. The FACA recognized this concern and
included the following language in the Agreement in Principle under Section 2.11 .a:
Comment Response for the LT2ESWTR 17-51 December 2005
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If the availability of adequate laboratory capacity or data management software for microbial monitoring
under LT2ESWTR for large or medium systems is delayed then monitoring, implementation, and
compliance schedules for both the LT2ESWTR and Stage 2 DBPR described under 2.11 .c will be delayed
by an equivalent period.
Response: See Response 1830.
EPA Letter ID: 643
Comment ID: 12722
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: * Many states believe that adequate laboratory capacity to support large system
Cryptosporidium monitoring six months after rule promulgation will not be available. Although the state-
preferred approach (an 18-month delay as described in the previous bullet) would likely address this
issue, some states have indicated that they would support a staggered approach for large system
Cryptosporidium monitoring (possibly in two or three stages) to address a lack of adequate laboratory
capacity. However, as explained under the state-preferred approach in the previous bullet, EPA would
need to ensure that changing to a staggered approach does not result in an unacceptably large number of
systems being required to monitor for Cryptosporidium at the same time.
Response: See Response 1830.
EPA Letter ID: 643
Comment ID: 12745
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Laboratory Issues
As indicated previously, states have concerns with laboratory capacity for Cryptosporidium. These
concerns include the overall number of approved laboratories, the geographic distribution of the approved
laboratories, and the potential spiking of the number of Cryptosporidium samples that need to be analyzed
in a short timeframe if many systems are required to monitor for Cryptosporidium at the same time. EPA
must ensure that adequate laboratory
Response: See Response 1830.
EPA Letter ID: 647
Comment ID: 12880
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment Response for the L T2ESWTR 17-52 December 2005
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Comment: Laboratory Capacity
MDE is concerned with laboratory capacity for Cryptosporidium including the overall number of
approved laboratories, the geographic distribution of the approved laboratories, and the potential spiking
of the number of Cryptosporidium samples that need to be analyzed in a short timeframe if many systems
are required to monitor for Cryptosporidium at the same time. The FACA recognized this concern and
included the following language in the Agreement in Principle under Section 2.11 .a:
If the availability of adequate laboratory capacity or data management software for microbial monitoring
under LT2ESWTR for large or medium systems is delayed then monitoring, implementation, and
compliance schedules for both the LT2ESWTR and Stage 2 DBPR described under 2.11 .c will be delayed
by an equivalent period.
Response: See Response 1830.
EPA Letter ID: 647
Comment ID: 12899
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Laboratory Issues
There are concerns with laboratory capacity for Cryptosporidium. These concerns include the overall
number of approved laboratories, the geographic distribution of the approved laboratories, and the
potential spiking of the number of Cryptosporidium samples that need to be analyzed in a short timeframe
if many systems are required to monitor for Cryptosporidium at the same time.
Response: See Response 1830.
EPA Letter ID: 654
Comment ID: 13120
Commenter: William Brant, Director, Miami-Dade Water and Sewer Department
Commenter Category: Regulated Community (Utilities)
Comment: The MDWASD is concerned that the proposed compliance and implementation schedule
could be delayed because of the lack of availability of sufficient analytical capacity for Cryptosporidium
at approved laboratories. The MDWASD contacted the Florida Department of Health and requested a list
of all the laboratories in the Nation that are accredited for method 1623 for Cryptosporidium. According
to the Florida Department of Health, there is only 1 laboratory, in the entire nation, accredited for Method
1623. There are about 4 additional laboratories that are not yet accredited, but have applied. The
MDQASD does not believe that 5 laboratories will be able to handle the volume of samples that this
proposed regulation would require. The MDWASD respectfully requests that the EPA include a clause or
provision that will not penalize the PWS if the laboratory capacity is not available.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-53 December 2005
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EPA Letter ID: 662
Comment ID: 14025
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: IV. Discussion of Proposed LT2ESWTR Requirements
A. 3. Request for Comment
(pages 47678-47679)
EPA requests comment on all aspects of the monitoring and treatment requirements proposed in this
section.
(page 47678)
Analytical capacities to meet the monitoring requirements of LT2ESWTR are essential. Lack of
laboratory capacity should not influence a utilities compliance with this rule. The same concerns hold for
lack of appropriate
Response: See Response 1830.
EPA Letter ID: 678
Comment ID: 14661
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 372 2. Electronic data reporting and review system
Comment: 4. Section 141.702 - We are concerned that there may be monitoring compliance issues
caused by factors beyond the control of many water systems. These factors may include a lack of
sufficient laboratory capacity and unavailability of data management software from the EPA. The
Agreement in Principle states that the compliance schedules for the LT2 Rule will be tied to the
availability of sufficient analytical capacity for Cryptosporidium at approved laboratories and the
availability of data management software. If either is unavailable, the monitoring, implementation, and
compliance schedules for the LT2 Rule will be delayed an equivalent period of time. As written, the
proposed rule indicates the EPA is taking the position that if the agency requires monitoring then the
monitoring capability will be expanded to meet the market demand. Some water systems with analytical
capabilities and laboratories, however, state that it is unreasonable for them to develop additional capacity
just for a short duration of time to meet the first and second rounds of monitoring. Furthermore, the past
history (e.g., the ICR and UCMR databases) shows that appropriate data management software was not in
place or had problems prior to the final rule promulgation.
Response: See Responses 371(A) and 1830.
EPA Letter ID: 683
Comment ID: 14763
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Comment Response for the L T2ESWTR 17-54 December 2005
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Department
Commenter Category: Regulated Community (Utilities)
Comment: Laboratory capacity is a concern for New Mexico water systems. The Environmental
Microbiology Supervisor of the New Mexico EPA certified drinking water laboratory has stated that the
lab does not intend to address Cryptosporidium analyses at this time and not until the methods are clearly
defined, if then. Further, as additional training or hiring for what will be lab requirements for temporary
monitoring for only three (3) water systems statewide, it will not likely be cost effective for the laboratory
to become certified for Cryptosporidium analysis. Therefore, water systems in New Mexico must
submit samples to out-to-state laboratories. Likewise, no certification program
for Cryptosporidium analysis is planned for the City-s Water Quality Laboratory.
Response: See Response 1830.
EPA Letter ID: 704
Comment ID: 14796
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: This follows into the issue of lab capacity in general. Currently, only EPA has 19 approved
labs to handle -2500 Cryptosporidium samples per month; there currently is not the capacity to meet the
rule implementation schedule. How is EPA going to handle this issue? Will there be a change in the
implementation schedule? Will the rule have to be re-proposed? These issues and circumstances must be
addressed before this rule can move forward.
Response: See Response 1830.
EPA Letter ID: 706
Comment ID: 14807
Commenter: John Spatz, Deputy Commissioner, City of Chicago Department of Water Management
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 372 2. Electronic data reporting and review system
Comment: 1. PROMULGATION OF RULE
Laboratory Capacity and Software Availability
The EPA should be sure to have the laboratory space and software available to perform the analyses and
accept the information requested for the LT2SWTR prior promulgation of the rule.
Response: See Response 1830.
EPA Letter ID: 707
Comment ID: 14824
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment Response for the L T2ESWTR 17-55 December 2005
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Comment: Since there are only 22 EPA approved laboratories listed for Cryptosporidium
analysis at this time, how does the EPA expect to have enough laboratories
certified before promulgation of the LT2ESWTRto perform analysis for all
public water systems serving more than 10,000 people?
Response: See Response 1830.
17.2.2.1 Need to delay or modify rule implementation schedule
Response to Code 1833
See response 1830.
Individual Comments on Code 1833
EPA Letter ID: 430
Comment ID: 10595
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: are available. If unavailable, the final rules should be delayed or modified to appropriately
stretch out time frames so that the capacity available is sufficient.
Response: See Response 1830.
EPA Letter ID: 437
Comment ID: 10610
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: We understand from the EPA that they are considering a "phased-in" approach in requiring
Utilities to begin their 24 month monitoring period. Though we believe this to be unnecessary, BioVir
supports this approach to implementing the LT2.
Response: See Response 1830.
EPA Letter ID: 439
Comment ID: 10749
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment Response for the L T2ESWTR 17-56 December 2005
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Comment: schedule for these few laboratories.) The final rule should be delayed until
lab capacity has been demonstrated and until all data management software has been proven to be
functional. EPA should have a database for the submitted
Response: See Response 1830.
EPA Letter ID: 441
Comment ID: 10773
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: could exceed laboratory capacity. If the availability of approved laboratories is insufficient for
a specific period, then the monitoring and compliance schedules for LT2 should be delayed by an
equivalent period.
Response: See Response 1830.
EPA Letter ID: 453
Comment ID: 10946
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: 5. There should be a five-year window to conduct the 2 years of cryptosporidium monitoring.
Otherwise there will be a nationwide laboratory overload. The five-
year window would be consistent with the IDSE time frame of three years to do one year of monitoring.
Systems also should be given some time to be assured by the State or EPA that monitoring plans are
acceptable.
Response: See Response 1830.
EPA Letter ID: 457
Comment ID: 11888
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: monitoring for all the public systems affected by this rule. We are aware that the FACA
recognized the laboratory capacity concern (the Agreement in Principle, Section 2.11 .a) and support their
recommendation: -If the availability of adequate laboratory capacity or data management software for
microbial monitoring under LT2ESWTR for large or medium systems is delayed then monitoring,
implementation, and compliance schedules for both the LT2ESWTR and Stage 2 DBPR described under
2.11 .c will be delayed by an equivalent period.-
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-5 7 December 2005
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EPA Letter ID: 464
Comment ID: 11002
Commenter: Dr. Susan Boutrous, President, Environmental Associates Ltd.
Commenter Category: Independent Laboratories
Comment: utilities would take advantage of the grandfathering provision. Another suggestion to
improved both utility readiness and laboratory preparedness would be to stagger the start of the rule.
While this could be based on size, the real challenge will be in working with the smaller utilities. As one
alternative method, utilities could be chosen at random and assigned start dates spread over a six-month
period.
Response: See Response 1830.
EPA Letter ID: 470
Comment ID: 11092
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: If adequate laboratory capacity is not available to support large system Cryptosporidium
monitoring under EPA-s proposed approach, the state-preferred approach would be to delay
implementation as described in the previous paragraph. Alternatively, EPA could develop a staggered
approach for large system Cryptosporidium monitoring (possibly in two or three stages). Although we
recognize that the number of systems in each size category would directly impact the breakpoints, one
approach for large systems that would be consistent with the timeframes in the proposed rule would be:
[SEE TABLE, PAGE 4 OF PDF]
We encourage EPA to consider the pitfalls of data management from the staggered approach by ensuring
that SDWIS-State and other state legacy systems are able to adequately manage this.
Response: See Response 1830.
EPA Letter ID: 471
Comment ID: 11109
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: sufficient. Additionally, both final rules should specifically provide for delaying
implementation if capacity proves insufficient, or data management software fails after the rules become
effective. Additionally, we suggest that EPA-s database be beta-tested, in-place, and operational prior to
rule implementation.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-58 December 2005
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EPA Letter ID: 484
Comment ID: 10678
Commenter: Anonymous484,, Metro Nashville Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Lab Capacity:
EPA should conform to the Agreement in Principle. The proposed schedules will be impossible to meet
and utilities should not fall into noncompliance due to the lack of analytical laboratories and data
software(Beta testing should be completed).
The fmalization of the rules should be delayed until these problems are addressed.
Response: See Response 1830.
EPA Letter ID: 496
Comment ID: 10687
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 1. Monitoring Key Issue 1: Lab Capacity: Compliance schedules for the LT2ESWTR will be
tied to the availability of sufficient analytical capacity for Cryptosporidium at approved laboratories and
the availability of data management software. If either is unavailable, the monitoring, implementation,
and compliance schedules for both the LT2ESWTR and the Stage-2 DBPR will be delayed an equivalent
period of time.
At present EPA appears to be taking the position that if the agency requires monitoring, that monitoring
capability will be extended to meet market demand.
In the past, databases for data management were not established or had problems prior to rule
promulgation (There were no clear explanations of required data elements leading to significant
compliance problems in the ICR and UCMR databases).
Comments for Monitoring Key Issue 1 (Lab Capacity): Water systems should not be held responsible for
meeting impossible schedules and falling into non-compliance if analytical capacity or data management
software is unavailable. To ensure that this issue is not ignored, EPA should, prior to issuing final rules,
publish a formal determination in the Federal Register open for comments that laboratory capacity and
data management software are available. If unavailable, the final rules should be delayed or modified to
appropriately extend time frames so that the capacity available is sufficient. Additionally, both final rules
should specifically provide for delaying implementation if capacity proves insufficient, or data
management software fails after the rules become effective. The EPA should have a database that has
been beta-tested and is operational prior to rule implementation.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-59 December 2005
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EPA Letter ID: 497
Comment ID: 10652
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: monitoring. The MDEQ drinking water laboratory, for one, is considering seeking
certification for Cryptosporidium analysis. However, large water systems are forced to make monitoring
location and sampling date commitments to the EPA three months after rule promulgation.
Implementation decisions this soon may not allow time for laboratories seeking certification to meet the
large water system monitoring requirements. Again, the EPA should delay source water monitoring for
large supplies an additional 18 months to allow laboratories and surface water plants time to coordinate
sampling protocols. As an alternative, the EPA should include language in the LT2ESWTRthat allows
water systems to delay Cryptosporidium monitoring based on laboratory availability.
Response: See Response 1830.
EPA Letter ID: 503
Comment ID: 10624
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment: Issue No. 3 - Lab Capacity and Data Management Software
The Final Rule should not be issued until the laboratory capacity and data management software is
available as stated in the Agreement in Principle. Not having the data management system available for
ICR and the UCMR on time created an enormous strain on utilities and caused a lot of undue repeat data
submission and serious compliance issues due to the mismanagement of data collection systems.
Response: See Response 1830.
EPA Letter ID: 506
Comment ID: 10729
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: should then be issued, prior to the scheduled start of monitoring. If laboratory capacity is not
sufficient, an alternative for USEPA to consider would be a phased monitoring approached where a
certain percentage of water systems would be required to perform the monitoring each year. While this
might make the rule more complicated to implement, it would prevent an overload on laboratories.
CWD is also concerned that the data management software will not be ready for general use at the
specified time. The database should be beta tested and completely operational prior to rule
implementation. After utilizing both the ICR and UCMR databases, CWD knows from firsthand
experience that when the database is not fully operational, it makes compliance considerably more
difficult.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-60 December 2005
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EPA Letter ID: 507
Comment ID: 11464
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: laboratory capabilities are available and can meet the demands of this rule. If EPA determines
that sufficient laboratory capacity does not presently exist, then the rule should be modified accordingly
or the Cryptosporidium monitoring schedule be expanded to compensate.
Response: See Response 1830.
EPA Letter ID: 514
Comment ID: 11549
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: Other Issues - Lab Capacity: Most laboratories and others are worried about lab
capacity for this rule, especially after the rule is promulgated since a large number of facilities are not
monitoring at this time. An idea to help laboratories increase capacity once the rule is promulgated is to
stagger the beginning month for certain facility-s monitoring requirement (e.g. a third start 6 months after
promulgation, another third start 8 months after promulgation and the last third start 10 months or another
combination). This would help provide a "reasonable" rate of sample load increase to compliance levels
and laboratories would have a better idea of the type of waters they will be receiving, especially the
number of subsamples required for each water sample (which could increase workload tremendously),
what filter types are best suited for the samples, and be in a better position to train more analysts if
necessary.
Response: See Response 1830.
EPA Letter ID: 520
Comment ID: 11593
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 1831 1. Need for EPA estimate
Comment: Cryptosporidium at the same time. EPA must ensure that adequate laboratory capacity is
available or delay implementation of the rule in accordance with the FACA Agreement in Principle.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-61 December 2005
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EPA Letter ID: 527
Comment ID: 10847
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: finalized. Additionally, based on experience with the ICR and in keeping with the spirit of the
Agreement in Principle, we believe that each rule must contain a specific provision that will stop the
implementation clock if significant implementation problems arise after the rules are finalized, and keep
the clock stopped until the issues are resolved. Finally, we suggest that EPA begin thinking now about
how the rule might be most effectively implemented should laboratory capacity prove to be insufficient or
data management software unavailable. This might involve further staging of the rule by system size.
Such staging may have additional benefits of easing primacy agency implementation issues by allowing
time for states to attain primacy before medium and smaller systems (which make up the majority of
systems but serve a minor portion of the population) need to take action.
Response: See Response 1830.
EPA Letter ID: 527
Comment ID: 10847
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: finalized. Additionally, based on experience with the ICR and in keeping with the spirit of the
Agreement in Principle, we believe that each rule must contain a specific provision that will stop the
implementation clock if significant implementation problems arise after the rules are finalized, and keep
the clock stopped until the issues are resolved. Finally, we suggest that EPA begin thinking now about
how the rule might be most effectively implemented should laboratory capacity prove to be insufficient or
data management software unavailable. This might involve further staging of the rule by system size.
Such staging may have additional benefits of easing primacy agency implementation issues by allowing
time for states to attain primacy before medium and smaller systems (which make up the majority of
systems but serve a minor portion of the population) need to take action.
Response: See Response 1830.
EPA Letter ID: 533
Comment ID: 12215
Commenter: Edward Urheim,,
Commenter Category: Consultants: (where self-identified)
Comment: I am also concerned about adequate laboratory capacity and data management being
ready to meet the proposed rule-s schedules. I am aware that the FACA recognized the laboratory
capacity concern (the Agreement in Principle, Section 2.11.a) and I support their recommendation: -If the
availability of adequate laboratory capacity or data management software for microbial monitoring under
LT2ESWTR for large or medium systems is delayed then monitoring, implementation, and compliance
schedules for both the LT2ESWTR and Stage 2 DBPR described under 2.11 .c will be delayed by an
equivalent period.-
Comment Response for the L T2ESWTR 17-62 December 2005
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Response: See Response 1830.
EPA Letter ID: 562
Comment ID: 12351
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA suspects that commercial laboratory capacity is currently inadequate and believes
capacity will likely continue to be inadequate at the time of rule promulgation unless a substantial
capacity development program appears. As an alternative to increasing the In the absence of adequate
laboratory capacity, AWWA offers the staggered sampling plan below as one approach to addressing the
anticipated laboratory capacity shortfall. This plan extends the sampling for source water
Cryptosporidium over a period of six years. Not only does this reduce the instantaneous impact to
laboratory demand for laboratory capacity, but it will also promote the likelihood that laboratories will
develop staff capabilities to manage the Cryptosporidium analytical burden. If a laboratory is assured of
having an ongoing analytical business for six years instead of two, investment in additional capacity will
be a more attractive business decision for that business.
Table 1. Example Approach to Staged LT2ESWTR Monitoring
[SEE TABLE 1, P.22 IN PDF]
This table assumes that the available lab capacity is approximately 33% of what is needed and that the
population binning will evenly distribute the load over the six years of sampling. If EPA elects to select
this example approach in the final rule, the need for a NODA to address the five issues listed in 3.4 does
not change.
Response: See Response 1830.
EPA Letter ID: 562
Comment ID: 12361
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: the LT2ESWTR provisions are being developed. If the agency proceeds to promulgate the
final rule as proposed, AWWA believes that such action is contrary to law, arbitrary and capricious, and
an abuse of discretion for the following reasons:
3. EPA would abuse its discretion if it subjected public water systems to penalties for failure to comply
with monitoring requirements during what is an unreasonably short timeframe during a period of limited
laboratory capacity.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-63 December 2005
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EPA Letter ID: 595
Comment ID: 12603
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Based upon the proposed implementation schedule EPA will serve as the Primacy Agency for
the large surface water systems until the state can receive Primacy. Maine believes that this will create
confusion for the water systems and confusion for the DWP when primacy is transferred. A delay to the
implementation schedule of 18 to 24 months will allow states to receive primacy at approximately the
same time as the large surface water systems begin monitoring.
A delay to the implementation will also allow states to get a handle on how to administer the other new
rules as well as allowing water systems a chance to make necessary adjustments to the other rules.
Response: See Response 1830.
EPA Letter ID: 597
Comment ID: 12608
Commenter: Roger Hulbert, Senior Assistant Director, City of Houston Department of Public Works and
Engineering
Commenter Category: Regulated Community (Utilities)
Comment: ISSUE 1: -Laboratory Capacity and Data Management Systems
The Rule will require all Crytopsporidium analyses be performed at laboratories approved by the Agency
for this analysis. The Laboratory approval process is quite lengthy and extensive. Large utilities will
likely enter into a contractual arrangement with the approved laboratory. This is a process which takes
time, and cannot begin until the utility has a reasonable level of confidence that the preferred laboratory
will be approved. Houston has had a long-term relationship with three analytical laboratories since 1993.
Our source waters contain a cross reacting algae, which can often be misidentified as a Cryptosporidium,
if the analyst is unaware of its presence in the sample. For us, it is critically important that the laboratory
performing our analyses is familiar with our waters, and properly identifies our cross reactors as algae,
and not Cryptosporidium. To date no laboratories have received final approval, and there are only 22
laboratories on the Agency-s website rated as -Approval Pending-. This is insufficient laboratory
capacity, and the Agency has been slow to perform the necessary sight visits, etc. required to grant
approval. The Rule should not progress until the laboratory approval process has been completed, and the
regulated community can be presented with a complete listing of their options.
EPA should not promulgate the final rule until finding that sufficient laboratory capacity exists, and the
data handling software has been beta tested, and is fully operational. In Item 2.1 la -Implementation
Schedule of the Agreement in Principle with the Federal Advisory Committee Act (FACA), EPA agreed
that monitoring, implementation, and compliance schedules would be delayed by an equivalent time
period, if there were a delay in establishing adequate laboratory capacity, or data management system
readiness. EPA should not unilaterally reject their agreement with the FACA on this issue. The entire
FACA process is dependent on each party honoring the agreement. By ignoring their obligation under
Item 2.1 la, EPA is calling into question the integrity of the FACA process, and jeopardizing the trust of
the regulated community that the Agency will honor any future agreements.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-64 December 2005
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EPA Letter ID: 601
Comment ID: 13032
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Additionally, delaying implementation by 18 months will allow for certification of additional
laboratories for Cryptosporidium analysis.
Response: See Response 1830.
EPA Letter ID: 601
Comment ID: 13044
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: the holding times. EPA must ensure that adequate laboratory capacity is available or delay
implementation of the rule in accordance with the FACA Agreement in Principle.
Response: See Response 1830.
EPA Letter ID: 609
Comment ID: 14119
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: water plants time to coordinate sampling protocols. As an alternative, the USEPA should
include language in the LT2ESWTR that allows water systems to delay Cryptosporidium monitoring
based on laboratory availability.
Response: See Response 1830.
EPA Letter ID: 614
Comment ID: 12971
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: and data management software are available. If unavailable, the final rules should be delayed
or modified to appropriately stretch out time frames so that the capacity available is sufficient.
Response: See Response 1830.
Comment Response for the L T2ESWTR 17-65 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
EPA Letter ID: 620
Comment ID: 13289
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: period beginning. If laboratory capacity is inadequate or if data collection software is not
functional, SPRWS suggests delaying the final rule.
Response: See Response 1830.
EPA Letter ID: 624
Comment ID: 13184
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: from monitoring to compliance. A well-planned and thoughtful compliance date(s) is needed
to facilitate the accomplishment of mutual the goal of "microbial risk" mitigation.
Response: See Response 1830.
EPA Letter ID: 631
Comment ID: 13239
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: Laboratory Capacity: The Agreement in Principle states that the compliance schedules for the
LT2ESWTR will be tied to the availability of sufficient analytical capacity for Cryptosporidium at
approved laboratories and the availability of data management software. The final rule should, therefore,
specifically provide for delaying implementation if capacity proves insufficient, or data management
software fails after the rules become effective.
Response: See Response 1830.
EPA Letter ID: 641
Comment ID: 13581
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Other EPA Comment Codes and Descriptions: 1200 VIII. Compliance Schedules
Comment: that have already confirmed schedules with the lab. (b) Also, requiring sampling schedules
within 3 months may not be feasible. For example, if purchasing policies require PWSs to wait for
promulgation to put out a RFQ, then they write the RFQ, put it out to bid (typically 30 days later), and
then award the bid (rarely done in less than 30 days). This will result in the laboratories being under
Comment Response for the L T2ESWTR 17-66 December 2005
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tremendous pressure to generate responses to RFQs (conceivably, 100s or 1000s will arrive
approximately 30 days after promulgation) and the PWSs will have to award the bid and set up the
schedule very quickly, (c) Lastly, since
Response: See Responses 1200.c and 1830.
EPA Letter ID: 641
Comment ID: 13617
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: In regard to laboratory capacity, we do not foresee any need for EPA to consider revising the
proposed schedule for implementation. Specifically, we oppose a staggered start to PWS monitoring,
particularly if it would require re-proposing the Rule.
Response: See Response 1830.
EPA Letter ID: 646
Comment ID: 13563
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: Laboratory Capacity - As proposed, Santa Fe will be required to begin monitoring for
Cryptosporidium six months after the LT2ESWTR is finalized. The FACA agreement (Agreement in
Principle) states that the compliance schedule for the LT2ESWTR will be tied to the availability of
sufficient analytical capability for Cryptosporidium at approved laboratories and the availability of data
management software. If either is unavailable the monitoring, implementation, and compliance schedules
for both the LT2ESWTR and the Stage-2 DBPR will be delayed. The City requests that EPA adhere to
the Agreement in Principle and delay monitoring as necessary and ensure sufficient laboratory capability
is available at the time of implementation. It may be necessary for EPA to delay implementation of the
Rule until adequate laboratory capability is available.
Response: See Response 1830.
EPA Letter ID: 667
Comment ID: 14007
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment: A.
1. Lab Capacity: I am concerned about lab availability, capacity and test reliability along with data
management which could cause serious reporting delays. Provision should be made to extend the
implimentation deadline until these issues could be resovled should they occur.
Comment Response for the LT2ESWTR 17-67 December 2005
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Response: See Response 1830.
EPA Letter ID: 678
Comment ID: 14662
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: We request the EPA conform to the requirements of the Agreement in Principle so that water
systems are not held responsible for meeting impossible schedules and falling into noncompliance if
analytical capacity or data management software is unavailable. If unavailable, the final rule should be
delayed or modified to appropriately extend the compliance schedules so that the available laboratory
capacity is sufficient. Additionally, the final rule should specifically provide for delaying implementation
if capacity proves insufficient, or data management software fails after the rule becomes effective. We
also recommend the EPA have a database
Response: See Response 1830.
EPA Letter ID: 683
Comment ID: 14762
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
Comment: Laboratory Capacity: The Agreement in Principle states that the compliance
schedules for the LT2ESWTR will be tied to the availability of sufficient analytical capacity for
Cryptosporidium at approved laboratories and the availability of data management software. The final
rule should, therefore, specifically provide for delaying implementation if capacity proves insufficient, or
data management software fails after the rules become effective.
Water systems cannot be held responsible for monitoring requirements if these implementation tools are
unavailable. Because failure to comply with monitoring requirements is punishable by delegation to the
most conservative bin, water systems must insist that EPA conform to the requirements of the Agreement
in Principle.
Response: See Response 1830.
EPA Letter ID: 712
Comment ID: 16582
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Specifically, NYSDOH offers the following comments:
1. Issue: Implementation Schedule
Comment Response for the L T2ESWTR 17-68 December 2005
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NYSDOH recommends delaying the schedule for microbial monitoring for 18 months. This will allow
more time for certification of additional laboratories. It will also provide for better long-term treatment,
because States will have the time
to work with systems to assess their current levels of treatment, and to ensure that monitoring properly
assesses the microbial risks that additional treatment
requirements will be based on.
In addition, the state drinking water program is the appropriate regulator to
determine appropriate monitoring locations and frequencies. NYSDOH has established a solid
relationship with its water systems, which allows us and water systems to work together to determine rule
applicability, determine appropriate monitoring requirements, and assess whether a waiver from
monitoring should be granted, especially for complex rules that effect water systems with advanced
treatment trains and/or intricate distribution systems.
Additionally, this time is needed to prepare state rules, update data systems, and undertake other
implementation-related activities.
Response: See Response 1830.
17.2.3 Comment Code 1834, Approaches to increase capacity
Response to Code 1834
See response 1830.
Individual Comments on Code 1834
EPA Letter ID: 464
Comment ID: 11001
Commenter: Dr. Susan Boutrous, President, Environmental Associates Ltd.
Commenter Category: Independent Laboratories
Comment: We have not seen more than a handful of utilities express a desire to grandfather data. It
would be one way to bolster laboratory capacity if more utilities would take advantage of the
grandfathering provision. Another
Response: See Response 1830.
EPA Letter ID: 610
Comment ID: 12989
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Comment Response for the L T2ESWTR 17-69 December 2005
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Engineering
Commenter Category: Local Government
Comment: other test. It would seem to me that for a short term capacity need such as this, the Country
would be better off if the EPA provided the necessary equipment and training to the State laboratories.
Response: See Response 1830.
EPA Letter ID: 704
Comment ID: 14804
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 9. Due to laboratory limitations, we suggest that systems that detected higher cryptosporidium
concentrations under the ICR, be required to begin source water monitoring in advance of other systems.
The rule should allow states the flexibility to target systems with known higher cryptosporidium
concentrations first, to reduce the burden on limited laboratories.
Response: See Response 1830.
17.3 Comment Code 1840, E. coli Laboratory Approval
Summary of Issues
Comments expressed concern that most drinking water laboratories are certified for qualitative analyses
not quantitative. Due to this concern, some comments suggested EPA implement a Proficiency Testing
(PT) program for E. coli similar to the Cryptosporidium PT program. While other comments supported
requiring laboratories to obtain certification for quantitative E. coli analyses for monitoring under
LT2ESWTR. One comment agreed that laboratories certified for total coliform or fecal coliform analyses
under 40 CFR 141.74 should be approved for the same analytical technique for E. coli monitoring under
LT2ESWTR.
Response to Code 1840
E. coli laboratory approval
EPA does not agree that laboratories should be certified specifically for quantitative analyses of total or
fecal coliform in a source water matrix. EPA believes that analysts certified for specific analytical
techniques under the drinking water certification program have the capability to perform the same
methods for a source water matrix, even though additional steps may be required (such as dilutions).
EPA has revised the Laboratory Certification Manual to recommend Proficiency Testing (PT) samples for
source water matrix analyses. States have the option to require PT samples as needed in their State
laboratory certification programs.
Comment Response for the L T2ESWTR 17- 70 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
Individual Comments on Code 1840
EPA Letter ID: 514
Comment ID: 11544
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: L. Laboratory Approval
2. E.coli Laboratory Approval: EPA should establish guidelines for a lab QA
program for E.coli monitoring similar to the Cryptosporidium analyses with data quality objectives in
order to assess the ability of laboratories to reliably measure E.coli occurrence with the outlined methods.
The financial ramifications are too great to not insist upon reliable E.coli data used to trigger
Cryptosporidium monitoring for the small facilities. Laboratories should be able to demonstrate that an
on-site evaluation has been performed for total coliform or fecal coliform in SOURCE water, not just for
drinking water. Many laboratories seeking drinking water certification do not request approval in this area
so the inspectors do not assess the parameters pertinent to this matrix.
Response: See Response 1840.
EPA Letter ID: 514
Comment ID: 11545
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: Laboratories seeking to participate in the Lab QA program for E.coli analyses
should submit an interest application to the State or EPA and successfully analyze a set of initial
performance testing samples or PT sample set for quantitative analysis for total and/or fecal coliform
analyses in a non-potable matrix (non-potable E.coli PT sets are not currently available). In addition and
in the same light as Cryptosporidium testing, laboratories should participate in annual PT samples
(quantitative analyses in a nonpotable matrix). The requirement for laboratories demonstrating capability
by participating in quantitative PT samples is critical because most small drinking water laboratories are
now just performing presence/absence testing and do not have the experience in the quantitative source
water testing arena. This is supported by the fact that when Iowa initiated wastewater certification in 1997
and sent out PT samples for quantitative analyses, 40% of the drinking water laboratories seeking
wastewater certification had serious analytical and reporting errors (John Kempf, Iowa Lab Appraisal
Officer, personal communication). These laboratories would not have known that they were performing
the method incorrectly if it wasn-t for that initial PT sample set. Four years later, after annual PT sets,
training, and guidance, this percentage was down to 8% for the drinking water laboratories. The
wastewater laboratories still had an error rate of 25%.
Response: See Response 1840.
Comment Response for the L T2ESWTR 17- 71 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
EPA Letter ID: 514
Comment ID: 11546
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: We disagree that the general analytical technique the laboratory is certified to use under the
drinking water certification program should be the method the laboratory can use to conduct E.coli source
water analyses. Laboratories should demonstrate certification for quantitative analyses of total or fecal
coliform in a source water matrix (e.g. State wastewater certification, NELAC certification for a total or
fecal coliform quantitative method in either microbiology field of testing - 101 Microbiology of Drinking
Water or 107 Microbiology of Wastewater, etc.) and submit this certificate with the interest application as
outlined above.
Response: See Response 1840.
EPA Letter ID: 707
Comment ID: 14825
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: 2. E. coli Laboratory Approval
Comment: Certification of existing laboratories for E. coli under the LT2ESWTR should not present a
problem for Kentucky since several of their PWS already perform mFC counts on their source water.
Therefore, PWS in Kentucky could use mFC to detect and enumerate E. coli and use NA/MUG to
confirm the E. coli on mFC. The confirmation step using NA/MUG should not present a problem since
laboratories are experienced in the reading the fluorescence of this medium. In addition, the Kentucky
Microbiology Laboratory Certification Manual presently includes all acceptable methods under the
LT2ESWTR. The laboratories, however, should be required to complete an additional set of proficiency
samples for method(s) the lab is not currently certified to perform to isolate and confirm E. coli from
source water, such as mFC (Method 9222D and G), mTEC (EPA 1603), MI (EPA 1604), mColiBlue24 or
Colilert (ONPG-MUG SM 9223B). Our experience
Response: See Response 1840.
EPA Letter ID: 711
Comment ID: 16574
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: - For E. coli analyses, EPA proposes to approve laboratories that have been certified by EPA,
the National Environmental Laboratory Accreditation Conference, or the State for total coliform or fecal
coliform analysis in source water under 40 CFR 141.74. The laboratory must use the same analytical
technique for E. coli that the laboratory uses for total coliform or fecal coliform analysis under 40 CFR
141.74.
Comment Response for the L T2ESWTR 17- 72 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
Comment: We agree with this proposal.
Response: See Response 1840.
17.4 Comment Code 1850, Turbidity Analyst Approval
Summary of Issues
Several commenters expressed concern that any person that is currently approved to conduct turbidity
analysis under the existing regulations should continue to be able to conduct turbidity analyses and not be
affected by the rule. A commenter also expressed concern over small water systems that do not have the
resources to establish licensed laboratories to perform turbidity monitoring. The commenter recommends
that the rule should include provisions for the State to approve licensed operators to perform turbidity
testing.
Response to Code 1850
Turbidity Analyst
Today's final rule indicates that measurements for turbidity must be made by a party approved by the
State. This is consistent with existing requirements under 40 CFR 141.28(a). Typically States consider a
certified operator acceptable for turbidity measurement. For clarification on exact State requirements,
interested parties should contact their State.
Individual Comments on Code 1850
EPA Letter ID: 711
Comment ID: 16575
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: - Turbidity analyses must be conducted by a person approved by the State for analysis of
turbidity in drinking water under 40 CFR 141.74.
Comment: We agree turbidity analyses should be conducted per 40 CFR 141.74. Any
person that is currently approved to conduct turbidity analysis under the existing regulations should
continue to be able to conduct turbidity analyses and not be affected by this rule.
Response: See Response 1850. A person currently approved to conduct turbidity analysis under existing
regulations will continue to be able to conduct turbidity analyses required under today's rule.
Comment Response for the L T2ESWTR 17- 73 December 2005
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Chapter 17: Laboratory Approval and Capacity Comment Codes 1810-1870
17.5 Comment Code 1870, Guidance
Individual Comments on Code 1870
EPA Letter ID: 678
Comment ID: 14673
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 9. Section 141.706(c) - Measurements of turbidity must be made by a party approved by the
State. It is unclear whether or not this requirement also applies to the party who collects other samples
and measures the turbidity in the field. If so, does it mean that the sample collector has to be certified by
the State? Would a sample collector who has received proper training on the use of the turbidimeter be
considered an approved party? ACWA requests clarification on this issue.
Response: See Response 1850.
EPA Letter ID: 704
Comment ID: 14791
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section 3.2. Labs can test under the rule if they are approved by states that certify labs for
Cryptosporidium analysis.
Does this mean that EPA will not site visit and audit labs approved by states. Will New York State (NYS)
be developing a certification program for Cryptosporidium? Will samples analyzed outside NYS be
accepted by the State when they are granted primacy or will lab services rendered from labs outside NYS
need to be certified by the State and EPA (and possibly the state they do business in)?
Response: See Response 1810.
EPA Letter ID: 707
Comment ID: 14823
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: pg. 47735
Laboratory Approval
1. Cryptosporidium Laboratory Approval
EPA expects, however, that States will include Cryptosporidium analysis in their
state certification program in the future
Comment:
What will be the criteria for a state to certify laboratories for Cryptosporidium analysis? Will the states
Comment Response for the L T2ESWTR 17- 74 December 2005
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principal laboratory be required to be certified by their Respective USEPA Region for Cryptosporidium in
order for their certification program to certify in-state laboratories? Does the EPA intend to train
certification officers on how to perform an on-site audit of laboratories performing Cryptosporidium
analysis? If this is the case, would each certification officers have to have the same qualifications as the
principal analyst/supervisor in each laboratory with respect to their knowledge of Cryptosporidium
procedures for 1622/1623 and microscopies?
Response: See Response 1810.
EPA Letter ID: 707
Comment ID: 14828
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: pg. 47736
EPA evaluation of State Approval Programs to determine if they are equivalent
to the Lab QA Program
Comment: Does this statement mean that for a state to be able to certify its own laboratories for
Cryptosporidium analysis that it must be capable of performing the method in its own principal
microbiology laboratory? The statement that the laboratory must be audited, have auditors that meet the
qualifications of the principal analyst, etc., would force states to perform Cryptosporidium analysis in
order to certify their own laboratories. If the state does not meet these requirements, how will in-state
laboratories receive their certification after the EPA discontinues their certification program?
If the EPA requires the state to maintain Cryptosporidium certification in order to certify their own
laboratories, the state will have an increase in cost to maintain their principal microbiology laboratory
(certification and cost of analysis).
Response: See Response 1810.
Comment Response for the L T2ESWTR 17- 75 December 2005
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18. Sanitary Survey Requirements for Systems Where EPA
Has Primacy: Comment Code 1900
18.1 Comment Code 1900, XV. Sanitary Survey Requirements for
Systems Where EPA Has Primacy
Summary of Issues
Most commenters supported including the proposed requirements. Commenters noted that the proposed
requirements ensured that all surface water systems were subject to the same requirements for addressing
significant deficiencies. One commenter requested that EPA include an appeal process for systems to
appeal significant deficiencies that the system did not agree were significant.
Response to Code 1900: 1900.1 Sanitary Survey Requirements should be consistent
Most public comment on the August 11, 2003 proposal supported requiring PWSs to correct significant
deficiencies identified in sanitary surveys conducted by EPA. Commenters stated that requirements for
sanitary surveys should be consistent for PWSs and consistent with other rules. EPA believes the
requirements in today's final rule will establish this consistency.
Individual Comments on Code 1900
EPA Letter ID: 457
Comment ID: 11949
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Section IV.M Requirements for Sanitary Surveys Conducted by EPA (pages 47736-
47737)
Requirements should be consistent across system type and with the requirements already established
under other rules.
Response: See Response 1900.1
EPA Letter ID: 485
Comment ID: 11338
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: EPA requests comment on establishing requirements for public water systems under
EPA-s direct jurisdiction (i.e. Wyoming, Tribal systems) with significant deficiencies as identified in a
Comment Response for LT2ESWTR 18-1 December 2005
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Chapter 18: Sanitary Survey Requirements for Systems Where EPA Has Primacy Comment Code 1900
sanitary survey conducted by EPA under SDWA section 1445.
Response: The Department believes EPA should establish the requirements as
proposed and supports the reasons outlined in the rule document on the establishment of such
requirements. The sanitary survey requirements as established by the IESWTR require primacy States to
have the authority to assure that systems take necessary steps to address significant deficiencies identified
in sanitary survey reports if such deficiencies are within the control of the system. EPA should be given
the same authority under 40 CFR 141 to ensure timely correction of significant deficiencies identified
during sanitary surveys for systems under EPA jurisdiction.
Response: See response 1900.1.
EPA Letter ID: 488
Comment ID: 11876
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4.9 Sanitary Surveys Can the response to deficiencies be in writing within 45 days?
Comments The time for response depends on the level of response needed. For example, it would be
difficult if not impossible for a utility to obtain a contract in 45 days by which to describe a schedule for
correction.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11663
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: IEPA believes that requirements for sanitary surveys should be consistent across system type
and not dependent on the primacy agency. EPA should include requirements consistent with the
requirements established under other rules.
Response: See Response 1900.1
EPA Letter ID: 562
Comment ID: 12535
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4.5 Sanitary Survey Provisions
EPA proposes and requests comment on implementation authority to address significant deficiencies
identified during a sanitary survey. The agency proposes two provisions (1) PWSs would respond to the
agency in writing as to how and when significant deficiencies identified by EPA would be corrected and
Comment Response for the L T2ESWTR 18-2 December 2005
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Chapter 18: Sanitary Survey Requirements for Systems Where EPA Has Primacy Comment Code 1900
(2) PWSs would be required to correct significant deficiencies. This proposal lacks two important
components:
1. An administrative process in which a system could appeal a significant deficiency determination; and
2. A clear statement that the significant deficiency provision is NOT directly tied to MCL or
determinations of a treatment technique violation.
Response: EPA expects that PWSs will raise any concerns regarding significant deficiency
determinations with the primacy agency, either the State or EPA, that conducts the sanitary survey. States
or EPA may withdraw or amend their significant deficiency determinations as appropriate. The IESWTR
did not establish a separate appeal process for sanitary surveys conducted by States, and EPA has not
established such a process for sanitary surveys conducted by EPA under today's rule. A significant
deficiency includes a defect in design, operation, or maintenance, or a failure or malfunction of the
sources, treatment, storage, or distribution system that EPA determines to be causing, or has the potential
for causing the introduction of contamination into the water delivered to consumers. This definition does
not use "MCL or determinations of a treatment technique violation" as part of the definition. The
requirements in today's final rule follow closely on the language presented in the proposal. EPA has not
changed the language nor felt it necessary to discuss what is not part of the significant deficiency
definition.
EPA Letter ID: 595
Comment ID: 12601
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: Section IV.M Requirements for Sanitary Surveys Conducted by EPA (pages 47736-
47737)
Maine believes that watersheds should be evaluated consistently for all surface water systems during
sanitary surveys.
Response: Please see Response 1900.1.
EPA Letter ID: 643
Comment ID: 12819
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section IV.M Requirements for Sanitary Surveys Conducted by EPA (pages 47736-
47737)
States believe that requirements for sanitary surveys should be consistent across system type and not
dependent on the primacy agency. EPA should include requirements consistent with the requirements
established under other rules.
Response: See Response 1900.1.
Comment Response for the L T2ESWTR 18-3 December 2005
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Chapter 18: Sanitary Survey Requirements for Systems Where EPA Has Primacy Comment Code 1900
EPA Letter ID: 647
Comment ID: 12948
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Section IV.M Requirements for Sanitary Surveys Conducted by EPA (pages 47736-
47737)
Requirements for sanitary surveys should be consistent across system type and not dependent on the
primacy agency. EPA should include requirements consistent with the requirements established under
other rules. The frequency of the sanitary survey of the watershed should not be a component of this
regulation.
Response: Please see response 1900.1. The frequency of sanitary survey was put in place by the
IESWTR; this frequency remains unchanged by this rule.
Comment Response for the L T2ESWTR 18-4 December 2005
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19. State Implementation: Comment Codes 2000-2090
19.1 Comment Code 2000, State Implementation
Summary of Issues
Commenters generally supported the special primacy requirements proposed and many commenters
expressed appreciation for the flexibility the special primacy requirements provided the states. One
commenter expressed concern that a state that adopted this rule by reference would lose the flexibility
intended in the proposal. Another commenter requested that EPA evaluate the implementation of all new
rules to ensure state-to-state consistency.
Several commenters were concerned that early implementation would negatively impact state drinking
water programs. One commenter expressed concern that PWSs would no longer support state funding of
drinking water programs due to the lack of state participation in LT2ESTWR implementation. Another
commenter suggested that the LT2ESTWR rule not be implemented until states have adequately
addressed previous rules. Two commenters were concerned that the special primacy requirement to assess
changes in watersheds as part of the sanitary survey process would be difficult to meet due to a lack of
resources or large watersheds that overlapped state boundaries.
Response to Code 2000
See individual responses below.
Individual Comments on Code 2000
EPA Letter ID: 449
Comment ID: 10836
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: And finally, the EPA should evaluate the implementation of each of the new rules once they
are approved even if the states have primacy. It is imperative that all states be held to the same
requirements. To allow each state to implement the rules as they interpret them would undermine the
effectiveness of the testing. We feel that to implement this on a national level additional staffing will be
needed at both the federal and state levels.
Response: Thank your for support for the final rule. EPA intends to continue working with all primacy
agencies on national drinking water issues and implementation of drinking water rules throughout the
foreseeable future.
EPA Letter ID: 472
Comment ID: 11142
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Comment Response for LT2ESWTR 19-1 December 2005
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Chapter 19: State Implementation Comment Codes 2000-2090
Department
Commenter Category: Local Government
Comment: Water systems in Arizona have further concerns of lost flexibility EPA provides to state
primacy agencies. The Arizona Department of Environmental Quality (ADEQ) published the following in
the December 12, 2003 Arizona Administrative Register
.-it plans to revise the rules that implement the federal safe drinking water act in Arizona pursuant to the
delegation of the PWSS to ADEQ by the U.S. Environmental Protection Agency, in part by utilizing
incorporation by reference to simplify the rule amendment and approval process. Second, the rulemaking
will incorporate a number of federal drinking water rules into 18 A.A.C. 4 of the Arizona Administrative
Code, including the following: Radionuclides, Arsenic and Clarifications to Compliance and New Source
Contaminants Monitoring, Filter Backwash Recovery, Long Term 1 Enhanced Surface Water Treatment,
and possibly the Long Term 2 Enhanced Surface Water Treatment and Disinfection/Disinfection By-
Products rules. (AAR, Vol. 9, No. 50, 12/12/2003, page 5335).
This loss of flexibility will greatly impact Arizona water systems and how these and future rules are
finalized.
Response: States may choose to incorporate these regulations by reference and States may also choose
not to implement some of the flexible provisions. Whatever decisions that the States may make must be
described in the primacy application to EPA.
19.2 Comment Codes 2010, Special State Primacy Requirements
Response to Code 2010
See individual responses below.
Individual Comments on Code 2010
EPA Letter ID: 457
Comment ID: 11909
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Special Primacy Requirements
We support the proposed special primacy requirements and appreciate the flexibility provided by these
requirements.
Response: See Response lOO.a.
EPA Letter ID: 457
Comment ID: 11950
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Comment Response for the L T2ESWTR 19-2 December 2005
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Chapter 19: State Implementation Comment Codes 2000-2090
Branch
Commenter Category: State/Tribe Government
Comment: State Implementation (pages 47737-47738)
We support the proposed special primacy requirements and appreciate the flexibility provided by these
requirements.
Response: See Response lOO.a.
EPA Letter ID: 470
Comment ID: 11099
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: State Implementation pp. 47737-47738
Vermont is, in general, supportive of the special primacy requirements and appreciates the flexibility that
they provide the states.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11609
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Special Primacy Requirements
IEPA generally supports the proposed special primacy requirements and appreciate the flexibility
provided by these requirements.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11664
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: State Implementation (pages 47737-47738)
Comment Response for the L T2ESWTR 19-3 December 2005
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Chapter 19: State Implementation Comment Codes 2000-2090
IEPA generally supports the proposed special primacy requirements and appreciate the flexibility
provided by these requirements.
Response: See Response lOO.a.
EPA Letter ID: 601
Comment ID: 13045
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Special Primacy Requirements
Utah generally supports the proposed special primacy requirements and appreciate the flexibility provided
by these requirements.
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12761
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Special Primacy Requirements
States generally support the proposed special primacy requirements and appreciate the flexibility provided
by these requirements.
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12820
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: State Implementation (pages 47737-47738)
States generally support the proposed special primacy requirements and appreciate the flexibility provided
by these requirements.
Response: See Response lOO.a.
Comment Response for the L T2ESWTR 19-4 December 2005
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Chapter 19: State Implementation Comment Codes 2000-2090
EPA Letter ID: 647
Comment ID: 12910
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Special Primacy Requirements
MDE generally supports the proposed special primacy requirements and appreciate the flexibility
provided by these requirements.
Response: See Response lOO.a.
19.2.1 Comment Codes 2030, Assessing changes in watershed as
part of sanitary survey process
Response to Code 2030
See individual responses below.
Individual Comments on Code 2030
EPA Letter ID: 536
Comment ID: 11812
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Special primacy conditions
Colorado has significant concern with the special primacy requirement for states to assess significant
changes in the watershed and source water as part of the sanitary survey process and determine
appropriate follow-up. This is an impossible requirement within the resources available to state programs.
In Colorado and many western states, water is transferred across multiple watersheds that cover
geographic areas much too extensive to be reviewed by state staff. A review of source water quality as
determined by a review of monitoring results at the intake may be feasible, but to expect state staff to
determine changes in potential sources of contamination within the watershed is absolutely not feasible.
We have commented that we believe the EPA estimated state implementation costs for this rule may be
insufficient. If EPA insists that watersheds be assessed as part of the sanitary survey, the state cost
estimates must be revised to address this workload, and more importantly, additional funding to state
programs to cover these costs must be included as part of the rule.
Response: EPA notes that States are already required to evaluate PWS sources under the existing sanitary
survey requirements (40 CFR 142.16(b)(3)). If a State determines during a sanitary survey that significant
changes have occurred in the watershed that could lead to increased contamination of the source by
Cryptosporidium, today's rule gives the State the authority to require the PWS to take actions to mitigate
or treat the contamination. Because the treatment requirements in today's rule depend on the degree of
source water contamination, EPA believes that this assessment of changes in a PWS's source water
following initial bin classification is necessary. EPA acknowledges that this final rule will impose
substantial direct compliance costs on some State and local governments, some small systems as well as
Comment Response for the L T2ESWTR 19-5 December 2005
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Chapter 19: State Implementation Comment Codes 2000-2090
some tribal systems. EPA has met all requirements for analysis of costs for this final rule. Limited
funding is available from programs administered by EPA and other Federal agencies to assist PWSs,
States and Tribes in complying with the LT2ESWTR.
EPA Letter ID: 601
Comment ID: 13003
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: A. Additional Cryptosporidium Treatment Techniques for Filtered Systems
(page 47667)
Comments on the proposal to have States determine during Sanitary Survey that significant changes have
occurred in the watershed that could lead to increased contamination of the source water, the State may
require systems to implement specific actions to address the contamination. These actions include
implementing options from the microbial toolbox.
Utah believes that any requirement for States to determine significant changes in the watershed should be
flexible to coincide with individual state programs, i.e. SWAP programs and other pollution prevention
programs which differ greatly from state to state.
Response: EPA encourages PWSs to leverage other Federal, State, and local programs in developing the
elements of their watershed control plans. For example, SDWA section 1453 requires States to carry out a
source water assessment program (SWAP) for PWSs. Depending on how a State implements this
program, the SWAP may be used to define the area of influence in the watershed and identify actual and
potential contamination sources. EPA believes this rule provides States with flexibility to meet these
needs.
19.2.2 Comment Codes 2040, Determining adequacy of risk
mitigation plans for uncovered finished water reservoirs
Response to Code 2040
See individual response below.
Individual Comments on Code 2040
EPA Letter ID: 520
Comment ID: 11597
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: a state-approved risk mitigation plan are appropriate, but there are concerns with the level of
state resources needed to implement the last option.
Response: Today's rule does not allow a risk mitigation plan as an alternative to covering or treating
Comment Response for the LT2ESWTR 19-6 December 2005
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Chapter 19: State Implementation Comment Codes 2000-2090
uncovered finished water reservoirs. As discussed in the preamble, EPA has determined that a risk
mitigation plan would not provide equivalent public health protection to covering or treating. Open
reservoirs are subject to many pathways for contamination and systems are constrained in the steps they
can implement to mitigate these pathways.
19.3 Comment Code 2090, Interim Primacy
Response to Code 2090
See individual comment responses below.
Individual Comments on Code 2090
EPA Letter ID: 442
Comment ID: 10782
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: The EPA FACA Agreement in Principle was signed and published in September 2000.
Approximately three years later the EPA is proposing to promulgate rules triggering early
implementation of monitoring by Subpart H systems for cryptosporidium. Public water systems must file
a monitoring plan and report data directly to the EPA bypassing the state primacy agency. If EPA felt this
proposed rule was so important it should have published it in late 2000 and allowed the states to carryout
the role assigned them by the Safe Drinking Water Act. Due to the states being relegated to a bystander's
role, public water systems will eventually decide that do not need to continue to support state activities
and may attempt to have state funding decreased. The health risks caused by lack of additional
cryptosporidium control will pale in comparison to the public health risk caused by underfunded and
ineffective state programs. The EPA does not have the resources to take over the responsibilities of state
programs.
Response: Response 1200.b and 1200.C. EPA does not believe that the primacy status of a State agency
with respect to a particular rule is a barrier to State-EPA partnerships in implementation. States may
choose to have as active a role as they desire in rule implementation even prior to obtaining interim
primacy. As a result, there is no basis to assume that the implementation schedule for today's rule will
lead to underfunded or ineffective state programs.
EPA Letter ID: 449
Comment ID: 10825
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: It is our understanding that EPA does not have the manpower to oversee these regulations if
they are implemented now. Our feeling is that the EPA should not consider implementing these rules
unless the regulatory agency for each state has primacy and is equipped to perform this monitoring. The
proposed regulations are quite extensive and based on the current state backlog it is apparent that
additional staffing at the state level would be necessary.
Comment Response for the LT2ESWTR 19-7 December 2005
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Chapter 19: State Implementation Comment Codes 2000-2090
Response: Response 1200.b and 1200.c and lOO.z. EPA has accounted for costs and staffing burden to
states due to implementing today's rule in the Economic Analysis for the rule. EPA expects systems, not
states, to perform the required monitoring.
EPA Letter ID: 562
Comment ID: 12297
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.2 Notice of Data Availability AWWA recommends that the agency publish a Notice of Data
Availability (NODA) that includes these subjects:
5. A plan for EPA regional offices to make bin determinations, if state primacy is lacking at the time such
determinations need to be made.
Response: Response 500.1 EPA will approve the bin determinations that systems report if state primacy
is lacking. For EPA to oversee implementation activities when states are unable is standard and does not
require a NODA in advance of the final rulelmaking.
EPA Letter ID: 562
Comment ID: 12350
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5. A plan for EPA regional offices to make bin determinations, if state primacy is lacking at
the time such determinations need to be made.
Response: Response 500.1 EPA will approve the bin determinations that systems report if state primacy
is lacking. For EPA to oversee implementation activities when states are unable is standard and does not
require a NODA in advance of the final rulelmaking.
EPA Letter ID: 647
Comment ID: 12884
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Comments in Case EPA Retains the Proposed Implementation Schedule
If EPA retains the proposed implementation schedule, EPA should consider using the term primacy
agency in the rule language when referring to the entity to which systems must submit sample results,
reports, or requests. Then, at the appropriate time, states and EPA could work together to inform water
systems that the state has primacy for rule implementation and is then the primacy agency.
Response: Response 1200.C. The term "state" in rule language refers to the entity with primacy.
Therefore, EPA uses this term in rule language, rather than "primacy agency" as the commenter suggests.
Comment Response for the L T2ESWTR 19-8 December 2005
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Chapter 19: State Implementation Comment Codes 2000-2090
EPA agrees that the Agency should work with states to inform water systems regarding which entity will
oversee implementation of the rule at different stages.
Comment Response for the L T2ESWTR 19-9 December 2005
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20. Economic Analysis: Comment Codes 2200-2280
20.1 Comment Code 2200, Economic Analysis
Response to Code 2200
a. VSL: Valuing fatal cases:
Some commenters felt that the Value of a Statistical Life (VSL) used by EPA in its analysis of benefits is
flawed or not correct. EPA disagrees with these commenters for several reasons. First, the VSL value
used by the Agency is based on the most current data available. The VSL value, as recommended by
Agency guidance and the EEAC subcommittee of the SAB, is derived from a statistical distribution of the
values found in twenty-six wage-risk studies, which were chosen as the best such studies available from a
larger body of studies. EPA believes the VSL distribution to be the best estimate at this time, and is
recommending that this value be used by the various program offices within the Agency. To account for
uncertainty in the VSL estimate, EPA uses the entire distribution in a Monte Carlo analysis. The Agency
VSL estimate will be updated in the future as additional information becomes available to assist the
Agency in refining the estimate.
Also, the use of the VSL for benefits valuation is consistent with recommendations from EPA's SAB,
which discussed this issue in their meeting on February 25, 2000 in Washington, DC. The SAB's report
on their findings and recommendations from the February meeting stated that "despite limitations of the
VSL estimates, these seem to offer the best available basis at present for considering the value of fatal
cancer risk reduction. We therefore recommend that the Agency continue to use a wage-risk-based VSL
as its primary estimate, including appropriate sensitivity analyses to reflect the uncertainty of these
estimates" (SAB 2000).
Another commenter noted that mortality benefits account for a large portion of total benefits. This is due
to the fact that the valuation of each mortality avoided is much higher than for each non-fatal case even
though there are significantly more non-fatal cases avoided by the LTESWTR.
b. COL Valuing non-fatal cases:
Several commenters questioned various aspects of the enhanced cost of illness (ECOI) methodology
including that it was beyond economic bounds and unrealistic. EPA respectfully disagrees and believes
the enhance cost of illness approach provides a more comprehensive evaluation of the potential rule
benefits then the traditional cost of illness. The ECOI methodology, as described in Appendix L, has been
peer reviewed by three external reviewers.
As discussed in the proposed and final EA, EPA recognizes that the preferred approach for valuing health
risk reductions is to rely on estimates of individual willingness to pay (WTP). In the absence of suitable
WTP estimates, analysts often rely on approaches similar to the Traditional COI approach used for this
rule, as noted by the commenter. However, as in any empirical approach, EPA recognizes that the
limitations of available data introduce some uncertainty into this relationship.
While the Enhanced COI approach is innovative, it is rooted in standard welfare economic theory and
builds on approaches used to value time in numerous studies in the labor, transportation, recreation, and
Comment Response for LT2ESWTR 20-1 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
health economic literature. The commenter is concerned, however, that the Enhanced COI approach
values nonwork time as a higher rate than many recreational studies, several of which value travel time at
one-third of the wage rate. EPA's extensive review of the recreation literature, however, suggests that
there is no consensus regarding the value of travel time' as discussed in Appendix P of the EA. In
addition, travel has both pleasant and unpleasant aspects and hence may be valued less than other leisure
activities, many of which may be valued at a rate higher than foregone wages.
To test the plausibility of the results, the commenter compares the value of a "lifetime case" of
cryptosporidiosis to the value of statistical life (VSL) and suggests that the results (which show that such
a case would be roughly 70 percent of VSL) are improbably high. However, EPA believes that this
comparison is seriously flawed. There is no generally accepted standard for determining whether values
for nonfatal risk reductions are "reasonable" compared to values for fatal risk reductions. In addition, the
calculation of the value of a lifetime case of cryptosporidiosis contains several computational errors, and
represents the loss of all waking time (not just losses attributable to cryptosporidiosis) and so is seriously
overstated. Perhaps most important, the approach used to value time losses in the Enhanced COI estimate
is appropriate only for marginal changes in time use; it is not appropriate for the types of lifetime changes
considered in the comparison.
Other commenters said that using a COI methodology underestimates the benefits of the rule. EPA agrees
that the cost of illness methodology underestimates the economic impact of illness and prefers to use
willingness-to-pay WTP values when available. Unfortunately, a WTP value for cryptosporidisis is not
available. To partially address the underestimation problem, EPA included an enhanced COI approach
that attempts to more fully account for with elements missing in the traditional COI approach such as
losses to nonwork time.
c. Discount rates/Discounting Benefits and Costs:
Several commenters stated that EPA should not discount benefits. They noted that doing so discounts our
children's future or that of future generations or other subpopulations. EPA believes that we should
discount the benefits of the LT2ESWTR. Discounting is carried out in order to make future benefits and
costs comparable in today's dollars. It equally impacts both benefits and costs that occur in the future.
EPA followed both its Economic Guidelines and OMB's A-4 Economic Guidelines in applying
discounting to the benefits and costs of the LT2ESWTR. Both of these documents have extensive
discussion of discounting including the economic rationale for discounting and also explain why we use
3% and 7% discount rates.
Other commenters noted that future costs and benefits must be discounted to present values. EPA
discounted future benefits and costs to present values in both the proposed and final LT2ESWTR.
Some commenters requested that EPA discount implementation costs over 10 years because
implementation will continue well after the rule is promulgated. This is not necessary as EPA already
considers costs and benefits in the year they are expected to occur. EPA then uses the social discount rate
to calculate present values for the stream of benefits and costs that occur in different years.
d. Value of Statistical Life Years and Cost Effectivness/QALYs:
Several commenters suggested that the Agency use a Quality Adjusted Life Years (QALY) or Life Years
approach in its valuation of health benefits for the Stage 2 DBPR . EPA has added a QALY analysis in
response to and in accordance with the new OMB Circular A- 4 Guidelines for Economic Analysis. The
QALY analysis can be found in Appendix N of the final EA. However, EPA still has concerns about
using both QALYs and other life year approaches.
Comment Response for the LT2ESWTR 20-2 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
The use of cost effectiveness methodologies, such as Quality Adjusted Life Years (QALYs) and life years
approach, has been extensively discussed both within EPA and also before the Environmental Economics
Advisory Committee (EEAC) of EPA's Science Advisory Board (SAB). The QALY method allows
information on life expectancy and quality of life to be combined into a single number for benefits
valuation purposes. QALYs involve rating each year of life on a scale from zero to one, where one
represents perfect health and zero represents the worst possible health state. Because patients themselves,
or sometimes citizens of the community, are responsible for "rating" each year, these quality-of-life
tradeoffs are highly subjective and may not be very meaningful.
Regarding the use of QALYs, the SAB committee stated that there are no published studies that show that
persons with physical limitations or chronic illnesses are willing to pay less to increase their longevity
than persons without these limitations. People with physical limitations appear to adjust to their
conditions, and their WTP to reduce fatal risks is therefore not affected. The EEAC suggests that no
adjustments be made to the VSL to reflect the health status of persons whose cancer risks are reduced,
unless additional research documents such effects" (SAB 2000). Consistent with this idea, the QALYs
analysis of the Stage 2 DBPR EA values the starting health of all members of the population at "1.0" and
does not account for varying degrees of wellness or ability of sub-populations. Hence, the value of
avoiding the illnesses associated with exposure to DBFs is treated as equal for all members of the
population
EPA is still evaluating the appropriate methods for application of cost effectivness analysis (CEA)
(including QALYs) to environmental regulations. To summarize, benefit-cost analysis has been the
preferred method of choosing among regulatory alternatives in terms of economic efficiency for
environmental regulations. Most environmental regulations have multiple categories of benefits, and
environmental economists have preferred to aggregate results in terms of monetary net benefits. QALY-
based analyses also have not been as accepted in the environmental economics literature because of
concerns about the theoretical consistency of QALYs with individual preferences (Hammitt, 2002),
treatment of benefits other than human health, and a number of other factors (Freeman, Hammitt, and De
Civita, 2002). Concerns with the standard QALY methodology include consistency of CEA indices across
multiple contexts; the treatment of people with fewer years to live (the elderly); fairness to people with
preexisting conditions that may lead to reduced life expectancy and reduced quality of life; and how the
analysis should best account for nonhealth benefits.
Use of QALYs as a measure of effectiveness for environmental regulations is still developing, and while
the analysis in the appendix to the final economic analysis provides one framework for using QALYs to
evaluate environmental regulations, there are clearly many issues, both scientific and ethical, that need to
be addressed with additional research. Currently, the Intitutes of Medicine panel is evaluating QALYs and
other effectiveness measures will attempt to develop criteria for choosing among the measures that will
potentially be useful in regulatory impact analysis; make recommendations regarding measures
appropriate for assessing the health benefits of regulatory interventions; and propose criteria for
identifying regulations for which CEA is appropriate and informative. However, it remains uncertain
when consensus on the applicability of the QALY approach to environmental regulations, and the
appropriate methodology for doing so, will be reached and whether additional guidance will be provided
by EPA. Please refer to the final EA, Appendix N, for a more in-depth discussion of QALY issues.
A Life Years approach involves use of a Value of Statistical Life Year (VSLY) measure. The VSLY
measure values life-years that would be lost if an individual were to die prematurely. The relationship
between the value of risk reductions and expected life years remaining is complex; current research does
not provide a definitive way of developing estimates of VSLY that are sensitive to such factors as current
age, latency of effect, life years remaining, and social valuation of risk reduction. While age adjustments
may be desirable from a theoretical standpoint, in the absence of such information, the mainstream
economics literature does not support developing VSLY estimates.
Comment Response for the LT2ESWTR 20-3 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
The SAB's Environmental Economics Advisory Committee (EEAC), in its report, confirmed this finding.
The use of VSLY for valuing life-years lost was found by the EEAC to not have a sufficient theoretical
and empirical basis for making any adjustments at this time. While the EEAC agreed that the theoretically
appropriate method is to calculate WTP for individuals whose ages correspond to those of the affected
population, the Committee recommended that more research be conducted on this topic before the
Agency make any adjustments for age in its estimates of health risk reduction benefits.
Therefore, because of the limitations enumerated above, EPA disagrees with the use of the VSLY as a
measure of benefits as well as the use of cost per VSLY. This position has also been incorporated in the
Agency's Guidelines for Preparing Economic Analyses (US EPA. 2000k). The Agency's economic
analysis guidelines were reviewed and approved by the Regulatory Policy Council and are considered
when the Agency makes economic policy determinations.
At this time, current Agency policy is to use VSL estimates for the monetization of health risk reduction
benefits. This policy is also consistent with recommendations from the EPA's SAB, which discussed this
issue in a meeting held on February 25, 2000 in Washington, DC. The SAB's report on their findings and
recommendations states that "despite limitations of the VSL estimates, these seem to offer the best
available basis at present for considering the value of fatal cancer risk reduction. We therefore
recommend that the Agency continue to use a wage-risk-based VSL as its primary estimate, including
appropriate sensitivity analyses to reflect the uncertainty of these estimates" (SAB 2000). EPA agrees
with these SAB recommendations and they are reflected in the economic analysis for the final LT2
ESWTR.
e. Analysis by System Size/Type:
Some commenters noted that the costs may exceed benefits for smaller size systems. EPA agrees that for
some drinking water regulations the quantified costs may exceed the quantified benefits because the
populations served by these systems are much smaller. Generally, large systems benefit from economies
of scale which eases the relative impact on these systems.
Other commenters suggested that EPA should exclude or set different standards for small systems based
on benefit and cost analysis, including incremental analysis, by systems size or type. However, the
SDWA does not generally provide a basis for establishing tailored drinking water standards as these
commenters suggest. Rather, the SDWA is designed to ensure uniform levels of public health protections
across the country (except a specifically provided for in variances from the standard). Moreover,
Congress expressly prohibited EPA from altering drinking water rules addressing Cryptosporidium based
on cost/benefit analysis or affordability, in contrast to other drinking water standards. See SDWA sections
1412(b)(6)(c) and 1415(e)(6). In addition, certain Executive Orders such as the Executive Order 12898
(Environmental Justice) reinforce this approach to the SDWA and are specifically designed to ensure that
low-income and minority communities are protected at levels afforded to those nationally.
Thus EPA disagrees with the suggestion that the level of the final standard be altered to address system
size or type. However, as discussed in detail in the preamble to the final rule, SDWA does provide some
ability to tailor the standards to reflect individual system conditions through such mechanisms as
variances, exemptions, and various funding authorities. Regarding affordability, as noted above variances
based on affordability are not allowed by the SDWA for regulations addressing microbial contamination,
and EPA did not conduct an affordability analysis. However, EPA has considered the SAB review of the
arsenic rule and the suggestions of the NDWAC arsenic cost working group regarding the further
desegregation of the analyses. The NDWAC group recommended calculation and presenting cost
information in multiple size categories, which is done in the EA.
Comment Response for the LT2ESWTR 20-4 December 2005
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In addition, the Agency took many steps to reduce the burden on small systems where possible. More
information regarding this effort can be found in Chapter 6 of the EA. In response to the general request
for further disaggregation of data, EPA revised the presentations of benefit and cost estimates in the
related chapters of the EA. Specifically, costs and benefits by size category and for filtered versus
unfiltered PWSs are now reported in more detail in the Chaters 5 and 6 of the EA.
f Cumulative Impact of Regulations:
Commenters were concerned that EPA's methodology for estimating rule costs for States and systems
fails to consider the cumulative burden posed by the Safe Drinking Water Act (SDWA). Systems have a
strong dependency upon States for technical and information assistance, and States find it increasingly
difficult to absorb and communicate regulatory requirements.
EPA recognizes the burden that the various regulations under the SDWA places on States and water
systems. Congress required EPA to promulgate the LT2ESWTR as part of the 1996 SDWA Amendments
(section 1412(b)(2)(C)). EPA calculates the cost for each regulation independently to ensure that the
benefits of each rule justify the cost, as was determined for the LT2ESWTR. In today's final rule, EPA
has made several changes to the proposed LT2 ESWTRto decrease the burden of the rule on systems and
States, as detailed in the preamble and Chapter 6 and 7 of the EA.
Additionally, States and systems can obtain financial assistance for rule implementation from the
Drinking Water State Revolving Fund (DWSRF). Systems can also obtain funding from the Department
of Agriculture's Rural Utility Service (RUS) and the Housing and Urban Development's Community
Block Grant (UDCB) Program. Systems that apply for funding for implementation of SDWA rules are
expected to receive priority.
One commenter proposed including a regulatory circuit breaker clause that would take effect when
compliance with SDWA rules exceeds 1.75 Adjusted Gross Income (AGI) of the consumers of small
systems. At this time, commenters suggest small systems initiate negotiations with the State regarding
SDWA rules with which they must comply and rules from which small systems can be excused. EPA
does not believe that a circuit breaker clause or other prioritization among contaminants and regulations is
appropriate because itis not provided for in the SDWA and it can lead to inferior water quality in certain
systems. EPA is committed to ensuring that all systems provide equally high quality water, regardless of
size, source water, or location (e.g., urban versus rural).
g. Incremental benefits and costs:
Several commenters have stated that EPA has not met the SDWA requirement in §1412(b)(3)(C)(i)(IV)
that states that the Agency must analyze the incremental costs and benefits associated with each
alternative maximum contaminant level considered. EPA has met this requirement by conducting an
incremental analysis which is described in the section VI-F of the preamble for the proposed rule.
Incremental benefits are also discussed in the Economic Analysis of the proposed.
Several other commenters stated that the proper interpretation of SDWA is to use only an incremental
analysis to determine if the benefits justify the costs. EPA respectfully disagrees with this interpretation
because 1412(b)(4)(C) of the SDWA states "...the Administrator shall publish a determination as to
whether the benefits of the maximum contaminant level justify, or do not justify, the costs based on the
analysis conducted under paragraph (3)(C)." Paragraph (3)(C) contains the description of the seven
Health Risk Reduction and Cost Analysis elements that the Agency must consider. These seven elements
include quantifiable and nonquantifiable heath risk reduction benefits, quantifiable and nonquantifiable
Comment Response for the LT2ESWTR 20-5 December 2005
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health risk reduction benefits from reducing co-occurring co ntaminants, quantifiable and nonquantifiable
costs, incremental costs and benefits, effects of the contaminant on the general population as well as on
any sensitive sub-populations, possible increased health risks, and uncertainties in the analysis of any of
these elements. Therefore, the Agency must consider all seven elements, not just incremental benefits and
costs, when determining if the benefits of the proposed rule justify the costs.
Some commenters noted that we should only consider incremental costs by system size. Other
commenters suggested that EPA should exclude or set different standards for small systems based on
OO J
benefit and cost analysis, including incremental analysis, by systems size. EPA's response to these
comments can be found in response code 2200 E.
h. Clarity and transparency:
EPA recognizes that analyses supporting assessments of costs, benefits, and other impacts of today's final
rule are inherently complex. As discussed in the Economic Analysis, this complexity is due the number of
factors that must be addressed, the variability and uncertainty in those factors, and the national scope of
the rule (and, consequently, the analyses). Recognizing this complexity, the Agency has attempted to
present these analyses clearly in order to achieve the goals or transparency and reproducibility. This has
involved presenting all data sources and assumptions and adding or clarifying discussions and figures in
response to comments by the Science Advisory Board, peer reviewers, and the public. Nevertheless, EPA
is aware that some analytical techniques applied in these assessments require specialized expertise to
understand (e.g., statistical analyses of occurrence or dose-response). However, EPA believes that the use
of these techniques is appropriate in order to achieve the most accurate impact assessments for the rule.
i. Did not meet HRRCA requirements
Several commenters stated that EPA did not correctly comply with Health Risk Reduction and Cost
analysis requirements outlined in the SDWA. EPA respectfully disagrees and we have analyzed all seven
HRRCA elements that are outlined in §1412 (b)(3)(C) of the SDWA. These seven elements include
quantifiable and nonquantifiable heath risk reduction benefits, quantifiable and nonquantifiable health risk
reduction benefits from reducing co-occurring contaminants, quantifiable and nonquantifiable costs,
incremental costs and benefits, effects of the contaminant on the general population as well as on any
sensitive sub-populations, possible increased health risks, and uncertainties in the analysis of any of these
elements. The Agency conducted an analysis of all seven elements for both the proposed and final rules.
The summary of the analysis is included in the preamble while the complete analysis can be found in the
Economic Analysis document. The EA has a HRRCA cross-walk index located near the table of contents
that directs the reader to where they can locate the HRRCA analysis in the EA document. Commenters
also noted that EPA is required to use the HRRCA analysis to set MCLs or treatment techniques. SDWA
does require the agency to prepare a HRRCA for all rules; however, it specifically excludes the LT2 rule
from the authority to change either treatment techniques or MCLs as a result of the HRRCA. See
1412(b)(6)(c). Other commenters stated that the HRRCA requires EPA to only include benefits that are
likely to occur as a result of the rule. The Agency has included in its benefit analysis both qualitative and
quantitative discussion of the benefits likely to occur as a result of the LT2ESWTR as required by the
SDWA. In order to give further perspective on the likely benefits of the rule, both the quantitative and
qualitative analyses explore data uncertainties that results in a range of likely quantified rule
cryptosporidiosis reductions benefits and a qualitative discussion of other benefits.
Specific issues regarding HRRCA elements can be found in these responses:
1) Incremental analysis: see response 2200g.
2) System size/Type: see response 2200e
3) Use of science and applicable statutes: see response lOOh.
Comment Response for the LT2ESWTR 20-6 December 2005
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4) Use best available data: see response lOOb.
j. Endemic risk already addressed in LT1:
A commenter noted that we do not need the LT2ESWTR because we already addressed endemic risk in
the LT1 rule. EPA respectfully disagrees. The IESWTR and LT1ESWTR achieved a degree of
Cryptosporidium risk reduction for large and small systems, respectively. As discussed in the preamble,
EPA believes that this risk reduction is sufficient for the majority of filtered systems. However, data
discussed in the preamble indicate that additional risk reduction is required for a subset of vulnerable
systems. These include all unfiltered systems and those filtered systems with relatively high source water
Cryptosporidiu levels where the treatment required by the IESWTR or LTIESWTR is not sufficient.
k. Benefits overestimated/costs underestimated:
EPA received several comments that the benefits or costs were either over or under estimated.
Assessment of benefits and costs in cases where not all information can be precisely known, as is the case
here, is a challenging exercise. However, we believe the benefits and costs have been correctly calculated,
within the limits of available data and information, and that they adequately support both the proposed
and final rules. The Agency understands the importance of uncertainty analysis given the data limitations
and has analyzed the major sources of uncertainties in today's rule. Chapters 5 and 6 of the EA provide
more in-depth information on uncertainty analyses. The assessments of costs and benefits for today's final
rule have undergone review by the Science Advisory Board and peer review. Further, the Agency has
incorporated data on costs for UV disinfection and uncovered reservoirs submitted by commenters to
improve the accuracy of those cost estimates.
1. Benefits and costs uncertain: (see general comments 100 s)
m. Isolate costs for finished water reservoirs:
The Economic Analysis for today's final rule shows isolated costs for covering or treating uncovered
finished water reservoirs.
n. Follow EPA and OMB Economic guidelines
EPA agrees that we need to follow Agency and OMB economic guidelines and we have done so for both
the proposed and final rules. The Agency worked closely with Agency economists and OMB to ensure
that both guidelines are fully met for both the proposed and final rule.
o. Don't consider benefits from endemic cases
A commenter stated that we should not consider endemic cases when calculating benefits because many
don't show up in public health surveillance data and they may be too mild to be economically significant.
EPA believes that endemic cases are significant in terms of public health risk and economic impacts.
Only a small fraction of the millions of cases of gastrointestinal illnesses are traced back to a specific
illness (such as cryptosporidiosis), yet it is clear that endemic disease exists and those illnesses, even if
mild, have public health consequences and economic impacts. For example, the benefits model in the EA
assumes that 88 percent of all cases are mild, and those illnesses represent significant impacts nationally.
Further, the risk assessment model separately computes infections and illnesses. Thus, asymptomatic
infections are excluded: only avoided illnesses are assigned monetary benefits.
p. Nonqualified benefits and Toolbox options
Comment Response for the LT2ESWTR 20-7 December 2005
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A commenter emphasized that the unquantfied benefits that derive from the microbial toolbox are the
essence of the appeal of the toolbox approach, but are not discussed in enough depth in the EA. These
technologies can, for example, remove additional contaminants and enhance the performance of the
primary treatment train by stabilizing water quality. EPA agrees that there are substantial unquantified
benefits from the toolbox technologies, and has briefly summarized these benefits in this preamble and
the EA. However, EPA lacked specific data to quantify these benefits but we agree that by not including
many of these alternatives that costs may be overestimated.
q. Did not follow EPA's or OMB's Economic Guidelines
Several commenters noted that EPA failed to follow EPA's or OMB's Economic Guidelines. For
example, they note that EPA failed to consider incremental net benefits. EPA respectfully disagrees with
these commenters. EPA followed both EPA and OMB's economic guidelines, as well as the economic
guidelines outlined in the SDWA (HRRCA), in developing the proposed and final rules.
Please see response 2200i for specific HRRCA issues and response 2200g for incremental net benefit
analysis concerns.
r. Household cost analysis and equitable treatment of small systems
A commenter noted that the household cost analysis in the preamble indicates that a larger burden of the
LT2ESWTR will be placed on small systems and that instead costs should be spread evenly across the
community and small systems should be subsidized by the government. EPA treats all drinking water
systems equitably in the sense that treatment is only tied to source water quality and not size or type. The
main reason that the household cost analysis indicates higher costs for those served by small systems is
the direct result of having fewer household to share the costs. In addition, small systems do not have
economies of scale that large systems do which often results in relatively higher operation costs.
Furthermore, the drinking water state revolving fund has special set-asides to assist small drinking water
systems. Government assistance may also be available from other programs as explained in more detail in
Chapter 7 of the EA.
s. Sensitivity analyses.
In the Economic Analysis for today's rule, the Agency has used different values for critical parameters to
show the sensitivity of the estimates to those parameters. Specifically, the Agency has analyzed benefits
and costs independently using different distributions of Cryptosporidium occurrence and with different
dose-response models. Further, the Agency has used distributions, rather than point estimates, to account
for uncertainty in parameter values and reflect this uncertainty in estimates of benefits and costs.
Individual Comments on Code 2200
EPA Letter ID: 101
Comment ID: 10916
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: NRWA believes that (1) Risk assessments should be fully transparent and based on the use of
central tendency estimates of the value of risk parameters, (2) USEPA should use sensitivity analyses to
Comment Response for the LT2ESWTR 20-8 December 2005
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demonstrate the collective impact of precautionary assumptions, and (3) USEPA should account for
latency in cancer induction by appropriate discounting. (Raucher 2003) [SEE P. 283 OF .PDF FILE]
NRWA believes that (1) USEPA should practice full disclosure and provide complete transparency by
listing all precautionary assumptions imbedded in MCL development and the HRRCA assessment of a
regulation, and (2) for those contaminants that risk assessment shows need regulation, MCL values
should be based on a comprehensive HRRCA that utilizes central tendency estimates of incremental net
benefits and on risk assessments that consider exposures of various magnitudes, frequencies, and
durations (MDFs). (Koorse 2003) [SEE P. 257 OF .PDF FILE]
USEPA should be required in developing MCLs to provide an objective MDF+-basis for determining
under what circumstances noncompliance will be deemed "significant noncompliance" from a public
health perspective. (Koorse 2003)
The SDWA should be amended to require USEPA to establish compliance provisions for MCLs that
reflect the analytical error band associated with each contaminant. For example, a system should not be
deemed out of compliance with an MCL until it exceeds the MCL by two standard deviations of the
results of the USEPA approved analytical method(s). (Koorse 2003)
Rationale: USEPA bases regulatory decisions on an assessment of the potential human health risk of the
contaminant(s) to be regulated. These risk assessments typically include conservative assumptions based
on Agency policy (Raucher 2003). Blending of science and policy occurs because of the uncertainties and
variabilities that exist in estimating risks. These uncertainties cannot be easily resolved or circumvented,
and because decision-makers sometimes must proceed despite the existence of large and unresolved
uncertainties. As a result, many policy-based judgments are embedded in how risk assessments are
performed. These science policy assumptions tend to be very conservative, based on a precautionary
approach that seeks to err on the side of safety.
Precautionary assumptions and adjustment factors are suitable when the calculations are used strictly in a
risk assessment context such as establishing a no risk goal such as the MCLG. However, for risk
management decisions in determining how strictly to set an MCL, it is contrary to good science and
statutory directives to carry forward risk estimates impacted by precautionary policy assumptions.
Science policy assumptions that are too conservative result in an inflated estimate of the level of risk
posed by contaminants, and therefore to an overstatement of the benefits of regulation. It is not
unreasonable to expect that benefit estimates derived using precautionary assumptions may be 10, 20,
100, or even many more times higher than expected using mean or median estimates.
Response: See responses 2200.h, 2200.k, and 2200.s. Today's rule does not address cancer risk. Today's
rule establishes treatment technique requirements rather than MCLs. As described in the preamble, EPA
has considered the accuracy of analytical methods in establishing compliance requirements in today's
rule.
EPA Letter ID: 101
Comment ID: 10917
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 20-9 December 2005
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Comment: USEPA is required to prepare a Health Risk Reduction and Cost Analysis (HRRCA)
and use the analysis when setting MCLs. Raucher and Damodaran (2003) [SEE P. 316 OF .PDF FILE]
note that HRRCAs developed to date have not consistently adhered to applicable guidelines, directives, or
recommendations of the Office of Management and Budget (OMB), USEPA Science Advisory Board
(SAB), and the US General Accounting Office (GAO). Among the key areas needed to improve the
technical content of HRRCAs are the following:
- Improved transparency and consistency, including illustration of the extent to which precautionary
assumptions influence the projected health risks and benefits.
- Presentation of the "most likely" or "central tendency" estimates of benefits and costs. To the extent
possible, central tendency estimates should be used in MCL development and in HRRCA estimates with
upper and lower bounds provided for these estimates.
- Consistently using incremental net benefits as a basis for identifying the potential health standards most
likely to maximize net social benefits and, hence, as a core criterion for interpreting when costs are
"justified" by the benefits.
- Consistently providing benefit and cost information on a system size basis, so that incremental-net-
benefits information for small systems (and not only aggregate national estimates) is available to
decision-makers. USEPA should develop cost estimates by system sizes rather than as national
aggregates.
- Properly accounting for latencies and cessation lags in cancer risk reductions, and then discounting
benefits appropriately.
- Providing HRRCA information in a timely fashion to stakeholders and decision-makers so that the
information precedes the MCL decision and can be used to enlighten deliberations about regulatory
option selection.
Response: See responses lOOh, lOOc, 100k, 2200e, 2200i, 2200g
EPA Letter ID: 101
Comment ID: 10918
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: In setting MCLs, USEPA should be required to develop information not just on lifetime
exposure, but also on the risks associated with excursions of varying magnitude, duration, and frequencies
(MDFs). Obviously, short duration exposures to contaminants that require years to produce any
measurable effect are of limited significance and yet exceeding the MCL by any amount is potentially a
noncompliance requiring treatment under present practice. EPA accounts for this to a degree by looking at
average concentrations over time, but quantitative guidelines to govern enforcement actions are badly
needed.
Response: This comment is not relevant to the LT2ESWTR, which establishes treatment technique
requirements, rather than MCLs, to control an acute contaminant - Cryptosporidium.
EPA Letter ID: 101
Comment ID: 10919
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 20-10 December 2005
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Comment: Regulatory Practice and Balance
There are a wide variety of regulatory practices that have varying impacts on small systems, but perhaps
not as directly or forcefully as those in the previous two areas. These practices are concerned with topics
ranging from acceptable risk to sensitive subpopulations to benefit-cost analysis and NRWA is concerned
that small systems receive equitable treatment compared to large systems in the application of these
practices and that proper balance is maintained between regulatory expediency and these equity issues.
NRWA has adopted a large number of policies as follows that deal with these wide ranging issues. For
ease of reference, these policies are subdivided into sub-categories of Risk Assessment, Risk
Management, and Benefit-Cost Analysis (note: BCA is really a subset of Risk Management, but is
considered separately because of its importance)
Response: See responses 2200e, 2200r
EPA Letter ID: 101
Comment ID: 10920
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Risk Assessment
NRWA strongly believes that all rules under the Safe Drinking Water Act should be based on solid peer
reviewed science and supported by adequate, quality data appropriate to all sized systems.)
NRWA believes that occurrence of and exposure to contaminants should be assessed across all water
system sizes and take into account the most sensitive population groups for each contaminant. (Griffiths
2001)
NRWA supports the consideration of sensitive sub-populations in the development of drinking water
standards. To do so, small and rural water systems must have the flexibility to meet local sub-population
needs through alternative approaches appropriate to local conditions. (Griffiths 2001)
Rationale: The 1996 SDWA amendments specifically require USEPA, to the degree that an Agency
action is based on science, to use the best available, peer-reviewed science and supporting studies
conducted in accordance with sound and objective scientific practices. USEPA must use data collected by
accepted methods or best available methods (if the reliability of the method and the nature of the decision
justifies use of the data).
Application of the SDWA 'sound science' requirement to the regulatory process was clarified on March
31, 2000, when the U.S. District Court issued a ruling vacating the MCLG for chloroform (Court of
Appeals 2000). The Court found that USEPA had indeed violated the SDWA by failing to use the best
available, peer-reviewed science in setting the MCLG. The Court found the zero MCLG to be arbitrary
and capricious, and in excess of statutory authority at the time of a rulemaking. The possibility of
contradiction based on future scientific data or peer review is not a legitimate basis for rejecting the
science that currently exists. USEPA may be acting illegally when it relies on default assumptions,
when the best available science supports less-conservative approaches for assessing risk.
A sensitive sub-population is one that is at increased risk of some adverse health event or outcome after
exposure to a contaminant in drinking water. By increased risk, this means an increase when compared to
Comment Response for the LT2ESWTR 20-11 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
the total general population.
Griffiths (2001) has reviewed the characteristics of and issues associated with sensitive sub-populations.
He notes that all people, no matter their personal beliefs, customs, or health, move in and out of being a
sensitive sub-population through their normal life cycle. The 1996 SDWA amendments require USEPA
to consider susceptible subpopulations when making health risk assessments.
Response: See responses lOOb, lOOp, 2200e, 2200i.
EPA Letter ID: 101
Comment ID: 10928
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Benefit-Cost Analysis
NRWA believes that (1) both benefits and costs are an important consideration in setting drinking water
standards and (2) in balancing the benefits and costs of regulations, the appropriate parameter to use is
incremental net benefits. (Raucher 2001) [SEE P. 89 OF .PDF FILE]
Rationale: The SDWA as amended in 1996 requires USEPA to conduct a benefit-cost analysis (known as
a Health Risk Reduction and Cost Analysis, or HRRCA) that contains both quantitative and non-
quantitative information, compares incremental benefits to incremental costs, and indicates the presence
and impacts of uncertainties. Based on the HRRCA, USEPA is required to issue a formal determination
that the benefits of each standard justify the costs. The agency may set MCLs at levels other than what is
technologically feasible if the benefits are found not to justify the costs.
Raucher (2001) notes that, in accordance with standard economic principles, the objective should be to
identify the MCL at which the benefits exceed the costs by the widest margin-the point where the "net
benefits" are the greatest. The MCL that yields the greatest net benefits is the point where "incremental
benefits" still outweigh "incremental" costs and where moving to a more stringent option would add more
costs than benefits (where incremental benefits become outweighed by incremental costs).
Response: See responses lOOc, 2200g, 2200i
EPA Letter ID: 470
Comment ID: 11100
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Economic Analysis pp.47738-47758
Vermont is in support of the Association of State Drinking Water Administrators- comments on this
section.
Comment Response for the LT2ESWTR 20-12 December 2005
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Response: response lOO.a.
EPA Letter ID: 472
Comment ID: 11186
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: P. 47758. L. Request for Comment
The Agency requests comment on all aspects of the proposed rule-s economic impact analysis.
Specifically, EPA seeks input into the following issues:
In general, the COP requests the cost benefit comparisons include several system size categories instead
of the two very broad categories of <10,000 population and >10,000 population. We suggest these
population categories, 0-10,000, 10,001-50,000, 50,001-250,000, 250,000-1,250,000 and > 1,250,000.
The COP also suggests the Agency should follow the tenants of its own Guidelines for Economic
Analyses to support the final rule. If the Agency chooses not to follow its- own guidelines, an explanation
is due as to why this rule is an exception.
Response: See responses 2200e, 2200q
EPA Letter ID: 516
Comment ID: 11713
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 2. COST-BENEFIT AND RISK ANALYSIS
While EPA has prepared an extensive and detailed compilation of background material, and conducted a
rigorous risk analysis, no attempt has been made to compare the risk conclusions against public health
data, or to clearly describe the uncertainties in the assessment, in relation to these data. Moreover, DEP
believes that EPA has consistently overestimated risk and underestimated cost to oversell both the need
for the rule and its purported benefits. The following represent some of the issues.
Response: responses 100.s, 500.b, and 2200.k
EPA Letter ID: 516
Comment ID: 11717
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Finally, EPA-s assessment does not address the substantive costs for other related water
supply risk mitigation efforts that water utilities supplying very large urban systems have to consider.
Comment Response for the LT2ESWTR 20-13 December 2005
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While the EA should be somewhat independent of these other cost demands, the information should be
included as part of the evaluation of whether the health risk reduction measures are truly worth the costs,
given all of the uncertainties in the analysis, and the effect of all of the other engineering projects on
water rates. These other costs include those incurred from projects to improve system reliability and
repair aging infrastructure. For example, DEP is spending upwards of $6 billion for Water Tunnel # 3 to
enhance system reliability. Also, as a result of 9/11, large systems such as New York-s have to spend
additional monies for substantive new security measures. While the incremental costs of each capital
measure may be small, the added effect of all of the risk reduction measures for infrastructure reliability,
security, and water treatment, may exceed the financial capabilities of even the largest cities.
Response: See response 100s, 100k, 2200e, 2200f
EPA Letter ID: 516
Comment ID: 11727
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Overall, with the large number of charts and analyses, DEP found it difficult to determine
what is EPA-s judgement regarding a realistic assessment of costs and benefits associated with the rule,
for different size systems, and the degree of uncertainty. This problem was compounded by EPA-s
modeling of risk cost and benefit using different categories of systems sizes (i.e. number of people
served). For example, as indicated on page 4-10 of the EA, in some analyses nine system size categories
are used, and in other analyses four sizes or even (for net benefit estimates) two sizes are used. The
rationale for grouping different size systems in different ways is not readily apparent. The analysis would
be more transparent if EPA aggregated the different type of systems in a consistent manner in the cost,
benefit, and risk analyses sections. After EPA incorporates any comments, it should be explicit as to
whether the response to comments changes any of the Agency-s conclusions regarding the net benefits.
Response: See response 100k, 2200e. No comments submitted on the proposed rule have changed the
Agency's overall conclusions regarding the net benefits of the LT2ESWTR. The Agency continues to
believe that the benefits of this rule significantly exceed the costs, so that the net benefits are positive.
EPA Letter ID: 522
Comment ID: 14130
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: costly requirements for overlapping safety and redundancy factors. Third, that even where we
agreed with the substance of the regulation, the supporting cost-benefit analysis in the preamble seemed
to be substantially over-reaching what the science and evidence would justify. It was clear during the
FACA process that the data to develop a cogent risk and benefits estimation was lacking. It still seems to
be lacking. EPA will need to carefully rework this material if the analysis is to be believable and provide
a basis for what will be substantial investments by water systems across the nation.
Response: See responses lOOr, lOOb
Comment Response for the LT2ESWTR 20-14 December 2005
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EPA Letter ID: 527
Comment ID: 10865
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Economic Analysis
The Agreement in Principle calls for EPA to prepare a health risk reduction and cost analysis (HRRCA)
for LT2ESWTR. EPA has prepared an extensive and detailed compilation of background material.
However, the analysis does not clearly communicate the most critical information to interested and
involved parties such as ourselves.
The Agency-s analysis involves a number of assumptions that have significant impacts on the resulting
estimates of risks, benefits and costs. The Agency does not always clearly articulate what assumptions it
is making and it often takes a one-sided view of relevant uncertainties and data limitations to derive its
interpretation.
EPA should follow the basic tenants of its own Guidelines for Economic Analyses in revising the EA to
support the final rule. Following these Guidelines the Agency should: (1) be explicit regarding its core
assumptions, (2) document the basis for those assumptions, and (3) develop some useful sensitivity
analyses to evaluate and convey the impact of core uncertainties on the outcomes of the analysis. The net
effect of following the Agency-s guidelines would be a more robust and transparent analysis that will be
more realistic and, we believe, reduce the lower bound estimate of anticipated benefits from the proposal.
Response: See responses 100k, 100s, 2200i, 2200q
EPA Letter ID: 527
Comment ID: 10865
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Economic Analysis
The Agreement in Principle calls for EPA to prepare a health risk reduction and cost analysis (HRRCA)
for LT2ESWTR. EPA has prepared an extensive and detailed compilation of background material.
However, the analysis does not clearly communicate the most critical information to interested and
involved parties such as ourselves.
The Agency-s analysis involves a number of assumptions that have significant impacts on the resulting
estimates of risks, benefits and costs. The Agency does not always clearly articulate what assumptions it
is making and it often takes a one-sided view of relevant uncertainties and data limitations to derive its
interpretation.
EPA should follow the basic tenants of its own Guidelines for Economic Analyses in revising the EA to
support the final rule. Following these Guidelines the Agency should: (1) be explicit regarding its core
assumptions, (2) document the basis for those assumptions, and (3) develop some useful sensitivity
analyses to evaluate and convey the impact of core uncertainties on the outcomes of the analysis. The net
Comment Response for the LT2ESWTR 20-15 December 2005
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effect of following the Agency-s guidelines would be a more robust and transparent analysis that will be
more realistic and, we believe, reduce the lower bound estimate of anticipated benefits from the proposal.
Response: See responses 100k, 100s, 2200i, 2200q
EPA Letter ID: 556
Comment ID: 12045
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. Uncertainty
Discussion: The proposal discusses the significant uncertainties involved in all aspects of the rule. There
is a major disconnect between what utilities are measuring and what may be causing problems. This
follows from the fact that the analytical method (1622/1623) does not allow measurement of the
contaminant of interest in source water, nor is the risk assessment based on what is actually measured to
occur in source water. This method measures a surrogate and the Agency (and other researchers) do not
know how that surrogate relates to actual risks.
Specifically, the analytical method does not measure the Cryptosporidium that is infectious to humans.
Rather it detects a long list of items, which may or may not be relevant to human health, or may or may
not be relevant at the levels found. It is certainly not specific to the three strains of Cryptosporidium used
in the risk assessment. A further problem is the fact that the hypothetical mix of the three strains used to
characterize the risk of Cryptosporidium certainly does not exist in surface waters.
Although AMWA believes that EPA has made and justified educated estimates to bridge these and other
major uncertainties, the bottom line is that many remain speculative. Many of these estimates are not
addressed through uncertainty analyses. AMWA continues to believe that the benefits of the regulation
will be positive and that the action outlined by the FACA is appropriate. Nevertheless, AMWA does not
find the apparent certainty portrayed in cost-benefit discussions compelling.
Recommendation: AMWA believes EPA has done a credible job of stating that there are many
uncertainties involved in the regulation, but could do a better job of portraying the uncertainties in the
proposal, particularly in the area of benefits, so that they are understood by the average reader.
Response: Response 100.s and 2221.2. EPA disagrees with the statement that the analytical methods
(1622 or 1623) required for monitoring under the rule only measure a surrogate that is not infectious to
humans. These methods measure Cryptosporidium directly, including the infectious Cryptosporidium that
today's rule is designed to reduce in treated water. As discussed in the preamble, EPA has accounted for
the fact that these methods also measure Cryptosporidium that may not be infectious and for false
positives.
EPA Letter ID: 556
Comment ID: 12081
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
Comment Response for the LT2ESWTR 20-16 December 2005
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(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: E. Economic Analysis
Discussion: The Agreement in Principle calls for EPA to prepare a health risk reduction and cost analysis
(HRRCA) for LT2ESWTR. EPA has prepared an extensive and detailed compilation of background
material. However, the analysis does not clearly communicate the most critical information to interested
and involved parties.
The Agency-s economic analysis (EA) involves a number of assumptions that have significant impacts on
the resulting estimates of risks, benefits and costs. The Agency does not always clearly articulate what
assumptions it is making and often takes a one-sided view of relevant uncertainties and data limitations to
derive its interpretation.
Recommendations: EPA should follow the basic tenants of its own Guidelines for Economic Analyses in
revising the EA to support the final rule. Following these Guidelines the Agency should: (1) be explicit
regarding its core assumptions; (2) document the basis for those assumptions; and (3) develop some
useful sensitivity analyses to evaluate and convey the impact of core uncertainties on the outcomes of the
analysis. The net effect of following the Agency-s guidelines would be a more robust and transparent
analysis that will be a more realistic, and we believe reduced, lower-bound estimates of anticipated
benefits from the proposal.
Response: See responses 2200i, 2200q
EPA Letter ID: 562
Comment ID: 12285
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA is very concerned that the agency-s Economic Analysis documents and preamble
text have created an unrealistic expectation and implied a significantly greater benefit than will actually
be realized through implementation of the LT2ESWTR. The projected risk of endemic cryptosporidiosis
creates a perception of certainty that is then reflected in the urgency of the implementation schedule, the
microbial toolbox, and other rule requirements. This consistent stringency in the microbial toolbox is a
fundamental flaw in the proposal, as the restrictive operational and reporting requirements are out of
balance with the uncertainties surrounding the endemic Cryptosporidium risk. The LT2ESWTR is a
proactive step by the drinking water utility community to further enhance public health in the face of this
uncertainty.
Response: Responses 100.s, 500.b, and 2200.k.
EPA Letter ID: 562
Comment ID: 12320
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1.12 Economic Analysis
The Economic Analysis (EA) and associated support documentation offer extensive detail and
Comment Response for the LT2ESWTR 20-17 December 2005
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information. However, EPA needs to find a better balance in the support documentation so that it provides
not only complete, but also the most critical information to interested and involved parties. To find this
balance, EPA should use more fundamental, informative, and simple analyses of core components rather
than using more sophisticated approaches for some less important aspects of the EA.
In some critical elements of the EA, the agency makes powerful assumptions that can have significant
impacts on the final results of the EA. The agency does not always clearly articulate what assumptions are
being made and often presents a one-sided view of relevant uncertainties and data limitations to derive its
interpretation. In some instances where the agency has made key assumptions, the supporting analysis
lacks sensitivity analyses based on equally or more plausible alternative assumptions.
Our major observations and findings with respect to the EA include:
1. Overall, we believe EPA has considerably overstated the occurrence and risks associated with endemic
levels of cryptosporidium in finished waters, and thus the agency overstates the benefits of the proposed
rule to a considerable degree. The costs of the rule may also be overstated to some degree.
Response: See responses 100s, 100k, 2200h, 2200k.
EPA Letter ID: 562
Comment ID: 12331
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: EPA should follow the basic tenants of its own Guidelines for Economic Analyses in revising
the EA to support the final rule. Following these Guidelines the agency should: (1) be explicit regarding
its core assumptions, 2) document the basis for those assumptions, and (3) develop some useful sensitivity
analyses to evaluate and convey the impact of core uncertainties on the outcomes of the analysis. AWWA
believes the net effect of a more robust and transparent analysis will be a lower and more realistic, lower
bound estimate of anticipated benefits from the proposal.
Response: See responses 2200q, 100k
EPA Letter ID: 562
Comment ID: 12362
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: the LT2ESWTR provisions are being developed. If the agency proceeds to promulgate the
final rule as proposed, AWWA believes that such action is contrary to law, arbitrary and capricious, and
an abuse of discretion for the following reasons:
4. The Economic Analysis (EA) is arbitrary and capricious and an abuse of discretion as the EA
overstates the risk and benefits of the proposed rule, is based on a flawed statistical analysis, and
understates the compliance costs.
Response: See response lOOb, lOOc, 100s, 100k, 2200k, 2200q.
Comment Response for the LT2ESWTR 20-18 December 2005
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EPA Letter ID: 562
Comment ID: 12536
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5 Cost/Benefit Analysis
EPA has made progress by providing considerable discussion and sophisticated numeric evaluation of
several of the uncertainties and variabilities (e.g., using Monte Carlo simulations) for some aspects of the
analysis. On the other hand, EPA neglects to detail, justify, or fully explore some of the most fundamental
of its assumptions. In the face of these core uncertainties, sensitivity analyses are essential for evaluating
the impact of core assumptions at key junctures of the analysis. EPA needs to find a better balance by
using more fundamental, informative, and comprehensive analyses of core components rather than using
more sophisticated approaches for less critical aspects of its analysis.
Hence, at the core of our critique, is the message that EPA needs to take better stock of its analyses,
determine what components are most critical in terms of driving the benefit or cost estimates, and focus
its attention (and that of the reviewers) on those aspects. Models, analytic tools, and documentation
should be presented in a way that facilitates understanding and review.
Response: Responses 2200.h, 2200.k, 2200.s, and lOO.t.
EPA Letter ID: 562
Comment ID: 12537
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.1 Communication of Uncertainty in the Cryptosporidium Risk Characterization As arbiter
of-sound science,- the agency has a number of responsibilities when it communicates to the public. First
and foremost among these responsibilities is being direct, honest, and transparent in its analyses and
decision making processes. With respect to transparency in the LT2ESWTR rulemaking record,
substantial documentation of analyses conducted by the agency is provided and information is provided
that allows informed, interested parties to replicate the LT2ESWTR analyses. However, when AWWA
reviewed the LT2ESWTR record, it was unable to conclude that the agency has been direct and honest in
its analysis of the rule-s benefits.
While SDWA makes provision for the LT2ESWTR to be exempt from the formal cost/benefit, health-risk
reduction analyses required of most other rules promulgated since the 1996 SDWA Amendments, the
agency has a fundamental responsibility to clearly articulate the costs and benefits of proposed and final
rules. A clear accounting of benefits in the case of the LT2ESWTR would allow AWWA to better inform
its members about the steps they will be required to take under the LT2ESWTR. It would assist the
consulting engineering community and regulatory community in balancing competing design issues and
defining regulatory expectations. And perhaps most importantly, it would assist EPA in articulating to the
American public and its congressional overseers the impact of the LT2ESWTR. It would also help to
direct needed research. The LT2ESWTR EA fails to provide a credible estimate of benefit from the
proposal and in so doing, makes implementation of the rule more difficult and contentious. The EA may
fulfill the letter of the agency-s obligation to conduct certain analyses and relate them to the public. The
agency has not successfully complied with the spirit of those requirements, which are intended to ensure
Comment Response for the LT2ESWTR 20-19 December 2005
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that the agency provides a clear and logical explanation of the critical policy decisions and assumptions
that underlie the rule provisions.
Response: See responses 2200i, 100k
EPA Letter ID: 590
Comment ID: 12029
Commenter: Steve Robbins, General Manager-Chief Engineer, Coachella Valley Water District
Commenter Category: Regulated Community (Utilities)
Other EPA Comment Codes and Descriptions: 100 General Comments
Comment: Although Coachella Valley Water District supports, in principle, the aims of the proposed
LT2ESWTR, we believe the economic analysis by the EPA is flawed.
Response: See Response lOO.r.
EPA Letter ID: 590
Comment ID: 12030
Commenter: Steve Robbins, General Manager-Chief Engineer, Coachella Valley Water District
Commenter Category: Regulated Community (Utilities)
Comment: This District remains unconvinced that the benefit of cryptosporidium removal is as great as
EPA states. The language used in the economic analysis and EPA's preamble creates an expectation of
greater benefit than can be achieved under the LT2ESWTR provisions. The main reason for concern is
the frequency and immediacy of analysis required for cryptosporidium under the draft microbial
laboratory manual. Considering the scarcity of laboratories capable of analyzing cryptosporidium, the
relatively short holding times and the requirement for temperature maintenance, sample invalidation can
be expected on a routine basis, especially for communities in remote areas. The additional cost to ensure
the timely arrival of samples at the nearest laboratory is an additional concern.
Response: Responses lOO.r and 2200.k.
EPA Letter ID: 628
Comment ID: 12845
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: The SFPUC believes that the EPA has overestimated the risks of Cryptosporidium and
underestimated the cost of complying with the additional layer of protection. According to the preamble
to the LT2 Rule, once the SFPUC-s
Response: Response 2200.L
Comment Response for the LT2ESWTR 20-20 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
EPA Letter ID: 668
Comment ID: 13889
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: EPA May Not Legally Consider Cost-Benefit Analysis in Setting Crypto Standards, and in
Any Event, the Health Effects and Benefits of the LT2ESWTR Are Likely Substantially Underestimated
The Safe Drinking Water Act expressly prohibits EPA from considering cost-
benefit analysis as a basis for the standard for Cryptosporidium. The Act states that -The Administrator
may not use the [cost-benefit] authority -to establish a maximum contaminant level for the control of
cryptosporidium.- SDWA § 1412(b)(6)(C). Thus, no consideration of costs and benefits legally may be
used to drive this standard.
Moreover, EPA has substantially underestimated the benefits of this proposed rule. The Agency-s
reliance upon the ICR and supplemental surveys overlooks several facts. First, these surveys were never
intended concentrate or assure that worst case events-such as major runoff after storms that often carry
far higher Crypto levels-are subject to monitoring. Water systems do have to test during certain general
periods, but could easily avoid testing at times of peak risk. Thus, the occurrence data that EPA has used
likely understate risk during the worst times that are most likely to trigger serious outbreaks or
widespread endemic disease. The agency should analyze the data it has collected to determine what
percentage of peak precipitation events were actually captured before assuming that they were captured.
Second, EPA has failed to consider many other methods of determining the potential extent of waterborne
Crypto that suggest far higher rates of disease. Examples include several published and unpublished time
series studies that link widespread endemic waterborne disease and possibly even outbreaks to spike
turbidity levels and seasonal fluxes in water quality due to rain and other climatic events. Also ignored are
serologic studies showing widespread Crypto infections, and the possibility to link such evidence to water
exposure based upon comparison of location of samples (e.g. groundwater vs. surface water systems,
etc.). There also is emerging evidence from Tuft University studies that hospitalizations due to GI
illnesses often associated with waterborne disease is grossly underreported. Finally, EPA also has
underestimated the benefits of avoiding waterborne disease, including the benefits of reduced pain and
suffering.
Response: See responses lOOc, 2200b
20.2 Comment Code 2220, Risk Assessment
Individual Comments on Code 2220
EPA Letter ID: 562
Comment ID: 12543
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 226 iii. Use of occurrence data sets in benefit and cost
analyses; 2221 1. Dose-response; 2222 2. Drinking water consumption (including averting behavior);
2224 4. Sensitive subpopulations; 2225 5. Uncertainty; 2226 6. Cases of illness compared to IESWTR or
LT1ESWTR estimates; 2230 C. Benefits; 2231 1. Valuation of Non-fatal Cryptosporidiosis
Comment Response for the LT2ESWTR 20-21 December 2005
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Comment: Figure 3. Factors Affecting Benefit Analysis
[SEE FIGURE 3, P.83 IN PDF]
Response: See Responses 2200b, 2221.7, and 2221.6. Thank you for your comment. EPA agrees that
additional data will provide an improved understanding of the national occurrence picture for all sizes and
types of systems. Such data will become available after LT2 rule is implemented.
EPA Letter ID: 580
Comment ID: 12627
Commenter: Bruce Aptowicz, Chairman, Water Utility Council of the Pennsylvania American
Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: AWWA is very concerned that the Agency-s Economic Analysis documents and preamble
text have created an unrealistic expectation and implied a significantly greater benefit than will actually
be realized through implementation of the LT2ESWTR. The projected risk of endemic cryptosporidiosis
creates a perception of certainty that is then reflected in the urgency of the implementation schedule, the
microbial toolbox, and other rule requirements. This consistent stringency in the microbial toolbox is a
fundamental flaw in the proposal, as the restrictive operational and reporting requirements are out of
balance with the uncertainties surrounding the endemic Cryptosporidium risk. The LT2ESWTR is a
proactive step by the drinking water utility community to further enhance public health in the face of this
uncertainty.
Response: Responses 100.s, SOO.b, and 2200.k.
20.2.1 Comment Code 2221, Dose-response (including infectivity and
morbidity)
Response to Code 2221
1. In regard to Cryptosporidium dose-response assessment the Agency received significant comments on
the following issues:
o Limited dose-response data (small number of studies, small number of isolates, small numbers of
naive subjects).
o Representativeness of Cryptosporidium isolates used in studies.
o Extrapolating from high study doses to low drinking water doses.
o Identification of infected study subjects (presumed infected).
o Assumption that severity of outcome, following infection, is independent of dose.
2. EPA recognizes there are uncertainties regarding the Cryptosporidium dose-response(infectivity)
analyses. The analyses described in the Economic Analysis for today's final LT2ESWTR properly
account for statistical uncertainties, such as due to the small number of studies, small number of isolates,
and small number of subjects. The statistical models treat the Cryptosporidium isolates studied as a
random sample from a larger population of environmental isolates. The model recognizes that the sample
of isolates may be unlike the parent population (all environmental oocysts) due to chance, but EPA has no
Comment Response for the LT2ESWTR 20-22 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
basis to assume any systematic bias in the selection of these particular isolates. Similarly, the statistical
model treats the number of human subjects as random samples from the larger U.S. population of healthy
individuals. Finally, it treats each individual's outcome as a chance event, where the individual's infection
probability is a simple function of the challenge dose. Collectively, the modeled uncertainties contribute
to the rather large uncertainty in our estimate of the important parameter r, the "expected probability of
infection, given one oocyst ingested."
3. Some commenters expressed concerns that the study isolates may have been more potent than those
found in the environment. EPA recognizes this concern and has accounted for it in the dose-response
models used in in the Economic Analysis. Although study isolates were harvested from animal hosts, they
were carefully prepared, preserved, and handled to ensure they were "healthy" when ingested by the
human volunteers. In contrast, environmental isolates can have either human or animal origins and are
exposed to numerous physical, chemical, and biological threats from they time they are shed until the
time they arrive at the drinking water tap. As described in the Economic Analysis, EPA used data from
the ICR and ICRSS, along with results from LeChevallier et al. (2003), to estimate the fraction of
Cryptosporidium oocysts in the environment that are capable of infecting humans. EPA included a
parameter for this estimate in the dose response models. Further, data from new dose-response studies
suggest that oocysts of the human genotype (hominis) have potency similar to that of the isolates with
non-human origin.
Reference: LeChevallier, M.W., G.D. Di Giovanni, J.L. Clancy, Z. Bukhari, S. Bukhari, J.S. Rosen, J.
Sobrinho, and M.M. Frey. 2003. Comparison of method 1623 and cell culture-PCR for detection of
Cryptosporidium spp. in source waters. Appl. Environ. Microbiol. 69(2):971-979.
4. EPA agrees that the extrapolation of Cryptosporidium infectivity from high study doses (the lowest
study dose was ten oocysts) to the most common drinking water dose (typically one oocyst) is an area of
uncertainty. To address this uncertainty, EPA has evaluted dose-response using different statistical
models for the extrapolation in the LT2ESWTR Economic Analysis. While these models produce a range
of values, the results are consistent with the infectivity values used in the LT2ESWTR proposal. Further,
EPA estimated an infectivity value for the Cryptosporidium involved in the Milwaukee outbreak using
available exposure data, which suggested atypical exposure level of one oocyst. Results of this analysis
also support the infectivity values used in the Economic Analysis for the proposal and today's final rule.
Lacking information to suggest a defensible alternative, EPA believes its current analysis model to be
appropriate for estimating low-dose risk.
5. Among the dose-response study subjects were some who developed symptoms consistent with
cryptosporidiosis, but whose stool samples returned negative results. Recognizing the high false negative
rate of the stool test, the study principal investigators believed that these individuals should be counted as
infected and ill and classified them as such in peer-reviewed study results. EPA has no basis to doubt the
investigators' classification used in the peer-reviewed studies and has followed it in the dose-resposne
analysis for the LT2ESWTR.
6. Among dose-response study participants, neither the probability of illness given infection, nor severity
of infection was found to increase with dose. Because probability of illness is the product of a constant
(probability of illness given infection) and the probability of infection (which increases with dose), EPA's
model predicts an increasing probability of illness with increasing dose. As described in the Economic
Analysis, information on morbidity is derived from the dose-response studies, which used both naive
subjects and subjects with previous exposure. To estimate mortality (probability of death, given illness),
EPA relied on data from the Milwaukee outbreak. Follow-up studies of this outbreak provided the best
available information on mortality associated with cryptosporidiosis in a large population. As described in
the EA, we have adjusted the mortality rate observed in this outbreak to reflect new information on AIDS
prevalence and AIDS mortality.
Comment Response for the LT2ESWTR 20-23 December 2005
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7. As described in the LT2ESWTR Economic Analysis, EPA has included parameters to address
uncertainty in its Cryptosporidium dose-response models where information is available to estimate these
parameters. We recognize that additional uncertainties exist that the dose-response models do not address
due to lack of information. These include risk to persons with compromised immune systems and risk to
persons showing some immune response. Such persons were excluded from the dose-response studies.
Accounting for additional sources of uncertainty would probably produce wider credible bounds about the
key parameter of interest (probability of infection, given one oocyst ingested), but it is not clear whether
the central estimate (mean) would be increased or decreased. Because of the difficulty in expressing these
uncertainties mathematically, EPA will not model them at this point, but recognizes that the overall
uncertainties are understated.
Individual Comments on Code 2221
EPA Letter ID: 427
Comment ID: 10583
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: -The organisms found in the Bull Run watershed originate in wildlife -Wildlife
Crvptosporidium spp. are unlikely to infect humans (1) -The organisms found in Bull Run wildlife are
cattle in origin -Calf oocysts have a low -5% infection rate -Because of the absence sewage,
Cryptosporidium hominis has not been isolated in the Bull Run C. hominis is emerging as the genotype of
interest, and its relationship to humans supports the many observed phenomena we see in the
Cryptosporidium spp. disease process. FR-p.47650-47651 Cryptosporidium spp. infectivity comes from
dose response studies where healthy human subjects ingest different numbers of oocysts and are evaluated
for signs of illness. New studies show Cryptosporidium spp. infectivity varies over a wide range. Human
dose response studies consisted of three separate trials. 1. IOWA- calf origin, 29 individuals. Stool test.
2.UCP- calf origin, 17 individuals. Stool test and symptoms. 3.TAMU- foal origin - student, 14
individuals. Stool test and symptoms. Comment - The sample sizes are extremely small to extrapolate
data to the general population. Only the zoonotic genotype is used. The organisms originated from
domestic animals, and interestingly the pass-through human organism proved to be the most infective.
There are questions about age variation both human an organism in the groups studied, and previous
exposure of the participants to the organism is not certain.
Response: See Responses 2221.2 and 2221.3.
EPA Letter ID: 488
Comment ID: 11835
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: There are three main issues of concern with the infectivity data. The validity of extrapolating
the high exposure infectivity data to lower exposure levels (one oocyst) is not addressed, the way results
from these three studies were combined for a central-tendency estimate of infectivity is questionable, and
the relevance of the three study strains to environmental (source water) Cryptosporidium is not addressed.
Comment Response for the LT2ESWTR 20-24 December 2005
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All the infectivity data are for ingestion of 10 or more oocysts per subject. In fact only one of the three
studies had any subjects exposed at the 10 oocyst level. Minimum exposure levels in the other two studies
were 30 and 500 oocysts, respectively. There is presently no evidence that human infection can result
from ingestion of a single oocyst, the exposure relevant for endemic cryptosporidiosis.
Response: See Responses 2221.2, 2221.3, and 2221.4.
EPA Letter ID: 488
Comment ID: 11836
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Using an exponential dose-response model the EPA derived individual risk estimate
distributions for the three strains. The estimated mean risks of infection from ingesting one oocyst were
0.00034, 0.0053, and 0.059 for the UCP, IOWA, and TAMU strains, respectively (Messner 2001).
Discussion of how these three data sets were statistically combined for a -mixed- or -unknown- strain is
very difficult to follow for a non-statistician. Nevertheless common sense renders it difficult to believe
that a combined risk estimate on the order of 0.07-0.10 is a credible output. This is greater than the
estimate using the most virulent strain, which in turn was one or two orders of magnitude greater than the
alternate strains studied. In circumstances where nothing is known about the distributional characteristics
of a population being sampled (in this case the degree of infectivity of the universe of human infective
oocyst strains) the best estimate of the central tendency is the median value. For the data in question this
corresponds to the IOWA strain. Thus, a defensible estimate of the mean risk of infection from ingesting
one (human infective) oocyst is 0.0053, or 0.5%, more than an order of magnitude lower than EPA-s
current estimate.
Response: See Response 2221.2.
EPA Letter ID: 488
Comment ID: 11837
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: There is no known relationship between the three study isolates and occurrence of
Crytposporidium in the environment, nationally or locally. However the strains employed for these three
studies were certainly known to be human infective because they were isolated from calves or infected
persons (note that C. parvum is known to be human infective). In contrast, recent research suggests that
only a small fraction of waterborne environmental Crytposporidium oocyst genotypes are human
infective. In a recent study of storm water samples in two New York watersheds, Jiang, Alderisio, and
Xiao (2003) reported that, of eighteen identified Cryptosporidium genotypes, only one (about 5%) was
pathogenic to humans.
The infectivity data used for the LT2ESWTR risk characterization are only relevant for humanpathogenic
strains of Cryptosporidium. Application of these infectivity estimates (applicable to human-pathogenic
strains) directly to environmental oocyst exposure (i.e. treated drinking water) without adjusting for the
small fraction of human-pathogenic Cryptosporidium strains in environmental samples represents a
critical flaw in the risk characterization.
Comment Response for the LT2ESWTR 20-25 December 2005
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For the reasons outlined above, the PWD believes that the risk characterization presented in the proposed
LT2ESWTR is approximately two orders of magnitude too high. Analysis of the infectivity data appears
to be driven by the most virulent strain studied, and direct application of the findings to oocyst strains
occurring in source waters measured during LT2 monitoring is inappropriate. Outstanding questions
remain about the validity of extrapolating high dose exposure data to the low dose ingestion scenario
relevant for endemic drinking-
waterborne cryptosporidiosis.
Response: See Responses 2221.3 and 2221.4.
EPA Letter ID: 516
Comment ID: 11742
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: p. 47647. EPA cites some reports regarding the potential influence of an immune response but
indicates, -The implications of these data for studies of Cryptosporidium infectivity are unclear-. In
contrast, in other areas, such as estimates of mortality from Cryptosporidium, where the data are equally
sparse (the Milwaukee incident whose implications for endemic risk are also unclear), EPA has had no
trouble in using the sparse data in the risk estimates. As the question of an immune response is likely to
have a substantive impact on the dose-response estimates (particularly at low dose), and the benefits of
the proposed rule, the Agency should have included a more in-depth analysis of this issue. At the very
least, the issue of immunity should be addressed (preferably quantitatively) in an uncertainty analysis, p.
47651 EPA utilizes a limited set
Response: See Response 2221.7.
EPA Letter ID: 516
Comment ID: 11743
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: of data from 3 separate infectivity studies to model the crypto dose-response. That
information coupled with estimates of exposure for filtered and unfiltered systems is then used to estimate
cases of illness. As EPA has provided a lot of discussion about the inadequacy of the methods used to
analyze crypto in water samples at low dose, EPA should address the adequacy and accuracy of the dose
estimates used in the infectivity studies. Certainly, this should be discussed in the uncertainty analysis.
For example, the low doses used for the Iowa and Tamu strains (10 oocysts) coupled with the few number
of subjects seem to drive the dose-response estimates. EPA should report on and evaluate how the dose
was determined, what the accuracy and precision of the method was, and the impact, if any that any
potential variance in determining the delivered dose may have on the calculation of the risk of infection.
DEP-s experience with conducting Cryptosporidium log removal studies for wastewater treatment, with
EPA Region II oversight, indicates the need to pay careful attention to experimental design when
determining dose.
Comment Response for the LT2ESWTR 20-26 December 2005
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Response: The doses ingested by volunteers in the dose-response studies were prepared by pulling
carefully measured volumes from a well-mixed suspension. Theoretically, these doses would vary about
their target value (the product of the suspension concentration and the aliquot volume) as Poisson random
variables. Selected aliquots were pulled aside and their oocysts were counted to test whether Poisson
variability was reasonable. This was also what EPA did to confirm its oocyst distributions among spiking
materials (used to estimate measurement method recovery variability for both the ICR Method and
Method 1622/1623). In both cases (dosing and spiking studies), standard deviation of counts was
approximately equal to the dose level, which we would expect under the Poisson. Poisson dose is also
consistent with our use of the exponential dose-repsonse model.
EPA Letter ID: 562
Comment ID: 12324
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5. The infectivity dose-response relationship applied by EPA is subject to considerable
uncertainty and probably overstates the risk associated with exposures to an infectious oocyst by a
significant degree, a. The underlying clinical studies are use extremely high doses relative to oocyst levels
in finished waters (levels of oocysts ingested of 23,000 to 2.3 billion times higher than now found in
finished waters) and rely on extremely small number of subjects and strains (between 14 and 29 subjects,
for each of only 3 strains), b. The results of the clinical studies are interpreted liberally, based on a -
presumed infection- approach that assumes that any subject with symptoms has cryptosporidiosis, even
when several of the symptomatic subjects had no documented infection (e.g., via positive oocyst
shedding). EPA-s risk estimates are overstated to the extent that reported symptoms could be attributable
to causes other than cryptosporidiosis.
Response: See Responses 2221.4 and 2221.5.
EPA Letter ID: 562
Comment ID: 12328
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 7. EPA needs to explore the soundness and implications of its questionable assumption that
the risk of illness (as well as severity and duration of illness) are independent of dose. The morbidity
assessment ~ used to project the number, severity, and duration of illnesses due to a possible infection -
is based exclusively on results from the Milwaukee outbreak of 1993, where oocyst levels were much
higher, exposure durations much longer, and opportunities for secondary spread and exposure more
pervasive than anticipated under the endemic low dose exposure context addressed by the proposed rule.
Response: See Response 2221.6.
EPA Letter ID: 562
Comment ID: 12543
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 20-27 December 2005
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Other EPA Comment Codes and Descriptions: 226 iii. Use of occurrence data sets in benefit and cost
analyses; 2220 B. Risk Assessment; 2222 2. Drinking water consumption (including averting behavior);
2224 4. Sensitive subpopulations; 2225 5. Uncertainty; 2226 6. Cases of illness compared to IESWTR or
LT1ESWTR estimates; 2230 C. Benefits; 2231 1. Valuation of Non-fatal Cryptosporidiosis
Comment: Figure 3. Factors Affecting Benefit Analysis
[SEE FIGURE 3, P.83 IN PDF]
Response: See Responses 2200b, 2221.7, and 2221.6. Thank you for your comment. EPA agrees that
additional data will provide an improved understanding of the national occurrence picture for all sizes and
types of systems. Such data will become available after LT2 rule is implemented.
EPA Letter ID: 562
Comment ID: 12548
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.4.4 Dose-Response
The dose-response portion of the EA is a very complex and highly significant component of the overall
analysis. Critical assumptions must be made at several points in the analysis because of pervasive
scientific uncertainties. EPA makes several plausible and reasonable assumptions and inferences, but
there are also components of the analysis where alternative assumptions or scenarios seem more plausible
or, at a minimum, equally plausible. In such instances, the agency should be more explicit and balanced
about the assumptions being made, and should conduct meaningful sensitivity analyses to reveal the
impact of the alternative assumptions on the overall findings. Of particular concern from our review of
the EA, are the following:
1. The estimation and use of r-values for inherent infectivity. The estimation process is not well
documented and is poorly presented; the underlying data have significant limitations; and the results that
EPA apparently uses are appreciably higher than findings published in the peer-reviewed literature. EPA
should provide greater documentation, discussion, and review.
2. The morbidity assessment is dose-independent. Given the extremely high doses used in the clinical
trials relative to the levels in finished water, and the evidence of dose-dependent morbidity in some
studies, it seems prudent to at least conduct reasonable sensitivity analyses on the impact of this key
assumption.
Each of these limitations in the EA are discussed in greater detail in Chapter 5 of a report prepared for
AWWA by Stratus Consulting evaluating the LT2ESWTR EA. A copy of the report is contained in
Appendix 12. An implication of this report is that the use of obvious alternative assumptions in any of the
above four aspects of the dose-response relationship would significantly reduce the morbidity predicted in
the EA and consequently the benefit derived from LT2ESWTR.
Response: Responses 2200.h, 2200.S, 2221.2, 2221.4, 2221.6, and 2221.7.
Comment Response for the LT2ESWTR 20-28 December 2005
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EPA Letter ID: 562
Comment ID: 12550
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. Morbidity levels, the allocation of cases across severity classifications, and the
characterization of the duration and impact of illnesses in each severity class are all based on data from
the Milwaukee outbreak of 1993. The use of data from a massive outbreak (with very high levels and
durations of primary and secondary exposure) as a basis for estimating numbers, severity, and duration of
illness from endemic exposures to far lower doses seems problematic. Here again, given the core
uncertainties and the importance that these assumptions have on the final benefit outcomes, some
alternative scenarios should be developed and assessed using sensitivity analysis.
Response: See Response 2221.4.
20.2.2 Comment Code 2222, Drinking water consumption
(including averting behavior)
Response to Code 2222
A few commenters were concerned with the distribution for drinking water consumption that EPA used in
the proposed LT2ESWTR. This distribution, which was based on a 1994-1996 survey by the United
States Department of Agriculture (USDA), reflects water consumption from all sources. Commenters
recommended two modifications to this approach: (1) adjust the distribution to account for factors like
use of bottled water, boiled water, and home filtration devides and (2) use an alternative distribution from
the USDA survey that reflects consumption of community water system (CWS) water only.
In response, EPA agrees that the distribution should be adjusted to remove consumption attributable to
bottled water. For the consumption distribution in today's final rule, EPA subtracted bottled water usage,
based on information in the USDA survey, which had the effect of reducing consumption by
approximately 14 percent in comparison to the proposal. EPA believes that this survey provide the most
comprehensive and accurate information on bottled water usage. EPA does not have information on the
effectiveness of heating water to make coffee or tea for inactivating Cryptosporidium. Similarly, EPA
does not have information on the use of effectiveness of home filtration devices for removing
Cryptosporidium. Many home filtration devices do not effectively remove microorganisms.
Consequently, EPA has not modified the consumption distribution to address heated water usage or home
filtration devices.
EPA continues to believe that the USDA distribution for consumption of water from all sources, minus
bottled water consumption, provides the best available estimate for consumption of water from CWSs for
people served by CWSs. The USDA distribution for consumption of CWS water only, which a
commenter recommended, includes people not served by CWSs (e.g., people with private wells).
Inclusion these individuals has the effect of underestimating the consumption of CWS water for people
served by CWSs in this distribution. In contrast, the distribution for consumption of water from all
sources includes people not served by CWSs and the sources those people use (e.g., private wells). This
avoids the problem of underestimating consumption for individuals served by CWS. Accordingly, EPA
has retained the use of this distribution in today's final rule, with the adjustment stated previously for
bottled water consumption. See Chapter 5 of the LT2ESWTR Economic Analysis for a fuller description
of these distributions.
Comment Response for the LT2ESWTR 20-29 December 2005
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B. EPA has not used separate consumption distributions for AIDS patients or other sensitive
subpopulations. First, EPA does not have information on the fraction of sensitive subpopulations that
practice averting behaviors (e.g., drinking bottled water or filtering tap water) in comparison to the
population at large or the effectiveness of these behaviors for reducing risk from Cryptosporidium. This
information would be necessary to develop a separate distribution for sensitive subpopulations. Second,
due to how the benefits analysis is constructed, EPA does not believe that the use of a separate
consumption distribution for sensitive subpopulations is necessary or appropriate. The effect of sensitive
subpopulations in the LT2 benefits analysis is reflected in the fraction of cryptosporidiosis cases that
result in severe illness (e.g., hospitalization). People with underlying health conditions such as AIDS
likely account for a significant portion of such cases. EPA's estimates of the fractions of cases that are
severe are taken directly from data on the 1993 Milwaukee cryptosporidiosis outbreak. These fractions
account for the averting behaviors of the entire population, including sensitive subpopulations within the
larger population. EPA does not have information showing that averting behaviors that would reduce
cyptosporidiosis risk among sensitive subpopulations are significantly different now than in Milwaukee in
1993. EPA has accounted for the improved health status of people with AIDS through reduced mortality
rates, as described in the EA.
Third, EPA disagrees that sensitive subpopulations should bear the primary responsibility for treating tap
water to make it safe or or avoiding tap water. SDWA directs EPA to consider sensitive subpopulations in
establishing safe drinking water standards.
Individual Comments on Code 2222
EPA Letter ID: 101
Comment ID: 10910
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Cost/Benefit Analysis
The Agency should remove cooking water and other indirect uses of water from their cost/benefit
analysis. Clearly, water used for cooking is boiled which kills cryptosporidium. Further, water that is not
consumed cannot cause a cryptosporidium related health effect.
Response: Response 2222.A.
EPA Letter ID: 562
Comment ID: 12323
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 4. EPA-s exposure assessment is based on considerably over-estimated levels of direct
ingestion of CWS-provided waters. Relevant exposures (and, hence, risks) may be overstated by a factor
of 2 or 3 when direct ingestion rates for CWS waters, and increased bottled water use, are properly
considered.
Response: Response 2222.A.
Comment Response for the LT2ESWTR 20-30 December 2005
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EPA Letter ID: 562
Comment ID: 12543
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 226 iii. Use of occurrence data sets in benefit and cost
analyses; 2220 B. Risk Assessment; 2221 1. Dose-response; 2224 4. Sensitive subpopulations; 2225 5.
Uncertainty; 2226 6. Cases of illness compared to IESWTR or LT1ESWTR estimates; 2230 C. Benefits;
2231 1. Valuation of Non-fatal Cryptosporidiosis
Comment: Figure 3. Factors Affecting Benefit Analysis
[SEE FIGURE 3, P.83 IN PDF]
Response: See Responses 2200b, 2221.7, and 2221.6. Thank you for your comment. EPA agrees that
additional data will provide an improved understanding of the national occurrence picture for all sizes and
types of systems. Such data will become available after LT2 rule is implemented.
EPA Letter ID: 562
Comment ID: 12547
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.4.3 Exposure Estimate
A fundamental component of the risk assessment and benefits analysis is the amount of tap water ingested
by the public. The discussion above examines several concerns with the assumptions employed by EPA
in this aspect of its EA. For example:
1. Accounting for exclusive use of bottled water by an increasing number of households would reduce the
subsequent risk analysis and benefits results by approximately 20%.
2. Adjusting exposures to reflect direct ingestion in the home might reduce the risk and benefits results by
another 50%.
3. Reflecting averting behavior by AIDS patients and other sensitive populations would directly and
proportionally affect the largest component of the monetized benefits estimates.
While the drinking water intake values used in an analysis are not often the focal point of much scrutiny,
the values used do have a very sizable impact on the ultimate risk and benefit findings. EPA should
reconsider how it has approached this aspect of the EA, and provide improved and more expansive
analysis and documentation. EPA needs to correct the EA to reflect the issues and data noted here.
To estimate the amount of water ingested per day, EPA uses data from the U.S. Department of
Agriculture-s (USDA-s) 1994 - 1996 Continuing Survey of Food Intakes by Individuals (CSFII).
According to the EA, USDA provides two distributions of water ingestion levels:
1. -Distribution 1- is based on total water ingestion from all sources and has a median (50th percentile)
level of 1.05 L/day and a 90th percentile of 2.35 L/day. EPA uses the mean from this distribution, 1.24
L/day, as the basis for its national-level risk estimates. 2. -Distribution 2- is based on water ingestion
from CWS sources, and has a median (50th percentile) level of 0.71 L/day and a 90th percentile of 2.02
L/day. The mean from this distribution is 0.93 L/day (or 75% of the mean from Distribution 1 that is used
by EPA as the basis for its national-level risk estimates).
Comment Response for the LT2ESWTR 20-31 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
AWWA believes it would be more accurate and reasonable to use the mean or median value from
Distribution 2 instead of Distribution 1. This would result in risk estimates and benefits that would be
75% (0.93/1.05) or 57% (0.71/1.05) of the current EPA estimates, respectively, all else being equal.
Distribution 2 reflects use of CWS waters by their customers, a more relevant use level for the regulation
that is targeted on water utilities than -water from all sources,- which includes bottled water, household
wells, household rain cisterns, and household or public springs, in addition to CWS. Water from CWS
represents approximately 75% of total daily water intake (U.S. EPA, 2000). Hence, Distribution 2 is by its
definition a more suitable fit for CWS-relevant tap water exposure than Distribution 1.
Distribution 2 may also over estimate drinking water exposure. A recent EPA-sponsored Gallup poll
(U.S. EPA, 2003c) and AwwaRF-sponsored research by Raucher et al. (submitted for publication)
indicate that as of 2002, 75% of Americans drink bottled water, 14% to 20% drink only bottled water,
37% use in-home filtration devices, and only 49% to 56% drink exclusively tap water in their homes.
The ingestion levels for both USDA distributions as presented by EPA in the EA (U.S. EPA, 2003a, p. 5-
23) are higher than applied or derived previously. For example, EPA-s prior estimate of tap water intake
(U.S. EPA, 1999) reflects a mean of 0.67 L/day, a median of 0.50 L/day, and a 90th percentile of 1.31
L/day. These are 72%, 70%, and 65%, respectively, of the same measures EPA now reports for
Distribution 2 (and the mean from U.S. EPA, 1999, is 54% of the mean EPA now uses, as drawn from
Distribution 1).
If one nets out the exclusive bottled water drinkers, and also reduces applicable daily intake for the
remaining homes to reflect the nonrisk-bearing portions of current water ingestion patterns, then the
overall result would be benefits at 40% to 43% of the levels currently presented in the EA. This implies
that the EPA national estimates are quite possibly overstated by a factor of 2.3 to 2.5 (i.e., 1.0/0.4 = 2.5),
simply on the basis of how much relevant tap water ingestion the agency assumes.
Response: Response 2222.A.
EPA Letter ID: 562
Comment ID: 12552
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.4.6 Special Populations
Exposure
In its summary of the risk assessment guidelines, EPA notes that -when the risks posed are not the same
for all persons, that variability should be described.- Further, the summary of guidelines notes that ideally
these risks will be addressed through -the use of scientific data (or reasonable assumptions if data are not
available) to produce estimates of the nature, extent, severity, and degree of risk- (U.S. EPA, 2003a; p. 5-
4 for both quotes).
Using benefits estimates in the EA, Exhibit 5.24, AIDS patients account for 85% of fatal risk, and fatal
risk reductions account for more than 67% of total benefits. These estimates are premised on the
consumption of tap water - without any additional precautions - by these members of the sensitive
subpopulation. For almost a decade, CDC, EPA, the water community, and AIDS organizations have
been strongly and consistently encouraging AIDS patients to be aware that additional precautions are
Comment Response for the LT2ESWTR 20-32 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
warranted regarding tap water. The EA should reflect this advice and the practical observation that this
guidance has altered consumption patterns in the AIDS community.
Response: Resposne 2222.B.
20.2.3 Comment Code 2223, Comparison with epidemiological
data
Response to Code 2223
A. In assessing costs and benefits of today's rule, EPA has conducted a risk assessment at the national
level only. EPA has not assessed risk at specific cities. As discussed in the Economic Analysis, EPA
recognizes that risk among different cities will vary significantly depending on their source water
Cryptosporidium level and treatment effectiveness. Therefore, EPA does not believe that
extrapolating EPA's national level risk assessment results to estimate disease levels for specific cities
is appropriate.
B. EPA does not believe that disease surveillance data by the CDC or others provide an appropriate
information basis to estimate the risk of cryptosporidiosis in a community or nationally. As discussed in
response SOO.b, most cases of cryptosporidiosis are not reported and, thus, not reflected in disease
surveillance data. For example, during the 1993 Milwaukee, the fraction or reported cases to total cases
was on the order of 1 per 1000.
C. EPA has considered several studies noted by commenters as providing information on microbial
disease risk associated with drinking water. EPA does not believe that their results provide a basis for
revising the risk assessment supporting today's final LT2ESWTR. EPA's National Estimate of
Waterborne Disease remains under development and has provided no final results to date. The Melbourne
study obviously didn't address plants complying with US drinking water standards - the sole focus of the
LT2ESWTR risk assessment. The Davenport study (also called the Waterborne Evaluation Trial (WET)
study) lacked the sensitivity to detect disease due to drinking water at the level projected in the
LT2ESWTR risk assessment. As a commenter noted, the study had the power to discern a difference of
10% in disease burden between the controls and tap water. Current CDC estimates of the national
incidence of waterborne disease is 200 to 300 million cases per year. Applied nationally, the Davenport
results suggest that drinking water is contributing less than 10 percent of these cases, meaning less that 20
to 30 million cases per year. However, the LT2ESWTR risk assessment predictions range from
approximately 100,000 to 1.5 million cases per year - far less than the level the Davenport study would
detect (when extrapolated from a national level to a local level).
Individual Comments on Code 2223
EPA Letter ID: 488
Comment ID: 11834
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: With regard to the LT2ESWTR we have particular concerns about the validity of EPA-s risk
characterization for endemic Cryptosporidiosis attributable to drinking water. In the absence of endemic
Cryptosporidiosis public health data the Agency has projected the associated risk by using highly
uncertain assumptions to link source water cryptosporidium concentrations to anticipated disease
Comment Response for the LT2ESWTR 20-33 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
occurrence. Our comments address this issue in some detail and provide a brief review of our own
experience with Public Health Deprtment surveillance for Cryptosporidiosis in Philadelphia.
Response: Responses SOO.b and 2200.s.
EPA Letter ID: 488
Comment ID: 11877
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: To develop the benefits, and therefore, the justification for this proposed rule, very sparse data
was available to EPA. Although, EPA did evaluate several data sets, most results indicating high risk
from waterborne Cryptosporidiosis as a result of drinking tap water depend on the data set manufactured
from Bayesian analysis of the ICR data rather than actual observed data. Therefore, EPA should take
great caution in considering the value of this data. Whenever, modeled data is used in place of actual data,
every effort to validate or ground truth the model results with observed data should be used. To that
extent, EPA needs to work with the Center for Disease Control (CDC) and the Public Health community
as a whole to determine if the derived benefits actually are realistic. The City of Philadelphia believes that
EPA-s resultant benefits are conservatively at least two orders of magnitude too high.
The City of Philadelphia has been performing Cryptosporidiosis investigations for nearly a decade and
has now in place one of the most advanced disease surveillance system in the world. Mandatory reporting
of Cryptrosporidiosis was implemented in 1994. Surveillance initially consisted of collecting reports from
all laboratories, health care providers, and agencies and performing follow-up epidemiological
investigations. Active surveillance consisting of routine monitoring of diarrhea in a health center
population, with City funded facilitated laboratory testing was later adopted.
Recently, the City of Philadelphia, working with the CDC began a pilot program for Hospital Syndromic
Surveillance. This program was established with the help of the Federal Bureau of Investigations (FBI)
prior to Philadelphia-s hosting of the Republican National Convention. In this program, daily collection
of chief complaints from 5 local hospitals are tabulated and compared to historical prevalence of visits for
each syndrome and an e-mail of the results is sent daily to the Philadelphia Health Department-s Division
of Disease Control. At the City of Philadelphia-s request, diarrhea was added to this program as a
monitored syndrome. Additionally, pharmaceutical sales of over the counter (OTC) drugs at major drug
store chains in Philadelphia are monitored and analyzed by the University of Pittsburgh Realtime
Outbreak and Disease Surveillance Laboratory (RODS). Maps and graphs of OTC sales are provided to
the Philadelphia Health Department over a secure server.
Given our extensive public health experience with Cryptosporidiosis, we would like to share with EPA
some of our findings. Figure 1 shows all the confirmed Cryptosporidiosis cases by year from 1995 to
2002 for Philadelphia. As can be seen, the number of total cases from all sources of acquisition averaged
approximately 20 cases per year. Figure 2 shows the Cryptosporidiosis cases by month of laboratory test.
Clearly, there is discernable increase in cases in the summer months that can be seen. It is very interesting
to note that this warm water temperature peak in actual disease occurrence is in stark contrast to the
observed Cryptosporidium peak in our source waters. Figure 3 shows our historical Cryptosporidium
occurrence by month using the ICR Method and/or Method 1622, while Figure 4 shows our newer source
water Cryptosporidium occurrence data using Method 1623 for March 2001 through March 2003. This
alone would give one pause to believe that the observed endemic Cryptosporidiosis cases are due to
drinking water since the peaks in oocyst occurrence are clearly out of sync with the disease pattern.
Comment Response for the LT2ESWTR 20-34 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
Furthermore, after a decade of epidemiological investigations of actual cases, the City of Philadelphia has
consistently found that the risk factors associated with cases are predominately attributable to foreign
travel (36%), aquatic recreational activities (25%), secondary contact with a known case (25%) and
immunocompromised medical conditions (25%). At least one risk factor has been reported in 86% of the
confirmed cases in Philadelphia, with only 10% having no reported risk factor (4 % have no data
available). Clearly, the dominance of cases in which one or more risk factors unrelated to drinking water
have been identified strongly suggests that Cryptosporidium in drinking water is unlikely to be a major
contributor to any background or endemic level in Philadelphia. These findings are further supported by
the recently completed EPA/CDC triple blind intervention study in Davenport, Iowa.
In contrast to the results and analysis of the City of Philadelphia-s actual Cryptosporidiosis surveillance,
the EPA-s model estimates that the City-s population is subjected to approximately 3.7 Cryptosporidiosis
infections per 10,000 customers per year due to drinking water, based on current source water monitoring
results and an assumed 3-log removal from treatment. This yields a total of 3,000 infections per year
attributable to drinking water alone. Even using a very conservative assumption about surveillance miss-
rates (only 5% of cases identified), gastrointestinal disease surveillence data indicate EPA-s estimates
using the modeled data sets to be at least one order of magnitude too high for all Cryptosporidiosis cases
from all acquisition sources. Therefore, for drinking water, which has not been confirmed as source of
actual Cryptosporidiosis in over a decade of disease surveillance, EPA-s estimate is conservatively most
likely at least two orders of magnitude too high.
[SEE GRAPHS, PAGES 29 AND 30 ON PDF]
Response: Response 500.b, 2223.A, 2223.B, and 2223.C. EPA does not believe that these data cited by
the commenter are inconsistent with the national level risk assessment in the LT2ESWTR.
EPA Letter ID: 504
Comment ID: 11345
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment:
Response: Response lOO.a.
EPA Letter ID: 504
Comment ID: 11351
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: We are concerned that EPA has made no comparison of its estimates to epidemiological
evidence that is used by the public health establishment to judge the extent and relative significance of the
more important infectious illnesses in society.
Epidemiologic data on the occurrence of Cryptosporidiosis are readily available from official public health
sources both in the US and abroad. The same sources compile comparable data on the occurrence of other
gastrointestinal illnesses that provide some useful perspective on data describing Cryptosporidiosis
Comment Response for the LT2ESWTR 20-35 December 2005
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incidence. Data from the most recent Centers for Disease Control (CDC) compilation of notifiable disease
incidence is published in the Morbidity and Mortality Weekly Report (MMWR) 50(53): 1-10 May 2,
2003. These data are for 2001, the latest year for which a comprehensive summary is available. In that
year, CDC records show that 3785 cases of cryptosporidiosis were reported among the 2001 US
population of 281,000,000. That corresponds to an incidence rate of 1.35/100,000 per year.
It may be argued that the CDC data underestimate true occurrence. However, comparison of the 2001 rate
to incidence rates compiled by communities conducting active surveillance of cryptosporidiosis, including
New York, Los Angeles, and San Francisco is useful. Such systems report incidence rates that range from
ca. 2/100,000 per year to ca. 8/100,000 per year with considerable variation from year to year.
Response: Response 500.b, 2223.A, and 2223.B.
EPA Letter ID: 504
Comment ID: 11352
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: The EPA estimates appear further to suggest that all of the cryptosporidiosis that is occurring
is due to transmission via water. This is not consistent with available information on the nature and likely
order of importance of risk factors contributing to the occurrence of cryptosporidiosis.
Response: EPA recognizes that not all cryptosporidiosis is due to water. The cost-benefit analysis
supporting today's rule uses data to estimate specifically the risk from drinking water. Risk from other
sources is not addressed.
EPA Letter ID: 504
Comment ID: 11353
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: Further, the EPA mean estimates of cases avoided would result from the control provided by
the utilities falling in BINs 2-4. The proportion of population falling under utilities required to make BINs
2 to 4 improvements is likely on the order of 10% of the total population. This adds an additional order of
magnitude over-estimation to the incidence rates implied in comparison to reported epidemiologic rates.
Response: EPA's estimates of the risk reduction that the LT2ESWTRwill achieve include an estimate
that 22 to 34 percent of the population affected by the rule will be served by PWSs assigned to Bins 2-4.
Responses 500.b and 2223.B.
EPA Letter ID: 504
Comment ID: 16539
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment Response for the LT2ESWTR 20-36 December 2005
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Comment:
Response: Response lOO.a.
EPA Letter ID: 516
Comment ID: 11719
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Overestimatation of Risk:
DEP finds EPA-s risk numbers - for illnesses and deaths due to cryptosporidiosis in drinking water - to
be far off the mark from empirical data which NYC has collected. While DEP acknowledges that there
are limitations in the available public health data, EPA should at least have considered such empirical
data, and should have compared its risk estimates with these data, as a means of-groundtruthing- and
testing with the limitations of the risk analysis modeling exercise. Below we provide a review of EPA-s
projections for illness (morbidity) and death (mortality) and we compare these projections against
available public health data.
Morbidity
As described above, EPA-s Economic Analysis (as reported on page 47743 of the LT2 preamble)
projected 168,000 to 547,000 cases of illness averted from Cryptosporidium for unfiltered water systems.
As New York City represents 2/3 of the population served by unfiltered systems (8 million people out of
12 million total unfiltered population), presumably the number of cases of illness averted in NYC alone
would be 112,000-365,000. These numbers reflect an illness rate for NYC of 1.4% to 4.6%. In other
words, as many as 1 in 22 people in New York are projected by EPA to be getting ill with
cryptosporidiosis from the drinking water each year (EPA-s estimate is based on estimated morbidity not
infection). In comparison, the average annual number of laboratory-confirmed cryptosporidiosis cases in
NYC for recent years was 143 (this is an average of data from 2000, 2001 and 2002), or an annual rate of
less than 2/100,000. Though NYC conducts active disease surveillance (thus insuring that essentially
every single laboratory confirmed case is captured), we recognize that not all ill persons will seek medical
care, and thus many, if not most cases will be missed. However, using the Corso ratio of crypto illness
referenced by EPA ~ of 88:11:1 for mild:moderate:severe illness ~ one could predict that if there are
112,000 to 365,000 cases of illness in New York City, then at least the -severe- cases and some moderate
cases would likely be picked up in the health surveillance system. (EPA defines moderate illness as
patients with one or more outpatient visits to a physician or ER but not requiring hospitalization-Severe
cases are those requiring hospitalization). However using EPA-s above numbers and counting just the 1%
of cases estimated to be classified as severe, the projection would be 1,120 to 3,650 -severe- cases in
NYC, which is vastly greater than the number of cases we actually observe. Even if one looked at illness
in the AIDS population (a population which receives more careful health monitoring than the general
population, and for which cryptosporidiosis testing is much more likely to be conducted), NYC
surveillance system observed a total of 94 cases of cryptosporidiosis in this group in 2002, while the New
York City Department of Health and Mental Hygiene-s AIDS branch reported approximately 80,000
persons in NYC living with AIDS at that time (from NYCDOHMH, HIV Surveillance and Epidemiology
Program, 4th Quarter Report, Oct 2003, p.2). Even if one assumed that all 94 cases per year were from
water (which is clearly not the case, given the importance of other routes of infection), out of 80,000
persons living with AIDS in New York City gives an illness rate of approximate 0.1%, which is also far
below EPA-s illness projections.
Other data from New York City, which can be used to provide some perspective on EPA-s assessment
comes from a pilot program conducted by the NYCDOHMH in which cryptosporidium analyses were
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conducted on stool samples submitted by the Child Health Clinics and the School Health Program. While
this pilot program population was not representative of the overall population (as it involved
predominantly, if not entirely, school-aged children), and was known to have certain limitations, the
findings do not support very high estimates of endemic cryptosporidium. Out of a total of 22,000 stools
tested over a 5 year period, only 7 were found to be positive for cryptosporidium (or a rate of 0.03%).
Although one of the limitations of the data is that we cannot describe the exact population tested,
regardless of who was tested, if one in 20 New Yorkers had cryptosporidiosis, higher rates would have
been expected. +
Response: Responses 2223.A, 2223.B, and SOO.b.
EPA Letter ID: 516
Comment ID: 11720
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Mortality
Again using EPA-s estimates of illness averted from page 47743, and considering NYC to represent 2/3
of the total unfiltered population, EPA estimates that the LT2 could avert the number of premature deaths
annually by 19-61. This estimate appears to be too high. In the last 6 years of National Death Registry
data for NYC, cryptosporidiosis was indicated only 1 time as a cause of death. While we recognize that
death certificate information is imperfect and incomplete, this finding does suggest that EPA-s predicted
death rate is a significant overestimation. It is also worth noting a study that was reported recently from
San Francisco on causes of death among persons with AIDS, and covering the period 1994 - 1998. This
study reported no deaths at all from cryptosporidiosis in the San Francisco population during the final
year of the study (i.e., 1998) (Louie, et al., Journal of Infectious Disease, 2002).
Response: Response SOO.b, 2223.A, and 2223.B.
EPA Letter ID: 516
Comment ID: 11721
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Inadequate Acknowledgement of Uncertainties and Insufficient Consideration of Recent
Epidemiolgy Study Results:
DEP feels that insufficient acknowledgement is given of the many uncertainties inherent at this time in
cryptosporidiosis risk assessment The overall impression that a reader can get is that there is indeed a
significant amount of endemic waterborne cryptosporidiosis occurring across the Unites States based on
the current oocyst levels observed in source waters, and the current levels of drinking water treatment.
However, we do not really know that this is the case. In fact some recent epidemiology studies designed
to assess waterborne GI risk raise significant questions about this assumption. A number of research
efforts which EPA should have considered in the analysis are summarized below:
-The National Estimate of Waterborne Disease ~ A national effort has been underway for a number of
years to estimate the amount, if any, of disease caused by water across the country. This research effort is
being led by the CDC and the EPA, as mandated by the U.S. Congress. This estimate is a number of years
Comment Response for the LT2ESWTR 20-38 December 2005
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overdue, apparently due to the fact that the authors of this report, have found the various uncertainties
involved in the estimation process to be daunting. Despite a congressional deadline and the expenditure of
considerable funds for research, this group has not been able to provide a national estimate of waterborne
disease.
- Melborne Study ~ A study was recently conducted in Melbourne, Australia looking at gastrointestinal
illness and an unfiltered drinking water supply with a protected watershed. This study utilized the -gold
standard- type of protocol for assessing health effects from a drinking water supply - i.e., a randomized,
blinded and controlled household intervention protocol (using a home-filtering device designed to reduce
microbial/protozoan risk). The results of this investigation found no evidence of waterborne illness, and
the treatment devices installed were not found to reduce illness. (Hellard, et al., Env. Hlth. Persp., August
2001).
- Davenport Study - The study that EPA and CDC were most looking towards to answer the question of
whether drinking water was causing GI illness was recently completed. This study again used the -gold
standard- study design of a randomized, blinded, controlled household intervention protocol, but in this
case the water supply was filtered. In this study, again no illness was attributed to the drinking water, and
no illness was found to be averted by installation of advanced-level household treatment devices.
(Unpublished, but presented by Colford, 2003).
- Other Studies ~ A case-control study was recently conducted in San Francisco among
immunocompetent patients. Though this was a small study, the findings are interesting: drinking water
was not found to be a risk factor for cryptosporidiosis. (Khalakdina A, Vugia DJ, Nadle J, Rothrock GA,
Colford JM Jr. -Is drinking water a risk factor for endemic cryptosporidiosis?-). Finally, CDC has been
working on a multi-State casecontrol study examining the risk factors for cryptosporidiosis, including
drinking water. The study is complete and submitted for publication. Once these results are available, they
should be considered by EPA, as studies such as this one can help assess the question of whether drinking
water is truly a significant risk.
It is also interesting to note that efforts to study cryptosporidiosis have been limited by the fact that it is
too difficult to find people with the illness to conduct the needed studies. Several years ago, the CDC and
DEP co-funded a cross-sectional study of cryptosporidiosis in the HIV-infected population, in an attempt
to determine the prevalence of current infection and past exposure to Cryptosporidium and to study risk
factors, including exposure to drinking water. (The study was conducted at the New York Hospital-
Cornell Medical Center, in collaboration with the NYCDOHMH). The study was conducted from 1995 to
1997, and it was during this period that the new anti-retroviral therapies (HAART) became available. As a
result, the researchers found it difficult to find an adequate number of HIV-infected patients with
cryptosporidiosis to conduct the study
Response: Response 2223.A, 2223.B, and 2223.C.
EPA Letter ID: 516
Comment ID: 11722
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Table IV-5 in the preamble to the rule summarizes the estimated annual risk of crypto
infection as a function of source water oocyst concentration and treatment efficiency. This table suggests
that the annual risk of infection at a source water concentration of 0.01 oocyst/liter and 2 log removal
Comment Response for the LT2ESWTR 20-39 December 2005
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capability is 3.7 x 10-3. From this table it can be inferred that an unfiltered system with no log removal
capability would have an annual risk of infection of 3.7 x 10-1 or 37%. As this source water concentration
is representative of a levels found in NYC-s source water (this is higher than NYC-s average, but close
enough for this example), this number seems not supportable, given some of the other data noted above.
EPA should make some effort to include in the discussion of uncertainty, some comparison of the results
of the risk estimates with measured determinations of waterborne disease illness and infection rates.
The above-mentioned findings suggest that the level of concern indicated by the LT2 as currently
proposed, may be not in line with the actual public health findings.
Response: Response SOO.b, 2223.A, and 2223.B.
EPA Letter ID: 522
Comment ID: 14134
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: MWRA urges EPA to carefully conduct a risk analysis based on current occurrence and
health data, and provide that documentation in the preamble to the final rule before finalizing the two
primary disinfectants requirement.
Response: EPA has conducted a risk assessment using current occurrence and health data for today's final
rule. This assessment is described in detail in the Economic Analysis and summarized in the preamble.
EPA Letter ID: 522
Comment ID: 14152
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Inaccuracies in Risk and Cost Information Presented in the Preamble:
EPA estimates on page 47743 that the new rule is expected to reduce cases of illness for the 12 million
people served by unfiltered systems by an estimated 168,000-547,000 cases, and 28 to 91 premature
deaths annually. The EPA estimates that up to 1 in 22 people in unfiltered systems are getting ill.
EPA's estimates come with we 11-developed lists of studies referenced, and assumptions made. However,
notably absent is any attempt to "ground truth" the results. A primary responsibility of any analyst
creating an estimate is to look for alternative ways to validate the answers: if the answer is not the correct
order of magnitude, additional research or an alternative approach may be called for. This step appears to
have been missed out. MWRA and several other systems with aggressive public health surveillance
systems have conducted a ground- truthing of the preamble estimates based on actual local data on
illnesses and deaths.
With approximately 1.6 million customers in fully supplied communities, MWRA represents 13.3% of
EPA's estimate of the 12 million person served by unfiltered systems. Thus, the EPA estimate would yield
Comment Response for the LT2ESWTR 20-40 December 2005
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a presumed annual reduction of between 22,400 and 72,900 cases, and between 4 and 12 deaths. Yet,
under active surveillance, there were only 11 cases of Massachusetts-
acquired cryptosporidiosis in 2001 and 7 in 2002. Recognizing that even active surveillance does not
capture every case (although it generally will catch the most serious cases), and adjusting for an under-
reporting factor of 50 or 100, as reported by the CDC (Mead et al, Emerging Infectious Diseases, Vol. 5,
No.5), the preamble estimates appear to be off by a substantial amount. Essentially, the analysis suggests
that adding additional disinfection will reduce 22,000 to 72,000 more cases than the actual public health
surveillance indicates occur in total.
Response: Responses SOO.b, 2223.A, and 2223.B. EPA does not agree that available data support an
underreporting factor for cryptosporidiosis of 50 to 100.
EPA Letter ID: 522
Comment ID: 14153
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: The deaths attributed to cryptosporidiosis also seem high. Through our active
surveillance and an informal review of Massachusetts Vital Records, there is no record of any deaths in
Massachusetts associated with cryptosporidiosis in the past several years. While it is possible that some
deaths might be misattributed to other causes, it is reasonable to assume that any death caused by
cryptosporidiosis would at least result in a reported case. The estimates in the preamble assume that
improved disinfection will reduce more water-borne illness related deaths than were reported as total
cases, yet there are no reported deaths in Massachusetts, let alone the MWRA service area. This estimate
for mortality associated with cryptosporidiosis seems incorrect.
Response: Response 500.b, 2223.A, and 2223.B.
EPA Letter ID: 522
Comment ID: 14154
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Another way to ground truth the estimates is to review the information now being collected
by state and local health authorities as part of bio-
terrorism detection systems. MWRA participates with the Massachusetts Department of Public Health
and Boston Public Health Commission in a series of surveillance programs to detect any changes in a
variety of syndromic based illnesses including monitoring sentinel sites (nursing homes, schools, and
prisons) for diarrheal disease, daily analysis of electronic records at a cooperating HMO and hospital
emergency room admissions, and weekly review of antidiarrheal medicine sales.
The level of diarrheal disease estimated to be caused by cryptosporidiosis in unfiltered systems is not
credible, and ignores years of active surveillance work completed by MWRA and other large utilities
across the country. MWRA understands that the preamble numbers are estimates, but the degree to which
the estimated number of cases assumed to be reduced is different than the actual number of total cases
Comment Response for the LT2ESWTR 20-41 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
from all sources found is dramatic. Of course, if the number of cases of illnesses is grossly overestimated,
then the estimates of benefits are also grossly overestimated. MWRA urges EPA to reach out to state and
local health authorities to develop more realistic estimates for the final rule.
Response: Response SOO.b, 2223.A, and 2223.B.
EPA Letter ID: 523
Comment ID: 11697
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Morbidity Analysis: EPA's analysis, based on a series of assumptions and estimates, of the
number of cryptosporidiosis cases averted in areas supplied by unfiltered supplies through the new
regulations does not come even close to the actual numbers that utilities have found through actual active
surveillance.
If the results from New York City's and MWRA (Metro-Boston) customer bases are combined, the actual
active surveillance results demonstrate a much different picture than EPA. The two areas combined serve
about 10 million people, almost 5/6 of the 12 million that are supplied by unfiltered source waters, and are
projected, under EPA's estimate, to avert close to 140,000 to 455,000 cases of disease with improved
disinfection. Yet combined the two active surveillance systems average only about 150 total
cryptosporidiosis cases per year. Not every case of cryptosporidiosis is picked up by the active
surveillance system, but even using the Corso ratio of disease underreporting of about 88:1, or the CDC
estimate listed by Mead et al (CDC Emerging Infectious Diseases, Vol. 5, No.5) of about 50:1 to 100:1,
the difference between the two estimates is substantial. Somehow, the preamble analysis seems to indicate
both active surveillance systems (after under-reporting is taken into account) missed over 125,000-
440,000 cases of disease. This seems unreasonable, as virtually every lab in the service areas is checked
for confirmed positive cryptosporidiosis tests, which leads to the conclusion that the EPA estimate is
excessively high.
Response: Response 500.b, 2223.A, and 2223.B.
EPA Letter ID: 523
Comment ID: 11698
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Mortality: EPA's estimate of the number of deaths that will be averted with new treatment is
quite high compared to the surveillance results. The estimate for deaths averted in the New York City and
MetroBoston areas would be an estimated 23-75 deaths. Over the last 6 years, only once has
cryptosporidiosis been indicated as cause of death in New York City, with zero cases listed in Boston
over the last three years (the informal review of death certificates is for 2001-2003). Death certificate data
is imperfect, but with active surveillance looking for cryptosporidiosis cases, one would think that 23-75
deaths related to cryptosporidiosis would not be completely overlooked. Also, the estimated number of
deaths seems quite when (23-75) when compared to the total number of actual confirmed cases of the
disease from all sources of only about 150 per year.
Comment Response for the LT2ESWTR 20-42 December 2005
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Response: Response SOO.b, 2223.A, and 2223.B.
EPA Letter ID: 556
Comment ID: 12041
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Additionally, AMWA believes that it is important to keep in mind that the data on the
potential health effects of Cryptosporidium driving the regulation remain uncertain as reflected in the risk
assessment. For this reason, all parties to the FACA need to be open to new information on endemic risk
as it becomes available. Additionally, AMWA believes that the numerous, compounded
Response: Response 2200.s. EPA believes that the risk assessment supporting today's rule is based on the
best information available at the time the Agency developed the rule.
EPA Letter ID: 556
Comment ID: 12044
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. New Information
Discussion: The analysis of the risk posed by Cryptosporidium in source waters contains significant
uncertainties as acknowledged in the proposal. AMWA is aware that a number of related studies on
microbial disease occurrence are presently underway, nearing completion, or recently completed.
One such study is -THE WET STUDY: A randomized, controlled crossover trial of in-home drinking
water intervention for the reduction of gastrointestinal illness-, a joint effort of University of California,
Berkeley School of Public Health, the Centers for Disease Control and Prevention, and the U.S.
Environmental Protection Agency.
This study reportedly found no evidence that in-home drinking water treatment with combined filtration
and ultraviolet light is effective in reducing gastrointestinal illness in a healthy population receiving
drinking water that meets or exceeds regulatory standards. Parallel studies are investigating the
occurrence of Cryptosporidium and other pathogens and indicators at the same time in-home intervention
was taking place.
The microbial risk assessment developed by EPA provides an excellent framework for considering such
new information and how that information might impact current estimates of risk.
Recommendation: AMWA recommends that as information becomes available that may resolve or lessen
the uncertainties in the risk assessment that EPA incorporate this information.
Response: Response 2200.s, 2223.A, 2223.C.
Comment Response for the LT2ESWTR 20-43 December 2005
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EPA Letter ID: 562
Comment ID: 12538
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.2 Davenport, Iowa, Study
A useful comparison EPA did not draw on in its EA is the recent Davenport, Iowa, study and similar
work. Comparing the anticipated benefits from the LT2ESWTR with the findings of the fourth in a series
of sound epidemiological studies that have failed to demonstrate a significant linkage between public
health (including various forms of gastroenteritis) and tap water. The absence of strong correlation (the
study had the power to discern a difference of 10% in disease burden between the controls and tap water
consuming groups) is significant. This is the second large-scale, triple-
blinded surface water epidemiology study to reach this finding (follows on Hellard et al.). While
Melbourne draws its source water from a protected watershed and employs chlorination as its primary
treatment mechanism, Davenport draws its water from the Mississippi River and operates a conventional
plant meeting PSW Phase III criteria.
The absence of discernable disease attributable to drinking water exposure gives considerable pause to
one reviewing the LT2ESWTR EA. Through an assumption-driven analysis, it estimates a disease burden
that should be readily discernable in a well-funded study such as the one undertaken in Davenport by
Colford et al.
Response: 2223.C
20.2.4 Comment Code 2224, Sensitive subpopulations
Individual Comments on Code 2224
EPA Letter ID: 562
Comment ID: 12543
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 226 iii. Use of occurrence data sets in benefit and cost
analyses; 2220 B. Risk Assessment; 2221 1. Dose-response; 2222 2. Drinking water consumption
(including averting behavior); 2225 5. Uncertainty; 2226 6. Cases of illness compared to IESWTR or
LT1ESWTR estimates; 2230 C. Benefits; 2231 1. Valuation of Non-fatal Cryptosporidiosis
Comment: Figure 3. Factors Affecting Benefit Analysis
[SEE FIGURE 3, P.83 IN PDF]
Response: See Responses 2200b, 2221.7, and 2221.6. Thank you for your comment. EPA agrees that
additional data will provide an improved understanding of the national occurrence picture for all sizes and
types of systems. Such data will become available after LT2 rule is implemented.
EPA Letter ID: 562
Comment ID: 12553
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Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Approach
In one respect, EPA-s approach could be interpreted as being consistent with the previously summarized
risk assessment guidelines because sensitive population subgroups are identified and separate outcome-
based risks are developed for the subgroup and for the rest of the population. However, the health benefit
estimates for the LT2 raise questions when considering how specific characteristics of the critical
population subgroup (i.e., persons living with AIDS) that could influence the results are lost in the
approach ultimately used.
Specifically, EPA makes adjustments to its mortality risk estimates to try to account for the distribution of
persons living with AIDS in the United States, but the adjustment effectively assumes a uniform
dispersion of persons living with AIDS in specific types of water systems. The clear limitation to this
approach is that persons living with AIDS in the United States are not uniformly dispersed, but highly
concentrated. Consequently the EA-s analytical approach accrues benefits where the AIDS population in
reality is not present in sufficient density to actually accrue the predicted benefit.
Response: EPA believes that the risk assessment supporting today's final rule accounts for the dispersion
of persons with AIDS to the extent possible. The Agency recognizes that persons with AIDS are not
uniformly dispersed. To accout for this, EPA used separate estimates of AIDS rates for unfiltered and
filtered systems. This approach was possible due to two factors: (1) EPA conducted a separate risk
assessment for unfiltered systems since distinct occurrence and treatment data applied to these systems;
and (2) Most people receiving water from unfiltered systems are served by a few large municipal systems
(e.g., New York, Portland, San Francisco, Tacoma) and information on the populations and AIDS rates in
these cities was available. As described in the LT2ESWTR Economic Analysis, EPA used this
information to calculate an AIDS rate for unfiltered systems, then subtracted the unfiltered system
populations from national data to calculate an average AIDS rate for filtered systems (see the EA for
details). Because the risk assessment for filtered systems was only made at the national level (i.e., EPA
did not conduct site specific risk assessments for filtered systems), accounting for the dispersion of
persons with AIDS among filtered systems was not possible. Further, even if the Agency had been able to
account for the nonuniform dispersion of persons with AIDS among filtered systems, EPA does not
believe that this would have significantly changed benefits estimates for the rule. No data suggest any
correlation between drinking water Cryptosporidium levels and AIDS rates among filtered systems.
Filtered systems with higher AIDS populations would receive, on average, higher benefits from the rule
and vice versa. However, overall, benefits would change little.
20.2.5 Comment Code 2225, Uncertainty
Individual Comments on Code 2225
EPA Letter ID: 516
Comment ID: 11703
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 1) LT2 overestimates risk presented by cryptosporidium DEP is troubled by the analysis
presented by EPA as justification for the proposed rule (i.e., in the preamble to the rule and the economic
analysis). DEP believes the analysis overstates the risk of illness presented by cryptosporidium in U.S.
Comment Response for the LT2ESWTR 20-45 December 2005
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drinking water supplies; overstates the benefits to be derived from promulgation of the rule; and
understates the degree of uncertainty that exists with regard to estimating these risks and benefits. In
addition, DEP feels that the rule's preamble language does not fully and accurately reflect the spirit of the
FACA process. Specifically, during the FACA process, the uncertainties in risk assessment were raised,
but the group agreed that despite these uncertainties, certain measures could be taken as proactive steps,
and this proactive context is the true basis of the Agreement in Principle. This more accurate context
should be included in the preamble.
Response: Responses 2200.k and lOO.i.
EPA Letter ID: 516
Comment ID: 11723
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Conclusion:
Given all of the above, DEP feels that in its LT2 proposal and supporting documents, EPA has
overestimated and overstated the level of endemic risk presented by cryptosporidium in U.S. drinking
water supplies, and has insufficiently conveyed the degree of uncertainty which remains with regard to
this organism. EPA should provide better discussion of the above topics so that the public and other
stakeholders have some perspective on the issues and uncertainties associated with the reported risks and
benefits of the regulation.
Response: Responses 2200.k and 2200.h.
EPA Letter ID: 556
Comment ID: 12042
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: available. Additionally, AMWA believes that the numerous, compounded conservative
assumptions used both in the risk assessment and the economic analysis overstate benefits that are likely
to result for the rule.
Response: Response 2200.k.
EPA Letter ID: 562
Comment ID: 12325
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: c. The results of the clinical studies were interpreted via complex statistical models that are
driven by ~ and highly sensitive to ~ unsubstantiated assumptions. While the modeling approaches used
by EPA in the EA were suggested by the SAB, the obscurity of the presentation and the sensitivity of the
Comment Response for the LT2ESWTR 20-46 December 2005
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results to the model assumptions (e.g., increasing a key estimated mean risk parameter by a factor of 4 or
5 over the level found in the peer reviewed published literature) reveals the need for more transparency,
continued scientific discourse, and greater use of sensitivity analyses in portraying the possible risk levels.
Response: Responses 2200.h, 2200.S, 2221.2, and 2221.7.
EPA Letter ID: 562
Comment ID: 12540
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.4 Exposure Estimate
EPA-s EA employs data and assumptions that, individually and cumulatively, significantly overestimate
exposure. In predicting exposure, EPA does not demonstrate that the agency has explored critical
assumptions nor that it has a clear and cogent rationale for those assumptions. The agency does not reflect
on the compounding levels of conservatism in its analysis.
Response: Responses 2200.k and 2200.s.
EPA Letter ID: 562
Comment ID: 12543
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 226 iii. Use of occurrence data sets in benefit and cost
analyses; 2220 B. Risk Assessment; 2221 1. Dose-response; 2222 2. Drinking water consumption
(including averting behavior); 2224 4. Sensitive subpopulations; 2226 6. Cases of illness compared to
IESWTR or LT1ESWTR estimates; 2230 C. Benefits; 2231 1. Valuation of Non-fatal Cryptosporidiosis
Comment: Figure 3. Factors Affecting Benefit Analysis
[SEE FIGURE 3, P.83 IN PDF]
Response: See Responses 2200b, 2221.7, and 2221.6. Thank you for your comment. EPA agrees that
additional data will provide an improved understanding of the national occurrence picture for all sizes and
types of systems. Such data will become available after LT2 rule is implemented. 20.2.6 Comment Code
2226, Cases of illness compared to IESWTR or LT1ESWTR estimates
20.2.6 Comment Code 2226, Cases of illness compared to
IESWTR or LT1ESWTR estimates
Response to Code 2226
EPA does not believe that comparison of Agency risk estimates prepared for the IESWTR or LT IESWTR
with those prepared for the LT2ESWTR is appropriate or provides a valid basis to question the accuracy
Comment Response for the LT2ESWTR 20-47 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
of LT2ESWTR estimates. Major drivers for the risk estimates for all these regulations are
Cryptosporidium occurrence and infectivity. As discussed in the preambles for the proposed and final
LT2ESWTR, the occurrence and infectivity data used to support this rulemaking were significantly
different and better than data supporting the IESWTR or LT1ESWTR. For those earlier rules, EPA
considered regional surveys of Cryptosporidium occurrence and had results from one Cryptosporidium
infectivity study. For the LT2ESWTR, EPA used data from two national surveys of Cryptosporidium
occurrence and from six infectivity studies. Further, EPA has used a significantly more detailed and
refined model to estimate risk for the LT2ESWTR in comparison to the models used for the IESWTR or
LT1ESWTR. The LT2ESWTR risk modeling refects advances in statistical techniques and input from the
Science Advisory Board.
Given these significant differences in underlying risk data and modeling approaches, major differences in
results between the IESWTR/LTIESWTR and LT2ESWTR are expected. EPA does not believe that these
differences indicate that the LT2ESWTR results are in error. Rather, EPA regards the LT2ESWTR as
incorporating improved estimates reflecting better data and more sophisticated modeling.
Individual Comments on Code 2226
EPA Letter ID: 516
Comment ID: 11718
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 2. B. Overestimating Endemic Risk
DEP has a number of major concerns with regard to the health impacts analysis provided by EPA to
justify promulgation of the LT2ESWTR. In summary, DEP-s concerns are that: (1) internal
inconsistencies in EPA-s analysis raise question about it-s validity; (2) risk numbers presented by EPA
appear to overestimate endemic risk of cryptosporidiosis, and no attempt was made to rovide a reality
check or to -groundtruth- the risk estimates; (3) the degrees of uncertainty in the risk analysis are not
adequately acknowledged; and (4), there has been little attempt to assess any of the various health studies,
including those that might call into question EPA-s risk analysis. These issues are discussed in greater
depth below.
Internal Inconsistencies in Risk Projections:
Risk projections are included in a few different locations of EPA-s analyses (re: LT2 and prior rules), and
the projections do not all match up. For example, as is pointed out in the Stratus report prepared for
AWWA (Raucher, et al., Dec 2003, pg. 5-8), based on the analysis conducted for the Regulatory Impact
Analysis (RIA) for the IESWTR, the number of endemic cases of cryptosporidiosis projected to remain
after implementation of the IESWTR was 59,500 to 111,000. However, the number of illnesses that EPA
is now projecting it would avoid with promulgation of LT2 is 256,000 to 1.02 million illnesses ~ or
approximately 4 to 9 times more illness than the projected baseline. Inconsistencies such as the above call
into question the credibility of EPA-s risk estimates.
Response: Response 2200.k, 500.b, 2223.c, and 2226.
EPA Letter ID: 562
Comment ID: 12327
Comment Response for the LT2ESWTR 20-48 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 6. The extent by which EPA-s risk model overstates risks can be viewed, in part, by
comparing the agency-s estimated number of waterborne cases of cryptosporidiosis at the pre-LT2
baseline to its estimated reduction in cases due to the proposed LT2 rule:
a. EPA estimates the pre-LT2 baseline (i.e., post IESWTR) is between 60,000 and 111,000 cases per year.
b. The agency-s risk model used for the LT2 rule benefit-cost analysis predicts 256,000 to over 1,000,000
cases per year will be avoided due to the rule as proposed.
c. Therefore, EPA estimates a reduction in cases that is up to 9+ times higher than the number of cases it
has stated exist at baseline.
Response: Response 2226.
EPA Letter ID: 562
Comment ID: 12543
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 226 iii. Use of occurrence data sets in benefit and cost
analyses; 2220 B. Risk Assessment; 2221 1. Dose-response; 2222 2. Drinking water consumption
(including averting behavior); 2224 4. Sensitive subpopulations; 2225 5. Uncertainty; 2230 C. Benefits;
2231 1. Valuation of Non-fatal Cryptosporidiosis
Comment: Figure 3. Factors Affecting Benefit Analysis
[SEE FIGURE 3, P.83 IN PDF]
Response: See Responses 2200b, 2221.7, and 2221.6. Thank you for your comment. EPA agrees that
additional data will provide an improved understanding of the national occurrence picture for all sizes and
types of systems. Such data will become available after LT2 rule is implemented.
EPA Letter ID: 562
Comment ID: 12549
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. EPA-s projected number of cases avoided is implausible given the baseline level of illness
projected by the agency. In fact, EPA estimates of avoided cases are between 4 and 10 times higher than
its baseline.
Response: Response 2226.
Comment Response for the LT2ESWTR 20-49 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
20.3 Comment Code 2230, Benefits
Individual Comments on Code 2230
EPA Letter ID: 523
Comment ID: 11696
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 2240 D. Costs
Comment: Inaccuracies in Risk and Cost Information Presented in the Preamble:
The preamble and its supporting appendices present risk, benefit and cost data to support that the
proposed rule provides more benefit than it costs. Our review of the component parts raises concerns that
the benefits may be overestimated and the costs underestimated. Both may cause harm to the regulated
community. An overestimate of risk reduces the consumer's confidence in public water supply and may
be misused by less scrupulous interest groups. Underestimating the cost of compliance misrepresents
what the the national investment will actually be, and may misdirect public investment from more cost-
effective system improvements.
Response: See responses lOOb, lOOc, 100s, 2200k
EPA Letter ID: 562
Comment ID: 12539
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.3 Overview of the Benefits Analysis
Figure 3 is a flowchart of the factors affecting each step of the benefit analysis. When examining the
issues identified in Figure 3, the risk reduction benefits developed by EPA may be overstated in many
ways. Compounding the changes at each step as depicted in the figure, the overall estimate of benefits
derived by EPA could be an order of magnitude or more larger than a more plausible and likely estimate.
Response: See response 100s, 2200k
EPA Letter ID: 562
Comment ID: 12543
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 226 iii. Use of occurrence data sets in benefit and cost
analyses; 2220 B. Risk Assessment; 2221 1. Dose-response; 2222 2. Drinking water consumption
(including averting behavior); 2224 4. Sensitive subpopulations; 2225 5. Uncertainty; 2226 6. Cases of
illness compared to IESWTR or LT1ESWTR estimates; 2231 1. Valuation of Non-fatal Cryptosporidiosis
Comment Response for the LT2ESWTR 20-50 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
Comment: Figure 3. Factors Affecting Benefit Analysis
[SEE FIGURE 3, P.83 IN PDF]
Response: See Responses 2200b, 2221.7, and 2221.6. Thank you for your comment. EPA agrees that
additional data will provide an improved understanding of the national occurrence picture for all sizes and
types of systems. Such data will become available after LT2 rule is implemented.
20.3.1 Comment Code 2231, Valuation of Non-fatal
Cryptosporidiosis
Individual Comments on Code 2231
EPA Letter ID: 522
Comment ID: 14156
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: concerned that the dollar values placed on the cases of illness are overstated. Many of the
illnesses indicated may be minor or even asymptomatic. Cases that do not show up on any of the public
health radar screens may simply be too mild to be economically significant. Based on the discussion
above, it is clear that the only way to arrive at the number of cases included in the analysis is to include a
vast number of "illnesses" in which the individual did not realize they were sick.
Response: See responses 2200b, 2200o
EPA Letter ID: 562
Comment ID: 12329
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 8. EPA-s use of an -enhanced- cost of illness (COI) approach to value avoided cases of
nonfatal Cryptosporidiosis is highly problematic. The approach is a significant departure from standard
economics practice, does not appear to have been subjected to expert peer review, and yields results that
seem implausible and unrealistic compared to other well-established risk valuation benchmarks.
Response: See rsponse 2200b
EPA Letter ID: 562
Comment ID: 12543
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 20-51 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
Other EPA Comment Codes and Descriptions: 226 iii. Use of occurrence data sets in benefit and cost
analyses; 2220 B. Risk Assessment; 2221 1. Dose-response; 2222 2. Drinking water consumption
(including averting behavior); 2224 4. Sensitive subpopulations; 2225 5. Uncertainty; 2226 6. Cases of
illness compared to IESWTR or LT1ESWTR estimates; 2230 C. Benefits
Comment: Figure 3. Factors Affecting Benefit Analysis
[SEE FIGURE 3, P.83 IN PDF]
Response: See Responses 2200b, 2221.7, and 2221.6. Thank you for your comment. EPA agrees that
additional data will provide an improved understanding of the national occurrence picture for all sizes and
types of systems. Such data will become available after LT2 rule is implemented.
EPA Letter ID: 562
Comment ID: 12551
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.4.5 Valuation of Health Effects
EPA-s use of cost of illness (COI) based estimates to attempt to value the ex ante risk reduction WTP for
cryptosporidiosis is understandable, given the lack of reliable data from which to infer the preferred
measure of ex ante WTP. The agency-s traditional COI is a reasonable estimate for EPA to use in this
regard, and it may reflect a lower bound. The development and application by EPA of the -enhanced COI
approach-, which the agency characterizes as a surrogate willingness to pay analysis, is lacking in both
credibility and plausibility. Differences between COI and enhanced COI approaches are enumerated in
Table 4.
Table 4. Differences in the Valuation of Time in the Traditional and Enhanced COI Methods
[SEE TABLE 4, P.88 IN PDF]
The enhanced COI approach does not adhere to standard practice in the economics profession (e.g., with
regard to valuing time spent out of the workplace), and it generates results that do not appear to be
reasonable relative to other benchmarks, such as value of a statistical life (VSL). A simple illustration vis-
a-vis ex ante willingness-to-pay provide a context to assess the reasonableness of the enhanced COI
approach. VSL estimates reveal the ex ante willingness-to-pay of individuals to reduce risks of premature
fatality. A VSL of roughly $6.3 million if often used as a measure of the value of reducing risks of
premature fatality, based on a large body of well-
reviewed literature in which individuals (e.g., median aged workers) in effect reveal a willingness-to-pay
to reduce a mortality risk typically in the range of 1 in 10,000 per year. What this literature actually tells
us is that a typical, median aged person has an ex ante willingness-to-pay of $630 per year, on average, to
reduce a 10-5 risk of premature fatality in the coming year. This widely accepted $630 per person of ex
ante willingness-to-pay to avoid a 1 in 10,000 annual risk of immediate fatality serves as our frame of
reference.
The following illustrative example completes this comparison to a VSL estimate. Lets assume that the
risk posed by cryptosporidiosis was permanent and that symptoms were suffered through a recurring
cycle of typically mild or moderate cases (with perhaps a rare severe episode as well, but no risk of
fatality). Thus, a median aged worker struck by the disease under this assumption would face
Comment Response for the LT2ESWTR 20-52 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
predominantly mild illness (and the associated COI) for the balance of his or her life. If one were to
contend that EPA-s enhanced COI approach provided useful and reasonable approximations of ex ante
willingness-to-pay to avoid a lifelong case of cryptosporidiosis such as depicted in this example, then this
implies an average ex ante willingness-to-pay of $455 per person exposed to the 1 in 10,000 annual risk
of this version of the disease outcome. While this illustration uses a somewhat contrived version of
cryptosporidiosis (lifelong continuous recurrence of atypical, severity-weighted nonfatal case), it does
provide useful context for considering the valuation issue. A lifelong cycle of diarrhea and other mild
symptoms would no doubt be unpleasant, and no doubt a typical person would be willing to pay a
considerable amount to reduce the risk of such an outcome. However, would they have a willingness-to-
pay that is over 72% of their willingness-to-pay a comparable level of risk of immediate fatality (i.e.,
$455/$630 = 72.2%)? This does not seem to be plausible or likely.
