xvEPA
United States
Environmental Protection'
Agency
Office of Water
(4303) " '
EPA 821rR-98-020
ttecfetniber 1998
Development Document for
Proposed Effluent Limitations
Guidelines and Standards for
the Centralized Waste
Treatment Industry
Volume
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vvEPA
Development Document for
Proposed Effluent Limitations
Guidelines and Standards for
the Centralized Waste
Treatment Industry
Volume I
(EPA821-R-98-020)
Carol M. Browner
Administrator
J. Charles Fox
Assistant Administrator, Office of Water
Tudor T. Davies
Director, Office of Science and Technology
Sheila E. Frace
Acting Director, Engineering and Analysis Division
Elwood H. Forsht
Chief, Chemicals and Metals Branch
Jan S. Matuszko
Project Manager
Timothy E. Connor
Project Engineer
Maria D. Smith
Project Statistician
December 1998
U.S. Environmental Protection Agency
Office of Water
Washington, DC 20460
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ACKNOWLEDGEMENTS AND DISCLAIMER
The Agency would like to acknowledge the contributions of Jan Matuszko, Maria Smith,
Richard Witt, Tim Connor, Ahmar Siddiqui, Ed Terry, Hugh Wise, Steve Geil, Henry Kahn,
and Beverly Randolph to development of this technical document. In addition EPA acknowledges
the contribution of Science Applications International Corporation under contract 68-C5-0040.
Neither the United States government nor any of its employees, contractors, subcontractors,
or other employees makes any warranty, expressed or implied, or assumes any legal liability or
responsibility for any third party's use of, or the results of such use of, any information, apparatus,
product, or process discussed in this report, or represents that its use by such a third party would not
infringe on privately owned rights.
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TABLE OF CONTENTS
Volume 1:
Chapter 1 BACKGROUND 1-1
1.0 LEGAL AUTHORITY i-l
l.l LEGISLATIVE BACKGROUND i-l
1.1.1 Clean Water Act 1-1
1.1.1.1 Best Practicable Control Technology Currently Availabl
(BPT)-Sec.304(b)(l) of the CWA 1-1
1.1.1.2 Best Conventional Pollutant Control Technology (BCT)-Sec
304(b)(4) of the CWA 1-2
1.1.1.3 Best Available Technology Economically Achievable (BAT)—
Sec. 304(b)(2) of the CWA 1-2
1.1.1.4 New Source Performance Standards (NSPS)~Sec.306 of the
CWA 1-2
1.1.1.5 Pretreatment Standards for Existing Sources (PSES)—
Sec.307(b) of the CWA 1-3
1.1.1.6 Pretreatment Standards for New Sources (PSNS)-Sec.307(b)
of the CWA 1-3
1.1.2 Section 304(m) Requirements and Litigation 1-3
1.1.3 The Land Disposal Restrictions Program: 1-3
1.1.3.1 Introduction to RCRA Land Disposal Restrictions (LDR) 1-3
1.1.3.2 Overlap Between LDR Standards and the Centralized Waste
Treatment Industry Effluent Guidelines 1-5
1.2 CENTRALIZED WASTE TREATMENT INDUSTRY EFFLUENT GUIDELINE
RULEMAKMG HISTORY 1-5
1.2.1 January 27,1995 Proposal 1-5
1.2.2 September 16,1996 Notice of Data Availability 1-6
Chapter2 DATA COLLECTION 2-1
2.1 PRELIMINARY DATA SUMMARY 2-1
2.2 CLEAN WATER ACT SECTION 308 QUESTIONNAIRES 2-2
2.2.1 Development of Questionnaires 2-2
2.2.2 Distribution of Questionnaires 2-3
2.3 WASTEWATER SAMPLING AND SITE VISITS 2-3
2.3.1 Pre-1989 Sampling Program 2-3
2.3.2 1989-1997 Site Visits 2-4
2.3.3 Sampling Episodes 2-4
2.3.3.1 Facility-Selection 2-4
2.3.3.2 Sampling Episodes 2-5
2.3.3.3 Metal-Bearing Waste Treatment and Recovery Sampling ... 2-10
: 2.3.3.4 Oily Waste Treatment and Recovery Sampling 2-10
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2.3.3.5 Organic-Bearing Waste Treatment and Recovery Sampling .2-11
2.3.4 1998 Characterization Sampling of Oil Treatment and Recover
Facilities 2-11
2.4 PUBLIC COMMENTS TO THE 1995 PROPOSAL AND THE 1996 NOTICE OF DATA
AVAILABILITY 2-11
2.5 ADDITIONAL DATA SOURCES 2-13
2.5.1 Additional Databases 2-13
2.5.2 Laboratory Study on the Effect of Total Dissolved Solids on Metal
Precipitation 2-13
2.6 PUBLIC PARTICIPATION 2-14
Chapter 3 SCOPE/APPLICABILITY OF THE PROPOSED REGULATION 3-1
3.1 APPLICABILITY 3-1
3.1.1 Facilities Subject to 40 CFR (Parts 400 to 471) 3-1
3.1.2 Pipeline Transfers (Fixed Delivery Systems) 3-4
3.1.3 Product Stewardship 3-5
3.1.4 Solids, Soils, and Sludges 3-7
3.1.5 Sanitary Wastes 3-8
3.1.6 Transporters and/or Transportation Equipment Cleaners 3-8
3.1.7 Publicly Owned Treatment Works (POTWs) 3-8
3.1.8 Silver Recovery Operations from Used Photographic and X-Ray
Materials 3-9
3.1.9 High Temperature Metals Recovery 3-10
3.1.10 Landfill Wastewaters 3-11
3.1.11 Industrial Waste Combustors 3-11
3.1.12 Solvent RecycUng/Fuel Blending 3-12
3.1.13 Re-reBning 3-12
3.1.14 Used Oil Filter Recycling 3-13
3.1.15 Marine Generated Wastes 3-13
3.1.16 Stabilization 3-14
3.1.17 Grease Trap/Interceptor Wastes 3-14
Chapter4 DESCRIPTION OF THE INDUSTRY 4-1
4.1 INDUSTRYSIZE 4-1
4.2 GENERAL DESCRIPTION 4-2
4.3 WATER USE AND SOURCES OF WASTEWATER 4-4
4.4 VOLUME BY TYPE OF DISCHARGE 4-5
4.5 OFF-SITE TREATMENT INCENTIVES AND COMPARABLE TREATMENT 4-6
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Chapter 5 INDUSTRY SUBCATEGORIZATION 5-1
5.1 METHODOLOGY AND FACTORS CONSIDERED AS THE BASIS FOR
SUBCATEGORIZATION 5-1
5.2 PROPOSEDSUBCATEGORIES ...' 5-2
5.3 SUBCATEGORY DESCRIPTIONS 5-2
5.3.1 Metal-Bearing Waste Treatment and Recovery Subcategory 5-2
5.3.2 Oily Waste Treatment and Recovery Subcategory 5-3
5.3.3 Organic Waste Treatment and Recovery Subcategory 5-3
5.4 MIXED WASTE SUBCATEGORY CONSIDERATION 5-4
Chapter 6 POLLUTANTS OF CONCERN FOR THE CENTRALIZED WASTE
TREATMENT INDUSTRY 6-1
6.1 METHODOLOGY 6-1
6.2 POLLUTANTS OF CONCERN FOR THE METALS SUBCATEGORY 6-24
6.3 POLLUTANTS OF CONCERN FOR THE OILS SUBCATEGORY 6-25
6.4 POLLUTANTS OF CONCERN FOR THE ORGANICS SUBCATEGORY 6-27
6.5 REFERENCES 6-27
Chapter 7 POLLUTANTS SELECTED FOR REGULATION 7-1
7.1 TREATMENT CHEMICALS 7-1
7.2 NON-CONVENTIONAL BULK PARAMETERS 7-1
7.3 POLLUTANTS NOT DETECTED AT TREATABLE LEVELS 7-1
7.4 POLLUTANTS NOT TREATED 7-6
7.5 VOLATILE POLLUTANTS 7-6
7.6 POLLUTANTS SELECTED FOR PRETREATMENT STANDARDS AND
PRETREATMENT STANDARDS FOR NEW SOURCES (INDIRECT DISCHARGERS) .7-15
7.6.1 Background 7-15
7.6.2 Determination of Percent Removals for well-Operated POTWs 7-16
7.6.3 Methodology for Determining Treatment Technology Percent
Removals 7-21
7.6.4 Pass-Through Analysis Results 7-21
7.6.4.1 Pass-Through Analysis Results for the Metals Subcategory . 7-21
7.6.4.2 Pass-Through Analysis Results for the Oils Subcategory ... 7-24
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7.6.4.3 Pass-Through Analysis Results for the Organics
Subcategory 7-26
7.7 FINAL LIST OF POLLUTANTS SELECTED FOR REGULATION 7-27
7.7.1 Direct Dischargers 7-27
7.7.2 Indirect Dischargers 7-34
Chapter 8 WASTEWATER TREATMENT TECHNOLOGIES 8-1
8.1 TECHNOLOGIES CURRENTLYW USE : 8-1
8.2 TECHNOLOGY DESCRIPTIONS 8-3
8.2.1 Best Management Practices 8-3
8.2.2 Physical/Chemical/Thermal Treatment 8-3
8.2.2.1 Equalization 8-3
8.2.2.2 Neutralization 8-5
8.2.2.3 Flocculation/Coagulation 8-5
8.2.2.4 Emulsion Breaking 8-8
8.2.2.5 Gravity Assisted Separation 8-10
1. GRAVITY OIL/WATER SEPARATION 8-10
2. CLARIFICATION 8-10
3. DISSOLVED AIR FLOTATION 8-13
8.2.2.6 Chromium Reduction 8-15
8.2.2.7 Cyanide Destruction 8-16
8.2.2.8 Chemical Precipitation 8-19
8.2.2.9 Filtration 8-24
l. SAND FILTRATION 8-24
2. MULTIMEDIA FILTRATION 8-25
3. PLATE AND FRAME PRESSURE FILTRATION 8-26
4. MEMBRANE FILTRATION 8-28
A ULTRAFILTRATION 8-28
B. REVERSE OSMOSIS 8-28
5. LANCY FILTRATION 8-30
8.2.2.10 Carbon Adsorption 8-33
8.2.2.11 lonExchange 8-35
8.2.2.12 Electrolytic Recovery '. 8-36
8.2.2.13 Stripping 8-39
1. AlRSTRIPPING 8-39
8.2.2.14 Liquid Carbon Dioxide Extraction 8-41
8.2.3 Biological Treatment 8-41
8.2.3.1 Sequencing Batch Reactors 8-43
8.2.3.2 Attached Growth Biological Treatment Systems 8-45
1. TRICKLING FILTERS 8-45
2. BIOTOWERS 8-47
8.2.3.3 Activated Sludge 8-47
8.2.4 Sludge Treatment and Disposal 8-51
8.2.4.1 Plate and Frame Pressure Filtration 8-52
8.2.4.2 BeltPressureFiltration 8-54
8.2.4.3 Vacuum Filtration 8-54
8.2.4.4 Filter Cake Disposal '. 8-57
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8.2.5 Zero or Alternate Discharge Treatment Options 8-57
8.3 REFERENCES 8-58
Chapter 9 REGULATORY OPTIONS CONSIDERED AND SELECTED FOR
BASIS OF REGULATION 9-1
9.1 ESTABLISHMENT OF BPT 9-1
9.1.1 Rationale for Metals Subcategory BPT Limitations 9-2
9.1.2 Rationale for Oils Subcategory BPT Limitations 9-6
9.1.3 Rationale for Organics Subcategory BPT Limitations 9-11
9.2 BEST CONVENTIONAL TECHNOLOGY (BCT) 9-13
9.3 BEST AVAILABLE TECHNOLOGY (BAT) 9-13
9.4 NEW SOURCE PERFORMANCE STANDARDS (NSPS) 9-14
9.5 PRETREATMENT STANDARDS FOR EXISTING SOURCES (PSES) 9-15
9.6 PRETREATMENT STANDARDS FOR NEW SOURCES (PSNS) 9-16
Chapter 10 LONG-TERM AVERAGES, VARIABILITY FACTORS, AND
LIMITATIONS AND STANDARDS 10-1
10.1 FACILITY SELECTION 10-1
10.2 SAMPLE POINT SELECTION 10-2
10.2.1 Effluent Sample Point 10-2
10.2.2 Influent Sample Point 10-2
10.2.3 Special Cases 10-3
10.3 DETERMINATION OF BATCH AND CONTINUOUS FLOW SYSTEMS 10-3
10.4 DATA SELECTION 10-5
10.4.1 Data Exclusions and Substitutions 10-5
10.4.1.1 Operational Difficulties 10-5
10.4.1.2 Treatment Not Reflective of BPT/BCT/BAT Treatment 10-5
10.4.1.3 Exclusions to EPA Sampling Data Based Upon the
: Availability of the Influent and Effluent 10-6
10.4.1.4 More Reliable Results Available 10-6
10.4.1.5 Data from the Facilities Which Accept Waste from More
than One Subcategory 10-7
10.4.1.6 Substitution Using the Baseline Values 10-7
10.4.2 Data Aggregation 10-7
10.4.2.1 Aggregation of Field Duplicates 10-8
10.4.2.2 Aggregation of Grab Samples and Multiple Daily Values .. 10-9
10.4.2.3 Aggregation of Data Across Streams ("Flow-
Weighting") 10-10
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10.4.3 Data Editing Criteria 10-11
10.4.3.1 Long-Term Average Test 10-12
10.4.3.2 Percent Removal Test 10-12
10.4.3.3 Evaluation of Self-Monitoring Data 10-13
10.5 DEVELOPMENT OF LONG-TERM AVERAGES , — 10-13
10.5.1 Estimation of Facility-Specific Long-Term Averages 10-14
10.5.2 Estimation of Pollutant-Specific Long-Term Averages 10-14
10.5.3 Substitutions for Long-Term Averages 10-14
10.5.3.1 Baseline Values Substituted for Long-term Averages 10-14
10.5.3.2 Arsenic Long-Term Average for Metals Subcategory
Option 4 10-15
10.6 DEVELOPMENT OF VARIABILITY FACTORS — 10-15
10.6.1 Basic Overview of the Modified Delta-Lognormal Distribution .. 10-15
10.6.2 Discrete Portion of the Modified Delta-Lognormal Distribution . 10-18
10.6.3 Continuous Portion of the Modified Delta-Lognormal
Distribution 10-18
10.6.4 Estimation Under the Modified Delta-Lognormal Distribution .. 10-19
10.6.5 Estimation of Facility-Sped fie Variability Factors 10-21
10.6.5.1 Facility Data Set Requirements 10-21
10.6.5.2 Estimation of Facility-Specific Daily Variability Factor 10-21
10.6.5.3 Estimation of Facility-Specific Monthly Variability
Factors 10-22
10.6.5.4 Evaluation of Facility-Specific Variability Factors 10-28
10.6.6 Estimation of Pollutant-Specific Variability Factors 10-29
10.6.7 Estimation of Group-Level Variability Factors 10-29
10.6.S Transfers of Variability Factors 10-29
10.7 LIMITATIONS 10-31
10.7.1 Steps Used to Derive Limitations 10-32
10.7.2 Example 10-33
10.8 TRANSFERS OF LIMITATIONS 10-34
10.8.1 Transfer of Oil and Grease Lhnitation for Metals Subcategory
for Option 4 to Option 3 10-34
10.&2 Transfers of Limitations from Other Rulemakings to CWT
Industry 1°-35
10.8.2.1 Transfer ofBOD5 and TSS for the Organics Subcategory 10-35
10.8.2.2 Transfer of TSS for Option 4 of the Metals Subcategory . 10-38
10.9 EFFECT OF GROUP AND POLLUTANT VARIABILITY FACTORS ON
LIMITATIONS 1Q-38
10.10 ATTACHMENTS l°-39
10.11 REFERENCES l°-40
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Chapter 11 COST OF TREATMENT TECHNOLOGIES 11-1
ll.l COSTS DEVELOPMENT l l-l
11.1.1 Technology Costs 11-1
11.1.2 Option Costs 11-2
11.1.2.1 Land Requirements and Costs 11-2
11.1.2.2 Operation and Maintenance Costs 11-3
11.2 PHYSICAL/CHEMICAL WASTEWATER TREATMENT TECHNOLOGY COSTS 11-5
11.2.1 Chemical Precipitation 11-5
11.2.1.1 Selective Metals Precipitation-Metals Option 2 and
Metals Option 3 11-5
11.2.1.2 Secondary Precipitation-Metals Option 2 and Metals
Option3 ...' 11-6
11.2.1.3 Tertiary Precipitation and pH Adjustment-Metals
Option 3 11-8
11.2.1.4 Primary Chemical Precipitation-Metals Option 4 11-9
11.2.1.5 Secondary (Sulfide) Precipitation for Metals Option 4 .. 11-12
11.2.2 Plate and Frame Liquid Filtration and Clarification 11-13
11.2.2.1 Plate and Frame Liquid Filtration Following Selective
Metals Precipitation 11-14
11.2.2.2 Clarification for Metals Options 2,3, and 4 11-14
11.2.3 Equalization 11-17
11.2.4 Air Stripping 11-18
11.2.5 Multi-Media Filtration 11-19
11.2.6 Cyanide Destruction 11-20
11.2.7 Secondary Gravity Separation 11-21
11.2.8 Dissolved Air Flotation 11-22
11.3 BIOLOGICAL WASTEWATER TREATMENT TECHNOLOGY COSTS 11-25
11.3.1 Sequencing Batch Reactors 11-25
11.4 SLUDGE TREATMENT AND DISPOSAL COSTS 11-26
11.4.1 Plate and Frame Pressure Filtration-Sludge Stream 11-26
11.4.2 Filter Cake Disposal 11-29
11.5 ADDITIONAL COSTS 11-30
11.5.1 Retrofit Costs 11-30
11.5.2 Monitoring Costs 11-31
11.5.3 RCRA Permit Modification Costs 11-32
11.5.4 Land Costs 11-33
11.6 REFERENCES 11-43
11.7 SUMMARY OF COST OF TECHNOLOGY OPTIONS 11-44
11.7.1 BPTCosts 11-44
11.7.2 BCT/BATCosts 11-44
11.7.3 PSES Costs 11-44
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Chapter 12 POLLUTANT LOADING AND REMOVAL ESTIMATES 12-1
12.1 INTRODUCTION 12-1
12.2 DATA SOURCES 12-1
12.3 METHODOLOGY USED TO DEVELOP CURRENT LOADINGS ESTIMATES 12-2
12.3.1 Current Loadings Estimates for the Metals Subcategory 12-2
12.3.1.1 Raw Loadings for the Metals Subcategory 12-4
12.3.1.2 Primary Precipitation with Solids-Liquid Separation
Loadings 12-4
12.3.1.3 Secondary Precipitation with Solids-Liquid Separation
Loadings 12-5
12.3.1.4 Technology Basis for the Proposed BPT/BAT/PSES
Option 4 Loadings 12-5
12.3.1.5 Selective Metals Precipitation (NSPS/PSNS Proposed
Option 3) Loadings 12-5
12.3.2 Current Loadings Estimates for the Oils Subcategory 12-5
12.3.2.1 Issues Associated with Oils Current Performance
Analyses 12-9
12.3.2.1 Random Assignment of Seven Emulsion Breaking/Gravity
Separation Data Sets 12-31
12.3.3 Organics Subcategory Current Loadings 12-33
12.4 METHODOLOGY USED TO ESTIMATE POST-COMPLIANCE LOADINGS 12-35
12.5 METHODOLOGY USED TO ESTIMATE POLLUTANT REMOVALS 12-41
12.6 POLLUTANT LOADINGS AND REMOVALS 12-41
Chapter 13 NON-WATER QUALITY IMPACTS '. 13-1
13.1 AIR POLLUTION 13-1
13.2 SOLID WASTE 13-3
13.3 ENERGY REQUIREMENTS 13-5
13.4 LABOR REQUIREMENTS 13-5
Chapter 14 IMPLEMENTATION 14-1
14.1 APPLICABLE WASTE STREAMS 14-1
14.2 DESCRIPTION OF SUBCATEGORY 14-2
14.2.1 Metals Subcategory Description 14-2
14.2.2 Oils Subcategory Description 14-2
14.2.3 Organics Subcategory Description 14-3
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14.3 FACILITY SUBCATEGORIZATION IDENTIFICATION 14-3
14.4 ON-SITE GENERATED WASTEWATER SUBCATEGORY DETERMINATION 14-7
14.4,1 On-site Industrial Waste Combustors, Landfills, and
Transportation Equipment Cleaning, Operations 14-7
14.5 SUBCATEGORY DETERMINATION IN EPA QUESTIONNAIRE DATA BASE 14-7
14.5.1 Wastes Classified in the Metals Subcategory - Questionnaire
Responses 14-14
14.5.2 Wastes Classified in the Oils Subcategory - Questionnaire
Responses 14-14
14.5.3 Wastes Classified in the Organics Subcategory - Questionnaire
Responses 14-14
14.6 ESTABLISHING LIMITATIONS AND STANDARDS FOR FACILITY DISCHARGES 14-15
14.6.1 Existing Guidance for Multiple Subcategory Facilities 14-16
14.6.1.1 Direct Discharge Guidance 14-16
14.6.1.2 Indirect Discharge Guidance 14-19
14.6.2 CWT Facilities Also Covered By Another Point Source
Category . 14-26
Chapter 15 ANALYTICAL METHODS AND BASELINE VALUES 15-1
15.1 INTRODUCTION 15-1
15.2 ANALYTICAL RESULTS 15-1
15.3 NOMINAL QUANTITATION LIMITS 15-2
15.4 BASELINE VALUES 15-2
15.5 ANALYTICAL METHODS 15-5
15.5.1 Methods 1613,1624,1625,1664 (Dioxins, Organics, HEM) 15-5
15.5.2 Method 413.1 (Oil and Grease) 15-5
15.5.3 Method 1620 15-5
15.5.4 Method 85.01 15-6
15.5.5 Methods D4658 and 376.1 (Total SulRde) 15-7
15.5.6 Methods 410.1, 410.2, and 410.4 (COD andD-COD) 15-7
15.5.7 Method420.2 (TotalPhenols) 15-7
15.5.S Method 218.4 and 3500D (Hexavalent Chromium) 15-8
15.5.9 Methods 335.2 and 353.2 (Total Cyanide and Nitrate/Nitrite) 15-8
15.5.10 Remaining Methods 15-8
15.6 ANALYTICAL METHOD DEVELOPMENT EFFORTS ...• 15-8
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LIST OF DEFINITIONS Defmitions-1
LIST OF ACRONYMS Acronyms-1
INDEX Index-1
Volume 2:
Appendix A POLLUTANT GROUPS A-l
Appendix B LISTING OF CHARACTERIZATION DATA FROM
NON-HAZARDOUS OILS FACILITIES B-l
Appendix C LISTING OF DAILY INFLUENT AND EFFLUENT
MEASUREMENTS C-l
Appendix D FACILITY-SPECIFIC COMPLIANCE COSTS D-l