AWWA does not believe that the enhanced COI analysis should used to evaluate this rulemaking, and
should instead be subjected to far greater peer review and revision before EPA attempts to inject it into
any future matter of public health policy-making.
Response: See response 2200b
EPA Letter ID: 668
Comment ID: 13890
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: associated with waterborne disease is grossly underreported. Finally, EPA also has
underestimated the benefits of avoiding waterborne disease, including the benefits of reduced pain and
suffering.
Response: See response 2200b
20.3.2 Comment Code 2232, Valuation of Mortality
Individual Comments on Code 2232
EPA Letter ID: 101
Comment ID: 10929
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: NRWA feels the currently used value of a statistical life is seriously flawed and that future
benefits and costs must be discounted to present value. (Raucher 2001; 2003)
The benefits of a drinking water regulation are often thought of as a reduced number of illnesses
(morbidity) or deaths (mortality). However, there is no identifiable individual whose life is saved or
illness avoided. Instead, the benefits reflect "statistical lives" because regulations reduce low-level risk
borne across a large population. Also, because every person is mortal, no regulatory action truly "saves
lives." Instead, MCLs reduce a number of premature fatalities, or increase life expectancy expressed as
life years saved (LYS).
Comment Response for the LT2ESWTR 20-53 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
To assign a monetary value to risk reductions, analysts rely on estimates developed for the "value of a
statistical life" (VSL) by looking at how people state or reveal their "willingness to pay" for lower (or
elevated) risks. These estimates represent monetary measures of the value individuals place on the
change in quality of life achieved as a result of a risk reduction. This approach is appropriate when
conducted in accordance with well-established and broadly accepted principles of welfare economics.
Response: See responses 2200a, 2200c, 2200d
EPA Letter ID: 516
Comment ID: 11724
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 2.C. Overestimating Benefit
In addition to overestimating risk, and underestimating cost, EPA has also overestimated benefit. The
overestimation of benefit is directly related, of course, to EPA-s overestimation of risk which we have
discussed above. However, beyond those issues, EPA makes certain assumptions for its benefits analysis
which we believe to be questionable. First, EPA applies rates of morbidity and mortality from the
Milwaukee incident, and uses these rates to derive the cost of illness and death. The benefits are thus
derived from avoiding these costs. DEP believes that the application of the lessons learned from a large-
scale outbreak like Milwaukee, to projections of costs and benefits for situations such as in the typical
U.S. drinking water supply, is not appropriate. In EPA-s own words (p. 5-14 of the EA), the -mortality
rate from the Milwaukee outbreak may not reflect the overall mortality rates from low-level endemic
exposure-. Second, approximately half the benefit is derived from the value of reduced mortality. In other
words, the benefit of avoiding up to as many as an estimated 91 premature deaths is approximately equal
to the benefits from avoiding up to 500,000 cases of illness. Given the sensitivity of the overall benefit
calculation to the estimate of mortality, DEP does not understand why the mortality rate is a fixed number
rather than a statistical distribution as was used in other parts of the risk, cost, and benefit analysis. EPA
compounds the
Response: See response 2200a and 2200.k. EPA believes that the Milwaukee outbreak provided the best
available data for estimating illness severity rates and mortality rates due to cryptosporidiosis from
drinking water. EPA has no basis to conclude that these rates would differ for endemic cryptosporidiosis.
EPA Letter ID: 516
Comment ID: 11726
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: DEP also has concerns about the methodology used to estimate benefits through the value of
life analysis. As noted in the Proposed Rule, EPA used the value of statistical life [VSL] methodology to
calculate mortality benefits. Specifically VSL estimates from 26 studies were used to get a mean VSL of
$ 6.3 million. Some details on this analysis were presented in EPA-s -Guidelines for Preparing Economic
Analyse- and the report -The Benefits of the Clean Air Act, 1990-2010.- The latter report notes how
complex and controversial VSL estimates can be, and points out that the majority of the 26 studies
Comment Response for the LT2ESWTR 20-54 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
utilized middle-age working populations. Since these working populations differ dramatically from the
AIDS population of greatest concern in the LT2 Rule mortality calculation, both in terms of health status
and statistical life expectancy, it would appear that the calculation provided needs to take this difference
into account. While the Clean Air Act report discusses the problems of life expectancy citing the value of
statistical life year [VSLY] concept and life quality citing the quality- adjusted life years [QALY]
concept, it appears that these approaches were ignored in the report-s VSL calculations. In fact, these
concerns and approaches were not mentioned or discussed at all in the Proposed Rule. It is recommended
that this substantial issue be reviewed, discussed, and if warranted (as appears to be the case) the
mortality benefits analysis be re-calculated and adjusted accordingly.
Response: See responses 2200a, 2200d
20.3.3 Comment Code 2234, Nonquantifiable benefits
Individual Comments on Code 2234
EPA Letter ID: 562
Comment ID: 12556
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Utilities that make an investment in watershed control, RBF, off-stream storage, pre-
sedimentation, enhanced filtration, and dual filtration are not simply adding a capital facility. These
utilities are committing to an ongoing program that will improve influent water quality, improve the
stability and reliability of the treatment process, and improve overall management/operation of the
facility. The costs and benefits of these operational changes are not reflected in the simple selection of an
add-on disinfection unit operation. Likewise, it does not reflect the ability of these unit operations to
reduce either the challenge facing the primary treatment train or the enhanced removal of other
contaminants, both known and unknown. For example, RBF is known to reduce organic contaminants
entering the water treatment facility, off-stream storage allows for settling of particulates, and enhanced
filtration clearly results in increased particle removal. The current EA-s non-quantifiable benefits section
is not reflected in Table VI-2 of the proposed rule and did not receive any substantive discussion in the
EA itself. For the water supply community, these non-quantifiable benefits are the essence of the
microbial toolbox, a substantial reason for supporting the LT2ESWTR proposal, and a critical aspect of
the regulatory framework and guidance for the LT2ESWTR. AWWA believes that the agency has a
responsibility to articulate the above benefits in the final rule preamble and reflect these benefits in the
final rule regulation and guidance.
Response: see response 2200p and lOO.t.
EPA Letter ID: 562
Comment ID: 12557
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 20-55 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
Comment: Request for Comment
How can the agency estimate the potential benefits from reduced epidemic outbreaks of
cryptosporidiosis?
Response
LT2ESWTR is actually one in a series of rulemakings. In 1998, EPA promulgated the IESWTR, which
established controls on water treatment plants employed by Subpart H utilities serving 10,000 or more
persons. Shortly thereafter the agency promulgated the LTIESWTR that expanded very similar regulatory
controls to water treatment plants employed by Subpart H systems serving less than 10,000 persons. Both
IESWTR and LT IESWTR were explicitly intended to address reduction of epidemic waterborne
cryptosporidiosis. The agency recognized in those rulemakings that epidemic waterborne
cryptosporidiosis attributable to drinking water were principally associated with disruption of treatment.
Consequently, those two rulemakings increased the rigor of the regulatory standard for turbidity at the
combined filter effluent and set individual filter effluent reporting requirements that trigger systematic
evaluation of the drinking water treatment facility. The central distinction between IESWTR/
LT IESWTR and LT2ESWTR is that LT2ESWTR is intended to address endemic waterborne
cryptosporidiosis attributable to drinking water.
EPA has already implemented regulations (the IESWTR/LTIESWTR) to manage epidemic outbreaks of
cryptosporidiosis and estimated benefits from those regulations. Therefore, an estimate of additional
benefits from epidemic outbreaks is not needed within the LT2ESWTR EA.
Response: The risk assessment for today's final rule addresses endemic (not epidemic) risk (such as
would be associated with a treatment failure or major contamination incident). However, EPA believes
that when systems install additional treatment under today's rule, these steps will reduce the likelihood of
an epidemic outbreak.
20.4 Comment Code 2240, Costs
Individual Comments on Code
EPA Letter ID: 523
Comment ID: 11696
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Other EPA Comment Codes and Descriptions: 2230 C. Benefits
Comment: Inaccuracies in Risk and Cost Information Presented in the Preamble:
The preamble and its supporting appendices present risk, benefit and cost data to support that the
proposed rule provides more benefit than it costs. Our review of the component parts raises concerns that
the benefits may be overestimated and the costs underestimated. Both may cause harm to the regulated
community. An overestimate of risk reduces the consumer's confidence in public water supply and may
be misused by less scrupulous interest groups. Underestimating the cost of compliance misrepresents
what the the national investment will actually be, and may misdirect public investment from more cost-
effective system improvements.
Response: See responses lOOb, lOOc, 100s, 2200k
Comment Response for the LT2ESWTR 20-56 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
EPA Letter ID: 592
Comment ID: 12113
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: why they need to spend more money and raise rates again. This rule as proposed represents an
expensive proposal and the economic analysis included in this proposal is unrealistic in scope,
particularly for Maine and other predominantly rural states with unfiltered surface water sources. While
the goals of this
Response: See response 100cand2200.k.
EPA Letter ID: 601
Comment ID: 13048
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Further, the implementation activities in the first six to nine years following promulgation of
the final rule are expected to be quite significant with somewhat of a reduction in activity after that time.
States therefore suggest that EPA discount the labor and material costs associated with implementation
over a 10-year period rather than a 20-year period as in the proposed rule.
Response: See response 2200c
20.4.1 Comment Code 2250, Water System Costs
Response to Code 2250
A. EPA believes that the costs for water systems and States in the final LT2ESWTR Economic Analysis
accurately represent the full costs attributable to the rule. In developing these costs, EPA has considered
cost information submitted by commenters. For the most critical costs, such as UV, EPA has surveyed
actual treatment facilities and used equipment vendor quotes to ensure that cost estimates are accurate.
EPA has recognized that costs for individual systems will vary from the average costs presented in unit
cost tables for technologies. However, using average costs is appropriate for estimating the national cost
of the rule.
B. EPA believes that the Agency's estimates of monitoring costs are accurate within the limits of available
information. These costs are based on surveys of what commercial laboratories charge to perform
analyses using methods required by the rule. In estimating costs, EPA has included the cost of required
quality control samples. Costs also include the analysis of multiple subsamples where required for
Cryptosporidium samples. EPA recognizes that costs for individual water systems will vary but believes
that the Agency has accurately characterized the range of typical costs. EPA recognizes that these or any
costs could potentially increase or decrease in the future. However, EPA does not expect these costs to
Comment Response for the LT2ESWTR 20-57 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
change significantly. Dozens of laboratories are approved to conduct analyses for Cryptosporidium and E.
coli under the LT2ESWTR. This number will facilitate market competition, which will help to hold down
costs.
C. EPA's estimated costs for systems to comply with uncovered finished water reservoir requirements
under the LT2ESWTR reflect are reasonable. The Agency has adjusted costs from the proposed rule in
response to information submitted by commenters. Under the rule, systems must cover the reservoir or
treat the reservoir discharge for Crypto, Giardia, and viruses. Accordingly, EPA has considered costs of
floating covers (for covering) or UV and chlorine (for treatment). Cost estimates for both are based on
real vendor quotes. EPA recognizes that systems may choose to pursue more expensive alternatives, such
as building alternative storage or fixed covers. However, EPA does not believe that the greater
incremental costs of such alternatives are attributable to the rule.
D. EPA believes that the State costs in today's final rule accurately account for the activities that the rule
requires of States. As described in the Economic Analysis, these activities include the following: adopting
the regulation and developing the program, training State staff, training PWS staff, providing technical
assistance to PWSs, and updating the data management system. Estimates for the cost of required
activities are based on previous experience with other rules. Because EPA will directly manage the data
collection for initial source water monitoring of large and medium systems, States are predicted not to
incur any costs for these activities. They will, however, incur costs from the small system initial
monitoring requirement.
EPA has revised the presentation of State costs in the LT2ESWTR Economic Analysis to make the
analysis more understandable to readers. EPA conducted this analysis to determine average state costs in
order to estimate national costs for the rule. It is based on estimating the average FTEs that states will use
for different rule activities and the cost of those FTEs. Costs for individual states will vary. EPA's
analysis can provide guidelines to a state for estimating its resource needs (e.g., identify activities a state
must consider). However, EPA's analysis is not intended to be used by States directly to calculate their
specific costs under the rule, as these will depend on state-specific factors (e.g., number of water systems
in state).
Individual Comments on Code 2250
EPA Letter ID: 101
Comment ID: 10930
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: NRWA believes that differences between USEPA and industry cost estimates must be
resolved. (Raucher 2001)
It is not uncommon for compliance cost estimates developed by USEPA to be lower, and in some cases
substantially lower, than the compliance costs estimated by regulated water utilities and/or their national
representatives. It is important for USEPA to recognize that costs faced by water systems are regressively
increasing, and that most water systems may have only one, or in a few cases two, opportunities to make
major treatment upgrades or changes in treatment processes within any 10 year period. Accurate and
reasonable compliance cost estimates are needed to fairly judge the impact of regulatory options under
consideration. When differences exist between Agency and industry cost estimates, USEPA should seek
Comment Response for the LT2ESWTR 20-58 December 2005
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to resolve these differences and provide national cost estimates that fairly represent the totality of costs
that will be faced by the regulated community.
Response: Response 2250.A.
EPA Letter ID: 588
Comment ID: 12093
Commenter: Lance Nielson, Manager, Idaho Drinking Water Program, Department of Environmental
Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 2256 4. State costs
Comment: 2) We are concerned that EPA's methodology for estimating costs of new rules to State
programs and to regulated water systems fails to take into account the concept of "cumulative burden."
The body of regulation that has been promulgated pursuant to the Safe Drinking Water Act is large and
complex. The knowledge required of water system operators long ago reached insurmountable
proportions, resulting in a strong dependency upon technical and informational assistance from state
regulators. At the same time, State programs find it increasingly difficult to absorb and communicate
regulatory requirements, both to the regulated community and to overloaded agency personnel. Our point
is that each new rule has a cumulative impact that is greater than would be the case if the rule were not
incremental to an already large and demanding body of regulations. Although this may be difficult to
quantify, we would urge EPA to lean toward a more generous estimation of cost impacts.
Response: Response 2200.f.
EPA Letter ID: 595
Comment ID: 12574
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: The analysis portions of the proposed rules are very expensive and the best available
treatment options may require more capital spending. When EPA determines the effective dates, we hope
that EPA will consider balancing costs to benefits to allow implementation dates to follow bond pay offs
so that the consumers will not be unduly burdened with high rates if even for a short period of time. The
monitoring costs for LT2 could be a per household cost of $30 to $40 in some of our smaller surface
water supplies
Response: Response 1200.b.
20.4.1.1 Comment Code 2251, Monitoring
Individual Comments on Code 2251
Comment Response for the LT2ESWTR 20-59 December 2005
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EPA Letter ID: 439
Comment ID: 10755
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment: The estimated costs given by EPA range from $389-$713 per sample is probably
low since supply and demand (see issue 1) may cause significant variation from this estimate. Utilities
themselves will not spend this money to gear up and invest in equipment and employees for a temporary
data collection time period.
Response: Response 2250.b.
EPA Letter ID: 484
Comment ID: 10680
Commenter: Anonymous484,, Metro Nashville Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Laboratory Costs:
Lab costs will be a major impact to our utility($ 100,000- $200,000).
Response: Response 2250.b. EPA's cost data indicate that this estimate provided by the commenter
greatly exceeds monitoring costs that today's rule will require systems to incur.
EPA Letter ID: 491
Comment ID: 10665
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: 4. The costs for Cryptosporidium monitoring may be higher than EPA estimates. EPA has
estimated the average cost per Cryptosporidium sample to be $530. ACWD has estimated the costs to
conduct bi-weekly monitoring for two years, based on lab analysis cost (sample analysis, matrix spikes
and sample delivery), planning/scheduling, sample collection, data entry, quality control, and data
analysis and reporting, to be $30,338 per year in staff time and laboratory services. With 26 samples per
year, this works out to be an average of $ 1167 per sampling event.
Response: Response 2250.b. EPA has accounted for data analysis and reporting costs separately from
monitoring costs.
EPA Letter ID: 496
Comment ID: 10692
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: 5. Monitoring Key Issue 5 Laboratory Costs: In their costs and technology
document, the EPA has estimated the average lab cost per Crypto sample is $530
(minimum $389 and maximum $713). The increase in lab costs due to monitoring, as
well as the additional training and/or hiring for what will only be lab requirements for
temporary monitoring for this and the DBP rule, is a major concern for water systems.
Comment Response for the LT2ESWTR 20-60 December 2005
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Many large labs and utilities are not eager to invest time and money for what they see
as a temporary requirement adding to the laboratory capacity problems. Certification
is expensive and large utilities that have certified labs do not ordinarily take work
from outside.
Comments for Monitoring Key Issue 5 (Laboratory Costs): EPA should be
concerned about the financial burden placed on water systems.
Response: Responses 2250.b and 100.c.
EPA Letter ID: 524
Comment ID: 12209
Commenter: Gary Larimore, Executive Director, Kentucky Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: States. Coupled with the fact that the cost of monitoring for Cryptosporidium is
approximately $400 per sample and that the testing accuracy for Cryptosporidium is suspect - producing a
high number of false positives, this should be enough to suggest that EPA proceed with caution. The rule,
as proposed, is cost-
prohibitive for public water systems.
Response: Responses lOO.c and SOO.f
EPA Letter ID: 561
Comment ID: 12237
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Comment: SECTION IV.K. - Analytical Methods for Cryptosporidium
The minimum sample volume for analysis is 10 L, or up to a 2 ML sample size for filtered material. With
a source water such as Lake Winnebago, which can be difficult to filter and also can generate a large
filtered volume; this Rule provides for a sampling procedure which results in nearly a doubling in
sampling and analytical cost under Method 1623. For a small utility, the sampling burden will be
significant. According to the Wisconsin State Lab of Hygiene, which is certified for this analytical
procedure, the analysis cost will nearly double from $350/sample to $700/sample.
Response: Response 2250.b.
EPA Letter ID: 592
Comment ID: 12101
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment: Cryptosporidium sampling for small surface water sources
Any small surface water system that meets the E. coli trigger and finds itself being required to monitor for
Comment Response for the LT2ESWTR 20-61 December 2005
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Cryptosporidium will be forced to look for alternate underground sources because the testing represents
such a sigdicant expense, even if there never is any Cryptosporidium present.
Response: Response lOO.c.
EPA Letter ID: 610
Comment ID: 12988
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: Cryptosporidium and E. Coli monitoring prior to promulgation of LT2ESWTR. Even if
sufficient laboratory capacity is developed, the current costs in our area are approximately $450.00 per
sample, which is more than 5 times the cost of any other test. It would seem to me that for a short term
capacity need such as
Response: Response lOO.c. and 2250.b.
EPA Letter ID: 620
Comment ID: 13287
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: for the amount of samples to be collected. Costs associated with sampling and analysis is also
unclear to SPRWS. EPA should also ensure that the data
Response: Response 2250.b.
EPA Letter ID: 620
Comment ID: 13295
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: Key Issue 5: Laboratory Costs
Comments: Based on an average cost of $530 per sample, the laboratory costs would be approximately
$6,360 per year for SPRWS. SPRWS contract lab budget for 2004 is $29,000. Cryptosporidium testing
will therefore add 22% growth to the testing budget for future years. Planning for such increase should be
made at least 8 months prior to the sampling year.
Response: Responses lOO.c, 1200.c, and 2250.b.
EPA Letter ID: 625
Comment ID: 13142
Comment Response for the LT2ESWTR 20-62 December 2005
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Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 5) Laboratory costs Currently, the Cobb County -Marietta Water Authority pays
approximately $lOOO/month for two samples for Cryptosporidium sampling, shipping and analysis.
Response: These costs are consistent with EPA's estimates for today's final rule.
20.4.1.2 Comment Code 2252, Treatment
Individual Comments on Code 2252
EPA Letter ID: 516
Comment ID: 11704
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 2) LT2 underestimates major capital costs DEP believes that the rule-s cost-
benefit analysis significantly underestimates the cost of treatment options required under LT2. Both the
cost estimates for UV disinfection and for reservoir covering as presented by EPA appear to be
considerably lower than the City-s own estimates. For example, DEP estimates capital costs for a UV
facility to be $600,000,000 ~ whereas, the proposed rule-s Economic Analysis seems to project a cost of
$92,000,000 for a facility of the same capacity. DEP-s projected unit costs for reservoir covers also
exceed EPA-s estimate by a factor of 5 - 25.
Response: EPA has adjusted the costs for UV disinfection in today's final rule in response to information
submitted by the commenter. Response 2250.c.
EPA Letter ID: 516
Comment ID: 11714
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 2.A Underestimating Cost
The LT2-s Economic Analysis (EA) clearly underestimates the capital and O&M costs for compliance.
DEP is specifically concerned with two areas, the cost estimate for uncovered finished water reservoirs
and the cost estimate for a UV disinfection facility.
UV Facility: The EA includes cost estimates for construction and maintenance within existing water
treatment facilities, and for installing pumping facilities at many locations. The unit cost for construction
used by EPA was $48.95/sq. ft. However, typical estimates for water treatment facilities in the Northeast
range from $150-200 per sq. ft. or 3-4 times the cost proposed by EPA. The cost of pumping is also
substantially greater than projected by EPA. For a 2000 MGD facility (that proposed by DEP), EPA
would estimate the cost at approximately $120 million including pumping. The current planning cost
estimate being used by DEP for the UV facility is $600,000,000. Thus, EPA has underestimated the cost
for this type of facility by a factor of approximately four.
Comment Response for the LT2ESWTR 20-63 December 2005
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Response: EPA has adjusted the costs for UV disinfection in today's final rule in response to information
submitted by the commenter.
EPA Letter ID: 516
Comment ID: 11716
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: EPA makes several statements in the EA that the per capita cost for large systems should be
smaller than for smaller systems but provides no documentation regarding that assumption. Nor does EPA
provide any assessment about the costs likely to be incurred by larger older urban systems with aging
infrastructure that have to retrofit and reconfigure the systems to support the new technology. Capital
costs for such systems may be geometrically greater than for newer systems.
Based on the above information, and related information for other facilities, DEP believes that EPA
should recalculate and reassess its cost analysis. That reassessment should reevaluate the basis of the cost
estimates, and reassess whether the management conclusions are still supported by the analysis.
Response: EPA's Economic Analysis for the LT2ESWTR clearly shows that treatment costs per gallon
decrease as system size (hence, flow rate)increases. This results in lower per capita costs for large
systems. In estimating treatment costs, EPA has accounted for retrofitting existing plants. Response
2250.A.
EPA Letter ID: 522
Comment ID: 14155
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: The Appendices to the Economic Analysis present the cost estimating tables and graphs used
by EPA is estimating the cost of complying with the proposed rule. MWRA is currently in the process of
conceptual design for two UV facilities - one with a capacity of 405 mgd, the other with a capacity of 25
mgd. In each case the capital costs to add UV to the water treatment plants are almost twice what the cost
tables would estimate. The larger plant is estimated by EPA to cost about $24 million; our current
estimate is $43.5. The smaller plant is estimated by EPA to cost $1.8 million versus our cost estimate of
$4.7 million. We are aware of many other water systems with similar experiences, with actual cost
estimates about twice what EPA is using in the cost/benefit analyses. We urge EPA to conduct additional
work in developing realistic cost estimates for the final rule. MWRA is also
Response: Response 2250.A.
EPA Letter ID: 523
Comment ID: 11699
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for the LT2ESWTR 20-64 December 2005
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Comment: Capital Costs: Just as the benefits appear to be overestimated, the costs of the capital
improvements needed to come into compliance seem underestimated. Individual systems will be
presenting information on the estimated site-specific costs of adding UV to their systems based on
conceptual or preliminary designs in their own comment letter. The range of underestimation appears to
range from about 2 to 4 times the actual anticipated costs.
Response: Response 2250.A.
20.4.1.2.1 Comment Code 2253, Incorporation of toolbox
technologies
Individual Comments on Code 2253
EPA Letter ID: 562
Comment ID: 12339
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: UV treatment to comply with LT2ESWTR.* Additionally, the UV compliance estimates for
smaller systems is likely underestimated as the agency-s analysis reflects substantial reliance on bag
filters (on the order of 1,236 - 1,545 PWSs). This estimate is unrealistic, due to the lack of manufacturer
ongoing performance and integrity testing for bag filters.
Response: EPA believes that equipment vendors will be able to meet the market demand for bag filters
estimated under today's rule. EPA has not identified any factors, including equipment testing, that would
constrain bag filter sales below the level estimated under the rule. Performance testing is required only for
a product line, not all individual filters.
EPA Letter ID: 562
Comment ID: 12343
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: employing bag filtration. Bag filtration is limited in application to very small water treatment
facilities; moreover,
once utilities attempt to comply with the provisions enumerated in guidance it is unlikely that bag
filtration will be a
feasible compliance technology under LT2ESWTR.
Response: EPA has estimated that only small systems will use bag filters. EPA's assessment is that small
systems will be able to use bag filters to comply with Cryptosporidium treatment requirements under
today's rule. As described in the preamble, this assessment is based on performance testing of bag filters
that meets the recommendations of EPA's guidance.
Comment Response for the LT2ESWTR 20-65 December 2005
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20.4.1.3 Comment Code 2254, Uncovered finished water
reservoirs
Individual Comments on Code 2254
EPA Letter ID: 474
Comment ID: 11206
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Water Works
Commenter Category: Regulated Community (Utilities)
Comment: Because we have been actively working to address our open reservoirs, we can provide very
specific feedback on the costs of replacing large open reservoirs with buried storage or providing floating
covers:
- Replacement of two reservoirs (75 MG) with buried storage $65 Million
- Providing floating covers for two reservoirs (30 MG) $ 2 Million
Within a 20 year period, we would expect to have to either replace floating covers installed on the two
reservoirs now or, should facility conditions warrant, may need to incur the full cost of replacing
reservoirs with buried storage.
Response: Response 2250.A and 2250.C.
EPA Letter ID: 516
Comment ID: 11705
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: required under LT2. Both the cost estimates for UV disinfection and for reservoir covering as
presented by EPA appear to be considerably lower than the City-s own estimates. For example, DEP
estimates capital costs for a UV facility
Response: Response 2250.A and 2250.C.
EPA Letter ID: 516
Comment ID: 11715
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 2.A Underestimating Cost
The LT2-s Economic Analysis (EA) clearly underestimates the capital and O&M costs for compliance.
DEP is specifically concerned with two areas, the cost estimate for uncovered finished water reservoirs
Comment Response for the LT2ESWTR 20-66 December 2005
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and the cost estimate for a UV disinfection facility.
Uncovered Reservoirs: For reservoirs in the 250-1000 MGD category, the EA estimates a capital cost of
$9.4 Million (for a floating cover based on a unit cost of $2/sq. ft of reservoir surface and an annual O&M
of $280,000). These estimates are unrealistically low, particularly for large reservoirs. DEP estimates the
cost of a cover for its 90-acre, 900 million gallon, Hillview Reservoir, would be from $42.6 million
($10.87 per square foot) for a floating cover to $218 million ($55.60 per square foot) for a domed fabric
cover (based on 1998 numbers). DEP-s projected unit costs exceed EPA-s estimate by a factor of 5-25.
Response: Responses 2250.A. and 2250.C.
20.4.2 Comment Code 2255, Household costs
Individual Comments on Code 2255
EPA Letter ID: 391
Comment ID: 10498
Commenter: Ricardo Nelson Rios,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: Revision #1: Household Costs of the Proposed Rule:
We feel that the household costs should be spread out throughout the entire community or subsidized by
the government as opposed to impose large charges on the smaller serviced (10 percentile). As stated in
under the "Household costs of the Proposed Rule", "over 90 percent of all households will face an annual
cost increase of less than $5. Households served by small systems that install advanced technologies will
face the greatest increases in annual costs." Moreover, we suggest that in those cases of households with
smaller services that the EPA be required not to disclose the underlying charges for them. A leak of this
information will cause an outbreak of protests over a small charge which can be divided at a resonable
rate throughout the entire community. Our concern is that all the people affected by the Cryptsporidium
be protected without placing a larger burden on any portion of the community.
Response: See response 2200r. Todays rule does not contain requirements affecting how systems bill for
water services or the information they disclose regarding that billing.
EPA Letter ID: 595
Comment ID: 12576
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: of time. The monitoring costs for LT2 could be a per household cost of $30 to $40 in some of
our smaller surface water supplies
Response: Response lOO.c and 2250.B.
Comment Response for the LT2ESWTR 20-67 December 2005
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20.4.3 Comment Code 2256, State costs
Individual Comments on Code 2256
EPA Letter ID: 457
Comment ID: 11910
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Estimated Cost
We are concerned with EPA-s estimated cost to state drinking water programs to implement the
LT2ESWTR. The proposed rule is complex and will require significant monitoring and reporting by
systems and significant oversight of these activities by states. The economic analysis implies an
annualized total cost to each state of less than $25,000. This estimate appears to significantly
underestimate the implementation cost of the rule. Specifically, it does not accurately capture the costs of
revisions to primacy applications, state rule adoption, compliance actions against water systems, and
significant data management requirements. In addition, the implementation activities in the first six to
nine years following promulgation of the final rule are expected to be quite significant with somewhat of
a reduction in activity after that time. We suggest that EPA discount the labor and material costs
associated with implementation over a 10-year period rather than a 20-year period as in the proposed rule.
Response: See response 2200c and 2250.D.
EPA Letter ID: 466
Comment ID: 11026
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: ND is concerned that EPA-s annualized total cost of less than $25,000 appears to
significantly underestimate the implementation cost of the rule. It does not accurately capture the costs of
revisions to primacy applications, state rule adoption, technical assistance to water systems, enforcement
activities, plan review for treatment improvements, and significant data management requirements.
Response: Response 2250.D.
EPA Letter ID: 485
Comment ID: 11339
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Comment Response for the LT2ESWTR 20-68 December 2005
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Response: The Department strongly disagrees with the estimated cost of compliance oversight by States
as outlined in the rule. We concur with the comments provide by the Association of State Drinking Water
Administrators which are repeated below
-The proposed rule is complex and will require significant monitoring and reporting by systems and
significant oversight of these activities by states. The economic analysis implies an annualized total cost
to each state of less than $25,000. This estimate appears to significantly underestimate the implementation
cost of the rule. Specifically, it may not accurately capture the costs of revisions to primacy applications,
state rule adoption, compliance actions against water systems, and significant data management
requirements.
Further, the implementation activities in the first six to nine years following
promulgation of the final rule are expected to be quite significant with somewhat of a reduction in activity
after that time. States therefore suggest that EPA discount the labor and material costs associated with
implementation over a 10-year period rather than a 20-year period as in the proposed rule.-
Response: See response 2200c and 2250.D.
EPA Letter ID: 497
Comment ID: 10658
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Estimated Cost
The economic analysis implies an annualized total cost to each state of less than $25,000, but this appears
to be understated. The cost of technical assistance, compliance, and enforcement related efforts may not
be accurately captured in this cost. In the event that a single contested case results in escalated
enforcement by the MDEQ, the cost to the state can greatly exceed $25,000. This type of enforcement is
rarely necessary for large water systems but that may change if EPA proceeds with bin placement and the
required capital costs based on missed samples and missed sampling dates. The EPA should revise the
cost of analysis to reflect all implementation efforts and anticipated enforcement.
Response: Response 2250.D.
EPA Letter ID: 520
Comment ID: 11610
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Estimated Cost
IEPA is quite concerned with EPA's estimated cost to state drinking water programs to implement the
LT2ESWTR. The proposed rule is complex and will require significant monitoring and reporting by
systems and significant oversight of these activities by IEPA. The economic analysis implies an
annualized total cost to each state of less than $25,000, but appears to be developed based upon a single
Comment Response for the LT2ESWTR 20-69 December 2005
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year of implementation. Several of the implementation activities will span multiple years, especially the
technical assistance, compliance, and enforcement related efforts. EPA should revise the cost analysis be
to reflect a multiple year implementation effort.
The estimate also appears to significantly underestimate the implementation cost of the rule. Specifically,
it may not accurately capture the costs of revisions to primacy applications, state rule adoption, technical
assistance to water systems, enforcement activities, plan review for treatment improvements, and
significant data management requirements.
Response: Response 2250.D.
EPA Letter ID: 520
Comment ID: 11611
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Further, the implementation activities in the first six to nine years following promulgation of
the final rule are expected to be quite significant with somewhat of a reduction in activity after that time.
IEPA therefore suggests that EPA discount the labor and material costs associated with implementation
over a 10-year period rather than a 20-year period as in the proposed rule.
Response: See response 2200c
EPA Letter ID: 528
Comment ID: 12269
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Estimated Cost
We are quite concerned with EPA-s estimated cost to state drinking water programs to implement the
LT2ESWTR. The proposed rule is complex and will require significant monitoring and reporting by
systems and significant oversight of these activities by states. The economic analysis implies an
annualized total cost to each state of less than $25,000. This estimate appears to significantly
underestimate the implementation cost of the rule. Specifically, it may not accurately capture the costs of
revisions to primacy applications, state rule adoption, technical assistance, compliance actions against
water systems, and significant data management requirements.
Response: Response 2250.D
EPA Letter ID: 536
Comment ID: 11801
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 20-70 December 2005
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Comment: FACA Agreement in Principle. Further, we were unable to determine if the state
implementation cost analysis provided by EPA includes the cost of laboratory certification activities.
Response: EPA is currently certifying laboratories for Cryptosporidium analyses, so State costs for
today's rule do not include this cost.
EPA Letter ID: 536
Comment ID: 11811
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: Estimated Cost
Colorado is quite concerned with EPA-s estimated cost to state drinking water programs to implement the
LT2ESWTR. We are also quite concerned with the lack of a reasonable explanation in the Federal
Register of how the listed costs were developed and how we can use this effort to realistically estimate the
resources (and their temporal distribution) we will need to implement the rule. The proposed rule is
complex and will require significant monitoring and reporting by systems and significant oversight of
these activities by states. The economic analysis implies an annualized total cost to each state of less than
$25,000, but after reading multiple appendices we have been unable to determine the process by which
the final costs were determined and how to adjust the national figures to determine Colorado needs. EPA
should revise the cost analysis to make it easy for all states to estimate their resource needs and to verify
that the analysis prepared by EPA is reasonably accurate.
The estimate also appears to significantly underestimate the implementation cost of the rule. Specifically,
it may not accurately capture the costs of revisions to primacy applications, state rule adoption, technical
assistance to water systems, enforcement activities, plan review for treatment improvements, and
significant data management requirements.
Further, the implementation activities in the first six to nine years following promulgation of the final rule
are expected to be quite significant with somewhat of a reduction in activity after that time. States
therefore suggest that EPA discount the labor and material costs associated with implementation over a
10-year period rather than a 20-year period as in the proposed rule.
Response: See response 2200c and 2250.D.
EPA Letter ID: 588
Comment ID: 12093
Commenter: Lance Nielson, Manager, Idaho Drinking Water Program, Department of Environmental
Quality
Commenter Category: State/Tribe Government
Other EPA Comment Codes and Descriptions: 2250 2. Water System Costs
Comment: 2) We are concerned that EPA's methodology for estimating costs of new rules to State
programs and to regulated water systems fails to take into account the concept of "cumulative burden."
Comment Response for the LT2ESWTR 20-71 December 2005
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The body of regulation that has been promulgated pursuant to the Safe Drinking Water Act is large and
complex. The knowledge required of water system operators long ago reached insurmountable
proportions, resulting in a strong dependency upon technical and informational assistance from state
regulators. At the same time, State programs find it increasingly difficult to absorb and communicate
regulatory requirements, both to the regulated community and to overloaded agency personnel. Our point
is that each new rule has a cumulative impact that is greater than would be the case if the rule were not
incremental to an already large and demanding body of regulations. Although this may be difficult to
quantify, we would urge EPA to lean toward a more generous estimation of cost impacts.
Response: Response 2200.f.
EPA Letter ID: 601
Comment ID: 13047
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: Estimated Cost
Utah is quite concerned with EPA-s estimated cost to state drinking water programs to implement the
LT2ESWTR. The proposed rule is complex and will require significant monitoring and reporting by
systems and significant oversight of these activities by states. The economic analysis implies an
annualized total cost to each state of less than $25,000. This estimate appears to significantly
underestimate the implementation cost of the rule. Specifically, it may not accurately capture the costs of
revisions to primacy applications, state rule adoption, compliance actions against water systems, and
significant data management requirements.
Response: Response 2250.D.
EPA Letter ID: 603
Comment ID: 12683
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: (Pg. 47738) Section VI. Economic Analysis
The economic analysis implies an annualized total cost to each state of only $20,000. This estimate
appears to significantly underestimate the implementation cost of the rule. It appears that the state costs
were developed based upon a single year of implementation. Several of the implementation activities will
span multiple years, especially the technical assistance, compliance, and enforcement related efforts. It is
recommended that the cost analysis be revised to reflect a multiple year implementation effort.
Considering the complexity of the rule and a multiple year implementation effort, average annual state
costs on the order of $120,000 to $160,000 per state are more reasonable.
The implementation activities in the first six years following promulgation of the final rule axe expected
to be significant. It is inappropriate to discount the labor and material costs associated with
implementation over a 20-year period since most States cannot enact deficit spending for basic
Comment Response for the LT2ESWTR 20-72 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
government services. It is more appropriate to estimate State costs annually over a 10-year or shorter
period.
Response: See response 2200c and 2250.D.
EPA Letter ID: 609
Comment ID: 14124
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: Estimated Cost
The economic analysis implies an annualized total cost to each state of less than $25,000, but this appears
to be understated. The cost of technical assistance, compliance, and enforcement-related efforts may not
be accurately captured in this cost. In the event that a single contested case results in escalated
enforcement by the MDEQ, the cost to the state can greatly exceed $25,000. This type of enforcement is
rarely necessary for large water systems but that may change if the USEPA proceeds with bin placement
and the required capital costs based on missed samples and missed sampling dates. The USEPA should
revise the cost of analysis to reflect all implementation efforts and anticipated enforcement.
Response: Response 2250.D.
EPA Letter ID: 643
Comment ID: 12762
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Estimated Cost
States are quite concerned with EPA-s estimated cost to state drinking water programs to implement the
LT2ESWTR. The proposed rule is complex and will require significant monitoring and reporting by
systems and significant oversight of these activities by states. The economic analysis implies an
annualized total cost to each state of less than $25,000, but appears to be developed based upon a single
year of implementation. Several of the implementation activities will span multiple years, especially the
technical assistance, compliance, and enforcement related efforts. EPA should revise the cost analysis to
reflect a multiple year implementation effort. Further, the implementation activities in the first six to nine
years following promulgation of the final rule are expected to be quite significant with somewhat of a
reduction in activity after that time. States therefore suggest that EPA discount the labor and material
costs associated with implementation over a 10-year period rather than a 20-year period as in the
proposed rule.
EPA-s cost estimates also appear to significantly underestimate the cost to states to implement the rule.
Specifically, states have indicated that the number of FTEs required for revisions to primacy applications,
state rule adoption, technical assistance to water systems, enforcement activities, plan review for
treatment improvements, data management programming, and other state implementation activities is
underestimated. Some states also indicated that the proposed hourly rate does not clearly reflect the true
rate in their state. It is imperative that the final rule accurately portrays the resources a state will need to
implement the rule since many states need to use this information to justify staffing levels and funding.
Comment Response for the LT2ESWTR 20-73 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
Response: See responses 2200c and 2250.D.
EPA Letter ID: 647
Comment ID: 12911
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Estimated Cost
EPA-s estimates may underestimate the total costs to state drinking water programs to implement the
LT2ESWTR. The proposed rule is complex and will require significant monitoring and reporting by
systems and significant oversight of these activities by states. The economic analysis implies an
annualized total cost to each state of less than $25,000, but appears to be developed based upon a single
year of implementation. Several of the implementation activities will span multiple years, especially the
technical assistance, compliance, and enforcement related efforts. EPA should revise the cost analysis be
to reflect a multiple year implementation effort.
The estimate also appears to significantly underestimate the implementation cost of the rule. Specifically,
it may not accurately capture the costs of revisions to primacy applications, state rule adoption, technical
assistance to water systems, enforcement activities, plan review for treatment improvements, and
significant data management requirements.
Further, the implementation activities in the first six to nine years following promulgation of the final rule
are expected to be quite significant with somewhat of a reduction in activity after that time. EPA should
discount the labor and material costs associated with implementation over a 10-year period rather than a
20-year period as in the proposed rule.
Response: See responses 2200c and 2250.D.
20.5 Comment Code 2280, Benefit/cost determination
Individual Comments on Code 2280
EPA Letter ID: 562
Comment ID: 12330
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 9. EPA-s presentation of regulatory costs and benefits is overly aggregated, and fails to reveal
how affordability and net benefits vary across system size categories or across other relevant program
elements in the proposed rule (e.g., reservoir covering, filtered versus unfiltered systems).
Response: See response 2200e
Comment Response for the LT2ESWTR 20-74 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
EPA Letter ID: 562
Comment ID: 12554
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 5.4.7 Affordability Based on System Size
We have not conducted a detailed review of EPA-s cost estimates for the proposed LT2 rule.
Nonetheless, it seems unlikely that the information provided regarding confidence intervals is realistic.
EPA appears to have either ignored or understated many key uncertainties and variabilities appear to a
considerable degree in order to generate a very narrow 90% confidence interval (only +/- 11% around the
mean).
The lack of meaningful disaggregation according to system size is cause for particular, critical
disappointment with the agency-s cost and affordability analyses, and with the benefit/cost comparisons
portrayed in the EA. The lumping by EPA of size categories serves only to mask and obscure important
information regarding the equity and efficiency implications of the proposed rule. This is a serious flaw
and a considerable disservice to the public, stakeholders, and decision-makers.
Finally, the agency-s approach to comparing benefits to costs could be far more meaningful and
informative if it also disaggregated the benefit/cost results in two important additional dimensions: (1)
filtered and unfiltered system benefits and costs, and (2) the costs and benefits of the finished water
reservoir cover requirement as embodied in the preferred option. The agency needs to do much better
with regard to system size and other levels of disaggregation, and it would take only a modest effort on
the agency-s part to do so (if it musters the will).
Response: See responses 100s, 2200e
EPA Letter ID: 562
Comment ID: 12555
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The agency faces two significant hurdles in appropriately reflecting the costs and benefits of
complete implementation of the microbial toolbox. First, application of the toolbox elements is site-
specific and intimately related to both the existing water treatment facility design and water quality
treatment challenges. Consequently, even an expert Delphi group process fully informed as to the final
rule-s regulatory requirements and guidance is unlikely to predict with any high degree of accuracy the
range and extent of microbial toolbox application. It may be possible through a combination of survey
and expert evaluation to prepare a reasonably accurate estimate of toolbox element application for the
largest water systems (i.e., ICR utilities). As this group of utilities represents a significant fraction of the
cost and accrued benefit from the rule, perhaps such an effort would be adequate for the agency-s
purposes.
An effort like that described above would not be possible unless the utilities surveyed and the experts
involved had a very clear understanding of the regulatory provisions and final agency guidance. This
approach, while capturing the bulk of the national costs and benefits of the rule, would not provide a
sound approach for determining system level costs for small to medium sized systems. Because this group
Comment Response for the LT2ESWTR 20-75 December 2005
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Chapter 20: Economic Analysis Comment Codes 2200-2280
of systems is so large and the water quality challenges and treatment designs so diverse, reasonable
estimates of cost and benefit are highly uncertain.
Response: See responses 100s, 2200p, and 2200k.
Comment Response for the LT2ESWTR 20-76 December 2005
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21. Statutory and Executive Order Reviews: Comment
Codes 2300-2420
21.1 Comment Code 2300, Statutory and Executive Order Reviews
Response to Code 2300
2300.01 Technical, Financial and Managerial Capacity
EPA has met the SDWA requirement (see 1420(d)(3)) to analyze the effect of the final LT2 ESWTR on
the technical, financial, and managerial capacity (TMF capacity) of pubic water systems. This analysis is
discussed in detail in section 8.5 of the Economic Analysis. EPA does not feel that it is necessary to seek
input on the TMF capacity prior to promulgation. Rather, capacity issues should be part of
implementation of any final rule as an ongoing discussion between the primacy agency and PWSs
(SDWA, see 1420 (d)) after promulgation of any national primary drinking water regulation, TMF
capacity is part of the implementation of a final rule. Nonetheless, EPA fully estimates, discusses and
seeks comment on all impacts of our drinking water regulations on all public water systems through the
Economic Analysis for the proposed rule. Stakeholders can and do comment on our estimates found in
every proposed drinking water rule, and many of the Economic Analysis estimates are also TMF capacity
issues. For example, technology and cost discussions in the Economic Analysis are the same issues found
in a technical capacity discussion.
Individual Comments on Code 2300
EPA Letter ID: 457
Comment ID: 11911
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Impact on System Capacity
Although we are concerned with the impact this rule will have on system capacity, especially on small
systems, we will hold any further comment until the EPA provides its final analysis of the rule-s
anticipated impact with the LT2ESWTR.
Response: See Response 2300.01.
EPA Letter ID: 601
Comment ID: 13046
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment Response for LT2ESWTR 21-1 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
Comment: Impact on System Capacity
Utah is concerned with the impact this rule will have on system capacity, especially on small systems. For
future rules, Utah suggests that EPA include this type of analysis in the proposed rule to allow for
stakeholder review and comment.
Response: See Response 2300.01.
21.2 Comment Code 2350, Executive Order 13132: Federalism
Response to Code 2350
See individual comment responses below (see Response 100.a.)
Individual Comments on Code 2350
EPA Letter ID: 457
Comment ID: 11951
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: VIII.E Executive Order 13132: Federalism (page 47765)
We support EPA-s policy to promote communications between EPA and state and local governments and
appreciate this opportunity to provide comment.
Response: See Response lOO.a.
EPA Letter ID: 520
Comment ID: 11665
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: VIII.E Executive Order 13132: Federalism (page 47765)
IEPA supports EPA's policy to promote communications between EPA and states and
local governments and appreciate this opportunity to provide comment.
Response: See Response lOO.a.
EPA Letter ID: 595
Comment ID: 12604
Comment Response for the LT2ESWTR 21-2 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: VIII.E Executive Order 13132: Federalism (page 47765)
Maine supports EPA-s policy to promote communications between EPA and state and local governments
and appreciates this opportunity to provide comment.
Response: See Response lOO.a.
EPA Letter ID: 643
Comment ID: 12821
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: VIII.E Executive Order 13132: Federalism (page 47765)
States support EPA-s policy to promote communications between EPA and state and local governments
and appreciate this opportunity to provide comment.
Response: See Response lOO.a.
21.3 Comment Code 2360, Executive Order 13175: Consultation With
Indian Tribal Governments
Response to Code 2360
See individual comment response below.
Individual Comments on Code 2360
EPA Letter ID: 391
Comment ID: 10499
Commenter: Ricardo Nelson Rios,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: Revision #4: Impacts on Small Governments: Consultation and Coordination with Indian
Tribal Governments:
The EPA has identified the 66 of the 67 Tribal water systems serving a total population of 78, 956 will be
subject to the LT2ESWTR. The Indian Tribes are actually crying wolf complaining that they are not able
to endure the funding of the regulation, when the Indian Tribes are one of the richest groups, at least in
the state of Florida. The Micossukee Tribe owns a Las Vegas style casino and resort as well as sponsors
many of the professional sport teams of the state. The government is willing to give a 7% discount to
Comment Response for the LT2ESWTR 21-3 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
assist in the implementation funding. Yet the Indian Tribes do not consider the health risks associated
with Cryptosporidium warrants the cost. The Indian Tribes want to be independent of the general
population, with their own police department and government; so then they should be treated as such. If
they do not want to cover the costs to implement the regulation then they should not benefit from
protection of it. As the saying goes, you cannot have your cake and eat it too.
Response: As discussed in the proposed and final rule, Executive Order 13175, requires EPA to consult
with Indian tribes on proposed regulations that may impact Indian tribes. EPA has met all requirements
for analysis and consultation for this final rule. During implementation of this final rule, EPA will work
with States and Tribes to meet all requirements of the rule.
21.4 Comment Code 2400, Executive Order 12898: Environmental
Justice
Response to Code 2400
See individual comment response below (see Response 100.a).
Individual Comments on Code 2400
EPA Letter ID: 470
Comment ID: 11101
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: Executive Order 13132: Federalism p. 47765
Vermont is in support of EPA-s policy to promote communications between EPA, states, and local
governments.
Response: See Response lOO.a.
21.5 Comment Code 2410, Consultations with the Science Advisory
Board, National Drinking Water Advisory Council, and the
Secretary of Health and Human Services
Response to Code 2410
See individual comment response below (see Response 2420.02).
Individual Comments on Code 2410
EPA Letter ID: 637
Comment ID: 13109
Comment Response for the LT2ESWTR 21-4 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: Executive Order 12866 encourages Federal agencies to write rules in plain language. EPA
invites comments on how to make this proposed rule easier to understand.
For example: Has EPA organized the material to suit commenters- needs?
Are the requirements in the rule clearly stated?
District recommends that a comprehensive list of all of the questions or issues that EPA is requesting
comment on be provided at the end of the preamble. A comprehensive list of all of the questions would
reduce the amount of time required to identify and respond to all of the requests.
Response: See Response 2420.02.
21.6 Comment Code 2420, Plain Language
Response to Code 2420: 2420.01 Plain Language
EPA believes that communication is important during rule development as well as implementation of a
regulation. EPA is required by various Executive Orders and Statutory Requirements to perform various
analysis and provide various discussions on specific topics and to provide this information to the public
for comment through the proposed rule. EPA provided draft guidance documents, technical analysis and
other types of documents for comment with the proposed rule. These documents and support documents
are each aimed at a different audience or different topic. EPA did not expect every person to read every
document or every portion of every document nor does EPA believe that the volume of support
documents means that the rule is not plainly written. This rule affects many different audiences, however,
it should be clear for each audience to understand and follow. Also, EPA supports a hotline (1-800-426-
4791) and a website (www.epa.gov/safewater) to support the regulated community with specific questions
concerning drinking water regulations.
2420.02. Format for requesting comments.
Thank you for your comment. EPA chose to include questions and include them in the pertinent sections
to focus review on the analysis supporting the various conclusions and decisions made by EPA. EPA will
consider your comment for future proposals.
2420.03 State Regulations in plain format.
EPA does not direct States on their use of plain or regulatory formatting of State regulations. The LT2
regulatory language continues to be presented in a traditional format which allows these requirements to
fit in with the existing drinking water regulations.
Individual Comments on Code 2420
EPA Letter ID: 423
Comment ID: 10574
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Comment Response for the LT2ESWTR 21-5 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: PLAIN LANGUAGE RULES
Plain language can add additional bulk to the rules without adding clarity. Give the states the option to
use regulatory or plain language. Prepare crosswalks for both types of language.
Response: See Response 2420.03.
EPA Letter ID: 442
Comment ID: 10787
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: PLAIN LANGUAGE RULES
Plain language can add additional bulk to the rules without adding clarity. Give the states the option to
use regulatory or plain language. Prepare crosswalks for both types of language.
Response: See Response 2420.03.
EPA Letter ID: 457
Comment ID: 11952
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment:
VII.L Plain Language (page 47770)
We do not believe that the requirements in the rule are clearly stated. The number and the volume of
guidance manuals that have already been and/or planned to be issued, in order to interpret the intentions
of the rules, support the claim that the requirements in the rules are not clearly stated. However, we still
support EPA-s continued efforts to write these regulations in plain language.
Response: See Response 2420.01.
EPA Letter ID: 470
Comment ID: 11102
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment Response for the LT2ESWTR 21-6 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
Comment: Plain Language p.47770
Vermont supports EPA-s efforts to write rules which are easily understood.
Response: See Response 2420.01.
EPA Letter ID: 520
Comment ID: 11666
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: VII.L Plain Language (page 47770)
IEPA supports EPA's efforts to ensure regulations are written in plain language.
Response: See Response 2420.01.
EPA Letter ID: 595
Comment ID: 12605
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: VII.L Plain Language (page 47770)
Maine supports the EPA-s efforts to ensure regulations are written in plain language, although more
effort should be put forth into this matter in the future.
Response: See Response 2420.01.
EPA Letter ID: 643
Comment ID: 12822
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: VII.L Plain Language (page 47770)
States support EPA-s efforts to ensure regulations are written in plain language.
Response: See Response 2420.01.
Comment Response for the LT2ESWTR 21-7 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
EPA Letter ID: 660
Comment ID: 14086
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: VII. Statutory and Executive Order Reviews
L. Plain Language
(page 47770
Executive Order 12866 encourages Federal agencies to write rules in plain language. EPA invites
comments on how to make this proposed rule easier to understand.
For example: Has EPA organized the material to suit commenters- needs?
Are the requirements in the rule clearly stated?
The requirements for the LT2ESWTR were provided in the Federal Register Notice dated August 11,
2003 totaling 135 pages. The EPA subsequently issued the following guidance manuals:
- Source Water Monitoring Guidance Manual for Public Water Systems for the Long-Term 2 Enhanced
Surface Water Treatment Rule (LT2 Rule)
- Microbial Laboratory Manual for the Long-Term 2 Enhanced Surface Water Treatment Rule (LT2 Rule)
- Ultraviolet Disinfection Guidance Manual
- Ultraviolet Disinfection Guidance Manual Workbook
- Membrane Filtration Guidance Manual
- Long Term 2 Enhanced Surface Water Treatment Rule Toolbox Guidance Manual
- Guidance on Generation and Submission of Grandfathered Cryptosporidium Data for Bin Classification
Under the Long Term 2 Enhanced Surface Water Treatment Rule
- Guidance on Grandfathering Cryptosporidium Data For the Long Term 2 Enhanced Surface Water
Treatment Rule
This massive volume of new regulations with accompanying guidance manuals is too complex to be
clearly understood. In addition, the Stage 2 D/DBPR is being developed simultaneously with the
LT2ESTWR. Between the two rules, the EPA issued a combined total of over 2,400 pages of proposed
rules and guidance documents that has placed a significant burden on the resources of water systems and
State agencies to interpret and plan for compliance with this regulation.
Response: See Response 2420.01.
EPA Letter ID: 662
Comment ID: 14048
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment:
L. Plain Language
(page 47770
Comment Response for the LT2ESWTR 21-8 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
Executive Order 12866 encourages Federal agencies to write rules in plain language. EPA invites
comments on how to make this proposed rule easier to understand.
For example: Has EPA organized the material to suit commenters- needs?
Are the requirements in the rule clearly stated?
This is a very complex regulation especially considering the simultaneous release of the Stage 2DBPR.
These two rules are complex enough that EPA also prepared numerous guidance documents to support
the effort. Utilities on the whole are not staffed to adequately review and comment on this size effort.
Response: See Response 2420.01.
EPA Letter ID: 673
Comment ID: 14003
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: VII. Statutory and Executive Order Reviews
L. Plain Language
(page 47770)
Executive Order 12866 encourages Federal agencies to write rules in plain language. EPA invites
comments on how to make this proposed rule easier to understand.
For example: Has EPA organized the material to suit commenters- needs?
Are the requirements in the rule clearly stated?
Jordan Valley Water recommends that a comprehensive list of all of the questions or issues that EPA is
requesting comment on be provided at the end of the preamble. A comprehensive list of all of the
questions would reduce the amount of time required to identify and respond to all of the requests.
The requirements for the LT2ESWTR were provided in the Federal Register Notice dated August 11,
2003 totaling 135 pages. The EPA subsequently issued the following guidance manuals:
* Source Water Monitoring Guidance Manual for Public Water Systems for the Long-Term 2 Enhanced
Surface Water Treatment Rule (LT2 Rule)
* Microbial Laboratory Manual for the Long-Term 2 Enhanced Surface Water Treatment Rule (LT2
Rule)
* Ultraviolet Disinfection Guidance Manual
* Ultraviolet Disinfection Guidance Manual Workbook
* Membrane Filtration Guidance Manual
* Long Term 2 Enhanced Surface Water Treatment Rule Toolbox Guidance Manual
* Guidance on Generation and Submission of Grandfathered Cryptosporidium Data for Bin Classification
Under the Long Term 2 Enhanced Surface Water Treatment Rule
* Guidance on Grandfathering Cryptosporidium Data For the Long Term 2 Enhanced Surface Water
Treatment Rule
Comment Response for the LT2ESWTR 21-9 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
Jordan Valley Water asserts that this massive volume of new regulations with accompanying guidance
manuals is too complex to be clearly understood. In addition, the Stage 2 D/DBPR is being developed
simultaneously with the LT2ESTWR. Between the two rules, the EPA issued a combined total of over
2,400 pages of proposed rules and guidance documents which has placed a significant burden on the
resources of water systems and State agencies to interpret and plan for compliance with these regulations.
Response: See Responses 2420.02 and 2420.01.
Comment Response for the LT2ESWTR 21-10 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
22. References: Comment Code 2510-2511
22.1 Comment Code 2510, Amendments to SWTR, IESWTR, or
LT1ESWTR
Response to Code 2510
a. EPA did not propose to amend the existing criteria for filtration avoidance established by the SWTR.
Today's final rule does not either modify existing criteria or add new criteria for filtration avoidance.
EPA continues to believe that the existing filtration avoidance criteria are important for public health
protection. Filtration avoidance is only appropriate for surface waters that have a low risk of pathogen
contamination and high water quality that will not interfere with subsequent disinfection. The existing
filtration avoidance criteria, including the standards for coliforms and turbidity, are intended to ensure
that these conditions are met. Specifically, the coliform criterion is an indicator of microbial
contamination levels and the turbidity criterion is an indicator of water quality parameters that could
inhibit disinfection. EPA has not identified any new data indicating that these criteria should be revised.
Accordingly, the Agency continues to require systems that cannot meet these criteria to filter the water.
As stated in the preamble, EPA believes that an unfiltered system that meets the Cryptosporidium
treatment requirements of today's rule will achieve public health protection equivalent to filtered systems.
However, this equivalency is premised on the unfiltered system meeting all filtration avoidance criteria,
so that the source water pathogen contamination risk is low. If an unfiltered system does not meet the
filtration avoidance criteria, EPA does not believe that the installation of UV will achieve equivalent
public health protection to a filtered system (and thereby eliminate the need for the unfiltered system to
install filtration).
Filtration can achieve high levels of removal of all pathogen types and is effective under a wide range of
water quality conditions. In contrast, disinfectants like UV appear to be very effective for some
contaminants like protozoa but are much less effective against others, such as certain viruses. Further,
poor water quality can significantly hinder disinfectants like UV. Thus, EPA believes that unless systems
can demonstrate a very low contamination risk and high water quality by meeting the avoidance criteria,
systems should install filtration.
EPA does not believe that failure to meet the filtration avoidance criteria is equivalent to a monitoring or
treatment violation by a filtered system. Failure to meet the avoidance criteria shows that a system is
unable to maintain the low pathogen contamination risk and high quality in its source water such that
filtration isn't necessary. Where this is the case, the system should filter the water.
b. The purpose of public notice is to inform the public about the performance of their water system in
meeting applicable regulations to provide safe water. EPA has not identified any new data indicating that
existing public notification requirements established by the SWTR should be revised. EPA continues to
believe that these requirements are important for informing the public about a system's performance in
meeting critical monitoring and treatment requirements to protect public health.
Comment Response for LT2ESWTR 22-1 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
Individual Comments on Code 2510
EPA Letter ID: 516
Comment ID: 15038
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 4) LT2 must provide new flexibility in meeting the 1989 SWTR Filtration Avoidance Criteria
either by deletion or modification of the rigid filtration-
for-noncompliance mandate DEP is most concerned with the -trap door- that threatens unfiltered water
supplies who are operating under a Filtration Avoidance Determination pursuant to the SWTR but who
can still be ordered to filter for even a minor divergence from the original standards. DEP - like other
unfiltered surface water supply systems - has invested heavily in watershed management and protection
strategies and is now implementing further costly measures to comply with LT2 as an unfiltered system.
Still, DEP and similar unfiltered systems have no assurance against a loss of filtration avoidance as a
result of a single violation of the 1989 Criteria that in many cases might represent neither a significant
change in water quality nor a threat to public health. Significantly, filtration would not necessarily be the
most appropriate means of addressing violations of the Criteria were they to occur. For filtered systems
that experience similar disturbances, disruptions or violations, EPA-s protocol is to assess the problem
and determine the most appropriate means of solving it; there is no automatic trigger requiring installation
of costly new treatment infrastructure. DEP argues for equivalence with filtered systems with regard to
enforcement of SWTR violations. Therefore, DEP strongly urges that the 1989 SWTR Filtration
Avoidance Criteria be dropped, modified, or at the very least, thoroughly reviewed, one by one, to
demonstrate their current applicability.
Response: See Response 2510.a.
EPA Letter ID: 516
Comment ID: 15039
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: For example, one very disturbing aspect of the proposed regulations is the provision requiring
continued compliance with all of the Filtration Avoidance Criteria from the 1989 Surface Water
Treatment Rule, particularly considering the rigid nature of these criteria as implemented in the 1989 rule.
As a large unfiltered system, which maintains the highest quality water through vigorous (and costly)
watershed protection programs, and which will be installing UV treatment (also at great cost) to comply
with the proposed LT2ESWTR, DEP is very much concerned that, despite all these investments in the
name of enhanced public health protection, DEP could be subjected to the unreasonable and unwarranted
requirement to install filtration, as a result of failure to comply with each and every Filtration Avoidance
Criterion, at all times. This requirement for continued application of the stringent 1989 Filtration
Avoidance Criteria places an unreasonable burden on both DEP and on the ratepayers who consume City
water, and who must shoulder the financial responsibility (not insignificant) for all enhanced treatment
that is required under these rules.
We strongly urge EPA to reassess the proposed rule in light of the comments contained herein. We
remain ready and willing to assist EPA in whatever manner we can to formulate a rule that provides
necessary public health protection while allowing systems such as ours the flexibility to address water
quality problems in the most cost-effective manner. DEP-s comments are provided in 3 parts: Part I:
Comment Response for LT2ESWTR 22-2 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
General Comments, Part II: Additional Comments, and Part III:
Attachments [See pdf].
Response: See Response 2510.a.
EPA Letter ID: 516
Comment ID: 15040
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment:
PART I - GENERAL COMMENTS
1) S.W.T.R FILTRATION AVOIDANCE CRITERIA
The Department strongly believes that the proposed rule should be worded in such a manner that any
unfiltered system-s substantial investment and demonstrated success in watershed protection not be
subject to costly and potentially arbitrary change due to the implicit LT2 requirement that unfiltered
systems continue to comply with all filtration avoidance requirements of the SWTR (40 CFR 141.71). For
example, the language in the LT2 in Section 141.721 (a) and elsewhere conditions the applicability to the
new treatment and monitoring requirements for -unfiltered systems that meet all filtration avoidance
criteria of 141.71.-
In 1989, the rigid imposition of the filtration avoidance criteria in 40 CFR 141.71 perhaps had a rational
basis. During the development of the SWTR, little was known about the quality of the water supplied by
unfiltered water supplies (particularly from a microbial risk perspective) and about the degree of
variability in the source water microbial risk under varying environmental, demographic, and climatologic
conditions. In addition, the effectiveness of watershed protection programs, as a risk management
strategy, was untested. Thus, EPA imposed conditions requiring not only a program of demonstrated
ownership and control within a watershed, but the requirement that source water as well as finished water
meet certain objective conditions for turbidity, coliform bacteria, disinfection byproducts, etc. These
criteria primarily represented parameters that acted as direct or indirect indicators of potential microbial
risk and/or were parameters, such as turbidity, that affected disinfection capabilities.
The rationale for the rigid application of some if not all of these criteria no longer exists. In the last 10
years, DEP has implemented comprehensive watershed monitoring, mapping, modeling and research
programs that have verified that our source waters are not only of high quality, but are consistently so.
Like other unfiltered systems, we have substantially enhanced watershed protection and pollution
prevention measures by implementing a variety of programs, including but not limited to: acquiring
additional watershed lands (having recently attained the 50,000 acre mark of new acquisitions); upgrading
wastewater treatment plants; implementing engineering controls to reduce pollution from stormwater and
wastewater; and promulgating enhanced watershed rules and regulations. We have also developed
partnerships with watershed stakeholders that are regarded as a national model of excellence for
watershed programs. DEP has conducted extensive research into the sources of cryptosporidium in the
watershed, and for almost 8 years now, we have been conducting weekly source water monitoring for
Cryptosporidium and Giardia with Quality Assurance (QA) requirements that are vastly more rigorous
than those proposed by EPA under the LT2. By 2007, DEP will have spent or committed in excess of $1
Billion dollars for NYC-s watershed protection effort. Our watershed management programs and our
monitoring programs confirm that our water quality is excellent, and will remain so into the future.
Through our extensive investment and achievement of the many goals set forth through EPA-s filtration
Comment Response for LT2ESWTR 22-3 December 2005
-------
Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
avoidance determinations, we have demonstrated our long term financial commitment to watershed
protection, pollution prevention and a multiple barrier approach.
As clearly indicated in the Preamble to the LT2 rule, the overarching rationale for the treatment
requirement for unfiltered systems in the LT2, comes from EPA-s assessment of data from the ICR and
other surveys which in EPA-s words -do not support the finding described in the IESTWR of equivalent
risk in filtered and unfiltered systems- (p. 47649). In response, the proposed rule now provides an extra
layer of protection by mandating that all unfiltered systems provide an additional 2 or 3 log removal of
Cryptosporidium. Without addressing the merits of EPA-s argument regarding the need for additional
protection (DEP believes that EPA has overestimated the risks of Cryptosporidium and substantially
underestimated the cost of compliance with the rule), as called for in the draft regulation, we are moving
forward with the construction of a UV facility to provide the required additional log inactivation of
Cryptosporidium. However, as the preamble to the LT2 notes, once an unfiltered system has complied
with the new treatment requirements, the unfiltered systems will be -equivalent- to the filtered systems.
If equivalent, then the requirements for continued compliance with the treatment technique should be
equivalent to those requirements set forth for filtered systems. Specifically, if a filtered system
experiences an MCL or treatment technique violation (e.g., for coliforms, DBFs) the initial compliance
step is not to require the filtered system to install an entirely new treatment facility. The first steps are: (1)
assess the cause of the violation, (2) determine an appropriate solution, and (3) allow the water supplier
time to implement the determined solution. This same reasonable approach should be granted to
unfiltered systems that are in compliance with the LT2 (or prior to the effective date of the LT2, those
systems that are taking concrete steps toward compliance with LT2). For unfiltered systems that fall out
of compliance with one of the Filtration Avoidance criteria, installation of a filtration plant may NOT be
the most appropriate solution, and thus should not be automatically triggered.
Clearly, given all of the above and the enormous financial implications that failure to achieve the original
avoidance criteria will potentially have on unfiltered systems, even after they have achieved -
equivalence-, the maintenance of all of the filtration avoidance requirements in an unmodified form is
patently unreasonable. DEP strongly recommends that the application of the SWTR Filtration Avoidance
Criteria be modified, or at the very least, that each criterion be thoroughly reviewed to demonstrate their
current applicability, and those without current applicability be dropped. DEP along with other unfiltered
systems would be pleased to be participate in any technical analysis EPA chooses to undertake on this
matter.
Response: See Response 2510.a.
EPA Letter ID: 522
Comment ID: 14143
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: Minor Exceedances of Filtration Avoidance Criteria: Another area where the regulations
might be improved by consistent adoption of the approaches afforded the filtered systems is the
consequence of minor exceedances of the filtration avoidance criteria. As the SWTR regulations have
been promulgated, and as their approach is extended by these new regulations, almost any minor water
quality variation or upset in treatment plant operation automatically triggers a violation, but more
critically, the requirement for that system to add filtration. Filtered systems, on the other hand, receive the
violation, and must work with their state primacy agency to come back into compliance. Normally, a
Comment Response for LT2ESWTR 22-4 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
water quality or process upset results in changes to standard operating procedures, additional staff
training, or adjustments to process control set points. Normally it would not result in an immediate and
unconsidered requirement for substantial capital investment in new treatment processes. This, however, is
the situation in the current and proposed rules for unfiltered systems.
MWRA urges EPA to consider language in the final rule that allows the state primacy agency to examine
the specifics of any exceedance of an avoidance criterion, and determine with the water system, the most
appropriate means to come back into compliance. In some cases this may very well be to add filtration,
but in others it may be to adjust disinfectant doses or chemicals, or to move an intake location, or simply
change operating procedures. Water systems must be sure that any capital investment costeffectively
results in real risk reductions and water quality improvements for consumers. There are always competing
investment opportunities at the source, within the treatment processes and within the distribution system.
Let the primacy agency and the specific facts dictate the solution.
Response: See Response 2510.a.
EPA Letter ID: 523
Comment ID: 16535
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Minor Exceedances of Filtration Avoidance Criteria: The Unfiltered Systems Working Group
requests that EPA consider modifying the application of the filtration avoidance requirements of the
SWTR (40 CFR 141.71). In general as a group, our concern is not as much with the criteria themselves,
which are generally related to source water protection and disinfection effectiveness, but with their overly
rigid application. The addition of the Cryptosporidium inactivation requirements of the LT2 rule will
require all the unfiltered systems to make substantial capital investments in treatment changes. As the
SWTR criteria are currently structured, a strict reading of the regulations requires any excursion outside
the criteria, no matter how minor result in the automatic requirement that filtration be added, abrogating
the substantial investment in treatment improvements. We request that EPA make explicit in the
regulations the authority of state primacy agencies to examine the particular situation, and require
whatever appropriate changes are necessary to bring the system back into compliance.
What we are requesting is that EPA create an equivalent approach to that in place for filtered systems.
Specifically, if a filtered system experiences an MCL violation (e.g., for coliforms or DBFs) or a
Treatment Technology violation (e.g. for finished water turbidity), the initial compliance step is not to
require the filtered system to install an entirely new treatment facility. The steps are: (1) assess the cause
of the violation, (2) determine an appropriate solution, and (3) require that the water supplier implement
the determined solution, whether it be a change in operating procedures, modifications to existing
treatment processes, or the additional of capital improvements. This same reasonable approach should be
granted to unfiltered systems that are in compliance with the LT2. For unfiltered systems that fall out of
compliance with one of the Filtration Avoidance criteria, installation of a filtration plant may NOT be the
most appropriate solution, may NOT be the cost effective public health investment, and thus should not
be automatically triggered.
Response: See Response 2510.a.
Comment Response for LT2ESWTR 22-5 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
EPA Letter ID: 628
Comment ID: 12844
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: 3. Treatment Requirements for Unfiltered Systems Revise filtration avoidance criteria under
Surface Water Treatment Rule to be consistent with the LT2 Rule. The SFPUC strongly believes that the
proposed rule should be worded in such a manner that any unfiltered system-s substantial investment and
demonstrated success in watershed protection not be subject to costly and potentially arbitrary change due
to the LT2 requirement. Alternatively, the filtration avoidance criteria under the SWTR be dropped or
modified, or at the very least, be thoroughly reviewed, one by one, to demonstrate their current
applicability in the context of the LT2 Rule.
During the development of the SWTR, little was known about the quality of the water supplied by
unfiltered water systems and the degree of variability in the source water microbial risks under varying
environmental, demographic, and climatologic conditions. The effectiveness of watershed protection
programs as a risk management strategy was untested at that time, and thus the EPA imposed conditions
requiring not only a program of demonstrated ownership and control within a watershed, but the
requirement that source water as well as finished water meet certain objective conditions for turbidity,
coliform bacteria, disinfection byproducts, etc. These criteria primarily represented parameters that acted
as direct or indirect indicators of potential microbial risk and/or were parameters that affected disinfection
capabilities such as turbidity.
In the last ten years, the SFPUC has implemented comprehensive watershed monitoring and maintained
effective watershed management measures to protect its high quality water sources. These protection
measures consist of restricted land uses, engineering controls to prevent source water contamination due
to stormwater and wastewater discharges. Additionally, the SFPUC has undertaken extensive monitoring
programs to identify potential sources of protozoan risk and to monitor protozoan concentrations in the
source waters. These protection measures and monitoring programs have demonstrated that this high
quality of water will likely improve or at least continue to be of high quality in the long term that will
surpass the time frame established under the LT2 Rule for treatment determination and the re-opener
period of 108 months. Through the extensive investment and achievement of the many goals set forth in
the filtration avoidance criteria, the SFPUC has also demonstrated its long range and financial
commitment to watershed protection, pollution prevention and a multiple barrier approach.
As clearly indicated in the Preamble to the LT2 Rule, the overarching rationale for the treatment
requirement for unfiltered systems in the LT2 Rule comes from EPA-s assessment of data from the ICR
and other surveys which in EPA-s words -do not support the finding described in the IESTWR of
equivalent risk in filtered and unfiltered systems (p. 47649 and meaning microbial risk). In response, the
proposed rule now provides an extra layer of protection by mandating that all unfiltered systems provide
an additional 2 or 3 log removal of Cryptosporidium. The SFPUC believes that the EPA has
overestimated the risks of Cryptosporidium and underestimated the cost of complying with the additional
layer of protection. According to the preamble to the LT2 Rule, once the SFPUC-s unfiltered system has
installed the UV disinfection treatment to comply with the new Cryptosporidium inactivation
requirements, it will be considered -equivalent- to a filtered system. If equivalent, then the requirements
for continued compliance with the treatment technique should be equivalent to those requirements set
forth for filtered systems. For instance, if a filtered system experiences an MCL violation (e.g., for
coliform or DBFs), the initial compliance step is not to require the filtered system to install an entirely
new treatment facility. Rather, the first steps of compliance action include (1) the assessment of the cause
of the violation, (2) determining an appropriate solution, and (3) allowing time to implement the
Comment Response for LT2ESWTR 22-6 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
determined solution. This same reasonable approach should be granted to unfiltered systems that are in
compliance with the LT2. Similarly, for an unfiltered system that complies with the LT2 but falls out of
compliance with one of the Filtration Avoidance criteria, installation of a filtration plant may not be the
most appropriate solution and thus should not be automatically triggered. Alternative analysis and public
selection process should be applied to ensure most cost effective expenditure of limited public resources.
Given all of the above and the enormous financial implications that failure to achieve older filtration
avoidance criteria will potentially have on unfiltered systems, even after they have achieved equivalence,
the maintenance of all of the filtration avoidance requirements in an unmodified form is unreasonable.
Thus, the SFPUC recommends that the SWTR filtration avoidance criteria be dropped or modified, or at
the very least, be thoroughly reviewed, one by one, to demonstrate their current applicability in the
context of the LT2 Rule.
Response: See Response 2510.a.
EPA Letter ID: 704
Comment ID: 14800
Commenter: Steven G. Gould, Chairman, New York State American Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: that source water quality is high and watershed protection is strong. With the implementation
of UV disinfection for unfiltered systems, should the existing avoidance criteria under the Surface Water
Treatment Rule be reconsidered, or additional flexibility provided to unfiltered utilities due to dual barrier
treatments afforded?
Response: See Response 2510.a.
22.2 Comment Code 2511, Amendments to Public Notification Rule
Individual Comments on Code 2511
EPA Letter ID: 516
Comment ID: 15037
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 3) LT2 should amend burdensome or redundant public notification requirements for violation
of the SWTR DEP fully recognizes the importance of public notification in instances where there are
legitimate public health concerns for populations using the water supply. However, in important cases
DEP believes that certain notifications now required under the SWTR lead to mis- or overapplication of
this rule. Unwarranted notification may sounds an alarm in a community not directly impacted by the
violation, creating the perception of a threat where there is no actual health risk. Overapplication also
diminishes the impact of notification when it is in fact necessary.
Response: See Responses 1300.c and 2510.b.
Comment Response for LT2ESWTR 22-7 December 2005
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Chapter 21: Statutory and Executive Order Reviews Comment Code 2300
EPA Letter ID: 516
Comment ID: 15041
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: 3) PUBLIC NOTIFICATION
DEP is deeply concerned that EPA-s public notification requirements ~ under the existing microbial
regulations and the proposed LT2 rules ~ are too restrictive, with little to no flexibility for discretion by
the primacy agency. While DEP fully recognizes the critical importance of public notification in
circumstances where warranted, DEP is also acutely aware of the problem of-over-notification- (or in
other words -crying wolf-). There is significant danger to the public, in addition to a real financial cost,
of making notifications in circumstances where notification is not warranted. Therefore, DEP strongly
suggests that EPA modify the regulations as needed to provide for greater discretion, and it appears that
such a modification could be made via LT2. Specifically, DEP is concerned with the requirement that -
Tier 2- violations require quarterly public notification, and that per CFR 141.203, primacy agencies are
directed NOT to permit notification at a frequency less than every 3 months, in the case of treatment
technique violations under the SWTR, or IESWTR.
DEP firmly believes that quarterly notification is neither necessary nor helpful to consumers in the case of
certain treatment technique violations. For example, as an unfiltered system, DEP is concerned that a
violation of the SWTR Filtration Avoidance Criteria, even after providing for 2 or 3 log inactivation with
UV under LT2, may trigger a Tier 2 notice addressing microbial risk, whether or not the SWTR criteria
violation relates at all to such risk. Certainly, primacy agencies should be given some discretion in
determining the frequency and need of the Tier 2 notification, when the violation does not affect the level
of risk from Cryptosporidium.
In addition, DEP is deeply troubled by the requirement that it issue quarterly public notices with regard to
the Croton system-s temporary status of non-compliance with the SWTR requirement for filtration. DEP
strongly requests that EPA modify its reporting requirements such that: in the case of systems with high
quality source waters which are not yet in compliance with the SWTR filtration requirement but which
are under an administrative order or consent decree from the Primacy agency or USEPA to construct
filtration, public notice on an annual basis shall suffice, rather than quarterly notification. DEP currently
spends $200,000 per year on mandated quarterly notices regarding the DEP-s Croton System and its
noncompliance with the SWTR. These notices are not only an unnecessary expenditure of limited city
funds, but they also can frighten consumers unnecessarily, so they should be eliminated as they do not
serve a useful purpose.
Response: See Responses 2510.a, 2510.b, and 1300.c.
Comment Response for LT2ESWTR 22-8 December 2005
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Public Comment and
Response Document
for the Long Term 2
Enhanced Surface Water
Treatment Rule
Volume IV: Appendices
-------
APPENDICES
Appendix A Commenter Information Log
Appendix B List of Letters with Multiple Signatories
Appendix C Comment Tables and Graphics
Appendix D Attachments and Appendix Materials Submitted with Comment
Letters: Code 9999
Appendix E Greetings, Signatures, Commenter Background, and Introductory
Statements: Codes 9990-9997
-------
Appendix A - Commenter Information Log
EPA Letter ID1
100
101
387
388
389
390
391
392
393
394
395
397
398
402
403
405
406
407
408
409
410
411
412
413
414
415
Date Obtained
9/15/2003
1/5/2004
9/6/2003
9/8/2003
9/15/2003
9/2/2003
9/19/2003
9/26/2003
9/26/2003
9/24/2003
10/1/2003
10/6/2003
10/6/2003
10/21/2003
10/21/2003
10/23/2003
10/23/2003
10/23/2003
10/28/2003
11/12/2003
11/19/2003
11/24/2003
11/13/2003
11/25/2003
11/25/2003
12/1/2003
Commenter Name
Papacosta, Kemon
Thomas, Ed
anonymous 387
Kolch, Andreas
Papacosta, Kemon
Taylor, Jeff
Rios, Ricardo
anonymous 392
anonymous 393
Rose, Marian
anonymous 395
Kailey, Ron
Kailey, Ron
anonymous 402
anonymous 403
anonymous 405
anonymous 406
anonymous 407
Bareness, Craig
Gryder, Leslie
Saltzman, Dan
Cole, Devon
Illegible 0412
Sliwoski, Thomas
Amodeo, John
Arroyo, Miguel
Organization
NRWA
WEDECO AG
ASTM
City of Houston Public Utilities
Division
Croton Watershed Clean Water
Coalition Inc.
Cheyenne Board of Public Utilities
Cheyenne Board of Public Utilities
Shoshone Municipal Pipeline
City of Lynchburg Utilities
Portland Water Bureau
Utah Department of Health Laboratory
PWS WY5600045
City of Staunton, Virginia
Vista Irrigation District
City of Fort Lauderdale Public Services
Department
Supporting Information
Contained in the Stage 2 Docket under
OW-2002-0043-0294
Contained in the Stage 2 Docket under
OW-2002-0043-0397
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1 The EPA Letter ID is the last four numbers of the EPA Docket Number. Include "OW-2002-0039-" at the beginning of each EPA Letter ID to locate the
comment letter in the LT2ESWTR docket.
Comment Response for LT2ESWTR
A-l
December 2005
-------
EPA Letter ID
417
419
420
421
422
423
424
425
427
429
430
431
432
433
434
435
436
437
439
440
441
444
445
446
447
449
451
452
453
454
455
Date Obtained
12/1/2003
12/1/2003
12/1/2003
11/30/2003
12/22/2003
12/22/2003
12/24/2003
12/29/2003
12/21/2003
1/2/2004
1/5/2004
1/5/2004
1/5/2004
1/5/2004
1/5/2004
1/5/2004
1/5/2004
1/5/2004
1/5/2004
1/5/2004
1/5/2004
1/6/2004
1/6/2004
1/7/2004
1/7/2004
1/7/2004
1/6/2004
12/30/2003
1/6/2004
1/7/2004
1/8/2004
Commenter Name
Brown, Kenneth
Turner, Billy
Partlow, Eddie
Poole, David
Cabaj, Alexander
Foster, Robert
Ray, Frank
Papacosta, Kemon
Fernandez, Scott
Montz, Janet
Stribley, Chris
Stribley, Chris
Stribley, Chris
Stribley, Chris
Stribley, Chris
Stribley, Chris
Stribley, Chris
Danielson, Richard
Colalancia, Don
Hum, Gary
Gordon, Jeffrey
Pelletier, Rene
Hubbs, Stephen and
Fay, James
Scanlan, James
Barsotti, Michael
Lewis, David J.
Abrams, Eric
Strong, Jacqueline
Wurtz, Thomas A.
Letterman, Raymond D.
Stacker, Kurt
Organization
Stroudsburg Municipal Water
Authority
Columbus Water Works
The Old Hickory Utility District
David A. Poole Consultants, Ltd.
Institut Fur Medizinische Physik Und
Biostatistik, Veterinarmedizinische
Tennessee Division of Water Supply
ASTM
OCI Wyoming LP
Colorado Springs Utilities
Colorado Springs Utilities
Colorado Springs Utilities
Colorado Springs Utilities
Colorado Springs Utilities
Colorado Springs Utilities
Colorado Springs Utilities
BioVir Laboratories
Board of Water Works of Pueblo, Colorado
Central Arkansas Water
Division of Drinking Water
Management, Bureau of Water Supply
& Wastewater Management, PA
Department of Environmental Protection
New Hampshire Department of
Environmental Services
The Partnership for Safe Water
Fort Worth Water Department
Camplain Water District
Kenosha Water Utility
McMinnville Water and Light
City of Chandler, Arizona
Metropolitan Utilities District of Omaha
Department of Civil and Environmental
Engineering, Syracuse University
City of Kearney Utilities Department
Supporting Information
Includes 416
Includes 418
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Includes 428
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Comment Response for LT2ESWTR
A-2
December 2005
-------
EPA Letter ID
456
457
458
460
461
462
463
464
466
467
468
470
471
472
473
474
475
476
478
479
480
481
483
484
485
486
487
488
489
491
492
Date Obtained
1/5/2004
1/8/2004
1/8/2004
1/7/2004
1/6/2004
1/7/2004
1/8/2004
1/8/2004
1/8/2004
1/9/2004
1/8/2004
1/9/2004
1/9/2004
1/9/2004
1/8/2004
1/9/2004
1/9/2004
1/9/2004
1/8/2004
1/8/2004
1/8/2004
1/8/2004
1/9/2004
1/9/2004
1/9/2004
1/12/2004
1/9/2004
1/9/2004
1/8/2004
1/9/2004
Commenter Name
Hunter, Valerie
Johnson, Nolton G.
Anonymous458
Land, Vernon R.
Merrigan, Greg
Anonymous462
Wilson, Richard
Boutrous, Susan
Thelen, Larry
Anonymous467
McGlinchy, Michael L.
Rutherford, Jay L.
Griffin, John R.
Van Fleet, Dave
Wagner, Mary Carol
Anoushiravani, Morteza
Archuleta, Edmund G.
Anonymous476
Anonymous478
Joyner, Brad
McMeen, Chris K.
Kumm, Michael
Brooks, Jane
Anonymous484
Spath, David P.
Schulz, Christopher R.
Skadsen, Janice
Kishinchand, Kumar
Dinkloh, Ludwig
Chun, Doug
Anonymous492
Organization
Friends of the Reservoirs
Georgia Department of Natural Resources,
Water Resources Branch
West Viriginia Bureau of Public Health,
Office of Environmental Health Services
City of Norfolk, Virginia
South Dakota Section of the American
Water Works Association/ Clay Rural
Water System, Inc.
Washington Aqueduct
Anaheim Public Utilities Department
Environmental Associates, Ltd.
North Dakota Department of Health
Louisville Water Company
City of Akron Public Utilities Bureau
Vermont Water Division, Vermont
Department of Environmental Conservation
Washington Suburban Water Commission
City of Peoria, Arizona Utilities
Department
Northern Kentucky Water District
City of Portland Bureau of Water Works
El Paso Water Utilities
Department of Defense
Town of Forest City WTP
Tacoma Public Utilities - Water Division
Sturgeon Bay Utilities
Springfield Water and Sewer Commission,
MA
Metro Nashville Water Services
California Department of Health Services
COM, Inc.
City of Ann Arbor Water Plant
Philadelphia Water Department
WEDECO AG Water Technology
Alameda County Water District
City of Walla Walla Public Works/Water
Division
Supporting Information
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Comment Response for LT2ESWTR
A-3
December 2005
-------
EPA Letter ID
493
494
496
497
499
502
503
504
505
506
507
509
510
511
512
513
514
515
516
520
521
522
523
524
526
527
528
529
530
531
533
534
Date Obtained
1/9/2004
1/9/2004
1/7/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
Commenter Name
Becnel, Sidney
Bircher, Keith
Brown, Les
Powers, Richard
Waldo, David F.
1/9/2004
1/9/2004
1/9/2004
1/8/2004
1/9/2004
1/8/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
Steele, Matthew
Weber, Chuck
Sykes, Richard
Busch, Darron
Rodgers, Maggie
Bonacquisti, Thomas P.
Parker, Greg
Gowman, Linda
Cartnick, Keith W.
Brown, Jerry
Nelson, Richard P.
Hall, Nancy
Valade, Matthew
AnonymousS 16
Selburg, Roger
Rush, Leslie
Hornbrook, Michael
Anonymous523
Larimore, Gary
Jackson, Nick
Curtis, Thomas and others
Godfrey, Lyle
Anonymous
Ferran, Bruno
Swaim, Paul
Uhreihm, Edward
Reddy, John
Organization
State of Louisiana Department of Health
and Hospitals
Calgon Carbon Corporation
Mobile Area Water and Sewer, Mobile, AL
Michigan Department of Environmental
Quality
Public Water Supply Section, Bureau of
Water, Kansas Department of Health and
Environment
City of Columbus, Division of Water
WaterOne
East Bay Municipal Utility District
Department of Environment and Natural
Resources, Drinking Water Division
Cleveland Division of Water
Fairfax County Water Authority
Florida Department of Environmental
Protection Drinking Water Program
Trojan Technologies Inc.
United Water New Jersey
Contra Costa Water District
Nebraska Health and Human Services
System
University Hygienic Laboratory
Hazen Sawyer/CDM
New York City
Illinois EPA
Dalton Utilities
MWRA
Unfiltered Systems Working Group
KY Rural Water Association
Knoxville Utilities Board
AWWA/AMWA/NAWC/NLOC
ARDOH
Ondeo
CH2MHill
person
Kansas City MO
Supporting Information
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Comment Response for LT2ESWTR
December 2005
-------
EPA Letter ID
536
537
538
540
548
554
556
559
561
562
563
580
585
586
587
588
589
590
591
592
593
595
597
598
601
603
607
608
609
610
612
614
617
618
620
621
Date Obtained
1/9/2004
1/9/2004
1/9/2004
1/8/2004
1/9/2004
1/8/2004
1/7/2004
1/8/2004
1/9/2004
1/9/2004
1/20/2004
1/9/2004
1/8/2004
12/30/2003
1/7/2004
1/9/2004
1/9/2004
1/8/2004
1/8/2004
1/9/2004
12/23/2003
1/5/2004
1/9/2004
1/5/2004
1/6/2004
1/5/2004
1/9/2004
1/9/2004
1/8/2004
1/7/2004
12/29/2003
1/6/2004
1/6/2004
1/5/2004
Commenter Name
Pauls, Chester
Anonymous537
Taylor, J. Scott
Blazer, Manja
Stewart, Mic
Price, Wayne
Pappathopoulos, Bill
Weltering, Larry
Curtis, Thomas
Curtis, Thomas
Aptowicz, Bruce
Hoffman, Margaret
Rutz, Carl
Deem, Stephen
Nielson, Lance
Libeu, Lawrence
Robbins, Steve
Jones, Christopher
McNelly, Jeffrey L.
Young, Leonard D.
Beardsley, Nancy
Hulbert, Roger W.
Lippe, Chris
Bousfield, Kenneth H.
Hoey, Richard T.
Ferguson, Cam
Hunter, Valerie
Powers, Richard
Link, Donald
Throckmorton, Jeff
Rexing, David
Bowen, Thomas
Bryant, Craig
Schneider, Stephen
Edzwald, James
Organization
CO Department of Public Health and
Environment
person
City of Witchita Falls
IDEXX
Met WD of South CA
Broad River Auth, NC
AMWA
City of Two Rivers
Neenah Water Department
AWWA
AWWA
Water Utility Council of the PA AWWA
Texas Commission on Environmental
Quality
Alyeska Pipeline Service Company
citizen
ID Drinking Water Program
The Western Coalition of Arid States
Coachella Valley Water District
Ohio EPA
Maine Water Utilities Association
San Antonio
Maine
City of Houston
City of Austin
Utah
WADOH
Greenville Water System
Friends of the Reservoirs
MI Department of Environmental Quality
City of Monroe
Hach Company
Southern NV Water Authority
Manchester Water Works
Chesterfield County Department of Utilities
Saint Paul Regional Water Services
University of Massachusetts
Supporting Information
N/A
N/A
N/A
Includes 541 through 545
N/A
N/A
N/A
N/A
N/A
Contains twelve appendices
Includes Appendices 1, 2, 5, 11, and 12 from
letter 562
N/A
Includes 583 & 584
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Includes 594
Includes 596
N/A
N/A
Includes 602
N/A
N/A
N/A
N/A
N/A
N/A
Includes 613
N/A
N/A
Includes 619
Includes 622
Comment Response for LT2ESWTR
A-5
December 2005
-------
EPA Letter ID
624
625
627
628
629
630
631
633
634
635
637
641
643
645
646
647
651
652
653
654
660
662
664
666
667
668
673
675
677
678
681
683
686
687
688
Date Obtained
1/8/2004
1/9/2004
1/7/2004
1/9/2004
1/9/2004
1/7/2004
1/9/2004
1/14/2004
1/12/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/7/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
1/9/2004
Commenter Name
DeMarco, Jack
Parsons, James M
Land, Vernon R.
DeGraca, Andrew
Rho, Melinda A.
Kinman, Linda
Asbury, Charles "Ted"
Kinman, Linda
Neher, Michael A.
Hollander, Robert A.
Owens, Marie E.
Warden, Paul
Taft, James D.
Moriarty, Kathy
Martinez, Gary P.
Reilman, Nancy
Sturbaum, Greg
Warden, Paul
Stefanich, Tim
Brant, William
Yates, D. Gerard
Reynolds, Florence
Young, Douglas
Jones, Wellington H.
Holden, Carl
Olson, Erik D.
Terry, Shazelle
Rindal, David
Reents, Gary A.
Clark, Krista
Rose, Leah
Sedillo, Dolores
Jones, Rick
Pearson, David
Osterhoudt, Darrell C.
Organization
Cincinnati Water Works
Cobb County-Marietta Water Authority
City of Norfolk, Virginia
San Francisco Public Utilities Commission,
Water Quality Bureau
City of Los Angeles
Iowa Association of Water Agencies
City of Albuquerque
Des Moines Water Works
City of Henderson
City of Phoenix, Water Services
Department
Metropolitan Water District for Salt Lake
& Sandy
Analytical Services, Inc.
ASDWA
Bangor Water District
Sangre De Cristo Water Division
Maryland Department of the Environment
CH Diagnostic & Consulting Services
Analytical Services, Inc.
City of Sioux Falls
Miami-Dade Water and Sewer Department
Central Utah Water Conservancy District
Salt Lake City Public Utilities
Menasha Utilities
Frederick County Sanitation
Traverse City Water Treatment Plant
National Resources Defense Council
Jordan Valley Water Conservancy District
Minnesota Department of Health
City of Sacramento
Association of California Water Agencies
American Chemistry Council
City of Albuquerque, New Mexico, Public
Works Department
Pall Life Sciences
PCI Membrane Systems Inc.
State of Missouri
Supporting Information
Includes 623
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Comment Response for LT2ESWTR
A-6
December 2005
-------
EPA Letter ID Date Obtained Commenter Name Organization Supporting Information
699 1/8/2004 Visintainer, David A. City of Saint Louis N/A
703 1/12/2004 Weirich, Rich Frenchtown Water Treatment N/A
704 1/13/2004 Gould, Steven G. New York State AWWA N/A
706 1/15/2004 Spatz, John City of Chicago Department of Water N/A
Management
707 1/16/2004 Pratt, Jeffrey W. Kentucky Division of Water N/A
710 1/19/2004 Papakosta, Kemon N/A
Comment Response for LT2ESWTR A-7 December 2005
-------
Appendix B - List of Letters with Multiple Signatories
EPA Letter ID
445
527
Commenter First Name
James
Peter
Diane
Donald J.
Commenter Last Name
Fay
Cook
Van de Hei
Borut
Commenter Organization
The Partnership for Safe Water
NAWC
AMWA
NLC
Comment Response for LT2ESWTR
B-l
December 2005
-------
Appendix C. Comment Tables and Graphics
This appendix contains graphs and tables that could not be imported into the comment response
database, since the database accepts text only. These tables can also be found in the .pdf files on
the electronic docket website on the pages provided in the tables. Lists of the tables and graphs
are provided below.
Tables from Public Comments
EPA
Letter ID
425
457
470
470
489
502
510
520
528
536
562
562
562
562
624
628
647
647
Table Description
Reporting data to elaborate the need for a base point calibration and
verification of accuracy at 0. 1 0 NTU and 0.15 NTU
Existing System Size Breakdowns
Cryptosporidium monitoring timeframe
Cryptosporidium monitoring: small systems approaches
Specific comments regarding the Draft UV Disinfection Manual
Aerobic Spore Log Removal by Softening
Comments by sections in the GM
Cryptosporidium monitoring time table
Cryptosporidium monitoring time table
Cryptosporidium monitoring time table
Table 1 : Example Approach to Staged LT2ESWTR Monitoring
Table 2: Impact of Achieving IESWTR Required Effluent turbidity (<0.3
NTU)
Table 3: Summary of Spore Removal Data at Four Pre-Sedimentation
Facilities
Table 4: Differences in the Valuation of Time in the Traditional and
Enhanced COI Methods
Table 1: Cryptosporidium Log removals
Cryptosporidium data from SFPUC water systems
Cryptosporidium monitoring time table
Minimum monitoring requirements supported by MDE
Page
Number in
.PDF File
8
22
5
6
1 -3
3
26-31
7
4
6
22
56
65
102
6
2
9
11
Comment Response for LT2ESWTR
C-l
December 2005
-------
Graphs from Public Comments
EPA
Letter ID
421
421
421
421
452
480
488
488
488
488
502
510
510
510
516
562
562
562
562
624
624
624
624
Figure Description
Table 3.4 Summary of Recommended Hydraulic
Combination of Table 3.4 and Appendix C
Option 2 :UV Reactor
Option 3 : Velocity at the validation facility
Figure 1: Example calculation of 12-sample arithmetic mean where plant is in
service less than 12 consecutive months. Make-up samples are at the end
during a 30-month period in which 24 monthly samples are collected.
Influence of off-line or off-spec reactor on total theoretical percent inactivation
as a function of number of reactors
Figure 1: Cryptosporidiosis: Cases by Year Philadelphia, 1995 -2002
Figure 2: Cryptosporidiosis by Month of Lab Test Philadelphia, 1995 - 2002
Figure 3 : Source Water Crypto Trends
Figure 4: Source Water Crypto by Method 1623
Aerobic Spore Log Removal by Softening
Figures la and Ib: Figure la shows the dose distribution of a commercially
available reactor whose dose distribution is worse than the default distribution
in the draft guidance manual. Figure Ib shows that use of the dose distribution
in Figure la predicts a RED Bias value that would result in aggressive sizing
relative to the proposed default in the draft guidance manual.
Figure 2: Reactor Performance relative to a reactor with a 90 Elbow upstream.
A 90 Elbow Upstream is no the worst case: performance can be better or
worse under different installation configurations.
Optimizing a Multiple Barrier/Multiple Disinfectant Strategy (Microbes &
DBFs)
Field Filtration Apparatus
Figure 1 : Temperature Profiles from Newport News, VA., and Tampa Bay,
Fla.
Figure 2: Tracer Testing Results from an Over-Under Ozone Contactor in
Florida
Figure 3: Factors Affecting Benefit Analysis
Equations
Figure 1: Pre-sedimentation log-removals at GCWW's SWTP
Figure 2: Endospore reduction through GCWW SWTP
Figure 3: Cryptosporidium Inactivation for GCWW's Carbon-Filtered Water
Riverbank Filtration Scenarios Demonstrating Inequality with Sampling
Existing Wells for Bin Classification
Page
Number in
.PDF File
3
7
9
11
3
4
29
29
30
30
3
5
10
63
23
85
88
97
90
5
7
9
11
Comment Response for LT2ESWTR
C-2
December 2005
-------
Tables from Public Comments
EPA Letter ID: 425
Reporting data to elaborate the need for a base point calibration and verification of
accuracy at 0.10 NTU and 0.15 NTU
REPORTING
ALL INSTRUMENT WITHIN
BETWEEN
OVERALL
MATERIAL AVERAGE
INSTRUMENT INSTRUMENT
BIAS TEST
(NTU) SEQUENCE
(NTU)
REPEATABILITY REPRODUCIBILITY EXPECTED
(NTU)
(NTU)
(NTU)
Combined Filter
Effluent
StablCalA
SDVB-APSB
StablC alB
South Applied Filters
#2
SDVB-APSA
Formazin B
South Applied to Filters
#2
SDVB-APS C
Raw Water Delaware
Raw Water Schuylkill
StablCal C
Filtered (Tap)
Formazin A
0.0433
0.1156
0.2222
0.2308
0.2543
0.5635
0.6667
1.0071
2.0953
3.5426
3. 7849
3.9849
0.0644
1.0841
0.0143
0.0240
0.0136
0.0141
0.0241
0.0231
0.0462
0.0428
0.0566
0.1499
0.2118
0.1237
0.0155
0.4517
0.0214
0.0543
0.0689
0.0685
0.0720
0.1372
0.2071
0.1228
0.3614
0.6859
0.5211
0.2564
0.0301
0.4517
0.050
0.122
*NOTE #1
0.262
0.270
0.625
1.000
4.090
* NOTE #2
0.900
-0.0067 3
-0.0064 6
N/A 7
-0.0312 8
-0.0157 4 Day
N/A 5
0.0417 2
0.0071 9 Baxter
N/A 10
N/A 11
N/A 12
-0.1051 13
0.0644 14
0.1841 1 Day #1
Comment Response for LT2ESWTR
C-3
December 2005
-------
EPA Letter ID: 457
Existing System Size Breakdowns
Population
<500
501 to 3300
3301 to 10,000
10,001 to 50,000
> 50,000
Number of Samples
1 sample/year (2 if HAAS and TTHM high points
are different)
2 samples/year
2 samples/quarter
4 samples/quarter
4 samples/quarter+ 1 sample per additional
50,000/quarter; up to a maximum of 24
EPA Letter ID: 470
Cryptosporidium monitoring timeframe
System size
>50K
30K-50K
10K-30K
Cryptosporidium Monitoring
2 years of monitoring beginning
1 year after rule promulgation
2 years of monitoring beginning
2 years after rule promulgation
2 years of monitoring beginning
3 years after rule promulgation
Date of Bin
Determination
3.5 years after rule
promulgation
4.5 years after rule
promulgation
5.5 years after rule
promulgation
Compliance Date
6.5 years after rule
promulgation
7.5 years after rule
promulgation
8.5 years after rule
promulgation
Cryptosporidium monitoring: small systems approaches
CryptosporidiumMonitoring
2 years of monitoring beginning 3 years
after rule promulgation
2 years of monitoring beginning 3 years
after rule promulgation
1 year of monitoring beginning 4 years
after rule promulgation
1 year of monitoring beginning 4 years
after rule promulgation
1 year of monitoring beginning 4 years
after rule promulgation
Number of
Samples
48
24-47
24
12
8
Method of Determining
Bin
48-sample arithmetic mean
24-max sample RAA
24-sample arithmetic mean
12-sample second highest
value
8-sample maximum value
Comment Response for LT2ESWTR
C-4
December 2005
-------
EPA Letter ID: 489
Specific Comments Regarding the Draft UV Disinfection Manual
Clause
1-7; Table 1.4
2-13; Figure 2.10
2-14; Figure 2.11
2-15; Table 2.2
2-17; 2.4.4
2-18/19; 2.4.5
2-20; Figure 2. 16
2-21; Figure 2.17
2-21; 2.4.8
Comment
It should be highlighted that the selected virus strand is adenovirus.
The depicted UV reactor is manufactured by one specific UV manufacturer. We would recommend using a figure
of a generic UV reactor.
The depicted UV reactors are manufactured by one specific UV manufacturer. We would recommend using
figures of generic UV reactors.
The comparative disadvantage of low pressure "larger footprint" is correct for a certain flow rate range only and
only for the reactor itself. At very large flows, both technologies have reactors of almost identical size.
Additionally, the cabinet size of low pressure reactors is usually smaller compared to cabinets of medium
pressure reactors (a comparative advantage).
Sleeve diameters for LP lamps are 2.5 - 5.0 cm. Sleeve diameters for MP lamps are 3.5 - 10.0 cm.
It should be highlighted that the OCC system cleans the entire reactor (sleeve, sensor window and reactor walls)
while an OMC system only keeps the quartz sleeves clean. The OMC system consists of a wiping mechanism
located inside the UV reactor. This may result in potential shading and obviously impacts the hydraulic
characteristic of the UV reactor.
The depicted UV reactor is manufactured by one specific UV manufacturer. We would recommend using a figure
of a generic UV reactor.
The depicted UV transmittance monitor is manufactured by one specific UV manufacturer. We would
recommend using a figure of a generic UV transmittance monitor.
Temperature sensors are provided as a standard feature for MP reactors. Due to the lower excess heat
production and the ability to operate under zero flow conditions for some time, temperature sensors are usually
not provided for LP reactors.
Comment Response for LT2ESWTR
C-5
December 2005
-------
3-6; 3.1.2.1
During the stakeholder meeting in Washington in December 2003, there were some disputes about the UVDGM
providing recommendations.
In our opinion, recommendations are definitely welcome.
3-10; 3.1.3.1
Manganese should be added to list 2.
3-20; 3.1.3.3
1st paragraph
The impact of UPS costs is higher for MP reactors than for LP reactors due to their much higher power draw.
3-20/21; 3.1.4.1
Last/1st paragraph
LPHO reactors are also built in various shapes and sizes. The described in-line version is typically used for flows
> 5 MGD while S- or U-shaped LPHO reactors are typically used for smaller flows. WEDECO would be happy to
provide photos and/or drawings upon request.
3-21; 3.1.4.1
1st paragraph
LPHO reactors having a "larger footprint" is correct for a certain flow rate range only and only for the
reactor itself (not for the hydraulic requirements during validation). At very large flows, both technologies
have reactors of almost identical size.
Additionally, the cabinet size of low pressure reactors is usually smaller compared to cabinets of medium
pressure reactors.
3-21; 3.1.4.1
•>nd
2ng paragraph
We would recommend stating the actual power efficiency difference between LPHO and MP reactors: MP
reactors consume approx. 3 -4 times more energy than LPHO reactors.
3-21; 3.1.4.1
3rd paragraph
The reason for LPHO reactors typically having OCC systems is not the larger number of lamps: A wiping system
within an enclosed reactor is adding a lot of complex maintenance work (difficult access and sealing). If is cost-
effective to keep the reactor clean without an OMC system, there is no reason why one should add one. This is
the case with the majority of LP and LPHO installations: due to the low temperature operation, the fouling
potential is low, hence only occasional chemical cleanings are required. This is not the case with the majority of
MP installations: due to the high temperature operation, the fouling potential is high, hence a wiping system is
necessary to maintain the operational capability of the UV reactor. As an OMC system adds consumables to the
operational costs (wiper rings, actuator, seals etc.) and the time to replace those items may be fairly long due to
difficult access, a LPHO reactor with an OCC system may have lower maintenance costs than a MP reactor with
an OMC system.
3-37; 3.3.1.5
The material of the valves should also be able to withstand occasional chemical cleanings, which may be
required irrespective of the UV reactor cleaning system.
Comment Response for LT2ESWTR
C-6
December 2005
-------
3-44; 3.3.4.2
3-49; Table 3.9
Control Systems
The power back-up load needs to be equal to the full UV load including stand-by. All other electrical consumables
provided (wiping motors, air-conditioners etc.) can be served via the normal power source and not necessarily via
the UPS.
Depending on the control strategy, the signal "accumulated runtime for individual lamps" is of questionable
benefit.
It should not be listed as a minimum requirement.
3-49; Table 3.9
Warranties
3-50; Warranties
2nd paragraph
4-8; 4.3.2.4
4-16; Table 4.1 and 4.2
5-12; 5.2.3.1
Point 6
5-15; Table 5.3
5-18; 5.3.2.3
UV manufacturers usually use lamp and quartz sleeve manufacturers, who also have certain warranty
conditions.
We would like to highlight that all parties should use common commercial standards, especially as there is little
operational UV history in the US.
As the lamp output is neither subject to validation nor measured in the process, the sentence should be worded
based upon lamp intensity at the validated condition.
LP and LPHO UV lamps do not undergo non-uniform ageing in respect to disinfection as the only wavelength of
concern is 253.7 nm. The ageing effect can therefore be simulated with lamp power turn-down and measuring
the intensity.
During the stakeholder meeting in Washington in December 2003, there were some voices wishing to equalize
the dose rates between LP/LPHO and MP. In our opinion, this would violate the idea of the innovation concept: if
one technology or solution is more efficient than another, it should be rewarded. Due to the polychromatic nature
of MP lamps, there is clearly a higher uncertainty in comparison to monochromatic LP lamps in respect to all
aspects of simulation, validation and monitoring. Eliminating or adjusting the polychromatic bias for the sake of
equalization is surely not a correct approach.
This step is only necessary for MP reactors.
Due to the lower temperature at LP and LPHO reactors, solarization of quartz sleeves is not such an issue.
Consequently, sleeves do not need to be replaced every 3-5 years for LP or LPHO systems.
Due to the lower temperature at LP and LPHO reactors, solarization of quartz sleeves is not such an issue.
Consequently, sleeves do not need to be replaced every 3-5 years for LP or LPHO systems.
Comment Response for LT2ESWTR
C-7
December 2005
-------
5-20/21; 5.3.2. 7
5-34; 5.6.2
1st paragraph
5-38; Table 5. 14
A-34; A.3.1.4
Temperature sensors are provided as a standard feature for MP reactors. Due to the lower excess heat
production and the ability to operate under zero flow conditions for some time, temperature sensors are usually
not provided for LP reactors.
While a UV reactor may be theoretically able to compensate, the operation at a low UVT may be outside the
validated range.
MP reactors are usually more complex than LP or LPHO reactors (wiping, temperature sensors, higher voltage
connections, heavier transformers etc.), hence staffing requirements at MP reactors may be higher.
Complete power efficiencies are given for A. 3. 1.2 (LP) and A. 3.1. 3 (LPHO) but not for MP.
We would recommend to provide an equivalent break-down.
Comment Response for LT2ESWTR
December 2005
-------
EPA Letter ID: 502
Aerobic Spore Log Removal by Softening
Min.
Max.
Avg.
1995
1.60
3.23
2.39
1996
1.20
3.12
2.19
1997
1.86
2.90
2.32
1998
1.87
3.26
2.42
1999
1.83
3.00
2.40
2000
1.20
3.01
2.07
2001
1.69
2.80
2.32
2002
1.18
2.81
2.29
EPA Letter ID: 510
Comments by sections in the GM
Sec.
3.
3.1.2
3.1.4.2
3.1.4.3,
C.3.1.5
& 3.3.1
3.1.6.1
3.1.7
3.3.3
Item
Planning and Design Aspects
for UV Installations
Identifying Potential Locations
for UV installations
UV Reactor Control Strategy
Equipment Validation Issues
Hydraulic Consideration
Preparing Preliminary Costs
and Selecting the UV
Installation Option
Instrumentation and Control
Required by UVGM
Comments (questions for clarification,
suggestions, mistakes and typos)
In general, this section is long, repetitive in nature. It gives the wrong perception that UV is
very difficult to work with and has many disadvantages and potential liabilities. The GM
should avoid being prescriptive and should, instead, provide guidance with rationale
It was a negative assessment approach for UV installation. The preferred approach would
be to highlight the advantages/disadvantages of each and outline considerations that must
be taken into account for successful application. This would allow flexibility and process
design innovation for meeting various objectives.
Intensity sensors can be used in many, and significantly different ways. They can be used
strictly as a monitor, or they can be used as part of a control algorithm. In systems with
multiple sensors, no guidance is provided about how those sensors are used.
Restrictive hydraulic
configurations
Observations/generalizations
regarding sleeve strength.
Recommend performance based criteria rather than
prescribed hydraulic requirements. See comments in
the main body of text.
UVDGM should reference appropriate study/literature
with respect to sleeve strength and integrity. Reference
to a telephone conversation with a manufacturer is not
sufficient.
A recommended NPV calculation for bid assessment would be of potential value. It could establish
an equal playing field for everyone, page 3-29, paragraph one states, "Selection of the best
option may not be based solely on capital and operation and maintenance costs. The final
selection criteria should also consider the following factors:" This sentence should change
to read, "Selection of the best option should be based on the disinfection and design
objectives with consideration given to the following final selection criteria: Capital and
operation and maintenance costs, ease of installation, etc."
The last sentence on p. 3-38 is not finished.
3.3.3.1
Table
3.8
UV Reactor Start-up
Typical Alarm Conditions for
UV Reactors
Suggests lamp warm-up times
(and off-spec period) on order
of 10 minutes
Critical alarm occurs if wiper
function fails
Clarify lamp warm-up times by lamp technology
Critical alarm is not necessary. Temporary mal-function
of a wiper would not affect disinfection. Alarm is mainly
for protecting equipment. GM should let manufacturers
determine the level of alarm.
Comment Response for LT2ESWTR
C-9
December 2005
-------
3.3.4.3
&
5.3.2.8
Ground Fault Interrupt and
Electrical Lockout
GFI for operator protection
The statement in GM is incorrect. GFI does not provide
adequate safety protection for people. It is designed for
equipment protection, but not for people protection. For
example, it responds too slowly, and its sensitivity is too
low. The misunderstanding of GFI is present among
design engineers. Safety protection of operators from
electrical shock can be achieved by proper grounding
and bonding of the equipment and by proper electrical
lockout procedures.
GM should remove the statement of "all UV reactor
suppliers should provide GFI circuits for their lamps".
Table
3.9
Content for UV Reactor
Specification
Redundancy
The redundancy requirement for unfiltered systems or
individual filter treatment systems is not described.
Rationale should be provided.
4.3
Considerations for Validation
Testing
Clarification required regarding threshold on design impacting validation, changes
especially with respect to lamp and sleeve changes.
4.3.1 &
C.3.1.5
Inlet and Outlet Hydraulics
Regarding CFD-based dose
modeling. Due to uncertainty,
predicted dose delivery during
validation should be at least
20% greater than the dose
delivery predictions at the WTP.
Question whether this additional factor is necessary
and request additional clarification regarding the
circumstances under which it would apply. This
additional "hidden" safety factor is inappropriate. In
C.3.1.5, GM did not quote Petri and Olson 2001
reference properly. In this paper, it was clearly shown
that CFD prediction was consistently conservative
compared with measured RED. The proposed 20%
safety in GM is contradictory with the results published.
4.3.2
Lamps for Testing
Aged lamps required for
validation testing.
Guidance will become a barrier to product validation. It
is not reasonable to expect new products be validated
with aged lamps (and sleeves) especially as
engineered lamp life becomes longer. Requirement that
aged lamps and sleeves be used in validation is cost
prohibitive and design restrictive.
4.5
Data Analysis
Complicated and difficult to follow. Data fitting
techniques in 4.5.1.2 are not clear. Are the techniques
for pooling multiple collimated beam data sets truly
applicable to the problem? They seem to be non-
rigorous. Polynomial equation option ignores the
intercept term. Rationale is required. Otherwise this is a
mistake. More specific comments are provided later.
4.6.1
UV Intensity Sensors
Sensors should view a point
along the length of the lamp
that is between the electrode
and within 25% of arc length
away from electrode.
Rationale is required. W hy must sensor view point on
arc within 25% of the arc length from an electrode?
This will restrict future design options available to
manufacturers. There are questions regarding aging
effects like lamp aging. Lamp end darkening of medium
pressure lamps is a normal phenomenon in the aging
process. Empirical evidence available so far with these
lamps in our reactors shows that disinfection
performance is not compromised. This is due to the
control algorithm that we use and the reactors'
hydraulic performance. The guidance manual's
advocated response to lamp end darkening, to require
that an intensity sensor be placed near the lamp, at a
distance of % of the arc length from the lamp end, will
not have the desired effect of ensuring proper reactor
performance with lamp end darkening. Firstly, it is not
necessarily the case that a decrease in output will be
measured at this distance. Secondly, if there is a
decrease in output, then blocking light by putting a
sensor at this location will likely make the performance
conditions worse. Manufacturers that can show that
lamp end darkening does not affect
Comment Response for LT2ESWTR
C-10
December 2005
-------
4.6.1
4.6.1
5.1.2
5.1.2.3
5.3.2
5.3.2.3
5.3.2.3
& 2.4.4
5.4.1
5.6.5 &
3.1.3.2
A.3.5.1
C.
C. 1.4.2.
C.2.
C.2.1
UV Intensity Sensors
UV Intensity Sensors
Functional Testing
Verification of Instrumentation
and Control Systems
Lamp substitution
Lamp Sleeves
Lamp Sleeves
Monitoring and Recording
Power Quality Problems
UV Intensity Sensor
Properties
Validation of UV Reactors
UV Validation for Utilities
UV Reactor
Provisions for Testing
Appears to require systems all
to have a PLC
Sensor reading may be used to
approve lamps other than that
used during validation
Lamp sleeves must be certified
as described in section F.6.3
EPA Guideline recognizes a
solarization phenomenon in
quartz sleeves
UV intensity must be monitored
and recorded
Statements re. power quality
reactor performance should face no further
requirements or design constraints on their equipment.
Clarification is required regarding NIST traceable
sensor measurement requirement, for all
measurements, or irradiance calibration only. Clarify if
15% is irradiance or total uncertainty.
The expression for the uncertainty check is not
consistent. Shouldn't the expressions on pages 4-17
and C-36 be the same as Equations C-2 and C-3 on
page C-18 (absolute value signs instead of brackets on
the LHS of the equations)?
Clarify who is responsible for functional test, and
provide guidance.
Clarify whether all systems must be PLC based control
- if so, provide rationale.
Sensor reading is not adequate to qualify the entire
lamp germicidal output. The risk is potentially due to
non-uniform output distribution, spectral changes, and
other lamp performance changes, which are not
detected by the sensor in the reactor. Manufactures
should be required to demonstrate equal or better lamp
performance using standardized protocols.
Certification requirements require elaboration. Section
F.6.3 does not provide any further detail than 5.3.2.3.
Solarization and its impact on material strength and
disinfection efficacy appear to be speculative.
References or data should be provided to demonstrate
the magnitude of the issues.
No absolute need to record/track UV intensity under a
calculated dose methodology
Statements are exaggerated and can lead to
unnecessary stringent power quality requirements for
power distribution that will require additional
conditioning equipment and lead to higher costs for UV
installations
Sensor angular response: this section states that the ideal sensor has a cosine response.
This is not generally true. A good sensor can have a variety of angular response functions.
In fact, if the sensor is to give the best indication of dose at a point, then the sensor should
have a uniform response to light from all angles (fluence), not a cosine response
(irradiance). The same mistake is made in the caption for figure A21 , which calls it the
"ideal cosine response". This becomes prescriptive, leading the reader to believe that the
best sensor is one with cosine response. Manufacturers can design excellent sensors with
a variety of angular response functions, so long as this response is constant for all sensors
they provide for the reactor. The same general comment applies to the discussion of
linearity, where it is stated that the ideal sensor response is linear. A sensor could be
designed with other responses.
In general, the calculation of safety factors are test-specific. Each test will produce its own
unique safety factor value. The GM fails to consider how to rationalize all of the results of a
test validation - i.e. a validation effort should produce one safety factor for a piece of
equipment. How is the GM technique implementable? Many examples throughout the GM,
do not give the quoted results when using the numerical inputs provided. Many examples
reference former examples, and bring forward values that are inconsistent with the former
example. The GM requires a thorough check and clean-up of calculations in examples.
Optoelectronic Instrumentation verification by third-party - Can the guide provide a list of
possible labs capable of doing this?
page C-8, 5th bullet contains typo (..as per section C.4.9.2. SHOULD READ C.4.9.4)
If lamp aging affects the
relationship between the
inactivation and sensor output,
aged lamps should be used
during validation.
Clarify whether the aged lamps require third party
certification. Provide definition of end-of-lamp life. This
may not be a fixed number. Add calculated dose in the
monitoring strategy, because sensor readings alone
may not be adequate for correlating to dose.
Comment Response for LT2ESWTR
C-ll
December 2005
-------
C. 3.1.1.
C.3.1.4.
C.3.2
C.4.6.
C.4.7
C. 4.7.1
C. 4.7.2.
0.4.8
0.4.8.
0.4.9.2.
0.4.9.3
Water Supply
Sample Taps
UV Intensity Sensor Test
Stand
Evaluation of the Mixing of
Surviving Microorganisms
Evaluate UV Sensors
Intensity
Assessing Uncertainty Using
Reference Sensors
Assessing Uncertainty Using
a Sensor Test Stand
Evaluate Impact of Lamp
Aging
Evaluation of Lamp and
Sleeve Aging on Dose
Monitoring
Reactor Preparation
Flowrates
Re: on-site validation -RPZ backflow preventers/check valves are very expensive
propositions for sites to invest in for purposes of validation, especially large pipe-diameters
(generally thought of as one-time only procedure). Sites need to make these types of
decisions and set budgets for these types of capital outlays for on-site validation.
More detail would be helpful to a site preparing for validation -give some guidance on the
equation to calculate the drop-off in UVT %/cm (254nm) and give some guidance on
calculating distance where 0.1% of the germicidal intensity occurs. Give some guidance on
how taps should be installed (sampling from the middle of the pipe or the wall of the pipe).
Installing these into working sites is not trivial. More attention should be given to describing
to sites how manifolds and adjoining piping (hydraulics) can impact validation results;
reducers, expanders, etc. Shoe-horning reactors into existing piping makes for difficult on-
site validations (and expensive bioassay testing that, according to the UVDGM, will
probably not be applicable to most other sites due to site-specific hydraulics).
Duty and reference sensors
should be measured by an
independent lab to measure
sensor properties.
Clarify whether measurements done in a
manufacturer's facility under third party be treated as
independent. Provide a list of accredited labs.
Remove this suggested test from the guide. It is impractical to use microbes to test mixing.
The result is not immediately known and it is not trivial to run phage at a site. Usually have
issues of drainage, clearing phage from piping. To test mixing of post-UV pipe section
inject modifier at outlet of reactor (same flow and injections conditions as previously
tested). Sample as above from outlet & distant outlet ports, measure transmittance of all
samples -reasonable variation within a sample set and between sample locations would be
+/- 1 % transmittance (depends on the absolute transmittance being measured, variability in
background UVT, measurement uncertainty, precision and repeatability of calibrated
spectrophotometer). +/- 2% of absorbance measurements produces inconsistent bounds
from high to low absorbance. Better clarification of "per cent of what" would be
recommended whenever the guide suggests using percent variation (per cent is a relative
term and therefore it must be stipulated what the measurements should be related to - min,
max, mean, range).
Two approaches: Approach 1 ,
on-site evaluation during
validation Approach 2, off-site
evaluation by a sensor lab.
Clarify whether off-site evaluation can be conducted in
a manufacturer's lab under the third party.
Use of 3 calibration sensors to test duty sensors is excessive and is not in agreement with
what the site would operationally use.
Can the guide provide a list of possible labs capable of doing this?
Requirement:
- Validation requires both new
and aged lamps and sleeves if:
- Lamps experience spectral
shift with age.
- Provide lamps and sleeve
data to demonstrate the
absence of the spectral shifts.
- Conduct bioassay to
demonstrate that sensor
readings can detect the
changes.
Clarify whether lamp and sleeve testing require third
party witness.
The requirement for sensor intensity correlating to dose
delivery is restricted to the intensity set-point control
method. The requirement should be broadened to
cover the calculated dose method. Ultimately, it is
about having a reliable dose monitoring system for the
UV systems when lamps age.
This procedure is impractical with EM ballasts especially -not enough power settings to
comply. Preparing and maintaining aged lamps/sleeves for all product lines will be cost
prohibitive.
If we were validating a reactor with "sensor per reactor" instead of "sensor per lamp" the
suggested procedure requires either remote measurement of the lamps to select the one
with highest output (not very realistic for on-going operations - the lamps will not be
measured and installed per this characteristic). Suggestion is to install the lamp with
highest output to be measured by the sensor - seems aggressive.
Dictating the choice of flow rates for validation tests, based on an assumption of dose
being proportional to inverse flow, is over prescriptive and flawed. Although an adequate
rule of thumb, in a real reactor dose is not linearly proportional to inverse flow, so there is
Comment Response for LT2ESWTR
C-12
December 2005
-------
C. 4.9.5.
C. 4.9.7.
C. 4.9.8.
C. 4.9.9.
C. 4.9. 10.
C. 4.10.1
C. 4.10.2.
C.4.11.
C.5.4.
F.3
Measuring Challenge
Microorganism Inactivation
by the UV Reactor
Challenge Microorganism
Dose-Response
Fitting Dose-Response Data
Fitting Dose-Response Data
Combining Dose-Response
Data
Reactor Log Inactivation and
RED
Interpretation of Results
Interpolation of Results
Tier 1 Approach
Tier 2 Approach
Validation Test Report
MP Reactor Using a Single
UV Intensity Setpoint and UV
Transmittance Setpoint
UV intensity sensors
no rationale for having to choose flow conditions on this basis. The industry deals with
flow on a linear, not an inverse scale (e.g. typical performance curves). This should not be
a requirement.
Allows for just 3 inlet/3 outlet samples per test condition (good); suggests a time interval
between sample collections equivalent to 'system' residency time -if mixing test was
passed this should not be necessary. At some sites large change-out volumes of the pipe
system require >2 minutes for residency at low flow rates. When injecting phage/coffee,
time is money.
This section requires further numbering of sections (C. 4. 9. 7.1, etc).
This is where the manual starts inverting dose-response curves. Also, the sections
describing data analysis talk about confidence levels (95, 80%) as if the audience are all
statisticians - Could this entire section be simplified for the average reader and include
complete examples. Where the manual gives examples they are broken up throughout the
different sections making the analysis difficult to follow. Could there be a section that
shows a complete analysis, start to finish?
The example on page C-29 where the manual suggests using a 'power equation' to test fit
- makes no sense that one would chose a function without an intercept - has no basis in
reality for this type of system. Again, this section discusses some rather complicated
analyses. Could the section be simplified with complete examples?
Regression is a fairly complicated analysis. Could t-test be used instead? The impact to
RED when using one method instead of the other, is so small - may not be measurable. Is
there a need to put such a fine point on the calibration curve - is there enough resolution
in the microbiological technology as to be sensitive to this analysis?
Missing an equation describing UoR-also, reference should be to Section C.4.9.7, Fig C.3,
not section CAS. 7. There is a contradiction between UD (Appendix E) and UD described
on page C-33.
This section is confusing. At this point in the analysis, having spent so much time & effort
to analyze/calculate the SF for each test condition, the manual indicates that the reactor
should be rated at the lowest inactivation observed for each calculated dose setpoint
evaluated. Assumption 1 here is that there are several combinations of relevant
operational conditions that result in the same dose. However, this phrase suggests that at
different dose setpoints (should this be required by a site) there would be different ratings
(SF's). Not clear how this would/could be applied at a site.
In this section the manual states that "if the RED is interpolated as a function of the
measured intensity of the inverse flow rate, the equation used should pass through the
origin(0,0)"- this is further reason NOT to use the power function as detailed above (that
doesn't mean you can't use a quadratic function but then you are dealing with 3 variables,
not 2).
The guide should start this section by clearly stating that Tier 1 is actually more stringent
than Tier 2 - it may seem simpler to fulfill (although many/most of the calculations/analysis
req'd for Tier 2 need to be completed to determine IF you can use the Tier 1 approach) but
the site will carry a large safety factor (penalty) for choosing Tier 1 . Use of Tier 1 approach
is not ultimately safe.
Quite a complicated analysis, with a relatively high degree of statistical knowledge req'd -
lots of detail and effort that doesn't seem to show up in the Final Analysis or
application/implementation of a safety factor across a wide range of operational
conditions.
Not sure why there needs to be two reports -we normally report everything highlighted
next two sections, but in one format called a REPORT
Reading through this section highlights how weak this approach is, and how difficult it
would be to control with or even monitor the system with this approach. The written
example on page C-68 and the titling of Table C.18 are inconsistent with one another.
-Sensor location: If lamps -Clarify the requirement for sensor location. Most
experience non-uniform aging, lamps have some degree of end darkening as they
sensor should be located to age. Can does and sensor modeling be used to
monitor the section that determine the impact of sensor location, and to
experienced the greatest determine the location?
decrease in UV output with - Clarify in the main body of text Tier 1 and Tier 2
aging. requirements on the number of sensors, especially for
-No. of sensors: the monitoring MP. Based on this section, it is possible not to require
strategy should sensor per lamp for MP.
Comment Response for LT2ESWTR
C-13
December 2005
-------
F.3.3
F.6
F
F.4.2
F.4.3
G.4
J.5.4
1.6
Example 18.
Re-validation
Polychromatic bias:
Water Absorption
Spectral Shifts
Off-Spec Requirements
Lamps for testing
Issues for small systems
account for lamp-to-lamp
variability. If No. of sensors <
No. of lamps,
oThe lowest output lamp
should be monitored;
oOr include a safety
factor to account for
lamp-to-lamp variability.
Dose delivery modeling and
sensor modeling can be used to
assess the impact of design
changes, and to justify whether
re-validation is needed.
-The guidelines talk about the sensor monitoring the
first 25% of a lamp - which is not necessarily the same
thing as monitoring the section of lamp that
experiences the greatest decrease. Consistency within
the guideline is required, as is rationale.
The < sign should be > if the sensors are out of spec on
page F-21 .
-Clarify who performs the modeling, and if there is any
third party requirement. -In addition to modeling, UVGM
should allow empirical approach to demonstrate
equivalent or better performance by the component
changes, such as showing lamp output and spectral
data.
Polychromatic bias: This is a concept that is not proven experimentally. A great deal of
effort and large equipment factors are being incorporated based on theoretical derivation.
Unproven factors have no place in a USEPA guidance manual. In Appendix F4.1 , the
uncertainty in the action spectra from Rauth, Linden et al is greater than the polychromatic
factors that are being calculated. The argument is an interesting one, but the conclusions
cannot be supported by the data.
F4.2 is an interesting theoretical calculation. However, unless the models used have been
thoroughly validated, the predictions remain speculative, and should not be used. Accurate
model input relies on reliable physical measurements. For example, spatial distribution and
spectral output of a lamp can not be modeled by simple assumptions, but be measured
experimentally. In addition, the proposed modeling was based on an annular reactor,
which is not representative of a wide range of reactor configurations in the industry. It
would be unwise to base sizing factors on models that are not proven and are based on
incorrect assumptions of lamp output and reactor hydraulics.
F4.3 bases calculations of lamp spectrum shift on data from Phillips that is at least 20
years old. Current experience with production MP lamps does not show this spectral shift.
Again, the calculations are based on particular assumptions of spatial UV power, and on a
fictitious annular reactor. It would be unwise to base sizing factors on a theoretical analysis
that is not supported by experiment.
Off specification limits not
indicated for filtered systems
Requires that the lamp output
be measured.
Guidance suggests small
systems will buy sensor set-
point systems
Guidance is required regarding off specification limits
for filtered systems.
Clarification is required regarding appropriate method
of lamp output measurement. A standardized lamp
measurement protocol is required because different
measurement techniques can result in significantly
different lamp output results.
Guidance shouldn't speculate.
Comment Response for LT2ESWTR
C-14
December 2005
-------
EPA Letter ID: 520
Cryptosporidium monitoring time table
System size
>50K
30K-50K
10K-30K
Cryptosporidium Monitoring
2 years of monitoring beginning
1 year after rule promulgation
2 years of monitoring beginning
2 year after rule promulgation
2 years of monitoring beginning
3 year after rule promulgation
Bin Determination
Date
3.5 years after rule
promulgation
4.5 years after rule
promulgation
5.5 years after rule
promulgation
Compliance Date
6.5 years after rule
promulgation
7.5 years after rule
promulgation
8.5 years after rule
promulgation
EPA Letter ID: 528
Cryptosporidium monitoring time table
System size
>25,000
<25,000
Cryptosporidium
Monitoring
2 years of monitoring beginning 1
year after rule promulgation
2 years of monitoring beginning 3
years after rule promulgation
Date of Bin
Determination
3.5 years after rule
promulgation
5.5 years after rule
promulgation
Compliance
Date
6.5 years after rule
promulgation
8.5 years after rule
promulgation
EPA Letter ID: 536
Cryptosporidium monitoring time table
System
size
>50K
30K-50K
10K-30K
Cryptosporidium
Monitoring
2 years of monitoring
beginning 1 year after rule
promulgation
2 years of monitoring
beginning 2 year after rule
promulgation
2 years of monitoring
beginning 3 year after rule
promulgation
Bin Determination
Date
3.5 years after rule
promulgation
4.5 years after rule
promulgation
5.5 years after rule
promulgation
Compliance Date
6.5 years after rule
promulgation
7.5 years after rule
promulgation
8.5 years after rule
promulgation
Comment Response for LT2ESWTR
C-15
December 2005
-------
EPA Letter ID: 562
Table 1. Example Approach to Staged LT2ESWTR Monitoring
Years
1-2
3-4
5-6
Population Served
>50,000
30,000-50,000
10,000-30,000
Number of
Systems
401
460
460
Population
Served*
120,300,000
18,400,000
9,200,000
Population estimates derived from Community Water System
Note: Survey and may be underestimates due to assumptions made in
CWSS.
Table 2: Impact of Achieving IESWTR Required Effluent turbidity (<0.3 NTU)
Literature Source
Clarification + filtration
States et al. 2002
Cornwell et al. 2000
Halletal. 1994
Duganetal. 2001
Pataniaetal. 1995
McTigue et al. 1998
Nieminski and Bellamy
2000
Direct filtration
Swaimetal. 1996
Pataniaetal. 1995
Ongerth and Pecoraro 1995
Westetal. 1994
Cryptosporidium
N
15
44
33
6
63
115
138
12
24
O
4
Mean
5.8
5.2
4.8
4.9
4.3
4.0
*
3.8
2.9
3.0
3.1
Log Removal Data
Median
6.0
5.3
5.1
5.0
4.3
4.0
3.6
2.9
2.8
3.3
Range
6.6-2.3
6.0-3.1
6.5-2.9
5.2-4.5
6.0-2.6
5.6-1.5
4.4-3.3
4.0-1.5
3.4-2.7
3.4-2.6
Percent of
Filtered
Data 3-log removal associated with the raw water
concentration present.
N= number of observations
Comment Response for LT2ESWTR
C-16
December 2005
-------
Table 3: Summary of Spore Removal Data at Four Pre-Sedimentation Facilities
Observations
Number of Observations
Median Log Removal of
Paired Datai
Median
Concentration
(Spores /L)2
Raw
Pre-
sedimentation
Median Log
Removal
Facility A
2002
1,112
0.59
165,000
48,000
0.54
2003
225
0.69
255,000
64,000
0.60
Facility B
1998-
2000
273
0.79
290,000
61,750
0.67
2003
68
0.73
435,000
101,000
0.63
Facility C3
2001-
2002
268
0.45
300,000
138,333
0.34
2003
63
1.68
377,778
9,067
1.62
Facility
D
1996-
2003
325
0.60
90,000
19,000
0.68
JNotes.
"Median log removal of paired data" is the median of log(in/out) "Median log removal" is
calculated as log (median in/median out). Improved removal overtime at facility C
reflects changes in operational practice. For multiple columns of data for a given facility,
the first column reflects a period of record previously reported to EPA and the second
reflects additional data.
Table 4: Differences in the Valuation of Time in the Traditional and Enhanced COI
Time category
Paid work time
Unpaid work time
(household production)
Leisure time
Sleeping time
Traditional COI valuation
Median pre-tax wage plus
benefits
l/2 of median post tax wage
Not valued
Not valued
Enhanced COI valuation
Median pre-tax wage plus
benefits
Median post tax wage
Median post-tax wage
Not valued
Comment Response for LT2ESWTR
C-17
December 2005
-------
EPA Letter ID: 624
Table 1. Cryptosporidium Log removals
Literature Source
States et al. 2002
Cornwell et al. 2000
Halletal. 1994
Duganetal. 2001
Pataniaetal. 1995
McTigue et al. 1998
Westetal. 1994
Totals
Average
N
15
44
33
6
63
115
4
280
log rem
5.8
5.2
4.8
4.9
4.3
4
3.1
Cryptosporidium log removal data
mean
N*log
87
229
158
29
271
460
12
1247
4.5
median
log rem
6
5.3
5.1
5
4.3
4
3.3
N*log
90
233
168
30
271
460
13
1266
4.5
EPA Letter ID: 628
Cryptosporidium data from SFPUC water systems
10 L volume
100 L volume
Unfiltered water system
59 data
83 data
2 Filtered water system
57 data
69 data
EPA Letter ID: 647
Cryptosporidium monitoring time table
System size
>50K
30K-50K
10K-30K
Cryptosporidium Monitoring
2 years of monitoring beginning
1 year after rule promulgation
2 years of monitoring beginning
2 year after rule promulgation
2 years of monitoring beginning
3 year after rule promulgation
Bin Determination
Date
3.5 years after rule
promulgation
4.5 years after rule
promulgation
5.5 years after rule
promulgation
Compliance Date
6.5 years after rule
promulgation
7.5 years after rule
promulgation
8.5 years after rule
promulgation
Minimum monitoring requirements supported by MDE
Comment Response for LT2ESWTR
C-18
December 2005
-------
Population
<500
501 to 3300
3301 to 10,000
10001 to 50,000
> 50,000
Number of Samples for Initial
Monitoring
2 samples/year
4 samples/ year
4 samples/quarter3
8 samples/ quarter3
8 samples/quarter+ 2 samples per
additional 50,000/quarter; up to a
maximum of 483
Number of Samples for
Reduced Monitoring
1 sample/3 years '
1 samples/ year
2 samples/quarter3
4 samples/ quarter3
4 samples/quarter+ 1 sample
per additional 50,000/quarter;
up to a maximum of 243
1-2 samples per year if TTHM and HAAS high concentrations are at different locations.
2 - Taken during the month(s) of warmest water temperature as determined by the state. Surface
water systems would sample I/year.
3 - At least one quarterly sample must be taken during the month(s) of warmest water
temperature as determined by the state.
Comment Response for LT2ESWTR
C-19
December 2005
-------
Graphics
EPA Letter ID: 421
Table 3.4 Summary of Recommended Hydraulic
Configurations for Validation and Installation
Option Validation
UV Installation
The inlet and outlet configuration
is the same as the installation for
10 diameters upstream and 5
diameters downstream of the UV
reactor.
a]
The inlet and outlet configuration
is the same as when the UV
reactor was validated for 10
diameters upstream and 5
diameters downstream of the UV
reactor.
The UV reactor is validated with a
90-degree bend directly upstream
of the UV reactor. The UV reactor
is defined to include a specific
amount of straight pipe upstream
or downstream of the UV reactor
as specified by the UV
manufacturer
c]
The UV reactor should be
installed with a minimum of 5
pipe diameters of straight piping
between the UV reactor and any
upstream hydraulic configuration.
{ This approach is not acceptable if the
upstream filling is an expansion or if
the upstream valve will be used for
flow control. A valve that will be
exclusively used for open/close service
(e.g., isolation) is acceptable.}
tf]
The velocity at the validation
facility is measured at evenly
points through a given
! cross section of the flow upstream
! and downstream of the UV
reactor
e]
Velocity at the installation is
measured at evenly spaced points
through a given cross section, of
the flow upstream and
downstream and is within 20
percent of the theoretical velocity
determined during validation
n
Comment Response for LT2ESWTR
December 2005
-------
Combination of Table 3.4 and Appendix C
O
P
t
o
n
Table 3.4 Summary of Recommended
Hydraulic Configurations for Validation and
Installation
Validation
UV Installation
Appendix C. Validation ofUV
Reactors
The inlet and outlet
configuration is the
same as the installation
for 10 diameters
upstream and 5
diameters downstream
of the UV reactor.
a]
The inlet and outlet
configuration is the
same as when the UV
reactor was validated
for 10 diameters
upstream and 5
diameters downstream
of the UV reactor.
b]
Inlet and outlet conditions used at the
WTP match those used during
validation for at least 10 pipe diameters
upstream and 5 pipe diameters
downstream of the reactor.
a) The intent of a] is unclear as to 'chicken or egg'. It could be taken to mean
that the validation is completed after the installation, to validate that actual, or
intended, configuration. Although possible, it is difficult to believe that such a
sequence would ever occur; that is, a number of manufacturers being asked to
validate a specific unique configuration just so presumably they can compete for
procurement on that project with a validated unit.
The Appendix x] is unambiguous and logical; first know the validation
configuration and then match the installation to that.
b) The major drawback to the use of this Option is its absolute rigidity. The
designer must choose his installation configuration to be the SAME as (must
MATCH) that of the known validation.
First the Designer may be contemplating using a number of alternative reactors
all of which may have different validation configurations. Lets assume then that
after the procurement process the preliminary design configuration should be
amended to conform to the validation configuration of the selected reactor. But
what if the validation configuration of the selected reactor is difficult, unsuitable
or impossible for the design configuration to achieve? Must the designer discard
the selected reactor because he cannot duplicate exactly (the SAME) the
validation configuration of that reactor?
c) The wording of this Option does not allow the designer any judgment on
"better" than validation hydraulics. For example (real world case) in a filter
gallery 3 diameters of straight pipe can be achieved upstream of a reactor that
was validated with a 90° bend immediately upstream. The 3 diameters should
logically provide better hydraulics than the bend but the designer may not use
that configuration since it would not be the SAME—he has to put a 90° bend
immediately upstream, to qualify as SAME!
Comment Response for LT2ESWTR
December 2005
-------
d) The downstream configuration spawns more problems of "sameness",
If an installation configuration has a tee, say 4 diameters downstream of the
reactor then it will not qualify under this option unless the validation of the
reactor to be installed also has a tee 4 diameters downstream! The reason for the
5 diameters downstream requirement is unclear. A number of manufacturers
have said that they are not really concerned with downstream hydraulics, and also
e) Overall the SAME configuration is nearly impossible to comply with. For
example, look at a bank of parallel reactors which the designer wishes to use with
inlet flow-splitting weirs (Page 3-33 of the Manual) How will he find a reactor
that has been validated with a valve and a weir upstream? Without that (even
ignoring the downstream conditions) the installation cannot qualify as SAME.
f) Perhaps the irony of this Option i is that it Is noted as:
"...most applicable when unique piping configurations are needed or If the inlet
and outlet conditions validated in Option i (may be typo? Option 2 intended?)
cannot be achieved because of site constraints. For example, Option i may be the
only validation option for an individual filter effluent location, which probably
does not have 5 diameters of straight pipe before the UV reactors (Option 2),
because of existing site constraints."
Option 1 is hardly suitable for "unique piping configurations" unless the Designer
can find a reactor whose validation configuration had the SAME uniqueness as
the installation. Although seemingly intended to address the unique situations,
the use of Option 1 is between 'problematical' and Impossible' for virtually all
situations.
Comment Response for LT2ESWTR C-22 December 2005
-------
Option 2: UV Reactor
The UV reactor is
validated with a 90-
degree bend directly
upstream of the UV
reactor. The UV reactor
is defined to include a
specific amount of
straight pipe upstream
or downstream of the
UV reactor as specified
by the UV
manufacturer
The UV reactor should
be installed with a
minimum of 5 pipe
diameters of straight
piping between the UV
reactor and any
upstream hydraulic
configuration, 3}
1} This approach is not
acceptable if the
upstream filling is an
expansion or if the
upstream valve will be
used for Row control, A
valve that will be
exclusively used for open
close service (e.g.,
isolation) is acceptable.
UV reactor is validated either with a
90-dcgree bend immediately upstream
of the reactor inlet or a with go-degree
bend followed by a length of straight
pipe immediately upstream of the
reactor inlet. The reactor is installed at
the WTP with a length of straight pipe
immediately upstream of the reactor
equal to 5 pipe diameters plus any
length used after the go-degree bend
during validation. To avoid jetting
effects, piping upstream of the straight
pipe length should not have expansions
for at least 10 pipe diameters and any
valves located in that length of pipe
should always be fully open during
operation of the reactor. With this
approach, it is assumed that the go-
degree bend immediately upstream of
the reactor inlet provides worse
hydraulics than the installation. This
approach assumes that the reactor
design has not been optimized for the
go-degree bend inlet.
y]
a) Appendix C, y] clarifies the LoC wording of c] to a large extent albeit with a
conflict, c] states "straight pipe upstream or downstream", while yj Ignores
the downstream configuration (as does d] )
b) The statement in y] : "With this approach, it is assumed that the go-degree
bend immediately upstream of the reactor inlet provides worse hydraulics than
the installation. This approach assumes that the reactor design has not been
optimized for the go-degree bend inlet" is not clearly understood, Since the
installation is required to have 5 diameters of straight pipe upstream of the
reactor even when the validation was made with the bend immediately upstream
of the reactor, the reason for stating an "assumption" of "worse hydraulics" is
unclear.
Why the reactor is assumed not to be optimized for the 90° bend is unclear.
Many manufacturers are validating and optimizing their reactors with a 90° bend
immediately upstream.
c) The contingency length of 5 diameters makes this Option onerous and presents
practical difficulties. Assume a bank of parallel 1200 mm/48" UV reactors
between an inlet manifold and outlet manifold. Assume that two UV reactors
being considered have validation with (in one case) a bend immediately
upstream and in the other case with 5 diameters of straight pipe upstream.
Comment Response for LT2ESWTR
December 2005
-------
The relative installations required under this Option would be:
Case 1: upstream straight piping 6.0 m / 20 ft.
Case 2: upstream straight piping 12.0 m / 40 ft
Does EPA consider that these kinds of installations represent reasonable
expectations/requirements? This especially as many manufacturers are
validating their units with an 90° bend immediately upstream, with the thought
that their equipment would be used in retrofits in tight areas. The additional
5 diameters for "contingency" hydraulics can nullify that approach completely tn
many real life situations. What is the point of a validation with a 90° bend
immediately upstream of the reactor if the actual installation can not be
configured to take advantage of this, but is required automatically to have an
added contingency length of 5 diameters of straight pipe?
Option 3: Velocity at the validation facility
The velocity at the
validation facility is
measured at evenly
spaced points through
a given cross section of
the flow upstream and
downstream of the UV
reactor
Velocity at the installation
is measured at evenly
spaced points through a
given cross section of the
flow upstream and
downstream and is within
20 percent of the
theoretical velocity
determined during
validation
Velocity of the water measured at
evenly-spaced points through a
given cross section of the flow
upstream and downstream of the
reactor is within 20 percent of the
theoretical velocity with both the
validation test stand and the
installation. The theoretical velocity
is defined as the flowrate divided by
the cross-sectional area.
,.'JU
a) What is a "given" cross section? Who 'gave' (determined) this?
b) What means "at evenly spaced points through a given section". A cross
section is a plane. Must velocity be measured at points across the whole plane?
Commonly velocities are measured at points along a diameter to give the velocity
profile and hence the average velocity (say by insert pitometer tube, or insert
wand style, magnetic flow meter). How many points are required? Are say, just
2 "evenly spaced" points OK?
c) In f ] "theoretical velocity" could be challenged—In the absence of a definition—
for logic since surely some actual velocity would have been determined during
validation by field measurements? However, z] does provide a definition which
really confuses the Issue. "The theoretical velocity is defined as the flowrate
divided b}' the cross-sectional area." It is unclear how this differs from the
normal pipe hydraulics of Q=AV, And there of course, the V Is the average velocity
of the flow Q. Neither Q nor A requires measurement of a number of points
through the cross section. For example Q may be determined with a flow meter of
good accuracy well upstream of the UV installation. Is "theoretical velocity" as
defined not really "average actual velocity"? How do we get from the measured
velocity at the x number of measurement points to the flowrate? Average them?
Multiply the average by the cross-sectional area?
Comment Response for LT2ESWTR
December 2005
-------
d) in the absence of any definition "within 20 percent of the theoretical velocity"
is a "given" i.e. will always be achieved, since the average velocity by flow meter
(or even by a profile along a diameter) is virtually certain to be within 20% on a
V=Q/A basis. The intent of this Option Is not readily dlscernable since the target is
stated to be Just within 20% of the velocity in the overall cross section ??
Let me step back and make a wild guess about possible reasons, logic, thinking....
Assume the overall idea is to match the field installation to the validation in some
way so that the Designer can reasonably assume that the proposed installation
will hydraulically perform similarly to the validation set-up. In other words tha
designer can take the validation data for a UV reactor and say with some
confidence;
"...because i match the validation hydraulics in "this" way, I can
reasonably assume that the performance validation data is applicable to
my installation
So one way that I can match the validation hydraulics is to mimic in my
installation the degree of turbulence and erratic flow lines and velocity
variations present in the validation set-up. To achieve this mimicry 1 must
first find out what the "original" was. Yep! The validation did determine
some type of velocity profile by "qwqwqw'' {That is, In this speculative
case. Don't see that the measurement of velocities upstream and
downstream over the cross section is mandatory In a validation) So what if
1 run similar (or identical) flow measurements in the full scale installation?
And if the field profile is within 20% of the velocity at all points in the
validation profile, then 1 should be OK? Yes? Maybe? What if most points
match nearly perfectly but a couple of points are off by 23 %?
Now 1 have no idea if that line of thought is even close to the intent, but I can say
with some certainty that this option 3 should be rewritten to state (without LoC)
exactly what the intent and required procedures are. And this should be written
clearly in just one place, to avoid taxing the reader/user with the duplication and
conflicts between Table 3.4 and Appendix C
e) The 2nd, paragraph of text accompanying table 3.4 notes; "Option 3 also
provides flexibility, but may have the practical limitation of measuring the
velocity through a cross section at the installation"
However, it is If this Option 3 gives much "flexibility" at all and It is not
that 'limitation to of velocities" on site Is the supreme headache
for the Designer, but rather the potential venture Into an of gross
uncertainty.
With this option a reactor has to be selected and on faith that
later of velocity will allow the for that reactor
to be applied the installation.
Comment Response for LT2ESWTR C-25 December 2005
-------
EPA Letter ID: 452
Month
Test Results
1
0.1
0
10
11
0.1
0.1
0
0
0.1
0
0
••••(>-•
0.1
0
0
0.1
0
Mig
0
0
mm
12
13
14
15
16
17
S
S
0
0
S
:'.,':Q;!"'.;
0
-&£:••
S
0
0
Q.i
0
18
19
20
21
22
0.2
Q
0.2
0,2
0.2
0 0 0 0
23
24
25*
26*
27*
S
S
S
I o
0
0.5
0
0.5
0
28*
29*
30*
12-Sample
Mean
0.017
0.025
0.027
0.025
0.027
0.025
0.025
0.025
0.058
0.058
S = Sample collected; X = No sample collected; * Denotes make-up sample.
Figure 1. Example calculation of 12-sample arithmetic mean where plant is in service less than 12
consecutive months. Make-up samples are at the end during a 30-month period in which 24 monthly
samples are collected.
Comment Response for LT2ESWTR
December 2005
-------
EPA Letter ID: 480
Influence of off-line or off-spec reactor on total theoretical percent
inactivation as a function of number of reactors
100.0
9?,0
90.0
_ S5.0
SO.O
.2 75.0
70.0
65.0
60.0
M.O
50.0
z
D o Imc:iv;i<:on with 0115 isac toi1 pro'.i
1 -los m^tivato::.
i^i.-atioii witli 0115 i'e.i:toi- pro'.idiuf 0 .5-lo§ miitvadon. rsnjitiiis piwidins 3 -lo
i'atiou witli oue reactor off-liufi. LediiiiLns pi-o\-ldris 3-loz itiactivatLoii
10 i; :o
Tot.il Number of Reactors
Comment Response for LT2ESWTR
December 2005
-------
EPA Letter ID: 488
Cryptosporidiosis: Cases by Year
Philadelphia, 1995-2002
30
25 H
gj 20 H
tfl
5 15
10 -
5 -
0
24
20
14
14
22
13
1995 1996 1997 1998 1999 2000 2001 2002
Figure 1
Cryptosporidiosis by Month of Lab Test
Philadelphia, 1995-2002
Month
Figure 2
Comment Response for LT2ESWTR
December 2005
-------
Source Water Crypto Trends
Source vYste' Oyptosooridium Conceniration by Monti
(Non-Detects are Zeros)
1000
s
§
100
10
*
0
n
—
*
*
—
n
*
8
*
n
-
*
*-
pi
n
-
n
*
D
—
*
*
R
D
*
'
*
a
ip,
0
4
n
1234
6 7 8 9 10 11 12
MONTH
II Mean-SE
Mean-SE
n Mean
o Outliers
w Extremes
Figure 3
Source Water Crypto by Method 1623
0.200
fe 0.150
*j
jj
o 0.100
Q.
O 0.050
0.000
Month
DJan BFeb DMar DApr •May •Jun BJul DAug BSep lOct DNov DDec
Figure 4
Comment Response for LT2ESWTR
December 2005
-------
EPA Letter ID: 510
Figjrs 1a
e-o
•20
160
200
Dose (mJ/cm )
3.0
2.5 --
0.5 --•
0.0
O - -LVDGM
—* Cormierca Reactor
Figure 1b
5 10 15 20 25
Challenge Microbe D10 (mJ/cmVLog)
Figures 1a and 1b. Figure 1a shows the dose distribution of a commercially available reactor whose dose distribution is
worse than the default distribution in the draft guidance manual. Figure 1b shows that use of the dose distribution in
Figure 1a predicts a RED Bias value that would result in aggressive sizing relative to the proposed default in the draft
guidance manual: hence this sizing would not be safe.
Comment Response for LT2ESWTR
C-30
December 2005
-------
1 .£.
-
1.0 -
o
•M
0>
re O p. Q
"3 £ U.o -
C£ UJ
E | !
tj w
re
0)
oc: o.2 -
n n .
—
__
—
-
—
^
—
—
^™
--
—
— i
-
—
r-i
•
, _ J
1
1
— .
1
--
--
--
--
80 82 85 87 90 92
Transmittance [%)
97
99
D Straight Pipe D Upstream Elbow D Upstream Elbow & Diffuser
Figure 2: Reactor performance relative to a reactor with a 9Q[] Elbow ups:rean. A 90f| -IDow
Upstream is not the worst case: performance can be better or worse under different installation
configurations.
Comment Response for LT2ESWTR
C-31
December 2005
-------
4
TIHM
l<)
i»i in 10 100 l.ooo ifi.oofi HIO.OOO 1,000.000 10.000,000
•hi. inn.. rvij-.iiiu^iHJuj^l^jgijj
»">
Optimizing a Multiple Barrier/Multipl*
Disinfectant Strategy (Microbes & DBFs)
EPA Letter ID: 516
pressure gauge
11 Jt.
pressure regulator
inlet hose
now control valve
-4— . — WATER SOURCE
| ffwmfl Ofjrtorwl aj ,'h«s» pom (I)
orator meter
effluent hose
capsule
filter
Field Filtration Apparatus
Comment Response for LT2ESWTR
C-32
December 2005
-------
EPA Letter ID: 562
Figure 1. Temperature Profiles from Newport News. Va.. and Tampa Bay. Fla.
35
30
0 25
i
g 20
4)
I 15
5
H 10
7
£
A
:,;
£
i
g
s.
S
(3
5
S
S
I
S
Comment Response for LT2ESWTR
C-33
December 2005
-------
Figure 2. Tracer Testing Results fixmi an Over-Under Ozone Contactor in Florida
Comment Response for LT2ESWTR
C-34
December 2005
-------
Figure 3. Factors Affecting Benefit Analysis
Source water occurrence
Finished water occurrence
Exposure
Infectivity
dose-response
Infections
\
Mild
1
Illness
\
|
Moderate
1
1
i
j
Severe
1
"s own baseline estii
I
Mortality
!!
Value of
statistical life
T
Total benefits
Using the relatively more reliable ICRSS data, net benefits
may be 20% of the level implied by the ICR data.
EPA does not account for ability of processes or operators to
respond to source water challenges.
Aboytes and LeChevallier (2003) indicate finished water
Ciypto levels are independent of source water conditions.
Using direct CWS water consumption rather than total ingestion
of all waters, the mean ingestion of risk-bearing water declines
by 50% or more.
Increased averting behavior, especially by sensitive
subpopulations. may appreciably reduce exposures and risks.
Clinical data reflect oocyst doses at least 23.000 times higher
than observed in finished water.
Infectivity r values derived m the EA are 5 times higher than
r values published by Messner et al. (2001).
EPA assumes morbidity is independent of dose.
EPA predicts avoided cases that are 4 to 9 times higher than
Illness seventy and mortality rate
based on Milwaukee outbreak data.
which may overstate seventies
anticipated at endemic dose rates.
Enhanced cost of illness
approach steps beyond the
bounds of established
economics practice.
Based on each step above, total endemic
benefits estimated by EPA may be greatly
overstated.
Comment Response for LT2ESWTR
C-35
December 2005
-------
YL,J
= // ±crZ
0.5
f=>1
0)
where: X = x-value of the T data point
X = mean x-value of all individual data points
Yj = regression-line predicted value of Y for J' data point
Yu.j = Y value of the upper confidence limit at 'j' data point
YLJ = Y value of the lower confidence limit at 'j" data point
n = number of data points
Z = single-sided probability distribution parameter
(Z = 1.2817 for 90% confidence limit)
f = Average fraction of error attributed to variability in the oocysts and the
water matrix effect on inactivation efficiency
o = standard deviation of the entire dataset, calculated using Equation 2.
a =
(n-2]
0.5
(2)
Comment Response for LT2ESWTR
C-36
December 2005
-------
EPA Letter ID: 624
Presedimentation Log Removals
Jan 2002 - Dec 2002
N = 46
I Average BMax
2.41
Pre-Sedrmentation
Turb Log Removal
Pre-Sedimentalion
Endospore Log Removal
Figure 1. Pre-sedimentation log-removals at GCWW's SWTP.
Comment Response for LT2ESWTR
C-37
December 2005
-------
Endospore Log Removals
Feb 2003 - October 2003
N = 41
Minimum • Maximum D Average
Conventional Filtration Secondary Filtration Combined Log Removals
Figure 2. Endospore reduction through GCWW SWTP
Cryptosporidium Inactlvation
4n
M
c i n
o J-°
V
I
u o n
B 2'°
£
D)
J 1 fl
On &
— * — MP UV —A -LP UV * > MP UV A > LP UV
A
•
ts*
,S j*
*^^^^^
.U * i i ; i
012345
Delivered UV Dose (mJ/cm2)
Figure 3. Cryptosporidium Inactivation for GCWW's Carbon-Filtered Water
Comment Response for LT2ESWTR
C-38
December 2005
-------
Riverbank Filtration Scenarios Demonstrating Inequity
with Sampling Existing Wells for Bin Classification
Ciypto concentration >3.0 oocysts/L
Existing Bin 1 based
GWUDISW © upon GW monitoring
Well
Utility
A
fNo detects);
Requires 3.0 fog
treatment
Bin 4 based
upon SW monitoring;
Requires 5.5 log
treatment
Utility
B
Install
RBF Well
1.0 log credit
Comment Response for LT2ESWTR
C-39
December 2005
-------
Appendix D - Attachments and Appendix Materials
Submitted with Comment Letters: Code 9999
Response to Code 9999
These are appendices to rule comments. EPA has responded to the rule comments in the relevant section
of this comment response document.
Individual Comments on Code 9999
EPA Letter ID: 562
Comment ID: 12562
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 4. Specific Comments on Draft Source Water Monitoring Guidance
[SEE PDF]
EPA has prepared a number of individual documents that bear on source water monitoring. Specific items
within these documents should be modified and inconsistencies between the various documents should be
resolved.
General Comments
Guidance on Generation and Submission of Grandfathered Cryptosporidium Data for Bin Classification
Under the Long Term 2 Enhanced Surface Water Treatment Rule contains recommendation missing from
Source Water Monitoring Guidance Manual for Public Water Systems for the Long Term 2 Enhanced
Surface Water Treatment Rule. The April 2003 guidance indicates that when there is chemical addition
that interferes with a desirable monitoring location, one option is to discontinue application of the
chemical feed and sample after the chemical has dissipated. This recommendation is not found in the June
2003 guidance. While haphazardly stopping and re-initiating chemical feeds is not appropriate,
circumstances could occur where this option may facilitate implementation. If this approach is a valid, the
final guidance for source water monitoring should include this approach so that the primacy agency will
have a clear signal that this is an appropriate practice. This clarity is particularly important where the
primacy agency must provide a priori approval of such changes in chemical addition (i.e., changes that
affect CT, achieving enhanced coagulation, etc.).
Specific Comments on WCP/Toolbox Guidance Manual
p.2-6, 2.2.3 Giving credit to existing system SWP/WCP program efforts Requiring more effort ~ in
addition to what is already being done by an existing WCP ~ is punitive and would prevent any
program that could readily make any progress through WCP to reduce Cryptosporidium levels from using
the WCP credit. EPA should reword the guidance to state that upon review, the state may determine that
the focus of existing efforts could be redirected to other areas or that additional efforts may be
necessary, but not required. For example, just because a system has a WCP in place and is observing
source water concentrations over 0.075 oocysts/L doesn-t mean the program isn-t effective and
needs more effort and resources. By agreeing to WCP, EPA recognizes that there are 10-20 year
timeframes prior to observing true impacts on water quality. Planning, funding, constructing, and
monitoring BMPs such as filter strips can take up to five years to accomplish at each site. Consequently,
existing WCPs should be reviewed and credited appropriately for toolbox credit.
Comment Response for LT2ESWTR D-l December 2005
-------
p.2-8, 2.2 Watershed Sanitary Survey frequency should be 10 years Watershed sanitary surveys should be
required every 5-10 years at most. Even a fast changing watershed will not change in one year. The
monitoring intensity needed to demonstrate watershed improvement will divert needed resources away
from all other watershed protection program elements, including special sampling needed to support
watershed program elements. Assimilating, compiling, analyzing, and evaluating information to
determine effectiveness of actions and new efforts will require a 12-month effort to be done properly at
least for larger watersheds.
p.2-9, 2.3.3.2 Sanitary survey-s conducted by approved persons. AWWA recommends that states allow
PWSs to conduct the sanitary survey if they desire in lieu of the primacy agency. AWWA does
not believe the primacy agency has the financial or personnel time or expertise to implement this
requirement effectively. By way of example, the CWA primacy agencies are behind in their efforts to
assess all of the streams for impairment under the Clean Water Act.
2-39, 2.5.2 The PWS should be allowed to have a representative participate in the watershed sanitary
survey if desired or requested.
AWWA recommends that states allow PWSs to conduct the sanitary survey if they desire in lieu of the
state. AWWA does not believe the states have the resources financial or otherwise to implement this
requirement to the extent needed.
2-39, 2.5.3 Removal of the -re-approval- process
The re-approval of the Watershed Control Program every six years is an added requirement by EPA that
is beyond that required of any of the other toolbox items and violates the spirit of the Stage 2 M/DBP
FACA agreement. EPA should eliminate the re-approval process and design the program so that systems
need to gain approval only once. However, if the state or supervising agency identifies that the system
fails to meet the requirements of the WCP plan or program, then the utility would not be eligible for the
0.5-log removal credit until the primacy agency re-approves the program.
The inclusion of a six-year re-approval process in the WCP creates an upward spiral of requirements. This
process is in direct conflict with current EPA approaches to watershed protection that are designed for
steady and incremental progress. As it currently stands, even systems with the best watershed
control programs currently in place would not consider the WCP option due to the uncertainty of re-
approval every six years.
Response: See Response 471.
EPA Letter ID: 562
Comment ID: 12563
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 5. Focused Review of Peer-Reviewed Literature as It Pertains to
Issues Raised by Preamble and Guidance on Bank Filtration
[Document appended to comments as a separate electronic file.]
[SEE PDF]
Response: See response to Comment Code 770, paragraph Bank Filtration Guidance.
Comment Response for LT2ESWTR D-2 December 2005
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EPA Letter ID: 562
Comment ID: 12564
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 6. Comments regarding LT2ESWTR Microbial Toolbox Guidance Manual
- Bank Filtration
4.2.1 Statement is made that each sample must be -examined- to determine grain size. This discussion
should specify sieving by ASTM methodology.
4.4.2.3 This section is too general. Various methodologies for determining the extent of cementation are
given, but the section does not define which are appropriate, nor who should determine what are
acceptable levels of cementation. Does the agency with primacy?
Rotary core drilling will likely give the most disturbed sample of any drilling methodology. Because
samples are carried by a drilling fluid and then separated from the fluid, the sample will be exceptionally
disturbed. How can core intervals be determined? Split-spoon samples collected in glacial settings
with auger drilling may not be able to achieve the 90% core retrieval requirement. A single cobble can
result in no retrieval from a particular core.
The most efficient method for obtaining relatively undisturbed core samples is rotasonic drilling. It is
likely to have the best retrieval percentage also. This should be included. Cable tool drilling in
combination with split-spoon or Shelby tube sampling should also be discussed.
The standards listed for design and construction of wells are acceptable, but a bit dated. Additional
references are the NGWA 2nd Edition of Manual of Water Well Construction Practices, the AWWA
Water Well Standards, Roscoe Moss Handbook of Water Well Development
page 4-28 After figure 4.5, there should be another section heading for the geophysics discussion.
Geophysics may provide additional site exploration and supporting information, but cannot be used
alone to determine the suitability of a site for bank filtration. The current methodology is not sufficiently
refined to provide the level of detail required. There may be certain cases where geophysics alone can rule
out a site (e.g., if it is determined that the site is exclusively bedrock, or cemented with fractures), but it
cannot definitively determine that a site is appropriate for bank filtration. Geophysics are most
effective when used in conjunction with exploratory boreholes, not in place of them.
page 4-30 It is incorrect to state that utilities will find it preferable and simpler to use the previously
mapped limits of the 100-year floodplain to determine the edge of the river. In some river-aquifer
systems, virtually all wells taking advantage of the induced infiltration are located within the 100-year
floodplain. The wells would not be able to induce infiltration and in many cases would be outside the
aquifer, if located outside the 100-year floodplain. By virtue of being located near the river to induce
infiltration increases the likelihood that the well would be located within the 100-year floodplain.
While the FEMA definition of floodway is a nationally recognized definition, its application will
significantly reduce the number of utilities that can implement RBF without obtaining state
approval for siting wells in the floodway or investing in significantly more expensive boreholes in order
to reach productive portions of the aquifer.
The FEMA floodway is determined for the purpose of identifying where structures might impede flow
Comment Response for LT2ESWTR D-3 December 2005
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during flooding and consequently where floodproofing measures are appropriate when building does take
place. While it is a very convenient definition because of its wide availability, it is much less
appropriate in context of bank filtration. Using the FEMA definitions can result in well locations that are
not productive bank filtration locations. The use of the FEMA definition in the BF guidance is another
reason why pilot well and full-scale demonstration of performance is an important complement to the
criteria provided by EPA for BF log credit.
page 4-32 Research by Golnitz, et al., indicates that estimated ground water flow velocities during high
river stage do not increase to levels that would be a threat to the riverbank filtration system. In fact, most
estimated velocities were below or within the range for an engineered slow sand filter, even during high
stage. EPA is not giving bank filtration its due -credit- by making blanket statements that high ground
water velocities can be a significant threat to a riverbank filtration system.
Response: See response to Comment Code 770, paragraph Bank Filtration Guidance.
EPA Letter ID: 562
Comment ID: 12565
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix S.Appendix 7. References for Pre-Sedimentation Discussion
1. Cornwell, D. and M. MacPhee. 2001. Effects of Spent Filter Backwash Recycle on Cryptosporidium
Removal. JAWWA. 93(4): 153-162.
2. Cornwell, D., M. MacPhee, N. McTigue, H. Arora, G. DiGiovanni, and J. Taylor. 2000. Treatment
Options for Giardia, Cryptosporidium, and Other Contaminants in Recycled Backwash Water. Denver,
CO: AWWARF and AWWA.
3. Dugan, N., K. Fox, R Miltner, D. Lytle, D. Williams, C. Parrett, C. Feld, and J. Owens. 1999. Control
of Cryptosporidium Oocysts by Steady-State Conventional Treatment. Proc. Of 1999 Annual Conference.
Denver, CO: AWWA.
4. Dugan, N., K. Fox, J. Owens, and R. Miltner. 2001. Cryptosporidium Control Through Conventional
Treatment. JAWWA, forthcoming.
5. Edzwald, J., and Kelley, M., 1998. Control Of Cryptosporidium: From Reservoirs To Clarifiers to
Filters. Water Science and Technology. 37(2): 1-8.
6. Edzwald, J., J. Tobiason, L. Parento, M. Kelley, G. Kaminski, H. Dunn, and P. Galant. 2000. Giardia
and Cryptosporidium Removals by Clarification and Filtration Under Challenge Conditions. JAWWA.
92(12):70-84.
7. Hall, T., Pressdee, J., and Carrington, N. 1994. Removal of Cryptosporidium Oocysts by Water
Treatment Process. London, England: Foundation for Water Research Limited.
8. Patania, N., J. Jacangelo, L. Cummings, A. Wilczak, K. Riley, and J. Oppenheimer. 1995. Optimization
of Filtration for Cyst Removal. Denver, CO: AWWARF and AWWA.
9. Plummer, J., J. Edzwald, and M. Kelley. 1995. Removing Cryptosporidium by Dissolved-Air Flotation.
Comment Response for LT2ESWTR D-4 December 2005
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JAWWA. 87(9):85-95.
Response: See response to comment code 760.
EPA Letter ID: 562
Comment ID: 12566
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 9.Appendix 8. Review of UV Disinfection Guidance Manual
Evaluation of Validation Protocol, CH2M Hill
[Document appended to comments as a separate electronic file.]
[SEE PDF]
Response:
EPA Letter ID: 562
Comment ID: 12567
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 9. Technical Memoranda from Process Applications on kK* and CT10
a. Memorandum to Steve Via from Kerwin Rakness, October 21, 2003, Rejecting and retesting for >20%
k* variance.
b. Memorandum to Steve Via from Kerwin Rakness, December 8, 2003, Extended-integrated CT10
calculations (w/ supporting electronic spreadsheets)
[Documents appended to comments as a separate electronic file.]
[SEE PDF]
Response:
EPA Letter ID: 562
Comment ID: 12568
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 11. Technical Memoranda from Water Quality and Treatment Solutions
on Synergistic Inactivation Between Ozone and Chloramines
a. Memorandum to Steve Via from Issam Najm, December 4, 2003, Synergistic Inactivation between
Ozone and Chloramine (Synergy Analysis)
b. Memorandum to Steve Via from Issam Najm, December 4, 2003, Synergistic Inactivation between
Ozone and Chloramine (Response to Questions)
c. Chloramine Synergy Database WQTS (Excel File)
[Documents appended to comments as a separate electronic file.]
Comment Response for LT2ESWTR D-5 December 2005
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[SEE PDF]
Response:
EPA Letter ID: 562
Comment ID: 12569
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 12. Review of LT2ESWTR Economic Analysis, Stratus
Consulting
[Document appended to comments as a separate electronic file.]
[SEE PDF]
Response: See responses 220.2, 220.4, 220.5, 220.6, 220.7, 2221.2, 2221.3, 2221.4, 2221.5, and 2221.6.
EPA Letter ID: 562
Comment ID: 16410
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Appendix 1. LT2ESWTR Treatment Requirements Cryptosporidium Monitoring, Bin Assignment, Core
Treatment, And Microbial ToolboxMicrobial Toolbox Report, EET, 2003
[Document appended to comments as a separate electronic file.]
[SEE PDF]
Response: See Responses 361 and 380.
EPA Letter ID: 562
Comment ID: 16890
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 13.Appendix 10. Segregated Flow Analysis Guidance
Response:
EPA Letter ID: 562
Comment ID: 16891
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR D-6 December 2005
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Comment: Appendix IS.Appendix 10. Segregated Flow Analysis Guidance
[Document appended to comments as a separate electronic file.]
Response:
EPA Letter ID: 562
Comment ID: 16892
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 2. Cryptosporidium Removal Credit Assignable in the LT2ESWTR
Toolbox, EET, 2001
[Document appended to comments as two separate electronic files (Appendix 2a
and Appendix 2b).]
[SEE PDF]
Response:
EPA Letter ID: 562
Comment ID: 16893
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 3. Summary of Relevant Articles Pertaining To Cryptosporidium and
Watershed Control Program Effectiveness
[SEE PDF]
AWWARF Studies
1. Source Water Assessment: Variability of Pathogen Concentrations (LeChevallier et. al, 2002)
2. Impacts of Major Point and Non-Point Sources on Raw Water Treatability (Pyke et al, 2003)
3. AWWARF Project 2671 - Development of Event-Based Pathogen Monitoring Strategies for
Watersheds, currently under way.
4. AWWARF #251 - Evaluation of Sources of Pathogens & NOM in Watersheds (Kaplan et al, 2002)
5. AWWARF Field Transport of Cryptosporidium Surrogate in a Grazed Catchment, (Pennell et al.,
2002)
WERF Studies
1. -OO-WSM-3 : Field Calibration and Verification of A Pathogen Transport Model. Montemagno, et. al,
2003, currently under way, contact Dean Carpenter at dcarpenter@werf.org, (703-684-2470, ext. 7152).
2. WERF 99-FIHE-2- Sources and Variability of Cryptosporidium in The Milwaukee River Watershed.
(Corsi, et. al, 2003).
3. WERF 99-FIHE-l - Methods to Detect Cryptosporidium in Wastewater (underway, lead researcher -
Jennifer Clancy)
Comment Response for LT2ESWTR D-7 December 2005
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Pertinent Articles
1. Atwill, E. R., L. Hou, B. Karle, T. Harter, K. Tate, and R. Dahlgren, Transport of Cryptosporidium
parvum Oocysts through Vegetated Buffer Strips and Estimated Filtration Efficiency. Appl.
Environ. Micro 68(11):5517-5527, 2002.
2. Bradford, S. and J. Schijven. Release of Cryptosporidium and Giardia from Dairy Calf Manure: Impact
of Solution Salinity. Environ. Sci. Tech. 36(18):3816-3923, 2002.
3. Dayton, E., N. Basta, C. Jakober, and J. Hattey. Using Treatment Residuals to Reduce Phosphorus in
Agricultural Runoff. JAWWA 95(4): 151-158, 2003.
4. Finstein, M., Watershed Protection: Review of Literature on Inactivation of Cryptosporidium in
Manure. Submitted JAWWA, 2003 (in review). Contact finstein@envsci.rutgers.edu. (304-242-0341).
5. Gracyk, T. and J. Grace. Maryland Department of the Environment Cryptosporidium Occurrence Study
in the Potomac River. Presented, November 5, 2003, AWWA Water Quality Technology Conference,
Philadelphia, Penn. Also presented to EPA Headquarters in August 2003.
6. Suwa, M. and Y. Suzuki, Occurrence of Cryptosporidium in Japan and countermeasures in wastewater
treatment plants. Water Sci. Tech. 43(12):183-186, 2001.
7. Suwa, M. and Y. Suzuki, Control of Cryptosporidium with wastewater treatment to prevent its
proliferation in the Water Cycle. Water Sci. Tech. 47(9):45-49, 20031.
8. Stott, R., E. May, E. Matsushita, and A. Warren, Protozoan predation as a mechanism for the removal
of Cryptosporidium oocysts from wastewaters in constructed wetlands. Water Sci. Tech. 44(11-12):191-
198,2001.
9. USEPA, Overland Migration of Cryptosporidium Oocysts - Final Draft Issue Paper. September 21,
1999. Contact: Mike Borst, borst.mike@epa.gov, (732-321-6631).
10. Rose, J, L. Dickson, S. Farah, and R. Carnahan. Removal of pathogenic and indicator microorganisms
by a full-scale water reclamation facility. Water Research 30(11):2785-2797.
Response:
EPA Letter ID: 563
Comment ID: 16894
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment focusing on "our support for the Stage 2 M/DBP Agreement in
Principle (AIP) developed by Stage 2 Microbial/Disinfection By-Product (M/DBP) Federal Advisory
Committee (FACA)" submitted by Thomas W. Curtis, American Waterworks Association (AWWA)
Company/Group/Association Name: American Water Works Association (AWWA)
Comment:
Appendix 1
Comment Response for LT2ESWTR D-8 December 2005
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LT2ESWTR TREATMENT REQUIREMENTS
CRYPTOSPORIDIUM MONITORING, BIN ASSIGNMENT,
CORE TREATMENT, AND MICROBIAL TOOLBOX
Prepared for:
American Water Works Association
Government Affairs Office
Washington, D.C.
Prepared by:
Environmental Engineering & Technology, Inc.
Newport News, Virginia
CHAPTER 1 5
INTRODUCTION 5
LT2ESWTR Overview 5
Report Outline 9
Bibliography 10
CHAPTER 2 15
SOURCE WATER CRYPTOSPORIDIUM MONITORING 15
24 vs. 48 sampling dates 15
Sampling location 16
Existing Pre-Treatment Structures 16
Proposed (New) Alternate Intake 16
Sampling prior to "treatment" for other existing intakes 17
5-day sampling window 17
Grandfathering 19
Bin placement 19
Bibliography 20
CHAPTER 3 21
CRYPTOSPORIDIUM PROTECTION CREDITS: 21
MICROBIAL TOOLBOX AND CORE TREATMENT OVERVIEW 21
Minimum Credit for Core Treatment (Clarification plus Filtration or Direct
Filtration) 21
Qualifications for Minimum Core Treatment Credits (Expanded definition of
"conventional treatment") 23
Toolbox Alternatives 24
What are the alternatives? 24
Need for Availability of Realistically Defined Toolbox Credits 25
What the Microbial Toolbox should be versus how it is defined in the current
draft rule and guidance manuals 26
Compliance Strategies 29
Recycle Impacts 30
Maintenance of microbial toolbox credits (consequences of non-compliance with
toolbox requirements) 31
Proposal 32
Basis for this proposal 33
Bibliography 34
CHAPTER 4 47
Comment Response for LT2ESWTR D-9 December 2005
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DEMONSTRATION OF PERFORMANCE (OOP) 47
Full-Scale Studies 48
Aerobic spores and other Cryptosporidium surrogates 50
Raw and finished water spore occurrence 53
Calculating the Numerical Value of the DOP Credit Using Spore Data (mean versus
median) 57
Using full-scale spore monitoring to evaluate treatment performance other than
DOP 66
Pilot-Scale Microbial Challenge Studies 66
Other DOP issues 69
Costs 69
Maintenance of DOP credit 70
Process specific demonstration studies 70
Potential DOP penalty 72
Summary 73
Bibliography 75
CHAPTER 5 93
ENHANCED FILTRATION (CFE AND IFE CREDITS) 93
Cryptosporidium Oocyst Removal 94
Additional Benefits 97
Application of the CFE and IFE Credits at Existing Facilities 98
Current definition of the CFE and IFE credit, and some alternatives proposed in
this chapter 98
Evaluation of current CFE and IFE credit definitions, and comparison to
alternatives proposed in this chapter 99
Proposed change in definition of CFE and IFE credits 102
Summary 102
Bibliography 104
CHAPTER 6 114
LIME SOFTENING 114
Cryptosporidium Oocyst Removal and/or Inactivation 115
Occurrence and Removal of Other Indicators 116
Facility Descriptions 116
Comparison of Cryptosporidium and aerobic spore occurrence 118
Aerobic spore removal during lime softening 119
Summary 122
Bibliography 122
CHAPTER 7 134
PRE-SEDIMENTATION 134
Cryptosporidium Oocyst Removal 134
Additional Treatment Barrier 137
Additional Benefits 137
Summary 137
Bibliography 138
Concentration 141
CHAPTER 8 149
TWO-STAGE FILTRATION 149
Credit for Second Rapid Sand or GAC Media Filter 150
Removal of Cryptosporidium surrogates (spores) 151
Additional Benefits 152
Summary 152
Comment Response for LT2ESWTR D-10 December 2005
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Slow Sand Filtration 152
Cryptosporidium Oocyst Removal 152
Summary 155
Bibliography 156
CHAPTER 9 161
INDIRECT CREDITS - INTAKE MANAGEMENT AND RELOCATION 161
Defining "As Measured" Log Credit 161
CHAPTER 10 163
RIVERBANK FILTRATION (RBF) 163
Current requirements for the RBF credit 163
Bank filtration: a natural process 163
Scouring 164
Bed forms and stream-subsurface exchange 165
Filtration and Cryptosporidium 166
LT2ESWTR Compliance Requirements 169
Characterization of the aquifer 170
Filtrate flow path and well location 170
Over-pumping and unsaturated zone 171
Primary and secondary references 173
Bibliography 174
APPENDIX A 178
ALTERNATIVE APPROACHES FOR MISSING CRYPTOSPORIDIUM SAMPLING EVENTS 178
APPENDIX B 182
GLOSSARY 182
Selected terms: 182
Abbreviations: 183
CHAPTER 1
INTRODUCTION
LT2ESWTR Overview
The upcoming update to the Surface Water Treatment Rule (SWTR) is called the Long-Term 2 Enhanced
SWTR (LT2ESWTR) and it will supplement current requirements contained in the Interim Enhanced
SWTR (IESWTR), which pertains to large surface water systems (> 10,000 persons), and the Long-Term
1 Enhanced SWTR (LT1ESWTR), which essentially applies provisions of the IESWTR to small systems
(<10,000 persons). The LT2ESWTR has recently been proposed (USEPA 2003), and a final version of
the Rule is expected in mid 2005. For a short review of the rule requirements, including some illustrative
examples from a case study at an existing surface water plant, please see Cornwell et al. 2003.
These rules are intended to increase microbial protection for drinking water consumers supplied by
surface water sources, especially protection against Cryptosporidium. Cryptosporidium occurrence data
collected since the existing rules were promulgated, including monitoring data associated with the
Information Collection Rule (ICR) and the ICR Supplemental Surveys (ICRSS), suggest that although
Cryptosporidium occurrence nationwide is probably lower than originally estimated prior to the IESWTR,
a portion of the worst source waters may potentially have greater Cryptosporidium levels than predicted
prior to the IESWTR (USEPA 2003). After consultation with nationally recognized experts assembled as
part of the FACA (Federal Advisory Committee Act) process, USEPA recognized that despite evaluation
of a large amount of data, uncertainty remains in a number of areas regarding the precise nature and
magnitude of risk associated with pathogens in drinking water. In light of this uncertainty, USEPA
Comment Response for LT2ESWTR D-ll December 2005
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and the FACA recommended a series of balanced steps to address the areas of greatest health concern,
taking into careful consideration the costs and potential impacts on public water systems.
The balanced approach incorporated into the LT2ESWTR includes two phases, a monitoring phase
followed by a treatment phase. The first phase includes at least two years of monitoring to establish
Cryptosporidium risk in the source water. Depending upon the results of Cryptosporidium monitoring,
source waters will be classified into one of four USEPA defined risk levels called "bins", as illustrated in
Figure 1.1. Facilities in the lowest bin (bin 1) will be required to maintain continued compliance with the
current IESWTR. Facilities in higher bins (bins 2 to 4) will be required to either: a) provide additional
Cryptosporidium protection from new facilities or programs not currently in use at a facility or b)
demonstration of greater Cryptosporidium protection capabilities of existing facilities and programs. The
LT2ESWTR will include a group of USEPA approved treatment technologies, watershed programs, and
demonstration studies, referred to collectively as the "Microbial Toolbox", that utilities can use in various
combinations to meet the treatment requirements of these upper bins. Utilities can use existing facilities
and programs, or they can develop new ones, if they meet the requirements of the Rule.
It is important to recognize that the LT2ESWTR is not a compilation of independent modules developed
in isolation, but rather it includes a complex, integrated framework which takes into account multiple
inter-related factors and incorporates multiple layers of interwoven safety factors. Nevertheless, for the
sake of simplicity it is convenient to compartmentalize the rule in order to make it easier to understand
and describe (i.e., Cryptosporidium analytical methods vs. Cryptosporidium occurrence vs. treatment
performance, etc.). This report focuses only on those components of the rule dealing with
Cryptosporidium protection credits and the associated Cryptosporidium monitoring protocol that
establishes the amount of credits required. Other issues related to the LT2ESWTR (i.e., Cryptosporidium
analytical methods, variable Cryptosporidium occurrence/viability/infectivity, risk and cost estimates,
etc.) will be subject of other comments from AWWA.
Most of the discussion in this report, including Chapter 4 onward, describes the characteristics and
technical justification for individual toolbox credits. Cryptosporidium source water monitoring is
described in Chapter 2, including an evaluation of details regarding the protocol used to establish bin
assignment and consequent treatment requirements, as well as a discussion of logistical implications of
the required data collection process. Chapter 3 is an important link between Cryptosporidium sampling
and the capability of existing and/or new facilities to meet treatment requirements. Chapter 3 contains an
overview of Cryptosporidium protection requirements in the LT2ESWTR, including how these
requirements can be met using a combination of "core treatment" and the microbial toolbox.
The term "core treatment" is used in this report to refer to the minimum 3.0-log credit allowed in the
LT2ESWTR for certain existing treatment systems, as well as 2.5-log minimum automatic credits for
other core treatment technologies. USEPA acknowledges in the rule that many of these existing facilities
can achieve much greater Cryptosporidium protection than the minimum credits allowed for core
treatment. Facilities in bin 1 will not need to demonstrate this additional capability for compliance with
the regulation, even though many of the bin 1 facilities will possess this greater Cryptosporidium
protection capability. However, facilities in bin 2 and higher will need to use microbial toolbox credits.