AppendixE , ATTACHMENTS TO CHAPTER 10 E-l
Appendix F LISTING OF POLLUTANTS OF CONCERN AND CAS NUMBERS ... F-l
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LIST OF TABLES
Chapter 1
Table 1-1 Technology Basis for 1995 BPT Effluent Limitations 1-6
Chapter 2
Table 2-1 Chemical Compounds Analyzed Under EPA Analytical Methods 2-7
Chapter 3
Table 3-1 Summary of the Frequency of the Types of Activities and Dispositions
Reported 3-6
Table 3-2 Summary of Frequency of Each Product Class Reported by Facilities 3-6
Chapter 4
Table 4-1 Geographic Distribution of CWT Facilities (145 Facilities) 4-3
Table 4-2 Waste Form Codes Reported by CWT Facilities in 1989 4-3
Table 4-3 RCRA Codes Reported by Facilities in 1989 4-3
Table 4-4 Facility Discharge Options 4-6
Table 4-5 Quantity of Wastewater Discharged (205 Facilities) 4-6
Chapters
Table 6-1 Pollutants of Concern for the Metals Subcategory 6-4
Table 6-2 Pollutants of Concern for the Oils Subcategory 6-6
Table 6-3 Pollutants of Concern for the Organics Subcategory 6-9
Table 6-4 Pollutants Not Selected as Pollutants of Concern for the Metals
Subcategory 6-11
Table 6-5 Pollutants Not Selected as Pollutants of Concern for the Oils
Subcategory 6-16
Table 6-6 Pollutants Not Selected as Pollutants of Concern for the Organics
Subcategory 6-20
Table 6-7 Concentration of Benzo(a)pyrene in Industrial Products (Osborne &
Crosby, 1987) 6-26
Chapter 7
Table 7-1 Pollutants Not Detected At Treatable Levels 7-4
Table 7-2 Volatile Organic Pollutant Properties By Subcategory 7-8
Table 7-3 Non-Regulated Volatile Organic Pollutants by Subcategory and Option . .7-14
Table 7-4 CWT Pass-Through Analysis Generic POTW Percent Removals 7-18
Table 7-5 Final POTW Percent Removals 7-19
Table 7-6 Final Pass-Through Results For Metals Subcategory Option 3 7-22
Table 7-7 Final Pass-Through Results For Metals Subcategory Option 4 7-23
Table 7-8 Final Pass-Through Results For Oils Subcategory Option 9 7-24
Table 7-9 Final Pass-Through Results For Organics Subcategory Option 3/4 7-26
Table 7-10 Pollutants Eliminated Due to Non-Optimal Performance 7-27
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Table 7-11 Pollutants Eliminated Since Technology Basis is Not Standard Method
of Treatment 7-28
Table 7-12 Frequency of Detection of n-Paraffins in CWT Oils Subcategory Wastes . 7-30
Table 7-13 Frequency of Detection of Polyaromatic Hydrocarbons in CWT Oils
Subcategory Wastes 7-31
Table 7-14 Frequency of Detection of Phthalates in CWT Oils Subcategory Wastes .. 7-32
Table 7-15 Final List of Regulated Pollutants for Direct Discharging CWTs 7-33
Table 7-16 Final List of Regulated Pollutants for Indirect Discharging CWT
Facilities 7-34
Chapter 8
Table 8-1 Percent Treatment In-place by Subcategory and by Method of Wastewater
Disposal 8-2
Chapter 9
Table 9-1 Average Influent and Effluent Oil and Grease and Total Petroleum
Hydrocarbon (TPH) Concentrations at Sampled Industrial Laundry
Facilities 9-10
Chapter 10
Table 10-1 Facilities and Sample Points Used to Develop Long-term Averages and
Limitations 10-4
Table 10-2 Aggregation of Field Duplicates 10-9
Table 10-3 Aggregation of Grab Samples and Daily Values 10-10
Table 10-4 Aggregation of Data Across Streams 10-11
Table 10-5 Metals Subcategory: Long-Term Averages Replaced by the Baseline
Values ....' 10-15
Table 10-6 Cases where Variability Factors were Transferred 10-31
Table 10-7 Long-Term Averages and Variability Factors Corresponding to Exampl
for Hypothetical Group X 10-34
Table 10-8 BOD5 and TSS Parameters for Organics Subcategory 10-38
Table 10-9 TSS Parameters for Metal Finishing 10-38
Chapter 11
Table 11-1 Standard Capital Cost Algorithm 11-2
Table 11-2 Standard Operation and Maintenance Cost Factor Breakdown 11-3
Table 11-3 CWT Treatment Technology Costing Index - A Guide to the Costing
Methodology Sections 11-4
Table 11-4 Cost Equations for Selective Metals Precipitation in Metals Options 2
and3 H-6
Table 11-5 Cost Equations for Secondary Chemical Precipitation in Metals Options
2 and 3 11-8
Table 11-6 Cost Equations for Tertiary Chemical Precipitation in Metals Option 3 ..11-9
Table 11-7 Cost Equations for Primary Chemical Precipitation in Metals Option 4 11-12
Table 11-8 Cost Equations for Secondary (Sulfide) Precipitation for Metals
Option 4 11-5
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Table 11-9 Cost Equations for Clarification and Plate and Frame Liquid Filtration
inMetals Option2,3,4 11-16
Table 11-10 Design Parameters Used for Equalization in CAPDET Program 11-17
Table 11-11 Summary of Cost Equations for Equalization 11-18
Table 11-12 Cost Equations for Air Stripping ' 11-19
Table 11-13 Cost Equations for Multi-Media Filtration 11-20
Table 11-14 Cost Equations for Cyanide Destruction 11-21
Table 11-15 Cost Equations for Secondary Gravity Separation 11-21
Table 11-16A Estimate Holding Tank Capacities for DAF. Systems 11-22
Table 11-16B Estimate Labor Requirements for DAF Systems 11-23
Table 11-17 Cost Equations for Dissolved Air Flotation (DAF) in Oils Options 8
and 9 11-25
Table 11-18 Cost Equations for Sequencing Batch Reactors 11-26
Table 11-19 Cost Equations for Plate and Frame Sludge Filtration in Metals
Option2, 3 and4 11-28
Table 11-20 Cost Equations for Filter Cake Disposal for Metals Options 2 and 3 . 11-30
Table 11-21 Monitoring Frequency Requirements 11-31
Table 11-22 Analytical Cost Estimates 11-32
Table 11-23 RCRA Permit Modification Costs Reported in WTI Questionnaire ... 11-33
Table 11-24 State Land Costs for the CWT Industry Cost Exercise 11-34
Table 11-25 Cost of Implementing BPT Regulations [in 1997 dollars] 11-44
Table 11-26 Cost of Implementing PSES Regulations [in of 1997 dollars] 11-45
Chapter 12
Table 12-1 Metals Subcategory Pollutant Concentration Profiles for Current
Loadings 12-3
Table 12-2 Example of Metals Subcategory Influent Pollutant Concentration
Calculations 12-4
Table 12-3 Treatment-in-Place Credit Applied to Oils Facilities 12-9
Table 12-4 Biphasic Sample Calculations (Summary of rules for combining
aqueous/organic phase cones.) ' 12-11
Table 12-5 Examples of Combining Aqueous and Organic Phases for Sample
32823 12-12
Table 12-6 A Example of Five Substitution Methods for Non-Detected
Measurements of Hypothetical Pollutant X 12-14
Table 12-6B Difference in Oils Subcategory Loadings After Non-Detect
Replacement Using EPA Approach 12-15
Table 12-7 Oils Subcategory Emulsion Breaking/Gravity Separation Data Sets
Before and After Sample-Specific Non-Detect Replacement 12-16
Table 12-8 Current Loadings Estimates for the Organics Subcategory (units = ug/L) 12-34
Table 12-9 Long Term Average Concentrations (ug/L) for All Pollutants of Concer 12-37
Table 12-10 Summary of Pollutant Loadings and Removals for the CWT Metals
Subcategory 12-42
Table 12-11 Summary of Pollutant Loadings and Removals for the CWT Oils
Subcategory 12-43
Table 12-12 Summary of Pollutant Loadings and Removals for the CWT Organics
Subcategory 12-45
Table 12-13 Summary of Pollutant Loadings and Removals for the Entire CWT
Industry 12-47
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Chapter 13
Table 13-1 Projected Air Emissions at CWT Facilities 13-3
Table 13-2 Projected Incremental Filter Cake Generation at CWT Facilities 13-4
Table 13-3 National Volume of Hazardous and Non-hazardous Waste Sent to
Landfills I3'4
Table 13-4 Projected Energy Requirements for CWT Facilities 13-5
Table 13-5 Projected Labor Requirements for CWT Facilities 13-6
Chapter 14
Table 14-1 Waste Receipt Classification 14-4
Table 14-2 RCRA and Waste Form Codes Reported by Facilities in 1989 14-8
Table 14-3 Waste Form Codes in the Metals Subcategory 14-14
Table 14-4 Waste Form Codes in the Oils Subcategory 14-14
Table 14-5 Waste Form Codes in the Organics Subcategory 14-15
Table 14-6 Proposed BAT Daily Maximum Limits for Selected Parameters 14-17
Table 14-7 "Building Block Approach" Calculations for Selected Parameters for
Example 14-1 14-18
Table 14-8. Proposed Daily Maximum Pretreatment Standards for Selected
Parameters 14-21
Table 14-9 CWF Calculations for Selected Parameters for Example 14-1 Using 40
CFR 403 and Guidance in EPA's Industrial User Permitting Guidance
Manual 14'21
Table 14-10 CWF Calculations for Selected Parameters in Example 14-1 Using the
Guidance Manual for Use of Production-Based Pretreatment Standards
and Combined Waste Stream Formula 14-22
Table 14-11 Daily Maximum Limits and Standards for Example 14-1 14-22
Table 14-12 Allowances for Use in Applying the Combined Waste Stream Formula
for CWT Oils Subcategory Flows (PSES or PSNS) 14-23
Table 14-13 Allowances for Use in Applying the Combined Waste Stream Formula
for CWT Organics Subcategory Flows 14-23
Table 14-14 CWF Calculations for Example 14-1 Including Allowances 14-24
Chapter 15
Table 15-1 Analytical Methods and Baseline Values 15-4
Table 15-2 Baseline values for Method 85.01 15-7
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LIST OF FIGURES
Chapter 6
Figure 6-1 Pollutant of Concern Methodology 6-3
Chapter 7
Figure 7-1 Selection of Pollutants That May Be Regulated for Direct Discharge
for Each Subcategory 7-2
Figure 7-2 Selection of Pollutants to be Regulated for Indirect Discharges fo
Each Subcategory 7-3
Figure 7-3 Determination of Volatile Pollutants for Oils Subcategory. 7-7
Chapter 8
Figure 8-1 Equalization System Diagram 8-4
Figure 8-2 Neutralization System Diagram 8-6
Figure 8-3 Clarification System Incorporating Coagulation and Flocculation 8-7
Figure 8-4 Emulsion Breaking System Diagram 8-9
Figure 8-5 Gravity Separation System Diagram 8-11
Figure 8-6 Clarification System Diagram 8-12
Figure 8-7 Dissolved Air Flotation System Diagram 8-14
Figure 8-8 Chromium Reduction System Diagram 8-17
Figure 8-9 Cyanide Destruction by Alkaline Chlorination 8-18
Figure 8-10 Chemical Precipitation System Diagram 8-20
Figure 8-11 Calculated Solubilities of Metal Hydroxides 8-23
Figure 8-12 Multi-Media Filtration System Diagram 8-27
Figure 8-13 Ultrafiltration System Diagram 8-29
Figure 8-14 Reverse Osmosis System Diagram 8-31
Figure 8-15 Lancy Filtration System Diagram 8-32
Figure 8-16 Carbon Adsorption System Diagram 8-34
Figure 8-17 Ion Exchange System Diagram '. 8-37
Figure 8-18 Electrolytic Recovery System Diagram 8-38
Figure 8-19 Air Stripping System Diagram 8-40
Figure 8-20 Liquid CO2 Extraction System Diagram 8-42
Figure 8-21 Sequencing Batch Reactor System Diagram 8-44
Figure 8-22 Trickling Filter System Diagram 8-46
Figure 8-23 Biotower System Diagram 8-48
Figure 8-24 Activated Sludge System Diagram 8-49
Figure 8-25 Plate and Frame Filter Press System Diagram 8-53
Figure 8-26 Belt Pressure Filtration System Diagram 8-55
Figure 8-27 Vacuum Filtration System Diagram 8-56
Chapter 10
Figure 10-1
Modified Delta-Lognormal Distribution 10-17
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Chapter 11
Figure 11-1 Metals Option 4 Model Facility Diagram 11-35
Figure 11-2 Treatment Diagram For Oils Option 9 Facility Improvements 11-39
Chapter 12
Figure 12-1 Calculation of Current Loadings for Oils Subcategory 12-8
Figure 12-2 Methodology for Current Loadings Estimates in Oils Subcategory . 12-32
Chapter 14
Figure 14-1 Waste Receipt Subcategory Classification Diagram 14-6
Figure 14-2 Facility Accepting Waste in All Three Subcategories With Treatment
inEach 14-17
Figure 14-3 Facility Which Accepts Wastes in Multiple Subcategories and Treats
Separately 14-25
Figure 14-4 Categorical Manufacturing Facility Which Also Operates as a CWT 14-26
Figure 14-5 Facility that Commingles Wastewaters after Treatment 14-27
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Chapter
1
BACKGROUND
This chapter provides background
information on the development of this re-
proposed rule. The first sections detail the
legislative backround while the later sections
provide information on the 1995 CWT proposal
and the 1996 CWT Notice of Data Availability.
LEGAL AUTHORITY
1.0
These regulations are proposed under the
authority of Sections 301, 304, 306, 307, 308,
402, and 501 of the Clean Water Act, 33
U.S.C.1311,1314,1316,1317, 1318, 1342, and
1361.
LEGISLATIVE BACKGROUND
Clean Water Act
1.1
1.1.1
Congress adopted the Clean Water Act
(CWA) to "restore and maintain the chemical,
physical, and biological integrity of the Nation's
waters" (Section 101(a), 33 U.S.C. 1251(a)). To
achieve this goal, the CWA prohibits the
discharge of pollutants into navigable waters
except in compliance with the statute. The Clean
Water Act confronts the problem of water
pollution on a number of different fronts. Its
primary reliance, however, is on establishing
restrictions on the types and amounts of
pollutants discharged from various industrial,
commercial, and public sources of wastewater.
Congress recognized that regulating only
those sources that discharge effluent directly into
the nation's waters would not be sufficient to
achieve the CWA's goals. Consequently, the
CWA requires EPA to promulgate nationally
applicable pretreatment standards which restrict
pollutant discharges for those who discharge
wastewater indirectly through sewers flowing to
publicly-owned treatment works (POTWs)
(Section 307(b) and (c), 33 U.S.C. 1317(b) &
(c)). National pretreatment standards are
established for those pollutants in wastewater
from indirect dischargers which may pass through
or interfere with POTW operations. Generally,
pretreatment standards are designed to ensure
that wastewater from direct and indirect industrial
dischargers are subject to similar levels of
treatment. In addition, POTWs are required to
implement local treatment limits applicable to
their industrial indirect dischargers to satisfy any
local requirements (40 CFR 403.5).
Direct dischargers must comply with
effluent limitations in National Pollutant
Discharge Elimination System ("NPDES")
permits; indirect dischargers must comply with
pretreatment standards. These limitations and
standards are established by regulation for
categories of industrial dischargers and are based
on the degree of control that can be achieved
using various levels of pollution control
technology.
Best Practicable Control Technology
Currently Available (BPT) -
Sec.304(b)(l)oftheCWA 1.1.1.1
In the guidelines, EPA defines BPT
effluent limits for conventional, priority,1 and
TIn the initial stages of EPA CWA regulation, EPA
efforts emphasized the achievement of BPT limitations
for control of the "classical" pollutants (for example,
TSS, pH, BODS). However, nothing on the face of
the statute explicitly restricted BPT limitation to sue
pollutants. Following passage of the Clean Water Act
of 1977 with its requirement for points sources to
achieve best available (continued on next page)
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Chapter 1 Background
Development Document for the CWT Point Source Category
non-conventional pollutants. In specifying BPT,
EPA looks at a number of factors. EPA first
considers the cost of achieving effluent reductions
in relation to the effluent reduction benefits. The
Agency also considers: the age of the equipment
and facilities, the processes employed and any
required process changes, engineering aspects of
the control technologies, non-water quality
environmental impacts (including energy
requirements), and such other factors as the
Agency deems appropriate (CWA 304(b)(l)(B)).
Traditionally, EPA establishes BPT effluent
limitations based on the average of the best
performances of facilities within the industry of
various ages, sizes, processes or other common
characteristics. Where, however, existing
performance is uniformly inadequate, EPA may
require higher levels of control than currently in
place in an industrial category if the Agency
determines that the technology can be practically
applied.
Best Conventional Pollutant
Control Technology (BCT) -
Sec. 304(b)(4) of the CWA 1.1.1.2
The 1977 amendments to the CWA
required EPA to identify effluent reduction levels
for conventional pollutants associated with BCT
technology for discharges from existing industrial
point sources. In addition to other factors
specified in Section 304(b)(4)(B), the CWA
requires that EPA establish BCT limitations after
consideration of a two part "cost-reasonableness"
test. EPA explained its methodology for the
development of BCT limitations in July 1986 (51
FR 24974).
Section 304(a)(4) designates the
following as conventional pollutants: biochemical
technology limitations to control discharges of toxic
pollutants, EPA shifted the focus of the guidelines
program to address the listed priority pollutants. BPT
guidelines continue to include limitations to address all
pollutants.
oxygen demand (BOD5), total suspended solids
(TSS), fecal coliform, pH, and any additional
pollutants defined by the Administrator as
conventional. The Administrator designated oil
and grease as an additional conventional pollutant
on July 30, 1979 (44 FR 44501).
Best Available Technology
Economically Achievable (BAT) -
Sec. 304(b)(2) of the CWA 1.1.1.3
In general, BAT effluent limitations
guidelines represent the best economically
achievable performance of plants in the industrial
subcategory or category. The factors considered
in assessing BAT include the cost of achieving
BAT effluent reductions, the age of equipment
and facilities involved, the process employed,
potential process changes, and non-water quality
environmental impacts, including energy
requirements. The Agency retains considerable
discretion in assigning the weight to be accorded
these factors. Unlike BPT limitations, BAT
limitations may be based on effluent reductions
attainable through changes in a facility's
processes and operations. As with BPT, where
existing performance is uniformly inadequate,
BAT may require a higher level of performance
than is currently being achieved based on
technology transferred from a different
subcategory or category. BAT may be based
upon process changes or internal controls, even
when these technologies are not common industry
practice.
New Source Performance Standards
(NSPS) - Sec. 306 of the CWA 1.1.1.4
NSPS reflect effluent reductions that are
achievable based on the best available
demonstrated control technology. New facilities
have the opportunity to install the best and most
efficient production processes and wastewater
treatment technologies. As a result, NSPS should
represent the most stringent controls attainable
through the application of the best available
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Chapter 1 Background
Development Document for the CWT Point Source Category
control technology for all pollutants (that is,
conventional, nonconventional, and priority
pollutants). In establishing NSPS, EPA is
directed to take into consideration the cost of
'achieving the effluent reduction and any non-
water quality environmental impacts arid energy
requirements.
Pretreatment Standards for Existing
Sources(PSES) —
Sec. 307(b) of the CWA 1.1.1.5
PSES are designed to prevent the
discharge of pollutants that pass-through,
interfere-with, or are otherwise incompatible with
the operation of publicly-owned treatment works
(POTW). The CWA authorizes EPA to establish
pretreatment standards for pollutants that pass-
through POTWs or interfere with treatment
processes or sludge disposal methods at POTWs.
Pretreatment standards are technology-based and
analogous to BAT effluent limitations guidelines.
The General Pretreatment Regulations,
which set forth the framework for the
implementation of categorical pretreatment
standards, are found at 40 CFR Part 403. Those
regulations contain a definition of pass-through
that addresses localized rather than national
instances of pass-through and establish
pretreatment standards that apply to all-
non-domestic dischargers. See 52 FR 1586,
January 14, 1987.
Pretreatment Standards for New
Sources (PSNS) -
Sec. 307(b) of the CWA 1.1.1.6
Like PSES, PSNS are designed to
prevent the discharges of pollutants that pass-
through, interfere-with, or are otherwise
incompatible with the operation of POTWs.
PSNS are to be issued at the same time as NSPS.
New indirectdischargers have the opportunity to
incorporate into their plants the best available
demonstrated technologies. ' The Agency
considers the same factors in promulgating PSNS
as it considers in promulgating NSPS.
Section 304(m) Requirements
and Litigation
1.1.2
Section 304(m) of the CWA, added by
the Water Quality Act of 1987, requires EPA to
establish schedules for (1) reviewing and revising
existing effluent limitations guidelines and
standards ("effluent guidelines") and (2)
promulgating new effluent guidelines. On
January 2, 1990, EPA published an Effluent
Guidelines Plan (55 FR 80) that established
schedules for developing new and revised effluent
guidelines for several industry categories. One of
the industries for which the Agency established a
schedule was the Centralized Waste Treatment
Industry.
The Natural Resources Defense Council
(NRDC) and Public Citizen, Inc. filed suit against
the Agency, alleging violation of Section 304(m)
and other statutory authorities requiring
promulgation of effluent guidelines (TSTRDC et
al v. Browner. Civ. No. 89-2980 (D.D.C.)).
Under the terms of a consent decree dated
January 31, 1992, which settled the litigation,
EPA agreed, among other things, to propose
effluent guidelines for the "Centralized Waste
Treatment Industry Category by April 31, 1994
and take final action on these effluent guidelines
by January 31, 1996. On February 4, 1997, the
court approved modifications to the Decree which
revised the deadline to August 1999 for final
action. EPA provided notice of these
modifications on February 26, 1997 at 62 FR
8726.
The Land Disposal
Restrictions Program: 1.1.3
Introduction to RCRA Land
Disposal Restrictions (LDR) 1.1.3.1
The Hazardous and Solid Waste
Amendments (HSWA) to the Resource
Conservation and Recovery Act (RCRA), enacted
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Chanter 1 Background
Development Document for the CWT Point Source Category
on November 8, 1984, largely prohibit the land
disposal of untreated hazardous wastes. Once a
hazardous waste is prohibited from land disposal,
the statute provides only two options for legal
land disposal: meet the treatment standard for the
waste prior to land disposal, or dispose of the
waste in a land disposal unit that has been found
to satisfy the statutory no migration test. A no
migration unit is one from which there will be no
migration of hazardous constituents for as long as
the waste remains hazardous (RCRA Sections
3004(d),(e),(g)(5)). .
Under section 3004, the treatment
standards that EPA develops may be expressed as
either constituent concentration levels or as
specific methods of treatment. The criteria for
these standards is that they must substantially
diminish the toxicity of the waste or substantially
reduce the likelihood of migration of hazardous
constituents from the waste so that short-term
and long-term threats to human health and the
environment are minimized (RCRA Section
3004(m)(l)). For purposes of the restrictions, the
RCRA program defines land disposal to include
any placement of hazardous waste in a landfill,
surface impoundment, waste pile, injection well,
land treatment facility, salt dome formation, salt
bed formation, or underground mine or cave.
Land disposal restrictions are published in 40
CFR Part 268.
EPA has used hazardous waste
treatability data as the basis for land disposal
restrictions standards. First, EPA has identified
Best Demonstrated Available Treatment
Technology (BDAT) for each listed hazardous
waste. BDAT is that treatment technology that
EPA finds to be the most effective for a waste
which is also readily available to generators and
treaters. In some cases, EPA has designated, for
a particular waste stream, a treatment technology
which has been shown to successfully treat a
similar, but more difficult to treat, waste stream.
This ensured that the land disposal restrictions
standards for a listed waste stream were
achievable since they always reflected the actual
treatability of the waste itself or of a more
refractory waste.
As part of the Land Disposal
Restrictions (LDR), Universal Treatment
Standards (UTS) were promulgated as part of the
RCRA phase two final rule (July 27,1994). The
UTS are a series of concentrations for
wastewaters and non-wastewaters that provide a
single treatment standard for each constituent.
Previously, the LDR regulated constituents
according to the identity of the original waste;
thus, several numerical treatment standards might
exist for each constituent. The UTS simplified
the standards by having only one treatment
standard for each constituent in any waste
residue.
The LDR treatment standards established
under RCRA may differ from the Clean Water
Act effluent guidelines proposed here today both
in their format and in the numerical values set for
each constituent. The differences result from the
use of different legal criteria for developing the
limits and resulting differences in the technical
and economic criteria and data sets used for
establishing the respective limits.
The differences in format of the LDR and
effluent guidelines is that LDR establishes a
single daily limit for each pollutant parameter
whereas the effluent guidelines establish monthly
and daily limits. Additionally, the effluent
guidelines provide for several types of discharge,
including new vs. existing sources, and indirect
vs. direct discharge.
The differences in numerical limits
established under the Clean Water Act may
differ, not only from LDR. and UTS, but also
from point-source category to point-source
category (for example, Electroplating, 40 CFR
Part 413; and Metal Finishing, 40 CFR Part 433).
The effluent guidelines limitations and standards
are industry-specific, subcategory-specific, and
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Chapter 1 Background
Development Document for the CWT Point Source Category
technology-based. The numerical limits are
typically based on different data sets that reflect
the performance of specific wastewater
management and treatment practices. Differences
in the limits reflect differences in the statutory
factors that the Administrator is required to
consider in developing technically and
economically achievable limitations and
standards -- manufacturing products and
processes (which, for CWTs involves types of
waste received for treatment), raw materials,
wastewater characteristics, treatability, facility
size, geographic location, age of facility and
equipment, non-water quality environmental
impacts, and energy requirements. A
consequence of these differing approaches is that
similar waste streams can be regulated at
different levels.
Overlap Between LDR Standards and
the Centralized Waste Treatment
Industry Effluent Guidelines 1.1.3.2
EPA's survey for this guideline identified
no facilities discharging wastewater effluent to
land disposal units. There is consequently no
overlap between the proposed regulations for the
CWT Industry and the Universal Treatment
Standards.
by tanker truck, trailer/roll-off bins, drums, barge
or other forms of shipment." Facilities which
received waste from off-site solely from via
pipeline were excluded from the proposed rule.
Facilities proposed for regulation included both
stand-alone waste treatment and recovery
facilities that treat waste received from off-site as
well as those facilities that treat on-site generated
process wastewater with wastes received from
off-site.
The Agency proposed limitations and
standards for an estimated 85 facilities in three
subcategories. The subcategories for the
centralized waste treatment (CWT) industry were
metal-bearing waste treatment and recovery, oily
waste treatment and recovery, and organic waste
treatment and recovery. EPA based the BPT
effluent limitations proposed in 1995 on the
technologies listed in Table 1.1 below. EPA
based BCT, BAT, NSPS, PSES, and PSNS on
the same technologies as BPT.
CENTRALIZED WASTE TREATMENT
INDUSTRY EFFLUENT GUIDELINE
RULEMAKING HISTORY
January 27,1995 Proposal
1.2
1.2.1
On January 27,1995 (60 FR 5464), EPA
proposed regulations to reduce discharges to
navigable waters of toxic, conventional, and non-
conventional pollutants in treated wastewater
from facilities defined in the proposal as
"centralized waste treatment facilities." As
proposed, these effluent limitations guidelines
and pretreatment standards would have applied to
"any facility that treats any hazardous or non-
hazardous industrial waste received from off-site
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Chanter 1 Background
Development Document for the CWT Point Source Category
Table 1.1 Technology Basis for 1995 BPT Effluent Limitations
Proposed Name of Subcategory Technology Basis
Subpart
Metal-Bearing Waste Selective Metals Precipitation, Pressure Filtration, Secondar
Treatment and Precipitation, Solid-Liquid Separation, and Tertiary
Recovery Precipitation
For Metal-Bearing Waste Which Includes
Concentrated Cyanide Streams:
Pretreatment by Alkaline Chlorination
at Elevated Operating Conditions
B
Oily Waste Treatment Ultrafiltration or Ultrafiltration, Carbon Adsorption, and
and Recovery Reverse Osmosis
Organic Waste
Treatment and
Recovery
Equalization, Air Stripping, Biological Treatment, and
Multimedia Filtration
September 16,1996 Notice
of Data Availability
1.2.2
Based on comments received on the 1995
proposal and new information, EPA reexamined
its conclusions about the Oily Waste Treatment
and Recovery subcategory, or "oils subcategory".
(The 1995 proposal had defined facilities in this
subcategory as "facilities that treat, and/or
recover oil from oily waste received from off-
site.") Subsequently, in 1996 EPA noticed the
availability of the new data on this subcategory.
EPA explained that it had underestimated the size
of the oils subcategory, and that the data used to
develop the original proposal may have
mischaracterized this portion of the CWT
industry. EPA had based its original estimates on
the size of this segment of the industry on
information obtained from the 1991 Waste
Treatment Industry Questionnaire. The basis
year for the questionnaire was 1989. Many of the
new oils facilities discussed in this notice began
operation after 1989. EPA concluded that many
of these facilities may have started up or modified
their existing operations in response to
requirements in EPA regulations, specifically, the
provisions of 40 CFR 279, promulgated on
September 10, 1992 (Standards for the
Management of Used Oil). These regulations
govern the handling of used oils under the Solid
Waste Disposal Act and CERCLA. EPA's 1996
notice discussed the additional facilities, provided
a revised description of the subcategory and
described how the 1995 proposal limitations and
standards, if promulgated, would have affected
such facilities. The notice, among other items,
also solicited comments on the use of dissolved
air flotation in this subcategory.
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Chapter
2
DATA COLLECTION
EPA gathered and evaluated technical and
economic data from various sources in the
course of developing the effluent limitations
guidelines and standards for the centralized waste
treatment industry. These data sources include:
• EPA's Preliminary Data Summary for the
Hazardous Waste Treatment Industry,
• Responses to EPA's "1991 Waste Treatment
Industry Questionnaire";
• Responses to EPA's "Detailed Monitoring
Questionnaire";
• EPA's 1990 - 1997 sampling of selected
Centralized waste treatment facilities;
Public comments to EPA's 1995 Proposed
Rule; .
• Public comments to EPA's 1996 Notice of
Data Availability;
• Contact with members of the industry,
environmental groups, pretreatment
coordinators, Association of Municipal
Sewage Authorities (AMSA), regional, state,
and other government representatives; and
• Other literature data, commercial
publications, and EPA data bases.
EPA used data from these sources to profile
the industry with respect to: wastes received for
treatment and/or recovery; treatment/recovery
processes; geographical distribution; and
wastewater and solid waste disposal practices.
EPA then characterized the wastewater generated
by treatment/recovery operations through an
evaluation of water usage, type of discharge or
disposal, and the occurrence of conventional,
non-conventional, and priority pollutants.
The remainder of this chapter details the data
sources utilized in the development of this
reproposal.
PRELIMINARY DATA SUMMARY
2.1
EPA began an effort to develop effluent
limitations guidelines and pretreatment standards
for waste treatment operations in 1986. In this
initial study, EPA looked at a range of facilities,
including centralized waste treatment facilities,
landfills, and industrial waste combustors, that
received hazardous waste from off-site for
treatment, recovery, or disposal. The purpose of
the study was to characterize the hazardous waste
treatment industry, its operations, and pollutant
discharges into national waters. EPA published
the results of this study in the Preliminary Data
Summary for the Hazardous Waste Treatment
Industry in 1989 (EPA 440/1-89/100). During
the same time period, EPA conducted two similar,
but separate, studies of the solvent recycling
industry and the used oil reclamation and re-
refining industry. In 1989, EPA also published
the results of these studies in two reports entitled
the Preliminary Data Summary for the Solvent
Recycling Industry (EPA 440/1-89/102) and the
Preliminary Data Summary for Used Oil
Reclamation and Re-refining Industry (EPA
440/1-89/014).
Based on a thorough analysis of the data
presented in the Preliminary Data Summary for
the Hazardous Waste Treatment Industry, EPA
decided it should develop effluent limitations
guidelines and standards for the centralized waste
treatment industry. EPA also decided to develop
standards for landfills and industrial waste
combustors which were proposed on February 6,
1998 in the Federal Register (63 FR 6426 and 63
FR 6392, respectively). In addition to centralized
waste treatment facilities, EPA also studied fuel
blending operations and waste solidification/
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Chapter 2 Data Collection
Development Document for the CWT Point Source Category
stabilization facilities. As detailed and defined in
the applicability section of the preamble, EPA
has decided not to propose nationally applicable
effluent limitations guidelines and standards for
fuel blending and stabilization operations.
CLEAN WATER ACT
SECTION 308 QUESTIONNAIRES 2.2
Development of Questionnaires 2.2.1
A major source'of information and data used
in developing the proposed effluent limitations
guidelines and standards for the CWT category is
industry responses to questionnaires distributed
by EPA under the authority of Section 308 of the
CWA. EPA developed two questionnaires, the
1991 Waste Treatment Industry Questionnaire
and the Detailed Monitoring Questionnaire, for
this study. The 1991 Waste Treatment Industry
Questionnaire was designed to request 1989
technical, economic, and financial data from,
what EPA believed to be, a census of the
industry. The Detailed Monitoring Questionnaire
was designed to elicit daily analytical data from a
limited number of facilities which would be
chosen after receipt and review of the 1991
Waste Treatment Industry Questionnaire
responses.
In order to niinirnize the burden to centralized
waste treatment facilities, EPA designed the 1991
Waste Treatment Industry Questionnaire such
that recipients could use information reported in
their 1989 Hazardous Waste Biennial Report as
well as any other readily accessible data. The
technical portion of the questionnaire, Part A,
specifically requested information on:
/
• Treatment/recovery processes;
• Types and quantities of waste received for
treatment;
• The industrial waste management practices
used;
• Ancillary waste management operations;
• The quantity treatment, and disposal of
wastewater generated during industrial waste
management;
• Summary analytical monitoring data;
• The degree of co-treatment (treatment of
CWT wastewater with wastewater from other
industrial operations at the facility);
• Cost of the waste treatment/recovery
processes; and
• The extent of wastewater recycling or reuse
at facilities.
Since the summary monitoring information
requested in the 1991 Waste Treatment Industry
Questionnaire was not sufficient for
determination of limitations and industry
variability, EPA designed a follow-up
questionnaire, the Detailed Monitoring
Questionnaire (DMQ), to collect daily analytical
data from a limited number of facilities. EPA
requested all DMQ facilities to submit effluent
wastewater monitoring data in the form of
individual data points rather than monthly
aggregates, generally for the 1990 calendar year.
Some facilities were also requested to submit
monitoring data for intermediate waste treatment
points in an effort to obtain pollutant removal
information across specified treatment
technologies.
Since most CWT facilities do not have
analytical data for their wastewater treatment
system influent, EPA additionally requested
DMQ facilities to submit copies of their waste
receipts for a six week period. Waste receipts are
detailed logs of individual waste shipments sent
to a CWT for treatment EPA selected a six week
period to minimize the burden to recipients and to
create a manageable database.
EPA sent draft questionnaires to industry
trade associations, treatment facilities who had
expressed interest, and environmental groups for
review and comment. EPA also conducted a
pre-test of the 1991 Waste Treatment Industry
Questionnaire at nine centralized waste treatment
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Chanter 2 Data Collection
Development Document for the CWT Point Source Category
facilities to determine if the type of information
necessary would be received from the questions
posed as well as to determine if questions were
designed to minimize the burden to facilities.
EPA did not conduct a pre-test of the Detailed
Monitoring Questionnaire due to the project
schedule limitations.
Based on comments from the reviewers, EPA
determined the draft questionnaire required minor
adjustments in the technical section and
substantial revisions for both the economic and
financial sections. EPA anticipated extensive
comments, since this was EPA's first attempt at
requesting detailed information from a service
industry as opposed to a manufacturing-based
industry.
As required by the Paperwork Reduction Act,
44 U.S.C. 3501 et seq., EPA submitted the
questionnaire package (including the revised
1991 Waste Treatment Industry Questionnaire
and the Detailed Monitoring Questionnaire) to the
Office of Management and Budget (OMB) for
review, and published a notice in the Federal
Register to announce the questionnaire was
available for review and comment (55 FR
45161). EPA also redistributed the questionnaire
package to industry trade associations,
centralized waste treatment industry facilities,
and environmental groups that had provided
comments on the previous draft and to any others
who requested a copy of the questionnaire
package.
No additional comments were received and
OMB cleared the entire questionnaire package for
distribution on April 10,1991.
Distribution of Questionnaires
2.2.2
In 1991, under the authority of Section 308
of the CWA, EPA sent the Waste Treatment
Industry Questionnaire to 455 facilities that the
Agency had identified as possible CWT facilities.
Because there is no specific centralized waste
treatment industry Standard Industrial Code
(SIC), identification of facilities was difficult.
EPA looked to directories of treatment facilities,
other Agency information sources, and even
telephone directories to identify the 455 facilities
which received the questionnaires. EPA received
responses from 413 facilities indicating that 89
treated or recovered material from off-site
industrial waste in 1989. The remaining 324
facilities did not treat, or recover materials from
industrial waste from off-site. Four of the 89
facilities only received waste via a pipeline (fixed
delivery system) from the original source of
wastewater generation.
EPA obtained additional information from
the 1991 Waste Treatment Industry
Questionnaire recipients through follow-up phone
calls and written requests for clarification of
questionnaire responses.
After evaluation of the 1991 Waste
Treatment Industry Questionnaire responses,
EPA selected 20 in-scope facilities from the 1991
Waste Treatment Industry Questionnaire mailing
list to complete the Detailed Monitoring
Questionnaire. These facilities were selected
based on: the types and quantities of wastes
received for treatment; the quantity of on-site
generated wastewater not resulting from
treatment or recovery of off-site generated waste;
the treatment/recovery technologies and practices;
and the facility's wastewater discharge permit
requirements. All 20 DMQ recipients responded.
WASTEWATER SAMPLING
AND SITE VISITS
Pre-1989 Sampling Program
2.3
2.3.1
From 1986 to 1987, EPA conducted site
visits and sampled at twelve facilities to
characterize the waste streams and on-site
treatment technology performance at hazardous
waste incinerators, Subtitle C and D landfills, and
hazardous waste treatment facilities as part of the
Hazardous Waste Treatment Industry Study. All
2-3
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Chapter 2 Data Collection
' Development Document for the CWT Point Source Category
of the facilities in this sampling program had
multiple operations, such as incineration and
commercial wastewater treatment The sampling
program did not focus on characterizing the
individual waste streams from individual
operations. Therefore, the data collected cannot
be used for the characterization of centralized
waste treatment wastewater, the assessment of
treatment performance, or the development of
limitations and standards. Information collected
in the study is presented in the Preliminary Data
Summary for the Hazardous Waste Treatment
Industry (EPA 440/1-89/100).