Many of the toolbox credits are included in order to account for the fact that many existing facilities and
programs will have Cryptosporidium protection capabilities greater than the minimum 3.0 and 2.5
baseline core treatment credits. Consequently, data and discussion regarding capability of existing
treatment processes is not only directly related to validating the minimum credits for core treatment, it
also indirectly forms the basis for some of the other credits in the toolbox (e.g., IFE, CFE, and DOP)
intended to establish the true Cryptosporidium protection credit for these existing systems.
With respect to individual credits in the microbial toolbox, USEPA, the FACA, and other groups involved
Comment Response for LT2ESWTR D-12 December 2005
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in rule development were concerned with maintaining a balanced approach to enhancing treatment given
the uncertainty in the available data on occurrence and associated risk. Consequently, these groups
weighed five factors in recommending treatment actions for potential compliance with the LT2ESWTR:
1. Data on Cryptosporidium oocyst removal.
2. Effectiveness as an additional barrier to Cryptosporidium oocysts reaching finished water.
3. Other benefits such as
a. Reducing peaks in occurrence of pathogens,
b. Making other processes more stable or effective, and
c. Reducing other contaminants (i.e. TOC, DBF formation potential), etc.
4. Encouraging use of a variety of technologies.
5. Encouraging viable alternatives to UV disinfection.
Figure 1.2 and Table 1.1 summarize the resulting list of treatment approaches for the Microbial Toolbox
and their respective credit recommended by the FACA. The magnitude of the credit reflects the strengths
of each toolbox component relative to the five factors listed earlier.
The "Microbial Toolbox" concept developed by the FACA ensures the availability of a suite of individual
tools that could be applied at a particular drinking water treatment plant to reduce the risk of
Cryptosporidium oocysts entering the finished drinking water. The FACA's concerns included the
diversity of water quality challenges and treatment systems in use, as well as ensuring that water
treatment plant (WTP) improvements at individual utilities are as cost effective as possible and
sufficiently flexible to attain multiple drinking water treatment objectives.
Members of the FACA were very concerned that compliance with the LT2ESWTR not be
dependent on a single technology, particularly available disinfection technologies, such as ozone and UV
disinfection. The FACA and USEPA recognized that ozone will be appropriate in some facilities, but
future research on the health effects associated with bromate and improved analytical methods to detect
bromate may support a lower bromate MCL in the Agency's next review of the bromate standard. While
ozone use in drinking water is a mature technology, UV disinfection is not. USEPA believes that UV is
sufficiently developed to allow its use in compliance with the LT2ESWTR, but the lack of generally
accepted UV equipment verification systems, limited UV equipment production capacity, and lack of
experience in field preparation for and installation of UV systems at U.S. drinking water utilities that treat
surface water represent significant impediments to UV disinfection use under LT2ESWTR. In joining the
other FACA members in signing the Agreement, USEPA made significant commitments to reducing
some of the barriers to UV disinfection implementation.
The FACA discussion of the "Toolbox" concept also encompassed the use of multiple tools concurrently
to achieve an overall "credit" goal. The FACA frequently pointed out the value of combining activities to
reduce source water oocyst levels with improvements in treatment at the plant. Likewise there was
discussion on the benefits of adding pre-treatment technologies like pre-sedimentation basins while
improving the performance of existing conventional treatment or adding a disinfectant like ozone or UV.
Recognizing that each item in the toolbox was selected by the FACA because of combined value of the
five factors considered for each item in the Toolbox, USEPA proposes to treat the credit associated with
each toolbox item independently and that they would be additive. The terms "log credit", "log removal",
or "log inactivation" are often referred to in association with the credits for the toolbox components.
While these factors are important and are included in the five factors mentioned earlier, there are other
factors that are to be considered when establishing the numerical value of the credit that have nothing to
do with log removal or log inactivation. Consequently, the term "credit" rather than one of these other
terms is used in this report in order to relay the importance of all of these factors, not just the removal and
inactivation aspects.
Comment Response for LT2ESWTR D-13 December 2005
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Report Outline
Though Cryptosporidium occurrence, health effects, analytical methods, and other issues are important
foundations for the Rule, these issues will not be discussed in this report, but will be included in other
reports and comments prepared by AWWA. Instead, this report focuses on the treatment requirements of
the rule, the appropriateness and technical basis for these requirements, and only deals with details of
Cryptosporidium monitoring as they relate to bin assignment (i.e., logistical and other implications of the
data collection protocol establishing bin assignment).
Also, although some general cost information will be evaluated in order to compare one set of toolbox
and Cryptosporidium sampling alternatives with another, this report will not include an analysis of overall
economic cost/benefit analysis of the entire rule, nor will it include a critique of USEPA's efforts in these
areas. Discussion of these areas will be included in other reports and comment documents prepared by
AWWA and others.
The first details to be discussed include the Cryptosporidium monitoring requirements described in
Chapter 2 because they impact bin assignment and Cryptosporidium protection credit requirements.
Chapter 2 also discusses indirect credits associated with timing, depth of withdrawal, and location of
surface water intakes. Chapter 3 deals with information about the Cryptosporidium protection capability
of existing facilities, and how this impacts the core treatment and microbial toolbox credits. Other issues
related to performance of existing treatment systems, including impacts of recycle practices and
definitions of qualifying facilities for core treatment will be addressed in Chapter 3. Chapter 4 and later
chapters deal with individual toolbox credits, including DOP, enhanced filtration (CFE & IFE), RBF, pre-
sedimentation, and two stage filtration (including slow sand filtration when used as a toolbox credit). A
brief discussion is included for lime softening, even though this is a "core treatment" process as discussed
in Chapter 3. The lime softening chapter does discuss one toolbox credit, two-stage lime clarification in
the two-stage lime softening process. Appendices will be included for further elaboration of specific
details, such as the description of alternate approaches to handling missing Cryptosporidium sampling
events in Appendix A. A glossary is included in Appendix B. Each chapter includes abibliography of all
references cited within a particular chapter, for the convenience of the reader.
Bibliography
Cornwell, D., R. Brown, M. MacPhee, and R. Wichser. 2003. Applying the LT2ESWTR Microbial
Toolbox at a Surface Water Treatment Plant. AWWA e-Journal
http://www.awwa.org/community/doc_view.cfm?id=190 (cited November 12, 2003).
USEPA 2003a. 40 CFR Parts 141 and 142. National Primary Drinking Water Regulations: Long-Term 2
Enhanced Surface Water Treatment Rule, Proposed Rule. Fed Reg. 68:154:47640.
[Seep. 12 of PDF for Table 1.1]
[See p. 14 of PDF for Figure 1.1]
[See p. 15 of PDF for Figure 1.2]
CHAPTER 2
SOURCE WATER CRYPTOSPORIDIUM MONITORING
Since the Cryptosporidium source water monitoring results establish the degree of Cryptosporidium
Comment Response for LT2ESWTR D-14 December 2005
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protection necessary for a surface water treatment system, the requirements and other conditions
associated with scheduling, collecting, analyzing, and interpreting Cryptosporidium monitoring data will
be vitally important to water utilities. The following paragraphs discuss some of the key issues related to
Cryptosporidium monitoring as outlined in the proposed Rule, identification of some of the utility
concerns with certain provisions related to Cryptosporidium sampling, and some proposed solutions to
these concerns.
24 vs. 48 sampling dates
One of the concepts incorporated into the LT2ESWTR is to link treatment requirements in the rule to
results from Cryptosporidium source water monitoring. In developing the LT2ESWTR source water
Cryptosporidium monitoring requirements, USEPA and the FACA stakeholders had to weigh two
competing factors. On the one hand, collecting samples for a long time period spanning several months or
years is desired so that events representing fluctuations in water quality conditions have a greater chance
of being captured during the monitoring period. On the other hand, if the source water is characterized by
a high Cryptosporidium risk (i.e., bin 2, 3, or 4), the presence of this risk needs to be identified as quickly
as possible so that corrective action can be initiated. Therefore, the compromise solution was to require
collection of at least two years of data collected within three years after the Rule is promulgated in order
to limit the length of time prior to initiation of corrective action, while collecting sufficient data in the two
year period to capture events during multiple seasons (eight seasons in a two year study).
Evaluations during preparation of the LT2ESWTR indicated that the overall mean for 48 or more samples
had an error rate of <2% for both false positives (facility assigned to bin level that is too high) and false
negatives (facility assigned to bin level that is too low). The overall mean of 24 samples had a false
negative rate that was too high (6%), but using the MRAA approach produced a more acceptable false
negative error rate (<2%), though the false positive error rate is higher with the MRAA approach (5.3
versus 2.8 %). Therefore, the LT2ESWTR allows overall mean to be used for 48 or more samples, but
requires MRAA when 24-47 samples are used.
LT2ESWTR compliance monitoring for 48 samples is expected to cost about $25,000 (including one
filter per sample), versus $13,000 for 24 samples. Therefore, analyzing two samples a month for 24
months will cost about $12,000 more than analyzing only one sample per month. However, most utilities
would probably consider this cost difference a worthwhile investment given the consequences of being
improperly assigned to a bin level that is too high (false positive). Using LT2ESWTR information on
false positive and negative error rates, for the $12,000 investment of increasing from 24 to 48 total
samples, a utility would marginally improve the false negative error rate (1.7 to 1.4%), but would
markedly improve the false positive error rate (5.3 to 1.7%). Consequently, a utility could potentially
avoid unnecessary expenditures and regulatory harassment by collecting enough samples to make sure
they are assigned to the correct bin.
Sampling location
Existing Pre-Treatment Structures
Cryptosporidium bin assignment samples will be collected from the end of the surface water intake prior
to "treatment", except that facilities with existing riverbank filtration (RBF), off-stream raw water storage,
or pre-sedimentation must mandatoraly collect bin assignment samples from discharge of these processes.
This will be discussed in more detail in later chapters.
Proposed (New) Alternate Intake
Comment Response for LT2ESWTR D-15 December 2005
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A utility with an existing intake must collect samples and report results to USEPA for this intake.
However, if a utility wants to evaluate an alternate intake location, either a different location on the
existing source or an entirely different source water, the utility can implement a sampling protocol
negotiated with and approved by the State for this alternate location. One of the important questions to be
addressed when setting up this sampling protocol is how to collect a sample representative of what will be
coming out of the intake when there is no intake yet.
After completion of sampling at the alternative location using the State approved program, the monitoring
results from this program can be used to establish bin assignment for the new intake location if the utility
decides to install an intake at this new location. Utilities need this assurance, otherwise they will not want
to make the commitment to install the intake if they do not know whether it will result in better source
water quality, and hence a lower bin assignment, until after the intake is built. It is in USEPA's, the
utility's, and everyone's best interest that utilities try, when they can, to find and develop better raw water
sources.
This allowance of using a State approved program to collect Cryptosporidium bin assignment samples
from an alternative intake location is listed as part of the Microbial Toolbox, but it does not result in a
direct "credit", although it can result in an indirect credit if the alternate location results in a lower bin
assignment than the existing intake location (i.e., assignment to bin 1 instead of bin 2 is the same as
getting a 1.0 credit).
Sampling prior to "treatment" for other existing intakes
Except for facilities with existing RBF, off-stream raw water storage, or pre-sedimentation,
Cryptosporidium bin assignment samples will be collected from the end of the surface water intake prior
to "treatment". Another way to state this is that the Cryptosporidium bin assignment sampling location
should be located prior to core treatment (see Chapter 3) and any toolbox credits allowed in the Rule.
Consequently, the Rule does not allow credit for existing RBF or pre-sedimentation, so Cryptosporidium
bin assignment samples can be collected after these pre-treatment processes. Similarly, since potassium
permanganate used as a pre-oxidant or copper sulfate used in pre-treatment for algae control do not have
an impact on Cryptosporidium (if they did have an impact, they would have been included in the
toolbox), Cryptosporidium bin assignment samples can be collected subsequent to the application point
for these chemicals. Although this is implicit from the current draft regulation, it would be helpful if the
final rule was explicit on this issue. This doesn't make sense there wouldn't be treatment for other intakes?
5-day sampling window
Utilities that are not "grandfathering" existing data must collect two years of Cryptosporidium samples
during the three years after publication of the final version of the Rule. The three year time allowance to
complete this sampling includes 6 months prior to start of project to develop and submit a sampling
schedule to the State, 24 months to perform sampling, and 6 months to submit data to State and obtain
certification from State for bin classification.
After utilities submit their sampling schedule to the state and begin sampling, they must collect samples
within a five-day window (±2 days) around the scheduled collection date. Facilities that do not collect
samples within this 5-day window will incur a Tier 3 Public Notification Rule monitoring violation,
unless they can document the reason for not being able to sample within this time interval. Therefore,
utilities can re-schedule samples due to weather (unsafe conditions at sample collection location),
personnel availability (illness, jury duty, etc.), and other reasons if they document the reasons for
not collecting the samples within the required 5-day window.
Comment Response for LT2ESWTR D-16 December 2005
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However, it seems inevitable that many facilities at least once, maybe a few additional times, will not be
able to collect a sample on a scheduled date and will not be able to re-schedule sample collection prior to
next regularly scheduled sample collection date. Therefore, since there is a possibility of this incident
happening at a number of facilities subject to the Rule, there needs to be some alternatives available to
deal with this situation.
Appendix A lists some alternative approaches that USEPA or States may propose, and some arguments
against using these approaches, as well as some other alternatives that might be more suitable. This
Appendix focuses on new data, i.e. NOT GRANDFATHERED DATA. Grandfathered data will be
discussed later - but many of the alternative approaches may be similar.
In general, the approach USEPA wants to use (automatic assignment to bin 4, plus Tier 3 violation),
seems much too severe a penalty for missing one or two samples, but may not be inappropriate in the
event a facility misses a large number of samples (but how many is "too many"? Five? Three?). Some of
the options listed in Appendix A seem more appropriate, especially option 3 (ignore missing samples) or
option 4 (collect replacement samples during later time periods). Utilities that collect 48 or more samples
should be given more flexibility to miss some sample dates, as opposed to systems with exactly 24
originally scheduled sampling dates. Furthermore, the consequences of a missing sample are different for
a facility well within bin 1 as opposed to one close to the bin 1 & 2 threshold (0.075 oocysts/L) or the bin
2 & 3 threshold (1 oocysts/L). Therefore, there may need to be different allowances and different
approaches based upon the number of samples collected relative to the number of samples missing, plus
an assessment of the bin assignment that results without the missing data.
Grandfathering
Samples collected prior to publication of the final version of the LT2ESWTR can be "grandfathered" if
they meet the same requirements outlined for new samples in the LT2ESWTR. Facilities can also use
existing grandfathered data combined with new data collected after Rule is published. Requirements for
both new and grandfathered data are outlined in the LT2ESWTR Draft Rule and in the Cryptosporidium
sampling Guidance Manual (USEPA 2003b).
Some of the requirements for new samples when applied to existing data may be too restrictive,
particularly when utilities were not clairvoyant enough to predict all of these requirements when
scheduling, collecting, and analyzing these historical samples. Bin assignment for the source water should
be based on water quality and Cryptosporidium concentration concerns, and not on the ability (or
inability) of utilities to predict USEPA requirements for sample collection. Grandfathered data that
accurately reflects Cryptosporidium source water concentrations should be suitable for establishment of
bin assignment even if: a) samples do not always have 10 L sample volumes, b) required number of
"subsamples" were not performed during all analyses, c) samples were not collected exactly within the (2
day sample windows required for "evenly spaced" samples, and d) some QA/QC samples are missing.
In addition, more allowance should be made for facilities to miss some of these requirements if their
grandfathered data includes either more than 24 months of data or more than 48 samples, especially if
they are also well below the threshold (0.075 oocysts/L) between bins 1 and 2.
Bin placement
Bayesian modeling of ICR data as presented in Figure III-l of the Draft Rule indicates that use of ICR
data for bin assignment would have resulted in about 56% of plants in bin 1, 88% in bins 1 and 2, and 6%
above bin 4 threshold. This would translate into 56% bin 1, next 32% in bin 2, and 6% each in bins 3 and
4. However, this evaluation is for all ICR data including groundwater and surface water, the latter
Comment Response for LT2ESWTR D-l 7 December 2005
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including flowing streams (FS), groundwater under direct influence of surface water (GWUDI), and
reservoirs and Lakes (RL). A greater percentage of facilities located on flowing streams could end up in
higher bins, based on ICR data (about 13% of "FS" results in the ICR database had detectable levels of
Cryptosporidium above 3 oocysts/L, the threshold for bin 4). By contrast, GWUDI systems are less likely
to end up higher than bin 1.
Bin assignment in the LT2ESWTR will require Method 1622/1623 (USEPA 2001a&b) not the ICR
Method (USEPA 1996) and the Method 1622/1623 is expected to provide lower Cryptosporidium
concentrations than the ICR method. Consequently, it may turn out that 90% or more of the surface water
sources of all types may end up in bin 1, 10% or less in bin 2, and perhaps none in bins 3 or 4. For
example, data reported by Cornwell et al. (2003_) for the City of Richmond (VA) shows ICR data close
to the bin 1 & 2 threshold (0.075 oocysts/L), but Method 1623 results (<0.030 oocysts/L) were well
below this threshold.
Bibliography
Cornwell, D., R. Brown, M. MacPhee, and R. Wichser. 2003. Applying the LT2ESWTR Microbial
Toolbox at a Surface Water Treatment Plant. AWWA e-Journal
http://www.awwa.org/community/doc_view.cfm?id=190 (cited November 12, 2003).
USEPA. 1996. ICR Microbial Laboratory Manual. Washington, DC: USEPA.
USEPA 2001a. Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA. EPA/821/R-
01/025. Washington, D.C.
USEPA. 2001b. Method 1622: Cryptosporidium in water by Filtration/IMS/FA. EPA/821/R-01-026.
USEPA 2003a. 40 CFR Parts 141 and 142. National Primary Drinking Water Regulations: Long-Term 2
Enhanced Surface Water Treatment Rule, Proposed Rule. Fed Reg. 68:154:47640.
USEPA. 2003b. Public Water System Guidance Manual for Source Water Monitoring under the Long-
Term 2 Enhanced Surface Water Treatment Rule. Washington, D.C.
CHAPTER 3
CRYPTOSPORIDIUM PROTECTION CREDITS:
MICROBIAL TOOLBOX AND CORE TREATMENT OVERVIEW
Minimum Credit for Core Treatment (Clarification plus Filtration or Direct Filtration)
Cryptosporidium occurrence data collected since the LT1ESWTR and IESWTR were promulgated,
including monitoring data associated with the Information Collection Rule (ICR) and the ICR
Supplemental Surveys (ICRSS), suggest that although Cryptosporidium occurrence nationwide is
probably lower than originally estimated prior to the IESWTR, a portion of the worst source waters may
potentially have greater Cryptosporidium levels than predicted prior to the IESWTR (USEPA 2003).
After consultation with nationally recognized experts assembled as part of the FACA (Federal Advisory
Committee Act) process, USEPA recognized that despite evaluation of a large amount of data, uncertainty
remains in a number of areas regarding the precise nature and magnitude of risk associated with
pathogens in drinking water. In light of this uncertainty, USEPA and the FACA recommended a series of
balanced steps to address the areas of greatest health concern, taking into careful consideration the costs
Comment Response for LT2ESWTR D-18 December 2005
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and potential impacts on public water systems.
The balanced approach incorporated into the LT2ESWTR includes two phases, a monitoring phase
followed by a treatment phase. The first phase includes at least two years of monitoring to establish
Cryptosporidium risk in the source water. Depending upon the results of Cryptosporidium monitoring,
source waters will be classified into one of four USEPA defined risk levels called "bins", as illustrated in
Figure 3.1. Facilities in the lowest bin (bin 1) will be required to maintain continued compliance with the
current IESWTR. Facilities in higher bins (bins 2 to 4) will be required to either: a) provide additional
Cryptosporidium protection from new facilities or programs not currently in use at a facility or b)
demonstration of greater Cryptosporidium protection capabilities of existing facilities and programs. The
LT2ESWTR will include a group of USEPA approved treatment technologies, watershed programs, and
demonstration studies, referred to collectively as the "Microbial Toolbox", that utilities can use in various
combinations to meet the treatment requirements of these upper bins. Utilities can use existing facilities
and programs, or they can develop new ones, if they meet the requirements of the Rule.
Available data during development of the IESWTR and LT1ESWTR indicated that combined
clarification plus filtration treatment or filtration alone (i.e., direct filtration) achieved at least 2-log
Cryptosporidium removal. Studies published in the literature since then, coupled with a re-evaluation of
previous literature data, indicate that a conventional clarification plus filtration system operated under
conditions representative of compliance with the IESWTR or LT1ESWTR (turbidity (0.3 ntu) produces a
mean and median Cryptosporidium removal of 4 to 6 log, as illustrated in Table 3.1 and Figure 3.2. In
fact, the actual removal capabilities of these systems may be even greater than indicated in this table
because the filtered water Cryptosporidium concentrations were typically below detection limits in these
studies (see last column of table). Similarly, direct filtration studies typically demonstrated a mean and
median Cryptosporidium removal of more than 2.5 log.
Based on this data, USEPA will allow a minimum 2.5 log credit for direct filtration and 3.0 log credit for
combined clarification plus filtration treatment at existing facilities that continue to comply with the
IESWTR (or LT1ESWTR). Although many, if not most, individual facilities may be capable of higher
Cryptosporidium removal, they will not need to demonstrate higher levels of removal if the facility is
assigned to bin 1 (the lowest Cryptosporidium risk level). For higher bins, additional treatment will be
required. The higher level of treatment can be achieved by either adding something new to an existing
system, or by demonstrating that an existing system has greater capability than the minimum automatic
3.0 (or 2.5) credit.
The Microbial Toolbox was intended to provide a wide selection of alternatives in each of these areas, not
only new technologies and programs to attach to existing facilities that need additional credit, but also
many options that were expected to be used to demonstrate or establish higher Cryptosporidium
protection capabilities already present in existing systems. These latter credits were included with the
recognition, as illustrated in previously cited literature data, that compliance with the IESWTR for some
specific individual treatment systems may translate into 4.0-log, 5.0-log, or higher Cryptosporidium
protection potential, not just the 2.5 or 3.0-log minimum credit allowed for a generic system. Therefore, a
key objective of the Microbial Toolbox is to provide enough realistically defined Cryptosporidium
protection credits that a facility for which IESWTR compliance results in more than 2.5 or 3.0 log of
protection can receive enough credits from the microbial toolbox to reflect the higher treatment capability
of the system.
Qualifications for Minimum Core Treatment Credits (Expanded definition of "conventional treatment")
The Surface Water Treatment Rule (SWTR) and Interim Enhanced Surface Water Treatment Rule
(IESWTR) were premised on conventional treatment where conventional treatment was not distinctly
Comment Response for LT2ESWTR D-19 December 2005
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defined, thereby resulting in a much narrow definition of allowable technologies in some states than is
appropriate. Implementation of the M/DBP FACA recommendations for Cryptosporidium removal,
particularly within the Microbial Toolbox concept, will require more clarity in definitions associated with
LT2ESWTR. In addition, separate definitions are now required for direct filtration versus clarification
plus filtration, as discussed below.
LT2ESWTR as proposed will provide a broader definition of conventional treatment in order to explicitly
include a variety of clarification technologies other than conventional gravity sedimentation prior to rapid
sand filters. USEPA still uses the term "conventional treatment", though it is probably more appropriate
to replace this term with the more general term "clarification plus filtration treatment".
The term "clarification and filtration treatment" applies to a treatment train employing separate, equential,
unit processes for coagulation/flocculation, clarification, and granular media filtration. Essentially, this is
the same definition as the "direct filtration" definition, with the additional requirement of a clarification
step located between coagulant addition and granular media filtration. The clarification step can include
any solid/liquid separation process where accumulated solids are removed during this separate
component of the treatment system. This additional separation step serves as an additional barrier to
pathogen passage, as well as dampening raw water turbidity spikes prior to filtration. This would include
systems with mono- or dual-media filters preceded by any of the following clarification technologies:
gravity sedimentation basins, tube settlers, plate settlers, sand-ballasted coagulation, dissolved air
flotation (DAF), upflow solids contact reactor-clarifiers, or buoyant or non-buoyant media upflow
clarifiers. Since single-stage lime softening includes a clarification stage followed by a filtration stage,
these facilities would also be allowed the same 3.0-log credit as other "clarification plus filtration"
technologies (two-stage lime softening will be allowed a 3.5-log credit). The findings for credits
associated with lime softening are supported by spore removal data reported by lime softening plants in
Kansas City (MO), St. Louis (MO), and Columbus (OH), as presented in Cornwell et al. (2003a), and
updated for two of these plants in Cornwell and Brown (2003).
Direct filtration is treatment using coagulation/flocculation followed only by granular media filtration (no
separate solid/liquid separation barrier (clarification) prior to filtration). Available research (Patania et al.
1995, Nieminski 1995, Nieminski and Ongerth 1995, and West et al. 1994) indicates that direct filtration
consistently achieves removals of 2.5 log.
Research studies show that slow sand filters can achieve the same removal as a "clarification plus
filtration" system (Schuler et al. 1991, Hall et al. 1994, Timms et al. 1995) and consequently will be
allowed the same 3.0-log Cryptosporidium removal credit in the LT2ESWTR, which means they would
meet requirements for bin 1 as stand-alone systems but would need components from the Microbial
Toolbox following or preceding the slow sand filter if the facility is assigned to higher bins. Membranes
can also be used as stand-alone systems, with log credit allowed as determined during approved
manufacturer validation testing (confirmed by integrity testing outlined in the LT2ESWTR). Slow sand
filters and membranes can also be used as one of the Microbial Toolbox alternatives if they
are added to a system that already includes a "clarification plus filtration" or direct filtration system as
defined by the LT2ESWTR.
Toolbox Alternatives
What are the alternatives?
The Microbial Toolbox includes treatment facilities, watershed programs, and demonstration studies that
can be employed to either: a) provide additional Cryptosporidium protection beyond what existing
facilities and programs currently provide or b) demonstrate that existing facilities already provide
Comment Response for LT2ESWTR D-20 December 2005
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additional protection beyond the automatic minimum 3.0 (or 2.5 ) credit. Consequently, although any of
the toolbox alternatives can be added by systems that do not already include these toolbox programs or
facilities, many of the alternatives were included in the toolbox so that facilities that already employ
these facilities or programs can receive the Cryptosporidium protection credit that they already deserve.
The Microbial Toolbox alternatives are listed below in the following four groups:
* Group "A" - Increased Credit Beyond Minimum 3.0 (2.5) Credit for Existing Systems
* Enhanced filtration - CFE (combined filter effluent) turbidity
* Enhanced filtration - IFE (individual filter effluent) turbidity
* Demonstration of performance (DOP)
* Two-stage filtration or clarification (including slow sand filtration)
* Group "B" - Add-on Credits - upper bin Technologies (UBT)
* Membranes (including bag and cartridge filters)
* Inactivation [ultraviolet (UV) irradiation, ozone, and chlorine dioxide]
* New riverbank filtration systems
* Group "C" - Add-on Credits - not UBT
* Watershed control program (WCP)
* New pre-sedimentation basins
* Group "D" - Indirect Credits (source water sampling location)
* Existing pre-treatment structures (off-stream raw water storage, pre-sedimentation, or any existing
GWUDI/RBF well)
* Alternate source or intake location
An important consideration for the Microbial Toolbox is that while any combination of credits can be
used for bin 2, 3, or 4, the latter two bins must include at least 1.0 credits from one or more specific upper
bin technologies (UBT) designated by USEPA, most of which are in Group "B" above (except slow
sand filtration).
Need for Availability of Realistically Defined Toolbox Credits
Before, during, and after the FACA negotiations, USEPA has favored the Group "B" alternatives,
especially inactivation and membranes. This is reflected in the current Draft Rule and associated
Guidance Manuals, particularly in the definitions and requirements assigned to other toolbox alternatives
that essentially either:
a. directly eliminate previously discussed toolbox alternatives (roughing filters and off-stream storage),
Comment Response for LT2ESWTR D-21 December 2005
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b. define requirements for credits that are unachievable at most facilities that will need the credits (IFE
and new pre-sedimentation basins),
c. include provisions aimed at making a toolbox alternative unattractive to utilities that might otherwise
choose them [DOP (potential penalty if demonstration is under 3.0 credits) or WCP (no guarantee WCP
will be available after three years due to need to re-apply or start over], or
d. provide misleading information to discourage utilities from using or at least investigating toolbox
alternatives (DOP "too expensive" and use of full-scale aerobic spore monitoring will not be possible due
to low raw water spore concentrations, characterizing hydrogeologic investigations of new RBF as a
search for "negatives" as opposed to a search for "positives").
By contrast, the position of water utilities before, during, and after the FACA negotiations has been to
have some realistic definitions of alternatives like those in Group "B1 that facilities can use if they need
them or choose to use them, but to include enough other realistically defined alternatives that utilities
could use rather than reliance on only Group "B" technologies. Especially for bin 2, utilities need toolbox
alternatives that are potentially less expensive than the Group "B alternatives (especially since costs for
qualifying existing facilities would be essentially $0), as well as allowing demonstration that many
existing facilities in compliance with IESWTR can already achieve higher than the 3.0 (2.5) minimum
credit.
What the Microbial Toolbox should be versus how it is defined in the current draft rule and guidance
manuals
The current Draft Rule and Guidance Manuals do not include realistic requirements for some of the
credits, or they do not include enough assurances to utilities that a credit will always be available to the
utility (e.g., see WCP discussion). If a credit can not be reliably depended upon, a utility will have to
choose other credits they will have more confidence in being available. A credit that a utility can not
depend upon is not really a credit. Therefore, USEPA can claim that the Microbial Toolbox as currently
defined includes a number of credits utilities can use, but several of them are credits in name only and can
not be reliably used by utilities as currently defined.
If the Draft Rule and Guidance Manual remain unchanged in the Final version, facilities will essentially
only have the Group "B" alternatives, particularly membranes and inactivation. The CFE credit will also
probably be available, but since it is only worth 0.5 credits, credits from Group "B" will still be needed
if no other 0.5 credit options are realistically available. In addition, the Stage 2 DBPR considerations will
take away a significant number of applications where ozone or chlorine dioxide may have been suitable
for microbial protection, leaving membranes and UV inactivation as the only alternatives for
simultaneous compliance with both rules. Given the much higher cost of membranes, except
potentially bag and cartridge filters for small systems, this will leave only UV. Although UV inactivation
has enormous potential for benefit to the water treatment industry, reliance on a single technology seems
a little short-sighted and potentially prone to error if any future difficulties develop with the respect to UV
disinfection systems. Furthermore, while UV facilities will not be as expensive as ozone, membranes, or
some other toolbox alternatives, the costs to construct and operate them can be significant, especially for
bin 2 if realistically defined credits for WCP, DOP, IFE, and CFE could be available instead.
In order for the Microbial Toolbox concept to provide a variety of alternatives, as originally intended, and
to allow establishment of credit that existing facilities already deserve, several of the requirements for
some of the credits needs to be refined, and some additional information provided to more objectively
present the benefits of some of the toolbox alternatives to utilities that might potentially use them. In
particular, while some facilities with two-stage filtration or clarification may get some benefit from these
Comment Response for LT2ESWTR D-22 December 2005
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specific credits, and some systems with existing RBF or pre-sedimentation may get an indirect benefit
because they will be collecting Cryptosporidium bin assignment samples from the end of these processes,
the four toolbox alternatives that will probably have the most widespread use are CFE, IFE, DOP, and
WCP. If these are properly defined, many utilities will be able to use existing facilities to meet
requirements for bin 2, or they can add 0.5 credit with WCP if they need the additional credit or if they
want an additional 0.5 credit safety factor. Even though utilities in bin 3 or 4 can use Group "B"
alternatives to meet all of their treatment requirements, utilities should be encouraged to use CFE, IFE,
DOP, or WCP as inexpensive alternatives to provide the additional 1.0 to 2.0 credits needed to meet most
of the bin 3 or 4 treatment requirements, while officially relying on Group "B" technologies only for the
required 1.0 UBT credit, with the additional capability (i.e., UV should easily be able to provide 3.0
credits under most circumstances) used as a safety factor.
WCP, IFE, CFE, and DOP credits should be encouraged because they have far reaching positive benefits
for Cryptosporidium protection from source water through all phases of treatment. A realistically defined
IFE credit, for example, will not mean the credit will be easy to achieve. It will require careful
management and operational practices from source water through all stages of treatment. Encouraging
improved performance, and rewarding facilities that already achieve a suitably high level of performance,
serves everyone's best interest, including the drinking water consumer. Many forward thinking utilities
will strive to achieve this level of performance without needing the additional motivation of the IFE
credit. Still, it would be belter to include a more realistic definition of the IFE credit (see later discussion
in Chapter 5) in order to encourage more utilities to try to improve performance to meet the credit. The
IFE credit as currently defined is so unattainable that it provides no incentive to even try for the credit,
and consequently no benefit to utilities who otherwise might have tried to improve filtration performance
in order to achieve the credit.
The WCP credit is another toolbox alternative that can have far-reaching and long-lasting benefits for
facilities that perform WCP related activities. However, there is little motivation for utilities to even try
for the WCP credit as currently defined, and consequently facilities that might have tried for a more
realistically defined credit will not gain the benefits which WCP related activities can provide (see more
in Chapter 6).
Therefore, it is apparent that USEPA has seriously miscalculated during their development of
requirements for much of the toolbox, particularly WCP, DOP, and IFE, because they do not properly
credit Cryptosporidium protection potential of existing utilities and also because they have missed an
opportunity to encourage practices and programs that have potential long-term consequences for
Cryptosporidium protection. Instead, they are encouraging utilities to rely on high cost, technology
intensive (as opposed to operational practices intensive) treatment processes that are grafted onto the end
of existing treatment processes (with no processes after these add-on process in case they fail).
The last sentence in the above paragraph applies to all Group "B" alternatives, except RBF, although it
would be easy to argue that USEPA has not really encouraged RBF as much as the others in Group "B".
RBF has multi-faceted, multi-barrier, long-range benefits. In addition, because it located at the beginning
of the treatment process, a facility not only gets the benefit of a component that by itself is an effective
Cryptosporidium barrier, but also gets a component that prepares the water for better treatment during
subsequent processes.
Compliance Strategies
Utilities in bin 2 or higher should always first look to evaluate the ability of the existing facility to
demonstrate higher than the 3.0 (or 2.5) minimum credit. In particular, full-scale DOP studies using
aerobic spores or pilot-scale challenge studies using spores, Cryptosporidium, or other State approved
Comment Response for LT2ESWTR D-23 December 2005
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microbial surrogate are potentially cost effective credits. Improvements in infrastructure and operational
or management practices should be identified and implemented. However, if utilities still need additional
credits, WCP, UV, or other credits should be evaluated to see which alternatives in combination with
existing facilities prove the most cost effective Cryptosporidium protection combination.
Utilities will be required to have required level of treatment in place within 6 years after final version of
LT2ESWTR is published, 3 years after the deadline for certification of bin assignment by the State.
Utilities are encouraged to begin preparing contingency plans and evaluating alternatives for all four bins
as early as possible, and not to wait until the last moment. In particular, utilities are encouraged not to
assume they are going to be in bin 1 until after they have received official certification by the State.
Utilities are also encouraged to develop and establish all credits the existing facilities can achieve, even if
this is more credit that needed for their required bin assignment.
Recycle Impacts
Allowable recycle practices at treatment plants are regulated by the Filter Backwash Recycle Rule
(FBRR). The intent of the FBRR is to encourage implementation of recycle practices that do not
negatively impact performance of a treatment plant. In other words, facilities operated using practices
consistent with the FBRR should achieve equivalent, or superior, performance to the same facility
operated without recycle. Consequently, other regulations do not need to incorporate provisions for
recycle because all consequences of recycle practices are accounted for in systems complying with the
FBRR.
Cornwell and MacPhee 2001, Cornwell et al. 2001, and Nieminski and Bellamy 2000 provide data
supporting the contention that recycle practices consistent with FBRR do not negatively impact
performance of clarification systems, or the combined performance of a clarification plus filtration
system. Data for spore, Cryptosporidium, and other microbial indicators were collected during a study
reported by Nieminski and Bellamy (2000). This study included samples from 24 full-scale plants,
including 19 facilities with combined clarification and filtration, 4 facilities with only direct filtration, and
1 facility with disinfection only. Some facilities involved in the study did not have the capability of
recycling spent filter backwash water (SFBW), and other facilities with SFBW collected samples during
periods both with and without recycle. Data for Cryptosporidium, Bacillus subtilis, and total aerobic
spores (which includes Bacillus subtilis) are summarized in Figures 3.3, 3.4, and 3.5. These results
show that mean and median log removal for spores and Cryptosporidium was nearly the same, or slightly
higher, at facilities where SFBW was recycled versus facilities that did not recycle. For example, in
Figure 3.5 the median removal of total aerobic spores for all systems was about 2.9 when SFBW was
recycled versus about 2.6 when SFBW was not recycled. Compartmentalizing the results further into
groups of direct filtration facilities versus facilities with both clarification and filtration, median removal
of total aerobic spores was slightly higher when recycle was used versus when recycle was not used at
direct filtration facilities (2.4 versus 2.3) and systems with both clarification and filtration (3.1 versus
2.7).
Cornwell et al. 2001 and Cornwell and MacPhee 2001 reported results from pilot studies involving
impact of SFBW recycle on a system with clarification (plate settler) followed by a dual media filter.
Cryptosporidium oocysts were spiked into rapid mix and then oocysts were sampled after clarification
and after filtration under four sets of recycle conditions: a) no recycle, b) continuous recycle (4.3 percent
of plant flow), and c) two sets of intermittent recycle conditions (10 percent and 20 percent of plant flow).
Results in Figures 3.6 and 3.7 summarize Cryptosporidium removal data for sedimentation only and for
the combined clarification and filtration process (raw to filter). Figure 3.8 summarizes the impact of
recycle by characterizing removal of the combined oocyst concentration entering the clarifier (i.e., oocyst
spike + oocysts in recycle flow) versus oocyst concentration in the filter effluent (raw + recycle to filter).
Comment Response for LT2ESWTR D-24 December 2005
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In all instances, Cryptosporidium removal was as high or higher during periods of intermittent or
continuous recycle as when no SFBW recycle was used.
Therefore, results from full-scale plants reported by Nieminski and Bellamy (2000) and from pilot-scale
Cryptosporidium challenge studies reported by Cornwell and co-workers, Cornwell et al. 2001, and
Cornwell and MacPhee 2001 demonstrate that recycle can be implemented without deteriorating the
Cryptosporidium removal performance of subsequent clarification and filtration processes. Recycle issues
should not be part of LT2ESWTR.
Maintenance of microbial toolbox credits (consequences of non-compliance with toolbox requirements)
The LT2ESWTR and associated guidance manuals have not directly or completely addressed important
issues with respect to requirements for maintaining a microbial toolbox credit, once awarded, and
consequences of not being able to meet one of the requirements for a specific credit for a short time
period (i.e., one month). The regulatory consequences of violation of the requirements for a microbial
toolbox credit probably will entail a Tier 2 (30-day) notice. The question, however, becomes how to
identify or define when a violation occurs, and once it occurs, how long should consequences apply. The
following discussion describes one proposal for how to handle this question, dealing with facilities in bin
2 differently than facilities in bins 3 or 4. This proposal also deals more leniently with non-UBT toolbox
credits, and also with UBT that are used for smaller numerical credits (i.e., UV used for 2.0 credits is held
to higher standard than UV only used for 1.0 credit). An evaluation of these factors is discussed in the
paragraphs after this proposal. Table 3.2 lists some hypothetical situations and how the proposal would be
applied in these situations.
Proposal
Facilities in bin 2 shall not be considered in violation of the LT2ESWTR treatment requirements as long
as each individual toolbox credit is able to meet the requirements of the credit for 11 of 12 months. This
means a facility that does not meet a particular requirement for an individual credit during one month
will not be in violation as long as it meets every single requirement for this particular credit during the
next 11 months. This does mean, however, that another credit can be out of compliance during these 11
months (see example 1 in Table 3.2). This applies to any toolbox credit used for bin 2 compliance, no
matter what the numerical value of the credit (0.5, 1.0, or higher) or whether the credit is UBT or not.
Credit used for bin 3 or 4 will be treated differently depending upon: a) whether credit is a UBT or not
and b) the numerical value of the credit needed for a specific UBT credit. Any non-UBT toolbox credit
and all individual credits 1.0 or lower will be treated the same way as credits described above for bin 2
(i.e., a utility can fail requirements during one month if all requirements for this credit are met during the
next 11 months). UBT credits greater than 1.0 must meet all requirements every single month or else the
facility is in violation for that month.
There are certain aspects of some credits for which the above discussion is not applicable due to the
nature of the credit or the method by which the initial credit is established. For example, once the WCP is
approved, the credit should be allowed indefinitely as long as utility complies with program approved by
state when credit was first awarded, including preparation of required reports and completion of required
sanitary surveys. Therefore, there is no mechanism for evaluation of the WCP, except for the benchmarks
established for completion of the progress reports, sanitary survey, and other state designated benchmarks
which are not expected to occur at monthly or quarterly frequencies. If a facility fails to satisfy the state
requirements for the WCP, the facility should not be considered out of compliance with the LT2ESWTR
at that instant, but should instead be able to negotiate with the state and make arrangements to
re-establish the WCP credit or replace it with another credit. A different situation exists with credits like
Comment Response for LT2ESWTR D-25 December 2005
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DOP, two-stage filtration, and two-stage clarification. These credits are based on facilities and capabilities
in place when the credits are originally awarded. These credits are not subject to routine monitoring
requirements on monthly basis, or any other basis, expect routine monitoring needed for IESWTR
compliance. As long as the facilities used to establish these particular credits are still in place and treating
100 percent of plant flow on a regular basis, the only requirement for maintenance of these three credits is
compliance with the IESWTR.
Table 3.3 summarizes the monitoring requirements and other provisions necessary for maintenance of
toolbox credits after they are originally awarded.
Basis for this proposal
The above proposal is based on the following factors and issues, discussed in more detail below:
Different requirements for credits in bin 2 versus bin 3 or 4.
The LT2ESWTR already acknowledges that facilities in bin 3 and 4 are subject to greater and different
kinds of risk than facilities in bin 2. Therefore, the proposed guidelines described earlier allow utilities in
bin 2 to remain in compliance if a facility fails to meet one of the requirements for a specific toolbox
credit as long as the facility meets all requirements for this credit in the next 11 months. Facilities can fail
a requirement (one month) for another credit within this 11 month period. One reason for this last
interpretation is that the opposite approach would discourage use of multiple toolbox credits. In
bin 2 all credits are treated the same way, unlike bin 3 and 4 which treat UBT credits greater than 1.0
differently than other credits.
Different requirements for UBT greater than 1.0 in bin 3 or 4 versus other credits.
Credits in bin 3 or 4 are proposed to be treated the same as credits in bin 2 (compliance required in 11 of
12 months), except that UBT credits above 1.0 are treated with less lenience. UBT credits were
specifically identified and targeted to provide Cryptosporidium inactivation which the FACA members
agreed was important to provide for facilities in these two highest risk bins. Therefore, this requirement
can provide some encouragement for utilities to employ multiple barrier approaches to regulatory
compliance in these bins by promoting use of multiple toolbox credits. USEPA can further enhance the
multiple barrier approach, if they wish to, by incorporating provisions that encourage utilities to avoid
dependence on only a single toolbox credit to meet the UBT requirements.
However, it is important to note that slow sand filtration and RBF are intrinsically multiple barriers to
pathogen passage due to the multiple and varied physical and microbiological mechanisms associated
with these credits. Therefore, the UBT credits that should be encouraged to be accompanied by other
toolbox credits are the UBT credits that involve a single barrier to pathogen passage (membrane filtration,
UV inactivation, and chemical inactivation).
Bibliography
Cornwell, D. and M. MacPhee. 2001. Effects of Spent Filter Backwash Recycle on Cryptosporidium
Removal. Jour. AWWA. 93(4): 153-162.
Cornwell, D. and R. Brown. [N.d.]. DOP Credit in the LT2ESWTR Using Ambient Spore Monitoring.
Jour. AWWA. (pending).
Cornwell, D., M. MacPhee, N. McTigue, H. Arora, G. DiGiovanni, and J. Taylor. 2000. Treatment
Comment Response for LT2ESWTR D-26 December 2005
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Options for Giardia, Cryptosporidium, and Other Contaminants in Recycled Backwash Water. Denver,
CO: AWWARF and AWWA.
Cornwell, D., M. MacPhee, R. Brown, and S. Via. 2003a. Demonstrating Cryptosporidium Removal
using Spore Monitoring at Lime Softening Plants. Jour. AWWA. 95:5:124.
Cornwell, D., R. Brown, M. MacPhee, and R. Wichser. 2003b. Applying the LT2ESWTR Microbial
Toolbox at a Surface Water Treatment Plant. AWWA e-Journal
http://www.awwa.org/community/doc_view.cfm?id=190 (cited November 12, 2003).
Dugan, N., K. Fox, J. Owens, and R. Miltner. 2001. Cryptosporidium Control Through Conventional
Treatment. Jour. AWWA, 93:12:64.
Hall, T., J. Pressdee, and N. Carrington. 1994. Removal of Cryptosporidium Oocysts by Water Treatment
Process. London, England: Foundation for Water Research Limited.
Nieminski, E. and J. Ongerth. 1995. Removing Giardia and Cryptosporidium by Conventional Treatment
and Direct Filtration. Jour. AWWA. 87(9):96-106.
Nieminski, E. and W. Bellamy. 2000. Application of Surrogate Measures to Improve Treatment Plant
Performance. Denver, CO: AwwaRF and AWWA.
Ongerth, J. and J. Pecoraro. 1995. Removing Cryptosporidium Using Multimedia Filters. Jour. AWWA.
87(12):83-89.
Patania, N, J. Jacangelo, L. Cummings, A. Wilczak, K Riley, and J. Oppenheimer. 1995. Optimization of
Filtration for Cyst Removal. Denver, CO: AWWARF and AWWA.
States, S., R. Tomko, M. Scheuring, and L. Casson. 2002. Enhanced Coagulation and Removal of
Cryptosporidium. Jour. AWWA, 94(ll):67-77.
Swaim, P., M. Heath, N. Patania, W. Wells, and R. Trussell. 1996. High-rate Direct Filtration for Giardia
and Cryptosporidium Removal. In Proc. of 1996 Annual Conference. Denver, CO: AWWA.
USEPA 2003. 40 CFR Parts 141 and 142. National Primary Drinking Water Regulations: Long-Term 2
Enhanced Surface Water Treatment Rule, Proposed Rule. Fed Reg. 68:154:47640.
West, T., P. Daniel, P. Meyerhofer, A. DeGraca, S. Leonard, and C. Gerba. 1994. Evaluation of
Cryptosporidium Removal through High-Rate Filtration. Proc. of 1994 Annual Conference. Denver, CO:
AWWA.
[See p. 37 of PDF for Table 3.1]
[See p. 38 of PDF for Table 3.2]
[See p. 39 of PDF for Table 3.3]
[See p. 40 of PDF for Figure 3.1]
[See p. 41 of PDF for Figure 3.2]
Comment Response for LT2ESWTR D-27 December 2005
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[See p. 42 of PDF for Figure 3.3]
[See p. 43 of PDF for Figure 3.4]
[See p. 44 of PDF for Figure 3.5]
[See p. 45 of PDF for Figure 3.6]
[See p. 46 of PDF for Figure 3.7]
[See p. 47 of PDF for Figure 3.8]
CHAPTER 4
DEMONSTRATION OF PERFORMANCE (DOP)
Experimental data shows that it is possible for existing surface water treatment facilities to achieve 4.0-
log or greater Cryptosporidium removal, as discussed in Chapter 3. Although this does not necessarily
mean that the baseline automatic credit should be increased across the board from 3.0 to 4.0 for all US
facilities, it does mean that it should be recognized that many existing US facilities do already possess
Cryptosporidium protection capabilities equivalent to 4.0 or greater total credits, and enough realistically
and appropriately defined credits need to be available to establish the greater capability demonstrated for
these existing systems. Stated another way, since IESWTR compliance for some facilities results in
treatment capabilities of 4.0 credits or greater, not just 3.0, some of the toolbox credits should be thought
of not as something added to an existing facility, but rather as a correction or adjustment to the 3.0
baseline credit.
IFE, CFE, two-stage filtration, and two-stage clarification credits are examples of toolbox credits included
to adjust the total credit for an existing facility upward from the 3.0 baseline automatic credit (2.5 for
direct filtration) to its appropriate higher level. However, the most direct, useful, and cost effective
way to establish the true Cryptosporidium removal capability of existing systems is to demonstrate this
capability in pilot-scale challenge studies or full-scale evaluation studies included in the demonstration of
performance (DOP) credit. The DOP credit is expected to be especially advantageous for facilities in bin
2 that do not have existing facilities, or are not planning to build new facilities, that can achieve the 4-log
total requirement using automatic credits. The DOP study can be conducted on an entire treatment
process, or on a specific segment of the process. It can include monitoring of ambient aerobic spores in
full-scale treatment processes, or pilot-scale microbial challenge (spiking) studies using Cryptosporidium,
aerobic spores, or pilot studies using a suitable microbial surrogate, or some combination of all of these
alternatives.
Full-scale studies using ambient aerobic spores are a preferable demonstration study because they
evaluate full-scale facility itself, plus these full-scale spore monitoring studies are significantly less costly
than pilot-scale DOP studies. However, it may not be possible to demonstrate the full potential of
the full-scale process if the raw water spore levels are not high enough. Consequently, pilot-scale
microbial challenge studies may be necessary to demonstrate the full treatment potential of full-scale
processes. Pilot-scale microbial challenge studies could be used in at least two different ways. The
most direct use of pilot-scale testing is to replace full-scale spore monitoring studies with pilot-scale
microbial challenge studies as a means of establishing the DOP credit. However, pilot-scale studies could
also be combined with full-scale spore monitoring studies in a hybrid approach where the ratio of spore
and Cryptosporidium removal could be established in pilot-scale studies and then this ratio used as a
correction factor in full-scale spore monitoring studies. Even though these pilot-scale studies will be more
Comment Response for LT2ESWTR D-28 December 2005
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expensive than full-scale aerobic spore monitoring studies ($50-60 K versus $0.5-0.6 M), these costs are
still significantly less than some of the other toolbox alternatives, which can cost several million dollars.
Furthermore, since the costs for both full-scale and pilot-scale DOP studies are not dependent upon size
of the full-scale facility, the DOP credit becomes more cost effective as the facility size increases.
Full-Scale Studies
One year of weekly full-scale aerobic spore monitoring data is a suitable and appropriate process for
establishing the DOP credit. This approach is fairly straightforward, simple, and cost-effective, especially
for facilities in bin 2. Establishing this credit can also be useful for bin 3 or 4, in conjunction with an
upper bin technology (like UV), where DOP provides all of the credit needed for these bins (4 credits in
bin 3 and 4.5 credits in bin 4) except for the 1.0 credit provided by one or more upper bin technologies.
The following discussion illustrates some of the key issues with respect to using full-scale spore
monitoring to establish the DOP credit, including the following:
* Aerobic spore removal is a conservative indicator of Cryptosporidium removal
* Approved analytical methods are available for aerobic spores that use equipment, materials, and
procedures that are familiar and available to drinking water microbial laboratories
* Finished water detection limits for spores can be lowered by using larger sample volumes in order to
increase the ability to mathematically demonstrate higher credits [higher detection limits (lower sample
volumes) can underestimate true treatment capability of system]
* Use of mean to calculate the numerical value of the DOP credit will either result in gross miscalculation
of the true spore removal (can be over- or under-estimated) or will require complicated statistical methods
to identify and correct data outliers and account for censored (below DL) data. Use of median spore
concentration data avoid these problems, and will result in a suitable and simpler approach to establishing
the numerical value of the DOP credit.
* Geometric mean results in similar numerical values of the DOP credit as when median is used.
However, geometric mean may create some difficulties or confusion due to numerical limitations of the
geometric mean algorithms in some spreadsheet software.
* Low raw water occurrence can inhibit ability to mathematically demonstrate true treatment capability of
systems being evaluated, but consequences of this have been overstated in the draft version of the
LT2ESWTR and associated guidance manual
* Facilities using at least one year of weekly full-scale spore monitoring data can mathematically
demonstrate 4.0 log or greater spore removal, and hence are capable of achieving at least the same level
or higher of Cryptosporidium removal
* Spore sample collection more frequently than once per week is not necessary to establish the DOP
credit (though facilities may voluntarily choose to collect samples more often)
* Once established, the DOP credit should be retained as long as the facility maintains compliance with
the IESWTR
Some of the results listed in the following discussion are provided from available literature sources which
are cited below. Other information is provided from a pending literature article by Cornwell and Brown
summarizing a study jointly funded by AWWA and six US drinking water utilities. Spore monitoring data
Comment Response for LT2ESWTR D-29 December 2005
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was collected at six facilities described in this document as facilities "A" through "F". Facility "A"
includes a conventional treatment facility with two-stage filtration using a river as source water. Facilities
"B" through "D" utilize two-stage lime softening preceded by pre-sedimentation to treat a river source.
Facilities "C" and "D" incorporate polymer and ferric sulfate throughout each of their three clarification
stages plus polymer added to filter influent, but facility "B" only uses filter aide polymer to supplement
the lime softening process, though they do recycle lime softening solids from the middle clarification
stage to the pre-sedimentation basin influent. Facilities "E" and "F" use high quality lake sources as
source water, with facility "E" using conventional clarification and filtration treatment and facility "F"
using direct filtration.
Aerobic spores and other Cryptosporidium surrogates
As illustrated in Figure 4.1, data reported in the literature for pilot-scale microbial spiking studies indicate
that Cryptosporidium is typically removed more readily than aerobic spores during physical treatment
process like clarification and filtration. Consequently, facilities that demonstrate around 4-log removal of
aerobic spores during treatment are probably capable of greater than 4-log Cryptosporidium removal.
These findings are the basis for the inclusion of aerobic spore monitoring at full-scale facilities as an
option for the demonstration of performance (DOP) credit in the upcoming LT2ESWTR. This is also the
reason why some participating utilities in this project have already initiated spore monitoring as a tool to
help them evaluate treatment plant performance. The guidance manual should clearly state that spores are
an accepted conservative estimator or Cryptosporidium removal.
Figure 4.1 includes data published in the literature from pilot-scale Cryptosporidium spiking studies
conducted under stable hydraulic and coagulation conditions. These results are representative of DOP
sampling which will be conducted as outlined in the LT2ESWTR to measure spore removal from raw
water through combined filter effluent at a surface water treatment facility operated in compliance with
the IESWTR under normal conditions. Other conditions were tested in some studies (Huck et al. 2002 and
Dugan et al. 2001) to simulate conditions of non-stable coagulation or stressing of an individual filter.
Interpretation of the "stable" and "non-stable" data reported by Huck et al. (2002) and Yates et al. (1998)
is complicated by the fact that added Cryptosporidium and spores were coagulated in ajar, then spiked
into the filter influent, which contained ambient spores coagulated in the rapid mix that passed through
the sedimentation basin. By contrast, other studies listed were conducted by spiking Cryptosporidium into
the raw water or rapid mix and using ambient or spiked spores also coagulated in the rapid mix.
The first preference when monitoring treatment effectiveness for a target organism would be to monitor
the target organism itself. Cryptosporidium monitoring has obvious limitations as a tool for monitoring
treatment performance because they are not always present in raw water, are typically found at low
concentrations when they are present, and analytical methods are poor. By contrast, aerobic spores are
ubiquitous in almost all source waters (especially surface water) at all times of the year, whether
Cryptosporidium is present or not, and are present in larger concentrations than Cryptosporidium.
In addition, analytical methods for enumeration of spores are more reliable and simpler than
Cryptosporidium methods, as will be discussed later. If no Cryptosporidium are present in the raw water,
Cryptosporidium monitoring does not allow determination of treatment efficiency. Conversely, aerobic
spore monitoring can evaluate the capability for Cryptosporidium removal throughout the year under a
variety of environmental conditions even when no Cryptosporidium is present in the raw water.
Even though monitoring of ambient aerobic spores in full-scale treatment processes is superior to
Cryptosporidium monitoring as a tool for evaluation of treatment performance, the raw water occurrence
and filtered water concentrations of aerobic spores may still cause some difficulties in mathematically
demonstrating the full capability of a treatment process for spore removal and by inference
Cryptosporidium removal. For example, even though spores are present at higher concentrations than
Comment Response for LT2ESWTR D-30 December 2005
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Cryptosporidium, the raw water spore levels may not be high enough and the filtered water detection
levels may not be low enough to mathematically demonstrate the full potential for the treatment process
to remove spores. In this case, the only way to demonstrate the full potential of the treatment process is to
artificially increase the raw water spore levels. Since spiking of full-scale facilities is logistically and
economically infeasible, the only way to realistically perform spiking studies is to use pilot-scale studies.
A recent case study completed for the City of Richmond (VA) as part of an AwwaRF tailored
collaboration project included contingency plans the facility can use to comply with the upcoming
LT2ESWTR. The findings from this study (Cornwell et al. 2003) illustrate that the OOP credit using
aerobic spore monitoring is the most cost-effective alternative for the facility if it ends up in bin 2
(-$60,000 versus several million dollars for many other alternatives, even if they could fit these
alternatives at the existing space-limited site), and that DOP would also be useful for bins 3 or 4 as a low
cost safety factor.
Aerobic spore samples reported in this chapter were collected and analyzed using a protocol based upon
the pending Method 9218 scheduled for publication in the next version of Standard Methods (APHA
N.d.). This method is derived from a procedure originally developed to count aerobic spores in milk
products (APHA 1993), and has been previously reported by Rice et al. (1996). This method does
not limit sample size. The method explicitly allows use of 200, 500, and 1,000 mL containers during the
heating step, but a sample can be distributed into multiple identically sized containers during this step
(i.e., a 5-L sample can be heated in five 1-L sample containers).
One of the attractive features of aerobic spore monitoring is that it involves a fairly simple analytical
method which essentially includes the membrane filtration procedure already used by many utilities for
coliform analysis, preceded by a "heating" step. The heating step kills bacteria in the vegetative
state, leaving only heat-resistant bacterial spores to be counted in the remainder of the procedure. Many
utilities already possess the equipment and expertise to perform the filtration procedure, including the
membrane filtration apparatus and an appropriate incubator. The only new equipment needed for most
facilities that do not already analyze spores is an oscillating water bath or a stirring hotplate needed for
the heating step. The only other materials needed, which some utilities may already have, are autoclavable
glass or plastic containers suitable for the heating step. In order to get spore counts on the plates into the
countable range (20-80 spores per plate), some raw water samples and other samples early in the
treatment process need to be diluted prior to the heating step. Container sizes used for the heating step
need to be the same for all samples and blanks. For example, this may mean a single 500 mL sterilized
container will be used for a diluted raw water sample, two or more sterilized 500 mL containers for an
undiluted finished water sample, and a single 500 mL container for the temperature control blank during
the heating step.
Bacillus subtilis is a specific aerobic spore forming bacteria counted when total aerobic spore spores are
measured. Therefore, a possible alternative to counting total aerobic spores is to only count B. subtilis.
Unfortunately, since B. subtilis is a subset of total aerobic spores, counting B. subtilis would exacerbate
the mathematical difficulties associated with demonstrating target log removals when raw water spore
levels are low.
Total anaerobic spores are another surrogate that could be used to demonstrate Cryptosporidium removal.
Since anaerobic spores behave similarly to aerobic spores during drinking water treatment; therefore, it is
unclear what additional benefit can be obtained by using total anaerobic spores as opposed to total
aerobic spores. Furthermore, since raw and finished anaerobic spore counts are typically much lower than
aerobic spore counts (Nieminski and Bellamy 2000), the mathematical difficulties described earlier with
low aerobic spore counts would be worse using anaerobic spore data.
Comment Response for LT2ESWTR D-31 December 2005
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Another possible Cryptosporidium surrogate is polystyrene (latex) microspheres. These have been used
successfully in pilot-scale challenge studies (e.g., Huck et al. 2002) and have been proposed for full-scale
studies. Under appropriate circumstances, these could be useful DOP studies, though probably they will
be most useful in pilot-scale studies. However, even if used in pilot-scale studies in place of inactivated
Cryptosporidium oocysts, studies will still need to be conducted using spores to establish similar
treatment capability of full-scale and pilot-scale facilities.
Raw and finished water spore occurrence
Table 4.1 summarizes median raw and finished water spore concentrations at the utilities mentioned
earlier using historical data (typically analyzed with a 5 spore/L detection limit (DL) in finished water)
and data collected during the 2003 AWWA study (typically 1 spore/L DL in finished water). These data
show higher raw water spore occurrence in the four river sources than in the two lake sources, but
typically <5 spores/L in finished water from all sources. Finished water spore levels at all participating
facilities were <1 spore/L part of the time (10 to 56 percent of values), especially facilities "A", "B", and
"E", indicating that these facilities could potentially demonstrate lower finished water spore levels if they
used a lower DL.
Since log removal for a process, or part of a process, is calculated by taking the base-10 logarithm of the
ratio of the influent and effluent concentrations, as shown in equation 4.1, the use of lower detection
limits for finished water decreases the denominator, thereby increasing the numerical value of the
calculated log removal from raw through filtration. Conversely, use of a finished water detection limit
that is not low enough will result in an under-estimation of the log removal capability. Therefore, these
data demonstrate that in order to mathematically demonstrate the true treatment capability of many
existing facilities, sample volumes >200 mL will be needed in order to achieve DL of 5 spores/L, and
some facilities may need to use sample volumes >1 L in order to produce DL below 1 spore/L.
Equation 4.1 Calculation of log removal
Log Removal=log(base 10)x(in/out)
Figure 4.2 shows the seasonal variation in raw and finished water at one participant, and also shows the
lower values reported for finished water ("filt") during this study due to the lower DL used in 2003. This
figure shows that raw water occurrence during this study was similar to the previous historical record, and
finished water occurrence also appeared similar, except that use of lower DL in this study allowed for a
more accurate indication of finished water spore concentration. In fact, at this facility it appeared that
an even lower DL could be used since most of the finished water samples did not have detectable levels
of spores using the 1 spore/L DL.
Table 4.1 indicates that the spore removal capability of facility "B" was >4.5-log during calendar years
2000 through 2002. During 2003 the same treatment facility was able to demonstrate >5.4-log spore
removal. The increase in the numerical value of the calculated log removal was due to three factors: a)
higher raw water occurrence, b) slightly better treatment performance, and c) lower finished water DL
during this study. The higher median raw water occurrence (255,000 versus 175,000 spores/L) and
increased treatment performance (as demonstrated in the greater percentage of finished water results that
were less than 5 spores/L [81 versus 98 percent]), may have resulted in a slight increase in the
demonstrated spore removal during the two time periods. However, 0.7 log of this 0.9 log increase was
due to the use of a finished water DL that was five times lower than in the past (log of 5 equals ~0.7). In
fact, since most of the finished water results (56 percent) are still below the new lower DL, it is possible
that a DL lower than 1 spore/L may be needed in order to mathematically demonstrate the true spore
removal capability of this treatment system. Similar spore removal calculations for the other participants
Comment Response for LT2ESWTR D-32 December 2005
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are also summarized in Table 4.1.
The reduction of the finished water DL by a factor of 5 allowed facilities "A" and "B" to mathematically
demonstrate a greater capability for spore removal, although a slight improvement in treatment
performance was noted as well (see last column in Table 4.1). To further illustrate this point, Table 4.2
compares the spore removal calculated during calendar year 2003 at facility "B" using the 1 spore/L DL
versus the calculated removal that would have resulted if a 5 spore/L DL had been used instead. Facility
"E" had no historical data to compare at the higher DL, and facility "F" used a 0.2 spore/L detection limit
before and during this study.
Facilities "C" and "D" demonstrated >4.5-log spore removal from raw to finished water. The median
finished water spore concentrations at these two facilities were <5 spores/L prior to 2003, and 8.5 and 4.6
spores/L, respectively, during this study (2003). These data indicate that for much of the year a DL of 5
spores/L may be sufficient to mathematically demonstrate the spore removal capabilities of these two
systems. However, during certain seasons of the year the monitoring data indicate that a lower DL would
be useful. For example, between July 1 and September 30, 2003, the median finished water spore
concentration at the two plants was 2.6 and 1.1 spores/L, respectively, resulting in a median log spore
removal during this period of >5.4 log. Therefore, a 1 spore/L detection limit seems warranted for this
facility, although a DL of 5 spores/L could be used part of the year, and a DL lower than 1 spore/L should
be considered for other parts of the year.
Figure 4.3 is a plot of finished water spore concentration versus Cryptosporidium log removal measured
in microbial challenge studies reported in the literature by Huck et al. (2002), including data from
Southern California and Central Canada, and by Dugan et al. (2001), including studies conducted
under normal (optimal) and suboptimal coagulation conditions. These data suggest that when filters are
operated to achieve a level of performance where finished water spore levels are below 100 spores/L, the
facility is capable of at least 3-log Cryptosporidium removal. Most filtered water samples, including data
reported by all participating facilities in this project, are expected to be well below this level. Data in
Figure 4.3 also suggest that when filters achieve performance capable of maintaining finished water spore
levels below 10 spores/L, the filtration facility is capable of >4-log Cryptosporidium removal. This
implies that in the future it may be possible to establish at least a 4-log credit for facilities achieving <10
spores/L in finished water, or perhaps 5 spores/L as a factor of safety, as an alternative to calculating log
removal of spores as an indicator of Cryptosporidium removal. Unfortunately, the existing data are not
sufficient to justify the credit based on filtered water concentration alone, although utilities should be
encouraged to perform spore analyses as more sensitive and direct indicators of Cryptosporidium removal
than are turbidity and particle counts, and achievement of the finished water spore levels outlined above
should be considered as treatment objectives.
Existing historical data coupled with data from this study indicate that some facilities have filtered water
concentrations that are lower than 1 spore/L much of the time, but in general it appears that even well run
filtration plants will detect spores at the 1-5 spore/L level. Consequently, with a finished water
spore concentration between 1-5 spores/L, the raw water levels will need to be >10,000-50,000 spores/L
in order to demonstrate 4-log removal. In the Draft Rule and Guidance Manual (USEPA 2003), USEPA
claims the DOP credit using full-scale spore monitoring data may not be useful to many utilities because
they will not have high enough raw water spore levels to demonstrate 4-log or greater spore removal. This
may be correct for a number of surface water sources, but may not reflect the situation at the subset of
these facilities that end up in bin 2 or higher that may be able to use and benefit from the DOP credit.
For example, Nieminski and Bellamy (2000) performed an extensive survey of spore occurrence in the
US which showed that roughly 60% of the facilities had a mean and median raw water concentration
>10,000 spores/L, more than 25% were >50,000 spores/L, and more than 10 % had >100,000 spores/L
Comment Response for LT2ESWTR D-33 December 2005
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(enough for a potential 5-log DOP credit). Consequently, it appears that full-scale aerobic spore
monitoring may be suitable for demonstrating 4.0-log or greater removal in a large number of US
facilities. Furthermore, although there has been no demonstrated correlation between Cryptosporidium
and spore occurrence in raw water (perhaps due mostly to inadequacies of the Cryptosporidium analytical
method), it is possible that the facilities that happen to be in bin 2 and higher may also include a
disproportionate number of facilities with high raw water spore levels, and consequently more able to
gain a benefit from using the DOP credit.
In the AWWA and utility sponsored DOP study (Cornwell and Brown [N.d]), three of the river sources
sampled during 2003 had median raw water levels > 100,000 spores/L and the other river source had
>40,000 spores/L. The participants have indicated that they expect these facilities to be in bin 1, but if not
they and other river sources with similar raw water spore levels should be able to mathematically
demonstrate at least a 4-log DOP credit if the filters provide the expected level of treatment (1-5
spores/L). By contrast, one of the lake sources in this study had a median raw water occurrence of <6,000
spores/L and the other was <400 spores/L. These two sources are expected to have raw water
Cryptosporidium levels well below the bin 2 threshold (0.075 oocysts/L) and therefore not in need of a
DOP credit. Other facilities with similar raw water spore levels are also not expected to have raw water
Cryptosporidium levels high enough to put them outside bin 1. If these facilities do end up in bin 2 or
higher, or if they are in bin 1 but still want to evaluate the true capability of their treatment process for
Cryptosporidium removal, they probably will not be able to establish this capability using full-scale spore
monitoring since the ambient levels of spores are so low, but could demonstrate this treatment capability
using pilot-scale microbial challenge studies.
Calculating the Numerical Value of the DOP Credit Using Spore Data (mean versus
median)
The following paragraphs discuss alternative approaches to calculate the numerical value of the DOP
credit using spore data from the participating utilities. These alternatives are described mathematically in
equations 4.2 through 4.7.
Equation 4.2 Calculation of mean log spore removal as defined in this
report
[See p. 59 of PDF for Equation 4.2]
Equation 4.3 Calculation of median log spore removal as defined in this
report
[See p. 59 of PDF for Equation 4.3]
Equation 4.4 Calculation of geometric mean log spore removal as defined in
this chapter
[See p. 59 of PDF for Equation 4.4]
Equation 4.5 Calculation of the log ratio for each pair of raw and treated water data used to calculate
"median of logs" and "mean of logs" as defined in this chapter
[See p. 59 of PDF for Equation 4.5]
Equation 4.6 Calculation of "median of logs" as defined in this chapter
Comment Response for LT2ESWTR D-34 December 2005
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[See p. 59 of PDF for Equation 4.6]
Equation 4.7 Calculation of "mean of logs" as defined in this chapter (equivalent to log of geometric
mean of paired data)
[See p. 59 of PDF for Equation 4.7]
Figure 4.4 compares log spore removal at the six participants listed in Table 4.1 using the five approaches
listed above. Please note that although five approaches are listed, two of the alternatives are theoretically
identical ("log of geometric mean" and "mean of logs"), and this is reflected in the calculated results for
the six participants (note identical third and fourth bars in Figure 4.4 for each participant). Consequently,
there are actually only four alternatives, but one of the alternatives can be mathematically calculated in
two separate ways. The numerical value of the DOP credit listed in Table 4.1 was estimated using the
"log of median" approach as described above. This approach is used throughout this report and is
proposed by the authors of this report as the method to calculate the numerical value of the DOP credit
because it is simple to calculate and produces a calculated value similar to the other calculation methods.
However, the other approach using median ("median of logs") would be equally suitable, as well as the
two methods related to the geometric mean ("log of geometric mean" and "mean of logs"). In fact only the
"log of means" approach (equation 4.2) is clearly unsuitable for determination of the DOP credit, as will
be demonstrated later in this chapter. Unfortunately, this was the method selected by USEPA in the draft
guidance manual to calculate the DOP credit.
Two factors that can lead to unsuitability of the "log of means" approach favored by USEPA for
establishing the numerical value of the DOP credit include: a) impact of large amounts of censored
(below DL) data for finished water samples and b) the sensitivity of the calculated mean raw and treated
water concentration when data outliers are present for either location. Each of these issues will be
discussed in more detail below. Another topic to be discussed below is the issue of whether weekly paired
samples of raw and finished water samples are sufficient, or whether the credit should be calculated using
greater sample collection frequency. A general topic of importance to whatever method is used to
calculate the numerical value of the DOP credit is a recommendation by the authors of this report that this
credit only be calculated using paired data. Finally, another topic specific to the calculation of geometric
mean is included due to numerical limitations of some simple spreadsheet software to calculate geometric
mean for a large number of observations with large numerical values. The following paragraphs discuss
the paired data issue first, then data outliers, censored data, sample collection frequency, and finally the
numerical limitations of some software programs to calculate geometric mean. Recommendation for use
of only paired data
Whatever method is used, approaches that use paired data are probably the most appropriate since these
approaches offer a better opportunity for links that exists between raw and treated water spore levels, if
any, to be reflected. Therefore, "mean of logs" or "median of logs" would be the most preferable
approaches. If any of the other three alternatives are proposed by USEPA as a method to calculate the
DOP credit, these methods should recommend that only paired data be used to calculate the central
tendency (i.e., suggest discarding raw data if treated result is missing, or vice versa).
Impact of outliers
Either of the median approaches described above are relatively insensitive to data "outliers", for example
incorrect or abnormally high or low numerical values for either raw or finished water relative to the other
data. By contrast, the mean concentration and consequently the calculated mean log removal using
equation 4.2 ("log of means") can be greatly impacted by the presence of even a single raw or finished
Comment Response for LT2ESWTR D-35 December 2005
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outlier. Table 4.3 and Figures 4.5 and 4.6 illustrate an example of a situation where one abnormally high
finished water sample biased the estimate of mean log spore removal at one participant during one year.
The table and corresponding figures represent data for calendar year 2001 at facility "B". Daily samples
were collected and analyzed at this facility for raw, finished, and intermediate points in the treatment
process. On one of the sample collection dates there appears to have been a transcription error. The
raw water result seems correct, but it appears that the pre-sedimentation data value (53,000 spores/L) was
entered into the finished water column by mistake, and all other data for that date were shifted by one
column.
Table 4.3 and Figures 4.5 and 4.6 illustrate that including this erroneous filtered water value causes the
calculated mean finished water concentration to be >10 times higher, resulting in a corresponding
decrease of >1 log in the log credit calculated using the mean raw and finished water concentrations [i.e.,
log(661,868/159) = 3.6 including outlier versus log(661,868/10.1) = 4.8 without outlier]. By contrast, the
median value is less sensitive to potential outliers and results in the same calculated credit with or without
the outlier included [log(370,000/5) = 4.8 with or without outlier included].
The "median of logs" approach described earlier is an equally suitable approach to estimate the log credit.
Figure 4.6 includes a plot of the distribution of the paired log removal values calculated in this manner,
and how these relate to "mean" and "median" estimates calculated using mean and median concentration
for the year, as described previously. Using "median of logs" makes more intuitive sense than the
"median" as described in this article because the "median of logs" maintains the link between the paired
raw and finished water values. Therefore, impacts of raw water conditions on finished water, if any, are
reflected in the calculated values. The "median" approach divorces the two paired values from one
another. However, the "median" approach is simpler and more straightforward to calculate and explain,
and results from the participating utilities indicate little difference between "median" and "median
of logs", and both are preferable to the "log of means" for reasons described in this article.
In this particular example, the log credit should be at least 4.8, and this result can be mathematically
demonstrated using either of the approaches described above using the median, or using the mean if the
probable outlier (53,000 spores/L) is excluded. In fact, it appears that there may be more than just one
potential outlier biasing the mean (more than 95 percent of the finished water values are lower than the
mean in Figure 4.5, with or without excluding the one identified potential outlier). Therefore, if the "log
of means" approach outlined in equation 4.2 is used to determine the numerical value of the DOP credit as
described above, a protocol needs to be incorporated to identify and account for and exclude outliers. In
this example, the outlier was a finished water value that was too high, resulting in an under-estimate of
the DOP credit. There were examples from other participants in which a single high raw water value
resulted in an over-estimate of the DOP credit using the mean approach, unless this outlier was excluded.
A better and simpler alternative to using the mean and then developing and employing a complicated
procedure to evaluate and identify potential outliers is to use the median approach described above. The
median is simple and straightforward to determine and yet would be less sensitive to these potential
outliers.
Impact of censored data
Inspection of Figure 4.5 also reveals another reason to use median as opposed to mean to calculate the
numerical value of the DOP credit. More than 85 percent of the finished water values are below the 5
spore/L DL used at this facility during calendar year 2001. Greater than 55 percent of the finished water
concentrations were less than the DL in 2003, even though the DL was lowered to 1 spore/L (see Table
4.2).
When calculating the mean or determining the median of data with censored values, one approach is to
Comment Response for LT2ESWTR D-36 December 2005
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substitute the numerical value of the DL for all of the censored data. Other methods, such as using half
the DL, are often used but are far too arbitrary. A method to estimate descriptive statistics for flood
discharge data containing censored values is described by Helsel and Cohn (1988) and Hirsch and
Stedinger (1987). The method ("plotting positions") essentially involves predicting the distribution of the
censored data by evaluating the distribution of the uncensored (i.e., the above DL) data. Figure 4.7
compares the actual data from 2003 for facility "B" using the DL value for censored data versus synthetic
data generated using the "plotting positions" method described in the two articles referenced above.
Please note that 56 percent of the finished water values are censored, plus spores were detected in an
additional 18 percent of the samples at exactly 1 spore/L (the numerical value of the DL).
This analysis of the data reveals that the predicted median using the synthetic data is about 0.23 spores/L,
which would result in a calculated log spore removal of 6.0-log, or 0.6-log higher than estimated using 1
spore/L (i.e., the DL) as the median. The calculations for the mean show the impact of two factors.
First, the mean using the synthetic data is slightly lower (about 7.2 versus 7.7 spores/L), but the mean in
either case represents about the 93 percentile of the data, indicating that the mean may be biased by some
outliers in the upper 7 percent of the data. Consequently, the mean can be biased by data outliers, as
noted earlier, and this bias can be further exacerbated by using the value of the DL for the censored data
when calculating the mean or other descriptive statistics. Use of lower detection limits and employing
techniques to estimate the distribution of censored data can help better estimate the mean, but a method to
identify and account for data outliers is also needed. By contrast, a simpler and better estimate of the
central tendency of the data can be obtained without employing complex methods to identify and account
for outliers or censored data by: a) using the median instead of the mean and b) using a detection limit
low enough so that more than 50 percent of the finished water values are above the DL. Even if more than
50 percent of the values are below the DL, using the value of the DL as the median will still be better than
using the mean because of the potential impact of data outliers on the calculation of the mean. Some
facilities may wish to choose to employ more complicated methods to account for censored data, like the
approach using "plotting positions" described earlier, to better estimate the median, though it should not
be a requirement for all facilities.
Weekly versus more frequent spore monitoring to establish the DOP credit
Section 12.5.2.3 of the MTGM indicates that calculating DOP credit using spore monitoring data should
be based on sampling frequency of at least once per week for 52 consecutive weeks. More frequent
collection is probably not necessary, though utilities can voluntarily choose to perform more frequent
monitoring. For example, one utility has been collecting daily spore samples from multiple locations in
the treatment process, including raw and finished water, since January 2000. The facility uses this data to
evaluate treatment performance on a daily basis. Table 4.4 compares the results for median log removal
from raw to finished water at facility "B" using daily paired samples collected during calendar year 2001
versus similar calculated median log spore removal using data collected once per week. This comparison
shows that the numerical results are not much different using daily samples versus any of the sets of
weekly data. Therefore, while some facilities may wish to collect samples more frequently than once per
week for their own purposes, it should not be necessary to collect samples more frequently than once per
week to establish the DOP credit.
Numerical limitations of some software to calculate geometric mean
Previous discussion indicates that "log of means" is not an appropriate approach for calculating the
numerical value of the DOP credit. For this reason, either of the approaches using the median are
preferable because they are simple and straightforward to determine and yet are less sensitive to data
outliers than "log of means" that USEPA prefers.
Comment Response for LT2ESWTR D-37 December 2005
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However, USEPA may have some interest in replacing the mean with geometric mean, instead of using
median, in particular because the geometric mean is also less sensitive to data outliers. For example, the
numerical value of the DOP credit during 2003 for the six facilities in Table 4.1 using the median and
geometric mean are similar (median and geometric mean estimates of the DOP credit for these facilities
are as follows: "A" = 4.2 vs. 4.0, "B" = 5.4 vs. 5.3, "C" = 4.7 vs. 4.9, "D" = 4.9 vs. 4.9, "E" = 3.3 vs. 3.1,
and "F" = 2.1 vs. 2.0). Similarly, conclusions for data at Facility "B" in Table 4.4 would be similar if
median or geometric mean were used (DOP credit ranges from 4.5 to 4.6 using either median or
geometric mean, and about 4.55 using data from all seven days of the week). The geometric mean can
also benefit from use of methods to account for censored data. The estimate of geometric mean of filtered
water concentration for the synthetic data in Figure 4.7 is 0.23 spores/L, the same as the estimate using
the median. Since the geometric mean of the raw water concentration is slightly higher than the median of
raw water, the calculated value for the DOP credit using geometric mean is slightly higher (6.1 vs. 6.0).
However, the "log of geometric mean", though theoretically suitable, may create some difficulties during
implementation for utilities depending on the geometric mean function in some commonly used
spreadsheet software. For example, the geometric mean function used in Microsoft EXCEL 2000
("geomean") has a limitation of about 150 data values when the geometric mean has a numerical
value of about 0.01, and a limitation of 70-80 data points when the numerical value of the geometric mean
is about 10,000, such as you might find in a raw water for spores expressed in units of spores/L. By
contrast, some other software may not suffer from this limitation. For example, the geometric mean
function ("@geomean") in the Lotus Development Corporation spreadsheet software called "Lotus 1-2-3"
does not have this limitation.
Consequently, although most utilities using the DOP credit should not have any difficulty since they will
typically only have about 50 or so data points (weekly paired data for one year), utilities that want to use
more than one year of historical data or that are collecting samples more than once a week may have
some difficulty due to this numerical limitation in some spreadsheet software. They can get around this
limitation, when it exists, by manually calculating the geometric mean for raw and treated water without
using the geometric mean function. This can be accomplished by taking the mean of the base-10 log
values, then taking the anti-log of the mean of these log values as shown in equation 4.8. Furthermore, as
shown in Equation 4.7, a mathematically equivalent calculation of the "log of geometric mean" can be
determined by using the "mean of logs" approach.
Equation 4.8 Calculation of geometric mean when numerical limitations do not allow direct calculation
using internal spreadsheet functions (e.g., "geomean" function in Microsoft EXCEL)
[See p. 66 of PDF for Equation 4.8]
Summary of methods to determine numerical value of DOP credit
Two alternatives related to median and two alternatives related to the geometric mean are the preferred
methods for establishing the numerical value of the DOP credit using spore data or other Cryptosporidium
surrogates. Of these, either approach using median are simplest and most straightforward to determine.
The two approaches related to geometric mean (see equations 4.4 or 4.7) are also suitable, though the "log
of geometric mean" approach as outlined in equation 4.4 may be complicated under certain situations
described above. The "log of means" approach outlined in equation 4.2 is identical to the approach
proposed by USEPA in the Microbial Toolbox Guidance Manual. This approach is the only approach
described above that can be demonstrated as clearly unsuitable for use in establishing the numerical value
of the DOP credit, unless complicated provisions are included by USEPA to help identify and manage
data outliers and censored data. Instead of requiring development of complicated guidance needed
for other approaches, USEPA should explicitly recommend either of the median approaches to establish
Comment Response for LT2ESWTR D-38 December 2005
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the numerical value of the DOP credit. If these other approaches are also listed, they should be described
as alternatives to the median approaches and the guidance manual should adequately outline the
limitations of these other approaches so states and utilities reviewing the guidance manual can make
informed decisions.
Whatever method is adopted, use of data collected at least once a week for one year should be sufficient
to establish the numerical value of the DOP credit. Sample collection for periods longer than one year or
at frequencies greater than once a week should not be required by the states or USEPA, however
utilities that voluntarily choose to collect more data should be allowed to do so. Samples should be
collected at regular, evenly spaced intervals throughout an entire 52 week period, or multiples of 52
weeks when more than one year of data is used. However, utilities should be allowed some discretion on
sampling
dates and number of samples, especially if more than 50 samples are collected. For example, 50 out of 52
samples for weekly sampling dates or about 350 daily samples excluding holidays seems reasonable. In
addition, while utilities collecting samples once a week, for example, should be encouraged to collect
samples on the same day each week, utilities should be allowed some discretion in establishing sample
collection dates as needed due to holidays, vacations, or other issues related to availability of sample
collection personnel.
Using full-scale spore monitoring to evaluate treatment performance other than DOP
Utilities performing spore monitoring to evaluate performance of treatment facilities may get some value
out of collecting samples from raw water and intermediate points in the process. However, most utilities
will focus most of their attention on finished water spore levels as an indicator of performance of the
filters in particular, and the entire treatment process in general. For example, since spores are more
sensitive than particle counts or turbidity and reflect more closely factors that may impact
Cryptosporidium removal, monitoring of filtered water spore levels like that illustrated in Figure 4.8 can
be used to illustrate improvements over time due to changes in infrastructure, operational practices, or
management strategies. This greater sensitivity may allow demonstration of treatment enhancements for
costly but difficult to quantify improvements, such as operational practices and management policies.
Figure 4.8 shows progressive improvement overtime at one facility from 1997 to 2002 due to refinements
in operational practices. Chapter 6 includes spore monitoring data to illustrate treatment performance
during different stages at lime softening plants.
Pilot-Scale Microbial Challenge Studies
A DOP pilot-scale challenge study would involve measuring removal of spiked Cryptosporidium or
appropriate surrogate in a 2 to 5 gpm pilot facility mimicking the full-scale treatment plant. Source water
for the pilot facility should be provided from the location representative of where the Cryptosporidium
bin assignment samples are/were collected. Although explicit guidance on pilot studies is not available
from USEPA, the following would be reasonable for most facilities:
* Challenge studies conducted for two (2) weeks during each of four consecutive quarters
* The study should be preceded by two (2) weeks of side-by-side studies comparing performance of full-
scale facility to pilot plant operated under identical conditions (it must be shown that full-scale
performance equals or exceeds pilot-scale performance through the final filtration stage)
* Monitoring of raw, spiked, and finished water grab samples to include turbidity, particle counts, and
Cryptosporidium (or other microbial indicator)
Comment Response for LT2ESWTR D-39 December 2005
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* On-line, continuous turbidity and particle count monitoring of individual filter and combined filter
effluent is recommended for the benefit of the utility so they can evaluate operations of the pilot facility,
but this monitoring should not be a requirement or condition for the credit
* Pilot-study protocol to be negotiated with, and approved by the State.
* Objectives of testing should be to establish performance under routine or typical conditions (not "worst-
case" scenarios - see later discussion), with "typical" performance established by monitoring removal of
Cryptosporidium (or approved surrogate) in combined filter effluent (not in individual filters - see
discussion below)
* DOP credit established in pilot studies will be applicable to full-scale plant at full-scale flow rates
consistent with unit process loading rates used in pilot-scale unit processes (flocculation, clarification,
filtration) during DOP evaluation, unless otherwise negotiated with the State
The above discussion proposes an aggressive schedule incorporating two weeks of quarterly studies,
although a less aggressive schedule would be appropriate under most conditions. For example, a few
weeks of one-time testing would be appropriate for many facilities, and would be consistent with existing
performance testing requirements for some states. However, Chapter 12 of the draft MTGM outlines an
extravagantly expensive and overly aggressive program that includes 52 weeks of testing (Table 12.3,
page 12-13 of drat MTGM). Furthermore, the objective of testing should be to represent performance
under routine or typical conditions, not "worst-case" conditions emphasized in the MTGM. This is
consistent with the characteristics of the LT2ESWTR framework which incorporates typical
Cryptosporidium occurrence, viability, and infectivity along with typical treatment performance to
establish overall risk to drinking water consumer. In addition, "typical" treatment performance is
reflected by measuring treatment performance from raw (plus spike) through combined filter effluent, not
raw through each individual pilot filter. This is consistent with the requirements for the DOP credit using
spores, and is also consistent with Section 12.5.2.1 of the MTGM, although Table 12.3 on the previous
page of the guidance manual implies the opposite.
The DOP credit established in pilot studies should be applicable to the full-scale plant at full-scale flow
rates consistent with unit process loading rates used in pilot-scale unit processes (flocculation,
clarification, filtration) during the DOP evaluation, unless otherwise negotiated with the State. For
example, a pilot study which achieves >4.5 log removal of Cryptosporidium using the State approved
protocol when pilot filters were operated at 8 gpm/sf means that the full-scale plant should be certified for
a total credit of at least 4.5, not the 3.0 automatic credit, as long as the full-scale plant filtration rate is <8
gpm/sf. This does not mean the State is required to certify the full-scale plant for filtration rates up to 8
gpm/sf. However, it does mean that as long as the State establishes the maximum filtration rate for the
plant anywhere below 8 gpm/sf (e.g., 4.5 gpm/sf), the State can not award a credit lower than 4.5.
Spore monitoring results can also be used to evaluate performance of pilot-scale facilities, in particular
comparison of pilot- versus full-scale performance, like results shown in Figure 4.9. Most water treatment
professionals with experience interpreting pilot study data have observed similar results numerous times
demonstrating that pilot-scale facilities do not overestimate full-scale treatment performance in areas such
as removal of spores and other particulates. In fact, results like those in Figure 4.9 demonstrating better
spore or particulate removal in full-scale clarifiers and filters than in analogous pilot-scale facilities are
commonly observed.
Other DOP issues
Some DOP issues were inadequately addressed or not addressed at all in the Draft Toolbox Guidance
Comment Response for LT2ESWTR D-40 December 2005
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Manual for the LT2ESWTR. These issues are discussed separately below: costs, maintenance of toolbox
credits, process specific studies, and potential DOP penalty.
Costs
The cost for the DOP credit using either aerobic spores or pilot-scale microbial challenge studies would
not be dependent upon the size of the facility being demonstrated. For example, a full-scale spore
monitoring study will include the same number of samples collected at the same sampling frequency
whether a facility is 2 mgd or 200 mgd (one raw and one finished water sample, once per week for a year
is proposed for both). A pilot-scale facility will similarly be about the same size (~5 gpm) and will
include about the same duration of testing (about 2 weeks of testing per quarter for one year is reasonable)
associated with full-scale facilities of a variety of sizes (the one difference perhaps is that larger utilities
may have enough in-house staff to design, build, and operate the pilot whereas a smaller utility may not
be able to do it without hiring an outside consultant). Therefore, the DOP credit will be cost-effective
for a wide variety of facility sizes, and will be even more cost-effective for larger facilities.
A DOP spore study is expected to involve a minimum of 50 weeks of two paired spore samples (plant
influent and effluent) per week. Median cost for spore analysis from a survey of eight commercial
laboratories is about $60/sample. The resulting analytical cost is about $6,000 for the entire study. Cost
for data interpretation and report preparation, would increase the total cost to about $60,000 for the entire
study. Facilities performing the analyses in-house could reduce costs even further. Many facilities may
already possess most of the required equipment (an incubator, an autoclave, a membrane filtration
apparatus, and a microscope), and may only need to purchase a shaking water bath capable of achieving
and maintaining at least 90°C ($3,000 to $6,000) or a stirring hotplate ($300-$1,200) capable of achieving
the same temperatures. The analytical technique does not require special training or certification, for
example like is needed for Cryptosporidium analyses, for personnel familiar with standard microbial
analyses, in particular the membrane filtration technique for coliform analyses. For a pilot-scale study, a
5-gpm pilot plant with all required hardware and instrumentation, plus design, construction, operation,
monitoring, data evaluation, and report preparation would require $600,000 or less. Consequently, even
the latter pilot-scale DOP cost is more cost effective than some other toolbox credits for facilities capable
of achieving up to 4.0 log of Cryptosporidium removal (or approved surrogates), and becomes even more
cost effective for larger facilities. The guidance manual should clearly indicate that spores are an accepted
surrogate for Cryptosporidium spiking.
Maintenance of DOP credit
Once established, the DOP credit should be retained as long as the facility maintains compliance with the
IESWTR. Determination of alternative compliance criteria, and requirements to comply with these
alternate criteria, are not appropriate. The DOP credit establishes a correction or adjustment to the
Cryptosporidium protection capability of an existing treatment facility in compliance with the IESWTR.
Whereas a utility in compliance with the IESWTR is allowed a minimum 3.0 credit (2.5 for direct
filtration) without having to prove what the true treatment capability of the existing system really is, once
a utility completes a DOP study and proves what the actual capability of the system is when it is in
compliance with the IESWTR, it should not be required to establish and attain a compliance requirement
beyond IESWTR compliance.
Process specific demonstration studies
DOP studies can be applied to entire treatment processes (raw to finished), to intermediate segments of
the treatment process (e.g., pre-sedimentation effluent to finished water), or to individual treatment
processes (second stage of two filter process). Due to practical limitations resulting from decreased ability
Comment Response for LT2ESWTR D-41 December 2005
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to mathematically demonstrate DOP credit when process influent levels are lower, the DOP approach
using ambient spores becomes less useful when the starting point for the process gets later and later in the
process. Consequently, DOP studies using full-scale spore monitoring work best when measured from
raw water to some later point in the treatment process. Pilot-scale challenge studies can be used instead of
full-scale spore monitoring studies under conditions when influent ambient spore levels are too low,
whether this is due to low raw water levels or due to low ambient influent levels at points in the process
after previous stages in treatment.
One unit process that is potentially particularly well suited for DOP studies using spore monitoring is
RBF. DOP studies for RBF systems can be performed at full-scale pilot facilities, for example a
monitoring well/collector representing a future monitoring well network or other river bank, river bottom,
lake bank, or lake bottom collection system similar to the pilot well/collector. This facility will not be
able to use microbial challenge studies, but can measure removal of ambient Cryptosporidium indicators,
such as aerobic spores. DOP studies for RBF are unique in that these are the only opportunities to use
DOP to establish UBT credits. Therefore, a facility that is ineligible for an automatic RBF credit for one
reason or another (media gradation, distance from surface water source, etc.) can receive whatever credit
can be proven in a DOP study, and the first 1.0 of this credit can be used for UBT and the remainder
can be used for the additional 1.0 or 1.5 credits needed for bins 3 and 4, respectively. Once the pilot
well/collector establishes the Cryptosporidium protection capability of the riverbank in the vicinity of the
well/collector, the utility will be allowed to construct the RBF system outlined in the State approved DOP
protocol and the facility will be awarded the credit demonstrated in the pilot well without need of further
testing (analogous to the alternate intake indirect "credit" in the toolbox). This credit will be useable until
the second round of Cryptosporidium bin assignment samples, at which time the new bin assignment
sample location will be the combined discharge from the RBF system.
Figure 4.10 and Table 4.5 summarize spore removal in a pair of wells associated with an existing RBF
system. Mean Cryptosporidium occurrence in the river source is >0.8 oocysts/L, which is close to the bin
3 threshold of 1.0 oocysts/L. Giardia occurrence in the river is also high. Yet, no Giardia or
Cryptosporidium have been detected in the RBF wells. Spore monitoring data indicates that the
spore removal capability for the RBF process at this location is at least 4.0 log. Since the wells are
existing, this RBF system is not eligible for a direct RBF credit, although it will receive what amounts to
an indirect credit of 1.0 credit since the river sample would put the facility in bin 2, at minimum, but
collecting bin assignment sample from the RBF system, as mandated by the LT2ESWTR, will ensure
assignment to bin 1 at this facility. However, if these were pilot wells for a proposed RBF system, results
from spore monitoring would justify a credit >2.5 log (including 1.0 credit of UBT), sufficient for any bin
assignment
Potential DOP penalty
DOP studies inherently provide conservative estimates of the true treatment performance of the full-scale
facilities being evaluated. For example, the DOP credit established using full-scale aerobic spore
monitoring includes an inherent safety factor because the numerical value of the Cryptosporidium
removal credit will be assumed to be equal to the measured spore removal, even though Cryptosporidium
removal in literature studies is always greater than spore removal (see later discussion). Similarly, pilot-
scale microbial challenge studies will be conservative indicators of full-scale Cryptosporidium removal
(especially if conservative Cryptosporidium indicators like spores are used) because widespread
experience of water treatment practitioners with experience using pilot studies indicates that full-scale
clarification and filtration facilities routinely provide greater removal of particulates, turbidity, and
microbial indicators than do pilot-scale systems. In addition, even if this was not a common observation
for pilot facilities, the USEPA requirements for the DOP credit using pilot studies include a precaution
requiring the verification of the relationship between pilot-scale and full-scale facilities associated with
Comment Response for LT2ESWTR D-42 December 2005
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the DOP study by requiring a period of comparison where both are operated under identical conditions
(same influent raw water, similar coagulation conditions, filter and clarifier loading rates, etc.).
A provision in the draft rule (section IV.C.17) and in Chapter 12 of the microbial toolbox guidance
manual allows State's the discretion to potentially penalize facilities that try a DOP study and end up
mathematically demonstrating a total credit that is less than the automatic credits allowed by the Rule.
Therefore, for example, a State can choose to award a 3.3 credit to a facility that qualifies for 3.5 total
automatic credits if the utility was only able to mathematically demonstrate 3.3 log removal in a DOP
spore study or pilot study.
However, it is difficult to see any benefit from inclusion of this potential penalty since the automatic
credit is based on a national mean, not on individual performance. The use of national mean was
purposely done by USEPA and deducting credits at an individual plant basis is contrary to that approach.
Several huge potential negative consequences are associated with inclusion of this penalty provision,
including the potential to increase costs and nuisance for facilities attempting to achieve the DOP credit
using spores, and the potential to deter facilities that may have benefited from using the credit from
even trying for the credit.
In summary, the prospective penalty USEPA is attempting to incorporate as part of the DOP credit
requirements demonstrates a lack of understanding of the conservative nature of proposed demonstration
studies for the DOP credit (full-scale spore monitoring or pilot-scale microbial challenge studies). This
potential penalty is not expected to be applied to many, if any, facilities since most that will try for the
credit are expected to demonstrate sufficient removal in pilot-scale microbial challenge studies or full-
scale studies. However, the greatest potential impact of this potential penalty is that the mere prospect that
a utility could be penalized for trying to achieve a DOP credit will deter a number of utilize from even
trying for the credit, even though most facilities will probably be able to demonstrate great enough
Cryptosporidium removal capabilities that they not only would not be subject to a penalty, but would be
able to easily establish a higher credit for their existing facilities using the DOP credit. Therefore, a
number of utilities may pursue more expensive or less readily achievable credits that could have been
achieved more easily and inexpensively using the DOP credit.
Summary
1. Literature data indicates that treatment facilities capable of achieving finished water turbidities <0.3 ntu
as needed for compliance with the IESWTR and LT1ESWTR can achieve >4-log removal of
Cryptosporidium. A large portion of the credits available to utilities in the LT2ESWTR Microbial
Toolbox, including the DOP credit, were included so that existing facilities capable of achieving this
higher level of performance could be allowed the credit they deserve.
2. Cryptosporidium is typically removed more readily than aerobic spores during physical treatment
process like clarification and filtration. Consequently, facilities that demonstrate around 4-log removal of
aerobic spores during treatment are probably capable of greater than 4-log Cryptosporidium removal.
This is the basis behind allowing use of full-scale monitoring of ambient (i.e., background) aerobic spore
levels in order to calculate the numerical value of the DOP credit.
3. Median finished water spore concentration in well run treatment plants typically ranges from 1 to 5
spores/L.
4. Facilities with 1 to 5 spores/L in finished water will need more than 10,000 to 50,000 spores/L in raw
water in order to demonstrate a 4-log DOP credit. 25 percent of the facilities during a national study
conducted by Nieminski and Bellamy (2000) had a median spore concentration of >50,000 spores/L.
Comment Response for LT2ESWTR D-43 December 2005
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Furthermore, it is possible that the number of facilities that happen to be in Bin 2 and higher as a result of
LT2ESWTR required Cryptosporidium monitoring may also include a disproportionate number of
facilities with high raw water spore levels, and consequently more able to gain a benefit from using the
OOP credit.
5. Full-scale spore studies reported by Cornwell and Brown ([N.d.]) showed that a DOP credit greater
than 4.5 could be demonstrated at four facilities from river sources with raw water spore concentrations
> 10,000 spores/L.
6. Facilities with fewer than 10,000 spores/L in the influent water (see equation 4.1) will probably need to
use pilot-scale microbial challenge studies to establish the full DOP credit these facilities deserve.
7. USEPA needs to explicitly acknowledge that monitoring aerobic spore removal in full- or pilot-scale
studies is a suitable surrogate and provides a conservative estimate of Cryptosporidium removal, and
consequently spore monitoring is suitable for establish the numerical value of the DOP credit.
8. Spore monitoring can be used to determine treatment removal for an entire treatment process, as well
as individual components of the process. For example, participating utilities demonstrated >0.8 median
log removal associated with adding a second filtration stage (post-filter GAC), 0.6 to 1.6 median log
removal for pre-sedimentation, 1.4 median log removal for a SFBW clarifier, and >4 log removal in RBF
wells.
9. Spore monitoring has been used by water utilities to evaluate treatment performance.
10. The alternative to monitoring ambient aerobic spore removal in full-scale treatment processes in order
to establish the DOP credit is to use pilot-scale microbial challenge studies. However, spore monitoring
can also be an important part of these studies as well, including: a) use of spores instead of
Cryptosporidium as the challenge organism in the spiking studies and b) to verify similar (or lower)
treatment performance in the pilot-scale facility versus the full-scale facility when both are operated in a
similar manner and are treating similar source water. It may also be possible to combine the two in a
hybrid approach where pilot-scale studies are conducted to establish a correction factor relating
Cryptosporidium to spore removal at a given facility, and this correction factor applied to full-scale
ambient aerobic spore monitoring results.
Bibliography
APF£A (American Public Health Association) 1993. Aerobic Bacterial Spores (Section 8.9). Standard
Methods for the Examination of Dairy Products. 16th ed. Edited by Robert T. Marshall. Washington, DC:
APHA, pp. 280-281.
APHA (American Public Health Association) [N.d.]. Method 9218: Aerobic Endospores in Water.
Standard Methods for the Examination of Water and Wastewater. 21st ed. Washington, DC: APHA,
forthcoming.
Clark, S., M. Morabbi, T. Hargy, J. Chandler, and J. Wiginton. 2001. Softening: The Ultimate Microbial
Tool? In Proc. of 2001 Water Quality Technology Conference. Denver, CO: AWWA.
Cornwell, D. and R. Brown. [N.d.]. DOP Credit in the LT2ESWTR Using Ambient Spore Monitoring.
Jour. AWWA. (pending).
Cornwell, D., M. LeChevallier, M. MacPhee, N. McTigue, H. Arora, G. DiGiovanni, and J. Taylor. 2000.
Comment Response for LT2ESWTR D-44 December 2005
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Treatment Options for Giardia, Cryptosporidium, and other contaminants in Recycled Backwash Water.
Denver, CO: AwwaRF and AWWA.
Cornwell, D., R. Brown, M. MacPhee, and B. Wichser. 2003a. Application of the LT2ESWTR Microbial
Toolbox at an Existing Surface Water Treatment Plant, [full article = Available:
http://www.awwa.org/community/doc_view.cfm?id=190 (November 12, 2003)]. Expanded summary
available at Jour. AWWA 95:9:76-79.
Cornwell, D., M. MacPhee, R. Brown, and S. Via. 2003b. Demonstrating Cryptosporidium Removal
using Spore Monitoring at Lime Softening Plants. Jour. AWWA., 95:5:124.
Dugan, N., K. Fox, J. Owens, and R. Miltner. 2001. Cryptosporidium Control Through Conventional
Treatment. Jour. AWWA., 93:12:64.
Emelko, M. 2001. Removal of Cryptosporidium parvum by Granular Media Filtration. Ph.D. diss.
University of Waterloo, Waterloo, Ontario, Canada.
Hall, T., J. Pressdee, and N. Carrington. 1994. Removal of Cryptosporidium Oocysts by Water Treatment
Process. London, England: Foundation for Water Research Limited.
Helsel, D., and T. Cohn. 1988. Estimation of Descriptive Statistics for Multiply Censored Water Quality
Data. Water Resources Research, 24:12:1997-2004.
Hirsch, R., and J. Stedinger. 1987. Plotting Positions for Historical Floods and Their Precision. Water
Resources Research, 23:4:715-727.
Huck, P., et al. 2001. Filter Operation Effects on Pathogen Passage. Denver, CO: AwwaRF and AWWA.
Mazounie, P., F. Bernazeau, and P. Alia. 2000. Removal of Cryptosporidium by High Rate Contact
Filtration: The Performance of the Prospect Water Filtration Plant During the Sydney Water Crisis. Water
Science and Technology. 41(7):93-101.
McTigue, N., M. LeChevallier, H. Arora, and J. Clancy. 1998. National Assessment of Particle Removal
by Filtration. Denver, CO: AWWARF and AWWA.
Nieminski, E. and W. Bellamy 2000. Application of Surrogate Measures to Improve Treatment Plant
Performance. Denver, CO: AwwaRF and AWWA.
Ongerth, J. and J. Pecoraro. 1995. Removing Cryptosporidium Using Multimedia Filters. Jour. AWWA,
87(12):83-89.
Patania, N., J. Jacangelo, L. Cummings, A. Wilczak, K. Riley, and J. Oppenheimer. 1995. Optimization
of Filtration for Cyst Removal. Denver, CO: AwwaRF and AWWA.
Rice, E., K. Fox, R. Miltner, D. Lytle, and C. Johnson. 1996. Evaluating Plant Performance with
Endospores. Jour. AWWA., 88 (9): 122-130.
States, S., R. Tomko, M. Scheuring, and L. Casson. 2002. Enhanced Coagulation and Removal of
Cryptosporidium. Jour. AWWA, 94(ll):67-77.
Swaim, P., M. Heath, N. Patania, W. Wells, and R. Trussell. 1996. High-rate Direct Filtration for Giardia
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and Cryptosporidium Removal. In Proc. of 1996 Annual Conference. Denver, CO: AWWA.
West, W., P. Daniel, P. Meyerhofer, A. DeGraca, S. Leonard, and C.P. Gerba. 1994. Evaluation of
Cryptosporidium Removal Through High-Rate Filtration. Proceedings of 1994 Annual Conference.
Denver, CO: AWWA.
USEPA. 2000. Stage 2 Microbial and Disinfection Byproducts Federal Advisory Committee Agreement
in Principle. Fed. Reg. 65(251):83015-83024.
USEPA. 2003. National Primary Drinking Water Regulations: Long-Term 2 Enhanced Surface Water
Treatment Rule. Fed. Reg. 68(154):47640-47795.
Yates, R., K. Scott, J. Green, J. Bruno, and R. DeLeon. 1998. Using Aerobic Spores to Evaluate
Treatment Plant Performance. In Proc. of 1998 Annual
Conference. Denver, CO: AWWA.
[See p. 79 of PDF for Figure 4.1]
[See p. 80 of PDF for Table 4.1]
[See p. 81 of PDF for Table 4.2]
[See p. 82 of PDF for Table 4.3]
[See p. 83 of PDF for Table 4.4]
[See p. 84 of PDF for Table 4.5]
[See p. 85 of PDF for Figure 4.2]
[See p. 86 of PDF for Figure 4.3]
[See p. 87 of PDF for Figure 4.4]
[See p. 88 of PDF for Figure 4.5]
[See p. 89 of PDF for Figure 4.6]
[See p. 90 of PDF for Figure 4.7]
[See p. 91 of PDF for Figure 4.8]
[See p. 92 of PDF for Figure 4.9]
[See p. 93 of PDF for Figure 4.10]
CHAPTER 5
ENHANCED FILTRATION (CFE AND IFE CREDITS)
In listing potential treatment approaches in the Microbial Toolbox, the M/DBP FACA recommended a
Comment Response for LT2ESWTR D-46 December 2005
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0.5-log credit for a water treatment plant achieving lower finished water turbidities than required by the
IESWTR. Compliance with the IESWTR requires 95 percent of all combined filter effluent (CFE)
turbidities, measured every four hours during a given month, to be =0.3 ntu. The M/DBP FACA
recommended that reducing 95th percentile CFE turbidities to =0.15 ntu would provide additional
Cryptosporidium removal necessary for a 0.5-log credit within the Microbial Toolbox.
During FACA discussions developing the rule, a 1.0 credit was proposed for facilities awarded Phase IV
status in the Partnership for Safe Water (PSW), or other similar peer-review processes developed in the
future. This alternative ended up being dropped because the PSW is a voluntary program intended to
provide feedback and recommendations for improvements to finished water quality at participating
utilities, but the PSW process was not intended to have any regulatory consequences. However, as a
substitute for this peer-review credit, it was proposed that a 1.0 credit could be awarded for facilities
meeting one of the guidelines suggested in the PSW Phase IV process that facilities achieve <0.15 ntu for
each individual filter. This credit is analogous to the CFE credit, except this credit will be established
using individual filter effluent (IFE) turbidity data. As will be discussed later in this chapter, this report
uses a simpler definition of the IFE credit than is outlined in the draft rule and guidance manual by
defining the IFE credit as an independent 0.5 credit that can be combined with a 0.5 credit for CFE,
resulting in a total 1.0 credit when the two are used in combination (equivalent to the total credit allowed
for these two in the draft rule).
Justification for each of these credits, and discussion of each, are included in the following paragraphs.
Proposed modifications to the LT2ESWTR definitions for these credits will also be discussed.
Cryptosporidium Oocyst Removal
Chapter 3 described literature data demonstrating that conventional treatment facilities with single
clarification and filtration stages in compliance with IESWTR requirements (including finished water
turbidity <0.3 ntu) are capable of achieving 4.0-log or greater removal of Cryptosporidium, indicating that
existing facilities with these capabilities need to have microbial toolbox credits available to them to
establish credits beyond the minimum automatic 3.0 credits. In other words, IESWTR compliance for
some facilities translates into 4.0 or greater removal capabilities.
This does not mean that the automatic 3.0 credit for a single clarification and filtration process should be
increased to an automatic credit of 4.0 or higher, but it does point out that it is consistent with the
literature to expect that many existing, well-run surface water treatment plants will be able to provide
4.0-log or greater Cryptosporidium removal. Consequently, as agreed during the FACA negotiations, the
microbial toolbox is intended to provide enough appropriately and realistically defined credits that
existing facilities with these 4-log or greater capabilities will be able to establish these credits without
having to install new technologies (at least for bin 2). In other words, some of the credits, including IFE,
CFE, DOP, two-stage filtration and clarification, etc. were included so that utilities would have enough
credits available to them to correct or adjust the 3.0 baseline credit (2.5 for direct filtration) to the 4.0 or
higher credit some facilities already deserve.
Corrections to the 3.0 credit minimum baseline credit can be provided directly by demonstration (DOP) or
indirectly by a combination of automatic credits. For example, facilities that have two-stage filtration or
clarification can use an additional 0.5 credit for each additional stage. However, corrections or
adjustments to the baseline credits for all existing facilities can also be provided for facilities meeting the
definition of the automatic CFE and IFE credits.
Previously described data indicate that existing facilities with clarification and filtration in compliance
with the IESWTR can achieve 4.0, 4.5, or higher log removal of Cryptosporidium. The 1.0, 1.5, or greater
Comment Response for LT2ESWTR D-47 December 2005
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correction of the minimum 3.0 baseline credit can be partially provided by the CFE and IFE credits.
These credits both involve providing additional Cryptosporidium protection credits when the filter
effluent turbidity improves from 0.3 to 0.15 ntu. Existing literature contains evidence demonstrating that
improvements in effluent turbidity from 0.3 to 0.15 ntu translates to an improvement in Cryptosporidium
removal of more than 1.5 log. Consequently, a 1.0 log adjustment for a combination of CFE and IFE
credits is actually a conservative correction for the 1.5-log or greater improvement associated with this
reduction in filter effluent turbidity. Figure 5.1 depicts these relationships, and the conservative 1.0-
credit correction provided by the combined CFE and IFE credits.
The data reported by Huck et al. (2002) from separate pilot-scale studies conducted in Ottawa and
Southern California provide the most unambiguous demonstration of the improvement in
Cryptosporidium removal associated with reduction of filter effluent turbidity form 0.3 to 0.15 ntu. Data
from other literature sources will be discussed in more detail later. The information from the Ottawa and
California studies reported by Huck et al. (2002) are listed in Table 5.1. These data reflect log removal
calculated for each pair of filter influent and effluent samples reported from these studies. The Ottawa
data demonstrated a >3 log improvement in the median calculated log removal when filter effluent
turbidity was <0.15 ntu versus when turbidity was between 0.15 and 0.3 ntu. Similar reduction in
turbidity resulted in an improvement of 1.8 log for median removal in the California studies. Please note
that both of these studies reflect Cryptosporidium removal for the filtration stage only since jar coagulated
Cryptosporidium were spiked into filter influent.
The studies described by Huck et al. (2002) were conducted under a variety of conditions. Most of these
studies were conducted under normal or stable operating conditions, resulting in a number of turbidity
results <0.15 ntu as would be expected in most filters operated under stable conditions. However, these
studies also evaluated conditions in which the filter was hydraulically stressed or coagulation was not
optimized, as well as sample collection representing filter operations where filter-to-waste was not
properly used during the filter ripening period or when filter was operated at filter run times beyond
breakthrough. Consequently, more results were available during periods when turbidity was between 0.15
and 0.3 ntu than are typically observed in most experimental or field studies. Other studies in the
literature not only have this limitation, but the numerical values calculated for log removal typically
underestimate Cryptosporidium removal potential, especially when turbidity was <0.15 ntu, because the
raw water Cryptosporidium concentrations were too low for the filtered water detection limits used.
Consequently, even when enough results with turbidity between 0.15 or 0.3 ntu were available from
other literature studies, low raw water occurrence often limited the ability to mathematically demonstrate
the true difference in Cryptosporidium removal between the two groups.
Table 5.1 summarizes data for other full- and pilot-scale studies published in the literature. Most of the
other data cited in this table either has a limited number of results in one or both groups, or includes data
where the true difference in removal between the two groups can not be numerically established with the
filtered water detection limits used given the low raw water occurrence. The few situations where a
comparison between <0.15 ntu versus between 0.15 and 0.3 ntu can be made indicate a difference in log
Cryptosporidium removal of >0.7-log to >3-log.
In Chapter 4, an analysis of spore removal data was presented for a facility which includes two-stage lime
softening preceded by a pre-sedimentation basin. Data from this facility is evaluated later in the current
chapter in order to compare spore removal with CFE and IFE turbidity data. Full-scale aerobic spore
monitoring data at this facility reported in Chapter 4 indicates that the facility achieves median spore
removal greater than 5.4 log. Since Cryptosporidium are removed more readily than spores, and since full
potential of spore removal at this facility is unknown since filtered water spore levels were below
detection limit, it is expected that the median Cryptosporidium removal potential for this facility is much
greater than 5.4-log. Consequently, 5.4-log removal would be consistent with the 5.0 automatic credits
Comment Response for LT2ESWTR D-48 December 2005
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potentially available for this facility if the IFE credit and other credits are realistically and appropriately
defined (3.0 credit baseline, 0.5 credit for second clarifier, 0.5 credit for pre-sedimentation, 0.5 credit for
CFE, and 0.5 credit for IFE). Therefore, although this facility can use the spore monitoring data to
establish a DOP credit >5.0 from raw to filter (or >4.8 from pre-sedimentation to filter), it is reasonable to
expect that a realistically and properly defined IFE credit would apply to this facility given the treatment
performance capability demonstrated from the spore data. Conversely, a definition of the IFE credit that
does not apply to this facility may be an indication that the credit is not appropriately defined.
Consequently, comparisons of spore monitoring data and IFE and CFE turbidity data for this facility and
a few others described in Chapter 4 are discussed later in this chapter in order to illustrate requirements
for the IFE and CFE requirements that are unrealistic and too restrictive, as well as those requirements
that appear more appropriate.
Additional Benefits
As recognized in the existing SWTR, filtration processes provide removal not only of Cryptosporidium
oocysts but also removal of Giardia cysts and viruses (Logsdon, 1987, 1988; Roebeck, 1962). The
IESWTR focused considerable attention on improving the performance of the filtration process, setting
not only a more stringent treatment technique but also drawing attention to controlling the variability in
turbidity from individual filters. While lacking a causal link between low-level turbidity and the risk of
waterborne disease, the Stage 1 M/DBP FACA recommended that the IESWTR incorporate a lower
turbidity standard as a measure of filtration performance. The Stage 1 M/DBP FACA reasoned, and
USEPA agreed in the subsequent rulemaking, that lower turbidity standards necessitated more stringent
operation of the treatment process thereby benefiting overall removal and that lower turbidity values also
resulted in greater control of turbidity levels over the course of the filtration cycle. Improved filtration
has similar positive benefits in that it provides another filtration barrier to pathogen passage, and provides
for more stringent control of treatment and therefore less variable effluent quality.
There are potential benefits for utilities and their customers if utilities are induced to make improvements
in facilities and operational practices in order to achieve the CFE and IFE credits. Conscientious and
forward thinking utilities, for example PSW members, will not need this inducement since these utilities
are usually already actively and continuously pursuing these improvements. However, utilities that
otherwise may not have pursued improvements in their facilities and operational practices may be induced
to make these improvements in order to attain realistically defined credits that these utilities consider
achievable. By contrast, the current IFE credit and some of the alternatives being considered are
unachievable by many facilities and most utilities readily recognize this. Consequently, a realistically
defined IFE credit (and other realistically defined toolbox credits) will not only produce direct
consequences regarding regulatory compliance for some utilities but may also produce indirect benefits
by encouraging utilities to pursue improvements in facilities and operational practices to achieve these
credits. The LT2ESWTR could benefit by more efforts to induce improvements that produce benefits for
the consumer rather than focusing so much on penalties and restrictions intended to control the drinking
water utility.
Application of the CFE and IFE Credits at Existing Facilities
Current definition of the CFE and IFE credit, and some alternatives proposed in this chapter
The requirements for the current CFE and IFE credits are summarized below, along with some
alternatives to the IFE credit:
* Current CFE credit = 95 percent of 4-hour readings each month <0.15 ntu
Comment Response for LT2ESWTR D-49 December 2005
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* Current IFE credit = two requirements, both must be met by each separate filter (i.e., worst performing
filter establishes compliance vs. non-compliance): a) 95 percent of daily maximum results (maximum of
96 daily readings recorded at 15-minute intervals) must be <0.15 ntu for the month and b) no two
consecutive 15-minute readings >0.3 ntu (this becomes 0.349 ntu due to rounding issues)
* Alternate IFE credit (15-minute data, each filter) = 95 percent of all 15-minute readings at each filter
<0.15 ntu (worst performing filter still governs, but calculations based on up to -2,880 readings per
month instead of ~30 with daily max). Eliminate requirement based on consecutive readings <0.349 ntu.
* Alternate IFE credit (cumulative IFE) = 95 percent of cumulative IFE data <0.15 ntu each month
(combined IFE data for all filters during the month, i.e., 8 filters could include up to -23,000 readings per
month). No consecutive readings requirement, as above.
The current rule defines the CFE credit as a 0.5 credit and the IFE credit as a 1.0 credit that can not be
used in combination with the CFE credit. The net maximum credit is 1.0 credit. The same net effect can
be achieved more simply by defining the two credits as separate 0.5 credits that can be combined, thereby
still resulting in a maximum credit of 1.0. The main impact of the current definition is that it promotes
confusion, and this certainly could not have been the actual regulatory goal. One other solution to this
dilemma would be to eliminate the IFE credit altogether and replace it with a modified CFE credit,
as described below.
Evaluation of current CFE and IFE credit definitions, and comparison to alternatives proposed in this
chapter
Table 5.2 compares ability of five surface water plants to comply with each of these CFE and IFE
requirements for a give time period (available data varies from 6 to 12 months, depending upon plant).
Also lists on the table, where appropriate, is the average number of filters each month that fail versus pass
all the requirements in a month. Each plant appears to be able to reliably comply with CFE requirement
almost every month. However, more filters fail than pass the requirements of the current IFE credit at
these five plants, and the IFE credit requires every single filter to pass these requirements in order to
get the credit. Replacing the current IFE requirement with a credit based on 15-minute IFE data at each
filter is slightly better, but most facilities, including the five listed, at best will only be able to meet the
reliably meet this requirement every month, and therefore these facilities would not be able to use this
credit if they could not count on it being available every month. Most other US facilities will not be able
to meet the current IFE requirement, and it is expected that facilities needing the credit (bin 2) will not be
able to reliably achieve the credit using the 15-minute alternative based on individual filters. However,
the cumulative IFE option appears to be a more realistic requirement that these facilities, and probably
other utilities, can reliably achieve every month. This cumulative IFE approach is analogous to the
approach used for the UV credit where compliance is based on the cumulative production of UV treated
water from al reactors throughout the entire month and not on the individual performance of each separate
UV reactor.
Facility "A" has collected daily spore monitoring data to accompany the IFE and CFE turbidity data. The
median raw water spore levels are 255,000 spores/L and finished water levels are <1 spore/L, below the
finished water spore detection limit of 1 spore/L 56 percent of the time. This results in a median spore
removal of >5.4-log. Since Cryptosporidium are removed more readily than spores, and since full
potential of spore removal at this facility is unknown since filtered water spore levels were below
detection limit, it is expected that the median Cryptosporidium removal potential for this facility is much
greater than 5.4 log. Consequently, 5.4-log removal would be consistent with the 5.0 automatic credits
potentially available for this facility if the IFE credit and other credits are realistically and appropriately
defined (3.5 total credits for two-stage lime softening, 0.5 credit for pre-sedimentation, 0.5 credit for CFE,
Comment Response for LT2ESWTR D-50 December 2005
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and 0.5 credit for IFE). Therefore, although this facility can use the spore monitoring data to establish a
DOP credit >5.0 from raw to filter (or >4.8 from pre-sedimentation to filter), it is reasonable to expect
that a realistically and properly defined IFE credit would apply to this facility given the treatment
performance capability demonstrated from the spore data. Conversely, a definition of the IFE credit that
does not apply to this facility may be an indication that the credit is not appropriately defined.
CFE and IFE data previously summarized in Table 5.2 for this facility are listed in more detail in Table
5.3 and Figure 5.2. The bars in the figure show the number of filters each month that fail the two
requirements for the current IFE credit (daily max and consecutive readings >0.3 ntu) and the alternate
IFE credit definition based on 15-minute data at each filter. The line on the figure shows the percentage of
cumulative IFE results that are <0.15 ntu each month. This facility with >5.4-log spore and
Cryptosporidium removal capability only had three CFE values for the entire year that were >0.15 ntu
(none >0.30 ntu) and consequently easily qualifies for the CFE credit. Yet this facility with this
demonstrated spore and Cryptosporidium removal capability can not come close to meeting the
requirements for the IFE credit, except the one based on cumulative IFE. In fact, this facility and the other
four facilities listed earlier could probably meet a cumulative IFE requirement of 97 percent <0.15 ntu
during most months.
Table 5.4 summarizes IFE data available from a facility with conventional clarification followed by sand
filtration, followed by a second filtration stage (post-filter GAC contactor). The facility did not provide
data to be evaluated for the CFE credit, either from the sand filters or the post-filter GAC contactor.
However, the facility did report spore and IFE monitoring data which can be compared and evaluated for
the portion of the facility from raw water through the first sand filter stage, and separately from raw water
through both filtration stages including the GAC filters. The measured median log spore removal was 3.3
log and 4.2 log through sand filter and GAC filters, respectively. None of the data evaluating IFE data
from the sand filters, including the cumulative IFE data, indicates that the facility would be eligible
for the IFE credit if this was the last treatment stage at the treatment plant. This is consistent with the
spore monitoring data which indicates only 3.3-log removal from raw water to this point in the treatment
process*. Conversely, spore removal from raw through GAC filtration was 4.2-log, consistent with a 4.0
or perhaps 4.5 log removal of Cryptosporidium*, and consequently consistent with at least 4.0 total
automatic credit for this facility based on 3.0 credits for core treatment, 0.5 credit for second filtration
stage, and 0.5 credit for CFE. The facility could qualify for the IFE credit at the GAC filters if the credit
is based on cumulative IFE data as shown in Table 5.4.
* Although Cryptosporidium removal through this portion of the process may possibly be 3.5-log or
greater since spore removal is a conservative indicator of Cryptosporidium removal. It should also be
noted that the 3.3 log removal is based on data collected from February to September 2003, and
consequently, may be slightly higher when data from a full year are collected by February 2004. Similar,
statements can be made with respect to the 4.2-log median spore removal from raw through GAC
filtration during this time period.
The current IESWTR already includes provisions to monitor, identify, and remediate conditions that lead
to turbidity spikes in individual filters. Consequently, the requirement in the current IFE credit regarding
consecutive turbidity readings >0.349 ntu is not necessary due to these existing provisions in the
IESWTR. Furthermore, these existing IESWTR requirements for individual filters may justify eliminating
the IFE credit altogether and instead replacing it with a modified CFE credit, as discussed below.
Proposed change in definition of CFE and IFE credits
One alternative to the IFE credit would be to eliminate the credit and replace it with a new CFE credit or a
second CFE credit. Literature data cited above establishes that improving finished water turbidity from
Comment Response for LT2ESWTR D-51 December 2005
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0.3 to 0.15 ntu versus <0.15 ntu results in an improvement in Cryptosporidium removal of more than 1.5
log. Consequently, a 1.0 credit for CFE (95 percent <0.15 ntu) would be consistent with these data, and in
fact would be conservative. Another approach would be to convert the CFE credit into a two-tiered credit.
The first tier would be a 0.5 credit for the current definition of the CFE credit (95 percent <0.15 ntu). The
second tier would be an additional 0.5 credit for some higher threshold, for example 97 percent <0.15 ntu.
In either case it would be possible for qualifying utilities to add a total 1.0 credit, thereby allowing a
facility with a clarification and filtration treatment process and the capability of 4.0-log or greater
Cryptosporidium protection to qualify for enough credits to satisfy bin 2 requirements (direct filtration
plants would have to get 0.5 credit from somewhere else in the toolbox, or use DOP). The current
IESWTR already includes provisions to monitor, identify, and remediate conditions that lead to IFE
turbidity spikes, so additional regulatory requirements for IFE turbidity data would not be necessary.
Summary
Existing surface water treatment systems are capable of providing more than the minimum 3.0 or 2.5
credits allowed for "core treatment" in the LT2ESWTR. In fact, existing literature cited earlier illustrates
that many existing treatment systems employing a clarification step followed by a separate filtration step
are probably capable of more than 4-log Cryptosporidium removal, perhaps as high as 5-log or higher.
Consequently, the microbial toolbox needs to include realistically defined credits for these utilities to use
to correct or adjust the 3.0 or 2.5 minimum core treatment credits to the 4.0 or higher credits these
facilities deserve. The DOP credit discussed in Chapter 4 is an important one of these correction or
adjustment credits. However, the CFE and IFE credits should also be realistically defined so that many
utilities can apply these credits to provide these corrections.
Existing literature data indicates that Cryptosporidium removal improves by at least 1.5-log, and it may
even increase as much as 3-log or more, when filtered water turbidity is reduced to <0.15 ntu versus
between 0.15 and 0.3 ntu. Consequently, some combination of CFE and IFE credits totaling up to 1.0
credit is a conservative correction for this improvement in finished water turbidity, and includes at least a
0.5-log safety factor. Facilities in need of more than 1.0 credit (e.g., direct filtration plants needing to
establish 4.0 total credits for bin 2) could attempt to use the DOP credit instead, or could combine the
CFE and IFE credits with other toolbox credits.
The current CFE credit is realistically defined and is achievable by facilities needing and deserving the
credit. However, the IFE credit as currently defined is excessively restrictive and inappropriate for
facilities that need the credit and should be able to qualify for an appropriately defined credit. The current
IFE credit includes two provisions. One provision requires 95 percent of the daily max to be <0.15 ntu
each month (daily max is the largest of the 96 turbidity readings collected at 15-minuite intervals from
midnight to midnight at a single filter). The second provision disallows the credit if any filter during a
month has two consecutive 15-minute readings >0.349 ntu. Even considered separately, these provisions
are unrealistically restrictive and unachievable by facilities needing to achieve the 1.0 credit correction.
Data reported in this chapter, most of which probably should be able to qualify for a realistically defined
credit, including some facilities with such high quality source water that they will be well within bin 1,
are unable to qualify for the credit as currently defined, nor are they likely to able to achieve the credit
on a consistent basis in the future.
Some numerical alternatives to the current IFE credit were proposed and evaluated. These alternatives
were an improvement, but some were still too restrictive. For example, replacing the daily max
(maximum of 96 daily 15-minute readings) with all 15 minute data (all 96 data points) or with 4-hour data
(6 of the 96 data points for each day) was an improvement, and could possibly be achieved at some
facilities with only minor refinements in operational practices. However, both of these alternatives are
probably too restrictive and ot readily achievable on a consistent basis by facilities that need the credit.
Comment Response for LT2ESWTR D-52 December 2005
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Alternatives for combined CFE and IFE credits which seemed most appropriate based upon results
discussed in this chapter include the following (alternatives 2 or 3 are probably most appropriate):
1. Keep current CFE credit as currently defined (0.5 credit), and modify the IFE credit to make it a 0.5
credit for facilities with 95 percent of the cumulative IFE data <0.15 ntu (cumulative IFE is based on
combining all 15-minute data from all filters in service during a month). The CFE and IFE credits can be
combined for a total of 1.0 credit.
2. Keep current definition of CFE credit, but increase the credit from 0.5 to 1.0 credit. Eliminate the IFE
credit from the microbial toolbox.
3. Convert current CFE credit into a two-tiered credit. The current definition of the CFE credit will be
used as the first tier, and will continue to be allowed a 0.5 credit. The second tier would be an additional
0.5 credit, or a total of 1.0 credits, for facilities meeting a higher threshold using CFE turbidity data, for
example 97 percent <0.15 ntu. Eliminate the IFE credit from the microbial toolbox.
In all cases, even if some form of the IFE credit is retained as in the first option above, it will not be
necessary to include a provision to monitor, identify, and remediate turbidity spikes in individual filters
since the existing IESWTR already includes provisions to address this issue. The requirement in the
currently proposed IFE credit disallowing the credit if two consecutive 15-minute readings are >0.349 ntu
should be eliminated, and other similar approaches should not be included to replace it. This provision is
excessively restrictive and unachievable by facilities that need and deserve the credits. Concerns this
provision were included for, specifically reduction of IFE turbidity spikes, are adequately addressed by
the current requirements of the IESWTR (and LT1ESWTR).
Bibliography
Cornwell, D., M. LeChevallier, M. MacPhee, N. McTigue, H. Arora, G. DiGiovanni, and J. Taylor. 2000.
Treatment Options for Giardia, Cryptosporidium, and other contaminants in Recycled Backwash Water.
Denver, CO: AwwaRF and AWWA.
Cornwell, D., R. Brown, M. MacPhee, and B. Wichser. 2003a. Application of the LT2ESWTR Microbial
Toolbox at an Existing Surface Water Treatment Plant.
Available: http://www.awwa.org/community/doc_view.cfm?id=190. [Cited November 12, 2003].
Cornwell, D., M. MacPhee, R. Brown, and S. Via. 2003b. Demonstrating Cryptosporidium Removal
using Spore Monitoring at Lime Softening Plants. Jour. WWA., 95:5:124.
Dugan, N., K. Fox, J. Owens, and R. Miltner. 2001. Cryptosporidium Control Through Conventional
Treatment. Jour. AWWA., 93:12:64.
Emelko, M. 2001. Removal of Cryptosporidium parvum by Granular Media Filtration. Ph.D. diss.
University of Waterloo, Waterloo, Ontario, Canada.
Hall, T., J. Pressdee, and N. Carrington. 1994. Removal of Cryptosporidium Oocysts by Water Treatment
Process. London, England: Foundation for Water Research Limited.
Huck, P., et al. 2001. Filter Operation Effects on Pathogen Passage. Denver, CO: AwwaRF and AWWA.
McTigue, N., M. LeChevallier, H. Arora, and J. Clancy. 1998. National Assessment of Particle Removal
Comment Response for LT2ESWTR D-53 December 2005
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by Filtration. Denver, CO: AWWARF and AWWA.
Nieminski, E. and W. Bellamy 2000. Application of Surrogate Measures to Improve Treatment Plant
Performance. Denver, CO: AwwaRF and AWWA.
Ongerth, J. and J. Pecoraro. 1995. Removing Cryptosporidium Using Multimedia Filters. Jour. AWWA,
87(12):83-89.
Patania, N., J. Jacangelo, L. Cummings, A. Wilczak, K. Riley, and J.Oppenheimer. 1995. Optimization of
Filtration for Cyst Removal. Denver, CO: AwwaRF and AWWA.
States, S., R. Tomko, M. Scheuring, and L. Casson. 2002. Enhanced Coagulation and Removal of
Cryptosporidium. Jour. AWWA, 94(ll):67-77.
Swaim, P., M. Heath, N. Patania, W. Wells, and R. Trussell. 1996. High-rate Direct Filtration for Giardia
and Cryptosporidium Removal. In Proc. of 1996 Annual Conference. Denver, CO: AWWA.
West, W., P. Daniel, P. Meyerhofer, A. DeGraca, S. Leonard, and C.P. Gerba. 1994. Evaluation of
Cryptosporidium Removal Through High-Rate Filtration. Proceedings of 1994 Annual Conference.
Denver, CO: AWWA.
USEPA. 2003. National Primary Drinking Water Regulations: Long-Term 2 Enhanced Surface Water
Treatment Rule. Fed. Reg. 68(154):47640-47795.
[See p. 108 of PDF for Table 5.1]
[See p. 110 of PDF for Table 5.2]
[See p. 111 of PDF for Table 5.3]
[See p. 112 of PDF for Table 5.4]
[See p. 113 of PDF for Figure 5.1]
[See p. 114 of PDF for Figure 5.2]
CHAPTER 6
LIME SOFTENING
Lime softening is a drinking water treatment process that uses chemical precipitation with lime and other
chemicals to reduce hardness and enhance clarification prior to filtration. Carbonate hardness can be
removed through use of lime alone, or in combination with soda ash to remove non-carbonate hardness.
Lower lime doses can be used to induce a pH of 9.4 or higher in order to remove calcium as a calcium
carbonate precipitate. Higher lime doses can be used to produce conditions of pH 10.6 or higher in order
to remove magnesium as a magnesium hydroxide precipitate (AWWA 1995, Benefield and Morgan 1999)
As in other drinking water treatment processes, materials removed from the water during the softening
process are concentrated in the residuals streams. The residuals streams not only include calcium
carbonate and magnesium hydroxide from the softening process, but also particulate material from the
raw water. The lime softening process is consequently not only a hardness removal process but also a
Comment Response for LT2ESWTR D-54 December 2005
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turbidity/particle removal process. Flocculation/solids-contact in the softening process that promotes
hardness removal also increases the likelihood of particle reduction through co-precipitation,
enmeshment, and collision/agglomeration of raw water particles with softening solids.
Although the softening process can remove hardness and particulate matter without use of "coagulants"
(aluminum- or iron-based salts or organic polymers), utilities often use small doses of coagulants on
either a continuous or intermittent basis to prevent fine calcium and magnesium precipitates from
passing through clarifiers and building up on the filters. These coagulants also add to the mass of material
collected in the residuals streams, though most of that mass at softening plants is composed of calcium
and magnesium solids.
As depicted in Figure 6.1, the softening process can include one or two clarification stages in series. The
single-stage or two-stage processes can utilize lime alone, or they can be supplemented with soda ash,
metal salt coagulants, or organic polymers. Some unit processes, like solids contact clarifiers, utilize
recirculation of softening solids within the unit process to increase the possibility of particle-particle
contact and to increase the density of the sludge blanket. However, some utilities also recycle softening
solids from clarifiers to earlier points in the treatment process in order to reduce chemical doses and
promote particle-particle collisions.
After softening, the water may pass through a recarbonation step where carbon dioxide gas is dissolved in
the water to reduce the pH. Depending on the dissolved carbon dioxide and bicarbonate alkalinity content
of the raw water, it is possible to reduce or eliminate carbon dioxide addition in the recarbonation step
through use of "split softening" as depicted in Figure 6.1. Under this scenario, a portion of raw water by-
passes treatment in order to produce the desired pFi/alkalinity of the mixed water.
Cryptosporidium Oocyst Removal and/or Inactivation
The literature contains few data demonstrating Cryptosporidium removal through lime softening, and no
pilot spiking studies using the lime softening process have been reported. Bell et al. (2000) report a 2-log
reduction of both Cryptosporidium and Giardia during precipitative lime softening during bench-scale jar
tests (i.e., equivalent to single-stage lime softening without filtration). Logsdon et al. (1994) reported data
from 13 full-scale, lime softening plants. For facilities where Cryptosporidium were detected in raw water
(6 plants), removal through sedimentation ranged from 1 to 2.3 logs, and from raw water through
filtration ranged from 2.5 to 3.5 logs.
A pilot study investigating the removal of aerobic spores and Cryptosporidium during single-stage lime
softening was conducted at the City of Austin (TX) Water and Wastewater Utility (Clark et al. 2001).
Because of the low raw water concentrations at this facility, both Cryptosporidium and aerobic spores
were spiked during the pilot study. The pilot study was conducted under similar conditions to the full-
scale facility, including lime and ferric sulfate doses (90 and 13.6 mg/L, respectively). Removal through a
single clarification stage followed by dual-media filtration was 1.5 to 2.0 log for aerobic spores versus
5.0 to 6.0 log for Cryptosporidium. The conservative removal of aerobic spores relative to
Cryptosporidium is consistent with other studies, although the difference between spore and
Cryptosporidium removal in the Clark et al. 2001 study is more pronounced than indicated in other
research (Nieminski and Bellamy 2000, Dugan et al. 2001, and others).
Occurrence and Removal of Other Indicators
The first preference when monitoring treatment effectiveness for a target organism would be to monitor
the target organism itself. Cryptosporidium monitoring has obvious limitations as a tool for monitoring
treatment performance because they are not always present in raw water, are typically found at low
Comment Response for LT2ESWTR D-55 December 2005
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concentrations when they are present, and analytical methods are poor. By contrast, aerobic spores are
ubiquitous in almost all source waters (especially surface water) at all times of the year, whether
Cryptosporidium is present or not, and are present in larger concentrations than Cryptosporidium.
In addition, analytical methods for enumeration of spores are more reliable and simpler than
Cryptosporidium methods, as will be discussed later. If no Cryptosporidium are present in the raw water,
Cryptosporidium monitoring does not allow determination of treatment efficiency. Conversely, aerobic
spore monitoring can evaluate the capability for Cryptosporidium removal throughout the year under a
variety of environmental conditions even when no Cryptosporidium is present in the raw water.
Literature data (see discussion in Chapter 4) indicates that Cryptosporidium are removed more efficiently
than spores in physical removal processes involving clarification and filtration, including processes
involving lime softening. Therefore, spore removal is a conservative indicator for the potential for
Cryptosporidium removal in lime softening and other processes. These findings are the basis for the
inclusion of aerobic spore monitoring at full-scale facilities as an option for the demonstration of
performance (DOP) credit. In addition, existing historical spore monitoring data from full-scale lime
softening plants can be used to illustrate the potential for spore and Cryptosporidium removal in these and
similar facilities in the US. Furthermore, some existing lime softening plants use spore monitoring as a
tool to help them evaluate and troubleshot treatment plant performance.
Facility Descriptions
This section includes data reported in Cornwell et al. (2003a) and a pending article by Cornwell et al.
[N.d.], including data from these studies describing aerobic spore monitoring at lime softening plants. The
five facilities involved in one or both of these studies are described in this chapter as facilities "A" though
"E". Descriptions of each are included in the following paragraphs.
Source water for facility "A" is primarily river water, supplemented with about 5 percent from local
groundwater wells. The treatment process includes pre-sedimentation followed by two-stage lime
softening. Lime (-220 mg/L) is added prior to the primary clarifier and cationic polymer is added prior to
filters during all seasons, with the same cationic polymer (<1 mg/L) and/or ferric sulfate (0.2 to 20 mg/L)
added prior to pre-sedimentation during periods of high raw water turbidity (>100 ntu), which typically
occurs about 50 days per year. Lime softening solids removed from the primary clarifiers are recycled to
the pre-sedimentation basin influent throughout the year. The softening pH is about 10 to 10.5.
Facilities "B" and "C" treat river water using processes that include pre-sedimentation prior to two-stage
clarification. Lime (-100 mg/L) is added prior to the primary clarifier, cationic polymer is added as a
filter aid, and cationic polymer plus ferric sulfate are typically added prior to pre-sedimentation and prior
to both clarification stages in the lime softening process. The combined doses at all three locations are
approximately 50-mg/L ferric sulfate and 4-mg/L cationic polymer. Softening solids are not recycled to
pre-sedimentation basins. The softening pH is about 10.
Facilities "D" and "E" receive about 85 percent of their source water from surface water reservoirs and the
remaining 15 percent from groundwater. Both plants use identical treatment processes with two
clarification stages. The first stage at both plants is preceded by alum coagulation and acts as a
conventional clarifier, with lime (Plant "D") or lime plus soda ash (Plant "E") added prior to the second
clarifier in order to produce softening. Plant "D" uses about 40-mg/L alum, 100-mg/L lime, and no soda
ash while Plant "E" uses 80- to 90-mg/L alum, 160-mg/L lime, and 60-mg/L soda ash (or occasionally 55-
mg/L caustic soda). These two facilities also use a softening pH of about 10.5. Differences between the
five softening facilities include the following:
* All five plants use two-stage clarification, but facilities "A", "B", and "C" also have pre-sedimentation
Comment Response for LT2ESWTR D-56 December 2005
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* Lime softening occurs in two stages at facilities "A", "B", and "C", but only in second clarification stage
at facilities "D" and "E"
* Lime and soda ash are used for softening at facility "E", while only lime is used at the others
Comparison of Cryptosporidium and aerobic spore occurrence
The five facilities have collected monitoring data demonstrating removal of total aerobic spores during
various stages of the lime softening process. Cryptosporidium data were also collected at these utilities;
however, oocysts were rarely detected in raw water and, consequently, it was not possible to calculate
oocyst removal. Table 6.2 includes Cryptosporidium and Giardia monitoring data from facility "A" that is
typical of most U.S. drinking water sources (USEPA 2003, Nieminski and Bellamy 2000) in that
Cryptosporidium is rarely detected in raw water at least partially because both the ICR and 1622/1623
methods lack sensitivity and specificity to provide data on occurrence. When Cryptosporidium were
detected in the raw water, concentrations were not high enough to demonstrate the full potential of the
treatment process to remove these organisms. In this study, Cryptosporidium was only found above
detection limits in 1 of 41 samples in raw water, and never in finished water. Giardia was detected at low
levels in a few more raw water samples (8 of 41), but Giardia was not detected in the finished water of
raw and finished water monitoring results from other utilities. Spores were detected more readily in
raw water than were Cryptosporidium, making it possible to calculate log removals at these three
utilities(-).
(-) All these utilities use analytical procedures described in Rice et al. 1996
Data were obtained for total aerobic spore concentrations at facility "A" from January 1, 2000 through
September 30, 2003, facility "B" from July 1998 through September 2000 and January through September
2003, facility "C" from March 2001 through October 2002 and January through September 2003, and
from facilities "D" and "E" during 1997 through 2000. Figures 6.2 through 6.6 illustrate the variation in
spore concentrations at various stages in the treatment process for facilities "A" though "E", respectively
(facilities "A" through "C" for one typical calendar year, and cumulative data for all four years at facilities
"D" and "E"). Comparison of the raw water concentrations reported by these utilities with data reported in
Table 6.3 from Nieminski and Bellamy (2000) and Rice et al. (1996) indicate that spore concentrations at
these four locations (especially facilities "A", "B", and "C") are much higher than typically observed at
other locations. The higher levels make it easier to demonstrate the potential for spore removal in the
treatment processes at these facilities than it might be at other US facilities with lower raw water spore
concentrations. However, the results in Figures 6.2 to 6.6 also indicate that most of the raw water spores
are removed prior to the filters, as will discussed in more detail in the next section.
Aerobic spore removal during lime softening
Figures 6.2 through 6.6 illustrate progressive removal of spores from raw water during each stage in the
treatment process at the five facilities. Figure 6.7 and 6.8 show the variation in log removal for all data at
facility "A" from raw through filtration (Figure 6.7) and from the pre-sedimentation basin through
filtration (Figure 6.8), the latter representing removal through the two-stage lime softening portion of the
process. These data represent the results of an analysis of the log removal calculated for each pair of data
(raw and filtered or pre-sedimentation and filtered) on each sample collection date.
The median of the paired log removal data in Figures 6.7 and 6.8 is summarized in Table 6.4 in the two
rows below "number of observations". Also listed are similar calculated values for the other four
facilities. One set of values lists log removal from raw through filtration, the other from pre-sedimentation
Comment Response for LT2ESWTR D-57 December 2005
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through filtration at each of the five facilities, as appropriate. The log removal is also calculated by taking
the log of the ratio of the median concentration data for raw, pre-sedimentation, and filtration (see
discussion in Chapter 4 regarding mean versus median for log removal calculations). Similar calculations
for log spore removal from raw through pre-sedimentation are presented later in Chapter 7. Please note
that these log removal calculations are biased due to the large number of censored (i.e., below detection
limit data) for filtered water results. Consequently, the actual removal of spores through filtration is
probably greater than the log removal values calculated in this table. Furthermore, since spores are
conservative indicators or Cryptosporidium removal, it is expected that the Cryptosporidium removal is at
least as high, probably higher, than the log removal values listed in this table.
Observations from data in Figures 6.2 through 6.8 and Table 6.4 are as follows:
* Facilities "A", "B", and "C" achieved about 5 log or greater spore removal from raw through filtration
(pre-sedimentation plus two-stage lime softening)
* These three facilities were capable of 4 log or greater spore removal for the two-stage lime softening
process following the pre-sedimentation basin (see discussion regarding facility "C" below)
* When lower filtered water detection limits were used at facility "A", it was able to demonstrate >5 log
removal from raw through filters and >4.5 log from the pre-sedimentation basin through filters.
* Each lime softening clarification stage typically achieved at least 1.5 log of spore removal, except for
the final clarification stage in facility "A" (see figures 6.2 to 6.6)
* Filtered water influent was typically <100 spores/L. For example, between 25 and 50 percent of filter
influent results for facilities "B" and "C" were <5 spores/L. Consequently, most of the spore removal
occurred prior to filtration. Flow surges and other conditions leading to particle detachment in filters can
not cause release of spores and Cryptosporidium that never make it to the filters (see discussion below).
Raw and filtered water concentrations for facility "C" were similar during the pre-2003 period as during
the 2003 sampling period. However, during 2003 the pre-sedimentation basin performance increased by
more than 1 log. Therefore, overall removal from raw to filtered was about the same during both periods
(4.5 to 5.0 log). However, since there were fewer spores in pre-sedimentation basin effluent during 2003,
the two-stage lime softening process was not challenged with enough spores during this time period to
demonstrate its true treatment potential. The 2001-2002 data indicate that the two-stage lime softening
portion of the process achieves >4 log spore removal when challenged with enough spores in the pre-
sedimentation basin effluent.
Improvement in early stages of the treatment process should be encouraged. For example, data discussed
above indicate that most spores are removed prior to filtration in lime softening plants. Furthermore,
efforts to further improve removal in existing clarification processes, or providing additional pre-
treatment such as pre-sedimentation should be encouraged, even if they do not result in measurable
improvement in filtered water spore concentrations. Since the final physical barrier to pathogen passage
are the filters, Cryptosporidium and other microorganisms that are removed prior to the filters will not be
susceptible to detachment from the filter if they never make it to the filter. Consequently, for example,
USEPA's concern in one of the comments associated with the DOP credit (Section IV.C.17 of the draft
rule) that improvement in a clarifier may not result in an increase in overall performance is not a
"concern" but rather is actually a desired outcome (i.e., what USEPA views as a negative, is actually a
positive that should be encouraged, not discouraged).
Filtration is still a good physical barrier to pathogen passage. For example, greater than 1.5 log removal
Comment Response for LT2ESWTR D-58 December 2005
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was achieved at facility "A", with the actual spore removal potential unknown since filtered water spore
levels were below detection limit. Literature studies indicate that when challenged, mono and dual media
rapid sand filters by themselves can remove about 3 log or greater of spores and Cryptosporidium (e.g.,
Huck et al. 2002 and Dugan et al. 2001). Therefore, the filters can act as an important barrier to
Cryptosporidium passage. However, while an additional barrier to pathogen passage could include post-
filter UV or other inactivation of Cryptosporidium and other pathogens that are detached from filters, a
better barrier would be to remove pathogens prior to filtration by optimizing existing clarification stages
as much as possible, or adding new clarification or pre-treatment structures (e.g., RBF, pre-
sedimentation).
Additional Benefits
There are a substantial number of benefits associated with softening beyond its functioning as a robust
coagulation-clarification process. With respect to regulated compounds, softening removes heavy metals
(i.e., arsenic, mercury, nickel, etc.), radium 226 and 228, some organic compounds, total organic carbon
(TOC), iron, and manganese. Softening reduces the need for the use of chemical disinfectants for algal
control and other oxidative applications prior to primary disinfection. It is useful in corrosion control in
some instances by increasing the Langelier Saturation Index; corrosion control is fundamental to
control of lead and copper levels under the Lead and Copper Rule. Softening resolves consumer hard
water issues including reducing household cleaning agent consumption, dissolved mineral levels, and
scale-formation.
Summary
Available data indicate that a typical single-stage softening processes routinely provides as much or more
Cryptosporidium removal as traditional coagulation-clarification- filtration treatment processes.
Consequently, drinking water treatment plants that practice lime softening should achieve an average 3-
log removal of Cryptosporidium, as was assumed for other clarification and filtration treatment
("conventional") plants in the Bin Requirements Table of the M/DBP Agreement in Principle. When a
secondary clarification step is included in a treatment process, such as with two-stage softening, available
data suggest that the second clarification step provides increased redundancy and stability to the treatment
train, plus an additional treatment barrier to the passage of protozoa into the potable water supply.
Consequently, an additional 0.5-log credit is appropriate for two-stage softening and other plant designs
that employ multiple, continuously operated, clarification processes in series.
Bibliography
Bell, K., M. LeChevallier, M. Abbaszadegan, G. Amy, S. Sinha, M. Benjamin, and E. Ibrahim. 2000.
Enhanced and Optimized Coagulation for Particulate and Microbial Removal. Denver, CO: AWWARF
and AWWA.
Logsdon, G., M. Frey, T. Stefanich, S. Johnson, D. Feely, J. Rose, and M. Sobsey. 1994. The Removal
and Disinfection Efficiency of Lime Softening Processes for Giardia and Viruses. Denver, CO:
AWWARF and AWWA.
Rice, E., K. Fox, R. Miltner, D. Lytle, and C. Johnson. 1996. Evaluating Plant Performance with
Endospores. JAWWA. 88(9): 122-130.
USEPA. 1996. ICR Microbial Laboratory Manual. Washington, DC: USEPA.
USEPA. 1999. Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA. Washington,
Comment Response for LT2ESWTR D-59 December 2005
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DC: USEPA.
USEPA 2003a. 40 CFR Parts 141 and 142. National Primary Drinking Water Regulations: Long-Term 2
Enhanced Surface Water Treatment Rule, Proposed Rule. Fed Reg. 68:154:47640.
[See p. 125 of PDF for Table 6.1]
[See p. 125 of PDF for Table 6.2]
[See p. 126 of PDF for Table 6.3]
[See p. 127 of PDF for Figure 6.1]
[See p. 128 of PDF for Figure 6.2]
[See p. 129 of PDF for Figure 6.3]
[See p. 130 of PDF for Figure 6.4]
[See p. 131 of PDF for Figure 6.5]
[See p. 132 of PDF for Figure 6.6]
[See p. 133 of PDF for Figure 6.7]
[See p. 134 of PDF for Figure 6.8]
CHAPTER 7
PRE-SEDIMENTATION
Pre-sedimentation is achieved through a clarifier or retention basin with the following characteristics:
* Continuously operated (i.e., all raw water from source must pass through basin before proceeding to
remainder of plant)
* Located prior to point at which entire flow reaches the "treatment plant" (i.e., prior to clarification and
filtration)
Metal salts, organic polymers, or recycled softening sludge are typically added in order to enhance
physical separation within the pre-sedimentation basin, though some facilities do not add coagulant on a
regular basis.
Off-stream storage and pre-sedimentation are similar in many respects in that both act as additional
barriers to Cryptosporidium exposure for drinking water consumers, and both provide general benefits to
subsequent treatment processes by equalizing the raw water source, including dampening of water quality
spikes. However, off-stream storage generally refers to structures such as lakes or reservoirs with storage
times on the order of weeks, versus pre-sedimentation that refers to tanks and retention basins with
storage times on the order of hours or days.
Cryptosporidium Oocyst Removal
Comment Response for LT2ESWTR D-60 December 2005
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Pre-sedimentation is also similar to conventional clarification, except that pre-sedimentation is only
intended to meet pretreatment objectives and, consequently, are often operated at higher overflow rates
than conventional clarification. Data are available demonstrating 1 log and greater Cryptosporidium
removal with conventional clarification (Edzwald et al. 2000, Cornwell and MacPhee 2001, Cornwell, et
al. 2001, Edzwald and Kelley 1998, Plummer et al. 1995, Dugan et al. 1999 and 2001, Hall et al. 1994,
Patania et al. 1995, and others).
Data regarding the removal of Cryptosporidium and total aerobic spores (including Bacillus subtilis)
during operation of full-scale pre-sedimentation basins have been collected independently by personnel
from four US utilities. Cryptosporidium oocysts were rarely detected in raw water at these locations
and, consequently, it was not possible to calculate oocyst removal through these processes. Spores were
detected more readily in raw water than were Cryptosporidium, making it possible to calculate log
removal of spores at these utilities, as summarized in Table 7.1.*
* All three utilities use analytical procedures similar to those described in Rice et al. 1996 to quantify
aerobic spores. Cryptosporidium and Giardia were analyzed using the ICR Method (USEPA 1996) prior
to Summer-Fall 2000, and Method 1623 (USEPA 1999) thereafter.
Facilities "B" and "C" both employ pre-sedimentation prior to two-stage lime softening. Coagulant
addition prior to pre-sedimentation basins at this plant typically includes ~0.1 mg/L of polymer and
occasional dosages of ferric sulfate (7-10 mg/L). Overflow rates ranged from 0.3 to 2.8 gpm/ft2. Figure
7.1 and 7.2 summarize distribution of raw and pre-sedimentation concentration data for facilities "B" and
"C", respectively. As summarized in Table 7.1, the median log removal of the paired spore samples at
facility "B" was 0.73 log during 1998-2000, and 0.79 log during 2003. By contrast, during 2001-2002 the
pre-sedimentation basin at facility "C" removed about 0.45 log of spores, but improvement in basin
operations increased this to >1.6 log during 2003. Turbidity data were reported from raw and pre-
sedimentation samples on the dates spore samples were collected during 2003 at both facilities, as
summarized in Figure 7.3. Calculated turbidity log removal compared to spore log removal on these dates
are summarized in Figure 7.4. These data show that turbidity removal may not be the best indicator, or an
appropriate indicator, of acceptable performance for pre-sedimentation basins. Table 7.2 summarizes
average turbidity (average of data collected once per day) each month for one calendar year (September
2002 through August 2003) for raw and pre-sedimentation samples from facility "B". One of the
requirements for the 0.5 credit for new pre-sedimentation basins will be to demonstrate at least 0.5 log
turbidity removal for average turbidity data for 11 out of every 12 months. However, this facility, which
achieves >0.7 log spore removal, can only meet this turbidity requirement 7 of 12 months. Therefore, this
requirement may not be appropriate to establish acceptable pre-sedimentation basin performance.
Total aerobic spore samples were collected at facility "A" from January 2000 through September 2003
from locations before and after pre-sedimentation. Sludge generated within the primary clarifier in the
two-stage lime softening process following the pre-sedimentation basin was recycled to the head of the
pre-sedimentation basins during the entire study period. When raw water turbidities were higher (>100
ntu) polymer dosages 0.5-1.0 mg/L and/or ferric sulfate dosages of 0.2-20 mg/L were added along with
recycle sludge prior to the pre-sedimentation basins. Exact overflow rate data are not available, but
calculations show that the overflow rates ranged from 0.4 to 0.9 gpm/ft2.
Figure 7.5 illustrates raw and pre-sedimentation spore concentrations for each year from 2000 through
2003. As noted in Table 7.1, the median spore removal in this facility is 0.6-0.7 log.
Facility "D" reported spore removal data for pre-treatment using lamella-plate settlers for periods from
1996 through 2002. This facility adds coagulant to the raw water (alum at 5.5-21 mg/L and polymer at
Comment Response for LT2ESWTR D-61 December 2005
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0.5-4.0 mg/L) prior to lamella basins. The pre-sedimentation overflow rate at average flow conditions is
0.52 gpm/ft2. Cryptosporidium and Giardia samples were collected from August 1992 through December
2000 and total aerobic spore samples from January 1998 through December 2000. The data summarized
in Table 7.3 and Figures 7.6 and 7.7 demonstrate that:
* Cryptosporidium was only detected once in the raw water and once in lamella basin effluent during the
study period
* Giardia was detected in about 35 percent of raw water samples and 12 percent of samples following pre-
sedimentation, with median log removal of about 1.5 for paired samples with detectable quantities of
Giardia in the raw water
* Median spore removal was 0.6-0.7
Primary clarification has been shown to be suitable for at least 1.0-log removal of Cryptosporidium prior
to filtration. Pre-sedimentation basins are similar, but can be operated at higher overflow rates since the
objectives are different. Spore removal data from the four facilities referenced above support a 0.5-log
removal credit for pre-sedimentation basins operated at overflow rates =3 gpm/ft2.
Additional Treatment Barrier
When coagulant addition is occurring and the treatment process is being actively managed to achieve
clarification, solids removal achieved in pre-sedimentation reduces the solids load on the primary
clarification process in the water treatment plant. The water treatment plant can operate the two processes
in a complementary fashion so that the overall treatment process is less dependent on the removal of
solids overflow during filtration.
Additional Benefits
Conventional drinking water treatment processes are operated in such a way as to match treatment (i.e.,
the addition of coagulant and operation of filters) to influent water challenge, in this instance particle
removal. While the coagulation-flocculation-clarification-filtration process is robust, an important
operational goal is process stability. Pre-sedimentation is a useful tool in managing the initial particulate
load reaching the primary treatment process. Pre-sedimentation not only begins the solids removal
process it also helps to equalize water quality reaching the primary treatment process. The equalization
can be used to address short periods of high contaminant concentrations (i.e., a chemical spill event).
Such an approach is used by the City of Philadelphia Water Department, and others. It also provides this
equalizing effect on a continuous basis at run-of-the-river facilities where the relative quiescence of the
pre-sedimentation process allows water quality to equalize and consequently represent a more consistent
constant challenge to the primary treatment train.
Summary
The data suggest that pre-sedimentation basins located prior to a point at which raw water flow reaches
the principal treatment train, and that are continuously operated using a coagulant (polymer, metal salts,
or recycled sludge), achieve a 0.5-log toolbox credit at overflow rates up to 1.6 gpm/ft2.
Bibliography
Cornwell, D. and M. MacPhee. 2001. Effects of Spent Filter Backwash Recycle on Cryptosporidium
Removal. JAWWA. 93(4): 153-162.
Comment Response for LT2ESWTR D-62 December 2005
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Cornwall, D., M. MacPhee, N. McTigue, H. Arora, G. DiGiovanni, and J. Taylor. 2000. Treatment
Options for Giardia, Cryptosporidium, and Other Contaminants in Recycled Backwash Water. Denver,
CO: AWWARF and AWWA.
Dugan, N., K. Fox, R. Miltner, D. Lytle, D. Williams, C. Parrett, C. Feld, and J. Owens. 1999. Control of
Cryptosporidium Oocysts by Steady-State Conventional Treatment. Proc. Of 1999 Annual Conference.
Denver, CO: AWWA.
Dugan, N., K. Fox, J. Owens, and R. Miltner. 2001. Cryptosporidium Control Through Conventional
Treatment. JAWWA, forthcoming.
Edzwald, J., and Kelley, M., 1998. Control Of Cryptosporidium: From Reservoirs To Clarifiers to Filters.
Water Science and Technology. 37(2): 1-8.
Edzwald, J., J. Tobiason, L. Parento, M. Kelley, G. Kaminski, H. Dunn, and P. Galant. 2000. Giardia and
Cryptosporidium Removals by Clarification and
Filtration Under Challenge Conditions. JAWWA. 92(12):70-84.
Hall, T., Pressdee, J., and Carrington, N. 1994. Removal of Cryptosporidium Oocysts by Water Treatment
Process. London, England: Foundation for Water Research Limited.
Patania, N., J. Jacangelo, L. Cummings, A. Wilczak, K. Riley, and J. Oppenheimer. 1995. Optimization
of Filtration for Cyst Removal. Denver, CO: AWWARF and AWWA.
Plummer, J., J. Edzwald, and M. Kelley. 1995. Removing Cryptosporidium by Dissolved-Air Flotation.
JAWWA. 87(9):85-95.
Rice, E., K. Fox, R. Miltner, D. Lytle, and C. Johnson. 1996. Evaluating Plant Performance with
Endospores. JAWWA. 88(9): 122-130.
USEPA. 1996. ICR Microbial Laboratory Manual. Washington, DC: USEPA.
USEPA. 1999. Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA. Washington,
DC: USEPA.
[See p. 140 of PDF for Table 7.1]
[See p. 141 of PDF for Table 7.2]
[See p. 142 of PDF for Table 7.3]
[See p. 143 of PDF for Figure 7.1]
[See p. 144 of PDF for Figure 7.2]
[See p. 145 of PDF for Figure 7.3]
[See p. 146 of PDF for Figure 7.4]
[See p. 147 of PDF for Figure 7.5]
Comment Response for LT2ESWTR D-63 December 2005
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[See p. 148 of PDF for Figure 7.6]
[See p. 149 of PDF for Figure 7.7]
CHAPTER 8
TWO-STAGE FILTRATION
The Surface Water Treatment Rule (40 CFR 141.73) (SWTR) promulgated by U.S. EPA in 1989 (54 FR
27486) requires drinking water plants that employ surface water or ground water under the influence of
surface water to employ filtration to remove Giardia lamblia, Legionella, and other waterborne pathogens.
Subsequently, U.S. EPA developed the Guidance Manual for Compliance with the Filtration and
Disinfection Requirements for Public Water Systems Using Surface Water Sources (SWTR Guidance
Manual). While filtration processes are many and varied, all rely on the passage of water through a bed of
media (i.e., sand, gravel, carbon, etc.). The SWTR Guidance Manual established rapid sand filtration in
combination with coagulation and sedimentation, as the benchmark filtration technology for the SWTR
performance objectives. Those performance objectives were 2-log removal of Giardia cysts and3 1-log
removal of viruses without disinfection. The SWTR Guidance Manual also recognized that some
filtration processes like slow sand and diatomaceous earth filtration provide greater removals (EPA 1990).
The SWTR Guidance Manual did not address filtration processes that typically provide <1 log of Giardia
removal nor did it address filtration in series. With promulgation of the Interim Enhanced Surface Water
Treatment Rule (IESWTR), U.S. EPA expanded the SWTR to encompass removal of Cryptosporidium.
The requirements of the IESWTR are also premised on the benchmark filtration technology of rapid
sand filtration following coagulation and sedimentation. In the IESWTR, the treatment performance
objective was =2-log removal for Cryptosporidium (EPA 1998). Consequently surface water treatment
plants will in 2001 be required to operate their rapid sand filtration processes to achieve more stringent
operational control levels. Like the initial SWTR guidance, the IESWTR did not address filtration
processes that provided less than 2-log Cryptosporidium removal nor did it address water treatment plants
that have multiple filtration processes.
Filtration processes can be generally characterized as unit operations where water passes through a bed of
granular filter media or other filtering material and solids are physically retained on the media (EPA
1999). The M/DBP FACA recommended credits for two-stage filtration stages involving a granular
media filter either preceded by a "roughing filter" or followed by a second filter. An example of the latter
includes post-filter granular activated carbon (GAC) contactors. Another example is a granular media
conventional rapid sand filter followed by a slow sand filter (though slow sand filters can also be used as
core treatment - see discussion in Chapter 3). Limited data are available for "roughing filters", and this
data does not support the credit originally envisioned in the FACA negotiations. Therefore, roughing
filters will not be discussed in this chapter. However, there is data supporting the use of two-stage
filtration, in particular using a second granular media rapid sand filter (e.g., GAC post-filter contactors)
and using slow sand filtration. These will be discussed separately below. Please note that the discussion
for slow sand filtration provided information supporting use of slow sand filtration for at least a 3.0 log
baseline credit when used as a stand-alone process, and consequently also supporting its use as at least a
2.5 log credit as a toolbox add-on (i.e., enough to meet requirements for all bins if slow sand filtration
combined with conventional clarification and filtration, or enough for bin 3 if combined with direct
filtration).
Credit for Second Rapid Sand or GAC Media Filter
Comment Response for LT2ESWTR D-64 December 2005
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The removal achieved through filtration processes is achieved through a number of mechanisms, many of
which are quite complex and not completely quantified. There is physical removal with depth in the filter
and also straining at the surface of the filter. Correctly operated depth filtration is reliant on transport
mechanisms including gravitational settling, diffusion, and interception. The specific mechanisms that
dominate in a particular filtration process are a function of that filter design and the chemical
characteristics of the particulates in the raw or treated water. Specific filtration systems take advantage of
different filtration mechanisms. Consequently, the total removal achieved by each multiple filtration
processes will be filtration system specific. However, available data suggest that multiple filtration steps
provide not only increased removal, but they also increase redundancy and stability to the treatment train.
Multiple filtration steps also provide an additional treatment barrier to the passage of protozoan into the
potable water supply.
Alternatives for incorporating multiple filtration processes in drinking water treatment include
* Rapid sand or dual media filter following another rapid sand or dual media filter,
* Granular activated carbon (GAC) filter following a rapid sand or dual media filter
Filters are increasingly employed as biologically active processes for removal of assimilable organic
carbon (AOC) associated with ozone disinfection. High rate filtration processes are also employed to
remove manganese. There will be an increasing number of granular activated carbon (GAC) contactors
installed to achieve compliance with the Stage 1 D/DBPR and Stage 2 D/DBPR. Some systems subject to
LT2ESWTR will make treatment changes including adding filtration processes like activated alumina and
ion exchange to meet more stringent arsenic levels recently promulgated by EPA (Number of WTPs
impacted dependent on arsenic MCL). Consequently, there will be an increasing number of facilities
which will need to install multiple filtration processes while complying with the LT2ESWTR. By
recognizing the multiple benefits of these additional filtration processes, the LT2ESWTR Microbial
Toolbox provides an additional incentive to systems wishing to invest in the principle of multiple barrier
treatment encouraged by the M/DBP FACA Agreement in Principle. In meeting multiple water quality
objectives the combined cost of compliance for the Stage 2 DBPR and LT2ESWTR will be reduced.
Removal of Cryptosporidium surrogates (spores)
Facility "D" described in Chapter 4 includes a conventional treatment facility which employs GAC
contactors for DBP, taste, and odor control after rapid sand filtration. This facility has compiled full-scale
spore monitoring data since 1999. Log removal of spores from GAC influent to GAC effluent are
summarized in Table 8.1 and Figure 8.1. These data indicate that mean and median log removal through
the secondary GAC filters, as an isolated process, is approximately >1 log. Furthermore, about 27 percent
of the GAC filtered water results were below detection limits (1 spore/L), the actual log spore removal
was probably greater than the calculated value from these results.
Additional Benefits
The IESWTR introduced more stringent operational controls to reduce turbidity in finished water. In the
IESWTR, EPA used turbidity as an indicator of treatment plant performance and found that managing
finished water effluent turbidity provided a suitable control measure where the treatment objective was
Cryptosporidium oocyst removal. The Cincinnati data set also includes turbidity measurements.
Comparison of individual sand filter and secondary filter effluent turbidities in Figure 8.3 illustrates that
the second stage GAC filter dampens or eliminates spikes and other intermittent releases of turbidities
from the preceding dual media filters during ripening, end-of-run, and other periods over the course of a
35 hour filter run. The Cincinnati data set shows that dual filtration will dampen turbidity spiking when
Comment Response for LT2ESWTR D-65 December 2005
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filtration consistently provides individual filtered water turbidities required by the IESWTR, suggesting
that additional benefits in solids removal and system redundancy are being achieved.
Summary
The data demonstrate a direct benefit of at least an additional 0.5-log removal for spores by the GAC
filter acting as a separate process. In addition, turbidity data demonstrate the ability of additional barriers,
such as a GAC filter following a dual media filter, to further dampen or eliminate intermittent particle,
turbidity, and microbial spikes from preceding processes. Due to the usefulness of a secondary filter to
remove additional particles, dampen spikes, and serve as an additional Cryptosporidium barrier, any filter
of conventional design (ES <1.3 mm, depth >24 inches) should be an effective secondary barrier, and
should receive a 0.5-log credit.
Slow Sand Filtration
Cryptosporidium Oocyst Removal
Data from Schuler et al. 1991, Hall et al. 1994, and EES et al. 2000 demonstrate >4-log removal in slow
sand filters during Cryptosporidium spiking studies. Timms et al. 1995 did not find any oocysts in
effluent from slow sand filters during similar spiking studies; however, at the raw water spiking levels
used, the filtered water detection limits were not low enough to demonstrate >3.6-log removal of
Cryptosporidium.
Schuler et al. 1991 (also described in Schuler and Ghosh 1991) describe results of challenge studies
conducted between March 1988 and January 1989 investigating removal of Cryptosporidium and other
microorganisms using pilot-scale slow sand filters. Pilot-filters were 0.286-m diameter (11.2 in), 0.90-m
deep (3 ft) composed of sand with effective size (dlO) of 0.27 mm and uniformity coefficient of 1.63.
Filter loading rates were 3.6 to 9.6 m/day (0.06 to 0.16 gpm/ft2). Temperature ranges tested were 4.5 to
16.5 (C. Raw water was seeded with Giardia muris (2,000 cysts/L), E. Coli. (10-2,400 organisms/L), and
inactivated Cryptosporidium parvum (2,000 oocysts/L). The slow sand filter used in this study was able to
achieve >4-log removal under all temperature and loading conditions tested.
Hall et al. 1994 reported data from Cryptosporidium challenge studies conducted between November
1992 and February 1994 using a slow sand filter with 2 m2 filtration area and 0.22- to 0.42-mm sand
media (depth not specified). The reported flow rate was 10 m3/d, resulting in a filtration rate of 5 m/d
(0.085 gpm/ft2). Some studies included removal of seeded Cryptosporidium by a slow sand filter (SSF)
preceded by a rapid sand filter (RGF), and others with a slow sand filter by itself. Two observations of
removal using SSF and RGF were <3.0 log, and three other observations were about 4 log. For removal
by SSF alone, three observations were ~4 log and one observation was <3 log. Therefore, whether or
not SSF was preceded by RGF, these studies generally demonstrate approximately 4-log Cryptosporidium
removal using slow sand filtration.
Timms et al. 1995 reported data from Cryptosporidium challenge studies using a slow sand filter with
1.13 m2 filtration area, sand depth 0.5 m, but filter media size was unspecified. The filtration rate was 0.3
m/hr (0.12 gpm/ft2) during the first 4.5 hours, and increased to 0.4 m/hr (0.16 gpm/ft2) thereafter. The
total study duration was 5.75 hours. Cryptosporidium was seeded for the first 3.5 hours, then unseeded
raw water was fed to the filter during the remainder of the study period. The authors report measuring an
average of 400,000 oocysts/lOOL in the filter influent, with measured concentrations ranging from 96,000
to 560,000 oocysts/lOOL. No oocysts were detected in the sand filter effluent throughout the study period.
This includes 20 samples with detection limits of either 133 or 2,000 oocysts/lOOL. At the seeded raw
water Cryptosporidium concentrations used during this study, the filtered water detection limits were not
Comment Response for LT2ESWTR D-66 December 2005
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low enough to demonstrate >3.6-log removal.
EES et al. 2000 describe a Cryptosporidium challenge study conducted in July 1996 (also described in
Krueger et al. 1999) in Salem, OR. Oocysts were seeded into raw, untreated water prior to two test filters
and allowed to pass through the filters continually for 4 hours at a filter loading rate of 0.12 gpm/ft2
(0.3 m/hr). Each filter has a sand depth of approximately 30 inches, with effective sand size (dlO) in one
filter of 0.29 mm and 0.33 mm in the other. Cryptosporidium oocyst concentration in the applied water
was approximately 820 oocysts/L in each filter. Filter effluent from each filter was monitored for 28
hours after the starting from the introduction of contaminants. During the first 12 to 13 hours during
which the spiked applied water passed out of the filters, all effluent from each filter was directed through
filter cartridges. For 13 hours after this period of continuous sampling, effluent was sampled
periodically for oocysts. No oocysts were detected in the filter effluent samples from either filter at any
time during the study period. With detection limit of 1 oocyst/lOOL, this indicates that removal of oocysts
was >4 log.
Removal of pathogens in slow sand filters is due not only to physical removal, but also due to microbial
antagonism (Bellamy et al. 1985b and Lloyd 1996 cited by Kohne and Logsdon 2001) resulting from
microbial competitors and predators within the upper, biologically active, layers of the filter
("schmutzdecke"). Furthermore, natural polymers produced by the microbial community within the
filter increase the ability of the pathogens, particles, and other materials in the influent stream to attached
to filter media (Wheeler et al. 1998 and Evans 1998, cited in Kohne and Logsdon (2001).
Because of the importance of the microbial population within the slow sand filter, factors which impact
the establishment and maintenance of the microbial community will also impact the capability of the slow
sand filter to act as a pathogen barrier. For example, new clean sand is less efficient than a mature,
biologically active slow sand filter for removal of bacteria, viruses, and protozoans. For example, Poynter
and Slade (1977) report that a biologically mature filter is capable of removing one log greater levels of
viruses than a new filter. Wheeler at al. 1988 (cited by Kohne and Logsdon 2001) reported 1-log
rotavirus removal in a biologically active filter versus no reduction in a sterile, acid-washed sand or sterile
clean sand filter. Chlorination applied prior to slow sand filters produces poorer particle and microbial
removal than without pre-chlorination, because the long lasting chlorine residual inhibits microbial
activity in the filter. Conversely, pre-ozonation breaks down influent organic material into more
biodegradable fractions and, since ozone residual does not last long, the result is enhanced biological
activity and improved removal of pathogens and other particles in slow sand filters.
Lower temperature can reduce microbial activity and, consequently, can reduce effectiveness of slow
sand filters for removal of organic and particulate matter, including pathogens. For example, Poynter ad
Slade (1977) reported about 1 log lower virus removal at 5-8(C (1.7-2.5 log) than at 16-18(C (2.8-4.5
log). Bellamy (1985b) reports 1-log lower removal of coliforms and heterotrophic plate count bacteria, a
reduction of from -99- to -90- percent removal, at 5(C versus 17(C.
However, the temperature impact on removal of protozoans, particularly Giardia and Cryptosporidium,
may not be as significant. For example, while Bellamy et al. (1985a and b) report higher effluent levels of
coliform and heterotrophic plate count at 5(C versus 17(C, the Giardia removal at each of these
temperatures was about the same (-2 log or greater). The authors did note that Giardia removal improved
to almost 100 percent in a mature filter bed as opposed to clean media. The implication, at least for
Giardia, is that once a stable microbial community is established in the filter under a given set of
conditions, including temperature, the filter should be able to remove almost 100 percent of influent
Giardia under these conditions.
Data on the impact of temperature on removal of Cryptosporidium by slow sand filters is not extensive.
Comment Response for LT2ESWTR D-67 December 2005
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Schuler et al. 1991 report about 4-log removal Cryptosporidium removal during all periods tested,
including temperature changes of 4.5-16.5(C.
Guidance for slow sand filtration design parameters are outlined in Hendricks 1991, Kohne and Logsdon
2001, Visscher 1990, and others.
Summary
Existing studies have shown >4-log Cryptosporidium removal during slow sand filtration. This data
justifies a 3.0-log baseline credit equivalent to a clarification and filtration treatment system, as defined in
the LT2ESWTR, for a slow sand filtration process operated as a stand alone system. A slow sand
filtration unit process added to a clarification and filtration system would be justified to receive a 2.5-log
credit as a toolbox component.
Studies on slow sand filtration have established that removal of bacteria and viruses are temperature
dependent due to the importance of biological processes for removal (due to presence of microbial
predators and competitors). However, Giardia removal during slow sand filtration has not been shown to
be temperature dependent, even though microbial activity of competitors and predators is also an
important contributor to Giardia removal in slow sand filters. It is believed that Cryptosporidium and
other protozoans will behave similar to Giardia in slow sand filters, meaning Cryptosporidium removal in
slow sand filters is probably not impacted by low temperatures, though studies explicitly addressing
temperature impacts on Cryptosporidium during slow sand filtration are not extensive.
Bibliography
AWWA/ASCE 1997. Water Treatment Plant Design; McGraw Hill. 3rd Edition. 1997.
Bellamy, W., D. Hendricks, and G. Logsdon. 1985b. Slow Sand Filtration: Influences of Selected Process
Variables. JAWWA. 77(12), 62-66.
Bellamy, W., G. Silverman, D. Hendricks, and G. Logsdon. 1985a. Removing Giardia Cysts with Slow
Sand Filtration. JAWWA. 77(2):52-60.
Economic and Engineering Services (EES), University of New Hampshire, Black and Veatch Consulting
Engineers, and Thames Water Utilities. 2000. City of Salem (OR) - Slow Sand Filtration Pilot Study
Report, Geren Island Treatment Facility Improvements - May 2000. Kansas City, MO: Black and Veatch
Consulting Engineers.
EPA 1990. Guidance Manual for Compliance with the Filtration and Disinfection Requirements for
Public Water Systems Using Surface Water Sources; EPA 570/9-89-018, October, 1990.
EPA 1998. National Primary Drinking Water Regulations: Interim Enhanced Surface Water Treatment;
Final Rule. 63 FR 69478 December, 1998.
EPA 1999. Guidance Manual for Compliance with the Interim Enhanced Surface Water Treatment Rule:
Turbidity Provisions. EPA 815-R-99-010. April, 1999.
Evans, H. 1998. Particle Removal within Biological Water Treatment Filters, Volume 1. Portfolio
submitted for partial fulfillment of the degree of Engineering Doctorate in Environmental Technology,
University of Surrey, Guilford, Surrey, UK p. 252.
Comment Response for LT2ESWTR D-68 December 2005
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Hall, T., J. Pressdee, and N. Carrington. 1994. Removal of Cryptosporidium Oocysts by Water Treatment
Process. London, England: Foundation for Water Research Limited.
Hendricks, D. ed. 1991. Manual of Slow Sand Filtration. Denver, CO: AWWARF and AWWA.
Kohne, R., and G. Logsdon. 2001. Slow Sand Filtration (Chapter 5). In Manual on Control of Microbes in
Drinking Water. Reston, VA: ASCE, forthcoming.
Krueger, R., D. Prock, D. Sundseth, and G. Logsdon. 1999. Salem, Oregon Expands and Improves its
Slow Sand Filtration Facility to Prepare for Water Quality and Regulatory Challenges. Proc. Of 1999
Annual Conference. Denver, CO: AWWA.
LeChevallier, M. and K. Au. 2001. Impact of Treatment on Microbial Water Quality: A Review
Document on Treatment Efficiency to Remove Pathogens. Washington, DC: World Health Organization,
forthcoming.
Lloyd, B. 1996. Chapter 14. The Significance of Protozoal Predation and Adsorption for the Removal of
Bacteria by Slow Sand Filtration (Chapter 14). In Advances in Slow Sand and Alternative Biological
Filtration. N. Graham and R. Collins, Eds. Chichester, England: John Wiley & Sons.
Poynter, S., and J. Slade. 1977. The Removal of Viruses by Slow Sand Filtration. Progress in Water
Technology. 9(l):75-88.
Schuler, P., and M. Ghosh. 1991. Slow Sand Filtration of Cysts and Other Particulates. Proc. of 1991
Annual Conference. Denver, CO: AWWA.
Schuler, P., M. Ghosh, and P. Gopalan. 1991. Slow Sand and Diatomaceous Earth Filtration of Cysts and
Other Particulates. Water Research. 25(8)995-1005.
Timms, S., J. Slade, and C. Fricker. 1995. Removal of Cryptosporidium by Slow Sand Filtration. Water
Science and Technology. 31(5-6):81-84.
Visscher, J. 1990. Slow Sand Filtration: Design, Operation, and Maintenance. JAWWA. 82(6):67-71.
Wheeler, D., J. Bartram, and B. Lloyd. 1988. The Removal of Viruses by Filtration Through Sand. In
Slow Sand Filtration: Recent Developments in Water Treatment Technology, Edited by N. Graham.
Chichester, UK: Ellis Horwood, Ltd.
[See p. 159 of PDF for Table 8.1]
[See p. 160 of PDF for Figure 8.1]
[See p. 161 of PDF for Figure 8.2]
CHAPTER 9
INDIRECT CREDITS - INTAKE MANAGEMENT AND RELOCATION
Defining "As Measured" Log Credit
The recommended Microbial Toolbox included seven treatment approaches for which the potential log
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credit was "as measured:"
Watershed Control: Reduction in oocyst concentrationReduction in viable oocyst concentration
Alternative Source: Intake relocation
Change to alternative source of supply
Management of intake to reduce capture of oocysts in source water.
Managing timing of withdrawal
Managing level of withdrawal in water column
The FACA recommended that, in these instances, additional monitoring for Cryptosporidium oocysts
after the action was taken would determine the new bin classification and whether additional treatment is
required. The FACA also recommended that when reductions are anticipated but not documented, post-
installation of treatment monitoring is appropriate. This approach will be effective in assisting WTPs
which make changes prior to conducting LT2ESWTR source water Cryptosporidium oocyst monitoring
to gauge their ability to comply with the rule's objectives. It will also be effective for monitoring to the
impacts of newly instituted operation changes, such as intake withdrawal management.
There will, however, be instances where proactive monitoring prior to implementation of a treatment
approach would be as informative as a post-treatment change following the monitoring effort. Examples
include intake relocation and use of alternative sources of water supply. In these instances, USEPA
proposes to allow oocyst concentrations collected prior to treatment approach changes to be used for bin
determination if the data are collected according to the requirements for the Cryptosporidium oocyst
source water occurrence monitoring. In these instances, the data will establish the source water bin that
best characterizes the source of supply on which the WTP will rely post-LT2ESWTR. It is believed that
this approach provides equity to systems that seek higher quality water sources with those that manage
Cryptosporidium risk through addition of treatment.
Intake management and intake relocation are not associated with direct automatic credits in the toolbox,
but instead can result in indirect credits by adjusting the bin assignment. A utility attempting to use the
intake relocation credit will be required to collect Cryptosporidium source water samples from the
existing intake, but can work out a protocol with the State to simultaneously collect samples at a
prospective alternate intake location. If the alternate location results in a lower bin assignment and if
sampling complies with requirements of the State approved protocol, the utility can construct the new
intake structure and use the bin assignment based upon the above results (until the second round of
sampling).
The indirect intake management credit in the toolbox is not associated with a specific structure or even a
defined program. Instead, it is recognition that a utility can reduce its Cryptosporidium risk at the intake
by monitoring upstream water quality and controlling depth and timing of withdrawals in a river or
lake/reservoir in response to events with high risk for Cryptosporidium exposure. These can include
natural events, like lake turnover or "first flush" after a rainstorm, but can also include acute man-made
events like wastewater spill and overflow events.
CHAPTER 10
RIVERBANK FILTRATION (RBF)
Current requirements for the RBF credit
Automatic 0.5 and 1.0 toolbox credits, including qualification as "UBT", are available for riverbank
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filtration (RBF). However, greater credits should be allowed via demonstration of performance (DOP).
This implicit possibility is included in the DOP discussion, but should also be explicitly mentioned in the
RBF discussion of the Rule and associated guidance manual. Also, it is interesting that a detailed
hydrogeologic assessment is required in order to be eligible for any automatic credits, and yet the results
of this assessment do not enter into the establishment of numerical value of the credit. After all of your
hydrogeologic assessments and subsurface sampling, the magnitude of the RBF credit depends on a
measurement made by a yardstick. This is not necessarily a negative development for water utilities.
Instead of the credit being determined on a case-by-case basis as a result of the hydrogeologic assessment,
facilities at least know an automatic minimum credit of 0.5 or 1.0 credit is available based on distance
from the surface water source. However, these utilities should also be allowed the possibility of even
greater credits if results of the hydrogeologic assessment justify it, or if DOP studies prove it, and credits
should not be limited to 0.5 or 1.0 and should not be based solely on distance measurements in all cases.