1989-1997 Site Visits
2.3.2
Between 1989 and 1993, EPA visited 27
centralized waste treatment facilities. The
purpose of these visits was to collect various
information about the operation of CWTs, and, in
most cases, to evaluate each facility as a potential
week-long sampling candidate. EPA selected
these facilities based on the information gathered
by EPA during the selection of the Waste
Treatment Industry Questionnaire recipients and
the subsequent questionnaire responses. ,
In late 1994, EPA visited an additional four
facilities which specialize in the treatment of
bilge waters and other dilute oily wastes. These
facilities were not in operation at the time the
questionnaire was mailed, but were identified by
EPA through contact with the industry and
AMSA. EPA visited these facilities to evaluate
them as potential sampling candidates and to
determine if CWT operations at facilities which
accept dilute oily wastes or used material were
significantly different than CWT operations at
facilities that accept concentrated oily wastes.
Following the 1995 proposal, EPA visited
nine centralized waste treatment facilities,
including eight additional oils facilities and one
metals facility which had also been visited prior
to the proposal. EPA selected these facilities
based on information obtained by EPA through
proposal public comments, industry contacts, and
EPA regional staff. In late 1997, EPA visited
two pipeline facilities identified prior to the
proposal (one via the questionnaire and the
second through review of the OCPSF database
and follow-up phone calls) in order to
characterize operations at pipeline facilities.
During each facility site visit, EPA gathered
the following information:
• The process for accepting waste for
treatment or recovery;
• The types of waste accepted for treatment;
• Design and operating procedures for
treatment technologies;
• The location of potential sampling points;
• Site specific sampling requirements;
• Wastewater generated on-site and its sources;
• Wastewater discharge option and limitations;
• Solid waste disposal practices;
• General facility management practices; and
• Other facility operations.
Site visit reports were prepared for all visits and
are located in the regulatory record for this
proposal.
Sampling Episodes 2.3.3
Facility Selection 2.3.3.1
EPA selected facilities to be sampled by
reviewing the information received during site
visits and assessing whether the wastewater
treatment system (1) was theoretically effective in
removing pollutants, (2) treated wastes received
from a variety of sources, (3) was operated in
such a way as to optimize the performance of the
treatment technologies, and (4) applied waste
management practices mat increased the
effectiveness of the treatment unit.
EPA also evaluated whether the CWT
portion of each facility flow was adequate to
assess the treatment system performance for the
2-4
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Chapter 2 Data Collection
Development Document for the CWT Point Source Category
centralized waste treatment waste stream. At
some facilities, the centralized waste treatment
operations were minor portions of the overall site
operation. In such cases, where the centralized
waste treatment waste stream is commingled with
non-centralized waste treatment streams prior to
treatment, characterization of this waste stream
and assessment of treatment performance is
difficult. Therefore, data from these commingled
systems could not be used to establish effluent
limitations guidelines and standards for the
centralized waste treatment industry.
Another important consideration in the
sampling facility selection process was the
commingling of wastes from more than one
centralized waste treatment subcategory. For'
example, many facilities treated metal-bearing
and oily waste in the same treatment system. In
such cases, EPA did not select these facilities for
treatment technology sampling since EPA could
not determine whether a decrease in pollutant
concentrations in the commingled stream would
be due to ,an efficient treatment system or
dilution.
Using the criteria detailed above, EPA
selected 14 facilities to sample in order to collect
wastewater treatment efficiency data to be used to
establish effluent limitations guidelines and
standards for the centralized waste treatment
industry. Twelve facilities were sampled prior to
the 1995 proposal and four facilities (two
additional and two resampled) were sampled after
the proposal.
Sampling Episodes 2.3.3.2
After EPA selected a facility to sample, EPA
prepared a draft sampling plan which described
the location of sample points, the analysis to be
performed at specified sample points, and the
procedures to be followed during the sampling
episode. Prior to sampling, EPA provided a copy
of the draft sampling plan to the facility for
review and comment to ensure EPA properly
described and understood facility operations. All
comments were incorporated into the final
sampling plan.
During the sampling episode, EPA collected
samples of influent, intermediate, and effluent
streams, preserved the samples, and sent them to
EPA-approved laboratories. Facilities were given
the option to split samples with EPA, but most
facilities declined. Sampling episodes were
generally conducted over a five-day period during
which EPA obtained 24-hour composite samples
for continuous systems and grab samples for
batch systems.
Following the sampling episode, EPA
prepared a draft sampling report that included
descriptions of the treatment/recovery processes,
sampling procedures, and analytical results. EPA
provided draft reports to facilities for comment
and review. All corrections were incorporated
into the final report. Both final sampling plans
and reports for all episodes are located in the
regulatory record for this reproposal.
The specific constituents analyzed at each
episode and sampling point varied and depended
on the waste type being treated and the treatment
technology being evaluated. At the initial two
sampling episodes, the entire spectrum of
chemical compounds for which there are
EPA-approved analytical methods were analyzed
(more than 480 compounds). Table 2-1 provides
a complete list of these pollutants. After a review
of the initial analytical data, the number of
constituents analyzed was decreased by omitting
analyses for dioxins/furans, pesticides/herbicides,
methanol, ethanol, and formaldehyde.
Pesticides/herbicides were analyzed on a limited
basis depending on the treatment chemicals used
at facilities. Dioxin/furan analysis was only
performed on a limited basis for solid/filter cake
samples to assess possible environmental
impacts.
Data resulting from the influent samples
contributed to the characterization of this
2-5
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Chapter 2 Data Collection
Development Document for the CWT Point Source Category
industry, development of the list of pollutants of
concern, and development of raw waste
characteristics. EPA used the influent,
intermediate, and effluent points to analyze the
efficacy of treatment at the facilities and to
develop current discharge concentrations,
loadings, and treatment technology options for
the centralized waste treatment industry. Finally,
EPA used data collected from the effluent points
to calculate the long term averages (LTAs) for
each of the proposed regulatory options. The use
of this data is discussed in detail in subsequent
chapters.
2-6
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Chapter 2. Data Collection
Development Document for the CWTPoint Source Category
Table 2-1. Chemical Compounds Analyzed Under EPA Analytical Method
Pollutant
CasNum
CLASSSICAL WET CHEMISTRY
Amenable Cyanide
Ammonia Nitrogen
BOD
Chloride
COD
Fluoride
Hexane Extractable Mater.
Hexavalent Chromium
Nitrate/nitrite
PH
Recoverable Oil & Grease
TDS
TOC
Total Cyanide
Total Phenols
Total Phosphorus
Total Solids
Total Sulfide
TSS
C-025
7664-41-7
C-002
16887-00-6
C-004 .
16984-48-8
C-036
18540-29-9
C-005
C-006
C-007
C-010
C-012
57-12-5
C-020
14265-44-2
C-008
18496-25-8
C-009
1613: DlOXINS/FURANS
2378-TCDD *
2378-TCDF
12378-PECDD
12378-PECDF
23478-PECDF
123478-HXCDD
123678-HXCDD
123789-HXCDD
123478-HXCDF
123678-HXCDF
123789-HXCDF
234678-HXCDF
1234678-HPCDD
1234678-HPCDE
1234789-HPCDF
Ocdd
Ocdf
1746-01-6
51207-31-9
40321-76-4
57117-41-6
57117-31-4
39227-28-6
57653-85-7
19408-74-3
70648-26-9
57117-44-9
72918-21-9
60851-34-5
35822-46-9
67562-39-4
55673-89-7
3268-87-9
39001-02-0
1657: PESTICIDES/HERBICIDES
Azinphos Ethyl
Azinphos Methyl
Chlorfevinphos
Chlorpyrifos
Coumaphos
Crotoxyphos
Def
Demeton a
Demeton B
Diazinon
Dichlorfenthion
Dichlorvos
Dicrotophos
Dimethoate
Dioxathion
2642-71-9
86-50-0
470-90-6
2921-88-2
56-72-4
7700-17-6
78-48-8
8065-48-3A
8065-48-3B
333-41-5
97-17-6
62-73-7
141-66-2
60-51-5
78-34-2
Pollutant
Disulfoton
Epn
Ethion
Ethoprop
Famphur
Fensulfothion
Fenthion
Hexamethylphosphoramide
Leptophos
Malathion
Merphos
Methamidophos
Methyl Chlorpyrifos
Methyl Parathion
Methyl Trithion
Mevinphos
Monocrotophos
Naled
Parathion (Ethyl)
Phorate
Phosmet
Phosphamidon E
Phosphamidon Z
Ronnel
Sulfotepp
Sulprofos
Tepp .
Terbufos
Tetiachlorvinphos
Tokuthion
Trichlorfon
Trichloronate
Tricresylphosphate
Trimethylphosphate
CasNum
298-04-4
2104-64-5
563-12-2
13194-48-8
52-85-7
115-90-2
55-38-9
680-31-9
21609-90-5
121-75-5
150-50-5
10265-92-6
5598-13-0
298-00-0
953-17-3
7786-34-7
6923-22-4
300-76-5
56-38-2
298-02-2
732-11-6
297-99-4
23783-98-4
299-84-3
3689-24-5
35400-43-2
107-49-3
13071-79-9
22248-79-9
34643-46-4
52-68-6
. 327-98-0
78-30-8
512-56-1
1656: PESTICIDES/HERBICIDES
Acephate
Acifluorfen
Alachlor
Aldrin
Atrazine
Benfluralin
Alpha-bhc
Beta-bhc
Gamma-bhc
Delta-bhc
Bromacil
Bromoxynil Octanoate
Butachlor
Captafol
Captan
Carbophenothion
Alpha-chlordane
Gamma-chlordane
Chlorobenzilate
30560-19-1
50594-66-6
15972-60-8
309-00-2
1912-24-9
1861-40-1
319-84-6
319-85-7
58-89-9
319-86-8
314-40-9
1689-99-2
23184-66-9
2425-06-1
133-06-2
786-19-6
5103-71-9
5103-74-2
510-15-6
Pollutant
Chloroneb
Chloropropylate
Chlorothalonil
Dibromochloropropane
Dacthal (Dcpa)
4,4'-ddd
4,4'-dde
4,4'-ddt
Diallate a
Diallate B
Dichlone
Dicofol
Dieldrin
Endosulfan I
Endosulfan li
Endosulfan Sulfate
Endrin
Endrin Aldehyde
Endrin Ketone
Ethalfluralin
Etradiazole
Fenarimol
Dicofol
Dieldrin
Endosulfan I
Endosulfan li
Endosulfan Sulfate
Endrin
Endrin Aldehyde
Endrin Ketone
Ethalfluralin
Etradiazole
Fenarimol
Dicofol
Dieldrin
Endosulfan I
Endosulfan li
Endosulfan Sulfate
Endrin
Endrin Aldehyde
Endrin Ketone
Ethalfluralin
Etradiazole
Fenarimol
Dicofol
Dieldrin
Endosulfan I
Endosulfan li
Endosulfan Sulfate
Endrin
Endrin Aldehyde
Endrin Ketone
Ethalfluralin
CasNum
2675-77-6
5836-10-2
1897-45-6
96-12-8
1861-32-1
72-54-8
72-55-9
50-29-3
2303-16-4A
2303-16-4B
117-80-6
115-32-2
60-57-1
959-98-8
33213-65-9
1031-07-8
72-20-8
7421-93-4
53494-70-5
55283-68-6
2593-15-9
60168-88-9
115-32-2
60-57-1
959-98-8
33213-65-9
1031-07-8
72-20-8
7421-93-4
53494-70-5
55283-68-6
2593-15-9
60168-88-9
115-32-2
60-57-1
959-98-8
33213-65-9
1031-07-8
72-20-8
7421-93-4
53494-70-5
55283-68-6
2593-15-9
60168-88-9
115-32-2
60-57-1
959-98-8
33213-65-9
1031-07-8
72-20-8
7421-93-4
53494-70-5
55283-68-6
2-7
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Chanter 2 Data Collection
Development Document for the CWT Point Source Category
Table 2-1. Chemical Compounds Analyzed Under EPA Analytical Methods (continued
Pollutant
Cas
Pollutant
CasNum
Pollutant
Trifluralin 1582-09-8
1658: PESTICIDES/HERBICIDES
Dalapon 75-99-0
Dicamba 1918-00-9
Dichloroprop 120-36-5
Dinoseb 88-85-7
Mcpa 94-74-6
Mcpp 7085-19-0
Picloram 1918-02-1
2,4-d 94-75-7
2,4-db 94-82-6
2,4,5-t 93-76-5
2,4,5-tp 93-72-1
1620: METALS
Aluminum 7429-90-5
Antimony 7440-36-0
Arsenic 7440-38-2
Barium 7440-39-3
Beryllium 7440-41-7
Bismuth 7440-69-9
Boron 7440-42-8
Cadmium 7440-43-9
Calcium 7440-70-2
Cerium 7440-45-1
Chromium 7440-47-3
Cobalt 7440-48-4
Copper 7440-50-8
Dysprosium 7429-91-6
Erbium 7440-52-0
Europium 7440-53-1
Gadolinium 7440-54-2
Gallium 7440-55-3
Germanium 7440-56-4
Gold 7440-57-5
Hamium 7440-58-6
Holmium 7440-60-0
Beryllium 7440-41-7
Bismuth 7440-69-9
Boron 7440-42-8
Cadmium 7440-43-9
Calcium 7440-70-2
Cerium 7440-45-1
Chromium 7440-47-3
Cobalt 7440-48-4
Copper 7440-50-8
Dysprosium 7429-91-6
Erbium 7440-52-0
Europium 7440-53-1
Gadolinium 7440-54-2
Gallium 7440-55-3
Germanium 7440-56-4
Gold 7440-57-5
Hafnium 7440-58-6
Phosphorus
Platinum
Potassium
Praseodymium
Rhenium
Rhodium
Ruthenium
Samarium
Scandium
Selenium
Silicon
Silver
Sodium
Strontium
Sulfur
Tantalum
Tellurium
Terbium
Thallium
Thorium
Thulium
Tin
Titanium
Tungsten
Uranium
Vanadium
Ytterbium
Yttrium
Zinc
Zirconium
7723-14-0
7440-06-4
7440-09-7
7440-10-0
7440-15-5
7440-16-6
7440-18-8
7440-19-9
7440-20-2
7782-49-2
7440-21-3
7440-22-4
7440-23-5
7440-24-6
7704-34-9
7440-25-7
13494-80-9
7440-27-9
7440-28-0
7440-29-1
7440-30-4
7440-31-5
7440-32-6
7440-33-7
7440-61-1
7440-62-2
7440-64-4
7440-65-5
7440-66-6
7440-67-7
1624: VOLATILE ORGANICS
1,1-dichloroethane 75-34-3
1,1-dichloroethene 75-35-4
1,1,1-trichloroethane 71-55-6
1,1,1,2-tetrachloroethane 630-20-6
1,1,2-trichloroethane 79-00-5
1,1,2,2-tetrachloroethane 79-34-5
1,2-dibromoethane 106-93-4
1,2-dichloroethane 107-06-2
1,2-dichloropropane 78-87-5
1,2,3-trichloropropane 96-18-4
1,3-dichloropropane 142-28-9
1,4-dioxane 123-91-1
2-butanone (Mek) 78-93-3
2-chloro-l,3-butadiene 126-99-8
2-chloroethylvinyl Ether 110-75-8
2-hexanone 591-78-6
2-methyl-2-propenenitrile 126-98-7
2-propanone (Acetone) 67-64-1
2-propenal (Acrolein) 107-02-8
Vanadium 7440-62-2
Ytterbium 7440-64-4
Yttrium 7440-65-5
Acrylonitrile 107-13-1
Benzene 71-43-2
Bromodichloromethane 75-27-4
Bromoform 75-25-2
Bromomethane 74-83-9
Carbon Disulfide 75-15-0
Chloroacetonitrile 107-14-2
Chlorobenzene 108-90-7
Chloroethane 75-00-3
Chloroform 67-66-3
Chloromethane 74-87-3
Cis-l,3-dichloropropene 10061-01-5
Crotonaldehyde 4170-30-3
Dibromochloromethane 124-48-1
Dibromomethane 74-95-3
Diethyl Ether 60-29-7
Ethyl Benzene 100-41-4
Ethyl Cyanide 107-12-0
Ethyl Methacrylate 97-63-2
lodomethane 74-88-4
Isobutyl Alcohol 78-83-1
Methylene Chloride 75-09-2
M-xylene 108-38-3
O+pXylene 136777-61-2
Tetrachloroethene 127-18-4
Tetrachloromethane 56-23-5
Toluene 108-88-3
Trans-l,2-dichloroethene 156-60-5
Trans-l,3-dichloropropene 10061-02-6
Trans-l,4-dichloro-2-butene 110-57-6
Trichloroethene 79-01-6
Trichlorofluoromethane 75-69-4
Vinyl Acetate 108-05-4
Vinyl Chloride 75-01-4
1625: SEMIVOLATILE ORGANICS
1-methylfluorene 1730-37-6
1-methylphenanthrene 832-69-9
1-phenylnaphthalene 605-02-7
l,2-dibromo-3-chloropropane 96-12-8
1,2-dichlorobenzene 95-50-1
1,2-diphenylhydrazine 122-66-7
1,2,3-trichlorobenzene 87-61-6
1,2,3-trimethoxybenzene 634-36-6
1,2,4-trichlorobenzene 120-82-1
1,2,4,5-tetrachlorobenzene 95-94-3
l,2:3,4-diepoxybutane 1464-53-5
1,3-benzenediol (Resorcinol) 108-46-3
l,3-dichloro-2-propanol 96-23-1
1,3-dichlorobenzene 541-73-1
1,3,5-trithiane 291-21-4
1,4-dichlorobenzene 106-46-7
1,4-dinitrobenzene 100-25-4
1.4-naphthoquinone 130-15-4
2-8 -
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Chapter 2 Data Collection
Development Document for the CWTPoint Source Category
Table 2-1. Chemical Compounds Analyzed Under EPA Analytical Methods (continued
Pollutant
1,5-naphthalenediamine
2-bromochlorobenzene
2-chloronaphthalene
2-chlorophenol
2-isopropylnaphthalene
2-methyl-4,6-dinitrophenol
2-methylbenzothioazole
2-methylnaphthalene
2-nitroaniline
2-nitrophenol
2-phenyInaphthalene
2-picoline
2-(Methylthio)benzothiazole
2,3-benzofluorene
2,3-dichloroaniline
2,3-dichloronitrobenzene
2,3,4,6-tetrachlorophenol
2,3,6-tricWorophenol
2,4-diaminotoluene
2,4-dichlorophenol
2,4-dimethyiphenol
2,4-dinitrophenol
2,4-dinitrotoIuene
2,4,5-trichlorophenol
2,4,5-trimethylaniline
2,4,6-trichlorophenol
2,6-dichloro-4-nitroaniline
2,6-dichlorophenol
2,6-dinitrotoluene
2,6-di-tert-bu1yl-p-benzoquinone
3-bromochlorobenzene
3-chIoronitrobenzene
3-methylcholanthrene
3-nitroaniline
3,3-dichlorobenzidine
3,3'-dimethoxybenzidine
3,5-dibromo-4-hydroxybenzonitriIe
3,6-dimethylphenanthrene
4-aminobiphenyl
4-bromophenyl Phenyl Ether
4-chloro-2-nitroaniline
4-chIoro-3-methylphenol
4-chloroaniIine
4-chlorophenyl Phenyl Ether
4-nitroaniIine
4-nitrobiphenyl
4-nitrophenol
4,4-methylene-bis(2-chloroaniline)
4,5-methylene-phenanthrene
5-chloro-o-toluidine
5-nitro-o-toluidine
7,12-dimethylbenz(a)anthracene
Acenaohthene
CasNum
2243-62-1
694-80-4
91-58-7
95-57-8
2027-17-0
534-52-1
120-75-2
91-57-6
88-74-4
88-75-5
612-94-2
109-06-8
615-22-5
243-17-4
608-27-5
3209-22-1
58-90-2
933-75-5
95-80-7
120-83-2
105-67-9
51T28-5
121-14-2
95-95-4
137-17-7
88-06-2
99-30-9
87-65-0
606-20-2
719-22-2
108-37-2
121-73-3
56-49-5
99-09-2
91-94-1
119-90-4
1689-84-5
1576-67-6
92-67-1
101-55-3
89-63-4
59-50-7
106-47-8
7005-72-3
100-01-6
92-93-3
100-02-7
101-14-4
203-64-5
95-79-4
99-55-8
57-97-6
83-32-9
Pollutant
Acenaphthylene
Acetophenone
Alpha-naphthylamine
Alpha-terpineol
Aniline
Anthracene
Aramite
Benzanthrone
Benzenethiol
Benzidine
Benzole Acid
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(ghi)perylene
Benzo(k)fluoranthene
Benzyl Alcohol
CasNum
208-96-8
98-86-2
134-32-7
98-55-5
62-53-3
120-12-7 '
140-57-8
82-05-3
108-98-5
92-87-5
65-85-0
56-55-3
50-32-8
205-99-2
191-24-2
207-08-9
100-51-6
1625: SEMNOLATILE ORGANICS
Beta-naphthylamine
Biphenyl
Bis(2-chloroethoxy) Methane
Bis(2-chloroethyl) Ether
Bis(2-chloroisopropyl) Ether
Bis(2-ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Carbazole
Chrysene
Crotoxyphos
Dibenzofuran
Dibenzothiophene
Dibenzo(a,h)anthracene
Diethyl Phthalate
Dimethyl Phthalate
Dimethyl Sulfone .
Di-n-butyl Phthalate
Di-n-octyl Phthalate
Diphenyl Ether
Diphenylamine
Diphenyldisulfide
Ethyl Methanesulfbnate
Ethylenethiourea
Ethynylestradiol-3-
methyl Ether
Fluoranthene
Fluorene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Hexachloropropene
HexanoicAcid
Indeno( 1 ,2,3-cd)pyrene
Isophorone
Isosafrole
91-59-8
92-52-4
111-91-1
111-44-4
108-60-1
117-81-7
85-68-7
86-74-8
218-01-9
7700-17-6
132-64-9
132-65-0
53-70-3
84-66-2
131-11-3
67-71-0
84-74-2
117-84-0
101-84-8
122-39-4
882-33-7
62-50-0
96-45-7
72-33-3
206-44-0
86-73-7
118-74-1
87-68-3
77-47-4
67-72-1
1888-71-7
142-62-1
193-39-5
78-59-1
120-58-1
Pollutant
Longifolene
Malachite Green
Methapyrilene
Methyl Methanesulfonate
Naphthalene
N-C10(N-decane)
N-C12 (N-dodecane)
N-C14 (N-tetradecane)
N-C16 (N-hexadecane)
N-C18 (N-octadecane)
N-C20 (N-eicosane)
N-C22 (N-docosane)
N-C24 (N-tetracosane)
N-C26 (N-hexacosane)
N-C28 (N-octacosane)
N-C30 (N-triacontane)
Nitrobenzene
N-nitrosodiethylamine
N-nitrosodimethylamine
N-nitrosodi-n-butylamine
N-nitrosodi-n-propylamine
N-nitrosodiphenylamine
N-nitrosomethyl -Ethylamine
N-nitrosomethyl-phenylamine
N-nitrosomorpholine
N-nitrosopiperidine
N,n-dimethylformamide
O-anisidine
O-cresol
O-toluidine
P-cresol
P-cymene
P-dimethylamino-azobenzene
Pentachlorobenzene
Pentachloroethane
Pentachlorophenol
Pentamethylbenzene
Perylene
Phenacetin
Phenanthrene
Phenol
Phenothiazine
Pronamide
Pyrene
Pyridine
Safrole
Squalene
Styrene
Thianaphthene
(2,3-benzothiophene)
Thioacetamide
Thioxanthone
Triphenylene
Tripropyleneglycolmethyl Ether
CasNum
475-20-7
569-64-2
91-80-5
66-27-3
91-20-3
124-18-5
112-40-3
629-59-4
544-76-3
593-45-3
112-95-8
629-97-0
646-31-1
630-01-3
630-02-4
638-68-6
98-95-3
55-18-5
62-75-9
924-16-3
621-64-7
86-30-6
10595-95-6
614-00-6
59-89-2
100-75-4
68-12-2
90-04-0
95-48-7
95-53-4
106-44-5
99-87-6
60-11-7
608-93-5
76-01-7
87-86-5
700-12-9
198-55-0
62-44-2
85-01-8
108-95-2
92-84-2
23950-58-5
129-00-0
110-86-1
94-59-7
7683-64-9
100-42-5
95-15-8
62-55-5
492-22-8
217-59-4
20324-33-8
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Chapter 2 Data Collection
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Metal-Bearing Waste Treatment
and Recovery Sampling 2.3.3.3
Between 1989 and 1994, EPA conducted six
sampling episodes at facilities classified in the
metals subcategory. Two of these facilities were
re-sampled in 1996 following the proposal. Only
one of those facilities sampled discharged to a
surface water. The rest are indirect dischargers.
All of the facilities used metals precipitation
as a means for treatment, but each of the systems
was unique due to the treatment chemicals used
and the system configuration and operation.
Most facilities precipitated metals in batches.
One facility segregated waste shipments into
separate batches to optimize the precipitation of
specific metals, then commingled the treated
batches to precipitate additional metals. Another
facility had a continuous system for precipitation
in which the wastewater flowed through a series
of treatment chambers, each using a different
treatment chemical. EPA evaluated the following
treatment technologies: primary, secondary, and
tertiary precipitation, selective metals
precipitation, gravity separation, multi-media
filtration, clarification, liquid and sludge
filtration, and treatment technologies for cyanide
destruction.
EPA conducted sampling at metals facilities
after the 1995 proposal to determine what effect
total dissolved solids (TDS) concentrations had
on the performance of metals precipitation
processes. This issue was raised in public
comments to the 1995 proposed rule. EPA
resampledtwo facilities which had been sampled
prior to the first proposal. The first facility
formed the technology basis for the 1995
proposed metals subcategory regulatory option
and the second was a facility with high levels of
TDS in the influent waste stream. EPA was
interested in obtaining additional data from the
proposal option facility since they had altered
their treatment systems from those previously
sampled and because EPA failed to collect TDS
information during the original sampling episode.
EPA was interested in collecting additional data
from the second facility because the facility has
high TDS values. EPA used data from both of
the post-proposal sampling episodes to develop
regulatory options considered for the re-proposal.
Oily Waste Treatment
and Recovery Sampling 2.3.3.4
Between 1989 and 1994, EPA conducted
four sampling episodes at oils subcategory
facilities. Two additional oils facilities were
sampled in 1996 following the proposal. All six
are indirect dischargers and performed an initial
gravity separation step with or without emulsion
breaking to remove oil from the wastewater. At
two facilities, however, the wastewater from the
separation step was commingled with other
non-oily wastewater prior to further treatment.
As such, EPA could only use data from these
facilities to characterize the waste streams after
emulsion breaking. The other four facilities
treated the wastewater from the initial separation
step without commingling with non-oils
subcategory wastewaters in systems specifically
designed to treat oily wastewater. EPA evaluated
the following treatment technologies for this
subcategory: gravity separation, emulsion
breaking, ultrafiltration, dissolved air flotation,
biological treatment, reverse osmosis, carbon
adsorption, and air stripping.
EPA conducted sampling at oils facilities in
late 1994 (just before the proposal) and again
after the proposal to address concerns raised at
the 1994 public meeting and in the proposal
public comments. Specifically, in regards to oils
wastewater treatment, the commenters stated that
(1) the facility which formed the technology basis
for EPA's 1995 proposed option did not treat
wastes which were representative of the wastes
treated by many other oils facilities, and (2) EPA
should evaluate dissolved air flotation as a basis
for the regulatory option. All three of the
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Chapter 2 Data Collection
Development Document for the CWT Point Source Category
facilities sampled between 1994 and 1996
utilized dissolved air flotation and treated wastes
which were generally more dilute than those
treated by the 1995 proposal option facility. EPA
used data from both of the post-proposal
sampling episodes to develop regulatory options
considered for this re-proposal. Data from the
1994 episode were not used to develop a
regulatory option due to non-optimal performance
and highly diluted influent streams; however,
EPA used data from this facility to characterize
the waste stream after emulsion breaking.
Organic-Bearing Waste Treatment
and Recovery Sampling 2.3.3.5
EPA had difficulty identifying facilities that
could be used to characterize waste streams and
assess treatment technology performance in the
organics subcategory. A large portion of the
facilities, whose organic waste treatment
operations EPA evaluated, had other industrial
operations on-site. For these facilities, CWT
waste streams represented a minor component of
the overall facility flow.
Between 1989 and 1994, EPA did identify
and sample three facilities that treated a
significant volume of off-site generated organic
waste relative to non-CWT flows. None of these
facilities were direct discharging facilities. EPA
evaluated treatment technologies including: air
stripping, biological treatment in a sequential
batch reactor, multi-media filtration,
coagulation/flocculation, carbon adsorption, and
CO2 extraction. EPA chose not to use data from
one of the three facilities in calculating effluent
levels achievable with its in-place technologies
because the facility was experiencing operational
difficulties with the treatment system at the time
of sampling. In addition, after reviewing the
facility's waste receipts during the sampling
episode, EPA determined that the facility
accepted both oils subcategory and organics
subcategory wastestreams and commingled them
for treatment. EPA has also not used data from
a second facility in calculating effluent levels
achievable with its in-place technologies because,
after reviewing this facility's waste receipts
during the'sampling episode, EPA determined
that this facility also accepted both oils
subcategory and organics subcategory
wastestreams and commingled them for
treatment
1998 Characterization Sampling of Oil
Treatment and Recovery Facilities 2.3.4
EPA received many comments to the original
proposal concerning the size and diversity of the
oils treatment and recovery subcategory. Many
suggested that the subcategory needed to be
further subdivided in an effort to better depict the
industry. As a result, in March and April 1998,
EPA conducted site visits at eleven facilities
which treat and/or recover non-hazardous oils
wastes, oily wastewater, or used oil material from
off-site. While the information collected at these
facilities was similar to information collected
during previous site visits, these facilities were
selected based on waste receipts. The facilities
represent a diverse mix of facility size, treatment
processes, and geographical locations. EPA
collected wastewater samples of their waste
receipts and discharged effluent at 10 of these
facilities. These samples were one-time grabs
and were analyzed for metals, classicals, and
semi-volatile organic compounds. The analytical
results are located in Appendix B, but EPA has
not incorporated the results into the analysis
presented today. EPA plans to use this analytical
data to supplement its wastewater
characterization database prior to promulgation.
PUBLIC COMMENTS TO THE 1995
PROPOSAL AND THE 1996
NOTICE OF DATA AVAILABILITY
2.4
In addition to data obtained through the
Waste Treatment Industry Questionnaire, DMQ,
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Chapter 2 Data Collection
Development Document for the CWT Point Source Category
site visits and sampling episodes, commenters on
the January 27, 1995 proposal (55 FR 45161)
and the September 16, 1996 Notice of Data
Availability (61 FR 48805) also provided data to
EPA. In fact, much of EPA's current
characterization of the oily waste treatment and
recovery subcategory is based on comments to
the 1996 Notice of Data Availability.
As described earlier, following the 1995
proposal, EPA revised its estimate of the number
of facilities in the oils subcategory and its
description of the oils subcategory. Using new
information provided by the industry during the
1995 proposal comment period in conjunction
with questionnaire responses and sampling data
used to develop the proposal, EPA
recharacterized this subcategory of the industry.
This recharacterization reflected new data on the
wastes treated by the subcategory, the technology
in-place, and the pollutants discharged. As part
of this recharacterization, EPA developed
individual profiles for each of the newly identified
oils facilities by modeling current wastewater
treatment performance and treated effluent
discharge flow rates. In addition, assuming the
same treatment technology options identified at
proposal, EPA recalculated the projected costs of
the proposed options under consideration,
expected pollutant reductions associated with the
options, and the projected economic impacts.
EPA presented its recharacterization of the oils
subcategory in the September 1996 Notice of
Data Availability (61 FR 48806).
At the time of the 1995 proposal, EPA
estimated there were 35 facilities in the oily waste
treatment and recovery subcategory. Through
comments received in response to the proposed
rule, and communication with the industry, the
National Oil Recyclers Association, and EPA
Regional staff, EPA identified an additional 240
facilities that appeared to treat oily wastes from
off-site. While attempting to confirm mailing
addresses for each facility, EPA discovered that
20 of these facilities were either closed or could
not be located. EPA then revised its profile of the
oily waste treatment and recovery subcategory to
include 220 newly-identified facilities. The
information in the Notice of Data Availability
was based on these 220 additional facilities.
In lieu of sending questionnaires out to the
newly-identified oils facilities to collect technical
and economic information, EPA used data from
secondary sources to estimate facility
characteristics such as wastewater flow. For
most facilities, information about total facility
revenue and employment were available from
public sources (such as Dunn and Bradstreet).
EPA then used statistical procedures to match the
newly-identified facilities to similar facilities that
had provided responses to the 1991 Waste
Treatment Industry Questionnaire. This
matching enabled EPA to estimate the flow of
treated wastewater from each of the newly
identified facilities. Where EPA had actual
estimates for facility characteristics from the
facility or public sources, EPA used the actual
values. The estimated facility characteristics
included the following:
• RCRA status;
• Waste volumes;
• Recovered oil volume;
• Wastewater volumes treated and discharged;
• Wastewater discharge option;
• Wastewater characteristics;
• Treatment technologies utilized; and
• Economic information.
EPA hoped to obtain information from each of
the newly identified facilities through comments
to the 1996 Notice of Data Availability. In order
to facilitate that effort, copies of the Notice and
the individual facility profile were mailed to each
of the 220 newly identified facilities. Of these,
EPA received comments and revised profiles
from 100. Therefore, 120 facilities did not
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Chapter 2 Data Collection
Development Document for the CWT Point Source Category
provide comments to the Notice or revised facility
profiles.
EPA determined the following about the list
of newly identified oils facilities:
• 50 facilities were within the scope of the oily
waste treatment and recovery subcategory;
• 16 facilities were fuel blenders;
• 31 facilities were out of scope of the oily
waste treatment and recovery subcategory;
and
• . 3 facilities were closed.
total estimate of oils facilities to 164.
For this reproposal, EPA has again revised
its characterization of the subcategory based on
information provided prior to the 1995 proposal,
during the proposal comment period, and during
the Notice comment period. EPA has used the
revised facility profiles and the earlier
information to perform the technical and
economic analyses presented for the oils
subcategory. Unless noted otherwise, the final
results of the analyses are scaled to represent the
total population of oil facilities.
EPA polled 9 of the 120 non-commenting
facilities and determined that approximately half
are within the scope of the industry. As a result,
EPA estimates that half, or sixty, of the 120
non-commenting facilities are within the scope of
the oily waste treatment and recovery
subcategory. As to these sixty facilities that did
not comment, EPA does not necessarily have
facility specific information for them.
Finally, through comments to the Notice,
EPA also obtained facility specific information
on 19 facilities that EPA had not previously
identified as possible CWT oils subcategory
facilities.
Therefore, EPA's updated data base includes
facility-specific information for a total of 104
facilities that are within the scope of the oily
waste treatment and recovery subcategory. This
total includes the 50 facilities for which EPA
prepared facility information sheets, 19 new
facilities identified through the Notice, and 35
facilities from the questionnaire data base. The
number of in-scope facilities from the
questionnaire data base has changed from the
time of proposal due to other facility applicability
issues, as discussed in Section 3.1. Finally, as
described above, EPA estimates that the entire
population of oils subcategory facilities includes
an additional 60 facilities for which EPA does not
have facility specific information. This brings the
ADDITIONAL DATA SOURCES
Additional Databases
2.5
2.5.1
Several other data sources were used in
developing effluent guidelines for the centralized
waste treatment industry. EPA used the data
included in the report entitled Fate of Priority
Pollutants in Publicly Owned Treatment Works
(EPA 440/1-82/303, September 1982),
commonly referred to as the "50 POTW Study",
in determining those pollutants that would pass
through a POTW. EPA's National Risk
Management Research Laboratory (NRMRL),
formerly called the Risk Reduction Engineering
Laboratory (RREL), treatability data base was
used to supplement the information provided by
the 50 POTW Study. A description of references
is presented in Section 7.6.2.
Laboratory Study on the Effect
of Total Dissolved Solids
on Metals Precipitation
2.5.2
During the comment period for the 1995
proposal, EPA received comments which asserted
that high levels of total dissolved solids (TDS) in
CWT wastewaters may compromise a CWT's
ability to meet the proposed metal subcategory
limitations. The data indicated that for some
metal-contaminated wastewaters, as TDS levels
increased, the solubility of the metal in
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Chanter 2 Data Collection
Development Document for the CWT Point Source Category
wastewater also increased. As such, the
commenters claimed that metal-contaminated
wastewaters with high TDS could not be treated
to achieve the proposed limitations.
At the time of the original proposal, EPA had
no data on TDS levels in CWT wastewaters.
None of the facilities provided TDS data in their
response to the Waste Treatment Industry
Questionnaire or the Detailed Monitoring
Questionnaire. Additionally, during the sampling
episodes prior to the 1995 proposal, EPA did not
collect TDS data. As such, EPA lacked the data
to estimate TDS levels in wastewaters at the
CWT facility which formed the technology basis
for the 1995 proposed metals subcategory
limitations.
In order to address the comment, EPA (1)
collected additional information on TDS levels in
metals subcategory wastewaters; (2) conducted
additional sampling; (3) consulted literature
sources; and (4) conducted bench scale studies.
First, EPA needed to determine the range of
TDS levels in CWT metals subcategory
wastewaters. As such, EPA contacted the metals
subcategory Waste Treatment Industry
Questionnaire respondents to determine the level
of TDS in their wastewaters. Most CWT
facilities do not collect information on the level of
TDS in their wastewaters. Those facilities that
provided information indicated that TDS levels in
CWT metals subcategory wastewaters range from
10,000 ppm to 100,000 ppm (1 - 10 percent).
Second, EPA resampled the facility which
formed the technology basis for the 1995
proposed metals subcategory limitations as well
as one other metals subcategory facility, in part,
to determine TDS levels in their wastewaters.
EPA found TDS levels of 17,000 to 81,000
mg/L.
Third, EPA consulted various literature
sources to obtain information about the effect of
TDS levels on chemical precipitation. EPA found
no data or information which related directly to
TDS effects on chemical precipitation.
Fourth, EPA conducted a laboratory study
designed to determine the effect of TDS levels on
chemical precipitation treatment performance. In
this study, EPA conducted a series of bench-scale
experiments on five metals: arsenic, chromium,
copper, nickel and titanium. These metals were
selected because (1) they are commonly found in
CWT metals subcategory wastewaters, (2) their
optimal precipitation is carried out in a range of
pH levels; and/or (3) the data provided in the
comments indicated that TDS may have a
negative effect on the precipitation of these
metals. The preliminary statistical analyses of
the data from these studies show no consistent
relationship among the five metals, pH levels,
TDS concentrations and chemical precipitation
effectiveness using hydroxide or a combination of
hydroxide and sulfide. (DCN 23.32 describes the
study and the statistical analyses in further
detail.)
Therefore, because none of these four sources
provided consistent and convincing evidence that
TDS compromises a facility's ability to meet the
proposed metal subcategory limitations, EPA has
not incorporated the TDS levels into the
development of limitations on metals discharges.
PUBLIC PARTICIPATION
2.6
EPA has strived to encourage the
participation of all interested parties throughout
the development of the CWT guidelines and
standards. EPA has met with various industry
representatives including the Environmental
Technology Council (formerly the Hazardous
Waste Treatment Council), the National Solid
Waste Management Association (NSWMA), the
National Oil Recyclers Association (NORA), and
the Chemical Manufacturers Association (CMA).
EPA has also participated in industry meetings as
well as meetings with individual companies that
may be affected by this regulation. EPA also met
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Chapter 2 Data Collection
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with environmental groups including members of
the Natural Resources Defense Council. Finally,
EPA has made a concerted effort to consult with
EPA regional staff, pretreatment coordinators,
and other state and local entities that will be
responsible for implementing this regulation.
EPA sponsored two public meetings, one
prior to the original proposal on March 8, 1994
and one prior to this re-proposal on July 27,
1997. The purpose of the public meetings was to
share information about the.content and status of
the proposed regulation. The public meetings
also gave interested parties an opportunity to
provide information and data on key issues.
On March 24, 1995, following the original
proposal, EPA sponsored a workshop and public
hearing. The purpose of the workshop was to
provide information about the proposed
regulation and to present topics on which EPA
was soliciting comments. The public hearing
gave interested parties the opportunity to present
oral comments on the proposed regulation.