Bank filtration: a natural process
Bank filtration is defined by the guidance manual as a surface water pretreatment process using the bed
and bank of a river and the adjacent aquifer as a natural filter and relying solely on the natural properties
of the surface water bed and aquifer, unmodified by engineering works or activity, except for the recovery
of ground water via a pumping well. This definition of bank filtration characterizes this process by
emphasizing natural properties and filtration capacity of surface water bed and aquifer, but throughout the
guidance manual and Federal Register, significantly less importance and information is given to the
aquifer as far as its capability to achieve natural contaminants removal. Bank filtration includes physical,
chemical, and biological mechanisms impacting transport and removal of contaminants in porous media.
Some specific characteristics of certain zone, such as the river bed surface or interface, should not shadow
the main and key characteristics of the aquifer itself. As we will demonstrate in this document, through
the citations of peer-reviewed publications and description of key phenomena, both the river bed and the
aquifer are subject to filtration theory and perform natural effective contaminants removal when it comes
to transport and fate of contaminants in porous media.
Scouring
During flood events, the entrainment and deposition of sediment result in a decrease and increase in the
vertical position of an alluvial streambed, respectively. These fluctuations are known as scour and fill, and
represent sediment transfers in a channel, [Haschenburger, 1999]. The depth and activity depends on the
interactions between hydraulic forces and channel boundary, which are defined by its morphology and
sediment characteristics, and the magnitude and distribution, in space and time, of sediment transported to
and from a given location within a channel reach. Scour and fill processes exchange sediment between the
streambed and mobilized particles. These exchanges control the vertical and longitudinal sorting of
sediment throughout river channel [Parker, 1991; Hassan and Church, 1994; Hoey and Ferguson, 1994].
Scour and fill depths fluctuate within a channel [Jackson and Beschta, 1982; Laronne and Duncan, 1989;
Hassan, 1990] because of non-uniform, unsteady flow, heterogeneous bed material texture and
arrangement, variable bed configurations, and local sediment supply introduce complexity into the
process of sediment transfer during flooding events. The mean depth of scour for a given flow magnitude
dictates in part the rates of bed material transport [Einstein, 1937; Hubbell and Sayre, 1964]. It was
observed that some areas of the channel may not experience any bed activity, while in other locations the
maximum scour depth can extend to values as high as 8 times the surface layer [Lisle, 1995;
Haschenburger, 1996].
Scour and fill are two processes that take place when flooding occurs and should not be analyzed
separately, but as a combined natural process. Through these scour and fill processes, some sediments are
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removed and other are deposited on the river bed. In some cases, it will lead to temporary exposure of the
river-bed subsurface and in other cases, it will lead to new sediments been lay over the river-bed
subsurface. By exposing the river-bed subsurface, the interface is removed. It also allows contaminant to
be in direct or close contact to the aquifer itself. The potential bioclogging of the interface disappears and
better water pumping rate and production can be achieved, but also it is important and it will be
demonstrated later in this document, that the aquifer is able to have an effective filtration to ensure proper
water quality and contaminants removal. When fill occurs on the river-bed, it could be compared to a fast
and new interface development, ready to perform filtration with no bio-clogging at the beginning. In fact,
scouring and fill should be described as an natural and automatic regeneration of the interface or river-
bed, that could beneficiate or least that do not penalized bank filtration, allowing to achieve good water
production both in term of quality and quantity.
Bed forms and stream-subsurface exchange
Bed forms influence the exchange of solutes [Marion et al, 2002]. Stream-subsurface exchange fluxes are
based on channel hydraulics and subsurface flows. The stream and subsurface streamlines for flow over a
wavy porous boundary were derived by Ho and Gelhar [1973]. Marion et al. (2002) observed and
concluded that solute exchange from a flowing stream to a permeable sediment bed is dominated by
advection of water produced by head gradients at the porous media boundary. The existence of river-bed
forms induces an advective pumping flow that is mainly responsible for mixing phenomena in the
hyporheic zone. The subsurface flow is affected by the amplitude of bed topographical features and
their wavelength, which leads to cases where very different bed configurations produce the same amount
of solute penetration. A model developed by Elliott and Brooks [1997a] provides a direct explanation of
this behavior. Elliott and Brooks [1997a] used this type of fundamental approach to calculate the net
exchange resulting from stream flow over a sand bed. Sediment transport produces bed forms or
topographical features (dunes or ripples) on the bed surface. Then, flow over bed forms produces a
periodic variation in the dynamic head at the stream-subsurface interface that induces a corresponding
pattern of advective flow through the porous sand bed. Exchange is produced by flow into the bed at
regions of high pressure and corresponding flow out of the bed at regions of low pressure. The net stream
subsurface exchange due to this process is named "pumping" Savant et al. [1987]. Experiments with a
conservative dye demonstrated subsurface dye penetration due to pumping and verified that net
pumping exchange from the stream could be predicted using a fundamental hydraulic model [Elliott and
Brooks, 1997b]. Under typical stream flow conditions, advective pumping exchange is 2 orders of
magnitude greater than diffusive transport [Savant et al., 1987; Elliott and Brooks, 1997a]. In addition to
pumping phenomena, bed form motion produces additional mixing, termed "turnover" exchange. When
stream flow is high enough to mobilize bed sediments but flow is still subcritical, downstream-
propagating dunes and ripples can be often found. As a result, sediment transport causes scour of the
upstream side of bed forms and fill on the downstream side, producing a net downstream bed form
propagation. Pore water and stream water are then exchanged by this alternating scour and fill
(deposition) of the upper layer of the bed. A model was also developed for combined turnover and
pumping exchange due to relatively fast-moving bed forms, when turnover dominates the exchange in the
upper part of the bed where active bed sediment transport occurs [Packman and Brooks, 2001]. While
turnover rapidly mixes the upper layer of the bed, advective pumping produces exchange with the deeper,
un-scoured region of the subsurface region.
Bed formation and stream-subsurface exchanges demonstrate the natural and regenerating processes that
govern the interface or river bed formation. This bed formation is an important element of the bank
filtration that should also be emphasized as it is correlated to scour and fill issues. Bank filtration is
described to achieve the removal of contaminants by facilitating or enhancing physical and chemical
filtering, sorption, reduction/oxidation, precipitation, ion exchange, and biodegradation (Schijven et al.,
2003; Ray et al., 2002; Tufenkji et al., 2002).
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Filtration and Cryptosporidium
The interface is a location of an intense natural and biological removal processes, but straining and
filtration mechanisms, as well as biodegradation and predation phenomena are not limited to the interface
and occurred over the whole aquifer. Up to now, these contaminants removal processes have been
quantify and characterize for the whole bank filtration process, but not independently to assess the role of
the interface layer and the aquifer. It seems that this role is complementary, however, the interface and the
aquifer, have the necessary characteristics to function and achieve enough contaminant removal as a
combined process or as independent processes. The interface has the capacity to achieved contaminants
removal over short distance due to its intensive biofiltration process and enhanced physical filtration
(resulting bioclogging), while the aquifer also has the potential or removal of contaminants over long
distance due to physical filtration and extensive biofiltration. Physical filtration is the key component of
bank filtration, by its definition, both the interface and the aquifer possess the characteristics for effective
physical filtration.
Scouring phenomena may impact the bank filtration system, as it may remove a part of the river bed or
bank that are the location of an intense and active biological zone, where removal of contaminant is well
established and documented. However, removal of contaminant occurs in majority in that interface
zone, not only because of the biofiltering, but also, because this is the first filtering media that the water
from the river, carrying contaminants, encounter. This findings are related to the well established and
demonstrated porous media filtration theory and process.
Colloid transport studies in the literature have focused on the quantification of clean bed first-order
attachment coefficients to describe particle removal in filter beds (porous media) [Fitzpatrick and
Spielman, 1973; Tobiason and O'Melia, 1988; Vaidyanathan and Tien, 1991]. According to these research
and theoretical approach, colloid removal by the filter bed decreases exponentially with depth [Tobiason
and O'Melia, 1988; Amirtharajah, 1988, Packman and Bencala, 2000; Bradford et al., 2002]. Colloid
attachment theory also predicts an optimum particle size for transport for a given aqueous-porous medium
system [Tobiason and O'Melia, 1988]. Smaller particles are predicted to be removed more efficiently by
diffusive transport, and larger particles are predicted to be removed more efficiently by sedimentation and
interception.
As expected from the filtration theory, maximum eluent concentration, and fractional penetration of
Cryptosporidium. parvum decrease with smaller grain size and lower pore velocity leading to the largest
residual concentrations in the slow medium sand and fast fine sand experiments. The concentration
profiles in all but the fast coarse sand column show the largest concentration of oocysts near the top
(inflow boundary) of the sand column (Harter et al., 2000). Similar to outflow concentrations, sorbed
concentrations in the profile decrease exponentially with the distance from the inflow boundary, in
agreement with the filtration theory (Harter et al., 2000).
The statement in the guidance manual on bank filtration that most of the removal of the contaminants and
microbes occurs during the first few centimeters of flow path cannot be monopolized by the interface or
river bed characteristics and filtering and sorptive capabilities of sediments in the riverbed, simply
because, with the filtration theory and the experiments on Cryptosporidium, any porous media possess,
such as the aquifer, possess the same characteristics and is capable of contaminants removal within its top
layer.
Wang et al. (2002) found that removal of particles increased with filtration distance of the riverbank
filtration process, although most of the removal occurred at the surface of the riverbed, within the first
two feet of filtration. Wang et al. (2002) attributed the removal in their bank filtration system to a
Comment Response for LT2ESWTR D-73 December 2005
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combination of mechanical filtering and biological activity (e.g. biofiltering) at the surface of the
riverbed. These relevant findings demonstrated the effectiveness and complexity of the natural bank
filtration process, but also, do not take away the natural filtration and removal capacity of the aquifer
itself, once 2 ft away from the river bed. These findings corroborate the filtration theory and demonstrate
the effectiveness of both the riverbed and aquifer when it comes to contaminants removal, as removal of
particles increase with filtration distance.
Even if, scouring is significant and has a temporary impact on the river bed, the filtration theory and
experiment on Cryptosporidium demonstrate that filtration capacity exit in the aquifer, and that like in any
porous media, contaminants concentration in the profile decrease exponentially with distance
from the inflow boundary in the aquifer [Harter et al., 2000]. At the USEPA/USGS meeting of September
2003, data on log removal of Cryptosporidium were provided: 3.3 log removal at the interface and 0.6 log
removal in the aquifer. These data corroborate well the filtration theory as less contaminant is present as
you move away from the inflow boundary, which correspond to less contaminant removal in the aquifer,
because most of the removal has been achieve at the inflow boundary location, which was in that case the
interface or river bed.
In the Federal Register, it is stated that: "This proposal is generally supported by the colloid filtration
theory modeling results using data characteristics of the aquifers in Louisville and Cincinnati and column
studies of oocysts transport in sand (Harter et al., 2000)", however, it seems that the filtration theory is not
used properly in the text of the Federal Register, as in the original papers and research involving
Cryptosporidium [Tobiason and O'Melia, 1988; Harter et al., 2000], it clearly demonstrates the
phenomena of filtration in a porous media, and some of the conclusions presented in the Federal Register
can not be established if the filtration theory is followed and applied [See filtration theory described in the
section above].
LT2ESWTR Compliance Requirements
In the LT2ESWTR compliance requirements, systems that propose to install bank filtration wells to meet
any additional treatment requirements imposed by the LT2ESWTR may be eligible for 0.5 or 1.0 log
Cryptosporidium removal credit (40 CFR 141.726(c)). Additionally, systems using horizontal or vertical
wells located 25 feet from the surface water source are eligible for a 0.5 log removal credit and those
located at least 50 feet from the surface water source are eligible for a 1.0 log removal credit. In these
statements, no references to any experiments, theory or modeling is presented. It is important for the
public and the water industry to understand the processes that led to these criteria. It will serve the water
utilities to understand clearly how these 0.5 and 1.0 log removal were established in order to implement
bank filtration. In all criteria development, data and peer-review publication are keys to support new
approach or concept. In the case of bank filtration, little if no data is presented to support the criteria as
needed. Best engineering practice combined with knowledge and expertise of the different stakeholders
should be fully and extensively used for the development of criteria.
Data from Louisville and Cincinnati on the removal of spores or colloids demonstrate more than 3.0 or
4.0 log removal by bank filtration (Wang et al. 2002, Gollnitz et al. 2003). As a result, based on these data
and the filtration and removal theory describe above, more log removal credit should be available
to water utility that are developing bank filtration.
Characterization of the aquifer
Systems must characterize the aquifer at the proposed production well site to determine aquifer
properties. The characterization of the aquifer is essential to the development of the bank filtration site,
but instead of enhancing the log removal credit based on the findings of the aquifer characteristics, the
Comment Response for LT2ESWTR D-74 December 2005
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characterization of the aquifer seems to be use to limit the bank filtration applicability and does not
encourage its development. Characterization of the aquifer aims to focus on the core of the riverbank
filtration process, however, there is no characterization of the interface, although, this one appears to be
critical when it comes to give more credit removal or scouring issue. By characterizing the aquifer,
potential of contaminant removal can be determined and the best site can be selected to produce the best
water quality and in enough quantity, while giving more credit than the systematic 0.5 and 1.0 log
removal. All these characterization efforts should benefit the utilities with significant credit
encouragement. Determination and characterization of the aquifer is necessary and justify, but why
limiting and relating the removal credit to this interface, when characterization is concentrated towards
the aquifer itself, which will attenuate potential scouring effects, by its natural filtration as mentioned
previously.
Measurable criteria are based on aquifer characterization, key to the bank filtration process, but when it
comes to risk assessment, the natural properties of an aquifer that have been fully characterized are not
taken into consideration. Filtration is present in both the interface and the aquifer: biofiltration, bio-active
removal (degradation and predation) and physical filtration are intensive in the interface over a short
distance; while extensive biofiltration and intensive filtration occur in the aquifer, over a longer distance.
Filtrate flow path and well location
For systems to receive Cryptsoporidium log removal credits, the ground water flow path length between
the edge of the surface water body and the well is expected to be sufficient for effective oocysts removal.
It is well stated that the full distance between the river bed or bank to the well is included in the definition
and calculation of the process, so it is not limited to 2 feet of interface where intense biofiltering and
contaminants removal occurred. The description of the flow path demonstrated that in some cases the
bank filtration processes is described an independently process to achieved certain conclusion, while in
other cases, bank filtration is described as a whole process to achieved other goals and conclusion.
Consistency should be applied throughout the text while stating facts and drawing conclusions. The fact
that log removal credits is related to the distance between the edge of the surface water body and the well,
demonstrate the importance of the filtration theory in the bank filtration process, however, a more details
description of this filtration theory should be implemented in the guidance the guidance manual, as it will
clearly explained why more contaminants removal is obtained at the top of inflow boundary, and why less
contaminant is removed afterwards, as contaminants concentration (e.g. Cryptosporidium) in the profile
decrease exponentially with distance from the inflow boundary [Tobiason and O'Melia, 1988; Harter et
al.,2000].
Over-pumping and unsaturated zone
Over-pumping results in a decrease of the aquifer thickness and in a development and formation of an
unsaturated zone. The formation of the unsaturated zone - variably saturated zone - has advantages and
disadvantages regarding the fate and transport of the contaminants in the subsurface. Description of the
key processes occurring in the unsaturated zone, such as its role on contaminants transport and fate, could
benefit the section on the Bank Filtration. In addition, while USEPA chooses to dwell on some benefits of
over-pumping, it does not appear to sufficiently address some of the negative issues. The following is
a more complete list of potential advantages and disadvantages of over-pumping (i.e., excessive
drawdown) in RBF systems.
Advantages of unsaturated zone consist of potential contaminants entrapments through gas-water
interfaces, degradation and sorbption. The capillary zone, zone of high water content (not saturation) just
above the groundwater contained a significant number of gas-water interfaces that will allow high
potential entrapment of contaminants that combined with the top of groundwater will be an effective
Comment Response for LT2ESWTR D-75 December 2005
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porous media combination for physical filtration, [Wan et al, 1994a, 1994b; Darnault et al., 2003;
Darnault et al., 2004]. Additionally, physical, chemical and biological phenomena affecting the
contaminants fate, transportation and degradation are enhanced by gas-water interfaces.
The main disadvantage of unsaturated zone is preferential flow phenomena. Preferential flow (such as
macropores flow, fingered flow or funneled flow) facilitates the movement of water and the transport of
pollutants through the soil to the groundwater [Selker et al., 1996; Darnault et al., 2003; Darnault et
al., 2004]. Preferential flow not only facilitate the transport of pollutant to groundwater but also decrease
the residence time of pollutant in the soil matrix, which is generally a place of significant physical,
chemical and biological processes and activities leading to inactivation, degradation and transformation of
numerous pollutants. As a result, pollutants will reach groundwater rapidly and in high concentration
when subjected to preferential flow phenomena. These contaminants will then undergo filtration in the
groundwater, as described by the filtration theory.
Therefore, while USEPA is correct about the advantages they list, they fail to balance the discussion by
mentioning or emphasizing some of the disadvantages. Furthermore, when they mention the
disadvantages of over-pumping, they attribute the potential for decreased water quality to the decreased
thickness of the saturated aquifer, due to the formation of a large variably saturated zone, and that this
may cause faster ground water flow. Faster ground water flow provides less time for contaminants
attenuation within the aquifer. However, they do not acknowledge an additional factor with potentially
greater impact, the development of preferential flow paths in the unsaturated zone. Preferential
flow allowing rapid transport and less residence time throughout the unsaturated zone seems to have
greater effect on the fate and transport of contaminant than more rapid ground water flow and less
contaminant attenuation due to decreased thickness of the saturated aquifer. Preferential flow paths result
in rapid contaminant transport and degradation in the unsaturated zone, which then flow into a saturated
aquifer of reduced thickness, which may not be able to attenuate the pollutants.
A description of the preferential flow phenomena, advantages and disadvantages would benefit the
section 4.5.2 on filtrate flow path and well location.
Primary and secondary references
Throughout the chapter on bank filtration, secondary references are occasionally used, primary references
should also be added and incorporated to the text as they are the original source of phenomena or results
described or discussed.
Enclosed below are some examples of additional references that could contribute to the information on
the fate and transport of pathogens in soil and aquifers.
Bitton, G. and R.W. Harvey. 1992. Transport of pathogens through soils and aquifers. In R. Mitchell
(Editor). Environmental microbiology. Wiley-Liss, New-York, p. 103-124.
Fontes D.E., A.L. Mills, G.M. Hornberger, and J.S. Herman (1991) Physical and chemical factors
influencing transport of microorganisms through porous media. Applied Environ Microbiol 57: 2473-
2481
Mawdsley, J.L., A.E. Brooks and R.J. Merry. 1996a. Movement of the protozoan pathogen
Cryptosporidium parvum in three contrasting soil types. Biology and Fertility of Soils. 21: 30-36.
Mawdsley, J.L., A.E. Brooks, R.J. Merry and B.F. Pain. 1996b. Use of a novel soil tilting table apparatus
to demonstrate the horizontal and vertical movement of the protozoan pathogen Cryptosporidium parvum
Comment Response for LT2ESWTR D-76 December 2005
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in soil. Biology and Fertility of Soils. 23: 215-220.
Tufenkji, N., J.A. Redman, and M. Elimelech. 2003. Interpreting deposition patterns of microbial
particles in laboratory-scale column experiments. Environ. Sci. Technol. 2003, 37, 616-623.
Wan, J. and J.L. Wilson. 1994. Colloid transport in unsaturated porous media. Water Resour Res 30: 857-
864
Wan, J. and T.K. Tokunaga. 1997. Film straining of colloids in unsaturated porous media: Conceptual
model and experimental testing. Environ. Sci. Technol. 31:2413-2420.
Bibliography
Amirtharajah, A. Some Theoretical and conceptual views of filtration. J. Am.Water Works Assoc., 80,
36-46, 1988.
Bradford, S. A., S. R. Yates, M. Bettahar, and J. Simunek, Physical factors affecting the transport and fate
of colloids in saturated porous media, Water Resour. Res., 38(12), 1327, 2002
Brush, C.F., W.C. Ghiorse, L.J. Anguish, J.-Y. Parlange, and H.G. Grimes. 1999. Transport of
Cryptosporidium parvum oocysts through saturated columns. J. Environ. Qual. 28:809-815.
Darnault, C.J.G., P. Gamier, Y.J. Kim, K. Oveson, T.S. Steenhuis, J.-Y. Parlange, M. Jenkins, W.C.
Ghiorse, and P.C. Baveye. (2003). Preferential Transport of Cryptosporidium Parvum Oocysts in
Variably-Saturated Subsurface Environments. Water Environment Research 75:113-120.
Darnault, C.J.G., P. Gamier, K. Oveson, Y.J. Kim, M. Jenkins, T.S. Steenhuis, J.-Y. Parlange, P.C.
Baveye and W.C. Ghiorse. Preferential Flow and the Transport of Cryptosporidium Parvum Oocysts
through the Vadose Zone: Experiments and Modeling. (Accepted with Revisions, Vadose Zone Journal,
2004)
Einstein, H. A., Bedload transport as a probability problem, in Sedimentation, edited by W. H. Shen, pp.
C1-C105., Colo. State Univ., Fort Collins, 1937.
Elliott, A. H., and N. H. Brooks, Transfer of nonsorbing solutes to a streambed with bed forms:
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soils and aquifer sediments. Environ. Sci. Technol. 2000, 34, 62-70.
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APPENDIX A
ALTERNATIVE APPROACHES FOR MISSING CRYPTOSPORIDIUM SAMPLING EVENTS
* Option 1. Automatic assignment to bin 4
*How?
? If you miss one sampling event, you are automatically assigned to highest bin (bin 4)
*Pros
? Simple. Straightforward. Enormous incentive to utilities not to miss sampling dates. This is the option
that USEPA currently proposes to use.
* Cons
? Inappropriately severe penalty for missing just one sampling event, or even a few sampling events.
Completely unacceptable alternative, except perhaps for facility that has missed "too many" samples (how
many?).
* Option 2. Move up one bin level
*How?
? Calculate overall mean or MRAA using data that was collected (see option 3 below), determine bin
level based on this data, then move up one bin level.
* Pros
? Simple. Straightforward. Easy to calculate and explain.
* Cons
? Although not as severe as option 1, this still seems an inappropriately severe penalty for missing just
one sampling event. If this option is applied to facilities with a "few" missed sampling events (one or
two), this option is unacceptably severe.
Comment Response for LT2ESWTR D-79 December 2005
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? However, this option might be a reasonable intermediate between more acceptable options for missing a
"few" samples (one? Two? Three? More?) versus missing "too many". Therefore, one approach would be
to set one threshold for a "few" missed sampling events and use one of the less severe options below, set
another threshold and increase bin level by one when number of missed samples is under this second
threshold, then automatic assignment to bin 4 when you miss "too many". For example, first threshold
might be two missed samples, the next one five missed samples, and automatic bin 4 for more than five
missed samples.
* Option 3. Take overall mean or MRAA of data that was collected within 24 month period
*How?
? For 48 (or more) sample dates, take mean of samples that were collected and ignore missing dates (i.e.,
if two sampling dates missed, take mean of 46 samples that were collected)
? For 24 sample periods, calculate RAA for each 12 month period ignoring missing data (e.g., if sample
for 23rd month is missing then last two RAA values will be an average of the other 11 months in each of
the last two 12 month periods).
? For sampling schedules more aggressive than twice a month (i.e., more than 48 samples in two years),
this option should be the method of choice.
* Pros
? Simple (to explain and to perform). Straightforward.
* Cons
? How many can you miss? If one, why not two. If two, why not three, etc.
* Option 4. Take additional samples maintaining existing sampling frequency until required total number
of samples collected
*How?
? For each sample you miss, add one sample to the end of your previously scheduled sampling program
(two missed samples when sampling twice a month means you collect two samples in the 25th month to
replace the two you missed). Is it mandatory to wait until end of 24 month period to collect replacement
samples, or could they be collected any time?
*Pros
? Simple. Straightforward.
*Cons
? Even with this option, there may need to be a limit to number of samples you can miss. In order to use
this option we will need to show that the additional period for collection of replacement samples will not
delay certification of bin assignment by State (they need data 2.5 years after Rule published, so they can
certify bin placement by 3.0 years after Rule.
* Option 5. Replace the 48 sample option (two samples per month) with a 52 sample option (one sample
every two weeks, 26 samples per year)
*How?
? Schedule sample every two weeks, totaling 52 samples if all are collected. Then argue with USEPA and
State that any missed samples (up to 4) would be essentially equivalent to 48 samples collected twice per
month for 24 months. Option 5 is essentially a slight variation of Option 3.
* Pros
? Simple (to explain and to perform). Straightforward. Seems like a good compromise that utilities could
live with (especially compared with other less desirable alternatives) and may be good enough for
USEPA/States to accept. Cost increase for 4 more samples would be about $2,000-$2,500 per plant.
* Cons
? Will USEP A/States have a concern that utilities will schedule 52 sampling events, then when they get to
48 they will not have any incentive (in fact an enormous disincentive) to collect the remaining samples?
Also, if this option is acceptable (52 scheduled samples with an allowance for some missed samples),
Comment Response for LT2ESWTR D-80 December 2005
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why not just keep it at 48 and also allow some missed samples (i.e., just like Option 3).
* Option 6. Analogously to Option 5, replace the 24 sample option (one sample per month) with a 26
sample option (one sample every four weeks, 13 samples per year)
*How?
? Schedule sample every four weeks, totaling 26 samples if all are collected. Then argue with USEPA and
State that any missed samples (up to 2) would be essentially equivalent to 24 samples collected twice per
month for 24 months. For this option, MRAA would need to be calculated on 13 samples collected in 52
week period (or fewer samples if one or two samples are missing within a given 52 week period).
* Pros
? Same as Option 5. Cost increase for 4 more samples would be about $1,000-$ 1,500 per plant.
*Cons
? Same as Option 5.
* Option 7. Replace missing values with a replacement value
*How?
? Replacement value could be a variable (equal to maximum value of all samples that were collected), or
some pre-determined constant (related to bin thresholds? Established some other way?).
*Pros
? This is a way to keep within USEPA's approach to have evenly spaced samples for each 12 month
period, with a replacement value used to substitute for a missing value.
* Cons
? Determining numerical value to use for replacement of missing values may be difficult to do without
being arbitrary (but then so is deciding how many missing sample events are "too many").
? One drawback that could be argued for this approach is that if no limit is placed on the number of
missing samples, you could collect a few samples and never find any Cryptosporidium, then you could
stop collecting samples and use the maximum (zero) for missing values when calculating bin using this
option. Therefore, penalties may need to be included for missing more and more sampling events, plus a
maximum placed on the total number you can miss. For example, you could use the maximum or some
constant value for the first missing value, then a greater replacement value for the second missed sample,
still higher for the third, then keep going or just stop and say more than three missed samples (or some
other number of missed samples) means automatic bin 4.
* Option 8. Use MRAA for <48 samples
*How?
? For 48 or more samples, use option 3. For 24 to 47 samples, calculate RAA for each 52 week period,
then maximum RAA is MRAA. For <24 samples, use Option 2.
* Pros
? This is consistent with USEPA's definition for using MRAA versus overall mean (overall mean when
(48, MRAA when 24-47).
*Cons
? Option 3 is better.
* Option 9. Tiered approach
*How?
? Use one option for 48 or more samples, another for less than 48 samples up to a certain minimum
number of samples, then another option when below this minimum number of samples. For example, use
option 3 when number of samples is (48, Option 2 when 22-47 samples are collected, and Option 1 when
21 or fewer samples are collected.
APPENDIX B
Comment Response for LT2ESWTR D-81 December 2005
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GLOSSARY
Selected terms:
cyst = Form of Giardia that is found in the environment, including raw source water. Characteristics of
Giardia cysts and Cryptosporidium oocysts are similar (see "oocyst"), but two important differences
include: a) larger size of Giardia (~13 (im versus ~5 (im) and b) greater resistance of Cryptosporidium to
chemical disinfectants (free chlorine, chloramines, chlorine dioxide, ozone).
ICR Method = Analytical method used for Cryptosporidium during the ICR data collection period. This
method has since been superseded by Method 1623/1622 (USEPA 200la and b)
log removal = Refers to logarithm of reduction observed, i.e., logarithm of the ratio of influent to effluent
concentration. For example, 1 log equals a reduction by a factor of 10, 2 log equals reduction by a factor
of 100, etc.
Method 1623 = Analytical method used for Cryptosporidium analysis (USEPA 200la and b) as required
in the LT2ESWTR. Method 1622 and 1623 are identical with respect to analysis of Cryptosporidium,
with 1622 applying only to Cryptosporidium while 1623 applies to both Giardia and Cryptosporidium.
oocyst = An environmentally resistant structure formed during the normal Cryptosporidium life cycle. In
this form, the organism can not move by itself or multiply, but can cause infection in a host animal or
human after ingestion. The Cryptosporidium is released from infected hosts and is found in the
environment, including water, in this form.
the City = City of Richmond Department of Public Utilities, Richmond, VAAbbreviations:
AMWA = Association of Metropolitan Water Agencies
AWWA = American Water Works Association
AwwaRF = AWWA Research Foundation
BMP = Best management practices
CAFO = Combined animal feed operations
CFE = Combined filter effluent. In the Microbial Toolbox, the "CFE" credit is measured using monthly
turbidity data collected from the combined filter effluent
cfu/L = Colony forming units per liter
C1O2- = Chlorite ion
C1O2 = Inactivation with chorine dioxide
CT = Concentration multiplied by time, for example the IESWTR includes a "CT" requirement for
inactivation of viruses with different disinfectant chemicals
DAF = Dissolved air flotation
Comment Response for LT2ESWTR D-82 December 2005
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DBF = Disinfection by-products
DBPR = Disinfectants and disinfection by-products rule. Currently the Stage 1 DBPR is in effect, but this
will be modified by the Stage 2 DBPR scheduled to be promulgated in conjunction with the LT2ESWTR
DNA = Deoxyribonucleic acid
DOC = Dissolved organic carbon - dissolved fraction of TOC
DOP = Demonstration of performance
FACA = Federal Advisory Committee Act (the FACA committee working on the LT2ESWTR and the
Stage 2 DBPR is called the M/DBP FACA)
FBRR = filter backwash recycle rule
GAC = Granular activated carbon
GIS = Geographic information systems
gpm = Gallons per minute
GWUDI = Groundwater under direct influence of surface water
ICR = Information collection rule
IESWTR = Interim enhanced SWTR (current version of the SWTR). The IESWTR only applies to large
systems (serving > 10,000 people)
IFE = Individual filter effluent. In the Microbial Toolbox, the "IFE" credit is measured using monthly
turbidity data collected from the effluent in each individual filter
IM = Intake Management
L = Liter
LTIESWTR = Long-term 1 enhanced SWTR, which applies provisions similar to the IESWTR to small
systems (< 10,000 people)
LT2ESWTR = Long-term 2 enhanced SWTR (upcoming update of the IESWTR). Both small (< 10,000
people) and large (> 10,000 people) systems will be subject to this rule, except application to small
systems will be delayed by three years
M/DBP = Microbial and disinfection by-products = the term used to refer to the combined LT2ESWTR
and Stage 2 DBPR that will be jointly proposed and promulgated in 2003-2004
MCL = Maximum contaminant level (regulatory limit established by USEPA for a chemical or microbial
constituent in water)
MBF = Microfiltration membranes, typically capable of removing particles greater than about 0.1 (im
Comment Response for LT2ESWTR D-83 December 2005
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mg/L = Milligram per liter
mgd = Million gallons per day
MRAA = Maximum RAA (highest of the 13 RAA values)
MS = Matrix spike and recovery (see USEPA 200la and b)
NPW = Net present worth (or value)
O&M = Operation and maintenance
O3 = Inactivation with ozone
OPR = Ongoing precision and recovery (see USEPA 200la and b)
OS = Off-stream raw water storage
PAC = Project (or technical) advisory committee
PS = Pre-sedimentation
QA/QC = Quality assurance / quality control
RAA = Running annual average, calculated for each 12 month period. In a 24 month period there will be
13 RAA values, one for months 1 through 12, a second RAA for months 2 through 13, etc. with the final
RAA covering months 13 through 24 (see also "MRAA")
RBF = Riverbank filtration. Also called "in-bank" filtration.
SFBW = Spent filter backwash water
SWTR = Surface water treatment rule (and associated updates, e.g., IESWTR and LT2ESWTR)
TMDL = Total maximum daily load
TOC = Total organic carbon
UBT = Upper bin technology (see Table 1 or Figure 1)
USAGE = United States Army Corps of Engineers
USEPA = United States Environmental Protection Agency
USGS = United States Geological Survey
UV = Inactivation with ultraviolet irradiation
WCP = Watershed control program
Comment Response for LT2ESWTR D-84 December 2005
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WITAF = Water Industry Technical Action Fund, administered by the AWWA Water Utility Council
Response:
EPA Letter ID: 563
Comment ID: 16895
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 2
CRYPTOSPORIDIUM REMOVAL CREDIT
ASSIGNABLE IN THE LT2ESWTR TOOLBOX
Prepared for:
American Water Works Association
Government Affairs Office
Washington, D.C.
Prepared by:
David A. Cornwell, Ph.D., P.E.
Michael J. MacPhee, Ph.D.
RICHARD BROWN
Environmental Engineering & Technology, Inc.
Peer Reviewed by:
David Rexing, Southern Nevada Water Authority
DR. APPIAH AMIRTHARAJAH, GEORGIA INSTITUTE OF TECHNOLOGY
Steve Hubbs, Louisville Water Company
December 20, 2001
Mr. Steve H. Via
AWWA Government Affairs Office
1401 New York Avenue, North West
Suite 640
Washington, DC 20005
Dear Steve:
Enclosed please find the peer-reviewed document that addresses Cryptosporidium removal credit in the
LT2ESWTR for the following:
* Off-stream storage
* Pre-sedimentation
* Lime softening
* Improved filtration
* Multiple filtration processes
* Slow sand filtration
Comment Response for LT2ESWTR D-85 December 2005
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Discussions on relative removal of Cryptosporidium, aerobic spores and the impact of recycle on
Cryptosporidium removal are also included.
This document was peer-reviewed by Mr. David Rexing of the Southern Nevada Water Authority, Dr.
Appiah Amirtharajah at the Georgia Institute of Technology, and Mr. Steve Hubbs of the Louisville
Water Company. Appropriate changes have been made to the text based on their comments. A complete
set of comments along with the author's responses is appended to this document.
Please call if you have any questions or comments.
Sincerely,
ENVIRONMENTAL ENGINEERING & TECHNOLOGY, INC.
David A. Cornwell, P.E., Ph.D.
President
DAC/tgb
Enclosures
712 gum rock court - newport news, Virginia 23606 - (757) 873-1534 - fax: (757)
873-2392
CONTENTS
List of Tables vi
List of Figures vii
Executive Summary xi
CHAPTER 1: MICROBIAL TOOLBOX OVERVIEW 1
APPLYING TOOLS FROM THE MICROBIAL TOOLBOX TO ACHIEVE COMPLIANCE 2
CRYPTOSPORIDIUM MONITORING LOCATIONS FOR TOOLBOX BIN ASSIGNMENTS
SAMPLES
4
New structures 4
Existing structures 5
DEFINING "AS MEASURED" LOG CREDIT 6
CHAPTER 2: DEFINITION OF CONVENTIONAL TREATMENT 8
Summary 9
Bibliography 10
CHAPTER 3: RELATIVE REMOVAL OF CRYPTOSPORIDIUM AND AEROBIC SPORES 11
Summary 16
Comment Response for LT2ESWTR D-86 December 2005
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Bibliography 17
CHAPTER 4: OFF-STREAM STORAGE 19
Physical removal of Cryptosporidium Oocysts 19
Microbial antagonism 21
Additional treatment barrier 23
Additional benefits 24
Summary 24
Bibliography 25
Chapter 5: Pre-sedimentation 26
Cryptosporidium Oocyst removal 26
Additional treatment barrier 33
Additional benefits 33
Summary 33
Bibliography 34
CHAPTER 6: LIME SOFTENING 35
Cryptosporidium Oocyst removal 35
Additional treatment barrier 36
Additional benefits 41
Summary 41
Bibliography 43
CHAPTER 7: IMPROVED FILTRATION 44
Cryptosporidium Oocyst removal 44
Additional benefits 47
Summary 48
Bibliography 50
CHAPTER 8: MULTIPLE FILTRATION PROCESSES 52
Roughing filters 53
Cryptosporidium Oocyst removal 53
Comment Response for LT2ESWTR D-87 December 2005
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Additional benefits 54
Multiple filtration processes 54
Cryptosporidium Oocyst removal 56
Additional benefits 56
Summary 57
Bibliography 58
CHAPTER 9: SLOW SAND FILTRATION 59
Summary 62
Bibliography 63
CHAPTER 10: IMPACT OF RECYCLE PRACTICES ON CRYPTOSPORIDIUM REMOVAL 65
Summary 66
Bibliography 67
TABLES
1.1 MICROBIAL TOOLBOX COMPONENTS TO BE USED IN ADDITION TO EXISTING
TREATMENT 3
5.1 MEASURED REMOVAL OF BACILLUS SUBTILIS DURING PRE-SEDIMENTATION AT ST.
LOUIS 28
5.2 MEASURED REMOVAL OF BACILLUS SUBTILIS DURING PRE-SEDIMENTATION AT
KANSAS
CITY (WITH AND WITHOUT COAGULATION ADDITION)2 29
5.3 MEASURED REMOVAL OF CRYPTOSPORIDIUM, GIARDIA, AND TOTAL AEROBIC
SPORES
BY
LAMELLA PRE-SEDIMENTATION BASINS AT CINCINNATI 30
5.4 REDUCTION OF BACILLUS SUBTILIS DURING TWO-STAGE LIME SOFTENING
AT ST. LOUIS (WITH AND WITHOUT PRE-SEDIMENTATION) 32
5.5 REDUCTION OF BACILLUS SUBTILIS DURING TWO-STAGE LIME SOFTENING
AT KANSAS CITY (WITH AND WITHOUT PRE-SEDIMENTATION) 32
6.1 GIARDIA AND CRYPTOSPORIDIUM MONITORING AT KANSAS CITY, MO 36
6.2 REDUCTION IN BACILLUS SUBTILIS CONCENTRATIONS DURING LIME
SOFTENING PRECEDED BY PRE-SEDIMENTATION AT ST. LOUIS, MO: 1998 TO 2000
37
6.3 REDUCTION IN BACILLUS SUBTILIS CONCENTRATIONS DURING LIME SOFTENING
PRECEDED BY PRE-SEDIMENTATION AT KANSAS CITY, MO: JANUARY
THROUGH NOVEMBER 2000 39
6.4 REDUCTION IN TOTAL AEROBIC SPORE CONCENTRATIONS AT TWO LIME
SOFTENING PLANTS IN COLUMBUS, OH 40
Comment Response for LT2ESWTR D-88 December 2005
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FIGURES
Follows Page:
3.1 COMPARISON OF CRYPTOSPORIDIUM REMOVAL TO REMVOAL OF BACILLUS
SUBTILIS
OR OTHER TOTAL AEROBIC SPORES DURING DRINKING WATER TREATMENT 13
3.2 LOG REMOVAL OF SPORES AND CRYPTOSPORIDIUM DURING CLARIFICATION
ALONE, FILTER ALONE, AND COMBINED CLARIFIER + FILTER 15
3.3 LOG CRYPTOSPORIDIUM REMOVAL VERSUS LOG SPORE REMOVAL DURING MEDIA
FILTRATION 15
3.4 LOG REMOVAL OF AEROBIC SPORES AND CRYPTOSPORIDIUM OOCYSTS FOLLOWING
CLARIFICATION AND FILTRATION TREATMENT 15
3.5 LOG CRYPTOSPORIDIUM REMOVAL VERSUS LOG SPORE REMOVAL DURING DIRECT
FILTRATION PILOT STUDIES 16
4.1 DISTRIBUTION OF CALCULATED LOG SPORE REMOVAL VALUES FOR
OFF-STREAM STORAGE: CINCINNATI, OH 20
4.2 COMPARISON OF LOG REMOVAL FOR MICROBIAL INDICATORS DURING
OFF-STREAM RAW WATER STORAGE 20
4.3 LOG CRYPTOSPORIDIUM REMOVAL DURING OFF-STREAM RAW WATER STORAGE 20
5.1 DISTRIBUTION OF CALCULATED LOG REMOVAL OF BACILLUS SUBTILIS
DURING PRE-SEDIMENTATION AT ST. LOUIS 27
5.2 MEASURED SPORE LOG REMOVAL DURING PRE-SEDIMENTATION AS A
FUNCTION OF OVERFLOW RATE AND INFLUENT SPORE CONCENTRATION AT ST.
LOUIS 27
5.3 DISTRIBUTION OF CALUCULATED LOG SPORE REMOVAL VALUES FOR
PRE-SEDIMENTATION AT KANSAS CITY (WITH AND WITHOUT COAGULATION) 28
5.4 IMPACT OF RAW WATER CONCENTRATION ON REMOVAL OF BACILLUS SUBTILI
DURING
PRE-SEDIMENTATION AT KANSAS CITY (WITH AND WITHOUT COAGULATION ADDITION)
28
5.5 IMPACT OF RAW WATER SPORE COUNT ON LOG REMOVAL BY LAMELLA
PRE-SEDIMENTATION BASINS AT CINCINNATI 30
5.6 DISTRIBUTION OF CALCULATED LOG SPORE REMOVAL FOR LAMELLA
PRE-SEDIMENTATION BASINS AT CINCINNATI 30
5.7 REMOVAL OF SPORES THROUGH PRE-SEDIMENTATION ONLY 31
5.8 REMOVAL OF BACILLUS SUBTILIS DRUING TWO-STAGE LIME SOFTENING
AT ST. LOUIS (WITH AND WITHOUT PRE-SEDIMENTATION) 31
5.9 REMOVAL OF BACILLUS SUBTILIS DURING TWO-STAGE LIME SOFTENING
AT KANSAS CITY (WITH AND WITHOUT PRE-SEDIMENTATION) 31
6.1 SCHEMATIC OF LIME SOFTENING ALTERNATIVES 35
6.2 REDUCTION IN BACILLUS SUBTILIS CONCENTRATION DURING LIME
SOFTENING AT ST. LOUIS, MO: 1998-2000 37
6.3 DISTRIBUTION OF CALCULATED LOG SPORE REMOVAL VALUES FOR TWO-STAGE
LIME SOFTENING IN ST. LOUIS, MO: EXCLUDING PRE-SEDIMENTATION 37
6.4 REDUCTION IN BACILLUS SUBTILIS CONCENTRATION DURING LIME SOFTENING
AT KANSAS CITY, MO: JANUARY-NOVEMBER 2000 38
6.5 DISTRIBUTION OF CALCULATED LOG SPORE REMOVAL VALUES FOR TWO-STAGE
LIME SOFTENING IN KANSAS CITY, MO, EXCLUDING PRE-SEDIMENTATION 38
6.6 REDUCTION IN TOTAL AEROBIC SPORE CONCENTRATION DURING TWO STAGE
Comment Response for LT2ESWTR D-89 December 2005
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LIME SOFTENING AT COLUMBUS, OH: PLANT #1 40
6.7 REDUCTION IN TOTAL AEROBIC SPORE CONCENTRATION DURING TWO STAGE
LIME SOFTENING AT COLUMBUS, OH: PLANT #2 40
6.8 DISTRIBUTION OF CALCULATED LOG SPORE REMOVAL VALUES FOR TWO-STAGE
LIME SOFTENING IN COLUMBUS, OH 40
6.9 SPORE LOG REMOVAL DURING PRIMARY CLARIFICATION AT LIME SOFTENING
PLANTS
41
6.10 SPORE LOG REMOVAL DUIRNG SECONDARY CLARIFICATION AT LIME SOFTENTING
PLANTS
41
6.11 SPORE LOG REMOVAL DURING LIME SOFTENING: PRIMARY AND SECONDARY
CLARIFICATION COMBINED 41
6.12 SPORE LOG REMOVAL FROM PRIMARY CLARIFIER INFLUENT THROUGH FILTRATION
AT FOUR LIME SOFTENING PLANTS WITH TWO-STAGE CLARIFICATION PRECEDING
FILTRATION 41
7.1 IMPACT OF FILTERD WATER TURBIDITY ON REMOVAL OF CRYPTOSPORIDIUM
DURING FULL-SCALE STUDIES (I.E., REMOVAL OF AMBIENT, RAW WATER
OOCYSTS) 45
7.2 IMPACT OF FILTERED WATER TURBIDITY ON REMOVAL OF BACILLUS SUBTILIS
DURING FULL-SCALE STUDIES (I.E., REMOVAL OF AMBIENT, RAW WATER
SPORES) 45
7.3 IMPACT OF FILTERED WATER TURBIDITY ON REMOVAL OF TOTAL AEROBIC SPORES
DURING FULL-SCALE STUDIES (I.E., REMOVAL OF AMBIENT, RAW WATER
SPORES) 45
7.4 RELATIONSHIP OF FILTERED WATER TURBIDITY TO REMOVAL OF
CRYPTOSPORIDIUM
DURING COMBINED CLARIFICATION AND FILTRATION TREATMENT PILOT-SCALE
CHALLENGE STUDIES REPORTED IN THE LITERATURE 46
7.5 IMPACT OF FILTERED WATER TURBIDITY ON CRYPTOSPORIDIUM REMOVAL DURING
PILOT-SCALE CHALLENGE STUDIES 46
7.6 IMPACT OF FILTERED WATER TURBIDITY ON CRYPTOSPORIDIUM REMOVAL DURING
PILOT-SCALE CHALLENGE STUDIES (<0.15 TO 0.30) 46
7.7 CRYPTOSPORIDIUM LOG REMOVAL DUIRNG FILTRATION (OOCYSTS SEEDED PRE-
FILTER)
47
8.1 ROUGHING FILTER SCHEMATICS 53
8.2 DISTRIBUTION OF CALCULATED LOG SPORE REMOVAL VALUES FOR SECONDARY
(GAC) FILTRATION: CINCINNATI, OH 56
8.3 TYPICAL TURBIDITY PROFILE FOR DUAL FILTRATION 57
10.1 IMPACT OF RECYCLE PRACTICES ON CRYPTOSPORIDIUM REMOVAL 65
10.2 IMPACT OF RECYCLE PRACTICES ON BACILLUS SUBTILIS REMOVAL 65
10.3 IMPACT OF RECYCLE PRACTICES ON TOTAL AEROBIC SPORE REMOVAL 65
10.4 IMPACT OF SFBW RECYCLE ON CRYPTOSPORIDIUM LOG REMOVAL
DURING SEDIMENTATION: AWWA MASS BALANCE ANALYSIS 66
10.5 IMPACT OF SFBW RECYCLE ON PROCESS LOG REMOVAL FOR CRYPTOSPORIDIUM
(RAW TO FILTER): AWWA MASS BALANCE ANALYSIS 66
10.6 IMPACT OF SFBW RECYCLE ON PROCESS LOG REMOVAL FOR
CRYPTOSPORIDIUM (RAW + RECYCLE TO FILTER): AWWA MASS BALANCE
ANALYSIS 66
Comment Response for LT2ESWTR D-90 December 2005
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EXECUTIVE SUMMARY
This report includes a discussion of the technical basis for the Cryptosporidium log- removal credits
assigned for several items in the proposed Long-term 2 Enhanced Surface Water Treatment Rule
(LT2ESWTR) microbial toolbox. Included is a presentation of available literature data and full-scale and
pilot-scale data from U.S. drinking water utilities for the following toolbox components: off-stream raw
water storage, pre-sedimentation, lime softening (single- and two-stage), improved filtration (combined
filter effluent turbidity <0.15 ntu, 95 percent of the time), multiple filtration processes (separate
serial filtration stages), and slow sand filtration. Associated with information provided for each of these
individual toolbox components are additional support material that essentially apply to all toolbox items,
including: a) an overview of the regulatory basis for the microbial toolbox, b) a definition of
"conventional treatment" (i.e., the core treatment processes with which the toolbox components are
coupled), c) technical evidence suggesting a relationship between removal of Cryptosporidium and
aerobic bacterial spores (especially Bacillus subtilis) in drinking water treatment processes, and d) an
evaluation of the impact of recycle practices on log Cryptosporidium removal through drinking water
treatment.
Findings outlined in this report include the following:
- Conventional dual media or mono-media filtration following clarification treatment are assigned a 3.0-
log baseline Cryptosporidium removal credit in the LT2ESWTR toolbox. Toolbox components provide
additional log Cryptosporidium removal above the 3.0-log credit assigned for combined clarification and
filtration treatment
- Clarification technologies suitable for the 3.0-log Cryptosporidium baseline credit, if followed by a
conventional dual-media or mono-media filter operating in compliance with the Interim Enhanced
Surface Water Treatment Rule (IESWTR), include: gravity sedimentation basins, tube settlers, plate
settlers, sand-ballasted coagulation, dissolved air flotation (DAF), upflow solids contact reactor-clarifiers,
or buoyant or non-buoyant media upflow clarifiers
- No indicators have yet been identified that accurately reflect occurrence of Cryptosporidium in either
raw or finished water
- Numerous pilot and spiking studies indicate that total aerobic spores, as well as Bacillus subtilis spores
(a subset of total aerobic spores), are a reliable conservative indicator of Cryptosporidium removal using
clarification and filtration technologies typically employed for drinking water treatment, as long as water
is properly coagulated
- 0.5-log Cryptosporidium credit for 21-day off-stream raw water storage and 1.0 log for >60 day storage
are indicated from currently available literature data. Log credit for off-stream storage is associated not
only with Cryptosporidium removal, but also due to microbial antagonism (predators and competitors)
and natural die off
- Continuously operated pre-sedimentation basins are suitable for a credit of at least 0.5 log at loading
rates of at least up to 1.6 gpm/ft2 using coagulated water
- Single-stage lime softening, i.e., a single clarification stage followed by conventional filtration, is
suitable for at least a 3.0-log credit, identical to the credit assigned to other combined clarification plus
filtration technologies
- Two-stage lime softening (a second clarification stage added to single-stage softening) is suitable for a
total Cryptosporidium removal credit of at least 3.5 log, consistent with a 0.5-log toolbox credit added for
the second clarification stage
- Two-stage lime softening preceded by a pre-sedimentation basin provides at least 4.0-log
Cryptosporidium removal, consistent with a 0.5-log credit for pre-sedimentation and a 0.5-log credit for
the second clarification stage
- Log removals cited for lime softening are not dependent upon addition of a coagulant such as organic
Comment Response for LT2ESWTR D-91 December 2005
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polymer or a metal salt
- Available information indicate that achieving a 0.15-ntu combined filtered water turbidity (CFE)
achieves at least 0.5-log greater Cryptosporidium removal than a facility achieving 0.30 ntu in CFE
- Two filtration stages operated in series are capable of providing at least 0.5 log additional
Cryptosporidium removal above the level capable of being achieved by either of these filters acting alone.
Additional benefits of the second filtration stage is that it dampens turbidity spikes observed in first
filtration stage
- Slow sand filtration, when operated as outlined in the Surface Water Treatment Rule (SWTR), is
capable of achieving a 3.0-log baseline Cryptosporidium removal credit as a stand alone system, or a
>2.5-log credit as an add-on toolbox component
- Available studies demonstrate that recycle of spent filter backwash water, using acceptable practices
consistent with the Filter Backwash Recycle Rule, should not deteriorate Cryptosporidium removal
during conventional clarification plus filtration technologies, nor should it deteriorate log credits assigned
for individual toolbox components
CHAPTER 1
MICROBIAL TOOLBOX OVERVIEW
As described in EPA's December 29, 2000 (65 FR 83015) notice on the Stage 2 M-DBP FACA
Agreement in Principle, EPA, in consultation with nationally recognized experts and the FACA
participants, evaluated the occurrence of Cryptosporidium and the possible risk associated with
Cryptosporidium in drinking water. Despite the evaluation of a large amount of data, the FACA
recognized that uncertainty remains in a number of areas regarding the precise nature and magnitude of
risk associated with pathogens in drinking water. In light of this uncertainty, the FACA recommended a
series of balanced steps to address the areas of greatest health concern, taking into careful consideration
the costs and potential impacts on public water systems.
With respect to microbial pathogens, the FACA recognized that systems with poor quality source waters
may need to provide additional protection against Cryptosporidium. This concept is captured in the
"Microbial Toolbox" for the LT2ESWTR. The FACA also provided guidance as to appropriate treatment
barriers for systems that fell within specific source water Cryptosporidium oocyst occurrence "bins." In
recommending these treatment alternatives, the FACA was concerned with maintaining a balanced
approach to enhancing treatment given the uncertainty in the available data on occurrence and associated
risk. Consequently, the FACA weighed five factors in recommending treatment actions for potential
compliance with the LT2ESWTR:
1. Data on Cryptosporidium oocyst removal.
2. Effectiveness as an additional barrier to Cryptosporidium oocysts reaching finished water.
3. Other benefits such as
a. Reducing peaks in occurrence of pathogens,
b. Making other processes more stable or effective, and
c. Reducing other contaminants (i.e. TOC, DBP formation potential), etc.
4. Encouraging use of a variety of technologies.
5. Encouraging viable alternatives to UV disinfection.
Table 1.1 summarizes the resulting list of treatment approaches for the Microbial Toolbox and their
respective potential "log credit" recommended by the FACA. The magnitude of the log credit assigned
reflect the strengths of each toolbox component relative to the five factors listed earlier.
APPLYING TOOLS FROM THE MICROBIAL TOOLBOX TO ACHIEVE COMPLIANCE
Comment Response for LT2ESWTR D-92 December 2005
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The "Toolbox" concept developed by the FACA ensures the availability of a suite of individual tools that
could be applied at a particular drinking water treatment plant to reduce the risk of Cryptosporidium
oocysts entering the finished drinking water. The FACA's concerns included the diversity of water
quality challenges and treatment systems in use, as well as ensuring that water treatment plant (WTP)
improvements at individual utilities are as cost effective as possible and sufficiently flexible to attain
multiple drinking water treatment objectives.
Members of the FACA were very concerned that compliance with the LT2ESWTR not be dependent on a
single technology, particularly available disinfection technologies, such as ozone and UV disinfection.
The FACA and EPA recognized that ozone will be appropriate in some facilities, but future research on
the health effects associated with bromate and improved analytical methods to detect bromate may
support a lower bromate MCL in the Agency's next review of the bromate standard. While ozone use in
drinking water is a mature technology, UV disinfection is not. EPA believes that UV is sufficiently
developed to allow its use in compliance with the LT2ESWTR, but the lack of generally accepted UV
equipment verification systems, limited UV equipment production capacity, and lack of experience in
field preparation for and installation of UV systems at U.S. drinking water utilities that treat surface water
represent significant impediments to UV disinfection use under LT2ESWTR. In joining the other FACA
members in signing the Agreement, EPA made significant commitments to reducing some of the barriers
to UV disinfection implementation. With this proposal, EPA seeks comment on the status of UV
disinfection in the U.S., the guidance material EPA has prepared, and information on remaining barriers
to the implementation of UV disinfection under the LT2ESWTR.
[See p. 204 of PDF for Table 1.1]
Key to table symbols: (X) indicates potential log credit based on proper design and implementation in
accordance with EPA guidance. Arrow indicates estimation of potential log credit based on site specific
or technology specific demonstration of performance.
Table footnotes: (1) Criteria to be specified in guidance to determine allowed credit, (2) Inactivation
dependent on dose and source water characteristics, (3) Additional monitoring for Cryptosporidium after
this action would determine new bin classification and whether additional treatment is required.
The FACA discussion of the "Toolbox" concept also encompassed the use of multiple tools concurrently
to achieve an overall "log credit" goal. The FACA frequently pointed out the value of combining
activities to reduce source water oocyst levels with improvements in treatment at the plant. Likewise there
was discussion on the benefits of adding pre-treatment technologies like pre-sedimentation basins while
improving the performance of existing conventional treatment or adding a disinfectant like ozone or UV.
Recognizing that each item in the toolbox was selected by the FACA because of combined value of the
five factors considered for each item in the Toolbox, EPA proposes to treat the log credit associated with
each toolbox item independently and that they would be additive.
CRYPTOSPORIDIUM MONITORING LOCATIONS FOR TOOLBOX BIN ASSIGNMENT
SAMPLES
The FACA recommendations for the LT2ESWTR establishes requirements for more rigorous treatment
and source water protection strategies for raw water sources with greater potential risk of
Cryptosporidium exposure. Potential Cryptosporidium risk is established by collecting and analyzing two
years of Cryptosporidium monitoring data at the treatment plant influent. EPA proposes that the sampling
point for Cryptosporidium bin assignment be located either before or after off-stream storage, pre-
sedimentation (with or without coagulant), or in-bank filtration, depending upon whether these toolbox
Comment Response for LT2ESWTR D-93 December 2005
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items are in operation at the time the LT2ESWTR goes into effect, as described below.
New Structures
Off-stream storage, pre-sedimentation, and in-bank filtration facilities that are not in place prior to
required dates for Cryptosporidium monitoring will be granted the automatic 0.5 or higher log credit
outlined in the toolbox if they meet the requirements defined in the rule. After installation, facilities that
do not meet the requirements for an automatic log credit, or facilities that believe they can achieve a
higher log credit than is automatically given, can be granted a log credit based upon a "demonstration of
performance".
Existing Structures
Facilities with off-stream storage, pre-sedimentation, or in-bank filtration in place prior to the time
Cryptosporidium monitoring begins can collect their raw water Cryptosporidium bin assignment samples
from either the influent or effluent of these facilities. If collected from influent, then the toolbox
guidelines apply. If collected from effluent, then bin assignment is based upon collected samples and
toolbox credit is not applicable. At the utility's discretion, the utility can voluntarily collect samples at
both influent and effluent locations during the two years of Cryptosporidium sampling in order to
establish their bin assignment. At any time during this period, at the utility's discretion, the utility can
discontinue collection of the influent sample, and they will not be required to report the results of these
samples to state or federal regulatory agencies, and results do not need to be included in the Consumer
Confidence Reports (CCR) or other public disclosure documents.
At the end of the two year sample collection period, at the utility's discretion, the utility can proceed along
either of the following scenarios:
- Bin assignment can be based upon sample collected after off-stream storage, pre-sedimentation, or in-
bank filtration without regard to results from influent samples collected at these facilities. In this situation,
since the sample establishing bin assignment is collected from the effluent, no credit will be allowed for
the presence of the off-stream structure, pre-sedimentation basin, or in-bank filtration system
- Bin assignment can be based upon results of sample collected prior to off-stream storage, pre-
sedimentation, or in-bank filtration with the automatic 0.5 or higher log credit allowed as outlined in the
LT2ESWTR
- Bin assignment can be based upon results of sample collected prior to off-stream storage, pre-
sedimentation, or in-bank filtration with a 0.5 or higher log "demonstration of performance" credit
allowed depending upon the difference between the influent and effluent sample results
DEFINING "AS MEASURED" LOG CREDIT
The recommended Microbial Toolbox included seven treatment approaches for which the potential log
credit was "as measured:"
Watershed Control: Reduction in oocyst concentration
Reduction in viable oocyst concentration
Alternative Source: Intake relocation
Change to alternative source of supply
Management of intake to reduce capture of oocysts in source water.
Managing timing of withdrawal
Managing level of withdrawal in water column
Comment Response for LT2ESWTR D-94 December 2005
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The FACA recommended that, in these instances, additional monitoring for Cryptosporidium oocysts
after the action was taken would determine the new bin classification and whether additional treatment is
required. The FACA also recommended that when reductions are anticipated but not documented, post-
installation of treatment monitoring is appropriate. This approach will be effective in assisting WTPs
which make changes prior to conducting LT2ESWTR source water Cryptosporidium oocyst monitoring
to gauge their ability to comply with the rule's objectives. It will also be effective for monitoring to the
impacts of newly instituted operation changes, such as intake withdrawal management.
There will, however, be instances where proactive monitoring prior to implementation of a treatment
approach would be as informative as a post-treatment change following the monitoring effort. Examples
include intake relocation and use of alternative sources of water supply. In these instances, EPA proposes
to allow oocyst concentrations collected prior to treatment approach changes to be used for bin
determination if the data are collected according to the requirements for the Cryptosporidium oocyst
source water occurrence monitoring. In these instances, the data will establish the source water bin that
best characterizes the source of supply on which the WTP will rely post-LT2ESWTR. It is believed that
this approach provides equity to systems that seek higher quality water sources with those that manage
Cryptosporidium risk through addition of treatment.
CHAPTER 2
DEFINITION OF CONVENTIONAL TREATMENT
The Surface Water Treatment Rule (SWTR) and Interim Enhanced Surface Water Treatment Rule
(IESWTR) were premised on conventional treatment where conventional treatment was very broadly
defined. Implementation of the M/DBP FACA recommendations for Cryptosporidium removal,
particularly within the Microbial Toolbox concept will require more clarity in definitions associated
with LT2ESWTR.
The term "clarification and filtration treatment" applies to a treatment train employing separate,
sequential, unit processes for coagulation/flocculation, clarification, and granular media filtration.
Essentially, this is the same definition as the "direct filtration" definition, with the additional
requirement of a clarification step located between coagulant addition and granular media filtration. The
clarification step can include any solid/liquid separation process where accumulated solids are removed
during this separate component of the treatment system. This additional separation step serves as an
additional barrier to pathogen passage, as well as dampening raw water turbidity spikes prior to filtration.
Examples of clarification steps include, but are not limited to, the following:
- Traditional gravity sedimentation basins with continuous or intermittent sludge collection/removal,
including plate settlers, tube settlers, or other variations. This would also include sand ballasted
coagulation processes, known by trade names of "Actiflow" and other names
- Dissolved air flotation (DAF)
- Upflow solids contact clarification, including those known by trade names such as "Pulsator",
"Superpulsator", or others
- Buoyant or non-buoyant media, upflow clarifiers, including units such as "contact clarifiers" and similar
processes
Therefore, the LT2ESWTR will replace the term "conventional treatment" with the term "clarification and
filtration treatment" which is defined as a treatment train employing separate sequential unit processes of
coagulation/flocculation, clarification, and granular media filtration. Clarification is any solid/liquid
separation process with solids removal capability, including gravity sedimentation (traditional, plate, tube,
Comment Response for LT2ESWTR D-95 December 2005
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ballasted sand), dissolved air flotation (DAF), upflow solids contact, and buoyant and non-buoyant media
clarifiers. The clarification step is a separate barrier (i.e., treatment stage) and accumulated solids are
removed from this stage. "Clarification and filtration treatment" provides at least 3-log Cryptosporidium
removal when meeting IESWTR treatment technique turbidity requirements.
Direct filtration is treatment using coagulation/flocculation followed only by granular media filtration (no
separate solid/liquid separation barrier (clarification) prior to filtration). Available research (Patania et al.
1995, Nieminski 1995, Nieminski and Ongerth 1995, and West et al. 1994) indicates that direct filtration
consistently achieves removals of 2.5 log.
Summary
The LT2ESWTR needs to include an expanded and clarified definition of "conventional treatment"
beyond what is defined in the SWTR and IESWTR. The LT2ESWTR will replace the term "conventional
treatment" with the term "clarification and filtration treatment", which is defined as a treatment train
employing separate sequential unit processes composed of coagulation/flocculation, clarification, and
granular media filtration. The general definition of clarification includes any solid/liquid separation
process with solids removal capability. This includes processes such as traditional gravity sedimentation
basins, tube settlers, plate settlers, sand-ballasted coagulation, dissolved air flotation, upflow solids
contact reactor-clarifiers, and buoyant or non-buoyant media clarifiers. Such combined clarification and
filtration technologies are capable of achieving at least 3.0-log Cryptosporidium removal. Direct filtration
technologies, i.e., similar to the above but without a separate clarification stage, are consistently able to
achieve at least 2.5-log Cryptosporidium removal. Later chapters in this report present data establishing
that single-stage lime softening (Chapter 6) and slow sand filtration (Chapter 9) can act as stand alone
systems and achieve the same 3.0-log Cryptosporidium log removal credit as the clarification and
filtration technologies.
Bibliography
Nieminski, E. 1995. Effectiveness of Direct Filtration and Conventional Treatment in Removal of
Cryptosporidium and Giardia. Proc. of 1995 Annual Conference. Denver, CO: AWWA.
Nieminski, E. and J. Ongerth. 1995. Removing Giardia and Cryptosporidium by Conventional Treatment
and Direct Filtration. JAWWA, 87(9):96-106.
Patania, N, J. Jacangelo, L. Cummings, A. Wilczak, K Riley, and J. Oppenheimer. 1995. Optimization of
Filtration for Cyst Removal. Denver, CO: AWWARF and AWWA.
West, T., P. Daniel, P. Meyerhofer, A. DeGraca, S. Leonard, and C. Gerba. 1994. Evaluation of
Cryptosporidium Removal through High-Rate Filtration. Proc. of 1994 Annual Conference. Denver, CO:
AWWA.
CHAPTER 3
RELATIVE REMOVAL OF CRYPTOSPORIDIUM AND AEROBIC SPORES
At the raw water concentrations typically encountered in most raw water sources, the detection limit for
Cryptosporidium in raw water and intermediate points in a drinking water treatment plant does not allow
for calculation of the full log removal capability that water treatment processes are capable of achieving.
Consequently, some alternative is needed to establish and verify the performance of drinking water
treatment processes, as well as verifying improvements due to watershed protection or source water
Comment Response for LT2ESWTR D-96 December 2005
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control strategies. Several potential surrogates have been evaluated in recent years, including turbidity,
particle counts, heterotrophic plate count, algae, and others (McTigue et al. 1998, Hendricks et al. 2000,
Nieminski and Bellamy 2000, Nieminski and Ongerth 1995, and others). However, these studies all
demonstrated that there are no suitable surrogates for Cryptosporidium.
Inactivated Cryptosporidium oocysts have been used during pilot and bench-scale spiking studies in order
challenge the system with a high enough Cryptosporidium concentrations to demonstrate the actual level
of Cryptosporidium removal that the system is capable of achieving. Unfortunately, spiking of full-scale
systems cannot be performed due to cost, potential health risks, etc.
It would be desirable to use a suitable naturally occurring indicator for Cryptosporidium that is present at
high enough levels (and with a low enough analytical detection limit) to demonstrate removal/reduction
associated with water treatment or source water control strategies. Ideally, Cryptosporidium would be
removed to roughly the same degree, or perhaps a little belter, than the proposed natural surrogate. If such
a naturally occurring surrogate could be used for the full-scale system, the surrogate would also need to
be suitable for use in pilot and bench-scale spiking studies. Use of the surrogate in pilot and bench-scale
spiking studies would be necessary in order to compare with full-scale removal of the naturally occurring
surrogate in order to demonstrate scale-up.
Various investigations reported recently (Rice et al. 1996, Coallier et al. 1996, Dugan et al. 1999 and
2001, Yates et al. 1998, Emelko 2001, and others) have used total aerobic spores, or a subset of this
group, Bacillus subtilis as indicators of removal of particles in the Cryptosporidium size range.
Characteristics of total aerobic spores, including Bacillus subtilis, include:
- Naturally present in most source water (Nieminski and Bellamy 2000, Jakubowski et al. 1996)
- Do not pose health risks (Jakubowski et al. 1996, Rice et al. 1996)
- Can be detected at very low concentrations (
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viruses, and somatic and male specific coliphage. Conclusions cited by the authors included the
following:
- Giardia and Cryptosporidium were found in more than half of raw water samples.
- With current detection limits for Giardia cysts and Cryptosporidium oocysts, these cysts and oocysts are
not found at high enough concentrations in raw water, or at intermediate points in water treatment
processes, to demonstrate the log removal that water treatment processes were capable of achieving.
- Total aerobic spores, and separate quantification of Bacillus subtilis, were found at high enough
concentrations in most raw water sources to be suitable indicators of treatment performance. Even when
present at low raw water concentrations, removal of these spores could still be used as relative indicators
of treatment performance.
- Although total aerobic spores, including Bacillus subtilis, are suitable indicators for treatment
performance, none of the potential surrogates tested, including aerobic spores, proved to be suitable
indicators for Giardia or Cryptosporidium occurrence in raw water or in filtered water.
- Anaerobic spores (including Clostridium perfringens), did not prove to be suitable indicators of Giardia
or Cryptosporidium presence in raw source waters, nor did removal of these potential indicators correlate
with the removal of cysts and/or oocysts during water treatment.
Data from Nieminski and Bellamy 2000 for Cryptosporidium, Bacillus subtilis, and total aerobic spores
are summarized in Figure 3.1. These data demonstrate that both Bacillus subtilis separately, and total
aerobic spores as a group, show similar log removal to Cryptosporidium. It is important to note that the
calculated values for log removal in this figure were based upon using the value of the detection limit
when these organisms were found below detection limits in filtered water. In other words, the true log
removal is actually higher than the numerical value calculated in each of these instances. This is less of an
issue for the total aerobic spore results since most of the filtered water samples had total aerobic spore
levels above detection limits (85 percent of filtered sample results were above detection limits). However,
since most of the filtered water results for Bacillus subtilis (76 percent) and almost all of the
Cryptosporidium results (78 of 80, or 98.5 percent) were below detection limits, the true log removal of
these organisms is actually higher than indicated in Figure 3.1. Data from other studies indicate that
removal of total aerobic spores and Bacillus subtilis are conservative indicators of Cryptosporidium
removal, meaning that Cryptosporidium removal is greater than removal of these bacterial spores.
However, due to the numeric limitations of the data set listed in Figure 3.1 (i.e., the underestimation of
Cryptosporidium removal), the full extent of Cryptosporidium removal in these studies is not known.
Consequently, it is not possible to use this data set to verify that Cryptosporidium is removed less
effectively than bacterial spores, the data are only sufficient to demonstrate that Cryptosporidium removal
is at least similar (i.e., on same order of magnitude) to removal of bacterial spores.
Pilot plant data where higher loadings and more defined conditions can be evaluated provide strong
support for the use of aerobic spores as being conservative indicators when evaluating oocyst removal
achieved through treatment. Dugan et al. 1999 and 2001 summarize data from a study during which
approximately 108 oocysts/lOOL were spiked into Ohio River raw water treated by a 0.45 L/min pilot
plant. The pilot plant included coagulant addition (alum or ferric chloride), rapid mix (195/s, 90 s)
flocculation (tapered - 56, 31, 20, 11/s), sedimentation (0.04 gpm/ft2), filtration (2 gpm/ft2, mono-media
sand, mono-media anthracite, or dual media sand and anthracite). The raw water was not spiked with
aerobic spores, but did have measurable background total aerobic spore counts. Sampling included total
aerobic spores and Cryptosporidium oocysts at the following monitoring points: after oocyst spike was
applied to raw water, after sedimentation, and after filtration. The study included 3-9 experimental
runs each for 10 different experimental conditions. Five of the experimental conditions were conducted at
coagulant conditions that can be described as stable or normal dosages. The other five test conditions
were purposely conducted at lower than required coagulant dosages.
Comment Response for LT2ESWTR D-98 December 2005
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Results of log spore removal versus log Cryptosporidium removal under the conditions tested during this
study are summarized in Figure 3.2, with results included for log removal reported from raw water
through sedimentation, from sedimentation through filtration, and from raw water through filtration.
Results collected during periods of stable versus periods of poor coagulation are also distinguished in this
figure. Data in Figure 3.2 imply that spores are conservative estimators of Cryptosporidium during
sedimentation and filtration, especially when water is properly coagulated.
Studies conducted in Ottawa, Canada, have been reported by Emelko and others (Huck et al. 2001,
Emelko et al. 1999 and 2000), and have been summarized and updated in Emelko 2001. These data were
collected during challenge studies investigating the impact of spiking Cryptosporidium oocysts and
Bacillus subtilis spores on top of the filter under various conditions during direct filtration (i.e., does not
include contribution of a sedimentation basin on log removal). The studies were conducted under
different filtration conditions, including periods of poor coagulation and during hydraulic surges, and
during different stages of the filtration cycle (ripening period at beginning of run, "stable" conditions
during middle of run, and end-of-run through breakthrough). Cryptosporidium removal and spore removal
during these studies are summarized in Figure 3.3. These data demonstrate that, at least during filtration,
Cryptosporidium were removed at least as well, if not better, than spores under all combinations of
conditions tested.
Yates et al. 1998 reported removal data for naturally occurring Cryptosporidium and total aerobic spores,
as well as studies seeded with Cryptosporidium oocysts and Bacillus subtilis spores. The pilot facility
included pre-ozonation, coagulant addition, tapered flocculation (75, 50, 25/s), sedimentation (1.2
gpm/ft2), and dual or tri-media filtration (6 gpm/ft2). However, spore and Cryptosporidium data cited by
authors was for the filtration components only. During both seeded and unseeded studies, spore removal
was slightly lower than Cryptosporidium for paired samples collected during periods when water was
properly coagulated (i.e., spore removal was a conservative indicator for Cryptosporidium removal). Two
samples were collected under conditions where uncoagulated oocysts were seeded on top of the filter.
These were the only instances where spore removal was greater than Cryptosporidium removal. These
data are summarized in Figure 3.4.
Mazounie et al. 2000 reported data for direct filtration challenge studies using ambient levels of total
aerobic spores and spiked levels of Cryptosporidium, as summarized in Figure 3.5. Spore removal was
about 3 log and Cryptosporidium removal was >5 log, which is consistent with Dugan et al. 1999 and
2001, Yates et al. 1998, Emelko 2001, and others.
Overall, these studies demonstrate that spores are conservative indicators of Cryptosporidium removal
during sedimentation and filtration, when they can be measured during full-scale operations or during
pilot-scale challenge studies. While spores are a good indicator of treatment plant performance, spores are
not necessarily a good indicator of the presence of Giardia or Cryptosporidium in the raw source water, or
in the finished water.
Summary
The detection limit for Cryptosporidium in raw water and intermediate points in drinking water treatment
plants does not allow for calculation of the full Cryptosporidium log removal potential of drinking water
treatment processes. Pilot-scale Cryptosporidium spiking studies demonstrate that removal of bacterial
spores are conservative indicators of Cryptosporidium removal during clarification and filtration
processes when the water is coagulated. Even though bacterial spores demonstrate Cryptosporidium
removal during typical drinking water treatment, no parameter has been demonstrated as a suitable
indicator for Cryptosporidium occurrence in raw or finished water.
Comment Response for LT2ESWTR D-99 December 2005
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Bibliography
Coallier, J., M. Prevost, B. Barbeau, L. Boulos, and R. Desjardins. 1996. Full-Scale Physical and
Chemical Removals of a Fast Response and Economic Microbiological Indicator. Proc. Of 1996 Water
Quality Technology Conference. Denver, CO: AWWA.
Dugan, N., K. Fox, R. Miltner, D. Lytle, D. Williams, C. Parrett, C. Feld, and J. Owens. 1999. Control of
Cryptosporidium Oocysts by Steady-State Conventional Treatment. Proc. Of 1999 Annual Conference.
Denver, CO: AWWA.
Dugan, N., K. Fox, J. Owens, and R. Miltner. 2001. Cryptosporidium Control Through Conventional
Treatment. JAWWA, forthcoming.
Emelko, M., P. Huck, and R. Slawson. 1999. Design and Operational Strategies for Optimizing
Cryptosporidium Removal by Filters. Proc. Of 1999 Water Quality Technology Conference. Denver, CO:
AWWA.
Emelko, M., P. Huck, and I. Douglas, and J. van den Oever. 2000. Cryptosporidium and Microsphere
Removal During Low Turbidity End-of-Run and Early Breakthrough Filtration. Proc. Of 2000 Water
Quality Technology Conference. Denver, CO: AWWA.
Emelko, M. 2001. Removal of Cryptosporidium parvum by Granular Media Filtration. Ph.D. diss.
University of Waterloo, Waterloo, Ontario, Canada.
Hendricks, D., W. Cline, W. Anderson, G. Sturbaum, D. Klein, T. Champlin, P.
Kugrens, J. Hirsch, B. Evans, B. McCourt, P. Wendling, G. Nordby, M. Sobsey, and J. Hunt. 2000.
Biological Particle Surrogates for Filtration Performance Evaluation. Denver, CO: AWWARF and
AWWA.
Huck, P., B. Coffey, C. O'Melia, and M. Emelko. 2001. Removal of Cryptosporidium by Filtration Under
Various Process Conditions. Proc. Of CIWEM International Conference on Advances in Rapid Granular
Filtration in Water and Wastewater, London, UK, April 4-6, 2001. London, UK: Chartered Institution of
Water and Environmental Management (CIWEM).
Jakubowski, W., S. Boutros, W. Faber, R. Payer, W. Ghiorse, M. LeChevallier, J. Rose, S. Schaub, A.
Singh, and M. Stewart. 1996. Environmental Methods for Cryptosporidium. JAWWA. 88(9): 107-121.
Mazounie, P., F. Bernazeau, and P. Alia. 2000. Removal of Cryptosporidium by High Rate Contact
Filtration: The Performance of the Prospect Water Filtration Plant During the Sydney Water Crisis. Water
Science and Technology. 41(7):93-101.
McTigue, N., M. LeChevallier, H. Arora, and J. Clancy. 1998. National Assessment of Particle Removal
by Filtration. Denver, CO: AWWARF and AWWA.
Nieminski, E. and W. Bellamy. 2000. Application of Surrogate Measures to Improve Treatment Plant
Performance. Denver, CO: AWWARF and AWWA.
Nieminski, E. and J. Ongerth. 1995. Removing Giardia and Cryptosporidium by Conventional Treatment
and Direct Filtration. JAWWA. 87(9):96-106.
Rice, E., K. Fox, R. Miltner, D. Lytle, and C. Johnson. 1996. Evaluating Plant Performance with
Comment Response for LT2ESWTR D-100 December 2005
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Endospores. JAWWA. 88(9): 122-130.
Yates, R., K. Scott, J. Green, J. Bruno, and R. De Leon. 1998. Using Aerobic Spores to Evaluate
Treatment Plant Performance. Proc. Of 1998 Annual Conference. Denver, CO: AWWA.
CHAPTER 4
OFF-STREAM STORAGE
Off-stream storage is a reservoir or other storage structure with the following characteristics:
- Continuously operated (i.e., all raw water from source must pass through off-stream storage before
proceeding to remainder of plant)
- Located prior to point at which entire flow reaches the "treatment plant" (i.e., prior to clarification and
filtration)
- Lacks coagulant addition
The first two characteristics mean that all the raw water must pass through the off-stream storage structure
before proceeding to the head of the conventional treatment plant. This would exclude intermittently used
reservoirs from the definition of off-stream storage, i.e., reservoirs into which raw water is diverted only
as needed during unusual events.
Physical Removal of Cryptosporidium Oocysts
Van Breemen, Oskam, Ketelaars, Medema, and others have individually or jointly published articles
describing studies investigating the reduction of Giardia, Cryptosporidium, and other microbial indicators
during off-stream reservoir storage in the Netherlands (van Breemen et al. 1998, Ketelaars et al. 1995,
Oskam 1995, Medema et al. 1998). These data indicate average of 1.7-log Cryptosporidium removal
during five or more months of off-stream storage for one system, and about 1.3 log after 70-days storage
in another reservoir. Bertolucci et al. 1998 report data from Turin, Italy demonstrating mean
Cryptosporidium removals of about 1 log after 18 days of storage.
The City of Cincinnati, OH has a treatment plant that includes pre-sedimentation with lamella plate
settling, followed by off-stream storage (~3 days), prior to conventional sedimentation. During August
1992 to March 1995, 31 paired Cryptosporidium and Giardia samples were collected from raw water and
off-stream storage effluent. On one sample date, both raw and off-stream samples were positive for both
Giardia and Cryptosporidium. No other samples of raw or off-stream storage effluent were
Cryptosporidium positive during this time period. From April 1995 until December 2000, 67 raw water
samples and 2 off-stream storage effluent samples were collected, and none of these were positive for
Cryptosporidium. Giardia were detected more frequently than Cryptosporidium in raw water during the
1992 to 2000 time period (about 1 out of every 3 samples). Only 3 of 31 off-stream storage effluent
samples were Giardia positive during the August 1992 to March 1995 period. Giardia was not found
above detection limits in either of the two samples collected from off-stream storage effluent
during the April 1995 to December 2000 time period. All of the Giardia and Cryptosporidium data
reported are from presumptive tests. However, it should be noted that on the date of the positive
presumptive Cryptosporidium samples in raw water and off-stream storage basin effluent, the confirmed
analyses were also positive. The detection limit during the August 1992 to March 1995 sample period, the
only period when positive Cryptosporidium samples were detected, was 0.23 to 22 oocysts/L in raw water
and 0.26 to 2.0 oocysts/L in off-stream storage effluent.
Weekly total aerobic spore samples (147 sets) were collected from raw water, off-stream storage influent,
Comment Response for LT2ESWTR D-101 December 2005
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and off-stream storage effluent at Cincinnati from January 1998 to December 2000. Median log removal
of total aerobic spores during off-stream storage during this time period was approximately 1 log, with
over 85 percent of the observations > 0.5 log. The cumulative distribution of spore log removal results
during off-stream storage at Cincinnati is summarized in Figure 4.1.
Spore data from Cincinnati, Cryptosporidium data from Turin, Italy (Bertolucci et al. 1998), and
Cryptosporidium data from the Netherlands (van Breemen et al. 1998) are summarized in Figures 4.2 and
4.3. Cryptosporidium and spore removal was 1.0 or greater for storage times greater than three days.
Skerrett and Holland (2000) present Cryptosporidium data from five locations, including a pair of
monitoring locations at inlet and outlet of a lake (the first lake in a two lake reservoir complex). No data
are available from the authors regarding travel time between the two sampling points (i.e., storage
time in the lake). However, results of Cryptosporidium monitoring revealed the following:
- Mean of four weekly inlet and outlet samples in June 1997 was 2.25 and 0.87 oocysts/L, respectively.
Log of these mean values is 0.4.
- In July 1997, mean inlet and outlet values were 0.62 and 0.12 oocysts/L, respectively, corresponding to
a removal of about 0.7 log.
- No oocysts detected in the Lake Inlet or outlet during August 1997.
Oskam (1995) reported data supporting the use of first order kinetics to model microbial die-off in storage
reservoirs. The estimated first order rate constant (natural logarithmic base e) for Cryptosporidium cited
by the author is approximately 0.07/day. Using this first order decay constant, and assuming plug
flow, the storage times required for 0.5- and 1.0-log die-off would be -16 and -33 days, respectively.
Using the same rate constant for a completely mixed reactor, the storage times required for 0.5- and 1.0-
log die-off would be 31 and 129 days, respectively. Since real reservoirs behave somewhere between
these two ideal extremes, storage times for 0.5- and 1.0-log Cryptosporidium die-off are probably
between the values indicated. For example, the three reservoir system described by Oskam, modeled as
three completely mixed reactors in series, would produce a die-off of 0.8 log in the first reservoir (77
days), 0.7 log in the second (63 days), and 0.5 log in the final reservoir (28 days), for a combined die-off
of 2.0 log for the system.
Microbial Antagonism
Medema et al. 1997 conducted studies investigating the impact of temperature and indigenous microbial
populations on viability of Cryptosporidium in surface water. Studies were conducted at 5°C and 15°C
and involved inoculation of both autoclaved and non-autoclaved surface water samples. Inoculated
organisms included Cryptosporidium parvum, E. Coli., faecal enterococci, and Clostridium perfringens
(spores). First order die-off constants (logarithmic) reported by the authors for Cryptosporidium were
about 0.023 and 0.048/day at 5°C and 15°C, respectively, in non-autoclaved surface water. Therefore, the
Medema constant at 15°C is 70 percent of the Oskam constant, but the Medema constant at 5°C is about
three times lower than the value reported by Oskam. However, Medema et al. caution that their die-off
constants underestimate Cryptosporidium die-off because non-viable oocysts that disintegrate prior to
analysis were not accounted for in their viability assays. Calculation of storage times needed
for 0.5- and 1.0-log reductions in viable oocysts at different source water temperatures using the
conservative rate constants developed by Medema et al. are as follows:
- 0.5-log reduction at 5°C = 24 days
- 0.5-log reduction at 15°C = 50 days
- 1.0-log reduction at 5°C = 47 days
- 1.0-log reduction at 15°C = 100 days
Comment Response for LT2ESWTR D-102 December 2005
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Sattar et al. (1999) describe factors impacting Cryptosporidium and Giardia survival in watersheds. This
included in vitro survival studies to evaluate the impact of microbial antagonism on parasite survival.
These studies were conducted between January and July 1996, at three locations, along the Ottawa and St.
Lawrence J^ivers in Canada, and on the Mississippi J^iver in the U.S. The studies involved seeding
heterotrophic bacteria, Giardia muris, and Cryptosporidium parvum into survival chambers (dialysis
cassettes), which were immersed in a continuously fed tank containing raw water from a given location.
Absolute numbers of parasites and heterotrophic bacteria were counted in the survival chambers over
time, as well as parasite viability analysis. These were compared with controls, which included parasites
seeded into microtubes and immersed in the same raw water tank. Giardia levels were reduced in absolute
numbers and in viability overtime. The numbers of Cryptosporidium over the same time period did not
decrease, but viability was decreased. After about 3 weeks, Giardia viability was reduced by about 2 log
and Cryptosporidium by about 0.7-1.5 log, with 50 percent of the viability reduction occurring during the
first seven days. Heterotrophic plate counts over this same time period increased by 2 to 3 log.
LeChevallier and Au (2001) have summarized many of the literature sources currently available that
address the removal or reduction in viability of Cryptosporidium and other microbial indicators during
off-stream storage.
Additional Treatment Barrier
Off-stream storage and pre-sedimentation are similar in many respects in that both act as additional
barriers to Cryptosporidium exposure for drinking water consumers, and both provide general benefits to
subsequent treatment processes by equalizing the raw water source, including dampening of both
hydraulic and water quality spikes. Off-stream storage generally refers to structures such as lakes or
reservoirs with storage times on the order of days, versus pre-sedimentation that refers to clarifiers and
other retention basins with storage times on the order of hours or days and generally include the use of a
coagulant. Prolonged storage in off-stream storage reservoirs not only results in physical removal of
microorganisms, but also reduces viability of Cryptosporidium oocysts (and other microorganisms).
Oskam (1995) identified equalization of raw water quality peaks (chemical and microbial) and
sedimentation of microorganisms and particles as some of the positive benefits of off-stream storage. The
author also identified algal growth and contamination from runoff, if uncontrolled, and contamination
from roosting birds as potential negative impacts on water quality associated with poorly maintained off-
stream storage structures. The factors identified by the author that can enhance the positive benefits of
off-stream storage include the following:
- Higher degree of compartmentalization (three or four smaller reservoirs, or segments of reservoir
systems, are better than one large uncompartmentalized structure)
- Greater hydraulic residence time
- Hydraulic characteristics of reservoir (shape) - this item is related to the first item
- Higher quality raw water entering reservoir
Additional Benefits
One of the benefits of off-stream storage is that an off-stream storage reservoir can be isolated from the
raw water source when needed, for example during short periods of poor raw water quality. The treatment
plant can operate using the storage in the reservoir until water quality in the raw water source returns to
typical quality. Therefore, continuously operated only means that all raw water that makes it to the head
of the conventional treatment process must first pass through the off-stream storage reservoir.
Comment Response for LT2ESWTR D-103 December 2005
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LeChevallier et al. 1998, in a study on the Delaware River, noted that peak levels of microbial
contaminants following storm events were associated with peak turbidity spikes. By discontinuing
pumping from source water during this period, the authors noted that Cryptosporidium spikes of 12-16
times baseline levels could be avoided. This illustrates that off-stream storage coupled with proper intake
management practices can allow operations personnel to discontinue raw water pumping to avoid
exposure to high risk events, such as first flush following a storm.
Summary
The data presented support a 0.5-log credit for storage times greater than a few days, and 1.0-log credit
for greater than a few weeks of storage. A 21-day storage requirement appears appropriate for a 0.5-log
credit and 60 days for 1.0-log credit, based upon annual average flows. These detention times are
deemed conservative benchmarks, presuming adequate precautions are in place to limit short-circuiting,
control of human and other detrimental activities in areas surrounding the reservoir, and other protections
consistent with sound engineering practice.
Bibliography
Bertolucci, G., G. Gilli, E. Carraro, D. Giacosa, and M. Puppo. 1998. Influence of Raw Water Storage On
Giardia, Cryptosporidium andNematodes. Water Science and Technology. 37(2):261-267.
Ketelaars, H., G. Medema, L. van Breemen, D. Van der Kooij, P. Nobel, and P. Nuhn. 1995. Occurrence
of Cryptosporidium Oocysts and Giardia Cysts in the River Meuse and removal in the Biesbosch
Reservoirs. Aqua. 108-111.
LeChevallier, M., W. Norton, M. Abbaszadegan, T. Atherholt, and J. Rosen. 1998. Development of a
Monitoring Strategy to Determine Variations in Giardia and Cryptosporidium Levels in a Watershed.
Presented at Source Water Assessment and Protection 98. Fountain Valley, CA: National Water Research
Institute.
LeChevallier, M. and K. Au. 2001. Impact of Treatment on Microbial Water Quality: A Review
Document on Treatment Efficiency to Remove Pathogens. Washington, DC: World Health Organization,
forthcoming.
Medema, G., M. Bahar, and F. Schets. 1997. Survival of Cryptosporidium parvum, Escherichia Coli,
Faecal Enterococci, and Clostridium perfringens in River Water: Influent of Temperature and
Autochthonous Microorganisms. Water Science and Technology, 35(ll-12):249-252.
Medema, G., F. Schets, P. Teunis, and A. Havelaar. 1998. Sedimentation of Free nd Attached
Cryptosporidium Oocysts and Giardia Cysts in Water. Appl. Environ. Microbiol. 64:4460-4466.
Oskam, G. 1995. Main Principles of Water Quality Improvement in Reservoirs. Aqua, 44:23-29.
Sattar, S., C. Chauret, V. Springthorpe, D. Battigelli, M. Abbaszadegan, and M. LeChevallier. 1999.
Giardia Cyst and Cryptosporidium Oocyst Survival in Watersheds and Factors Affecting Inactivation.
Denver, CO: AWWARF and AWWA.
Skerrett, H. and C. Holland. 2000. The Occurrence of Cryptosporidium in Environmental Waters in the
Greater Dublin Area. Water Research, 34(15):3755-3760.
Van Breemen, L., H. Ketelaars, W. Hoogenboezem, and G. Medema. 1998. Storage Reservoirs-A First
Comment Response for LT2ESWTR D-104 December 2005
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Barrier For Pathogenic Micro-Organisms In The Netherlands. Water Science and Technology. 37(2):253-
260.
CHAPTER 5
PRE-SEDIMENTATION
Pre-sedimentation is achieved through a clarifier or retention basin with the following characteristics:
- Continuously operated (i.e., all raw water from source must pass through basin before proceeding to
remainder of plant)
- Located prior to point at which entire flow reaches the "treatment plant" (i.e., prior to clarification and
filtration)
- Addition of metal salts, organic polymers, or recycled softening sludge in order to enhance physical
separation within the pre-sedimentation basin
Off-stream storage and pre-sedimentation are similar in many respects in that both act as additional
barriers to Cryptosporidium exposure for drinking water consumers, and both provide general benefits to
subsequent treatment processes by equalizing the raw water source, including dampening of water quality
spikes. However, off-stream storage generally refers to structures such as lakes or reservoirs with storage
times on the order of weeks, versus pre-sedimentation that refers to tanks and retention basins with
storage times on the order of hours or days.
Cryptosporidium Oocyst Removal
Pre-sedimentation is also similar to conventional clarification, except that since pre-sedimentation is only
intended to meet pretreatment objectives, so generally pre-sedimentation basins may be operated at higher
overflow rates. Data are available demonstrating 1 log and greater Cryptosporidium removal with
conventional clarification (Edzwald et al. 2000, Cornwell and MacPhee 2001, Cornwell, et al. 2001,
Edzwald and Kelley 1998, Plummer et al. 1995, Dugan et al. 1999 and 2001, Hall et al. 1994, Patania et
al. 1995, and others).
Data regarding the removal of Cryptosporidium and spores (Bacillus subtilis and total aerobic spores)
during operation of full-scale pre-sedimentation basins have been collected independently by personnel
from three US utilities: St. Louis, MO; Kansas City, MO; and Cincinnati, OH. Cryptosporidium oocysts
were rarely detected in raw water at these locations and, consequently, it was not possible to calculate
oocyst removal through these processes. Spores were detected more readily in raw water than were
Cryptosporidium, making it possible to calculate log removal of spores at these three utilities.*
* All three utilities use analytical procedures similar to those described in Rice et al. 1996 to quantify
Bacillus subtilis and other aerobic spores. Cryptosporidium and Giardia samples were analyzed using the
ICR Method (USEPA 1996) prior to Summer-Fall 2000, and Method 1623 (USEPA 1999) thereafter.
The St. Louis Water Division operates four pre-sedimentation basins at one facility. Coagulant addition
prior to pre-sedimentation basins at this plant typically includes ~0.1 mg/L of polymer and occasional
dosages of ferric sulfate (7-10 mg/L). From June 1998 to September 2000, overflow rates ranged from 0.3
to 1.6 gpm/ft2 on dates when Bacillus subtilis spore samples were collected. The median influent spore
concentration during the study period was 33,100 cfu/lOOmL, and the resulting mean and median log
spore removal was approximately 0.8 for 275 paired data points as summarized in Table 5.1. Figure 5.1
and 5.2 illustrate the distribution of Bacillus subtilis removal during pre-sedimentation (Figure 5.2
includes additional data from a second St. Louis facility described below). Greater than 76 percent of all
Comment Response for LT2ESWTR D-105 December 2005
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log removals calculated for the pre-sedimentation basin were >0.5 log during this time period, and many
instances when <0.5-log spore removal was observed resulted from removal calculations based on lower
influent spore concentrations. Spore removal at this facility was not impacted by overflow rate during the
study period for overflow rates up to 1.6 gpm/ft2. Preliminary data from another St. Louis facility indicate
that >0.5-log spore removal can be achieved at overflow rates from 1.7 to 2.8 gpm/ft2. However, data
from this facility are limited, and have not yet been collected over a number of seasons like the data from
the other St. Louis facility (the only data available to date were collected in March 2001). Overall, data
from St. Louis demonstrate that pre-sedimentation basins can achieve >0.5-log spore removal at overflow
rates as high as 1.6 gpm/ft2, and perhaps as high as 2.8 gpm/ft2.
[See Work file for Table 5.1]
Bacillus subtilis spore removal data (n=335) were also collected during a separate effort by personnel
from the Kansas City Water Services Department. Samples were collected from January to November
2000 from locations before and after one of the facility's six pre-sedimentation basins. Sludge generated
within the primary clarifier in the Kansas City two-stage lime softening process was recycled to the head
of the pre-sedimentation basins during the entire study period. When raw water turbidities were higher
(roughly 50 dates) polymer dosages 0.5-1.0 mg/L and/or ferric sulfate dosages of 0.2-20 mg/L were added
along with recycle sludge prior to the pre-sedimentation basins. Exact overflow rate data are not
available, but calculations show that the overflow rates ranged from 0.4 to 0.9 gpm/ft2.
Median log removal under these sets of conditions at Kansas City were 0.88 (mean 0.85) with coagulant
and 0.44 (mean 0.46) without, as summarized in Table 5.2. When polymer and/or iron-based coagulant
were used, >85 percent of the calculated log spore removal values were >0.5 log as demonstrated in
Figure 5.3. Figure 5.4 shows the impact of coagulant addition (polymer and/or iron-based coagulant) and
raw water spore counts on observed removal of Bacillus subtilis during pre-sedimentation at Kansas City.
Please note that even when no polymer or iron-based coagulant was used, a "coagulant" was present
because softening sludge was recycled to the pre-sedimentation basin.
[See Work file for Table 5.2]
Cincinnati Water Works operates a treatment plant using lamella-plate settlers for pre-sedimentation.
Lamella-plate sedimentation is a high-rate clarification process in which the surface area is dramatically
increased through the addition of numerous inclined plates perpendicular to flow through the
sedimentation basin. Cincinnati adds coagulant to the raw water (alum at 5.5-21 mg/L and polymer at 0.5-
4.0 mg/L) prior to sending it to one of five lamella basins. The pre-sedimentation overflow rate at average
flow conditions is 0.52 gpm/ft2. Cryptosporidium and Giardia samples were collected from August 1992
through December 2000 and total aerobic spore samples from January 1998 through December 2000. The
data summarized in Table 5.3 and Figures 5.5 and 5.6 demonstrate that:
- Cryptosporidium was only detected once in the raw water and once in lamella basin effluent during the
study period
- Giardia was detected in about 35 percent of raw water samples and 12 percent of samples following pre-
sedimentation, with median log removal of about 1.5 for paired samples with detectable quantities of
Giardia in the raw water
- Median raw water spores levels at Cincinnati were 7,400 cfu/lOOmL
- Mean and median log spore removal was 0.49 and 0.39, respectively, during the study period (147
paired observations)
[See Work file for Table 5.3]
Comment Response for LT2ESWTR D-106 December 2005
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Primary clarification has been shown to be suitable for at least 1.0-log removal of Cryptosporidium prior
to filtration. Pre-sedimentation basins are similar, but can be operated at higher overflow rates since the
objectives are different. Spore removal data from St. Louis, Kansas City, and Cincinnati support a 0.5-log
removal credit for pre-sedimentation basins operated at overflow rates =1.6 gpm/ft2. Additional data
being collected at St. Louis may demonstrate greater than 0.5-log credit for higher pre-sedimentation
basin overflow rates. Log spore removal was much higher when coagulant was added prior to the pre-
sedimentation basin. Figure 5.7 presents a comparison of the mean, median, 90th percentile, and 10th
percentile log removal values associated with pre-sedimentation practice at water works in St. Louis
(coagulant always used), Cincinnati (coagulant always used), and Kansas City (with and without
coagulant).
Data from Kansas City and St. Louis also support that the 0.5-log removal achieved by pre-sedimentation
is additive to the primary process as indicated in Tables 5.4 and 5.5 and Figures 5.8 and 5.9. Kansas City
achieves a median spore log removal of about 3.7 without including pre-sedimentation, versus a mean and
median of 4.3 when pre-sedimentation is included. St. Louis achieves a median log spore removal of 3.9
(mean 3.8) excluding pre-sedimentation, versus 4.7 (mean and median) with pre-sedimentation included.
[See Work file for Table 5.4]
[See Work file for Table 5.5]
Pre-sedimentation basins located prior to the point at which raw water flow reaches the principal
treatment train and that are continuously operated using a coagulant (polymer, metal salts, or recycled
sludge) achieved at least 0.5-log toolbox credit at overflow rates up to 1.6 gpm/ft2. In many cases
removal is more than 0.5 log.
Additional Treatment Barrier
When coagulant addition is occurring and the treatment process is being actively managed to achieve
clarification, solids removal achieved in pre-sedimentation reduces the solids load on the primary
clarification process in the water treatment plant. The water treatment plant can operate the two processes
in a complementary fashion so that the overall treatment process is less dependent on the removal of
solids overflow during filtration.
Additional Benefits
Conventional drinking water treatment processes are operated in such a way as to match treatment (i.e.,
the addition of coagulant and operation of filters) to influent water challenge, in this instance particle
removal. While the coagulation-flocculation-clarification-filtration process is robust, an important
operational goal is process stability. Pre-sedimentation is a useful tool in managing the initial particulate
load reaching the primary treatment process. Pre-sedimentation not only begins the solids removal
process it also helps to equalize water quality reaching the primary treatment process. The equalization
can be used to address short periods of high contaminant concentrations (i.e., a chemical spill event).
Such an approach is used by the City of Philadelphia Water Department, and others. It also provides this
equalizing effect on a continuous basis at run-of-the-river facilities where the relative quiescence of the
pre-sedimentation process allows water quality to equalize and consequently represent a more consistent
constant challenge to the primary treatment train.
Summary
The data suggest that pre-sedimentation basins located prior to a point at which raw water flow reaches
Comment Response for LT2ESWTR D-107 December 2005
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the principal treatment train, and that are continuously operated using a coagulant (polymer, metal salts,
or recycled sludge), achieve a 0.5-log toolbox credit at overflow rates up to 1.6 gpm/ft2.
Bibliography
Cornwell, D. and M. MacPhee. 2001. Effects of Spent Filter Backwash Recycle on Cryptosporidium
Removal. JAWWA. 93(4): 153-162.
Cornwell, D., M. MacPhee, N. McTigue, H. Arora, G. DiGiovanni, and J. Taylor. 2000. Treatment
Options for Giardia, Cryptosporidium, and Other Contaminants in Recycled Backwash Water. Denver,
CO: AWWARF and AWWA.
Dugan, N., K. Fox, R. Miltner, D. Lytle, D. Williams, C. Parrett, C. Feld, and J. Owens. 1999. Control of
Cryptosporidium Oocysts by Steady-State Conventional Treatment. Proc. Of 1999 Annual Conference.
Denver, CO: AWWA.
Dugan, N., K. Fox, J. Owens, and R. Miltner. 2001. Cryptosporidium Control Through Conventional
Treatment. JAWWA, forthcoming.
Edzwald, J., and Kelley, M., 1998. Control Of Cryptosporidium: From Reservoirs To Clarifiers to Filters.
Water Science and Technology. 37(2): 1-8.
Edzwald, J., J. Tobiason, L. Parento, M. Kelley, G. Kaminski, H. Dunn, and P. Galant. 2000. Giardia and
Cryptosporidium Removals by Clarification and Filtration Under Challenge Conditions. JAWWA.
92(12):70-84.
Hall, T., Pressdee, J., and Carrington, N. 1994. Removal of Cryptosporidium Oocysts by Water Treatment
Process. London, England: Foundation for Water Research Limited.
Patania, N., J. Jacangelo, L. Cummings, A. Wilczak, K. Riley, and J. Oppenheimer. 1995. Optimization
of Filtration for Cyst Removal. Denver, CO: AWWARF and AWWA.
Plummer, J., J. Edzwald, and M. Kelley. 1995. Removing Cryptosporidium by Dissolved-Air Flotation.
JAWWA. 87(9):85-95.
Rice, E., K. Fox, R. Miltner, D. Lytle, and C. Johnson. 1996. Evaluating Plant Performance with
Endospores. JAWWA. 88(9): 122-130.
USEPA. 1996. ICR Microbial Laboratory Manual. Washington, DC: USEPA.
USEPA. 1999. Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA. Washington,
DC: USEPA.
CHAPTER 6
LIME SOFTENING
Lime softening is a drinking water treatment process that uses chemical precipitation with lime and other
chemicals to reduce hardness and to enhance clarification prior to filtration. Lime softening can be
categorized into two general types: single-stage lime softening used to remove calcium hardness and
two-stage lime softening used to achieve greater levels of calcium hardness and to remove magnesium
Comment Response for LT2ESWTR D-108 December 2005
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hardness. Figure 6.1 includes process flow schematics for these three types of lime softening plants. A
third type called split softening is similar to two-stage softening, except that a portion of the raw water
flow by-passes the first clarifier. Both single and two-stage lime softening may include conventional
sedimentation basins or solids contact units. Please note that carbon dioxide (CO2) is used to control pH
during single-and two-stage softening, whereas control of raw water by-pass flows are used to control pH
during split softening.
Cryptosporidium Oocyst Removal
The literature contains few data demonstrating Cryptosporidium removal through lime softening, and no
pilot spiking studies using the lime softening process have been reported. Bell et al. (2000) report a 2-log
reduction of both Cryptosporidium and Giardia during precipitative lime softening during bench-
scale jar tests (i.e., equivalent to single-stage lime softening without filtration). Logsdon et al. (1994)
reported data from 13 full-scale, lime softening plants. For facilities where Cryptosporidium were
detected in raw water (6 plants), removal through sedimentation ranged from 1 to 2.3 logs, and from raw
water through filtration ranged from 2.5 to 3.5 logs.
Additional Treatment Barrier
To the extent that two-stage softening is employed, the softening process provides a second clarification
unit process affording water treatment plants that soften redundancy in this process barrier.
St. Louis, MO; Kansas City, MO; and Columbus, OH have collected monitoring data demonstrating
removal of Bacillus subtilis and total aerobic spores during various stages of the lime softening process.
Cryptosporidium data were also collected at these utilities; however, oocysts were rarely detected in raw
water and, consequently, it was not possible to calculate oocyst removal. Table 6.1 includes
Cryptosporidium and Giardia monitoring data from Kansas City that is typical of raw and finished water
monitoring results from other utilities. Spores were detected more readily in raw water than were
Cryptosporidium, making it possible to calculate log removals at these three utilities3.
[See Work file for Table 6.1]
Approximately 300 Bacillus subtilis spore samples were collected between June 1998 and September
2000 from a lime softening plant operated by the City of St. Louis Water Division. This facility employs
a two-stage lime softening process preceded by pre-sedimentation. Ferric sulfate and polymer are added
at various points in the process. Table 6.2 and Figure 6.2 summarize spore concentrations recorded during
the study period from raw water, finished water, and various points in the treatment process at St. Louis.
The median spore concentration entering the lime softening portion of the process (i.e., after pre-
sedimentation) was 6,200 cfu/lOOmL, with a mean of 8,100 cfu/100 mL. Calculated log removals for
various segments of the process are summarized below:
- Primary clarifier only = median log removal 1.9, mean 1.7
- Secondary clarifier only = median log removal 1.6, mean 1.1
- Primary + secondary clarifier = median log removal 3.4, mean 3.3
- Primary and secondary clarification + filtration = median log spore removal 3.9, mean 3.8, with >74
percent of the paired observations demonstrating >3.5-log removal (see Figure 6.3)
[See Work file for Table 6.2]
Since most of the filtered water results from St. Louis (>56 percent) were below detection limit (1 cfu/100
mL), the true log spore removal through filtration was actually higher than indicated by these calculated
Comment Response for LT2ESWTR D-109 December 2005
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values. In fact, spore counts in the secondary clarifier effluent were so low (90 percent of observations
were <2.0 cfu/100 mL) that actual spore removal through secondary clarification was also probably
higher than calculated log removal values. In a separate study, the Kansas City Water Services
Department collected daily Bacillus subtilis spore data from a two-stage lime softening plant from
January through November 2000 (n=335). The Kansas City facility includes pre-sedimentation prior to
two-stage lime softening, similar to St. Louis. One difference between the Kansas City and St. Louis
process trains is that softening sludge from the primary clarifier are recycled back to the pre-
sedimentation basin at Kansas City. Table 6.3 and Figure 6.4 summarize spore concentrations recorded
during the study period from raw water, finished water, and various points in the treatment process at
Kansas City. The median spore concentration entering the lime softening process in Kansas City (i.e.,
after pre-sedimentation) was 3,700 cfu/lOOmL, with a mean of 6,000 cfu/100 mL. Calculated log
removals for various segments of the process are summarized below:
- Primary clarifier only = median log spore removal 2.8, mean 3.0
- Secondary clarifier only = median log spore removal 0.3, and mean 0.4, but these were limited by low
spore concentrations in primary clarifier effluent
- Primary + secondary clarifier = median log removal 2.6, mean 2.8
- Primary and secondary clarification + filtration = mean and median log spore removal 3.7, with >75
percent of the paired observations demonstrating >3.5-log removal (see Figure 6.5)
[See Work file for Table 6.3]
As was the case in St. Louis, since most of the filtered water observations (>74 percent) were below
detection limits, the actual log spore removal through filtration was higher than these calculated values.
The primary clarification step at Kansas City demonstrated high spore removal, limiting the amount of
spores reaching the second stage clarifier (30 percent of primary clarifier effluent samples were below the
detection limit). Consequently, the spore data collected were not sufficient to calculate the removal
attributable to the second stage clarifier alone.
The City of Columbus, Ohio, operates two lime-softening plants. The two Columbus facilities do not
have pre-sedimentation and do not practice sludge recycle. They do have two clarification stages, but they
do not practice two-stage line softening. Unlike Kansas City, St. Louis, and the two-stage lime
softening process depicted in Figure 6.1, coagulant is added but lime is not added prior to the first
clarification stage at the two Columbus facilities. This first clarification stage acts like any other clarifier
at a non-softening plant. Lime is added prior to the second clarifier at both Columbus plants, with
softening solids removed in the second-stage clarifier and the filters.
Between 1997 and 2000, approximately 50 monthly samples for total aerobic spores were collected at
each plant from raw water, filtered water, and from each clarification step, as summarized in Table 6.4
and Figures 6.6 and 6.7. Spore counts and calculated log removals for each of the facilities are
summarized below:
- Mean and median raw water spore counts at Plant #2 were 12,000 and 23,000 cfu/lOOmL, respectively,
whereas they were 6,600 and 10,600 cfu/lOOmL, respectively, at plant #1. Hence, plant #2 had more
spores available to demonstrate higher removals
- Primary clarifier only = median log spore removal 1.1 and mean 1.2 at plant #1, versus mean and
median log removal of 1.3 at plant #2
- Secondary clarifier only = mean and median log spore removal of 1.9 at plant #1 and 2.4 at plant #2
- Primary + secondary clarifier = mean and median log spore removal 2.8 at plant #1 and 3.7 at plant #2
- Primary and secondary clarification + filtration = median log spore removal 3.1 and mean 3.3 at plant
#1. Median 3.7 and mean 3.8 at plant #2 (see Figure 6.8)
Comment Response for LT2ESWTR D-110 December 2005
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[See Work file for Table 6.4]
The Columbus study is consistent with the Kansas City and St. Louis studies for removal of spores from
primary clarifier influent to filter effluent (i.e., excluding pre-sedimentation from Kansas City and St.
Louis) with one of the Columbus facilities producing slightly lower removals than the other three
plants. The Columbus plant with higher influent raw water spore counts (plant #2) consistently exhibited
higher overall and individual unit process log removals, suggesting that the calculation of removal at the
other facility (plant #1) may be limited by the influent spore levels.
Spore log removal data from these four softening plants are summarized in Figures 6.9 through 6.12, with
Figure 6.9 comparing removal through primary clarifier only, Figure 6.10 for secondary clarifier only,
Figure 6.11 for combined effect of primary and secondary clarification, and Figure 6.12 for primary and
secondary clarification plus filtration.
Additional Benefits
There are a substantial number of benefits associated with softening beyond its functioning as a robust
coagulation-clarification process. With respect to regulated compounds, softening removes heavy metals
(i.e., arsenic, mercury, nickel, etc.), radium 226 and 228, some organic compounds, total organic carbon
(TOC), iron, and manganese. Softening reduces the need for the use of chemical disinfectants for algal
control and other oxidative applications prior to primary disinfection. It is useful in corrosion control in
some instances by increasing the Langelier Saturation Index; corrosion control is fundamental to
control of lead and copper levels under the Lead and Copper Rule. Softening resolves consumer hard
water issues including reducing household cleaning agent consumption, dissolved mineral levels, and
scale-formation.
Summary
Available data indicate that a typical single-stage softening processes routinely provides as much or more
Cryptosporidium removal as traditional coagulation-clarification- filtration treatment processes.
Consequently, drinking water treatment plants that practice lime softening should achieve an average 3-
log removal of Cryptosporidium, as was assumed for other clarification and filtration treatment
("conventional") plants in the Bin Requirements Table of the M/DBP Agreement in Principle. When a
secondary clarification step is included in a treatment process, such as with two-stage softening, available
data suggest that the second clarification step provides increased redundancy and stability to the treatment
train, plus an additional treatment barrier to the passage of protozoa into the potable water supply.
Consequently, an additional 0.5-log credit is appropriate for two-stage softening and other plant
designs that employ multiple, continuously operated, clarification processes in series.
Bibliography
Bell, K., M. LeChevallier, M. Abbaszadegan, G. Amy, S. Sinha, M. Benjamin, and E. Ibrahim. 2000.
Enhanced and Optimized Coagulation for Particulate and Microbial Removal. Denver, CO: AWWARF
and AWWA.
Logsdon, G., M. Frey, T. Stefanich, S. Johnson, D. Feely, J. Rose, and M. Sobsey. 1994. The Removal
and Disinfection Efficiency of Lime Softening Processes for Giardia and Viruses. Denver, CO:
AWWARF and AWWA.
Rice, E., K. Fox, R. Miltner, D. Lytle, and C. Johnson. 1996. Evaluating Plant Performance with
Comment Response for LT2ESWTR D-lll December 2005
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Endospores. JAWWA. 88(9): 122-130.
USEPA. 1996. ICR Microbial Laboratory Manual. Washington, DC: USEPA.
USEPA. 1999. Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA. Washington,
DC: USEPA.
CHAPTER 7
IMPROVED FILTRATION
In listing potential treatment approaches in the Microbial Toolbox, the M/DBP FACA recommended a
0.5-log credit where a water treatment plant achieved lower finished water turbidities than required by the
IESWTR. Compliance with the IESWTR requires 95 percent of all combined filter effluent (CFE)
turbidities, measured every four hours during a given month, to be = 0.3 ntu; the M/DBP FACA
recommended that reducing 95th percentile CFE turbidities to = 0.15 ntu would provide additional
Cryptosporidium removal necessary for a 0.5-log credit within the Microbial Toolbox.
Cryptosporidium Oocyst Removal
Existing literature contains evidence demonstrating an additional 0.5 log or higher removal of
Cryptosporidium when filtered water turbidity is <0.15 ntu versus when it is > 0.15 ntu. Some of these
data were collected from full-scale treatment plants (McTigue et al. 1998, Nieminski and Bellamy 2000,
and Kelley et al. 1995), but most information was collected during pilot-scale challenge studies (Dugan et
al. 1999 and 2001, EE&T 1996, Hall et al. 1994, Ongerth and Pecoraro 1995, Patania et al. 1995, Swaim
et al. 1996, and West et al. 1994). The following is a brief summary of these studies and applicable
findings from the data collected.
McTigue et al. (1998) cites data for finished water turbidity and Cryptosporidium removal from samples
collected at 100 full-scale plants in U.S. In >60 percent of the paired samples (n = 50) in this study, the
raw water concentrations were not high enough to demonstrate 2.0-log removal, and the highest raw
water concentration was only high enough to demonstrate 3.4-log removal. In addition to collecting
Cryptosporidium levels, McTigue also collected total aerobic spores data in both raw and filtered water
samples from 30 water treatment plants. Calculated log removals using spore data was also restricted by
the limited numbers of spores detected in filtered water effluent, but less so than in the calculation of
oocyst removal. Plants achieving 95th percentile filtered water effluent turbidities <0.15 ntu produced
approximately 0.5-log greater spore removal. Plants achieving <0.15 ntu in filtered effluent produced
mean and median spore removal of about 3 log (n = 24), whereas plants achieving >0.15 ntu produced
mean and median spore removal of 2.7 and 2.4 log, respectively (n = 6).
Nieminski and Bellamy 2000 reported data from a study during which Cryptosporidium, Giardia, total
aerobic spores, Bacillus subtilis spores, turbidity, and other microbial indicators were analyzed from 24
U.S. water treatment plants. The study encompassed a range of treatments including water treatment
plants with direct filtration, but the majority employed clarification and filtration. As in the McTigue et al.
(1998) study, the raw water Cryptosporidium concentrations were not high enough to demonstrate the
degree of Cryptosporidium removal that these facilities were capable of achieving; Cryptosporidium was
observed in a single finished water sample from a facility employing filtration. For systems with either
direct filtration or clarification plus filtration (n = 75) where Cryptosporidium was detected in both raw
water and filtered water, the mean and median Cryptosporidium removal was about 2.3 log when filtered
water turbidity was <0.15 ntu (n = 68), and 1.8 to 2.0 when filtered water turbidity was >0.15 ntu (n = 7)
(Figure 7.1).
Comment Response for LT2ESWTR D-112 December 2005
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Calculated log removal of aerobic spores reported by Nieminski and Bellamy had some of the same
limitations as calculated log removals for Cryptosporidium as approximately 15 percent of filtered water
spore counts were below detection limits. Observed mean and median total aerobic spore removal were
both 2.8 when turbidity was <0.15 ntu, versus 1.7 and 1.9 log respectively when turbidity was >0.15 ntu
(Figure 7.2 and 7.3). Overall, Nieminski and Bellamy reported 0.5 log or greater removal of spores and
Cryptosporidium when filtered water turbidity was <0.15 ntu than when turbidity was >0.15 ntu.
Kelley et al. 1995 describe Cryptosporidium and Giardia monitoring results from the two full-scale water
treatment facilities operated by the US Army. One facility produces about 1 mgd and the other produces
about 3 mgd. The smaller facility is operated about 16 hours per day and utilizes alum coagulation, lime
softening, two-stage clarification, and rapid sand filtration, including recycle of spent filter backwash
water (SFBW). The larger facility is operated continuously and utilizes alum coagulation, two-stage
filtration, and rapid sand filtration. The latter facility does not normally recycle SFBW, but did for
this study. Both plants utilize a surface water as their principal raw water source, though the larger facility
also blends in groundwater prior to second stage clarification during certain times of the year.
The results from this study were inconclusive with respect to Cryptosporidium removal relative to filtered
water turbidity. During most time periods during this study, filtered water turbidity was < 0.10 ntu and
observed Cryptosporidium removal was > 2 log. Unfortunately, no Cryptosporidium were detected in raw
water on most dates when filtered water turbidity was >0.15 ntu. Therefore, it was not possible to
calculate and compare Cryptosporidium removal during periods when turbidity was <0.15 ntu versus
dates when turbidity was >0.15 ntu. The only two instances where raw water Cryptosporidium were
detected and where filtered water turbidity was >0.15 ntu included one instance where turbidity was 0.18
ntu and Cryptosporidium removal was > 2 log, and one instance where filtered water turbidity was 0.46
ntu and filtered water Cryptosporidium was below detection limits.
In addition to the full-scale data described above, there are also six well-documented studies that contain
data on Cryptosporidium oocyst removal data and filtered water turbidity from pilot-scale systems. Dugan
et al. 1999, EE&T 1996, Hall et al. 1994, Patania et al. 1995, Swaim et al. 1996, and West et al. 1994 cite
data from seeding experiments using pilot scale systems with both clarification and filtration. These data
are summarized in Figure 7.4. The studies reporting <0.15 ntu in filter effluent produced Cryptosporidium
oocyst removals that were >1 log higher than studies reporting >0.15 ntu in filter effluent. The mean and
median Cryptosporidium removal when filtered water turbidity was <0.15 ntu was >4.0 log, versus 2.4 -
2.6 mean and median log removal for Cryptosporidium when filtered water turbidity was >0.15 ntu
(Figure 7.5). Figure 7.6 groups the observed removal data in context of existing IESWTR turbidity goal
and proposed Microbial Toolbox turbidity goal for additional log credit. When filtered water turbidity is
between 0.15 and 0.30 ntu, median Cryptosporidium removal is about 3.0 log, and that median
Cryptosporidium removal improves by about 1.0 log when filtered water turbidity is lowered to <0.15
ntu.
Ongerth and Pecoraro (1995) report Cryptosporidium removal data associated with direct filtration. In one
set of experiments, the average filtered water turbidity was 0.36 ntu and the corresponding
Cryptosporidium removal was 1.5 log. In three other sets of experiments, the filtered water turbidity was
<0.10 ntu and the mean Cryptosporidium removal cited by the authors was 2.7, 2.8, and 3.1 log.
In addition to these pilot-scale studies, Emelko 2001 (also Emelko et al. 1999 and 2000, and Huck et al.
2001) investigated removal of Cryptosporidium oocysts by filtration alone under a range of filtration
conditions. Emelko reported data from pilot-scale studies investigating impact of coagulation and other
conditions during different stages of filter operation on removal of Cryptosporidium, spores, and
microspheres. Studies included application of bench coagulated Cryptosporidium spikes into a 2-in. (51-
Comment Response for LT2ESWTR D-113 December 2005
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mm) diameter pilot-scale, dual media filter. Reported log removals under various conditions as a function
of filtered water turbidity from these studies are summarized in Figure 7.7. These results demonstrate that
Cryptosporidium removal through filtration alone was >1.5 log higher when the filtered water turbidity
was <0.15 ntu versus when filtered water turbidity was >0.15 ntu. Median Cryptosporidium removal
during periods when filtered water turbidity was <0.15 ntu was 4.9 (mean 4.2) versus 1.8 (mean 2.5)
when turbidity was >0.15 ntu.
Additional Benefits
As is recognized by the existing Surface Water Treatment Rule filtration processes provide removal not
only of Cryptosporidium oocysts but also removal of Giardia cysts and viruses (Logsdon, 1987, 1988;
Roebeck, 1962). The IESWTR focused considerable attention on improving the performance of the
filtration process, setting not only a more stringent treatment technique but also drawing attention to
controlling the variability in turbidity from individual filters. While lacking a causal link between low-
level turbidity and the risk of waterborne disease, the Stage 1 M/DBP FACA recommended that the
IESWTR incorporate a lower turbidity standard as a measure of filtration performance. The Stage 1
M/DBP FACA reasoned, and EPA agreed in the subsequent rulemaking, that lower turbidity standards
necessitated more stringent operation of the treatment process thereby benefiting overall removal and that
lower turbidity values also resulted in greater control of turbidity levels over the course of the filtration
cycle. Improved filtration has similar positive benefits in that it provides another filtration barrier to
pathogen passage, and provides for more stringent control of treatment and therefore less variable effluent
uality.
Summary
These studies demonstrate the validity of at least a 0.5-log credit for improved filtration where CFE
turbidities are maintained below 0.15 ntu 95 percent of the time. The available information indicates that
when filtered water turbidity is <0.15 ntu, the observed Cryptosporidium removal will be at least 0.5 log
higher than when filtered water turbidity was >0.15 ntu. This is consistent for a dual media filter by itself,
as well as for the combined impact of clarification and filtration.
Assignment of 0.5-log credit for CFE turbidities reliably maintained below 0.15 ntu is consistent with the
in-plant data presented above, whereby the Cryptosporidium removal is higher when the apparent
turbidity (i.e., as measured by plant turbidimeter) is lower. Significant analytical issues associated with
low level turbidity measurements were identified during development of the IESWTR. In implementing
the IESWTR, compatability among WTPs was necessary to ensure that the rule could be implemented
effectively and fairly. These issues necessitated developing the Guidance Manual for Compliance with the
Interim Enhanced Surface Water Treatment Rule: Turbidity Provisions (USEPA 1990). Analytical
uncertainty in turbidity measurement remains pertinent to the proposed log credit for improved filtration,
but in this application comparison among WTPs is less relevant than the quality assurance measures
identified in the IESWTR guidance. The important issue for this toolbox component is that an individual
plant develops practices that lower the apparent turbidity measured by the plant turbidimeter, but it needs
to be understood that this apparent turbidity measurement may not be a true indicator of the absolute or
actual turbidity present. The IESWTR guidance on turbidity measurement will provide quality assurance
and quality control measures that can be employed to reduce analytical uncertainty in turbidity
measurements required when demonstrating reliable treatment. While the analytical challenge associated
with demonstrating reliable performance at 0.15 ntu may be unachievable for many WTPs, available
research is sufficient to establish the 0.5-log credit for improved filtration as defined in the LT2ESWTR.
The data available for supporting 0.5-log removal credit for improved performance to 0.15 ntu (measured
as CFE) are also supportive of the FACA recommendation to provide an additional 0.5-log credit for
Comment Response for LT2ESWTR D-114 December 2005
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operating each individual filter to a higher performance standard. The removal of Cryptosporidium
through the filtration process depends on proper chemical pretreatment, and the integrity of the individual
filters. The CFE performance standard of 0.15 ntu provides assurance that the chemical treatment
elements of the plant are operating at a high level. However, in plants with multiple filters, short-term
transients in individual filter performance can be masked by blending with the balance of the filtered
process water.
The full scale treatment plant data indicate the impact of improved performance (below 0.15 ntu) on the
overall treatment process. These data combine the performance enhancements resulting from coagulation,
sedimentation, and filtration in a single experimental block. Within these full scale evaluations, the
overall performance of multiple basins and filters were grouped into a single observation, justifying a
removal credit of 0.5 log for the improved performance.
The pilot plant data provided in this chapter indicate that improved performance on an individual filter
basis (Figure 7.4) has a definite impact on particle and Cryptosporidium passage. The pilot plant filters
operate under steady state conditions, without flow variations-in essence, under ideal filter operation
conditions. The pilot studies look only at the performance of one filter. Data are compelling that when
evaluating single filters in pilot studies, improved performance of the individual filters results in increased
removal of Cryptosporidium. Median values of log removal above 0.15 ntu were approximately
2.5, compared to median 4.0-log removal for those values below 0.15 ntu (see Figure 7.4).
These data support the hypothesis that enhanced plant performance depends on both optimized chemical
treatment and optimized individual filter performance. This also supports the allowance of an additional
0.5-log treatment credit for operation of individual filters in a way that minimizes short-term transients in
filter performance.
The monitoring of each filter effluent at a frequency of every 15 minutes provides the database upon
which excellent treatment performance can be evaluated. A performance standard focusing on individual
filter effluent provides further assurance that particle passage through the filter is minimized during
portions of the filter run most prone to deteriorated performance: during initial ripening, during flow-rate
changes, and at the end of the filter run.
Bibliography
Dugan, N., K. Fox, R. Miltner, D. Lytle, D. Williams, C. Parrett, C. Feld, and J. Owens. 1999. Control of
Cryptosporidium Oocysts by Steady-State Conventional Treatment. Proc. Of 1999 Annual Conference.
Denver, CO: AWWA.
Dugan, N., K. Fox, J. Owens, and R. Miltner. 2001. Cryptosporidium Control Through Conventional
Treatment. JAWWA, forthcoming.
Emelko, M., P. Huck, and R. Slawson. 1999. Design and Operational Strategies for Optimizing
Cryptosporidium Removal by Filters. Proc. Of 1999 Water Quality Technology Conference. Denver, CO:
AWWA.
Emelko, M., P. Huck, and I. Douglas, and J. van den Oever. 2000. Cryptosporidium and Microsphere
Removal During Low Turbidity End-of-Run and Early Breakthrough Filtration. Proc. Of 2000 Water
Quality Technology Conference. Denver, CO: AWWA.
Emelko, M. 2001. Removal of Cryptosporidium parvum by Granular Media Filtration. Ph.D. diss.
University of Waterloo, Waterloo, Ontario, Canada. Environmental Engineering & Technology, 1996.
Comment Response for LT2ESWTR D-115 December 2005
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Technical Report: Giardia/Cryptosporidium Spiking Investigations 1994-1996. Newport News, VA:
EE&T and Erie County Water Authority.
Hall, T., J. Pressdee, and N. Carrington. 1994. Removal of Cryptosporidium Oocysts by Water Treatment
Process. London, England: Foundation for Water Research Limited.
Huck, P., B. Coffey, C. O'Melia, and M. Emelko. 2001. Removal of Cryptosporidium by Filtration Under
Various Process Conditions. Proc. Of CIWEM International Conference on Advances in Rapid Granular
Filtration in Water and Wastewater, London, UK, April 4-6, 2001. London, UK: Chartered Institution of
Water and Environmental Management (CIWEM).
Kelley, M., P. Warrier, J. Brokaw, K. Barrett, and S. Komisar. 1995. A Study of Two US Army
Installation Drinking Water Sources and Treatment Systems for the Removal of Giardia and
Cryptosporidium. Proc. Of 1995 Water Quality Technology Conference. Denver, CO: AWWA.
McTigue, N., M. LeChevallier, H. Arora, and J. Clancy. 1998. National Assessment of Particle Removal
by Filtration. Denver, CO: AWWARF and AWWA.
Nieminski, E. and W. Bellamy. 2000. Application of Surrogate Measures to Improve Treatment Plant
Performance. Denver, CO: AWWARF and AWWA.
Ongerth, J. and J. Pecoraro. 1995. Removing Cryptosporidium Using Multimedia Filters. JAWWA.
87(12):83-89.
Patania, N., J. Jacangelo, L. Cummings, A. Wilczak, K. Riley, and J. Oppenheimer. 1995. Optimization
of Filtration for Cyst Removal. Denver, CO: AWWARF and AWWA.
Swaim, P., M. Heath, N. Patania, W. Wells, and R. Trussell. 1996. High-rate Direct Filtration for Giardia
and Cryptosporidium Removal. Proc. Of 1996 Annual Conference. Denver, CO: AWWA.
USEPA. 1990. Guidance Manual for Compliance with the Filtration and Disinfection Requirements for
Public Water Systems Using Surface Water Sources; EPA 570/9-89-018.
West, W., P. Daniel, P. Meyerhofer, A. DeGraca, S. Leonard, and C.P. Gerba. 1995. Evaluation of
Cryptosporidium Removal Through High-Rate Filtration. Proceedings of 1994 Annual Conference.
Denver, CO: AWWA.
CHAPTER 8
MULTIPLE FILTRATION PROCESSES
The Surface Water Treatment Rule (40 CFR 141.73) (SWTR) promulgated by U.S. EPA in 1989 (54 FR
27486) requires drinking water plants that employ surface water or ground water under the influence of
surface water to employ filtration to remove Giardia lamblia, Legionella, and other waterborne pathogens.
Subsequently, U.S. EPA developed the Guidance Manual for Compliance with the Filtration and
Disinfection Requirements for Public Water Systems Using Surface Water Sources (SWTR Guidance
Manual). While filtration processes are many and varied, all rely on the passage of water through a bed of
media (i.e., sand, gravel, carbon, etc.). The SWTR Guidance Manual established rapid sand filtration in
combination with coagulation and sedimentation, as the benchmark filtration technology for the SWTR
performance objectives. Those performance objectives were 2-log removal of Giardia cysts and ( 1-log
removal of viruses without disinfection. The SWTR Guidance Manual also recognized that some
Comment Response for LT2ESWTR D-116 December 2005
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filtration processes like slow sand and diatomaceous earth filtration provide greater removals (EPA 1990).
The SWTR Guidance Manual did not address filtration processes that typically provide <1 log of Giardia
removal nor did it address filtration in series. With promulgation of the Interim Enhanced Surface Water
Treatment Rule (IESWTR), U.S. EPA expanded the SWTR to encompass removal of Cryptosporidium.
The requirements of the IESWTR are also premised on the benchmark filtration technology of rapid
sand filtration following coagulation and sedimentation. In the IESWTR, the treatment performance
objective was (2-log removal for Cryptosporidium (EPA 1998). Consequently surface water treatment
plants will in 2001 be required to operate their rapid sand filtration processes to achieve more stringent
operational control levels. Like the initial SWTR guidance, the IESWTR did not address filtration
processes that provided less than 2-log Cryptosporidium removal nor did it address water treatment plants
that have multiple filtration processes.
Filtration processes can be generally characterized as unit operations where water passes through a bed of
granular filter media or other filtering material and solids are physically retained on the media (EPA
1999). The M/DBP FACA recommended that a particular type of filtration be included in the Microbial
Toolbox concept, "roughing filters" and recommended that this type of filtration could consistently
achieve 0.5-log removal of Cryptosporidium.
Roughing Filters
Roughing filters are described in general drinking water treatment plant design texts as a pretreatment
method to reduce turbidity and solids levels prior to subsequent treatment processes. In the United States,
the most widespread application is as a pretreatment for slow sand filtration (AWWA/ASCE 1997).
Roughing filters are composed of coarse grained filtration media, where contact with the media occurs in
either downflow, upflow, or horizontal flow (Figure 8.1). Roughing filters are used to remove solids by
both acting as a physical barrier and by promoting flocculation. Several studies are available that
describe the performance of roughing filters with several different configurations.
Cryptosporidium Oocyst Removal
Information from the literature associated with roughing filters placed prior to slow sand filters indicates
that these devices reduce turbidity from 0.3 to 0.5 log, suspended solids 0.5-2 log, and coliforms about 1
log (Galvis et al. 1993 and 1994, Weglin 1994 and 2001, Pardon 1994, and others). Information on
performance, design, and operation of roughing filters used prior to slow sand filters are summarized in
Collins and Graham 1994, Weglin 1996, and others. LeChevallier and Au (2001) also include a
discussion of literature pertaining to removal of turbidity, suspended solids, coliforms, and other materials
by roughing filters.
To date, authors evaluating roughing filters have not explicitly evaluated Cryptosporidium removal,
however, Weglin (1988) did find "complete" removal of organisms which are similar in size to
Cryptosporidium, Chlorophyta (2-10 (im) and Merismopedia (0.5 (im) after filter ripening. Weglin and
other authors have evaluated typical roughing filter designs for the removal achieved of total suspended
solids, turbidity, and other microbial indicators.
Galvis et al. (1993, 1994) present data demonstrating removal by roughing filters alone of >0.5 log for
suspended solids, 0.5 log for turbidity, and about 1.0 log for fecal coliforms using one or more roughing
filters in series prior to slow sand filtration. Configurations tested included downflow, upflow, and
horizontal flow filters with 0.6 to 4.0 meters of total filter media, where the effective diameter of media
employed generally ranged from 3-25 mm. Loading rates for roughing filters ranged from 0.25-0.40
gpm/ft2(0.6-l.lm/hr).
Comment Response for LT2ESWTR D-117 December 2005
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Weglin (1994, 2001) reported the combined effect of two roughing filters in series (i.e., an intake filter
coupled with a horizontal flow roughing filter) to be 0.5-1.0 log removal of turbidity (i.e., 7-100 ntu in
raw water) and about 1 log removal of fecal coliforms where coliforms in raw water were >l,000/100mL.
The filter media were unspecified, but loading rates were reported as 0.5 and 2.0 gpm/ft2 (1.2 and 4.7
m/hr), through the two filters respectively.
Pardon (1994) reports particle and fecal coliform reduction data for a three-stage, downflow, roughing
filter (i.e., 0.6 meters of 25-50 mm, 12-25 mm, and 6-12 mm gravel). The log removal using these mean
values was 0.5 and 1.1 for particles within the 1-2 (m size range and for fecal coliforms, respectively
where the mean influent concentration to the first-stage of the roughing filter was 3,502 particles/L (1-2
(m particles) and 3,330 fecal coliforms/lOOmL.
Additional Benefits
In addition to particle removal, roughing filters serve to dampen fluctuations in source water
contaminants allowing subsequent treatment to be operated more effectively. The available data on
roughing filter performance are consistent with the M/DBP FACA recommendation of 0.5-log credit
within the Microbial Toolbox when the roughing filter is an independent unit operation.
Multiple Filtration Processes
The removal achieved through filtration processes is achieved through a number of mechanisms, many of
which are quite complex and not completely quantified. There is physical removal with depth in the filter
and also straining at the surface of the filter. Correctly operated depth filtration is reliant on transport
mechanisms including gravitational settling, diffusion, and interception. The specific mechanisms that
dominate in a particular filtration process are a function of that filter design and the chemical
characteristics of the particulates in the raw or treated water. Specific filtration systems take
advantage of different filtration mechanisms. Consequently, the total removal achieved by each multiple
filtration processes will be filtration system specific. However, available data suggest that multiple
filtration steps provide not only increased removal, but they also increase redundancy and stability to the
treatment train. Multiple filtration steps also provide an additional treatment barrier to the passage of
protozoan into the potable water supply.
Kawamura (1985) reported results from two separate sets of pilot study conditions involving a two-stage
filtration process, the first stage being a roughing filter and the second stage similar to a stand alone,
conventional rapid sand filter. In one set of studies, two-stage filtration was compared to a single stage
rapid sand filter. Both the two-stage and single-stage filter trains treated settled water following
conventional coagulation, flocculation, and sedimentation. In the second set of studies, two-stage
filtration of raw water was compared to both single stage, direct filtration and conventional clarification
plus filtration. In each set of studies using two-stage filters, the first stage or "roughing" filter was
composed of coarser material (gravel or coke versus sand) and was operated at a higher loading rate (8 to
15 gpm/ft2) than for the second stage, conventional rapid sand filter (2 gpm/ft2). Overall, the two-stage
filtration system achieved the same effluent particle and turbidity levels as the clarification plus filtration
process. The two-stage filtration system used the same coagulant dosage as the direct filtration system,
but achieved longer filter run times and had lower effluent particle counts than the direct filtration system.
In effect, the roughing filter-direct filtration system achieved performance equivalent to a conventional
clarification system.
Alternatives for incorporating multiple filtration processes in drinking water treatment are not limited to
roughing filters, but also include
Comment Response for LT2ESWTR D-118 December 2005
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- Rapid sand or dual media filter following another rapid sand or dual media filter,
- Granular activated carbon (GAC) filter following a rapid sand or dual media filter
Filters are increasingly employed as biologically active processes for removal of assimilable organic
carbon (AOC) associated with ozone disinfection. High rate filtration processes are also employed to
remove manganese. There will be an increasing number of granular activated carbon (GAC) contactors
installed to achieve compliance with the Stage 1 D/DBPR and Stage 2 D/DBPR. Some systems subject to
LT2ESWTR will make treatment changes including adding filtration processes like activated alumina and
ion exchange to meet more stringent arsenic levels recently promulgated by EPA (Number of WTPs
impacted dependant on arsenic MCL). Consequently, there will be an increasing number of facilities
which will need to install multiple filtration processes while complying with the LT2ESWTR. By
recognizing the multiple benefits of these additional filtration processes, the LT2ESWTR Microbial
Toolbox provides an additional incentive to systems wishing to invest in the principle of multiple barrier
treatment encouraged by the M/DBP FACA Agreement in Principle. In meeting multiple water quality
objectives the combined cost of compliance for the Stage 2 DBPR and LT2ESWTR will be reduced.
Cryptosporidium Oocyst Removal
The City of Cincinnati, Ohio operates a conventional treatment facility which employs GAC contactors
for DBP, taste, and odor control after rapid sand filtration. The City of Cincinnati compiled full-scale
monitoring data for total aerobic spores in 1999 and 2000. Log removal of spores from GAC influent to
GAC effluent are summarized in Figure 8.2. These data indicate that mean and median log removal
through the secondary GAC filters, as an isolated process, is approximately 0.9 log with >80 percent of
the paired observations demonstrating >0.5-log removal. However, since 16 percent of the GAC filtered
water results were below detection limits (1 cfu/100 mL), the actual log spore removal was probably
greater than indicated by these results.
Additional Benefits
The IESWTR introduced more stringent operational controls to reduce turbidity in finished water. In the
IESWTR, EPA used turbidity as an indicator of treatment plant performance and found that managing
finished water effluent turbidity provided a suitable control measure where the treatment objective was
Cryptosporidium oocyst removal. The Cincinnati data set also includes turbidity measurements.
Comparison of individual sand filter and secondary filter effluent turbidities in Figure 8.3 illustrates that
the second stage GAC filter dampens or eliminates spikes and other intermittent releases of turbidities
from the preceding dual media filters during ripening, end-of-run, and other periods over the course of a
35 hour filter run. The Cincinnati data set shows that dual filtration will dampen turbidity spiking when
filtration consistently provides individual filtered water turbidities required by the IESWTR, suggesting
that additional benefits in solids removal and system redundancy are being achieved.
Summary
The data demonstrate a direct benefit of at least an additional 0.5-log removal for spores by the GAC
filter acting as a separate process. In addition, turbidity data demonstrate the ability of additional barriers,
such as a GAC filter following a dual media filter, to further dampen or eliminate intermittent particle,
turbidity, and microbial spikes from preceding processes.
Due to the usefulness of a secondary filter to remove additional particles, dampen spikes, and serve as an
additional Cryptosporidium barrier, any filter of conventional design (ES <1.3 mm, depth >24 inches)
should be an effective secondary barrier, and should receive a 0.5-log credit.
Comment Response for LT2ESWTR D-119 December 2005
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Bibliography
Collins, M, and M. Graham, eds. 1994. Slow Sand Filtration. Denver, CO: AWWA.
Galvis, G., J. Fernandez, and J. Visscher 1993. Comparative Study of Different Pre-Treatment
Alternatives. Aqua. 42:337-346.
AWWA/ASCE 1997. Water Treatment Plant Design; McGraw Hill. 3rd Edition. 1997.
EPA 1990. Guidance Manual for Compliance with the Filtration and Disinfection Requirements for
Public Water Systems Using Surface Water Sources; EPA 570/9-89-018, October, 1990.
EPA 1998. National Primary Drinking Water Regulations: Interim Enhanced Surface Water Treatment;
Final Rule. 63 FR 69478 December, 1998.
EPA 1999. Guidance Manual for Compliance with the Interim Enhanced Surface Water Treatment Rule:
Turbidity Provisions. EPA 815-R-99-010. April, 1999.
Galvis, G., J. Visscher, and B. Lloyd. 1994. Overcoming Water Quality Limitations with the Multi-
Barrier Concept: A Case Study from Colombia. In Slow Sand Filtration. Edited by M. Collins and M.
Graham. Denver, CO: AWWA.
Kawamura, S. 1985. Two-stage Filtration. JAWWA. 77(12):42-47.
LeChevallier, M. and K. Au. 2001. Impact of Treatment on Microbial Water Quality: A Review
Document on Treatment Efficiency to Remove Pathogens. Washington, DC: World Health Organization,
forthcoming.
Pardon, M. 1994. Removal Efficiency of Particulate Matter Through Vertical Flow Roughing Filters. In
Slow Sand Filtration. Edited by M. Collins and M. Graham. Denver, CO: AWWA.
Weglin, M. 1988. Roughing Gravel Filters for Suspended Solids Removal. In Slow Sand Filtration:
Recent Developments in Water Treatment Technology. Edited by N. Graham. Chichester, UK: Ellis
Horwood, Ltd.
Weglin, M. 1994. Roughing Filters for Surface Water Treatment. In Slow Sand Filtration. Edited by M.
Collins and M. Graham. Denver, CO: AWWA.
Weglin, M. 1996. Surface Water Treatment by Roughing Filters - A Design, Construction, and Operation
Manual (SANDEC Report No. 02/96). London, UK: Intermediate Technology Publications.
Weglin, M. 2001. Personal Communication, January 31, 2001. (Duebendorf, Switzerland).
CHAPTER 9
SLOW SAND FILTRATION
Data from Schuler et al. 1991, Hall et al. 1994, and EES et al. 2000 demonstrate >4-log removal in slow
sand filters during Cryptosporidium spiking studies. Timms et al. 1995 did not find any oocysts in
effluent from slow sand filters during similar spiking studies; however, at the raw water spiking levels
Comment Response for LT2ESWTR D-120 December 2005
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used, the filtered water detection limits were not low enough to demonstrate >3.6-log removal of
Cryptosporidium.
Schuler et al. 1991 (also described in Schuler and Ghosh 1991) describe results of challenge studies
conducted between March 1988 and January 1989 investigating removal of Cryptosporidium and other
microorganisms using pilot-scale slow sand filters. Pilot-filters were 0.286-m diameter (11.2 in), 0.90-m
deep (3 ft) composed of sand with effective size (dlO) of 0.27 mm and uniformity coefficient of 1.63.
Filter loading rates were 3.6 to 9.6 m/day (0.06 to 0.16 gpm/ft2). Temperature ranges tested were 4.5 to
16.5 (C. Raw water was seeded with Giardia muris (2,000 cysts/L), E. Coli. (10-2,400 organisms/L), and
inactivated Cryptosporidium parvum (2,000 oocysts/L). The slow sand filter used in this study was able to
achieve >4-log removal under all temperature and loading conditions tested.
Hall et al. 1994 reported data from Cryptosporidium challenge studies conducted between November
1992 and February 1994 using a slow sand filter with 2 m2 filtration area and 0.22- to 0.42-mm sand
media (depth not specified). The reported flow rate was 10 m3/d, resulting in a filtration rate of 5 m/d
(0.085 gpm/ft2). Some studies included removal of seeded Cryptosporidium by a slow sand filter (SSF)
preceded by a rapid sand filter (RGF), and others with a slow sand filter by itself. Two observations of
removal using SSF and RGF were <3.0 log, and three other observations were about 4 log. For removal
by SSF alone, three observations were ~4 log and one observation was <3 log. Therefore, whether or
not SSF was preceded by RGF, these studies generally demonstrate approximately 4-log Cryptosporidium
removal using slow sand filtration.
Timms et al. 1995 reported data from Cryptosporidium challenge studies using a slow sand filter with
1.13 m2 filtration area, sand depth 0.5 m, but filter media size was unspecified. The filtration rate was 0.3
m/hr (0.12 gpm/ft2) during the first 4.5 hours, and increased to 0.4 m/hr (0.16 gpm/ft2) thereafter.
The total study duration was 5.75 hours. Cryptosporidium was seeded for the first 3.5 hours, then
unseeded raw water was fed to the filter during the remainder of the study period. The authors report
measuring an average of 400,000 oocysts/lOOL in the filter influent, with measured concentrations
ranging from 96,000 to 560,000 oocysts/lOOL. No oocysts were detected in the sand filter effluent
throughout the study period. This includes 20 samples with detection limits of either 133 or 2,000
oocysts/lOOL. At the seeded raw water Cryptosporidium concentrations used during this study, the
filtered water detection limits were not low enough to demonstrate >3.6-log removal.
EES et al. 2000 describe a Cryptosporidium challenge study conducted in July 1996 (also described in
Krueger et al. 1999) in Salem, OR. Oocysts were seeded into raw, untreated water prior to two test filters
and allowed to pass through the filters continually for 4 hours at a filter loading rate of 0.12 gpm/ft2
(0.3 m/hr). Each filter has a sand depth of approximately 30 inches, with effective sand size (dlO) in one
filter of 0.29 mm and 0.33 mm in the other. Cryptosporidium oocyst concentration in the applied water
was approximately 820 oocysts/L in each filter. Filter effluent from each filter was monitored for 28
hours after the starting from the introduction of contaminants. During the first 12 to 13 hours during
which the spiked applied water passed out of the filters, all effluent from each filter was directed through
filter cartridges. For 13 hours after this period of continuous sampling, effluent was sampled
periodically for oocysts. No oocysts were detected in the filter effluent samples from either filter at any
time during the study period. With detection limit of 1 oocyst/lOOL, this indicates that removal of oocysts
was >4 log.
Removal of pathogens in slow sand filters is due not only to physical removal, but also due to microbial
antagonism (Bellamy et al. 1985b and Lloyd 1996 cited by Kohne and Logsdon 2001) resulting from
microbial competitors and predators within the upper, biologically active, layers of the filter
("schmutzdecke"). Furthermore, natural polymers produced by the microbial community within the
filter increase the ability of the pathogens, particles, and other materials in the influent stream to attached
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to filter media (Wheeler et al. 1998 and Evans 1998, cited in Kohne and Logsdon (2001).
Because of the importance of the microbial population within the slow sand filter, factors which impact
the establishment and maintenance of the microbial community will also impact the capability of the slow
sand filter to act as a pathogen barrier. For example, new clean sand is less efficient than a mature,
biologically active slow sand filter for removal of bacteria, viruses, and protozoans. For example, Poynter
and Slade (1977) report that a biologically mature filter is capable of removing one log greater levels of
viruses than a new filter. Wheeler at al. 1988 (cited by Kohne and Logsdon 2001) reported 1-log rotavirus
removal in a biologically active filter versus no reduction in a sterile, acid-washed sand or sterile clean
sand filter. Chlorination applied prior to slow sand filters produces poorer particle and microbial removal
than without pre-chlorination, because the long lasting chlorine residual inhibits microbial activity in the
filter. Conversely, pre-ozonation breaks down influent organic material into more biodegradable fractions
and, since ozone residual does not last long, the result is enhanced biological activity and improved
removal of pathogens and other particles in slow sand filters.
Lower temperature can reduce microbial activity and, consequently, can reduce effectiveness of slow
sand filters for removal of organic and particulate matter, including pathogens. For example, Poynter ad
Slade (1977) reported about 1 log lower virus removal at 5-8(C (1.7-2.5 log) than at 16-18(C (2.8-4.5
log). Bellamy (1985b) reports 1-log lower removal of coliforms and heterotrophic plate count bacteria, a
reduction of from ~99- to ~90- percent removal, at 5(C versus 17(C.
However, the temperature impact on removal of protozoans, particularly Giardia and Cryptosporidium,
may not be as significant. For example, while Bellamy et al. (1985a and b) report higher effluent levels of
coliform and heterotrophic plate count at 5(C versus 17(C, the Giardia removal at each of these
temperatures was about the same (~2 log or greater). The authors did note that Giardia removal improved
to almost 100 percent in a mature filter bed as opposed to clean media. The implication, at least for
Giardia, is that once a stable microbial community is established in the filter under a given set of
conditions, including temperature, the filter should be able to remove almost 100 percent of influent
Giardia under these conditions.
Data on the impact of temperature on removal of Cryptosporidium by slow sand filters is not extensive.
Schuler et al. 1991 report about 4-log removal Cryptosporidium removal during all periods tested,
including temperature changes of 4.5-16.5(C.
Guidance for slow sand filtration design parameters are outlined in Hendricks 1991, Kohne and Logsdon
2001, Visscher 1990, and others.
SUMMARY
Existing studies have shown >4-log Cryptosporidium removal during slow sand filtration. This data
justifies a 3.0-log baseline credit equivalent to a clarification and filtration treatment system, as defined in
the LT2ESWTR, for a slow sand filtration process operated as a stand alone system. A slow sand
filtration unit process added to a clarification and filtration system would be justified to receive a 2.5-log
credit as a toolbox component.
Studies on slow sand filtration have established that removal of bacteria and viruses are temperature
dependent due to the importance of biological processes for removal (due to presence of microbial
predators and competitors). However, Giardia removal during slow sand filtration has not been shown to
be temperature dependent, even though microbial activity of competitors and predators is also an
important contributor to Giardia removal in slow sand filters. It is believed that Cryptosporidium and
other protozoans will behave similar to Giardia in slow sand filters, meaning Cryptosporidium removal in
Comment Response for LT2ESWTR D-122 December 2005
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slow sand filters is probably not impacted by low temperatures, though studies explicitly addressing
temperature impacts on Cryptosporidium during slow sand filtration are not extensive.
Bibliography
Bellamy, W., G. Silverman, D. Hendricks, and G. Logsdon. 1985a. Removing Giardia Cysts with Slow
Sand Filtration. JAWWA. 77(2):52-60.
Bellamy, W., D. Hendricks, and G. Logsdon. 1985b. Slow Sand Filtration: Influences of Selected Process
Variables. JAWWA. 77(12), 62-66.
Economic and Engineering Services (EES), University of New Hampshire, Black and Veatch Consulting
Engineers, and Thames Water Utilities. 2000. City of Salem (OR) - Slow Sand Filtration Pilot Study
Report, Geren Island Treatment Facility Improvements - May 2000. Kansas City, MO: Black and Veatch
Consulting Engineers.
Evans, H. 1998. Particle Removal within Biological Water Treatment Filters, Volume 1. Portfolio
submitted for partial fulfillment of the degree of Engineering Doctorate in Environmental Technology,
University of Surrey, Guilford, Surrey, UK p. 252.
Hall, T., J. Pressdee, and N. Carrington. 1994. Removal of Cryptosporidium Oocysts by Water Treatment
Process. London, England: Foundation for Water Research Limited.
Hendricks, D. ed. 1991. Manual of Slow Sand Filtration. Denver, CO: AWWARF and AWWA.
Kohne, R., and G. Logsdon. 2001. Slow Sand Filtration (Chapter 5). In Manual on Control of Microbes in
Drinking Water. Reston, VA: ASCE, forthcoming.
Krueger, R., D. Prock, D. Sundseth, and G. Logsdon. 1999. Salem, Oregon Expands and Improves its
Slow Sand Filtration Facility to Prepare for Water Quality and Regulatory Challenges. Proc. Of 1999
Annual Conference. Denver, CO: AWWA.
Lloyd, B. 1996. Chapter 14. The Significance of Protozoal Predation and Adsorption for the Removal of
Bacteria by Slow Sand Filtration (Chapter 14). In Advances in Slow Sand and Alternative Biological
Filtration. N. Graham and R. Collins, Eds. Chichester, England: John Wiley & Sons.
Poynter, S., and J. Slade. 1977. The Removal of Viruses by Slow Sand Filtration. Progress in Water
Technology. 9(l):75-88.
Schuler, P., and M. Ghosh. 1991. Slow Sand Filtration of Cysts and Other Particulates. Proc. of 1991
Annual Conference. Denver, CO: AWWA.
Schuler, P., M. Ghosh, and P. Gopalan. 1991. Slow Sand and Diatomaceous Earth Filtration of Cysts and
Other Particulates. Water Research. 25(8)995-1005.
Timms, S., J. Slade, and C. Fricker. 1995. Removal of Cryptosporidium by Slow Sand Filtration. Water
Science and Technology. 31(5-6):81-84.
Visscher, J. 1990. Slow Sand Filtration: Design, Operation, and Maintenance. JAWWA. 82(6):67-71.
Wheeler, D., J. Bartram, and B. Lloyd. 1988. The Removal of Viruses by Filtration Through Sand. In
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Slow Sand Filtration: Recent Developments in Water Treatment Technology, Edited by N. Graham.
Chichester, UK: Ellis Horwood, Ltd.
CHAPTER 10
IMPACT OF RECYCLE PRACTICES ON CRYPTOSPORIDIUM REMOVAL
Allowable recycle practices at treatment plants will be regulated by the Filter Backwash Recycle Rule
(FBRR). The intent of the FBRR is to encourage implementation of recycle practices that do not
negatively impact performance of a treatment plant. In other words, facilities operated using practices
consistent with the FBRR should achieve equivalent, or superior, performance to the same facility
operated without recycle. Consequently, other regulations do not need to incorporate provisions for
recycle because all consequences of recycle practices are accounted for in systems complying with the
FBRR.
Cornwell and MacPhee 2001, Cornwell et al. 2001, and Nieminski and Bellamy 2000 provide data
supporting the contention that recycle practices consistent with FBRR do not negatively impact
performance of clarification systems, or the combined performance of a clarification plus filtration
system. Data for spore, Cryptosporidium, and other microbial indicators were collected during a study
reported by Nieminski and Bellamy (2000). This study included samples from 24 full-scale plants,
including 19 facilities with combined clarification and filtration, 4 facilities with only direct filtration, and
1 facility with disinfection only. Some facilities involved in the study did not have the capability of
recycling spent filter backwash water (SFBW), and other facilities with SFBW collected samples during
periods both with and without recycle. Data for Cryptosporidium, Bacillus subtilis, and total aerobic
spores (which includes Bacillus subtilis) are summarized in Figures 10.1, 10.2, and 10.3. These results
show that mean and median log removal for spores and Cryptosporidium was nearly the same, or slightly
higher, at facilities where SFBW was recycled versus facilities that did not recycle. For example, in
Figure 10.3 the median removal of total aerobic spores for all systems was about 2.9 when SFBW was
recycled versus about 2.6 when SFBW was not recycled. Dividing the results further into direct filtration
facilities versus facilities with both clarification and filtration, median removal of total aerobic spores was
slightly higher when recycle was used versus when recycle was not used at direct filtration facilities (2.4
versus 2.3) and systems with both clarification and filtration (3.1 versus 2.7).
Cornwell et al. 2001 and Cornwell and MacPhee 2001 reported results from pilot studies involving
impact of SFBW recycle on a system with clarification (plate settler) followed by a dual media filter.
Cryptosporidium oocysts were spiked into rapid mix and then oocysts were sampled after clarification
and after filtration under four sets of recycle conditions: a) no recycle, b) continuous recycle (4.3 percent
of plant flow), and c) two sets of intermittent recycle conditions (10 percent and 20 percent of plant flow).
Results in Figures 10.4 and 10.5 summarize Cryptosporidium removal data for sedimentation only and for
the combined clarification and filtration process (raw to filter). Figure 10.6 summarizes the impact of
recycle by characterizing removal of the combined oocyst concentration entering the clarifier (i.e., oocyst
spike + oocysts in recycle flow) versus oocyst concentration in the filter effluent (raw + recycle to filter).
In all instances, Cryptosporidium removal was as high or higher during periods of intermittent or
continuous recycle as when no SFBW recycle was used.
Summary
Therefore, results from full-scale plants reported by Nieminski and Bellamy (2000) and from pilot-scale
Cryptosporidium challenge studies reported by Cornwell and co-workers, Cornwell et al. 2001, and
Cornwell and MacPhee 2001 demonstrate that recycle can be implemented without deteriorating the
Cryptosporidium removal performance of subsequent clarification and filtration processes. Recycle issues
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should not be part of LT2ESWTR.
Bibliography
Cornwall, D. and M. MacPhee. 2001. Effects of Spent Filter Backwash Recycle on Cryptosporidium
Removal. JAWWA. 93(4): 153-162.
Cornwell, D., M. MacPhee, N. McTigue, H. Arora, G. DiGiovanni, and J. Taylor. 2000. Treatment
Options for Giardia, Cryptosporidium, and Other Contaminants in Recycled Backwash Water. Denver,
CO: AWWARF and AWWA.
Nieminski, E. and W. Bellamy. 2000. Application of Surrogate Measures to Improve Treatment Plant
Performance. Denver, CO: AWWARF and AWWA.
APPENDIX
1. Chapter 1 = Microbial Toolbox Overview
Peer-reviewer comment:
The chapter is a very good overview of the FACA Agreement in principle and the microbial toolbox.
Table 1.1 summarizes the potential log credits recommended by the FACA.
Peer-reviewer comment:
It would be worthwhile under this chapter to mention why the current report does not address the
potential log credit for In-bank filtration, and some discussion on why the FACA committee did not
specify a specific potential log credit for lime softening but a range of values greater than 0.5 in Table 1.1.
In addition, if the scope of work of this report by EE&T and AWWA was such that the other processes
such as membranes, bag filters, cartridge filters and improved disinfection were to be analyzed in other
studies, it would be worthwhile for completeness of this chapter to mention where these assessments
will be made.
Author's response:
USEPA is preparing separate guidance documents for the following:
* in-bank (riverbank) filtration,
* UV irradiation
* Ozone inactivation
* Chlorine dioxide inactivation
* Membranes, cartridge filters, and bag filters
* Watershed protection and control
As for the peer reviewer's comment regarding the current status of lime softening, USEPA and other
FACA members have re-defined lime softening in the LT2ESWTR so that now single-stage lime
softening (one clarifier followed by granular media filtration) is one of the "core treatment" technologies
that will be granted the same 3.0 log Cryptosporidium credit as other "clarification plus filtration"
technologies. The main requirement for the 3.0 log credit, as for other clarification plus filtration
technologies, is compliance with the IESWTR. One of these requirements is for a measured combined
filter effluent (CFE) turbidity of <0.30 ntu >95 percent of the time, although for lime softening this
compliance can be based upon acidified samples (to dissolve calcium carbonate (CaCO3) solids), if
necessary.
2. Chapter 2 = Definition of Conventional Treatment - reviewer 1
Comment Response for LT2ESWTR D-125 December 2005
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Peer-reviewer comment:
The expanded definition for conventional treatment as clarification-filtration to include newer
clarification technologies such as dissolved air flotation, actiflo is very good.
3. Chapter 3 = Relative Removal of Cryptosporidium and Aerobic Spores
Peer-reviewer comment:
I agree with the central conclusion of the chapter that bacterial spores are a good indicator of treatment
performance but are not a good indicator of the occurrence of Giardia or Cryptosporidium in raw and
finished water.
Peer-reviewer comment:
On page 13, line 3 from the bottom says, ".... as a group, show similar log removal to Cryptosporidium. "
The next sentence says that," ... it was not possible to calculate the true log removal..." reads like a
contradiction. Several of the later figures do indeed compare log spore removal with log Cryptosporidium
removal. I think that total aerobic spores are indeed a good conservative indicator of Cryptosporidium
removal and the data in Figure 3.1 are also consistent with this premise.
Author's response:
In order to clarify the section of the report that was the subject of the reviewer's comments, the old
version of discussion was replaced by the new version listed below.
Old Version
Data from Nieminski and Bellamy 2000 for Cryptosporidium, Bacillus subtilis, and total aerobic spores
are summarized in Figure 3.1. These data demonstrate that both Bacillus subtilis separately, and total
aerobic spores as a group, show similar log removal to Cryptosporidium. It was not possible to
demonstrate whether or not these spores were conservative indicators for Cryptosporidium because it was
not possible to calculate the true log removal of Cryptosporidium since 98 percent of the filtered water
Cryptosporidium observations were less than detection limits (i.e., only two filtered water observations
were > detection limit).
New Version
Data from Nieminski and Bellamy 2000 for Cryptosporidium, Bacillus subtilis, and total aerobic spores
are summarized in Figure 3.1. These data demonstrate that both Bacillus subtilis separately, and total
aerobic spores as a group, show similar log removal to Cryptosporidium. It is important to note that the
calculated values for log removal in this figure were based upon using the value of the detection limit
when these organisms were found below detection limits in filtered water. In other words, the true log
removal is actually higher than the numerical value calculated in each of these instances. This is less of an
issue for the total aerobic spore results, since most of the filtered water samples had total aerobic spore
levels above detection limits (85 percent of filtered sample results were above detection limits). However,
since most of the filtered water results for Bacillus subtilis (76 percent) and almost all of the
Cryptosporidium (78 of 80, or 98.5 percent) were below detection limits, the true log removal of these
organisms is actually higher than indicated in Figure 3.1. Data from other studies indicate that removal of
total aerobic spores and Bacillus subtilis are conservative indicators of Cryptosporidium removal,
meaning that Cryptosporidium removal is greater than removal of these bacterial spores. However, due to
the numeric limitations of the data set listed in Figure 3.1 (i.e., the underestimation of Cryptosporidium
removal), the full extent of Cryptosporidium removal in these studies is not known. Consequently, it is
not possible to use this data set to verify that Cryptosporidium is removed less effectively than bacterial
spores, the data are only sufficient to demonstrate that Cryptosporidium removal is at least similar (i.e., on
same order of magnitude) to removal of bacterial spores.
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Chapter 4 = Off-Stream Storage
Peer-reviewer comment:
The data presented in this chapter to support 0.5 log credit for a 21-day storage requirement and a 1.0 log
credit for 60 days storage is not entirely convincing. If the Medema, et al. 1997 (page 20) studies with
conservative rate constants are plotted on Figure 4.3 it shows that 50 days storage is required to obtain a
0.5 log credit at 15° C. Thus, a temperature increase from 5° C to 15° C seems to indicate a significant
increase of storage time. Perhaps the 21-day storage requirement for 0.5 log credit needs to be increased
or validated with additional literature sources.
Author's response:
The main response to the reviewer's comment is that the data in Figure 4.3 involve a different
Cryptosporidium removal/reduction mechanism than from the Medema et al. studies, plus the samples
being evaluated are different (data in Figure 4.3 includes viable and non-viable oocysts, Medema et al.
only reflects viable forms).
The mechanisms by which the risk of Cryptosporidium exposure are reduced during off-stream raw water
storage are depicted in Figure Q4.1. The number of raw water Cryptosporidium that end up in off-stream
storage effluent can be reduced via physical removal (deposition) or by decomposition (destruction). The
results listed in Figure 4.3 reflect data measuring the removal of all Cryptosporidium in raw water relative
to total amounts in off-stream storage effluent. These data do not take into account whether or not the raw
water, effluent, and/or removed oocycts were viable.
Conversely, the Medema et al. data are for die-off of viable Cryptosporidium as a function of time in
controlled laboratory studies, without allowing physical removal or microbial antagonism mechanisms to
act as they would in the off-stream reservoir environment. In these controlled experiments, losses due to
deposition are not accounted for. Furthermore, losses of Cryptosporidium due to decomposition do occur,
but were not measured or controlled. Consequently, the Medema et al. data reflect an entirely different set
of mechanisms than do the studies summarized in Figure 4.3. Furthermore, the samples being evaluated
are reflecting entirely different characteristics, because the Medema et al. studies tracked viable oocysts,
while the data in Figure 4.3 were based on total oocysts (i.e., viable and non-viable). Consequently, it
might be misleading to plot the Medema et al. data with the data in Figure 4.3. Accordingly, the authors
have not modified the text, data tables, or figures in Chapter in response to the peer reviewer's comments.
Peer-reviewer comment:
This reviewer is also concerned that off-stream storage maybe construed as raw water source lakes which
can have creeks feeding the lake at locations close to outlet structures which will result in short circuiting
and detention times much lower than mean storage times of the lake. This is particularly important since
some of the data shown are indeed from lakes (page 19). If it is a constructed storage structure with single
inlet and outlet then the detention times will be much closer to having a plug flow characteristic. The
report should include a cautioning note or explanation on this aspect at the beginning of this chapter.
Author's response:
LT2ESWTR guidelines for off-stream storage will include hydraulic requirements limiting short-
circuiting, plus the Rule will include requirements controlling input of potential Cryptosporidium sources
into the off-stream storage basin.
Peer-reviewer comment:
On pages 18 & 19, Cryptosporidium data indicate that 1 out of 97 raw water samples were positive and 1
out of 33 off-stream storage effluent samples were positive. This may be worth clarifying since some
Comment Response for LT2ESWTR D-127 December 2005
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people may misuse these data and attempt to say that off-stream storage increases risk of
Cryptosporidium passage since 96 of 97 raw water samples were negative (99%), but only 32 of 33
off-stream storage effluent results (97%).
Author's response:
The following information has been incorporated into the final version of the report in order to clarify the
Cryptosporidium sampling results reported from Cincinnati.
Old Version
The City of Cincinnati, OH has a treatment plant that includes pre-sedimentation with lamella plate
settling, followed by off-stream storage (~3 days), prior to conventional sedimentation. During 1992 to
2000, only 1 sample out of 97 was positive for Cryptosporidium in the off-stream storage influent, and
only 1 out of 33 was positive in the off-stream storage effluent. Giardia was detected in about 10 percent
of off-stream storage inlet and outlet samples from 1992 to 2000, with a median log removal of 0.17.
Median log removal of total aerobic spores during off-stream storage from 1998 to 2000 (period during
which aerobic spore data was collected) was approximately 1 log, with over 85 percent of the
observations > 0.5 log. The cumulative distribution of spore log removal results during off-stream storage
at Cincinnati is summarized in Figure 4.1.
Old Version
The City of Cincinnati, OH has a treatment plant that includes pre-sedimentation with lamella plate
settling, followed by off-stream storage (~3 days), prior to conventional sedimentation. During August
1992 to March 1995, 31 paired Cryptosporidium and Giardia samples were collected from raw water and
off-stream storage effluent. On one sample date, both raw and off-stream samples were positive for both
Giardia and Cryptosporidium positive. No other samples of raw or off-stream storage effluent were
Cryptosporidium positive during this time period. From April 1995 until December 2000, 67 raw water
samples and 2 off-stream storage effluent samples were collected, and none of these were positive for
Cryptosporidium. Giardia were detected more frequently than Cryptosporidium in raw water during the
1992 to 2000 time period (about 1 out of every 3 samples). Only 3 of 31 off-stream storage effluent
samples were Giardia positive during the August 1992 to March 1995 period. Giardia was not found
above detection limits in either of the two samples collected from off-stream storage effluent during the
April 1995 to December 2000 time period. All of the Giardia and Cryptosporidium data reported are from
presumptive tests. However, it should be noted that on the date of the positive presumptive
Cryptosporidium samples in raw water and off-stream storage basin effluent, the confirmed analyses were
also positive. The detection limit during the August 1992 to March 1995 sample period, the only period
when positive Cryptosporidium samples were detected, was 0.23 to 22 oocysts/L in raw water and 0.26 to
2.0 oocysts/L in off-stream storage effluent.
Weekly total aerobic spore samples (147 sets) were collected from raw water, off-stream storage influent,
and off-stream storage effluent at Cincinnati from January 1998 to December 2000. Median log removal
of total aerobic spores during off-stream storage during this time period was approximately 1 log, with
over 85 percent of the observations > 0.5 log. The cumulative distribution of spore log removal results
during off-stream storage at Cincinnati is summarized in Figure 4.1.
4. Chapter 5 = Pre-Sedimentation
Peer-reviewer comment:
Data from three water treatment plants (two softening and one lamella sedimentation) are used to suggest
a 0.5 log toolbox credit for pre-sedimentation basins with coagulant addition and overflow rates less than
1.6 gpm/ft2. The 0.5 log credit is based on reduction of aerobic spores only (no Cryptosporidium data)
and two of the plants are softening plants (St. Louis and Kansas City) and the third has lamella
Comment Response for LT2ESWTR D-128 December 2005
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sedimentation (Cincinnati). The St. Louis data (Figures 5.1 and 5.2) indicate that 24% of the observations
have removals less than 0.5 logs and a considerable part of these observations are at overflow rates less
than 1 gpm/ft2.
Author's response:
The LT2ESWTR uses the mean or median, rather than a 90th, 95th, or some other percentile to determine
bin assignment from source water Cryptosporidium monitoring. The Rule bases log removal credit for
individual toolbox items on the mean or median removal demonstrated for these individual processes. The
justification for using the mean or median for individual components is that pre-sedimentation and other
toolbox components are not intended to be the sole Cryptosporidium barrier. Each of these toolbox
components are assigned a given Cryptosporidium removal credit only if they are associated with a
clarification plus filtration system, or a direct filtration system. The 3-log credit for clarification plus
filtration treatment and the 2.5 log credit for direct filtration are both conservative estimators of the
Cryptosporidium removal potential of these core processes in drinking water treatment. In each case,
data indicate that these core treatment processes can potentially achieve 0.5 to 2.0 logs more than the
default (minimum) log removal credit for these core processes. Consequently, the foundation of the
"Toolbox" approach is that if the average Cryptosporidium removal of a specific toolbox component is
0.5 log when considered as a separate process, the system as a whole (toolbox component combined with
clarification plus filtration treatment) will be capable of achieving 3.5 log removal.
The reviewer's comments also imply that because two of the case studies investigated were softening
plants, the data from these sites may be justified in establishing a 0.5 log credit for pre-sedimentation
basins used at softening plants, but may not necessarily apply to pre-sedimentation basins at non-
softening plants. In the case of St. Louis, it should be pointed out that pre-sedimentation basins are
located prior to lime addition and no softening sludge recycle to the pre-sedimentation basin is used.
Consequently, the presence of the softening process subsequent to this pre-sedimentation basin is
irrelevant to the performance of pre-sedimentation. Since Kansas City recycles softening sludge, the
presence of the softening process does impact performance of the pre-sedimentation basins. However, the
impact of recycling softening sludge is really one of supplying a "coagulant" for pre-sedimentation (see
also the next reviewer comment), not unlike the use of iron or aluminum based coagulants used to
performance of other pre-sedimentation basins.
Peer-reviewer comment:
The Kansas City data is also from a softening plant with sludge recycle. The mean and median Bacillus
subtilis removals without ferric sulfate or polymer (but with sludge recycle) are 0.46 and 4.44 logs as
indicated in Table 5.2. These results apply to the definition of pre-sedimentation with coagulant addition.
The use of headings indicating no coagulant addition for the Kansas City data, which included sludge
recycle, in Table 5.2, Figures 5.3 and 5.4 and in the text are in contradiction with the definition of pre-
sedimentation.
Author's response:
The reviewer makes a very good point. Softening solids are "coagulants", even when no iron salts or
polymers are added anywhere in the process at Kansas City. Therefore, it is not possible to do a
comparison of "coagulant addition" versus "no coagulant addition" at this site. It is more accurate to
describe the Kansas City results comparing "coagulant" versus "no coagulant" as really being results
comparing addition of metal salt and/or polymer treatment chemical versus no treatment chemical
addition, but both situations involve having a coagulant present since lime softening solids are recycled to
pre-sedimentation in all cases.
Peer-reviewer comment:
The mean and median aerobic spore removals in Cincinnati with lamella sedimentation is 0.60 and 0.46
Comment Response for LT2ESWTR D-129 December 2005
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(Table 5.3), which is borderline to the 0.5 log toolbox credit. Table 5.3 also indicates that 27 of 147
observations (18.4%) have effluent spore counts higher than influent values. This needs some
explanation and discussion, perhaps indicating the standard error of the measurements. Otherwise,
significant doubt on the log removal data will occur.
Author's response:
As stated in a response to a previous peer-reviewer comment, USEPA and other FACA members have
incorporated use of mean and median data to establish log credit for individual toolbox components and
to establish Cryptosporidium risk. As for the second part of the reviewer's comments, since spores do not
replicate during treatment, instances where effluent spore counts are greater than influent spore counts are
either the result of analytical or sampling anomalies. One of the issues regarding evaluation of statistical
data from Kansas City, St. Louis, and Cincinnati is how to handle these situations where the calculated
log removal was negative (i.e., effluent level > influent level). In the original report, the negative values
were excluded (27 of 147 observations) when calculating mean and median for Cincinnati data. For St.
Louis the negative values were included and for Kansas City a log removal value of zero was assumed
when effluent spore levels were higher than influent levels. Of these approaches, the one used for the
Kansas City data is probably more appropriate. Consequently, Table Q5.1 and data tables in the revised
version of the report reflect the statistical results when all calculated negative log removal values are
assigned a log removal value of zero.
[See p. 279 of PDF for Table Q5.1]
Peer-reviewer comment:
The use of pre-sedimentation tanks to dampen water quality degradation spikes is definitely a plus for this
process.
Peer-reviewer comment:
There are several unanswered questions:
1. What would be the removal in a pre-sedimentation tank with metal salt addition with no plate or tube
settlers and is not a softening plant?
2. What would be the removals of Cryptosporidium if seeding studies are done with a slug of oocysts?
3. Will coagulant doses be optimized in pre-sedimentation tanks as is done in pre-treatment (i.e.
destabilization and flocculation) prior to sedimentation?
Additional data from pre-sedimentation tanks that are currently in operation to answer these questions
will be very worthwhile.
Author's response:
In response to the peer reviewer's general comments regarding additional data, the authors agree that
additional data to verify the findings related to Cryptosporidium removal credits for pre-sedimentation, as
well as other toolbox items, would be welcome. Water utilities, research personnel, and other
organizations interested in collecting this information should be encouraged to do so. The authors have
tried to uncover whatever information sources were currently available and fortunately were able to
contact people from Kansas City, St. Louis, and Cincinnati (plus others for other toolbox items) who have
already collected the information cited in this report.
In response to some of the specific issues raised by the peer reviewer,
Question 1. The important issue is overflow rate in regards to whether pre-sedimentation will produce the
desired Cryptosporidium removal is overflow rate. Whether or not subsequent process is lime softening is
not relevant, unless softening sludge solids are recycled to pre-sedimentation.
Comment Response for LT2ESWTR D-130 December 2005
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Question 2. To our knowledge, oocyst seeding studies have not been performed on pre-sedimentation
basins.
Question 3. Optimization of coagulation prior to pre-sedimentation is desirable and should be encouraged.
Peer-reviewer comment:
The credit of 0.5 logs for pre-sedimentation is not unreasonable based on removals that occur in
sedimentation tanks in conventional treatment trains. But this needs to be documented, perhaps by
collating data from the references noted on page 24. In addition, the pre-sedimentation tanks must be
operated with optimum coagulation.
Author's response:
References in the report mentioned in the peer reviewer's comments do support a 1.0 log or more
potential for Cryptosporidium removal during clarification. However, these studies were conducted under
conditions suitable for clarifiers operated as part of "clarification plus filtration" treatment as defined in
Chapter 2, but not for conditions under which most pre-sedimentation applications would be used. For
example, use of a primary coagulant for pre-sedimentation are rare, and doses of coagulants used prior to
the pre-sedimentation basin are not normally "optimized". Clarifiers operated as pre-sedimentation basins
also tend to be operated at higher overflow rates than would be used for clarifiers as part of the core
treatment processes defined in Chapter 2. The authors believe that the full-scale monitoring data from the
three water treatment facilities using pre-sedimentation basins were considered a better indication of the
potential for Cryptosporidium reduction in pre-sedimentation applications.
As for the comment about operating pre-sedimentation with "optimum coagulation", this would be
desirable but it is doubtful whether it could or would be implementable at most water treatment facilities.
Data from the utilities cited in this report indicate that when coagulation is not "optimized", even in some
cases when no coagulants other than recycled softening solids are used, the pre-sedimentation basins are
able to reduce Cryptosporidium by 0.5 log, perhaps more. When evaluating Cryptosporidium log removal
credits proposed in the LT2ESWTR Toolbox, including the 0.5 log credit proposed for pre-sedimentation,
it is important for the reader to remember that none of these toolbox items are intended as the sole
Cryptosporidium barrier. Each toolbox component is only intended as a component of a multiple barrier
system.
5. Chapter 6 = Lime Softening
Peer-reviewer comment:
The introductory paragraph and Figure 6.1 needs significant changes. The description and figure should
include recarbonation tanks or carbon dioxide flow streams for single-stage or two-stage softening (see
AWWA, Water Quality and Treatment, 5th Ed., 1999, page 10.29 or AWWA, Water Treatment Plant
Design, 3rd Ed., 1998-pages 287 and 291. In addition, many plants in the country use split treatment
softening and the flow schematics and associated toolbox log credits are not easily deciphered from single
and two-stage softening. At least mention must be made of this process train. The data used to generate
the log credits for softening described in this chapter are from three two-stage softening plants, St. Louis,
Kansas City and Columbus. There are no data for Cryptosporidium or aerobic spore removal in single
stage softening plants to validate the 3 log removal credit indicated in the Summary of this chapter.
Author's response:
The authors were not explicit about split softening; however, the implication in the discussion was that in
order for a facility to get the additional 0.5 log credit for the second clarification stage, all of the raw
water would need to pass through both clarifiers before proceeding to subsequent processes. Therefore, a
Comment Response for LT2ESWTR D-131 December 2005
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treatment scenario like split softening, where part of raw water (e.g., 10 percent) by-passes the first
clarifier, would not be considered a two-stage process (3.5 log credit, but would instead only be granted
the 3.0 log credit for single-stage lime softening).
Figure 6.1 has been modified to describe the three basic treatment scenarios typically used for lime
softening. The treatment processes at the two Columbus plants are slightly different. At the two
Columbus plants, lime is added after the first clarification stage so that removal of softening solids only
occurs in the second clarifier or in the subsequent dual media filter. The first stage in these two plants is
operated like any other clarifier at a non-softening plant. True "two-stage softening" is practiced at
Kansas City and St. Louis because lime is added to the first clarifier. All four lime softening facilities
described in this report process all of the incoming flow through both clarification stages (i.e., no raw
water by-pass, like in split softening). Consequently, under proposed credits in the LT2ESWTR Toolbox,
each facility would be allowed a 3.5 log credit equivalent to a 3.0 baseline log credit for clarification plus
filtration treatment, coupled with a 0.5 log credit for the second clarification stage.
In addition to St. Louis, Kansas City, and Columbus, a few other utilities had collected spore data for
their lime softening processes. These included split softening water plants and lime softening plants with
only a single clarification stage. Unfortunately, the raw water spore concentrations were not high enough
to allow the full capabilities of the lime softening process to be demonstrated at these locations (i.e., the
same reason why the full potential of Cryptosporidium removal cannot be demonstrated at many full-
scale water plants with low raw water Cryptosporidium and aerobic spore levels). Lacking specific data
from lime softening plants with only one clarification stage, the authors presented available data
indicating that lime softening plants with two separate clarification stages provide at least 3.5 log removal
(often greater than 4.0 log), thereby consistent with a 3.0 log credit for the first clarification stage and an
additional 0.5 log for the second clarification stage.
Peer-reviewer comment:
On page 36 and Table 6.3, the Kansas City data are presented and analyzed. From Table 6.3 the mean and
median concentrations of Bacillus subtilis are higher in the effluent from the secondary clarifier (25.7 and
8.0) as compared to the primary clarifier (21.1 and 4.5). How were the log spore removals calculated as
0.3 (median) and 0.4 (mean), when the data indicated negative removals? This needs explanation,
otherwise doubts will be generated on the quality of the data and the validity of the analysis.
Author's response:
The main source of the confusion is due to the difference between taking the "log of means" versus taking
the "mean of logs". The data reported for mean and median log removal associated with the second
clarification stage at Kansas City as a separate unit process was calculated by taking the log of each pair
of basin effluent and influent samples, then determining the mean and median of these calculated log
values, in other words a "mean of logs".
Another aspect of these calculations that needs to be pointed out is that the spore counts are low in the
influent and effluent of the second clarifier. Consequently, the influent or effluent spore counts are often
below detection limits, and in many other instances the influent spore levels were recorded below the
detection limit, while the paired effluent sample was recorded as slightly above the detection limit. In
these instances, plus all other instances where effluent spore counts were slightly higher influent levels,
no log removal was calculated because negative log removal has no physical meaning for these spores in
clarifiers.
The spore data associated with the second clarification stage at Kansas City indicate that the influent and
effluent values are essentially identical, i.e., no identifiable removal is associated with this second stage.
However, this is mostly because the first stage performs so efficiently at removing spores that few spores
Comment Response for LT2ESWTR D-132 December 2005
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are left to be removed in the second stage. If more spores were present in the first stage effluent, the
second stage would provide additional removal.
Peer-reviewer comment:
The conclusion that 3-log removal credit for lime softening plants similar to clarification-filtration plants
is probably a valid conclusion. While two-stage softening does provide increased redundancy and stability
and possibly an additional treatment barrier, the available data (Figures 6.11 and 6.12) particularly that
from the Columbus Plant, do not validate an additional credit of 0.5 logs to give a total credit of 3.5 for
these types of plants. Again, some mention must be made of split treatment and whether it should be
considered single-stage or two-stage treatment.
Author's response:
The authors believe the available data demonstrate that a single-stage lime softening plant should be
allowed a 3.0 log credit, and an additional 0.5 log credit should be allowed for two-stage lime softening.
In order to get the additional 0.5 log allowed for two-stage lime softening, all of the raw water would
have to pass through both clarification stages, meaning that "split softening" where part of the raw water
by-passes the first clarification stage would only be allowed the 3.0 automatic log credit equivalent to a
single-stage lime softening plant.
6. Chapter 7 = Improved Filtration
Peer-reviewer comment:
The report assesses the recommended 0.5 log toolbox credit for improved filtration with turbidities less
than 0.15 NTU. I agree with this conclusion and sufficient data are presented for both Cryptosporidium
removal and aerobic spore removal to validate this toolbox credit.
Peer-reviewer comment:
What about the 1.0 log credit for 0.15 ntu IFE turbidity (last paragraph of page 45)?
Author's response:
The 0.5 log credit for 0.15 ntu CFE turbidity (combined filter effluent) was discussed in Chapter 7, but
the additional 0.5 log (i.e., 1.0 log total) for 0.15 ntu in IFE turbidity (individual filter effluent) was not
described in detail. The last five paragraphs in Chapter 7 were proposed by the peer-reviewer, and have
been incorporated into the attached revised version of the document.
Peer-reviewer comment:
To support the above, I'd recommend you divide Figure 7.4 into two blocks at 0.15 NTU. I eye-balled the
median values for the two blocks of data (above .015 and below 0.15) at 2.5 logs and 4.0 logs, to support
the discussion above for IFE credit.
Author's response:
This suggestion was already addressed in Figure 7.5.
7. Chapter 8 = Multiple Filtration Processes
Peer-reviewer comment:
A secondary filter of conventional design is given an additional 0.5 log toolbox credit. On the basis of
data presented in the previous Chapter 7, as well as data that supports the IESWTR, the additional 0.5 log
credit for filters in series, such as a roughing filter, is a valid toolbox credit.
8. Chapter 9 = Slow Sand Filtration
Comment Response for LT2ESWTR D-133 December 2005
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Peer-reviewer comment:
There are substantial data to justify a baseline credit of 3.0 log removal in slow sand filtration as a stand-
alone process. It is not clear that slow sand filtration added to a clarification-filtration system would
justify an additional 2.5 log credits. This would indicate a total credit of 5.5 logs. Data from Hall et al.
1994 for a rapid sand filter-slow sand filter system indicated only < 3.0 log and 4 log removals.
Additional data maybe necessary to justify the 5.5 log credit for a treatment system of clarification-
filtration followed by slow sand filtration or a modification of this log credit.
Author's response:
The 3.0 log baseline credit for slow sand filtration as a stand-alone system is justified by the available
data indicating >4 log Cryptosporidium removal. Data demonstrating the impact of slow sand filtration
added to direct filtration or added to clarification plus filtration treatment (see Chapter 2)] are limited.