Finally, as detailed in the Economic Analysis
of Effluent Limitations Guidelines and
Standards for the Centralized Waste Treatment
Industry (EPA 821-R-98-019) , onNovember 6,
1997, EPA convened a Small Business
Regulatory Flexibility Act (SBREFA) Review
Panel in preparing this reproposal. The review
panel was composed of employees of the EPA
program office developing this proposal, the
Office of Information and Regulatory Affairs
within the Office of Management and Budget and
the Chief Counsel for Advocacy of the Small
Business Administration (SBA). The panel met
over the course of two months and collected the
advice and recommendations of representatives of
small entities that may be affected by this re
proposed rule and reported their comments as
well as the Panel's findings on the following:
• The type and number of small entities that
would be subject to the proposal.
• Record keeping, reporting and other
compliance requirements that the proposal
would impose on small entities subject to the
proposal, if promulgated.
• Identification of relevant Federal rules that
may overlap or conflict with the proposed
rule.
• Description of significant regulatory
alternatives to the proposed rule which
accomplish the stated objectives of the CWA
and minimize any significant economic.
The small entity CWT population was
represented by members of the National Oil
Recyclers Association (NORA), the
Environmental Technology Council, and a law
firm representing a coalition of CWTs in
Michigan. EPA provided each of the small entity
representatives and panel members many
materials related to the development of this
reproposal. As such, the small entity
representatives had the opportunity to comment
on many aspects of this reproposal in addition to
those specified above. All of the small entity
comments and the panel findings are detailed in
the "Final Report of the SBREFA Small Business
Advocacy Review Panel on EPA's Planned
Proposed Rule for Effluent Limitations
Guidelines and Standards for the Waste
Treatment Industry" which is located in the
regulatory record accompanying this rule.
2-15
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Chapter
3
SCOPE/APPLICABILITY OF THE PROPOSED REGULATION
Over half of the comments received on the
original proposal and the notice of data
availability related to the applicability of this rule.
EPA has reviewed these comments and is
proposing a revised scope for this rule. The vast
majority of these issues are discussed in the
following chapter.
APPLICABILITY
3.1
The universe of facilities which would be
potentially subject to this guideline include the
following. First, EPA is proposing to establish
limitations and pretreatment standards for stand-
alone waste treatment and recovery facilities
receiving materials from off-site — classic
"centralized waste treaters." These facilities may
treat and/or recover or recycle hazardous or non-
hazardous waste, hazardous or non-hazardous
wastewater, and/or used material from off-site.
Second, industrial facilities which process their
own, on-site generated, process wastewater with
hazardous or non-hazardous wastes, wastewaters,.
and/or used material received from off-site, in
certain circumstances may be subject to this
proposal with respect to a portion of their
discharge.
The wastewater flows which EPA is
proposing to regulate include some or all off-site
waste receipts and on-site wastewater generated
as a result of centralized waste treatment
operations. The kinds of on-site wastewater
generated at these facilities would include, for
example, solubilization wastewater, emulsion
breaking/gravity separation wastewater, used oil
processing wastewater, treatment equipment
washes, transport washes (tanker truck, drum,
and roll-off boxes), laboratory-derived
wastewater, air pollution control wastewater,
industrial waste combustor wastewater from on-
site industrial waste combustors, landfill
wastewater from on-site landfills, and
contaminated stormwater. A detailed discussion
of CWT wastewaters is provided in Chapter 4.
FacUities Subject to 40 CFR
(Parts 400 to 471)
3.1.1
At the time of the original proposal, EPA
defined a centralized waste treatment facility as
any facility which received waste from off-site for
treatment or recovery on a commercial or non-
commercial basis. Non-commercial facilities
were defined as facilities that accept off-site
wastes from facilities under the same ownership.
EPA received many comments concerning the
applicability of the CWT rule to facilities that
perform waste treatment and/or recovery of off-
site generated wastes, but whose primary
business is something other than waste treatment
or recovery. These facilities are generally
manufacturers who treat wastes generated as a
result of thek on-site manufacturing operations
and whose wastewater discharges are already
subject to existing effluent guidelines and
standards. Many of these facilities also accept
off-site generated wastes for treatment. In some
instances, these off-site wastes received at these
industrial facilities are generated by a facility
under the same corporate ownership —
intracompany transfer — and treated on a non-
commercial basis. In other instances, the off-site
waste streams originate from a company under a
different ownership, an intercompany transfer.
In general, commenters urged that the scope
of the guideline should be limited to facilities
3-1
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CHAPTERS Scope/Applicability
Development Document for the CWT Point Source Category
whose sole purpose is the treatment of off-site
wastes and wastewater. Reasons provided by
commenters for limiting the scope of the
guideline in this manner include:
• The wastes transferred from different
locations within a company (and different
companies) for treatment with on-site wastes
are usually generated from the same
categorical process as the on-site generated
wastes. Since most of these facilities are
already covered by an existing effluent
guideline, coverage of these wastestreams is
redundant Monitoring, record keeping, etc.
would be duplicative.
• This proposed rale will prevent effective
waste management practices at many
manufacturing facilities. Currently, many
companies operate a single, central treatment
plant and transport waste from "satellite"
facilities to the central treatment facility.
This allows for effective treatment while
controlling costs. Additionally, many
facilities transfer a specific wastestream to
other company owned treatment systems
(intracompany) that are designed for the most
efficient treatment of that type of
wastestream.
• Many of these types of facilities only accept
wastestreams which are comparable and
compatible with the on-site generated process
wastestreams.
• These facilities are not primarily in the
business of waste treatment. Only a small
percentage of wastes treated are from off-
site.
• EPA has not performed the technical
analyses that are necessary to support
application of the CWT rule to
manufacturing facilities regulated by existing
effluent guidelines and pretreatment
standards.
EPA reexamined the database of facilities
which form the basis of the CWT rule. EPA's
database contains information on 17
manufacturing facilities which commingle waste
generated by on-site manufacturing activities for
treatment with waste generated off-site and one
manufacturing facility which does not commingle
waste generated by on-site manufacturing
activities for treatment with waste generate off-
site. Nine of these facilities treat waste on a non-
commercial basis only and nine treat waste on a
commercial basis. Of the eighteen facilities, eight
facilities only accept and treat off-site wastes
which are from the same categorical process as
the on-site generated wastestreams. Ten of the
facilities, however, accept off-site wastes which
• are not subject to the same categorical standards
as the on-site generated wastewater. The
percentage of off-site wastewaters being
commingled for treatment with on-site
wastewater varies from 0.06% to 80% with the
total volumes varying between 87,000 gallons per
year to 381 million gallons per year.
The guidelines, as proposed in 1995, would
have included both types of facilities within the
scope of this rule. EPA included these facilities
in the 1995 proposed CWT rule to ensure that all
wastes receive adequate treatment — even those
shipped between facilities already subject to
existing effluent limitations guidelines and
standards (ELGs). EPA agrees that, for off-site
wastes which are generated by the same
categorical process as on-site generated wastes,
intracompany and intercompany transfers are a
viable and often preferable method to treat
wastestreams efficiently at a reduced cost. EPA
does not want to discourage these management
practices. EPA is still concerned, however, that
the effluent limitations and categorical standards
currently in place may not ensure adequate
treatment in circumstances where the off-site
generated wastes are not from the same
categorical group as the on-site generated wastes.
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It is not duplicative to include within the scope of
the CWT guideline, wastewater that results from
the treatment of off-site wastes not subject to the
guidelines and standards applicable to the
treatment of wastewater generated on-site.
Additionally, even though the primary business at
these facilities is not the treatment of off-site
wastes, EPA does not believe that the burden to
these facilities exceeds that of the facilities whose
primary business is the treatment of off-site
wastes. EPA has included these facilities in all of
its economic analyses.
Therefore, based on the Agency's evaluation
of the comments submitted on its earlier proposal
and consideration of additional information, EPA
proposes to include within the scope of the CWT
rule wastewater received from off-site (and
commingled for treatment with on-site
wastewater) at facilities subject to effluent
limitations guidelines for existing source,
standards of performance for new sources and
pretreatment standards for new and existing
sources unless all of the following conditions are
met:
• The receiving facility is subject to national
effluent limitations guidelines for existing
sources, standards of performance for new
sources, or pretreatment standards for new
and existing sources; and
• The wastes received from .off-site for
treatment would be subject to the same
national; effluent limitations guidelines for
existing sources, standards of performance
for new sources, or pretreatment standards
for new and existing sources as the on-site
generated wastes.
For purposes of developing its effluent
limitations and pretreatment standards, EPA has
included manufacturing facilities which accept
off-site waste for treatment in all of its analyses
unless the above mentioned conditions were met.
EPA contemplates that this approach would
be implemented in the following manner. A
facility that is currently subject to an ELG
receives wastewater from off-site for treatment.
The wastewater is commingled for treatment with
wastewater generated on-site. If the off-site
wastewater is subject to the same ELG as the
onsite wastewater (or would be if treated where
generated), the CWT limitations would not apply
to the discharge associated with the off-site
wastewater flows. In that case, another guideline
or standard applies. If, however, the off-site
wastewater is not subject to the same ELG (or if
none exist) or if the off-site wastewater is not
commingled .with on-site wastewater for
treatment, that portion of the discharge associated
with off-site flow would be subject to CWT
requirements. The portion of the commingled or
non-commingled wastewater associated with on-
site generated wastewater remains subject to
applicable limitations and standards for the
facility. Alternatively, EPA is considering an
option that requires manufacturing facilities that
treat off-site wastes to meet all otherwise
applicable categorical limitations and standards.
This approach would determine limitations and
standards for the off-site wastewater using the
"combined waste stream formula" or "building
block approach" (see Chapter 14). EPA
envisions the second alternative would be
preferable for facilities which only receive
continuous flows of process wastewaters with
relatively consistent pollutant profiles from no
more than five customers. The decision to base
limitations in this manner would be at the permit
writers discretion only.
In addition, there are manufacturing facilities
that may not currently be subject to any effluent
limitations guidelines or pretreatment standards.
Some of these may accept off-site wastewater
that is commingled for treatment with on-site
process wastewater. Under EPA regulations, the
permit writer would develop Best Professional
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Judgement (BPJ) local limits for indirect
dischargers for the on-site generated wastewater
flows. The portion of the discharge resulting
from the treatment of off-site flows would be
subject either to CWT limitations and standards
or to the same BPJ requirements as on-site flows.
CWT limitations would apply if the off-site
wastes treated at the facility were different from
those generated on-site, whether or not the wastes
were subject to existing guidelines and standards
(or would be, if treated at the site where
generated). Alternatively, applying either a
building block or combined wastestream formula
approach, on-site wastewater would be subject to
BPJ limits or standards and the off-site
categorical wastewater subject to categorical
limits for the industry generating the wastewater.
Pipeline Transfers
(Fixed Delivery Systems)
3.1.2
As previously noted, the scope of EPA's
1995 proposal did not extend to facilities which
received off-site wastes for treatment solely via
an open or enclosed conduit (for example,
pipeline, channels, ditches, trenches, etc.). At
that time, EPA had concluded that facilities which
receive all their wastes through a pipeline or
trench (fixed delivery systems) from the original
source of waste generation are receiving
continuous flows of process wastewater with
relatively consistent pollutant profiles. As such,
EPA concluded that these wastes differ
fundamentally from those received at centralized
waste treatment facilities it had studied as part of
this rulemaking.
The Agency received many comments on the '
proposal to limit the applicability of the proposed
limits to wastewaters received other than by
pipelines or fixed delivery systems. Many
commented that this approach is arbitrary and
that the mode of transportation should not be the
determining factor as to whether or not a facility
is included in the scope of the rule. Commenters
asserted that the character of the waste remains
unchanged regardless of whether it is trucked or
piped to another facility for treatment. Many also
questioned EPA's conclusion that piped waste is
more consistent in strength and treatability from
typical CWT wastewaters studied for this
proposal.
EPA has reevaluated the database for this
rule. EPA received questionnaire responses from
four centralized waste treatment facilities which
receive their wastestreams solely via pipeline.
EPA also examined the database that was
developed for the organic chemicals, plastics, and
synthetic fibers (OCPSF) ELG to gather
additional data on OCPSF facilities which also
have centralized waste treatment operations.
Based on the OCPSF database, 16 additional
facilities are treating wastewater received solely
via pipeline from off-site for treatment. A review
of the CWT and OCPSF databases supplemented
by telephone calls to selected facilities reveals
that one facility no longer accepts wastes from
off-site, one facility is now operating as a POTW,
and 11 facilities only accept off-site wastes that
were generated by a facility within the same
category as on-site generated waste. (The latter
facilities, under the criteria explained above,
would no longer be within the scope of the
proposed rule because they are already subject to
existing effluent guidelines and standards.)
Therefore, EPA identified. 7 facilities which
receive off-site wastes solely via pipeline which
may be subject to this rulemaking.
Of these seven facilities, one is a dedicated
treatment facility which is not located at a
manufacturing site. The other six pipeline
facilities are located at manufacturing facilities
which are already covered by an existing ELG.
All of the facilities are direct dischargers and all
receive waste receipts from no more than five
customers (many receive waste receipts from
three or fewer customers).
Since the 1995 proposal, EPA conducted site
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visits at two of these pipeline facilities.
Information collected during these site visits
confirmed EPA's original conclusion that wastes
received by pipeline are more consistent in
strength and treatability than "typical" CWT
wastewaters. These wastewaters are traditional
wastewaters from the applicable industrial
category that generally remain relatively constant
from day to day in terms of the concentration and
type of pollutant parameters. Unlike traditional
CWTs, their customers and wastewater sources
do not change and are limited by the physical and
monetary constraints associated with pipelines.
EPA has also reviewed the discharge permits
for each of these pipeline facilities. EPA found
that, in all cases, permit writers had carefully
applied the "building block approach" in
establishing the facility's discharge limitations.
Therefore, in all cases, the treating facility was
required to treat each of the piped wastewaters to
comply with otherwise applicable effluent
guidelines and standards.
Consequently, based on the information it
has obtained to date, EPA continues to believe
that (except as discussed below) wastes that are
piped to waste treatment facilities should be
excluded from the scope of the CWT rule and
covered by otherwise applicable effluent
guidelines and standards. The Agency has
concluded that effluent limitations and
pretreatment standards for centralized waste
treatment facilities should not apply to pipeline
treatment facilities. EPA believes that it is more
appropriate for permit writers to develop
limitations for treatment facilities that receive
wastewater by pipeline on an individual basis by
applying the "combined waste stream formula" or
"building block" approach. The one exception to
this approach is for facilities which receive waste
via conduit (that is, pipeline, trenches, ditches,
etc.) from facilities that are acting merely as
waste collection or consolidation centers that are
not the original source of the waste. These
wastewaters would be subject to CWT. EPA has
not identified any pipeline facility that is
receiving waste from waste consolidators, but has
received public comment that these facilities
exist.
EPA notes that 40 CFR §122.44(m) of the
Agency's NPDES permitting regulations require
that an NPDES permit for a private treatment
works must include conditions expressly
applicable to any user, as a limited co-permittee,
necessary to ensure compliance with applicable
NPDES requirements. In the case of a pipeline
treatment system, this may require that the permit
writer include conditions in a permit issued to the
pipeline treatment system and its users, as co-
permittee, if necessary for the pipeline facility to
comply with the applicable limitations.
Alternatively, EPA may need to issue permits
both to the private treatment works and to the
users or require the user to file a permit
application.
Product Stewardship
3.1.3
Many members of the manufacturing
community have adopted "product stewardship"
programs as an additional service for their
customers to promote recycling and reuse of
products and to reduce the potential for adverse
environmental impacts from chemical products.
Many commenters on the proposal have defined
"product stewardship" in this way: "taking back
spent, used, or unused products, shipping and
storage containers with product residues, off-
specification products and waste materials from
use of products." Generally, whenever possible,
these manufacturing plants recover and reuse
materials in chemical processes at their
operations. Manufacturing companies that
cannot reuse the spent, used, or unused materials
returned to them treat these materials in their
wastewater treatment plant. In industry's view,
such materials are inherently compatible with the
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treatment system. EPA received no specific
information on these product stewardship
activities in the responses to the 308 Waste
Treatment Industry Questionnaire. EPA obtained
information on this program from comment
responses to the 1995 CWT proposal and in
discussions with industry since the 1995
proposal. As part of their comment to the 1995
proposal, the Chemical Manufacturer's
Association (CMA) provided results of a survey
of their members on product stewardship
activities. Based on these survey results, which
are shown in Table 3.1 and Table 3-2, the vast
majority of materials received under the product
stewardship programs are materials received for
product rework. A small amount is classified as
residual recycling and an even smaller amount is
• classified as drum take backs. Of the materials
received, the vast majority is reused in the
manufacturing process. With few exceptions, all
of the materials (which are not reused in the
manufacturing process) that are treated in the on-
site wastewater treatment systems, appear to be
from the same categorical group as the on-site
manufactured materials.
Table 3-1 Summary of the Frequency of the Types of Activities and Dispositions Reported
Activity
Disposition
Item
Drum Returns
Residual Recycling
Product Rework
Other
Rework/Reuse
On-site Wastewater Treatment
Off-site Disposal
Number
3
7
50
2
53
22
29
% of Total J
5%
12%
86%
3%
91%
38%
50%
JBased on information submitted by 33 CMA member facilities. Of these 33 members, 13 reported
information concerning more than one product type, or activity. Therefore, the percentage of the total is
based on 58 separate entries on the survey.
Table 3-2 Summary of Frequency of Each Product Class Reported by Facilities
Product Class
Polymers, Plastics, and Resins
Organic Chemicals
Solvents and Petroleum Products
Inorganic Chemicals
Pesticides
Unspecified
Number of Facilities
17
6
3
4
2
4
Percent of Total'
52%
18%
9%
12%
6%
12%
JBased on Responses from 33 CMA facilities.
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EPA has decided that wastewater generated
from materials which are taken back for recycling
or reuse should be subject to the CWT regulation
(except as discussed elsewhere). EPA applauds
the efforts of manufacturing facilities to reduce
pollution and the environmental impacts of their
products and does not want to discourage these
practices. In most of the instances stated in the
product stewardship definition, manufacturing
facilities are essentially taking back product
which has not been utilized or has not been
chemically altered. In these cases where the
treatment of these wastes would be subject to
current guidelines or pretreatment standards,
under the approach discussed in Section 3.1.1,
these wastewater flows would not be subject to
CWT requirements.
EPA remains concerned, however, that there
are circumstances in which used materials or
waste products may not be compatible with the
otherwise existing treatment system. Therefore,
EPA is not proposing to remove all product
stewardship activities from the scope of this
rulemaking. Those activities that involve used
products or waste materials that are not subject to
effluent guidelines or standards from the same
category as the on-site generated wastes are
subject to today's proposal. Based on the
information provided by manufacturing facilities,
EPA believes that very few product stewardship
activities would be subject to this rule. EPA's
approach will not curtail product stewardship
activities, in general, but will ensure that all
wastes are treated effectively.
Solids, Soils, and Sludges
3.1.4
EPA did not distinguish in its information
gathering efforts between those waste treatment
and recovery facilities treating aqueous waste and
those treating non-aqueous wastes or a
combination of both. Thus, EPA's 308 Waste
Treatment Industry Questionnaire and related
CWT Detailed Monitoring Questionnaire (DMQ)
asked for information on CWT operations
without regard to the type of waste treated.
EPA's sampling program also included facilities
which accepted both aqueous and solid wastes for
treatment. In fact, the facility which formed the
technology basis for the metals subcategory
limitations selected at the time of the original
proposal treats both liquid and solid wastes. As
such, a facility that accepts wastes from off-site
for treatment and/or recovery and which
generates a wastewater is subject to the CWT rule
regardless of whether the wastes are aqueous or
non-aqueous. Therefore, wastewater generated in
the treatment of solids received from off-site
would be subject to the CWT rule.
As a further point of clarification, the main
concern in the treatment or recycling of off-site
"solid wastes" is that pollutants contained in the
solid waste may be transferred to a process or
contact water resulting in a wastewater that may
require treatment. Examples of such wastewaters
are:
• entrained water directly removed through
dewatering operations (for example, sludge
dewatering);
• contact water added to wash or leach
contaminants from the waste material;
• stormwater that comes in direct contact with
waste material; and
• solvent contaminated wastewater removed
from scrap metal recycling.
The treatment or recovery of solids that remain in
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solid form when contacted with water and which
do not leach any chemicals into the water are
necessarily not subject to this rule. Examples of
excluded solids recovery operations are the
recycling of aluminum cans, glass and plastic
bottles.
Sanitary Wastes
3.1.5
The CWT proposal would regulate facilities
which treat, or recover materials from, off-site
industrial wastes and wastewaters. Sanitary
wastes such as chemical toilet wastes and septage
are not covered by the provisions of the proposed
CWT rule. EPA would expect that, permit
writers would develop Best Professional
Judgment limitations or local limits to establish
site-specific permit requirements for any
commercial sanitary waste treatment facility.