Justification for a 2.5 log toolbox credit is based upon the fact that: a) it is an effective and reliable
Cryptosporidium barrier, and b) slow sand filtration includes a biological component that provides a
different and complimentary removal mechanism to conventional rapid granular filtration.
9. Chapter 10 = Impact of Recycle Practices on Cryptosporidium Removal
Peer-reviewer comment:
The chapter provides additional perspective on recycle practices. This reviewer agrees with the summary
statement.
10. Overall comments
Peer-reviewer comment:
The report is well written and in general the technical justifications for Cryptosporidium removal of the
various toolbox components are valid for the processes that have been researched and reported on in the
document. The data and analyses presented for the toolbox credits for off-stream storage and pre-
sedimentation are not entirely convincing. Some data to validate toolbox credits for single-stage lime
softening are necessary. This chapter also needs some modification to describe treatment train schematics
and a discussion of split treatment softening.
Author's response:
The authors believe the reviewers comments about off-stream storage, pre-sedimentation, and lime
softening are addressed in the appropriate chapters (Chapter 4 for off-stream storage, Chapter 5 for pre-
sedimentation, and Chapter 6 for lime softening).
Peer-reviewer comment:
I'd like to see a brief description of the mechanism at work in Cryptosporidium removal in the first
paragraph of each chapter.. .like for storage, it could be die-off and predators, pre-sed is physical removal
by...?. In most chapters, the mechanism (or the hypothesis for the mechanism) was eventually discussed,
but I think it would have been good to introduce the reader to the theory of why this treatment process
works, right up front. It makes it easier to accept the sparse data sets if the process of removal generally
makes sense in the first place.
Even though the data are sparse in many instances, I know that I believed that the conclusions follow the
data because I think I know why each process would be expected to work...and the relative order that I
would rank them in. Thus my comment above. Given no other background knowledge about treatment,
and given the scarcity of Cryptosporidium data for log removal calculations, the reader is forced to
Comment Response for LT2ESWTR D-134 December 2005
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believe the spore- Cryptosporidium removal similarities, and I think you did a pretty convincing job of
this in Chapter 3. In my opinion, this is critical for the report...if you believe the spore data is a good
indicator of Cryptosporidium removal, the rest is pretty easy to follow.
Author's response:
The authors believe that the existing text provides this information.
Peer-reviewer comment:
Each reviewer suggested minor spelling, grammatical, or format modifications throughout the document.
Author's response:
These changes have been incorporated, when appropriate.
[See p. 289 of PDF for Figure 3.1]
[See p. 290 of PDF for Figure 3.2]
[See p. 291 of PDF for Figure 3.3]
[See p. 292 of PDF for Figure 3.4]
[See p. 293 of PDF for Figure 3.5]
[See p. 294 of PDF for Figure 4.1]
[See p. 295 of PDF for Figure 4.2]
[See p. 296 of PDF for Figure 4.3]
[See p. 297 of PDF for Figure 6.1]
[See p. 298 of PDF for Figure 7.1]
[See p. 299 of PDF for Figure 7.2]
[See p. 300 of PDF for Figure 7.3]
[See p. 301 of PDF for Figure 7.4]
[See p. 302 of PDF for Figure 7.5]
[See p. 303 of PDF for Figure 7.6]
[See p. 304 of PDF for Figure 7.7]
[See p. 305 of PDF for Figure 8.1]
[See p. 306 of PDF for Figure 8.2]
[See p. 307 of PDF for Figure 8.3]
Comment Response for LT2ESWTR D-135 December 2005
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[See p. 308 of PDF for Figure 6.2]
[See p. 309 of PDF for Figure 6.3]
[See p. 310 of PDF for Figure 6.4]
[See p. 311 of PDF for Figure 6.5]
[See p. 312 of PDF for Figure 6.6]
[See p. 313 of PDF for Figure 6.7]
[See p. 314 of PDF for Figure 6.8]
[See p. 315 of PDF for Figure 6.9]
[See p. 316 of PDF for Figure 6.10]
[See p. 317 of PDF for Figure 6.11]
[See p. 318 of PDF for Figure 6.12]
[See p. 319 of PDF for Figure 5.1]
[See p. 320 of PDF for Figure 5.2]
[See p. 321 of PDF for Figure 5.3]
[See p. 322 of PDF for Figure 5.4]
[See p. 323 of PDF for Figure 5.5]
[See p. 324 of PDF for Figure 5.6]
[See p. 325 of PDF for Figure 5.7]
[See p. 326 of PDF for Figure 5.8]
[See p. 327 of PDF for Figure 5.9]
[See p. 328 of PDF for Figure 10.1]
[See p. 329 of PDF for Figure 10.2]
[See p. 330 of PDF for Figure 10.3]
[See p. 331 of PDF for Figure 10.4]
[See p. 332 of PDF for Figure 10.5]
Comment Response for LT2ESWTR D-136 December 2005
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[See p. 333 of PDF for Figure 10.6]
Response:
EPA Letter ID: 563
Comment ID: 16896
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 5
Bank Filtration - LT2ESWTR Toolbox Guidance Manual and Federal Register
Review and Comments
Current requirements for the RBF credit
Automatic 0.5 and 1.0 toolbox credits, including qualification as "UBT", are available for riverbank
filtration (RBF). However, greater credits should be allowed via demonstration of performance (DOP).
This implicit possibility is included in the DOP discussion, but should also be explicitly mentioned in the
RBF discussion of the Rule and associated guidance manual. Also, it is interesting that a detailed
hydrogeologic assessment is required in order to be eligible for any automatic credits, and yet the results
of this assessment do not enter into the establishment of numerical value of the credit. After all of
the hydrogeologic assessments and subsurface sampling, the magnitude of the RBF credit depends on a
measurement made by a yardstick. These utilities should be allowed the possibility of greater credits if
results of the hydrogeologic assessment justify it, or if DOP studies prove it, and credits should not be
limited to 0.5 or 1.0 and should not be based solely on distance measurements in all cases.
Bank filtration: a natural process
Bank filtration is defined by the guidance manual as a surface water pretreatment process using the bed
and bank of a river and the adjacent aquifer as a natural filter and relying solely on the natural properties
of the surface water bed and aquifer, unmodified by engineering works or activity, except for the recovery
of ground water via a pumping well. This definition of bank filtration characterizes this process by
emphasizing natural properties and filtration capacity of the surface water bed and aquifer, but throughout
the guidance manual and Federal Register, significantly less importance and information is given to the
aquifer as far as its capability to achieve natural contaminants removal. Bank filtration includes physical,
chemical, and biological mechanisms impacting transport and removal of contaminants in porous media.
Some specific characteristics of certain zone, such as the river bed surface or interface, should not shadow
the main and key characteristics of the aquifer itself. As we will demonstrate in this document, through
the citations of peer-reviewed publications and description of key phenomena, both the river bed and the
aquifer are subject to filtration theory and perform natural effective contaminants removal when it comes
to transport and fate of contaminants in porous media.
Scouring
During flood events, the entrainment and deposition of sediment results in a decrease and increase in the
vertical position of an alluvial streambed. These fluctuations are known as scour and fill, and represent
sediment transfers in a channel, [Haschenburger, 1999]. The depth and activity depends on the
interactions between hydraulic forces and channel boundary, which are defined by its morphology and
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sediment characteristics, and the magnitude and distribution, in space and time, of sediment transported to
and from a given location within a channel reach. Scour and fill processes exchange sediment between the
streambed and mobilized particles. These exchanges control the vertical and longitudinal sorting of
sediment throughout the river channel [Parker, 1991; Hassan and Church, 1994; Hoey and Ferguson,
1994].
Scour and fill depths fluctuate within a channel [Jackson and Beschta, 1982; Laronne and Duncan, 1989;
Hassan, 1990] because of non-uniform, unsteady flow, heterogeneous bed material texture and
arrangement, variable bed configurations, and local sediment supply introduce complexity into the
process of sediment
transfer during flooding events. The mean depth of scour for a given flow magnitude dictates in part the
rates of bed material transport [Einstein, 1937; Hubbell and Sayre, 1964]. It was observed that some areas
of the channel may not experience any bed activity, while in other locations the maximum scour depth
can extend to values as high as 8 times the surface layer [Lisle, 1995; Haschenburger, 1996].
Scour and fill are two processes that take place when flooding occurs and should not be analyzed
separately, but as a combined natural process. Through these scour and fill processes, some sediments are
removed and others are deposited on the river bed. In some cases, it will lead to temporary exposure of
the river-bed subsurface and in other cases, it will lead to new sediments being laid over the river-bed
subsurface. By exposing the river-bed subsurface, the interface is removed. This exposure allows
contaminants to be in direct or close contact to the aquifer itself. The potential bioclogging of the
interface disappears and belter water pumping rate and production can be achieved, but also it is
important and it will be demonstrated later in this document, that the aquifer is able to have an effective
filtration to ensure proper water quality and contaminants removal. When fill occurs on the river-bed, it
could be compared to a fast and new interface development, ready to perform filtration with no bio-
clogging at the beginning. In fact, scouring and fill should be described as an natural and automatic
regeneration of the interface or riverbed, that could beneficiate or least that do not penalize bank filtration,
allowing RBF to achieve good water production both in term of quality and quantity.
Bed forms and stream-subsurface exchange
Bed forms influence the exchange of solutes [Marion et al, 2002]. Stream-subsurface exchange fluxes are
based on channel hydraulics and subsurface flows. The stream and subsurface streamlines for flow over a
wavy porous boundary were derived by Ho and Gelhar [1973]. Marion et al. (2002) observed and
concluded that solute exchange from a flowing stream to a permeable sediment bed is dominated by
advection of water produced by head gradients at the porous media boundary. The existence of riverbed
forms induces an advective pumping flow that is mainly responsible for mixing phenomena in the
hyporheic zone. The subsurface flow is affected by the amplitude of bed topographical features and their
wavelength, which leads to cases where very different bed configurations produce the same amount of
solute penetration. A model developed by Elliott and Brooks [1997a] provides a direct explanation of this
behavior. Elliott and Brooks [1997a] used this type of fundamental approach to calculate the net exchange
resulting from stream flow over a sand bed. Sediment transport produces bed forms or topographical
features (dunes or ripples) on the bed surface. Then, flow over bed forms produces a periodic variation in
the dynamic head at the stream-subsurface interface that induces a corresponding pattern of advective
flow through the porous sand bed. Exchange is produced by flow into the bed at regions of high pressure
and corresponding flow out of the bed at regions of low pressure. The net streamsubsurface exchange due
to this process is named "pumping" Savant et al. [1987]. Experiments with a conservative dye
demonstrated subsurface dye penetration due to pumping and verified that net pumping exchange from
the stream could be predicted using a fundamental hydraulic model [Elliott and Brooks, 1997b]. Under
typical stream flow conditions, advective pumping exchange is 2 orders of magnitude greater than
diffusive transport [Savant et al., 1987; Elliott and Brooks, 1997a]. In addition to pumping phenomena,
Comment Response for LT2ESWTR D-138 December 2005
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bed form motion produces additional mixing, termed "turnover" exchange. When stream flow is high
enough to mobilize bed sediments but flow is still subcritical, downstream-propagating dunes and
ripples can be often found. As a result, sediment transport causes scour of the upstream side of bed forms
and fill on the downstream side, producing a net downstream bed form propagation. Pore water and
stream water are then exchanged by this alternating scour and fill (deposition) of the upper layer of the
bed. A model was also developed for combined turnover and pumping exchange due to relatively fast-
moving bed forms, when turnover dominates the exchange in the upper part of the bed where active bed
sediment transport occurs [Packman and Brooks, 2001]. While turnover rapidly mixes the upper layer of
the bed, advective pumping produces exchange with the deeper, un-scoured region of the subsurface
region.
Bed formation and stream-subsurface exchanges demonstrate the natural and regenerating processes that
govern the interface or river bed formation. This bed formation is an important element of the bank
filtration that should also be emphasized as it is correlated to scour and fill issues. Bank filtration is
described to achieve the removal of contaminants by facilitating or enhancing physical and chemical
filtering, sorption, reduction/oxidation, precipitation, ion exchange, and biodegradation (Schijven et al.,
2003; Ray et al., 2002; Tufenkji et al., 2002).
Filtration and Cryptosporidium
The interface is a location of intense natural and biological removal processes, but straining and filtration
mechanisms, as well as biodegradation and predation phenomena are not limited to the interface and
occur through the whole aquifer. Up to now, the contaminant removal processes have been quantified and
characterized for the whole bank filtration process, but not independently to assess the role of the
interface layer and the aquifer. It seems that this role is complementary, however, the interface and the
aquifer, have the necessary characteristics to function and achieve enough contaminant removal as a
combined process or as independent processes. The interface has the capacity to achieve contaminants
removal over short distance due to its intensive biofiltration process and enhanced physical filtration
(resulting bioclogging), while the aquifer also has the potential for removal of contaminants over long
distance due to physical filtration and extensive biofiltration. Physical filtration is the key component of
bank filtration, by its definition, both the interface and the aquifer possess the characteristics for effective
physical filtration.
Scouring phenomena may impact the bank filtration system, as it may remove a part of the river bed or
bank that are the location of an intense and active biological zone, where removal of contaminant is well
established and documented. However, the majority of the contaminant removal occurs in the interface
zone because this is the first filtering media that the water from the river, carrying contaminants,
encounters. This phenomena is described by the well established and demonstrated porous media
filtration theory and process.
Colloid transport studies in the literature have focused on the quantification of clean bed first-order
attachment coefficients to describe particle removal in filter beds (porous media) [Fitzpatrick and
Spielman, 1973; Tobiason and O'Melia, 1988; Vaidyanathan and Tien, 1991]. According to these research
and theoretical approach, colloid removal by the filter bed decreases exponentially with depth [Tobiason
and O'Melia, 1988; Amirtharajah, 1988, Packman and Bencala, 2000; Bradford et al., 2002]. Colloid
attachment theory also predicts an optimum particle size for transport for a given aqueous-porous medium
system [Tobiason and O'Melia, 1988]. Smaller particles are predicted to be removed more efficiently by
diffusive transport, and larger particles are predicted to be removed more efficiently by sedimentation and
interception.
As expected from the filtration theory, maximum eluent concentration, and fractional penetration of
Comment Response for LT2ESWTR D-139 December 2005
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Cryptosporidium. parvum decrease with smaller grain size and lower pore velocity leading to the largest
residual concentrations in the slow medium sand and fast fine sand experiments. The concentration
profiles in all but the fast coarse sand column show the largest concentration of oocysts near the top
(inflow boundary) of the sand column (Harter et al., 2000). Similar to outflow concentrations, sorbed
concentrations in the profile decrease exponentially with the distance from the inflow boundary, in
agreement with the filtration theory (Harter et al., 2000).
The statement in the guidance manual on bank filtration that most of the removal of the contaminants and
microbes occurs during the first few centimeters of flow path cannot be monopolized by the interface or
river bed characteristics and filtering and sorptive capabilities of sediments in the riverbed, simply
because, with the filtration theory and the experiments on Cryptosporidium, any porous media possess,
such as the aquifer, possess the same characteristics and is capable of contaminants removal within its top
layer.
Wang et al. (2002) found that removal of particles increased with filtration distance of the riverbank
filtration process, although most of the removal occurred at the surface of the riverbed, within the first
two feet of filtration. Wang et al. (2002) attributed the removal in their bank filtration system to a
combination of mechanical filtering and biological activity (e.g. biofiltering) at the surface of the
riverbed. These relevant findings demonstrated the effectiveness and complexity of the natural bank
filtration process, but also, do not take away the natural filtration and removal capacity of the aquifer
itself, once 2 ft away from the river bed. These findings corroborate the filtration theory and demonstrate
the effectiveness of both the riverbed and aquifer when it comes to contaminants removal, as removal of
particles increase with filtration distance.
Even if, scouring is significant and has a temporary impact on the river bed, the filtration theory and
experiment on Cryptosporidium demonstrate that filtration capacity exists in the aquifer, and that like in
any porous media, contaminants concentration in the profile decrease exponentially with distance from
the inflow boundary in the aquifer [Harter et al., 2000]. At the USEPA/USGS meeting of September
2003, data on log removal of Cryptosporidium were provided: 3.3 log removal at the interface and 0.6 log
removal in the aquifer. These data corroborate well the filtration theory as less contaminant is present as
you move away from the inflow boundary, which correspond to less contaminant removal in the aquifer,
because most of the removal has been achieved at the inflow boundary location, which was in that case
the interface or river bed.
In the Federal Register, it is stated that: "This proposal is generally supported by the colloid filtration
theory modeling results using data characteristics of the aquifers in Louisville and Cincinnati and column
studies of oocysts transport in sand (Harter et al., 2000)", however, it seems that the filtration theory is not
used properly in the text of the Federal Register, as in the original papers and research involving
Cryptosporidium [Tobiason and O'Melia, 1988; Harter et al., 2000], it clearly demonstrates the
phenomena of filtration in a porous media, and some of the conclusions presented in the Federal Register
can not be established if the filtration theory is followed and applied [See filtration theory described in the
section above].
LT2ESWTR Compliance Requirements
In the LT2ESWTR compliance requirements, systems that propose to install bank filtration wells to meet
any additional treatment requirements imposed by the LT2ESWTR may be eligible for 0.5 or 1.0 log
Cryptosporidium removal credit (40 CFR 141.726(c)). Additionally, systems using horizontal or vertical
wells located 25 feet from the surface water source are eligible for a 0.5 log removal credit and those
located at least 50 feet from the surface water source are eligible for a 1.0 log removal credit. In these
statements, no references to any experiments, theory or modeling is presented. It is important for the
Comment Response for LT2ESWTR D-140 December 2005
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public and the water industry to understand the processes that led to these criteria. It will serve the water
utilities to understand clearly how these 0.5 and 1.0 log removal were established in order to implement
bank filtration. In all criteria development, data and peer-review publication are keys to support new
approach or concept. In the case of bank filtration, little if no data is presented to support the criteria as
needed. Best engineering practice combined with knowledge and expertise of the different stakeholders
should be fully and extensively used for the development of criteria.
Data from Louisville and Cincinnati on the removal of spores or colloids demonstrate more than 3.0 or
4.0 log removal by bank filtration (Wang et al. 2002, Gollnitz et al. 2003). As a result, based on these data
and the filtration and removal theory describe above, more log removal credit should be available
to water utility that are developing bank filtration.
Characterization of the aquifer
Systems must characterize the aquifer at the proposed production well site to determine aquifer
properties. The characterization of the aquifer is essential to the development of the bank filtration site,
but instead of enhancing the log removal credit based on the findings of the aquifer characteristics, the
characterization of the aquifer seems to be used to limit the bank filtration applicability and does not
encourage its development. Characterization of the aquifer aims to focus on the core of the riverbank
filtration process, however, there is no characterization of the interface, although, this one appears to be
critical when it comes to give more credit removal or scouring issue. By characterizing the aquifer,
potential of contaminant removal can be determined and the best site can be selected to produce the best
water quality and in enough quantity, while giving more credit than the systematic 0.5 and 1.0 log
removal. All these characterization efforts should benefit the utilities with significant credit
encouragement. Determination and characterization of the aquifer is necessary and justify, but why
limiting and relating the removal credit to this interface, when characterization is concentrated towards
the aquifer itself, which will attenuate potential scouring effects, by its natural filtration as mentioned
previously.
Measurable criteria are based on aquifer characterization, key to the bank filtration process, but when it
comes to risk assessment, the natural properties of an aquifer that have been fully characterized are not
taken into consideration. Filtration is present in both the interface and the aquifer: biofiltration, bio-active
removal (degradation and predation) and physical filtration are intensive in the interface over a short
distance; while extensive biofiltration and intensive filtration occur in the aquifer, over a longer distance.
Filtrate flow path and well location
For systems to receive Cryptsoporidium log removal credits, the ground water flow path length between
the edge of the surface water body and the well is expected to be sufficient for effective oocysts removal.
It is well stated that the full distance between the river bed or bank to the well is included in the
definition and calculation of the process, so it is not limited to 2 feet of interface where intense
biofiltering and contaminants removal occurs. The description of the flow path demonstrates that in some
cases the bank filtration processes is described as an independent process to reach certain conclusions,
while in other cases, bank filtration is described as a whole process to reach conclusions. Consistency
should be applied throughout the text while stating facts and drawing conclusions. The fact that log
removal credits are related to the distance between the edge of the surface water body and the well,
demonstrate the importance of the filtration theory in the bank filtration process. A more details
description of this filtration theory should be implemented in the guidance the guidance manual, as it will
clearly explain why more contaminant removal is obtained at the top of inflow boundary, and why less
contaminant is removed afterwards, as contaminants concentration (e.g. Cryptosporidium) in the profile
decrease exponentially with distance from the inflow boundary [Tobiason and O'Melia, 1988; Harter et
Comment Response for LT2ESWTR D-141 December 2005
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al., 2000]. The theory will clearly explain that if the interface is removed, the exponential decrease
in contaminant concentration will still occurs in the remaining aquifer.
Over-pumping and unsaturated zone
Over-pumping results in a decrease of the aquifer thickness and in a development and formation of an
unsaturated zone. The formation of the unsaturated zone - variably saturated zone - has advantages and
disadvantages regarding the fate and transport of the contaminants in the subsurface. Description of the
key processes occurring in the unsaturated zone, such as its role on contaminants transport and fate, could
benefit the section on the Bank Filtration. In addition, while USEPA chooses to dwell on some benefits of
over-pumping, it does not appear to sufficiently address some of the negative issues. The following is
a more complete list of potential advantages and disadvantages of over-pumping (i.e., excessive
drawdown) in RBF systems.
Advantages of unsaturated zone consist of potential contaminants entrapments through gas-water
interfaces, degradation and sorbption. The capillary zone, zone of high water content (not saturation) just
above the groundwater contained a significant number of gas-water interfaces that will allow high
potential entrapment of contaminants that combined with the top of groundwater will be an effective
porous media combination for physical filtration, [Wan et al, 1994a, 1994b; Darnault et al., 2003;
Darnault et al., 2004]. Additionally, physical, chemical and biological phenomena affecting the
contaminants fate, transportation and degradation are enhanced by gas-water interfaces.
The main disadvantage of unsaturated zone is preferential flow phenomena. Preferential flow (such as
macropores flow, fingered flow or funneled flow) facilitates the movement of water and the transport of
pollutants through the soil to the groundwater [Selker et al., 1996; Darnault et al., 2003; Darnault et
al., 2004]. Preferential flow not only facilitate the transport of pollutant to groundwater but also decrease
the residence time of pollutant in the soil matrix, which is generally a place of significant physical,
chemical and biological processes and activities leading to inactivation, degradation and transformation of
numerous pollutants. As a result, pollutants will reach groundwater rapidly and in high concentration
when subjected to preferential flow phenomena. These contaminants will then undergo filtration in the
groundwater, as described by the filtration theory.
Therefore, while USEPA is correct about the advantages they list, they fail to balance the discussion by
mentioning or emphasizing some of the disadvantages. Furthermore, when they mention the
disadvantages of over-pumping, they attribute the potential for decreased water quality to the decreased
thickness of the saturated aquifer, due to the formation of a large variably saturated zone, and that this
may cause faster ground water flow. Faster ground water flow provides less time for contaminants
attenuation within the aquifer. However, they do not acknowledge an additional factor with potentially
greater impact, the development of preferential flow paths in the unsaturated zone. Preferential
flow allowing rapid transport and less residence time throughout the unsaturated zone seems to have
greater effect on the fate and transport of contaminant than a short ground water flow and less
contaminant attenuation occurring in the decreased thickness of the saturated aquifer. The main
disadvantage of the development of the unsaturated zone is not that the thickness of the aquifer is
reduced, but that preferential flow phenomena occurred in this unsaturated zone. Preferential flow paths
result in rapid contaminant transport and degradation in the unsaturated zone, which then flow into a
saturated aquifer of reduced thickness, which may not be able to attenuate the pollutants.
A description of the preferential flow phenomena, advantages and disadvantages would benefit the
section 4.5.2 on filtrate flow path and well location.
Primary and secondary references
Comment Response for LT2ESWTR D-142 December 2005
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Throughout the chapter on bank filtration, secondary references are occasionally used, primary references
should also be added and incorporated to the text as they are the original source of phenomena or results
described or discussed.
Examples of additional references on fate and transport of pathogens in soil and aquifers
Enclosed below are some examples of additional references that could contribute to the information on
the fate and transport of pathogens in soil and aquifers.
Bitton, G. and R.W. Harvey. 1992. Transport of pathogens through soils and aquifers. In R. Mitchell
(Editor). Environmental microbiology. Wiley-Liss, New-York, p. 103-124.
Fontes D.E., A.L. Mills, G.M. Hornberger, and J.S. Herman (1991) Physical and chemical factors
influencing transport of microorganisms through porous media. Applied Environ Microbiol 57: 2473-
2481
Mawdsley, J.L., A.E. Brooks and R.J. Merry. 1996a. Movement of the protozoan pathogen
Cryptosporidium parvum in three contrasting soil types. Biology and Fertility of Soils. 21: 30-36.
Mawdsley, J.L., A.E. Brooks, R.J. Merry and B.F. Pain. 1996b. Use of a novel soil tilting table apparatus
to demonstrate the horizontal and vertical movement of the protozoan pathogen Cryptosporidium parvum
in soil. Biology and Fertility of Soils. 23: 215-220.
Tufenkji, N., J.A. Redman, and M. Elimelech. 2003. Interpreting deposition patterns of microbial
particles in laboratory-scale column experiments. Environ. Sci. Technol. 2003, 37, 616-623.
Wan, J. and J.L. Wilson. 1994. Colloid transport in unsaturated porous media. Water Resour Res 30: 857-
864
Wan, J. and T.K. Tokunaga. 1997. Film straining of colloids in unsaturated porous media: Conceptual
model and experimental testing. Environ. Sci. Technol. 31:2413-2420.
References
Amirtharajah, A. Some Theoretical and conceptual views of filtration. J. Am. Waterworks Assoc., 80,
36-46, 1988.
Bradford, S. A., S. R. Yates, M. Bettahar, and J. Simunek, Physical factors affecting the transport and fate
of colloids in saturated porous media, Water Resour. Res., 38(12), 1327, 2002
Brush, C.F., W.C. Ghiorse, L.J. Anguish, J.-Y. Parlange, and H.G. Grimes. 1999. Transport of
Cryptosporidium parvum oocysts through saturated columns. J. Environ. Qual. 28:809-815.
Darnault, C.J.G., P. Gamier, Y.J. Kim, K. Oveson, T.S. Steenhuis, J.-Y. Parlange, M. Jenkins, W.C.
Ghiorse, and P.C. Baveye. (2003). Preferential Transport of Cryptosporidium Parvum Oocysts in
Variably-Saturated Subsurface Environments. Water Environment Research 75:113-120.
Darnault, C.J.G., P. Gamier, K. Oveson, Y.J. Kim, M. Jenkins, T.S. Steenhuis, J.-Y. Parlange, P.C.
Baveye and W.C. Ghiorse. Preferential Flow and the Transport of Cryptosporidium Parvum Oocysts
through the Vadose Zone: Experiments and Modeling. (Vadose Zone Journal, In Press, 2003)
Comment Response for LT2ESWTR D-143 December 2005
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Einstein, H. A., Bedload transport as a probability problem, in Sedimentation, edited by W. H. Shen, pp.
C1-C105., Colo. State Univ., Fort Collins, 1937.
Elliott, A. H., and N. H. Brooks, Transfer of nonsorbing solutes to a streambed with bed forms:
Laboratory experiments, Water Resour. Res., 33(1), 137-151,
1997a.
Elliott, A. H., and N. H. Brooks, Transfer of nonsorbing solutes to a streambed with bed forms: Theory,
Water Resour. Res., 33(1), 123-136, 1997b.
Fitzpatrick, J. A., and L. A. Spielman, Filtration of aqueous latex suspensions through beds of glass
spheres, J. Colloid Interface Sci., 43, 350-369, 1973.
Gollnitz, W.D., J.L. Clancy, B. Whitteberry, and J.A. Vogt. Riverbank filtration as a microbial water
treatment process. Proceedings of the 2003 AWWA Annual Conference in Anaheim, California.
Harter, T., S. Wagner and E.R. Atwill. Colloid transport and filtration of Cryptosporidium parvum in
sandy soils and aquifer sediments. Environ. Sci. Technol. 2000, 34, 62-70.
Haschenburger, J. K., Scour and fill in a gravel-bed channel: Observations and stochastic models, Ph.D.
thesis, 144 pp., Univ. of Br. Columbia, Vancouver, B. C., Canada, 1996.
Haschenburger, J.K., 1999. A probability model of scour and fill depths in gravel-bed channels. Water
Res. Research, 35(9):2857-2869.
Hassan, M. A., Scour, fill, and burial depth of coarse material in gravel bed streams, Earth Surf. Processes
Landforms, 15, 341-356, 1990.
Hassan, M. A., and M. Church, Vertical mixing of coarse particles in gravel bed rivers: A kinematic
model, Water Resour. Res., 30, 1173-1185, 1994.
Hoey, T., and R. Ferguson, Numerical simulation of downstream fining by selective transport in gravel
bed rivers: Model development and illustration, Water Resour. Res., 30, 2251-2260, 1994.
Ho, R. T., and L. W. Gelhar, Turbulent flow with wavy permeable boundaries, J. Fluid Mech., 58(2), 403-
414, 1973.
Hubbell, D. W., and W. W. Sayre, Sand transport studies with radioactive tracers, J. Hydraul. Div. Am.
Soc. Civil Eng., 90, 39-68, 1964.
Huettel, M., W. Ziebis, and S. Forster, Flow-induced uptake of particulate matter in permeable sediments,
Limnol. Oceanogr., 41(2), 309-322, 1996.
Jackson, W. L., and R. L. Beschta, A model of two-phase bedload transport in an Oregon Coast Range
stream, Earth Surf. Processes Landforms, 7, 517-527, 1982.
Laronne, J. B., and M. J. Duncan, Constraints on duration of sediment storage in a wide, gravel-bed river,
New Zealand, IAHS Publ., 184, 165-172, 1989.
Lisle, T. E., Particle size variations between bed load and bed material in natural gravel bed channels,
Comment Response for LT2ESWTR D-144 December 2005
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Water Resour. Res., 31, 1107-1118, 1995.
Marion, A., M. Bellinello, I. Guymer, and A. Packman. Effect of bed form geometry on the penetration of
nonreactive solutes into a streambed. Water Resour. Res., 38(10): 1209
Packman, A. I., and K. E. Bencala, Modeling methods in the study of surface-subsurface hydrological
interactions, in Streams and Ground Waters, edited by J. B. Jones and P. J. Mulholland, pp. 45-80,
Academic, San Diego, Calif, 1999.
Packman, Aaron I. ; Brooks, Norman H. 2001 Hyporheic exchange of solutes and colloids with moving
bed forms Water Resour. Res. Vol. 37 , No. 10 , p. 2591-2605
Parker, G., Selective sorting and abrasion of river gravel, I, Theory, J. Hydraul. Eng. Am. Soc. Civ. Eng.,
117, 131-149, 1991.
Ray, C., T. Grischek, J. Schubert, J. Wang, and T. Speth. 2002. A perspective of riverbank filtration. J.
AWWA, 94(4): 149-160
Savant, A. S., D. O. Reible, and L. J. Thibodeaux, Convective transport within stable river sediments,
Water Resour. Res., 23(9), 1763-1768, 1987.
Schijven, J., P. Berger and I. Miettenen. 2003. Removal of viruses, bacteria, protozoa and toxins using
bank filtration. In Riverbank Filtration: Improving Source Water Quality, edited by Ray, C., Melin, G.
and Lindsky, R., Kluwer, Dordretcht.
Selker, J.S., T.S. Steenhuis and J.-Y. Parlange. 1996. An engineering approach to fingered vadose
pollutant transport. Geoderma, 70: 197-206.
Tobiason, J. E., and C. R. O'Melia, Physicochemical aspects of particle removal in depth filtration, J. Am.
Waterworks Assoc., 80, 54- 64, 1988.
Tufenkji, N., J.N. Ryan, and M. Elimelech. 2002. The promise of bank filtration: a simple technology
may inexpensively clean up poor-quality raw surface water. Environmental Science and Technology. 36:
422A-428A.
Vaidyanathan, R., and C. Tien, Hydrosol deposition in granular media under unfavorable surface
conditions, Chem. Eng. Sci., 46, 967- 983, 1991.
Wan, J. and J.L. Wilson. 1994a. Visualization of the role of the gas-water interface on the fate and
transport of colloids in porous media. Water Resour Res 30: 11-23
Wan, J. and J.L. Wilson, and T. L. Kieft. 1994b. Influence of the gas-water interface on transport of
microorganisms through unsaturated porous media. Applied Environ Microbiol 60: 509-516
Wang, J.Z., S.A. Hubbs, and R. Song. 2002. Evaluation of riverbank filtration as a drinking water
treatment process. American Water Works Associations Research Foundation Report 90922, 145 p.
Response:
Comment Response for LT2ESWTR D-145 December 2005
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EPA Letter ID: 563
Comment ID: 16897
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 11
WQTS Technical Memorandum
Water Quality & Treatment Solutions, Inc.
An Environmental Engineering & Science Consulting Company
www. wqts. com
Date: December 4, 2003
To: Steve Via, AWWA
David Rexing, SNWA
Project No.: 001870010
From: Issam Najm, WQTS
Kerwin Rakness, PAI
Project: Comments on Proposed LT2ESWTR
Re: Synergistic Inactivation between Ozone and Chloramine
This technical memorandum (TM) summarizes the reported literature on synergistic inactivation of
cryptosporidium oocysts during the sequential application of ozone & chloramine. The TM includes a
discussion of the issues involved, models the available data, and proposes a CT table for the inactivation
of Cryptosporidium with chloramine downstream of inactivation with ozone.
1. DEFINITION & TERMINOLOGY
For clarity, synergistic inactivation is defined as the enhancement of the inactivation efficiency of a
disinfectant against a certain microorganism by pre-exposing that microorganism to another disinfectant.
For example, if an ozone CT of 5 mg-min/L achieves 0.5-log inactivation of cryptosporidium oocysts,
and a chloramine CT of 500 mg-min/L achieves no inactivation of cryptosporidium oocysts. Synergy
would exist if 1-log inactivation is measured when the oocysts are first exposed to an ozone CT of 5 mg-
min/L, and then exposed to a chloramine CT of 500 mg-min/L chlorine. This is defined as "synergistic
inactivation" because the combined effect of the two disinfectants in series is greater than the added sum
of their individual effects.
For the purposes of this TM, the following terms are defined:
Upstream Disinfectant - This term refers to the disinfectant applied first. For example, in the sequential
application of ozone followed by chloramine, ozone is the upstream disinfectant.
Downstream Disinfectant - This term refers to the disinfectant applied after the upstream disinfectant. In
the above example of the sequential application of ozone followed by chlramine, chlorine is the
downstream disinfectant.
Comment Response for LT2ESWTR D-146 December 2005
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2. AVAILABLE LITERATURE
Three peer-reviewed articles on synergistic inactivation with the sequential application of ozone and
chloramine were reviewed in the preparation of this TM. Table 1 lists the articles, their corresponding
research groups, and some of their distinguishing characteristics. The work reported in these articles was
conducted by two research groups: The first is the Marinas group at the University of Illinois, and the
second is the Finch group at the University of Alberta. It is noted that the reference of Biswas listed is that
of the AwwaRF report published in 2002. A peer-reviewed paper based on the Biswas work was
published in Water Research in 2003.
[See p. 348 of PDF for Table 1]
The primary difference between the two research groups is that the Finch group used the mouse-
infectivity method to measure inactivation efficiency, while the Marinas group used a modified in-vitro
excystation method to measure inactivation. Studies conducted using both methods were used in the
development of the CT tables for cryptosporidium inactivation with ozone under the proposed
LT2ESWTR.
3. ANALYSIS OF RESULTS
The raw data of Biswas et al. (2002), Driedger et al. (2001), and Rennecker et al. (2000) are listed in
Tables A.I through A.3. The data of Rennecker et al. (2000) and Driedger et al. (2001) were provided
directly by Dr. Benito Marinas of the University of Illionois. The data of Biswas et al. (2002) listed in
Table A.3 were taken directly from the appendix of the AwwaRF report. Some of the data points reported
by Biswas et al. (2002) were excluded from the analysis. These included those with a reported negative
log-inactivation, zero-log inactivation, or censored data (i.e., the log-kill was reported as < or > a specific
value). The reason these data points were excluded was that the calculation of a Log(klO) value for those
data points would not be possible. The requirement of a Log(klO) calculation is mandated by the type of
modeling conducted.
In order to develop a CT table for the inactivation of cryptosporidium oocysts with chloramines
downstream of ozone, it will be necessary to determine an expression for klO as a function of relevant
water quality parameters and pretreatment conditions. For the purposes of this TM, the effects of the
following parameters were considered:
* Water Temperature, T
* Amount of upstream log kill (ULK) achieved with ozone
The significance of temperature to the inactivation kinetics of cryptosporidium and other microorganisms
is well documented. The effect of the ULK achieved is unique to the concept of sequential disinfection
and is proposed herein for consideration. The idea is that the value of klO for the downstream inactivation
of cryptosporidium with chloramine is dependent on the amount of ULK achieved by the upstream
disinfectant (i.e., ozone). This hypothesis is illustrated by Figure 1 showing the inactivation of
cryptosporidium with chloramine at 20°C downstream of three levels of log kill values achieved with
upstream ozone. The ULK values used in this analysis were calculated by taking the ozone CT value
reported by the authors for each data point and then calculating the Log Kill according to the procedure
described in the proposed LT2ESWTR.
[See p. 349 of PDF for Figure 1]
Comment Response for LT2ESWTR D-147 December 2005
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The modeling effort used the same linear Chick-Watson equation adopted by the USEPA in the
development of the cryptosporidium CT tables for ozone and chlorine dioxide in the proposed
LT2ESWTR. In its simplified form, the model is represented by Equation 1:
[See p. 349 of PDF for Equation 1]
If the value of klO is known, Equation 1 can be used to calculate the Log Kill (or log inactivation)
achieved for a specific CT value, or calculate the CT value required to achieve a certain Log Kill goal.
Equation 2 was used to express k 10 as a function of temperature and the level of ULK achieved (at pH
6.0):
[See p. 350 of PDF for Equation 2]
The data from the three studies were pooled together and modeled using Equation 2. The values of ko, a,
& 0 were determined by minimizing the square of the difference between the experimental Log(klO)
value and the Log(klO) value calculated by Equation 2. The resulting expression for klO as a function of
ULK and temperature is shown in Equation 3:
[See p. 350 of PDF for Equation 3]
Figure 2 shows a plot of the calculated Log(klO) values versus the measured Log(klO) values for the
three datasets. While some datapoints are far from the 45-degree line (which is the "perfect-fit" line), the
vast majority of the data are scattered closely around the line. This suggests that the model represents
the data well. Figure 3 shows a plot of the quality of fit of Equation 3 to the dataset. To generate this plot,
the experimental klO values were normalized to a ULK of 0.5-Logs. This was done by dividing each
experimental klO value by [ULK/0.5J0.4289, where ULK is the upstream log-kill achieved with ozone for
that data point. The quality of fit shows very good agreement between the three datasets, and the model,
with the obvious exception of three data points from the Biswas et al. (2002) dataset. A careful
examination of the raw data showed that the log-inactivation values achieved with chloramine for these
three data points were 0.03 logs, 0.05 logs, and 0.1 logs. The high degree of error in data points with such
low inactivation values is understandable since the difference between the starting count (No) and the
final count (N) is well within the anticipated error of the mouse-infectivity method. It is noted that the log
inactivation measured for all the other klO data points in the Biswas et al. (2002) dataset were between
0.44 and 3.2 logs. Based solely on this observation, it can be argued that the three outliers should be
excluded from this analysis. Nevertheless, these data were not excluded from the analysis reported in this
TM.
[See p. 350 of PDF for Figure 2]
[See p. 351 of PDF for Figure 3]
Using Equation 3 for the dataset modeled, three CT tables (Tables 2, 3, & 4) were developed for the
inactivation of Cryptosporidium with chloramine downstream of 0.25-Log, 0.5-Log, and 1.0-Log
inactivation with ozone, respectively. It is important to note that the CT values listed are based on the
regression fit of the data. It is highly likely that EPA will add an uncertainty factor to these values. The
extent by which these values will increase as a result of this action is not known at this time.
[See p. 351 of PDF for Table 2]
[See p. 352 of PDF for Table 3]
Comment Response for LT2ESWTR D-148 December 2005
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[See p. 352 of PDF for Table 4]
[See p. 353 of PDF for Table A.I]
[See p. 354 of PDF for Table A.2]
[See p. 355 of PDF for Table A.3]
9814 Penfield Avenue, Chatsworth, CA 91311; Tel: 818-701-9555; Fax: 818-701-9133
18914 Walnut Road, Castro Valley, CA 94546; Tel: 510-538-1979; Fax: 510-538-1872
WQTS Technical Memorandum
Water Quality & Treatment Solutions, Inc.
An Environmental Engineering & Science Consulting Company
www.wqts.com
Date: December 4, 2003
To: Steve Via
American Water Works Association
Project No.: 0018*0010
From: Issam Najm
Project: Comments on Proposed LT2ESWTR
Re: Synergistic Inactivation between Ozone and Chloramine
This Technical Memorandum (TM) is a follow-up to the meeting yesterday between AWWA and USEPA
staff and representatives. After presenting our findings regarding the potential synergy between ozone and
chloramine for the inactivation of Cryptosporidium, USEPA staff raised several questions regarding the
data and the approach used. The responses to these questions are included in this TM.
Question 1 - The AWWA analysis excluded some of the Biswas et al. (2002) data points because they had
a zero log inactivation or were expressed as < or > a specific Log inactivation. USEPA staff asked for a
description of how many data points were in each of the excluded categories.
Response: The entire Biswas et al. (2002) dataset on the synergy between ozone and chloramine for
Cryptosporidium inactivation, which is detailed in Table 1, contained 54 data points. Of these data points,
19 were excluded from the modeling effort. The breakdown of the 19 excluded points is as follows:
Zero Log Kill 1
No Given (i.e., noted as "na") 1
Left-Censored Data point (i.e.,
Right-Censored Data points (i.e., >X) 14
In addition, three data points are potential outliers that are candidates for statistical outlier analysis. These
are data points #7, #11, & #33 in Table 1. Nevertheless, these data points were not excluded from the
modeling effort reported in Technical Memorandum Dated December 4, 2003. While the exclusion of
Comment Response for LT2ESWTR D-149 December 2005
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data points with zero log kill or left-censored log kill values eliminates data points that may suggest no
synergistic effect, the majority of the excluded data points are right-censored data points, which are ones
that suggest a high synergistic effect. Therefore, the exclusion of the 19 data points has a "conservative"
impact on the outcome of the analysis.
[Seep. 357 of PDF for Table 1]
Question 2 - Which ozone residual values were used to calculate the upstream ozone CT in the Biswas et
al. dataset?
Response: As stated on pages 12 and 13 of the Biswas et al. report published by AwwaRF, the following
is the procedure used to calculate the "average CT" value:
1. Four ozone residual measurements were made through each ozone decay profile
2. The four residuals were then used to calculate the "starting" residual, Co, and the firstorder ozone
decay coefficient, kd.
3. Based on the values reported in the appendix, it appears that the average CT was calculated as the
integrated CT from Co to the final C measured at time "t" representing the of the decay curve and the
point at which the oocyst samples were taken. The integrated CT is calculated as follows:
[See p. 358 of PDF for equation]
It appears that while the ozone dose was reported, it was not used in the calculation of the CT value.
Question 3 - Are the infectivity-based data of Biswas et al. statistically different from the excystation-
based data of Driedger et al. and Rennecker et al.?
Response: This question can be answered with an ANOVA test on the three datasets. However, this
should only be done after an outlier analysis is conducted and any outliers are removed. A preliminary
outlier analysis test on the Biswas et al. dataset showed that at least two datapoints should possibly be
excluded because the absolute values of their Standard Residuals were >2.
Question 4 - Should the "C" and the "T" of upstream ozone disinfection be separated in the modeling
effort or should they be combined as a "CT" product?
Response: The current model used to express klO is as follows:
[See p. 359 of PDF for equation]
Two other options discussed during the meeting with EPA staff were as follows:
[See p. 359 of PDF for equation]
or
[See p. 359 of PDF for equation]
where: "UCT" is the upstream "CT" product achieved with ozone,
"UC" is the upstream disinfectant "C" value
"UT" is the upstream disinfectant "T" value
Preliminary analysis shows that either model can also be used to represent the results, but it is not
Comment Response for LT2ESWTR D-150 December 2005
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apparent that the difference in the goodness of fit is greatly improved by going to the other models. This
statement will require confirmation using statistical analysis to compare the goodness of fit between
the three models.
Response:
EPA Letter ID: 563
Comment ID: 16898
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Appendix 12
Critique of the
Economic Analysis for the Proposed Long-Term 2 Enhanced Surface Water Treatment Rule
Final Report
Prepared for:
AWWA
1401 New York Ave.,NW
Suite 640
Washington, DC 20005
Prepared by:
Robert Raucher, PhD
David Mills
Lauraine Chestnut
Stratus Consulting Inc.
PO Box 4059
Boulder, CO 80306-4059
(303)381-8000
January 8, 2004
SC10364
Contents
EXECUTIVE SUMMARY S-l
CHAPTER 1 INTRODUCTION 1.1
OBJECTIVES 1-1
1.2 OVERVIEW OF CRITIQUE 1-2
1.3 OUTLINE OF THIS EA CRITIQUE 1-3
1.4 SUMMARY
CONCLUSION 1-3
CHAPTER 2 OVERVIEW OF BENEFITS ANALYSIS 2-1
CHAPTER 3 OCCURRENCE ASSESSMENT: SOURCE AND FINISHED WATER
CHARACTERIZATION
3.1 SOURCE WATER OCCURRENCE DATA 3-1
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3.2 BAYESIAN INTERPRETATION OF THE SOURCE WATER DATA 3-2
3.3 CHARACTERIZATION OF FINISHED WATERS 3-4
3.4 CONCLUSIONS 3-5
CHAPTER 4 EXPOSURE ASSESSMENT 4.1 USE OF WATER CONSUMPTION DATA FROM
USDA 4-1
4.2 SENSITIVITY ANALYSES 4-3
4.3 AVERTED EXPOSURES BY SENSITIVE SUBPOPULATIONS 4-4
4.4 CONCLUSIONS 4-4
CHAPTER 5 DOSE-RESPONSE ASSESSMENT: QUANTIFIED HEALTH EFFECTS
5.1 FROM EXPOSURE TO INFECTION: INFECTIVITY ASSESSMENT 5-1
5.1.1 Infectious oocyst fraction 5-3
5.1.2 Inherent infectivity - oocyst survival probability (r) 5-3
5.2 FROM INFECTIVITY TO ILLNESS: MORBIDITY ASSESSMENT 5-7
5.2.1 Baseline levels of illness 5-8
5.2.2 Comparing baseline cases to EPA estimates for cases avoided by the proposed
rule 5-8
5.2.3 Morbidity assessment 5-9
5.3 FROM ILLNESS TO SEVERITY 5-10
5.3.1 Treatment of sensitive population subgroups in the LT2 risk
analysis 5-10
5.3.2 Quantification of the risk in sensitive population subgroups for the LT2
analysis 5-14
5.4 USE OF OUTBREAK DATA TO INFER INPUTS AND OUTCOMES FOR ENDEMIC
RISK 5-18
5.5 CONCLUSIONS 5-18
CHAPTER 6 VALUATION OF HEALTH IMPACTS
6.1 USE OF THE TRADITIONAL COST-OF-ILLNESS METHOD TO VALUE NONFATAL
INFECTIONS... 6-1
6.2 EPA'S ENHANCED COI ESTIMATES 6-2
6.3 PLACING THE ENHANCED COI ESTIMATES INTO CONTEXT 6-4
6.4 CONCLUSIONS 6-7
CHAPTER 7 COMPLIANCE COSTS AND NET BENEFITS
7.1 COMPLIANCE COSTS 7-1
7.2 COMPARISON OF BENEFITS TO COSTS 7-3
7.3 CONCLUSIONS 7-4
REFERENCES R-l
Appendices
A Issues with EPA's Modeling of Cryptosporidium Occurrence
B Issues and Practices for Valuing Time
EXECUTIVE SUMMARY
This report provides a critique of the U.S. Environmental Protection Agency (EPA) Economic Analysis
(EA) of the proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2). The EA provides a
benefit-cost analysis of the rule. Our review of the EA methods, data, results, and presentation by EPA
reveals some good efforts by the Agency, but also several critical areas of concern that require extensive
improvement.
Our major observations and findings with respect to the EA include the following:
Comment Response for LT2ESWTR D-152 December 2005
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1. Overall, we believe EPA has considerably overstated the occurrence and risks associated with endemic
levels of Cryptosporidium in finished waters, and thus the Agency overstates the benefits of the proposed
rule to a considerable degree. The costs of the rule may also be overstated to some degree.
2. The ICRSS data indicate a much smaller percentage of systems will end up in bins 3 and 4 under the
proposed rule than do the analyses based on the ICR data, implying that the net benefits (benefits minus
costs) of the proposed rule may be 20% of the high end estimates shown by EPA (all else equal). The
ICRSS data are better predictors than the ICR data are of what the impact of the rule will be as
proposed.(1)
(1) The ICRSS data are more indicative of what the rule's impacts will be because they (1) probably are
more accurate than the ICR data (ICRSS results are based on Method 1622/1623 with higher recovery
rates than the IFA method applied in the ICR data), and (2) reflect the method (1622/1623) that utilities
will apply in their compliance monitoring.
3. EPA applies a Bayesian interpretation to the ICR and ICRSS data that is suspect and driven by
unsubstantiated and perhaps extreme assumptions. For example, EPA imposes an assumption that only 1
out of every 1,000 "zeroes" observed in the database is truly a zero. The Agency is thus estimating
occurrence and risk based on a presumption that 999 out of every 1,000 observed zeroes in the database
are instead one oocyst or more.
4. EPA's exposure assessment is based on considerably overestimated levels of direct ingestion of CWS-
provided waters. Relevant exposures (and, hence, risks) may be overstated by a factor of 2 or 3 when
direct ingestion rates for CWS waters, and increased bottled water use, are properly considered.
5. The infectivity dose-response relationship applied by EPA is subject to considerable uncertainty and
probably overstates the risk associated with exposures to an infectious oocyst by a significant degree.
a. The underlying clinical studies use extremely high doses relative to oocyst levels in finished waters
(levels of oocysts ingested of 23,000 to 2.3 billion times higher than now found in finished waters) and
rely on extremely small numbers of subjects and strains (between 14 and 29 subjects, for each of only
three strains).
b. The results of the clinical studies are interpreted liberally, based on a "presumed infection" approach
that assumes that any subject with symptoms has cryptosporidiosis, even when several of the
symptomatic subjects had no documented infection (e.g., positive oocyst shedding). EPA's risk estimates
are overstated to the extent that reported symptoms could be attributable to causes other than
cryptosporidiosis.
c. The results of the clinical studies were interpreted via complex statistical models that are driven by -
and highly sensitive to - unsubstantiated assumptions. While the modeling approaches used by EPA in the
EA were suggested by the SAB, the obscurity of the presentation and the sensitivity of the results to the
model assumptions (e.g., increasing a key estimated mean risk parameter by a factor of 4 or 5 over the
level found in the peer reviewed published literature) reveal the need for more transparency, continued
scientific discourse, and greater use of sensitivity analyses in portraying the possible risk levels.
6. The extent by which EPA's risk model overstates risks can be viewed, in part, by comparing the
Agency's estimated number of waterborne cases of cryptosporidiosis at the pre-LT2 baseline to its
estimated reduction in cases due to the proposed LT2 rule:
a. EPA estimates that the pre-LT2 baseline (i.e., post IESWTR) is between 60,000 and 111,000 cases per
year.
b. The Agency's risk model used for the LT2 rule benefit-cost analysis predicts 256,000 to over 1,000,000
cases per year will be avoided because of the rule as proposed.
Comment Response for LT2ESWTR D-153 December 2005
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c. Therefore, EPA estimates a reduction in cases that is up to 9+ times higher than the number of cases it
has stated exist at baseline.
7. EPA needs to explore the soundness and implications of its questionable assumption that the risk of
illness (as well as severity and duration of illness) is independent of dose. The morbidity assessment -
used to project the number, severity, and duration of illnesses due to a possible infection - is
based exclusively on results from the Milwaukee outbreak of 1993, where oocyst levels were much
higher, exposure durations much longer, and opportunities for secondary spread and exposure more
pervasive than anticipated under the endemic low dose exposure context addressed by the proposed rule.
8. EPA's use of an "enhanced" cost-of-illness (COI) approach to value avoided cases of nonfatal
cryptosporidiosis is highly problematic. The approach is a significant departure from standard economics
practice, does not appear to have been subjected to peer review, and yields results that seem implausible
and unrealistic compared to other well-established risk valuation benchmarks.
9. EPA's presentation of regulatory costs and benefits is overly aggregated, and fails to reveal how
affordability and net benefits vary across system size categories or across other relevant program elements
in the proposed rule (e.g., reservoir covering, filtered versus unfiltered systems).
1. INTRODUCTION
This report provides a critique of the Economic Analysis (EA) (U.S. EPA, 2003a), developed by the U.S.
Environmental Protection Agency (EPA), in support of its proposed rulemaking for the Long-Term 2
Enhanced Surface Water Treatment Rule (referred to hereafter as LT2), published in the Federal Register
on August 11, 2003 (U.S. EPA, 2003b). In essence, the EA is a benefit-cost analysis, and as such it
contains many critical elements that support the rationale for the rulemaking and that are used to predict
the rule's expected impacts on public health and water costs. The EA includes issues of occurrence,
exposure, dose-response relationships, quantified risk characterization, and the valuation of health risk
reductions. Issues related to compliance technologies, and their performance and costs, are also integral to
the EA.
1.1 OBJECTIVES
The objective of this critique is to focus on key aspects of the Agency's empirical analysis, and highlight
where there appear to be actual or potential errors or omissions of consequence in the EA. Our primary
concerns are with the quality, transparency, replicability, objectivity, clarity, and reliability of the data
and methods used to develop and present estimates of the benefits and costs of the proposed rule. Our
focus is on the proper use and interpretation of sound methods and data, the presentation of the approach
and outcomes in a clear and unbiased manner, and the drawing of suitable inferences and policy
interpretations given the uncertainties and other limitations inherent in the data and analyses. The overall
objective is to help EPA identify and remedy potential errors and limitations in its own EA, and thereby
help EPA generate more reliable, accurate, and policy-useful benefit-cost analyses for the final LT2 and
other rules in the future.
No attempts are made here to develop or report independent estimates of the proposed rule's benefits,
costs, or incremental net benefits. Instead, we focus on identifying aspects of EPA's analysis that appear
to require correction or, at a minimum, further investigation and documentation. The overall goal is to
help identify areas in which improvements can and should be made, so that EPA's EA of the final LT2
rule - and of other future rulemakings - can embody improved quality, integrity, and meaning for the
important public health protection policies the Agency pursues in accordance with the mandates of the
Safe Drinking Water Act (SDWA). We hope and expect that EPA will embody changes in the EA
Comment Response for LT2ESWTR D-154 December 2005
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supporting the final LT2 Rule to address the key points raised in this report, and to represent the most
accurate benefits and costs to the public as possible.
1.2 OVERVIEW OF CRITIQUE
Our critique of the EPA EA and associated Agency-provided documentation focuses on the need to find a
better balance and sense of prioritization in its analyses and presentation. For example:
???EPA is to be commended for provided a vast quantity of detail and back-up documentation. On the
other hand, there is too much material to effectively review within the comment period. More important,
EPA is inconsistent in that its documentation is sometimes lacking enough information on some core
issues, while offering mountains of data on other matters of sometimes lesser significance. In general,
more balance and prioritization is needed in terms of detail and documentation.
???EPA is to be commended for attempting to quantify benefits to the greatest degree feasible, so that
benefits can be compared to costs. On the other hand, EPA has in places stretched credibility and the
bounds of "good science" in its efforts to generate estimates. "Good science" must always be the guiding
principle, and empirical estimates based on interpretations or assumptions that have strayed from that
principle are potentially misleading and a disservice to the public, stakeholders, and decision-makers.
???EPA has made some good strides forward by providing considerable discussion and sophisticated
numeric evaluation of several of the uncertainties and variabilities (e.g., using Monte Carlo simulations)
applicable to some aspects of the analysis. On the other hand, EPA neglects to detail, justify, or fully
explore some of the most fundamental of its assumptions. In the face of these core uncertainties,
transparent sensitivity analyses are essential for evaluating the impact of core assumptions at key
junctures of the analysis. EPA needs to find a better balance by using more fundamental, informative, and
simple analyses of core components rather than using more sophisticated approaches for some lesser
aspects of its analysis.
Hence, at the core of our critique is the message that EPA needs to take better stock of its analyses,
determine what components are most critical in terms of driving the benefit or cost estimates, and focus
its attention (and that of the reviewers) on those aspects. Models, analytic tools, and documentation
should be presented in a way that sheds light rather than obfuscates and overwhelms attempts at good
faith public review.
1.3 OUTLINE OF THIS EA CRITIQUE
Following this introductory chapter, the following analysis is provided:
???Chapter 2 provides a schematic overview of the EPA benefits analysis for the proposed LT2 rule,
along with a summary of the key concerns identified by our review.
???Chapter 3 explores issues with the first set of steps in the analysis, related to the use and interpretation
of occurrence data.
???Chapter 4 explores exposure issues and their impacts on the analysis.
???Chapter 5 discusses the dose-response elements of the analysis, notably the infectivity and morbidity
assessments for exposures to Cryptosporidium.
???Chapter 6 critiques the valuation of risk reductions, notably the enhanced cost of illness (COI)
Comment Response for LT2ESWTR D-155 December 2005
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approaches applied by the Agency.
???Chapter 7 evaluates the Agency's cost analyses, and the comparison of benefits to costs.
1.4 SUMMARY CONCLUSION
The EA and associated EPA-provided documents offer extensive detail, information, and background
material. It is evident that EPA has explored many aspects of the analysis and has provided a considerable
body of documentation.
However, some key elements of EPA's work are not sufficiently documented or detailed for an effective
review, and this has hampered our evaluation. Overall, the Agency needs to find a more suitable balance.
In some very critical elements of the EA, the Agency makes strong assumptions that can have a
significant impact on the final results, yet the Agency does not always clearly articulate what assumptions
it is making or it appears to take a one-sided view of the uncertainties and data limitations to derive its
interpretation. More important, in these instances of strong assumptions, EPA has in several instances
failed to offer sensitivity analyses based on equally or more plausible alternative assumptions. EPA
should follow the basic tenants of its own Guidelines for Economic Analyses and (a) be explicit regarding
its core assumptions, (b) document the basis for those assumptions, and (c) develop some useful
sensitivity analyses to evaluate and convey the impact of these core uncertainties on the outcomes of the
analysis.
2. OVERVIEW OF BENEFITS ANALYSIS
To best explain the nature of the EPA analysis, a simplified flow diagram is shown in Exhibit 2.1 to
identify and describe the key steps of the benefits assessment. The same underlying logic and data also
underlie the basis for the cost analysis (although the path of the cost analysis naturally differs from
that of the benefits after the initial occurrence assessment).
Along with each critical step in the analysis, Exhibit 2.1 displays a summary of some of the key issues
and concerns regarding each of these steps. Additional detail is then provided in each subsequent chapter
of this report.
It is apparent when examining the issues identified in Exhibit 2.1 that there are many ways in which the
risk reduction benefits developed by EPA may be overstated. Some components of the cost analysis may
be overstated as well, especially with regard to the number of water systems projected to be in higher
"bins" (i.e., bins 3 and 4). Therefore, EPA may over-predict the number of systems with relatively high
compliance costs (and benefits).
The "big picture" view of the EPA analysis, as afforded by Exhibit 2.1, allows us to glean how much the
overall EPA results might be altered if alternative (but equally or more plausible) assumptions and data
interpretations were investigated. Compounding the changes at each step as depicted in the figure,
the overall estimate of benefits derived by EPA could be an order of magnitude or more larger than a
more plausible and likely estimate. Detailed discussions are provided in the chapters that follow.
[See p. 372 of PDF for Exhibit 2.1]
ICRSS data are based on Method 1623 (as will be employed in LT2 compliance monitoring). Using
ICRSS data, net benefits may be 20% of the level implied by the ICR data.
EPA does not account for ability of processes or operators to respond to source water challenges.
Comment Response for LT2ESWTR D-156 December 2005
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Aboytes and LeChevallier (2003) suggest that finished water Cryptosporidium levels may be independent
of source water conditions.
Relative to EPA's estimate, the mean ingestion of risk-bearing water may decline by 50% or more if one
uses CWS direct water consumption rather than total ingestion of all waters.
Increasing use of bottled water and other "averting behavior" may appreciably reduce exposures and
risks.
Clinical data reflect oocyst doses at least 23,000 times higher than observed in finished water.
Infectivity r values EPA derives and uses in the EA are 5 times higher than peer reviewed r values
published by Messner et al. (2001).
EPA assumes morbidity is independent of dose.
EPA predicts avoided cases that are 4 to 9 times higher than its own baseline estimate of 60,000 to
111,000 cases per year.
Illness severity and mortality rate are based on Milwaukee outbreak data, which may overstate severities
anticipated at endemic dose rates.
Enhanced cost of illness approach steps beyond the bounds of established economics practice.
Based on each step above, total endemic benefits estimated by EPA may be greatly overstated.
3. OCCURRENCE ASSESSMENT: SOURCE AND FINISHED WATER CHARACTERIZATION
3.1 SOURCE WATER OCCURRENCE DATA
EPA uses data collected under the Information Collection Rule (ICR), and two subsequent smaller ICR
Supplemental Surveys (ICRSS), to assess the presence of Cryptosporidium oocysts in source waters.
???The initial ICR reflects data collected from nearly 300 Community Water Systems (CWS) serving
more than 100,000 people. Cryptosporidium monitoring was conducted for 350 influent locations (i.e.,
plants using surface waters or groundwater under the influence of surface waters), including unfiltered
systems. The data were collected over the 18 month period from July 1997 through December 1998. The
analysis relied on the "ICR method" of Cryptosporidium detection and analysis.
???The ICRSS includes data collected from 40 randomly selected volunteer medium-sized CWS serving
10,000 to 100,000 people (ICRSSM), and 40 randomly selected volunteer large systems of over 100,000
served (ICRSSL). The samples were drawn over a 12 month period spanning March 1999 through
February 2000. The analysis relied on the improved analytics of EPA method 1622/1623, which provides
better recovery rates than the older method used in the ICR.
There are appreciable differences between the results generated by the initial ICR and the follow-up
ICRSS. For example, the ICR data assign 7.6% of the systems into either bin 3 or bin 4, whereas the
ICRSS assign an average of less than 1.2% of the systems to those bins - a difference factor of over 6.4
(7.6/1.2). The magnitude of this difference raises questions about which set of ICR results are most
accurate and reliable (or, whether the apparent discrepancies reflect real differences due to temporal
and/or spatial variability in oocyst occurrence levels).
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EPA addressed the uncertainty associated with the differences between the ICR and ICRSS results by
conducting sensitivity analyses. The Agency presents benefit and cost estimates based on each data set
(i.e., there are three sets of benefit and cost results, one based on the ICR, one on the ICRSSL, and one on
the ICRSSM). This is an appropriate approach for addressing the uncertainty about which data set might
be the most accurate reflection of actual conditions. Ultimately, the estimated net benefits of the preferred
regulatory option differ by a factor of 4.5 to more than 5.2, depending on which dataset is used (EA
Exhibit ES.8, e.g., 705/135 = 5.22; U.S. EPA, 2003a).
While the use of sensitivity analysis in this manner is fully appropriate, EPA should also provide further
discussion of why the results from the ICRSS are so different from the results derived using the ICR.
There are several plausible and likely explanations that, if brought to light, would have provided readers
and decision makers with some useful context within which to evaluate the widely different sets of
results.
In particular, it is likely that the ICRSS data are more reliable than the ICR data because the ICRSS use a
much improved analytic method (1622/1623). While the ICR provides results from a larger sample, the
ICRSS results are likely to be considerably more accurate. It is very likely that the higher accuracy and
reliability of the ICRSS data outweigh the ICR's advantage of having more data. While we have not
attempted to develop or perform any statistical analyses of the potential tradeoff, it seems logical that this
is an instance of where more accurate data are more valuable and informative than larger quantities of
questionable data. In addition, because source water characteristics are not likely to be associated with the
size of the population served by a CWS drawing those waters, it may be suitable and appropriate to
consider merging the two ICRSS databases (at least for source water characterization purposes), creating
a combined dataset of observations from 80 utilities. Finally, because Method 1623 will serve as the basis
for LT2 compliance monitoring (bin determination), the ICRSS results are likely to provide a more
accurate characterization of the impact of the rule, in terms of compliance efforts, costs, and benefits.
3.2 BAYESIAN INTERPRETATION OF THE SOURCE WATER DATA
The ICR and ICRSS data present some challenges for interpretation for a national occurrence profile, in
large measure because of the limitations of the methods for identifying and counting Cryptosporidium
oocysts. There is considerable uncertainty about the accuracy of presence/absence findings, and of
numbers of oocysts derived in the ICR and ICRSS findings (more so with the ICR because of the lower
recovery factors with the analytic method).
For example, there is a very high likelihood of false positives because of limits in the immunofluorescent
antibody (IFA) methodology used in the ICR. This would erroneously push more systems into higher
bins.
Likewise, there is a large percentage of zeros. This is because Cryptosporidium may not be present in
many source water samples, and/or because of the low recovery rates associated with the analytic
methods available (especially for the ICR data). Positive samples were noted for only 5% of the ICR
observations (95% were zeros). Given the variability in recovery, this raises the question of how many of
the observed findings of "no oocysts detected" are true zeroes. If some fraction of the nondetects actually
reflect cases of a true value of one or more oocysts, then this potentially places systems erroneously in bin
1 instead of a higher bin.
To address the uncertainties associated with the data quality, EPA applied Bayesian statistical techniques
to the ICR and ICRSS data. Bayesian techniques can be very powerful and effective tools for dealing with
uncertainties. However, an integral part of the Bayesian approach is the use of "informed priors" that
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reflect what knowledge or outcomes the researchers believe to be true (e.g., using probabilities based on
known data). The specific priors that are applied in Bayesian applications typically drive the outcomes
that are derived from the analysis. In other words, the priors typically determine the outcomes.
In some instances, there are enough good data and other reliable information available that the priors can
be set with some degree of confidence and rationale. However, the less that is known a priori, the more
the priors become de facto (and perhaps unsubstantiated) assumptions. This appears to be the case with
the Cryptosporidium analytic method results from the ICR databases. Because so little is known about the
"true" values as opposed to the numbers of oocysts observed from the analytic methods, the Agency's
Bayesian approach is in effect driven by the critical assumptions that EPA established as its priors. EPA's
occurrence results are thus driven by the presumption that (1) at least 99.9% of the observed zeroes are in
fact integer values of 1 or more (i.e., that at most one out of 1,000 observed zeroes are true zeroes and the
remaining 999 observed zeroes are assigned a value of 1 or more oocysts); and (2) there are no more than
1% false positives.
Both of these assumptions appear to be extreme and arbitrary. For example, one expert noted that 25% to
50% of the observed zeroes might be true zeroes, in contrast to EPA's assumption of only 0.!%.(!) This is
a critical factor, because if the value of Zi were to increase by over two orders of magnitude (from 0.1%
to 25%), this would change EPA's results dramatically (see EA Appendix B, Section B.2.3). It is
important to determine if the EPA number is correct on page B-12 (i.e., 0.1%), and it is important that
EPA explain why it believes this number is so low. The text says that the model was tested with
percentages from 0 to 50%, but that the Agency's experts thought it should be 0.1%. It is essential that
EPA help the public understand the sensitivity of the model to the value of true zeros, and to provide
clarification of what is meant by true zero in this document. (2) Appendix A provides additional
discussion.
(1) Personal communication with Jeff Rosen (Perot Systems), relaying the expert opinion he obtained
from Jen Clancy (November 2003). (2) On EA page B-12, EPA states that the true zero assumption is
"the true proportion of systems with source water that is completely free of the target microbe." This is
not our understanding of the true zeros. The question is what percentage of the zeros were likely to be true
zeros and not some other number that needed to be estimated.
Likewise, for false positives, EPA analyses apparently were run at only 0% and 1%. False positives could
be much higher, and this distinct likelihood must be addressed in sensitivity analyses as well.(3)
(3) For example, EPA should document the effect of using ICR data on total Cryptosporidium, versus
non-empty oocysts, versus oocysts with internal structure, and justify why the Agency used total
Cryptosporidium to do the assessment. The original sensitivity analyses run suggests that the total is one
log higher than the non-empty option, which is one log higher than the internal structure approach.
Given that EPA's results are driven by assumptions (over which there was considerable disagreement with
stakeholder experts) rather than "prior knowledge," it is imperative that the Agency:
1. Identify explicitly and label clearly what assumptions it is using (i.e., identify them as assumptions and
clarify that they do not satisfy the intent of "prior knowledge" as generally applied or accepted in
Bayesian analysis).
2. Provide a clear and cogent rationale for why those assumptions are indeed reasonable and defensible.
3. Develop and/or accept alternative assumptions that are equally defensible or more plausible.
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4. Conduct sensitivity analyses to understand and reveal how the alternative assumptions (priors) affect
the outcomes of the analysis.
5. Present the results of the sensitivity analyses in a clear, objective, and informative manner.
6. Use the results of the sensitivity analyses to inform the decision-making process (and document the
same).
3.3 Characterization of Finished Waters
From source water quality, EPA needs to take two steps to assess the impacts of the regulation on oocyst
levels of finished waters to which consumers are exposed. First, EPA predicts what finished water will be
like without the LT2 rule. This establishes the finished water baseline for the proposed rule. Second, EPA
predicts how the proposed LT2 rule will reduce Cryptosporidium oocysts in post-rule finished water
relative to the baseline finished water.
Unfortunately, there has been limited finished water analysis of Cryptosporidium levels, so results for
both of the above steps were projected by EPA using various models and assumptions. Research by
Aboytes et al. (2000) is a notable exception and provides some finished water data that EPA uses as a
point of comparison to their projected (model-driven) outcomes.
In each step, EPA assumes a mix of treatment choices will be made by utilities, and the Agency applies
expected treatment performance information to estimate the occurrence levels of Cryptosporidium
oocysts in finished water (i.e., predicting changes from estimated finished water conditions pre LT2). The
technology selections and performance levels that EPA assigns may be reasonable in general, although a
few problems have been noted. For example, chlorine dioxide is not considered a viable choice for 0.5 or
better log removals (e.g., as depicted in EA Exhibit F-17), and therefore the 23% of systems that EPA
predicts will select this approach should instead be set at 0%. These systems instead should be assigned to
turbidity control or UV light in the compliance forecast, and costs adjusted accordingly.
Of greater concern for the EA, however, is that the EPA approach does not reflect the likely ability of
treatment processes and plant operators to handle challenges posed by source water conditions. There is
likely to be more of a leveling effect on finished water quality across source water conditions than is
reflected in the EPA approach. The research by Aboytes et al. (2000) suggests that source water quality
may not be a major determinant of finished water outcomes with respect to oocyst levels.(4)
(4) Although a single study and preliminary, further evaluation of those data reveal that "detection of
infectious oocyst in filtered water was not related to the historical levels of raw water Cryptosporidium"
(Aboytes and LeChevallier, 2003). If future research confirms this finding, then this observation suggests
that utilities with relatively poor source waters, and who will need to install the most additional
equipment and/or take the most other steps from amongst the toolbox options, may incur costs with
minimal additional benefit to be derived.
3.4 Conclusions
Estimating source and finished water levels of oocysts is extremely challenging because of the many
limitations inherent in the analytic methods that define the results found in the ICR and, to a lesser extent,
the ICRSS. Ultimately, the ICRSS findings may be more reliable. The ICRSS findings indicate relatively
low baseline oocyst occurrence and, hence, suggest that the costs and benefits of the proposed preferred
LT2 option may be lower than that projected using the ICR in the EA.
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The conclusions reached by EPA using Bayesian modeling are highly dependent on the assumptions
made, many of which are not "prior knowledge." These assumptions and opinions should be carefully
documented and justified by EPA, and sensitivity analyses should be run and documented in ranges
agreed to by a wide array of experts. The effects on the rule and on the benefits of these assumptions
should be ascertained, communicated, and considered.
Also, the ultimate objective is to better understand finished water quality. Thus, greater focus on
monitoring finished water (rather than analyzing source water and then projecting finished water quality
before and after projected treatment) seems to be a more suitable path for future investigation. Limited
finished water data suggest that oocyst levels may be more uniform across facilities, regardless of source
water, than EPA projects in the EA.
4. EXPOSURE ASSESSMENT
Given projected levels of Cryptosporidium oocysts in finished water, the next step in the analysis is to
determine the level of exposure faced by populations served by rule-impacted systems. This step entails
multiplying estimated finished water concentration levels (oocysts/100 L, at levels projected as described
in the previous chapter) by the number of liters of finished CWS water a person is expected to drink
(L/day). This results in an estimated level of (or distribution of) oocysts/day of exposure across the CWS-
impacted population. This chapter focuses on the issue of how many liters of CWS water a person is
likely to consume.
4.1 USE OF WATER CONSUMPTION DATA FROM USDA
To estimate the amount of water ingested per day, EPA uses data from the U.S. Department of
Agriculture's (USDA's) 1994 - 1996 Continuing Survey of Food Intakes by Individuals (CSFII).
According to the EA, USDA provides two distributions of water ingestion levels:
???"Distribution 1" is based on total water ingestion from all sources, and has a median (50th percentile)
level of 1.05 L/day and a 90th percentile of 2.35 L/day. EPA uses the mean from this distribution, 1.24
L/day, as the basis for its national-level risk estimates.
???"Distribution 2" is based on water ingestion from CWS sources, and has a median (50th percentile)
level of 0.71 L/day and a 90th percentile of 2.02 L/day. The mean from this distribution is 0.93 L/day (or
75% of the mean from Distribution 1 that is used by EPA as the basis for its national-level risk estimates).
There are several issues associated with EPA's use of the Distribution 1 mean for its national risk
assessment, as outlined below. Overall, it seems more accurate and reasonable to use the mean or median
value from Distribution 2 instead. This would result in risk estimates and benefits that would be 75%
(0.93/1.05) or 57% (0.71/1.05) of the current EPA estimates, respectively, all else equal.
First, Distribution 2 reflects use of CWS waters by their customers. This is a more relevant use level for
the regulation that is targeted on water utilities than "water from all sources," which includes bottled
water, household wells, household rain cisterns, and household or public springs, in addition to CWS.
Water from CWS represent approximately 75% of total daily water intake (U.S. EPA, 2000). Hence,
Distribution 2 is by its definition a more suitable fit for CWS-relevant tap water exposure than is
Distribution 1.
Second, there are several reasons to believe that even the results from Distribution 2 may overstate daily
ingestion levels for Cryptosporidium-relevant waters. These reasons include:
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???The USDA water consumption estimates that EPA cites include direct and indirect water consumption.
Indirect water is used for final food preparation in the home, and includes water used for coffee and tea,
beverages for which the water is boiled or steamed before ingestion (U.S. EPA, 2000). Hot coffee and tea
preparation therefore should inactivate any Cryptosporidium oocysts that may be present. Therefore, a
portion of the Distribution 2 ingested waters would not carry any risk of Cryptosporidium infection and
illness, even if viable and infectious oocyst were present in the tap water. Mean per capita direct water
use of community system water is 0.50 L/day (U.S. EPA, 2000), which is 54% of the total water use
mean of 0.93 L/day. Direct use consumption comprises 41% of total CWS water intake at the median, and
63% at the 90th percentile (U.S. EPA, 2000). Thus risk estimates based on total water consumption could
be overestimating actual risk substantially, assuming most water consumed indirectly has been boiled.
Using the direct water consumption estimates, rather than total consumption, would more accurately
reflect potential exposure to potentially infectious Cryptosporidium.
???When these data were collected, approximately 13% of daily water intake was from bottled water
(U.S. EPA, 2000). In the 7 to 9 years since the USDA data were collected, there has been a considerable
and well documented growth in the use of bottled water and in-home filtration devices [i.e., use of tap
water alternatives has grown at a 10% annual rate, according to the Water Quality Association (WQA,
1999)]. Therefore, tap water ingestion for many households has declined considerably since the USDA
data were collected. A recent EPA-sponsored Gallup poll (U.S. EPA, 2003c) and AwwaRF-sponsored
research by Raucher et al. (forthcoming) indicate that as of 2002, 75% of Americans drink bottled water,
14% to 20% drink ONLY bottled water, 37% use in-home filtration devices, and only 49% to 56% drink
exclusively tap water in their homes.
???The ingestion levels for both USDA distributions as presented by EPA in the EA (U.S. EPA, 2003a, p.
5-23) are higher than applied or derived previously. For example, for the proposed radon rule, the
National Research Council (1999) estimated ingestion risks based on 0.6 L/day. In the arsenic rule, EPA
applied a mean ingestion of 1.0 L/day (U.S. EPA, 1999). Tap water intake as estimated and reported by
Roseberry and Burmaster (1992) is similar to the older EPA (1999) levels, and is considerably lower than
either distribution that EPA now reports and applies (i.e., median of 0.6 L/day, mean of 0.7 L/day, and
90th percentile of 1.4 L/day). This may reflect differences in accounting for direct versus total (direct plus
indirect) use of tap water.
Based on the above, it seems very likely that even the use of estimates from Distribution 2 will overstate
(perhaps considerably) the level of tap water ingestion that is relevant and applicable to a
Cryptosporidium risk assessment.
4.2 SENSITIVITY ANALYSES
It seems likely that EPA is using an overstated level of relevant tap water ingestion as the basis of its
national Cryptosporidium risk assessment. We believe EPA is using results from the wrong USDA-based
distribution, and that even the use of Distribution 2 is likely to overstate (perhaps considerably) the
amount of relevant exposure that is occurring in U.S. households today. This section describes several
adjustments EPA should make to improve its analysis.
First, the households (14% to 20%) that no longer drink tap water should be removed from the risk
assessment and benefits analysis entirely. This would reduce the national risk and benefits estimates by
the same amount (given the near-linearity of the risk and benefits functions applied). In other words, this
indicates national results offered by EPA are overstated by 16% to 25% (i.e., 1.0 - 1.0/0.8 = 25%), due to
just exclusive bottled water drinkers alone. And, because use of bottled water is growing rapidly in the
United States, even higher percentage adjustments may be suitable to reflect the compliance period of
2013 and beyond.
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Second, the amount of relevant water exposure in homes that do rely on tap water (at least in part) should
be scaled back to reflect the nonrisk-bearing portions of current water ingestion patterns. These include
boiled water use (e.g., hot coffee and tea), and the in-home partial use of bottled water or applicable in-
home treatment devices. These adjustments might result in typical relevant in-home tap water exposures
of 0.5 L/day to 0.7 L/day, or perhaps lower. This lower relevant ingestion rate would apply in the 80% to
84% of homes that remain in the analysis once exclusive bottled water drinkers are properly netted out.
While we have not developed our own empirical estimates within the comment period, the data and logic
provided above suggest a more reasonable projection of what exposure level is most applicable. At a
minimum, a sensitivity analysis is warranted. For example, using a 0.6 L/day measure would imply that
the risk estimates EPA derives based on the Distribution 1 mean overstate individual risks by a factor of
nearly 2 or more (i.e., 1.24/0.6 = 2.1).
If one nets out the exclusive bottled water drinkers, and also reduces applicable daily intake for the
remaining homes (to half the level EPA uses, as suggested above), then the overall result would be
benefits at 40% to 43% of the levels currently presented in the EPA This implies that the EPA national
estimates are quite possibly overstated by a factor of 2.3 to 2.5 (i.e., 1.0/0.4 = 2.5), simply on the basis of
how much relevant tap water ingestion is assumed.
4.3 Averted Exposures by Sensitive Subpopulations
As described in Chapter 5, the largest component of the benefits estimates is derived from reduced risk of
premature fatality among individuals with AIDS and others among the immuno-compromised
community.(1) Premature fatality amongst AIDS patients accounts for over 67% of the EPA's estimated
total monetized benefits for the proposed rule.(2) However, these estimates are premised on the
consumption of tap water - without any additional precautions - by these members of the sensitive
subpopulation.
(1) Sensitive Subpopulations include the young, elderly with other underlying illnesses, malnourished,
disease impaired, and those with compromised immune systems.
(2) Using benefits estimates in the EA, Exhibit 5.24, AIDS victims account for 85% of fatal risk, and fatal
risk reductions account for over 79% of total benefits. Combined, this indicates that 67% (85% of 79%)
of EPA's projected LT2 benefits are associated with the Agency's projected fatality rate among AIDS
patients. Because such a large proportion of EPA's estimated benefits of the proposed LT2 rule are
associated with fatality risks among AIDS patients, it seems that much greater public health "bang per
buck" could be derived by focusing Cryptosporidium risk control measures on AIDS victims and others
who are immunocompromised, rather than setting national regulations.
Given the knowledge gained by medical providers, other caregivers, and the sensitive populations
themselves since the 1993 Milwaukee outbreak, it is possible that a large percentage of the at-risk
population are using boiled water, in-home UV- or RO-treated water, or bottled water, or are taking other
precautions against Cryptosporidium exposures associated with tap water. While direct evidence of
adoption of such averting behaviors has not been documented and such actions are not directly
recommended for all AIDS patients, cautions about the risks of Cryptosporidium infections and steps that
can be taken to reduce infection risks are a feature of information provided by both private AIDS
advocacy/education groups (Project Inform, 2003) and the federal government (Centers for Disease
Control and Prevention, 2003). Accordingly, the risk posed to these populations is potentially overstated
by some unknown degree by the Agency in its analysis.
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4.4 Conclusions
A fundamental component of the risk assessment and benefits analysis is the amount of tap water ingested
by the public. The discussion above examines several concerns with the assumptions employed by EPA
in this aspect of its EA.
For example:
* Accounting for exclusive use of bottled water by an increasing number of households would reduce the
subsequent risk analysis and benefits results by approximately 20%.
* Adjusting exposures to reflect direct ingestion in the home might reduce the risk and benefits results by
another 50%.
* Reflecting averting behavior by AIDS patients and other sensitive populations would directly and
proportionally affect the largest component of the monetized benefits estimates.
While the drinking water intake values used in an analysis are not often the focal point of much scrutiny,
the values used do have a very sizable impact on the ultimate risk and benefit findings. EPA should
reconsider how it has approached this aspect of the EA, and provide improved and more expansive
analysis and documentation. The EA needs to be corrected to reflect the issues and data noted here.
5. DOSE-RESPONSE ASSESSMENT: QUANTIFIED HEALTH EFFECTS
For its economic analysis of the proposed LT2 Enhanced Surface Water Treatment Rule, EPA develops a
risk assessment based on a multistep dose-response model linking expected reductions in the
concentration of Cryptosporidium oocysts to expected reductions in the annual incidence of adverse
health outcomes. The general steps within this risk assessment are presented in the highlighted
portion of Exhibit 5.1, which summarizes the general benefits analysis process used for the LT2 rule. In
the sections below, we review and critique of each of these steps within the dose-response analysis, in
sequence. Finally, we draw overall conclusions and inferences about the most critical issues with the
analysis, and about the potential magnitude and direction of any errors that may be embodied in the EPA
analysis.
5.1 FROM EXPOSURE TO INFECTION: INFECTIVITY ASSESSMENT
The dose-response sequence begins with an assessment of infectivity. This estimates the probability that a
person will be infected by cryptosporidiosis, given the presence of an oocyst in the water they ingest. This
in itself entails a multistep process:
1. What are the numbers of all Cryptosporidium oocysts - i.e., the exposure - that a person is likely to
ingest in a given day? This exposure variable is derived from the steps outlined in the previous two
chapters.
2. What is the duration of exposure (n)? EPA assumes this is 350 days per year.
3. What is the probability that an oocyst present in ingested water is infective? The infectious fraction,
multiplied by the exposure level (from step 1), provides an estimated expected dose (d) of infectious
oocysts ingested per day.
4. What is the probability (r) that an ingested infectious oocyst will generate an infection in a single host
human? This infection index is a measure of the inherent infectivity of multiple strains of
Cryptosporidium organisms in the water being ingested, which EPA refers to as oocyst survival rate (i.e.,
it is intended to reflect the probability that an infectious ingested oocyst will survive long enough to
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initiate an infection).
[See p. 385 of PDF for Exhibit 5.1]
Based on the estimates or assumptions applied in each of these steps, annual (or daily) infection risk can
be estimated (i.e., the probability of getting infected in any given year of exposure). To do this, EPA uses
a simple exponential dose-response model based on Haas et al. (1996). Our review focuses on steps 3 and
4 (since step 1 was addressed previously, and the assumption applied by EPA for step 2 is reasonable).
5.1.1 Infectious oocyst fraction
EPA bases the fraction of oocysts in finished waters that are expected to be infectious on research by
LeChevallier et al. (2003) in which oocysts were detected in 60 of 593 samples (using Method 1623) and
infective oocysts were identified in 22 of 60 samples (by the CC-PCR method). These results suggest
that roughly 37% of Cryptosporidium oocysts detected by Method 1623 are viable and are infectious.
To reflect uncertainty in the precision of this implied probability of detected oocysts from the ICRSS
databases being infectious, EPA applies a range of values from 30% to 50%, and applies a triangular
distribution to this range (so that the mean, median, and mode of random draws from the distribution will
approximate 40%). This seems to be a practical and reasonable approach if the 37% finding from
LeChevallier et al. is robust. Without additional studies, it is impossible to know if 37% is suitable or
representative, but it is the only apparently credible piece of data with which to proceed at this time.
For the ICR data, EPA uses a mode of 20%, with bounds of 15% and 25%. This lower infectious fraction
applied to the ICR data is intended to reflect differences in findings due to the lower reliability of the
oocyst counts developed using the ICR method (versus the ICRSS findings that were derived using
Method 1623). Such an adjustment by EPA seems appropriate in spirit, but we cannot evaluate whether
the specific empirical adjustment is suitable or not.
5.1.2 Inherent infectivity - oocyst survival probability (r)
Given ingestion of a viable and infectious oocyst, the next step of the dose-response assessment entails
estimating the probability that the ingested oocyst will initiate an infection. This is characterized as the
variable r in EPA's model, and it is the probability that a single ingested infectious oocyst will
survive long enough in its human host to cause an infection in the host.
As a probability, r can theoretically range from 0 to 1. An r value close to 1 is a highly infectious isolate
(and an r is near zero for strains not very infectious). The value of r is thus dependent on what strain of
Cryptosporidium is ingested, and very limited data are available with which to estimate values
for this critical variable. Thus, a core question for this review of the EPA EA is:
"Does EPA develop and use realistic and defensible r values?" This is a challenging question to answer,
given the sparse discussion and back-up documentation provided by EPA.
There are several issues of general concern with developing r values, given the limits of the available
data. There also are several additional concerns with how EPA appears to have interpreted these scant
data. These concerns are outlined below.
Data are limited to a few strains, and we do not know what strains may be in drinking water
Only three or four strains (the TAMU, IOWA, and UCP strains, plus perhaps one other) have some
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clinical trial data from which r values might be estimated. It is unknown how many strains that are
potentially infectious in humans may be present in water supplies, or which of the strains are most likely
to be present, or what mix(es) of strains may be present in what proportions. Thus, when oocysts are
present (or projected to be present) in finished waters, we typically have no idea if or how the strain(s)
present may or may not relate to the three or four strains for which some human health risk data exist. Nor
do we know how infectious the other strains might be relative to the three or four strains. Thus, we have
no strong basis for projecting real world risks based on limited health risk data available for only three or
four strains.
The data available on the three strains used in the analysis are extremely limited
Even for the three strains that EPA uses (TAMU, IOWA, and UCP), our knowledge of the infectivity of
these strains is very limited. The available data are based on observations from a small number clinical
human experiments. These clinical experiments may be well executed and adhere to good scientific
practices. However, each study used very small sample sizes and a limited range of dose levels (generally
much higher than applicable for the LT2 baseline and post-rule compliance scenarios).
EPA summarizes the clinical trial findings for each strain in Appendix N of the EA (U.S. EPA, 2003a),
and the data are also described in Messner et al. (2001). It is evident that:
1. Sample sizes were extremely small. The IOWA strain had 29 subjects tested spread over eight very
different dose levels, the TAMU study had 14 subjects spread over four dose ranges, and the UCP strain
study involved 17 subjects spread over four dose levels.
2. Dose levels were extremely high. The lowest dose level tested was 10 oocysts (TAMU, administered to
only three subjects), and the next lowest level was 30 oocysts (five subjects with IOWA, three with
TAMU). All other subjects (52 of the 60) were dosed at levels between 300 and 1 million oocysts (19
subjects were dosed at levels of 1,000 or more oocysts). These levels are extremely high compared to
human exposures in typical finished waters, which may have infectious oocysts a levels of only
0.00044/L (Aboytes et al., 2000). If a person directly consumes an average of 0.6 L/day of finished water,
it would take over 10 years to expect exposure to one infectious oocyst (and 104 years to have an
expected ingestion of 10 infectious oocysts).
3. Infectivity appears to be positively related to dose. While the sample sizes are small, the data for each
of the three strains show an unambiguous positive association between infection rates and dose levels.
Since the dose levels are so high in the studies, one has to question whether the results provide reliable
indications of risk of infection when extrapolated to the much lower doses expected in finished waters
(where the odds of ingesting an infectious oocyst may be 4.4 in 10,000 per liter, or lower according to the
EA).
4. The fraction of infectious oocysts in the clinical trials may be higher than in finished water. The clinical
trials administered oocysts of a single known infectious strain (either TAMU, UCP, or IOWA) to the
subjects. In finished waters through the United States, we do not know what strain(s) may be present
or the infectious fractions.
5. The use of "presumed infections" may significantly overstate the estimated risk. In Messner et al.
(2001), the clinical study data are used to estimate r values, using an expanded definition of infection.
Specifically, the estimates for infection are based on both demonstrated infections (e.g., the subject is
shedding oocysts and shows symptoms) and "presumed infections" (in which the subjects show
symptoms but no oocysts are observed in stool samples). For some doses of the clinical tests, these
presumed infections make up 50% or more of the total number of infections that Messner et al. (2001) use
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in their analysis to estimate r. Because some of the "presumed infections" may in fact reflect apparent
symptoms due to factors other than Cryptosporidium, the resulting r estimates may be overstated. Given
the extremely small sample sizes, any presumed infection that is actually not a case of cryptosporidiosis
would have a large impact in the resulting risk estimate.
EPA's basis for "r" values used in the EA is unclear and unsubstantiated
There are complex issues regarding how to estimate r values from the available data, and which r values
to use in the analysis. Despite the limitation with the underlying clinical data, r values for the three
studied strains and an unknown strain have been estimated by EPA researchers in a peer-reviewed
publication by Messner et al. (2001). They report r values ranging from a low of 0.038% (for UCP) to
0.53% (IOWA) to a high of 4.8% (TAMU). Thus the average across the three strains is 1.8%. They also
develop an r value of 2.8% for an unknown strain, and this 2.8% has been applied in subsequent studies
(i.e., Aboytes and LeChevallier, 2003).
Instead of using these published findings, EPA applies a complex set of modeling techniques to generate
estimated probability distributions for r, using two varieties of logit models and running each model using
data for either all three strains or for only the two more infectious strains (i.e., dropping UCP from the
analysis). The procedures EPA applies are described obtusely in Appendix N of the EA (U.S. EPA,
2003a), and appear to generate distributions of expected r values. EPA's means for expected r values are
estimated to be 7.3% to 8.9% using the logit normal model (with and without UCP in the analysis,
respectively), and 9.0% to 10.5% using the logit t model (with and without UCP in the analysis,
respectively) (bottom of page N-9). The simple average of these four results is over 8.9%.
It is noteworthy that estimated mean expected values for r that EPA derives and uses in the EA are
considerably higher than the r values reported in the published Messner et al. (2001) article. The average
of the EA-reported mean expected r values is over 8.93%, whereas the average known strain estimate
from Messner et al. is 1.80%. This reflects a difference of a factor of 5 (8.93/1.80), even though both sets
of estimates are derived from the same underlying data. The average of the EA results is also above the
upper 90th confidence limits for all of the meta-analysis risk factors estimated in Messner et al. (2001).
Given the magnitude of the difference between previously published findings and the results applied in
the EA by EPA, there is a need for much greater explanation and documentation by the Agency to
describe its rationale and justify its revised findings. It is neither apparent from the EA what EPA's
rationale is for the new approach nor very clear what analyses the Agency actually performed, how the
results it derived are used, what the range of outcomes are, and how they can or should be interpreted
relative to prior published peer-reviewed results. Appendix N in the EA does provide some highly
technical information and results, but these are obtuse and lacking in transparency or interpretation. Given
the importance of the r estimates in the calculation of risks and benefits for the LT2 EA, EPA must
provide much more complete and transparent discussion of its approaches, results, and applications.
From EPA's Appendix N, it appears that EPA has applied a complex modeling approach called Markov
Chain Monte Carlo (MCMC) in an attempt to overcome perceived and actual deficiencies in the available
data. These methods assume that there is information that is understood and from which additional
insights can be gained. While these MCMC methods have been extensively applied in the literature, they
are computer intensive, fairly complex, and most effective in situations where components of the process
are well understood. However, this is not a case in which the processes are well understood. In addition,
Appendix N is very difficult to follow, its assumptions are not well documented, and the graphics are also
not always clear (including many graphs that do not have labeled axises, e.g., Exhibits N.5 and N.I 1
through N. 16).
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The differences between Messner et al.'s results (1.8% to 2.8%) and those in Appendix N (7.3% to
10.5%) can be attributed to EPA's response to the Science Advisory Board (SAB) review. While these
SAB suggestions are presented, they are not explained, and the sensitivity to the models is rather dramatic
given that changes in the mean results for r are in the range of a factor of 4 or 5. This is of concern
especially given that the underlying models used [log normal and log t (3df)] are just approximations and
there is not solid evidence presented other than the SAB recommendation that these models may be the
correct underlying models. Yet the small changes suggested by the SAB resulted in significant changes in
the mean values of r, which are critical to the general benefits analysis. This is a kind of a sensitivity
analysis, and the results suggest that changing the distributional assumptions can dramatically alter the
results of the modeling. By the very nature of this process, the SAB and EPA have highlighted that the
assumptions made are not perfectly understood. Partially valid arguments can be made for log normal
distributions, Student t distributions, and blends of these two. Yet when the different distributions are
applied, significantly different results are observed. No one can say emphatically which distribution is
correct in the modeling. In fact, it is likely that the empirically true distribution is not one of the standard
distributions available to choose from for the modeling effort. Since the outcome appears to be very
sensitive to the underlying distributional assumptions, the results of the model should not be considered a
good estimation of the dose-response parameter. It would be prudent for the calculations to be done at
values of r ranging from 1.5% to 11% and to determine the differences based on these differences.
Appendix N needs to be rewritten with much clearer explanations of what is being done, the assumptions
being made, how it compares to Messner et al.'s peer-reviewed published paper (2001). The rewrite
should also make evident the effects of the assumptions made.
One other fact gleaned from Appendix N that is noteworthy is that EPA recognizes from its review of the
clinical studies that infectivity is positively related to dose (reflecting the number of infectious oocysts
ingested, as noted on page N-3 of the EA). However, as noted later in this chapter, EPA elsewhere
assumes that morbidity is independent of dose (e.g., in its use of the Milwaukee outbreak data to
characterize the number and severity of illnesses expected at the much lower endemic exposure rates
associated with the LT2 rulemaking). This potential inconsistency with respect to the impact of dose
requires greater elaboration and sensitivity analysis by EPA.
5.2 FROM INFECTIVITY TO ILLNESS: MORBIDITY ASSESSMENT
A person infected with cryptosporidiosis does not necessarily become ill - many infections are
asymptomatic. Therefore, the probability that a person will become ill (have symptoms) if they are
infected must be estimated.
5.2.1 Baseline levels of illness
As a starting point of the analysis, it is useful to assess how many cases of cryptosporidiosis are projected
for the regulatory baseline (pre-LT2), and then assess how many of these cases EPA expects will be
averted by implementation of the rule. For the baseline, we examined EPA's Regulatory Impact Analysis
(RIA) for the Interim Enhanced Surface Water Treatment Rule (IESWTR), which established the baseline
for LT2. According to the RIA (U.S. EPA, 1998), the endemic incidence of cryptosporidiosis is estimated
to be between 208,500 and 643,000 cases per year, pre-IESWTR, for the relevant impacted systems (the
range reflects alternative EPA assumptions about removal rates at baseline treatment).
This baseline is reasonably consistent with the results implied by Mead et al. (1999), as discussed in the
EPA EA (U.S. EPA, 2003a, p. 5-6). Mead et al.'s analysis suggests a pre-IESWTR baseline level of
270,000 cases of endemic cryptosporidiosis annually caused by contaminated water. This is based on
Mead et al. (1999) using 15 million doctor visits for diarrhea, assigning 2% to cryptosporidiosis, netting
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out 10% for food-borne cases, and leaving the balance to water and person-to-person contact. If these
assumptions are reasonable, then this might be a low estimate given typical under-reporting (i.e., many
people with diarrhea do not seek medical assistance). Hence, the range noted in the IESWTR as a baseline
seems reasonable.
The IESWTR RIA predicts that the enhanced filtration implemented under the IESWTR will reduce
endemic cases by between 149,000 and 432,000 cases per year (U.S. EPA, 1998). This leaves a remaining
level of endemic cases of cryptosporidiosis of between 59,500 and 111,000 per year (e.g., 643,000 minus
432,000 =111,000) after implementation of the IESWTR. This is the relevant baseline level of estimated
cases from which the LT2 rule should begin.
5.2.2 Comparing baseline cases to EPA estimates for cases avoided by the proposed rule
Given this estimated baseline for LT2, it is interesting to note that EPA estimates that because of LT2, the
mean number of annual endemic cases of cryptosporidiosis avoided will be 256,000 to 1.02 million
illnesses (and 37 to 141 avoided premature fatalities).(l)
(1) At the 95th percentile, EPA predicts over 2.3 million cases avoided annually (Exhibit 8.3), or more
than twenty times the baseline number of annual cases.
Comparing the estimated illnesses avoided to the estimated pre-rule baseline reveals an obvious problem:
the EPA benefits analysis for the LT2 rule is driven by a number of cases avoided that is between 4.3 and
9.2 times higher than the Agency's own estimate of the baseline. Granting that both the baseline LT2
estimate and the estimated reduction due to the proposed rule are subject to considerable uncertainty, the
EPA analysis of cases avoided is still problematic. The Agency should provide a more complete
explanation of both the suitable baseline and the cases it expects to avoid owing to the rule. As it stands,
the analysis lacks overall credibility.
5.2.3 Morbidity assessment
To move from its estimate of infections per year, EPA needs to predict how many infected persons
actually become ill (i.e., exhibit symptoms). EPA uses triangular distribution to model the morbidity rate,
using a mode of 50%, and lower and upper bounds of 30% and 70%, respectively. This is based on
human ingestion trials in which, according to EPA, morbidity rates were generally in the range of 39% to
58%, depending on strains used. This suggests that some midpoint between these values - such as the
40% EPA selects - is a practical and logical morbidity rate around which to anchor the uncertainty
analysis. However, the 40% level may be too high, given the nature of the underlying data upon which it
is based.
As noted above (Section 5.1.2), various critical limitations are associated with the clinical trials, including
the small number of subjects and the very high level dosing with known infectious oocysts. Since rates of
both infection and illness are believed to be positively related to higher doses - as acknowledged
by EPA (EA, p. 5-11) - and since the illness rates reported in the literature pertain to trials using
extremely high doses (well above the levels anticipated in endemic exposures in finished U.S. waters
post-IESWTR compliance), it follows that the observed numbers of illnesses are higher than would be
anticipated at lower, endemic dose levels.
In contrast, EPA argues that the clinical trial studies may underestimate morbidity because the subjects
were all healthy and because in some instances only diarrhea was used to indicate illness (possibly
ignoring other symptoms). These points may be relevant; however, it seems that the issue of dose rates
may more than counterbalance these factors and thus imply some level of underestimation. In addition,
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EPA's use of the "presumed infection" concept to estimate risk may wrongly attribute some symptoms
from the clinical trial subjects to Cryptosporidium, thereby overstating the risk. In general, EPA's
discussion in the EA seems a bit one-sided. The Agency should re-evaluate the morbidity rate assessment
and present a more balanced perspective.(2)
(2) EPA also needs to consider if the expanded definition of "infected" from Messner et al. (2001), and
used by the Agency in Appendix N, affects the application of these data to the morbidity assessment. The
inclusion of "presumed infected" may imply that a lesser fraction of "infected" become ill.
Of particular concern in this stage of the analysis is EPA's assumption that the "morbidity rate is
independent of dose . . . the results of this analysis would not be affected by using increased morbidity
rates with significantly higher doses" (EA, p. 5-11). Is this indeed a reasonable assumption? Might an
alternative approach be equally or more plausible? If so, what effect would this have on EPA's results in
the EA?
Given that infective dose levels in the clinical trails cited in Messner et al. (2001) are at levels between
23,000 and 2.3 billion times greater than observed in finished waters (Aboytes et al., 2000; Aboytes and
LeChevallier, 2003), and given that some studies do indicate higher morbidity rates at higher doses
(DuPont et al., 1995), it would seem prudent for EPA to explore alternative assumptions to dose
independence. These should be included as sensitivity analyses.
5.3 From Illness to Severity
While the dose-response framework incorporated in EPA's risk assessment of the LT2 is well suited for
quantifying the expected health impacts of the rule, EPA's execution of the analysis raises a number of
concerns and questions. Specifically, there is concern with respect to the process used to account for
risks to sensitive population subgroups. This concern includes the general process used to account for
adverse health outcomes experienced by sensitive population subgroups and how risks faced by
recognized sensitive population subgroups are presented and calculated. Cumulatively, these issues raise
questions with regard to the number and distribution, by severity, of adverse health outcomes estimated to
be a result of the LT2. These concerns are addressed in this section.
5.3.1 Treatment of sensitive population subgroups in the LT2 risk analysis
In its summary of the risk assessment guidelines, EPA notes that "when the risks posed are not the same
for all persons, that variability should be described." Further, the summary of guidelines notes that ideally
these risks will be addressed through "the use of scientific data (or reasonable assumptions if data are not
available) to produce estimates of the nature, extent, severity, and degree of risk" (U.S. EPA, 2003a; p. 5-
4 for both quotes).
For the LT2, EPA initially identifies several population subgroups that are expected or known to face
elevated risk of morbidity and mortality following a microbial pathogen infection. These population
subgroups include individuals with AIDS, the very young, elderly with other illnesses, and the disease
impaired (U.S. EPA, 2003a, p. 5-6). The common feature linking these individuals is that their immune
systems are weakened relative to those of persons in the remaining portion of the population through
some combination of illness, lack of maturity, or decline with age.
Evidence of the sensitivity of individuals in these subgroups to microbial pathogen infections abounds.
Specifically, EPA reports a risk of death of roughly 1 in 100,000 among healthy individuals infected by a
microbial pathogen (based on 1% of infections expected to result in hospitalization and a risk of
death following hospitalization of less than 1 in 1,000 - U.S. EPA, 2003a, p. 5-7). In contrast, EPA
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reports a range in mortality risks in AIDS patients following infection of Cryptosporidium of 52% to 68%
based on data from cryptosporidiosis outbreaks in Las Vegas, Nevada, and Milwaukee, Wisconsin,
respectively (U.S. EPA, 2003a, p. 5-14). This elevated sensitivity among the immunocompromised is
reflected in the baseline mortality parameter estimates in EPA's dose-response model, where 81% or 88%
of the mortality risk applied to the general population is attributable to expected deaths of AIDS patients
(U.S. EPA, 2003a, p. 5-14).
Ideally, for the LT2 analysis, EPA would have developed a population-based estimate of the avoided
health effects attributable to the rule by calculating and then summing the impacts for identified
population subgroups facing elevated risks and then for the remainder of the population. However, despite
the apparent availability of population and risk data specific to relevant subgroups (e.g., persons living
with and without AIDS), EPA did not pursue this option. Instead, EPA either ignores possible risk
differences for these subgroups (i.e., for morbidity outcomes) or uses population-based weights to
aggregate subgroup-based risk estimates (i.e., mortality risks) to create a general population risk
estimate.
In one respect, EPA's approach could be interpreted as being consistent with the previously summarized
risk assessment guidelines because sensitive population subgroups are identified and separate outcome-
based risks are developed for the subgroup and the rest of the population. However, the health benefit
estimates for the LT2 raise questions when considering how specific characteristics of the critical
population subgroup (i.e., persons living with AIDS) that could influence the results are lost in the
approach ultimately used.
Specifically, EPA makes adjustments to its mortality risk estimates to try to account for the distribution of
persons living with AIDS in the United States, but the adjustment effectively assumes a uniform
dispersion of persons living with AIDS in specific types of water systems. The clear limitation to this
approach is that persons living with AIDS in the United States are not uniformly dispersed but highly
concentrated, as shown in the state-level results in Exhibit 5.2.
Exhibit 5.2 shows that over 30% of the U.S. population living with AIDS in 2001 was concentrated in
three states and that 50% of this population was concentrated in only five states. Demonstrating that the
concentrations are independent of population are the results on the prevalence of persons living with
AIDS per million individuals in the state populations. These values range from a low of 72 in North
Dakota to a high of 12,595 in Washington, DC. While the data are not developed here, it is believed that
the state level data in fact mask an even greater heterogeneity in the distribution of persons with AIDS,
which would be revealed if the state AIDS populations were allocated by county. The data used to
calculate the AIDS-based mortality adjustment provide some indications of this because the data indicate
that 14% of those living with AIDS in the United States in 1999 resided in New York City alone (U.S.
EPA, 2003a, see Exhibits C.I and C.2).
[See p. 396 of PDF for Exhibit 5.2]
Ultimately the heterogeneity in the distribution of persons living with AIDS is important for the LT2 risk
assessment. It strongly suggests that accurate estimates of avoided health outcomes, and especially
avoided fatalities that are currently driven by outcomes attributable to persons with AIDS, require
accounting for expected impacts in the specific water systems serving the population with AIDS.
To emphasize this conclusion, consider the example of implementing the LT2 for a hypothetical
population served by two water systems, one that serves persons with AIDS and the other everyone else.
In the first case, the LT2 reduces microbial pathogens in each system's water by 2.5 logs, providing a
benefit of 10 avoided deaths. Using EPA's current mortality risk estimates, roughly eight of these deaths
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would be avoided in the AIDS population. In this scenario, knowing where the AIDS population is
residing is not important because everyone experiences the same initial risk reduction. However,
assuming a linear relationship between avoided outcomes and changes in contamination in a population,
consider if the system serving the non-AIDS population were to have its contamination reduced by 5 logs
while there was no change in the contamination of the system serving the AIDS population. In this
example, the simple average of the change in contamination across both systems is still a reduction of 2-3
logs but now only four lives would be expected to be saved (i.e., a doubling of the lives saved from the
original scenario estimate for the non-AIDS population and no lives saved for the AIDS population). As
this comparison clearly shows, recognizing risk differences within population subgroups and accurately
establishing the distribution of members of those groups among affected systems is a matter of
considerable importance in accurately estimating the LT2's health benefits.
5.3.2 Quantification of risk in sensitive subpopulations for the LT2 analysis
Section 5.3.1 argues that an accurate estimate of the health benefits of the LT2, both in terms of number
of avoided outcomes and the severity of those outcomes, requires developing risk estimates for identified
sensitive population subgroups and for the rest of the population. In general terms, the LT2's risk
analysis currently estimates avoided health outcomes by first calculating the number of expected
microbial pathogen illnesses in a population. From this illness total, the number of expected deaths are
then calculated. Nonfatal cases are calculated as the difference between the original morbidity estimate
and the number of deaths, and are then allocated across three categories of severity (mild, moderate, and
severe) (U.S. EPA, 2003a).
Starting from the assumption that the number of illnesses has already been estimated, this section
demonstrates how the health impact quantification could be completed separately for the population with
AIDS and the rest of the population, with data already being used or readily available.
Allocating populations to subgroups
Consistent with the approach partially adopted by EPA, we are interested in defining the population with
and without AIDS in the water systems that would be affected by the proposed LT2 rule with as much
geographic precision as possible. Clearly, AIDS population estimates are available at a level of precision
that allows for assignment of the national population to specific categories of water systems based on the
adjustment factors to the Milwaukee data that are proposed in the risk assessment using these results
(U.S. EPA, 2003a, p. 5-13). In the suggested framework, the AIDS and non-AIDS population, allocated at
least by system type, would serve as the baseline populations from which separate microbial infection
estimates are developed.
Calculating mortality risks
Mortality results from the 1993 Cryptosporidium outbreak in Milwaukee, Wisconsin, as reported by
Hoxie et al. (1997), provide the data currently used to start estimating mortality risks following infection
by a microbial pathogen in the LT2 ESWTR's risk analysis.
Hoxie et al. report that the Milwaukee outbreak was attributable for roughly 403,000 cases of watery
diarrhea among residents in a five county area likely to have been affected by the outbreak. The LT2 risk
analysis incorporates this number as the estimated number of infections from the outbreak. In a review of
death certificate data, Hoxie et al. then conclude that the outbreak was attributable for 54 deaths in the
affected population, and 46 of the 54 individuals also had AIDS (85.2%). EPA's approach in addressing
these data is to develop separate estimates of mortality risks based on the total number of infections and
whether or not the individuals who died were AIDS patients.
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What would be relevant for the proposed subgroup-specific analyses would be estimates of the mortality
rate among those infected who had AIDS and those infected who did not have AIDS. While Hoxie et al.
do not provide an estimate of the number of AIDS patients initially infected, the data are apparently
available because the risk analysis eventually reports that there was an observed fatality rate of 68% in the
Milwaukee outbreak among AIDS patients who experienced a Cryptosporidium infection (U.S. EPA,
2003a,p. 5-14).
Further, dividing the number of deaths among AIDS patients attributed to those who experienced a
Cryptosporidium infection by the reported mortality rate provides an estimate of the number of initial
infections in AIDS patients. To calculate a mortality rate specific to the non-AIDS population, the number
of deaths among non-AIDS patients (eight) would be divided by the estimated number of infections in
this population [402,932 = 403,000 - (46/0.68)].
With separate mortality and population estimates for the population with and without AIDS, it is worth
noting that the subsequent adjustment made to the mortality risk estimates in the LT2 to account for the
differences in the population with AIDS in Wisconsin relative to these populations in filtered and
unfiltered systems nationwide would no longer be required.
Finally, it is worth discussing the adjustment to the AIDS-based mortality rate estimates currently made
in the LT2 risk analysis to reflect improved survival of AIDS patients over time (U.S. EPA, 2003a, p. 5-
13). The argument presented for this substantial adjustment (i.e., it reduces the AIDS-based mortality rate
per 100,000 infected by Cryptosporidium by a factor of approximately 25%) is based on the impact of
recently developed AIDS medications.(3) It seems that an argument must be presented that the new
medications provide some sort of protective benefit against either infection from microbial pathogens or
mortality once infected; such justification is not presented.
(3) The overall general survival rate for AIDS patients is adjusted by EPA by a factor of roughly 8.
Allocating nonfatal cases across population subgroups and severity classes
Clearly data currently available and incorporated in the risk analysis could be used to develop separate
estimates of the avoided fatal cases of infection by microbial pathogens for a population subgroup of
individuals with AIDS and for the rest of the population. Subtracting these fatal case estimates from the
initial estimates of illnesses in each group yields the total number of nonfatal cases for each population
subgroup.
Currently, the risk analysis for the LT2 makes no allocation of nonfatal cases between population
subgroups. Consequently it makes no distinctions by population subgroup in allocating these infections
across severity categories using Corso et al. (2003) estimates for the Milwaukee outbreak that 88% of all
infections did not require medical attention, 11% were seen as outpatients, and 1% required
hospitalization to distribute nonfatal infection estimates across the mild, moderate, and severe outcome
categories.
While these estimates are believed to be an accurate representation of the disposition of infections in the
Milwaukee outbreak, they would need to be revisited for use in an application where separate nonfatal
infection estimates are calculated for population subgroups that either have or do not have AIDS.
Specifically, while the distribution is probably appropriate for use with the population that does not have
AIDS, it seems questionable for use with the AIDS population given the lack of available treatments and
the inability of that population to mount an effective resistance to the infection given their
immunocompromised status. Essentially then what would be needed is a separate distribution for nonfatal
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cases for AIDS patients. Very likely, this distribution would be heavily weighted toward nonfatal
infections being in the severe category.
Conclusions
Clearly, given the currently available data, it is not beyond the scope of EPA to develop estimates of the
health impacts of the proposed LT2 based on defining population subgroups that have different health
risks with respect to microbial pathogens. While doing so would clearly increase the precision of the
estimates, it is not currently clear in what direction the current estimates may be biased given the multiple
factors that would need to be accounted for, especially linking actual subgroup populations to specific
utilities that would be affected by the rule.
Finally, it is worth noting additional items that could and should be addressed qualitatively, if not
quantitatively, in the risk analysis. This is regardless of whether the alternative of developing population
health impact estimates by estimating totals for mutually exclusive population subgroups and then
summing is pursued.
First, EPA's risk assessment currently assumes one distribution for a morbidity factor that estimates the
probability of developing an illness if infected by a microbial pathogen (U.S. EPA, 2003a, p. 5-11). A
discussion of how this risk is likely to vary between those who are immunocompromised and the rest of
the population is warranted given the clear identification of this at-risk group.
Second, the risk assessment does not discuss averting behaviors that individuals could take to lower their
risk of exposure to infective microbial pathogens. For most of the general population, it could be
presumed that such steps are rarely taken. However, a discussion with respect to the identified sensitive
subgroup of immunocompromised individuals seems warranted. Such a discussion could evaluate
standard recommendations provided to those with AIDS by support groups or medical professionals on
best practices for using tap water and/or recommended preventative measures to reduce exposure to
microbial pathogens. While it is not clear that such measures are widely incorporated by members of
this population, it is fairly clear that outbreaks such as that for Cryptosporidium in Milwaukee in 1993
have heightened awareness of microbial pathogen risks among this population.
5.4 Use of Outbreak Data to Infer Inputs and Outcomes for Endemic Risk
A question of significance not addressed in Section 5.3, but one that plays a critical role in the calculation
of expected health benefits for the LT2 ESWTR once the number of infections from exposure has been
calculated, is the reliance on data from outbreaks of microbial pathogens to estimate fatal cases and the
severity of nonfatal cases.
Ideally, data on the impacts of endemic exposure to microbial pathogens would be used to estimate the
impacts of the LT2, but such data do not exist. A reasonable question then is whether the use of data
related to outbreaks such as that for Cryptosporidium reported by Hoxie et al. (1997) and Corso et al.
(2003) for Milwaukee's 1993 outbreak may bias the results and in what direction.
Results based on data from outbreaks used to estimate impacts on endemic illness may be biased upwards
if the response rates and the severity of the response increase with the level and duration of exposure.
This is a possibility EPA recognizes clearly in discussions on its mortality risk estimates (U.S. EPA,
2003a, p. 5-14). Second, there may be an upward bias in the observed health responses during an outbreak
if events that would have received a different medical code ordinarily are coded to imply attribution to the
outbreak, in part because of the awareness of medical providers of the event itself. Further, given the
general conclusion that most individuals will not seek care for mild microbial pathogen infections, it is
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very possible that the estimates of severe impacts based on estimated numbers of infections and case
distributions observed during an outbreak may be upwardly biased if the true number of infections is
much larger (e.g., due to greater awareness and concern by those mildly affected).
Unfortunately, this is a data shortcoming that is currently difficult to address. Because it is unlikely that
detailed and reliable information on the effects of endemic exposures will be developed, the only
alternative to using current data inputs is to incorporate additional sensitivity analyses designed to
evaluate the extent to which assumptions would have to change before critical decisions were altered.
Once such values are identified it may be possible to evaluate their plausibility in order to provide
additional information for consideration.
5.5 Conclusions
The dose-response portion of the EA is a very complex and highly significant component of the overall
analysis. Critical assumptions must be made at several points in the analysis because of pervasive
scientific uncertainties. EPA makes several plausible and reasonable assumptions and inferences, but
there also are components of the analysis where alternative assumptions or scenarios seem more plausible
or, at a minimum, equally plausible. In such instances, the Agency should be more explicit and balanced
about assumptions it is making, and should conduct meaningful sensitivity analyses to reveal the impact
of the alternative assumptions on the overall findings.
Of particular concern from our review of the EA are the following:
1. The estimation and use of r values for inherent infectivity. The estimation process is not well
documented and is poorly presented, the underlying data have significant limitations, and the results that
EPA apparently uses are appreciably higher than findings published in the peer-reviewed literature. This
requires greater documentation, discussion, and review. The inputs and assumptions that feed the model
are also nonstandard (including the use of presumed infections instead of the standard long established
strategy of using confirmed infections). The effects of this important assumption on the outcome
of the model have not been presented. A kind of sensitivity analysis has been done for the importance of
the underlying model and the change from a normal to a t distribution has had the effect of changing the
mean value of r by a factor of four or five. This demonstrates the importance of the underlying
assumptions regarding the distributions used, and requires greater explanation and justification.
2. The morbidity assessment is dose-independent. Given the extremely high doses used in the clinical
trials relative to the levels in finished water, and the evidence of dose-dependent morbidity in some
studies, it seems prudent to at least conduct reasonable sensitivity analyses on the impact of this key
assumption.
3. EPA's projected number of cases avoided is implausible given the baseline level of illness projected by
the Agency. In fact, EPA's estimates of avoided cases are between 4 and 10 times higher than its baseline.
4. Morbidity levels, the allocation of cases across severity classifications, and the characterization of the
duration and impact of illnesses in each severity class are all based on data from the Milwaukee outbreak
of 1993. It is problematic to use data from a massive outbreak (with very high levels and durations of
primary and secondary exposure) as a basis for estimating numbers, severity, and duration of illness from
endemic exposures to far lower doses. Here again, given the core uncertainties and the importance that
these assumptions have on the final benefit outcomes, some alternative scenarios should be developed and
assessed using sensitivity analysis.
6. VALUATION OF HEALTH IMPACTS
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The valuation of the fatal and nonfatal impacts expected to be avoided as a result of the LT2 ESWTR is a
critical component of estimating the benefits of the rule because it provides a basis for comparing the
benefits of this rule to other potential actions and to the anticipated costs for implementing and complying
with the rule. In the valuation process, different data sources and methods are used to monetize estimated
nonfatal and fatal infections. In this process EPA follows established precedents and treatments of data in
valuing the nonfatal infections using what is called the Traditional cost-of-illness (COI) method, and in its
valuation of fatal outcomes using a well established distribution of estimates for the value of a statistical
life (VSL estimates). In this regard it is only EPA's development and use of what is called the Enhanced
COI method to provide an alternative valuation of the nonfatal infections that merits significant
discussion because it is a considerable departure from standard COI practices and does not appear to have
been subjected to reliable peer review.
6.1 USE OF THE TRADITIONAL COST-OF-ILLNESS METHOD TO VALUE NONFATAL
INFECTIONS
As recognized in the LT2 EA, the preferred measure for valuing any adverse health outcome is a measure
of an individual's ex ante (ahead of time) willingness to pay (WTP) to avoid the outcome (U.S. EPA,
2003a). WTP measures for valuing an avoided health outcome are an economist's preferred measure
because they allow the individual to incorporate information about the expected direct financial costs of
the outcome (e.g., medical expenses, lost income, lost household production) along with those features of
the outcome that are not directly valued, such as any associated pain and suffering or activity limitations,
both short and long term, that may result from the outcome. Finally, because ex ante WTP responses are
necessarily bounded by an individual's income, they are constrained by the same limits that are faced
when making other economic decisions.
Unfortunately, WTP estimates exist for only a limited set of nonfatal adverse health outcomes and this
pool does not include outcomes similar enough to those experienced from nonfatal microbial pathogen
infections to be suitable for use in a benefits transfer for the economic evaluation of the LT2's expected
health benefits. In these situations, one option is to develop and use COI estimates that account for the
direct medical expenditures, lost income, and lost household productivity associated with the outcome.
Clearly, such COI estimates provide a lower bound valuation estimate with respect to WTP estimates
because the method fails to account for the value an individual would place on avoiding any pain and
suffering, as well as any activity limitations associated with the condition. Because of the general
availability of the data required to complete COI estimates and their known relationship as a lower bound
to WTP estimates, COI valuations are a useful tool for monetizing expected reductions in adverse health
outcomes such as those anticipated from the LT2.
The Traditional COI estimates incorporated in the LT2's economic analysis accurately follow the standard
COI method by accounting for the types and level of medical services and expenditures associated with
nonfatal microbial infections according to their severity level, along with estimating the associated
number of productive days that would be lost with each severity level of infection. The Traditional COI
results incorporated in the LT2's economic analysis reflect results originally developed in Corso et al.
(2003), updated from their 1993 base year values. The Corso et al. values were developed for different
severity categories of nonfatal Cryptosporidium infections observed in the Milwaukee, Wisconsin,
outbreak of 1993, based on a review of medical records and application of assumptions about some
required types of care (e.g., number of physician visits). Because the criteria used by Corso et al. to assign
nonfatal outcomes to severity levels were incorporated directly in estimating the distribution of nonfatal
cases in the LT2's economic analysis, there are no issues with respect to the valuation estimates reflecting
a different set of conditions than were used to assign outcomes by severity category. Further, because the
costs are developed for infections for one of the key microbial pathogens being targeted by the LT2, they
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are based on outcomes relevant for consideration in the rule.
The estimates developed by Corso et al. (2003) are noteworthy for the care that has been taken to
accurately estimate actual expenditures and the value of productivity losses. For example, the information
on hospital and emergency room charges that was initially available was adjusted using a regional cost-to-
charge adjustment ratio to reflect the fact that hospital charges are rarely what are paid by the patient
because of negotiated discounts with the hospital (e.g., for patients with private or public insurance). In
this regard, EPA's Traditional COI valuation estimates can be reliably interpreted as a lower bound
estimate on the value of avoided nonfatal infections.
6.2 EPA'S ENHANCED COI ESTIMATES
The Enhanced COI estimates developed by EPA build on the Traditional COI estimates by expanding on
the valuation of the estimates of the productive and leisure time affected by a nonfatal microbial infection
(there is no adjustment to the estimated medical expenditures). These differences can be easily
summarized in table form and are presented in Exhibit 6.1 (U.S. EPA, 2003a; see Appendix K, Exhibit
K.2, p. K-9).
[See p. 405 of PDF for Exhibit 6.1]
As Exhibit 6.1 shows, the fundamental difference with the Enhanced COI method relative to the
Traditional COI method is that it both doubles the value of time for lost household production and assigns
a value to impacts on leisure time that previously were not monetized. The leisure time values are
especially of concern, since they are at odds with standard practice in the economics profession with
regard to recreational activity valuation. In recreation demand modeling, it is typical to use only a fraction
(e.g., one-third) of the prevailing wage rate to infer the value of time spent traveling to a recreation
site (and time spent on-site engaged in the recreational activity generally is not counted as a cost in the
demand estimation via the travel cost approach). In contrast, EPA's Enhanced COI approach applies full
wage rates to all waking hours. Appendix B provides additional discussion of the problems associated
with values EPA assigns to time away from work in the Enhanced COI approach.
The effect of the Enhanced COI method is to increase the average (i.e., severity weighted) value per
nonfatal infection to $745 (2000 dollars) compared to $245 for the Traditional COI. In short, the
Enhanced COI roughly triples the average value per nonfatal infection from a microbial pathogen.
In placing the Enhanced COI method and results in context, EPA notes that studies that compared WTP
estimates for an adverse health outcome with COI estimates developed using essentially the Traditional
COI method have produced values ranging from 2 to 79, and that many of the ratios fall in a range of 3 to
6 (U.S. EPA, 2003a, p. 5-42). Implicitly, this provides a justification for the apparently more complete
valuation of time incorporated in the Enhanced COI and seems to suggest the results are some sort of
reliable proxy for WTP estimates.
It is because of the implicit comparisons that are made with the Enhanced COI results that great care
should be taken in their presentation and consideration. The Enhanced COI estimates should never be
taken as a proxy for WTP estimates for these outcomes. The only result that can be expressed with
confidence about the Enhanced COI results is that they exceed the Traditional COI estimates. Any
direct or implied comparisons with what WTP estimates would provide would be misleading because
there is no basis to say whether the Enhanced COI estimates are higher or lower than WTP.
Finally, it is worth noting how some of these issues are addressed in other regulatory analyses prepared by
EPA. For example, in its valuation of hospitalizations attributable to concentrations of airborne particulate
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matter, EPA currently uses a COI approach that considers only hospital charges (not adjusted for the ratio
of costs to charges) and time spent in the hospital valued at the median pretax daily wage (Apelberg et al.,
2003, p. 4-35). Using unadjusted charges probably overstates the medical costs of hospitalization, but
follow-up medical costs are not included so the amount of overstatement is uncertain. This treatment of
the value of time gives full wage value to essentially eight hours a day regardless of the person's
employment status or the day of the week. On average, about half of these hours are accounted for by
paid employment, leaving about four hours per day valued at the wage rate to cover the value of lost
household production and leisure. This is substantially less than counting all waking hours at the wage
rate as is done in the Enhanced COI approach.
6.3 PLACING THE ENHANCED COI ESTIMATES INTO CONTEXT
One of the key concerns with the EPA's Enhanced COI estimates is that it is difficult to gain perspective
on whether the resulting numerical levels "make sense" in terms of what might be considered credible as
an indicator of the more suitable WTP measure. This section attempts to develop some perspective on this
issue.
First, it is important to recognize that the suitable measure for valuing a reduced risk of a
cryptosporidiosis illness is ex ante WTP (i.e., what a person would be willing to pay, ahead of time, for an
opportunity to reduce a low level risk by some degree when provided with an accurate description of the
risks and consequences of the illness). When WTP estimates are not available, a Traditional COI is often
used as a convenient but less suitable conceptual and empirical substitute and as a recognized lower
bound proxy for value.
EPA's Traditional COI estimate excludes some important value components (e.g., pain and suffering), but
COI estimates also are an ex poste measure of what costs a realized illness imposes on an afflicted person.
The former feature allows analysts to consider that a Traditional COI will provide a lower bound estimate
of ex ante WTP (i.e., it is the cost of being ill, not the value of reducing the likelihood of illness). But with
EPA's aggressive accounting in its Enhanced COI estimate, one loses the ability to assess how the
Enhanced COI figure compares to the unknown but more suitable ex ante WTP value. With the
Enhanced COI, we no longer can say with confidence that incurred costs are less than or equal to the
value of reducing the probability of potential future illness - the enhanced approach removes our ability to
interpret the COI numbers relative to useful boundaries.
To help evaluate whether the Enhanced COI provides a numeric result that seems plausible and
reasonable - vis-a-vis ex ante WTP - a simple illustration is developed below using VSL estimates to
provide some context. VSL estimates reveal the ex ante WTP of individuals to reduce risks of premature
fatality. A VSL of roughly $6.3 million saved is often used as a measure of the value of reducing risks of
premature fatality, based on a large body of well-reviewed literature in which individuals (e.g., median
aged workers) in effect reveal a WTP to reduce a mortality risk typically in the range of 1 in 10,000 per
year. What this literature actually tells us is that a typical, median aged person has an ex ante WTP of
$630 per year, on average, to reduce a 1 in 10,000 per year risk of premature fatality in the coming year.
This widely accepted $630 per person of ex ante WTP to avoid a 1 in 10,000 annual risk of immediate
fatality thus serves as our frame of reference.(1)
(1) In deriving the VSL estimates from premature fatality risks in occupations, the wage risk studies are
based on annual risk of fatalities that typically range from 1*10-4 to 2* 10-4. Data from the U.S. Bureau
of Labor Statistics and the National Institute of Occupational Safety and Health, as summarized and
reported in Viscusi and Aldy (2003), indicate the average annual rates of fatality are about 3.6* 105 in
manufacturing, 1.5 * 10-4 in transportation and utilities, and 2.5* 10-4 in the relatively risky mining sector.
Viscusi and Aldy found a mean annual risk of occupational fatality of 2* 10-4 from the numerous
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risk-wage studies they include in their meta-analysis of VSL.
Viscusi and Aldy (2003) also review more than 60 risk-wage studies, and report the findings of a meta-
analysis conducted with 49 suitable studies. Their meta-analysis derives a mean VSL of $6.7 million
(2000 U.S. dollars) and a mean occupational risk level across the underlying studies of 2* 10-4. The VSL
estimate is based on wage premiums relative to less risky jobs, and assuming the implied risk reductions
are about 1 in 10,000 (i.e., that the comparison is on average to jobs with half the fatal risk as the chosen
occupation), this suggests an annual WTP premium of $670 per impacted risk-bearing worker.
Several factors could drive these estimates per person annual risk premiums up or down. For example,
because over half (25 of 49) of the underlying studies also embedded risk premiums for nonfatal (as well
as fatal) injury, the resulting WTP estimates are overstated for the risk of premature fatality alone.
In addition, if the risk differential between the risky and less risky occupations in the study differed by
more (less) than 0.0001 per year, then the implied annual per person value would increase (decrease).
According to EPA's analysis of the endemic risk of water-borne cryptosporidiosis, the baseline annual
risk is also on the order of 1 in 10,000 (U.S. EPA, 2003a, Chapter 5).(2) Compared to the VSL context,
however, the outcome is far less severe - i.e., the risk of getting an illness that, for 99% of the afflicted,
would entail a mild and short-lived period of discomfort and diarrhea (rather than immediate death as
would apply in the VSL estimates).(3)
(2) The median annual risk of cryptosporidiosis illness as estimated by EPA is about 1* 10-4 at baseline
(pre-LT2). This is based on EPA's Exhibits 5.12 and 5.13, wherein a 1*10-4 or higher baseline annual risk
of illness is anticipated for 46% of the persons served by filtered systems, and "essentially the entire
population served by unfiltered systems" (U.S. EPA, 2003a, p. 5-36). The exhibits suggest that over one-
third of filtered system customers, and well over 95% of unfiltered systems customers, face annual risks
of twice that level (i.e., 2* 10-4 or higher).
(3) EPA assigns 88% of cases to the "mild" category, in which (based on EPA's use of data from the
Milwaukee outbreak) the illness lasts 4.7 days on average and entails a mean loss of 1.3 work days, and
11% of the cases to the "moderate" category, in which EPA believes illness lasts a mean of 9.4 days (3.8
mean days lost from work). The remaining 1% of cases are labeled severe, and entail 34 days of mean
illness ( a mean loss of 5.4 days of work).
To facilitate comparison to the VSL, assume for this illustration that the risk posed by cryptosporidiosis
was permanent and that symptoms were suffered through a recurring cycle of typically mild or moderate
cases (with perhaps a rare severe episode as well, but no risk of fatality). Thus, a median aged worker
struck by the disease under this assumption would face predominantly mild illness (and the associated
COI) for the balance of their lives. What numeric result would the EPA Enhanced COI assign to such a
case?
???First, the value of time lost for the individual, based on EPA's approach, would be $217.86 per day
while they were employed ($18.47 per hour for 16 waking hours). Assuming the median aged person was
38 years old at onset and retirement is age 65, then the value of time lost through their remaining work
period would be $2.15 million (27 years times 365 days per year times $217.86 per day).
???Second, add the value of time lost due to illness through the retirement period (age 65 through a
typical conditional life expectancy to age 83). Using EPA's estimate of $10.92 per hour for 16 waking
hours per day for non-employed individuals, a value of time lost per person of $1.15 million is derived
(18 years times 365 days times $174.72 per day).
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???Third, the EPA Enhanced COI would add additional costs due to care-giving efforts and medical
expenses for each typical nonfatal case. For a typical nonfatal case, if extended throughout a lifetime from
age 38 onwards to age 83, these costs would amount to $1.25 million.
Combining these three Enhanced COI elements, the total cost associated with a permanent case of
cryptosporidiosis, incurred beginning at age 38, would thus be $4.55 million.
If one were to contend that EPA's Enhanced COI approach provided useful and reasonable
approximations of ex ante WTP to avoid a lifelong case of cryptosporidiosis such as depicted in this
example, then this implies an average ex ante WTP of $455 per person exposed to the 1 in 10,000 annual
risk of this hypothetical life-long version of the disease outcome.
While this illustration uses a somewhat contrived version of cryptosporidiosis (lifelong continuous
recurrence of a typical, severity-weighted nonfatal case), it does provide useful context for considering
the valuation issue. A lifelong cycle of diarrhea and other mild symptoms would no doubt be unpleasant,
and no doubt a typical person would be willing to pay a considerable amount to reduce the risk of such an
outcome. However, would they have a WTP that is over 72% of their WTP for a comparable level of risk
of immediate fatality (i.e., $455/$630 = 72.2%)? This does not seem to be plausible or likely.(4)
(4) The above Enhanced COI illustration does not account for either real income growth overtime (EPA
applies a real rate of 2.3% in the EA), nor does it account for discounting future values to reflect the real
rate of time preference (EPA uses a 3% real rate of discount to reflect time preference). When the above
Enhanced COI estimate for a hypothetical lifelong case of typical severity cryptosporidiosis is adjusted to
reflect real income growth and discounting over the applicable timeframe (at 2.3% and 3.0%,
respectively), the resulting present value is nearly $3.1 million per case. This is somewhat less
than the undiscounted, zero income growth estimate provided in the main text above, but still
disproportionately high relative to a VSL of $6 million. The same implication arises as above - is it
plausible and realistic to assert that the WTP to avoid a case of lifetime cryptosporidiosis (valued at over
$3 million using EPA's Enhanced COI approach) would be half as great as the well studied WTP to avoid
a like-sized risk of premature fatality? The answer, we believe, is clearly "no." The Enhanced COI
estimates are not likely to be plausible or realistic as proxies for WTP.
Therefore, this numeric illustration reveals that EPA's Enhanced COI approach does not appear to yield
plausible estimates of the value of reducing the risk of cryptosporidiosis. The EPA approach, if applied to
a hypothetical lifelong case, would result in an estimate of value that is implausibly high relative to
better understood risk avoidance values (i.e., VSL).
6.4 Conclusions
EPA's use of COI-based estimates to stand in for the ex ante risk reduction WTP for cryptosporidiosis is
understandable, given the lack of reliable data from which to infer the preferred, conceptually appropriate
measure of value (i.e., ex ante WTP). The Agency's Traditional COI is a reasonable estimate for EPA to
use in this regard, and these cost estimates may reflect a lower bound as a proxy for value. However, the
development and application by EPA of the so-called Enhanced COI approach seems to be lacking in
credibility and plausibility. This approach does not adhere to standard practice in the economics
profession (e.g., with regard to valuing time spent out of the workplace), and it generates results that do
not appear to be reasonable relative to other benchmarks (e.g., VSL) under simple illustrations that can be
constructed. Therefore, the Enhanced COI should not be used to evaluate this rulemaking, and should
instead be subjected to far greater peer review and revision before EPA applies it to any future matter of
public health policy-making.
Comment Response for LT2ESWTR D-180 December 2005
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7. COMPLIANCE COSTS AND NET BENEFITS
This chapter provides a cursory review of EPA's approach and results for estimating the costs of
compliance with the proposed LT2 rule. The chapter then reviews how EPA compares estimated benefits
to costs, with a particular focus on the extent to which an appropriate disaggregated incremental net
benefits perspective is followed by the Agency.
7.1 COMPLIANCE COSTS
National level compliance cost estimates
EPA estimates that the annualized cost of compliance for the preferred regulatory option will be from $73
million to $111 million (using a 3% interest rate to annualize capital costs), with the range dependent on
whether the ICRSSL or ICR data were used (U.S. EPA, 2003a, Exhibit ES.6). The costs developed based
on the ICR data are higher than the costs based on either ICRSS dataset because of higher allocations of
systems to higher bins.
EPA is fairly certain that compliance costs will approximate these estimates, as reflected in its 90%
confidence ranges that are only plus and minus 11% of the values reported above. For example, $65
million and $82 million are the reported 5th and 95th percentile cost estimates, respectively, around the
central estimate of $73 million derived using the ICRSSL database to estimate occurrence.
We have not conducted an in-depth review of the cost models and assumptions used to develop these
estimates, but we find it difficult to believe that EPA is 90% confident that it has accurately forecast the
LT2 compliance costs within ?11% for any given ICR-related database occurrence profile. There are
many complex and uncertain factors underlying the cost analysis, including:
???the extent to which utilities will mix and match elements of the toolbox, and the inherent difficulty of
predicting compliance choices to be made by utilities
???unit treatment costs for both capital outlays and operations and maintenance (O&M), for each of the
viable compliance options, for each utility size and source water
???site-specific retrofit challenges and associated costs
???the allocation of costs of some utility compliance efforts between the IESWTR and LT2
???the potential for price spikes for UV light disinfection units caused by regulation-driven increases in
demand (i.e., the cost ramifications of a possible sellers' market).
Given these and other issues, EPA's stated confidence intervals seem unrealistic. If EPA is going to
generate confidence intervals (which it should), then it needs to consider and reveal clearly what levels of
realism and precision apply at each stage of the cost analysis, and track how variabilities and uncertainties
can compound across stages of the assessment. The cost estimates provided by EPA, despite their
presentation of confidence bounds, do not realistically portray the expected level of uncertainty for
potential compliance costs.
Finally, within the costing analysis, there seems to be an error in the ozone contactor times EPA reports
for 2 log removal. EPA should review and correct this apparent error.
Per household cost estimates and affordability
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EPA estimates that the cost per household of LT2 compliance will in general be fairly modest, at $ 1.07
and $4.61 per household per year, at the mean (Exhibit ES.7). The lower estimate reflects mean costs
averaged for all systems (and ICRSSL database outcomes), and the upper estimate pertains to ICR-based
costs in systems serving less than 10,000 (U.S. EPA, 2003a). The mean household level cost increase
would be between $7.30 and $10.45 per year in "small systems" (less than 10,000 served) needing to add
treatment, and fewer than 0.3% of households in this category would be expected to face an increased
annual water bill of over $120 (U.S. EPA, 2003a, Exhibit J.4).
A critically important consideration related to interpreting the above EPA results is that the EA designates
any CWS of 10,000 or less served as a "small system." The reported per household costs thus reflect a
very large range in system sizes (e.g., from 25 served to 10,000 served). This reflects a range that varies
by a factor of 400 (10,000/25) in population served within this "small system" size category. Economies
of scale can be appreciable over this size range, and the aggregated results depicted by EPA are likely to
mask much higher per household cost burdens through the smaller end of the CWS size spectrum.
The EA for LT2 does not appear to provide any information whatsoever about how costs per household
vary across the various small system size categories. This lack of transparency and detail should be
rectified for the EA that accompanies the final rule. One data point available from the EA for the
proposed Stage 2 rule for disinfection byproducts reveals how important this small system disaggregation
can be for considering household-level cost impacts. In the Stage 2 affordability analysis, the mean
annual per household increase in costs for that proposed rule is nearly 6 times greater in systems serving
500 or fewer people than the mean for households served by systems in the 3,300 to 10,000 served end of
the range (and 5% of the households in the under 500 served category will face annual costs projected by
EPA to be over 12 times higher). In addition, for customers in systems of under 100 served, the mean per
household costs probably will be considerably higher than predicted by EPA for systems of up to 500
served. EPA does not reveal the costs on a CWS under 100 served basis, but even the limited
disaggregation found in the Stage 2 EA reveals how much important information is masked under the
inappropriate aggregation of all CWS of 10,000 served or less within the "small system" category.
The key point here is that EPA should provide more finely disaggregated cost results. This is important
because there are key equity and affordability implications that are masked (hopefully unintentionally) by
EPA under the approach the Agency uses in the LT2 EA to portray its cost and affordability findings.
Since the estimated compliance costs are developed using the typical nine system size category scheme
EPA has employed in the past, the results are all generated by (and available to) the Agency at that level
of disaggregation. Merging the five smaller size categories into one over-broad "small system" category
of 10,000 served or less is an extra step made by the Agency, and one that obscures rather than informs
public review and Agency decision-making.
7.2 Comparison of Benefits to Costs
It is vital that EPA provide suitable and informative comparisons of benefits to costs. The suitable
framework is to reveal incremental benefits, incremental costs, and incremental net benefits (i.e.,
incremental benefits minus incremental costs) for each relevant regulatory alternative. The increments
should start with the suitable regulatory baseline, and move to increasingly stringent (costly) alternatives.
Ideally, the preferred regulatory option would be identified where the last incremental net benefits is still
positive (i.e., just before incremental net benefits turn negative). To EPA's credit, there is some
incremental net benefits information in the LT2 EA. This type of outcome should continue to be a routine
and highlighted portion of all EPA EAs in the future (unfortunately, it is lacking in the Stage 2 EA).
Further, it is important that the incremental net benefits be provided not only at the national aggregate
Comment Response for LT2ESWTR D-182 December 2005
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level, but also according to informative system size categories (U.S. EPA, 2001). That is, incremental net
benefits should be reported for each of the nine CWS size categories EPA uses to build up its cost and
benefit estimates. Additional disaggregation is also worth portraying where important distinctions are
reflected in costs, benefits, or both. As noted below, other relevant levels of disaggregation include
separating results for unfiltered systems from those derived for filtered systems.
Regrettably, EPA fails to provide any meaningful disaggregated benefit-cost comparisons along the lines
described above. All benefit and incremental net benefit estimates are shown only at a national aggregate
level, with no disaggregation by system size. Cost estimates are at times disaggregated, but only across
very broad (and therefore meaningless) categories based on whether they serve 10,000 or fewer people or
over 10,000 people. Overall, the EA is severely disappointing in this regard, and completely at odds with
both best practices and recommendations issued in association with past critiques (including the
independent reviews of the arsenic EA by the SAB and a NDWAC working group).
Finally, along with disaggregating benefit and cost (and incremental net benefit) information by system
size (which EPA fails to do), the Agency should also disaggregate the findings according to at least two
other dimensions that are highly relevant to the proposed LT2 rule:
???EPA should reveal the costs, benefits, and incremental net benefits of the rulemaking options for
filtered systems alone and for unfiltered systems alone. In the current EA, some key portions of the risk
analysis are clearly specific to either filtered or unfiltered systems. EPA should continue with its separate
analyses (rather than revealing only final benefit and cost outcomes for all systems lumped together) so
that the public, stakeholders, and decision-makers can see how much more bang per buck may be derived
(if any) from focusing rulemaking efforts on unfiltered versus filtered systems.
???EPA should also isolate the costs and benefits for the provision of the rule related to covering finished
water reservoirs. It is useful to enlighten the public and government decision-makers alike as to the
benefits, costs, and incremental net benefits of such distinct elements of the proposed rule.
7.3 CONCLUSIONS
We have not conducted a detailed review of EPA's cost estimates for the proposed LT2 rule. Nonetheless,
it seems unlikely that the information provided regarding confidence intervals is realistic. Many key
uncertainties and variabilities appear to have been either ignored or understated to a considerable degree
in order to generate a very narrow 90% confidence interval (only +/- 11% around the mean).
A critical disappointment with the Agency's cost and affordability analyses, and with the benefit-cost
comparisons portrayed in the EA, is the lack of meaningful disaggregation according to system size. The
lumping by EPA of size categories serves only to mask and obscure important information regarding the
equity and efficiency implications of the proposed rule. This is a serious flaw and a considerable
disservice to the public, stakeholders, and decision-makers.
Finally, the Agency's approach to comparing benefits to costs could be far more meaningful and
informative if it also disaggregated the benefit-cost results in two important additional dimensions: (1)
filtered and unfiltered system benefits and costs, and (2) the costs and benefits of the finished water
reservoir cover requirement as embodied in the preferred option. The Agency needs to do much better
with regard to system size and other levels of disaggregation, and it would take only a modest effort on
the Agency's part to do so (if it musters the will).
REFERENCES
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Hoxie, N.J., J.P. Davis, J.M. Vergeront, R.D. Nashold, and K.A. Blair. 1997. Cryptosporidiosis-
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LeChevallier, M.W., G.D. Di Giovanni, J.L. Clancy, Z. Bukhari, S. Bukhari, J.S. Rosen, J. Sobrinho, and
M.M. Frey. 2003. Comparison of method 1623 and cell culture-PCR for detection of Cryptosporidium
spp. in source waters. Appl. Environ. Microbiol. 69(2):971-979.
Mead, P.S., L. Slutsker, V. Dietz, L.F. McCaig, J.S. Bresee, C. Shapiro, P.M. Griffin, and R.V. Tauxe.
1999. Food-related illness and death in the United States. Center for Disease Control and Prevention
5(5):607-625.
Messner, M.J., C.L. Chappell, and P.C. Okhuysen. 2001. Risk Assessment for Cryptosporidium: A
Hierarchical Bayesian Analysis of Human Dose Response Data. Wat. Res. 35(16):3934-3940.
National Research Council. 1999. Risk Assessment of Radon in Drinking Water. Washington, D.C.:
National Academies Press. The number was based on the following study: Ershow, A.G. and P.P. Cantor.
1989. Total Water and Tapwater Intake in the U.S.: Population-based estimates. Bethesda, MD:
Federation of American Societies for Experimental Biology, Life Sciences Research Office.
Project Inform. 2003. Preventing Cryptosporidiosis: a Guide for People with Compromised Immune
Systems. Internet: http://www.thebody.com/pinf/cryptosporidiosis.html. Accessed September 5, 2003.
Comment Response for LT2ESWTR D-184 December 2005
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Raucher, R.S., M.L. Hagenstad, J. Cotruvo, R. Narasimhan, K. Martin, H. Arora, R. Regunathan, J.A.
Drago, and F. Pontius. Forthcoming. Conventional and Unconventional Approaches to Water Service
Provision. Awwarf Project #2761. Awwa Research Foundation, Awwa Research Foundation, and
American Water Works Association.
Roseberry, A.M., and D.E. Burmaster. 1992. Lognormal Distributions for Water Intake by Children and
Adults. Risk Analysis, 12(1):99-104.
.S. Census Bureau. 2003. Census Fact Finder. Internet:
http://factfmder.census.gov/servlet/GCTTable?ds_name = DEC_2000_SFl_U&geo_id =
01000US&_box_head_nbr = GCT-PHl-R&format = US-9S. Downloaded September 18.
U.S. EPA. 1998. Regulatory Impact Analysis for Interim Enhanced Surface Water Treatment Rule. U.S.
Environmental Protection Agency, Washington, DC.
U.S. EPA. 1999. Estimated per Capita Water Consumption in the United States.
U.S. Environmental Protection Agency, Office of Science and Technology, Office of Water, Washington,
DC. February.
U.S. EPA. 2000. Estimated Per Capita Water Ingestion in the United States. U.S. EPA Office of Water.
April.
U.S. EPA. 2001. Arsenic Rule Benefit Analysis: An SAB Review. U.S. EPA Science Advisory. August.
U.S. EPA. 2003a. Economic Analysis for the Long Term 2 Enhanced Surface Water Treatment Rule.
Prepared for U.S. EPA by Cadmus Group. June.
U.S. EPA. 2003b. Federal Register. 40 CFR Parts 141 and 142, National Primary Drinking Water
Regulations: Long Term 2 Enhanced Surface Water Treatment Rules; Proposed Rule. 68(154).
U.S. EPA. 2003c. Analysis and Findings of the Gallup Organization's Drinking Water Customer
Satisfaction Survey. U.S. Environmental Protection Agency, Office of Groundwater and Drinking Water.
August 6.
Viscusi, W.K. and J.E. Aldy. 2003. The Value of a Statistical Life: A Critical Review of Market
Estimates Throughout the World. Journal of Risk and Uncertainty, 27:1; 5-76.
WQA (Water Quality Association). 1999. 1999 National Consumer Water Quality Survey. Lisle, 111.:
WQA.
A. Issues with EPA's Modeling of Cryptosporidium Occurrence(l)
(1) This appendix was prepared by, and reflects expert insights provided by, Jeff Rosen, Perot Systems,
December 2003.
A.I Summary of Cryptosporidium Modeling
The analyses performed with the objective of estimating the national distribution of Cryptosporidium
demonstrate that if you are certain of the answer before you begin the analysis you can certainly fine-tune
your model so that your preconceived notions are realized. This effort has some serious flaws that are best
described as indefensible assumptions. The underlying belief in all of these assumptions is that
Comment Response for LT2ESWTR D-185 December 2005
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Cryptosporidium is ubiquitous in the environment and that when samples are taken there are nearly no
zero counts that are true. Since the majority of the values measured in the ICR for Cryptosporidium were
zeros (not nondetects), this belief suggests that the method is terrible, but that this fact should not trouble
anyone since we already know that Cryptosporidium is ubiquitous. We patently disagree with this
conclusion and underlying assumption. Throughout the ICR data collection and analysis it has been
reiterated that a zero count of a discrete item (an oocyst) is a zero and should not be dealt with in any
other way. The fact that a modeling exercise can demonstrate that a zero count could be achieved 70% of
the time when there is a concentration less than or equal to 1 oocyst per 10 L does not change the fact that
the values counted were zeros and there is no additional information to suggest that any of these zeros
were something else.
EPA's overly confident conclusion (based on no data) leads the modelers to a series of other assumptions
that we do not trust. EPA has failed to furnish information to reveal the potential sensitivity of the model
to these assumptions. The specific assumptions that are of significant concern are the true zero values that
have been assumed to be 0.1%. That means that only one in 1,000 draws of the data can be considered
true zero values. Experts contacted by us believe this value may be as much as two to three orders of
magnitude too low. In other words, as many as one in four samples for which a zero was counted
may be a true zero. The authors have confused the question of a true zero in a sample with a true zero in a
body of water. This model should not be focusing on the concentration in the source water as a whole
since the source waters were not properly sampled to characterize the concentration of Cryptosporidium
in the water body. The best that can be hoped for with the sampling performed is that a gross estimate of
the distribution of Cryptosporidium at the intake can be estimated.
The second value that is of significant concern is the estimate of false positive counts. The modelers used
a value of 1%. This value could be much higher especially for the samples in which there are very high
counts.
By using the Cryptosporidium total counts, EPA has also assumed that anything that looks like an oocyst
should be counted. The only oocysts that should have been included in these analyses are those that could
be identified with high certainty. This would limit the counts to those oocysts that included recognizable
internal structures. Overall, we suggest that a detailed presentation of the sensitivity of the analysis to
these three assumptions be presented and considered in the benefit-cost evaluation.
Limits of the ICR data. The collection of the ICR data was done in spite of the assertion at the beginning
of the process that the data would not be adequate to develop a national distribution that could be trusted.
The issues raised related to a few key issues that, in general, all participants agreed were significant
problems. This included (but were not limited to) the poor and highly variable recovery, high possibility
of false positives (due to algal cells), inclusion of perceived but empty oocysts in counts, no idea of
viability or infectivity, inadequate sample volumes, inadequate number of samples, etc. In spite of all
these frailties with the methods and the expected results, EPA proceeded with the collection of the data.
When the data came back and were clearly inadequate for the intended purpose, rather than admitting that
the data were poor and could not be used to reliably to define a national distribution of occurrence of
Cryptosporidium in source waters, EPA chose to use a very complex modeling approach with a number
of unvalidated assumptions to define a national distribution in spite of all the frailties. Assumptions used
in the analysis presented in Appendix B of the EA, but which are not defended, include:
The assumed false positive rate (page B-9). It is the opinion of experts that the false positive rate is
analyst dependent and in fact could be analyst dependent along with further unquantifiable factors like the
hour of the day, the amount of sleep, the expertise of the analyst, etc. It is very possible that some of the
very high concentrations that were detected were mostly false positives. After all, if an analyst decided
that one algal cell was an empty oocyst, then perhaps the same analyst decided that 85 of the algal cells
Comment Response for LT2ESWTR D-186 December 2005
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were oocysts. The high end of the distributions is based on a very small percentage of the samples
collected. If these numbers are wrong then the higher bins are not properly defined.
A zero count is once again being called a nondetect (for example, see page 3-19). AWWA has raised this
issue repeatedly with EPA, and it is very disconcerting to once again see the zero counts being referred to
repeatedly as "nondetects." As stated in the EA at Section 4.1.2.1, "The model is not limited by the
observed detection limits and predicts a positive concentration for nearly all the observed non detects."
This indicates that the modeling effort continues to insist that a zero is not a zero even though experts
assert that some significant percentage (as high as 50%) of the zeros probably indicate that there are no
oocysts in the sample. This says nothing about whether or not there are any oocysts in the body of
water. If the intent of this effort is to characterize the concentration of oocysts in the water bodies, then
the monitoring should be designed to properly assess the concentration in the water body. Such a study
could be (but was not) designed. Disappointment in the quality of the data collected was predicted and
anticipated before the sampling was required by the ICR.
This issue continues to plague the analysis on page B-12 of the EA. Here the assertion that almost none of
the observed values are really zeros is established in the nomenclature of the model. The approach taken
is counter to the advice presented by experts and counter to the discussions that we had during the
technical working groups. Specifically, the definition of the true zero probability, which is called Zi,
should be the probability that an observed zero (not a nondetect) is in fact really a zero. This should be
defined as a zero in the sample taken, not the absence of pathogens from the source body of water. The
sampling unit here is a sample taken near the intake, not the water body. There is no way to estimate the
probability that there is not a single oocyst in a body of water (read Lake Superior) from which the
sample was taken. In fact, the crypto sample taken does not target quantifying the oocyst concentration in
the water body. No scientist in their right mind would suggest that a single 10-100 L sample taken on one
day at a single location in a large body of water could be used to characterize the concentration of
Cryptosporidium in the entire water body. Instead they would suggest multiple samples at multiple
locations at multiple time periods.
So if we assume that the sampling was meant to characterize the water near the intake, then the model
should not be taking the leap from the one sample to the concentration of the entire water body. Returning
to the true zero value then, we should estimate the number of samples taken for which a zero count was
observed and ask the experts what is the probability that the sample taken and counted as zero was truly a
zero value. The answer obtained from one expert was between 25 and 50%. This is a probability that
should be denoted by Zij, not Zi, to reflect the probability from sample j taken at location i.
It can be argued that this original intent is demonstrated on EA page B-12, where the authors mention that
the true zero range explored during model development, evaluation, and validation was between 0 and
50% (page B-12, 4th paragraph). After exploring ranges from 0 to 50%, EPA chose to set their value
for Zi to 0.001% which is four orders of magnitude lower than one expert thinks it should be. With Zi set
to 0.001%, one out of every 100,000 values of Zi generated would be a 1, there by making the
concentration Zij equal to 0. There is no justification for this value nor the philosophy under which the
model is defensible.
Zi is presented as a probability, which it is not. In fact, it is either a 0 or a 1. Since the multiplier in the
model is (1 - Zi), we assume that once out of every 100,000 draws of Zi a 1 will be drawn and the
concentration will be defined as a zero. A number of experts were asked if this is reasonable, and
they have indicated that it is not. EPA thus needs to explain the following:
1. What exactly is Zi and how was it decided to apply the true value to the entire water body instead of to
Comment Response for LT2ESWTR D-187 December 2005
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the single concentration?
2. Why is a true zero being applied for each water body instead of estimating it for each sample?
3. What is the effect of using a true zero value on each concentration instead of for the water body?
Likewise, EPA needs to show the sensitivity analyses related to values of true zero from 0.001% to 50%.
Does it matter? How will it change the results? What effect will it have on the benefit-cost analyses?
This same issue continues to emerge as a pivotal matter in yet another location in the document. In
Section B. 1.3 (page B-5 - the basis for modeling), the authors again try to defend that a counted zero is
something other than a zero. The discussion is missing one critical phrase in the second paragraph. It says
"... and if the "true" underlying average concentration in the source water is 0.1 oocyst per liter, it is
expected from the Poisson distribution that no Cryptosporidium oocysts would be observed in
approximately 74 percent of the samples." Since the chart shown in Exhibit B. 1 is a cumulative frequency
distribution, this statement is missing five critical words "less than or equal to" It should read "... and if
the "true" underlying average concentration in the source water is less than or equal to 0.1 oocyst per liter,
it is expected from the poisson distribution that no Cryptosporidium oocysts would be observed in
approximately 74 percent of the samples." The true value could be 1 oocyst per liter or it could be 1
oocyst in 10 liters or 1 oocyst in 100 liters. The fact of the matter is that the sampling that was done
counted 0 not 1. The method and sampling plan is targeted at counting discrete oocysts. While EPA's
arguments are elegant, they are irrelevant. At the end of the argument, we still do not know if the value is
a 1 or a zero. We counted zero. We discussed the counting of zero with many statistical experts who all
affirmed that the answer was that when a zero is counted with discrete items, it is a zero and not some
number less than a concentration that you don't feel you can detect because of the limitations in the
method. It is irrelevant if a model can demonstrate that with sufficient assumptions it is possible to say
that the answer could have been as high as 1 oocyst per liter. It was not. If this was a level that was
needed to answer the question asked, then the monitoring should have been designed to have a larger
volume or a larger sample size. The expected count can be manipulated based on models and
assumptions, but in the end, the count (not the expected count) is the value that matters.
B. ISSUES AND PRACTICES FOR VALUING TIME
EPA's "Enhanced COI" is an attempt to account for the value of time "lost" by individuals when they are
sick. More precisely, it is an attempt to reflect the utility (individual welfare) lost when an individual -
due to illness - cannot use their time as productively or in the manner they would otherwise prefer. In
other words, the intent is to reflect the loss of well-being associated with having some daily activities
impaired or restricted because of illness.
There are several problems and inconsistencies relative to standard and best practices in economics with
how EPA develops and applies its Enhanced COI approach:
* The approach can be simplified, because there is no need to make a distinction in the discussion
between "leisure time" and "unpaid work time" (household production). When away from work, an
individual will choose the activity that has the highest value (yields the mostutility), regardless of what it
is. Overall, EPA is searching for a proxy for the value of time away from work.
* In recreation demand modeling, this same issue of valuing time away from work arises. For example, in
using travel cost-based models developed to value recreation, the "cost" of time spent en route to a
recreation site (and perhaps the cost of time at the site while recreating) might be considered as part of
the incurred cost of the experience, and thus could be used in estimating a demand curve and associated
Comment Response for LT2ESWTR D-188 December 2005
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recreational "values." In recreation studies (for which a vast peer reviewed literature exists), time in
transit is predominantly valued at some fraction of the wage rate, such as one-third (and on-site time is
rarely included in the valuation).
* Why is a fraction of the wage rate appropriate (rather than 100% of the pre- or post-tax wage rate)?
From recreation studies, the following logic has been well articulated:
???Many workers are salaried, and they do not have an opportunity to make more money at their current
jobs by working longer hours.
???If a worker were to take on a second job, it is likely that the second job would pay less, per hour, than
the primary job. This is true for part-time work in many cases, which offers limited benefits and often
lower hourly wages than a full-time job.
???The primary job is more likely to have higher wages than a second job simply because a worker is
more likely to take a job with higher wages than lower wages, all else constant. The worker will typically
take the most lucrative position available given the level of training and education.
???There have been arguments that the value of time should be greater than 100%, if the worker is putting
in overtime hours and earning wages higher than the base wage (e.g., time-and-a-half holiday work).
However, this type of work is often sporadic and unpredictable for the worker and is limited in
availability, and the quantity is not controlled by the worker. Therefore, economists use the previous
arguments and use an estimate less than 100% of the wage rate.
???Finally, it is unreasonable to assume that the individual could be doing professional work during all
waking hours.
* The recreation demand literature is one good source of support for the use of one-third the wage rate as
the opportunity cost of time away from work. Some relevant literature includes:
???Carson, R. W.M. Hanemann, M. Costanzo, and T. Wegge. 1991. 1991 Southeast Alaska Sport Fishing
Economic Study. Prepared for the Sport Fish Division, Alaska Department of Fish and Game. Sacramento
CA: Jones and Stokes Associates, Inc.
???Morey, E.R., W.S. Breffle, and P.A. Greene. 2001. Two nested constant-elasticity-of-substitution
models of recreational participation and site choice: an "alternatives" model and an "expenditures" model.
American Journal of Agricultural Economics 83(2):414-427.
???Needelman, M.S. and M.J. Kealy. 1995. Recreational swimming benefits of New Hampshire lake
water quality policies: an application of a repeated discrete choice model. Agricultural and Resource
Economics Review 24(l):78-87
???Parsons, G.R. and M.J. Kealy. 1992. Randomly drawn opportunity sets in a random utility model of
lake recreation. Land Economics 68(1):93-106.
Response:
Comment Response for LT2ESWTR D-189 December 2005
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Appendix E - Greetings, Signatures, Commenter
Background, and Introductory Statements: Codes 9990-9997
Response to Code 9990
EPA acknowledges receipt of comments and all of their components including but not limited to
greetings, signatures, headings, background information, and introductory statements. EPA thanks the
commenters for their contribution. Where applicable, EPA responds to components of comments not
included in this section elsewhere in the Response to Comment Document.
Individual Comments on Code 9990
EPA Letter ID: 100
Comment ID: 10796
Commenter: Kemon Papacosta, ASTM Member D19, ASTM
Commenter Category: Unknown
Comment: CS Title: Comment for 68 FR 49548 from Kemon Papacosta
Company/Group/Association Name: Kemon Papacosta, ASTM Member D19 On Water
Media: Electronic File
Comment: Kemon Papacosta
09/15/2003-12:11-PM
To: Group Ow-Docket@EPA
cc:
Subject: Stage 2 Disinfection By-products
Attention: Docket ID NO. 2002-0043
UVD Guidance Manual
EPA815-D-03-007
June, 2003
Draft
Regards,
Kemon Papacosta
ASTM Member D19 On Water
Phone:(650)366-0119
Fax:(650)366-0152
E-mail: kpapacosta@apsstd.com
Comment Response for LT2ESWTR E-l December 2005
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Response: Response lOO.a.
EPA Letter ID: 101
Comment ID: 10866
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment focusing on "summary of small and rural America's (America)
regulatory positions and the white papers that providescientific support for those positions" submitted by
Ed Thomas, National Rural Water Association (NRWA)
Company/Group/Association Name: National Rural Water Association (NRWA)
Comment: January 5, 2004
Water Docket
Attn: Docket ID Number: OW-2002-0043
Attn: Docket ID Number: OW-2002-0039
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington DC 20460
To Whom It May Concern:
In addition to the comments NRWA has included a summary of small and rural America's regulatory
positions and the white papers that provide scientific support for those positions. We strongly encourage
EPA to use the concepts and information contained in these documents to revise the LT 2 and Stage 2
Final Rules.
We thank you for the opportunity to provide comments regarding this important
matter.
Sincerely,
Ed Thomas
nrwaet@comcast.net
202-742-4413
443-739-1358
Attachment
[SEE P. 55 OF .PDF FILE FOR CRITERIA TO ASSESS THE AFFORD ABILITY OF WATER
SERVICE]
[SEE P. 75 OF .PDF FILE FOR AFFORD ABILITY OF WATER SERVICE]
Comment Response for LT2ESWTR E-2 December 2005
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Stage 2 DBPR
Peaks and Characterization of Reproductive and Developmental Risk
There is a significant focus on reproductive and developmental health risk hazard in the preamble and
support documents for the Stage 2 Disinfection By-Product Proposed Rule (Stage 2). The following
language is in the preamble, "..Using the prevalence of fetal loss reported by CDC the median PARs' for
these three studies suggest that the incidence of fetal loss attributable to exposure to chlorinated drinking
water could range from 3,900 to 16,700 annually....(with a 28% reduction), this analysis implies that a
range of 1,100 to 4,700 fetal losses could be avoided per year as a result of the Stage 2 DBPR.
EPA lacks risk assessment data to support their conclusions. In fact, the Agency states in the preamble
that they "do not believe that the available evidence provides an adequate basis for quantifying potential
reproductive developmental risks" but then proceeds with the quantification - "Nevertheless....we
calculate the unadjusted population attributable risk associated with each of the ...studies of fetal loss."
Clearly there is a disconnect here. This is an admission that the basis for this rule is weak and lacks
scientific justification. We do not believe it is in the best interest of public health protection that such a
weak argument be forwarded as a justification for rule making. We believe it projects the EPA and all the
signers of the Agreement in Principle as careless participants. In general, risk assessors do not publish
"what if analysis - this is grossly misleading and clearly in conflict with the Safe Drinking Water Act
which directs EPA to use sound science. Not only is this bad science, it is unprotective of public health by
scaring pregnant mothers into drinking an insufficient quantity of water during the term of the pregnancy.
In addition, we believe EPA will rely on this language as a starting point for Stage 3 DBPR. Furthermore,
this language will only serve to promote more class action lawsuits against water utilities.
The "illustrative example" and other related language must be completely removed from the preamble in
the final rule. Most epidemiologists believe that the kind of analysis used to develop the illustrative
example is not appropriate until causality has been established, and causality has not been established
between fetal loss and chlorinated drinking water. A number of studies have been done on this issue and
the results are inconsistent. These two facts alone show that the illustrative example is not supported by
the best available peer reviewed science and it serves no useful purpose in this rulemaking.
EPA states in the proposed rule that "today's proposal reflects consensus recommendations from the Stage
2 Microbial/Disinfection By-Products Federal Advisory Committee....recommendations set forth in
the....Agreement in Principle." (page 49552) It is very clear to NRWA that the proposed rule does not
support the recommendations in the agreement in principle. By removing all of the health effect language
referencing benefits related to reproductive and developmental effects including miscarriages, stillbirth,
neural tube defects, and cleft palate then this portion of the final rule will be consistent with the
Agreement in Principle. NRWA encourages EPA to remove all of the above language to avoid a breech of
the Agreement-in-Principle.
Even if one were to accept the EPA methodology, the Agency did not develop the risk assessment data
correctly. For example, the Agency failed to recognize that over 90% of the exposure was to chloroform
which has shown absolutely no evidence (with or without a causal relationship) of causing premature
births. During the FACA the court ruling concerning chloroform was made, therefore EPA was not free to
discuss chloroform in the deliberations and it was agreed by all participants that it was a subject not to be
discussed. Now that the court ruling is history it can be discussed. It fact it must be discussed because it
has bearing on this rule making.
Trichloroacetic Acid (TCAA) and Monochloroacetic Acid (MCAA) NRWA does not believe the science
supports the use of additional safety factors for possible carcinogenicity for these contaminants. The use
Comment Response for LT2ESWTR E-3 December 2005
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of other precautionary factors and policy assumptions that inflate the estimated level of risk posed by
contaminants overstates the benefits of regulation. In the development of a regulation that concerns
protection of the public health, the Agency should be prudent to be conservative in its judgments and
assumptions so as to be "safe rather than sorry". However, the degree of conservatism used has a direct
effect on the cost of the regulation, and if the conservatism is extreme, there is a risk that the regulation
will be so costly that potential benefits are outweighed by unhealthful tradeoffs which consumers are
forced into because of the regulation.
EPA should move away from ultra conservatism in the three areas it has used to develop this regulation;
(1) in the selection of values for parameters involved in the calculation of MCL and MCLG values -
specifically the EPA should use central tendencies; (2) in the methodology and numbers used in the
evaluation of benefits versus costs of regulations required by the 1996 Amendments to the SDWA; and
(3) in the evaluation of the effect of magnitude, duration and frequency of exposure to a contaminant on
the choice of the MCL value and on the flexibility of its subsequent enforcement.
The precautionary assumptions and adjustment factors (for TCAA, MCAA and the other chronic
contaminants in this regulation) are suitable when the calculations are used strictly in a risk assessment
context such as establishing a no risk goal such as the MCLG. However, for risk management decisions in
determining how strictly to set an MCL, it is contrary to good science and statutory directives to carry
forward risk estimates impacted by precautionary policy assumptions. EPA should remove these
precautionary assumptions from risk management decisions and other data used to develop MCL's and
present data that show upper and lower bound risk estimates to policy makers and the public so that
informed decisions can be made. As a minimum, EPA should discuss the impact of these conservative
assumptions on the benefit analysis. In other words, EPA should be transparent to the Nth degree on this
matter.
Appropriate Treatment of Significant Excursions
EPA must use sound science to define significant excursions. NRWA believes that significant excursions
should not be addressed until the Agency can find scientifically sound data to support a defensible level.
However, significant excursions are not defined in regulatory text, but rather in guidance. If EPA does
decide to utilize the structure set up in the proposed rule, NRWA strongly opposes including any
regulatory definitions of significant excursions in the final rule. Further, the FACA agreed that this be
included in guidance and not in regulatory text. If EPA strays from the proposed rule language, then this
will represent a blatant violation of the agreement in principle.
Significant excursions as defined in the EPA significant excursion guidance manual are not violations and
do not require public notification. No special primacy condition is necessary for ensuring significant
excursions are evaluated.
Systems should not be required to take corrective action when significant excursions occur. Significant
excursions as defined in the EPA's draft guidance manual are not violations. Therefore, they are not
enforceable. PWS's should not be required to take corrective action for significant excursions that are not
enforceable.
The Agency requests comment on what should represent a significant excursion. As stated before, NRWA
does not support defining a significant excursion unless there is scientific data to support it. EPA should
rely on scientifically defensible data to recommend a level in guidance rather than relying on simple
subjective arithmetic formulas. This is contrary to the requirements of the Safe Drinking Water Act.
However, if the Agency insists on using arbitrarily set guidance, NRWA recommends significant
Comment Response for LT2ESWTR E-4 December 2005
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excursions be defined as any single sample that exceeds TTHM of 320 ug/L and HAAS that exceed 240
ug/L (These are arbitrary values set at four times the Stage 2B LRAA MCL's for TTHMs and HAAS).
Stage 2 Monitoring
Population Weighted Monitoring Scheme
As stated below all systems serving less than 10,000 people should collect the number of samples
appropriate for the water system for the IDSE. However, systems serving more than 10,000 people should
collect the number of samples based on the systems complexity and design of the system. Basing the
number of samples on either population or number of plants is riddled with implementation complexities.
The number of samples for systems serving more than 10,000 people should be a combination of plant
and population based. State primacy agencies can set up a sampling scheme based on EPA guidance and
evaluate individual water treatment plants on a case-by-case basis. NRWA would support a
ecommendation in guidance that most of the monitoring be based on population but maximum
flexibility must be provided to decrease or increase the number of samples based on system specific
characteristics.
Further, by setting up the proposed monitoring scheme, EPA has placed an undue burden on systems by
requiring entirely too many samples. No justification or reasoning behind the number of samples was
provided to adequately assess the need for so many samples. A more adequate sampling scheme to be
included in EPA guidance to state primacy agencies would be to cut the requirement in half. Statistically,
this approach is appropriate and the cost/benefit ratio is more acceptable.
Individual Distribution System Evaluation (IDSE) Monitoring
EPA should stick to a consistent definition of small water systems. In the Phase II/V chemical
regulations, the Agency defined small water systems as those serving less than 3,300 people. Waivers and
sampling requirements were based on systems greater than or less than 3,300 people. DBF's are identical
in nature - chronic contaminants (just like the phase II/V chemicals) and the State or community should
have the option of waiving IDSE requirement for all systems serving less than 3,300 people (not the
proposed waiver of systems serving 500 people or less). EPA should not create new definitions of small
systems. As recognized in the Phase II/V rules, small systems (<3,300) will be significantly burdened by
the regulations and were allowed some flexibility to shoulder the costs. The Stage 2 Rule IDSE
requirement should be NO different. There should be no limitations on this waiver - maximum flexibility
is essential to ensure protection of public health.
For all community water systems serving less than 10,000 people, the community in consultation with the
State should decide the adequate number of samples needed to make a sound evaluation of the levels of
DBFs in the distributions system (NOTE: NRWA does not support any Non-transient, non-community
water systems being subject to the IDSE requirements). Creating a national model for small systems is
impractical, burdensome and costly. Every community should base the number of samples on the factors
unique to their drinking water system. Typical factors could include configuration, population served,
complexity, and other considerations unique to the community. For example, one system may serve
a complex of large apartment houses and have a large population base, but virtually no distribution
system. A rural system serving a large agricultural area would have a small population base, but a large
distribution system. The community needs to be able to adjust the number of samples that the system
should take to better reflect the representative conditions. EPA could issue guidance to small communities
to help them understand the number of samples that they believe may be appropriate under certain
circumstances.
The Phase II/V monitoring framework could be used instead of the IDSE. This would involve simply
Comment Response for LT2ESWTR E-5 December 2005
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adopting the chronic inorganic monitoring framework with waivers from monitoring and requiring
samples every nine years based on the guidance and framework discussed above. Most small systems
would be waived from the requirements but the larger systems would be required to confirm that the
sampling locations are representative of the highest by-product levels.
NRWA supports EPA's proposal to not include monitoring results from the IDSE or other data used to
make the reduced monitoring determination in the CCR. NRWA also agrees that data from this effort not
be used to determine compliance with MCLs. NRWA also supports the proposed rule that systems with
less than two years of routine monitoring data have sufficient data to utilize the 40/30 certification. If a
system is meeting an extremely precautionary DBF level, then they only need a sample showing that
those levels are below the standard during times of peak conditions. Clearly, there should be no
prohibition against systems submitting a 40/30 certification.
By utilizing the Phase II/V monitoring framework discussed above, the problem with early
implementation is eliminated. No systems, regardless of size should be required to collect compliance
samples prior to States receiving primacy. This will lead to confusion and in many cases systems will
likely have to recollect data in accordance with State specific requirements. The effective date of both
regulations (Stage 2 and LT 2) should be based on the existing 1986 standardized monitoring framework
(SMF) and compliance periods (just like EPA relied on for the Radionuclides Rule - the monitoring
collection period did not correlate with the SDWA mandated effective date but rather required systems to
start collecting data four years and 15 days after the rule was promulgated to line up with the standardized
monitoring framework). The nine year compliance cycle starts and goes from 2002 to 2010; with the three
year periods of 2002-2004, 2005-2007, and 2008-2010. Large CWS could begin monitoring in 2008 and
small CWS could begin monitoring in 2009. Again, EPA should be consistent when establishing
monitoring dates and not arbitrarily set collection dates. The precedence had been established in 1986 and
the same pattern was continued in the revised arsenic standard and the Radionuclides Rule. Why should
this rule be any different? This rule should be consistent with predetermined regulatory practices.
No regulatory requirements should be specified in rule language for monitoring locations or monitoring
locations for specific buildings (high rise buildings, commercial facilities, etc.) but rather in guidance.
Further, all reference to issues of significance of monitoring and implementation issues such as common
aquifer determination, seasonal plants, and monitoring inequities, should be addressed in guidance.
Consecutive System Monitoring
NRWA does not support the recommended EPA approach requiring consecutive systems (or the
purchased water system) to collect compliance samples under the LT 2 proposed rule. This responsibility
should be maintained by the parent water system that is treating and providing the water (or the
wholesaler).
Placing the compliance requirements on the water system that purchases the water will result in an overly
burdensome monitoring and analysis costs for small systems. In addition, the responsibility and liability
for drinking water that is protective of public health must be maintained by the wholesaler. By placing
the monitoring burden on the purchaser it removes the liability from the wholesaler to provide safe water
that meets all the regulatory requirements.
NRWA recognizes that some implementation problems exist with this option. However, in those limited
circumstances where there are problems (i.e. the purchased water system installs a chlorine boost), we
believe local governments (or the local community) is in the best position to identify the appropriate
solutions to reconcile the situation. It is impossible for EPA to develop a national standard that will fit the
unique circumstances encountered by every small community. As opposed to regulations, EPA could
Comment Response for LT2ESWTR E-6 December 2005
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provide guidance to systems on contract language for purchased water contracts that would assist
in ensuring that the proper monitoring is completed.
NRWA is very concerned that if consecutive systems cannot comply with D/DBP rules and parent
systems won't help solve problems, the consecutive system would be better off not buying water with the
TTHM problem. The alternative would be to put in individual wells/supply to lower residence time and
address TTHM problem prior to development of problem. In other words it is harder to remove once they
are formed than to ensure they are not formed in consecutive system distribution system. This rule will
lead to reversing the EPA promoted consolidation efforts because consolidated systems will have a harder
time meeting this rule. Is this EPA's new message? Should rural water not help systems consolidate when
they think it is in their own best interest?
Reduced Monitoring
All systems regardless of size, source or purchased water (consecutive systems) should reduce the
monitoring to the minimum number required to establish critical variability and target the sampling to
periods of worst case conditions. Systems will be spending an incredible amount of time and money to
do a complex study of the distribution system. After completing such a thorough and scientific study, the
system will have a well documented report that describes the characteristics of the distribution system.
Further expense and collection of samples is redundant. With all the other stringent regulatory controls
and precautionary assumptions built into the regulation, only one sample is necessary to ensure the
system is in compliance. For example, the system could be in full compliance with all the DBP MCLs and
be optimized to the maximum extent possible but not meeting the precursor removal rates. The precursors
have absolutely no health impact. The system meets all MCLs but is in violation for not removing enough
of naturally organic matter that has absolutely no relation to increased public health protection.
However, should EPA decide to reduce the monitoring based on other methods (e.g. population), the
Agency should give sole discretion to the community (in consultation with the State) to decide the
appropriate number of samples and provide guidance with recommendations based on population This
clearly avoids the implementation complexities that EPA has articulated in the proposed rule. The EPA
should issue guidance that helps States and communities decide what the appropriate number of samples
would be. A national framework for reduced monitoring is not the answer to the many implementation
problems around population or plant based methods.
Water systems that draw water from the same aquifer or same surface water source (that maintains similar
water quality standards) should be allowed to use each others' compliance monitoring data. This concept
was first introduced and is an existing regulatory alternative through the EPA's Alternative Monitoring
Guidelines for the Phase II/V contaminants. The same argument that EPA made to promulgate those
regulations should be adopted for these chronic contaminants.
Communities in consultation with the State Primacy Agency should be able to completely eliminate
routine compliance monitoring. Full discretion should be given to the community (in consultation with
the State) to eliminate this requirement. NRWA would encourage EPA to issue guidance describing some
of the situations when eliminating compliance monitoring would be appropriate.
Reduced Bromate Monitoring
The Agency provided no rationale for reducing monitoring for bromate at 0.0025 mg/L. Bromate - a
chronic contaminant derived from a naturally occurring inorganic element - should be eligible for reduced
monitoring if the levels do not exceed the MCL (just like the Phase II/V inorganic reduced monitoring
requirements).
Comment Response for LT2ESWTR E-7 December 2005
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Use of Previous Monitoring Data
No stipulations should be placed on using data collected prior to the effective date of the Stage 2 rule
except the samples should be analyzed by EPA approved methods. The quality, frequency and quantity of
samples should be left up to the State Primacy Agency. This is the method EPA has used for
grandfathered data in the past. EPA should not be inconsistent with grandfathering provisions. EPA has
set precedence for grandfathering data in the Arsenic Rule, Radionuclides Rule, Radon Rule, and the
Phase II/V Rules. EPA should simply extrapolate the grandfathering provisions from these rules and
adopt them for the Stage 2 Final
Rule.
Public Notice
For the reasons described earlier, NRWA strongly opposes a mandatory PN requirement and supports
EPA's decision to not include information about reproductive or developmental health effects in public
notices.
Small System Variances
Scott Rubin's research shows that the lowest 20 percent of households (25 million households in the U.S.)
are already paying more in their public health expenditures than their income permits (Scott J. Rubin,
Criteria to Assess Affordability, NRWA 2002). Therefore, any increase in water rates for these
economically "sensitive subpopulations" is unaffordable. What is confounding to small communities is
that Rubin's studies and evidence are not in dispute by EPA. Yet, the Agency still recommended that the
Stage 2 Rule is affordable for these families.
Rubin's analysis of data from the 1990 census shows only a weak correlation between MHI and the level
of poverty in a community. Rubin found that at the median income of approximately $30,000 in 1989, the
level of poverty ranges from zero to more than 20% in U.S. counties. That is, communities with the same
median income can have poverty rates, and the presence of low-income households, that vary drastically
from one another.
The use of MHI computed as a national aggregate as the sole metric for determining affordability has
many problems. NRWA believes that MHI masks the financial hardship that low-income communities
and low-income households have in meeting many of the existing regulations. EPA must use multiple
criteria to assess affordability rather than a simple metric such as MHI. The purpose of the national-level
affordability determination is to identify the likelihood that small water systems will be able to afford to
comply with a regulation without creating a serious risk of adverse health consequences. The fact that a
certain level of expenditure is affordable to the median income household in a community tells us very
little about the ability of the low-income households in the community to afford the same level of
expenditure.
NRWA recommendation: Recognizing that any increase in water rates for economically "sensitive
subpopulations" is unaffordable and that the variance technology is always "protective of public health",
EPA should list variance technologies for this and all future rules (that have a variance provision).
Authority for implementing the variance technology should be retained at the state and local level. States
will decide on a caseby-case basis (based on local conditions) the appropriateness of variance technology.
For example, some states use their own affordability test of 1% of the specific communities MHI to
determine "disadvantaged community" eligibility for SRF funding - which may also be appropriate for
variance technology decisions.
Comment Response for LT2ESWTR E-8 December 2005
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Education, source water protection, bottled water and "other means" should be used as a variance
technology as authorized in the Safe Drinking Water Act. In some situations, communities are within the
range of being protective of public health and meet the affordability criteria but cannot afford installing
expensive treatment technology. This will require EPA to determine what is "protective of public health"
and the contaminant level that presents an "unreasonable risk to health" (URTH).
Total Organic Carbon
EPA should clarify in the rule language (40 CFR 141.135(c)(l)(iv)) that systems should not divide by 12
to determine compliance with the TOC requirement but rather divide by the total number of samples
collected. This provision is confusing and causing many systems to have violations when in fact they are
adequately meeting the standard.
LT 2 ESWTR
Microbial Tool Box
The Long Term 2 Enhanced Surface Water Treatment Proposed Rule (LT 2) addresses the requisite
microbial toolbox elements identified in the Agreement in
Response: Response lOO.a. Comments addressing requirements of the Stage 2 DBPR are outside the
scope of the LT2ESWTR. These comments are considered in the Stage 2 rulemaking.
EPA Letter ID: 101
Comment ID: 10867
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Monitoring and Reporting Violations
Intermittent and Multiple Source Monitoring
Unfiltered Systems and the Use of Two Disinfectants
The Agency requested comment on an alternative approach to requiring systems to use two different
disinfectants and for each disinfectant to meet by itself the
Options for Systems to Meet Cryptosporidium Treatment Requirements
Response: Response lOO.a
EPA Letter ID: 101
Comment ID: 10868
Comment Response for LT2ESWTR E-9 December 2005
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Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
General Comments for both LT 2 and Stage 2
Regulatory Affordability
The SDWA as amended in 1996 requires EPA to consider affordability of its regulations in the process of
determining if water systems will be granted variances from using approved compliance technology to
meet MCL requirements. For small systems in particular, a determination must be made for each of three
different size ranges of systems (serving 0-500; 501-3300; and 3301 - 10000 people) and if compliance
technology is determined to be unaffordable for any size range, then all systems of that size are eligible
for a variance. EPA must then define an acceptable technology for them to use. To date, however, no
technology has been determined unaffordable and no variances have been issued. EPA uses a single
parameter, 2.5% of Median Household Income (MHI) measured as a national aggregate, to assess
affordability. NRWA's concerns about this process fall into primarily three areas:
*Multiple criteria rather than the single metric of median household income (MHI) are needed.
*The criteria needs to be computed so as to account for differences between metropolitan and non-
metropolitan areas. *The modified criteria needs to be applied in the broadest possible sense so
that no systems or households are forced into unwise health choices because of an arbitrary affordability
trigger that is too narrow in concept or application.
These concerns are expressed in the following policies.
NRWA believes that the cost of delivering public health protective drinking water must be affordable to
small and rural water system customers. (Gray & Cohen 2001) [SEE P. 125 OF .PDF FILE]
NRWA believes that Median Household Income (MHI) by itself is not an appropriate measure of
affordability. USEPA must consider the affordability to low income households.(Rubin 2001 a&b [SEE
P. 242 AND P. 75 OF .PDF]; 2002 a&b; 2003 [SEE P. 55 OF .PDF])
NRWA believes that affordability analyses (1) must be broad in scope and (2) consider the cost of
treatment technology imposed on a community for compliance when estimating national compliance
costs, not just for variance determinations. (Rubin 2001 a&b; 2002 a&b; 2003)
The SDWA should be amended to enable water systems to raise affordability as an "affirmative defense"
in an enforcement action. (Koorse 2003)
Rationale: A simple dictionary definition of "afford," is the ability to bear a cost without undue burden or
hardship. For a small system or household that is struggling financially, the affordability concept is not
theoretical or legal, but is very practical. Limited funds must be spent wisely to avoid hardship.
SDWA affordability considerations must be reasonable, practical, and result in affordable outcomes, or
else small communities will spend limited funds for little or no benefit, while more important household
or community needs go unfunded.
Affordability of water service is becoming increasingly important on the local, state, and national level.
Water rates continue to increase because of new regulatory requirements, the need to replace aging
Comment Response for LT2ESWTR E-10 December 2005
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infrastructure, expenditures to address water system security, and overall cost pressures such as inflation.
Rubin (2001a,b; 2002a,b; 2003) has developed a series of analyses examining several critical aspects of
affordability, documenting clearly the economic differences between metropolitan and rural areas, and the
inadequacy of median household income (MHI) as a sole indicator of affordability.
A national affordability criteria of 2.5% MHI is currently used. Thus far, USEPA has determined that all
current and proposed regulations are affordable for all small systems, and therefore no small system
variances can be issued. This determination has been made because USEPA believes that, for each
regulation, either 1) not complying with the regulation would represent an unreasonable risk to health
(URTH) for customers on a national basis, or 2) a treatment technology exists that every small system can
afford, considering national affordability estimates. The first point does not recognize that precautionary
assumptions implicit in USEPA regulations may allow setting a value for URTH that differs from a
regulation. The second point does not recognize the severe limitations of using national median values in
national affordability estimates.
Use of MHI as a sole indicator of affordability is inadequate. Multiple indicators are needed to more
accurately capture the ability of a community to afford increased water rates. In addition, a national-level-
affordability analysis that focuses on the "typical or 'middle-of-the-road' household'" by definition does
not properly focus on communities with affordability concerns, and consequently overlooks the needs of
low-income households.
NRWA believes that the policy of setting an MCLG of zero for carcinogens is unrealistic and results in
inappropriate use of resources.(Bull 2001 ) [SEE P. 346 OF .PDF FILE]
Improvements in USEPA's approach is needed by including latency periods for delayed onset of health
effects, and discounting the results to present value (using the same discount rate applied to all other
benefits and costs.)
Response: SDWA does not allow small system variances from treatment technique requirements for
microbial pathogens based on affordability. Consequently, EPA has not analyzed affordability for the
LT2ESWTR. Comments addressing DBP risks addressed by the Stage 2 DBPR are outside the scope of
the LT2ESWTR.
EPA Letter ID: 101
Comment ID: 10869
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
REFERENCES
Bauman, K. 1998. Direct Measures of Poverty as Indicators of Economic Need: Evidence from the
Survey of Income and Program Participation. U.S. Census Bureau Population Division Technical
Working Paper No. 30.
Bull, R.J. 2001. Thresholds in Toxic Responses to Chemicals and Radiation and Their Use in Risk
Assessment and Regulation. In: Critical Issues in Setting Regulatory Standards. Duncan, OK: National
Rural Water Association.
Comment Response for LT2ESWTR E-ll December 2005
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Cohen, J.T. 2001. Acceptable Risk in the Context of Managing Environmental Hazards. In: Critical Issues
in Setting Regulatory Standards. Duncan, OK: National Rural Water Association.
Cotruvo, J.A. 2003. Approaches for Providing Potable Water in Small Systems. In: Critical Issues in
Setting Regulatory Standards. Duncan, OK: National Rural Water Association.
Court of Appeals. 2000. Chlorine Chemistry Council and Chemical Manufacturers Association v. EPA.
U.S. Court of Appeals, District of Columbia Circuit. No. 99-1627. (March 31, 2000).
Edin, K., and L. Lein. 1997. Making Ends Meet: How Single Mothers Survive Welfare and Low-Wage
Work. Russell Sage Foundation.
Fensterheim, R.J. 2003. Dual/Multiple Contaminant Standards Under the Safe Drinking Water Act. In:
Critical Issues in Setting Regulatory Standards. Duncan, OK: National Rural Water Association.
FCC. 2001. Telephone Subscribership in the United States. (March).
Gray, G.M., and J.T. Cohen. 2001. Confronting Tradeoffs in Protecting Human Health and the
Environment. In: Critical Issues in Setting Regulatory Standards. Duncan, OK: National Rural Water
Association.
Koorse, S.J. 2003. Enforcement Flexibility Under the Safe Drinking Water Act. In: Critical Issues in
Setting Regulatory Standards. Duncan, OK: National Rural Water Association.
Mercier, J., C. Mercier, and S. Collins. 2000. Iowa's Cold Winters: LIHEAP Recipient Perspective. Iowa
Dept. of Human Rights.
Pontius, F.W. 2001. Compounding Effects of Drinking Water Regulations on Small Water Systems. In:
Critical Issues in Setting Regulatory Standards. Duncan, OK: National Rural Water Association.
Raucher, R.S. 2001. Balancing Costs and Benefits. In: Critical Issues in Setting Regulatory Standards.
Duncan, OK: National Rural Water Association.
Raucher, R.S. 2003. Blending Science with Policy: Precautionary Assumptions and Their Impact on
Benefit-Cost Analyses and Drinking Water Standards. In: Critical Issues in Setting Regulatory Standards.
Duncan, OK: National Rural Water Association.
Raucher, R.S., and N. Damodaran. 2003. The HRRCA Review Process. In: Critical Issues in Setting
Regulatory Standards. Duncan, OK: National Rural Water Association.
Rubin, S. 2001a. Economic Characteristics of Small Systems. In: Critical Issues in Setting Regulatory
Standards. Duncan, OK: National Rural Water Association.
Rubin, S. 2001b. Affordability of Water Service. In: Critical Issues in Setting Regulatory Standards.
Duncan, OK: National Rural Water Association.
Rubin, S. 2002a. Criteria to Assess Affordability Concerns in Conference Report for H.R. 2620. Duncan,
OK: National Rural Water Association.
Rubin, S. 2002b. Comparison of Median Household Income Levels Between Metropolitan and Non-
Comment Response for LT2ESWTR E-12 December 2005
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Metropolitan Areas (November 2002).
Rubin, S. 2003. Criteria to Assess the Affordability of Water Service. In: Critical Issues in Setting
Regulatory Standards. Duncan, OK: National Rural
Water Association.
SAB. 2002. Affordability Criteria for Small Drinking Water Systems: An EPA Science Advisory Board
Report. EPA-SAB-EEAC-03-004. December 2002.
USEPA. 2000. National Primary Drinking Water Regulations for Lead and Copper; Final Rule. Federal
Register, 65:8:1950-2015 (Jan. 12).
USEPA. 2001. National Primary Drinking Water Regulations: Arsenic. Federal Register, 6975-7075 (Jan.
22).
Response: response lOO.a.
EPA Letter ID: 388
Comment ID: 10478
Commenter: Andreas Kolch,, WEDECO AG
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment:
Dr. Andreas Kolch
WEDECO AG Water Technology
Response:
EPA Letter ID: 389
Comment ID: 10485
Commenter: Kemon Papacosta, ASTM Member D19, ASTM
Commenter Category: Unknown
Comment:
Kemon Papacosta
09/15/2003 11:50 AM
To: Group OW-Docket@EPA
cc:
Subject: My comments regarding Turbidity section 7
Attention: Docket ID No. OW-2002-0039
Regards,
Comment Response for LT2ESWTR E-13 December 2005
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Kemon Papacosta
ASTM Member D19 On Water
Phone:(650)366-0119
Fax:(650)366-0152
E-mail: kpapacosta@apsstd.com
Response:
EPA Letter ID: 390
Comment ID: 10489
Commenter: Jeff Taylor, Deputy Director, City of Houston Public Utilities Division
Commenter Category: Regulated Community (Utilities)
Comment:
CITY OF HOUSTON
Public Works and Engineering Department
Jon C. Vanden Bosch, P.E.
Director
Public Works & Engineering
Department
P.O. Box 1562
Houston, Texas 77251-1562
T. 713.837.0037
F. 713.837.0040
www. citvofhouston. qov
September 2, 2003
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue NW
Washington, D.C. 20460
Attention: Docket ID No. OW-2002-0039
Again, we thank you for the opportunity to comment on the Proposed Long Term 2
Surface Water Treatment Rule.
Jeff Taylor
Deputy Director
Public Utilities Division
Department of Public Works and Engineering
Response: response lOO.a.
Comment Response for LT2ESWTR E-14 December 2005
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EPA Letter ID: 391
Comment ID: 10496
Commenter: Ricardo Nelson Rios,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment:
Ricardo Rios
09/19/2003 04:17PM
Please respond to ricardo.rios
To: Group Ow-Docket@EPA
cc:
Subject: Revisions
September 12th, 2003
Water Docket,
Environmental Protection Agency,
Mail Code 410IT,
1200 Pennsylvania Ave., NW.,
Washington, DC 20460,
Attention Docket ID No. OW-2002-003
To Whom It May Concern:
The Environmental Protection Agency (EPA) is proposing National Primary Drinking Water Regulations
that require the use of treatment techniques, along with monitoring, reporting, and public notification
requirements, for all public water systems (PWSs) that use surface water sources. The purposes of the
Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) are to improve control of microbial
pathogens, including specifically the protozoan Cryptosporidium, in drinking water and to address risk-
risk trade-offs with the control of disinfection byproducts. We support the EPA's proposed rule as a
positive step
Revision 2 Lori
Revision #3: What are the Benefits of the Proposed Rule and What Analyses Support Selecting the
Proposed Rule Option: The propose rule has as an objective to improve the drinking water exposure to
comparisons is 25 years. Approximately 5 years account for rule implementation and 20 years for the
average useful life of the equipment used to comply with treatment technique requirements.
EPA has quantified benefits and cost of each of the regulatory alternatives. To make these estimates the
Agency developed a two dimensional Monte Carlo model that accounts for uncertainty and variability in
key parameters like Cryptosporidium in drinking water, and then projecting the reductions in exposure
and risk resulting from the additional treatment for the LT2ESWTR rule. Cost will result largely from
installation of additional treatment, with lesser cost due to monitoring and other implementation activities.
Several factors were evaluated including predictions of costs and benefits. The Advisory Committee
Ricardo Nelson Rios
3616 SW 24th Terrace
Miami, Fl. 33145
305-301-6471
Comment Response for LT2ESWTR E-15 December 2005
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Read below for tips on putting your thoughts together;
Petitions submitted to FDA must contain:
• Action requested-What rule, order, or other administrative action does the petitioner want FDA to issue,
amend or revoke?
• Statement of grounds~The factual and legal grounds for the petition, including all supporting material,
as well as information known to the petitioner that may be unfavorable to the petitioner's position.
• Environmental impact—This information is generally required if the petition requests approval of food or
color additives, drugs, biological products, animal drugs, or certain medical devices, or for a food to be
categorized as GRAS (generally recognized as safe).
Procedures for preparing environmental impact statements can be found in Title 21 of the Code of
Federal Regulations, Sections 25.24 and 25.31. If an environmental impact statement is not required,
petitions should include a statement to that effect.
• The following official certification statement —The undersigned certifies, that, to the best knowledge and
belief of the undersigned, this petition includes all information and views on which the petition relies, and
that it includes representative data and information known to the petition which are unfavorable to the
petition.
• Identifying information- The petition must be signed and include the petitioner's address and phone
number.
Cryptosporidium, which is a protozoan pathogen that is widespread in surface water. EPA is particularly
concerned about Cryptosporidium because it is highly resistant to inactivation by standard disinfection
practices like chlorination. Ingestion of Cryptosporidium oocysts can cause acute gastrointestinal
illness, and health effects in sensitive subpopulations may be severe, including risk of mortality.
Cryptosporidium has been identified as the pathogenic agent in a number of waterborne disease outbreaks
across the U.S. and in Canada (details in section II).
The intent of the LT2ESWTR is to supplement existing microbial treatment requirements for systems
where additional public health protection is needed. Currently, the Interim Enhanced Surface Water
Treatment Rule (IESWTR) requires large systems that filter to remove at least 99% (2 log) of
Cryptosporidium (63 FR 69478, December 16, 1998) (USEPA 1998a). The Long Term 1 Enhanced
Surface Water Treatment Rule (LTIESWTR) extends this requirement to small systems (67 FR 1812,
January 14, 2002) (USEPA 2002a). Subsequent to promulgating these regulations, EPA has evaluated
significant new data on Cryptosporidium infectivity, occurrence, and treatment (details in section III).
These data indicate that current treatment requirements achieve adequate protection for the majority of
systems, but there is a subset of systems with higher vulnerability to Cryptosporidium where additionWe
urge you to consider the following comments when finalizing changes to the policy. The majority of
cases were associated with surface water, and specifically with the 1993 Cryptosporidium outbreak in
Milwaukee, WI with an estimated 403,000 cases (Mac Kenzie et al. 1994). A recent study by McDonald
et al. (2001), which used blood samples from Milwaukee children collected during and after the 1993
outbreak, suggests that Cryptosporidium infection, including asymptomatic infection, was more
widespread than might be inferred from the illness estimates by Mac Kenzie et al. (1994). Most
waterborne pathogens cause gastrointestinal illness with diarrhea, abdominal discomfort, nausea,
vomiting, and other symptoms. The effects of waterborne disease are usually acute, resulting from a
single or small number of exposures. Such illnesses are generally of short duration in healthy people.
However, some pathogens, including Giardia lamblia and Cryptosporidium, may cause disease lasting
weeks or longer in otherwise healthy individuals, though this is not typical for Cryptosporidium.
Waterborne pathogens also cause more serious disorders such as hepatitis, peptic ulcers, myocarditis,
paralysis, conjunctivitis, swollen lymph glands, meningitis, and reactive arthritis, and have been
associated with diabetes, encephalitis, and other diseases (Lederberg 1992). EPA is particularly
concerned about Cryptosporidium because, unlike pathogens such as bacteria and most viruses,
Comment Response for LT2ESWTR E-16 December 2005
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Cryptosporidium oocysts are highly resistant to standard disinfectants like chlorine and chloramines.
Consequently, control of Cryptosporidium in most treatment plants is dependent on physical removal
processes. Finished water monitoring data indicate that Cryptosporidium is sometimes present in
filtered, treated drinking water (LeChevallier et
Response: response 100.a. The language in this comment is entirely copied from the proposed
LT2ESWTR and instructions on submitting comments to the FDA.
EPA Letter ID: 394
Comment ID: 10552
Commenter: Marian Rose, President, Croton Watershed Clean Water Coalition Inc.
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment:
CROTON WATERSHED CLEAN WATER COALITION
September 24,2003
Mission: CWCWC is an alliance of organizations and individuals joining together for a common goal of
preserving, protecting, and improving the quality of the waters in the Croton watershed and to providing
alternatives to filtration.
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Art: Docket ll)No. OW-2002-0039
9 Old Corner Road
Bedford, New York 10506
Ph: 914-234-3179 914-234-6470
Fax: 914-234-6139
40 CFR Parts 141 and 142
National Primary Drinking Water Regulations -
Long Term 2 Enhanced Surface Water Treatment Rule
E/mail: marianr451@aol.com
crotonwshed@aol .com
Web site: www.newyorkwater.org
Summary of LT2ESWTR Regulations Pertaining to Unfiltered Systems
Future regulations that will come into force around 2010 call for a minimum of 2 disinfectants for
unfiltered systems. (See EPA 40 CFR Parts 141 and 142 Long Term 2 Enhanced Surface Water
Treatment Rule). "Further, each of the two disinfectants must achieve by itself the total inactivation
required for one of these three pathogen types." (Page 138) The pathogen types include viruses,
Comment Response for LT2ESWTR E-l 7 December 2005
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Giardia lamblia and Cryptosporidium. "
EPA has developed criteria, described in sections 1V.C. 14-15 for systems to determine Cryptosporidium
inactivation credits for chlorine dioxide, ozone and UV light. Unfiltered (emphasis added) systems are
allowed to use any of these disinfectants to meet the 2 (or 3) log Cryptosporidium disinfection
requirement." (Pages 138 and 139)
"For unfiltered (emphasis added) systems with mean source water Cryptosporidium levels of less than or
equal to 0.01 oocysts/L, 2-log Cryptosporidium inactivation is required. Where the mean source water
level is greater than 0.01 oocysts/L, 3-log inactivation is required." (Pagel38) Chlorine dioxide (C1O2)
and its disinfection by-products (DBPs)have been found to be less harmful to human health than
previously thought. As a result, EPA has significantly relaxed its standards for concentrations of C1O2
and chlorite and no longer regulates chlorates.(1)
EPA has also assigned Cryptosporidium inactivation credits for C1O2 and ozone for various CT values
(C is concentration in milligrams/liter, mg/L; T is the time of contact in minutes) for various water
temperatures.(2)
For a 2-log (99% removal) credit at 10 degrees centigrade (or 50 degrees Fahrenheit), the CT for C1O2 is
553 milligrams.minutes/liter. Assuming a C of 0.6 mg/L, then T=15 hours. For a 1 log credit at 50
degrees Fahrenheit and C=0.6 mg/L,T=7.7 hours. Both these CTs could be achieved by using the length
of New York City 's over 21 mile long New Croton Aqueduct.
EPA's Request for Comments
The following is a quote from page 305 outlining EPA's reasons for requiring a 2-log reduction in
Cryptosporidium concentrations for unfiltered systems even though such concentrations are so low as to
be undetectable. "EPA believes that granting an exemption to the Cryptosporidium treatment
requirements of the LT2ESWTR would result in an unreasonable risk to health...In theory, it would be
possible for an unfiltered system to demonstrate raw water Cryptosporidium levels that were 3 log lower
than the cutoff for bin 1 for filtered systems and thus, that it may be providing comparable public health
protection without additional inactivation. However, EPA has determined that in practice it is not
currently economically or technologically feasible for systems to ascertain the level of Cryptosporidium
at this concentration. This is due to the extremely large volume of samples that would be necessary to
make this demonstration with sufficient confidence. Based on this determination and the Cryptosporidium
data described in section III.C, EPA is not proposing to allow unfiltered systems to demonstrate raw
water Cvptosporidium levels low enough to avoid inactivation requirements. EPA requests comment on
the determination that granting an exemption to the Cryptuspuridium treatment requirements of the
LT2ESWTR would result in an unreasonable risk to health (emphasis added)."
(1) In 1994,these concentrations were 300 micrograms per liter, (ig/L for C1O2 and 80 (ig/L for chlorite.
In 1998,these were increased respectively to 800 (ig/L and 800 (igL.
(2) These are displayed in Tables IV-19 and IV-20, page 251.
Response: response lOO.a.
Comment Response for LT2ESWTR E-18 December 2005
-------
EPA Letter ID: 394
Comment ID: 10553
Commenter: Marian Rose, President, Croton Watershed Clean Water Coalition Inc.
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment:
Respectfully submitted,
Marian H.Rose,Ph.D.
President,CWCWC
9 Old Corner Road
Bedford,NY 10506
September 24,2003
Response:
EPA Letter ID: 397
Comment ID: 10534
Commenter: Ron Kailey, Laboratory Supervisor, Cheyenne Board of Public Utilities
Commenter Category: Regulated Community (Utilities)
Comment: well as terrorist, cannot access their surface waters. Thanks Ron Kailey Lab
Supervisor
Response:
EPA Letter ID: 398
Comment ID: 10535
Commenter: Ron Kailey, Laboratory Supervisor, Cheyenne Board of Public Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Required Monitoring and Reporting I have been in the Environmental Lab
industry for 22 years, 19 in Wastewater Treatment and 3 in Water Treatment. The
Thank you Ron Kailey Lab Supervisor Cheyenne BOPU
Response:
EPA Letter ID: 408
Comment ID: 10542
Commenter: Craig Barsness, Chief Plant Operator, Shoshone Municipal Pipeline
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-19 December 2005
-------
Comment: October 28,2003
Water Docket,EPA,Mail Code 410 IT
1200 Pennsylvania Avenue,NW
Washington,D. C. 02460
ATTN:Docket ID No.OW-2002-0039
RE: Comments on the Long Term 2 Enhanced Surface Water Treatment Rule
Sincerely ,
Craig Barsness,Chief Plant Operator
SHOSHONE MUNICIPAL PIPELINE
P.O.Box 488
Cody,Wyoming 82414
307-527-6492
CB:ah
Response:
EPA Letter ID: 409
Comment ID: 10481
Commenter: Leslie Gryder,, City of Lynchburg Utilities
Commenter Category: Regulated Community (Utilities)
Comment:
leslie .gryder@lynchburgva.gov
11/12/2003 11:49 AM
To: Group Ow-Docket@EPA
cc:
Subject: LT2ESWTR
Response:
EPA Letter ID: 409
Comment ID: 10484
Commenter: Leslie Gryder,, City of Lynchburg Utilities
Commenter Category: Regulated Community (Utilities)
Comment: Leslie Gryder
City of Lynchburg Utilities
525 Taylor Street
Lynchburg, VA 245 01
Comment Response for LT2ESWTR E-20 December 2005
-------
434 847-1322 extension 126
434 845-7353 (fax)
Response:
EPA Letter ID: 410
Comment ID: 10487
Commenter: Dan Saltzman, Commissioner-in-Charge, Portland Water Bureau
Commenter Category: Regulated Community (Utilities)
Comment: "Saltzman, Dan"
Sent by: "Campbell, Edward"
11/19/2003 03:32 PM
To: Group Ow-Docket@EPA
cc:
Subject: Attention Docket ID No. OW-2002-0039: Comment on Pending
LT2ESWTR Drinking Water Rule
Attention Docket ID No. OW-2002-0039
November 19, 2003
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave, NW
Washington DC 20460
The City of Portland owns and operates the unfiltered Bull Run water system serving over 800,000
Oregonians in the city and surrounding region. The 68,000 acres of land that drain into the Bull Run
reservoirs are closed to public access, provide no grazing for domestic animals, and are managed under
nearly 100 years of federal legislation designed to protect this watershed as a source of drinking water for
Portland area residents.
The Bull Run system has been in continuous compliance with all 11 Surface Water Treatment Rule
filtration avoidance criteria since 1991 and meets the current inactivation requirements for Giardia, virus,
and bacteria through in-line treatment with free chlorine. Years of monitoring for total and fecal coliforms
as well as Giardia and Cryptosporidium show that these organisms are found at very low levels in this
supply, a fact that is generally attributed to the very high level of protection for the watershed.
Over the years as rules governing the treatment of surface water supplies have changed, the Portland
Water Bureau has made modifications to its treatment processes to comply with those rules. In
anticipation of the forthcoming Long
Should you require additional information about this comment, please contact Edward Campbell of my
staff at 503-823-3030.
Sincerely,
Dan Saltzman
Commissioner-in-Charge, Portland Water Bureau
Comment Response for LT2ESWTR E-21 December 2005
-------
Return:
Commissioner Dan Saltzman
Att: Edward Campbell
1221 SW Fourth Avenue #230
Portland, Oregon 97204
p: (503) 823-4151
f: (503) 823-3036
Response: response lOO.a.
EPA Letter ID: 411
Comment ID: 10559
Commenter: Devon Cole,, Utah Department of Health Laboratory
Commenter Category: State/Tribe Government
Comment:
Devon Cole
Utah Department of Health Laboratory
LT2 Questions/Comments
Method Specific Questions
Response:
EPA Letter ID: 412
Comment ID: 10506
Commenter: Illegible 0412,, PWS WY5600045
Commenter Category: Regulated Community (Utilities)
Comment:
Proposed Long Term 2 Enhanced SlurfaceWater Treatment Rule
Comment Form
The following comments are concerning LT 2 Docket ID no. OW-2002-0039
Send 3 copies of Comments To:
Water Docket, Attention Docket ID No. W-2002-0039
Environmental Protection Agency, Mail code 410IT
1200Pennsylvania Ave. NW
Washington, DC 20460
Signature [illegible]
PWS # WY5600045
Address P.O. Box 953, Rawlins, WY 82301
Date: November 12, 2003
Comment Response for LT2ESWTR E-22 December 2005
-------
Response:
EPA Letter ID: 413
Comment ID: 10508
Commenter: Thomas C. Sliwoski, Director of Public Works, City of Staunton, Virginia
Commenter Category: Regulated Community (Utilities)
Comment:
Tom Sliwoski
11/25/2003 01:36 PM
To: Group Ow-Docket@EPA
cc: Sabrina McKenzie , Ned Davis , "Christopher J. DeWald"
Subject: Comments on Proposed Long-Term 2 Enhanced Surface Water Treatment Rule
As a utility serving over 30,000 customers each day, we would like to voice our concerns and comers
regarding the Proposed Long-Term 2 Enhanced Surface Water Treatment Rules.
Thank you for allowing us the opportunity to comment.
THOMAS C. SLIWOSKI
Director of Public Works
City of Staunton, Virginia
Response: response lOO.a.
EPA Letter ID: 414
Comment ID: 10514
Commenter: John Amodeo, General Manager and Chief Engineer, Vista Irrigation District
Commenter Category: Regulated Community (Utilities)
Comment:
John Amodeo
11/25/2003 02:38 PM
To: Group Ow-Docket@EPA
cc:
Subject: Long-Term 2 Enhanced Surface Water Treatment Rule
I am the General Manager and Chief Engineer of the Vista Irrigation District in San Diego County,
California. We own and operate a 50,000 Acre Foot Reservoir/Lake, Lake Henshaw and Dam in the
Northeast corner of the County. I have two concerns with the proposed LT2SWTR:
1. We have already been testing for Cryptosporidium for years, but
Comment Response for LT2ESWTR E-23 December 2005
-------
Thank you for considering my comments.
John Amodeo, P.E.
General Manager and Chief Engineer
Vista Irrigation District
1391 Engineer Street
Vista, CA 92081
760-597-3128
Response: response lOO.a.
EPA Letter ID: 415
Comment ID: 10517
Commenter: Miguel Arroyo, Water and Wastewater Treatment Manager, City of Fort Lauderdale Public
Services Department
Commenter Category: Regulated Community (Utilities)
Comment:
Miguel Arroyo
12/01/2003 11:04 AM
To: Group Ow-Docket@EPA
cc:
Subject: Comments on the proposed Long Term 2 Enhanced Surface Water Treatment Rule
(LT2ESWTR) and the Stage 2 Disinfectant and Disinfection Byproducts Rule
I am the City of Fort Lauderdale Water and Wastewater Treatment Manager and enclosed are my
comments:
Thanks.
Miguel R. Arroyo
Water & Wastewater Treatment Manager
City of Fort Lauderdale Public Services Department
Phone: (954) 828-7806
Email: MiguelA@ci.fort-lauderdale.fl.us ormiguela@cityfort.com
Response:
EPA Letter ID: 417
Comment ID: 10521
Commenter: Kenneth Brown, Authority Manager, Stroudsburg Municipal Water Authority
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-24 December 2005
-------
Comment: Stroudsburg Municipal Water Authority
12/01/2003 03:38 PM
To: Group Ow-Docket@EPA
cc:
Subject: Comments-Proposed Long Term #2 Enhanced Surface Water Treatment Rule
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.512 / Virus Database: 309 - Release Date: 8/19/03 STROUDSBURG MUNICIPAL
AUTHORITY.
STROUDSBURG MUNICIPAL AUTHORITY
410 Stokes Avenue
East Stroudsburg, PA 18301
TELEPHONE FAX
(570) 421-3232 (570) 421-2322
www.municipal-authority.stroudsburg.pa.us E-Mail:smah2o@ptdprolog.net
The Stroudsburg Municipal Authority is a small to medium sized water authority located in the Monroe
County area of Pennsylvania. It utilizes both groundwater and surface water sources and will be affected
by these new rule changes.
That is all the Stroudsburg Municipal Authority is asking the Agency to do. Thank you for your
consideration of the Authority's comments.
Sincerely,
Kenneth R. Brown
Authority Manager
Cc: KRB File
Response: response lOO.a.
EPA Letter ID: 419
Comment ID: 10500
Commenter: Billy Turner, President, Columbus Water Works
Commenter Category: Regulated Community (Utilities)
Comment: Billy Turner
12/02/2003 09:59 AM
To: Group Ow-Docket@EPA
cc:
Subject: Proposed Long-Term 2 Enhanced Surface Water Treatment Rule See Attachment
Billy Turner
December 1, 2003
Water Docket
Comment Response for LT2ESWTR E-25 December 2005
-------
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
ATTN: Docket ID No. OW-2002-0039
RE: Proposed Long-Term 2 Enhanced Surface Water Treatment Rule Water Docket:
These are four areas of significant concern in the referenced proposed rule. These are:
Thank you for the opportunity to comment on these rules
Sincerely,
Billy G.Turner
President
BGT/rsb
Response: response lOO.a.
EPA Letter ID: 420
Comment ID: 14087
Commenter: Eddie Partlow, General Manager, THE OLD HICKORY UTILITY DISTRICT
Commenter Category: Regulated Community (Development): Housing, FEEP, NAHB
Comment: CS Title: Comment referring to "source water quality monitoring requirements"
submitted by Eddie Partlow, General Manager, Old Hickory Utility District,
Davidson County, TN
Company/Group/Association Name: Old Hickory Utility District, Davidson County,
TN
Media: PAPER
Comment:
THE OLD HICKORY UTILITY DISTRICT of DAVIDSON COUNTY,TENNESSEE
1050 DONELSON AVENUE
OLD HICKORY, TENNESSEE 37138
TELEPHONE (615)847-2043
FAX (615)847-2628
December 1, 2003
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
ATTN:Docket ID NO OW-2002-0039
RE:Long-term 2 Enhanced Surface Water Treatment Rule
Comment Response for LT2ESWTR E-26 December 2005
-------
(LT2ESWTR)
Dear Sir:
Thank you for consideration of the above comments in relation to the LT2ESWTR.
Sincerely,
Eddie Partlow
General Manager
EP/jw
Response:
EPA Letter ID: 421
Comment ID: 10788
Commenter: David A. Poole,, David A. Poole Consultants, Ltd.
Commenter Category: Consultants: (where self-identified)
Comment: CS Title: Comment on "DRAFT Ultraviolet Disinfection Guidance Manual" submitted
by David A. Poole , David A. Poole Consultants, Ltd.
Company/Group/Association Name: David A. Poole Consultants Ltd.
Media: PAPER
Comment: David A. Poole Consultants Ltd.
1317 129ASt.
Surrey BC
Canada V4A 3Y5
Telephone (604)538-6151
Fax(604)535-3921
EMail DAPCL@sbaw. ca
The US Environmental Protection Agency.
30 November 2003.
Dear Sirs,
Comments on DRAFT Ultraviolet Disinfection Guidance Manual I am a long-in-the-tooth engineer, a
Designer of Water Treatment Plants. I am now working on my second UV project, a large plant of about
500 MGD. Naturally your Draft UV Guidance Manual is of supreme importance to me, and I have
devoured it eagerly. It is positively awesome and one has to admire and reflect on the amount of effort
and hard work that has gone into it. You have invited comments and I am pleased to respond.
My comments are focused on 2 aspects from a designer 's viewpoint:
- AA JHydraulic configuration at the facility relative to validation configuration.
- BB ]Selection of the point of UV application within the process train
Comment Response for LT2ESWTR E-27 December 2005
-------
My comments on those aspects are contained in the specific sections
following this cover letter, but I do have some overall comments, mainly on
Response: response lOO.a.
EPA Letter ID: 422
Comment ID: 10790
Commenter: Alexander Cabaj,, Institut Fur Medizinische Physik Und Biostatistik,
Veterinarmedizinische Universitat
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: CS Title: Comment focusing on the Ultraviolet Disinfection Guidance Manual
submitted by Alexander Cabaj of the Institut Fur Medizinische Physik Und
Biostatistik, Veterinarmedizinische Universitat
Company/Group/Association Name: Institut Fur Medizinische Physik Und
Biostatistik, Veterinarmedizinische Universitat
Comment: See attachment
OBERRAT
DIPL.-ING. ALEXANDER CABAJ
INSTITUT FUR MEDIZINISCHE PHYSIK UND BIOSTATISTIK
VETERINARMEDIZINISCHE UNIVERSITAT WIEN
VETERINARPLATZ 1
A 1210 WIEN
VORSTAND: UNIV.-PROF. DIPL.-ING. DR. G. WINDISCHBAUER
TEL.:+43 125077/4322
FAX : +43 1 250 77/4390
E-MAIL: ALEXANDER.CABAJ@VU-WIEN.AC.AT
UID: ATU37871308
Wien, 22.12.2003
E-MAIL: MED.PHYSIK@VU-WIEN.AC.AT
WWW-SERVER: WWW-MED-PHYSIK.VU-WIEN.AC.AT
INSTITUTE OF MEDICAL PHYSICS AND BIOSTATISTICS
UNIVERSITY OF VETERINARY MEDICINE VIENNA, AUSTRIA
Alexander Cabaj
Response:
EPA Letter ID: 423
Comment ID: 10568
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Comment Response for LT2ESWTR E-28 December 2005
-------
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: Company/Group/Association Name: Tennessee Division of Water Supply
Comment:
STATE OF TENNESSEE
DEPARTMENT OF ENVIRONMENT AND CONSERVATION
WATER SUPPLY
6th Floor, 401 Church Street
Nashville, Tennessee 37243-1549
December 22, 2003
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Attention: Docket No. OW-2002-0039
Dear Sirs:
40CFR141.702 Source Water Monitoring
40CFR141.703 Sampling Schedules
40CFR141.705 Analytical Methods
Response:
EPA Letter ID: 423
Comment ID: 10569
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment:
Thank you for the opportunity to comment.
Sincerely,
Robert L. Foster, Jr.
Deputy Director
Comment Response for LT2ESWTR E-29 December 2005
-------
Cc: Chris Thomas, Region IV
ASDWA
Response:
EPA Letter ID: 424
Comment ID: 10838
Commenter: Frank Ray,,
Commenter Category: Private Citizen (General): i.e., Concerned Citizen
Comment: CS Title: Comment referring to "MCLG of zero for Cryptosporidium is not based on
the best available science" submitted by Frank Ray Company/Group/Association Name:
Portland Oregon
Response:
EPA Letter ID: 425
Comment ID: 10890
Commenter: Kemon Papacosta, ASTM Member D19, ASTM
Commenter Category: Unknown
Comment: CS Title:
Company/Group/Association Name:
Comment:
Kemon Papacosta
12/29/2003 12:57 PM
To:Group Ow-Docket@EPA
cc:
Subject: Docket ID NO. OW-2002-0039 UPDATED COMMENTS
From Kemon Papacosta
Attention: Docket I.D. No. OW-2002-0039
My past comments regarding LT2 ESWTR Toolbox Guidance Manual, June 2003 Draft,
EPA 815-D-03-009, Turbidity Section 7.2.3.2 are based on two studies.
Regards,
Kemon Papacosta
ASTM Member D19 On Water
Phone:(650)366-0119
Fax:(650)366-0152
E-mail: kpapacosta@apsstd.com
Comment Response for LT2ESWTR E-30 December 2005
-------
Response:
EPA Letter ID: 427
Comment ID: 10575
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: CS Title: Comment focusing on "review of what is known about the Bull Run
watershed and Bull Run drinking water", submitted by Scott Fernandez
Company/Group/Association Name:
Comment:
CS Title: Comment focusing on "review of what is known about the Bull Run
watershed and Bull Run drinking water", submitted by Scott Fernandez
Company/Group/Association Name:
December 21,2003
Water Docket
EPA Docket Center
Environmental Protection Agency Room B102
1301 Constitution Ave. N.W.
Washington, D.C.
Attention Docket ID No.OW-2002-0039
202.566.2426 8130AM - 4:30PM
Enclosed please find two separate comment papers x three sets = six
total papers for the Water Docket OW-2002-0039 comment.
2.Allocution and Comment - Long Term 2 Enhanced Surface Water
Treatment Rule
Thank you.
Scott Fernandez
1821NE. 65th
Portland, Oregon, 97213
503.282.1894 message
gldrshci@earthlink.net
December 21,2003
Water Docket
Comments submitted to:
Environmental Protection Agency
Comment Response for LT2ESWTR E-31 December 2005
-------
Att: Docket ID No. OW-2002-0039
Environmental Protection Agency
National Primary Drinking Water Regulations
Long Term 2 Enhanced Surface Water Treatment Rule
The City of Portland, Oregon is served by the Bull Run water system, a historically pristine unfiltered
water source. We have had no illness related to drinking water, and we are not exposed to sewage.
I am a microbiologist and have studied water quality issues as a graduate student and as a private citizen
for many years. I have also been involved in epidemiological studies. We know Cryptosporidium spp.
exists in our watershed and many other places in our environment. This organism is extremely rare in the
Bull Run watershed, and the current disinfection process in conjunction with a long contact time, produce
a public health risk so low it cannot be measured. It is with this in mind I submit these comments. I
appreciate the hard work from the EPA, and thank them for their effort.
Sincerely,
Scott Fernandez, MSc.
[SEE .PDF FILE FOR ITEM #1 - SUMMARY OF BULL RUN TREATMENT -AN
INDEPENDENT REVIEW -LONG-TERM 2 ENHANCED SURFACE WATER TREATMENT
RULE]
ALLOCUTION AND COMMENT
EPA - LONG TERM 2 ENHANCED SURFACE
WATER TREATMENT RULE
AN INDEPENDENT REVIEW
DECEMBER 2003
Key provisions of the current proposed Long Term 2 Enhanced Surface
Water Treatment Rule (LT2ESWTR) regulation include the following;*
-Improve control of microbial pathogens including specifically the protozoan Cryptosporidium spp. in
drinking water
-Source water monitoring for Cryptosporidium spp., with reduced water monitoring requirements for
small systems
-Address health trade-offs with the control of disinfection by-products
-Additional Cryptosporidium spp. treatment for filtered systems based on source water Cryptosporidium
spp. concentrations
-Inactivation of Cryptosporidium spp. by unfiltered systems -Disinfection profiling and benchmarking to
ensure continued fevers of microbial protection while Public Water Systems (PWS) take necessary steps
to comply with new disinfectant byproduct standards
-Covering, treating, or implementing a risk management plan fur uncoverd finished water storage
facilities
-Establish criteria for a number of treatment and management options ie, toolbox' that certain PWS may
implement to meet additional Cryptosporidium spp. treatment requirements.
* Federal Register summary
Comments to the EPA will be presented in the following two part format;
Comment Response for LT2ESWTR E-32 December 2005
-------
-PART B - Comment on the methodology, data, and scientific evidence regarding the measurement,
interpretation, and true public health impact from the microorganism Cryptosporidium spp. in
public drinking water systems.
PartB
The following WQ assumptions are the basis for the EPA proposed regulation and LT2ESWTR
discussion;
1.Cryptosporidium parvum bas been responsible for significant waterborne disease outbreaks
2.1t is likely this organism has responsible for reports of significant endemic disease. *
* Endemic disease occurs continuously or in expected cycles with a certain number of cases expected for a
given period. (10) Or, a disease that occurs continuously and with predictable regularity in a specific area
or population, (measles, chicken pox) (11) These are measurable numbers. There is no measurable direct,
indirect, or collateral evidence demonstrating Cryptosporidium spp. is endemic to municipal treated
drinking water.
Federal Register (FR) p.47652 - Before IESWTR, the EPA had no national survey data and relied on
studies that were local or regional.
For filtered systems, several studies were used including one large study that handled sites from the
eastern and central US. The study included 69 sites with 1-16 samples taken. Some, but not all sites were
sampled 5 times.
Response: see response lOO.aand lOO.f and 1100.1.
EPA Letter ID: 427
Comment ID: 10576
Commenter: Scott Fernandez,,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment:
Thank you
REFERENCES
l.City of New York - Department of Environmental Protection. Information and Monitoring Program.
2003
2.Oregon Department of Human Services. 2003.
3 .Multnomah County Department of Health. 2003.
4.Finch, G.R.,et al. Ozone and Chlorine Inactivation of Cryptosporidium. Proc. AWWA. 1994. Water
Quality Technology Conference.
5. Jenner, A.M., Ruiz, E.J., Dunsten, C., et al. 2002. Arterioscler. Thrornb. Vase. Biol. 22. 574-580
6.EPA-Environmental Technology Initiative. 1998. Chlorine Disinfection. CX824652
7.Grisham,M.B., et al. Chlorination of Endogenous Amines by isolated Neutrophils. Ammonia
Dependent Bactericidal, Cytotoxic, and Cytolytic Activities of the Chloramines. J. Bid. Chem.Vol 259,
issue 16. Augustl984.
S.Englert, R.P.,and Schacter, E. Cell Death Induced by Different Reactive Oxygen Species. J. Biol.
Comment Response for LT2ESWTR E-33 December 2005
-------
Chem. Vol. 277, issue 23. June 7, 2002.
9.EPA Federal Register- p. 47687 microbial antagonism.
lO.Taber Medical Dictionary. 2001
1 l.Medline Dictionary. National Institute of Health. US. National Library of Medicine. May 2003.
12.Clancy, J.L., et al. 1994. Commercial Labs: how accurate are they? J.Am Waterworks Association.
86. 89 -97
13.EPA Federal Register- p. 47675 data inclusion
14.Rocelle, P.A., et al. 2001. Quantitation of Cryptosporidium infection in Cell Culture Using
Colorimetric Assay, J,Eukaryot. Microbial. 48: 565- 574
Response: response lOO.a
EPA Letter ID: 429
Comment ID: 10587
Commenter: Janet Montz, Environmental Specialist, OCI Wyoming, L.P.
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2 sampling for small water systems, submitted
by Janet Montz, OCI Wyoming, L.P.
Company/Group/Association Name: OCI Wyoming
Comment: January 2, 2003
OCI Wyoming, L.P.
P.O. Box 513
Green River, Wyoming 82935
307-872-7143 fax 307-872-7309
Water Docket
Attn: Docket ID Number: OW-2002-0043
Attn: Docket ID Number: OW-2002-0039
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington DC 20460
Please confirm to all the receipt and number for my records. Thanks
To Whom It May Concern:
Sincerely,
Janet Montz
Environmental Specialist
Comment Response for LT2ESWTR E-34 December 2005
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Stage 2 DBF rule comments
1 - IDSE is ridiculous for small systems. For most small systems, sampling anywhere in the system will
result in the same results. Typically, in southwest Wyoming, TTHM/HAA5 testing already resulted in a
waiver because they were below the maximum levels. Changing locations and testing more frequently
won't change that. Most of the Trona patch uses water from the Green River. We all bring in water from
the same source within 4 miles of each other. Our treatment techniques are all similar. If I am not
mistaken, High TTHM/HAA5's result from high TOC levels and since those don't exist, it seems
foolhardy to spend the time, money and effort to collect samples and have them tested to show something
that is already known. Problem areas have already been identified in Stage 1. Why continue to look in
Stage 2? Rather than force small systems to continue to look for something that is not there, effort should
be focused on reducinglevels in problem areas. Unless there is a good reason to believe that the Green
River will suddenly develop high TOC water, or that every water plant has money to burn by over
chlorinating, than I believe that IDSE is not necessary.
Also, If you look at large water systems (>10,000) utilizing the same source water as smaller systems
(< 10,000) and they don't have problems, why isn't triennial (or even biannual) sampling for smaller
systems sufficient.
It also seems redundant for consecutive systems that don't add chlorine to test. Their only purpose is to
distribute the water coming from the larger systems through one meter. These are usually trailer courts or
small apartment complexes that don't treat water anyway. If they were to find high TTHMs and HAAS's
they couldn't do anything, because the larger system is supplying them water and should have already
initiated a program to minimize these levels. Stage 1 should have identified areas of concern. These
problem areas are the ones that need to follow up with Stage 2. Conservative testing for all systems
<10,000 would be to test 1 site during the month of warmest water temperature. If any system is
below the 80/60 ug/L MCL they should be waived from IDSE monitoring no matter what size they are.
2 - Treatment plant monitoring is not warranted for this rule. It should be population based like all the
other water regs. There is no benefit to going to treatment plant vs. population size. If the EPA is
concerned about the general population, than that is best captured by population based sampling.
3 - Testing costs are high in Wyoming because we must send to private labs.
LT2 rule comments
Response: Stage 2 DBP comments are outside the scope of the LT2ESWTR. EPA considered these
comments in the Stage 2 rulemaking.
EPA Letter ID: 430
Comment ID: 10592
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to Source Water Monitoring: Laboratory Capacity,
"to perform cryptosporidium analyses", submitted by Chris Stribley,
Environmental Specialist, Colorado Springs Utilities
Company/Group/Association Name: Colorado Springs Utilities (PWSID # CO0121150)
Comment Response for LT2ESWTR E-35 December 2005
-------
Chris Stribley
Environmental Specialist
Colorado Springs Utilities (PWSID # CO0121150) and Fountain Valley Authority
(PWSID#CO0121300)
Email: cstribley@csu.org
Phone: 719-668-4580
2855 Mesa Rd.
Colorado Springs, CO 80904
Response:
EPA Letter ID: 431
Comment ID: 10596
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to: LT2's "Source Water Monitoring: Sampling
Schedule", submitted by Chris Stribley, Environmental Specialist, Colorado
Springs Utilities
Company/Group/Association Name: Colorado Springs Utilities (PWSID # CO0121150)
Chris Stribley
Environmental Specialist
Colorado Springs Utilities (PWSID # CO0121150) and Fountain Valley Authority
(PWSID #CO0121300)
Email: cstribley@csu.org
Phone: 719-668-4580
2855 Mesa Rd.
Colorado Springs, CO 80904
Response:
EPA Letter ID: 432
Comment ID: 13908
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2's "Source Water Monitoring: Failure to
Complete Monitoring", submitted by Chris Stribley, Environmental Specialist,
Colorado Springs Utilities
Comment Response for LT2ESWTR E-36 December 2005
-------
Company/Group/Association Name: Colorado Springs Utilities (PWSID # CO0121150)
Chris Stribley
Environmental Specialist
Colorado Springs Utilities (PWSID # CO0121150) and Fountain Valley Authority
(PWSID #CO0121300)
Email: cstribley@csu.org
Phone: 719-668-4580
2855 Mesa Rd.
Colorado Springs, CO 80904
Response:
EPA Letter ID: 433
Comment ID: 10599
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2's "Microbial Toolbox: Watershed Protection
Credit", submitted by Chris Stribley, Environmental Specialist, ColoradoSprings
Utilities
Company/Group/Association Name: Colorado Springs Utilities (PWSID # CO0121150)
Chris Stribley
Environmental Specialist
Colorado Springs Utilities (PWSID # CO0121150) and Fountain Valley Authority
(PWSID #CO0121300)
Email: cstribley@csu.org
Phone: 719-668-4580
2855 Mesa Rd.
Colorado Springs, CO 80904
Response:
EPA Letter ID: 434
Comment ID: 10602
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-37 December 2005
-------
Comment: CS Title: Comment referring to LT2's "Microbial Toolbox: Watershed Protection
Credit Re-Approval", submitted by Chris Stribley, Environmental Specialist,
Colorado Springs Utilities
Company/Group/Association Name: Colorado Springs Utilities (PWSID # CO0121150)
Chris Stribley
Environmental Specialist
Colorado Springs Utilities (PWSID # CO0121150) and Fountain Valley Authority
(PWSID #CO0121300)
Email: cstribley@csu.org
Phone: 719-668-4580
2855 Mesa Rd.
Colorado Springs, CO 80904
Response:
EPA Letter ID: 435
Comment ID: 10604
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2's "Reporting Source Water Monitoring
Results", submitted by Chris Stribley, Environmental Specialist, Colorado
Springs Utilities
Company/Group/Association Name: Colorado Springs Utilities (PWSID # CO0121150)
Chris Stribley
Environmental Specialist
Colorado Springs Utilities (PWSID # CO0121150) and Fountain Valley Authority
(PWSID #CO0121300)
Email: cstribley@csu.org
Phone: 719-668-4580
2855 Mesa Rd.
Colorado Springs, CO 80904
Response:
EPA Letter ID: 436
Comment ID: 10606
Comment Response for LT2ESWTR E-38 December 2005
-------
Commenter: Chris Stribley, Environmental Specialist, Colorado Springs Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2's "Uncovered Finished Water Reservoirs",
submitted by Chris Stribley, Environmental Specialist, Colorado Springs
Utilities
Company/Group/Association Name: Colorado Springs Utilities (PWSID # CO0121150)
and Fountain Valley Authority (PWSID # CO0121300)
Chris Stribley
Environmental Specialist
Colorado Springs Utilities (PWSID # CO0121150) and Fountain Valley Authority
(PWSID #CO0121300)
Email: cstribley@csu.org
Phone: 719-668-4580
2855 Mesa Rd.
Colorado Springs, CO 80904
Response:
EPA Letter ID: 437
Comment ID: 10608
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: CS Title: Comment entitled "EPA must evaluate State Approval programs to determine if
they are equivalent to the Lab QA Program" submitted by Richard E. Danielson, Ph.D., Laboratory
Director/Vice President, BioVir Laboratories
Company/Group/Association Name: BioVir Laboratories
Comment:
BioVir Laboratories, Inc.
685 Stone Road, Unit 6
Benicia, CA94510
(707) 747-5906
1-800-GIARDIA
FAX (707) 747-1751 ! WEB: www.biovir.com
DATE: January 5, 2004
TO: U.S. EPA
Water Docket
FROM: Richard E. Danielson, Ph.D.
Laboratory Director / Vice President
Comment Response for LT2ESWTR E-39 December 2005
-------
SUBJECT: Comments on the LT2ESWTR. Docket # OW-2002-0039.
Please find below our comments on 40 CFR Parts 141 & 142; EPA 815-Z-03-004.
Docket # OW-2002-0039.
Page 47732, Section IV. K.I. Approval of Updated Versions of EPA Methods 1622
and 1623; #5.
Page 47731, Section IV. K.I.
Page 47733, Section K.I. Approval of Updated Versions of EPA Methods 1622 and
1623
Response:
EPA Letter ID: 437
Comment ID: 10613
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment:
Page 47733, Section K.2. E. Coli
Response:
EPA Letter ID: 437
Comment ID: 10615
Commenter: Richard Danielson, Laboratory Director/Vice President, BioVir Laboratories
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment:
Page 47735. IV. L. Laboratory Approval.
Response:
EPA Letter ID: 439
Comment ID: 10746
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-40 December 2005
-------
Comment: CS Title: Attachment to comment referring to LT2's (LT2) source water
monitoring, microbial toolbox issue and filter backwash recycle issue, submitted
by Don A. Colalancia, Board of Water Works of Pueblo, Colorado
Company/Group/Association Name: Board of Water Works of Pueblo, Colorado
Comment: OW-2002-0039-0439
January 5, 2004
Don A. Colalancia
Water Quality Manager
Board of Water Works of Pueblo, Colorado
319 W. Fourth Street
Pueblo, CO 81003
PWSID#CO0151500
Attached are comments for the LT2ESWTR. Please E-mail with questions or concerns.
Thank you,
Don A. Colalancia
Subject: Docket ID No. OW-2002-0039 Comments LONG TERM 2 ENHANCED SURFACE WATER
TREATMENT RULE (LT2ESWTR)
Source Water Monitoring
Monitoring Issue 1 Lab Capacity
Monitoring Issue 2 Grandfathering Data
Monitoring Issue 3 Failure to Complete Monitoring
Monitoring Issue 4 Sampling Schedule
Response:
EPA Letter ID: 439
Comment ID: 10747
Commenter: Don Colalancia, Water Quality Manager, Board of Water Works of Pueblo, Colorado
Commenter Category: Regulated Community (Utilities)
Comment:
Monitoring Issue 5 Laboratory Costs
Monitoring Issue 6 Monitoring Location
Microbial Toolbox
Comment Response for LT2ESWTR E-41 December 2005
-------
Filter Backwash Recycle
Response:
EPA Letter ID: 440
Comment ID: 10798
Commenter: Gary Hum, Director of Source & Treatment, Central Arkansas Water
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2's monitoring for cryposporidium and E.coli,
laboratory availability and toolbox technologies, submitted by Gary Hum,
Director of Source and Treatment, Central Arkansas Water
Company/Group/Association Name: Central Arkansas Water
Comment:
Gary.Hum@carkw.com
01/05/2004 05:52PM
To: Group Ow-Docket@EPA
cc:
Subject: Comments on proposed LT2ESWTR
Thank you again for the opportunity to comment on this very important
environmental rule.
Sincerely,
Gary Hum
Director of Source & Treatment
Central Arkansas Water
338 Pleasant Valley Drive
Little Rock, AR 72212
(501)223-1577
gary.hum@carkw.com
Response:
EPA Letter ID: 441
Comment ID: 10763
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment Response for LT2ESWTR E-42 December 2005
-------
Comment: CS Title: Comment referring to LT2's surface source water treatment for
waterborne disease-causing organisms, submitted by Jeffrey Gordon, Pennsylvania
Department of Environmental Protection
Company/Group/Association Name: Division of Drinking Water Management, Bureau of
Water Supply and Wastewater Management, PA Department of Environmental
Protection
Comment:
"Gordon, Jeffrey"
01/05/2004 02:35 PM
To: Group Ow-Docket@EPA
cc: "Marrocco, Frederick", Nick Tymchenko/R3/USEPA/US@EP
A, Jason Gambatese/R3/USEPA/US@EPA, "Daniels, Lisa",
"Nesmith, Rodney" , "Consonery, Phil"
, Rick Rogers/R3/USEPA/US@EPA
Subject: Attention Docket ID No. OW-2002-0039
Water Docket (Mail Code 410IT)
Docket No. OW-2002-0039
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Docket Clerk:
One of the primary interests of a public water supplier is to remove numerous waterborne disease-causing
organisms that are present in surface water sources. If the source water concentrations overwhelm the
treatment processes, or if a treatment breakdown occurs due to human error or equipment malfunction,
the costs associated with a waterborne disease outbreak are staggering. Disease prevention saves millions
of dollars in expenses that businesses, homeowners, local government and state government would incur
in response to an outbreak. Accordingly, Pennsylvania has invested enormous resources in protecting
Pennsylvanians from waterborne diseases and other acute health risks. Public health protection under the
various Surface Water Treatment Rules remains a top priority and continues to require substantial State
agency resources.
This successful investment has resulted in no waterborne disease outbreaks associated with drinking
water obtained from Pennsylvania's surface water sources since 1995.
Sampling locations
EPA requested comments on how the effect of recycling backwash wastewater should be considered in
LT2 monitoring. Under LT2, water suppliers must conduct source water monitoring for Cryptosporidium
to determine Bin requirements. Some surface water treatment plants recycle spent filter backwash,
thickener supernatant, or liquids from dewatering processes.
* LT2 requires small suppliers using lake and reservoir sources to conduct source water monitoring for
Cryptosporidium if their annual mean E. coli concentration is greater than 10/100 ml. The criteria for
suppliers using
Comment Response for LT2ESWTR E-43 December 2005
-------
Response: response lOO.a.
EPA Letter ID: 441
Comment ID: 10764
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment:
DEP appreciates the opportunity to comment on the proposed LT2 rule. Please contact Phil Consonery of
my staff at (717) 772-2184 with questions regarding our comments. Please send confirmation of receipt to
me at jegordon@state.pa.us .
Sincerely,
Jeffrey A. Gordon
Chief
Division of Drinking Water Management
Bureau of Water Supply & Wastewater Management
PA Department of Environmental Protection
PO Box 8467
Harrisburg, PA 17105-8467
Response:
EPA Letter ID: 442
Comment ID: 10781
Commenter: Robert Foster, Deputy Director, State of Tennessee Department of Environment and
Conservation Water Supply
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "Compliance Requirements Table, Source Water
Monitoring, Sampling Schedules, Analytical Methods, and Plain Language Rules"
submitted by Robert L. Foster, Jr., Deputy Director, State of Tennessee
Company/Group/Association Name: State of Tennessee Department of Environment and
Conservation Water Supply
Comment:
STATE OF TENNESSEE
DEPARTMENT OF ENVIRONMENT AND CONSERVATION
WATER SUPPLY
6th Floor, 401 Church Street
Nashville, Tennessee 37243-1549
December 22, 2003
Comment Response for LT2ESWTR E-44 December 2005
-------
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Attention: Docket No. OW-2002-0039
Dear Sirs:
40CFR141.701 Compliance Requirements Table
Thank you for the opportunity to comment.
Sincerely,
Robert L. Foster, Jr.
Deputy Director
Cc: Chris Thomas, Region IV
ASDWA
Response:
EPA Letter ID: 444
Comment ID: 10806
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment: CS Title: Comment referring to "Section IV, Discussion of Proposed LT2ESWTR
Requirements" submitted by Rene Pelletier, P.O., Manager, New Hampshire Department of
Environmental Services
Company/Group/Association Name: New Hampshire Department of Environmental Services
Comment:
January 5, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington DC 20460
Attn. Docket ID No. OW-2002-0039
Subject: Proposed Regulations, Long Term 2 Enhanced Surface Water Treatment Rule (LT2)New
Hampshire (NH) Comments
The NH Department of Environmental Services is pleased to comment on the proposed rule as follows.
For clarity, our comments are ordered as issues appear in Section IV, Discussion of Proposed
Comment Response for LT2ESWTR E-45 December 2005
-------
LT2ESWTR Requirements:
A. Additional Cryptosporidium (Crypto) Treatment Technique Requirements for
Filtered Systems
B. Unfiltered System Treatment Technique Requirements for Crypto
C. Options for Systems to Meet Crypto Treatment Requirements - No comments
D. Disinfection Benchmarks for Giardia lamblia (Giardia) and viruses - No
comments
E. Additional Treatment Technique Requirements-Uncovered Storage - No comments
F. Compliance Schedules
G. Public Notice Requirements - No comments
H. Variances and Exemptions- No comments
I. Requirements for -Qualified Operators - No comments
J. System Reporting and Recordkeeping Requirements
Response:
EPA Letter ID: 444
Comment ID: 10807
Commenter: Rene Pelletier, Manager, Land Resource Programs, New Hampshire Department of
Environmental Services
Commenter Category: State/Tribe Government
Comment:
K. Analytical Methods - No comments
L. Laboratory Approval - No comments
M. Requirements for Sanitary Surveys - No comments
Please call Robert Mann at 603-271-2953 or at rmann@des.state.nh.us if there are
any questions about this letter.
Sincerely,
Rene Pelletier, P.G., Manager
Land Resource Programs
cc. ASDWA
Comment Response for LT2ESWTR E-46 December 2005
-------
Response:
EPA Letter ID: 445
Comment ID: 10817
Commenter: James Fay, Chair, PSW Steering Committee, The Partnership for Safe Water
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment referring to "LT2ESWTR: Toolbox Credit for Individual Filter
Performance" submitted by Stephen A. Hubbs Past Chair, PSW Steering Committee
and James W. Fay Chair, PSW Steering Committee, The Partnership for Safe Water
(PSW)
Company/Group/Association Name: The Partnership for Safe Water (PSW)
Comment:
January 6, 2004
To: Comments Clerk, LT2ESWTR
RE: LT2ESWTR: Toolbox Credit for Individual Filter Performance
Recommended Changes to the Individual Filter Effluent Performance Criteria
Specific Limit for Toolbox IFE and CFE credit
Consideration for Deviations from the Target Value Established in the Rule
Response:
EPA Letter ID: 445
Comment ID: 10818
Commenter: James Fay, Chair, PSW Steering Committee, The Partnership for Safe Water
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: objectives of improved public health through improved water quality, please do
not hesitate to contact us.
Sincerely,
Stephen A. Hubbs
Past Chair, PSW Steering Committee
James W. Fay
Chair, PSW Steering Committee
Response:
Comment Response for LT2ESWTR E-47 December 2005
-------
EPA Letter ID: 446
Comment ID: 10804
Commenter: James Scanlan,, Fort Worth Water Department
Commenter Category: Regulated Community (Utilities)
Comment:
Company/Group/Association Name: Fort Worth Water Department
Comment: These comments are from James Scanlan at the Fort Worth Water Department, 1000
Throckmorton, Fort Worth, TX 76102. Email-james.scanlan@fortworthgov.org
Response:
EPA Letter ID: 447
Comment ID: 10792
Commenter: Michael Barsotti, Water Quality Director, Camplain Water District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "Toolbox Credit for individual filter performance" submitted
by Michael Barsotti, Water Quality Director, Champlain Water District
Company/Group/Association Name: Champlain Water District
Comment: See attached comments
To: Comments Clerk, LT2SWTR
RE: Toolbox Credit for individual filter performance
Champlain Water District comments on LT2SWTR
Champlain Water District appreciates the opportunity to comment upon the
Contact information: Michael Barsotti
Water Quality Director
Champlain Water District
403 Queen City Park Road
South Burlington VT 05403
mikeb(g),cwd-h2o.org
Response:
EPA Letter ID: 449
Comment ID: 10823
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-48 December 2005
-------
Comment: CS Title: Attachment to comment referring to LT2's (LT2) monitoring for cryptosporidium,
e-coli, and turbidity for small water systems, submitted by David J. Lewis, Superintendent, Kenosha
Water Utility
Company/Group/Association Name: Kenosha Water Utility
Comment:
Dave Lewis 01/07/2004 07:19 AM
Please respond to Dave Lewis
To:Group Ow-Docket@EPA
cc:
Subject: Docket ID No. OW-2002-0039
Please consider the attached comments regarding the proposed LT2ESWTR.
Thank you,
David J. Lewis
Superintendent - Water Production Division
Kenosha Water Utility
4401 Green Bay Road
Kenosha, WI 53144
Bus: 262 653 4331
Fax: 262 653 4362
e-mail: dave.lewis@kenoshawater.org
OW-2002-0039-0449
Water Docket, EPA Mail Code 410IT, 1200
Pennsylvania Ave., NW/, Washington DC, 20460
Attention Docket ID No. OW-2002-0039
Dear Sir or Madam,
There are several areas of the proposed rules on which we would like to comment.
Response:
EPA Letter ID: 451
Comment ID: 14157
Commenter: Eric Abrams, Superintendent, McMinnville Water and Light
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Attachment to Comment referring to LT2's (LT2) proposed rule on source water
monitoring submitted by Eric Abrams, Superintendent, McMinnville Water and Light
Company/Group/Association Name: McMinnville Water and Light
Comment:
Comment Response for LT2ESWTR E-49 December 2005
-------
"Eric M. Abrams" 01/06/2004 02:05 PM
To: Group Ow-Docket@EPA
cc:
Subject: EPA OW-2002-0039
To Whom it may concern,
Attached are my comments on the proposed LT2 Rules.
Sincerely,
Eric Abrams
Water Supt.
McMinnville Water and Light
P.O. Box 638
855 Marsh Lane
McMinnville, Oregon 97128
OW-2002-0039-0451
20460
Attn: Docket ID No. OW-2002-0039
OW-Docket@epa.gov
To Whom It May Concern:
Sincerely,
Eric Abrams
Water Superintendent
1
e
r Treatment Rules (LT2ESWTR)
splayName
Response:
EPA Letter ID: 452
Comment ID: 10931
Commenter: Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "concerns with pivotal flawed areas of the
proposed rule" submitted by Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Company/Group/Association Name: City of Chandler, Arizona
Comment Response for LT2ESWTR E-50 December 2005
-------
Comment:
Chandler + Arizona
Where Values Make The Difference
December 30,2003
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue NW
Washington, DC 20460
Attention: Docket ID NO.OW-2002-0039
Proposed Long Term 2 Enhanced Surface Water Treatment Rule
Federal Register Volume 68, Number 154, August 11, 2003
Dear Comment Officer,
concerns about the following pivotal flawed areas of the proposed rule: 1 Requiring source water sample
collection points after presedimentation basins, 2) automatic Bin 4 classification for systems that fail to
complete monitoring requirements, and 3) the lack of bin classification provisions for plants that
operate less than 12 months per year.
We appreciate the opportunity to comment on the Long Term 2 Enhanced Surface Water Treatment Rule.
We hope these comments will be addressed.
Sincerely,
Jacqueline Strong Water Quality Advisor
C: Karen Barfoot
James Cairns
Dave Siege 1
Municipal Utilities Department
Water Resources/Water Conservation
Telephone (480) 782-3580
Fax (480) 782-3495
Mailing Address:
Mail Stop 404
PO Box 4008
Chandler, Arizona 85244-4008
Location:
249 East Chicago Street
Chandler, Arizona 85225
Comment Response for LT2ESWTR E-51 December 2005
-------
Response: response lOO.a.
EPA Letter ID: 453
Comment ID: 10940
Commenter: Thomas A. Wurtz, General Manager, Metropolitan Utilities District of Omaha
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to monitoring issues, flexibility for water suppliers, untreated
water sampling, fewer rules, longer time span to conduct testing, UV disinfection, and Part IV, C, 6 from
Thomas A. Wurtz, General Manager, Metropolitan Utilities District
Company/Group/Association Name: Metropolitan Utilities District of Omaha
Comment:
Metropolitan Utilities District of Omaha
1723 Harney Street
Omaha, NE 68102
January 6, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Attention: Docket ID No. OW-2002-0039
The following comments to the proposed Long Term 2 Enhanced Surface Water Treatment Rule are
submitted by the Metropolitan Utilities District of Omaha, a Public Water Supplier:
Provisions to ensure proper monitoring already exist in the regulations.
Thomas A. Wurtz
General Manager
Metropolitan Utilities District of Omaha
Response:
EPA Letter ID: 454
Comment ID: 10951
Commenter: Richard D. Letterman,, Department of Civil and Environmental Engineering, Syracuse
University
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment Response for LT2ESWTR E-52 December 2005
-------
Comment: CS Title: Comment focusing on "results published an American Water Works Association
Research Foundation on the low-level turbidity measurement" submitted by Raymond D. Letterman,
Department of Civil and Environmental Engineering, Syracuse University
Company/Group/Association Name: Syracuse University
Comment:
Comment focusing on "results published an American Water Works Association Research Foundation on
the low-level turbidity measurement" submitted by Raymond D. Letterman, Department of Civil and
Environmental Engineering, Syracuse University
Attention Docket ID No. OW-2002-0039
Federal Register/ Vol 68, No. 154/ Monday, August 11, 2003
Raymond D. Letterman
Department of Civil and Environmental Engineering
220 Hinds Hall
Syracuse University
Syracuse, New York 13244-1190
(315)443-3307
rdletter@syr.edu
Response:
EPA Letter ID: 455
Comment ID: 10955
Commenter: Kirk Stacker, Director of Utilities, City of Kearney Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to the monthly monitoring of source water for cryptosporidium
submitted by Kirk Stacker, Director of Utilities, City of Kearney Utilities Department
Company/Group/Association Name: City of Kearney Utilities Department
Comment:
January 8, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Comment Response for LT2ESWTR E-53 December 2005
-------
Attention: Docket ID No. OW-2002-0039
If you have any questions or need any additional information please don-t hesitate to contact me at 308-
233-3268 or by e-mail atkstocker@kearneygov.org.
Sincerely,
CITY OF KEARNEY
Kirk Stacker
Director of Utilities
Response:
EPA Letter ID: 456
Comment ID: 10959
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: CS Title: Comment referring to disagreement with certain provisions of the proposed rule
submitted by Valerie Hunter, MD, Friends of the Reservoirs
Company/Group/Association Name: Friends of the Reservoirs
Comment:
Friends of the Reservoirs
Citizens joining to protect Portland's historic reservoirs and water system
3534 S.E. Main Street, Portland, OR 97214
www.friendsofreservoir.org
www.lists.pdx.edu/mttabor
January 5. 2004
Water Docket
Environmental Protection Agency
Mail Code 410 IT
1200 Pennsylvania Ave, NW
Washington DC 20460
Attention Docket ID No. OW-2002-0039
Sincerely,
Valerie Hunter, MD
Member, Friends of the Reservoirs
1400 SE 60th Ave
Portland, OR 97215
vhunter@comcast.net
Comment Response for LT2ESWTR E-54 December 2005
-------
Response:
EPA Letter ID: 457
Comment ID: 11878
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on supporting Stage 2B MCLs, but do not supporting Stage 2A
MCLs" submitted by Nolton G. Johnson, Chief, Water Resources Branch, Georgia Department of Natural
Resources
Company/Group/Association Name: Georgia Department of Natural Resources
Comment:
Please direct any questions about the attached comments to:
Onder E. Serefli, Program Manager
Drinking Water Permitting & Engineering Program
Georgia Environmental Protection Division
2 MLK, Jr. Drive, S.E., Suite 1362 East
Atlanta, Georgia 30334
Tel #(404) 651-5156
Fax #(404) 651-9590
E-mail: onder_serefli@dnr.state.ga.us
Georgia Department of Natural Resources
2 MLK, Jr. Drive, S.E., East Floyd Tower, Atlanta, Georgia 30334
Lonice C. Barrett, Commissioner
Carol A. Couch, PhD., Director
Environmental Protection Division
January 5, 2004
Water Docket
Mail Code: 4101T
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
ATTN: Docket ID Nos. OW-2002-0039 and OW-2002-0043
Docket Clerk:
The State of Georgia appreciates the opportunity to comment on the proposed Long Term 2 Enhanced
Surface Water Treatment Rule (LT2ESWTR) and the Stage 2 Disinfectants and Disinfection Byproducts
Comment Response for LT2ESWTR E-55 December 2005
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Rule (Stage 2 DBPR) as listed in the August 11, 2003 Federal Register (68 FR 47639) and August 18,
2003 Federal
Our comments are provided by way of three attachments (see PDF):
Attachment A (pages 1-10): Overall Comments on the Proposed LT2ESWTR and Stage 2 DBPR. It
explains Georgia's views and preferred approaches to the two regulations
Attachment B (pages 11-15): Docket ID No. OW-2002-0039
Response to EPA Requests for Comment on the Proposed LT2ESTWR
Attachment C (pages 16-23): Docket ID No. OW-2002-0043
Response to EPA Requests for Comment on the Proposed Stage 2 DBPR
support the EPA's approach under the Stage 2 DBPR that all customers should receive water that meets
DBP standards, including those in consecutive systems. However, we are concerned about the monitoring
proposed under Stage 2 DBPR. We believe that the number of required samples be based on population
served only and not be based on the number of treatment plants and/or bulk purchase entry points. We
concur with the proposal that the compliance determination be based on locational running annual
average (LRAA).
requested comment in the Federal Register notices are included in Attachment B (LT2ESWTR)(see PDF)
and Attachment C (Stage 2 DBPR)(see PDF).
The State of Georgia again appreciates the opportunity to provide comments on these proposed rules and
looks forward to working with EPA to ensure that the final rules are both protective of public health and
implementable at the state and local level. Please direct any questions or concerns regarding these
comments to Onder Serefli of my staff at onder_serefli@dnr.state.ga.us or (404)
651-5156
Sincerely,
Nolton G. Johnson, P.E., Chief
Water Resources Branch
cc: Chris Thomas, Chief
Drinking Water Section, USEPA Region 4
Attachment A
State of Georgia Drinking Water Program
Overall Comments on the Proposed LT2ESWTR and Stage 2 DBPR
January 5, 2004
Rule Development Process
Response: Comments on the Stage 2 DBPR are outside the scope of the LT2ESWTR
Comment Response for LT2ESWTR E-56 December 2005
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EPA Letter ID: 457
Comment ID: 11879
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Overall Approach for the Stage 2 DBPR
In general, we support the Stage 2 DBPR approach that all customers should receive water that meets
disinfection byproduct (DBP) standards (including those in consecutive systems). We believe that the
number of required samples under this rule be based on population served only and not be based on the
number of treatment plants and/or bulk purchase entry points.
We concur with the proposal that the compliance determination be based on locational running annual
average (LRAA). Specifically, we support the use of location running annual averages to determine
compliance with the Stage 2B TTHM and HAAS MCLs of 0.080 mg/L and 0.060 mg/L, respectively,
using a population-based approach for determining the number of samples required.
We believe that the best way to control DBFs is at the water treatment plant (as opposed to solely through
the distribution system management for consecutive systems, although we recognize the benefits of
proper distribution system management). In addition, DBP monitoring should be based on a combined
distribution system of the wholesaler and the consecutive system(s) to the extent that the interconnection
of these systems justifies treating them as a single system for monitoring purposes. The state agency
should have the flexibility to determine when consecutive systems should be considered a combined
system for the DBP monitoring purposes.
Since changing to LRAAs using a population-based approach will result in a change in the number of
samples required for most systems, we believe that additional monitoring to identify optimal DBP
sampling points is appropriate only for some systems. Monitoring waivers should be available for those
systems in which additional monitoring would not assist in determining optimal sites. These are usually
small systems with limited distribution network (probably serving < 500 people).
We do not support the proposed approach of using the Stage 2A MCLs of 0.120 mg/L for TTHMs and
0.100 mg/L for HAASs as LRAAs at Stage 1 monitoring locations three years following the rule-s
promulgation (for systems serving > 10,000 people). The Stage 2A MCLs may cause more confusion than
public health protection and are of limited value since EPA projects that only a very small percent of the
systems in compliance with the Stage 1 RAAs will exceed the Stage 2 LRAAs. We believe that the Stage
2A MCLs will result in data management tracking problems, an increase in regulatory complexity,
expensive database upgrades, and unnecessary increase in monitoring and reporting violations. In
lieu of the transitional Stage 2A MCLs, we recommend that water systems be required to continue to
comply with the existing Stage 1 D/DBP RAA MCLs until such time as they are required to comply with
the Stage 2B MCLs. This will allow water systems to focus their efforts and resources on planning for
improvements needed to comply with Stage 2B MCLs.
Implementation Schedule
Stage 2 DBPR Implementation Schedule
We support the concept of water systems taking additional DBP samples to determine optimal locations
Comment Response for LT2ESWTR E-57 December 2005
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for Stage 2B monitoring, but would prefer incorporating this additional monitoring into the initial round
of compliance monitoring (not a separate IDSE).
We suggest an approach that retains the current implementation structure for most NPDWRs of setting
specific requirements and allowing water systems three years to comply with the new requirements. The
approach builds on the -Concurrent Compliance Monitoring- option that EPA briefly described on page
49606 of the Stage 2 DBPR preamble and would be in addition to the proposed requirements for water
systems to comply with the Stage 2A MCLs as a LRAA three years following rule promulgation.
EPA-s Proposed Approach: EPA-s proposed approach involves water systems performing additional
DBP monitoring to identify optimal Stage 2B sampling locations through a process that does not include
state review and/or approval prior to monitoring (e.g., Initial Distribution System Evaluation (IDSE),
system-specific studies). Under the proposed approach, water systems would conduct additional DBP
monitoring at an increased number of locations and submit a report to the primacy agency recommending
optimal DBP sampling locations for Stage 2B monitoring. This monitoring would occur soon after rule
promulgation and would be in addition to Stage I/Stage 2A monitoring, but would not be used for
compliance purposes. We are concerned about this proposed implementation schedule, because it does
not allow adequate time for the states and the water systems to determine those situations in which the use
of a combined distribution system is appropriate and prevents the states from reviewing DBP
monitoring locations and approve the monitoring plans before the sampling starts.
Georgia-s Preferred Approach: We prefer an approach that builds on the -Concurrent Compliance
Monitoring- option that EPA briefly described on page 49606 of the Stage 2 DBPR preamble. Under this
approach, water systems would be required to collect initial Stage 2B compliance samples at an increased
number of locations (possibly twice the number of samples that would be required for Stage 2B) during
the first year of compliance monitoring as a way to identify sites with high DBP levels, instead of
performing a separate IDSE or other system-specific study. Following one year of concurrent compliance
monitoring, the state and the water system would select routine Stage 2B compliance monitoring
locations using a protocol similar to the one used to recommend Stage 2B compliance monitoring
locations in the IDSE report.
The states and the water systems can work together soon after rule promulgation to determine which
systems will need to identify new monitoring locations for compliance with Stage 2B MCLs (identifying
which systems are eligible for a small system waiver or the 40/30 certification and which systems
are not) as well as which consecutive systems should be included in a larger combined distribution system
(and therefore not required to prepare their own DBP monitoring plan). States can work with those
systems that need to identify new monitoring locations for compliance with Stage 2B MCLs in the
development a DBP monitoring plan, using EPA-s IDSE guidance manual to assist in preparing the
plan.
Once a monitoring plan has been developed, the system would then submit the plan to the state for
approval. Since states will have been working with their water systems in preparing the monitoring plan,
states should be able to approve monitoring plans in a timely manner (most likely between three and six
months depending on the complexity of the system). Upon receiving state approval, the water system
would then have three years (with a possible two year extension for capital improvements) before
compliance monitoring at the selected sites would be required. All samples collected would be used for
determining compliance with the Stage 2B MCLs using LRAAs. After the first year of monitoring, water
systems would have the opportunity to request a reduction in the number of monitoring locations at which
they are required to monitor (similar to the proposed requirement to recommend Stage 2B sites in the
IDSE).
Comment Response for LT2ESWTR E-58 December 2005
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We believe this approach will provide better public health protection than that provided under the
proposed implementation schedule by ensuring that systems that are required to monitor do so in
appropriate locations and with adequate oversight. This approach also allows adequate time for states and
water systems to determine those situations in which use of a combined distribution system is appropriate.
Furthermore, this approach would require receipt of state approval of their DBF monitoring plans thus
ensuring the monitoring locations are acceptable to the state; would stagger the workload for reviewing
DBF monitoring plans; and, would require routine DBF monitoring on a calendar year basis instead of a -
years since rule promulgation- year and allow incorporation of the monitoring requirements into the
Standard Monitoring Framework.
Georgia-s Views on LT2EWSTR
Microbial Monitoring for Filtered Systems
Georgia-s Views on Stage 2 DBPR
DBF Health Effects
One key issue related to public health risk is the conclusion that EPA draws from the reproductive and
developmental health affects data. In the -Risk to Public Health- section (page 49562 of the preamble),
EPA describes how they -believe that the weight of evidence of both the reproductive and developmental
toxicological and epidemiological databases suggests that exposure to DBFs may induce potential adverse
health effects on reproduction and fetal development at some DBP exposures. However, additional
toxicological work is necessary to quantify the mode of action for the effects observed.- In this section,
EPA does not quantify the potential risks. We support this type of general discussion of the potential sub-
chronic health risks. We also support EPA-s efforts to obtain additional data on sub-chronic health effects
of DBFs and offer their assistance in those efforts.
Consecutive Systems
As stated previously, we support the use of location running annual averages to determine compliance
with the Stage 2B TTHM and HAAS MCLs of 0.080 mg/L and 0.060 mg/L, respectively, using a
population-based approach for determining the number of samples required. We also believe that the best
way to control DBFs is at the water treatment plant (as opposed to through distribution system
management). In addition, DBP monitoring should be based on a combined distribution system of the
wholesale system and the consecutive system(s) to the extent that the interconnection of these systems
justify treating them as a single system for monitoring purposes. The state primacy agency is the proper
agency in determining when consecutive systems should be considered a combined system for DBP
monitoring purposes.
We prefer to use special primacy requirements to describe how to address consecutive systems both when
the wholesale system proposes to include the consecutive system in the combined system as well as when
the wholesale system does not include the consecutive system. The special primacy description could
also describe how the states will address the question of timing of monitoring in consecutive systems.
Combined Distribution Systems
In the event a wholesaler proposes to include one or more consecutive systems in its DBP monitoring
plan, states and the water systems will need to work together to determine appropriate monitoring
locations for the initial Stage 2B DBP monitoring as well as any reduction in monitoring. While we
Comment Response for LT2ESWTR E-59 December 2005
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generally support requiring at least one sample in each consecutive system for initial Stage 2B
monitoring, we do not necessarily agree that at least one sample needs to be taken in each consecutive
system under reduced monitoring. The systems and the state primacy agency can collectively determine
the appropriate monitoring locations as well as how public notification should be handled in systems
where a sample was not taken.
Population-Based DBF Monitoring
We support population-based monitoring for all water systems in an effort to provide equal protection to
all. We do not anticipate significant transitional costs associated with moving from a plant-based to a
population-based approach.
DBF MCLs
We support the Stage 2B MCLs, but do not support the Stage 2A MCLs.
Significant Excursions
We concur with the control of peak DBFs if there is a sub-chronic health affect associated with the
exposure and believe that EPA should define a significant excursion as any result that exceeds the sub-
chronic level for each DBF. If EPA is unable to set such scientifically supportable limits, the significant
excursion requirements should be deferred until such time as limits can be set.
We would prefer that the concept of significant excursions be addressed as -guidance- only. However, if
EPA insists in retaining the proposed significant excursion provision in this rule without being able to set
specific sub-chronic limits, EPA should clearly define what constitutes a significant excursion and
not defer to states to define a significant excursion as a special primacy requirement.
We would be supportive of a simple site-specific determination such as one in which the sample result is
twice the MCL. If the locational sample results were twice the appropriate MCL, then the water system
would have incurred a significant excursion, and would need to investigate the circumstances that led
to the excursion for discussion with the state no later than the next sanitary survey. The primacy state
should have the flexibility to determine the appropriate level of corrective action.
IDSE
We understand the concept of an Initial Distribution System Evaluation (IDSE) to identify appropriate
DBP monitoring locations, but do not support the IDSE as a regulatory requirement.
Variances and Exemptions
We concur that variances and exemptions should not be allowed under the Stage 2 DBPR for the reasons
listed. Instead of exemptions, we prefer to use other mechanisms, such as Consent Orders, in instances
where water systems cannot achieve compliance in the required timeframe.
Best Available Technology for Consecutive Systems
We recognize EPA-s need to identify best available technologies (BATs) for a proposed rule, but we do
not agree that there is a practical or affordable BAT that consecutive systems can use to address high DBP
levels. The proposed BAT for consecutive systems is improved distribution system and storage tank
management to reduce detention time plus the use of chloramines for disinfectant residual maintenance.
Comment Response for LT2ESWTR E-60 December 2005
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Management of hydraulic flow and minimizing residence time is a practice that all systems should
already be doing and therefore most likely will not have a major impact on DBF levels. Chloramination is
an extremely complex treatment and most consecutive systems buy water because, they do not want to
construct water treatment facilities or operate chemical feed systems. Treating purchased water with
chloramines would raise many issues for consecutive systems as this treatment involves using either a
liquid or gaseous form of ammonia, a dangerous chemical that requires careful, daily observation and
adjustments. Also, consecutive systems would need to address issues that arise if the system that they
purchase water from practices chlorination and not chloramination. In addition, chloramines contribute to
nitrification problems in low flow areas and tanks that need to be monitored on a frequent basis
(monthly if no problems, daily to weekly if problems). EPA needs to clearly consider all impacts of
naming chloramination as a BAT for consecutive systems. Additionally, the consecutive system BAT
contradicts the premise of the Stage 1 Rule that DBFs are best controlled through TOC removal and
optimizing disinfection practices.
Public Right-to-Know
We support the public-s right to know about the quality of the water and the risks posed by violations of
drinking water standards. We concur that the Public Notification Rule and the Consumer Confidence
Report Rule are the appropriate vehicles to provide this information and that the proposed Tier 2
and Tier 3 violations are consistent with the Tiers established in the Public Notification Rule.
With respect to the need for changes to the health effects language for DBFs to address potential
reproductive and developmental health endpoints, we support EPA-s proposal that additional health
effects language is not needed at this time. Any new language would cause undue alarm among the public
as the reproductive and developmental endpoints are not well defined at this time.
Data Management Issues
In addition to the general concepts discussed in the LT2ESWTR section of these comments, which apply
equally to the Stage 2 DBPR, we are concerned with the potential data management implications of EPA
promulgating the DBP monitoring scheme included in the proposed rule. Specifically, programming data
management systems to determine compliance for DBFs under a scenario in which some water systems
perform DBP monitoring on a plant-based approach while other water systems perform DBP monitoring
on a population-based approach would be quite costly. Changing to a population-based approach for all
water systems would negate this problem and allow for consistency across systems.
Special Primacy Requirements
We do not think that the special primacy requirements are necessary under the Georgia-s preferred
approach, described in Attachment A.
Estimated Cost
We are concerned with EPA-s estimated cost to state drinking water programs to implement the Stage 2
DBPR. The proposed rule is complex and will require significant monitoring and reporting by systems
and significant oversight of these activities by states. The economic analysis implies an annualized total
cost to each state of less than $25,000. This estimate appears to significantly underestimate the
implementation cost of the rule. Specifically, it may not accurately capture the costs of revisions to
primacy applications, state rule adoption, compliance actions against water systems, and significant data
management requirements.
Comment Response for LT2ESWTR E-61 December 2005
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Further, the implementation activities in the first six to nine years following promulgation of the final rule
are expected to be quite significant with somewhat of a reduction in activity after that time. We suggest
that EPA discount the labor and material costs associated with implementation over a 10-year period
rather than a 20-year period as in the proposed rule.
Attachment B
Docket ID No. OW-2002-0039
Response to EPA Requests for Comment on the Proposed LT2ESWTR
January 5, 2004
Section I Summary (pages 47644-47645
No comments requested. N/A
Section II Background (pages 47645-47650)
No comments requested. N/A
Section III.C Cryptosporidium Occurrence (pages 47652-47659)
No comment.
Section IV.A Additional Cryptosporidium Treatment Technique Requirements for
Filtered Systems (pages 47665-47679)
Section IV.E Additional Treatment Technique Requirements for Systems with
Uncovered Finished Water Storage Facilities (pages 47718-47719)
No comment.
Section IV.F Compliance Schedules (pages 47719-47722)
Response: Comments on the Stage 2 DBPR are outside the scope of the LT2ESWTR. EPA considered
these comments as part of the Stage 2 rulemaking.
EPA Letter ID: 457
Comment ID: 11880
Commenter: Nolton G. Johnson, Chief, Georgia Department of Natural Resources, Water Resources
Branch
Commenter Category: State/Tribe Government
Comment: Section IV.J System Reporting and Recordkeeping Requirements (page 47724-47731)
No comment.
Analytical Methods (pages 47731-47734)
Comment Response for LT2ESWTR E-62 December 2005
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Laboratory Approval (pages 47735-47736)
No comment.
Section VI. Economic Analysis (pages 47738-47758)
No comment.
Section VII.B Paperwork Reduction Act (pages 47758-47759)
No comment.
Attachment C
Docket ID No. OW-2002-0043
Response to EPA Requests for Comment on the Proposed Stage 2 DBPR
January 5, 2004
I. Summary (pages 49552-49554)
No comment.
II. Background (pages 49554-49557)
No comment.
III.D.2.a Cancer Epidemiology (pages 49562-49564)
No comment.
III.G Public Health Risk (pages 49557-49565)
We do not support EPA-s attempts to quantify the potential risk or draw definitive conclusions from the
data due to the lack of completeness. The EPA implies that the overall cancer epidemiology and
toxicology data support the decision to pursue additional DBP control measures as reflected in the Stage 2
DBPR. Although the Stage 2 DBPR may attempt to reduce short-term exposures to address potential
reproductive and developmental health and cancer risks, it does not provide a maximum contaminant
level (MCL) or exposure dose at which the consumer, especially the sensitive populations (children,
elderly, pregnant women) would be greatly harmed.
IV.C DBP Occurrence within Distribution Systems (pages 49565-49576)
No comment.
V.A.3 MCLG for Chloroform (pages 49576-49579)
We do not have data to comment on this proposal.
V.B.3 MCLGs for TCAA and MCAA and Health Effects Data on DBAA and MBAA (pages
49579-49582)
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We do not have data to comment on this proposal. We also do not have additional health effect
information on DBAA or MBAA, for which MCLGs have not yet been established.
V.C.3 Consecutive Systems (pages 49582-49584)
As indicated previously, we support the use of location running annual averages to determine compliance
with the Stage 2B TTHM and HAA5 MCLs of 0.080 mg/L and 0.060 mg/L, respectively, using a
population-based approach for determining the number of samples required. We also believe that the best
way to control DBFs is at the water treatment plant (as opposed to through distribution system
management, although we recognize the benefits of proper distribution system management).
We agree that consumers in consecutive systems should be protected just as well as customers of
wholesale systems and vice versa. Consecutive systems should be required to comply within the same
time frame as the wholesale system with the earliest compliance date in the combined distribution system.
In addition, DBF monitoring should be based on a combined distribution system of the wholesale system
and the consecutive system(s) to the extent that the interconnection of these systems justifies treating
them as a single system for monitoring purposes. We strongly recommend that the monitoring criteria for
all consecutive systems (including the wholesale systems) be based solely on population. A population-
based approach would eliminate oversight and consistency problems associated with complicated
distribution system relationships (multiple sources, seasonal-use issues, etc.). The state primacy agency is
the proper agency in determining when consecutive systems should be considered as a combined system
for DBF monitoring purposes.
We propose to use special primacy requirements to describe how to address consecutive systems when
the wholesale system proposes to include the consecutive system in the combined system. We also
propose to use the primacy requirements to address the wholesale system without a distribution system of
its own, which sell all the water it produced to the consecutive systems. The special primacy description
would also describe how Georgia will address the question of timing of monitoring in consecutive
systems. We prefer flexibility in implementing the Stage 2 DBPR, including implementation in
consecutive systems.
We support the proposed approach of basing the number of DBF samples required for water systems that
purchase 100 percent of their water on the population served (instead of the number of bulk purchase
entry points) and believe that this approach should be extended to all water systems.
We have the following comments regarding EPA-s proposed definitions:
* Consecutive system: We do not object to the proposed definition, but prefer that 90 consecutive days
per year (or longer, possibly six months) be used as the length of time to be a consecutive system.
* Finished water: The application of corrosion control chemicals as post-treatment should not be
considered in the determination of whether the water is finished water.
* Wholesale system: The above comments on the definition of consecutive system apply equally to this
definition.
* Consecutive system entry point: The above comments on the definition of consecutive system apply
equally to this definition.
* Combined distribution system: This definition appears to be appropriate provided the states determine
which systems should be considered a combined distribution system.
* Need for additional definitions: Not needed.
With respect to the monitoring requirements, we support EPA-s proposal to provide states with the
opportunity to specify alternative requirements for multiple consecutive systems in a combined
distribution system. However, while we support requiring at least one sample in each consecutive system
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for initial Stage 2B monitoring, we do not necessarily agree that at least one sample needs to be taken in
each consecutive system under reduced monitoring. The systems and the state primacy agency can
collectively determine the appropriate monitoring locations as well as how public notification should be
handled in systems where a sample was not taken.
We do not object to the proposed requirement that all consecutive systems comply with the monitoring
requirements for disinfectant residual monitoring and the MRDLs for chlorine and chloramines.
V.D.3 MCLs for TTHM and HAAS (pages 49584-49587)
We support the proposed approach of using location running annual averages (LRAAs) to determine
compliance with DBF MCLs for the reasons listed in the preamble. We also support the Stage 2B TTHM
and HAA5 MCLs of 0.080 mg/L and 0.060 mg/L, respectively.
We do not support the proposed approach of using the Stage 2A MCLs of 0.120 mg/L for TTHMs and
0.100 mg/L for HAA5s as LRAAs at Stage 1 monitoring locations three years following the rule-s
promulgation (for systems serving > 10,000 people). The Stage 2A MCLs may cause more confusion than
public health protection and are of limited value since EPA projects that only a very small percent of the
systems in compliance with the Stage 1 RAAs will exceed the Stage 2 LRAAs. We believe that the Stage
2A MCLs will result in data management tracking problems, an increase in regulatory complexity,
expensive database upgrades, and opportunities for monitoring and reporting violations. In lieu of
the transitional Stage 2A MCLs, we recommend that water systems be required to continue to comply
with the existing Stage 1 D/DBP RAA MCLs until such time as they are required to comply with the
Stage 2B MCLs. This will allow water systems to focus their efforts and resources on planning for
improvements needed to comply with Stage 2B MCLs.
We support maintaining the Stage 1 MCL forbromate of 0.010 mg/L.
We do not support alternative approaches considered by the FACA for the reasons discussed in the
preamble. The Preferred Alternative in combination with the IDSE may not remove all DBP peaks. The
Preferred Alternative assumes that IDSE will identify compliance monitoring sites that represent peak
DBP levels in the distribution system. We are not convinced that IDSE (a one-time survey conducted over
the period of a year) would identify peak DBP concentrations within a distribution system. Distribution
systems are dynamic and can be influenced by several factors including changes in the population
densities, modifications of the distribution network, systems growth, addition or deletion of water supply
sources, seasonal variations in water consumption, recent flushing events, etc.
V.E.3 Requirements for Peak TTHM and HAA5 Levels (page 49587-49588)
We concur with the control of peak DBFs if there is a sub-chronic health affect associated with the
exposure; however, we believe that EPA must define a significant excursion as any result that exceeds the
sub-chronic level for each DBP. If EPA is unable to set such scientifically supportable limits, the
significant excursion requirements should be deferred until such time as limits can be set.
We would prefer that the concept of significant excursions be addressed as -guidance- only. However, if
EPA insists in retaining the proposed significant excursion provision in this rule without being able to set
specific sub-chronic limits, EPA must clearly define what constitutes a significant excursion and not
defer to states to define a significant excursion as a special primacy requirement.
We would be supportive of a simple site-specific determination such as one in which the sample result is
twice the MCL. If the locational sample results were twice the appropriate MCL, then the water system
Comment Response for LT2ESWTR E-65 December 2005
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would have incurred a significant excursion, and would need to investigate the circumstances that led
to the excursion for discussion with the state no later than the next sanitary survey. We do not believe that
significant excursions should be considered -violations- that would require enforceable corrective
action(s). We also believe that incurring a significant excursion should not require public notification or
additional language in the Consumer Confidence Report.
V.F.3 BAT for TTHM and HAAS (page 49588-49590)
We recognize EPA-s approach to identify best available technologies (BATs) for a proposed rule, but do
not agree that there is a practical or affordable BAT that consecutive systems can use to address high DBF
levels. The proposed BAT for consecutive systems is improved distribution system and storage tank
management to reduce detention time plus the use of chloramines for disinfectant residual maintenance.
Management of hydraulic flow and minimizing residence time is a practice that all systems should
already be doing and therefore most likely will not have a major impact on DBF levels. Chloramination is
an extremely complex treatment and most consecutive systems buy water because they do not want to
construct additional water treatment facilities or operate chemical feed systems. Treating purchased water
with chloramines would raise many issues for consecutive systems as this treatment involves using either
a liquid or gaseous form of ammonia, a dangerous chemical that requires careful, daily observation and
adjustments. Also, consecutive systems would need to address issues that arise if the system that they
purchase water from practices chlorination and not chloramination. In addition, chloramines contribute to
nitrification problems in low flow areas and tanks that need to be monitored on a frequent basis (monthly
if no problems, daily to weekly if problems). EPA needs to clearly consider all impacts of naming
chloramination as a BAT for consecutive systems. Additionally, the consecutive system BAT contradicts
the premise of the Stage 1 Rule that DBFs are best controlled through TOC removal and optimizing
disinfection practices.
V.G.3 MCL, BAT, and Monitoring for Bromate (pages 49590-49592)
No comment.
V.H.3 IDSE (pages 49592-49595)
In general, we do not support the assumption that IDSE (a one-time survey conducted over the period of
one year) would identify peak DBF concentrations within a distribution system. We support the concept
of an Initial Distribution System Evaluation (IDSE) to identify appropriate DBF monitoring locations, but
do not support the IDSE as a regulatory requirement. Water quality in the distribution systems can be
influenced by several factors including changes in the population densities, modifications of the
distribution network, systems growth, addition or deletion of water supply sources, seasonal variations in
water consumption, recent flushing events, etc. Instead, we suggest that EPA-s Standard Monitoring
Framework (nine-year compliance cycle) be used to perform additional monitoring to identify optimal
Stage 2B monitoring locations.
We believe that tc "a. Applicability " \1 4 non-transient non-community water systems should not be
required to perform additional monitoring to determine optimal Stage 2 DBF monitoring locations. They
should be eligible for waivers.
We support the proposed small water system waivers and believe that states should have the flexibility in
defining applicability. Although, we support EPA-s proposed population cutoff of 500 people, we also
suggest waivers for those systems serving less than 1000 people with limited distribution network.
V.I.3 Monitoring Requirements and Compliance Determinations for Stage 2A and 2B TTHM and HAA5
Comment Response for LT2ESWTR E-66 December 2005
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MCLs (pages 49595-49605)
We support basing DBF monitoring requirements on the population served only, not the number of
treatment plants and/or entry points for the reasons listed in the preamble. We believe that the population-
based approach would ensure more equal and rational monitoring requirements among systems serving
similar populations than the plant-based approach does, while providing improved representation of DBF
occurrence throughout the distribution system. This approach would simplify implementation of the rule
by the states and the water systems.
For the number of samples that should be required for different populations for routine monitoring, we
recommend using the existing system size breakdowns:
[SEE TABLE, P.22 IN PDF]
We believe that states should have the flexibility to determine the number of monitoring sites and samples
for the wholesale systems, on a case-by case basis, based on its connection with the consecutive systems
(assuming a worst case scenario where a combined distribution approach is not used). This is
especially true for those wholesale systems that do not have their own distribution systems.
We believe that waivers should be available for systems in which additional monitoring would not assist
in determining optimal sites. We oppose any rule language specifying specific monitoring locations in
high-rise buildings. We suggest that water systems collect not more than twice the number of samples
required for routine monitoring to determine the optimal Stage 2B sites.
V.J.3 Compliance Schedules (pages 49605-49607)
We prefer an approach that builds on the -Concurrent Compliance Monitoring- option that EPA briefly
described on page 49606 of the Stage 2 DBPR preamble. Under this approach, water systems would be
required to collect initial Stage 2B compliance samples at an increased number of locations (possibly
twice the number of samples that would be required for Stage 2B) during the first year of compliance
monitoring as a way to identify sites with high DBP levels, instead of performing a separate IDSE or
other system-specific study. Following one year of concurrent compliance monitoring, the state and the
water system would select routine Stage 2B compliance monitoring locations using a protocol similar
to the one used to recommend Stage 2B compliance monitoring locations in the IDSE report.
We suggest an approach in which each state has the flexibility to describe how it plans to ensure that all
systems complete the required compliance monitoring by the regulatory deadline as a special primacy
requirement. Such an approach would allow the states to use a -phased approach- for bringing water
systems into compliance and stagger the workload of reviewing DBP monitoring plans.
We believe that the states and the water systems can work together soon after rule promulgation to
determine which systems will need to identify new monitoring locations for compliance with Stage 2B
MCLs (identifying which systems are eligible for a small system waiver or the 40/30 certification and
which systems are not) as well as which consecutive systems should be included in a larger combined
distribution system (and therefore not required to prepare their own DBP monitoring plan). We can work
with the water systems and help them identify new monitoring locations for compliance with Stage 2B
MCLs and assist them in the development a DBP monitoring plans, by using the EPA-s IDSE guidance
manual.
Once a monitoring plan has been developed, the system would then submit the plan to the state for
approval. Since states will have been working with their water systems in preparing the monitoring plan,
Comment Response for LT2ESWTR E-67 December 2005
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we would be able to approve monitoring plans in a timely manner (most likely between three and six
months depending on the complexity of the system). Upon receiving state approval, the water system
would then have three years (with a possible two year extension for capital improvements) before
compliance monitoring at the selected sites would be required. All samples collected would be used for
determining compliance with the Stage 2B MCLs using LRAAs. After the first year of monitoring, water
systems would have the opportunity to request a reduction in the number of monitoring locations at which
they are required to monitor (similar to the proposed requirement to recommend Stage 2B sites in the
IDSE).
We believe this approach will provide better public health protection than that provided under the
proposed implementation schedule by ensuring that systems that are required to monitor do so in
appropriate locations and with adequate oversight.
V.K.2 Public Notification Requirements (page 49607)
We support the public-s right to know about the quality of its water and the risks posed by violations of
drinking water standards. We concur that the Public Notification Rule and the Consumer Confidence
Report Rule are the appropriate vehicles to provide this information and that the proposed Tier 2
and Tier 3 violations are consistent with the Tiers established in the Public Notification Rule.
With respect to the need for changes to the health effects language for DBFs to address potential
reproductive and developmental health endpoints, we support EPA-s proposal that additional health
effects language is not needed at this time. Any new required language could cause undue alarm among
the public as the reproductive and developmental endpoints are not well defined at this time.
Also, as indicated previously, we concur that incurring a -significant excursion- should not require public
notification nor additional language in the Consumer Confidence Report.
V.L.2 Variances and Exemptions (page 49607-49610)
We concur that variances and exemptions should not be allowed under the Stage 2 DBPR for the reasons
listed. We do not like to use the variance provisions of the SDWA because of the potential public
perception that a standard different than the one Federally promulgated is acceptable and defensible. In
regards to exemptions, we prefer to take corrective measures, such as the issuance of Consent Orders, in
instances where water systems cannot achieve compliance in the required timeframe.
V.N.3 System Reporting and Recordkeeping (page 49610)
We support EPA-s determination to retain the Stage 1 reporting and recordkeeping requirements. We do
not support the IDSE as a separate activity and therefore do not support the proposed reporting
requirement associated with the IDSE. We do not have the resources to adequately review, track, and
comment on individual IDSE reports submitted by the public water systems.
V.O.10 Analytical Methods (pages 49610- 49618)
No comment.
V.P.5 Laboratory Certification and Approval (pages 49618- 49622)
No comment.
Comment Response for LT2ESWTR E-68 December 2005
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VI.G State Implementation Issues (pages 49622- 49623)
We do not think that any special primacy requirements are necessary under the Georgia-s preferred
approach, described in Attachment A.
VII Economic Analysis pages 49623- 49648)
e are concerned with EPA-s estimated cost to state drinking water programs to implement the Stage 2
DBPR. The proposed rule is complex and will require significant monitoring and reporting by systems
and significant oversight of these activities by states. We believe EPA is significantly underestimating the
implementation cost of the rule. Specifically, it does not accurately capture the costs of revisions to
primacy applications, state rule adoption, compliance actions against water systems, and significant data
management requirements.
Further, the implementation activities in the first six to nine years following promulgation of the final rule
are expected to be quite significant with somewhat of a reduction in activity after that time. We suggest
that EPA discount the labor and material costs associated with implementation over a 10-year period
rather than a 20-year period as in the proposed rule.
Section VIII.B Paperwork Reduction Act (pages 49648- 49649)
No comment.
VIII.E Executive Order 13132: Federalism (pages 49654-49655)
We support EPA-s policy to promote communications between EPA and state and local governments and
appreciate this opportunity to provide comment.
VII.L Plain Language (page 49658)
We do not believe that the requirements in the rule are clearly stated. The number and the volume of
separate Stage 2 DBPR and LT2ESWTR guidance manuals that have to be issued to interpret the
intentions of the rules substantiate that the requirements in the rules are not clearly stated. However, we
still support EPA-s continued efforts to write these regulations in plain language.
Response: Comments on the Stage 2 DBPR are outside the scope of the LT2ESWTR. EPA considered
these comments as part of the Stage 2 rulemaking.
EPA Letter ID: 458
Comment ID: 10968
Commenter: Anonymous458,, West Virginia Bureau for Public Health, Office of Environmental Health
Services
Commenter Category: State/Tribe Government
Comment: CS Title: Comment referring to "The Source Water Protection Assessment would be
a better mechanism to monitor changes." submitted by the West Virginia Bureau
for Public Health, Office of Environmental Health Services
Company/Group/Association Name: West Virginia Bureau for Public Health, Office
of Environmental Health Services
Comment Response for LT2ESWTR E-69 December 2005
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Comment:
Docket ID: No. OW-2002-0039
On behalf of the Bureau for Public Health of the State of West Virginia, the following comments are
being submitted for your consideration for the Long Term 2 Enhanced Surface Water Treatment Rule,
published in the Federal Register on
August 11,2003:
Response:
EPA Letter ID: 460
Comment ID: 10990
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Public comments entitled "Comments on Proposed Long Term 2 Enhanced
Surface Water Treatment Rule (LT2ESWTR)" submitted by, Vernon R. Land, Water Quality Manager,
City of Norfolk, Virginia
Company/Group/Association Name: City of Norfolk, Virginia
Comment:
January 7, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
Attention: Docket ID No. OW-2002-0039
RE: Comments on Proposed LT2ESWTR
Ladies and Gentlemen:
The City of Norfolk, Department of Utilities has reviewed the proposed Long Term 2 Enhanced Surface
Water Treatment Rule and offers the following comments.
Sincerely,
Vernon R. Land
Water Quality Manager
City of Norfolk, Virginia
Comment Response for LT2ESWTR E-70 December 2005
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cc: EPA Comments file
Director of Utilities
Asst. Director of Utilities
Response:
EPA Letter ID: 461
Comment ID: 10985
Commenter: Greg Merrigan, Chair, South Dakota Section of the American Waterworks Association
(SDAWWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Attachment to comment referring to LT2's (LT2) monitoring requirements,
sampling schedule, laboratory capacity, Greg Merrigan, Chair, South Dakota Section of the American
Waterworks Association (SDAWWA)
Company/Group/Association Name: South Dakota Section of the American Water Works
Association (SDAWWA)
Comment: OW-2002-003 9-0461
Attachment to comment referring to LT2's (LT2) monitoring requirements, sampling schedule, laboratory
capacity, Greg Merrigan, Chair, South Dakota Section of the American Water Works Association
(SDAWWA)
January 7, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
Attention Docket ID No. OW-2002-0039
There are several issues that we would like to comment concerning the proposed
rules.
If you have any questions on the attached comments, please contact Greg
Merrigan, SDAWWA Chair, at 605-267-2088 or by e-mail at gpmcrws@iw.net.
Sincerely.
Greg Merrigan
Chair, SDAWWA
Comment Response for LT2ESWTR E-71 December 2005
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Response:
EPA Letter ID: 463
Comment ID: 10996
Commenter: Anonymous462,, Washington Aqueduct
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Public comment referring to "National Primary Drinking Regulations:
Stage 2 Disinfectants and Disinfection Byproducts Rule", submitted by Washington Aqueduct
Company/Group/Association Name: Washington Aqueduct
Comment:
National Primary Drinking Water Regulations: Stage 2 Disinfectants and
Disinfection Byproducts Rule
40 CFR 141 and 142
Docket ID Number: OW-2002-0039
Reference: Section IV.A Additional Cryptosporidium Treatment Technique
Requirements for Filtered Systems
Section IV.L Laboratory Approval
EPA requests comment
Whether the criteria for analyst experience in the Lab QA Program are necessary, whether systems are
experiencing difficulty in finding laboratories that have passed the Lab QA Program to conduct
Cryptosporidium analysis, and whether any of the Lab QA Program criteria should be revised to improve
the LT2ESWTR lab approval process.
Response:
EPA Letter ID: 463
Comment ID: 11027
Commenter: Richard Wilson, Environmental Services Manager, Anaheim Public Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2's monitoring requirements, microbial toolbox,
and filter backwash recycling submitted by Richard Wilson, Environmental Services Manager, Anaheim
Public Utilities Department
Company/Group/Association Name: Anaheim Public Utilities Department
Comment:
Dick Wilson 01/07/2004 11:23 AM
Comment Response for LT2ESWTR E-72 December 2005
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To:Group Ow-Docket@EPA
cc:
Subject: Attention Docket ID No. OW-2002-0039
January 7, 2004
USEPA
Office of Water
Docket ID No. OW-2002-0039
Subject: Comments on Long Term 2 Enhanced Surface Water Treatment Rule
Thank you for the opportunity to comment on this proposed drinking water regulation that appeared in the
August 11, 2003 Federal Register. In order to provide some perspective for our comments, here's a brief
description of our water system. The City of Anaheim's water system serves a population of 330,000
residents with 75% of the water supplied via 25 production wells, 15% as treated purchased water through
seven interconnections with Metropolitan Water District of Southern California and the remaining water,
also supplied by MWD, is treated at our own surface water treatment plant. Our conventional treatment
plant uses ozone and appears to meet all the proposed standards. The following are our
specific comments on the proposal:
2. The preamble to rule on page 47666 states, "Any filtered system that fails to complete LT2ESWTR
monitoring requirements must meet the treatment requirements for Bin 4."
If you have any question, or would like clarification on any of these issues, please call me a t 714-765-
4277.
Sincerely,
Richard Wilson
Environmental Services Manager
Anaheim Public Utilities Department
dwilson@anaheim.net
Response:
EPA Letter ID: 464
Comment ID: 10998
Commenter: Dr. Susan Boutrous, President, Environmental Associates Ltd.
Commenter Category: Independent Laboratories
Comment Response for LT2ESWTR E-73 December 2005
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Comment: CS Title: Public comments focusing on "proposed LT2 Rule" submitted by Dr. Susan
Boutros, President, Environmental Associates Ltd.
Company/Group/Association Name: Environmental Associates Ltd.
Comment:
Comments on LT2
Docket Identification Number: OW-2002-0039
Submitted by Dr. Susan Boutros, President, Environmental Associates Ltd.
Introduction
Proposed Changes to Methods
There are a few method issues that we would like to mention.
If further clarification is desired on any of the above comments I can be
contacted at the laboratory at (607) 272-8902 or by email: susanboutros@eal-
labs.com
Response:
EPA Letter ID: 466
Comment ID: 11005
Commenter: Larry Thelen, Manager, North Dakota Department of Health
Commenter Category: State/Tribe Government
Comment: CS Title: Public comment referring to "Long Term 2 Enhanced Surface Water Treatment
Rule (L2ESWTR) as listed in the August 11, 2003 Federal Register" submitted by Larry Thelen,
Manager, North Dakota Department of Health
Company/Group/Association Name: North Dakota Department of Health
Comment:
January 8, 2004
Water Docket (MC-4101T)
Docket No. OW-2002-0039
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Docket Clerk:
Comment Response for LT2ESWTR E-74 December 2005
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North Dakota (ND) appreciates the opportunity to comment on the proposed Long Term 2 Enhanced
Surface Water Treatment Rule (LT2ESWTR) as listed in the August 11, 2003 Federal Register (68 FR
47639).
We appreciate the opportunity to provide comments on this proposed rule.
Sincerely,
Larry Thelen, Manager
Drinking Water Program
Division of Municipal Facilities
North Dakota Department of Health
1200 Missouri Avenue
Bismarck, ND 58501
lthelen@state.nd.us
Response:
EPA Letter ID: 467
Comment ID: 11034
Commenter: Anonymous467,, Louisville Water Company
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "monitoring requirements that are problematic and may result
in monitoring failures due to circumstances beyond the utility's (utility) control" submitted by Louisville
Water Company
Company/Group/Association Name: Louisville Water Company
Comment:
Louisville Water Company
Page 1 of4
January 8, 2004
COMMENTS ON PROPOSED STAGE 2 D/DBP RULE AND LT2ESWTR
Louisville Water Company
550 S. 3rd Street
Louisville, Kentucky 40202
Issue 5: Combined and Individual Filter Performance
EPA proposed additional Cryptosporidium removal credits for filter performance
based on combined filter effluent (CFE) turbidity and individual filter effluent
Comment Response for LT2ESWTR E-75 December 2005
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(IFE) turbidity. LWC has two issues associated with the language in the proposed
rule.
Response:
EPA Letter ID: 468
Comment ID: 11050
Commenter: Michael L. McGlinchy, Public Utilities Bureau Manager, City of Akron Public Utilities
Bureau
Commenter Category: Regulated Community (Utilities)
Comment:
January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Subject: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule 68
Federal Register 47639, Docket No. OW-2002-0039
Dear Sir or Madam:
The City of Akron appreciates the opportunity to review and comment on the proposed Long-Term 2
Enhanced Surface Water Treatment Rule (LT2ESWTR). We have reviewed the proposed rule language
and associated guidance and have provided comments on the following key items:
More detailed discussions regarding our concerns with these issues are attached. We appreciate your
review and consideration of our concerns regarding these critical issues. If you have any questions
regarding these comments please contact me at (330) 375-2627.
Sincerely,
Michael L. McGlinchy, P.E.
Public Utilities Bureau Manager
MLM:BM:cw
Attachments
CitiCenter - 146 S. High Street - Room 900 - Akron, Ohio 44308 - (330) 375-2627
- FAX (330) 375-2072
www.ci.akron.oh.us
Mr. Conwill
January 9, 2004
Page 2
Comment Response for LT2ESWTR E-76 December 2005
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Microbial Toolbox, Application and Demonstration, General
Response:
EPA Letter ID: 470
Comment ID: 11057
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on raising issues of concern, suggested improvements and
agreeing with the premises of the rule submitted by Jay L. Rutherford, Director, Vermont Water Supply
Division, Vermont Department of Environmental Conservation
Company/Group/Association Name: Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Comment:
WATER SUPPLY DIVISION
103 South Main Street
Old Pantry Building
Waterbury, VT 05671-0403
TEL 802-241-3400
TOLL Free 800 823-6500
FAX 802-241-3284
January 8, 2004
Water Docket
Attn: Docket ID No. OW-2002-0039
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
Dear Water Docket Clerk:
The Vermont drinking water program is pleased to submit the enclosed comments on the proposed Long
Term 2 Enhanced Surface Water Treatment Rule which was published in the Federal Register on August
11,2003.
We are submitting this letter and our enclosed comments [SEE PDF] in electronic
and paper format for your consideration.
Sincerely,
Comment Response for LT2ESWTR E-77 December 2005
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Jay L. Rutherford, P.E., Director
c: Jeffrey Wennberg, Commissioner, Vermont Department of Environmental Conservation
Vermont Water Supply Division
Comments on the Proposed Long Term 2 Enhanced Surface Water Treatment Rule
General Comments
Vermont appreciates EPA-s efforts at providing a pre-publication version of this rule, as well as,
providing additional time to comment on this and the Stage 2 Disinfectants and Disinfection Byproducts
Rule. Additionally, we appreciate Linda Tsang of EPA Region I meeting with a variety of staff members
in Vermont to explain and discuss the proposed rule and draft guidance documents. We have a better
understanding of the impact that these rules will have on Vermont-s drinking water program and our
public water systems because of these efforts.
Specific Comments
Unfiltered System Treatment Technique Requirements for Cryptosporidium pp.
47679-47681
Response:
EPA Letter ID: 470
Comment ID: 11058
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment:
Options for Systems to Meet Cryptosporidium Treatment Requirements pp. 47681-47715
Disinfection benchmarks for Giardia lamblia and viruses pp. 47715-47718
Additional Treatment Technique Requirements for Systems with Uncovered Finished
Water Storage Facilities pp. 47718-47719
Comment Response for LT2ESWTR E-78 December 2005
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Compliance Schedules pp. 47719-47722
Response:
EPA Letter ID: 470
Comment ID: 11059
Commenter: Jay L. Rutherford, Director, Vermont Water Supply Division, Vermont Department of
Environmental Conservation
Commenter Category: State/Tribe Government
Comment:
Laboratory Methods pp.47734-47736
Vermont has no comments on this section.
Requirements for Sanitary Surveys Conducted by EPA pp.47736-47737
Vermont has no comments on this section.
Paperwork Reduction Act pp.47758-47759
Vermont has no comment on this section.
Response:
EPA Letter ID: 471
Comment ID: 11104
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment:
Company/Group/Association Name: The Washington Suburban Sanitary Commission (WSSC)
Comment:
January 9, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT, 1200 Pennsylvania Ave., NW
Washington, DC 20460
Attention: Docket ID No. OW-2002-0039.
Dear Sirs:
scientific/technical uncertainties facing drinking water utilities. It is with these thoughts in mind that we
Comment Response for LT2ESWTR E-79 December 2005
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respectfully offer the enclosed specific comments on the LT2ESWTR. We would appreciate your
thoughtful consideration of these comments and suggestions.
Please feel free to contact Dr. Mohammad Habibian, WSSC-s Environmental Group Leader, at 301/206-
8083 or mHabibi@wsscwater.com if you have any questions regarding these comments.
Sincerely,
John R. Griffin
General Manager
cc: Diane VanDe Hei (AMWA)
Source Water Monitoring and Compliance Provisions
Microbial Toolbox
Response:
EPA Letter ID: 471
Comment ID: 11161
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment:
Company/Group/Association Name: The Washington Suburban Sanitary Commission (WSSC)
Comment:
January 9, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT, 1200 Pennsylvania Ave., NW
Washington, DC 20460
Attention: Docket ID No. OW-2002-0039.
Dear Sirs:
scientific/technical uncertainties facing drinking water utilities. It is with these thoughts in mind that we
respectfully offer the enclosed specific comments on the LT2ESWTR. We would appreciate your
thoughtful consideration of these comments and suggestions.
Please feel free to contact Dr. Mohammad Habibian, WSSC-s Environmental Group Leader, at 301/206-
Comment Response for LT2ESWTR E-80 December 2005
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8083 or mHabibi@wsscwater.com if you have any questions regarding these comments.
Sincerely,
John R. Griffin
General Manager
cc: Diane VanDe Hei (AMWA)
Source Water Monitoring and Compliance Provisions
Microbial Toolbox
Response:
EPA Letter ID: 472
Comment ID: 11148
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment: CS Title: Comment focusing on "Stage 2 Microbial Disinfection Byproducts (Stage 2
M/DBP) Agreement in Principle and the basic components of that Agreement as reflected in the Long
Term 2 Enhance Surface Water Treatment Rule" submitted by Dave Van Fleet,
Company/Group/Association Name: City of Peoria, Arizona Utilities Department
Comment:
City of Peoria
UTILITIES DEPARTMENT
8401 W Mopnroe St, Peoria, AZ 85345
Phone: 623-773-7286 Fax: 623-773-7291
January 9, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave NW
Washington, DC 20460
Attention: 68 Federal Register 47639, Docket No. OW-2002-0039
Dear EPA:
Comment Response for LT2ESWTR E-81 December 2005
-------
Our general comments on the LT2ESWTR are:
Our comments on specifically requested areas are as follows:
P. 47678. 3. Request for comment. EPA requests comments on all aspects of the monitoring and
treatment requirements. EPA also requests comments on the following issues:
P. 47700. c. Request for comment. EPA invites comment on the following issues regarding the proposed
Cryptosporidium treatment credit for combined filter performance:
- Do the studies cited here support awarding 0.5 log credit for CFE jl)_0.15 NTU 95% of the time?
- Does currently available turbidity monitoring technology accurately distinguish differences between
values measured near 0.15 NTU?
Response:
EPA Letter ID: 472
Comment ID: 11149
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment:
P. 47711. c. Request for comments. EPA requests comment on the proposed approach to awarding credit
for inactivation of Cryptosporidium by chlorine dioxide and ozone, including the following specific
issues:
- Determination of CT and the confidence bounds used for estimating log inactivation of
Cryptosporidium;
_ The ability of systems to apply these CT tables in consideration of the MCLs for bromate and chlorite;
and
- Any additional data that may be used to confirm or refine the proposed CT tables.
P. 47714, Individual Filer Performance, c. Request for comment. The Agency invites comment on the
following issues related to the proposed credit for individual filter performance.
- Are there existing peer review programs for which treatment credit should be
awarded under the LT2ESWTR? If so, what role should primacy agencies play in
Comment Response for LT2ESWTR E-82 December 2005
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establishing and managing any such peer review program?
Response:
EPA Letter ID: 472
Comment ID: 11150
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment:
P. 47714. Other Demonstration of Performance, c. Request for comment. The Agency requests comment
on today-s proposal for systems to demonstrate higher Cryptosporidium removal levels. EPA specifically
requests comment on the following issues:
_ Approaches that should be considered or excluded for demonstration of performance(DOP) testing;
P. 47722. 3. Request for Comments. EPA requests comments on the treatment technique compliance
schedules for large and small systems in today-s proposal, including the following issues:
P. 47722. 3. Request for Comment. EPA requests comment on whether the violations of additional
treatment requirements for Cryptosporidium under the LT2ESWTR should require a Tier 2 public notice
and whether the proposed health effects language is appropriate.
Sincerely,
Dave Van Fleet
Environmental Quality Assurance Officer
File
Response:
EPA Letter ID: 472
Comment ID: 11153
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment:
COP staff members attended the October 9, 2003 Environmental Protection Agency (EPA) stakeholder
meeting via the Internet on the LT2ESWTR and Stage 2 M/DBP rules. We are greatly disappointed that
Comment Response for LT2ESWTR E-83 December 2005
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EPA has not provided the promised follow-up summary of all questions/responses presented. The
presenter indicated that all questions received and not answered during the presentation would also
be included in the stakeholder meeting summary. This meeting summary, to our knowledge, is not
available and would have been useful in preparing these comments.
Response: EPA believes that the proposed LT2ESWTR, preamble, and supporting documentation were
sufficient for the public to understand and comment on the proposed requirements. Public presentations
on the proposed requirements were not intended to substitute for or supplement the proposed rule
documents.
EPA Letter ID: 473
Comment ID: 10708
Commenter: Mary Carol Wagner, Water Quality Manager, Northern Kentucky Water District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on EPA should "reconsider the Failure to Complete
Monitoring Requirements", submitted by Mary Carol Wagner, Northern Kentucky
Water District, Water Quality Manager
Company/Group/Association Name: Northern Kentucky Water District
Comment:
Water Docket, EPA Docket Center
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC. 20460
Attention Docket ID No.: OW-2002-0039
The Northern Kentucky Water District would like to comment on the Proposed Long Term 2 Enhanced
Surface Water Treatment Rule. We would like to commend the Environmental Protection Agency for the
continual efforts put forth by the Agency to increase the awareness of the importance of our Drinking
Water and the quality of our Drinking Water. Overall we support the proposed Long Term 2 Enhanced
Surface Water Treatment Rule (LT2ESWTR). There are a few issues that we are concerned about and
would like to bring to your attention.
In conclusion we hope that the EPA will take these issues into consideration. We appreciate the chance to
be able to comment on this proposed regulation. We also thank you for your time.
Sincerely,
Mary Carol Wagner
Northern Kentucky Water District, Water Quality Manager
Phone: 859-441-0482 Email Address: wagner@nkywater.org
Response: response lOO.a
Comment Response for LT2ESWTR E-84 December 2005
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EPA Letter ID: 474
Comment ID: 11187
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "process of developing the microbial disinfection byproduct
rules" submitted by Morteza Anoushiravani, Administrator, City of Portland Bureau of Water Works
Company/Group/Association Name: City of Portland Bureau of Water Works
Comment:
CITY OF
PORTLAND, OREGON
BUREAU OF WATERWORKS
Dan Saltzman, Commissioner
Morteza Anoushiravani, P.E., Administrator
1120 SW 5th Avenue
Portland, Oregon 97204
Information (503) 823-7404
Fax (503)823-6133
TDD (503) 823-6868
January 8, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Long Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule
68 Federal Register 47639
Docket No. OW-2002-0039
Dear Sir or Madam:
The City of Portland, Oregon, Water Bureau appreciates the opportunity to review and provide comments
on the Proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2).
The comments in this letter specifically respond to several topics in the proposed rule where EPA has
requested comments, and provide other feedback on specific technical, operational or economic
information presented in the proposal.
We want to begin by acknowledging the strong commitment to working with utilities and other interested
stakeholders that EPA has brought to the decade long process of developing the microbial/disinfection
byproduct rules. We believe the involvement of these parties has produced rules that are better than
they would have been if developed using a more traditional approach. Moreover, EPA-s strong
commitment to working with utilities to develop risk-based rules provides local communities with the
flexibility to improve public health protection in a reasonable, cost-effective manner.
Comment Response for LT2ESWTR E-85 December 2005
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Comments on LT2 Monitoring Requirements
Comments on Requirement for the Use of Two Disinfectants by Unfiltered Utilities
Response:
EPA Letter ID: 474
Comment ID: 11188
Commenter: Morteza Anoushiravani, Administrator, City of Portland Bureau of Waterworks
Commenter Category: Regulated Community (Utilities)
Comment:
Comments on Treatment Requirements for Unfiltered Systems with Higher Cryptosporidium Levels
Comments on Membrane Filtration
Comments on Ultraviolet Light (UV)
Thank you again for the opportunity to provide input on this proposed rule. We will continue to
participate and partner with you to improve the quality and safety of the nation-s drinking water supply.
Please feel free to contact us if you have questions.
Sincerely,
Morteza Anoushiravani
Administrator
City of Portland Bureau of Water Works
1120 SW 5th Avenue, Room 600
Portland, OR 97204
503-823-7555
An Equal Opportunity Employer
Response:
EPA Letter ID: 475
Comment ID: 11209
Commenter: Edmund G. Archuleta, General Manager, El Paso Water Utilities
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-86 December 2005
-------
Comment:
Company/Group/Association Name: El Paso Water Utilities
Comment: Dear Sir or Madam,
Attached is a copy of a letter with El Paso Water Utility comments that was mailed to this Docket. Thank
you.
David Ornelas P.E.
Environmental Compliance Manager
El Paso Water Utilities
phone: 915-594-5730
El Paso Public Utilities Board
Water Service
EDMUND G. ARCHULETA, P.E
January 7, 2004
Water Docket
Environmental Protection Agency, Mail Code 4101 T
1200 Pennsylvania Avenue, N. W.
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal Register 47639,
Docket No. OW-2002-0039
Dear Sir or Madam:
The El Paso Water Utilities (EPWU) has reviewed the proposed Long-Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR). This letter contains our comments and concerns regarding how EPWU
surface water plants could comply with this proposed rule. El Paso Water Utilities relies on conjunctive
use of
Under the proposed Rule, the EPWU system serves more than 10,000 people and currently provides
filtration. In reviewing the Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) as
proposed there are concerns we have regarding the proposed rule. Specifically, the proposed rule requires
us to start within 6 months to collect 24 continuous months of source water monitoring for
Thank you for the opportunity to comment on this rule. Should you have any questions regarding this
information, please do not hesitate to contact me or my Environmental Compliance Manager at
915.594.5730. Thank you.
Sincerely,
Edmund G. Archuleta P .E.
General Manager
cc David R. Brosman P .E., Chief Operations Officer, EPWU
Comment Response for LT2ESWTR E-87 December 2005
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David O. Ornelas P.E., Environmental Compliance Manager, EPWU
Tom Curtis, American Water Works Association, Washington B.C.
Diane VanDe Hei, Association of Metropolitan Water Agencies
P.O. BOX 51 . EL PASO, TX 79961-0001 .PHONE: 915-594-5501 .FAX: 915-594-5699
Response:
EPA Letter ID: 476
Comment ID: 10673
Commenter: Anonymous476,, Department of Defense
Commenter Category: Other: Other hard to categorize commenters
Comment: CS Title: Comment referring to "Consolidated DoD Comments on Proposed Long-Term
2 Enhanced Surface Water Treatment Rule (LT2ESWTR)" submitted by Department of
Defense
Company/Group/Association Name: Department of Defense
Comment: The attached file contains consolidated DoD comments on the Proposed LT2ESWTR. These
comments are submitted by the SDWA Services Steering Committee.
Atch 1
Consolidated DoD Comments on Proposed Long-Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR)
Response:
EPA Letter ID: 478
Comment ID: 11215
Commenter: Anonymous478,,
Commenter Category: Unknown
Comment: CS Title: Anonymous Comment focusing on "States and Systems should have more
flexibility regarding the sampling dates"
Company/Group/Association Name:
Comment:
After reviewing EPA's draft LT2ESWTR regulations, we appreciate the opportunity
to share the following comments.
Thanks!
Comment Response for LT2ESWTR E-88 December 2005
-------
Response:
EPA Letter ID: 479
Comment ID: 11219
Commenter: Brad Joyner, Superintendent, Town of Forest City WTP
Commenter Category: Local Government
Comment: CS Title: Comment referring to monitoring requirements in the LT2ESWTR proposal,
submitted by Brad Joyner, Town of Forest City WTP, NC
Company/Group/Association Name: Town of Forest City WTP, NC
Comment:
Brad Joyner 01/08/2004 11:57 AM
To: Group Ow-Docket@EPA
cc:
Subject: LT2ESWTR comments
Town of Forest City WTP
P.O. Box 728 (581 Vance Street)
Forest City, North Carolina 28043
828-248-5215
FAX 828-248-5227
fcwtp@rfci.net
The Town of Forest City would like to make the following comments based on the EPA proposed Long-
Term 2 Enhanced Surface Water Treatment Rule.
Brad Joyner, Superintendent
Town of Forest City WTP
Response:
EPA Letter ID: 480
Comment ID: 11223
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2"s "source watering monitoring requirements", submitted
by Chris K. McMeen, Tacoma Water, WA, Tacoma Public Utilities - Water Division
Comment Response for LT2ESWTR E-89 December 2005
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Company/Group/Association Name: Tacoma Public Utilities - Water Division
Comment:
Tacoma Water
Tacoma Public Utilities
Tacoma Public Utilities - Water Division
3628 South 35th Street
Tacoma, WA 98409-3192
Contact: Chris R. McMeen
January 8, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal
Register 47639, Docket No. OW-2002-0039
Tacoma Water appreciates the opportunity to provide comment on the proposed Long-Term 2 Enhanced
Surface Water Treatment Rule. The development of this rule and associated guidance documents have
been enormous efforts, and we recognize that in total, these regulations will result in improved public
health protection.
§141.701 General requirements
§141.702 Source water monitoring
§141.703 Sampling Schedules
Response:
EPA Letter ID: 480
Comment ID: 11224
Commenter: Chris K. McMeen,, Tacoma Public Utilities - Water Division
Commenter Category: Regulated Community (Utilities)
Comment:
§141.711-§141.715, Disinfection Profiling and Benchmarking Requirements
§141.721 Treatment requirements for unfiltered systems
Response:
Comment Response for LT2ESWTR E-90 December 2005
-------
EPA Letter ID: 481
Comment ID: 11252
Commenter: Michael Kumm, General Manager, Sturgeon Bay Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "LT2's Unfiltered System Treatments Technique
Requirement for the use of two (2) disinfectants", submitted by Michael Kumm, General Manager,
Sturgeon Bay Utilities, WI
Company/Group/Association Name: Sturgeon Bay Utilities. WI
Comment:
Sturgeon Bay Utilities
January 8, 2004
Water Docket
USEPA
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
E-Mail: ow-docket@epa.gov
RE: Docket ID No. OW-2002-0039
LT2 ESWTR Proposed Rule
68 FR 47640, August 11, 2003
The following comments are offered in response to the Long Term 2 Enhanced Surface Water Treatment
Rule as proposed in the Federal Register (68 FR 47640,
Comments Submitted By: Michael Kumm, General Manager
Sturgeon Bay Utilities
230 East Vine Street / P.O. Box 249
Sturgeon Bay, WI 54235
Telephone: (920) 746-2820
E-mail: mkumm@wppisys.org
cc: Larry Landsness, WDNR [E-mail: larry.landsness@dnr.state.wi.us]
ID\Report\N0002\930546\LT2-ESWTR-GLR.doc(lml)
Response:
EPA Letter ID: 483
Comment ID: 11254
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-91 December 2005
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Comment: CS Title: Comment referring to LT2's compliance with the monitoring and reporting
requirements for small systems, submitted by Jane Brooks, Laboratory Regulatory Manager, Springfield
Water and Sewer Commission, MA
Company/Group/Association Name: Springfield Water and Sewer Commission, MA
Comment:
SPRINGFIELD WATER AND SEWER COMMISSION
P.O. Box 995
Springfield, MA 01101-0995
Phone - 413/787-6256 Fax - 413/787-6269
TO: U.S. Environmental Protection Agency
FROM: Jane Brooks, Laboratory/Regulatory Manager
Springfield Water and Sewer Commission
DATE: January 8, 2004
RE: Docket ID No. OW-2002-0039 - Comments on LT2ESWTR
The Springfield Water and Sewer Commission (SWSC), a large public water system located in Western
Massachusetts, respectfully submits the following comments:
GENERAL COMMENTS:
SPECIFIC COMMENTS:
Monitoring (141.701-707)
Source Toolbox components 141.725
Reporting and Recordkeeping Requirements 141.730
Response:
EPA Letter ID: 483
Comment ID: 11255
Commenter: Jane Brooks, Laboratory Regulatory Manager, Springfield Water and Sewer Commission,
MA
Commenter Category: Regulated Community (Utilities)
Comment:
UV Disinfection Criteria 141.729 (d)
Response:
Comment Response for LT2ESWTR E-92 December 2005
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EPA Letter ID: 484
Comment ID: 10677
Commenter: Anonymous484,, Metro Nashville Water Services
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "Lab Capacity: EPA should conform to the Agreement
in Principle.", submitted by Metro Nashville Water Services
Company/Group/Association Name: Metro Nashville Water Services PWSID-0000494, PWSID-
0000297.
Comment:
Response:
EPA Letter ID: 485
Comment ID: 11271
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "Section III Request for comments on data sets"
submitted by David P. Spath, California Department of Health Services
Company/Group/Association Name: California Department of Health Services
Comment:
David P. Spath, Chief
Division of Drinking Water & Environmental Management
California Department of Health Services
1616 Capitol Avenue, Suite 74.252, MS 7400
P.O. Box 997413
Sacramento, California 95899-7413
Phone:(916)449-5577
Fax: (916) 449-5575
dspath@dhs.ca.gov
January 9, 2004
Water Docket,
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave, NW.
Washington DC 20460
Attention: Docket ID No. OW-2002-0039
Dear Sir/Madam:
Comment Response for LT2ESWTR E-93 December 2005
-------
This letter is in response to the U.S. Environmental Protection Agency-s (EPA) request for comments for
the National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water Treatment Rule
(Federal Register/ Vol. 68, No 154 /Monday, August 11, 2003). California Department of Health Services
(Department) comments are outlined in the attachment to this letter (SEE PDF):
The Department appreciates the opportunity to comment on this document and the extra time that was
granted for this review.
Sincerely
David P. Spath, Ph.D., P.E., Chief
Division of Drinking Water and Environmental Management
Attachments:
Attachment A
California Department of Health Services
Response to EPA Request for Comments
LT-2 ESWTR
Section III Request for comments on data sets: In determining the exposure, costs and benefits estimates
for the LT2 ESWTR, EPA conducted an analysis of three different available Cryptosporidium exposure
data sets and presented a range of estimates for cost benefits. This was done because of significant
differences in the three data sets. EPA is also proposing to continue to evaluate the relevant strengths of
the different data sets and any new data that becomes available for the final rule.
Section IV Request for comments on source water monitoring: EPA requestscomment on how to handle
water systems that only operate part of the year and what level of monitoring should be required to
determine the appropriate treatment bin classification.
Section IV Request for comments on source water monitoring: EPA requests comment on use of
previously collected Cryptosporidium data, which does not meet the QA/QC requirements outlined in the
rule.
Section IV Request for comments on source water monitoring: EPA requests comment on where systems
that recycle backwash water should be required to collect their Cryptosporidium sample.
Response:
EPA Letter ID: 485
Comment ID: 11272
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Section IV Request for comments on source water monitoring: EPA requests comments for alternative
approaches for systems that fail to complete monitoring as outlined in the rule.
Section IV Request for comments on source water monitoring: EPA requests comments on collection of
Comment Response for LT2ESWTR E-94 December 2005
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data for new plants or new sources used as a supply that are placed into service after the rule has been in
effect.
Section IV Request for comments on source water monitoring: EPA requests comment on whether the bin
classification should be formally made or reviewed by states.
Section IV Request for comments on source water monitoring: EPA requests
comment on how to apply the E. coli criteria for triggering the Cryptosporidium
monitoring to the systems using multiple sources and groundwater under the
direct influence of surface water sources.
Response:
EPA Letter ID: 485
Comment ID: 11273
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Section IV Unfiltered Treatment: EPA requests comment on the level of treatment that should be required
for unfiltered systems where source water cryptosporidium level of 0.075 oocysts/L or higher is detected.
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox: Watershed Control
Program: EPA requests comment on the proposed watershed control program credit and associated
program components. EPA asks if the State should be allowed to reduce the frequency of the annual
watershed survey requirement for certain systems if systems engage in alternative activities like
public outreach?
EPA request comment as to whether there are confidential business information (CBI) concerns
associated with making information on the watershed control program available to the public? If so, what
are these concerns and how should they be addressed?
EPA requests comment on how should the —area of influence— (the area to be considered in future
watershed surveys) be delineated, considering the persistence of Cryptosporidium?
Response:
EPA Letter ID: 485
Comment ID: 11274
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Alternative Source
EPA requests comments on whether representative Cryptosporidium monitoring to
Comment Response for LT2ESWTR E-95 December 2005
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demonstrate a reduction in oocyst levels can be accomplished prior to
implementation of a new intake strategy.
EPA requests comments on how should the alternative source option be applied to
plants that use multiple sources which enter a plant through a common conduit,
or which use separate sources which enter the plant at different points.
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Off-stream raw water storage
EPA requests comments on the finding that there is not adequate data to support
a presumptive Cryptosporidium treatment credit for off-stream raw water storage,
and that systems using off-stream storage should conduct Cryptosporidium
monitoring at the outlet of the raw water storage reservoir for the purpose of
determining LT2ESWTR bin placement.
Response:
EPA Letter ID: 485
Comment ID: 11275
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
EPA requests comment on how to address secondary contamination that occurs in
off-stream raw water storage reservoirs through processes of run-off, human and
animal activities on the watershed.
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Pre-sedimentation with coagulant:
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Lime Softening: EPA requests comments on the studies that were presented
supporting an additional 0.5 log credit for two-stage softening, and the
associated criteria necessary for credit. EPA also requests submittal of
additional information that either support or suggest modifications to the
proposed criteria and credit.
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Combined filter performance. EPA requests comments on the studies that were
presented supporting the awarding of an additional 0.5 log removal credit of
Cryptosporidium if a plant-s combined filter effluent (CFE) turbidity was < 0.15
NTU 95% of the time. The EPA also requests comments on available turbidity
monitoring technology-s ability to accurately distinguish differences between
values measured near 0.15 NTU.
Response:
Comment Response for LT2ESWTR E-96 December 2005
-------
EPA Letter ID: 485
Comment ID: 11276
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Section IV, C, 9 - Roughing Filters:
The Stage 2 M-DBP Agreement in Principle recommends a 0.5 log presumptive credit towards additional
Cryptosporidium treatment requirements for roughing filters. However, the agreement further specifies
that EPA is to determine the design and implementation criteria under which the credit would be awarded.
EPA is unable to identify design and implementation conditions for roughing filters that would provide
reasonable assurance of achieving a 0.5 log removal of oocysts. In lieu of considering granting removal
credit through roughing filters, EPA is considering an equivalent log credit removal through a second
granular media filter (secondary filtration, Section IV, C, 13) following the primary filtration step.
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Slow sand filtration
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Membrane filtration
Response:
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Bag and cartridge filtration
Response:
EPA Letter ID: 485
Comment ID: 11277
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox: Secondary filtration:
EPA requested comment on their proposed granting of 0.5 log Cryptosporidium removal credit for
systems using secondary filtration as well as suggestions on the design and operational criteria that would
be associated with the secondary filtration process. EPA also requested comment as to whether or not to
allow this additional removal credit along with additional removal credit for second stage clarification and
lower finished water turbidity.
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox:
Ultraviolet light (UV)
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox: Individual filter
performance. The EPA requests comment of the proposal that plants that maintain individual filter
effluent (IFE) turbidity of <0.1 NTU 95% of the time based on 15 minute readings with a maximum of
0.3 NTU in two consecutive measurements be awarded an additional 1.0 log removal of Cryptosporidium.
Comment Response for LT2ESWTR E-97 December 2005
-------
The EPA also requests comments on additional performance measures that a utility should be required to
meet for the 1 log removal credit. The EPA asked for input on additional peer review programs that can
be evaluated.
Section IV C Cryptosporidium Treatment Requirements and the Microbial Toolbox: Other demonstration
of performance: EPA requested comments on the approaches that should be considered or excluded for
demonstration of performance testing and whether EPA should outline minimum elements of
performance testing that must be required by the states before granting additional credit. The EPA also
requested comments on whether a factor of safety should be applied to the results of the demonstration
studies.
Response:
EPA Letter ID: 485
Comment ID: 11278
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Section IV D Disinfection Benchmarks for Giardia lamblia and Viruses:
Response: No comment at this time.
Section IV E Additional Treatment Technique Requirements for Systems with Uncovered Finished Water
Storage Facilities:
Response: No comment at this time.
Section IV F - Compliance Schedules
EPA proposes that small water systems (SWS) begin one year of monitoring for E.Coli. the month
following the end of large water systems (LWS) completing their two-year sampling for
Cryptosporidium. Therefore, the implementation schedule does not leave any time between the end of
LWS monitoring and the initiation of SWS monitoring. EPA requests comment on whether an additional
time window between the end of LWS monitoring and the beginning of SWS monitoring is appropriate.
The Advisory Committee recommended that SWS that buy/receive from or sell/deliver finished water to
LWS (that is, they are part of the same -combined distribution system-) comply with the Stage 2 DBPR
requirements on the same schedule as the largest system. This proposed approach raises the possibility
that a SWS treating surface water and selling it to a LWS could be required to take compliance steps at an
earlier date under the Stage 2 DBPR than under the LT2ESWTR. EPA requests comment on how this
scenario should be addressed in the LT2ESWTR.
Section IV G Public Notice Requirements
Section IV H Variance and Exemptions
EPA has determined that systems will not be eligible for variances or exemptions to the requirements of
the LT2ESWTR for the following reasons:
Comment Response for LT2ESWTR E-98 December 2005
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Variances
The Cryptosporidium treatment technique requirements under this rule account for the degree of source
water contamination. This precludes the use of the first provision for variance issuance that addresses
source water quality.
The second provision for granting a variance is also not applicable to the LT2ESWTR because the
treatment technique requirements of this rule specify the degree to which systems must lower their source
water Cryptosporidium level. The microbial toolbox in the rule allows for broad flexibility in
demonstrating the treatment process removal efficiency.
Small system variances cannot be granted for treatment techniques for microbial contaminants.
Response: response 1400.b
EPA Letter ID: 485
Comment ID: 11279
Commenter: David P. Spath, Chief, California Department of Health Services
Commenter Category: State/Tribe Government
Comment:
Section IV: J. System Reporting and Record keeping Requirements
The proposed record keeping and reporting requirements for the LT2ESWTR are quite extensive. The
EPA provided the following summaries as part of the rule:
Initial Large Filtered System Reporting Requirements
Initial Small Filtered System Reporting Requirements
Initial Large Unfiltered System Reporting Requirements
Initial Small Unfiltered System Reporting Requirements
In addition, EPA proposes that 8 data elements are to be reported for each Cryptosporidium analyses and
a total of 9 data elements are to be reported for each E. Coli result.
The LT2ESWTR requires the Large water systems to submit their monitoring data directly to the EPA in
a manner similar to the Unregulated Contaminant Monitoring Rule (UCMR) using an EPA developed
internet based electronic data collection and management system. The database will be available at no
charge to the systems or their laboratories. The States will not have access to the data until they assume
primacy for the LT2ESWTR from the EPA.
In addition, there is significant discussion in the rule detailing the actions laboratories must take to report
the results and the procedures that must be followed should replacement samples be required. There are
also detailed requirements for submittal of information to the EPA that is necessary in order to utilize
grandfathered monitoring data for compliance.
The EPA is also proposing the reporting of approximately 13 different toolbox options within a variety of
timeframes for both Large and Small systems on a monthly basis. Also included in the LT2ESWTR is a
number of disinfection benchmarking reporting requirements for both the Large and Small systems. All of
these reporting requirements will pose a significant increase in workload on the data review and
Comment Response for LT2ESWTR E-99 December 2005
-------
management personnel in the State programs. Furthermore, it will be difficult to review the information in
detail on a monthly basis to verify compliance.
EPA requested comments on the proposed reporting and record keeping requirements. There is also a
request for comments on the microbial toolbox component monthly reporting requirements with a
possible alternative of keeping the required records at the facility for State review rather than monthly
reporting.
Section IV K Analytical Methods
Response: No comment at this time.
Section IV L Laboratory Approval
Response: No comment at this time.
Section IV M Sanitary Surveys Conducted by EPA
Section VI Economic Analysis
WTC COMMENTS 8-18-03
Response:
EPA Letter ID: 486
Comment ID: 14163
Commenter: Christopher R. Schulz, Drinking Water Practice Leader, CDM, Inc.
Commenter Category: Consultants: (where self-identified)
Comment: CS Title: Comment referring to "proposed LT2ESWTR and related Toolbox Guidance
Manual (TGM) and UV Disinfection Guidance Manual (UVDGM), were collected from CDM process
design engineers", submitted by Christopher R. Schulz, P.E., DEE,
CDM, Inc.
Company/Group/Association Name: CDM, Inc.
Comment:
Memorandum
To: EPA Water Docket
From: Chris Schulz, Drinking Water Practice Leader,CDM
Date: January 9, 2003
Subject: Comments on Long-Term 2 Enhanced Surface Water Treatment Rule
Comment Response for LT2ESWTR E-100 December 2005
-------
(LT2ESWTR), Proposed Rule
Proposed LT2ESWTR (Federal Register, Vol. 68, No. 154)
141.727 Treatment performance toolbox components
Response:
EPA Letter ID: 487
Comment ID: 11234
Commenter: Janice Skadsen, Water Quality Manager, City of Ann Arbor Water Plant
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment entitled "Long Term 2 Enhanced Surface Water Treatment Rule"
submitted by Janice Skadsen, Water Quality Manager, City of Ann Arbor Water
Plant
Company/Group/Association Name: City of Ann Arbor Water Plant
Comment:
January 12, 2004
Water docket
EPA, Mail Code 410IT
1200 Pennsylvania Ave NW
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water treatment Rule, Proposed Rule, 68 Federal
Register 47639, docket No. OW-202-0039
Dear Sir or Madam:
The City of Ann Arbor Water Treatment Plant has reviewed the proposed LT2 regulation and wishes to
offer the following comments for your considerations. We appreciate the extended comment period which
allowed us time to review the proposal.
Thank you for the opportunity to comment on this proposal.
Sincerely,
Janice Skadsen
Water Quality Manager
Response:
Comment Response for LT2ESWTR E-101 December 2005
-------
EPA Letter ID: 488
Comment ID: 11827
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "proportional treatment that emerged from the two
year FACA process for this rule represents a good new direction for Safe Drinking Water Act (SDWA)
regulations" submitted by Kumar Kishinchand, Water Comm., Philadelphia Water Dept.
Company/Group/Association Name: Philadelphia Water Department
Comment:
Philadelphia Water Department
The Aramark Tower
1101 Market Street
Philadelphia, PA 19107-2994
January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal
Register 47639, Docket No. OW-2002-0039
Dear Sir or Madam:
Please find enclose our comments [SEE PDF] on the Proposed Long-Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR) published on August 11, 2003 (68 Federal Register 47639). We recognize
the enormous effort undertaken in preparing the rule proposal and numerous supporting documents and
we commend the Agency for this work. We greatly appreciate the opportunity to provide comments on
this proposal. Please do not hesitate to contact me at (215) 685-6103 if you have any questions about our
comments.
Sincerely,
Kumar Kishinchand
Water Commissioner
cc: Cynthia Dougherty, USEPA OGWDW
Ephraim King, USEPA OGWDW
Tom Curtis, AWWA
Diane Van de Hei, AMWA
Formal Comments from the
Philadelphia Water Department
Comment Response for LT2ESWTR E-102 December 2005
-------
on the
Long-Term 2 Enhanced Surface Water Treatment Proposed Rule
68 Federal Register 47639, August 11, 2003
Submitted to: Water Docket, OW-2002-0039
January 9, 2004
Philadelphia Water Department
1101 Market Street
Philadelphia, PA 19107
(215)685-6103
Table of Contents
1. Introduction 1
2. Rule Background 1
3. Risk Characterization 4
3.1 Infectivity4
3.2 Occurrence 5
3.3 Treatment Efficiency 6
4. Proposed LT2ESWTR Requirements 7
4.1 Monitoring Requirements 7
4.2 Use of Previously Collected Data and Basis for Accepting Such Data 8
4.3 Future Monitoring and Reassessment 9
4.4 Options for Systems to Meet Cryptosporidium Treatment Requirements 10
4.4.1 Watershed Control Program 10
4.4.2 Combined Filter Performance 16
4.4.3 Ozone 16
4.4.4 Chlorine Dioxide 18
4.4.5 Demonstration of Performance 18
4.4.6 Individual Filter Performance 19
4.5 Uncovered Finished Water Storage 22
4.6 Maintaining Toolbox Compliance 22
4.7 Public Notification 22 4.8 Variances and Exemptions 23
4.9 Sanitary Surveys 24
5. Economic Analysis 24
6. Conclusions 28
1. Introduction
issues which we feel are specifically relevant for our utility, or for which we have additional or
contraditory comments to those put forth by the AWWA.
In addition to comments addressing our concern with the underlying basis for this rule, we have included
comments on the source water monitoring provision and on numerous toolbox elements. We hope that
these comments will help EPA ensure that, when finalized, the rule will provide a flexible suite of
feasible toolbox options to address the possibility of endemic cryptosporidiosis risk caused by drinking
water.
2. Rule Background
Comment Response for LT2ESWTR E-103 December 2005
-------
The Long-Term 2 Enhanced SWTR (LT2ESWTR), the forthcoming update to the Surface Water
Treatment Rule (SWTR), will supplement current requirements of the Interim Enhanced SWTR
(IESWTR) pertaining to large surface water systems (> 10,000 persons) and the Long-Term 1 Enhanced
SWTR (LT1ESWTR) pertaining to small systems (<10,000 persons). The LT2ESWTR proposal (August
11th, 2003) is expected to be finalized in 2005. Cornwell et al. (2003) provide a brief review of the
rule requirements, including some illustrative examples from a case study at an existing surface water
plant.
These rules are intended to increase microbial protection for drinking water consumers supplied by
surface water sources, especially protection against Cryptosporidium. The EPA believes that
Cryptosporidium occurrence data collected since the existing rules were promulgated, including
monitoring data associated with the Information Collection Rule (ICR) and the ICR Supplemental
Surveys (ICRSS), suggest that although Cryptosporidium occurrence nationwide is probably
lower than originally estimated prior to the IESWTR, a portion of the worst source waters may potentially
have greater Cryptosporidium levels than predicted prior to the IESWTR. After consultation with
nationally recognized experts assembled as part of the FACA (Federal Advisory Committee Act) process,
USEPA recognized that despite evaluation of a large amount of data, uncertainty remains in a number of
areas regarding the precise nature and magnitude of risk associated with pathogens in drinking water. In
light of this uncertainty, USEPA and the FACA recommended a series of balanced steps to address the
areas of greatest health concern, taking into careful consideration the costs and potential impacts on
public water systems.
This rule represents EPA-s first regulation under the SDWA that applies the concept of proportional
treatment. That is, treatment requirements depend on site-specific health risk levels. The LT2ESWTR
includes two phases, a monitoring phase followed by a treatment phase. The first phase includes at least
two years of monitoring to establish Cryptosporidium risk in the source water. Depending upon
monitoring results, source waters will be classified into one of four USEPA-defined risk levels called -
bins-. Facilities in the lowest bin (bin 1) will be required to maintain continued compliance with the
current IESWTR. Facilities in higher bins (bins 2 to 4) will be required to either: a) provide additional
Cryptosporidium protection from new facilities or programs not currently in use at a facility or b)
demonstrate greater Cryptosporidium protection capabilities of existing facilities and programs. The
LT2ESWTR will include a group of USEPA-approved treatment technologies, watershed programs,
and demonstration studies, referred to collectively as the -Microbial Toolbox-, that utilities can use in
various combinations to meet the treatment requirements of these upper bins. Utilities can use existing
facilities and programs, or they can develop new ones, if they meet the requirements of the Rule.
It is important to recognize that the LT2ESWTR is not a compilation of independent modules developed
in isolation, but rather includes a complex, integrated framework which takes into account multiple inter-
related factors and incorporates multiple layers of interwoven safety factors. We use the term -core
treatment- to refer to the minimum 3.0-log credit allowed in the LT2ESWTR for certain existing
treatment systems, as well as 2.5-log minimum automatic credits for other core treatment technologies.
USEPA acknowledges in the rule that many of these existing facilities can achieve much greater
Cryptosporidium protection than the minimum credits allowed for core treatment. Facilities in
bin 1 will not need to demonstrate this additional capability for compliance with the regulation, even
though many of the bin 1 facilities will possess this greater Cryptosporidium protection capability.
However, facilities in bin 2 and higher will need to use microbial toolbox credits. Many of the toolbox
credits are included in order to account for the fact that many existing facilities and programs will have
Cryptosporidium protection capabilities greater than the minimum 3.0 and 2.5 baseline core treatment
credits.
Comment Response for LT2ESWTR E-104 December 2005
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With respect to individual credits in the microbial toolbox, USEPA, the FACA, and other groups involved
in rule development were concerned with maintaining a balanced approach to enhancing treatment given
the uncertainty in the available data on occurrence and associated risk. Consequently, these groups
weighed five factors in recommending treatment actions for potential compliance with the LT2ESWTR:
1. Data on Cryptosporidium oocyst removal.
2. Effectiveness as an additional barrier to Cryptosporidium oocysts reaching finished water.
3. Other benefits such as:
- Reducing peaks in occurrence of pathogens,
- Making other processes more stable or effective, and
- Reducing other contaminants (i.e. TOC, DBF formation potential), etc.
4. Encouraging use of a variety of technologies.
5. Encouraging viable alternatives to UV disinfection.
The magnitude of the toolbox credits reflect the strengths of each toolbox component relative to the five
factors listed above. The "Microbial Toolbox" concept developed by the FACA was intended to ensure
the availability of a suite of individual tools that could be applied at a particular drinking water
treatment plant to reduce the presumed risk of Cryptosporidium oocysts entering the finished drinking
water. The FACA's concerns included the diversity of water quality challenges and treatment systems in
use, as well as ensuring that water treatment plant (WTP) improvements at individual utilities are as cost
effective as possible and sufficiently flexible to attain multiple drinking water treatment objectives.
Members of the FACA were very concerned that compliance with the LT2ESWTR not be dependent on a
single technology, particularly available disinfection technologies, such as ozone and UV disinfection.
The FACA and USEPA recognized that ozone will be appropriate in some facilities, but future research
on the health effects associated with bromate and improved analytical methods to detect bromate may
support a lower bromate MCL in the Agency's next review of the bromate standard. While ozone use in
drinking water is a mature technology, UV disinfection is not. USEPA believes that UV is sufficiently
developed to allow its use in compliance with the LT2ESWTR, but the lack of generally accepted UV
equipment verification systems, limited UV equipment production capacity, and lack of experience in
field preparation for and installation of UV systems at U.S. drinking water utilities that treat surface water
represent significant impediments to UV disinfection use under LT2ESWTR. In joining the other
FACA members in signing the Agreement, USEPA made significant commitments to reducing some of
the barriers to UV disinfection implementation.
The FACA discussion of the "Toolbox" concept also encompassed the use of multiple tools concurrently
to achieve an overall "credit" goal. The FACA frequently pointed out the value of combining activities to
reduce source water oocyst levels with improvements in treatment at the plant. Likewise there was
discussion on the benefits of adding pre-treatment technologies like pre-sedimentation basins while
improving the performance of existing conventional treatment or adding a disinfectant like ozone or UV.
Recognizing that each item in the toolbox was selected by the FACA because of combined value of the
five factors considered for each item in the Toolbox, USEPA proposes to treat the credit associated with
each toolbox item independently and that they be additive. The terms -log credit-, -log removal-, or -log
inactivation- are often referred to in association with the credits for the toolbox components. While
these factors are important and are included in the five factors mentioned earlier, there are other factors
that are to be considered when establishing the numerical value of the credit that have nothing to do with
log removal or log inactivation. Consequently, the term -credit- rather than one of these other
Comment Response for LT2ESWTR E-105 December 2005
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terms is used in order to relay the importance of all of these factors, not just the removal and inactivation
aspects.
3. Risk Characterization
3.1 Infectivity
Data from one human feeding study using the IOWA Cryptosporidium strain were available for the
IESWTR (Dupont et al. 1995). Data from a subsequent human feeding study using two additional strains,
TAMU and UCP, were available to support LT2 development (Okhuysen et al. 1999). Taken together, the
data indicate wide variability in virulence by isolate type (TAMU>IOWA>UCP). EPA-s new analysis
yields an estimate of between 7% and 10% for the risk of infection due to ingestion of one
Cryptosporidium oocyst. This is more than an order of magnitude higher than the previous estimate of
0.4% used for development of the IESWTR and LT1R.
Comments
3.2 Occurrence
The goal of the LT2 rule is to impose treatment requirements only on systems at relatively high risk for
source water Cryptosporidium contamination. Occurrence data for the IESWTR were obtained from a
1995 study reporting median (P50) and 90th percentile (P90) source water Cryptosporidium
concentrations of 2.31 and 10.63 oocysts/L, respectively. New occurrence information available for the
LT2 was obtained from the Information Collection Rule (ICR) and the ICR Supplemental Survey of
medium (SSM) and large (SSL) systems.
Fewer than 7% of the 5,838 ICR protozoan samples had detectable Cryptosporidium concentrations so
both the P50 and P90 Cryptosporidium concentrations were below the detection limit. One problem with
the ICR data was that detection limits varied widely among samples and were often high due to small
volumes analyzed. In an attempt to compensate for the lack of quantified results the EPA used
Response: response lOO.t.
EPA Letter ID: 488
Comment ID: 11828
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 3.3 Treatment Efficiency
EPA granted 2 logs of physical removal credit for filtration under the IESWTR and LT1R. EPA is
increasing this default assumption to 3 logs for the LT2, based on average performance data from seven
new studies. The Agency highlights the large variability in removal performance found in these new
studies (including instances where measured removal was less than 3 logs) as reason for caution in
not granting a higher default log removal assumption.
Comments
4. Proposed LT2ESWTR Requirements
Comment Response for LT2ESWTR E-106 December 2005
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4.1 Monitoring Requirements
Plants that use pre-sedimentation must collect source water samples after pre-sedimentation but before
treatment. This is not possible in cases where treatment chemicals are added in the presedimentation basin
(for example, oxidants for algae control).
Large systems are required to measure turbidity and E. coli on source water samples collected for LT2
Cryptosporidium monitoring. The EPA will use these data to develop a correlation that will be applied to
small system E.coli monitoring data to infer source water Cryptosporidium levels for these systems,
and thereby save most of these systems the expense of Cryptosporidium
monitoring.
Comments
4.2 Use of Previously Collected Data and Basis for Accepting Such Data The rule allows grandfathering
of Cryptosporidium monitoring data collected prior to rule promulgation. The EPA asks what data should
be allowed.
Comments
Our concerns and recommendations are discussed in more detail below:
§141.730 Re-approval
Response: see response 341
EPA Letter ID: 488
Comment ID: 11829
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: Specific Requests for Comment from EPA
Request for Comment
Should the State be allowed to reduce the frequency of the annual watershed survey requirement for
certain systems if the systems engage in alternative activities like public outreach?
Response
Request for Comment
The effectiveness of a watershed control program may be difficult to assess because of uncertainty in the
efficacy of control measures under site-specific conditions. In order to provide constructive guidance,
EPA welcomes reports on scientific case studies and research that evaluated methods for reducing
Cryptosporidium contamination of source waters.
Response
Request for Comment
Comment Response for LT2ESWTR E-107 December 2005
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Are there confidential business information (CBI) concerns associated with making information on the
watershed control program available to the public? If so, what are these concerns and how should they be
addressed?
Response
Request for Comment
How should the -area of influence- (the area to be considered in future watershed surveys) be delineated
considering the persistence of Cryptosporidium?
Response
Response:
EPA Letter ID: 488
Comment ID: 11830
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4.4.3 Ozone
The ozone CT tables, though prohibitive for cold waters, are unlikely to be adjusted downward any
further. The AWWA expended enormous effort negotiating the tables to this point from the previously
more conservative form presented in the October 2001 Stakeholder draft. The bromate MCL (part of the
Stage 2 DBPR) has been left at 10 (ig/L with a statement that it could be lowered in the future
(presumably to 5). The MCL was not lowered at this time, in response to improved analytical methods,
because the Agency did not want bromate concerns to restrict the feasibility of ozone as a toolbox option.
Comment
4.4.5 Demonstration of Performance
Demonstration of performance would subsume other credits taken for filter performance (CFE, IFE). In
the event that the tests indicated lower than default removal credit the system would be granted the lower
credit.
Comments
4.4.6 Individual Filter Performance
The Individual Filter Effluent 0.5 log credit requires that the 95% of maximum daily individual filter
turbidity measurements, on a monthly basis, remain at or below 0.1 NTU and that no two consecutive 15-
minute turbidity readings exceed 0.3 NTU. This toolbox element was conceived by the FACA as
following the Partnership for Safe Water (PfSW) Phase IV performance requirements.
Comments
4.5 Uncovered Finished Water Storage
Uncovered finished water reservoirs, including those prior to the entry point to the distribution system,
must be covered or have a risk management plan or have effluent treatment. The EPA requests comment
Comment Response for LT2ESWTR E-108 December 2005
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on whether this treatment should include Giardia and Cryptosporidium.
Comments
Response:
EPA Letter ID: 488
Comment ID: 11831
Commenter: Kumar Kishinchand, Water Commissioner, Philadelphia Water Department
Commenter Category: Regulated Community (Utilities)
Comment: 4.7 Public Notification
The LT2 rule involves a Treatment Technique (TT) to comply with Cryptosporidium removal
requirements and therefore Tier 2 notification (within 30 days) applies for TT violations and Tier 3
notification (within 1 year) for monitoring and testing violations. As with all provisions the Primacy
agency may be more stringent. Pennsylvania currently requires Tier 1 notification (within 24 hours)
for violation of the IESWTR 0.3 NTU CFE turbidity requirement. Without any explicit direction
otherwise, it is not unlikely that they would extend this to the LT2 TT provisions.
Comments
5. Economic Analysis
The EPA estimates that between 181,387 and 1,018,915 illnesses and between 26 and 141 deaths will be
avoided per year nationally as a result of LT2 implementation. These numbers translate to annualized
benefits between 216 million and 1.445 billion dollars with associated costs between 73.5 and 110
million dollars.
Comments
6. Conclusions
The PWD thanks the EPA for reviewing these comments. We want the Agency to understand that our
comments are written in the spirit of a cooperative effort to develop the best possible Safe Drinking Water
Act regulations for protecting public health in the United States. We look forward to any opportunities for
providing information to the EPA which it may find helpful as it goes forward in finalizing this rule.
References
Amirtharajah, A., M.H. Young, K.D. Pennell, J.L. Steiner, D.S. Fisher, D.M. Endale, and J.P. Campbell.
2002. Field Transport of Cryptosporidium Surrogate in a Grazed Catchment. Awwa Research Foundation
and American Waterworks Association: Denver.
Atwill, E. R., L. Hou, B. Karle, T. Harter, K. Tate, and R. Dahlgren. 2002. Transport of Cryptosporidium
parvum Oocysts through Vegetated Buffer Strips and Estimated Filtration Efficiency. Appl. Environ.
Micro. 68(11):5517-5527.
Bradford, S. and J. Schijven. 2002. Release of Cryptosporidium and Giardia from Dairy Calf Manure:
Impact of Solution Salinity. Environ. Sci. Tech. 36(18):3816-3923.
Clancy et al. in progress. Methods to Detect Cryptosporidium in Wastewater. Werf 99-FIHE-l.
Comment Response for LT2ESWTR E-109 December 2005
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Cornwall, D.A., R.A. Brown, M.J. MacPhee, and R.C. Wichser. 2003. Applying the LT2ESWTR
Microbial Toolbox at a Surface Water Treatment Plant. Jour. AWWA 95:9:76.
Corsi, et. al. 2003. Sources and Variability of Cryptosporidium in The Milwaukee River Watershed.
Werf#99-HHE-2.
Dayton, E., N. Basta, C. Jakober, and J. Hattey. 2003. Using Treatment Residuals to Reduce Phosphorus
in Agricultural Runoff. Jour. AWWA 95(4): 151-158.
Development of Event-Based Pathogen Monitoring Strategies for Watersheds (Project #2671, in progress
U. Mass Amherst). Awwa Research Foundation.
Finstein, M. 2004. Watershed Protection: Review of Literature on Inactivation of Cryptosporidium in
Manure. Submitted for publication in Jour. AWWA (contact
finstein@envsci.rutgers.edu) .
Grace, J. 2003. Maryland Department of the Environment Cryptosporidium Occurrence Study in the
Potomac River. Presented at the AWWA Water Quality
Technology Conference, Philadelphia.
Jiang, J., K.A. Alderisio, and L. Xiao. 2003. Comparison of the Distribution of Cryptosporidium
Genotypes in Storm Water Samples from Two Watersheds. In Proceedings of the AWWA Water Quality
Technology Conference. AWWA: Denver, Colo.
Kaplan, L.A., L.J. Standley, J.D. Newbold, J.H. Standridge, A.L. Mager, S.M. Kluender, L.L. Peterson,
D.B. Smith, W.C. Hession, and P. Luitweiler. 2002. Evaluation of Sources of Pathogens and NOM in
Watersheds (Project #251). Awwa Research Foundation: Denver.
LeChevallier, M.W., G.D. Giovanni, J.L. Clancy, Z. Bukhari, S. Bukhari, J.S. Rosen, J. Sobrinho, M.F.
Frey. 2002. Source Water Assessment: Variability of Pathogen Concentrations (Project #488). Awwa
Research Foundation and American Water Works Association: Denver.
Messner, M.J., C.L. Chappell, and P.C. Okhuysen. 2001. Risk Assessment for Cryptosporidium: A
Heirarchical Bayesian Analysis of Human Dose Response Data. Water Res. 35:16:3934.
Montemagno, et. al. in Progress. Field Calibration and Verification of A Pathogen Transport Model. Werf
#00-WSM-3. (contact Dean Carpenter: dcarpenter@werf.org 703-684-2470 ext.7152)
Pyke, G.W., W.C. Becker, R Head, and C.R O-Melia. 2003. Impacts of Major Point and Non-Point
Sources on Raw Water Treatability (Project #2616). Awwa Research Foundation: Denver.
Rose, J, L. Dickson, S. Farah, and R. Carnahan. 1996. Removal of pathogenic and indicator
microorganisms by a full-scale water reclamation facility. Water Res. 30(1 1):2785-2797.
Stott, R., E. May, E. Matsushita, and A. Warren. 200 1 . Protozoan predation as a mechanism for the
removal of Cryptosporidium oocysts from wastewaters in constructed wetlands. Water Sci. Tech. 44(1 1-
Suwa, M. and Y. Suzuki. 2001. Occurrence of Cryptosporidium in Japan and countermeasures in
wastewater treatment plants. Water Sci. Tech. 43(12): 183-186.
Comment Response for LT2ESWTR E-l 10 December 2005
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uwa, M. and Y. Suzuki. 2003. Control of Cryptosporidium with wastewater treatment to prevent its
proliferation in the Water Cycle. Water Sci. Tech.
47(9):45_49.
USEPA. 1999. Overland Migration of Cryptosporidium Oocysts - Final Draft Issue Paper (contact Mike
Borst, borst.mike@epa.gov 732-321-6631).
Response:
EPA Letter ID: 489
Comment ID: 11176
Commenter: Ludwig Dinkloh,, WEDECO AG Water Technology
Commenter Category: Manufacturer/Vendor
Comment: CS Title: Comment referring to "National Primary Drinking Water Regulations: Long Term 2
Enhanced Surface Water Treatment Rule" submitted by Ludwig Dinkloh, WEDECO AG Water
Technology
Company/Group/Association Name: WEDECO AG Water Technology
Comment:
WEDECO Ultraviolet Technologies
Comments on Draft UV Disinfection Guidance Manual
By Ludwig Dinkloh
Date 01/09/04
Response:
EPA Letter ID: 491
Comment ID: 10659
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comments focusing on "Alameda Cty Water District(ACWD) supports EPA efforts
to improve protection from Cryptosporidium and other pathogens through the development of the LT2
rule" submitted by Douglas G. Chun, Water Quality Manager, Alameda Cty Water
Company/Group/Association Name: Alameda County Water District
Comment: Attached are the comments from the Alameda County Water District in Fremont, California
for EPA Docket #OW-2002-0039. If there are any problems accessing this file please contact Doug Chun
with the ACWD at (510) 668-6510 or Laura Hidas at (510) 668-6516.
01/09/2004
Comment Response for LT2ESWTR E-l 11 December 2005
-------
12:48 PMEST
Alameda County Water District
43885 South Grimmer Blvd.
Fremont, California 94538
January 8, 2004
Water Docket (http://www.epa.gov/edocket)
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Ave. NW
Washington, DC 20460
Attn: Docket ID No. OW-2002-0039
Dear Sir or Madam:
Subject: Comments on the Environmental Protection Agency-s Proposed Long Term 2 Enhanced Surface
Water Treatment Rule (Docket No. OW-2002-0039)
The Alameda County Water District (ACWD) is pleased to have the opportunity to submit comments on
the Environmental Protection Agency-s (EPA-s) proposed Long Term 2 Enhanced Surface Water
Treatment Rule (LT2). As a public water utility
LT2 rule and the increased public health protection it will provide. We appreciate this opportunity to
participate in the rulemaking process. Should you have any questions about the above comments, please
feel free to contact me at (510) 668-6510 or by email at doug.chun@acwd.com. Thank you for your
consideration.
Sincerely,
Douglas G. Chun, P.E.
Water Quality Manager
By Electronic Form (http://www.epa.gov/edockets)
Response:
EPA Letter ID: 492
Comment ID: 11237
Commenter: Anonymous492,, City of Walla Walla Public Works/Water Division
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "the negative financial impacts upon smaller revenue
generating communities that have low incidence and low historical epidemiological evidence may
outweigh any potential small reduction in risk" submitted by City of Walla Walla
Comment Response for LT2ESWTR E-112 December 2005
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Company/Group/Association Name: City of Walla Walla
Comment:
Comment submitted by:
City of Walla Walla Walla
Public Works/Water Division
55 Moore
P.O. Box 478
Walla Walla, WA 99362
(509) 527-4380
rgordon(Sjci.walla-walla.wa.us
Response:
EPA Letter ID: 493
Comment ID: 11240
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "40 CFR 141.700 states that Failure to comply with
any requirement of this subpart is a violation and requires public notification, submitted by Sidney G.
Becnel, State of Louisiana Department Health and Hospitals
Company/Group/Association Name: State of Louisiana Department Health and
Hospitals
Comment:
State of Louisiana
Union Justice Confidence
M.J. -Mike- Foster, Jr.
GOVERNOR
Louisiana Department of Health and Hospitals
David W. Hood
SECRETARY
STATE OF LOUISIANA
DEPARTMENT OF HEALTH AND HOSPITALS
January 9, 2004
Water Docket
U.S. Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Comment Response for LT2ESWTR E-113 December 2005
-------
Washington, DC 20460
Re: Comments on the proposed LT2ESWTR
Docket ID No. OW-2002-0039
Dear Sirs:
Thank you for the opportunity to comment on the above referenced proposed rule.
My comments are as follows:
Comment #1:
Comment #2:
Comment #3:
[In like fashion, EPA should amend the current Stage 1 D/DBPR to give the same sampling consideration
for source water TOC monitoring when having multiple treatment trains [refer to 40 CFR 141.132(d)].
Relative to TOC also, EPA should consider providing a definition for -treated water- to differentiate it
from -finished water- wherein the term -treated water- would have gone through sedimentation and
filtration but possibly not yet disinfection, fluoridation, achievement of required CT, etc., which would
then make the water truly -finished water-[refer to 40 CFR 141.135 (a)(2)(vi)]. When having multiple
treatment trains, any treated water TOC sampling should be required before the treated water is combined
with other treated water from another treatment train. The flow-weighted averaging should then apply for
TOC [similarly as specified under 40 CFR 141.704(e) Multiple Sources for LT2 source water sampling
(even though, in this case, it is the same source] so that the relative differences in removals from each of
the treatment trains can be identified and accounted for.]
Comment #4:
Response: Requirements related to the control of DBFs are outside the scope of the LT2ESWTR. EPA
considered these comments as part of the Stage 2 rulemaking.
EPA Letter ID: 493
Comment ID: 11241
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment:
Comment #5:
Comment #7:
Again, thank you for this opportunity to comment on the proposed LT2ESWTR.
Should you have any questions, you may contact the undersigned at telephone
(225) 765-5063, fax (225) 765-5040, ore-mail at sbecnel@dhh.la.gov.
Comment Response for LT2ESWTR E-114 December 2005
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Sincerely,
Sidney G. Becnel, R.S.
Enforcement Unit Administrator
Safe Drinking Water Program
OFFICE OF PUBLIC HEALTH - ENGINEERING SERVICES
6867 BLUEBONNET BOULEVARD - BOX 5 - BATON ROUGE, LOUISIANA 70810
PHONE #: 225/765-5063 - FAX #: 225/765-5040
"AN EQUAL OPPORTUNITY EMPLOYER"
Response:
EPA Letter ID: 493
Comment ID: 11249
Commenter: Sidney G. Becnel, Enforcement Unit Administrator, State of Louisiana Department of
Health and Hospitals
Commenter Category: State/Tribe Government
Comment:
Comment #6:
Response:
EPA Letter ID: 494
Comment ID: 11178
Commenter: Keith Bircher,, Calgon Carbon Corporation
Commenter Category: Manufacturer/Vendor
Comment: CS Title: Comment referring to "National Primary Drinking Water Regulations:
Long Term 2 Enhanced Surface Water Treatment Rule" submitted by Keith Bircher,
Calgon Carbon Corporation
Company/Group/Association Name: Calgon Carbon Corp.
Response:
EPA Letter ID: 496
Comment ID: 10683
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2's source water monitoring issues: microbial
toolbox, laboratory costs and monitoring location, submitted by Joe Pitt, Chief Operator and Les Brown,
Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Comment Response for LT2ESWTR E-115 December 2005
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Company/Group/Association Name: Mobile Area Water & Sewer, Mobile, AL
Comment:
MAWSS
Mobile Area Water & Sewer System
U. S. Environmental Protection Agency
EPA Docket Center
Pennsylvania Avenue N.W.
Washington, D.C. 20460
January 7, 2004
Attention: Docket ID # OW 2002-0039
Sincerely,
Les Brown
Assistant Director
Mobile Area Water & Sewer
P.O. Box 2368
Mobile, AL 36652
lbrown@mawss.com
Joe Pitt
Chief Operator
Mobile Area Water & Sewer
P.O. Box 2368
Mobile, AL 36652
jpitt@mawss.com
LB/JP:jm
Myers Filtration Plant. 1475 Hubert Pierce Rd . Mobile, AL 36608 . Phone 251-
633-0200 . Fax 251-633-0383
A. Source Water Monitoring
Background: Under the LT2ESWTR, systems initially conduct source water monitoring for
Cryptosporidium to determine their treatment requirements. Filtered systems will be classified in one of
four risk bins based on their monitoring results. EPA predicts that the majority of systems will be
classified in the lowest risk bin, which carries no additional treatment requirements. Systems classified in
higher risk bins must provide 90 to 99.9 % (1.0 to 2.5 log) additional reduction of Cryptosporidium
levels. The regulation specifies a range of treatment and management strategies, collectively termed the
"microbial toolbox", that systems may select to meet their additional requirements. All unfiltered systems
Comment Response for LT2ESWTR E-116 December 2005
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must provide at least 99 or 99.9 % (2 or 3-log) inactivation of Cryptosporidium, depending on the results
of their monitoring.
Cryptosporidium monitoring by large systems (serving at least 10,000 people) will begin six months after
the LT2ESWTR is finalized and will last for a duration of two years. Systems must conduct a second
round of monitoring beginning six years after the initial bin classification. Systems may grandfather
equivalent previously collected data in lieu of conducting new monitoring. Systems are not required to
monitor if they provide the maximum level of treatment required under the rule.
Response:
EPA Letter ID: 496
Comment ID: 10684
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: B. UV Disinfection Criteria
Background: In order to receive UV disinfection credit, a system must demonstrate a UV dose as given in
IT Tables in the proposal using the results of a UV reactor validation test and ongoing monitoring. The
reactor validation test establishes the operating conditions under which a reactor can deliver a required
UV dose. Validation test requirements are given in the UV Guidance Manual. Monitoring is used to
demonstrate that the system maintains these validated operating conditions during routine use.
C. Microbial Toolbox
Background: The LT2ESTWR proposal contains a list of treatment processes and management practices
for water systems to use in meeting additional Cryptosporidium treatment requirements under the
LT2ESWTR. Components of the microbial toolbox include watershed control programs, alternative
sources, pre-treatment processes, additional filtration barriers, inactivation technologies, and enhanced
plant performance. The intent of the microbial toolbox is to provide water systems with a broad selection
of cost effective LT2ESTWR compliance strategies.
Moreover, the toolbox allows systems that currently provide additional pathogen barriers (or that can
demonstrate enhanced performance) to receive additional Cryptosporidium treatment credit.
A key feature of the microbial toolbox is that many of the components carry presumptive credits toward
Cryptosporidium treatment requirements. Plants will receive these credits for toolbox components by
demonstrating compliance with required design and implementation criteria, as described in the sections
that follow. Treatment credit greater than the presumptive credit may be awarded for a toolbox
component based on a specific site or technology-specific demonstration of performance.
The handling of ozone in the toolbox is one of the highlights of the rule.
Response:
EPA Letter ID: 497
Comment ID: 10642
Comment Response for LT2ESWTR E-l 17 December 2005
-------
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: CS Title: Comments focusing on "EPA reducing complex monitoring patterns in the
rule to allow water systems to concentrate on water treatment issues that improve water quality rather
than spending considerable time and effort to avoid monitoring violations"
Company/Group/Association Name: Michigan Department of Environmental Quality
Comment:
State of Michigan
Department of Environmental Quality
Lansing
JENNIFER M. GRANHOLM
GOVERNOR
DEQ
STEVEN E. CHESTER
DIRECTOR
January 9, 2004
LT2ESWTR
Water Docket (MC-4101T)
Docket ID No. OW-2002-0039
U.S Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Gentlemen:
This letter is submitted on behalf of the Michigan Department of Environmental Quality (MDEQ), the
primary enforcement agency for the Public Water System Supervision Program. This is in response to the
notice in the Federal Register dated August 11, 2003, containing the proposed Long Term 2 Enhanced
Surface Water Treatment Rule.
General Comments:
Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR)
Sincerely,
Richard A. Powers, Chief
Water Division
517-335-4176
Comment Response for LT2ESWTR E-118 December 2005
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cc: Mr. Miguel Del Toral, U.S. EPA, Region 5
Association of State Drinking Water Administrators
Mr. James K. Cleland, MDEQ
Response:
EPA Letter ID: 499
Comment ID: 10713
Commenter: David F. Waldo, Chief, Public Water Supply Section, Bureau of Water, Kansas Department
of Health and Environment
Commenter Category: State/Tribe Government
Comment: CS Title: Comment referring to "KDHE agreeing with the principle, design, and process of
the proposed LT2 Rule as described by EPA for meeting the stated objectives" submitted by David F.
Waldo, Bureau of Water, Kansas Department of Health and Environment
Company/Group/Association Name: Kansas Department of Health and Environment
Comment:
KANSAS
DEPARTMENT OF HEALTH AND ENVIRONMENT
RODERICK L. BREMBY, SECRETARY
KATHLEEN SEBELIUS, GOVERNOR
January 9, 2003
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW.
Washington, D.C. 20460
Attention Docket ID No. OW-2002-0039
RE: Long Term 2 Enhanced Surface Water Treatment Rule
Dear Associates,
The Kansas Department of Health and Environment (KDHE) appreciates the opportunity to submit
comments on the proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2 Rule). KDHE is
vitally concerned with the safety and
The following comments are intended to address particular items on which EPA has requested input as
well as to provide observations / insights / concerns about specific requirements of the rule and its
associated impacts:
Comment Response for LT2ESWTR E-119 December 2005
-------
Thank you.
Sincerely,
David F. Waldo
David F. Waldo, P.E., Chief
Public Water Supply Section
Bureau of Water
DIVISION OF ENVIRONMENT
Bureau of Water - Public Water Supply Section
CURTIS STATE OFFICE BUILDING, 1000 SW JACKSON ST., STE 420, TOPEKA, KS 66612-
1367
Voice 785-296-5514 Fax 785-296-5509 http://www.kdhe.state.ks.us
Response:
EPA Letter ID: 502
Comment ID: 10628
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "support of the LT2ESWTR, however, there are
several parts of the rule on which we feel compelled to provide additional commentary and request
modification consideration" submitted by Matthew Steele, City of Columbus,
Company/Group/Association Name: Columbus, Ohio Division of Water
Comment:
January 9, 2004
Water Docket, EPA Docket Center
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
RE: Docket No OW-2002-0039: Long Term 2 Enhanced Surface Water Treatment Rule,
Proposed Rule, 68 Federal Register 47639
Dear Sir or Madam:
Thank you for this opportunity to comment on the proposed Long Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR). The City of Columbus, Division of Water
Thank you for your considering our comments. We appreciate the opportunity to review and comment on
Comment Response for LT2ESWTR E-120 December 2005
-------
proposed rules and regulations. If you have any questions, please call or email Matt Steele at (614) 645-
7691 ormksteele@columbus.gov.
Respectfully,
Matthew Steele
Laboratory Manager
City of Columbus,
Division of Water
LT2ESWTR Comments from the City of Columbus, Division of Water:
Source Water Monitoring:
Response:
EPA Letter ID: 503
Comment ID: 10618
Commenter: Chuck Weber, Superintendent of Operations, WaterOne
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "The rule requiring monitoring cryptosporidium, E. Coli, and
turbidity on river sources for 24 consecutive months" submitted by Chuck Weber, Superintendent of
Operations, WaterOne
Company/Group/Association Name: WaterOne
Comment:
WaterOne
Water District No. 1 of Johnson County
One Mission...
Quality Water
Water Docket
Environmental Protection Agency
Attention: Docket ID No. OW-2002-0039
Please direct any questions regarding these comments to:
Chuck Weber
Superintendent of Operations
WaterOne
7601 Holiday Drive
Kansas City, Kansas 66106
Phone: 913.895.5821
Fax: 913.895.1828
Email: cweber@waterone.org
Comment Response for LT2ESWTR E-121 December 2005
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10747 RENNER BOULEVARD . LENEXA, KANSAS 66219 . TEL: 913.895.5500 .
www.waterone.org
Response:
EPA Letter ID: 504
Comment ID: 11340
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "Proposed Long Term 2 Enhanced Surface Water
Treatment Rule" submitted by Richard Sykes, Manager, Water Operation and Maintenance, East Bay
Municipal Utility District
Company/Group/Association Name: East Bay Municipal Utility District
Comment:
January 9, 2004
Water Docket: OW-Docket@epa.gov
Attention: Docket ID No. OW-2002-0039
Subject: Docket No. OW-2002-0039Long-Term 2 Enhanced Surface Water Treatment
Rule, Proposed Rule, 68 Federal Register 47639-47795.
To Whom It May Concern:
The East Bay Municipal Utility District (EBMUD or District) takes this opportunity to comment on our
review of the Proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) as
requested by EPA. We have reviewed documents that EPA released on August 11, 2003 (68 Federal
Register 47639) and associated guidance manuals and supporting references listed in the rule Docket.
The EBMUD staff has reviewed the rule language, preamble, guidance, and decision support documents
with respect to the FACA Stage 2 M/DBP Agreement in Principle
comments and suggestions will be viewed constructively and will contribute to improving the successful
implementation of this rule.