Similarly, sanitary wastes received from off-
site and treated at an industrial facility or a
centralized waste treatment facility are not
covered by provisions of the CWT rule. If these
wastes are mixed with industrial wastes, EPA
would expect that, as is the case now with
ancillary sanitary waste flows mixed for
treatment at categorical facilities, the permit
writer would establish Best Professional
Judgment, site-specific permit requirements.
Transporters and/or Transportation
Equipment Cleaners
3.1.6
As proposed, the transportation equipment
cleaning (TEC) regulation only applies to
facilities that solely accept tanks which have been
previously emptied or that contain a small
amount of product, called a "heel", typically
accounting for less than one percent of the
volume of the tank. A facility which accepts a
tank truck, rail tank car, or barge not considered
to be empty for cleaning or treatment is not
subject to the TEC Point Source Category, and
may be subject to the provisions established for
this rule.
There are some facilities which are engaged
in traditional CWT activities and also engaged in
traditional TEC activities. If the wastewaters
from the two operations are commingled, under
the approach adopted for the TEC proposal, the
commingled TEC wastewater flow would be
subject to CWT limits when promulgated.
Therefore, a facility performing transportation
equipment cleaning as well as other centralized
waste treatment services that commingles these
wastes is a centralized waste treatment facility.
All of the wastewater discharges are subject to
provisions of this rule. If, however, a facility is
performing both operations and the wastestreams
are not commingled (that is, transportation
equipment cleaning wastewater is treated in one
system and CWT wastes are treated in a second,
separate system), both the TEC rule and CWT
rules apply to the respective wastewaters.
As a further point of clarification, the CWT
proposal would subject transportation equipment
cleaning wastes received from off-site to its
provisions. Transportation equipment cleaning
wastes received from off-site that are treated at
CWTs along with other off-site wastes are
subject to provisions of this rule.
Publicly Owned Treatment
Works (POTWs)
3.1.7
The reproposed CWT pretreatment
regulations would not themselves establish any
requirements that apply directly to local POTWs
that receive off-site wastes In the case of
categorical wastes (subject to pretreatment
standards in 40 CFR parts 400 to 471), the
generator of the wastes must comply with any
applicable standards before introducing the waste
to the POTW regardless of whether the
wastewater is discharged directly to the sewer or
otherwise hauled to the POTW. Similarly, for
non-categorical wastes, the generator would need
to meet any applicable local limits regardless of
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the mode of transportation to the POTW. As
such, therefore, the proposed centralized waste
treatment rule does not apply to POTWs.
EPA is aware of a POTW which plans to
open a wastewater treatment system to operate in
conjunction with their POTW operations. This
CWT facility at a POTW will accept categorical
wastewaters, treat them, and then discharge them
to the POTW, As such, the CWT operation may
be subject to provisions of this rule. It is not a
POTW itself (even if the facility is located at the
same site). In this case, the facility is operating
as a centralized waste treatment facility and all
discharges are subject to provisions of this rule.
Silver Recovery Operations from Used
Photographic and X-Ray Materials 3.1.8
The proposal does not include electrolytic
plating/ metallic replacement silver recovery
operations of used photographic and x-ray
materials within the scope of this rule. Based on
the fundamental difference in technology used to
recover silver at facilities devoted exclusively to
treatment of photographic and x-ray wastes, the
Agency has decided to defer proposing
regulations for these facilities. The precipitation
processes to recover silver used as the basis for
its metal limits (including silver) is different from
that most widely used to recover silver at
facilities that treat only silver bearing wastes —
electrolytic plating followed by metallic
replacement. Facilities which only perform
centralized waste treatment silver recovery
operations .(electrolytic plating followed by
metallic replacement) would not fall within the
scope of today's proposal. Permit writers would
use Best Professional Judgement or local limits to
establish site-specific permit requirements.
However, off-site wastes which are
treated/recovered at these facilities through any
other process and/or waste generated at these
facilities as a result of any other CWT
treatment/recovery process are subject to
provisions of this rule.
Many commenters to the 1995 CWT
proposal expressed concern over the inclusion in
the metals subcategory of CWT operations that
recover metals from used photographic materials
and solutions and x-ray materials and solutions.
Commenters were particularly concerned mat
they would be unable to meet the limitations
established for silver in the metals subcategory.
In general, commenters stated that the scope of
the proposed rule should not include these
operations. Reasons provided include:
• The metals subcategory limitations proposed
for the CWT rule are not based on
technologies typically used in silver recovery
operations. Silver recovery facilities
typically use electrolytic plating followed by
metallic replacement with iron.
• The facility used to calculate the BAT silver
limitation is engaged in a variety of recovery
operations. This BAT treatment system .does
not reflect performance of facilities which
solely treat silver-bearing wastes.
• Existing effluent guidelines should be
sufficient. Many facility discharge permits
are based on Part 421, effluent guidelines for
non-ferrous metals manufacturing, Subpart L
secondary silver subcategory. In addition, an
effluent guideline also exists for the industry
which is the primary source of the recovered
materials — Part 459 photographic point
source subcategory.
• The Silver Coalition and the Association of
Metropolitan Sewerage Agencies (AMSA)
have prepared and issued recommendations
on technology, equipment and management
practices for controlling discharges from
facilities that process photographic materials.
• It is not economical or efficient for these
waste streams to be recovered on-site due to
their small volume. If this rule were enacted,
many of the CWTs processing used
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photographic materials would discontinue
this operation and silver recovery operations
would decrease greatly.
Based on information provided by the
industry, EPA estimates that there are 360,000
photographic and image processing facilities
which generate silver bearing wastes. Many of
these facilities generate very small volumes of
silver bearing waste which would not be
economical or efficient to recover on site. Thus,
there exists a large potential for facilities to
consolidate and treat silver bearing photographic
waste from various sources.
EPA believes that the off-site shipment of
silver bearing photographic wastestreams for the
purpose of consolidation and recovery is
beneficial and does not wish to discourage this
practice. EPA encourages the segregation of
wastestreams as this leads to more efficient
recovery. EPA is aware that some of these
consolidated wastestreams are treated at typical
CWTs and some are treated at facilities which
treat photographic wastestreams only. While
EPA has promulgated effluent guidelines for non-
ferrous metals manufacturing and the
photographic point source categories (40 CFR
421, Subpart L and 40 CFR 459, respectively),
the majority of these centralized silver recovery
facilities are not currently subject to any effluent
guideline.
EPA agrees with proposal commenters that
the BAT system selected at the time of the
original proposal does not reflect performance of
facilities which solely treat silver-bearing wastes.
Although the facility which formed the
technology basis for the 1995 proposed BAT
limitations was engaged in recovering silver from
photographic wastestreams, EPA does not have
information in its database on facilities which
perform centralized waste treatment of
photographic wastestreams only.
High Temperature Metals Recovery 3.1.9
During the development of the 1995
proposal, EPA did not include facilities which
perform high temperature metals recovery
(HTMR) within the scope of this rule. EPA is
aware of three facilities in the U.S. which utilize
the HTMR process. High temperature metals
recovery facilities generally take solid forms of
various metal containing materials and produce a
remelt alloy which is then sold as feed materials
in the production of metals. These facilities
utilize heat-based pyrometallurgical technologies,
not the water-based precipitation/filtration
technologies used throughout the CWT industry.
Based on questionnaire responses and industry
comments, the HTMR process does not generate
wastewater.
For these reasons, the high temperature
metals recovery operations have been excluded
from provisions of the CWT rule. Facilities which
only perform high temperature metals recovery
are not subject to this rule. However, off-site
wastes which are treated/recovered at these
facilities through any other process and/or wastes
generated at these facilities as a result of any
other CWT treatment/ recovery process are
subject to the provisions of this rule.
As noted, EPA's data show that HTMR
operations generate no process wastewater.
Accordingly, EPA is also considering whether
this rule, when promulgated, should include a
subcategory for HTMR operations with a zero
discharge requirement.
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Landfill Wastewaters
3.1.10
EPA proposed effluent guidelines and
pretreatment standards for Landfills, 40 CFR Part
445, on February 6, 1998 (63 FR 6426-6463).
There, EPA explains how it proposed to treat
categorical facilities that mix and treat categorical
wastewater with wastewater from on-site
landfills. EPA proposed to subject the mixed
wastewater to the applicable categorical limits
and not the proposed landfill limits. In the CWT
industry, there are some facilities which are
engaged both hi CWT activities and in operating
an on-site landfill(s). EPA is proposing to
evaluate the mixture of CWT wastewater and
landfill wastewater in the same way considered
for the proposed landfill guidelines. Therefore, a
facility performing landfill activities as well as
other centralized waste treatment services that
commingles the wastewaters would be a
centralized waste treatment facility and all of the
wastewater discharges would be subject to the
provisions of this rule when promulgated. If a
facility is performing both operations and the
wastestreams are not commingled (that is, landfill
wastewaters are treated in one treatment system
and CWT -wastewaters are treated in a second,
separate, treatment system), the provisions of the
. Landfill rule and CWT rule would apply to their
respective wastewaters.
Additionally, under the approach proposed
for the Landfills rulemaking, centralized waste
treatment facilities which are dedicated to landfill
wastewaters only, whether they are located at a
landfill "site or not, would be subject to the
effluent guidelines limitations and pretreatment
standards for landfills when promulgated. These
dedicated landfill centralized waste treatment
facilities would not be subject to provisions of the
centralized waste treatment rulemaking.
As a further point of clarification, landfill
wastewaters are not specifically excluded from
provisions of this rule. Landfill wastewaters that
are treated at CWTs along with other off-site
wastestreams are subject to provisions of this
rule. Furthermore, a landfill that treats its own
landfill wastewater .and off-site landfill
wastewater would be subject to the proposed
Landfill limits when promulgated in the
circumstance described in 3.1.1 above.
Industrial Waste Combustors
3.1.11
EPA proposed effluent guidelines and
pretreatment standards for Industrial Waste
Combustors, 40 CFR Part 444 on February 6,
1998 (63 FR 6392-6423). There, EPA explains
how it proposed to treat categorical facilities that
mix and treat categorical wastewater with
wastewater from on-site industrial waste
combustion. EPA proposed to subject the mixed
wastewater to the applicable categorical limits
and not the proposed industrial waste combustors
limits. In the CWT industry, there are some
facilities which are engaged both in CWT
activities and in industrial waste combustion.
EPA is proposing to evaluate the mixture of
CWT wastewater and industrial waste
combustion wastewater in the same way
considered for the proposed industrial waste
combustors guidelines. Therefore, a facility
performing industrial waste combustion activities
as well as other centralized waste treatment
services that commingles the wastewaters would
be a centralized waste treatment facility and all of
the wastewater discharges would be subject to the
provisions of this rule when promulgated. If a
facility is performing both operations and the
wastestreams are not commingled (that is,
industrial waste combustion wastewaters are
treated in one treatment system and CWT
wastewaters are treated in a second, separate,
treatment system), the provisions of the Industrial
Waste Combustor rule and CWT rule would
apply to their respective wastewaters
As a further point of clarification, industrial
3-11
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CHAPTERS Scope/Applicability
Development Document for the CWT Point Source Category
waste combustor wastewaters are not specifically
excluded from provisions of this rule. Industrial
waste combustor wastewaters that are treated at
CWTs along with other off-site wastestreams are
subject to provisions of this rule. Furthermore,
an industrial waste combustor that treats off-site
industrial waste combustor wastewater would be
subject to the proposed, Industrial Waste
Combustor limits when promulgated in the
circumstances described in 3.1.1 above.
Solvent Recycling/Fuel Blending 3.1.12
The solvent recycling industry was studied by
the EPA in the 1980s. EPA published the
"Preliminary Data Summary for the Solvent
Recycling Industry" (EPA 440/1-89/102) in
September 1989 which describes this industry
and the processes utilized. This document
defines solvent recovery as "the recycling of
spent solvents that are not the byproduct or waste
product of a manufacturing process or cleaning
operation located on the same site." Spent
solvents are generally recycled in two main
operations. Traditional solvent recovery involves
pretreatment of the wastestream (in some cases)
and separation of the solvent mixtures by
specially constructed distillation columns.
Wastewater discharges resulting from this
process are subject to effluent limitations
guidelines and standards for the organic
chemicals industry (40 CFR 414). As such,
wastewaters resulting from traditional solvent
recovery operations as defined above are not
subject to this effluent guideline.
Fuel blending is the second main operation
which falls under the definition of solvent
recovery. Fuel blending is the process of mixing
wastes for the purpose of regenerating a fuel for
reuse. At the time of the 1995 proposal, fuel
blending operations were excluded from the CWT
rule since EPA believed the fuel blending process
was "dry" (that is, no wastewaters were
produced). Based on comments to the original
proposal and the Notice of Data Availability,
EPA has concluded that this is valid and that true
fuel blenders do not generate any process
wastewaters and are therefore zero dischargers.
EPA is concerned, however, that the term "fuel
blending" may be loosely applied to any process
where recovered hydrocarbons are combined as a
fuel product. Such operations occur at nearly all
used oil and fuel recovery facilities. Therefore,
fuel blending operations as defined above would
be excluded from the CWT rule providing that
the operations do not generate a wastewater. In
the event that wastewater is generated at a fuel
blending facility, the facility is most likely
performing some pretreatment operations
(usually to remove water). These pretreatment
wastewaters would be subject to this rule.
Re-refining
3.1.13
When EPA initially proposed guidelines and
standards for CWTs, the regulations would have
limited discharges from used oil
reprocessors/reclaimers but did not specifically
exclude discharges from used oil re-refiners.
During review of information received on the
proposal and assessment of the information
collected, the Agency, at one point, considered
limiting the scope of this regulation to
reprocessors/reclaimers only. However, further
data gathering efforts have revealed that the
principal sources of re-refining wastewaters are
essentially the same for reprocessors/reclaimers
and re-refiners. Consequently, the re-refining
wastewater is included within the scope of this
proposal.
The used oil reclamation and re-refining
industry was studied by EPA in the 1980s. EPA
published the "Preliminary Data Summary for the
Used Oil Reclamation and Re-Refining Industry"
(EPA 440/1-89/014) in September 1989 which
describes this industry and the processes utilized.
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CHAPTER 3 Scope/Applicability
Development Document for the CWT Point Source Category
This document generally characterizes the
industry in terms of the types of equipment used
to process the used oil. Minor processors
(reclaimers) generally separate water and solids
from the used oil using simple settling
technology, primarily in-line filtering and gravity
settling with or without heat addition. Major
processors (reclaimers) generally use various
combinations of more sophisticated technology
including screen filtration, heated settling,
centrifugation, and light fraction distillation
primarily to remove water. Re-refiners generally
use the most sophisticated systems which
generally include, in addition to the previous
technology, a vacuum distillation step to separate
the oil into different components.
This proposal applies to the process
wastewater discharges from used oil re-refining
operations. The principal sources of wastewater
include oil-water gravity separation (often
accompanied by chemical/thermal, emulsion
breaking) and dehydration unit operations
(including light distillation and the first stage of
vacuum distillation).
Used Oil Filter Recycling
3.1.14
EPA did not obtain information on used oil
filter recycling through the Waste Treatment
Industry Questionnaire. However, in response to
the September 1996 Notice of Data Availability,
EPA received comments from facilities which
recycle used oil filters. In addition, EPA also
visited several used oil reprocessors that recycle
used oil filters as part of their operations.
Used oil filter recycling processes range from
simple crushing and draining of entrained oil to
more involved processes where filters are
shredded and the metal and filter material are
separated. In all cases, the oil is recycled, the
crushed filters and separated metal are sent to
smelters, and the separated filter material is
recovered as solid fuel. Also, in all cases
observed, the .operations generate no process
wastewater. Therefore, based on this
characterization, used oil filter recycling
operations would be not be subject to the
provisions of the CWT rule as proposed today.
EPA is also considering whether this rule, when
promulgated, should include a subcategory for
used oil filter recycling with a zero discharge
requirement for such operation.
Marine Generated Wastes
3.1.15
EPA received many comments on the original
proposal relating to marine generated wastes.
Since these wastes are often generated while a
ship is at sea and subsequently off-loaded at port
for treatment, the treatment site could arguably be
classified as a CWT. due to its acceptance of "off
site wastes. Commenters, however, claimed that
marine generated wastes should not be subject to
the CWT rule for the following reasons:
• Unlike most CWT wastestreams, bilge
and/or ballast water is generally dilute and
not toxic; and
• Most of the bilge water is generated while the
ship is docked. If only the small portion of
bilge water contained in the ship upon
docking is subject to regulation, it would be
expensive and inefficient to monitor only that
small portion for compliance with the CWT
rule.
EPA reexamined its database concerning
these wastes as well as additional data on the
characteristics of these types of wastes provided
through comments to the 1995 proposal. Based
on data provided by industry on bilge and ballast
water characteristics, bilge and ballast water can
vary greatly in terms of the breadth of analytes
and the concentration of the analytes from one
ship to another. In most instances, the analytes
and concentrations are similar to those found in
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CHAPTER 3 Scope/Applicability
Development Document for the CWT Point Source Category
wastes typical of the oils subcategory. EPA
found that while some shipyards have specialized
treatment centers for bilge and/or ballast wastes,
some of these wastes are being treated at
traditional CWTs.
For purposes of this rule, EPA is defining a
marine generated waste as waste generated as
part of the normal maintenance and operation of
a ship, boat, or barge operating on inland, coastal
or open waters. Such wastes include wash water
from equipment and tank cleaning, ballast water,
bilge water, and other wastes generated as part of
routine ship maintenance. EPA has determined
that a waste off-loaded from a ship shall be
considered as being generated on-site at the point
where it is off-loaded provided that the waste is
generated as part of the routine maintenance and
operation of the ship on which it originated. The
waste will not be considered an off-site generated
waste as long as it is treated and discharged at the
ship servicing facility where it is off-loaded.
Therefore, these facilities would not be
considered centralized waste treatment facilities.
If, however, marine generated wastes are off-
loaded and subsequently sent to a centralized
waste treatment facility at a separate location,
these facilities and their wastestreams would be
subject to provisions of this rule.
Stabilization
3.1.16
In the original CWT proposal, waste
solidification/stabilization operations were
specifically not subject to the CWT rule. The
reason stated for EPA's conclusion was that these
operations are "dry" and do not generally produce
a wastewater. EPA reexamined its database and
concluded that this assessment remains valid. As
such, stabilization/ solidification processes are
not subject to the CWT rule as proposed today.
If, however, the stabilization/solidification facility
produces a wastewater from treatment and /or
recovery of off-site wastes through any other
operation, those wastewaters would be subject to
the CWT rule. EPA is also considering whether
this rule, when promulgated, should include a
subcategory for stabilization operations with a
zero discharge requirement.
Grease Trap/Interceptor Wastes
3.1.17
EPA received comments on coverage of
grease, sand, and oil interceptor wastes by the
CWT rule during the comment period for the
original proposal and 1996 Notice of Data
Availability. Some of these wastes are from non-
industrial sources and some are from industrial
sources. Some are treated at central locations
designed to exclusively treat grease
trap/interceptor wastes and some of these wastes
are treated at traditional CWTs with traditional
CWT wastes.
Throughout the development of this rule,
EPA has maintained that this rule is designed to
cover the treatment and/or recovery of off-site
industrial wastes. As such, as proposed today,
grease/trap interceptor wastes do not fall within
the scope of the proposal. Grease
trap/interceptor wastes are defined as animal or
vegetable fats/oils from grease traps or
interceptors generated by facilities engaged in
food service activities. Such facilities include
restaurants, cafeterias, and caterers. Excluded
grease trap/interceptor wastes should not contain
any hazardous chemicals or materials that would
prevent the fats/oils from being recovered and
recycled. Wastewater discharges from the
centralized treatment of wastes produced from oil
interceptors, which are designed to collect
petroleum-based oils, sand, etc. from industrial
type processes, would be subject to this rule.
3-14
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Chapter
4
DESCRIPTION OF THE INDUSTRY
The adoption of the increased pollution
control measures required by CWA and
RCRA requirements had a number of ancillary
effects, one of which has been the formation and
development of a waste treatment industry.
Several factors haye contributed to the growth of
this industry. These include: (a) the manner in
which manufacturing facilities have elected to
comply with CWA and RCRA requirements; (b)
EPA's distinction for regulatory purposes
between on- and off-site treatment of wastewater
in the CWA guidelines program; and © the
RCRA 1992 used oil management requirements.