We wish to emphasize the following key issues as ones for which we believe regulatory revisions are
necessary prior to finalizing the rule. The four major issues that require regulatory revisions are:
EBMUD will appreciate your review and consideration of this letter and the attached detailed comments.
If you have any questions regarding this letter or the attached comments please contact me at (510) 297-
0964.
Sincerely
Richard Sykes, Manager
Comment Response for LT2ESWTR E-122 December 2005
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Water Operation & Maintenance
Attachment (l)-EBMUD Detailed Comments on LT2ESWTR Docket OW-2002-0039
Docket OW-2002-0039
January 9, 2004
EBMUD COMMENTS
January 9, 2004
EAST BAY MUNICIPAL UTILITITY DISTRICT COMMENTS
On the Proposed USEPA
Long-Term Stage 2 Enhanced Surface Water Treatment Rule (LT2ESWTR)
(FR 68(154):47640-47795, August 11, 2003 and Guidance Manuals)
Docket OW-2002-0039
Introduction
The District commends EPA for the effort that has gone into this rule and
appreciates the opportunity to comment.
Specific Comments
1. Benefits Estimate
Response:
EPA Letter ID: 504
Comment ID: 11341
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: The EPA estimate of cryptosporidiosis based on a predictive model using data on
Cryptosporidium concentrations from the ICR suggests that the mean predicted number of
cryptosporidiosis cases that will be avoided upon full implementation of LT2, depending on which data
set is used to describe Cryptosporidium concentration, would be between 240,000/year and
1,000,000/year, or 83/1000,000/yr and 345/100,000/yr.
2. Laboratory Capacity
he proposed rule stipulates that required monitoring is to be conducted by an
3. Implementation Schedule
4. BIN Classification
Comment Response for LT2ESWTR E-123 December 2005
-------
Response:
EPA Letter ID: 504
Comment ID: 11342
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: 10. UV Disinfection Safety Factors.
The guidance manual for UV disinfection (Docket OW-2002-0039-0031 and -0045 through - 0050)
describes conditions that would be required for design and operation of UV disinfection systems. While
EBMUD does not anticipate that UV disinfection will be required for it to comply with LT2 requirements
it may never the less choose to use UV disinfection to satisfy other water quality control objectives. The
District is therefore concerned for the influence that proposed guidance will have on equipment that will
be available from suppliers for whom the primary market will likely be LT2 compliance driven.
Accordingly, we have examined UV disinfection guidance in this light.
Response:
EPA Letter ID: 505
Comment ID: 11172
Commenter: Darron Busch, Administrator, Department of Environment and Natural Resources,
Drinking Water Program
Commenter Category:
Comment: CS Title: Comment referring to laboratory capacity, source water monitoring, microbial
sampling, submitted by Darron Busch, Drinking Water Program, Department of Environment and Natural
Resources, Pierre, SD
Company/Group/Association Name: Department of Environment and Natural Resources, Pierre, SD
Comment:
South Dakota
GREAT FACES. GREAT PLACES.
DEPARTMENT OF ENVIRONMENT
AND NATURAL RESOURCES
JOE FOSS BUILDING
523 EAST CAPITOL
PIERRE, SOUTH DAKOTA 57501-3182
www.state.sd.us/denr
January 8, 2004
Water Docket (MC-4101T)
Docket No. OW-2002-0039
U. S. Environmental Protection Agency
Comment Response for LT2ESWTR E-124 December 2005
-------
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Dear Clerk:
Thank you for the opportunity to provide comment on the proposed Long Term 2 Enhanced Surface
Water Treatment Rule as published in the August 11, 2003 Federal Register. We have reviewed the
proposed rule and offer the comments found in the attachment.
We hope EPA will carefully consider our comments and provide a final rule that implementable at the
state and local levels while still providing public health protection.
Sincerely,
Darron Busch, Administrator
SD Drinking Water Program
E-mail: darron.busch@state.sd.us
Phone: (605) 773-3754
Attachment
Attachment
Comments on the EPA Long Term 2 Enhanced Surface Water Treatment Rule by South Dakota
Department of Environment and Natural Resources (DENR)
Overall, we support the proposed rule and EPA-s efforts to increase public health protection. We do,
however, have a few concerns with the proposed rule and specific comments are noted below.
Specific Comments:
Response:
EPA Letter ID: 506
Comment ID: 10727
Commenter: Maggie Rodgers, Water Quality Manager, Cleveland Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment Referring to "Long Term 2 Enhanced Surface Water Treatment
Rule" submitted by Maggie Rodgers, Water Quality Manager, Cleveland Division of
Water
Company/Group/Association Name: Cleveland Division of Water
Comment:
LONG TERM 2 ENHANCED SURFACE WATER TREATMENT RULE
Comment Response for LT2ESWTR E-125 December 2005
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CLEVELAND DIVISION OF WATER COMMENTS
- Source Water Monitoring
o Lab Capacity - The Agreement in Principal states that the compliance schedules for the LT2ESWTR
will be tied to the availability of sufficient analytical capacity for Cryptosporidium at approved
laboratories and the availability of data management software. If either is unavailable then the monitoring,
implementation, and compliance schedules for both the LT2ESWTR and the Stage-2 DBPR will be
delayed an equivalent period of time.
For questions about these comments, please contact:
Maggie Rodgers
Water Quality Manager
Cleveland Division of Water
1201 Lakeside Avenue
Cleveland, OH 44114
maggie_rodgers@clevelandwater.com
(216)664-2444, ext. 5584
Response: response 1200.g
EPA Letter ID: 507
Comment ID: 11461
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to LT2's Source Water Monitoring for large systems, monitoring
location, sampling schedule, microbial toolbox and filter backwash recycle, submitted by Thomas P.
Bonacquisti, Fairfax County Water Authority
Company/Group/Association Name: Fairfax County Water Authority
Comment:
FAIRFAX COUNTY WATER AUTHORITY
8570 EXECUTIVE PARK AVENUE - P.O. BOX 1500
MERRIFIELD, VIRGINIA 22116-0815
WATER QUALITY AND PRODUCTION DIVISION
THOMAS P. BONACQUISTI, DIRECTOR
(703) 289-6537
FAX: (703) 289-6535
EDWARD PETROVITCH, MANAGER
WATER PRODUCTION
(703) 289-6462
FAX: (703) 289-6488
MELISSA A. BILLMAN, MANAGER
Comment Response for LT2ESWTR E-126 December 2005
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LABORATORY
(703)289-6561
FAX: (703) 289-6559
January 8, 2004
Docket Clerk
Environmental Protection Agency
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Re: Attention Docket ID No. OW-2002-0039, National
Primary Drinking Water Regulations: Long Term 2
Enhanced Surface Water Treatment rule
(LT2ESWTR) Comments
Dear Docket Clerk:
Thank you for providing the Fairfax County Water Authority (FCWA) the opportunity to review and
comment on the proposed Long Term 2 Enhanced Surface Water Treatment Rule. As a contributory
member of the LT2ESWTR Technical Advisory Group, FCWA realizes and appreciates the significant
efforts put forth by the many groups, associations and individuals that aided in the development
of this document.
Our comments are as follows:
Again, thank you very much for the opportunity to comment and participate
relative to the proposed Long Term 2 Enhanced Surface Water Treatment Rule.
Sincerely,
Thomas P. Bonacquisti, Director
Water Quality and Production
Fairfax County Water Authority
8570 Executive Park Avenue
Fairfax, VA 22031
tbonacquisti@fcwa.org
cc: General Manager, FCWA
Executive Officer, FCWA
Public Affairs Officer, FCWA
F:\gcorti\word\letters\Long Term 2 Enhanced Surface Water TPB
Response:
EPA Letter ID: 507
Comment ID: 11476
Comment Response for LT2ESWTR E-127 December 2005
-------
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: 9. Additional Treatment Technique Requirements for Systems with Uncovered Finished
Water Storage Facilities, IV.E.l., pg 47718.
FCWA is in full agreement with the proposed rule strategies relative to uncovered finished water storage
facilities and would like to commend EPA on this language.
Response:
EPA Letter ID: 509
Comment ID: 11477
Commenter: Greg Parker,, Florida Department of Environmental Protection Drinking Water Program
Commenter Category: State/Tribe Government
Comment: CS Title: Comments referring to "Compilation of Comments on Proposed Long Term
2 Enhanced Surface Water Treatment Rule" submitted by Florida Department of Environmental
Protection Drinking Water Program
Company/Group/Association Name: Florida DEP Drinking Water Section
Comment: We have made minor corrections to our earlier comments of 1/9. The corrected version is
attached.
COMPILATION OF COMMENTS ON
PROPOSED LONG TERM 2 ENHANCED
SURFACE WATER TREATMENT RULE
January 9, 2004
Here are comments on the Long Term 2 Enhanced Surface Water Treatment Rule developed by the
Florida Department of Environmental Protection Drinking Water Program. They are arranged by Rule
Section. Please contact Greg Parker at (850) 246-8635 or greg.parker@dep.state.fl.us to discuss any
question you may have concerning this material.
Response:
EPA Letter ID: 510
Comment ID: 11824
Commenter: Linda Gowman, VP Research, Trojan Technologies Inc.
Commenter Category: Manufacturer/Vendor
Comment: CS Title: Comments referring to "The UVDGM is a significant document that supports
introduction to the USA of technology to treat drinking water with ultraviolet light" submitted by Linda
Gowman, VP Research, Trojan Technologies Inc
Company/Group/Association Name: Trojan Technologies Inc.
Comment Response for LT2ESWTR E-128 December 2005
-------
Comment: Thank you for providing an opportunity for comment. Please see the
attached file.
Trojan Technologies Inc.
World Leader in UV Disinfection Systems
Docket ID No. OW - 2002 - 0039
COMMENTS ON:
EPA 815-D-03-0076 USEPA Ultraviolet Disinfection Guidance Manual
(JUNE 2003 DRAFT)
and LT2ESWTR (as embodied in the Federal Register Vol. 68, No. 154, August 11,
2003)
SUBMITTED: January 9, 2004
Submitted to: US EPA
Submitted by: Trojan Technologies Inc
3020 Gore Road
London, Ontario, Canada N5V 4T7
Contact person: Linda Gowman, Ph.D., P.Eng.
VP Research
LGowman@troj anuv. com
Tel: (519) 457-3400, ext2576
Thank you for giving us the opportunity to provide comments on both the Long
Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and the UV Disinfection
Guidance Manual (UVDGM).
Response:
EPA Letter ID: 511
Comment ID: 11486
Commenter: Keith W. Cartnick, Director Water Quality Assurance, United Water New Jersey
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "Long Term 2 Enhanced Surface Water Treatment Rule;
Proposed Rule" submitted by Keith W. Cartnick, Director, Water Quality Assurance, United Water New
Jersey
Company/Group/Association Name: United Water New Jersey
Comment:
Comments on:
Long Term 2 Enhanced Surface Water Treatment Rule; Proposed Rule
Keith W. Cartnick - Director Water Quality Assurance
United Water New Jersey - Haworth Water Treatment Plant
Comment Response for LT2ESWTR E-129 December 2005
-------
Haworth,NJ 07641
Phone: 201-599-6031 Email: keith.cartnick@unitedwater.com
Topic #1: EPA requests comment on - how the effect of recycling filter backwash should be considered
in LT2ESWTR monitoring. (Federal Register / Vol. 68, No. 154 / Monday, August 11, 2003 / Proposed
Rules, p. 47678)
Topic #3: EPA requests comment on - whether 0.15 NTU should be the standard for individual filter
performance credit. While the individual filter effluent criterion of 0.1 NTU is proposed because it is
consistent with Phase IV Partnership standards, allowable rounding would allow turbidity levels of less
than 0.15 NTU to be compliant with a standard of 0.1 NTU. (Federal Register / Vol. 68, No. 154 /
Monday, August 11, 2003 / Proposed Rules, p. 47714)
Topic #4: EPA requests comment on - the reporting and record keeping requirements proposed for the
LT2ESWTR. Specifically, the Agency requests comment on the proposed requirement that systems report
monthly on the use of microbial toolbox components to demonstrate compliance with their
Cryptosporidium treatment requirements. An alternative may be for systems to keep records on site for
State review instead of reporting the data. (Federal Register / Vol. 68, No. 154 / Monday, August 11,
2003 / Proposed Rules, p.
47731)
Response:
EPA Letter ID: 512
Comment ID: 11491
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: of Planning, Contra Costa Water
Company/Group/Association Name: Contra Costa Water District
Comment: Attached are the comments of the Contra Costa Water District. If there are questions or
problems with the attachment please contact:
Samantha A. Salvia, P.E.
Senior Water Resources Specialist
Contra Costa Water District
1331 Concord Avenue
P.O. Box H2O
Concord, CA 94524-2099
(925) 688-8057 (tel)
(925) 688-8142 (fax)
ssalvia@ccwater.com
Contra Costa Water District
1331 Concord Avenue
P.O. Box H2)
Comment Response for LT2ESWTR E-130 December 2005
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Concord, CA 94524
(925) 688-8000 FAX (925) 688-8122
Directors
Joseph L. Campbell
President
Elizabeth R. Anello
Vice President
Bette Boatmun
James Pretti
Karl L. Wandry
Walter J. Bishop
General Manager
January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Attention Docket ID No.: OW-2002-0039
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal Register 47639,
Docket No. OW-2002-0039
The Contra Costa Water District (CCWD) appreciates the opportunity to provide comments on the
Proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) that EPA released on
August 11, 2003 (68 Federal Register 47639). CCWD also appreciates the comment period extension to
January 9, 2004, which afforded more time for a thorough and thoughtful review of the proposed rule.
with water organization representatives, to develop many aspects of the proposed rule. CCWD-s
comments focus on revisions needed in six key areas which could improve the water industry-s ability to
meet the intent and purpose of this rule. These areas are summarized below. Additional detailed
comments are provided in Attachment 1.
CCWD appreciates the opportunity to provide comments on this proposed rule and intends to remain
active in EPA regulatory activities through its involvement with the American Water Works Association,
the Association of Metropolitan Water Agencies, and the Association of California Water Agencies. If
you have any questions regarding these comments, please contact me at (925) 688-8034 or
Samantha Salvia at (925) 688-8057.
Sincerely,
Jerry Brown
Director of Planning
JB/SAS:wec
Comment Response for LT2ESWTR E-131 December 2005
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Attachment
cc: Erica Michaels Brown, AMWA
Alan Roberson, AWWA
Steve Macaulay, CUWA
Christa Clark, ACWA
Contra Costa Water District-s Detailed Comments on the Proposed Long-Term 2 Enhanced Surface
Water Treatment Rule
Microbial Toolbox Elements
Ozone
Response:
EPA Letter ID: 513
Comment ID: 11518
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment: P. Nelson, Director, Nebraska
Company/Group/Association Name: Nebraska Health and Human Services System
Comment:
January 9, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
Attention: Docket ID No. OW-2002-0039
Re: Nebraska-s Comments on the Proposed Long Term 2 Enhanced Surface Water Treatment Rule
Dear Comment Clerk:
This letter is sent in regard to the U.S. Environmental Protection Agency-s Proposed Long Term 2
Enhanced Surface Water Treatment Rule. Nebraska provides the following comments and concerns with
the proposed rule.
General Comments on LT2
Comment Response for LT2ESWTR E-132 December 2005
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Section IV. A. Additional Cryptosporidium Treatment Technique Requirements for Filtered Systems
Laboratory Capacity and Data Management Software
Sampling Schedule/Failure to Complete Monitoring (p. 47666)
The proposed rule states that samples must be collected within 2 days before/after a scheduled sampling
date. Missing a single Cryptosporidium sampling event will result in a monitoring violation, unless one of
two listed conditions is met. Systems failing to complete monitoring (missing at least one sampling event)
will be required to meet treatment requirements of Bin 4 (potentially adding as much as 3.5 log treatment
for Cryptosporidium).
Section IV. C. Options for Systems to Meet Cryptosporidium Treatment Requirements
5. Pre-Sedimentation with Coagulants (and Cryptosporidium sampling instructions)
EPA has requested comment on how Cryptosporidium sampling should be handled when Chemical
treatment is provided to water prior to, or during, presedimentation.
Response:
EPA Letter ID: 513
Comment ID: 11519
Commenter: Richard P. Nelson, Director, Nebraska Health and Human Services System
Commenter Category: State/Tribe Government
Comment:
Contact information for issues related to comments by the State of Nebraska:
Jack L. Daniel, Administrator, Environmental Health Services
NHHS R&L, EHS
PO Box 95007
Lincoln, NE 68509-5007
Phone 402-471-0510
e-mail iack.daniel@hhss.state.ne.us
Response:
EPA Letter ID: 514
Comment ID: 11537
Commenter: Nancy Hall, Environmental Microbiology and Principal Analyst for Method 1623,
University Hygienic Laboratory
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment Response for LT2ESWTR E-133 December 2005
-------
Comment: CS Title: Comment entitled "National Primary Drinking Water Regulations: Long
Term 2 Enhanced Surface Water Treatment Rule: Proposed Rule" submitted by Nancy Hall,
Environmental Microbiology and Principal Analyst for Method 1623, University Hygienic Laboratory
Company/Group/Association Name: University Hygienic Laboratory
Comment:
January 9, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, D.C. 20460
Dear Sir or Madam:
Response to Request for Comments EPA 40 CFR Parts 141 and 142 National Primary Drinking Water
Regulations: Long Term 2 Enhanced Surface Water Treatment Rule: Proposed Rule, Monday August 11,
2003
Subject Line: Docket ID No. OW-2002-0039
K. Analytical Methods
Thank you for the opportunity to provide comments to this important regulation. If there are any
questions or clarifications needed, please let me know.
Sincerely,
Nancy Hall
Supervisor, Environmental Microbiology and Principal Analyst for Method 1623
University Hygienic Laboratory
102 Oakdale Campus H101-OH
Iowa City, Iowa 52242
319/335-4331
nhall@uhl.uiowa.edu
Response:
EPA Letter ID: 515
Comment ID: 11535
Commenter: Matthew Valade,, Hazen and Sawyer/Camp Dresser & McKee
Commenter Category: Consultants: (where self-identified)
Comment: CS Title: Comment focusing on "The most significant topic of concern is that of
the UV reactor validation, as the crux of effectively implementing UV disinfection for treatment water is
the validation" submitted by Matthew T. Valade, Hazen and Sawyer/CDM
Comment Response for LT2ESWTR E-134 December 2005
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Company/Group/Association Name: Hazen and Sawyer/CDM
January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, DC 20460
Re: Long Term 2 Enhanced Surface Water Treatment Rule,
Ultraviolet Disinfection Guidance Manual (Document No. 815-D-02-007),
Docket No. OW-2002-0039
Dear Sir or Madam:
The Joint Venture of Hazen and Sawyer/CDM appreciates the opportunity to review the Draft Ultraviolet
Disinfection Guidance Manual (EPA Document No. 815-D-02-007). The Joint Venture has been heavily
involved with the development of UV disinfection facilities for the City of New York and is thankful for
the
our comments, please contact me at mvalade@hazenandsawyer.com or 212-539-7136. We look forward
to continuing our involvement in the development of the UVDGM and the Long Term 2 Enhanced
Surface Water Treatment Rule
Very truly yours,
Hazen and Sawyer/Camp Dresser & McKee
Matthew T. Valade, P.E.
Associate
MTV:kas
File: Becker, Peters, Glaser, Freud 9452-320
Response:
EPA Letter ID: 516
Comment ID: 11700
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "tremendous impact on the operation of New York
City's (citys) water supply and surface water supplies nationwide" submitted by Christopher O. Ward,
Commisioner, New York City Department of Environmental Protection
Company/Group/Association Name: New York City Department of Environmental
Protection
Comment Response for LT2ESWTR E-135 December 2005
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Comment:
January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68
Federal Register 47639, Docket No. OW-2002-0039
DEPARTMENT OF ENVIRONMENTAL PROTECTION
59-17 JUNCTION BLVD., 19TH FLOOR, FLUSHING, NEW YORK 11373-5108
CHRISTOPHER O. WARD, COMMISSIONER
Dear Sir/Madam:
The New York City Department of Environmental Protection (-DEP-) appreciates this opportunity to
comment on the proposed Long-Term 2 Enhanced Surface Water Treatment Rule (-LT2-), which, when
implemented will have a tremendous impact on the operation of New York City-s water supply and
surface water supplies nationwide. As commissioner of the nation-s largest unfiltered drinking water
supplier, I want to highlight several specific concerns which DEP believes should be addressed before
final promulgation of the rule. These concerns will be addressed in further detail in the attached
comments. However, certain issues bear highlighting and are briefly summarized below:
Thank you for this opportunity to comment on a significant change to our nation-s water quality
standards which, if implemented with precision and balance, will go far towards improving the quality of
life for all Americans.
Sincerely,
Christopher O. Ward
NYC Comments on Long-Term 2 Enhanced Surface Water Treatment Rule
Docket No. OW-2002-0039
Page 1 of23
COMMENTS OF THE NEW YORK CITY DEPARTMENT OF ENVIRONMENTAL PROTECTION
ON THE PROPOSED REGULATION -LONG TERM 2 ENHANCED SURFACE WATER
TREATMENT RULE-
Docket # OW-2002-0039
January 9, 2004
submitting the following comments to assist EPA in promulgating a final regulation that is consistent with
good science, is transparent and supportable, and that is sufficiently flexible so as to not pose an
unreasonable burden on
provisions of the proposed regulations. DEP suggests herein a number of modifications to the proposed
regulations which we believe will, to some degree, ease the financial and operational burden created by
these regulations, while in no way increasing the risk to public health.
Response:
Comment Response for LT2ESWTR E-136 December 2005
-------
EPA Letter ID: 516
Comment ID: 11701
Commenter: Anonymous516,, New York City Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: Recovery and Infectiousness
For the purposes of bin assignments (and presumably for determining whether unfiltered systems require
2 or 3 log removal) EPA proposes that no adjustments be made for method recovery or percentage of
oocysts that are infectious (p. 47673). EPA-s basic premise is that recovery for the ICRSS averaged
approximately 40%, and that percent infectiousness was about 37% and thus these values are of opposite
sign and are therefore offsetting. For the purposes of the risk analysis, EPA assumed that the percent
infectiousness of the ICRSS data could be modeled as a triangular distribution with a mode of 40 percent
and bounds of 30 and 50%. The estimate for percentage of oocysts that are infectious
Response:
EPA Letter ID: 520
Comment ID: 11550
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "Illinois EPA (IEPA) is concerned with the implementation
schedule included in the proposed rules" submitted by Roger D. Selburg, Manager, Division of Public
Water Supplies, The Illinois Environmental Protection Agency (IEPA)
Company/Group/Association Name: The Illinois Environmental Protection Agency (IEPA)
Comment:
January 9, 2004
Water Docket (MC-4101T)
Docket No. OW-2002-0039
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Docket Clerk:
The Illinois Environmental Protection Agency (IEPA) appreciates the opportunity to comment on the
proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) as listed in the August 11,
2003 Federal Register (68 FR 47639).
Responses to those issues on which EPA specifically requested comment in the Federal Register notices
are included in the following Attachments.
IEPA appreciates the opportunity to provide comment on these proposed rules and looks forward to
working with EPA to ensure that the final rules are both protective of public health and are implementable
at the state and local levels.
Comment Response for LT2ESWTR E-137 December 2005
-------
Sincerely,
Roger D. Selburg, Manager
Division of Public Water Supplies
[SEE PAGE 6 OF PDF FILE FOR TABLE ON CRYPTOSPORIDIUM MONITORING]
Illinois Environmental Protection Agency
Overarching Comments on the Proposed LT2ESWTR
January 9, 2004
Rule Development Process
IEPA is suggesting changes to the proposed rules that vary from the Agreement in Principle in areas
where states believe an alternative approach will provide equal or greater public health protection. These
changes are discussed in detail later in these comments.
Response:
EPA Letter ID: 520
Comment ID: 11551
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment:
Specific comments on these and other LT2ESWTR issues are provided later in this document.
Implementation Schedule
Position on Rule Implementation
LT2ESWTR Implementation Schedule
Concerns
Preferred Approach
Based on the foregoing discussion, IEPA recommends the following approach for
implementing the LT2ESWTR:
Views on LT2EWSTR
Comment Response for LT2ESWTR E-138 December 2005
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Microbial Monitoring for Filtered Systems
Response:
EPA Letter ID: 520
Comment ID: 11552
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Illinois Environmental Protection Agency
Response to EPA Requests for Comment on the Proposed LT2ESWTR January 9, 2004
Section III.C Cryptosporidium Occurrence (pages 47652-47659)
Section IV.A Additional Cryptosporidium Treatment Technique Requirements for
Filtered Systems (pages 47665-47679)
Section IV.B Unfiltered System Treatment Technique Requirements for
Cryptosporidium (pages 47679-47681)
Section IV.C Options for Systems to Meet Cryptosporidium Treatment Requirements
(pages 47681-47715)
Response:
EPA Letter ID: 520
Comment ID: 11553
Commenter: Roger Selburg, Manager, Division of Public Water Supplies, The Illinois Environmental
Protection Agency (IEPA)
Commenter Category: State/Tribe Government
Comment: Section IV.F Compliance Schedules (pages 47719-47722)
The state-preferred implementation schedule is described above.
Section IV.G Public Notice Requirements (pages 47722-47723)
IEPA concerns related to laboratory capacity are included in the above.
Section IV.M Requirements for Sanitary Surveys Conducted by EPA (pages 47736-
47737)
Comment Response for LT2ESWTR E-139 December 2005
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Response:
EPA Letter ID: 521
Comment ID: 11756
Commenter: Leslie Rush,, Dalton Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "concern with the availability of reasonably priced laboratory
services for testing for Cryptosporidium" submitted by Leslie Rush, Dalton Utilities
Company/Group/Association Name: Dalton Utilities
Comment:
Attachment to EDOCKET
REQUESTED COMMENTS ON THE PROPOSED LT2ESWTR
January 9, 2004
Leslie Rush
Dalton Utilities
Dalton, Georgia
706-278-1313
Response:
EPA Letter ID: 522
Comment ID: 14125
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "overall broad structure of the proposed regulation represents
the generally reasonable compromises of the Agreement in Principle" submitted by Michael J.
Hornbrook, Chief Operating Officer, Massachusetts Water Resources Authority
Company/Group/Association Name: Massachusetts Water Resources Authority
Comment:
MASSACHUSETTS WATER RESOURCES AUTHORITY
Charlestown Navy Yard
100 First Avenue
Boston, Massachusetts 02129
Telephone: (617) 242-6000
Facsimile: (617)788-4899
Comment Response for LT2ESWTR E-140 December 2005
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January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68
Federal Register 47639, Docket No. OW-2002-0039
Filed Electronically to EPA Docket
Dear Sir or Madam:
The Massachusetts Water Resources Authority (MWRA) appreciates the opportunity to comment on the
Proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) released on August 11,
2003 (68 Federal Register 47639). Given the volume of related materials, we also appreciate that EPA
extended the comment period.
following provisions specifically related to unfiltered systems:
* Continue to meet filtration avoidance criteria, and
* Provide 4 log virus inactivation, and
* Provide 3 log Giardia lamblia inactivation, and
* Provide 2 log Cryptosporidium inactivation.
* Overall inactivation requirements must be met using a minimum of 2 disinfectants.
* Ongoing monitoring and any eventual reassignment to risk bins for unfiltered systems will be consistent
with requirements for other systems of their size, with the provision that unfiltered systems must
demonstrate that their Cryptosporidium occurrence level continues to be less than or equal to
1 in 100 liters (or equivalent, using advanced methods) or provide 3 logs of Cryptosporidium inactivation.
General Comments:
MWRA offers the following comments based on our review of the rule language, preamble, guidance,
and decision support documents. As we reviewed the documents three overall themes struck us.
Thank you for the opportunity to comment on these important regulations. If we can provide EPA any
additional data on any of these topics, please feel free to contact us. You may direct questions to Stephen
Estes-Smargiassi, Director of Planning at 617-788-4303 (smargias@mwra.state.ma.us).
Very Truly Yours,
Comment Response for LT2ESWTR E-141 December 2005
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~ Signed ~
Michael J. Hornbrook
Chief Operating Officer
Response:
EPA Letter ID: 523
Comment ID: 11667
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment focusing on "Responses to EPA's specific requests for comments
on the treatment requirements for unfiltered systems" submitted by Massachusetts Water Resources
Water Authority et al
Company/Group/Association Name: Unfiltered System Working Group
Comment:
Unfiltered Systems Working Group
January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68
Federal Register 47639, Docket No. OW-2002-0039
Filed Electronically to EPA Docket
Dear Sir or Madam:
The Unfiltered Systems Working Group, representing most of the largest unfiltered water systems in the
country, appreciates the opportunity to review the Proposed Long-Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR) released on August 11, 2003 (68 Federal Register 47639). Given the
volume of related materials we also appreciate that EPA extended the comment period.
The Unfiltered Systems Working Group was actively involved in the Stage 2 Microbial / Disinfection By-
Products Federal Advisory Committee (FACA) and was a signatory to the Agreement in Principle (AIP).
The Agreement in Principle included the following provisions specifically related to unfiltered systems.
Unfiltered systems must:
Continue to meet filtration avoidance criteria, and
Provide 4 log virus inactivation, and
Comment Response for LT2ESWTR E-142 December 2005
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Provide 3 log Giardia lamblia inactivation, and
Provide 2 log Cryptosporidium inactivation.
Overall inactivation requirements must be met using a minimum of 2
disinfectants.
Ongoing monitoring and any eventual reassignment to risk bins for unfiltered systems will be consistent
with requirements for other systems of their size, with the provision that unfiltered systems must
demonstrate that their Cryptosporidium occurrence level continues to be less than or equal to 1 in 100
liters (or equivalent, using advanced methods) or provide 3 logs of Cryptosporidium inactivation.
language, preamble, guidance, and decision support documents, and based on that review, offer the
following comments. The comments represent the general consensus opinion of the undersigned utilities.
Responses to EPA's specific requests for comments on the treatment requirementsfor unfiltered systems:
EPA solicited comments on the proposed requirement for unfiltered systems to use two disinfectants and
for each disinfectant to meet by itself the inactivation requirement for at least one regulated pathogen.
Responses to other aspects of the treatment requirements for unfiltered systems:
Thank you for the opportunity to comment on these important regulations. If the Unfiltereds Working
Group can provide EPA any additional data on any of these topics, please feel free to contact us.
Very Truly Yours:
Massachusetts Water Resources Water Authority
New York City Department of Environmental Protection
San Francisco Public Utilities Commission
Seattle Public Utilities
Tacoma Public Utilities
Response:
EPA Letter ID: 523
Comment ID: 11679
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment focusing on "Responses to EPA's specific requests for comments
on the treatment requirements for unfiltered systems" submitted by Massachusetts Water Resources
Water Authority et al
Company/Group/Association Name: Unfiltered System Working Group
Comment Response for LT2ESWTR E-143 December 2005
-------
Comment:
Unfiltered Systems Working Group
January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68
Federal Register 47639, Docket No. OW-2002-0039
Filed Electronically to EPA Docket
Dear Sir or Madam:
The Unfiltered Systems Working Group, representing most of the largest unfiltered water systems in the
country, appreciates the opportunity to review the Proposed Long-Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR) released on August 11, 2003 (68 Federal Register 47639). Given the
volume of related materials we also appreciate that EPA extended the comment period.
The Unfiltered Systems Working Group was actively involved in the Stage 2 Microbial / Disinfection By-
Products Federal Advisory Committee (FACA) and was a signatory to the Agreement in Principle (AIP).
The Agreement in Principle included the following provisions specifically related to unfiltered systems.
Unfiltered systems must:
Continue to meet filtration avoidance criteria, and
Provide 4 log virus inactivation, and
Provide 3 log Giardia lamblia inactivation, and
Provide 2 log Cryptosporidium inactivation.
Overall inactivation requirements must be met using a minimum of 2
disinfectants.
Ongoing monitoring and any eventual reassignment to risk bins for unfiltered systems will be consistent
with requirements for other systems of their size, with the provision that unfiltered systems must
demonstrate that their Cryptosporidium occurrence level continues to be less than or equal to 1 in 100
liters (or equivalent, using advanced methods) or provide 3 logs of Cryptosporidium inactivation.
language, preamble, guidance, and decision support documents, and based on that review, offer the
following comments. The comments represent the general consensus opinion of the undersigned utilities.
Responses to EPA's specific requests for comments on the treatment requirements for unfiltered systems:
EPA solicited comments on the proposed requirement for unfiltered systems to use
Comment Response for LT2ESWTR E-144 December 2005
-------
two disinfectants and for each disinfectant to meet by itself the inactivation requirement for at least one
regulated pathogen.
Responses to other aspects of the treatment requirements for unfiltered systems:
Thank you for the opportunity to comment on these important regulations. If the Unfiltereds Working
Group can provide EPA any additional data on any of these topics, please feel free to contact us.
Very Truly Yours:
Massachusetts Water Resources Water Authority
New York City Department of Environmental Protection
San Francisco Public Utilities Commission
Seattle Public Utilities
Tacoma Public Utilities
Response:
EPA Letter ID: 523
Comment ID: 11685
Commenter: Anonymous523,, Unfiltered Systems Working Group
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Issues Affecting Both Filtered and Unfiltered Systems:
Response:
EPA Letter ID: 524
Comment ID: 12205
Commenter: Gary Larimore, Executive Director, Kentucky Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment focusing on "assessment that the implementation schedule proposed by
EPA for Stage 2 D/DPB will be in conflict with current Kentucky monitoring requirements for Stage 1
D/DBP" submitted Gary Larimore, Kentucky Rural Water Association
Company/Group/Association Name: Kentucky Rural Water Association
Comment:
January 9, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
Comment Response for LT2ESWTR E-145 December 2005
-------
1200 Pennsylvania Avenue, N.W.
Washington, D. C. 20460
Attention Docket ID Nos. OW-2002-0039 and OW-2002-0043
Dear Sir or Madam,
The public utilities of Kentucky are committed to protecting our sources of drinking water and share
EPA's desire to increase public health protection by addressing risks from microbial contaminants and
disinfection byproducts (DBPs).
Consecutive Systems
KRWA supports the flexibility of considering "combined" distribution systems of producing and
purchasing systems for Stage 2 monitoring. Historically, EPA regulations have focused on the water
treatment plant exclusively. We believe that the public water system should be viewed in its entirety. The
primary focus should rightfully be placed on the treatment plant, but the distribution system also deserves
attention in regards to water quality regulations. The proposed regulations should not only encourage
cooperation between the consecutive systems but should also give our state primacy agency the flexibility
to find solutions and resolve conflicts locally. Therefore, we are requesting the EPA to consider not
implementing the requirements as proposed for consecutive systems.
KRWA agrees with the Kentucky Division of Water's assessment that the implementation schedule
proposed by EPA for Stage 2 D/DPB will be in conflict with current Kentucky monitoring requirements
for Stage 1 D/DBP. The confusion and problems created by this conflict can be avoided by allowing
states to develop a transitional monitoring schedule and accept primacy for the Stage 2 Rule before the
water systems are required to begin their Initial Distribution System Evaluation (IDSE).
Total Organic Carbon
EPA should clarify in the rule language (40 CFR 141.135(c)(l)(iv)) that systems should not divide by 12
to determine compliance with the TOC requirement but rather divide by the total number of samples
collected. This provision is confusing and causing many systems to have violations when in fact they are
adequately meeting the standards.
KRWA offers the following suggested language for the TOC compliance calculation. This is intended to
allow flexibility to the TOC calculation and still discourage water systems from intentionally not
monitoring for TOC.
This suggested language would allow the calculation of a running average to be based upon the available
data. The water system would be required to take the necessary actions to address the monitoring that is
missed and the primacy agency would have flexibility in enforcing the issue.
40 CFR 141 SubpartL
141.135 (c) (iv) Add together the results of paragraph (c) (1) (hi) of this section for the last 12 months and
divide by the number of samples collected. If a PWS fails to collect twelve consecutive monthly samples,
compliance with the TOC percent removal requirement must be based on an average of the available
Comment Response for LT2ESWTR E-146 December 2005
-------
data. The PWS shall be required to provide a separate public notification for each month that monitoring
does not occur. The public notice must be issued as soon as practical but within 30 days after the
monitoring violation occurs.
The EPA Public Notification Handbook provides instructions for providing public notices for several
surface water treatment violations. Failing to monitor for TOC could be treated similar to failing to
provide adequate filtration. The calculation for TOC is measuring the existence of adequate treatment for
precursors. If a water system provides adequate treatment for precursors but misses a sample and is then
required to divide by twelve, instead of the actual number of samples, then the water system is being
forced to provide false information to their consumers. The running annual average for disinfection
byproducts such as TTHM's, HAAS, Bromate, and disinfectant residuals allows for the calculation to be
based on an average of available data. The average for TOC should be allowed to be calculated likewise,
especially since DBP precursors themselves do not have adverse health effects. The public may need to
be informed that a sample has been missed but the public should not be misled with inaccurate averages.
Public Notification
KRWA strongly opposes a mandatory Public Notification requirement and supports EPA's decision to not
include information about reproductive or developmental health effects in public notices.
KRWA supports the idea of keeping the public informed concerning legitimate health risks, but has
become greatly concerned with the frequency of Public Notifications required by the SDWA. The
severity of the required language, coupled with the frequency of notification, undermines the public trust
which we as an industry (producers, purchasers, regulators, and Technical Assistance providers) have
worked so hard to achieve.
We should not be notifying the public every time our DBP levels exceed a somewhat dubious limit, as
required for Tier 1 and Tier 2 violations. An exception for DBP violations should be made so that they are
only reported once per year. This lessened requirement seems to more accurately fit the situation. We
seem to be creating alarm and distrust among our consumers for no good reason.
We thank you for the opportunity to comment on these regulations. If there are any questions, please do
not hesitate to contact the KRWA office.
Sincerely,
Gary Larimore
Executive Director
Kentucky Rural Water Association
3251 Spring Hollow Avenue
Bowling Green, KY 42104
270.843.2291
Response: Requirements for the control of DBFs are outside the scope of the LT2ESWTR. EPA
considered these comments as part of the Stage 2 rulemaking.
EPA Letter ID: 526
Comment ID: 11763
Comment Response for LT2ESWTR E-147 December 2005
-------
Commenter: Nick Jackson,, Knoxville Utilities Board
Commenter Category: Local Government
Comment: CS Title: Comment focusing on "EPA should not consider occasional noncompliance due to
sampling and analytical error as an automatic indicator of poor operation or the inability to produce safe
potable water" submitted by Nick Jackson, Knoxville Utilities Board
Company/Group/Association Name: Knoxville Utilities Board
Comment:
January 9, 2004
US Environmental Protection Agency
1200 Pennsylvania Avenue NW
Washington, DC 20460
Attention Dockett ID No.: OW-2002-0039
The Knoxville Utilities Board (KUB) in Knoxville, Tennessee appreciates the opportunity to comment on
the LT2ESWTR proposal as put forth in the above
However, there is some wording in the proposal which causes us concern:
Again, we appreciate the opportunity to comment on this upcoming regulation.
If there are questions concerning any of our comments, please contact:
Nick Jackson
2015 Neyland Drive
Knoxville, Tennessee 37916-4119
Telephone 865 594 7621
Email: njackson@kub.org
Response:
EPA Letter ID: 527
Comment ID: 10841
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment referring to "Proposed Long-Term 2 Enhanced Surface Water Treatment
Rule" submitted by American Water Works Association et al.
Company/Group/Association Name: American Water Works Association (AWWA), Association of
Metropolitan Water Agencies (AMWA), National Association of Water Companies (NAWC), and The
National League of Cities (NLC)
Comment Response for LT2ESWTR E-148 December 2005
-------
Comment: Attached are joint comments filed by the American Waterworks Association, Association of
Metropolitan Water Agencies, National Association of Water Companies, and National League of Cities
on the Proposed Long-Term 2 Enhanced Surface Water Treatment Rule. Please contact Steve Via at 202-
628-8303 if you have any problems receiving the attached transmittal.
January 9, 2004
Cynthia Dougherty
Environmental Protection Agency, Mail Code
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
RE: Proposed Long-Term 2 Enhanced Surface Water Treatment Rule
(Docket No. OW-2002-0039)
Dear Ms. Dougherty:
Overall, however, we greatly appreciate the efforts of EPA staff both in developing a very difficult and
demanding proposal, and in working closely with us on a number of important issues. We believe that this
joint effort will result in better regulations in the future and look forward to moving ahead in
the same spirit of cooperation.
Your review and consideration of this letter and the attached joint comments are appreciated. If you have
questions on the substance of these comments, please contact Diane VanDe Hei for the Association of
Metropolitan Water Agencies, Tom Curtis for the American Water Works Associations, Peter Cook for
the National Association of Water Companies, or Carol Kocheisen for the National League of Cities.
Best regards,
Thomas W. Curtis Peter Cook
Deputy Executive Director Executive Director
AWWA NAWC
Diane VanDe Hei Donald J. Borut
Executive Director Executive Director
AMWA NLC
cc: Water Docket, OW-2002-0043
Ephraim King, U.S. EPA
Joint Comments on the PROPOSED LONG TERM 2 ENHANCED SURFACE WATER TREATMENT
RULE
(LT2ESWTR)
The following comments should be taken as part of our continuing effort to Support prudent regulatory
action in the face of significant uncertainties in virtually every aspect of the occurrence, health effects,
and economic analysis information underlying the proposed rule.
Source Water Monitoring
Background: Under the LT2ESWTR, systems initially conduct source water Monitoring for
Cryptosporidium to determine their treatment requirements. Filtered systems will be classified in one of
four risk bins based on their monitoring results. EPA projects that the majority of systems will be
classified in the lowest risk bin, which carries no additional treatment requirements. Systems classified in
Comment Response for LT2ESWTR E-149 December 2005
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higher risk bins must provide 90 to 99.7 percent (1.0 to 2.5-log) additional reduction of Cryptosporidium
levels. The regulation specifies a range of treatment and management strategies, collectively termed
the -microbial toolbox,- that systems may select to meet their additional treatment requirements. All
unfiltered systems must provide at least 99 or 99.9 percent (2 or 3-log) inactivation of Cryptosporidium,
depending on the results of their monitoring.
Cryptosporidium monitoring by large systems (serving at least 10,000 people) will begin six months after
the LT2ESWTR is finalized and will last for two years. Systems must conduct a second round of
monitoring beginning six years after the initial bin classification. Systems may grandfather equivalent
previously collected data in lieu of conducting new monitoring, and systems are not required to monitor if
they provide the maximum level of treatment required under the rule.
Laboratory Capacity: The Agreement in Principle (Section 2.11 .a) states that the compliance schedules
for the LT2ESWTR will be tied to the availability of sufficient analytical capacity for Cryptosporidium at
approved laboratories and the availability of data management software. If either is unavailable, the
monitoring, implementation, and compliance schedules for both the LT2ESWTR and the Stage-2 DBPR
will be delayed an equivalent period of time.
UV Disinfection Criteria
Background: To receive UV disinfection credit, a system must demonstrate a UV dose as given in UV
dose tables in the proposal using the results of a UV reactor validation test and ongoing monitoring. The
reactor validation test establishes the operating conditions under which a reactor can deliver a
required UV dose. Validation test requirements are given in the UV Guidance Manual. Monitoring is
required to demonstrate that the system maintains these validated operating conditions during routine use.
Response: response 1200.g
EPA Letter ID: 527
Comment ID: 10841
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment referring to "Proposed Long-Term 2 Enhanced Surface Water
Treatment Rule" submitted by American Water Works Association et al.
Company/Group/Association Name: American Water Works Association (AWWA), Association of
Metropolitan Water Agencies (AMWA), National Association of Water Companies (NAWC), and The
National League of Cities (NLC)
Comment: Attached are joint comments filed by the American Waterworks Association, Association of
Metropolitan Water Agencies, National Association of Water Companies, and National League of Cities
on the Proposed Long-Term 2 Enhanced Surface Water Treatment Rule. Please contact Steve Via at 202-
628-8303 if you have any problems receiving the attached transmittal.
January 9, 2004
Cynthia Dougherty
Environmental Protection Agency, Mail Code
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Comment Response for LT2ESWTR E-150 December 2005
-------
RE: Proposed Long-Term 2 Enhanced Surface Water Treatment Rule
(Docket No. OW-2002-0039)
Dear Ms. Dougherty:
Overall, however, we greatly appreciate the efforts of EPA staff both in developing a very difficult and
demanding proposal, and in working closely with us on a number of important issues. We believe that this
joint effort will result in better regulations in the future and look forward to moving ahead in
the same spirit of cooperation.
Your review and consideration of this letter and the attached joint comments are appreciated. If you have
questions on the substance of these comments, please contact Diane VanDe Hei for the Association of
Metropolitan Water Agencies, Tom Curtis for the American Water Works Associations, Peter Cook for
the National Association of Water Companies, or Carol Kocheisen for the National League of Cities.
Best regards,
Thomas W. Curtis Peter Cook
Deputy Executive Director Executive Director
AWWA NAWC
Diane VanDe Hei Donald J. Borut
Executive Director Executive Director
AMWA NLC
cc: Water Docket, OW-2002-0043
Ephraim King, U.S. EPA
Joint Comments on the PROPOSED LONG TERM 2 ENHANCED SURFACE WATER TREATMENT
RULE
(LT2ESWTR)
The following comments should be taken as part of our continuing effort to Support prudent regulatory
action in the face of significant uncertainties in virtually every aspect of the occurrence, health effects,
and economic analysis information underlying the proposed rule.
Source Water Monitoring
Background: Under the LT2ESWTR, systems initially conduct source water Monitoring for
Cryptosporidium to determine their treatment requirements. Filtered systems will be classified in one of
four risk bins based on their monitoring results. EPA projects that the majority of systems will be
classified in the lowest risk bin, which carries no additional treatment requirements. Systems classified in
higher risk bins must provide 90 to 99.7 percent (1.0 to 2.5-log) additional reduction of Cryptosporidium
levels. The regulation specifies a range of treatment and management strategies, collectively termed
the -microbial toolbox,- that systems may select to meet their additional treatment requirements. All
unfiltered systems must provide at least 99 or 99.9 percent (2 or 3-log) inactivation of Cryptosporidium,
depending on the results of their monitoring.
Cryptosporidium monitoring by large systems (serving at least 10,000 people) will begin six months after
the LT2ESWTR is finalized and will last for two years. Systems must conduct a second round of
monitoring beginning six years after the initial bin classification. Systems may grandfather equivalent
previously collected data in lieu of conducting new monitoring, and systems are not required to monitor if
Comment Response for LT2ESWTR E-151 December 2005
-------
they provide the maximum level of treatment required under the rule.
Laboratory Capacity: The Agreement in Principle (Section 2.11 .a) states that the compliance schedules
for the LT2ESWTR will be tied to the availability of sufficient analytical capacity for Cryptosporidium at
approved laboratories and the availability of data management software. If either is unavailable, the
monitoring, implementation, and compliance schedules for both the LT2ESWTR and the Stage-2 DBPR
will be delayed an equivalent period of time.
UV Disinfection Criteria
Background: To receive UV disinfection credit, a system must demonstrate a UV
dose as given in UV dose tables in the proposal using the results of a UV
reactor validation test and ongoing monitoring. The reactor validation test
establishes the operating conditions under which a reactor can deliver a
required UV dose. Validation test requirements are given in the UV Guidance
Manual. Monitoring is required to demonstrate that the system maintains these
validated operating conditions during routine use.
Response: response 1200.g
EPA Letter ID: 527
Comment ID: 10842
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Microbial Toolbox
Background: The LT2ESWTR proposal contains a list of treatment processes and management practices
for water systems to use in meeting additional Cryptosporidium treatment requirements under the
LT2ESWTR. This list, termed the microbial toolbox, was recommended by the Stage 2 M-DBP Advisory
Committee in
Components of the microbial toolbox include watershed control programs, alternative sources,
pretreatment processes, additional filtration barriers, inactivation technologies, and enhanced plant
performance. The intent of the microbial toolbox is to provide water systems with broad flexibility in
selecting cost effective LT2ESWTR compliance strategies. Moreover, the toolbox allows systems that
currently provide additional pathogen barriers or that can demonstrate enhanced performance to receive
additional Cryptosporidium treatment credit.
A key feature of the microbial toolbox is that many of the components carry presumptive credits towards
Cryptosporidium treatment requirements. Plants will receive these credits for toolbox components by
demonstrating compliance with required design and implementation criteria, as described in the sections
that follow. Treatment credit greater than the presumptive credit may be awarded for a toolbox
component based on a site specific or technology-specific demonstration of performance.
Response:
EPA Letter ID: 527
Comment ID: 10842
Comment Response for LT2ESWTR E-152 December 2005
-------
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Microbial Toolbox
Background: The LT2ESWTR proposal contains a list of treatment processes and management practices
for water systems to use in meeting additional Cryptosporidium treatment requirements under the
LT2ESWTR. This list, termed the microbial toolbox, was recommended by the Stage 2 M-DBP Advisory
Committee in
Components of the microbial toolbox include watershed control programs, alternative sources,
pretreatment processes, additional filtration barriers, inactivation technologies, and enhanced plant
performance. The intent of the microbial toolbox is to provide water systems with broad flexibility in
selecting cost effective LT2ESWTR compliance strategies. Moreover, the toolbox allows systems that
currently provide additional pathogen barriers or that can demonstrate enhanced performance to receive
additional Cryptosporidium treatment credit.
A key feature of the microbial toolbox is that many of the components carry presumptive credits towards
Cryptosporidium treatment requirements. Plants will receive these credits for toolbox components by
demonstrating compliance with required design and implementation criteria, as described in the sections
that follow. Treatment credit greater than the presumptive credit may be awarded for a toolbox
component based on a site specific or technology-specific demonstration of performance.
Response:
EPA Letter ID: 528
Comment ID: 12238
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "public health may be better protected by taking additional
time at the outset of the rules", submitted by Lyle Godfrey, Engineer Supervisor, Division of Engineering,
Arkansas Department of Heath
Company/Group/Association Name: Arkansas Department of Health
Comment:
Arkansas Department of Health
815 West Markham • Little Rock, Arkansas 72205-3867 • Telephone (501) 661-2000
Fay Boozman, MD, MPH, Director
Mick Huckabee, Governor
Keeping Your Hometown Healthy
-An Equal Opportunity Employer-
January 12,2004
Water Docket (MC-4101T)
Docket Nos. OW-2002-0039 and OW-2002-0043
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Comment Response for LT2ESWTR E-153 December 2005
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Washington, DC 20460
Docket Clerk:
The Arkansas Department of Health appreciates the opportunity to comment on the proposed Long Term
2 Enhanced Surface Water Treatment Rule (LT2ESWTR) as listed in the August 11, 2003 Federal
Register (68 FR 47639).
Arkansas appreciates the opportunity to provide comment on these proposed rules and looks forward to
working with EPA to ensure that the final rules are both protective of public health and implementable at
the state and local level.
Sincerely,
Lyle Godfrey, Engineer Supervisor
Division of Engineering
Arkansas Department of Heath
Arkansas Department of Health-s Comments on LT2ESWTR Proposed Rule
LT2ESWTR Implementation Schedule
If the availability of adequate laboratory capacity or data management software for microbial monitoring
under LT2ESWTR for large or medium systems is delayed then monitoring, implementation, and
compliance schedules for both the LT2ESWTR and Stage 2 DBPR described under 2.11 .c will be delayed
by an equivalent period.
Preferred Approach
Based on the foregoing discussion, we recommend the following approach for
implementing the LT2ESWTR:
Response:
EPA Letter ID: 528
Comment ID: 12239
Commenter: Lyle Godfrey, Engineering Supervisor, Arkansas Department of Health
Commenter Category: State/Tribe Government
Comment: Other Comments
Microbial Monitoring for Filtered Systems
Response:
EPA Letter ID: 529
Comment ID: 13126
Commenter: Anonymous529,,
Commenter Category:
Comment:
Company/Group/Association Name:
Comment Response for LT2ESWTR E-154 December 2005
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Comment: Several comments:
Response:
EPA Letter ID: 533
Comment ID: 12210
Commenter: Edward Urheim,,
Commenter Category: Consultants: (where self-identified)
Comment: CS Title: Comment focusing on "The proposed start of source monitoring under the
LT2ESWTR should be no sooner than 24 months after the final rule is promulgated" submitted by
Edward Urheim
Company/Group/Association Name:
Comment:
Subject: Docket ID No. OW-2002-0039
The following comments on the proposed Long Term 2 Enhanced Surface Water Treatment Rule (as
listed in the August 11, 2003 Federal Register, Volume 68, Pages 47640 - 47795) are being submitted by
Edward Urheim, P.O. Box 941848, Atlanta, GA 31141, e-mail: eu2002grwa@yahoo.com. I have worked
with public water
trainer and provider of technical assistance). I appreciate the opportunity to
provide comments on the proposed LT2ESWTR.
Response:
EPA Letter ID: 534
Comment ID: 11996
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: CS Title: Comment focusing on "use of presedimentation during LT2ESWTR monitoring
must be consistent with routine plant operation and must be recorded by the system.? submitted by John
Reddy, Kansas City, Missouri Water Services Department
Company/Group/Association Name: Kansas City, Missouri Water Services Department
Comment:
To: EPA Docket Center
From: Kansas City, Missouri Water Services Department
4800 E. 63rd Street
Kansas City, MO 64131
Contact persons: John Reddy (john_reddy@kcmo.org)
Mary Lappin (mary_lappin@kcmo.org)
Comment Response for LT2ESWTR E-155 December 2005
-------
The City of Kansas City, Missouri appreciates the opportunity to review and comment on the Proposed
Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) published on August 11, 2003 at
68 FR 47639. Kansas City, Missouri appreciates the obvious effort that has been made to tailor the rule
for site-specific issues and offers the following additional comments, observations and suggestions are
offered.
Issue: Sampling Location/Presedimentation
On Page 47666 the proposed rule states: -Source water samples must be representative of the intake to
the filtration plant. Generally, sampling must be performed individually for each plant that treats a surface
water source. However, where multiple plants receive all of their water from the same influent (e.g.,
multiple plants draw water from the same pipe), the same set of monitoring results may be applicable to
each plant. Typically, samples must be collected prior to any treatment, with exceptions for certain
pretreatment processes. Directions on sampling location for plants using off-stream storage,
presedimentation, and bank filtration are provided in section IV.C. Systems with plants that use multiple
water sources at the same time must collect samples from a tap where the sources are combined prior to
treatment if available. If a blended source tap is not available, systems must collect samples from each
source and either analyze a weighted composite (blended) sample or analyze samples from each source
separately and determine a weighted average of the results.-
And on Page 47687 the proposed rule states:
-EPA is proposing to award a presumptive 0.5 log Cryptosporidium treatment credit for presedimentation
that is installed after LT2ESWTR monitoring and meets the following three criteria:
(1) The presedimentation basin must be in continuous operation and must treat all of the flow reaching the
treatment plant.
(2) The system must continuously add a coagulant to the presedimentation basin.
(3) The system must demonstrate on a monthly basis at least 0.5 log reduction of influent turbidity
through the presedimentation process in at least 11 of the 12 previous consecutive months. This monthly
demonstration of turbidity reduction must be based on the arithmetic mean of at least daily turbidity
measurements in the presedimentation basin influent and effluent, and must be calculated as follows:
Monthly mean turbidity log reduction = loglO(monthly mean of daily influent turbidity) - loglO(monthly
mean of daily effluent turbidity).
If the presedimentation process has not been in operation for 12 months, the system must verify on a
monthly basis at least 0.5 log reduction of influent turbidity through the presedimentation process,
calculated as specified in this paragraph, for at least all but any one of the months of operation. Systems
with presedimentation in place at the time they begin LT2ESWTR Cryptosporidium monitoring are not
eligible for the 0.5 log presumptive credit and must sample after the basin when in use for the
purpose of determining their bin assignment. The use of presedimentation during LT2ESWTR monitoring
must be consistent with routine plant operation and must be recorded by the system.-
Comment
Issue: Credit for 2-stage lime softening
On Page 47697 the proposed rule states:
-These data indicate that two-stage softening plants can remove high levels of Cryptosporidium, and, in
particular, that a second clarification stage can Achieve 0.5 log or greater removal. Three of the four
plants that provided data on removal of aerobic spores achieved greater than 1 log reduction in the
second clarifier. Kansas City, the one plant which achieved little removal in the second clarifier, achieved
a mean 2.4 log removal in the primary clarifier. This was approximately 1 log more reduction than
achieved in the primary clarifiers of the other three plants, so that the spore concentration entering
Comment Response for LT2ESWTR E-156 December 2005
-------
the second clarifier in Kansas City may have been too low to serve as an indicator of removal efficiency.
Consequently, EPA has concluded that these data support an additional Cryptosporidium treatment credit
of 0.5 log for a two-stage softening plant. EPA is proposing as a condition of the 0.5 log additional
credit that a coagulant, which could include excess lime and soda ash or precipitation of magnesium
hydroxide, be present in both clarifiers. This requirement is necessary to ensure that significant particulate
removal occurs in both clarification stages. Logsdon et al. (1994) identified effective flocculation as being
a key factor for removal of protozoa in softening plants. Among the softening plants that provided data on
aerobic spore removal, St. Louis added ferric and polymer coagulants at different points in the process,
and the two Columbus plants added lime to the second clarifier. Consequently, a requirement that plants
add a coagulant, which may be lime, in the secondary clarifier is consistent with the data used to support
the 0.5 log additional credit. The Science Advisory Board (SAB) reviewed the proposed Cryptosporidium
treatment credit for lime softening and supporting information, as presented in the November 2001 pre-
proposal draft of the LT2ESWTR (USEPA 200 Ig). In written comments from a December 2001 meeting
of the Drinking Water Committee, the SAB panel concluded that both single- and twostage softening
generally outperform conventional treatment due to the heavy precipitation that occurs. Further, the
panel found that 0.5 log of additional Cryptosporidium removal is an average value for a two-stage lime
softening plant. However, the SAB stated that the additional credit for two-stage softening should be
given only if all the water passes through both stages. Today-s proposal is consistent with these
recommendations by the SAB. EPA notes that by including a presumptive credit for softening plants,
today-s proposal differs from the Stage 2 M-DBP Agreement in Principle, which recommends up to 1 log
additional Cryptosporidium treatment credit for softening plants based on demonstration of performance,
but no additional presumptive credit-
-c. Request for comment. EPA requests comment on the proposed criteria for awarding credit to lime
softening plants. EPA would particularly appreciate comment on the following issues:
- Whether the information and analyses presented in this proposal supports an additional 0.5 log credit for
two-stage softening, and the associated criteria necessary for credit.
- Additional information that either support or suggest modifications to the proposed criteria and credit-
Comment
Issue: Sampling / Data Reporting/ Laboratory Certification
On Page 47666 the proposed rule states:
-Sampling Schedule
Large systems must submit a sampling schedule to EPA within 3 months after promulgation of the
LT2ESWTR. Small systems must submit a sampling schedule for E. coli monitoring to their primacy
agency within 27 months after rule promulgation; small systems required to monitor for Cryptosporidium
must submit a Cryptosporidium sampling schedule within 45 months after promulgation. The sampling
schedules must specify the calendar date on which the system will collect each sample required under the
LT2ESWTR. Scheduled sampling dates should be evenly distributed throughout the monitoring period,
but may be arranged to accommodate holidays, weekends, and other events when collecting or analyzing
a sample would be problematic. Systems must collect samples within 2 days before or 2 days after a
scheduled sampling date. If a system does not sample within this 5-day window, the system will incur a
monitoring violation unless either of the following two conditions apply:
(1) If extreme conditions or situations exist that may pose danger to the sample collector, or which are
unforeseen or cannot be avoided and which cause the system to be unable to sample in the required time
frame, the system must sample as close to the required date as feasible and submit an explanation for the
alternative sampling date with the analytical results.
(2) Systems that are unable to report a valid Cryptosporidium analytical result for a scheduled sampling
date due to failure to comply with analytical method quality control requirements (described in section
IV.K) must collect a replacement sample within 14 days of being notified by the laboratory or the State
Comment Response for LT2ESWTR E-157 December 2005
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that a result cannot be reported for that date. Systems must submit an explanation for the replacement
sample with the analytical results. Where possible, the replacement sample collection date should not
coincide with any other scheduled LT2ESWTR sampling dates.-
On Page 47678 the proposed rule states:
-Bin Assignment for Systems That Fail To Complete Required Monitoring Today-s proposal classifies
systems that fail to complete required monitoring in Bin 4, the highest treatment bin. EPA requests
comment on alternative approaches for systems that fail to complete required monitoring, such as
classifying the system in a bin based on data the system has collected, or classifying the system in a bin
one level higher than the bin indicated by the data the system has collected. The shortcoming to these
alternative approaches is that bin classification becomes more uncertain, and the likelihood of bin
misclassification increases, as systems collect fewer than the required 24 Cryptosporidium samples.
Consequently, the proposed approach is for systems to collect all required samples. Note that under
today-s proposal, systems may provide 5.5 log of treatment for Cryptosporidium (i.e., comply with Bin 4
requirements) as an alternative to monitoring. Where systems notify the State that they will provide
treatment instead of monitoring, they will not incur monitoring violations.-
Comment
On Page 47726 the proposed rule states:
-Reporting
Because source water monitoring by large systems will begin 6 months after promulgation of the
LT2ESWTR, EPA is proposing that monitoring results for large systems be reported directly to the
Agency though an electronic data system (described in section IV.J), similar to the approach currently
used under the Unregulated Contaminants Monitoring Rule (64 FR 50555, September 17, 1999)
(USEPA 1999c). Small systems will report data to EPA or States, depending on whether States have
assumed primacy for the LT2ESWTR.-
Comment
Response:
EPA Letter ID: 534
Comment ID: 11997
Commenter: John Reddy,, City of Kansas City, Missouri
Commenter Category: Local Government
Comment: Issue: Inclusion of Partnership for Safe Water individual filter criteria of 0.1
NTU
On Page 47714 the proposed rule states:
-c. Request for comment. The Agency invites comment on the following issues related to the proposed
credit for individual filter performance.
- Are there different or additional performance measures that a utility should be required to meet for the 1
log additional credit?
- Are there existing peer review programs for which treatment credit should be awarded under the
LT2ESWTR? If so, what role should primacy agencies play in establishing and managing any such peer
review program?
- The individual filter effluent turbidity criterion of 0.1 NTU is proposed because it is consistent with
Phase IV Partnership standards, as based on CCP goals. However, with allowable rounding, turbidity
levels less than 0.15 NTU are in compliance with a standard of 0.1. Consequently, EPA requests
comment on whether 0.15 NTU should be the standard for individual filter performance credit, as this
would be consistent with the standard of 0.15 NTU that is proposed for combined filter performance
Comment Response for LT2ESWTR E-158 December 2005
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credit in section IV.C.8.-
Comment
On Page 47668 the proposed rule states:
-d. Use of previously collected data.
Today-s proposal allows systems with previously collected Cryptosporidium data (i.e., data collected
prior to the required start of monitoring under the LT2ESWTR) that are equivalent in sample number,
frequency, and data quality to data that will be collected under the LT2ESWTR to use those data in lieu of
conducting new monitoring. Specifically, EPA is proposing that Cryptosporidium sample analysis results
collected prior to promulgation of the LT2ESWTR must meet the following criteria to be used for bin
classification:
- Samples were analyzed by laboratories using validated versions of EPA Methods 1622 or 1623 and
meeting the quality control criteria specified in these methods (USEPA 1999a, USEPA 1999b, USEPA
200le, USEPA2001f).
- Samples were collected no less frequently than each calendar month on a regular schedule, beginning
no earlier than January 1999 (when EPA Method 1622 was first released as an interlaboratory-validated
method).
- Samples were collected in equal intervals of time over the entire collection period (e.g., weekly,
monthly). The allowances for deviations from a sampling schedule specified under IV.A. 1 .b for
LT2ESWTR monitoring apply to grandfathered data.
- Samples were collected at the correct location as specified for LT2ESWTR monitoring. Systems must
report the use of bank filtration, presedimentation, and raw water offstream storage during sampling.
- For each sample, the laboratory analyzed at least 10 L of sample or at least 2 mL of packet pellet
volume or as much volume as two filters could accommodate before clogging (applies only to filters that
have been approved by EPA for use with Methods 1622 and 1623).
- The system must certify that it is reporting all Cryptosporidium monitoring results generated by the
system during the time period covered by the previously collected data. This applies to samples that were
(a)collected from the sampling location used for LT2ESWTR monitoring, (b) not spiked, and (c) analyzed
using the laboratory-s routine process for Method 1622 or 1623 analyses.
- The system must also certify that the samples were representative of a plant-s source water(s) and the
source water(s) have not changed.
If a system has at least two years of Cryptosporidium data collected before promulgation of the
LT2ESWTR and the system does not intend to conduct new monitoring under the rule, the system must
submit the data and the required supporting documentation to EPA no later than two months following
promulgation of the rule. EPA will notify the system within four months following LT2ESWTR
promulgation as to whether the data are sufficient for bin determination. Unless EPA notifies the system
in writing that the previously collected data are sufficient for bin determination, the system must conduct
source water Cryptosporidium monitoring as described in section IV.A.l.b of this preamble.
If a system intends to grandfather fewer than two years of Cryptosporidium data, or if a system intends to
grandfather 2 or more years of previously collected data and also to conduct new monitoring under the
rule, the system must submit the data and the required supporting documentation to EPA no later than
eight months following promulgation of the rule. Systems must conduct monitoring as described in
section IV.A. 1 .b until EPA notifies the system in writing that it has at least 2 years of acceptable data. See
section IV.J for additional information on reporting requirements associated with previously collected
data.-
Comment
Comment Response for LT2ESWTR E-159 December 2005
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Issue: Laboratory Certification
On Page 47735, laboratory certification to perform LT2ESWTR required analyses.
Comment
Issue: Restriction of Microbial Toolbox Options
40CFR141.720(c) as proposed restricts the available microbial toolbox options for water systems in Bin 3
and Bin 4.
Comment
Response:
EPA Letter ID: 536
Comment ID: 11772
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "EPA's (EPA) efforts to increase public health protection by
concurrently addressing risks from microbial contaminants and disinfection byproducts (DBPs)"
submitted by The Colorado Department of Public Health and Environment
Company/Group/Association Name: Colorado Department of Public Health and Environment
Comment:
January 9, 2004
Water Docket (MC-4101T)
Docket No. OW-2002-0039
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Docket Clerk:
Enclosed, Colorado provides greater detail on some of these concerns and responds to some of those
issues on which EPA specifically requested comment in the Federal Register notices.
Colorado appreciates the opportunity to provide comment on these proposed rules and looks forward to
working with EPA to ensure that the final rules are both protective of public health and implementable at
the state level. Please direct any questions or concerns regarding these comments to my attention at
Chester .pauls@state.co .us.
Sincerely yours,
Comment Response for LT2ESWTR E-160 December 2005
-------
Chester F. Pauls,
Manager, Drinking Water Program
Cc: Cynthia Dougherty, EPA OGWDW
Ephraim King, EPA OGWDW
Jennifer McLain, OGWDW
Tom Grubbs, EPA OGWDW
Dan Schmelling, EPA OGWDW
Enclosure
Implementation Schedule
State-Preferred Approach
Based on the foregoing discussion, Colorado recommends the following approach for implementing the
LT2ESWTR:
Response:
EPA Letter ID: 537
Comment ID: 14106
Commenter: Anonymous537,, Lincoln Water System
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "National Primary Drinking Water Regulations: Long Term 2
Enhanced Surface Water Treatment Rule" submitted by Lincoln Water System
Company/Group/Association Name: Lincoln Water System, 2021 North 27th Street,
Lincoln, NE 68503
Response:
EPA Letter ID: 538
Comment ID: 14093
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment:
Company/Group/Association Name: City of Wichita Falls
Comment:
January 11,2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
Comment Response for LT2ESWTR E-161 December 2005
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1200 Pennsylvania Av. N.W.
1201 Washington D.C. 20460
Attention Docket ID No. OW-2002-0039
Re: Comments on Proposed Long Term 2 Enhanced Surface Water Treatment Rule
Please accept the following comments concerning the above-mentioned regulation.
Comment Two:
The EPA is soliciting comments on how recycled filter backwash should be
considered in the LT2ESWTR. (page 47678)
Comment Three:
The EPA is requesting comment on whether bin classifications should be made
formally or reviewed by the States, (page 47679)
Comment Four:
The EPA is requesting comment on the use of Alternative Sources and Intake
Management, (page 47685).
Response:
EPA Letter ID: 538
Comment ID: 14094
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment:
The City of Wichita Falls appreciates the USEPA-s consideration of these
comments in the LT2 rule-making process.
Sincerely,
J. Scott Taylor, P.E.
Director of Public Works
City of Wichita Falls
Response:
EPA Letter ID: 538
Comment ID: 14104
Commenter: J. Scott Taylor, Director of Public Works, City of Wichita Falls
Commenter Category: Local Government
Comment Response for LT2ESWTR E-162 December 2005
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Comment:
Comment Six:
Response:
EPA Letter ID: 540
Comment ID: 12082
Commenter: Manja Blazer, Government Affairs and Market Development Manager, IDEXX
Laboratories
Commenter Category: Independent Laboratories
Comment: CS Title: Comment referring to cryptosporidium monitoring, grandfathering of
data, laboratory capacity, and method-specific holding time of 48 hours for E.coli samples submitted by
Manja Blazer, Government Affairs and Market Development Manager, IDEXX Laboratories
Company/Group/Association Name: IDEXX Laboratories, Inc.
Comment: OW-2002-0039-0540
"Blazer, Manja"
01/08/2004 11:58 AM
To: Group Ow-Docket@EPA
cc:
Subject: Attention Docket ID No. OW-2002-0039
Hello,
Please find attached below all our comments. Please address any inquiries
to the contact information below.
Thanks and regards,
Manja Blazer
IDEXX changes underlined. doc»
L. Manja R. Blazer, Ph.D.
Government Affairs & Market Development Manager
IDEXX Laboratories, Inc.
Worldwide Environmental Business
5367 Lake Normandy Court
Fairfax, VA 22030 USA
703-222-8060; 9613(fax)
mailto:manja-blazer@idexx.com
Comment Response for LT2ESWTR E-163 December 2005
-------
January 8, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
RE: Docket ID No. OW-2002-0039
Long Term 2 Enhanced Surface Water Treatment Rule
IDEXX Laboratories, Inc. (IDEXX) offers the following comments on the proposed Long Term 2
Enhanced Surface Water Treatment Rule (LT2ESWTR) published August 11, 2003 (68 FR 47640).
1. Under the proposed rule, large surface water systems (serving 10,000 people or more) monitor source
waters monthly for Cryptosporidium, E.coli, and turbidity for 24 months. Based on the highest monthly
RAA, or 2 year mean if 48 samples are collected, the system is assigned to a bin that will require
additional removal requirements for Cryptosporidium. There is no follow-up monitoring required during
or following treatment installation.
2. The proposed rule allows grandfathering of Cryptosporidium monitoring data as long as certain criteria
are met. The proposed rule guidance documents indicates that grandfathering will be allow as far back as
January 1999 (when method 1622 was first issued), which will be ~6 years prior to the anticipated date of
the final rule.
3. The proposed LT2ESWTR will result in a large number of Cryptosporidium analyses. Assuming the
final rule is published in January 2005,
- Large systems will take a total of-42,456 samples between mid-2005 and mid-
2007 to be analyzed for Cryptosporidium, E.coli, and turbidity.
- Small systems will take a total of-142,968 samples for E.coli between mid-2007 and mid-2008.
- Small systems exceeding the E.coli triggers will monitoring for Cryptosporidium from Jan. to Dec.
2009. If 50% of small systems exceed the trigger, then atotal of-71,484 samples would be taken for
Cryptosporidium.
4. The proposed rule includes a sample holding time of 24 hours for E.coli analysis. Currently, the
holding time for source water coliform samples is limited to 8 hours and samples must be kept below IOC
during transit. USEPA included in the proposal extensive data from new studies to justify the proposed 24
hour holding time, as long as samples are held below IOC and are not allowed to freeze. Test results
presented support an extended holding time (48 hours) for samples analyzed by ONPG-MUG. The results
of Pope et al (2003)(1) cited by USEPA in the proposed rule indicate that most E.coli samples analyzed
using ONPG-MUG incurred no significant degradation after a 30 to 48 hour holding time.
(1) Pope, M., at al. 2003. Assessment of the effects of holding time and temperature on E.coli densities in
surface water samples. Applied and Environmental Microbiology, 69(10): 6201-6207.
Response:
EPA Letter ID: 540
Comment ID: 12087
Comment Response for LT2ESWTR E-164 December 2005
-------
Commenter: Manja Blazer, Government Affairs and Market Development Manager, IDEXX
Laboratories
Commenter Category: Independent Laboratories
Comment: In addition to the general comments above, please find enclosed comments to the body of the
published proposed Rule plus comments to the Methods Manual accompanying the Rule.
Should you have any additional questions regarding these comments, please contact me.
Sincerely,
L. Manja R. Blazer, Ph.D.
Government Affairs and Market Development Manager
IDEXX Laboratories, Inc.
5367 Lake Normandy Court
Fairfax, VA 22030
703-222-8060
703-222-9613 fax
manja-blazer@idexx.com
IDEXX - Comments on the US EPA Proposal submitted January 8, 2004
Response:
EPA Letter ID: 548
Comment ID: 12145
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: CS Title: Comment focusing on agreement with many aspects of the proposed rule but
suggests some changes regarding implementation and clarify areas where information may be missing
submitted by Mic Stewart, Water Quality Section Manager, Company/Group/Association Name:
Metropolitan Water District of Southern California
Comment: OW-2002-0039-0548
MWD
METROPOLITAN WATER DISTRICT OF SOUTHERN CALIFORNIA
January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
OW-Docket@epa.gov
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal Register 47639,
Docket No. OW-2002-0039
Comment Response for LT2ESWTR E-165 December 2005
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Dear Sir or Madam,
The Metropolitan Water District of Southern California appreciates the opportunity to review and provide
comments on the Proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR)
published by EPA on August 11, 2003 (68 Federal Register 47639).
Metropolitan reviewed the rule language, preamble, guidance manuals and the accompanying appendices
with respect to the LT2ESWTR. Specific comments and recommendations on these documents are
attached. These include the following key issues:
3. Analytical methods for Cryptosporidium and E. coli. Specific comments on the holding times, storage
and shipping temperature, and analytical methods for Cryptosporidium and E. coli samples are stated in
the attached document.
Metropolitan appreciates EPA-s review and consideration of the attached comments. If you have any
questions on our recommendations, please contact me at (213) 217-5696.
Sincerely,
Mic Stewart, Ph.D.
Water Quality Section Manager
Attachments
Metropolitan Water District of Southern California 700 North Alameda Street,
Los Angeles, CA 90012
Mailing Address: P.O. Box 54153, Los Angeles, CA 90054-0153
Comments on the Proposed Long Term 2 Enhanced Surface Water Treatment Rule
Metropolitan Water District of Southern California
Comments as Requested:
1. Section III.C. New Information on Cryptosporidium Health Risks and Treatment: Cryptosporidium
Occurrence (p. 47650):
* EPA requests comments on the Information Collection Rule and ICRSS medium and large system data
sets. EPA conducted the analyses for this proposed rule using these three data sets. EPA requests
comment on this approach, (p. 47659)
EPA compared the three data sets and found that the -median values are 0.048, 0.050, and 0.045
oocysts/L, respectively, while the 90th percentile values are 1.3, 0.33, and 0.24 oocysts/L-. It is clear that
median values are very close and therefore appear to agree with each other, while the 90th percentile
values do not. This discrepancy was also shown upon comparing the results for the subset of 40 plants
that were in both the ICR and the ICRSS large system surveys. EPA found that the medians were 0.13
and 0.045 oocysts/L, respectively, while the 90th percentiles were 1.5 and 0.24 oocysts/L, suggesting that
the different sample groups in the full data sets are not the primary factor that accounts for the different
results. It appears that the source of differences in the data sets may be the different methods used for the
two surveys - the ICR Protozoa Method and the EPA Methods 1622/1623 for the ICRSS. The latter
methods used for the ICRSS have better quality control and higher recovery (43% vs. 12% for the ICR
method) but the survey sample size was much smaller (40 vs. 350 for the ICR).
Comment Response for LT2ESWTR E-166 December 2005
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Response:
EPA Letter ID: 548
Comment ID: 12146
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: EPA requests comment on all aspects of the monitoring and treatment requirements proposed
in this section and on the following issues (p. 47678):
* Requirement for systems that use surface water for only part of the year (possible approaches for
comment are included)
* Previously collected monitoring data that do not meet QC requirements (specifically on sampling
frequency requirement for grandfathered data, determination of unbiased and seasonally representative
data sets, averaging of data at varying frequency)
* Bin assignment for systems that fail to complete required monitoring, e.g. classifying the system in a
bin based (1) based on data the system has collected, or (2) one level higher than the bin indicated by the
data the system has collected
If a system fails to complete required monitoring, there is no assurance that the source water would have
Cryptosporidium concentrations that would put the system in a bin one level higher, lower or in a bin
indicated by the data so
4. Section IV.C.10. Options for Systems to Meet Cryptosporidium Treatment Requirements:
Slow Sand Filtration (p. 47701)
* The Agency requests comment on whether the available data are adequate to support awarding a 2.5 log
Cryptosporidium removal credit for slow sand filtration applied as a secondary filtration step, along with
any additional information related to this application, (p. 47702)
Response:
EPA Letter ID: 548
Comment ID: 12147
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: 5. Section IV.C. 11. Options for Systems to Meet Cryptosporidium Treatment Requirements:
Membrane Filtration (p. 47702)
EPA requests comment on the following issues (p. 47706):
* The inclusion of membrane cartridge filters that can be direct integrity tested under the definition of a
membrane filtration process in this rule.
Comment Response for LT2ESWTR E-167 December 2005
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6. Section IV.C.14. Options for Systems to Meet Cryptosporidium Treatment Requirements:
Ozone and Chlorine Dioxide (p. 47709)
* EPA requests comment on the proposed approach to awarding credit for inactivation of
Cryptosporidium by chlorine dioxide and ozone, including the following specific issues (p. 47711):
o Determination of CT and the confidence bounds used for estimating log inactivation of
Cryptosporidium
o The ability of systems to apply these CT tables in consideration of the MCLs for bromate and chlorite
7. Section IV.C.15. Options for Systems to Meet Cryptosporidium Treatment Requirements:
Ultraviolet Light (p. 47711)
* The Agency requests comment on whether the criteria described in this section for awarding treatment
credit for UV disinfection are appropriate, and whether additional criteria, or more specific criteria,
should be included (p. 47713)
8. Section IV.C.16. Options for Systems to Meet Cryptosporidium Treatment Requirements:
Individual Filter Performance (p. 47713)
The Agency invites comment on the following issues related to the proposed credit for individual filter
performance (p. 47714):
* The individual filter effluent turbidity criterion of 0.1 NTU is proposed because it is consistent with
Phase IV Partnership standards, as based on CCP goals. However, with allowable rounding, turbidity
levels less than 0.15 NTU are in compliance with a standard of 0.1. Consequently, EPA requests
comment on whether 0.15 NTU should be the standard for individual filter performance credit, as this
would be consistent with the standard of 0.15 NTU that is proposed for combined filter performance
credit in section IV.C.8.
Response:
EPA Letter ID: 548
Comment ID: 12148
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: 9. Section IV.C.17. Options for Systems to Meet Cryptosporidium Treatment
Requirements: Other Demonstration of Performance (p. 47714)
The Agency requests comment on the following issues (p. 47715):
* Approaches that should be considered or excluded for demonstration of performance testing
* Whether EPA should propose minimum elements that demonstration of performance must include
* Whether a factor of safety should be applied to the results of demonstration of performance testing to
account for potential differences in removal of an indicator and removal of Cryptosporidium, or
uncertainty in the application of pilot-scale results to full-scale plants
* Whether or under what conditions a demonstration of performance credit should be allowed for a unit
process within a plant - a potential concern is that certain unit processes, such as a sedimentation basin,
can be operated in a manner that will increase removal in the unit process but decrease removal in
subsequent treatment processes and, therefore, lead to no overall increase in removal through the plant.
An approach to address this concern is to limit demonstration of performance credit to removal
demonstrated across the entire treatment plant.
Comment Response for LT2ESWTR E-168 December 2005
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10. Section IV.F. Compliance Schedules (p. 47719) EPA requests comments on the treatment technique
compliance schedules for large and small systems in today-s proposal, including the following issues
(p. 47722):
* Time window between large and small system monitoring - EPA requests comment on whether an
additional time window between the end of large system monitoring and the beginning of small system
monitoring is appropriate and, if so, how long such a window should be.
11. Section IV.G. Public Notice Requirements (p. 47722)
* EPA requests comment on whether the violations of additional treatment requirements for
Cryptosporidium under the LT2ESWTR should require a Tier 2 public notice and whether the proposed
health effects language is appropriate (p. 47723)
12. Section IV.J. System Reporting and Recordkeeping Requirements (p. 47724)
EPA requests comment on the reporting and recordkeeping requirements proposed
for the LT2ESWTR (p. 47731):
* Specifically, the Agency requests comment on the proposed requirement that systems report monthly on
the use of microbial toolbox components to demonstrate compliance with their Cryptosporidium
treatment requirements. An alternative may be for systems to keep records on site for State review
instead of reporting the data.
Response:
EPA Letter ID: 548
Comment ID: 12149
Commenter: Mic Stewart, Water Quality Section Manager, Metropolitan Water District of Southern
California
Commenter Category:
Comment: 13. Section IV.K.l. Analytical Methods: Cryptosporidium (p. 47731) EPA requests comment
on the proposed method requirements for Cryptosporidium analysis, including the following specific
issues (p. 47732-47733):
Please refer to accompanying comments on the Microbial Laboratory Guidance Manual.
* Minimum sample volume - Today-s proposal requires systems to analyze at least 10 L of sample or the
maximum amount of sample that can be filtered through two filters, up to a packed pellet volume of 2
mL. EPA requests comment on whether these requirements are appropriate for systems with
source waters that are difficult to filter or that generate a large packed pellet volume. Alternatively,
systems could be required to filter and analyze at least 10 L of sample with no exceptions.
EPA requests comment on the laboratory approval requirements proposed today, including the following
specific issues:
* Analyst Experience Criteria - EPA requests comment on whether the criteria for analyst experience in
the Lab QA Program are necessary, whether systems are experiencing difficulty in finding laboratories
that have passed the Lab QA Program to conduct Cryptosporidium analysis, and whether any of the Lab
QA Program criteria should be revised to improve the LT2ESWTR lab approval process.
Comment Response for LT2ESWTR E-169 December 2005
-------
* State Programs to Approve Laboratories for Cryptosporidium Analysis - EPA requests comment on
how to establish that a State approval program for Cryptosporidium analysis is equivalent to the Lab QA
Program (p. 47736).
o Specifically, should EPA evaluate State approval programs to determine if they are equivalent to the
Lab QA Program?
Response:
EPA Letter ID: 554
Comment ID: 12219
Commenter: Wayne Price, Water Plant Superintendent, Broad River Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to filtered systems, monitoring requirements for
Cryptosporidium and E. coli and laboratories, submitted by Wayne Price, Water Plant Superintendent,
Broad River Water Authority Company/Group/Association Name: Broad River Water Authority
Comment:
Wayne Price
01/08/2004 01:43PM
Please respond to Wayne Price
To: Group Ow-Docket@EPA
cc: Ray McCall, Harlow Brown
Subject: Proposed LT2ESWTR
Below are comments didrected to the EPA from the Broad River Water Authority, located in
Rutherfordton, NC, in regards to the Proposed Long-Term 2 Enhanced Surface Water Treatment Rule
(LT2ESWTR) published in August, 2003.
Issue 1: In the proposal, on page 47666, it states that any filtered system that fails to complete
LT2ESWTR monitoring requirements must meet the treatment requirements for Bin 4.
Wayne Price
Water Plant Superintendent
Broad River Water Authority
Spindale,NC28160
828-286-0731
Response:
Comment Response for LT2ESWTR E-l 70 December 2005
-------
EPA Letter ID: 556
Comment ID: 12032
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Attachment to comment referring to rule implementation, improvements to the
proposal, flexibility in implementation, and data for cryptosporidium, submitted by Diane Van DeHei,
Executive Director, Association of Metropolitan Water Agencies (AMWA) Company/Group/Association
Name: Association of Metropolitan Water Agencies
Comment: OW-2002-0039-0556
January 7, 2004
EPA Docket Center
EPA West, Room B102
1301 Constitution Ave. NW
Washington, DC 20460
Attention: Docket ID OW-2002-0039
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal Register 47639
The Association of Metropolitan Water Agencies (AMWA) appreciates the opportunity to review and
comment on the Proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) that
EPA released on August 11, 2003 (68 Federal Register 47639).
AMWA acknowledges the efforts of all members of EPA staff who worked on developing the proposal
and the accompanying documents. It is a significant effort and a significant achievement. All who have
reviewed the document have been impressed with the very direct, clear and understandable presentation.
We also thank the Agency for extending the comment period for the proposal.
EPA Docket Center
January 7, 2004
Page 2
Our attached comments reflect the above concerns. AMWA appreciates the efforts of EPA to work
together with stakeholders in developing this rule and will do everything possible to assist in
implementing the rule based on the FACA agreement. If any additional information or clarification of
AMWA-s comments is needed, or if we can be of other help, please contact me at (202) 331-2820.
Sincerely,
Diane VanDe Hei
Executive Director
Comment Response for LT2ESWTR E-l 71 December 2005
-------
Cc: Cynthia Dougherty
A. General
1. Outreach
The Agreement in Principle (Section 2.11 .a) states that the compliance schedules for the LT2ESWTR will
be tied to the availability of sufficient analytical capacity for Cryptosporidium at approved laboratories
and the availability of data management software. If either is unavailable, the monitoring,
implementation, and compliance schedules for both the LT2ESWTR and the Stage 2 DBPR will be
delayed an equivalent period of time.
-2.11 Implementation Schedule
2.11 .a Compliance schedules for the LT2ESWTR will be tied to the availability of sufficient analytical
capacity at approved laboratories for all large and medium affected systems to initiate Cryptosporidium
and E. coli monitoring, and the availability of software for transferring, storing, and evaluating the results
of all microbial analyses.
(1) If the availability of adequate laboratory capacity or data management software for microbial
monitoring under LT2ESWTR for large or medium systems is delayed then monitoring, implementation,
and compliance schedules for both the LT2ESWTR and Stage 2 DBPR described under 2.11 .c will be
delayed by an equivalent time period.-
The proposed rule acknowledges this provision at (68 FR 4775):
-The Agency is monitoring sample analysis capacity at approved laboratories through the Lab QA
Program, and does not plan to implement LT2ESWTR monitoring until the Agency determines that there
is adequate laboratory capacity."
Response:
EPA Letter ID: 556
Comment ID: 12033
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2. Availability of Data Management Software:
Basic Principle from the FACA Discussions: The FACA recognized that the availability of adequate data
management software was as important as laboratory capacity to timely execution of the rule. If adequate
data management is not available to capture monitoring results, the implementation schedule for the
rule will be delayed until capacity is adequate.
Discussion: The Agreement in Principle (Section 2.1 La) states that the compliance schedules for the
LT2ESWTR will be tied to the availability of data management software in addition to sufficient
analytical capacity for Cryptosporidium as noted above.
Comment Response for LT2ESWTR E-l 72 December 2005
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3. Grandfathering Data
Basic Principle from the FACA Discussions: The FACA discussion of grandfathered data centered on
ensuring that any grandfathered data accepted do as good a job of assigning systems to an appropriate
action bin as monitoring undertaken under the new rule.
Discussion: The proposed rule on page 47666 states:
-Any filtered system that fails to complete LT2ESWTR monitoring requirements must meet the treatment
requirements for Bin 4.-
EPA discussion of the FBRR in the proposed rule:
-EPA promulgated the Filter Backwash Recycling Rule (FBRR) (66 FR 31085, June 8, 2001) (USEPA
200 la) to increase protection of finished drinking water supplies from contamination by Cryptosporidium
and other microbial pathogens. The FBRR requirements will reduce the potential risks associated with
recycling contaminants removed during the filtration process. The FBRR provisions apply to all systems
that recycle, regardless of population served. In general, the provisions include the following: (1)
Recycling systems must return certain recycle streams prior to the point of primary coagulant addition
unless the State specifies an alternative location; (2) direct filtration systems recycling to the treatment
process must provide detailed recycle treatment information to the State; and (3) certain conventional
systems that practice direct recycling must perform a one-month, one-time recycling self assessment.- (68
FR 47646).
Response:
EPA Letter ID: 556
Comment ID: 12034
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
C. Microbial Toolbox
The LT2ESWTR proposal contains a list of treatment processes and management practices for water
systems to use in meeting additional Cryptosporidium treatment requirements under the LT2ESWTR.
This list, termed the Microbial Toolbox, was recommended by the Stage 2 M-DBP Advisory Committee
in the Agreement in Principle.
The intent of the microbial toolbox is to provide water systems with broad flexibility in selecting cost
Comment Response for LT2ESWTR E-l 73 December 2005
-------
effective LT2ESWTR compliance strategies. Moreover, the toolbox allows systems that currently provide
additional pathogen barriers or that can demonstrate enhanced performance to receive additional
Cryptosporidium treatment credit.
Components of the Microbial Toolbox include watershed control programs, alternative sources,
pretreatment processes, additional filtration barriers, inactivation technologies, and enhanced plant
performance.
A key feature of the microbial toolbox is that many of the components carry presumptive credits towards
Cryptosporidium treatment requirements. Plants will receive these credits for toolbox components by
demonstrating compliance with required design and implementation criteria, as described in the sections
that follow. Treatment credit greater than the presumptive credit may be awarded for a toolbox
component based on a site-specific or technology-specific demonstration of performance.
1. Intent of the FACA Committee Regarding the Microbial Toolbox
Recommendations on other specific toolbox items are discussed in items 3 through
6 below.
3. Watershed Protection Credit
5. Revision of Enhanced Filter Performance Criteria
Discussion: The proposal of an IFE credit began with the Stage 2 M/DBP FACA-s inclusion of a -Peer
review program (e.g., Partnership Phase IV)- in the Microbial Toolbox. It remains important to foster
peer review programs like the Partnership for Safe Water, Area Wide Optimization Programs, and efforts
within individual states.
6. Bank Filtration
Discussion: Bank filtration when properly installed is an efficient, cost effective, -easy to operate-
technology that provides multiple benefits in
Response:
EPA Letter ID: 556
Comment ID: 12035
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: D. UV Disinfection
While the FACA discussions and agreement clearly indicated that Stage 2 was not to be a UV rule, the
FACA acknowledged the exceptional potential benefits of UV with respect to Cryptosporidium
inactivation. The agreement reflects the FACA-s desire that UV be both available and feasible.
Comment Response for LT2ESWTR E-l 74 December 2005
-------
To receive UV disinfection credit, a system must demonstrate a UV dose as given in UV dose tables in
the proposal using the results of a UV reactor validation test and ongoing monitoring. The reactor
validation test establishes the operating conditions under which a reactor can deliver a required UV dose.
Validation test requirements are given in the UV Guidance Manual. Monitoring to demonstrate that the
system maintains these validated operating conditions during routine use.
1. Conservative Assumptions:
Response:
EPA Letter ID: 556
Comment ID: 12078
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3. Off-Specification Limitation and Reporting:
Discussion: Off-specification simply means that water is delivered when UV reactors are not operating
within validation conditions. Unfiltered systems are specifically allowed off-specification conditions.
They must monitor each UV reactor while in use and must record periods when any reactor operates
outside of validated conditions. The disinfection treatment must guarantee at least 99 percent (or 99.9
percent if required) inactivation of Cryptosporidium in at
Response:
EPA Letter ID: 559
Comment ID: 12225
Commenter: Bill Pappathopoulos, Director, City of Two Rivers, Water & Light Utility
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "comments relative to the discussion Section IV of the Rule",
submitted by Bill Pappathopoulos, City of Two Rivers, Water & Light Utility
Company/Group/Association Name: City of Two Rivers, Water & Light Utility
Comment:
BILL
PAPPATHOPOULOS
01/09/2004 09:47 AM
To: Group Ow-Docket@EPA
cc: larry.landsness@dnr.state.wi.us
Subject: LT2 ESWTR Proposed Rule
Comment Response for LT2ESWTR E-l 75 December 2005
-------
Gentleperson —
Attached please find comments on behalf of the City of Two Rivers'
water utility relative to the LT2 ESWTR Proposed Rule.
Bill pappathopoulos
LT2-TwoRiversWater.doc
January 8, 2004
Water Docket
USEPA
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
E-mail: ow-docket@epa.gov
RE: Docket ID No. OW-2002-0039
LT2 ESWTR Proposed Rule
68 FR 47640, August 11, 2003
The following comments are offered in response to the Long Term 2 Enhanced Surface Water Treatment
Rule as proposed in the Federal Register (68 FR 47640, August 11, 2003) EPA 40 CFR Parts 141 and 142
Docket ID No. OW-2002-0039.
We offer the following comments relative to the discussion Section IV of the
Rule:
SECTION IV.C. - Options for Systems to Meet Cryptosporidium Treatment
Requirements
Comments Submitted By: William Pappathopoulos, Director
City of Two Rivers
Water & Light Utility
1415 Lake Street
Two Rivers, WI 54241
Telephone: (920) 793-3550
E-mail: bilpap@two-rivers.org
cc: Larry Landsness, WDNR [E-mail: larry.landsness@dnr.state.wi.us]
ID\Report\N0002\930546\LT2-ESWTR-GLR.doc(lml)
Response:
EPA Letter ID: 560
Comment ID: 14970
Comment Response for LT2ESWTR E-l 76 December 2005
-------
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "Proposed LT2 Enhanced Surface Water Treatment Rule and
Draft Ultraviolet Disinfection Guidance Manual", submitted by J. Stephen Schmidt, Director,
Environmental Management, American Water, Voorhees, NJ
Company/Group/Association Name: American Water, Voorhees, NJ
Comment:
01/07/2004 04:21PM
To: Group Ow-Docket@EPA
cc: JYoung@amwater.com, Dan Schmelling/DC/USEPA/US@EPA
Subject: Comments on Proposed LT2 Rule and Draft Ultraviolet Disinfection
Guidance Manual
Attention Docket ID No. OW-2002-0039:
Attached are the comments of American Water regarding USEPA's proposed National Primary Drinking
Water Regulations: Long Term 2 Enhanced Surface Water Treatment Rule. In addition, we have included
our comments on the June 2003 Draft Ultraviolet Disinfection Guidance Manual. Four documents
attached to our comments were sent directly to Daniel Schmelling in the Office of Ground Water and
Drinking Water.
If you have any difficulty receiving a legible version of these comments,
please contact me at the number below.
(See attached file: 1-7-04 LT2 Comments from American Water.doc)
Steve Schmidt
Director, Environmental Management
Americas Region
1025 Laurel Oak Road, P.O. Box 1770
Voorhees, NJ 08043
phone 856-346-8320
fax 856-782-3603
email sschmidt@amwater.com
1-7-04 LT2 Comments from American Water.do
Mr. Daniel Schmelling EPA East Building Room 2209W Office of Ground Water and
Drinking Water U.S. Environmental Protection Agency 1201 Constitution Ave, NW
Washington, DC 20004
January 7, 2004
Comments on Proposed LT2 Enhanced Surface Water Treatment Rule
and Draft Ultraviolet Disinfection Guidance Manual
Dear Mr. Schmelling:
American Water is providing the following comments on the U.S. Environmental Protection Agency-s
(EPA) proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2). We have submitted to you
personally the attached four documents so they are not lost in the mass of expected comments of the
Water Docket. We especially wanted you to see the newly prepared document, -Estimated Time
Commitment for Sample Processing for Method 1623-. We have also submitted this letter to the Water
Docket for compilation with other commenters. Finally, as you requested, we included comments
regarding both the LT2 Rule and the Draft Ultraviolet Disinfection Guidance Manual (UVGM). Both of
these USEPA documents are complementary, and in several cases our comments relate to both
documents. Our comments on the proposed rule are principally from Mark LeChevallier, Chief
Scientist, and the comments on the UVGM were authored by Richard Hubel, Director
Comment Response for LT2ESWTR E-l 77 December 2005
-------
of Design.
Introduction
The proposed LT2 is intended to improve the control of microbial pathogens, particularly
Cryptosporidium, in drinking water and to address risk trade-offs with disinfection byproducts. American
Water was a signatory to the Federal
Summary of Comments on the Proposed LT2ESWTR:
American Water appreciates the opportunity to comment on the proposed LT2 Enhanced Surface Water
Treatment Rule and the Draft Ultraviolet Disinfection Guidance Manual. This ongoing spirit of
collaborative effort with this complex
Please contact Mark LeChevallier, Richard Hubel, or me if you have any questions on these comments.
Sincerely,
J. Stephen Schmidt
Director, Environmental Management
jl/ss
c: USEPA Water Docket
Cynthia Dougherty, USEPA
Ephraim King, USEPA
John Young, American Water
Enc: - -Estimated Time Commitment for Sample Processing for Method 1623-
- -Detection of Infectious Cryptosporidium in Drinking Water-
- -Protozoa in Open Reservoirs-
- -Evaluation of Ultraviolet Technology for Disinfection of Finished Water-
Response:
EPA Letter ID: 561
Comment ID: 12229
Commenter: Larry Wettering, Director, Neenah Water Department
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to responses to Section IV of the proposed rule, submitted by
Larry Wettering, Director, Neenah Water Department Company/Group/Association Name: Neenah Water
Department
Comment:
LWettering@ci .neenah.wi .us
01/09/2004 09:47 AM
To: Group Ow-Docket@EPA
cc: larry.landsness@dnr.state.wi.us
Subject: Docket ID No OW-2002-0039
See attached for comments on LT2 ESWTR proposed rule.
(See attached file: LT2 ESWTR Rule Comments.doc)
Larry Wettering, P.E., Director
Neenah Water Department
Comment Response for LT2ESWTR E-l 78 December 2005
-------
Phone:920-751-4622
Fax:920-751-4933
e-mail: lwettering@ci.neenah.wi.us
LT2 ESWTR Rule Comments.do
January 8, 2004
Water Docket
USEPA
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
E-mail: ow-docket@epa.gov
RE: Docket ID No. OW-2002-0039
LT2 ESWTR Proposed Rule
68 FR 47640, August 11, 2003
The following comments are offered in response to the Long Term 2 Enhanced Surface Water Treatment
Rule as proposed in the Federal Register (68 FR 47640, August 11, 2003) EPA 40 CFR Parts 141 and 142
Docket ID No. OW-2002-0039.
SECTION IV.A. - Additional Cryptosporidium Treatment Technique
Requirement for Filtered Systems
SECTION IV.C. - Options for Systems to Meet Cryptosporidium Treatment
Requirements
Comments Submitted By: Larry Weltering, P.E. - Director
Neenah Water Utility
211 Walnut Street / P.O. Box 426
Neenah, WI 54956
Telephone: (920) 751-4622
E-mail: lwettering@ci.neenah.wi.us
cc: Larry Landsness, WDNR [E-mail: larry.landsness@dnr.state.wi.us]
LT2 ESWTR Rule Comments.doc
Response:
EPA Letter ID: 562
Comment ID: 12270
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment focusing on "our support for the Stage 2 M/DBP Agreement in
Principle (AIP) developed by Stage 2 Microbial/Disinfection By-Product (M/DBP) Federal Advisory
Committee (FACA)" submitted by Thomas W. Curtis, American Waterworks Association (AWWA)
Company/Group/Association Name: American Water Works Association (AWWA)
Comment:
January 9, 2004
Comment Response for LT2ESWTR E-l 79 December 2005
-------
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68
Federal Register 47639, Docket No. OW-2002-0039
Dear Sir or Madam:
The American Water Works Association (AWWA) appreciates the opportunity to review the Proposed
Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) that EPA released on August 11,
2003 (68 Federal Register 47639). We believe that the attached comments are much more constructive
because the agency extended the comment period for the proposal (68 Federal Register 58057), giving our
volunteers and staff time for a more thorough analysis.
AWWA appreciates the ongoing spirit of cooperation with EPA in the development of this complex
rulemaking. We appreciate your review and consideration of this letter and the attached detailed
comments. If you have any questions regarding this letter or the attached comments, please contact
me at (202) 628-8303.
Best regards,
- / Signed 1/9/2004 / -
Thomas W. Curtis
Deputy Executive Director
cc: Cynthia Dougherty-USEPA OGWDW
Ephraim King-USEPA OGWDW
Jennifer McLain-USEPA OGWDW
Dan Schmelling-USEPA OGWDW
P:\Regulatory\Comments\2004 Comments\LT2ESWTR Comments 1 9 04\AWWA Comments
on LT2ESWTR Jan 9 2004.doc
Formal Comments
of the
American Water Works Association
on the
Long-Term 2 Enhanced Surface Water Treatment Proposed Rule
68 Federal Register 47639, August 11, 2003
Submitted to: Water Docket, OW-2002-0039
January 9, 2004
Comment Response for LT2ESWTR E-180 December 2005
-------
American Water Works Association
1401 New York Avenue, NW, Suite 640
Washington, D.C. 20005
(202) 628-8303
Table of Contents
1 Executive Summary iv
1.1 Agreement in Principle iv
1.2 Notice of Data Availability v
1.3 Source Water Monitoring and Data v
1.4 Implementation Schedule vi
1.5 Microbial Toolbox vi
1.6 Watershed Control vi
1.7 Bank Filtration vii
1.8 Revision of Enhanced Filter Performance Criteria vii
1.9 Demonstration of Performance vii
1.10 Ultraviolet Light vii
1.11 Ozone viii
1.12 Economic Analysis viii
1.13 Legal Issues xi
2 Introduction 1
3 Agreement in Principle 2
3.1 AWWA Commitment to the Agreement in Principle 2
3.1.1 Bin Structure 3
3.2 Shared Objectives and Principles 3
3.2.1 Maintaining a Balanced Approach to Treatment 3
3.2.2 Range of Options - Not One-Size-Fits-All 4
3.2.3 Simultaneous Compliance with Stage 2 DBPR 5
3.2.4 Balance Between State Flexibility and Agreement in Principle 5
3.2.5 Retention of Ozone as a Viable Treatment Option 6
3.3 Adequate Laboratory Capacity for Microbial Monitoring 6
3.4 Notice of Data Availability 7
3.5 Agreement in Principle - General Issues 8
3.5.1 Commitment to Agreement by EPA in the Final Rule 9
3.5.2 Responsive to Previous Review of Stakeholder Draft 9
3.5.3 UV Representatives 10
3.6 Legal Issues 10
3.7 Implementation Schedule 10
4 Specific Provisions 12
4.1 -Source-Water Monitoring 12
4.1.1 Monitoring Location 12
4.1.2 Sample Schedule 14
4.1.3 Grandfathering Provisions 17
4.1.4 State Role in Bin Placement 19
4.1.5 5.5-Log Treatment Exemption 19
4.1.6 Six-Year Review of Bin Boundaries 20
4.1.7 Analytical Methods 21
4.2 Toolbox Components 25
4.2.1 Regulatory -Preference- vs. Agreement in Principle 27
Comment Response for LT2ESWTR E-181 December 2005
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4.2.2 Watershed Control Program 29
4.2.3 Off-Stream Storage and Alternative Intake 35
4.2.4 Bank Filtration 36
4.2.5 Enhanced Filtration (CFE Credit) 41
4.2.6 Peer Review (IFE) Credit 44
4.2.7 Pre-sedimentation 49
4.2.8 Softening 53
4.2.9 Demonstration of Performance 54
4.2.10 Membranes 58
4.2.11UV58
4.2.12 Ozone 68
4.2.13 Chlorine Dioxide 77
4.2.14 Requests for Comment on Ozone and Chlorine Dioxide 78
4.2.15 Microbial Toolbox- Maintaining Compliance 79
4.3 Public Notice Provisions 79
4.4 Variance and Exemptions 79
4.5 Sanitary Survey Provisions 79
5 Cost/Benefit Analysis 81
5.1 Communication of Uncertainty in the Cryptosporidium Risk Characterization 81
5.2 Davenport, Iowa, Study 82
5.3 Overview of the Benefits Analysis 82
5.4 Exposure Estimate 82
5.4.1 Occurrence Data 82
5.4.2 Occurrence Model 82
5.4.3 Exposure Estimate 85
5.4.4 Dose-Response 87
5.4.5 Valuation of Health Effects 88
5.4.6 Special Populations 89
5.4.7 Affordability Based on System Size 90
5.4.8 Requests for Comment Regarding Economic Analysis 90
6 Miscellaneous Requests for Comment 92
Appendices
Appendix 1. LT2ESWTR Treatment Requirements Cryptosporidium Monitoring, Bin
Assignment, Core Treatment, And Microbial Toolbox, EET, 2003
[SEE PDF]
Appendix 2. Cryptosporidium Removal Credit Assignable in the LT2ESWTR
Toolbox, EET, 2001
[SEE PDF]
Appendix 3. Summary of Relevant Articles Pertaining To Cryptosporidium and
Watershed Control Program Effectiveness
[SEE PDF]
Appendix 4. Specific Comments on Draft Source Water Monitoring Guidance
[SEE PDF]
Appendix 5. Focused Review of Peer-Reviewed Literature as It Pertains to Issues
Raised by Preamble and Guidance on Bank Filtration
Comment Response for LT2ESWTR E-182 December 2005
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[SEE PDF]
Appendix 6. Comments regarding LT2ESWTR Microbial Toolbox Guidance Manual - Bank
Filtration
[SEE PDF]
Appendix 7. References for Pre-Sedimentation Discussion
[SEE [PDF]
Appendix 8. Review of UV Disinfection Guidance Manual Evaluation of Validation
Protocol, CH2M Hill
[SEE PDF]
Appendix 9. Technical Memoranda from Process Applications on k* and CT10
[SEE PDF]
Appendix 10. Segregated Flow Analysis Guidance
[SEE PDF]
Appendix 11. Technical Memoranda from Water Quality and Treatment Solutions
on Synergistic Inactivation Between Ozone and Chloramines
[SEE PDF]
Appendix 12. Review of LT2ESWTR Economic Analysis, Stratus Consulting
[SEE PDF]
Tables
Table 1. Example Approach to Staged LT2ESWTR Monitoring 8
Table 2. Impact of Achieving IESWTR Required Effluent turbidity (<0.3 NTU) on Log Removal of
Cryptosporidium During Treatment with Clarification Plus Filtration or Direct Filtration Alone 42
Table 3. Summary of Spore Removal Data at Four Pre-Sedimentation Facilities 51
Table 4. Differences in the Valuation of Time in the Traditional and Enhanced COI Methods 88
Figures
Figure 1. Temperature Profiles from Newport News, Va., and Tampa Bay, Fla. 71
Figure 2. Tracer Testing Results from an Over-Under Ozone Contactor in Florida 74
Figure 3. Factors Affecting Benefit Analysis 83
Comments of the American Water Works Association on the Long-Term 2 Enhanced
Surface Water Treatment Proposed Rule
68 Federal Register 47639, August 11, 2003, Docket No. OW-2002-0039
Response:
EPA Letter ID: 562
Comment ID: 12271
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR E-183 December 2005
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Comment:
AWWA continues to support the Stage 2 M/DBP FACA Agreement in Principle. AWWA
commends the U.S. Environmental Protection Agency (EPA) for the enormous effort undertaken to
prepare the proposed rule and the supporting documents. AWWA appreciates the efforts of EPA in
issuing multiple draft guidance documents in conjunction with the rule proposal as requested by the
stakeholders in the Agreement in Principal. Our comments on the rule proposals do not include detailed
comments on the guidance documents. Rather, we assume that as the regulatory language is finalized and
the guidance documents are revised, AWWA will continue to be included in the guidance document
revision process. We look forward to providing additional input to all of the guidance documents.
the EPA with recommendations to the LT2ESWTR proposal and the supporting documents. This review
is meant to be proactive and constructive by focusing on specific recommendations for the final
regulation. This summary highlights our major concerns. More extensive detail is provided in the body of
our comments.
Comments of the
American Water Works Association
on the
Long-Term 2 Enhanced Surface Water Treatment Proposed Rule
68 Federal Register 47639, August 11, 2003, Docket No. OW-2002-0039
2 Introduction
The following comments in no way conflict with AWWA-s commitment to the Agreement in Principles
document as signed on September 25, 2000. AWWA believes that the Federal Advisory Committee
(FACA) process for the Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and Stage
2 Disinfectants and Disinfection By-Product Rule (Stage 2 DBPR) has been a successful endeavor for all
the stakeholders. The purpose of this review is to provide the U.S. Environmental Protection Agency
(EPA) with both policy recommendations and specific text revisions to the LT2ESWTR proposal. This
review is meant to be proactive and constructive by focusing on specific improvements to the proposal
that should be incorporated into the final regulation.
EPA should be commended for the effort undertaken to include all of the disparate data into the proposal.
The following comments will address areas where AWWA believes that the agency-s efforts successfully
integrated the available information within the framework of the Stage 2 M/DBP Agreement in
Principle and where the agency-s effort requires additional work.
Response:
EPA Letter ID: 562
Comment ID: 12272
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 3 Agreement in Principle
3.1 AWWA Commitment to the Agreement in Principle
Comment Response for LT2ESWTR E-184 December 2005
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On December 29, 2000, EPA published a Federal Register notice describing the Stage 2
Microbial/Disinfection By-Products Federal Advisory Committee Act (Stage 2 M/DBP FACA) process,
why the FACA was convened, and published the Agreement in Principle that was developed and
approved by the FACA. In that preamble notice, EPA summarized the FACA recommendations as
follows:
-Despite the evaluation of a large amount of data, the Committee recognized that uncertainty remains in a
number of areas regarding the precise nature and magnitude of risk associated with DBFs and
pathogens in drinking water. In light of this uncertainty, the Committee recommended a series of
balanced steps to address the areas of greatest health concern, taking into careful consideration the
costs and potential impacts on public water systems.-
* 65 Federal Register 83017, M/DBP FACA Agreement in Principle. Note this statement directly follows
a summary of the data collection effort undertaken in support of the FACA including enumeration of
Cryptosporidium oocyst occurrence, DBP occurrence, and health risks associated with DBFs.
This summary statement by EPA is an extraordinarily clear statement of the Stage 2 M/DBP FACA-s
intent in the Agreement in Principle. Indeed, this summary reflects the FACA discussion from its
initiation at the orientation meeting in December 15-16, 1998. Based on the meeting summary, the FACA
discussion reflected on the following points:
* Though deadlines for the completion of the ICR and other research activities have slipped, the schedule
for rule development is required in the 1996 SDWA Amendments.
* Though the 1996 SDWA Amendments require that EPA perform a cost/benefit analysis, the new
provisions do not require EPA to base the Stage 2 regulations on economic analysis.
* It will be important during the Stage 2 process to be realistic about what data will be available for
consideration and what uncertainties remain.-
[RESOLVE, Stakeholder Orientation Meeting, December 15-16, 1998, Park Hyatt,
Washington, DC, Final Meeting
Summary March 1, 1999]
The importance of these points is that the LT2ESWTR was developed on substantially the same scientific
basis as the IESWTR, save the availability of the ICR data. Note in particular the third bullet.
AWWA was an active participant in the Stage 2 M/DBP FACA and a signatory to the Agreement in
Principle. In signing the Agreement in Principle, AWWA agreed to the following provision:
-Each party and individual signatory that submits comments on the Stage 2 DBPR and LT2ESWTR
proposals agrees to support those components of the proposals that reflect the recommendations contained
in this Agreement in Principle.-*
*65 Federal Register 83017, M/DBP FACA Agreement in Principle, Section 2.3
The Agreement also specified:
-Each party agrees not to take any action to inhibit the adoption of final rule(s) to the extent it and
corresponding preamble(s) have the same substance and effect as the elements of the Agreement in
Principle Part A or Part B or both parts as evidenced by the signature following each part.-*
*65 Federal Register 83017, M/DBP FACA Agreement in Principle, Section 2.9
AWWA participated in the Stage 2 M/DBP FACA and in September 2000, signed the Agreement in
Comment Response for LT2ESWTR E-185 December 2005
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Principle because the FACA recognized the considerable uncertainties in the available information and
reflected those uncertainties in its limited but proactive recommendations. AWWA remains fully
committed to the execution of the spirit and intent of the Stage 2 M/DBP FACA-s recommendations as
stated in the Agreement in Principle. AWWA submits these comments to assist EPA in promulgating a
final regulation that is consistent
3.1.1 Bin Structure
AWWA has a number of concerns about the agency-s Economic Analysis (EA) that have implications for
how the agency describes specific rule requirements and communicates the LT2ESWTRto the public. As
previously stated, these concerns do not alter AWWA-s commitment to the Agreement in Principle and,
in particular, the bin boundaries identified in the Agreement in Principle and
3.2 Shared Objectives and Principles
Inherent to the Stage 2 M/DBP Agreement in Principle were a number of underlying shared objectives
and operating principles. AWWA believes EPA should reflect the principles below in the final
LT2ESWTR
framework for the LT2ESWTR. The FACA also provided guidance about appropriate treatment barriers
for systems that fell within specific source water Cryptosporidium oocyst occurrence "bins." In
recommending these treatment alternatives, the FACA was concerned with maintaining a balanced
approach to enhancing treatment given the uncertainty in the available data on occurrence and associated
risk. Consequently, the FACA weighed five factors in recommending particular treatments in
LT2ESWTR:
1. Data on Cryptosporidium oocyst removal.
2. Effectiveness as an additional barrier to Cryptosporidium oocysts reaching finished water.
3. Other benefits such as
* Reducing peaks in occurrence of pathogens,
* Making other processes more stable or effective, and
* Reducing other contaminants (i.e. TOC, DBP formation), etc.
4. Encouraging use of a variety of technologies.
5. Ensuring viable treatment alternatives to UV disinfection.
Each of the toolbox items has particular strengths among these five factors. Consequently, the microbial
toolbox is described in terms of "log credit" reflecting that inclusion in the toolbox reflected a variety of
factors other than explicit removal/inactivation of oocysts.
Response:
EPA Letter ID: 562
Comment ID: 12273
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: following AWWA comments will identify changes that should be made in the final rule to
achieve the Stage 2 M/DBP FACA-s objectives.
Comment Response for LT2ESWTR E-186 December 2005
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3.2.2 Range of Options - Not One-Size-Fits-All
The Stage 2 M/DBP FACA's concerns included the diversity of water quality challenges and treatment
systems in use, as well as ensuring that water treatment plant improvements at individual utilities are as
cost effective as possible and sufficiently flexible to attain multiple drinking water treatment objectives.
Indeed, the FACA frequently pointed out the value of combining activities to reduce source water oocyst
levels with improvements in treatment at the plant. The FACA members were very concerned that
compliance with the LT2ESWTR not be dependent on a single technology, particularly available
disinfection technologies, such as ozone and UV disinfection.
Technology Selection Forecast for Filtered Plants in the EA illustrates that UV will dominate
LT2ESWTR compliance, and other "tools" will not be employed at more than a handful of water
treatment plants. EPA-s analysis indicates that more than 70% of PWSs serving greater than 10,000
persons will rely on UV treatment to comply with LT2ESWTR.* Additionally, the UV compliance
*LT2ESWTR Economic Analysis, p.6-23, Note that Exhibit 6.9 reflects a large number of water
treatment plants
3.2.5 Retention of Ozone as a Viable Treatment Option
The Stage 2 M/DBP FACA recognized that ozone is an important oxidant in drinking water treatment.
Using ozone for disinfection has substantial benefits beyond inactivation of Cryptosporidium, including
control of other microorganisms, reduction of DBFs, degradation of chemical contaminants, and
reduction of offensive taste and odors. The FACA decided that these multiple benefits should continue to
be available to utilities under LT2ESWTR and Stage 2 DBPR. Consequently, the performance criteria for
Cryptosporidium
Response:
EPA Letter ID: 562
Comment ID: 12274
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
3.3 Adequate Laboratory Capacity for Microbial Monitoring
Adequate documentation of laboratory capacity should have been included in the preamble of the
proposed LT2ESWTR. Section 2.11.a. of the Agreement in Principle specifies that:
"Compliance schedules for the LT2ESWTR will be tied to the availability of sufficient analytical capacity
at approved laboratories for all large and medium affected systems to initiate Cryptosporidium and E. coli
monitoring - ."
3.5 Agreement in Principle - General Issues
Below are additional general issues that stem from the Agreement in Principle, along with our comments
on these issues.
3.5.2 Responsive to Previous Review of Stakeholder Draft
Comment Response for LT2ESWTR E-187 December 2005
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On December 31, 2001 AWWA submitted comments on a stakeholder draft of the LT2ESWTR. In those
comments, AWWA noted the following areas where the draft proposal required additional refinement:
1. Revise the preamble to clearly communicate the interdependence of the uncertainty in estimates of
Cryptosporidium, the proposed bin structure, and the log credits required in the microbial toolbox.
2. Clarify the basis for the -log credit- concept, which as articulated by the FACA was not limited to -log
removal .-3. Expand the preamble to include a more accurate description of Cryptosporidium occurrence
estimate.
4. Expand the preamble to include estimate of available laboratory capacity.
5. Clarify the grandfathering provisions for Cryptosporidium oocyst data.
6. Revise the language on state flexibility so that appropriate balance is maintained between the AIP and
state flexibility.
7. Reconsider the small-system binning algorithm based on a six-month running average.
8. Reconsider the ozone and chlorine dioxide CT requirements.
9. Identify ways to simplify LT2ESWTR Cryptosporidium oocyst monitoring reporting.
10. Clarify the Cryptosporidium oocyst monitoring re-sampling algorithm to allow primacy agency
acceptance of an alternative sample taken prior to agency recognition of initial sample date failure.
11. Reflect the recommendations of the National Drinking Water Advisory Council (NDWAC)
Workgroup and the Science Advisory Board (SAB) reviews of the arsenic cost/benefit determination and
regulatory process processes.
In reviewing the proposal, AWWA found that EPA responded to a number of these concerns. In some
instances, the proposal generated new issues and, in other instances, alleviated previous concerns. Areas
where the agency has made substantial progress include: (1) handling of small-system binning algorithm,
(2) development of CT tables, and (3) developing a simplified Cryptosporidium oocyst monitoring /
reporting. While a number of outstanding
3.6 Legal Issues
The following section is meant to provide a simple reference between the technical issues raised in
AWWA-s comments and the legal setting under which
Response:
EPA Letter ID: 562
Comment ID: 12275
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
4 Specific Provisions
The following are AWWA-s comments on specific rule provisions and the basis for those comments.
4.1 -Source- Water Monitoring
In general, the proposed LT2ESWTR rule language reflects the recommendations provided by the Stage 2
M/DBP FACA. In particular, the FACA recommended:
4.1.1 Monitoring Location
EPA proposed that -source water monitoring- take place after pre-treatment unit operations, such as off-
stream storage, pre-sedimentation, and bank filtration, but before chemical addition (§141.704(b),(c),(d)).
The agency also recognized that individual water treatment plants either (1) withdraw water from multiple
Comment Response for LT2ESWTR E-188 December 2005
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sources at different times of the year or (2) withdraw water from multiple sources in various blends over
the course of the year (§141.704(e)). Utilities with multiple sources may or may not have pre-
4.1.6 Six-Year Review of Bin Boundaries
The Agreement in Principle provides for a second round of monitoring six years after completion of
initial bin characterization. This provision is reflected in the proposed rule and described in the preamble
to the proposed rule. The preamble also notes that sanitary surveys provide an opportunity to evaluate any
change in average oocyst levels and associated changes in the watershed. The Stage 2 M/DBP FACA
explicitly provided for stakeholder
Specific Requests for Comment from EPA, 68 FR 47685 §IV(C)(2)(c)
The preamble discussion of LT2ESWTR monitoring provisions includes a number
of specific requests for comment (68 FR 47678).
Request(s) for Comment
Appropriate monitoring requirements for systems that use surface water for
only part of the year and how to apply LT2ESWTR monitoring requirements to
surface water systems that operate or use surface water for only part of the
year.
Response
Response:
EPA Letter ID: 562
Comment ID: 12276
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Request for Comment
Whether or under what conditions previously collected data that do not meet the proposed criteria for
LT2ESWTR monitoring data should be accepted for use in bin determination.
Response
Request for Comment
Sampling frequency requirement for previously collected data, and whether EPA should allow samples
collected at lower or varying frequencies to be used as long as the data are representative of seasonal
variation and include the required number of samples. If so, how should EPA determine whether such a
data set is unbiased and representative of seasonal variation? How should data collected at varying
frequency be averaged?
Response
Request for Comment
Comment Response for LT2ESWTR E-189 December 2005
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Alternative approaches for systems that fail to complete required monitoring, such as classifying the
system in a bin based on data the system has collected, or classifying the system in a bin one level higher
than the bin indicated by the data the system has collected.
Response
Request for Comment
Monitoring and treatment requirements for new plants and sources.
Response
Response:
EPA Letter ID: 562
Comment ID: 12277
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Request for Comment
How the effect of recycling filter backwash should be considered in LT2ESWTR monitoring.
Response
4.2 Toolbox Components
Both AWWA and EPA have undertaken detailed reviews of the available literature and observations from
utility operations. EPA indicates repeatedly in the LT2ESWTR preamble an interest in the objective
review of the data presented in the preamble and for new information. AWWA-s careful review of data
from the available literature and full-scale and pilot-scale data from U.S. drinking water utilities
substantiate meaningful log-credits for conventional clarification and filtration, direct filtration, and for
the following toolbox
components:
1. Off-stream raw water storage,
2. Pre-sedimentation,
3. Lime softening (single- and two-stage),
4. Improved filtration (combined filter effluent turbidity <0.15 NTU, 95 percent of the time),
5. Multiple filtration processes (separate serial filtration stages), and
6. Slow sand filtration.
A detailed review of the available data is included in Appendix 1 and Appendix 2 to these comments.
Appendix 2 was provided to EPA in January 2001 in response to the stakeholder draft of the LT2ESWTR
and Appendix 1 reflects both additional data and analysis specifically directed to issues posed by
the LT2ESWTR proposal. The following is a brief summary of observations from these analyses in
Appendix 2:
Comment Response for LT2ESWTR E-190 December 2005
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This analysis and these findings provide an important factual basis for the recommendations AWWA
offers in the following comments. AWWA-s review includes both research and data identified in the
LT2ESWTR proposal. AWWA believes the analysis in Appendix 1 and reflected in these comments more
correctly reflects the performance of some of these treatment technologies than the discussion provided in
the Federal Register notice and Microbial Toolbox Guidance. In addition to the literature and analysis
presented in Appendix 1 and Appendix 2, AWWA will also provide information and analysis
with respect to watershed control programs, bank filtration, ozone disinfection and UV disinfection.
4.2.1 Regulatory -Preference- vs. Agreement in Principle
Specific Requests for Comment from EPA, 68 FR 47685 §IV(C)(2)(c) EPA requests comment on the
following specific topics regarding watershed control programs in context of microbial toolbox.
Request for Comment
Should the state be allowed to reduce the frequency of the annual watershed survey requirement for
certain systems if the systems engage in alternative activities such as public outreach?
Response
Response:
EPA Letter ID: 562
Comment ID: 12278
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Request for Comment
The effectiveness of a watershed control program may be difficult to assess because of uncertainty in the
efficacy of control measures under site-specific conditions. In order to provide constructive guidance,
EPA welcomes reports on scientific case studies and research that evaluated methods for reducing
Cryptosporidium contamination of source waters.
Response
Request for Comment
Are there confidential business information (CBI) concerns associated with making information on the
watershed control program available to the public? If so, what are these concerns and how should they be
addressed?
Response
Request for Comment
How should the -area of influence- (the area to be considered in future watershed surveys) be delineated
considering the persistence of Cryptosporidium?
Response
Comment Response for LT2ESWTR E-191 December 2005
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Current Requirements for Bank Filtration Credit
Automatic 0.5 and 1.0 toolbox credits, including qualification as an upper
bin technology (UBT), are available for BF. The peer-reviewed literature
Response:
EPA Letter ID: 562
Comment ID: 12279
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Response to Requests for Comment, 68 FR 47695 §IV(C)(6)(c)
The agency requests comment on the following issues concerning bank filtration on page 47695 of the
proposed rule:
Request for Comment
The performance of bank filtration in removing Cryptosporidium or surrogates to date at sites currently
using this technology (e.g. sites with horizontal wells).
Request for Comment
The number of GWUDI systems in each state (i.e., the number of systems having at least one GWUDI
source) where bank filtration has been utilized as the primary filtration barrier (e.g., no other physical
removal technologies follow); also, the method that was used by the state to determine that each
system was achieving 2-log removal of Cryptosporidium.
Request for Comment
For GWUDI systems where natural or alternative filtration (e.g. bank filtration or artificial recharge) is
used in combination with a subsequent filtration barrier (e.g., bag or cartridge filters) to meet the 2-log
Cryptosporidium removal requirement of the IESWTR or LT1ESWTR, how much Cryptosporidium
removal credit has the state awarded (or is the state willing to grant if the bags/cartridges were found to be
achieving < 2.0-logs) for the natural or alternative filtration process and how did the state determine
this value?
Response
Request for Comment
Any additional information related to testing protocols and procedures for making site-specific
determinations of the appropriate level of Cryptosporidium removal credit to award to bank filtration
processes.
Response
Response:
Comment Response for LT2ESWTR E-192 December 2005
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EPA Letter ID: 562
Comment ID: 12280
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Request for Comment
The applicability of turbidity monitoring or other process monitoring procedures to indicate the ongoing
performance of bank filtration processes.
Response to Requests for Comment, 68 FR 47700 §IV(C)(8)(c)
The above discussion addresses all but one of the specific requests for EPA raises in the preamble. The
following request for comment is directed to practicality of using available methods and instruments to
reliably measure turbidity at or below 0.15 NTU.
Request for Comment
Does currently available turbidity monitoring technology accurately distinguish differences between
values measured near 0.15 NTU?
Response to Requests for Comment, 68 FR 47695 §IV(C)(16)(c)
The following are several requests for comments that bear on IFE credit, which the above comments do
not directly address. Responses are provided for each.
Request for Comment
Are there existing peer review programs for which treatment credit should be awarded under the
LT2ESWTR? If so, what role should primacy agencies play in establishing and managing any such peer
review program?
Response
AWWA directly addressed the first half of this request for comment earlier in this section. The latter
question is clearly a question that will need to be
Comments on Guidance Manual
EPA provided a Draft LT2ESWTR Toolbox Guidance Manual for review with the LT2ESWTR. AWWA
considered both the regulatory language and associated guidance in drafting its comments. AWWA
recommends that EPA respond to the comments in this section by modifying Chapter 7 of that Guidance
manual.
4.2.7 Pre-sedimentation
Response:
EPA Letter ID: 562
Comment ID: 12281
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR E-193 December 2005
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Comment:
Response to Requests for Comment, 68 FR 47691 §IV(C)(5)(c)
The agency requests comment on the following issues concerning pre-sedimentation on Page 47691 of the
proposed rule:
Request for Comment
Whether the information cited in this proposal supports the proposed credit for pre-sedimentation and the
operating conditions under which the credit will be awarded.
Response
Comments on Guidance Manual
EPA provided a Draft LT2ESWTR Toolbox Guidance Manual for review with the LT2ESWTR. AWWA
considered both the regulatory language and associated guidance in drafting its comments. AWWA
recommends that EPA respond to the comments in this section, as well as Section 4.1.1, by revising
Chapter 5 of that Guidance manual.
4.2.8 Softening
Comments on Guidance Manual
EPA provided a Draft LT2ESWTR Toolbox Guidance Manual for review with the LT2ESWTR. AWWA
considered both the regulatory language and associated guidance in drafting its comments. AWWA
recommends that EPA respond to the comments in this section, as well as Section 4.1.1, by revising
Chapter 5 of that Guidance manual.
4.2.9 Demonstration of Performance
As noted previously, data and discussion by EPA in the LT2ESWTR and associated guidance manuals
does not properly represent the true Cryptosporidium removal capabilities of existing surface water
treatment systems that are in compliance with the IESWTR. An important inaccuracy in the EPA
evaluation is that data were included that were not representative of IESWTR compliant water treatment
plants due to the researchers operating the process in a -non-optimized- mode. EPA is not alone in
erroneously characterizing the available data, as this mistake was not immediately identified in AWWA-s
initial analyses. AWWA has found that re-evaluation of data published both before and after the IESWTR
reveals that conventional clarification plus a filtration system operated under conditions representative of
compliance with the IESWTR or LT1ESWTR (turbidity <0.3 NTU) produces a mean and median
Cryptosporidium removal of 4 to 6 logs. In fact, the actual removal capabilities of these systems may be
even greater because the filtered water Cryptosporidium concentrations were typically below detection
limits in these studies. With the inclusion of data not representative of IESWTR compliance in the
analysis, the evaluation underestimates the true Cryptosporidium protection potential of existing
facilities that are in compliance with the IESWTR.
This does not mean that the automatic 3.0-log credit for a single clarification and filtration process should
be increased to an automatic 4.0-log credit or higher, but it does point out that, consistent with the
literature, many existing, well-run surface water treatment plants will be able to provide 4.0-log or greater
Cryptosporidium removal. The Stage 2 M/DBP FACA recognized this and included -demonstration of
performance- in the microbial toolbox recommendation to accommodate such cases.
Comment Response for LT2ESWTR E-194 December 2005
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4.2.11UV
Inactivation using ultraviolet light (UV) is the low-cost compliance technology for the LT2ESWTR for
utilities in Bins 3 and 4. UV will also be used by many utilities as a proactive measure and as an
additional treatment barrier. Therefore, feasibility of UV under the proposed validation and operation
protocols is especially critical for successful rule implementation. The availability of UV is a-
fundamental premise- of the Agreement in Principle
Response: Response 240.a.
EPA Letter ID: 562
Comment ID: 12282
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
4.2.12 Ozone
AWWA believes that retention of ozone as a viable technology was an essential component of the Stage 2
DBPR Agreement in Principle. The following comments follow directly from this understanding of the
Agreement in Principle.
Ozone is currently in use or in development at some of the largest water systems in the United States:
Southern Nevada Water, Metropolitan Water District of Southern California, Tampa, Milwaukee, Seattle,
Fairfax County (Va.) Water Authority, Dallas Water Utilities, and many other smaller communities.
Systems are choosing ozone for a number of reasons, in addition
that will:
1. Clarify the requirements and inform implementation;
2. Facilitate practical implementation of ozone; and
3. Further enhance the viability of ozone, particularly with respect to balancing ozone application with
bromate formation.
4.2.14 Requests for Comment on Ozone and Chlorine Dioxide
Request for Comment
Determination of CT and the confidence bounds used for estimating log inactivation of Cryptosporidium.
Response
AWWA supports the proposed approach. See comments above.
Stratus Consulting of Boulder, Colo., assisted AWWA-s review of the EA and supporting documents. A
copy of Stratus Consulting-s report is attached as Appendix 12.
Response: Response lOO.a.
Comment Response for LT2ESWTR E-195 December 2005
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EPA Letter ID: 562
Comment ID: 12283
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
5.4.8 Requests for Comment Regarding Economic Analysis
EPA poses three specific requests for comment with respect to the EA underlying LT2ESWR. Those
three questions and responses are provided below (68 FR 47758).
Request for Comment
How can the agency fully incorporate all toolbox options into the economic analysis?
Response
6 Miscellaneous Requests for Comment
Request for Comment
EPA requests comment on the proposed provisions of the inactivation profiling and benchmarking
requirement. (68 FR 47718)
Response
AWWA is a signatory to both the Stage 1 and Stage 2 M/DBP Agreements. Both of these Agreements
include provisions for risk balancing between DBP
Appendix 1. LT2ESWTR Treatment Requirements Cryptosporidium Monitoring,
Bin Assignment, Core Treatment, And Microbial ToolboxMicrobial
Toolbox Report, EET, 2003
[Document appended to comments as a separate electronic file.]
[SEE PDF]
Appendix 2. Cryptosporidium Removal Credit Assignable in the LT2ESWTR
Toolbox, EET, 2001
[Document appended to comments as two separate electronic files (Appendix 2a
and Appendix 2b).]
[SEE PDF]
Appendix 3. Summary of Relevant Articles Pertaining To Cryptosporidium and
Watershed Control Program Effectiveness
[SEE PDF]
AWWARF Studies
Comment Response for LT2ESWTR E-196 December 2005
-------
1. Source Water Assessment: Variability of Pathogen Concentrations (LeChevallier et. al, 2002)
2. Impacts of Major Point and Non-Point Sources on Raw Water Treatability (Pyke et al, 2003)
3. AWWARF Project 2671 - Development of Event-Based Pathogen Monitoring Strategies for
Watersheds, currently under way.
4. AWWARF #251 - Evaluation of Sources of Pathogens & NOM in Watersheds (Kaplan et al, 2002)
5. AWWARF Field Transport of Cryptosporidium Surrogate in a Grazed Catchment, (Pennell et al.,
2002)
WERF Studies
1. -OO-WSM-3 : Field Calibration and Verification of A Pathogen Transport Model. Montemagno, et. al,
2003, currently under way, contact Dean Carpenter at dcarpenter@werf.org, (703-684-2470, ext. 7152).
2. WERF 99-HHE-2- Sources and Variability of Cryptosporidium in The Milwaukee River Watershed.
(Corsi, et. al, 2003).
3. WERF 99-HHE-l - Methods to Detect Cryptosporidium in Wastewater (underway,
lead researcher - Jennifer Clancy)
Pertinent Articles
1. Atwill, E. R., L. Hou, B. Karle, T. Harter, K. Tate, and R. Dahlgren, Transport of Cryptosporidium
parvum Oocysts through Vegetated Buffer Strips and Estimated Filtration Efficiency. Appl. Environ.
Micro 68(11):5517-5527, 2002.
2. Bradford, S. and J. Schijven. Release of Cryptosporidium and Giardia from Dairy Calf Manure: Impact
of Solution Salinity. Environ. Sci. Tech. 36(18):3816-3923, 2002.
3. Dayton, E., N. Basta, C. Jakober, and J. Hattey. Using Treatment Residuals to Reduce Phosphorus in
Agricultural Runoff. JAWWA 95(4): 151-158, 2003.
4. Finstein, M., Watershed Protection: Review of Literature on Inactivation of Cryptosporidium in
Manure. Submitted JAWWA, 2003 (in review). Contact finstein@envsci.rutgers.edu. (304-242-0341).
5. Gracyk, T. and J. Grace. Maryland Department of the Environment Cryptosporidium Occurrence Study
in the Potomac River. Presented, November 5, 2003, AWWA Water Quality Technology Conference,
Philadelphia, Penn. Also presented to EPA Headquarters in August 2003.
6. Suwa, M. and Y. Suzuki, Occurrence of Cryptosporidium in Japan and countermeasures in wastewater
treatment plants. Water Sci. Tech. 43(12):183-186, 2001.
7. Suwa, M. and Y. Suzuki, Control of Cryptosporidium with wastewater treatment to prevent its
proliferation in the Water Cycle. Water Sci. Tech. 47(9):45-49, 20031.
8. Stott, R., E. May, E. Matsushita, and A. Warren, Protozoan predation as a mechanism for the removal
of Cryptosporidium oocysts from wastewaters in constructed wetlands. Water Sci. Tech. 44(11-
12):191-198, 2001.
9. USEPA, Overland Migration of Cryptosporidium Oocysts - Final Draft Issue Paper. September 21,
1999. Contact: Mike Borst, borst.mike@epa.gov, (732-321-6631).
10. Rose, J, L. Dickson, S. Farah, and R. Carnahan. Removal of pathogenic and indicator microorganisms
Comment Response for LT2ESWTR E-197 December 2005
-------
by a full-scale water reclamation facility. Water Research 30(11):2785-2797.
Response: response lOO.a.
EPA Letter ID: 562
Comment ID: 12401
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
The proposal preamble, regulatory language, and guidance are quite voluminous, but almost silent on the
mechanism by which bin determination actually occurs. Coverage of this issue is limited to the bin
definitions reflected in §141.709. However, tThe proposal contains no discussion on the associated
decision making process. One aspect discussed briefly in guidance is the flagging of contested data in the
electronic data system for submittal of §141.701(e) monitoring data. This brief discussion does not
address the handling of contested data.
Response: Response SOO.t. Contested data would be addressed during the bin classification approval
process by the State.
EPA Letter ID: 562
Comment ID: 12404
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
4.1.7 Analytical Methods
EPA Method 1623 As Applied
Response:
EPA Letter ID: 562
Comment ID: 12485
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
Response to Requests for Comment, 68 FR 47691 §IV(C)(5)(c)
The agency requests comment on the following issues concerning pre-sedimentation on Page 47691 of the
proposed rule:
Request for Comment
Whether the information cited in this proposal supports the proposed credit for pre-sedimentation and the
operating conditions under which the credit will be awarded.
Response
Comment Response for LT2ESWTR E-198 December 2005
-------
Response:
EPA Letter ID: 580
Comment ID: 12625
Commenter: Bruce Aptowicz, Chairman, Water Utility Council of the Pennsylvania American
Waterworks Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment focusing on "unrealistic expectation and implied benefit of
the LT2ESWTR" submitted by Bruce S. Aptowicz, Chairman, Water Utility Council of the Pennsylvania
American Waterworks Association Company/Group/Association Name: Water Utility Council of the
Pennsylvania American Waterworks Association
Comment:
awwa pa
Pennsylvania
Section
American Water
Works Association
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Re: Long-Term 2 Enhanuced Surface Water Treatment, Proposed Rule, 68 Federal
Register47639, Docket No. OW-2002-0039
Dear Sir or Madam:
The Water Utility Council of the Pennsylvania American Waterworks Association endorses and offersthe
same comments to the proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) as
those submitted by the American Water Works Association on January 9,2004 and attached to this letter.
Thank you.
Sincerely
Bruce S.Aptowicz
Chairman
Water Utility Council
Pa AWWA
cc: Jeffrey Hines, Chairman Pa AWWA
Pennsylvania SectionAmerican Water Works Association
1309 Bridge St., New Cumberland, PA 17070 717-774-8870 FAX 717-774-0288
American Water Works Association
Dedicated to Safe Drinking Water 1401 New York Avenue, NW Suite 640
Comment Response for LT2ESWTR E-199 December 2005
-------
Washington, DC 20005
(202) 628-8303
Fax (202) 628-2846
www.awwa.org
January 9,2004
Water Docket Environmental Protection Agency, Mail Code 41OZT 1200 Pennsylvania
Avenue, N.W. Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal
Register 47639, Docket No. OW-2002-0039
Dear Sir or Madam:
The American Water Works Association (AWWA) appreciates the opportunity to review the Proposed
Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) that EPA released on August 11,
2003 (68 Federal Register 47639). We believe that the attached comments are much more constructive
because the agency extended the comment period for the proposal (68 Federal Register 58057), giving
our volunteers and staff time for a more thorough analysis.
AWWA appreciates the ongoing spirit of cooperation with EPA in the development of this complex
rulemaking. We appreciate your review and consideration of this letter and the attached detailed
comments. If you have any questions regarding this letter or the attached comments, please contact me at
(202) 628-8303.
Best regards,
- / Signed 1/9/2004/ -
Thomas W. Curtis Deputy Executive Director
cc: Cynthia Dougherty-USEPA OGWDW
Ephraim King-USEPA OGWDW
Jennifer McLain-USEPA OGWDW
Dan Schmelling-USEPA OGWDW
P:\Regulatory\Comments\2004 Comments\Comments on LT2ESWTR-Jan 8 04.doc
Response:
EPA Letter ID: 585
Comment ID: 11953
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: CS Title: Comment referring to rule as proposed follows the "Agreement in
Principal" developed by the federal advisory committee but also need to address new issues" submitted by
Comment Response for LT2ESWTR E-200 December 2005
-------
Daniel Burke and Margaret Hoffman, Texas Commission on
Environmental Quality
Company/Group/Association Name: Texas Commission on Environmental Quality
Comment:
Daniel Burke
01/09/04 01:40PM
To: Group Ow-Docket@EPA
cc: "Ashley K. Wadick" , Carolyn Brittin
, "Duncan C. Norton"
, Dan Eden , Diane
Mazuca, David Schanbacher
, Derek Seal, Glenn
Shankle , Jack Schulze
, John Steib , Lydia
Gonzalez Gromatzky , Mark Vickery
, Randy Wood,
Stephen Minick , Tony Bennett
, Tamra-Shae Oatman
, Terri Seales
Subject: Docket ID No. OW-2002-0039, Long Term 2 Enhanced Surface Water
Treatment Rule
Dear Sirs:
The Texas Commission on Environmental Quality is pleased to submit its comments on the proposed
"Long Term 2 Enhanced Surface Water Treatment Rule " as published in the August 11, 2003 edition of
the Federal Register.
The comments are attached in WordPerfect 10 format. If you have any questions about the comments,
please contact Tony Bennett of our Water Supply Division at (512) 239-6029, or Jack Schulze at (512)
239-6046. If you have a problem with the format of the attachments or this electronic transmission, please
contact me by return email or at the address below.
A signed copy of our comments will follow via United States Postal Service mail. TCEQ appreciates the
opportunity to comment on this proposal and hopes that you will consider our comments and concerns as
you promulgate a final rule.
Daniel Burke
Texas Commission on Environmental Quality
Policy and Regulations Division MC 205
P.O. Box 13087
Austin TX 78711-3087
(512)239-1543
January 9, 2004
Water Docket
Comment Response for LT2ESWTR E-201 December 2005
-------
U. S. Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., N.W.
Washington, D.C. 20460
Re: Docket ID No. OW-2002-0039
Dear Sirs:
Comments to specific sections of the proposal are attached to this letter. We appreciate the opportunity to
comment on this important rulemaking. If you have uestions or concerns, please contact Mr. Tony
Bennett of our Water Supply Division at (512) 239-6029.
Sincerely,
Margaret Hoffman
Executive Director
Enclosure
TCEQ Comments on Long Term 2 Enhanced Surface Water Treatment Rule
Page 1
IV. A. (Pages 47665-47679)
p. 47665 [and §141.709(c) on p. 47781]
Response:
EPA Letter ID: 586
Comment ID: 12193
Commenter: Carl Rutz, Corporate Environment Manager, Alyeska Pipeline Service Company
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "requirements that should be reconsidered with respect to
small system operation" submitted by Carl Rutz, Corporate Environment Manager, Alyeska Pipeline
Service Company (APSC)
Company/Group/Association Name: Alyeska Pipeline Service Company (APSC)
Comment:
Alyeka Pipeline Service Company P.O. Box 60469 FAIRBANKS,ALASKA 99706 TELEPHONE
(907)450-7900
January 8,2004
Government Letter No. 421
Comment Response for LT2ESWTR E-202 December 2005
-------
Water Docket
US. Environmental Protection Agency
Mail Code 410IT 1200Pennsylvania Avenue, NW
Washington, DC 20460
01-15-04P04:11RCVD
January 9,2004
Attn: Docket No. OW-2002-0039
Dear Sir or Madam:
Alyeska Pipeline Service Company (APSC) respectfully submits comments on the Proposed National
Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water Treatment Rule (Federal
Register/Vol. 68, No. 154/Monday, August 11,2003).
We appreciate the opportunity to submit these comments.
Sincerely,
Alyeska Pipeline Service Company
Carl Rutz
Corporate Environment Manager
Response:
EPA Letter ID: 587
Comment ID: 12013
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: CS Title: Comment regarding "my review of the proposed rule and guidance document"
submitted by Stephen Deem, P.E.
Company/Group/Association Name:
Comment:
Stephen Deem, P.E.
11327-17thAvenueNE
Seattle, Washington 98125
December 30,2003
Water Docket
Environmental Protection Agency
Comment Response for LT2ESWTR E-203 December 2005
-------
Mail Code 410IT
1200Pennsylvania Avenue Northwest
Washington, D.C. 204600
Subject: Docket ID No. OW-2002-0039
Comments Regarding the Proposed Long Term 2 Enhanced Surface Water Treatment
Rule -Draft UVGM
To Whom It May Concern:
Sincerely,
Stephen Deem, P.E.
Cc: Dan Schmelling, EPA
Response:
EPA Letter ID: 588
Comment ID: 12089
Commenter: Lance Nielson, Manager, Idaho Drinking Water Program, Department of Environmental
Quality
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "agreement with comments submitted by the Association of
State Drinking Water Administrators (ASDWA)" submitted by Lance Nielsen, Manager, State of Idaho,
Department of Environmental Quality, Idaho Drinking Water Program
Company/Group/Association Name: State of Idaho, Department of Environmental
Quality, Idaho Drinking Water Program
Comment:
STATE OF IDAHO
DEPARTMENT OF ENVIRONMENTAL QUALITY
1410 North Hilton Boise, Idaho 83706-1255 (208) 373-0502
Dirk Kempthorne, Governor c. Stephen Alfred, Director
January 7,2004
Water Docket (MC-4101T)
Docket No. OW-2002-0039
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
01-15-04PO4:04RCVD
JAN 07 2004
Comment Response for LT2ESWTR E-204 December 2005
-------
Docket Clerk:
The Idaho Drinking Water Program appreciates the opportunity to comment on the proposed Long Term
2 Enhanced Surface Water Treatment Rule (LT2), as listed in the August 11,2003 Federal Register (68
FR 47639).
We would especially like to emphasize the following points, which are also addressed in the ASDWA
submittal:
The Idaho Drinking Water Program looks forward to working with EPA to improve public health
protection by implementing the LT2 Enhanced Surface Water Treatment Rule. Please feel free to contact
Tom John at (208) 373-0191 or tjohn@deq.state.id.us if you have questions.
Sincerely,
Lance Nielson, Manager
Idaho Drinking Water Program
cc: Tom John, DEQ
Response:
EPA Letter ID: 589
Comment ID: 13051
Commenter: Lawrence Libeu, President, The Western Coalition of Arid States
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment referring to lab capacity and data management, failure to complete
monitoring, and sampling schedule, submitted by Lawrence M. Libeu, President, Western Coalition of
Arid States (WESTCAS)
Company/Group/Association Name: Western Coalition of Arid States (WESTCAS)
Comment:
The Western Coalition of Arid States
WESTCAS
OFFICERS
PRESIDENT
Douglas W. Karafa
Clark County Sanitation Dist
Las Vegas, NV
VICE PRESIDENT
Comment Response for LT2ESWTR E-205 December 2005
-------
Bernard C. Kersey
City of San Bernardino San Bernardino, CA
SECRETARY
Chris Treese
Colorado River Water
Conservation District
Glenwood Springs, CO
TREASURER
D. Burnell Cavender
San Bernardino Valley
Water Conservation District
San Bernardino, CA
BOARD OF DIRECTORS:
ARIZONA
Ed Curley
Robert Hollander
CALIFORNIA
D. Burnell Cavender
Bernard C. Kersey
COLORADO
Dennis W. Stowe
Chris Treese
NEVADA
Douglas W. Karafa
Alec Hat
NEW MEXICO
Charlie Nylander
Dan Santantonio
OREGON
Vacant
TEXAS
John Burkstaller
IMMEDIATE PAST PRESIDENT
Lawrence M. Libeu
Eastern Mun. Wtr. District
ASSOCMTE DIRECTOR AT-LARGE
Gerald Shod
Redwine & Sherrill
Comment Response for LT2ESWTR E-206 December 2005
-------
WASHINGTON COUNSEL
Will & Carbon. Inc.
WEBSITE
www.westcas.org
GENERAL INFO
(909)928-6180
January 9, 2004
Water Docket, EPA Docket Center
U.S. Environmental Protection Agency
Mail Code 410IT,
1200 Pennsylvania Ave., NW
Washington, DC 20460
01-15-04/04:02 RCVD
JAN 09 2004
Attention Docket ID No: OW-2002-0039
Re: Notice of Proposed Rulemaking: National Primary Drinking Water Regulations; Long term 2
Enhanced Surface Water Treatment Rule; Proposed Rule (68 Federal Register 154, August 11,2003)
Dear Comments Clerk:
Sincerely,
Lawrence M. Libeu
President
The Voice of Water Quality in the Arid West
1015 18th Street N.W., Suite 600 Washington, D.C. 20036
(202) 429-4344 (202) 429-4342 fax
Response:
EPA Letter ID: 590
Comment ID: 12027
Commenter: Steve Robbins, General Manager-Chief Engineer, Coachella Valley Water District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "flawed economic analysis by EPA and laboratory
capacity has not been adequately taken into account" submitted by Steve Robbins General Manager-Chief
Engineer, Coachella Valley Water District (District)
Company/Group/Association Name: Coachella Valley Water District (District)
Comment Response for LT2ESWTR E-207 December 2005
-------
Comment:
ESTABLISHED IN 1918 AS A PUBLIC AGENCY
COACHELLA VALLEY WATER DISTRICT
POST OFFICE BOX 1058 COACHELLA, CALIFORNIA 92236 TELEPHONE (760) 398-2651 FAX
(760)398-3711
DIRECTORS:
JOHN W. McFADDEN, PRESIDENT
PETER NELSON, VICE PRESIDENT
TELLIS CODEKAS
RUSSELL KITAHARA
PATRICIA A. LARSON
OFFICERS:
STEVEN R. RORBINS, GENERAL MANAGER-CHIEF ENGINEER
MARK BEUHLER, AS ST. GENERAL MANAGER
JULIA FERNANDEZ, SECRETARY
DAN PARKS, AS ST. TO GENERAL MANAGER
REDWINE AND SHERRILL, ATTORNEYS
File: 0551.1111.1
January 9,2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
JAN 09, 2004
Gentlemen:
Subject: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68
Federal Register 47639
The Coachella Valley Water District (District) very much appreciates the opportunity to review the
Proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) released on August
11,2003, (68 FR 47639). Also, we would like to thank the Environmental Protection Agency (EPA) for
extending the comment period for the proposal (68 FR 58057).
It is because of our long association with the regulatory process that we feel the need to comment on the
proposed LT2ESWTR.
The District is encouraged that EPA continues to rely on the regulated community for input in the
development of this complex rulemaking.
Comment Response for LT2ESWTR E-208 December 2005
-------
If you have any questions regarding these brief comments, please call Steve Bigley, Water Quality
Specialist, extension 2286
Yours very truly,
Steve Robbins
General Manager-Chief Engineer
AH:j l\eng\wr\j an\epa-rule
COACHELLA VALLEY WATER DISTRICT
Response:
EPA Letter ID: 591
Comment ID: 12114
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment: CS Title: Comment referring to "Ohio EPA recommends that the proposed rule be
separated into two rules that would be promulgated successively" submitted by Christopher Jones,
Director, State of Ohio Environmental Protection Agency
Company/Group/Association Name: State of Ohio Environmental Protection Agency
Comment:
OhioEPA
State of Ohio Environmental Protection Agency
STREET ADDRESS: Lazarus Government Center 122 S. Front Street Columbus, Ohio
43215
TELE: (614) 644-3020 FAX: (614) 644-3184
MAILING ADDRESS: P.O. Box 1049 Columbus, OH 43216-1049
Water Docket
U.S. Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW.
Washington, DC 20460
01-13-04PO2:52RCVD
JAN 07 2004
Attention: Docket ID No. OW-2002-0039
RE: OHIO EPA COMMENTS FOR U. S. EPA PROPOSED LONG TERM 2 ENHANCED SURFACE
WATER
Comment Response for LT2ESWTR E-209 December 2005
-------
TREATMENT RULE
The Ohio EPA submits the following comments on 40 CFR 141 and 142: National Primary Drinking
Water Regulations; Long Term 2 Enhanced Surface Water Treatment Rule; Proposed Rule, published
August 11,2003.
Bob Taft, Governor
Jennette Bradley, Lieutenant Governor
Christopher Jones, Director
SPECIFIC COMMENTS:
Preamble Section IV. A. Additional Cryptosporidium Treatment Technique Requirements for Filtered
Systems (pages 47665-47679)
1. Page 47678, EPA requests comment on how to apply LT2ESWTR monitoring requirements to surface
water systems that operate or use surface water for only part of the year.
3. Page 47678, EPA requests comment on how the effect of recycling filter backwash should be
considered in LT2ESWTR monitoring.
4. Page 47678, EPA requests comment on alternative approaches for systems that fail to complete
required monitoring, such as classifying the system in a bin based on data the system has collected, or
classifying the system in a bin one level higher than the bin indicated by the data the system has collected.
Response:
EPA Letter ID: 591
Comment ID: 12115
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment:
5. Page 47678, EPA requests comment on monitoring and treatment requirements for
new plants and sources.
6. Page 47678, EPA requests comment on whether bin classifications be formally
made or reviewed by States.
Comment Response for LT2ESWTR E-210 December 2005
-------
7. Page 47679, EPA requests comment on how to apply the E. coli criteria for
triggering Cryptosporidium monitoring for systems using sources that are ground
water under the direct influence of surface water (GWUDI)?
Preamble Section IV. C. Options for Systems to Meet Cryptosporidium Treatment
(pages 47681-47715)
8. Page 4 7715, EPA requests comment on today's proposal for systems to demonstrate higher
Cryptosporidium removal levels. EPA specifically requests comment on the following issues:
* Whether EPA should propose minimum elements that demonstration of performance
must include.
Response:
EPA Letter ID: 591
Comment ID: 12116
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment:
* Whether or under what conditions a credit should be allowed for a single unit process within a plant?
Preamble Section IV. D. Disinfection Benchmarks for Giardia lamblia and Viruses (pages 47715-47718)
9. EPA requests comments on the proposed provision of the inactivation profiling and benchmarking
requirement.
Preamble Section IV. F. Compliance Schedules (pages 47719-47722)
10. EPA requests comments on whether an additional time window between the end of large system
monitoring and the beginning of small system monitoring is appropriate and, if so, how long such a
window should be.
Preamble Section IV. G. Public Notice Requirements (pages 47722-47723)
11. EPA requests comments on whether the violations of additional treatment requirements for
Cryptosporidium under the LT2ESWTR should require a Tier 2 public notice and whether the proposed
health effects language is appropriate.
Response:
Comment Response for LT2ESWTR E-211 December 2005
-------
EPA Letter ID: 591
Comment ID: 12117
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment:
Sincerely,
Christopher Jones
Director, Ohio EPA
cc: Michael Baker, Ohio EPA
Matt Corson, ASDWA
Miguel Del Toral, U. S. EPA, Region V
Response:
EPA Letter ID: 591
Comment ID: 12122
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment:
2. Page 47678, EPA requests comment on whether or under what conditions previously collected data that
do not meet the proposed quality criteria for LT2ESWTR monitoring data should be accepted for use in
bin determination. Specifically EPA requests comment on the sampling frequency requirement for
previously collected data.
Response:
EPA Letter ID: 591
Comment ID: 12130
Commenter: Christopher Jones, Director, State of Ohio Environmental Protection Agency
Commenter Category: State/Tribe Government
Comment:
* Whether a factor of safety should be applied to the result of the demonstration study to account for
potential difference in removal of an indicator and removal of Cryptosporidium, or uncertainty in the
application of pilot-scale results to full-scale plants.
Response:
EPA Letter ID: 592
Comment ID: 12094
Commenter: Jeffrey L. McNelly,, Maine Water Utilities Association, Water Resources Committee
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-212 December 2005
-------
Comment: CS Title: Comment referring to "the proposed LT2 rules represent an
unjustifiable economic hardship" submitted by Jeffrey L. McNelly, Maine Water
Utilities Association, Water Resources Committee
Company/Group/Association Name: Maine Water Utilities Association, Water
Resources Committee
Comment:
Maine Water Utilities Association
Organized 1925
P. O.BoxP
Waldoboro, ME 04572
(207) 832-2263
Fax:(207)832-2265
mwua@midcoast.com
Water Docket, EPA Docket Center
Mail Code 417IT
1200 PennsylvaniaAve., NW.
Washington, DC. 20460
Attn. Docket ## OW-2002-0039
VIA E-mail: Docket@epa.gov
January 8,2004
Proposed Long-Term Two Enhanced Surface Water Treatment Rule Comments
Maine is a State rich in beautitid pristine lakes, ponds and other water resources. The state is large, spread
out, predominately rural and in the northern tier of the State there is no large urban center. Maine has a
rich tradition of self-reliance because Maine hashistorically faced great economic and environmental
hardship. The proposed LT2 rules represent anunjustifiable
Sincerely
Jeffrey L. McNelly
Executive Director
for,
The Maine Water Utilities Association
Water Resources Committee
Jon VanBourg, Kennebec Water District
Phil Boissonneault, Portland Water District
Kathy Moriarty, Bangor Water District
Jon Ziegra, Boothbay Water District
Dennis Knowles, Sanford Water District
Jerry Scott, Woodard & Curran Engineers
John Boisvert, Weston and Sampson Engineers
Comment Response for LT2ESWTR E-213 December 2005
-------
John Peckenham, George Mitchell Center, University of Maine
Catherine Schmitt, George Mtchell Center, University of Maine
Andrews Tolman, Maine Drinking Water Program
Response:
EPA Letter ID: 593
Comment ID: 11813
Commenter: Leonard D. Young, Sr. Vice-President, San Antonio Water System
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "sections of the rule that cannot be endorsed and
other sections that need clarification or need to be amended" submitted by Leonard D. Young, Sr. Vice-
President, San Antonio Water System (SAWS) Company/Group/Association Name: San Antonio Water
System (SAWS)
Comment:
San Antonio Water System
January 8,2004
Water Docket, EPA Docket Center
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
Attention: Docket ID No. OW-2002-0039
Re: Long-Term 2 Enhanced Surface Water Treatment Rule
The San Antonio Water System (SAWS) is pleased to have the opportunity to submit comments on the
Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR),
SAWS, however, believes that there are several sections of the rule pertaining to EPA implementation of
LT2ESWTR that cannot be endorsed, and others that should be clarified or amended as detailed in the
enclosed Attachment A that contains SAWS' formal comments to LT2ESWTR.
SAWS will continue to participate, review and comment throughout the rulemalung process. Mrs.
Veronica J. Godley Director, Resource Quality Management is SAWS point of contact on this matter and
may be reached at (210) 704-7350.
Sincerely
Leonard D. Young, P.E.
Sr. Vice-president
Planning, Programming and Quality Control Company
xc: Bob Reeves, SAWS, Vice-president Treatment
Meg Conner, SAWS, Director Technical Services
John Reynolds, SAWS, Legal Counsel
Comment Response for LT2ESWTR E-214 December 2005
-------
Veronica J. Godley, SAWS, Director -Resource Quality Management
1001 E. Market St. - P.O. Box 2449 - San Antonio, TX - 78298-2449 - 210-704-SAWS
ATTACHMENT A
SAN ANTONIO WATER SYSTEM COMMENTS Long-Term 2 Enhanced Surface Water Treatment
Rule (LT2ESWTR)
A. SOURCE WATER MONITORING
Response:
EPA Letter ID: 595
Comment ID: 12570
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "EPA's (EPA) efforts to increase the protection of
public health" submitted by Nancy Beardsley, Director Maine Drinking Water
Program, Division of Health Engineering, Bureau of Health, Maine Department of
Human Services
Company/Group/Association Name: Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Comment:
STATE OF MAINE
DEPARTMENT OF HUMAN SERVICES
DIVISIONOF HEALTH ENGINEERING
11 STATE HOUSE STATION
AUGUSTA, MAINE
04333.0011
JOHN ELIAS BALDACCI
GOVERNOR
January 9,2004
Water Docket (MC-41O1T)
Docket No, OW-2002-0039
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Docket Clerk:
The State of Maine Drinking Water Program sincerely appreciates the opportunity to comment on the
proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). The Drinlung Water
Comment Response for LT2ESWTR E-215 December 2005
-------
Program is the agency responsible for
Please refer to Attachment 1 for further specific comments on LT2ESWTR from the State of Maine, as
requested by the EPA. Again, the State of Maine appreciates the opportunity to comment on the EPA-s
proposed LT2ESWTR.
Sincerely,
Nancy Beardsley, Director
Maine Drinking Water Program
Division of Health Engineering, Bureau of
Health Maine Department of Human Services
PRINTED OK RECYCLED PAPER
OFFICE: 161 CAPITOL STREET - TTY: (207) 287-2070 - FAX: (207) 287-4172
Attachment 1
State of Maine Drinking Water Program-ILH Response to EPA Requests for Comment
on the Proposed LT2ESWTR
lanuary 9,2004
Response:
EPA Letter ID: 597
Comment ID: 12607
Commenter: Roger Hulbert, Senior Assistant Director, City of Houston Department of Public Works and
Engineering
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "building more flexibility into the sampling schedule to allow
for sampling errors, shipping problems, laboratory accidents etc." submitted by Roger W. Hulbert,
Department of Public Works and Engineering,
City of Houston
Company/Group/Association Name: Department of Public Works and Engineering, City
of Houston
Comment:
CITY OF HOUSTON
Public Works and
Engineering Department
Lee P. Brown
Mayor
Ion C. Vanden Bosch, P.E.
Director
Public Works & Engineering
Comment Response for LT2ESWTR E-216 December 2005
-------
Department
P.O. Box 1562
Houston, Texas 77251-1562
T.713.837.0037
F. 713.837.0040
www. cityofhouston.gov
December 23,2003
Water Docket, EPA Docket Center
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue
Washington, D.C. 20460
Attention Docket ID No: OW-2002-0039, Long Term 2 Enhanced Surface Water
Treatment Rule
To Whom It May Concern:
The City of Houston appreciates the opportunity to submit additional comments regarding the
implementation of a final Long Term 2 Enhanced Surface Water Treatment Rule. We would like to
comment on the following issues, and ask that the Agency take them under advisement in developing the
final rule.
Again, the City of Houston appreciates the opportunity to offer these comments to EPA. Should you
require further information, please contact me at 713-837-0758.
Sincerely,
Roger W.Hulbert
Senior Assistant Director
Water Production Branch
Department of Public Works and Engineering
xc: Jon C. Vanden Bosch, P.E.
Jeff Taylor Robert Fiederlein
HPU Control # P-30338
Council Members: Bruce Tatro Carol M. Galloway Mark Goldberg Ada Edwards Addie
Wiseman Mark A. Ellis Bert Keller Gabriel Vasquez Carol Alvarado Annise D.
Parker Gordon Quan Shelley Sekula-Gibbs M.D. Michael Berry Carroll G. Robinson
Controller: Judy Gray Johnson
Response:
Comment Response for LT2ESWTR E-217 December 2005
-------
EPA Letter ID: 598
Comment ID: 12614
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "water and wastewater regulations that are based on sound
scientific and economic principles, and that are protective of environmental and public health" submitted
by Austin Water Utility (Utility), City of Austin
Company/Group/Association Name: Austin Water Utility (Utility), City of Austin
Comment:
City of Austin
Austin Water Utility, P. 0. Box 1088, Austin, TX 78767
January 5,2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
Attn: Docket ID No. OW-2002-0039
Subject: National Primary Drinking Water Regulations; Long Term 2 Enhanced Surface Water Treatment
Rule; Proposed Rule Federal Register Nol. 68, No. 154/Monday, August 11,2003
Gentlemen:
The Austin Water Utility (Utility) is pleased to have an opportunity to comment on the subject proposed
Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) published in the Federal Register
on August 11,2003. We provide
environmental and public health. Consequently, we offer the following comments on the proposed
LT2ESWTR:
The Utility appreciates the opportunity to comment on these proposed rules. Should you have any
questions regarding our comments, please contact Charles
Maddox, P.E., Water Regulatory Manager at 512-972-002 lor by e-mail at
charlie .maddox@ci.austin.tx.us.
Sincerely,
Chris Lippe, P.E., Director
Austin Water Utility
cc: Andrew P. Covar
Jane Burazer
Raj Bhattarai
Comment Response for LT2ESWTR E-218 December 2005
-------
Dan Pedersen
Jonathan Davis
The City of Austin is committed to compliance with the Americans with
Disabilities Act. Reasonable modifications and equal access to communications
will be provided upon request
Response:
EPA Letter ID: 601
Comment ID: 12994
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "efforts to construct rules that address the needs of the
various stakeholders through use of the Federal Advisory Committee Act (FACA)" submitted by Kenneth
H. Bousfield, P.E., State of Utah Department of Environmental Quality Company/Group/Association
Name: State of Utah Department of Environmental
Quality
Comment:
State of Utah
Department of
Environmental Quality
Dianne R. Nielson, Ph.D.
Executive Director
DIVISION OF DRINKING WATER
Kevin W. Brown, P.E.
Director
OLENE S. WALKER
Governor
GAYLE F. McKEACHNIE
Lieutenant Governor
January 9,2004
Water Docket (MC-4101T)
Docket No. OW-2002-0039
U.S. Environmental Protection Agency
1200Pennsylvania Avenue, NW
Washington, DC 20460
Docket Clerk:
Comment Response for LT2ESWTR E-219 December 2005
-------
The State of Utah appreciates the opportunity to comment on the proposed Long Term 2 Enhanced
Surface Water Treatment Rule (LTZESWTR) as listed in the August 11, 2003 Federal Register (68 FR
47639) [SEE PDF].
Again, Utah appreciates the opportunity to provide comment on these proposed rules and looks forward to
working with EPA to ensure that the final rules are both protective of public health and implementable at
the state and local level. Please direct any questions or concerns regarding these comments to me at
kbousfield@utah.gov or (801) 536-4207.
Sincerely,
Kenneth H. Bousfield, P.E.
Compliance Program Manager
150 North 1950 West - PO Box 144830 - Salt Lake City,UT 84114-4830 - phone(801)
536-4200 fax (801)536-4211
T.D.D. (801) 536-4414wwru.deq.utah.gov
Utah! Where ideas connect
STATE OF UTAH
Response to EPA Requests for Comment on the Proposed LT2ESWTR
January 9, 2004
Docket ID No. OW-2002-0039
IV. Discussion of Proposed LT2ESWTR Requirements
A. 1. What is the EPA Proposing Today?
(pages 47665-47679)
IV. Discussions of Proposed LT@ESWTR Requirements.
IV. Discussion of Proposed LT2ESWTR Requirements
A. 3. Request for Comment
(pages 47678-47679)
EPA requests comment on all aspects of the monitoring and treatment requirements proposed in this
section.
(page 47678)
Response:
Comment Response for LT2ESWTR E-220 December 2005
-------
EPA Letter ID: 601
Comment ID: 12995
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment:
EPA requests comment on Bin assignments for systems that fail to complete required monitoring
(page 47678)
IV. Discussion of Proposed LT2ESWTR Requirements
C. 1. Microbial Toolbox Overview
(pages 47681-47715)
For each microbial toolbox component, EPA requests comment on: (1) Whether available data support
the proposed presumptive credits, including the design and implementation conditions under which the
credit would be awarded, (2) whether available data are consistent with the decision not to award
presumptive credit for roughing filters and raw water off-stream storage, and (3) whether additional data
are available on treatment effectiveness of toolbox components for reducing Cryptosporidium levels. EPA
will consider modifying today's proposal for microbial toolbox components based on new information
that may be provided. EPA particularly solicits comment on the performance of alternative filtration
technologies that are currently being used, as well as ones that systems are considering for use in the
future.
See below for specific comments of proposed toolbox options
Watershed Control Program
IV. Discussion of Proposed LT2ESWTR Requirements
D. Disinfection Benchmarks for Giardia lamblia and Viruses
3. Request for Comments
(pages 47715-47718)
Response:
EPA Letter ID: 601
Comment ID: 12996
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment Response for LT2ESWTR E-221 December 2005
-------
Comment:
IV. Discussion of Proposed LT2ESWTR Requirements
F. Compliance Schedules
(pages 47719-47722)
IV. Discussion of Proposed LT2ESWTR Requirements
G. Public Notice Requirements
(pages 47722-47723)
IV. Discussion of Proposed LT2ESWTR Requirements
K. 2. E. coli
(page 47733-47734)
IV. Discussion of Proposed LT2ESWTR Requirements
K. 3. Turbidity
(page 47734)
Response:
EPA Letter ID: 601
Comment ID: 12997
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment:
VII. Statutory and Executive Order Reviews
L. Plain Language
(page 47770)
Executive Order 12866 encourages Federal agencies to write rules in plain language. EPA invites
comments on how to make this proposed rule easier to understand.
For example: Has EPA organized the material to suit commenters- needs?
Are the requirements in the rule clearly stated?
Response:
Comment Response for LT2ESWTR E-222 December 2005
-------
EPA Letter ID: 601
Comment ID: 13037
Commenter: Kenneth H. Bousfield, Compliance Program Manager, State of Utah Department of
Environmental Quality
Commenter Category: State/Tribe Government
Comment:
IV. Discussion of Proposed LT2ESWTR Requirements
J. System Reporting and Recordkeeping Requirements
(pages 47724-47731)
Response:
EPA Letter ID: 603
Comment ID: 12637
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: CS Title: Comment regarding "lack of consistency between the Long Term lEnhanced
Surface Water Treatment Rule and the LT2ESWTR with regard to Cvyptosporidium inactivation"
submitted by Richard T. Hoey, Washington State Department of Health Company/Group/Association
Name: Washington State Department of Health
Comment:
STATE OF WASHINGTON
DEPARTMENT OF HEALTH
DIVISION OF DRINKING WATER
NewMarket Industrial Campus, Bldg 3 * PO Box 47822 * Olympia, Washington 98504-
7822
Tel: (360) 236-3100 * FAX: (360) 236-2252 * TDD Relay Service: 1-800-833-6388
January 5, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue Northwest
Washington, D.C. 204600
To Whom It May Concern:
RE: Docket ID No. OW-2002-0039
Comments Regarding the Proposed Long Term 2 Enhanced Surface Water Treatment Rule
The Washington State Department of Health has reviewed the proposed Long Term 2 Enhanced Surface
Water Treatment Rule (LT2ESWTR). We appreciate the opportunity
Comment Response for LT2ESWTR E-223 December 2005
-------
The proposed rule and associated guidance manuals are substantial documents. As such, comments on
both the proposed rule and draft guidance are provided as attachments to this document as follows:
Attachment A -Comments on the Proposed Long Term 2 Enhanced Surface Water Treatment Rule
Attachment B -Alternative Filtration Technologies and Federal Requirements for Cryptosporidium
Removal
Attachment C -Comments on the draft Ultraviolet Disinfection Guidance Manual
The Washington State Department of Health appreciates the 60-day extension to the comment period to
allow a more thoughtful review of the proposed rule and associated guidance manuals. Three of our main
concerns, which are reiterated in the attachments to this letter, are as follows:
1. There is a lack of consistency between the Long Term Enhanced Surface Water Treatment Rule and the
LT2ESWTR with regard to Cryptosporidium inactivation. Specifically, we recommend including
language in the final LT2ESWTR, which modifies the Long Term 1 Enhanced Surface Water Treatment
Rule to allow states to approve the use of alternative filtration technologies that, in combination
with effective disinfection, meet the microbial risk reduction objective of both rules. This issue is
presented in more detail in the memorandum in Attachment B.
Washington State Department of Health position on these issues is explained in more detail in Attachment
C.
should be commended for their effort. If you have any questions or concerns, please contact me at (360)
236-3160 or contact me via email at
rich.hoey@doh.wa.gov.
Sincerely,
Richard T. Hoey,
Acting Director
Office of Drinking Water
Attachments
cc: Marie Jennings, USEPA Region 10
Attachment A
Comments on the Proposed Long Term 2 Enhanced Surface Water Treatment Rule Washington State
Department of Health, Office of Drinking Water
January 5,2004
In this attachment, comments are provided first for proposed additions and/or modifications to CFR Part
141 and Part 142, followed by comments to the preamble.
(Pg. 47775) Section 141.2-
Response: Response 500.z.
Comment Response for LT2ESWTR E-224 December 2005
-------
EPA Letter ID: 603
Comment ID: 12638
Commenter: Richard T. Hoey, Acting Director, Washington State Department of Health
Commenter Category: State/Tribe Government
Comment: Attachment C
Comments on the Ultraviolet Disinfection Guidance Manual
Washington State Department of Health, Office of Drinking Water
January 5,2004
The draft Ultraviolet Disinfection Guidance Manual (UVDGM) is a substantial document. The authors
should be commended for the thorough and detailed analysis of the issues and complexity that surround
this technology. The manual is well written and comprehensive. The focus of our review was on those
issues that are expected to most significantly impact State implementation of ultraviolet (UV)
disinfection, specifically monitoring and validation that will impact the inactivation credit assigned.
General Comments
Other Comments
Response:
EPA Letter ID: 607
Comment ID: 12975
Commenter: Cam Ferguson, Manager of Water Resources, Greenville Water System
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "failure to meet the proposed requirement for
consecutive monthly samples should no automatically trigger placement into a
lower bin assignment" submitted by Cam Ferguson, Manager of Water Resources,
Greenville Water System
Company/Group/Association Name: Greenville Water System
Comment:
Greenville Water System
COMMISSIONERS OF PUBLIC WORKS OF THE CITY OF GREENVILLE, S.C.
COMMISSIONERS
VARDRY RAMSEUR
Chairman
JAMES M. SHOEMAKER, JR.
Vice-chairman
PHILLIPA. KILGORE
KNOX H. WHITE
Comment Response for LT2ESWTR E-225 December 2005
-------
Mayor-Ex-Officio
DEB SOFIELD Commissioner
Ex-Officio
OFFICERS
LYNDON B. STOVALL
General Manager
W. FRANK ESKRIDGE
Manager of Engineering and Operations
DERRICK J. BROWN
Manager of Administration and Finance
C. CAMERON FERGUSON
Manager of Water Resources
January 6,2004
Water Docket
Environmental Protection Agency Mailcode 4010IT
1200 Pennsylvania Ave.
Washington, DC 20460
Re: Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) Proposed Rule,
68 Federal Resister 47639
Thank you for the opportunity for Greenville Water System to comment on the LT2.
Thank you for the opportunity to comment.
Sincerely,
Cam Ferguson
Manager of Water Resources
PROTECTING THE QUALITY OF LIFE
P.O. BOX 687 / GREENVILLE, SC 29602 / 407 WEST BROAD STREET / TELEPHONE (864)
241-6155
Response:
EPA Letter ID: 608
Comment ID: 13130
Commenter: Valerie Hunter, Member, Friends of the Reservoirs
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: CS Title: Comment focusing on "the proposed requirement that unfiltered source
water systems and systems with uncovered finished storage should build additional treatment, no matter
how pure its water is" submitted by Valerie Hunter, MD, Friends of the Reservoirs
Company/Group/Association Name: Friends of the Reservoirs of Portland, OR
Comment Response for LT2ESWTR E-226 December 2005
-------
Comment:
Friends of the Reservoirs
Citizens joining to protect Portland's historic reservoirs and water system
3534 S.E. Main Street, Portland, OR 97214 www.friendsofreservoirs.org
www.lists.pdx.edu/mttabor
January 5,2004
Water Docket
Environmental Protection Agency
Mail Code 410 IT
1200 Pennsylvania Ave, NW
Washington DC 20460
01-14-04PO3:31RCVD
JAN 06 2004
Attention Docket ID No. OW-2002-0039
Valerie Hunter, MD
1400 SE 60th Ave.
Portland, OR 97215
vhunter@comcast.net
Response:
EPA Letter ID: 609
Comment ID: 14109
Commenter: Richard Powers, Chief, Michigan Department of Environmental Quality
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "we strongly object to early implementation that
requires water supplies to begin compliance monitoring prior to state
involvement" submitted by Richard A. Powers, Water Division, Michigan Department
of Environmental Quality (MDEQ)
Company/Group/Association Name: Michigan Department of Environmental Quality
(MDEQ)
Comment:
STATE OF MICHIGAN
DEPARTMENT OF ENVIRONMENTAL QUALITY
LANSING
DEQ
JENNIFER M.GRANHOLM
GOVERNOR
STEVEN E.CHESTER
Comment Response for LT2ESWTR E-227 December 2005
-------
DIRECTOR
January 9,2004
LT2ESWTR
Water Docket (MC-4101T)
Docket ID No. OW-2002-0039
U.S Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
01-14-04PO3:24RCVD
JAN 09 2004
Gentlemen:
This letter is submitted on behalf of the Michigan Department of Environmental Quality (MDEQ), the
primary enforcement agency for the Public Water System Supervision Program. This is in response to the
notice in the federal Register dated August 11, 2003, containing the proposed Long Term 2 Enhanced
Surface Water Treatment Rule (LT2ESWTR).
General Comments
LT2ESWTR
Early Implementation
With regard to the draft Analytical Methods request for comment, the MDEQ's
Environmental Laboratory has no comments concerning Cryptosporidium due to its
If you have any questions, please contact Mr. James K. Cleland, Assistant Chief,
Water Division, at 517-241-1287.
Sincerely,
Richard A. Powers, Chief
Water Division
517-335-4176
cc: Mr. Miguel Del Toral, USEPA, Region 5
Association of State Drinking Water Administrators
Mr. James K. Cleland, MDEQ
CONSTITUTION HALL * 525 WEST ALLEGAN STREET * P.O. BOX 30273 * LANSING,
MICHIGAN
48909-7773 * www.michigan.gov * (517) 241-1300
Response:
Comment Response for LT2ESWTR E-228 December 2005
-------
EPA Letter ID: 610
Comment ID: 12981
Commenter: Donald Link, Director of Engineering & Utilities, City of Monroe Department of
Engineering
Commenter Category: Local Government
Comment: CS Title: Comment focusing on "basic components of that agreement as reflected
in the LT2ESWTR Proposal" submitted by Donald A. Link, P.E., Director of Engineering & Utilities,
City of Monroe Department of Engineering
Company/Group/Association Name: City of Monroe Department of Engineering
Comment:
CITY OF MONROE
Department of Engineering
January 9,2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, DC 20460
01-14-04PO3:19RCVD
JAN 09 2004
RE: LONG-TERM 2 ENHANCED SURFACE WATER RULE, PROPOSED RULE 68 FEDERAL
REGISTER
47639, DOCKET NO. OW-2002-0039
Dear Sir or Madam:
Sincerely,
Donald A. Link, P.E.
Director of Engineering & Utilities
DAL:srh
CC: Mike O'Connell, Acting City Manager
James Spas, Supervisor, Frenchtown Charter Township
Scott Allen, Monroe Water Treatment Superintendent
120 EAST FIRST STREET, MONROE, MICHIGAN 48161-2169 / (734) 243-0700 FAX: (734)
384-9108
Comment Response for LT2ESWTR E-229 December 2005
-------
Response:
EPA Letter ID: 612
Comment ID: 13145
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: CS Title: Comment focusing on "partnership with us" submitted by Dr. Jeff
Throckmorton, President Hach Homeland Security Technologies and Mr. Paul Caragher, Global Product
Manager, Hach Company
Company/Group/Association Name: Hach Company
Comment:
January 8,2003
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, D.C. 20460
01-12-04A10:03 RCVD
JAN 09 2004
Attention: Document ID No. OW-2002-0039
RE: Comments on LT2
Dear USEPA LT2 Committee,
Attached you will find Hach Company's comments regarding the proposed Long Term 2 Enhanced
Surface Water Treatment Rule. Qualified experts from Hach Company spent a significant amount of time
and effort conducting a thorough review of the proposed rule and have provided comments regarding this
proposal. Our comments are based upon Hach Company's more than 50 plus years of experience in
the development, manufacture, and application of drinking water monitoring technologies.
If the Agency determines that our comments warrant further discussion, we are at your disposal regarding
this discussion. We also encourages the Agency to consider partnership with us in an effort to resolve any
issues brought up in our comments associated with LT2 and across other areas of the Agency.
We are committed to helping the Agency and drinking water utilities provide safe drinking water supplies
far into the future.
Sincerely,
Dr. Jeff Throckmorton
President Hach Homeland Security Technologies
Hach Company
Comment Response for LT2ESWTR E-230 December 2005
-------
Mr. Paul Caragher
Global Product Manager
Hach Company
TO: Water Docket
EPA Docket Center
Environmental Protection Agency
Room B102
1301 Constitution Avenue
Washington, D.C. 20460
Attention: Document ID No. OW-2002-0039
FROM: Hach Company
SUBJECT: Draft Comments On the Long Term Enhanced Surface Water Treatment Rule
40 CFR Parts 141 and 142
Date: January 7,2004
4. Membranes:
Membranes have rapidly become a preferred filtration technology in the DW and WW industry. The
growth of this technology is exponential and with this growth has come the demonstrated need for
technologies to insure their performance is consistent over time. This technology is the exclusive toolbox
technology that is theoretically capable of achieving the maximum log removal credit for Bin 4 utilities in
and of itself. Although membrane filtration is a mature technology, its application and use in drinking
water production is relatively new and its application in large-scale drinking water production is still in its
infancy.
Hach Company has dedicated significant quantity of resources to understand this emerging technology.
This includes participation in several membrane pilot studies and in AWWARF studies. This discussion is
based on our experience and interaction with the manufacturers, consultants and end-users of this
technology. This includes many partnership studies to better understand what technologies work best with
respect to monitoring the performance and integrity of membrane systems.
Discussion:
The majority of installed micro-filtration (MF) and ultra-filtration (UF) facilities are relatively small in
comparison to the size of many proposed plants in the future. Much of the test criteria that relates to the
operation and monitoring of performance for systems was based upon studies that were conducted on
either small-scaled plants or under pilot conditions.
Over the last 2-5 years, membrane systems have become affordable and competitive with traditional
municipal water filtration systems. This has resulted in exponential growth of installed systems and
overall water production, with the future expectation of growth expected into the foreseeable future.
Membrane plant designs that exceed 100 MGD are being proposed.
Hach Company is willing to provide any assistance or partnership with the Agency related to the
Comment Response for LT2ESWTR E-231 December 2005
-------
assessment and implementation newer and more appropriate technologies for use in regulatory programs.
If any of these comments warrant further discussion by the Agency, Hach Company welcomes this
discussion. Hach Company also encourages the Agency to consider partnership with us in an effort to
resolve any issues brought up in our comments associated with LT2 and across other areas of the Agency.
Respectively submitted,
Michael J. Sadar
Application Scientist II
Hach Company
HACH COMPANY / 5600 Lindbergh Drive / PO Box 389 / Loveland, Colorado 80539 /
970.669.3050 / fax 970.669.2932 / www hach com
Response:
EPA Letter ID: 612
Comment ID: 13170
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment:
All comments pertain to the CFR Volume 68, No. 154, published August 11, 2003. Where appropriate,
specific references are to the page numbers of this document, which range from CFR 447640 through
47795.
General Comments:
1. Turbidity Monitoring:
Response:
EPA Letter ID: 614
Comment ID: 12957
Commenter: David Rexing, SNWA W.Q. R&D Manager, Southern Nevada Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on source water monitoring, microbial toolbox, ozone,
violations, laboratory capacity issues, grandfathering data, and filter backwash
recycling, submitted by David J. Rexing, SNWA W.Q. R&D Manager, Southern Nevada
Water Authority (SNWA)
Company/Group/Association Name: Southern Nevada Water Authority (SWNA)
Comment:
Comment Response for LT2ESWTR E-232 December 2005
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SOUTHERN WATER NEVADA AUTHORITY
Administrative Office
1001 S. Valley View Blvd.
Las Vegas, Nevada 89153
Telephone: (702) 258-3939
Fax:(702)258-3268
Project Office
1900 E. Flamingo, Ste. 170
Las Vegas, Nevada 89119
Telephone: (702) 862-3400
Fax:(702)862-3470
Southern Nevada Water System
243 Lakeshore Road
Boulder City, NV 89005
Telephone: (702) 564-7697
Fax:(702)564-7222
January 7,2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue N.W.
Washington DC 20460
01-12-04A09:54RCVD
JAN 07 2004
RE: Southern Nevada Water Authority (SNWA) Committee Comments on LT2 ESWTR, Proposed Rule,
68 Federal Register 47639, Docket No. OW-2002-0039
Dear Sirs,
Enclosed please find SNWA's comments and suggestions on referenced regulation.
Sincerely,
David J. Rexing
SNWA W.Q. R&D Manager
Encl
cc: Ron Zegers
Linda Blish
Don Razy
Greg Kodweis
Richard Giltner
Kelly TerAvest
Wilbur Frehner
Stan Van Wagenen
Comment Response for LT2ESWTR E-233 December 2005
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Eric Wert
JeffGebhart
Andrea Seifert
Dana Pennington
Galen Denio
BOARD OF DIRECTORS
Amanda M. Cyphers, Chair
Henderson Councilman
Rory Reid, Vice Chair
County Commissioner
Andrea Anderson
Boulder City Councilman
Shari Buck
North Las Vegas Councilman
Oscar Goodman
Las Vegas Mayor
Mark James
County Commissioner
Myrna Williams
County Commissioner
Patricia Mulroy
General Manager
January 7,2004
Water Docket
Environmental Protection Agency, Mail Code 4101 T
1200 Pennsylvania Avenue N.W.
Washington DC 20460
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal
Register 47639, Docket No. OW-2002-0039
The Southern Nevada Water Authority appreciates the opportunity to review and provide comments on
the proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) released by the EPA
on August 11, 2003 (68 Federal Register 47639):
Response:
EPA Letter ID: 617
Comment ID: 13252
Commenter: David Paris, Water Supply Administrator, Manchester Water Works
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "support of risk approach to regulatory standards
that recognizes certain supplies to be at higher risk than others" submitted by Thomas Bowen, Director
and David Paris, Water Supply Administrator, Manchester Water Works
Company/Group/Association Name: Manchester Water Works
Comment Response for LT2ESWTR E-234 December 2005
-------
Comment:
MANCHESTER WATER WORKS
Water Treatment Plant
1581 LAKE SHORE ROAD, MANCHESTER, NEW HAMPSHIRE 03109 Tel. (603)624-6482 Fax
(603)628-6030
BOARD OF WATER COMMISSIONERS
C. ARTHUR SOUCY
President
RAYMOND W PROVENCHER
Clerk
DONALD P. COUTURIER
JAMES W. CRAIG
PATRICIA H. CORNELL
RICHARD M. BUNKER
Ex Officio
HON ROBERT A. BAINES
Mayor
THOMAS M. BOWEN, P.E.
Director and Chief Engineer
ROBERT BEAURIVAGE, P.E.
Asst. Director
December 29, 2003
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
01-12-04PO3:56RCVD
JAN 05 2004
E: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal
Register 47639, Docket No. OW-2002-0039
Dear Sir or Madam:
With this in mind Manchester Water Works has the following concerns with the
proposal:
Comment Response for LT2ESWTR E-235 December 2005
-------
Manchester Water Works appreciates the opportunity to comment on this proposal. We recognize and
support the exceptional level of cooperation and collaboration EPA used in the development of this
complex rulemaking. Thank you for your consideration of this letter. If you have any questions regarding
this letter please feel free to contact us at 603-624-6494.
Sincerely,
Thomas Bowen, PE, Director
David Paris, Water Supply Administrator
Copy: Manchester Water Works Board of Water Commissioners
Robert Beaurivage, PE, Assistant Director
Response:
EPA Letter ID: 618
Comment ID: 13245
Commenter: Craig Bryant, Director, Chesterfield County Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to the proposal's (proposal) source water monitoring
requirement and presentation of health effects data, submitted by Craig S.
Bryant, Director, Chesterfield County, Virginia Utilities Department
Company/Group/Association Name: Chesterfield County, Virginia Utilities
Department
Comment:
Chesterfield County, Virginia Utilities Department
9840 Government Center Parkway - P.O. Box 608 - Chesterfield, VA 23832-0009
Phone: (804) 748-1401 - Fax: (804) 751-4607 - Internet: chesterfield.gov
CRAIG S.BRYANT
Director
January 6, 2004
Water Docket, EPA Docket Center
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, DC 20460
01-12-04PO3:58RCVD
JAN 07 2004
RE: DOCKET ID NO. OW-2002-0039
Sir or Madam:
Comment Response for LT2ESWTR E-236 December 2005
-------
Provided below are comments related to the Long Term 2 Enhanced Surface Water Treatment Rule
(LT2ESWTR) from Chesterfield County Department of Utilities, Chesterfield, Virginia.
1. Source Water Monitoring Requirement
Sincerely,
Craig S. Bryant
Director
CSB/jab
cc: Roy E, Covington, Assistant Director
George DuVal, Plant Manager
Response:
EPA Letter ID: 620
Comment ID: 13278
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "several concerns regarding the proposed Long Term
2 Enhanced Surface Water Treatment Rule language" submitted by Stephen P.
Schneider, General Manager, Board of Water Commissioners, Saint Paul Regional
Water Services (SPRWS)
Company/Group/Association Name: Board of Water Commissioners, Saint Paul
Regional Water Services (SPRWS)
Comment:
BOARD OF WATER COMMISSIONERS
President: James Reiter
Commissioners: Matt Anfang * Jerry Blakey * Robert Cardinal * Pat Harris *
Richard Vitelli
January 6,2004
Water Docket, EPA Docket Center
Environmental Protection Agency (EPA)
Mail Code 410IT
1200 Pennsylvania Avenue NW
Washington, DC 20460
01-12-04PO4:11RCVD
JAN 06 2004
Comment Response for LT2ESWTR E-237 December 2005
-------
Attention: Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR)
Docket ID No.: OW-2002-0039
Dear Sir or Madam:
Saint Paul Regional Water Services (SPRWS) appreciates the opportunity to submit our comments on the
proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) that EPA released on
August 11, 2003. We are a drinking water utility
SPRWS is aware of the complexity of developing of rules such as this. We will appreciate your review
and consideration of this letter and the attached detailed comments. If you have any questions regarding
this letter or the attached comments, please contact me at (651) 266-6274.
Sincerely,
Stephen P. Schneider
General Manager
SPS/saj
Copy: James Graupmann, SPRWS
James Bode, SPRWS
SAINT PAUL REGIONAL WATER SERVICES
Bernie R. Bullert, General Manager
8 4th St E Saint Paul MN 55101-1007 * TTY: 651-266-6299
Saint Paul Regional Water Services provides quality water services to the
following cities:
Arden Hills * Falcon Heights * Lauderdale * Little Canada * Maplewood * Mendota
* Mendota Heights * Roseville * Saint Paul * West St. Paul
A. Source Water Monitoring
B. UV Disinfection Criteria
Key Issue 1: Conservative Assumptions
Comments: No comment
C. Microbial Toolbox
Response:
EPA Letter ID: 620
Comment ID: 13279
Comment Response for LT2ESWTR E-238 December 2005
-------
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment:
D. Filter Backwash Recycle
Response:
EPA Letter ID: 621
Comment ID: 13162
Commenter: James Edzwald, Professor of Civil and Environmental Engineering, University of
Massachusetts
Commenter Category: Academia/Professional Societies: University Departments, Professors (even if
writing on their own behalf)
Comment: CS Title: Comment focusing on "one minor editorial comment and some technical
comments" submitted by James K. Edzwald, Professor of Civil and Environmental
Engineering, University of Massachusetts
Company/Group/Association Name: University of Massachusetts
Comment:
University of Massachusetts
224 Marston Hall
Box 35205
Amherst, MA 01003-5205
Department of Civil and Environmental Engineering
voice: 413.545.2508
fax: 413.545.2840
http://www.ecs.umass.edu/cee/
OW-2002-0039
January 5,2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
Attention Docket ID No.
1200 Pennsylvania Ave.
Washington, DC 20460
01-13-04PO2:56RCVD
JAN 06 2004
Dear Sir or Madam:
I appreciate the opportunity to comment on the National Primary Drinking Water Regulations: Long
Term 2 Enhanced Surface Water Treatment Rule: Proposed Rule and your consideration of my
comments. I have one minor editorial comment and some technical comments regarding Cryptosporidium
Comment Response for LT2ESWTR E-239 December 2005
-------
removal data and log removal credits.
Editorial Comment
In closing, I wish to thank you again for the opportunity to comment on the Proposed Rule. I hope that
my comments are useful.
Sincerely,
James K. Edzwald
Professor of Civil and Environmental Engineering
Attachments: AWWARF Exec. Summary, JAWWA Paper, and Aqua Paper
Response:
EPA Letter ID: 624
Comment ID: 13172
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "our strong belief that open communication and sharing of
expertise will best protect our customers' (customer) interests"
submitted by Jack DeMarco, Superintendent, Greater Cincinnati Water Works (GCWW)
Company/Group/Association Name: Greater Cincinnati Waterworks (GCWW)
Comment:
GREATER CINCINNATI
WATERWORKS
A Service of The City of Cincinnati
January 8,2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
01-13-04PO2:55 RCVD
JAN 09 2004
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68
Federal Register 47639, Docket No. OW-2002-0039
5651 Kellogg Avenue
Cincinnati, Ohio 45228-1123
513-624-5600 Phone
513-624-5670 Fax
Comment Response for LT2ESWTR E-240 December 2005
-------
David E. Rager
Director
Jack DeMarco
Superintendent
Water Quality & Treatment
Customer Service
513-591-7700
513-591-7730 TDD
Emergency Service
513-591-7700
513-591-7905 TDD
Dear Sir or Madam:
approximately a million people in the Greater Cincinnati Area. GCWW appreciates the opportunity to
review and comment on the Proposed Long-Term 2 Enhanced Surface Water Treatment Rule
(LT2ESWTR) that EPA published on August 11,2003 (68 FR 47639). Enclosed are GCWW's comments
and supporting documents on the proposed regulation. These comments are prepared with the intended
spirit of cooperation
Again, thank you for the opportunity to review and comment on the proposed regulations and guidance
documents. If you have any questions, please call Ramesh Kashinkunti at (513) 624-5622.
Sincerely,
Jack DeMarco, Superintendent
Water Quality and Treatment Division
cc: David Rager, GCWW
Steve Via, AWWA
Diane VanDe Hei, AMWA
[SEE PAGE 5 OF PDF FOR FIGURE 1]
[SEE PAGE 6 OF PDF FOR TABLE 1]
[SEE PAGE 7 OF PDF FOR FIGURE 2]
[SEE PAGE 9 OF PDF FOR FIGURE 3]
[SEE PAGE 11 OF PDF FOR GRAPHIC OF RIVERBANK FILTRATION]
Greater Cincinnati Water Work's Comments on the Long-Term 2 Enhanced Surface
Water Treatment Rule
Comment Response for LT2ESWTR E-241 December 2005
-------
General Comments:
Toolbox Components:
Response:
EPA Letter ID: 625
Comment ID: 13135
Commenter: James M. Parsons, Director of Engineering, Cobb County-Marietta Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "our concern that qualified laboratories would not be
available at a reasonable price when the final rule was promulgated" submitted by James M. Parsons,
P.E., Director of Engineering, Cobb County-Marietta Water Authority
Company/Group/Association Name: Cobb County-Marietta Water Authority
Comment:
Scott C. Craddock, Chair
Bo Pounds, Vice-Chair
Earl E. Smith, Secretary
A. Max Bacon, Member
COBB COUNTY-MARIETTA
WATER AUTHORITY
REGIONAL WATER RESOURCE MANAGEMENT
R. L. Jacobs, Member
Donald C. Mabry, Member
Sam Olens, Member
A. Roy Fowler, III, General Manager
January 9,2004
Water Docket, EPA Docket Center
U. S. Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
ATTN: Docket ID No. OW-2002-0039
Docket Clerk:
The Cobb County -Marietta Water Authority appreciates the opportunity to comment on the proposed
Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) as listed in the August 11,2003
Federal Register (68FR 47639). Our comments generally reflect the comments that have been provided
by The Association of Metropolitan Water Agencies (AMWA). The Water Authority has been collecting
Cryptosporidium data for the past eight months at our two water treatment plants. This step was taken
Comment Response for LT2ESWTR E-242 December 2005
-------
because of our concern that qualified laboratories would not be available at a reasonable price when the
final rule was promulgated. Our detailed comments are provided in Attachment A.
If there are any questions on these comments please contact Mr. Wayne Jackson our laboratory director at
wjackson@ccmwa.org or (770) 974-4286 ormyselfatjparsons@ccmwa.org or (770) 426-8788.
Sincerely,
James M. Parsons, P.E.
Director of Engineering
Cc: Roy Fowler
Glenn Page
Wayne Jackson
Tom Ginn
Patrick Pherson
1660 Barnes Mill Road, Marietta, GA 30062 770-426-8788, 770-426-9092 Fax
Attachment A
Cobb County -Marietta Water Authority
Comments on the Proposed LT2ESWTR
January 9,2004
A. Source Water Monitoring
1) Laboratory capacity
Response:
EPA Letter ID: 627
Comment ID: 12632
Commenter: Vernon R. Land, Water Quality Manager, City of Norfolk, Department of Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "Bin classification should be based solely on
occurrence data, not on monitoring compliance" submitted by Vernon R. Land,
Water Quality Manager, City of Norfolk, Department of Utilities
Company/Group/Association Name: City of Norfolk, Department of Utilities
Comment:
City of
Norfolk
Department of Utilities
January 7,2004
Water Docket
Environmental Protection Agency
Comment Response for LT2ESWTR E-243 December 2005
-------
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
Attention: Docket ID No. OW-2002-0039
RE: Comments on Proposed LT2ESWTR
Ladies and Gentlemen:
The City of Norfolk, Department of Utilities has reviewed the proposed Long Term 2 Enhanced Surface
Water Treatment Rule and offers the following comments.
Sincerely,
Vernon R. Land
Water Quality Manager
City of Norfolk, Virginia
cc: EPA Comments file
Director of Utilities
Asst. Director of Utilities
Division of Water Production
6040 Waterworks Road / Norfolk, Virginia 23502
(753)441-56787 Fax: (757) 441-5639
Response:
EPA Letter ID: 628
Comment ID: 12833
Commenter: Andrew DeGraca, Water Quality Bureau Manager, San Francisco Public Utilities
Commission
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on " concerns that would significantly affect
filtered and unfiltered systems without questionable benefits" submitted by San
Francisco Public Utilities Commission (SFPUC)
Company/Group/Association Name: San Francisco Public Utilities Commission
(SFPUC)
Comment:
SAN FRANCISCO PUBLIC UTILITIES COMMISSION
WATER QUALITY BUREAU
1657 Rollins Road, Burlingame, CA 94010 - Tel. (650)652-3100 - Fax (650)652-3142
SFPUC WATER
HETCH HETCHY
Comment Response for LT2ESWTR E-244 December 2005
-------
WATER & POWER
CLEAN WATER
GAVIN NEWSOM
MAYOR
E. DENNIS NORMANDY
PRESIDENT
ROBERT J. COSTELLO
VICE PRESIDENT
ANN MOLLER CAEN
ADAM WERBACH
RYAN L. BROOKS
PATRICIA E. MARTEL
GENERAL MANAGER
ANDREW F.DEGRACA
BUREAU MANAGER
January 9, 2004
Long Term 2 Enhanced Surface Water Treatment Rule
Water Docket
U.S. Environmental Protection Agency, Mail Code 4101T
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Attn: Docket ID No. OW-2002-0039
Subject: Comments on the Proposed Long Term 2 Enhanced Surface Water
Treatment Rule
Dear Rule Manager:
The San Francisco Public Utilities Commission (SFPUC) appreciate: the opportunity to review the
Proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2 Rule), which was published in 68
Federal Register 47639 on August 11, 2003. The proposed rule is a culmination of many years- efforts
contributed by numerous parties including the EPA staff, and these efforts are commendable.
Upon review of the proposed LT2 Rule, however, the SFPUC has identified several concerns that would
significantly affect filtered and unfiltered systems without questionable benefits. Comments on the
proposed rule are described in following sections.
Comments on Proposed LT2 Rule
1. Rule Applicability
5. Other Toolbox Requirements
Comment Response for LT2ESWTR E-245 December 2005
-------
Thank you for your consideration of the above.
Sincerely,
Andrew DeGraca, P.E.
Water Quality Bureau Manager
Cc: Cheryl Davis, AGM Operation
Manouchehr Boozarpour, WQB
Phil Caskey, WQ Lab
Enio Sebastiani, WQB
Eddy So, WQB
Shailen Talati, WQB
WQB Reading File
WQB File 04-01
WQB Records Management
Response:
EPA Letter ID: 629
Comment ID: 12825
Commenter: Melinda Rho, Manager of Regulatory Affairs and Consumer Protection, Los Angeles
Department of Water and Power
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment regarding "an extreme position that appears to penalize water
systems" submitted by Melinda A. Rho, Manager of Regulatory Affairs and Consumer Protection, Water
Quality and Operations, Los Angeles Department af
Water and Power (LADWP)
Company/Group/Association Name: Los Angeles Department af Water and Power
(LADWP)
Comment:
Department of Water and Power - the City of Los Angeles
JAMES K. HAHN
Mayor
Commission
DOMINICK W. RUBALCAVA, President
LELAND WONG , vice President
ANNE E. CHO
KENNETH T. LOMBARD
SID C. STOLPER
SUSAN C. PARKS, Secretary
DAVID H. WIGGS, General Manager
FRANK SALAS, Chief Administrative Officer
Comment Response for LT2ESWTR E-246 December 2005
-------
January 9,2004
Water Docket, Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Attention: Docket ID No. OW-2002-0039
Subject: Comments on Proposed Long-Term 2 Enhanced Surface Water Treatment Rule from the Los
Angeles Department of Water and Power
have the opportunity to provide the US. Environmental Protection Agency (EPA) with the following
comments on the proposed Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR).
Monitoring Requirements
Reporting and Recordkeeping Requirements
EPA requested comments on the proposed requirement that systems report monthly on the use of
microbial toolbox components to demonstrate compliance with their Cryptosporidium treatment
requirements. An alternative may be for systems to keep records on site for State review instead of
reporting the data.
LADWP appreciates the opportunity to provide comments on the LT2ESWTR. If you have any questions
regarding our comments, you may contact me at (213) 367-1329 or Mr. Robert Freeman of my staff at
(213) 367-3335.
Sincerely,
Melinda A. Rho
Manager of Regulatory Affairs and Consumer Protection
Water Quality and Operations
Water and Power Conservation- a way of life
111 North Hope Street, Los Angeles, California Mailing address: Box 51111, Los
Angeles 90051-0100
Telephone: (213) 367-4211 Cable address: DEWAPOLA
Response:
EPA Letter ID: 630
Comment ID: 13056
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-247 December 2005
-------
Comment: CS Title: Comment focusing on "some aspects of EPA's (EPA) implementation of the
rule could be improved" submitted by Linda Kinman, Iowa Association of Water Agencies
Company/Group/Association Name: Iowa Association of Water Agencies
Comment:
Iowa Association of Water Agencies
Comment Document
January 7,2004
LONG TERM 2 ENHANCED SURFACE
WATER TREATMENT RULE
(LT2ESWTR)
Docket ID No. OW-2002-0039
LTZESWTR Issues: Overall, the Iowa Association of Water Agencies supports the rule. However, some
aspects of EPA-s implementation of the rule could be improved as detailed in the following.
EPA staff has worked closely with AMWA, AWWA and other water organization representatives to
develop many aspects of the rule. Even though we are suggesting changes they should be commended for
their efforts.
A. Source Water Monitoring
Background: Under the LT2ESWTR, systems initially conduct source water monitoring for
Cryptosporidium to determine their treatment requirements. Filtered systems will be classified in one of
four risk bins based on their monitoring results. EPA projects that the majority of systems will be
classified in the lowest risk bin, which carries no additional treatment requirements. Systems classified in
higher risk bins must provide 90 to 99.7 percent (l.O to 2.5 log) additional reduction of Cryptosporidium
levels. The regulation specifies a range of treatment and management strategies, collectively termed
the -microbial toolbox,- that systems may select to meet their additional treatment requirements. All
unfiltered systems must provide at least 99 or 99.9 percent (2 or 3-log) inactivation of Cryptosporidium,
depending on the results of their monitoring.
Cryptosporidium monitoring by large systems (serving at least 10,000 people) will begin six months after
the LT2ESWTR is finalized and will last for a duration of two years. Systems must conduct a second
round of monitoring beginning six years after the initial bin classification. Systems may grandfather
equivalent previously collected data in lieu of conducting new monitoring, and systems are not required to
monitor if they provide the maximum level of treatment required under the rule.
1. Monitoring Key Issue Lab Capacity: The Agreement in Principle states that the compliance schedules
for the LT2ESWTR will be tied to the availability of sufficient analytical capacity for Cryptosporidium at
approved laboratories and the availability of data management software. If either is unavailable the
monitoring, implementation, and compliance schedules for both the LT2ESWTR and the Stage-2 DBPR
will be delayed an equivalent period of time.
B. UV Disinfection Criteria
Comment Response for LT2ESWTR E-248 December 2005
-------
Background: To receive UV disinfection credit, a system must demonstrate a UV dose as given in IT
Tables in the proposal using the results of a UV reactor validation test and ongoing monitoring. The
reactor validation test establishes the operating conditions under which a reactor can deliver a required
UV dose. Validation test requirements are given in the UV Guidance Manual. Monitoring is used to
demonstrate that the system maintains these validated operating conditions during routine use.
C. Microbial Toolbox
Background: The LT2ESWTR proposal contains a list of treatment processes and management practices
for water systems to use in meeting additional Cryptosporidium treatment requirements under the
LT2ESWTR. This list, termed the microbial toolbox, was recommended by the Stage 2 M-DBP Advisory
Committee in the Agreement in Principle.
Components of the microbial toolbox include watershed control programs, alternative sources,
pretreatment processes, additional filtration barriers, inactivation technologies, and enhanced plant
performance. The intent of the microbial toolbox is to provide water systems with broad flexibility in
selecting cost effective LT2ESWTR compliance strategies. Moreover, the toolbox allows systems that
currently provide additional pathogen barriers or that can demonstrate enhanced performance to receive
additional Cryptosporidium treatment credit.
A key feature of the microbial toolbox is that many of the componenets carry presumptive credits toward
Cryptosporidium treatment requirements. Plants will receive these credits for toolbox components by
demonstrating compliance with required design and implementation criteria, as described in the sections
that follow. Treatment credit greater than the presumptive credit may be awarded for a toolbox
component based on a site-specific or technology-specific demonstration of performance.
Thank you for the opportunity to comment.
Sincerely,
Linda Kinman
Iowa Association of Water Agencies
2201 George Flagg Parkway
Des Moines, Iowa 50321
Phone 515-283-8706
Fax 515-283-2610
E-mail kinman@dmww.com
Response: response 1200.g
EPA Letter ID: 631
Comment ID: 13226
Commenter: Charles -Ted- Asbury, Director, City of Albuquerque, New Mexico
Commenter Category: Local Government
Comment: CS Title: Comment focusing on "problem areas in monitoring requirements and the
microbial toolbox" submitted by Charles "Ted" Asbury, P.E., Director, Public
Works Department, City Albuquerque, New Mexico
Comment Response for LT2ESWTR E-249 December 2005
-------
Company/Group/Association Name: City Albuquerque, New Mexico
Comment:
City of Albuquerque
New Mexico
1706
P.O.Box 1293 Albuquerque, New Mexico 87103
January 9,2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Via electronic mail at: OW-Docket@epa.gov
Subject: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68
Federal Register 47639, DocketNo.OW-2002-0039
Dear Sir or Madam:
The City of Albuquerque appreciates the opportunity to review the Proposed LongTerm2 Enhanced
Surface Water Treatment Rule (LT2ESWTR)which was released on August 11, 21303 (68 Federal
Register 47639). We believe that the attached
The City of Albuquerque is planning for construction of a 92 million gallon per day surface water plant.
Review of the proposed regulation gave rise to questions relating to specific circumstances in the
planning, design, and operation of the plant. Specific comments are included as appropriate in each
section. These areas include:
1. Source Water Monitoring Location
2. Sampling Schedule and Failure to Complete Monitoring
3. Grandfathering Data
4. Laboratory capacity
5. Microbial Toolbox.
Comments on each of these areas are provided in the attached document.
If you have any questions regarding this letter or the attached comments please contact Barbara Gastian of
the Water Utility Division by mail at:
PWD/WUD
P.O. Box 1293
Albuquerque, NM 87103
Comment Response for LT2ESWTR E-250 December 2005
-------
Or by electronic mail at bgastian@cabq.gov
Sincerely,
Charles -Ted- Asbury, P.E.
Director, Public Works Department
COMMENTS ON THE PROPOSED LONG TERM 2 ENHANCED SURFACE WATER
TREATMENT RULE (LTZESWR)
Submitted by the City of Albuquerque, New Mexico
January 9,2004
These comments focus on problem areas in monitoring requirements and the microbial toolbox.
The City of Albuquerque is planning for construction of a 92 million gallon per day surface water
treatment plant. Review of the proposed regulation gave rise to questions relating to specific
circumstances in the planning, design, and operation of the plant. Specific comments that address
LT2ESVVTR monitoring requirements and microbial toolbox options for the plant are included as
appropriate in each section.
Microbial Toolbox: As recommended by the Stage 2 M-DBP Advisory Committee in the Agreement in
Principle, the LT2ESWTR proposal contains a list of treatment processes and management practices for
water systems to use in meeting additional Cryptosporidium treatment requirements under the
LT2ESWTR. The list, or the microbial toolbox, provides a variety of treatment technologies and
respective presumptive credits towards treatment process listed. Treatment plants will receive these
credits for toolbox components by demonstrating compliance with required design and implementation
criteria. Treatment credit greater than the presumptive credit may be awarded for a toolbox component
based on a site specific or technology-specific demonstration of performance.
Response:
EPA Letter ID: 633
Comment ID: 13262
Commenter: Linda Kinman, Research Regulatory Coordinator, Des Moines Water Works
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment regarding "We support the concept of having a toolbox of
viable alternatives to select from" submitted by Linda Kinman, Research
Regulatory Coordinator, Des Moines Waterworks
Company/Group/Association Name: Des Moines Waterworks
Comment:
DMWW
Des Moines Water Works
Comment Response for LT2ESWTR E-251 December 2005
-------
Comment Document
January 14,2004
LONG TERM 2 ENHANCED SURFACE WATER TREATMENT RULE (LT2ESWTR)
Docket ID No. OW-2002-0839
Thank you for the opportunity to comment.
Sincerely,
Linda Kinman
Research/Regulatory Coordinator
Des Moines Water Works
2201 George Flagg Parkway, Des Moines, Iowa 50321
Phone 515-283-8706 Fax 515-283-8706 E-Mail kinman@dmww.com
Response:
EPA Letter ID: 634
Comment ID: 13271
Commenter: Michael A. Neher, Environmental Services Manager, City of Henderson
Commenter Category: Local Government
Comment: CS Title: Comment referring to "City is concerned that these regulations could
be implemented before states are able to attain primacy" submitted by Michael A.
Neher, Environmental Services Manager, City of Henderson (City)
Company/Group/Association Name: City of Henderson (City)
Comment:
THE CITY OF
HENDERSON
A place to call home
January 12, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Subject: Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR), Proposed
Rule, 68 Federal Register 47639, Docket No. OW-2002-0039
Dear Sir or Madam:
Thank you very much for soliciting comments on the referenced proposed
regulation. The City of Henderson (City) is a member of American Waterworks
Comment Response for LT2ESWTR E-252 December 2005
-------
The issue of-significant excursions- is of great concern to the City. Although a significant excursion is
not defined as a maximum contaminant level, its importance from a health and compliance perspective is
just not clear. The purpose may be to provide water suppliers with an -early warning system,- but
significant excursions could readily be interpreted by customers, third party litigants, and regulatory
agencies as a health risk alarm, resulting in a confused and worried public. The associated health risk does
not appear to have been documented; therefore, the regulatory controls associated with significant
excursions seem not to be warranted.
Thank you for this opportunity to comment on the LT2ESWTR. We are hopeful the
Sincerely,
Michael A. Neher
Environmental Services Manager
MANlmw
cc: KurtR. Segler, P.E., Director of Utility Services
Dennis B. Porter, P.E., Assistant Director of Utility Services
Jeff Gebhart, Water Operations Manager
Dave Rexing, Southern Nevada Water System
F: \home\lmw\man\corr\lt2eswtr Itr 011204.doc
DEPARTMENT OF UTILITY SERVICES - ENVIRONMENTAL SERVICES DIVISION
200 ATHENS AVENUE - HENDERSON, NV - 89009-5050 - 702-267-2700
Response: Requirements for the control of DBFs under the Stage 1 or Stage 2 DBPR are outside the
scope of the LT2ESWTR. EPA considered these comments as part of the Stage 2 rulemaking.
EPA Letter ID: 635
Comment ID: 13111
Commenter: Robert A. Hollander, Compliance and Regulatory Affairs Administrator, City of Phoenix,
Water Services Department
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "lab capacity and data management, failure to
complete monitoring, and sampling schedule issues" submitted by Robert A.
Hollander, Compliance and Regulatory Affairs Administrator, City of Phoenix,
Water Services Department,
Company/Group/Association Name: City of Phoenix,, Water Services Department,
Compliance & Regulatory Affairs Office
Comment:
susan.kinkade@phoenix.gov
Comment Response for LT2ESWTR E-253 December 2005
-------
01/09/04 02:08 PM
To: Group Ow-Docket@EPA
cc: robert.hollander@phoenix.gov
Subject: Attention Docket ID No. OW-2002-0039
The attached Adobe Acrobat file contains the City Of Phoenix comments regarding the proposed Long
Term 2 Enhanced Surface Treatment Rule. The text of the file is included below in case there is a
problem opening the file, however we prefer the use of attached file because it contains the full signed
letter on City letterhead. Please contact Susan Kinkade at 602-262-5013 or Robert Hollander at
602-262-4992 if you have any questions.
City of Phoenix
Water Services Department
Compliance & Regulatory Affairs Office
January 9, 2004
Water Docket, EPA Docket Center
U.S. Environmental Protection Agency
Mail Code 410IT,
1200 Pennsylvania Ave., NW
Washington, DC 20460
Attention Docket ID No: OW-2002-0039
Re: Notice of Proposed Rulemaking:
National Primary Drinking Water Regulations;
Long Term 2 Enhanced Surface Water Treatment Rule; Proposed Rule
(68 Federal Register 154, August 11, 2003)
Dear Comments Clerk:
This transmits the City of Phoenix Water Services Department comments regarding
the proposed rule referenced above:
Issue 1: Presumptive Credit for Presedimentation (Federal Register Page 47691)
"Today's proposal requires systems using presedimentation to sample after the presedimentation basin,
and these systems are not eligible to receive additional presumptive Cryptosporidium removal credit for
presedimentation. However, systems are also required to collect samples prior to chemical treatment, and
EPA recognizes that some plants provide chemical treatment to water prior to, or during,
presedimentation. EPA requests comment on how this situation should be handled under the
LT2ESWTR"
We appreciate the opportunity to comment on the purposed Long Term 2 Enhanced Surface Water
Treatment Rule. Please feel free to call me at (602) 262-4992 if you have any questions.
Sincerely,
Robert A. Hollander, P.E.
Comment Response for LT2ESWTR E-254 December 2005
-------
Compliance and Regulatory Affairs Administrator
C: Michael Gritzuk
Wayne Janis
Carlos Padilla
Greg Ramon
Keith Greenberg
Paul Kinshella
Aimee Conroy
Mathew Palenica
Stephen Wetherell
Susan Kinkade
Larry Libeu - WESTCAS
Peter Carlson - WESTCAS
File: LT2ESWTR
LT2ESWTR.pdf
Response:
EPA Letter ID: 637
Comment ID: 13076
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "Section IV Discussion of Proposed LT2ESWTR
Requirements and Section VII Statutory and Executive Order Reviews" submitted by
Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake &
Sandy
Company/Group/Association Name: Metropolitan Water District of Salt Lake & Sandy
Comment:
"Marie E. Owens"
01/09/04 02:29 PM
To: Group Ow-Docket@EPA
cc: John Robert Carman , michaels@amwa.net
Subject: Docket OW-2002-0039 Submittal
Here are the Metropolitan Water District of Salt Lake & Sandy- comments on the proposed Long Term 2
Enhanced Surface Water Treatment Rule. Feel free to contact us with any questions you may have.
Marie E. Owens
Process Engineer
MWDSLS
3430 East Danish Rd.
Sandy, UT 84093
Ph: (801) 942-9652
Fax: (801) 942-3674
Comment Response for LT2ESWTR E-255 December 2005
-------
mowens@mwdsls.org
Metropolitan Water District of Salt Lake & Sandy
Response to EPA Requests for Comment on the Proposed LT2ESWTR
January 8, 2004
Water System Name: Metropolitan Water District of Salt Lake & Sandy
Water System ID: 18016
Utility PWID: UT4900392
Contact Name: Marie E. Owens
Process Engineer
Phone Number: 801-942-9652
Email address: mowens@mwdsls.org
Docket ID No. OW-2002-0039
IV. Discussions of Proposed LT@ESWTR Requirements.
A. Additional Cryptosporidium Treatment Techniques for Filtered Systems
(page 47667)
IV. Discussion of Proposed LT2ESWTR Requirements
A. 3. Request for Comment
(pages 47678-47679)
EPA requests comment on all aspects of the monitoring and treatment requirements
proposed in this section.
(page 47678)
EPA requests comment on each microbial toolbox component. EPA particularly solicits comment on the
performance of alternative filtration technologies that are currently being used, as well as ones that
systems are considering for use in the future.
See below for specific comments of proposed toolbox options:
Watershed Control Program
Response:
EPA Letter ID: 637
Comment ID: 13077
Commenter: Marie E. Owens, Process Engineer, Metropolitan Water District of Salt Lake & Sandy
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-256 December 2005
-------
Comment: EPA requests comment on the reporting and recordkeeping requirements proposed
for LT2ESWTR.
Response:
EPA Letter ID: 641
Comment ID: 13579
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: CS Title: Comment referring to "the Proposed Long Term 2 Enhanced Surface Water
Treatment Rule (EPA 815-Z-03-004, 11 Aug 2003) and Related Documents" submitted
by Paul Warden, Vice President, Analytical Services, Inc. (ASI)
Company/Group/Association Name: Analytical Services, Inc. (ASI)
Comment:
ANALYTICAL SERVICES, INC. (ANI)
Microbiological Testing, Research and Consulting
130 Allen Brook Ln., PO Box 515, Williston, VT 05495 USA
1.800.723.4432 / 802.878.5138 Fax: 802.878.6765
www.analyticalservices.com
Attention: Docket ID No. OW-2002-0039
Subject: Comments from Analytical Services, Inc. (ASI) Regarding the Proposed
Long Term 2 Enhanced Surface Water Treatment Rule (EPA 815-Z-03-004, 11 Aug
2003) and Related Documents
Contact: Brad Eldred
beldred@analyticalservices.com
800.723.4432 Ext 16
or Paul Warden
pwarden@analyticalservice s. com
800.723.4432 Ext 15
LT2 Proposed Rule (40 CFR Parts 141 and 142)
Section IV. Discussion of Proposed LT2ESWTR Requirements
Pg 47666 Sampling Schedule
Checklist for Beginning Grandfathered Crypto Monitoring -
Please see comments under PWS Guidance Manual, Appendix A
Checklist for Submitting Grandfathered Crypto Data -
Please see comments under PWS Guidance Manual, Appendix B
3.3.5 Quality Control Batches - same OPR comment as above.
Comment Response for LT2ESWTR E-257 December 2005
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3. Also, please see related comments above regarding Method 1623, Section 10.6,
analyst Verification.
Response:
EPA Letter ID: 643
Comment ID: 12696
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: CS Title: Comment focusing on "EPA's (EPA) efforts to increase public health
protection by concurrently addressing risks from microbial contaminants and
disinfection byproducts (DBPs)" submitted by James D. Taft, Association of State
Drinking Water Administrators
Company/Group/Association Name: Association of State Drinking Water
Administrators
Comment:
Matt Corson
01/09/2004 02:55 PM
To: Group Ow-Docket@EPA
cc: "'Rich Haberman (E-mail)'", '"Jack Schulze
(E-mail)'", '"Julie Roney (E-mail)'"
, '"Damon Guterman (E-mail)'"
, 'Ralph Baker'
, '"Sam.Perry@doh.wa.gov"'
, '"Mark.Mayer@state.sd.us"'
, '"Consonery, Phil'" ,
'Alicia Diehl', '"Kevin.Espeland@state.sd.us'"
, '"Alton Boozer (E-mail)'"
, '"Barker Hamill (E-mail)'"
, '"Bill Wong (E-mail)'" ,
'"Brad Addison (E-mail)'", '"Breck
Summerford (E-mail)'" , '"Buck Henderson
(E-mail)'", '"Chet Pauls (E-mail)'"
, '"Chris Hughes (E-mail)'"
, '"Darrell Osterhoudt (E-mail)'"
, '"Darron Busch (E-mail)'"
, '"Dave Leland (E-mail)'"
, '"Dave Spath (E-mail)'"
, '"Dave Terry (E-mail)'" ,
'"Dave Waldo (E-mail)'", '"David Draughon
(E-mail)'" , '"David Mitchell (E-mail)'"
, '"Dennis Alt (E-mail)'"
, '"Donna Marlin (E-mail)'"
, '"Doug Mandy (E-mail)'"
, '"Ed Hallock (E-mail)'"
Comment Response for LT2ESWTR E-258 December 2005
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, '"Fred Marrocco (E-mail)'"
, '"Galen Denio (E-mail)'"
, '"Gregg Grunenfelder (E-mail)'"
, '"Harold Seifert (E-mail)'"
, '"Jack Daniel (E-mail)'"
, '"James Weise (E-mail)'"
, '"Jay Rutherford (E-mail)'"
, '"Jeff Gordon (E-mail)'"
,'"Jeff Stuck (E-mail)'",
'"Jerry Iwan (E-mail)'" , '"Jerry Peaks (E-mail)'"
, '"Jerusalem Bekele (E-mail)'"
, '"Jessica Miles (E-mail)'"
, '"Jill Jonas (E-mail)'" ,
'"Jim Cleland (E-mail)'" , '"Jim Perry (E-mail)'"
, '"Joe Kaipat (E-mail)'"
, '"John Castro (E-mail)'"
, '"Jon Craig (E-mail)'"
, '"Jon Dilliard (E-mail)'"
, '"June Swallow (E-mail)'",
'"Karen Irion (E-mail)'" , '"Kevin Brown (E-mail)'"
, '"Kirk Leifheit (E-mail)'"
, '"Lance Nielsen (E-mail)'"
, '"Larry Robinson (E-mail)'"
, '"Larry Thelen (E-mail)'" ,
'"Mike Baker (E-mail)'" , '"Mike Burke
(E-mail)'" , '"Mike Harrell (E-mail)'"
, '"Nancy Beardsley (E-mail)'"
, "'Norton Johnson (E-mail)'"
, '"Olga Rivera (E-mail)'"
, '"Patrick Carroll (E-mail)'"
, '"Rich Hoey (E-mail)'"
, '"Roger Selburg (E-mail)'"
, '"Saeid Kasraei (E-mail)'"
, '"Thomas Arizumi (E-mail)'"
, '"Van Hoofnagle (E-mail)'"
,"'Vic Wilford (E-mail)'"
, '"William Price (E-mail)'"
, Anthony Derosa,
Bridget O'Grady , D Mason ,
James Taft, Matt Corson , Tom
Maves , 'Pat Cook',
'"sean.lieske@state.co.us"' , 'Michael W GRIMM'
, '"lora.gowins@ky.gov"'
, '"elizabeth.esseks@hhss.state.ne.us'"
, '"nreilman@mde.state.md.us"'
, '"Mark.Mayer@state.sd.us"'
, '"denise.springborg@state.ma.us"'
, '"McCabe.Sean@ev.state.az.us'"
, '"John.Capito@vdh.virginia.gov"'
, '"elizabeth.hunt@anr.state.vt.us"'
, '"tjohn@deq.state.id.us"'
Comment Response for LT2ESWTR E-259 December 2005
-------
, '"david.rindal@health.state.mn.us"'
, Cynthia
Dougherty/DC/USEPA/US@EPA, Ephraim King/DC/USEPA/US@EPA,
Jennifer Mclain/DC/USEPA/US@EPA, "Thomas Grubbs (E-mail)"
, Dan Schmelling/DC/USEPA/US@EPA
Subject: Docket Nos. OW-2002-0039 and OW-2002-0043
Attached please find comments from the Association of State Drinking Water Administrators on the
proposed Long Term 2 Enhanced Surface Water Treatment Rule and the Stage 2 Disinfectants and
Disinfection Byproducts Rule. Please direct all questions regarding these comments to Jim Taft,
ASDWA's Executive Director, at (202) 293-7654.
Matt Corson, Program Manager
Association of State Drinking Water Administrators
1025 Connecticut Avenue, Suite 903
Washington, DC 20036
Phone (202) 293-4640 Fax (202) 293-7656
E-mail mcorson@asdwa.org
ASDWA MDBP Comments 01-04.pd
January 9, 2004
Water Docket (MC-4101T)
Docket Nos. OW-2002-0039 and OW-2002-0043
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Docket Clerk:
The Association of State Drinking Water Administrators (ASDWA) appreciates the opportunity to
comment on the proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and the
Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR) as listed in the August 11, 2003
Federal Register (68 FR 47639) and August 18, 2003 Federal Register (68 FR 49547), respectively.
Stage 2 DBPR premise that all customers, including those in consecutive systems, should receive water
that meets DBP standards. States believe that the appropriate approach to meet this goal includes basing
the number of samples required on population served (not the number of treatment plants and/or bulk
purchase entry points) and determining compliance using a locational running annual average.
ASDWA expands on these issues and provides greater detail on the state-preferred approach in
Attachment 1. Responses to those issues on which EPA specifically requested comment in the Federal
Register notices are included in Attachment 2 (LT2ESWTR) and Attachment 3 (Stage 2 DBPR).
ASDWA appreciates the opportunity to provide comment on these proposed rules and looks forward to
working with EPA to ensure that the final rules are both protective of public health and implementable at
Comment Response for LT2ESWTR E-260 December 2005
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the state and local levels. Please direct any questions or concerns regarding these comments to my
attention atjtaft@asdwa.org or (202) 293-7654.
Sincerely,
James D. Taft
Executive Director
Cc: Cynthia Dougherty, EPA OGWDW
Ephraim King, EPA OGWDW
ennifer McLain, OGWDW
Tom Grubbs, EPA OGWDW
Dan Schmelling, EPA OGWDW
Association of State Drinking Water Administrators
Attachment 1
Overarching Comments on the Proposed LT2ESWTR and Stage 2 DBPR
January 9, 2004
Rule Development Process
States also commend EPA for providing pre-publication versions of both rules as well as additional time
for review and comment of the proposed rules. We believe that both actions will ultimately improve the
quality of the final rules.
Overall Approach for the LT2EWSTR
Response:
EPA Letter ID: 643
Comment ID: 12697
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Specific comments on these and other LT2ESWTR issues are provided later in this
Attachment as well as in Attachment 2.
Overall Approach for the Stage 2 DBPR
States support the Stage 2 DBPR premise that all customers, including those in consecutive systems,
should receive water that meets disinfection byproduct (DBP) standards. States believe that the
appropriate approach to meet this goal includes basing the number of samples required on population
served (not the number of treatment plants and/or bulk purchase entry points) and determining
compliance using a locational running annual average.
Specifically, states support the use of locational running annual averages (LRAAs) to determine
compliance with the Stage 2B TTHM and HAAS MCLs of 0.080 mg/L and 0.060 mg/L, respectively,
using a population-based approach for determining the number of samples required. States also believe
Comment Response for LT2ESWTR E-261 December 2005
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that the best way to control DBFs is at the water treatment plant (although states recognize the benefits of
proper distribution system management); that DBF monitoring should be based on a combined
distribution system to the extent that the interconnection of the systems justifies treating them as a single
system for monitoring purposes; and that states need to be involved in determining when consecutive
systems should be considered a combined system for DBF monitoring purposes.
Since changing to LRAAs using a population-based approach will result in a change in the number of
samples required for most systems, states believe that additional monitoring to identify optimal DBF
sampling points is appropriate for some systems. However, states also believe that waivers should be
available for systems in which additional monitoring would not assist in determining optimal sites.
States support the concept of an Initial Distribution System Evaluation (IDSE) to identify appropriate
DBF monitoring locations, but do not support the IDSE as a regulatory requirement. The state-preferred
approach is described later in this Attachment.
States do not support the proposed approach of using the Stage 2A MCLs of 0.120 mg/L for TTHMs and
0.100 mg/L for HAASs as LRAAs at Stage 1 monitoring locations three years following rule
promulgation. The Stage 2A MCLs may cause more confusion than public health protection and are of
limited value since EPA projects that only 2.8 percent of the systems in compliance with the Stage 1
RAAs will exceed the Stage 2 LRAAs. We believe that the Stage 2A MCLs will result in state and
Federal data management tracking problems, an increase in regulatory complexity, expensive database
upgrades, and monumental opportunities for monitoring and reporting violations.
In lieu of the transitional Stage 2A MCLs, states recommend that water systems should be required to
comply with the existing Stage 1 D/DBP RAA MCLs until such time as they are required to comply with
the Stage 2B MCLs. This will allow water systems to focus their efforts and resources on planning for
improvements needed to comply with Stage 2B MCLs.
Specific comments on these and other Stage 2 DBPR issues are provided later in this Attachment as well
as in Attachment 3.
Implementation Schedule
State Position on Rule Implementation
State-Preferred Approach
Based on the foregoing discussion, states recommend the following approach for implementing the
LT2ESWTR:
Stage 2 DBPR Implementation Schedule
States support the concept of water systems taking additional DBP samples to determine optimal loc
ations for Stage 2B monitoring, but would prefer incorporating this additional monitoring into the initial
round of compliance monitoring. States are suggesting an approach that retains the current
implementation structure for most NPDWRs of setting specific requirements and allowing water systems
three years to comply with the new requirements. The approach builds on the -Concurrent Compliance
Monitoring- option that EPA briefly describes on page 49606 of the Stage 2 DBPR preamble and would
be in addition to the proposed requirements for water systems to comply with the Stage 2A MCLs as a
Comment Response for LT2ESWTR E-262 December 2005
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LRAA three years following rule promulgation.
EPA-s Proposed Approach
EPA-s proposed approach involves water systems performing additional DBP monitoring to identify
optimal Stage 2B sampling locations through a process that does not include state review and/or approval
prior to monitoring (e.g., Initial Distribution System Evaluation (IDSE), system-specific studies). Under
the proposed approach, water systems would conduct additional DBP monitoring at an increased number
of locations and submit a report to the primacy agency recommending optimal DBP sampling locations
for Stage 2B monitoring. This monitoring would occur soon after rule promulgation and would be in
addition to Stage I/Stage 2A monitoring, but would not be used for compliance purposes.
States- concerns related to the proposed implementation schedule include:
* The schedule does not allow ample time for states and water systems to determine those situations in
which use of a combined distribution system is appropriate.
* States do not have input into determining DBP monitoring locations because water systems are not
required to submit monitoring plans to the state nor receive state approval of the monitoring plan.
* States will face a large, focused workload in reviewing all large system monitoring results at the same
time (two years after rule promulgation) and all small system monitoring results at the same time (four
years after rule promulgation).
* DBP monitoring will be on a -years since rule promulgation- year instead of a calendar year making
reductions in monitoring difficult to track.
State-Preferred Approach
As mentioned previously, the state approach builds on the -Concurrent Compliance Monitoring- option
that EPA briefly describes on page 49606 of the Stage 2 DBPR preamble. Under this approach, water
systems would be required to collect initial Stage 2B compliance samples at an increased number of
locations based on IDSE guidance instead of performing an IDSE or other system-specific study as a
requirement.
States and water systems would begin working together soon after rule promulgation to determine which
systems will need to identify new monitoring locations for compliance with Stage 2B MCLs (e.g.,
identifying which systems are eligible for a small system waiver or the 40/30 certification and which
systems are not) as well as which consecutive systems should be included in a larger combined
distribution system (and therefore not required to prepare their own DBP monitoring plan). States would
then work with those systems that need to identify new monitoring locations for compliance with Stage
2B MCLs. After initial discussions about appropriate locations, systems would develop a DBP monitoring
plan, using EPA-s IDSE guidance manual to assist in preparing the plan.
With respect to the number of samples that a system should collect, states generally support the following
as minimal monitoring requirements and suggest that states have the discretion to require additional
monitoring based on system-specific situations:
[SEE TABLE, P. 15 (OF 42) IN PDF]
1-2 samples per year if TTHM and HAAS high concentrations are at different locations
2 - Taken during the month(s) of warmest water temperature as determined by the state
3 - At least one quarterly sample must be taken during the month(s) of warmest water temperature as
determined by the state
Comment Response for LT2ESWTR E-263 December 2005
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Systems would be required to submit a DBF monitoring to the state for approval on the date that
Cryptosporidium monitoring is due under the LT2ESWTR for a system of that size (regardless of the
system type). This schedule would ensure simultaneous compliance between the two rules. States would
work with ground water systems and surface water systems that did not have to perform Cryptosporidium
monitoring on a case-by-case basis to determine if an accelerated DBF compliance schedule could be
implemented. This approach should allow states to incorporate DBF monitoring in a calendar year.
Since states will have been working with their water systems in preparing the monitoring plan, states
should be able to approve monitoring plans in a timely manner (most likely between three and six months
depending on the complexity of the system). Water systems would have three years from state approval
before compliance monitoring at the selected sites would be required. All samples collected would be
used for determining compliance with the Stage 2B MCLs using LRAAs. After the first year of
monitoring, water systems would have the opportunity to request a reduction in the number of required
monitoring locations (similar to the proposed requirement to recommend Stage 2B sites in the IDSE).
Some states support including a requirement that systems repeat the initial increased compliance
monitoring every nine years unless the system receives state approval to remain on the reduced
monitoring schedule. This approach would be consistent with the Standard Monitoring Framework. States
support this approach because distribution systems can be influenced by several factors including
population/distribution system growth closing or adding of wells, seasonal tourist demands, recent
flushing events, and a host of other factors.
States believe this approach will provide better public health protection than that provided under the
proposed implementation schedule by ensuring that systems that are required to monitor do so in
appropriate locations and with adequate oversight. Other benefits of this approach include:
* The schedule allows ample time for states and water systems to determine those situations in which use
of a combined distribution system is appropriate.
* Systems would be required to receive state approval of their DBF monitoring plans thus ensuring the
monitoring locations are acceptable to the state.
* Routine DBF monitoring could be based on a calendar year basis instead of a -years since rule
promulgation- basis and incorporated into the Standard Monitoring Framework.
Modifying the Proposed Approaches to Address State Concerns
Tables [SEE p 13 pdf] illustrating how the approaches proposed in the LT2ESWTR and Stage 2 DBPR
could be modified to address a number of state concerns are provided on the next two pages. The top
three lines on each table reflect the schedules included in the proposed rules. The remaining lines
incorporate state concerns described in the preceding sections while staying within the overall
compliance framework of the proposed rules (ensuring that all system are in compliance with both rules
within 8.5 years of promulgation). However, please note that the state-preferred approach, as described
previously, is to delay large system Cryptosporidium monitoring under the LT2ESWTRby 18 months
and modifying, as needed, other monitoring requirements (e.g., small system microbial monitoring, DBF
requirements).
Comments in Case EPA Retains the Proposed Implementation Schedule
If EPA retains the proposed implementation schedule, EPA should consider using the term primacy
agency in the rule language when referring to the entity to which systems must submit sample results,
reports, or requests. Then, at the appropriate time, states and EPA could work together to inform water
systems that the state has primacy for rule implementation and is then the primacy agency.
Comment Response for LT2ESWTR E-264 December 2005
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State Views on LT2EWSTR
Microbial Monitoring for Filtered Systems
State Views on Stage 2 DBPR
DBF Health Effects
One key issue related to public health risk is the conclusions that EPA draws from the reproductive and
developmental health effects data. In the -Risk to Public Health- section (page 49562 of the preamble),
EPA describes its belief-that the weight of evidence of both the reproductive and developmental
toxicological and epidemiological databases suggests that exposure to DBFs may induce potential adverse
health effects on reproduction and fetal development at some DBP exposures. However, additional
toxicological work is necessary to quantify the mode of action for the effects observed.- In this section,
EPA does not quantify the potential risks. States support this type of general discussion of the potential
sub-chronic health risks to present the potential acute health concerns with DBFS.
However, in the -Benefits of the Proposed Stage 2 DBPR- section (page 49629 of the preamble), EPA
discusses how it does not believe that the available evidence provides an adequate basis for quantifying
potential reproductive and developmental risks, but then in the next column quantifies the potential risks.
States do not support the quantification of the risks at this time and suggests that EPA delete the language
that quantifies the potential risk and instead is consistent with the language on page 49562.
States also support EPA-s efforts to obtain additional data on sub-chronic health effects of DBFs and
offer their future assistance in those efforts.
Consecutive Systems and Combined Distribution Systems
States believe that DBP monitoring should be based on a combined distribution system to the extent that
the interconnection of the systems justifies treating them as a single system for monitoring purposes and
that states need to be involved in determining when consecutive systems should be considered a
combined system for DBP monitoring purposes.
In the event a wholesaler proposes to include one or more consecutive systems in its DBP monitoring
plan, states and the water systems will need to work together to determine appropriate monitoring
locations for initial Stage 2B monitoring as well as any reduction in monitoring. While states generally
support requiring at least one sample in each consecutive system for initial Stage 2B monitoring, states do
not necessarily agree that at least one sample needs to be taken in each consecutive system under reduced
monitoring. The systems involved would need to work with the state to determine the appropriate
monitoring locations as well as how public notification would be handled in systems where a sample was
not taken.
Population-Based DBP Monitoring
States support population-based monitoring for all water systems in an effort to provide equal protection
to all. States do not anticipate significant transitional costs associated with moving from a plant-based to a
population-based approach.
DBP MCLs
Comment Response for LT2ESWTR E-265 December 2005
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As indicated previously, states support the Stage 2B MCLs, but do not support the Stage 2A MCLs.
Significant Excursions
Most states support control of peak DBFs if there is a sub-chronic health affect associated with the
exposure and believe that EPA should define a significant excursion as any result that exceeds the sub-
chronic level for each DBF. If EPA is unable to set such scientifically supportable limits, the significant
excursion requirements should be deferred until such time as limits can be set.
However, if EPA retains a significant excursion provision in this rule without being able to set specific
sub-chronic limits, most states believe that EPA should clearly define what constitutes a significant
excursion and not defer to states to define a significant excursion as a special primacy requirement.
These states would generally be supportive of a simple site-specific algorithm such as one in which the
result from the current quarter is doubled and then averaged with the previous two quarterly results. If this
four-quarter average is greater than the appropriate MCL, the water system would have incurred a
significant excursion.
States generally supported the proposed requirement that the system investigate the circumstances that led
to the excursion for discussion with the state no later than the next sanitary survey. However, a few states
indicated that they may take advantage of the proposed rule provision that allows for review of
significant excursions sooner than the next sanitary survey.
States concur with EPA-s proposal that incurring a significant excursion should not require public
notification nor additional language in the Consumer Confidence Report.
IDSE
As indicated previously, states support the concept of an Initial Distribution System Evaluation (IDSE) to
identify appropriate DBP monitoring locations, but do not support the IDSE as a regulatory requirement.
Variances and Exemptions
States concur that variances should not be allowed under the Stage 2 DBPR for the reasons listed and also
believe that exemptions should not be allowed. States have rarely, if ever, used the variance provisions of
the SDWA because of the potential public perception that a different standard than the one Federally
promulgated is acceptable and defensible. States generally do not use exemptions and prefer to use other
mechanisms, such as Consent Orders, in instances where water systems cannot achieve compliance in the
required timeframe.
Best Available Technologies
States recognize EPA-s need to identify best available technologies (BATs) for a proposed rule, but do
not agree that there is a practical or affordable BAT that consecutive systems can use to address high DBP
levels exists. This is especially true if the water delivered to the consecutive system is at or near DBP
MCLs.
The proposed BAT for consecutive systems is improved distribution system and storage tank
management to reduce detention time plus the use of chloramines for disinfectant residual maintenance.
Management of hydraulic flow and minimizing residence time is a practice that all systems (producing
and purchasing) should practice and states support this as a worthwhile activity for all types of water
Comment Response for LT2ESWTR E-266 December 2005
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systems. However, chloramination is an extremely complex treatment and most consecutive systems buy
water because, among other reasons, they do not want to operate chemical feed systems. Treating
purchased water with chloramines would raise many issues for consecutive systems as this treatment
involves using either a liquid or gaseous form of ammonia, a dangerous chemical that requires careful,
daily observation and adjustments. Also, consecutive systems would need to address issues that arise if
the system that they purchase water from practices chlorination and not chloramination. In addition,
chloramines contribute to nitrification problems in low flow areas and tanks that need to be monitored on
a frequent basis (monthly if no problems, daily to weekly if problems). EPA needs to clearly consider all
impacts of naming chloramination as a BAT for consecutive systems. Additionally, the consecutive
system BAT contradicts the premise of the Stage 1 Rule that DBFs are best controlled through TOC
removal and optimizing disinfection practices.
Public Right-to-Know
States support the public-s right to know about the quality of its water and the risks posed by violations of
drinking water standards. States concur that the Public Notification Rule and the Consumer Confidence
Report Rule are the appropriate vehicles to provide this information and that the proposed Tier 2 and Tier
3 violations are consistent with the Tiers established in the Public Notification Rule.
With respect to the need for changes to the health effects language for DBFs to address potential
reproductive and developmental health endpoints, states support EPA-s proposal that additional health
effects language is not needed at this time. Any new language could cause undue alarm among the public
as the reproductive and developmental endpoints are not well defined at this time. However, the current
Public Notification Rule does provide water systems the latitude to include additional language in their
public notices and EPA might consider including suggested language in the rule preamble for those
systems that desire to include health effects language on potential sub-chronic endpoints.
Data Management Issues
In addition to the general concepts on this issue discussed in the LT2ESWTR section of these comments,
which apply equally to the Stage 2 DBPR, states are concerned with the potential data management
implications of EPA promulgating the DBP monitoring scheme included in the proposed rule.
Specifically, programming data management systems to determine compliance for DBFs under a scenario
in which some water systems perform DBP monitoring on a plant-based approach while other water
systems perform DBP monitoring on a population-based approach would be quite costly. Changing to a
population-based approach for all water systems would negate this problem and allow for consistency
across systems.
States commend EPA for determining that no additional data is needed at the Federal level and therefore
not including any additional reporting requirements for states.
Special Primacy Requirements
States suggest revising the proposed special primacy requirements based on the comments above.
Estimated Cost
ASDWA-s comments on this issue in the LT2ESWTR section of these comments apply equally to the
Stage 2 DBPR.
Attachment 2
Comment Response for LT2ESWTR E-267 December 2005
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Association of State Drinking Water Administrators
Response to EPA Requests for Comment on the Proposed LT2ESWTR
January 9, 2004
Response: Requirements for the control of DBFs under the Stage 1 or Stage 2 DBPR are outside the
scope of the LT2ESWTR. EPA considered these comments as part of the Stage 2 rulemaking.
EPA Letter ID: 643
Comment ID: 12698
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section IV.F Compliance Schedules (pages 47719-47722)
The state-preferred implementation schedule is described in Attachment 1.
Section IV.G Public Notice Requirements (pages 47722-47723)
Attachment 3
Association of State Drinking Water Administrators
Response to EPA Requests for Comment on the Proposed Stage 2 DBPR
January 9, 2004
III.G Overall Public Health Risk (pages 49557-49565)
States support EPA-s discussion in the preamble of the potential sub-chronic health endpoints and the
state of current research, but do not support attempts to quantify the potential risk or draw definitive
conclusions from the existing data due to the lack of completeness. Based on this, and in response to a
request for comment from EPA, states believe that the sub-chronic endpoints should not impact the final
Stage 2 DBPR. States support EPA-s efforts to obtain additional data on sub-chronic health effects of
DBFs and offer their assistance in those efforts.
IV.C DBP Occurrence within Distribution Systems (pages 49565-49576)
States generally agree with the conclusions that EPA derived from its analysis and one state indicated that
data from systems within the state support EPA-s findings.
V.A.3 MCLG for Chloroform (pages 49576-49579)
States do not have data to suggest a different MCLG for chloroform (proposed as 0.07 mg/L) or comment
on the factors incorporated in the derivation of the MCLG.
V.B.3 MCLGs for TCAA and MCAA and Health Effects Data on DBAA and MBAA (pages
49579.49582)
States do not have data to suggest different MCLGs for TCAA (proposed as 0.02 mg/L) and MCAA
(proposed as 0.03 mg/L) or comment on the factors incorporated in the derivation of the MCLGs.
States do not have additional health effect information on DBAA or MBAA, for which MCLGs have not
Comment Response for LT2ESWTR E-268 December 2005
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yet been established.
V.C.3 Consecutive Systems (pages 49582-49584)
States believe that DBF monitoring should be based on a combined distribution system to the extent that
the interconnection of the systems justifies treating them as a single system for monitoring purposes and
that states need to be involved in determining when consecutive systems should be considered a
combined system for DBF monitoring purposes.
States believe that the best way to control DBFs is at the water treatment plant (although states recognize
the benefits of proper distribution system management); that DBF monitoring should be based on a
combined distribution system to the extent that the interconnection of the systems justifies treating
them as a single system for monitoring purposes; and that states need to be involved in determining when
consecutive systems should be considered a combined system for DBF monitoring purposes.
States have the following comments regarding EPA-s proposed definitions:
* Consecutive system: States do not necessarily object to the proposed definition, but some states
questioned whether 60 days per year was the appropriate length of time to use; whether the 60 days
needed to be consecutive; and whether a longer length of time (possibly six months) would be more
appropriate.
* Finished water: States identified the application of corrosion control chemicals as post-treatment and
believe that should not affect the determination of whether the water is finished water.
* Wholesale system: The above comments on the definition of consecutive system apply equally to this
definition.
* Consecutive system entry point: The above comments on the definition of consecutive system apply
equally to this definition.
* Combined distribution system: This definition appears to be appropriate provided states have input in
the final determination as to which systems should be considered a combined distribution system.
With respect to the monitoring requirements, states support EPA-s proposal to provide states with the
opportunity to specify alternative requirements for multiple consecutive systems in a combined
distribution system. However, as indicated in Attachment 1, while states generally support requiring at
least one sample in each consecutive system for initial Stage 2B monitoring, states do not necessarily
agree that at least one sample needs to be taken in each consecutive system under reduced monitoring.
The systems involved would need to work with the state to determine the appropriate monitoring
locations as well as how public notification would be handled in systems where a sample was not taken
under the states- suggested monitoring approach.
States do not object to the proposed requirement that all consecutive systems comply with the monitoring
requirements for disinfectant residual monitoring and the MRDLs for chlorine and chloramines.
V.D.3 MCLs for TTHM and HAA5 (pages 49584-49587)
States support the proposed approach over the alternative approaches considered by the FACA for the
reasons discussed in the preamble. Specifically, states support using location running annual averages
(LRAAs) to determine compliance with DBP MCLs, maintain TTHM and HAA5 MCLs of 0.080 mg/L
and 0.060 mg/L, respectively, and maintaining the Stage 1 MCL for bromate of 0.010 mg/L. However, as
discussed in Attachment 1, states do not support the inclusion of Stage 2A MCLs.
V.E.3 Requirements for Peak TTHM and HAA5 Levels (page 49587-49588)
Comment Response for LT2ESWTR E-269 December 2005
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State comment on requirements for peak DBF levels in included in Attachment 1.
V.F.3 BAT for TTHM and HAAS (page 49588-49590)
States do not object to the three proposed BATs for wholesale systems to address TTHM and HAA5.
State comments on consecutive system BATs are included in Attachment 1.
V.G.3 MCL, BAT, and Monitoring for Bromate (pages 49590-49592)
States support EPA-s decisions regarding regulation of bromate as proposed. States agree that the review
of the bromate MCL in the future after considerable information is available from the full implementation
of the LT2ESWTR and the use of UV and a disinfectant tool will allow for a wider selection of options
available to systems that would be affected by the lowering of the bromate MCL. States also support
changing the criterion for reduced bromate monitoring from a source water annual average bromide level
of less than 0.05 mg/1 to a treated water running average bromate level of less than 0.0025 mg/1 as well as
EPA-s decision that bromate monitoring should not be required at non-ozone systems that use
hypochlorite.
V.H.3 IDSE (pages 49592-49595)
Since changing to LRAAs using a population-based approach will result in a change in the number of
samples required for most systems, states believe that additional monitoring to identify optimal DBP
sampling points is appropriate for some systems, but that waivers should be available for systems in
which additional monitoring would not assist in determining optimal sites. States support the concept of
an Initial Distribution System Evaluation (IDSE) to identify appropriate DBP monitoring locations, but
do not support the IDSE as a regulatory requirement. The state-preferred approach is described in
Attachment 1.
States believe that all tc "a. Applicability " \1 4 non-transient non-community water systems should be
required to perform additional monitoring to determine optimal Stage 2 DBP monitoring locations, but
should also be eligible for waivers.
States support small system waivers and believe that states should have flexibility in defining
applicability. States generally support a population cutoff of 500 people, but also recognize that some low
population systems have lengthy distribution systems so suggest that states have discretion to apply
this waiver. States also support waivers for systems larger than 500 people if the distribution system is
short.
State should have discretion to apply the 40/30 certification on a case-by-case basis. Some states have
expressed concern about not requiring monitoring to determine optimal DBP locations based on results
from Stage 1 sites.
V.I.3 Monitoring Requirements and Compliance Determinations for Stage 2A and 2B TTHM and HAA5
MCLs (pages 49495-49605)
States support basing DBP monitoring requirements on the population served, not the number of
treatment plants and/or bulk entry points for the reasons listed in the preamble. States believe that the
population-basedapproach would ensure more equal and rational monitoring requirements among
systems serving similar populations than the plant-based approach does, while providing generally
improved representation of DBP occurrence throughout the distribution system. Such an approach would
simplify implementation and reduce transactional costs to states by facilitating determination of the
Comment Response for LT2ESWTR E-270 December 2005
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number of sampling locations. A complete discussion of this issue is provided in Attachment 1.
States should have the authority to increase or decrease the monitoring sites/samples if situations due to
physical system size, number of sources, location of source entry points, type and geometry of
distribution system justify the changes. States are concerned that using a population-based approach
without such discretion could result in situations where the wholesale system is actually required to
collect fewer samples than the consecutive system that they supply (assuming a combined distribution
system approach is not used). For example, one state indicated that it has a subpart H system that serves a
population of approximately 4,000 persons, but that sells water to several consecutive systems that have
populations that exceed 10,000 persons. Under this scenario, the consecutive systems would be required
to collect more TTHM/HAA5 samples than the wholesale system. To address this issue, EPA should
not set a maximum number of samples, but instead the rule should require the minimum number of
samples and allow states to require more samples on a case-by-case basis if conditions warrant.
V.J.3 Compliance Schedules (pages 49605-49607)
The state-preferred approach is described in Attachment 1.
V.K.2 Public Notification Requirements (page 49607)
States support the public-s right to know about the quality of its water and the risks posed by violations of
drinking water standards. States concur that the Public Notification Rule and the Consumer Confidence
Report Rule are the appropriate vehicles to provide this information and that the proposed Tier 2
and Tier 3 violations are consistent with the Tiers established in the Public Notification Rule.
With respect to the need for changes to the health effects language for DBFs to address potential
reproductive and developmental health endpoints, states support EPA-s proposal that additional health
effects language is not needed at this time. Any new language could cause undue alarm among the public
as the reproductive and developmental endpoints are not well defined at this time. However, the current
Public Notification Rule does provide water systems the latitude to include additional language in their
public notices and EPA might consider including suggested language in the rule preamble for those
systems that desire to include health effects language on potential sub-chronic endpoints.
Also, as indicated previously, states concur that incurring a significant excursion should not require public
notification nor additional language in the Consumer Confidence Report.
V.L.2 Variances and Exemptions (page 49607-49610)
As indicated in Attachment 1, states concur that variances should not be allowed under the Stage 2 DBPR
for the reasons listed. States have rarely, if ever, used the variance provisions of the SDWA because of
the potential public perception that a different standard than the one Federally promulgated is
acceptable and defensible. States generally do not use exemptions and prefer to use other mechanisms,
such as Consent Orders, in instances where water systems cannot achieve compliance in the required
timeframe.
States also note that although the section title indicates the section will address both variances and
exemptions, the preamble language only addresses variances.
V.N.3 System Reporting and Recordkeeping (page 49610)
States generally support EPA-s determination to retain the Stage 1 reporting and recordkeeping
Comment Response for LT2ESWTR E-271 December 2005
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requirements. States do not support the IDSE as a separate activity and therefore do not support the
proposed reporting requirement associated with the IDSE.
VI.G State Implementation Issues (pages 49622-49623)
States suggest revising the proposed special primacy requirements based on the comments in this
Attachment and Attachment 1.
VIII.E Executive Order 13132: Federalism (pages 49654-49655)
States support EPA-s policy to promote communications between EPA and state and local governments
and appreciates this opportunity to provide comment.
VII.L Plain Language (page 49658)
States support EPA-s efforts to ensure regulations are written in plain language.
Guidance Documents
States have reviewed the guidances prepared in support of the Stage 2 DBPR and are submitting
comments directly to EPA-s responsible program office. States also recommend that EPA modify
guidances based on changes made to the final rule in response to comments received.
Response: Requirements for the control of DBFs under the Stage 1 or Stage 2 DBPR are outside the
scope of the LT2ESWTR. EPA considered these comments as part of the Stage 2 rulemaking.
EPA Letter ID: 643
Comment ID: 12764
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Section IV.A Additional Cryptosporidium Treatment Technique Requirements for
Filtered Systems (pages 47665-47679)
Response:
EPA Letter ID: 643
Comment ID: 12818
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment:
State concerns related to laboratory capacity are included in Attachment 1.
Response:
Comment Response for LT2ESWTR E-272 December 2005
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EPA Letter ID: 645
Comment ID: 13556
Commenter: Kathy Moriarty, Water Quality Manager, Bangor Water District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment entitled "LT2 Comments" submitted by Kathy Moriarty, Water
Quality Manager, Bangor Water District
Company/Group/Association Name: Bangor Water District
Comment:
Kathy Moriarty
01/09/04 03:25PM
Please respond to moriarty
To: Group Ow-Docket@EPA
cc:
Subject: LT2 Comments
Attached please find comments to the LT2.
Kathy Moriarty
Water Quality Manager
Bangor Water District
(207)947-4516x375
moriarty@bangorwater.org
BANGOR WATER DISTRICT
P.O. BOX 1129 - BANGOR, MAINE 04402-1129
TEL: (207) 947-4516 - FAX: (207) 947-5707
Duane Hanselman, PhD
John Hwalek
Stanley Miller
Jeffrey Pitts, MD
Andrew E. Sturgeon
Robert Sypltkowski
Dan Wellington
Wayne J. Rogalski
General Manager
A. Gregory Reed
Assistant General Manager/
District Engineer
Comments on the LT2ESWTR Proposal
Submitted by: The Bangor Water District
Bangor, ME
Date January 9, 2004
Comment Response for LT2ESWTR E-273 December 2005
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Response:
EPA Letter ID: 646
Comment ID: 13562
Commenter: Gary P. Martinez, Source of Supply Manager, Sangre De Cristo Water Division, City of
Santa Fe
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "request that EPA set reasonable requirements for
the use of grandfather data so long as ICR requirements met" Gary P. Martinez,
Source of Supply Manager, Sangre De Cristo Water Division, City of Santa Fe, New
Mexico
Company/Group/Association Name: Sangre De Cristo Water Division, City of Santa
Fe, New Mexico
Comment:
"ROBERT M.
GALLEGOS"
01/09/2004 03:24PM
To: Group Ow-Docket@EPA
cc: "MARTINEZ, GARY P."
Subject: Santa Fe, New Mexico Comments to LT2ESWTR
Attention: Docket ID No. OW-2002-0039
Attached are the City of Santa Fe, New Mexico-s comments on LT2ESWTR (Docket ID
No. OW-2002-0039).
Santa Fe, NM Comments LT2ESWTR.doc
City of Santa Fe, New Mexico
200 Lincoln Avenue, P.O. Box 909, Santa Fe, N.M. 87404-0909
Larry Delgado, Mayor
Jim Romero, City Manager
Councilors:
Carol Robertson-Lopez, Mayor Pro Tern, Dist. 4
Parti J. Bushee, Dist. 1
David Pfeffer, Dist. 1
Karen Heldmeyer, Dist. 2
Rebecca Wurzburger, Dist. 2
Miguel M. Chavez, Dist. 3
David Coss, Dist 3
Matthew E. Ortiz, Dist. 4
Comment Response for LT2ESWTR E-274 December 2005
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January 9, 2004
Water Docket, EPA Docket Center
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC. 20460
Attention Docket ID No.: OW-2002-0039.
The City Santa Fe (Santa Fe) is pleased to provide comments to the Long Term 2 Enhanced Surface
Water Treatment Rule (LT2ESWTR).
Please contact me at 505.955.4340 or gpmartinez@ci.santa-fe.nm.us, if you have
any questions.
Respectfully Submitted,
Gary P. Martinez
Source of Supply Manager
Sangre De Cristo Water Division
Response:
EPA Letter ID: 647
Comment ID: 12861
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "concerns about the implementation schedules included in
the proposed rules" submitted by Nancy Reilman, Chief, Safe Drinking Water Act Implementation
Division, Water Supply Program, Maryland Department of the Environment
Company/Group/Association Name: Maryland Department of the Environment
Comment:
Nancy Reilman
01/09/04 03:34PM
To: Group Ow-Docket@EPAcc: Barry O'Brien , John Grace
, Janice Outen , Lyn
Poorman, Saeid Kasraei
Subject: Docket No. OW-2002-0039 and OW-2002-0043
Dear Sirs:
Attached are the comments from the Maryland Department of Environment- Water Supply Program on
Comment Response for LT2ESWTR E-275 December 2005
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the proposed rules for the Stage 2 Disinfectants and Disinfection Byproducts Rule, and the Long Term 2
Enhanced Surface Water Treatment Rule. If you have any questions, please call me at (410) 537-3729.
Nancy Reilman, Chief
Safe Drinking Water Act Implementation Division
Water Supply Program
Maryland Department of the Environment
1800 Washington Blvd. Ste. 450
Baltimore, MD 21230
The information contained in this communication may be confidential, is intended only for the use of the
recipient named above, and may be legally privileged. If the reader of this message is not the intended
recipient, you are hereby notified that any dissemination, distribution, or copying of this communication,
or any of its contents, is strictly prohibited. If you have received this communication in error, please re-
send this communication to the sender and delete the original message and any copy of it from your
computer system. Thank you.
Cryptosporidium2.doc
MARYLAND_comments-_01092004.doc
MARYLAND DEPARTMENT OF THE ENVIRONMENT
1800 Washington Boulevard * Baltimore MD 21230
410-537-3000- 1-800-633-6101
Robert L. Ehrlich, Jr.Governor
Michael S. Steele
Lt. Governor
Kendl P. Philbrick
Acting Secretary
January 9, 2004
Water Docket (MC-4101T)
Docket Nos. OW-2002-0039 and OW-2002-0043
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Docket Clerk:
The Maryland Department of the Environment (MDE) appreciates the opportunity to comment on the
proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and the Stage 2
Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR) as listed in the August 11, 2003 Federal
Register (68 FR 47639) and August 18, 2003 Federal Register (68 FR 49547), respectively. MDE is
responsible for the state drinking water program implementation of the Federal Safe Drinking Water Act.
Stage 2 DBPR premise that all customers, including those in consecutive systems, should receive water
that meets DBP standards The appropriate approach to meet this goal includes basing the number of
samples required on population served (not the number of treatment plants and/or bulk purchase entry
Comment Response for LT2ESWTR E-276 December 2005
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points).
MDE expands on these issues and provides greater detail in Attachment 1. Responses to those issues on
which EPA specifically requested comment in the Federal Register notices are included in Attachment 2
(LT2ESWTR) and Attachment 3 (Stage 2 DBPR).
MDE appreciates the opportunity to provide comments on these proposed rules and looks forward to
working with EPA to ensure that the final rules are both protective of public health and implementable at
the state and local levels. Please direct any questions or concerns regarding these comments to my
attention at: nreilman@mde.state.md.us.
Sincerely,
Nancy Reilman, Chief
SDWA Implementation Division
Water Supply Program
Maryland Department of the Environment
cc: Steve Maslowski, EPA Region III
Saeid Kasraei, MDE
Maryland Department of the Environment
Attachment 1
Overarching Comments on the Proposed LT2ESWTR and Stage 2 DBPR
January 9, 2004
Rule Development Process
MDE also commend EPA for providing pre-publication versions of both rules as well as additional time
for review and comment of the proposed rules. We believe that both actions will ultimately improve the
quality of the final rules.
Overall Approach for the LT2EWSTR
Response:
EPA Letter ID: 647
Comment ID: 12862
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: Specific comments on these and other LT2ESWTR issues are provided later in
this Attachment as well as in Attachment 2.
Overall Approach for the Stage 2 DBPR
MDE supports the Stage 2 DBPR premise that all customers, including those in consecutive systems,
should receive water that meets disinfection byproduct (DBP) standards. MDE believes that the
Comment Response for LT2ESWTR E-277 December 2005
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appropriate approach to meet this goal includes basing the number of samples required on the population
served (not the number of treatment plants and/or bulk purchase entry points).
Specifically, MDE supports the use of locational running annual averages (LRAAs) to determine
compliance with the Stage 2B TTHM and HAAS MCLs of 0.080 mg/L and 0.060 mg/L, respectively,
using a population-based approach for determining the number of samples required. The best way to
control DBFs is at the water treatment plant (although states recognize the benefits of proper distribution
system management); that DBF monitoring should be based on a combined distribution system to the
extent that the interconnection of the systems justifies treating these systems as a single system for
monitoring purposes; and that states need to be involved in determining when consecutive systems should
be considered a combined system for DBF monitoring purposes.
Since changing to LRAAs using a population-based approach will result in a change in the number of
samples required for most systems, additional monitoring to identify optimal DBF sampling points is
appropriate for some systems. However, waivers should be available for systems in which additional
monitoring would not assist in determining optimal sites.
MDE does not support the proposed approach of using the Stage 2A MCLs of 0.120 mg/L for TTHMs
and 0.100 mg/L for HAASs as LRAAs at Stage 1 monitoring locations three years following rule
promulgation. The Stage 2A MCLs may cause more confusion than public health protection and are of
limited value since EPA projects that only 2.8 percent of the systems in compliance with the Stage 1
RAAs will exceed the Stage 2 LRAAs. The Stage 2A MCLs will result in state and Federal data
management tracking problems, an increase in regulatory complexity, expensive database upgrades, and
monumental opportunities for monitoring and reporting violations.
In lieu of the transitional Stage 2A MCLs, water systems should be required to comply with the existing
Stage 1 D/DBP RAA MCLs until such time as they are required to comply with the Stage 2B MCLs. This
will allow water systems to focus their efforts and resources on planning for improvements needed
to comply with Stage 2B MCLs.
Specific comments on these and other Stage 2 DBPR issues are provided later in this Attachment as well
as in Attachment 3.
Implementation Schedule
MDE Position on Rule Implementation
MDE-Preferred Approach
Stage 2 DBPR Implementation Schedule
MDE supports the concept of water systems taking additional DBP samples to determine optimal
locations for Stage 2B monitoring, but would prefer incorporating this additional monitoring into the
initial round of compliance monitoring. An approach that retains the current implementation structure for
most NPDWRs of setting specific requirements and allowing water systems three years to comply with
the new requirements is preferred. The approach builds on the -Concurrent Compliance Monitoring-
option that EPA briefly describes on page 49606 of the Stage 2 DBPR preamble and would be in addition
to the proposed requirements for water systems to comply with the Stage 2A MCLs as a LRAA three
years following rule promulgation.
Comment Response for LT2ESWTR E-278 December 2005
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EPA-s Proposed Approach
EPA-s proposed approach involves water systems performing additional DBP monitoring to identify
optimal Stage 2B sampling locations through a process that does not include state review and/or approval
prior to monitoring (e.g., Initial Distribution System Evaluation (IDSE), system-specific studies). Under
the proposed approach, water systems would conduct additional DBP monitoring at an increased number
of locations and submit a report to the primacy agency recommending optimal DBP sampling locations
for Stage 2B monitoring. This monitoring would occur soon after rule promulgation and would be in
addition to Stage I/Stage 2A monitoring, but would not be used for compliance purposes.
Concerns related to the proposed implementation schedule include:
- The schedule does not allow ample time for states and water systems to determine those situations in
which use of a combined distribution system is appropriate.
- States do not have input into determining DBP monitoring locations because water systems are not
required to submit monitoring plans to the state nor receive state approval of the monitoring plan.
- States will face a large, focused workload in reviewing all large system monitoring results at the same
time (two years after rule promulgation) and all small system monitoring results at the same time (four
years after rule promulgation).
- DBP monitoring will be on a -years since rule promulgation- year instead of a calendar year making
reductions in monitoring difficult to track.
MDE-s Preferred Approach
As mentioned previously, the MDE approach builds on the -Concurrent Compliance Monitoring- option
that EPA briefly describes on page 49606 of the Stage 2 DBPR preamble. Under this approach, water
systems would be required to collect initial Stage 2B compliance samples at an increased number of
locations instead of performing an IDSE or other system-specific study.
MDE and water systems would begin working together soon after rule promulgation to determine which
systems will need to identify new monitoring locations for compliance with Stage 2B MCLs (e.g.,
identifying which systems are eligible for a small system waiver or the 40/30 certification and which
systems are not) as well as which consecutive systems should be included in a larger combined
distribution system (and therefore not required to prepare their own DBP monitoring plan). States would
then work with those systems that need to identify new monitoring locations for compliance with Stage
2B MCLs. After initial discussions about appropriate locations, systems would develop a DBP monitoring
plan, using EPA-s IDSE guidance manual to assist in preparing the plan.
With respect to the number of samples that a system should collect, MDE generally supports the
following as minimal monitoring requirements and suggest that states have the discretion to require
additional monitoring based on system-specific situations:
[SEE TABLE, P. 11 (OF 32) IN PDF]
Once a monitoring plan has been developed, the system would submit the plan to the state for approval. In
order to allow states to ultimately require monitoring based on a calendar year, states suggest the rule
require plans to be submitted by no later than XX years after rule promulgation as determined by the
state. The -XX- would be consistent with the due dates under the LT2ESWTR and would apply to all
systems regardless of source type.
Since states will have been working with their water systems in preparing the monitoring plan, states
Comment Response for LT2ESWTR E-279 December 2005
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should be able to approve monitoring plans in a timely manner (most likely between three and six months
depending on the complexity of the system). Water systems would have three years from state approval
before compliance monitoring at the selected sites would be required. All samples collected would be
used for determining compliance with the Stage 2B MCLs using LRAAs. After the first year of
monitoring, water systems would have the opportunity to request a reduction in the number of monitoring
locations at which they are required to monitor (similar to the proposed requirement to recommend Stage
2B sites in the IDSE).
MDE supports including a requirement that systems repeat the initial increased compliance monitoring
every nine years unless the system receives state approval to remain on the reduced monitoring schedule.
This approach would be consistent with the Standard Monitoring Framework. MDE supports this
approach because distribution systems can be influenced by several factors including
population/distribution system growth closing or adding of wells, seasonal tourist demands, recent
flushing events, and a host of other factors. However, states should have flexibility to waive the
requirement if the system has not had major changes.
This approach will provide better public health protection than that provided under the proposed
implementation schedule by ensuring that systems that are required to monitor do so in appropriate
locations and with adequate oversight.
Other benefits of this approach include:
- The schedule allows ample time for states and water systems to determine those situations in which use
of a combined distribution system is appropriate.
- Systems would be required to receive state approval of their DBF monitoring plans thus ensuring the
monitoring locations are acceptable to the state.
- States would be able to stagger the workload for reviewing DBF monitoring plans.- States could require
routine DBF monitoring on a calendar year basis instead of a -years since rule promulgation- year and
incorporate the monitoring requirements into the Standard Monitoring Framework if the state so desires.
MDE Views on LT2EWSTR
Microbial Monitoring for Filtered Systems
Response: Requirements for the control of DBFs under the Stage 1 or Stage 2 DBPR are outside the
scope of the LT2ESWTR. EPA considered these comments as part of the Stage 2 rulemaking.
EPA Letter ID: 647
Comment ID: 12863
Commenter: Nancy Reilman, Chief, Maryland Department of the Environment
Commenter Category: State/Tribe Government
Comment: MDE Views on Stage 2 DBPR
DBP Health Effects
One key issue related to public health risk is the conclusions that EPA draws from the reproductive and
developmental health effects data. In the -Risk to Public Health- section (page 49562 of the preamble),
EPA describes its belief-that the weight of evidence of both the reproductive and developmental
toxicological and epidemiological databases suggests that exposure to DBFs may induce potential adverse
Comment Response for LT2ESWTR E-280 December 2005
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health effects on reproduction and fetal development at some DBF exposures. However, additional
toxicological work is necessary to quantify the mode of action for the effects observed.- In this section,
EPA does not quantify the potential risks. MDE supports this type of general discussion of the potential
sub-chronic health risks to present the potential acute health concerns with DBFS.
However, in the -Benefits of the Proposed Stage 2 DBPR- section (page 49629 of the preamble), EPA
discusses how it does not believe that the available evidence provides an adequate basis for quantifying
potential reproductive and developmental risks, but then in the next column quantifies the potential risks.
EPA should delete the language that quantifies the potential risk and instead is consistent with the
language on page 49562.
Consecutive Systems and Combined Distribution Systems
DBP monitoring should be based on a combined distribution system to the extent that the interconnection
of the systems justifies treating them as a single system for monitoring purposes and that states need to be
involved in determining when consecutive systems should be considered a combined system for DBP
monitoring purposes.
In the event a wholesaler proposes to include one or more consecutive systems in its DBP monitoring
plan, states and the water systems will need to work together to determine appropriate monitoring
locations for initial Stage 2B monitoring as well as any reduction in monitoring. The systems involved
would need to work with the state to determine the appropriate monitoring locations as well as how
public notification would be handled in systems where a sample was not taken.
Population-Based DBP Monitoring
MDE supports population-based monitoring for all water systems in an effort to provide equal protection
to all. MDE does not anticipate significant transitional costs associated with moving from a plant-based to
a population-based approach.
DBP MCLs
As indicated previously, MDE supports the Stage 2B MCLs, but does not support the Stage 2A MCLs.
Significant Excursions
MDE supports control of peak DBFs if there is a sub-chronic health affect associated with the exposure
and believes that EPA should define a significant excursion as any result that exceeds the sub-chronic
level for each DBP. If EPA is unable to set such scientifically supportable limits, the significant
excursion requirements should be deferred until such time as limits can be set.
MDE concurs with EPA-s proposal that incurring a significant excursion should not require public
notification nor additional language in the Consumer Confidence Report.
IDSE
As indicated previously, MDE supports the concept of an Initial Distribution System Evaluation (IDSE)
to identify appropriate DBP monitoring locations, but does not support the IDSE as a regulatory
requirement.
Variances and Exemptions
Comment Response for LT2ESWTR E-281 December 2005
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MDE concurs that variances should not be allowed under the Stage 2 DBPR for the reasons listed and
also believes that exemptions should not be allowed.
Best Available Technologies
MDE recognizes EPA-s need to identify best available technologies (BATs) for a proposed rule, but does
not agree that there is a practical or affordable BAT that consecutive systems can use to address high DBF
levels exists. This is especially true if the water delivered to the consecutive system is at or near DBF
MCLs.
The proposed BAT for consecutive systems is improved distribution system and storage tank
management to reduce detention time plus the use of chloramines for disinfectant residual maintenance.
Management of hydraulic flow and minimizing residence time is a practice that all systems (producing
and purchasing) should practice and MDE supports this as a worthwhile activity for all types of water
systems. However, chloramination is an extremely complex treatment and most consecutive systems buy
water because, among other reasons, they do not want to operate chemical feed systems. Treating
purchased water with chloramines would raise many issues for consecutive systems as this treatment
involves using either a liquid or gaseous form of ammonia, a dangerous chemical that requires careful,
daily observation and adjustments. Also, consecutive systems would need to address issues that arise if
the system that they purchase water from practices chlorination and not chloramination. In addition,
chloramines contribute to nitrification problems in low flow areas and tanks that need to be monitored on
a frequent basis (monthly if no problems, daily to weekly if problems). EPA needs to clearly consider all
impacts of naming chloramination as a BAT for consecutive systems. Additionally, the consecutive
system BAT contradicts the premise of the Stage 1 Rule that DBFs are best controlled through TOC
removal and optimizing disinfection practices.
Public Right-to-Know
MDE supports the public-s right to know about the quality of its water and the risks posed by violations
of drinking water standards. MDE concurs that the Public Notification Rule and the Consumer
Confidence Report Rule are the appropriate vehicles to provide this information and that the proposed
Tier 2 and Tier 3 violations are consistent with the Tiers established in the Public Notification Rule.
With respect to the need for changes to the health effects language for DBFs to address potential
reproductive and developmental health endpoints, MDE supports EPA-s proposal that additional health
effects language is not needed at this time. Any new language could cause undue alarm among the public
as the reproductive and developmental endpoints are not well defined at this time. However, the current
Public Notification Rule does provide water systems the latitude to include additional language in their
public notices and EPA might consider including suggested language in the rule preamble for those
systems that desire to include health effects language on potential sub-chronic endpoints.
Data Management Issues
In addition to the general concepts on this issue discussed in the LT2ESWTR section of these comments,
which apply equally to the Stage 2 DBPR, MDE is concerned with the potential data management
implications of EPA promulgating the DBP monitoring scheme included in the proposed rule.
Specifically, programming data management systems to determine compliance for DBFs under a
scenario in which some water systems perform DBP monitoring on a plant-based approach while other
water systems perform DBP monitoring on a population-based approach would be quite costly. Changing
to a population-based approach for all water systems would negate this problem and allow for consistency
Comment Response for LT2ESWTR E-282 December 2005
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across systems.
MDE commends EPA for determining that no additional data is needed at the Federal level and therefore
not including any additional reporting requirements for states.
Attachment 2
Maryland Department of the Environment
Response to EPA Requests for Comment on the Proposed LT2ESWTR
January 9, 2004
Section IV.A Additional Cryptosporidium Treatment Technique Requirements for Filtered Systems
(pages 47665-47679)
Section IV.F Compliance Schedules (pages 47719-47722)
The preferred implementation schedule is described in Attachment 1.
Attachment 3
Maryland Department of the Environment
Response to EPA Requests for Comment on the Proposed Stage 2 DBPR
January 9, 2004
III.G Overall Public Health Risk (pages 49557-49565)
MDE supports EPA-s discussion in the preamble of the potential sub-chronic health endpoints and the
state of current research, but does not support attempts to quantify the potential risk or draw definitive
conclusions from the existing data due to the lack of completeness. Based on this, and in response
to a request for comment from EPA, the sub-chronic endpoints should not impact the final Stage 2 DBPR.
MDE supports EPA-s efforts to obtain additional data on sub-chronic health effects of DBFs and offers
its assistance in those efforts.
V.A.3 MCLG for Chloroform (pages 49576-49579)
MDE does not have data to suggest a different MCLG for chloroform (proposed as
0.07 mg/L).
V.B.3 MCLGs for TCAA and MCAA and Health Effects Data on DBAA and MBAA (pages
49579.49582)
MDE does not have data to suggest different MCLGs for TCAA (proposed as 0.02 mg/L) and MCAA
(proposed as 0.03 mg/L). MDE does not have additional health effect information on DBAA or MBAA,
for which MCLGs have not yet been established.
V.C.3 Consecutive Systems (pages 49582-49584)
DBP monitoring should be based on a combined distribution system to the extent that the interconnection
of the systems justifies treating these systems as a single system for monitoring purposes and that states
need to be involved in determining when consecutive systems should be considered a combined system
for DBP monitoring purposes.
Comment Response for LT2ESWTR E-283 December 2005
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The best location for control of DBF concentrations is at the water treatment plant; and DBF monitoring
should be based on a combined distribution system to the extent that the interconnection of the systems
justifies treating these systems as a single system for monitoring purposes.
Comments regarding EPA-s proposed definitions:
- Consecutive system: Is 60 days per year an appropriate length of time to use; do the 60 days need to be
consecutive; and is a longer length of time (possibly six months) more appropriate?
- Finished water: The application of corrosion control chemicals is post-treatment and should not affect
the determination of whether the water is finished water.
- Wholesale system: The above comments on the definition of consecutive system apply equally to this
definition.
- Consecutive system entry point: The above comments on the definition of consecutive system apply
equally to this definition.
- Combined distribution system: This definition appears to be appropriate provided states have input in
the final determination as to which systems should be considered a combined distribution system.
With respect to the monitoring requirements, MDE supports EPA-s proposal to provide states with the
opportunity to specify alternative requirements for multiple consecutive systems in a combined
distribution system.
MDE does not object to the proposed requirement that all consecutive systems comply with the
monitoring requirements for disinfectant residual monitoring and the MRDLs for chlorine and
chloramines.
V.D.3 MCLs for TTHM and HAAS (pages 49584-49587)
MDE supports the proposed approach over the alternative approaches considered by the FACA for the
reasons discussed in the preamble. Specifically, MDE supports using locational running annual averages
(LRAAs) to determine compliance with DBP MCLs, maintaining TTHM and HAA5 MCLs of 0.080
mg/L and 0.060 mg/L, respectively, and maintaining the Stage 1 MCL for bromate of 0.010 mg/L.
V.F.3 BAT for TTHM and HAA5 (page 49588-49590)
MDE does not object to the three proposed BATs for wholesale systems to address TTHM and HAA5.
V.G.3 MCL, BAT, and Monitoring for Bromate (pages 49590-49592)
MDE supports EPA-s decisions regarding regulation of bromate as proposed. MDE supports changing
the criterion for reduced bromate monitoring from a source water annual average bromide level of less
than 0.05 mg/1 to a treated water running average bromate level of less than 0.0025 mg/1 as well as EPA-s
decision that bromate monitoring should not be required at non-ozone systems that use hypochlorite.
V.H.3 IDSE (pages 49592-49595)
Since changing to LRAAs using a population-based approach will result in a change in the number of
samples required for most systems. Additional monitoring to identify optimal DBP sampling points is
appropriate for some systems, but waivers should be available for systems for which additional
monitoring would not assist in determining optimal sites.
All non-transient non-community water systems should be required to perform additional monitoring to
Comment Response for LT2ESWTR E-284 December 2005
-------
determine optimal Stage 2 DBF monitoring locations, but should also be eligible for waivers.
MDE supports small system waivers and believes that states should have flexibility in defining
applicability. MDE supports a population cutoff of 500 people, but also recognizes that some low
population systems have lengthy distribution systems and therefore suggests that states have discretion to
apply this waiver. MDE supports waivers for systems larger than 500 people if the distribution system is
short.
V.I.3 Monitoring Requirements and Compliance Determinations for Stage 2A and 2B TTHM and HAA5
MCLs (pages 49495-49605)
MDE supports basing DBF monitoring requirements on the population served, not the number of
treatment plants and/or bulk entry points for the reasons listed in the preamble. The population-based
approach would ensure more equal and rational monitoring requirements among systems serving similar
populations than the plant-based approach does, while providing generally improved representation of
DBF occurrence throughout the distribution system. Such an approach would simplify implementation
and reduce transactional costs to states by facilitating determination of the number of sampling locations.
A complete discussion of this issue is provided in Attachment 1.
States should have the authority to increase or decrease the monitoring sites/samples if situations due to
physical system size, number of sources, location of source entry points, type and geometry of
distribution system justify the changes. MDE is concerned that using a population-based approach
without such discretion could result in situations where the wholesale system is actually required to
collect fewer samples than the consecutive system that they supply (assuming a combined distribution
system approach is not used). To address this issue, EPA should not set a maximum number of samples,
but instead the rule should require the minimum number of samples and allow states to require more
samples on a case-by-case basis if conditions warrant.
V.K.2 Public Notification Requirements (page 49607)
MDE supports the public-s right to know about the quality of its water and the risks posed by violations
of drinking water standards. MDE concurs that the Public Notification Rule and the Consumer
Confidence Report Rule are the appropriate vehicles to provide this information and that the proposed
Tier 2 and Tier 3 violations are consistent with the Tiers established in the Public Notification Rule.
With respect to the need for changes to the health effects language for DBFs to address potential
reproductive and developmental health endpoints, MDE supports EPA-s proposal that additional health
effects language is not needed at this time. Any new language could cause undue alarm among the public
as the reproductive and developmental endpoints are not well defined at this time. However, the current
Public Notification Rule does provide water systems the latitude to include additional language in their
public notices and EPA might consider including suggested language in the rule preamble for those
systems that desire to include health effects language on potential sub-chronic endpoints.
Also, as indicated previously, states concur that incurring a significant excursion should not require public
notification nor additional language in the Consumer Confidence Report.
V.L.2 Variances and Exemptions (page 49607-49610)
MDE concurs that variances should not be allowed under the Stage 2 DBPR for the reasons listed.
V.N.3 System Reporting and Recordkeeping (page 49610)
Comment Response for LT2ESWTR E-285 December 2005
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MDE supports EPA-s determination to retain the Stage 1 reporting and recordkeeping requirements.
MDE does not support the IDSE as a separate activity and therefore does not support the proposed
reporting requirement associated with the IDSE.
Response: Requirements for the control of DBFs under the Stage 1 or Stage 2 DBPR are outside the
scope of the LT2ESWTR. EPA considered these comments as part of the Stage 2 rulemaking.
EPA Letter ID: 651
Comment ID: 12955
Commenter: Rhonda Sherman, Laboratory Director, CH Diagnostic & Consulting Services, Inc.
Commenter Category: Manufacturer/Vendor
Comment: CS Title: Comment entitled "LT2 Comments based on 'Method 1623: Cryptosporidium and
Giardia in Water by Filtration/IMS/FA'" submitted by Greg Sturbaum, President & Secretary, CH
Diagnostic & Consulting ServiceCompany/Group/Association Name: CH Diagnostic & Consulting
Service
Comment:
Greg Sturbaum
01/09/04 04:11PM
To: Group Ow-Docket@EPA
cc: '"gsturbaum@chdiagnostic.com"'
Subject: Attention Docket ID. OW-2002-0039
Please find attached Comments addressing Docket ID. OW-2002-0039.
Thank you,
Greg Sturbaum
President & Secretary
CH Diagnostic & Consulting Service
214 S.E. 19th Street
Loveland CO 80537
LT2 Comments based on "Method 1623: Cryptosporidium and Giardia in Water by
Filtration/IMS/FA" - June 2003
We sincerely appreciate the opportunity to provide comment on the proposed LT2 regulations and thank
you in advance for considering our comments.
Sincerely,
Brec Clay, President/Treasurer
Greg D. Sturbaum, President/Secretary
Tricia Klonicki, Water Quality Specialist
Comment Response for LT2ESWTR E-286 December 2005
-------
Rhonda Sherman, Laboratory Director
CH Diagnostic & Consulting Services, Inc.
214 SE 19th Street
Loveland, CO 80537
Phone: 970-667-9789
Fax: 970-667-9719
Response:
EPA Letter ID: 652
Comment ID: 12953
Commenter: Brad Eldred, President, Analytical Services, Inc.
Commenter Category: Manufacturer/Vendor
Comment: CS Title: Comment regarding "the Proposed Long Term 2 Enhanced Surface Water
Treatment Rule (EPA 815-Z-03-004, 11 Aug 2003) and Related Documents" submitted by Paul Warden,
Vice President, Analytical Services, Inc. (ASI) Company/Group/Association Name: Analytical Services,
Inc. (ASI)
Comment:
Brad Eldred
Please respond to beldred
To: Group Ow-Docket@EPA
cc:
Subject: Docket ID No. OW-2002-0039
To Whom It May Concern,
Attached please one additional comment that was not originally included in our previously emailed
comments (of this date) regarding the Proposed Long Term 2 Enhanced Surface Water Treatment Rule
(EPA 815-Z-03-004, Proposed Monday, 11 Aug 2003) and its related documents.
Please include the single attached comment with Analytical Services, Inc.'s previous submission; please
note that the attached comment should not replace our previous submission - it should only be
incorporated to that document as an additional comment.
If you have any questions regarding this comment, or difficulty opening the attachment, please contact us
at anytime.
Sincerely,
Paul Warden
Vice President, ASI
pwarden@analyticalservice s. com
800.723.4432 Ext 15
Comment Response for LT2ESWTR E-287 December 2005
-------
Brad Eldred
President, ASI
beldred@analyticalservices.com
800.723.4432 Ext 16
Attention: Docket ID No. OW-2002-0039
Subject: Additional Comment from Analytical Services, Inc. (ASI) Regarding the Proposed Long Term 2
Enhanced Surface Water Treatment Rule (EPA 815-Z-03-
004, 11 Aug 2003) and Related Documents
Contact: Brad Eldred or Paul Warden
beldred@analyticalservices.com
pwarden@analyticalservice s. com
800.723.4432 Ext 16
800.723.4432 Ext 15
Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA; June
2003 draft:
Response:
EPA Letter ID: 652
Comment ID: 12953
Commenter: Paul Warden, Vice President, Analytical Services, Inc.
Commenter Category: Independent Laboratories
Comment: CS Title: Comment regarding "the Proposed Long Term 2 Enhanced Surface Water
Treatment Rule (EPA 815-Z-03-004, 11 Aug 2003) and Related Documents" submitted by Paul Warden,
Vice President, Analytical Services, Inc. (ASI) Company/Group/Association Name: Analytical Services,
Inc. (ASI)
Comment:
Brad Eldred
Please respond to beldred
To: Group Ow-Docket@EPA
cc:
Subject: Docket ID No. OW-2002-0039
To Whom It May Concern,
Attached please one additional comment that was not originally included in our previously emailed
comments (of this date) regarding the Proposed Long Term 2 Enhanced Surface Water Treatment Rule
(EPA 815-Z-03-004, Proposed Monday, 11 Aug 2003) and its related documents.
Please include the single attached comment with Analytical Services, Inc.'s previous submission; please
note that the attached comment should not replace our previous submission - it should only be
Comment Response for LT2ESWTR E-288 December 2005
-------
incorporated to that document as an additional comment.
If you have any questions regarding this comment, or difficulty opening the attachment, please contact us
at anytime.
Sincerely,
Paul Warden
Vice President, ASI
pwarden@analyticalservice s. com
800.723.4432 Ext 15
Brad Eldred
President, ASI
beldred@analyticalservices.com
800.723.4432 Ext 16
Attention: Docket ID No. OW-2002-0039
Subject: Additional Comment from Analytical Services, Inc. (ASI) Regarding
the Proposed Long Term 2 Enhanced Surface Water Treatment Rule (EPA 815-Z-03-
004, 11 Aug 2003) and Related Documents
Contact: Brad Eldred or Paul Warden
beldred@analyticalservices.com
pwarden@analyticalservice s. com
800.723.4432 Ext 16
800.723.4432 Ext 15
Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA; June
2003 draft:
Response:
EPA Letter ID: 653
Comment ID: 14060
Commenter: Tim Stefanich, Environmental Engineer, Sioux Falls Water Purification, City of Sioux Falls
Commenter Category: Local Government
Comment: CS Title: Comment focusing on "several issues that we would like to comment on concerning
the proposed rules" submitted by Tim Stefanich, PE, Environmental Engineer, Sioux Falls Water
Purification, City of Sioux Falls, South Dakota
Company/Group/Association Name: City of Sioux Falls, South Dakota
Comment:
"Stefanich, Tim"
01/09/04 03:58PM
To: Group Ow-Docket@EPA
Comment Response for LT2ESWTR E-289 December 2005
-------
cc:
Subject: Attention Docket ID No OW-2002-0039
January 9, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, DC 20460
Attention Docket ID No. OW-2002-0039
The City of Sioux Falls, South Dakota appreciates the opportunity to comment on the Environmental
Protection Agency's (EPA) proposed rules for the Long Term 2 Enhanced Surface Water Treatment Rule
(LT2ESWTR). The City of Sioux
There are several issues that we would like to comment concerning the
proposed rules.
If you have any questions on the attached comments, please contact Tim Stefanich, Environmental
Engineer, Sioux Falls Water Purification Plant at 605-367-7025 or by e-mail at tstefanich@siouxfalls.org.
Sincerely.
Tim Stefanich, PE
Environmental Engineer
Sioux Falls Water Purification
2100 N Minnesota Ave
Sioux Falls, SD 57104
605-367-7025
605-367-8475 (FAX)
Response:
EPA Letter ID: 654
Comment ID: 13117
Commenter: William Brant, Director, Miami-Dade Water and Sewer Department
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "MDWASD requests that the EPA clarify the turbidity
standards that will apply in the LT2" submitted by William Brant, Director, Miami-Dade Water and
Sewer Department (MDWASD) Company/Group/Association Name: Miami-Dade Water and Sewer
Department (MDWASD)
Comment:
Comment Response for LT2ESWTR E-290 December 2005
-------
"Villamil, Sonia (WASD)"
01/09/04 04:02 PM
To: Group Ow-Docket@EPA
cc: "Goldenberg, Bertha M. (WASD)" , "Rodriguez, Jorge
S. (WASD)" , "Pitt, William A. (WASD)"
, "Segars, Allen Tom (WASD)"
, "Diaz, Raymond D. (WASD)"
Subject: Docket ID No. OW-2002-0039
To whom it may concern,
The Miami-Dade Water and Sewer Department respectfully submits the attached comments on the
proposed Long Term 2 Enhanced Surface water treatment rule, published in the Federal Register on
August 1 1, 2003. If you have any problems opening this document, please contact me via email at
villas@miamidade.gov or via telephone at (786) 552-8234.
Thank you very much,
Sonia Villamil
Engineer II
Planning, Permitting and Efficiency Section
Miami-Dade Water and Sewer Department
786-552-8234
Office #554-31
SERVE - CONSERVE
MIAMI-DADE WATER AND SEWER DEPARTMENT
P.O. Box 330316, Miami, Florida 33233-0316 - 3071 S.W. 38 Ave, Miami, Florida
33146-Tel: 305-665-7471
January 9, 2004
Electronic Correspondence
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue
Washington, D.C. 20460
OW-Docket@epa.gov
Attention: Docket ID No. OW-2002-0039
RE: Comments on the proposed National Primary Drinking Water Regulations: Long Term 2 Enhanced
Comment Response for LT2ESWTR E-291 December 2005
-------
Surface Water Treatment Rule, published on August 11, 2003, in the Federal Register Volume 68,
Number 154.
To Whom It May Concern:
The Miami-Bade Water and Sewer Department (MDWASD) appreciates the opportunity to provide
comments on the proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2), published on
August 11, 2003 in the Federal Register Volume 68, Number 154. The MDWASD recognizes the
difficult task that the Environmental Protection Agency (EPA) faces in creating regulation that is effective
in protecting human health, while allowing for economically feasible treatment
We would be pleased to discuss these comments with you in more detail, and will provide any additional
information you may be interested in. Thank you for the opportunity to provide these comments. Should
you have any questions, please call me at (786) 552-8086 or Mr. Jorge S. Rodriguez, P.E., at (786) 552-
8102.
Very Truly Yours,
William Brant, P.E.
Director
Miami-Dade Water and Sewer Department
Cc: John Renfrow, Department of Environmental Resource Management (DERM)
Samir Elmir, Department of Health
Response:
EPA Letter ID: 660
Comment ID: 14067
Commenter: Gerard Yates, Treatment Operations Manager, Central Utah Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment entitled "Response to EPA Requests for Comment on the Proposed
LT2ESWTR" submitted by Central Utah Water Conservancy District
Company/Group/Association Name: Central Utah Water Conservancy District
Comment:
Gerard Yates
01/09/04 04:15PM
To: Group Ow-Docket@EPA
cc:
Subject: Comments on the proposed LT2ESWTR
Attached are our utility comments for LT2ESWTR
Thank you
CENTRAL UTAH WATER CONSERVANCY DISTRICT
Comment Response for LT2ESWTR E-292 December 2005
-------
Response to EPA Requests for Comment on the Proposed LT2ESWTR
January 9, 2004
Water System Name: Central Utah Water Conservancy District
Contact Name: D. Gerard Yates
Treatment Operations Manager
Phone Number: 801-226-7189
Email address: gerard@cuwcd.com
Docket ID No. OW-2002-0039
IV. Discussion of Proposed LT2ESWTR Requirements
A. 3. Request for Comment
(pages 47678-47679)
EPA requests comment on all aspects of the monitoring and treatment requirements
proposed in this section.
(page 47678)
Response:
EPA Letter ID: 662
Comment ID: 14022
Commenter: Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public
Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "the risk based approach in LT2ESWTR" submitted by
Florence Reynolds, Water Quality and Treatment Administrator, Salt Lake City Public Utilities
Company/Group/Association Name: Salt Lake City Public Utilities
Comment:
Salt Lake City Public Utilities
Response to EPA Request for Comments on the Proposed Stage 2 D/DBPR
January 8, 2004
Salt Lake City Public Utilities
Response to EPA Requests for Comment on the Proposed LT2ESWTR
January 8, 2004
Water System Name: Salt Lake City Public Utilities
Water System ID: 18026
Contact Name: Florence Reynolds
Water Quality and Treatment Administrator
Phone Number: 801-483-6864
Email address: Florence.reynolds@slcgov.com
Docket ID No. OW-2002-0039
Comment Response for LT2ESWTR E-293 December 2005
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IV. Discussion of Proposed LT2ESWTR Requirements
Response:
EPA Letter ID: 664
Comment ID: 14049
Commenter: Douglas Young, General Manager, Menasha Utilities
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "Section IV of the Rule" submitted by Douglas
Young, General Manager, Menasha Utilities Company/Group/Association Name: Menasha Utilities
Comment:
Doug Young
01/09/04 04:20 PM
To: Group Ow-Docket@EPA
Cc: larry.landsness@dnr.state.wi.us
Subject: January 8, 2004
Please find attached our comments related to: Docket ID No. OW-2002-0039, LT2
ESWTR Proposed Rule, 68 FR 47640, August 11, 2003
Douglas Young
General Manager, Menasha Utilities
Menasha, WI 54952
920.967.5178
www .menashautilitie s. com
January 8, 2004
Water Docket
USEPA
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
E-Mail: ow-docket@epa.gov (Comments submitted electronically)
RE: Docket ID No. OW-2002-0039
LT2 ESWTR Proposed Rule
68 FR 47640, August 11, 2003
The following comments are offered in response to the Long Term 2 Enhanced Surface Water Treatment
Rule as proposed in the Federal Register (68 FR 47640, August 11, 2003) EPA 40 CFR Parts 141 and 142
Docket ID No. OW-2002-0039.
We offer the following comments relative to the discussion Section IV of the
Rule:
Comment Response for LT2ESWTR E-294 December 2005
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Comments Submitted
Electronically By: Douglas Young, General Manager
Menasha Utilities
321 Milwaukee Street / P.O. Box 340
Menasha, WI 54952
Telephone: (920) 967-5178
E-mail: dyoung@wppisys.org
cc: Larry Landsness, WDNR [E-mail: larry.landsness@dnr.state.wi.us]
Response:
EPA Letter ID: 666
Comment ID: 14018
Commenter: Wellington H. Jones, Engineer-Director, Frederick County Sanitation Authority
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment regarding "monitoring requirements are too rigid" submitted by
Wellington H. Jones, PE, Engineer-Director, Frederick County Sanitation Authority
Company/Group/Association Name: Frederick County Sanitation Authority
Comment:
"Wellington H. (Wendy) Jones"
01/09/04 04:21PM
To: Group Ow-Docket@EPA
cc:
Subject: Comments on LT2ESWTR, August 11, 2003, Federal Register
My comments are as follows:
Wellington H.Jones, PE
Engineer-Director
Frederick County Sanitation Authority
Phone 540.868.1418 Ext 20
Fax 540.868.1429
Response:
EPA Letter ID: 667
Comment ID: 14006
Commenter: Carl Holder,, Traverse City Water Treatment Plant
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-295 December 2005
-------
Comment: CS Title: Comment focusing on "lab availability, capacity and test reliability
along with data management" submitted by Carl Holder, Traverse City WaterTreatment Plant
Company/Group/Association Name: Traverse City WaterTreatment Plant
Comment:
Carl Holder
01/09/04 04:51PM
To: Group Ow-Docket@EPA
cc:
Subject: (no subject)
Attention Docket ID No. OW-2002-0039 Carl Holder, Traverse City Water
Treatment Plant, P.O. box 592, Traverse City, MI 49684
tcwtp@ptway.com
I would like to make some comments concerning the LT2ESWTRthat may affect our system.
Response:
EPA Letter ID: 668
Comment ID: 13883
Commenter: Erik D. Olson, Senior Attorney, National Resources Defense Council
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: CS Title: Comment regarding "NRDC supports the Agreement" submitted by Erik D.
Olson, Senior Attorney, Natural Resources Defense Council (NRDC)
Company/Group/Association Name: Natural Resources Defense Council (NRDC)
Comment:
"Olson, Erik"
01/10/04 12:21 AM
To: Group Ow-Docket@EPA
cc:
Subject: Attention: Docket ID OW-2002-0039
Attached are NRDC's comments on the LT2ESWTR
.— Forwarded by Wendy Glenn-Flood/DC/USEPA/US on 01/27/04 03:44 PM -—
"Olson, Erik"
01/10/04 12:31 AM
To: "Olson, Erik" , Group Ow-Docket@EPA
cc:
SubjectRE: Attention: Docket ID OW-2002-0039
Docket clerk: By the way, I tried to use the e-docket earlier several and it was so slow and cumbersome
Comment Response for LT2ESWTR E-296 December 2005
-------
my system locked up, so I had to use email, making the comments received slightly after midnight. Please
consider them timely filed.
Thank you.
Original Message
From: Olson, Erik
Sent: Sat 1/10/2004 12:21 AM
To: ow-docket@epa.gov
Cc:
Subject: Attention: Docket ID OW-2002-0039
Attached are NRDC's comments on the LT2ESWTR
NRDC
THE EARTH-S BEST DEFENSE
January 9, 2004
Water Docket
Environmental Protection Agency
1200 Pennsylvania Ave. NW
Washington, DC 20460
Attn: Docket ID No. OW-2002-0039. NPDWR-Long Term 2
Enhanced Surface Water Treatment Rule (-LT2ESWTR-)
Dear Sir or Madam:
The Natural Resources Defense Council (NRDC) appreciates this opportunity to comment up the
proposed National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water
Treatment Rule, appearing at 68 Fed. Reg. 47640 et seq.
Below, we comment upon these and a few other key issues in greater detail.
Again, thank you for this opportunity to comment.
Sincerely,
ErikD. Olson
Senior Attorney
NATURAL RESOURCES DEFENSE COUNCIL
1200 New York Avenue, NW Washington, DC 20005 (202) 289-6868
Response:
EPA Letter ID: 673
Comment ID: 13973
Comment Response for LT2ESWTR E-297 December 2005
-------
Commenter: Shazelle Terry,, Jordan Valley Water Conservancy District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "the risk-based approach proposed for Long Term 2
Enhanced Surface Water Treatment Rule (LT2ESWTR)" submitted by Shazelle Terry,
Jordan Valley Water Conservancy District
Company/Group/Association Name: Jordan Valley Water Conservancy District
Comment:
Shazelle Terry
01/09/04 06:50 PM
To: Group Ow-Docket@EPA
cc: Brian Harris , Ron Kidd
Subject: Attention Docket No. OW-2002-0039
Please see the attached for comments submitted by the Jordan Valley Water Conservancy District on the
proposed Long Term 2 Enhanced Surface Water Treatment Rule. Contact information has been provided
as part of the attached documents. Please contact me if you have any questions, or difficulty opening
this document.
.— Forwarded by Wendy Glenn-Flood/DC/USEPA/US on 01/27/04 03:43 PM -—
Shazelle Terry
01/14/04 01:49PM
To: Group Ow-Docket@EPA
cc: Shazelle Terry
Subject: Attention Docket No. OW-2002-0039
Please see the attached for comments submitted by the Jordan Valley Water Conservancy District on the
proposed Long Term 2 Enhanced Surface Water Treatment Rule. Contact information has been provided
as part of the attached documents. Please contact me if you have any questions, or difficulty opening
this document.
JORDAN VALLEY WATER CONSERVANCY DISTRICT
Response to EPA Requests for Comment on the Proposed LT2ESWTR
January 5, 2004
Water System Name: Jordan Valley Water Conservancy District
Water System ID: 18027
Contact Name: Brian L. Harris
Treatment Department Manager
Phone Number: 801-446-2000
Email address: brianh@jvwcd.org
Docket ID: No. OW-2002-0039
IV. Discussion of Proposed LT2ESWTR Requirements
Comment Response for LT2ESWTR E-298 December 2005
-------
Response:
EPA Letter ID: 675
Comment ID: 13961
Commenter: David Rindal,, Minnesota Department of Health
Commenter Category: State/Tribe Government
Comment: CS Title: Comment regarding "the State of Minnesota comments regarding the Long
Term 2 Enhanced Surface Water Treatment Rule" submitted by David Rindal, Minnesota Department of
Health Company/Group/Association Name: Minnesota Department of Health
Comment:
David Rindal
01/09/04 02:37 PM
To: Group Ow-Docket@EPA
cc: mcorson@asdwa.org
Subject: Attention Docket ID No. OW-2002-0039
Please find attached the State of Minnesota comments regarding the Long Term 2 Enhanced Surface
Water Treatment Rule.
—David
David Rindal
Minnesota Department of Health
651215-0788
State of Minnesota - Drinking Water Protection Section
Comments and Suggestions for LT2ESWTR
Response:
EPA Letter ID: 677
Comment ID: 13947
Commenter: Gary A. Reents, Director of Utilities, City of Sacramento
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "several concerns" submitted by Gary A. Reents,
Director of Utilities, City of Sacramento
Company/Group/Association Name: City of Sacramento
Comment:
CITY OF SACRAMENTO
FOUNDED IN 1849
CITY OF SACRAMENTO
Comment Response for LT2ESWTR E-299 December 2005
-------
CALIFORNIA
DEPARTMENT OF UTILITIES
Office of the Director
13 95 3 5th Avenue
Sacramento, CA 95822-2911
phone (916)264-1400
fax (916) 264-1497
January 7, 2004
40005:BS:EC
Long Term 2 Enhanced Surface Water Treatment Rule
Water Docket
U.S. Environmental Protection Agency, Mail Code 4101T
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Attn: Docket ID No. OW-2002-0039
Subject: COMMENTS ON THE PROPOSED LONG TERM 2
ENHANCED SURFACE WATER TREATMENT RULE
Dear Sir or Madam:
The purpose of this letter is to provide comment on the National Primary Drinking Water Regulations;
Long Term 2 Enhanced Surface Water Treatment Rule; Proposed Rule (Proposed LT 2 Rule) published
on August 11, 2003 in the Federal Register. The City of Sacramento (City) believes the Proposed LT 2
Rule should
(AWWA) and the Association of California Water Agencies (ACWA). We would like to thank the
USEPA for this opportunity to provide comment on the Proposed LT 2 Rule. If you have any questions
on the above, please do not hesitate to contact Elissa Callman of my staff at (916) 264-1424.
Sincerely,
Gary A. Reents
Director of Utilities
cc: Dave Spath, California Department of Health Services
Krista Clark, Association of California Water Agencies
Response:
EPA Letter ID: 678
Comment ID: 14652
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR E-300 December 2005
-------
Comment: CS Title: Comment focusing on praising EPA submitted by Krista Clark,
Regulatory Affairs Specialist, Association of California Water Agencies Company/Group/Association
Name: Association of California Water Agencies
Comment:
Krista Clark
01/09/04 04:39 PM
To: Group Ow-Docket@EPA
cc: mendochet@mcn.org, mboozarpour@sfwater.org
Subject: Docket ID No. OW-2002-0039
Attached to this e-mail are comments submitted by the Association of California Water Agencies
(ACWA) on EPA's proposed Long Term 2 Enhanced Surface Water Treatment Rule, Docket ID
No. OW-2002-0039. You should find two files attached:
1) our cover letter
2) our comments
Please let me know if these files are not received or are unreadable.
They are in Microsoft Word format.
Thank you,
Krista Clark
Krista Clark
Regulatory Affairs Specialist
Association of California Water Agencies
910 K Street, Suite 100
Sacramento, CA 95814
ph: 916-441-4545
fx: 916-325-2306
ACWA
Association of California Water Agencies
Leadership Advocacy Information Since 1910
January 9, 2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Ave., NW
Washington, D.C. 20460
Attn: Docket ID No. OW-2002-0039
To Whom It May Concern:
Comments for Docket ID No. OW-2002-0039
Proposed Long Term 2 Enhanced Surface Water Treatment Rule
The Association of California Water Agencies (ACWA) appreciates this opportunity to provide
comments on the U.S. Environmental Protection Agency's (EPA) proposed Long Term 2 Enhanced
Comment Response for LT2ESWTR E-301 December 2005
-------
Surface Water Treatment Rule (LT2). ACWA consists of 447 public water agencies in California.
for feedback. We hope our attached comments, along with those submitted by others, will only serve to
improve this important regulation.
Attached to this cover letter you will find our detailed review of this rule and its accompanying guidance
documents. Our comments are organized as follows:
_ General Comments on the Proposed LT2 Rule
_ Specific Comments on the Proposed LT 2 Rule
_ Comments on Issues Raised in the Preamble's Request for Comments
_ Comments on the UV Disinfection Guidance Manual
_ Comments on the Draft Microbial Laboratory Manual
_ Comments on the Draft Source Water Monitoring Guidance Manual
_ Comments on the Guidance on Generation and Submission of Grandfathered Cryptosporidium Data for
Bin Classification
We thank you again for this opportunity to comment. If you have any questions, please don't hesitate to
contact Krista Clark, ACWA Regulatory Specialist, at kristac@acwanet.com or 916-441-4545 or at the
following address:
Association of California Water Agencies
910 K Street, Suite 100
Sacramento, CA 95 814
Sincerely,
Dan Smith
Director of Regulatory Affairs
Association of California Water Agencies 910 K Street, Suite 100,
Sacramento,
California 95814-3577 917/441-4545 FAX 916/325-4849
Hall of the States 400 N. Capitol St., N.W., Suite 357 South,
Washington, D.C.
20001-1512 202/434-4760 FAX 202/434-4763
www.acwanet.com
ACWA Comments on Proposed Long Term 2 Enhanced Surface Water Treatment
Rule (LT2 Rule) and Associated Guidance Manuals
I. General Comments on Proposed LT2 Rule
Response:
EPA Letter ID: 681
Comment ID: 14767
Commenter: Leah Rose, Staff Associate, American Chemistry Council
Commenter Category: Other: Other hard to categorize commenters
Comment Response for LT2ESWTR E-302 December 2005
-------
Comment: CS Title: Comment referring to "chlorine dioxide residual measurements"
submitted by Leah Rose, Staff Associate, American Chemistry Council (ACC)
Company/Group/Association Name: American Chemistry Council (ACC)
Comment:
Leah_Rose@americanchemistry.com
01/09/04 04:41PM
To: Group Ow-Docket@EPA
cc:
Subject: Docket ID No. OW-2002-0039
To Docket Clerk,
Attached below is the American Chemistry Council's Sodium Chlorite-Chlorine Dioxide Panel's
comments on the proposed Stage 2 Disinfectants and Disinfection Byproducts Rule for filing with docket
ID No. OW-2002-0039.
Thank you. If there are any questions regarding this transmission please contact me at the telephone
number or email address listed below.
(See attached file: Long Term Rule Comments (1-9-04) final.pdf)
Leah Rose
Staff Associate
American Chemistry Council
13 00 Wilson Blvd
Arlington, VA. 22209
Telephone: 703-741-5606
Fax: 703-741-6606
Email: Leah_Rose@americanchemistry.com
COURTNEY M. PRICE
VICE PRESIDENT
CHEMSTAR
American
Chemistry
Council
Good Chemistry
Makes It Possible
January 9, 2004
Water Docket
U.S. Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Comment Response for LT2ESWTR E-303 December 2005
-------
Attn: Docket No. OW-2002-0043
Re: National Primary Drinking Water Regulations: Stage 2 Disinfectants and Disinfection Byproducts
Rule; National Primary and Secondary Drinking Water Regulations: Approval of Analytical Methods for
Chemical Contaminants; Proposed Rule
Dear Sir or Madam:
The American Chemistry Council (ACC) Sodium Chlorite-Chlorine Dioxide Panel (1) (Panel) is pleased
to have the opportunity to submit comments on the proposed Stage 2 Disinfectants and Disinfection
Byproducts Rule (Stage 2 DBP Proposed
If you have any questions or require additional information, please contact the
Panel Manager, John DiLoreto, at John_DiLoreto@AmericanChemistry.com or call him
at (703) 741-5615.
Sincerely yours,
Courtney M. Price
Vice President, CHEMSTAR
Response:
EPA Letter ID: 683
Comment ID: 14755
Commenter: Dolores Sedillo, Executive Assistant, City of Albuquerque, New Mexico, Public Works
Department
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "problem areas in monitoring requirements and the
microbial toolbox" submitted by Dolores Sedillo, Executive Assistant, City of Albuquerque, New
Mexico, Public Works Department
Company/Group/Association Name: City of Albuquerque, New Mexico, Public Works
Department
Comment:
DSedillo@cabq.gov
01/09/04 04:45 PM
To: Group Ow-Docket@EPA
cc: BGastian@cabq.gov, CAsbury@cabq.gov
Subject: Long-Term 2 Enhanced Surface Water Treatment Rule Comments
Originals of these documents, with signature, will be mailed via US Postal Service.
(See attached file: EPA Filing - 01-09-04 BG.doc)(See attached file: EPA
Comments - 01-09-04 BG.doc)
Comment Response for LT2ESWTR E-304 December 2005
-------
Dolores Sedillo
Executive Assistant
Public Works Department
Office: 505.768.3627
Fax: 505.768.3630
P.O. Box 1293 Albuquerque, New Mexico 87103
January 9, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Via electronic mail at: OW-Docket@epa.gov
Subject: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal Register
47639, Docket No. OW-2002-0039
Dear Sir or Madam:
The City of Albuquerque appreciates the opportunity to review the Proposed Long-Term 2 Enhanced
Surface Water Treatment Rule (LT2ESWTR) which was released on August 11, 2003 (68 Federal
Register 47639). We believe that the attached
section. These areas include:
1. Source Water Monitoring Location
2. Sampling Schedule and Failure to Complete Monitoring
3. Grandfathering Data
4. Laboratory capacity
5. Microbial Toolbox.
Comments on each of these areas are provided in the attached document.
If you have any questions regarding this letter or the attached comments please
contact Barbara Gastian of the Water Utility Division by mail at:
PWD/WUD
P.O. Box 1293
Albuquerque, NM 87103
Or by electronic mail at bgastian@cabq.gov.
Sincerely,
Comment Response for LT2ESWTR E-305 December 2005
-------
COMMENTS ON THE PROPOSED LONG TERM 2 ENHANCED SURFACE
WATER TREATMENT RULE (LT2ESWTR)
Submitted by the City of Albuquerque, New Mexico
January 9, 2004
Response:
EPA Letter ID: 686
Comment ID: 14752
Commenter: Rick Jones,, Pall Life Sciences
Commenter Category: Manufacturer/Vendor
Comment: CS Title: Comment entitled "Example for Field-Filtering Samples for
Crytosporidium Analysis Using Pall Life Sciences Envirochek or Envirochek HV
Filters" submitted by Rick Jones
Company/Group/Association Name:
Comment:
Rick Jones
01/09/04 05:05PM
To: Group Ow-Docket@EPA
cc:
Subject: Attention Docket ID No. OW-2002-0039
Response:
EPA Letter ID: 687
Comment ID: 14749
Commenter: David Pearson, General Manager, PCI Membrane Systems Inc.
Commenter Category: Manufacturer/Vendor
Comment: CS Title: Comment focusing on "your consideration of this issue" submitted by
David Pearson, General Manager, PCI Membrane Systems Inc.
Company/Group/Association Name: PCI Membrane Systems Inc.
Comment:
"Pearson, David - PCI Mem"
01/09/04 05:27PM
To: Group Ow-Docket@EPA
cc:
Subject: FW: Attention Docket ID No. OW-2002-0039
Water Docket
Environmental Protection Agency
1200 Pennsylvania Avenue N
Comment Response for LT2ESWTR E-306 December 2005
-------
Washington DC 20460
January 9, 2004
PCI Membrane Systems, Inc.
1615 State Route 131
Milford, OH45150
Tel 513 575 3500
Fax 513 575 7393
www.pcims.com
Ref: Docket ID No. OW-2002-0039
TO WHOM IT MAY CONCERN
Subject LT2ESWTR Draft for Comment
We welcome the invitation for comment on the Draft of the Long Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR) and we would like to submit the following comment. We preface our
comment with some background information.
We look forward to your consideration of this issue.
Sincerely yours
David Pearson
General Manager
PCI Membrane Systems Inc
Response:
EPA Letter ID: 688
Comment ID: 14734
Commenter: Darrell C. Osterhoudt, Drinking Water Branch Chief, State of Missouri
Commenter Category: State/Tribe Government
Comment: CS Title: Comment focusing on "concerns that overly restrictive lab analyst
criteria may have a negative impact on lab capacity and also analytical costs"
submitted by Darrell C. Osterhoudt, Drinking Water Branch Chief, State of
Missouri Company/Group/Association Name: State of Missouri
Comment:
Linda McCarty
01/09/04 05:17PM
To: Group Ow-Docket@EPA
cc: Darrell Osterhoudt
Subject: Attention Docket ID No. OW-2002-0039
Comment Response for LT2ESWTR E-307 December 2005
-------
Comment letter on Docket No. OW-2002-0039, EPA's Long-Term 2 Enhanced Surface Water Treatment
Rule, is attached in Word. If you have any problems accessing the file, please contact me.
Linda McCarty
linda.mccarty@dnr.mo.gov
(573)751-5331
Toll Free (800) 361-4827
DNR is changing all e-mail addresses to a new format. Old e-mail addresses will only work during a
transition period. Please update your records with my new e-mail address, above.
January 9, 2004
Water Docket (MC-4101T)
Docket Nos. OW-2002-0039 and OW-2002-0043
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Docket Clerk:
Comments on LT2SWTR
The State of Missouri appreciates the opportunity to offer the following comments on the proposed Long-
Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR).
If you have any questions regarding these comments, please contact me (573) 751-
5331.
Sincerely,
DEPARTMENT OF NATURAL RESOURCES
Darrell C. Osterhoudt
Drinking Water Branch Chief
Response:
EPA Letter ID: 699
Comment ID: 14772
Commenter: David A. Visintainer, Water Comissioner, City of Saint Louis
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment focusing on "reviewing the above referenced proposed
regulation" submitted by David A. Visintainer, P.E., Water Commissioner, City of
Saint Louis
Company/Group/Association Name: City of Saint Louis
Comment Response for LT2ESWTR E-308 December 2005
-------
Comment:
"David A. Visintainer"
01/09/04 06:57 PM
To: Group Ow-Docket@EPA
cc:
Subject: Attention Docket ID No. OW-2002-0039
Comments on proposed rule.
City of Saint Louis
DEPARTMENT OF PUBLIC UTILITIES
WATER DIVISION
Office of the Water Commissioner
1640 So. Kingshighway Blvd.
Saint Louis, MO 63110
(314)664-7899
Fax:(314)664-6786
FRANCIS G. SLAY
MAYOR
DAVID A. VISINTAINER, P.E.
WATER COMMISSIONER
January 08, 2004
Water Docket
Environmental Protection Agency, Mail Code 410IT
1200 Pennsylvania Avenue, NW
Washington, D.C. 20460
RE: Long-Term 2 Enhanced Surface Treatment Rule, Proposed Rule, 68 Federal
Register 4763 9,
Docket ID No. OW-2002-0039
Dear Sir/Madam:
Thank you for the opportunity to review the above referenced proposed regulation. We are providing
herewith a set of comments for your consideration in finalizing this rule
Your consideration of these comments is appreciated. Should you have any questions related to this
transmittal, please feel free to contact us.
Sincerely,
Comment Response for LT2ESWTR E-309 December 2005
-------
David A. Visintainer, P.E.
Water Commissioner
Response:
EPA Letter ID: 703
Comment ID: 14780
Commenter: Rich Weirich, Plant Superintendent, Frenchtown Water Treatment
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to "concerned with the cost associated with each
sample" submitted by Rich Weirich, Plant Superintedent, Frenchtown Water Treatment
Company/Group/Association Name: Frenchtown Water Treatment
Comment:
"Weirich, Rich J. - MPS"
01/12/04 01:18PM
To: Group Ow-Docket@EPA
cc:
Subject: Water Docket #OW-2002-0039
Water Docket
RE: Long Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal
Register 47639, Docket No. OW-2002-0039
Dear Sir or Madam:
As a member of the Michigan America Water Works Association and the Frenchtown
Water Treatment Plant Superintendent, I wanted to voice a few comments.
Thank you,
Rich Weirich
Frenchtown Water Treatment
Plant Superintedent
(734) 289-1015 office
Response:
EPA Letter ID: 704
Comment ID: 14786
Commenter: Steven G. Gould, Chairman, New York State American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR E-310 December 2005
-------
Comment: CS Title: Comment entitled "NYSAWWA-WUC January 2004 Comments on Stage 2 DBFs
and LT2ESWTR" submitted by Steven G. Gould PE, Chairman, New York State American
Waterworks Association's (Association) Water Utility Council
Company/Group/Association Name: New York State American Waterworks
Association's (Association) Water Utility Council
Comment:
Steve Gould
01/13/04 04:09 PM
To: Group Ow-Docket@EPA
cc: William Simcoe , "Anthony J. Geiss"
, Brian Bush , Charles Gonzalez
, Connie Schreppel, Donald
Abrew , Doug Withey ,
jzdrojewski@pirnie.com, John Milazzo , jmirando@amwater.com,
"Kevin Castro, P.E." , Martin Aman ,
Mary Ann Dooley , mehooker@ocwa.org, Neil Bonesteel
, plwd@optonline.net, Ralph VanDusen
, Richard Rouge , Robert Niederpruem
, "Steven G. Gould, P.E.", Tom
Shanahan tom@shanahangroup.com
Subject: NYSAWWA-WUC January 2004 Comments on Stage 2 DBFs and LT2ESWTR
On behalf of the New York State American Water Works Association-s Water Utility Council, please
accept our comments for the following:
Attn: Docket ID No. OW-2002-0043 and Docket ID No. OW-2002-0039
Respectfully: Steven G. Gould PE, NYSAWWA-WUC Chairman
New York Section AWWA - Regulatory Review Committee
COMMENTS ON THE USEPA LONG TERM 2 ENHANCED SURFACE WATER TREATMENT
RULE
PROPOSED: AUGUST 11, 2003
COMPILED BY THE NEW YORK SECTION AMERICAN WATERWORKS ASSOCIATION
REGULATORY REVIEW COMMITTEE
DECEMBER 22, 2003
Response:
EPA Letter ID: 706
Comment ID: 14806
Commenter: John Spatz, Deputy Commissioner, City of Chicago Department of Water Management
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-311 December 2005
-------
Comment: CS Title: Comment focusing on "general commentary regarding the Long Term 2
Enhanced Surface Water Treatment Rule (LT2ESWTR)" submitted by John Spatz,
Deputy Commissioner, City of Chicago Department of Water Management
Company/Group/Association Name: City of Chicago Department of Water Management
Comment:
John Spatz
01/15/04 05:03 PM
To: Group Ow-Docket@EPA
cc:
Subject: Comments on Prosposed Long Term 2 Enhanced Surface Water Treatment Rule
The City of Chicago, Department of Water Management would like to submit the
following general commentary regarding the Long Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR):
John Spatz
Deputy Commissioner
City of Chicago
Department of Water Management
1000 E. Ohio Street
Chicago, IL 60611
312-744-3702
This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and
may contain legally privileged and/or confidential information. If you are not the intended recipient of
this e-mail (or the person responsible for delivering this document to the intended recipient), you are
hereby notified that any dissemination, distribution, printing or coping of this e-mail, and any attachment
thereto, is strictly prohibited. If you have received this e-mail in error, please respond to the individual
sending the message, and permanently delete the original and any copy of any e-mail and printout thereof.
Response:
EPA Letter ID: 707
Comment ID: 14814
Commenter: Jeffrey W. Pratt, Director, Kentucky Division of Water
Commenter Category: State/Tribe Government
Comment: CS Title: Comment referring to "Kentucky supports EPA's efforts to increase
public health protection by addressing risks from microbial contaminants and disinfection byproducts
(DBPs)" submitted by Jeffrey W. Pratt, Director, Kentucky Division of Water
Company/Group/Association Name: Kentucky Division of Water
Comment:
LaJuana S. Wileher, SECRETARY
Comment Response for LT2ESWTR E-312 December 2005
-------
Ernie Fletcher, GOVERNOR
COMMONWEALTH OF KENTUCKY
ENVIRONMENTAL AND PUBLIC PROTECTION CABINET
DEPARTMENT FOR ENVIRONMENTAL PROTECTION
FRANKFORT OFFICE PARK
14 REILLY RD
FRANKFORT KY 40601
January 9,2004
Water Docket
Environmental Protection Agency
Mail Code 410IT
1200 Pennsylvania Avenue, N. W.
Washington, D. C. 20460
Attention Docket ID Nos. OW-2002-0039 and OW-2002-0043
Dear Sir or Madam,
The Commonwealth of Kentucky, Division of Water appreciates the opportunity to comment on the
proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and the Stage 2
Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR) as listed in the August 11,2003 Federal
Register (68 FR 47639) and August 18,2003 Federal Register (68 FR 49547), respectively.
against Cryptosporidium. Kentucky also agrees with the Stage 2 DBPR premise that all customers,
including those in consecutive systems, should receive water that meets DBP standards. In General,
Kentucky agrees with the comments
Consecutive Systems
Kentucky firmly supports the flexibility of considering "combined" distribution systems of producing and
purchasing systems for Stage 2 monitoring. However, KY does not feel that the focus of DBP control
should be the water plant. Such an emphasis on the water plant diminishes the importance of the
distribution system. It is not realistic to assume that all distribution systems are properly operated. As the
historical EPA regulations have focused solely on the water plant (with the Lead and Copper rule and
Total Coliform Rule as exceptions), distribution systems have been neglected or de-emphasized as a
major player in water quality. Thus distribution infrastructure, operations and maintenance are not up to
par and do adversely impact water quality. Several studies in Kentucky (in conjunction with the EPA
Technical Support Center and the University of Cincinnati) have shown the impacts of poor tank
operation and turnover rates on DBP formation. Kentucky favors a holistic approach to DBP control,
which considers both treatment plant and the distribution system issues.
The monitoring requirements Kentucky uses for implementation of the Stage 1 DDPB rule will make the
implementation schedule proposed by EPA for Stage 2 highly confusing and problematic in Kentucky.
Large wholesale systems, responsible in Kentucky for much of the monitoring in the systems where they
sell water, will be conducting their IDSE for EPA, while still responsible for monitoring in their
purchaser's systems under Kentucky's Stage 1 regulation. At the same time, the purchasing systems in the
Comment Response for LT2ESWTR E-313 December 2005
-------
combined distribution system will be conducting their IDSE for EPA while their wholesaler is conducting
routine monitoring in their system under the Kentucky regulation. It would be far less confusing if the
state could develop a transition monitoring schedule and accept primacy for the Stage 2 Rule before the
water systems are required to begin their IDSE.
EPA's assertion that consecutive systems "may set up a contract with its wholesale system that details
water quality delivery specifications" is, at best, optimistic. While no law or regulation would preclude
such a contract, neither will any law or regulation compel the wholesale system to agree to such
a contract. The fact of the matter is that many consecutive systems will be receiving water of dubious
quality, if not out of compliance, so near to being out of compliance that violations in the consecutive
system are inevitable.
EPA's proposed BAT for consecutive systems of "chloramination with management of hydraulic flow and
storage to minimize residence time in the distribution system" presents a number of problems. First and
foremost is the fact that many if not most consecutive systems purchase their water because they have
little or no ability or desire to be in the treatment business. While Kentucky agrees that management of
the distribution system is important and within the power of purchasing systems, chloramination is a
complex and potentially hazardous treatment process requiring sophisticated operational experience. In
addition, a consecutive system that buys from a wholesale system that uses chlorine would have no way
to compel the wholesaler to switch to chloramines, creating further problems for the consecutive system.
Again, consecutive systems have no desire to be in the treatment business, but at a minimum, EPA should
compel wholesalers to participate in any solution to problems that arise anywhere in the combined
distribution system.
Finally, the proposed definition for "Consecutive system entry point" would leave out the entry point
where one consecutive system buys from another consecutive system that does not treat water, since the
definition off "Wholesale system" includes the treatment of source water.
Significant Excursions:
An algorithm would be a simple means of identifying a significant excursion. However, would such a
mathematical method tend to over predict or under predict non-compliance? The majority of
noncompliance would happen in the 3rd and 4th quarters, during warm water conditions. Any significant
excursion limit should be based on scientifically sound and supportable data. Who will make the
decision that the data used is in fact scientifically based? Any trigger for a significant excursion level
should be set by sound, scientifically supported science, preferably validated by someone other than EPA.
Depending upon the scheduling of sanitary surveys, there could be as much as a three or five year lag (if a
system is deemed to have outstanding performance) between the excursion and the review by the primacy
agency.. Such a delay makes the usefulness of this provision highly questionable.
Monitoring
Kentucky would prefer that all monitoring be population based rather than treatment plant based or a
combination of population and treatment.
Data Management
EPA should be cognizant of the data management at the state level, considering the fact that not all states
are on SDWIS-State. Even those that are will need a quick working upgrade to SDWIS prior to
implementation. Those not on SDWIS will incur high programming costs to update their data system.
Comment Response for LT2ESWTR E-314 December 2005
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Laboratory Availability
Kentucky would like to underline the importance of having adequate numbers of certified laboratories
before testing begins for Cryptosporidium under the Long Term 2 Enhance Surface Water Treatment
Rule.
Attached are comments from the Kentucky microbiological laboratory, Morehead State University
regarding the laboratory issues associated with the Long Term 2 Enhanced Surface Water Treatment
Rule. You can reach Dr. Ted Pass or Rita Wright at Morehead State University at 606/783- 296 1 if you
have any questions.
Again, the Kentucky Division of Water appreciates the opportunity to comment on these two important
regulations. Kentucky shares EPA's desire for a consistently high quality and safe product being delivered
by our public water systems. Thank you.
Sincerely,
Jeffrey W. Pratt, Director
Kentucky Division of Water
JWP:DM:rh
KENTUCKY MICROBIOLOGY LABORATORY
CERTIFICATION PROGRAM
DIVISION OF WATER
FRANKFORT, KENTUCKY
National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water
Treatment Rule: Request for Comments
Response: Requirements for the control of DBFs are outside the scope of the LT2ESWTR. EPA
considered these comments as part of the Stage 2 rulemaking. Response 1200.g
EPA Letter ID: 710
Comment ID: 14812
Commenter: Kemon Papacosta, ASTM Member D19, ASTM
Commenter Category: Unknown
Comment: CS Title: Comment focusing on "the source water monitoring Guidance Manual For
Public Water Systems for the Long Term 2 Enhanced Surface Water Treatment (LT2 Rule)" submitted by
Kemon Papacosta, ASTM Member D19 On Water Company/Group/Association Name:
Comment:
Kemon Papacosta
01/19/04 11:39PM
To: Group Ow-Docket@EPA
cc:
Comment Response for LT2ESWTR E-315 December 2005
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Subject: Docket I.D. No. OW-2002-0039
Attention: Docket I.D. No. OW-2002-0039
Regards,
Kemon Papacosta
ASTM Member D19 On Water
Phone:(650)366-0119
Fax:(650)366-0152
E-mail: kpapacosta@apsstd.com
Response:
EPA Letter ID: 711
Comment ID: 16540
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: CS Title: Comment referring to USEPA should relax the sample collection dates so
that water systems will not be constricted by their sampling plan, submitted by Raymond Yep, Santa
Clara Valley Water District Company/Group/Association Name: Santa Clara Valley Water District
Comment:
Santa Clara Valley
Water District
5750 ALMADEN EXPWY
SAN JOSE, CA 951 18-3614
TELEPHONE (408) 265-2600
FACSIMILE (408) 266-0271
www.valleywaterorg
AN EQUAL OPPORTUNITY EMPLOYER
January 9,2004
Water Docket
Environmental Protection Agency
Mail Code 41 01 T
1200 Pennsylvania Avenue, N.W.
Washington, D.C. 20460
Attention Docket ID No.: OW-2002-0039
VIA E-MAIL
RE: Long-Term 2 Enhanced Surface Water Treatment Rule, Proposed Rule, 68 Federal Reaister 47639,
Docket No. OW-2002-0039
Comment Response for LT2ESWTR E-316 December 2005
-------
Dear Sir or Madam:
Response:
EPA Letter ID: 711
Comment ID: 16545
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: The District has dedicated time and effort to review the proposed rule and respond to EPA-s
request for comments. Please refer to the appendix for a complete list of the District's comments. We look
forward to a final rule that will provide public health protection while allowing water purveyors
reasonable flexibility. We will appreciate your review and consideration of this letter and the attached
detailed comments. If you have any questions regarding this letter or the attached comments, please
contact Angela Cheung at (408) 265-2607 ext.
2735, or Chris Carbone at (408) 265-2607 ext. 2126.
Sincerely,
Raymond Yep
Deputy Operating Officer
Water Utility Operations Division
Santa Clara Valley Water District
Attachment: Appendix - Formal Comments from Santa Clara Valley Water District on
LT2ESWTR Proposed Rule
cc: W. Wadlow, M. Hamer, B. Cabral, J. Scott, C. Carbone, A. Cheung
ac:ac
SCWD
January 9,2004
APPENDIX
Formal Comments
from
Santa Clara Valley Water District
On
Long-Term 2 Enhanced Surface Water Treatment Proposed Rule
68 Federal Register 47639, August 1 I, 2003
Submitted to: Water Docket, OW-2002-0039
January 8,2004
Santa Clara Valley Water District
5750 Almaden Expressway
San Jose, CA 951 18
Comment Response for LT2ESWTR E-317 December 2005
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Attention: Angela Cheung
(408)265-2607 ext. 2735
SCWVD
January 9,2004
Comments on Proposed LT2 Rule
Response:
EPA Letter ID: 711
Comment ID: 16565
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: 6. For each microbial toolbox component, EPA is requesting comment on: whether
available data support the proposed presumptive credits, including the design and implementation
conditions under which the credit would be awarded [47681, C3]
Response:
EPA Letter ID: 711
Comment ID: 16577
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: The mission of the Santa Clara Water District is [illegible] and enhanced
quality of living in Santa Clara County
Through the comprehensive management of water resources [illegible] cost effective and environmentally
sensitive manner.
Response:
EPA Letter ID: 712
Comment ID: 16580
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: CS Title: Comment referring to "supports the USEPA's (USEPAs) proposal to
provide additional protection from microbial contaminants, particularly cryptosporidium, in public
drinking water supplies" submitted by Michael E. Burke, New York State Department of Health
Company/Group/Association Name: New York State Department of Health
Comment:
DOH
STATE OF NEW YORK
Comment Response for LT2ESWTR E-318 December 2005
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DEPARTMENT OF HEALTH
Flanigan Square, 547 River Street, Troy, New York 12180-2216
Antonia C. Novello, M.D., M.P.H., Dr.P.H.
Commissioner
Dennis P. Whalen
Executive Deputy Commissioner
March 2,2004
Water Docket (MC-41017)
Docket No. OW-2002-0039
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, D.C. 20460
Docket Clerk:
The New York State Department of Health (NYSDOH) appreciates the opportunity to comment on the
proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2EWTR) as listed in the August
11,2003 Federal Register (6EFR47639). NYSDOH is the primary agent responsible for the
implementation and enforcement of the Safe Drinking Water Act in New York.
Response:
EPA Letter ID: 712
Comment ID: 16597
Commenter: Michael E. Burke, Director, New York State Department of Health
Commenter Category: State/Tribe Government
Comment: Sincerely,
Michael E. Burke, P.E.
Director
Bureau of Water Supply Protection
cc: Mr. Tramontane
Mr. Svenson
Mr. Wilber
Ms. Dougherty - EPA
Mr. Kiselica - EPA
\\DEPSERVWOLl\BWSP\SECTIONS\DIRECTOR\H2ODock.doc
Response:
Comment Response for LT2ESWTR E-319 December 2005
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Individual Comments on Code 9991
EPA Letter ID: 562
Comment ID: 12364
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 2.The FACA process and the resultant proposal violates the Administrative Procedures Act
(APA) because the agency did not conduct the assessment of laboratory capacity for Cryptosporidium
and E. coli monitoring as required by the Agreement in Principle. 3.EPA is subjecting public water
systems to penalties for failure to comply with requirements during what is an unreasonably short
timeframe due to inadequate laboratory capacity.
Response: Through EPA's laboratory approval program, the Agency has evaluated capacity at
Cryptosporidium laboratories. Based on information provided by laboratories, EPA believes that current
capacity at Cryptosporidium laboratories will be sufficient for the monitoring that PWSs serving at least
100,000 people will begin six months after the rule is effective. EPA expects that commercial laboratories
will increase capacity as needed to serve the demand of smaller PWSs that begin monitoring later.
Approximately six months are required to train Cryptosporidium analysts. Consequently, the staggered
compliance schedule should allow time for laboratories to hire and train staff as necessary. In addition,
with the compliance schedule in today's final rule, no break exists between the time that large PWSs end
and small PWSs begin Cryptosporidium monitoring. Thus, EPA has eliminated this potential disincentive
to laboratories investing in capacity. However, EPA will continue to monitor laboratory capacity and the
ability of PWSs to contract with laboratories to meet their monitoring requirements under the
LT2ESWTR. The Agency will assist with implementation of the rule to help maximize the use of
available laboratory capacity by PWSs. If evidence emerges during implementation of the rule that PWSs
are experiencing problems with insufficient laboratory capacity, the Agency will undertake appropriate
action at that time. EPA does not believe that capacity of laboratories for E. coli analysis is a concern.
Many laboratories are qualified to conduct E. coli analyses and the nature of the approved methods allow
laboratories to increase capacity easily. If a system collects a sample but is unable to have it analyzed due
to problems with the laboratory, today's rule allows the system to collect a replacement sample without
penalty.
Response to Code 9997
These comments provide background information on commenters. They do not address regulatory
requirements in the LT2ESWTR. Responses to the rule comments submitted by these commenters are
provided in the relevant section of this comment-response document.
Individual Comments on Code 9997
EPA Letter ID: 101
Comment ID: 10870
Commenter: Ed Thomas, National Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR E-320 December 2005
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Comment: On behalf of over 23,000 small and rural drinking water utilities, the National Rural Water
Association (NRWA) is pleased to submit comments on the Environmental Protection Agency's Long
Term 2 Enhanced Surface Water Treatment Proposed Rule (68 FR 47640) and Stage 2 Disinfectants and
Disinfection By-products Proposed Rule (68 FR 49548). NRWA represents the voice of small and
rural utilities with a sustaining membership of over 41% of community water systems. No other
organization represents such a large proportion of regulated entities and requests the Agency to seriously
consider the suggestions contained herein.
Response:
EPA Letter ID: 394
Comment ID: 10554
Commenter: Marian Rose, President, Croton Watershed Clean Water Coalition Inc.
Commenter Category: Enviro NGO: Environmental and conservation groups, such as NRDC, etc.
Comment: The Croton Watershed Clean Water Coalition, Inc (CWCWC), a not for-profit coalition of 55
groups dedicated to the protection of New York City 's Croton Watershed is hereby submitting comments
on EPA's request for comments "on the determination that granting an exemption to the Cryptosporidium
treatment requirements of the LT2ESWTR would result in an unreasonable risk to health" [p. 47724].
These treatment requirements refer to systems where concentrations of Cryptosporidium oocysts are
below detectable levels.
Response:
EPA Letter ID: 429
Comment ID: 10588
Commenter: Janet Montz, Environmental Specialist, OCI Wyoming, L.P.
Commenter Category: Regulated Community (Utilities)
Comment: On Behalf of my small NTNCWS drinking water system in Wyoming (PWS ID #5600634P)
we are very concerned about the Stage 2 Disinfection and Disinfection By-product Proposed Rule and
Long Term 2 Surface Water Treatment Proposed Rule.Please accept the attached comments on these two
rules and the significant impact it will have on our system.
Response:
EPA Letter ID: 440
Comment ID: 10799
Commenter: Gary Hum, Director of Source & Treatment, Central Arkansas Water
Commenter Category: Regulated Community (Utilities)
Comment: My name is Gary Hum, Director of Source & Treatment, with Central Arkansas Water
(CAW), a municipal drinking water utility serving approximately 350,000 people in the Little Rock/North
Little Rock area. I appreciate the opportunity given by USEPA to comment on the proposed LT2ESWTR.
Comment Response for LT2ESWTR E-321 December 2005
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My comments are:
Response:
EPA Letter ID: 441
Comment ID: 10765
Commenter: Jeffrey Gordon, Chief, Division of Drinking Water Management, Bureau of Water Supply
& Wastewater Management, PA Department of Environmental Protection
Commenter Category: State/Tribe Government
Comment: The Pennsylvania Department of Environmental Protection (DEP) is providing the following
comments on the proposed Long Term 2 Enhanced Surface Water Treatment Rule (LT2). DEP is the
primacy agency for Pennsylvania's Safe Drinking Water Program.
Response:
EPA Letter ID: 445
Comment ID: 10819
Commenter: James Fay, Chair, PSW Steering Committee, The Partnership for Safe Water
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The Partnership for Safe Water (PSW) is an association of 250 water utilities operating 416
water treatment plants working with six signatory agencies (EPA has removed itself from participation in
these comments) to address risks caused by Cryptosporidium in surface water treatment plants. The
Partnership membership represents all of the major drinking water professional organizations (public
and private) and Partnership utility members serve more than 90 million customers in the United States.
The Partnership has developed a four-tier systemfor utilities to voluntarily reduce risk due to
Cryptosporidium, portions of which are reflected in the development of the toolbox credit for enhanced
filter performance.
Response:
EPA Letter ID: 447
Comment ID: 10795
Commenter: Michael Barsotti, Water Quality Director, Camplain Water District
Commenter Category: Regulated Community (Utilities)
Comment: important to protect the public health. CWD has achieved the Partnership for Safe Water -
Excellence in Water Treatment- award for 5 years. Particle removal/disinfection and DBP control are the
-twin pillars- of CWD-s continuing commitment to water quality.
Response:
EPA Letter ID: 449
Comment ID: 10824
Comment Response for LT2ESWTR E-322 December 2005
-------
Commenter: David J. Lewis, Superintendent, Kenosha Water Utility
Commenter Category: Regulated Community (Utilities)
Comment: This letter is in response to the EPA-s National Primary Drinking Water Regulations; Long
Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). It is being written on behalf of the
Kenosha Water Utility in Kenosha, Wisconsin. The Kenosha Water Utility serves a population of
approximately 93,000 customers and wholesales water to approximately 10,000 additional customers via
3 consecutive systems.
The Kenosha Water Utility treats water from Lake Michigan utilizing two types of treatment processes.
These processes include a 20 MGD conventional rapid sand filtration process and a 22 MGD
microfiltration process (currently the largest in North America).
Response:
EPA Letter ID: 451
Comment ID: 14158
Commenter: Eric Abrams, Superintendent, McMinnville Water and Light
Commenter Category: Regulated Community (Utilities)
Comment: My name is Eric Abrams, I am the Water Superintendent for McMinnville Water and Light, a
municipality that serves approximately 10,000 water customers and 20,000 electric customers. The source
water for this system is two surface water impoundments in the Coast Range Mountains in western
Oregon. We have a treatment plant (which will be expanded and upgraded in the near future) that is
currently capable of producing 13.3 Million gallons of water a day.Please consider these comments
McMinnville Water and Light's response to the proposed Long-Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR).
Response:
EPA Letter ID: 452
Comment ID: 10932
Commenter: Jacqueline Strong, Water Quality Advisor, City of Chandler, Arizona
Commenter Category: Regulated Community (Utilities)
Comment: The City of Chandler is providing the following comments on the proposed Long Term 2
Enhanced Surface Water Treatment Rule. The City of Chandler provides both conventionally treated
surface water and disinfected groundwater to a population of about 218,000 in a 71 square mile service
area. About 6 percent of Chandler-s water supply is purchased from another larger water system.
Response:
EPA Letter ID: 455
Comment ID: 10956
Commenter: Kirk Stacker, Director of Utilities, City of Kearney Utilities Department
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-323 December 2005
-------
Comment: The City of Kearney Nebraska Utilities Department, a Public Water Supply System,
submits the following comments to the proposed Long Term 2 Enhanced Surface Water Treatment Rule.
Response:
EPA Letter ID: 461
Comment ID: 10986
Commenter: Greg Merrigan, Chair, South Dakota Section of the American Waterworks Association
(SDAWWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The South Dakota Section of the American Waterworks Association (SDAWWA)
appreciates the opportunity to comment on the Environmental Protection Agency-s (EPA) proposed rules
for the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). As directors, operators,
engineers, and regulators of large, and small drinking water systems in the State of South Dakota our
members are continually affected by new regulations promulgated by EPA.
Response:
EPA Letter ID: 464
Comment ID: 10999
Commenter: Dr. Susan Boutrous, President, Environmental Associates Ltd.
Commenter Category: Independent Laboratories
Comment: Environmental Associates Ltd. is one of the largest Cryptosporidium analysis laboratories in
the country. We participation in the ICR Rule and had the experience of a significant increase in work
load. The following comments are a result of our experience with both the ICR and our subsequent
experience with Methods 1622 / 1623. We will comment on laboratory capacity, staff training, utility
preparedness and method associated issues.
Response:
EPA Letter ID: 468
Comment ID: 11049
Commenter: Michael L. McGlinchy, Public Utilities Bureau Manager, City of Akron Public Utilities
Bureau
Commenter Category: Regulated Community (Utilities)
Comment:
Company/Group/Association Name: City of Akron Public Utilities Bureau
Comment:
1981 All America City 1995
City of Invention
Comment Response for LT2ESWTR E-324 December 2005
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Randall A. Monteith, P.E., Pilots Administrator
Brian M. Gresser, P.E., WPC Plant Administrator
Andre L. Blaylock, Business services Administrator
James L. Six, P.E., Water Supply Plant Administrator
DONALD L. PLUSQUELLIC
Mayor
Gerald Holland, Director
DEPARTMENT OF PUBLIC SERVICE
Michael L. McGlinchy, P.E.
PUBLIC UTILITIES BUREAU MANAGER
Response:
EPA Letter ID: 471
Comment ID: 11105
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: The Washington Suburban Sanitary Commission (WSSC) is one of the ten largest water and
wastewater utilities in the nation and serves more than 1.6 million customers. The WSSC appreciates this
opportunity to comment on the Long-Term 2
Response:
EPA Letter ID: 471
Comment ID: 11162
Commenter: John R. Griffin, General Manager, Washington Suburban Sanitary Commission
Commenter Category: Regulated Community (Utilities)
Comment: The Washington Suburban Sanitary Commission (WSSC) is one of the ten largest
water and wastewater utilities in the nation and serves more than 1.6 million customers. The WSSC
appreciates this opportunity to comment on the Long-Term 2
Response:
EPA Letter ID: 472
Comment ID: 11151
Commenter: Dave Van Fleet, Environmental Quality Assurance Officer, City of Peoria, Arizona Utilities
Department
Commenter Category: Local Government
Comment Response for LT2ESWTR E-325 December 2005
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Comment: The City of Peoria (COP), Arizona is a suburban community of the Greater Phoenix
Metropolitan Area and serves drinking water to a population of 110,000. Peoria-s water system obtains it
water from multiple sources including two surface water treatment plants and 25 groundwater wells
supplied from two identified aquifers. Thus, the COP has four defined and approved -water treatment
plants- in regards to disinfection byproducts compliance.
Our two surface water treatment plants supply approximately 80 percent of our water demand while the
remainder is supplied by our groundwater sources. The
Response:
EPA Letter ID: 475
Comment ID: 11210
Commenter: Edmund G. Archuleta, General Manager, El Paso Water Utilities
Commenter Category: Regulated Community (Utilities)
Comment: this proposed rule. El Paso Water Utilities relies on conjunctive use of groundwater and river
surface water. EPWU operates two surface water treatment plants a maximum of 8 months during the
year from February to October. This coincides with releases of irrigation water from Elephant Butte
Reservoir into the Rio Grande by two irrigation districts. The plants are completely shut down from mid
October to mid February during the winter months since the flows in the Rio Grande are very low due to
lack of irrigation water releases during these months. Currently, the Rio Grande is in a severe river
drought and last year we used river water for four months. We expect this to continue to be the case for
the next several years.
Response:
EPA Letter ID: 486
Comment ID: 14164
Commenter: Christopher R. Schulz, Drinking Water Practice Leader, CDM, Inc.
Commenter Category: Consultants: (where self-identified)
Comment: The following comments on the proposed LT2ESWTR and related Toolbox Guidance
Manual (TGM) and UV Disinfection Guidance Manual (UVDGM), were collected from CDM process
design engineers involved in the design of water treatment plant facilities across the United States. We
appreciate your review and consideration of these comments as you develop the final rule. If you have
any questions, please contact Chris Schulz by telephone at 303-298-13 1 1 or by email at
schulzcrcdm.com.
Response:
EPA Letter ID: 491
Comment ID: 10660
Commenter: Douglas G. Chun, Water Quality Manager, Alameda County Water District
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-326 December 2005
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Comment: Term 2 Enhanced Surface Water Treatment Rule (LT2). As a public water utility that serves
water to over 320,000 people in the cities of Fremont, Newark and Union City in the San Francisco Bay
Area, ACWD has a strong commitment to the protection of public health through the development of
more stringent drinking water regulations. ACWD supports EPA efforts to improve protection from
Response:
EPA Letter ID: 496
Comment ID: 10686
Commenter: Les Brown, Assistant Director, Mobile Area Water & Sewer, Mobile, AL
Commenter Category: Regulated Community (Utilities)
Comment: Under the recommendation and direction of the Association of Metropolitan Water Agencies,
MAWSS is requesting your consideration of the attached comments. [SEE PDF]
Comments:
Long Term 2 Enhanced Surface Water Treatment Rule
LT2ESWTR
by Mobile Area Water & Sewer System
(under direction of the Association of Metropolitan Water Agencies)
Response:
EPA Letter ID: 502
Comment ID: 10629
Commenter: Matthew Steele, Laboratory Manager, City of Columbus, Division of Water
Commenter Category: Regulated Community (Utilities)
Comment: Surface Water Treatment Rule (LT2ESWTR). The City of Columbus, Division of Water
currently operates three water treatment plants with an average annual water production of 53.3 billion
gallons. Two of our plants are surface water plant, drawing from either the Scioto River or the Hoover
Reservoir. Our third water plant is a ground water plant in southern Franklin County. We serve over one
million people in the central Ohio area.
Watershed Protection:
1. The City of Columbus has been very proactive in watershed protection. We have a watershed
management section that focuses on water quality protection and management of the surrounding City-
owned property. Our watershed protection specialists protect City property and preserve water quality by
identifying water quality impairments and educating visitors and landowners on environmental
stewardship. The City also has a land stewardship program to work with the 1,200 landowners who live
adjacent to the City-owned reservoirs. We are also actively involved with the federally recognized
Conservation Reserve Enhancement Program: The Upper Big Walnut Partnership. This partnership
includes farmers, landowners, business, industry, and government agencies, working together to protect
our source water quality. Therefore, we strongly
Response:
Comment Response for LT2ESWTR E-327 December 2005
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EPA Letter ID: 504
Comment ID: 11350
Commenter: Richard Sykes, Manager, East Bay Municipal Utility District
Commenter Category: Regulated Community (Utilities)
Comment: The East Bay Municipal Utility District (EBMUD, or District) is a municipal water supplier
serving approximately 1.3 million customers in Alameda and Contra Costa Counties in northern
California.
Water supplies come from four watersheds for which the District maintains active and advanced
management and control procedures including extensive recreation and cattle grazing control program
directed at minimizing Cryptosporidium. District source water quality control procedures have been
influenced by previous EPA regulations following the Surface Water Treatment Rule (SWTR), the
Enhanced SWTR (ESWTR), and the California Cryptosporidium Action Plan. The District has also been
proactive in working toward objectives of the LT2 rule as documented in 2000 by the FACA Agreement
in Principle (AIP) (FR 65(251):83015).
The high quality source water is conveyed to six water treatment plants, three using in-line filtration and
three using conventional treatment two of which employ ozone for disinfection and for taste and odor
control.
Historic Cryptosporidium and Giardia monitoring data shows rare positives, consistent with water quality
indicated by other physical, chemical, and microbiological parameters. All previous monitoring combined
with periodic sanitary survey assessments indicate that EBMUD source water microbiological quality is
at the most favorable, i.e., low concentration, end of the spectrum comprised of surface water sources
used for public water supply nation-wide.
Response:
EPA Letter ID: 507
Comment ID: 11472
Commenter: Thomas P. Bonacquisti, Director, Fairfax County Water Authority
Commenter Category: Regulated Community (Utilities)
Comment: FCWA will be employing the process of ozonation at both treatment facilities (maximum
capacity of 270 mgd) by the end of 2004, not only for Cryptosporidium inactivation but for other benefits
such as DBP and other pathogen reductions.
Response:
EPA Letter ID: 512
Comment ID: 11493
Commenter: Jerry Brown, Director of Planning, Contra Costa Water District
Commenter Category: Regulated Community (Utilities)
Comment: The Contra Costa Water District in northern California supplies water to over 450,000 people
in Contra Costa County. The primary source of water for this system is the surface water of the
Sacramento-San Joaquin Delta. The Sacramento and San Joaquin Rivers flow from the Sierra mountains
Comment Response for LT2ESWTR E-328 December 2005
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and join at the Delta. The water is then delivered to CCWD's raw water customers, stored in the Los
Vaqueros Reservoir, or treated and delivered to CCWD's treated water customers. CCWD operates two
treatment plants: the 75 MGD Bollman facility which uses chlorination for pre-oxidation, chlorination
and intermediate ozonation for disinfection and chloramine for disinfection residuals, and the 40 MGD
Randall- Bold Water Treatment Plant which is a direct/deep-bed filtration plant and utilizes both pre- and
post-ozonation.
CCWD is a member of the EPA's Partnership for Safe Water. CCWD is also a member of the American
Waterworks Association, the Association of Metropolitan Water Agencies, and the Association of
California Water Agencies and supports the comments submitted by these organizations. In addition,
CCWD submits the following comments for EPA-s consideration.
Response:
EPA Letter ID: 522
Comment ID: 14126
Commenter: Michael Hornbrook, Chief Operating Officer, MASSACHUSETTS WATER
RESOURCES AUTHORITY
Commenter Category: Regulated Community (Utilities)
Comment: MWRA is an independent authority providing wholesale water and wastewater service to
approximately 2.5 million people in 61 cities and towns primarily in the Boston metropolitan area.
MWRA provides water service from the well-protected Quabbin and Wachusett Reservoirs in Central
Massachusetts and is in the midst of a 10-year 1.7 billion dollar integrated water supply improvement
program which includes continued aggressive watershed protection, a new water treatment plant using
ozone and chloramines, a 17-mile long, 14-foot diameter new transmission tunnel for supply redundancy,
replacement of open distribution reservoirs with covered storage and pipeline rehabilitation in both the
MWRA system and our member community systems. Investments in our water and wastewater
infrastructure over the past 20 years total over 6 billion dollars.
MWRA was actively involved in the Stage 2 Microbial / Disinfection By-Products Federal Advisory
Committee (FACA) as a member of the Unfiltered Systems Working Group and agreed to the working
group being a signatory to the Agreement in Principle (AIP). The Agreement in Principle included the
Response:
EPA Letter ID: 524
Comment ID: 12206
Commenter: Gary Larimore, Executive Director, Kentucky Rural Water Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: On behalf of its 375 utility members, the Kentucky Rural Water Association (KRWA)
appreciates the opportunity to submit comments on the proposed Environmental Protection Agency's
Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and the Stage 2 Disinfectants and
Disinfection Byproducts Rule (Stage 2 DBPR) as listed in the August 11, 2003 Federal Register (68 FR
47639) and August 18, 2003 Federal Register (68 FR 49547), respectively.
Comment Response for LT2ESWTR E-329 December 2005
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Response:
EPA Letter ID: 527
Comment ID: 10843
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: American Water Works Association (AWWA), Association of Metropolitan Water Agencies
(AMWA), National Association of Water Companies (NAWC), and The National League of Cities
(NLC) appreciate the opportunity to review the Proposed Long-Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR). As signatories of the FACA Agreement, the commenting organizations
affirm their support for the Agreement in principle reached by the Federal Advisory Committee and the
basic components of that agreement as reflected in the proposed rule:
Response:
EPA Letter ID: 527
Comment ID: 10843
Commenter: Diane VanDe Hei, Executive Director, The Association of Metropolitan Water Agencies
(AMWA)
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: American Water Works Association (AWWA), Association of Metropolitan Water Agencies
(AMWA), National Association of Water Companies (NAWC), and The National League of Cities
(NLC) appreciate the opportunity to review the Proposed Long-Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR). As signatories of the FACA Agreement, the commenting organizations
affirm their support for the Agreement in principle reached by the Federal Advisory Committee and the
basic components of that agreement as reflected in the proposed rule:
Response:
EPA Letter ID: 533
Comment ID: 12211
Commenter: Edward Urheim,,
Commenter Category: Consultants: (where self-identified)
Comment: Atlanta, GA 31141, e-mail: eu2002grwa@yahoo.com. I have worked with public water
systems for almost thirty years (28+ years with the Georgia Drinking Water Primacy Agency and
currently with the Georgia Rural Water Association as a trainer and provider of technical assistance). I
appreciate the opportunity to
Response:
Comment Response for LT2ESWTR E-330 December 2005
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EPA Letter ID: 536
Comment ID: 11773
Commenter: Chester Pauls, Manager, Drinking Water Program, Colorado Department of Public Health
and Environment
Commenter Category: State/Tribe Government
Comment: The Colorado Department of Public Health and Environment, Drinking Water Program
appreciates the opportunity to comment on the proposed Long Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR) as listed in the August 11, 2003 Federal Register (68 FR 47639). The
Colorado Department of Public Health and Environment, Drinking Water Program is the primacy agency
responsible for implementation of the Federal Safe Drinking Water Act in Colorado.
Response:
EPA Letter ID: 560
Comment ID: 14972
Commenter: Steve Schmidt, Director, Environmental Management, American Water
Commenter Category: Regulated Community (Utilities)
Comment: American Water, a part of RWE Thames Water, is the largest US privately-owned
water utility, serving approximately 20 million customers in 28 states, 4 Canadian provinces, Puerto Rico,
and Chile. The issues involved in the
Response:
EPA Letter ID: 562
Comment ID: 12290
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: 1 Executive Summary
The American Water Works Association (AWWA) is an international non-profit, scientific and
educational society dedicated to the improvement of drinking water quality and supply. Our 56,000
members include more than 4,6900 utilities that supply roughly 80 percent of the nation's drinking water.
AWWA was one of the national associations representing the drinking water community in the Stage
2 Microbial/Disinfection By-Product Federal Advisory Committee (Stage 2 M/DBP FACA) as well as
previous FACA processes on the regulation of Disinfection By-Products (DBFs) and Cryptosporidium.
Response:
EPA Letter ID: 562
Comment ID: 12333
Commenter: Thomas W. Curtis, Deputy Executive Director, American Water Works Association
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment Response for LT2ESWTR E-331 December 2005
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Comment: The American Water Works Association (AWWA) is an international non-profit, scientific
and educational society dedicated to the improvement of drinking water quality and supply. Founded in
1881, the Association is the largest organization of water supply professionals in the world. AWWA's
more than 56,000 members represent the full spectrum of the "drinking water community": treatment
plant operators and managers, public health officials, scientists, academicians, and others who hold a
genuine interest in water supply and public health. Our membership includes more than 4,6900 utilities
that supply roughly 80 percent of the nation's drinking water.
The comments provided herein reflect the consensus of the AWWA that, given the depth and breadth of
its representation, also reflect the predominant view of the nation's drinking water professionals. It is
therefore appropriate that these AWWA comments be heard on behalf of the drinking water
community in general.
Response:
EPA Letter ID: 585
Comment ID: 11954
Commenter: Margaret Hoffman, Executive Director, Texas Commission on Environmental Quality
Commenter Category: State/Tribe Government
Comment: The Texas Commission on Environmental Quality is the primacy agency in Texas for
the Public Water Supply Supervisory program under the Safe Drinking Water Act. It is in that capacity
that we offer these comments on the proposed Long Term 2 Enhanced Surface Water Treatment Rule as
published in the August 11, 2003 Federal Register.
Response:
EPA Letter ID: 587
Comment ID: 12014
Commenter: Stephen Deem, P.E.,
Commenter Category: Private Citizen (Expert): Lawyers writing in their personal capacities, Graduate
students, Non-university scientists, Non-university engineers, etc.
Comment: I am a professional engineer licensed in the State of Washington. I work for the State Health
Department, which is the primacy agency for implementing the SDWA. I have over 12 years direct
experience with water treatment, water quality monitoring and regulatory compliance with the full gamut
of public water systems subject to both State and Federal drinking water regulations. During the past
two years I have been a principal representative for the Department of Health in its interactions with the
City of Seattle's efforts to implement UV disinfection treatment on its 180 MGD Cedar supply, and in the
City's efforts to pursue a Limited Alternative to Filtration (LAP). The Department is prepared to issue
regulatory inactivation credit for the Cedar UV system. These comments reflect my review of the
proposed rule and guidance document. The Department of Health's comments are being submitted under
separate cover.
Response:
Comment Response for LT2ESWTR E-332 December 2005
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EPA Letter ID: 589
Comment ID: 13052
Commenter: Lawrence Libeu, President, The Western Coalition of Arid States
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: The Western Coalition of Arid States (WESTCAS) is an organization comprised of
drinking water suppliers and wastewater systems in eight Arid West States, representing Arid West water
and wastewater issues. WESTCAS comments are provided herein.
Response:
EPA Letter ID: 590
Comment ID: 12028
Commenter: Steve Robbins, General Manager-Chief Engineer, Coachella Valley Water District
Commenter Category: Regulated Community (Utilities)
Comment: The District is a multifunction agency in the arid southeast of California. We rely on
groundwater for all domestic water supplies and are well aware of the need for constant vigilance over the
quality of water supplies. Because of this awareness, we applaud any reasonable attempt to protect public
health and have consistently stayed in the forefront of the legislative and regulatory process through our
association with the American Water Works Association, the AWWA Research Foundation, the
Association of California Water Agencies and other similar organizations. In addition, we have been
proactive in the protection of our consumers through water quality monitoring and innovative design for
our wells and water distribution systems.
Response:
EPA Letter ID: 595
Comment ID: 12571
Commenter: Nancy Beardsley, Director, Maine Drinking Water Program, Division of Health
Engineering, Bureau of Health, Maine Department of Human Services
Commenter Category: State/Tribe Government
Comment: administering the Safe Drinking Water Act in the State of Maine.
Response:
EPA Letter ID: 598
Comment ID: 12615
Commenter: Charlie Maddox,, Austin Water Utility
Commenter Category: Regulated Community (Utilities)
Comment Response for LT2ESWTR E-333 December 2005
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Comment: (LT2ESWTR) published in the Federal Register on August 11,2003. We provide drinking
water and wastewater service to customers in and near the City of Austin, Texas. The Utility has a history
of interacting with the Environmental Protection Agency (EPA) to develop water and wastewater
regulations that are based on sound scientific and economic principles, and that are protective of
environmental and public health. Consequently, we offer the following comments
Response:
EPA Letter ID: 607
Comment ID: 12976
Commenter: Cam Ferguson, Manager of Water Resources, Greenville Water System
Commenter Category: Regulated Community (Utilities)
Comment: The Greenville Water System is a public water utility and serves approximately 400,000
customers. It is located in the northwestern corner of South Carolina. Listed below are our concerns.
Response:
EPA Letter ID: 612
Comment ID: 13146
Commenter: Michael Sadar, Application Scientist II, Hach Company
Commenter Category: Manufacturer/Vendor
Comment: The following provides a synopsis of the pre-draft of Hach Company's comments
regarding the United States Environmental Protection Agency's August 11, 2003 draft of the Long Term 2
Enhanced Surface Water Rule (LT2). These comments are based upon the Hach Company's 50 plus years
of experience in developing and manufacturing the World's leading drinking water monitoring
technologies, and our expertise related to drinking water membrane treatment systems and their
respective monitoring systems.
Response:
EPA Letter ID: 620
Comment ID: 13280
Commenter: Stephen Schneider, General Manager, Saint Paul Regional Water Services
Commenter Category: Regulated Community (Utilities)
Comment: (LT2ESWTR) that EPA released on August 11, 2003. We are a drinking water utility
that serves 415,000 customers in and around Saint Paul, Minnesota. We utilize surface water for
approximately 90 percent of our raw water supply.
Response:
Comment Response for LT2ESWTR E-334 December 2005
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EPA Letter ID: 624
Comment ID: 13173
Commenter: Jack DeMarco, Superintendent, Greater Cincinnati Waterworks
Commenter Category: Regulated Community (Utilities)
Comment: The Greater Cincinnati Water Works (GCWW) is a public water utility serving approximately
a million people in the Greater Cincinnati Area. GCWW appreciates
Response:
EPA Letter ID: 629
Comment ID: 12826
Commenter: Melinda Rho, Manager of Regulatory Affairs and Consumer Protection, Los Angeles
Department of Water and Power
Commenter Category: Regulated Community (Utilities)
Comment: As the largest municipally owned utility in the nation, the Los Angeles Department of Water
and Power (LADWP) provides water and electric service to a population of 3.8 million residing in the
City of Los Angeles. LADWP-s water distribution system covers more than 464 square miles. We treat
and deliver 600 million gallons of high quality potable water daily to the residents and business in Los
Angeles. Situated in a semi-arid region of southern California, LADWP is heavily reliant on imported
surface water sources. LADWP is pleased to
Response:
EPA Letter ID: 634
Comment ID: 13272
Commenter: Michael A. Neher, Environmental Services Manager, City of Henderson
Commenter Category: Local Government
Comment: regulation. The City of Henderson (City) is a member of American Waterworks Association,
Association of Metropolitan Water Agencies, the Western Coalition of Arid States, and the Southern
Nevada Water Authority. We understand that
Response:
EPA Letter ID: 634
Comment ID: 13274
Commenter: Michael A. Neher, Environmental Services Manager, City of Henderson
Commenter Category: Local Government
Comment: The City-s water system serves a community of nearly a quarter-million people. Our water
supply is Lake Mead on the Colorado River. Potable water is provided by three (3) treatment facilities and
delivered through twelve (12) entry points to the City-s distribution system. Even though the City-s
supply involves three (3) treatment plants, they share the same source and equivalent processes. The
Comment Response for LT2ESWTR E-335 December 2005
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Response:
EPA Letter ID: 643
Comment ID: 12699
Commenter: James D. Taft, Executive Director, Association of State Drinking Water Administrators
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: ASDWA is the professional Association that represents the collective interests of the nation-s
state drinking water programs responsible for implementation of the Federal Safe Drinking Water Act.
Response:
EPA Letter ID: 653
Comment ID: 14061
Commenter: Tim Stefanich, Environmental Engineer, Sioux Falls Water Purification, City of Sioux Falls
Commenter Category: Local Government
Comment: Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). The City of Sioux Falls
provides high quality drinking water to over 135,000 people and 1 Rural Water District. As a large water
system, we are one of the first water utilities in South Dakota to be impacted by new regulations
promulgated by EPA.
Response:
EPA Letter ID: 678
Comment ID: 14653
Commenter: Krista Clark, Regulatory Affairs Specialist, Association of California Water Agencies
Commenter Category: Regulated Community (Organizations): i.e., AWWA, ASDWA, etc.
Comment: Rule (LT2). ACWA consists of 447 public water agencies in California. Our members serve
over 90% of the delivered water in California for domestic, industrial and agricultural uses.
Response:
EPA Letter ID: 681
Comment ID: 14769
Commenter: Leah Rose, Staff Associate, American Chemistry Council
Commenter Category: Other: Other hard to categorize commenters
Comment: (1) The current members of the ACC Panel are: Ashland Inc., Bio-Cide International, DuPont,
Engelhard Corporation, ERCO Worldwide, International Dioxcide, Sabre Oxidation Technologies and
Vulcan Chemicals.
Response:
Comment Response for LT2ESWTR E-336 December 2005
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EPA Letter ID: 687
Comment ID: 14750
Commenter: David Pearson, General Manager, PCI Membrane Systems Inc.
Commenter Category: Manufacturer/Vendor
Comment: Background Information:
PCI Membrane Systems manufactures a specialist process for the removal of organics prior to
chlorination for surface water treatment using a tubular nanofiltration membrane. Systems using this
process are already installed in the United Kingdom, Canada and Alaska. Over 40 tubular membrane
systems have now been installed for small community water systems with capacities ranging from 2
gpm to 150 gpm and a few spiral membrane systems installed with capacities up to SOOgpm. The water
treatment systems are specifically designed for small surface water systems and have proven to be a very
effective treatment of highly organic surface waters to meet European and US regulations on disinfection
by products.
The process was tested at Barrow, Alaska under the EPA Equipment Testing Verification Program on
water containing around 16 mg/1 TOC and results of this verification test are therefore available on both
the EPA and NSF web sites. A microbial challenge was not conducted as part of that verification. The
verification statement can be found at
http://www.epa.gov/etv/pdfs/vrvs/02_vs_pci.pdf and the complete report at
http://www.epa.gov/etv/pdfs/vrvs/02_vr_pci.pdf
Under the draft rule, a membrane system, to receive credit for cryptosporidium removal, must include a
direct integrity test method and possibly an additional indirect method. While integrity testing of hollow
fiber membranes is a proven technology, testing of spiral wound and tubular membranes is more difficult
and costly to perform, and reliable systems for accurate direct integrity testing have not yet been
developed or proven. Papers presented at the AWWA Membrane Conference 2003 evaluating integrity
test methods for spiral systems reflect this challenge using air pressure decay testing or surrogate testing
with microspheres.
Hollow fiber membranes have been extensively adopted as the configuration of choice for micro and
ultrafiltration applications however hollow fiber membranes are not suited for higher pressure
nanofiltration and reverse osmosis applications.
As compared to hollow fiber membranes, spiral and tubular membranes, once initially tested for integrity,
have significantly less risk of failure from overpressure. Hollow fiber membranes consist of extruded
polymers alone. The membranes of spiral, plate-and-frame and tubular construction are additionally
supported on a substrate layer which itself may be further supported by an additional plastic or stainless
steel support. Such a construction eliminates the possibility of a membrane bursting under the applied
pressure.
There is, of course, a risk of seal failure with non hollow-fiber membranes. The tubular module we use
has a strong positive seal sandwiched between two surfaces over a seal length of 1 cm to ensure
separation of raw water from filtered water.
Response:
Comment Response for LT2ESWTR E-337 December 2005
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EPA Letter ID: 711
Comment ID: 16541
Commenter: Raymond Yep, Deputy Operating Officer, Santa Clara Water District
Commenter Category: Regulated Community (Utilities)
Comment: The Santa Clara Valley Water District (District) is a large wholesale water agency that serves
drinking water to 1.7 million people in the Silicon Valley. We operate three water treatment plants with a
total capacity of 222 million gallons per day. Being that the District will be impacted by the proposed
rule, we appreciate the opportunity to review the Proposed Long-Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR) released on August 11, 2003 (68 Federal Register 47639). In our review of
the proposed rule, we have identified areas where the District believes changes are needed prior to
finalizing the rule. These areas include:
Response:
Comment Response for LT2ESWTR E-338 December 2005
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