A manufacturing facility's options for
managing wastes include on-site treatment or
sending them off-site. Because a large number of
operations (both large and small) have chosen to
send their wastes off-site, specialized facilities
have developed whose sole commercial operation
is the handling of wastewater treatment residuals
and industrial process by-products.
Many promulgated effluent guidelines also
encouraged the creation of these central treatment
centers. Inconsistent treatment of facilities
which send their waste off-site to CWTs in the
guidelines program has resulted in wastewater
that is treated off-site being subject to
inconsistent standards. EPA acknowledges that
this may have created a loop-hole for dischargers
to avoid treating their wastewater to standards
comparable to categorical standards before
discharge. Additionally, RCRA regulations, such
as the 1992 used oil management requirements
(40 CFR 279) significantly influenced the size
and service provided by this industry.
INDUSTRYSIZE
4.1
Based upon responses to EPA's data
gathering efforts, the Agency now estimates that
there are approximately 205 centralized waste
treatment facilities in 38 States. As shown below
in Table 4-1, the major concentration of
centralized waste treatment facilities is in EPA
Regions 4, 5 and 6 due to the proximity of the
industries generating the wastes undergoing
treatment. At the time of the original proposal,
EPA estimated there were 85 centralized waste
treatment facilities in the United States. EPA,
however, greatly underestimated the number of
facilities in the proposed oily waste and recovery
subcategory. Through additional data gathering
activities (see discussion in Chapter 2), EPA
obtained information on additional oils facilities.
Except for facilities that were included or
excluded because of scope changes/clarifications,
all of the facilities which have been added since
the original proposal treat and/or recover oily
waste and/or used oil. EPA is aware that
facilities in the metals and organics subcategories
have entered or left the centralized waste
treatment market also. This is expected in a
service industry. Even so, EPA believes its initial
estimate of facilities in the other subcategories is
reasonable and no adjustments, other than those
resulting from the redefined scope of the industry,
have been made.
As detailed in Chapter 2, while EPA
estimates there are 205 CWT facilities, EPA only
has facility-specific information for 145 of these
facilities. In preparing this reproposal, EPA
conducted its analysis with the known facility
specific information and then used the actual data
to develop additional information to represent the
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Chapter 4 Description of the Industry Development Document for the CWT Point Source Category
entire population. Unless otherwise stated,
information presented in this document represents
the entire population. Table 4-1 provides an
example where data is only presented for the
facilities for which EPA has facility-specific
information.
GENERAL DESCRIPTION
4.2
Centralized waste treatment facilities do not
fall into a single description and are as varied as
the wastes they accept Some treat wastes from
a few generating facilities while others treat
wastes from hundreds of generators. Some treat
only certain types of waste while others accept
many wastes. Some treat non-hazardous wastes
exclusively while others treat hazardous and non-
hazardous wastes. Some primarily treat
concentrated wastes while others primarily treat
more dilute wastes. For some, their primary
business is the treatment of other company's
wastes while, for others, centralized waste
treatment is ancillary to their main business.
Centralized waste treatment facilities treat
both hazardous and/or non-hazardous wastes. At
the time, of the original proposal, a few of the
facilities in the industry database solely accepted
wastes classified as non-hazardous under RCRA.
The remaining facilities accepted either
hazardous wastes only or a combination of
hazardous and non-hazardous wastes. The vast
majority of the newly identified oils facilities
accept non-hazardous materials only. As such,
EPA believes the market for centralized waste
treatment of non-hazardous materials has
increased during the 1990s.
EPA has detailed waste receipt information
for the facilities in the 1991 Waste Treatment
Industry Questionnaire data base. Of the 76
in-scope facilities from the proposal data base, 65
of them are RCRA-permitted treatment, storage,
and disposal facilities (TSDFs). As such, most of
these facilities were able to use information
reported in the 1989 Biennial Hazardous Waste
Report to classify the waste accepted for
treatment by the appropriate Waste Form and
RCRA codes. The Waste Form and RCRA codes
reported by the questionnaire respondents are
listed in Table 4-2 and Table 4-3, respectively.
(Table 14-2 in Chapter 14 lists these Waste Form
and RCRA codes along with their associated
property and/or pollutants). Some questionnaire
respondents, especially those that treat
non-hazardous waste, did not report the Waste
Form Code information due to the variety and
complexity of their operations.
EPA does not have detailed RCRA code and
waste code information on waste receipts for the
facilities identified after the original proposal. It
is known that the majority of these facilities
accept non-hazardous wastes. Of the 69
post-proposal oily waste facilities for which EPA
has specific data, only 19 are RCRA-permitted
TSDFs.
Centralized waste treatment facilities service
a variety of customers. A CWT generally
receives a variety of wastes daily'from dozens of
customers. Some customers routinely generate a
particular wastestream and are unable to provide
effective on-site treatment of that particular
wastestream. Some customers utilize CWTs
because they generate wastestreams only
sporadically (for example tank removal, tank
cleaning and remediation wastes) and are unable
to economically provide effective on-site
treatment of these wastes. Others, many which
are small businesses, utilize CWTs as their
primary source of wastewater treatment.
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Chapter 4 Description of the Industry Development Document for the CWT Point Source Category
Table 4-1. Geographic Distribution of CWT Facilities (145 Facilities)
Region
1
2
3
4
Table 4-2
State
Connecticut
Maine
Massachusetts
Rhode Island
New Jersey
New York
Delaware
Maryland
Pennsylvania
Virginia
Alabama
Florida
Georgia
Kentucky
Mississippi
North Carolina
South Carolina
Tennessee
#of
CWTs
5
1
1
1
6
4
1
2
6
4
3
8
3
2
1
1
2
6
%of
CWTs
5.5
6.8
8.9
17.9
Region
. Waste Form Codes Reported by CWT Facilities
5
6
7
8
9
10
State
Illinois
Indiana
Michigan
Minnesota
Ohio
Wisconsin
Louisiana
Oklahoma
Texas
Iowa
Kansas
Missouri
Colorado
Montana
Arizona
California
Hawaii
Nevada
Oregon
Washington
# of % of
CWTs CWTs
6
4
10
2
12
4
3
2
13
= 1
2
1
2
1
1
12
1
1
2
8
26.2
12.4
2.8
2.1
10.3
6.9
in 19891
Waste Form Codes
B001
B101
B102
BIOS
B104
BIOS
B106 B112
B107 B113
BIOS B114
B109 B115
B110 B116
Bill B117
B119
B201
B202
B203
B204
B205
B206
B207
B208
B209
B210
B211
B219
B305
B306
B307
B308
B309
B310
B312
B313
B315
B316
B319
B501
B502
B504
B505
B506
B507
B508
B510
B511
B513
B515
B518
B519
B601
B603
B604
B605
B607
B608
B609
JTable 14-2 in Chapter 14 lists Waste Form Codes and their associated properties.
Table 4-3
. RCRA Codes Reported by Facilities in 19892
RCRA Codes
D001
D002
D003
D004
D005
D006
D007
D008
D009
D010
D011
D012 F009
D017 F010
D035 F011
F001 F012
F002 F019
F003 F039
F004 K001
F005 K011
F006 KOI 3
F007 K014
F008 KOI 5
K016
K031
K035
K044
K045
K048
K049
K050
K051
K052
K061
K063
K064
K086
K093
K094
K098
K103
K104
P011
P012
P013
P020
P022
P028
P029
P030
P040
P044
P048
P050
P063
P064
P069
P071
P074
P078
P087
P089
P098
P104
P106
P121
PI 23
U002
U003
U008
U009 .
U012
U013
U019
U020
U031
U044
U045
U052
U054
U057
U069
U080
U092
U098
U105
U106
U107
U113
U118
U122
U125
U134
U135
U139
U140
U150
U151
U154
U159
U161
U162
U188
U190
U205
U210
U213
U220
U226
U228
U239
^Table 14-2 in Chapter 14 lists Waste Form Codes and their associated properties.
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Chapter 4 Description of the Industry Development Document for the CWT Point Source Category
Before a CWT accepts a waste for treatment,
the waste generally undergoes rigorous screening
for compatibility with other wastes being treated
at the facility. Waste generators initially furnish
the treatment facility with a sample of the waste
stream to be treated. The sample is analyzed to
characterize the level of pollutants in the sample
and bench-scale treatability tests are performed to
determine what treatment is necessary to treat the
waste stream. After all analyses and tests are
performed, the treatment facility determines the
cost for treating the waste stream. If the waste
generator accepts the cost of treatment., shipments
of the waste stream to the treatment facility will
begin. Generally, for each truck load of waste
received for treatment, the treatment facility
collects a sample from the shipment and analyzes
the sample to determine if it is similar to the
initial sample tested. If the sample is similar, the
shipment of waste will be treated. If the sample
is not similar but falls within an allowable range
as determined by the treatment facility, the
treatment facility will reevaluate the estimated
cost of treatment for the shipment. Then, the
waste generator decides if the waste will remain
at the treatment facility for treatment. If the
sample is not similar and does not fall within an
allowable range, the treatment facility will decline
the shipment for treatment.
Treatment facilities and waste generators
complete extensive amounts of paperwork during
the waste acceptance process. Most of the
paperwork is required by Federal, State, and local
regulations. The amount of paperwork necessary
for accepting a waste stream emphasizes the
difficulty of operating centralized waste treatment
facilities.
WATER USE AND SOURCES
OF WASTEWATER
4.3
Approximately 1.9 billion gallons of
wastewater are generated annually at CWT
facilities. It is difficult to determine the quantity
of wastes attributable to different sources because
facilities generally mix the wastewater prior to
treatment. EPA has, as a general matter,
however, identified the sources described below
as contributing to wastewater discharges at CWT
operations that would be subject to the proposed
effluent limitations and standards.
Waste Receipts. Most off-site waste received by
CWT facilities is aqueous. These aqueous off-
site waste receipts comprise the largest portion of
the wastewater treated at CWTs. Typical waste
receipts for the metals subcategory include but
are not limited to: spent electroplating baths and
sludges; spent anodizing solutions; metal
finishing rinse water and sludges; and chromate
wastes. Types of waste accepted for treatment in
the oils subcategory include but are not limited to:
lubricants, used petroleum products, used oils, oil
spill clean-up, bilge water, tank clean out, off-
specification fuels, and underground storage tank
remediation waste. Types of wastes accepted for
treatment in the organics subcategory include, but
are not limited to: landfill leachate; groundwater
clean-up; solvent-bearing waste; off-specification
organic products; still bottoms; used antifreeze;
and wastewater from chemical product operations
and paint washes.
Solubilization Water. A portion of the off-site
waste receipts is in a solid form. Water may be
added to the waste to render it treatable.
Waste Oil Emulsion-Breaking Wastewater. The
wastewater generated as a result of the emulsion
breaking or gravity separation process from the
processing of used oil constitutes a major portion
of the wastewater treated at oils facilities. EPA
estimates that, at a typical oils facility, half of the
wastewater treated is a result of oil/water
separation processes.
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Chapter 4 Description of the Industry Development Document for the CWT Point Source Category
Tanker Truck/Drum/Roll-Off Box Washes.
Water is used to clean the equipment used for
transporting wastes. The amount of wastewater
generated was difficult to assess because the
wash water is normally added to the wastes or
used as solubilization water.
Equipment Washes. Water is used to clean waste
treatment equipment during unit shut downs or in
between batches of waste.
Air Pollution Control Scrubber Blow-Down.
Water or acidic or basic solution is used in air
emission control scrubbers to control fumes from
treatment tanks, storage tanks, and other
treatment equipment.
Laboratory-Derived Wastewater. Water is used
in on-site laboratories which characterize
incoming waste streams and monitor on-site
treatment performance.
Industrial Waste Combustor or Landfill
Wastewater from On-Site Landfills. Wastewater
is generated at some CWT facilities as a result of
on-site landfilling or incineration activities.
Contaminated Stormwater. This is stormwater
which comes in direct contact with the waste or
waste handling and treatment areas. If this
contaminated CWT stormwater is introduced to
the treatment system, its discharge is subject to
the proposed limitations. The Agency is
proposing not to regulate under the CWT
guideline non-contact stormwater or
contaminated stormwater not introduced to the
treatment system. Such flows may, in certain
circumstances, require permitting under EPA's
existing permitting program under 40 CFR
122.26(b)(14) and 40 CFR 403. CWTs that
introduce non-contaminated stormwater into their
treatment system will need to identify this as a
source of non-CWT wastewater in their treatment
system in their permit applications. This is
necessary in order that the permit writer may take
account of these flows in developing permit
limitations that reflect actual treatment.
VOLUME BY TYPE OF DISCHARGE
4.4
In general, three basic options are available
for disposal of wastewater treatment effluent:
direct, indirect, and zero (or alternative)
discharge. Some facilities utilize more than one
option (for example, a portion of their wastewater
is discharged to a surface water and a portion is
evaporated). Direct dischargers are facilities
which discharge effluent directly to a surface
water. Indirect dischargers are facilities which
discharge effluent to a publicly-owned treatment
works (POTW). Zero or alternative dischargers
do not generate a wastewater or do not discharge
to a surface water or POTW. The types of zero
or alternative discharge identified in the CWT
industry are underground injection control (UIC),
off-site transfer for further treatment or disposal,
evaporation, and no wastewater generation.
Table 4-4 lists the number of facilities utilizing
each discharge option.
Average facility wastewater discharge
information is presented in Table 4-5 for the
indirect and direct discharge options. The
proposed effluent limitations guidelines and
standards for the CWT industry do not apply to
facilities with a zero or alternative discharge.
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Chapter 4 Description of the Industry Development Document for the CWT Point Source Category
Table 4-4 Facility Discharge Options
Discharge Option
Direct
Indirect
Indirect and off-site transfer
Indirect and no wastewater generation
UIC
Off-site transfer
Evaporation
Off-site transfer and evaporation
Zero (not specified)
Total
No. of Facilities with
Specific Data
12
101
1
2
7
14
3
1
4
145
No. of Scaled-Up
Facilities
14
144
1
2
9
22
5
1
7
205
Table 4-5 Quantity of Wastewater Discharged (205 Facilities)
Discharge
Option
Quantity of Wastewater Discharged (Million gallons/year)
Total
Average
Minimum
Maximum
Direct
Indirect
535
1,370
38.2
9.3
0.078
0.0013
225
177
OFF-SHE TREATMENT INCENTIVES
AND COMPARABLE TREATMENT
4.5
As noted before, the adoption of the
increased pollution control measures required by
the CWA and RCRA regulation was a significant
factor in the formation and development of the
centralized waste treatment industry. Major
contributors to the growth of this industry include
EPA decisions about how to structure its CWA
effluent limitations guidelines program as well as
the manner in which manufacturing facilities have
elected to comply with CWA and RCRA
requirements.
The CWA requires the establishment of
limitations and standards for categories of point
sources that discharge into surface waters or
introduce pollutants into publicly owned
treatment works. At present, facilities that do not
discharge wastewater (or introduce pollutants to
POTWs) may not be subject to the requirements
of 40 CFR Subchapter N Parts 400 to 471.
Such facilities include manufacturing or service
facilities that generate no process wastewater,
facilities that recycle all contaminated waters, and
facilities that use some kind of alternative
disposal technology or practice (for example,
deep well injection, incineration, evaporation,
surface impoundment, land application, and
transfer to a centralized waste treatment facility).
Thus, for example, in implementing CWA
and RCRA requirements in the electroplating
industry, many facilities made process
modifications to conserve and recycle process
wastewater, to extend the lives of plating baths,
and to minimize the generation of wastewater
treatment sludges. As the volumes of wastewater
were reduced, it became economically attractive
to transfer electroplating metal-bearing
wastewater to off-site centralized waste treatment
facilities for treatment or metals recovery rather
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Chapter 4 Description of the Industry Development Document for the CWT Point Source Category
than to invest in on-site treatment systems. In the
case of the organic chemicals, plastics, and
synthetic fibers (OCPSF) industry, many
facilities transferred selected process residuals
and small volumes of process wastewater to off-
site centralized waste treatment facilities. When
estimating the engineering costs for the OCPSF
industry to comply with the OCPSF regulation,
the Agency assumed, based on economies of
scale, in the case of facilities with wastewater
flows less than 500 gallons per day, such plants
would use off-site rather than on-site wastewater
treatment.
The Agency believes that any wastes
transferred to an off-site CWT facility should be
treated to at least the same level as required for
the same wastes if treated on-site at the
manufacturing facility. In the absence of
appropriate regulations to ensure at least
comparable or adequate treatment, the CWT
facility may inadvertently offer an economic
incentive for increasing the pollutant load to the
environment. One of the Agency's primary
concerns is the potential for a discharger to
reduce its wastewater pollutant concentrations
through dilution rather than through appropriate
treatment. This proposal is designed to ensure
that wastes transferred to centralized waste
treatment facilities would be treated to the same
levels as on-site treatment or to adequate levels.
This is illustrated by the information the
Agency obtained during the data gathering
activities for the 1995 proposal. EPA visited 27
centralized waste treatment facilities in an effort
to identify well-designed, well-operated candidate
treatment systems for sampling. Two of the
principal criteria for selecting plants for sampling
were based on whether the plant applied waste
management practices that increased the
effectiveness of the treatment system and whether
the treatment system was effective in removing
pollutants. This effort was complicated by the
level of dilution and co-dilution of one type of
waste with another. For example, many facilities
treated metal-bearing and oily wastes in the same
treatment system and many facilities mixed non-
CWT wastewater with CWT wastewater. 'Mixing
metal-bearing with non-metal-bearing oily
wastewater and mixing CWT with non-CWT
wastewater provides a dilution effect which
generally reduces the efficiency of the wastewater
treatment system. Of the 27 plants visited, many
were not sampled because of the problems of
assessing CWT treatment efficiencies due to
dilution of one type of wastewater with another.
This proposal would ensure, to the extent
possible, that metal-bearing'wastes are treated
with metals control technology, that oily wastes
are treated with oils control technology, and that
organic wastes are treated with organics control
technology.
In developing this proposal, EPA identified a
wide variation in the size of CWT facilities and
the level of treatment provided by these facilities.
Often, pollutant removals were poor, and, in
some cases, significantly lower than would have
been required had the wastewaters been treated at
the site where generated. In particular, EPA's
survey indicated that some facilities were
employing only the most basic pollution control
equipment and, as a result, achieved low
pollutant removals relative to that easily obtained
through the use of other, readily available
pollutant control technology. Further, as
explained below, EPA had difficulty in
identifying more than a handful of facilities
throughout the CWT industry that were achieving
optimal removals.
During consideration of this proposal, EPA
looked 'at whether it should limit the scope of
national regulation to facilities above a certain
size or flow level because of information before
the Agency suggesting, that, in the case of certain
smaller facilities, the costs of additional controls
would represent a significant increase in their
costs of operation. For the reasons explained
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Chapter 4 Description of the Industry Development Document for the CWT Point Source Category
above, however, EPA has decided not to limit the
scope of this proposal, based either on the size of
a facility or the volume of wastewater flows. The
effect of such an approach, given the structure of
the industry and treatment level currently
observed, would be effectively to encourage the
movement of wastewater to some of the very
facilities that are not providing treatment that is
equivalent to that which would be expected (and
required) if the wastewater were treated at the
point of origin. Since this proposal would ensure
adequate controls for wastewater discharges from
CWT facilities that accept waste and wastewater
that would otherwise be controlled by other
guidelines, all members of the CWT industry
should comply with the national CWT standards
regardless of size or potential economic impacts.
4-8
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Chapter
5
INDUSTRY SUBCATEGORIZATION
METHODOLOGY AND FACTORS
CONSIDERED As THE BASIS
FOR SUBCATEGORIZATION
5.1
The CWA requires EPA, in developing
effluent limitations guidelines and
pretreatment standards that represent the best
available technology economically achievable for
a particular industry category, to consider a
number of different factors. Among others, these
include the age of the equipment and facilities in
the category, manufacturing processes employed,
types of treatment technology to reduce effluent
discharges, and the cost of effluent reductions
(Section 304(b)(2)(b) of the CWA, 33 U.S.C. §
1314(b)(2)(B)). The statute also authorizes EPA
to take into account other factors that the Agency
deems appropriate.
One way in which the Agency has taken
some of these factors into account is by breaking
down categories of industries into separate
classes of similar characteristics. This recognizes
the major differences among companies within an
industry that may reflect, for example, different
manufacturing processes or other factors. One
result of subdividing an industry by subcategories
is to safeguard against overzealous regulatory
standards, increase the confidence that the
regulations are practicable, and diminish the need
to address variations between facilities through a
variance process (Weyerhaeuser Co. v. Costle,
590F.2d 1011, 1053 (D.C. Cir. 1978)).
The centralized waste treatment industry, as
previously explained, is not typical of many of
the industries regulated under the CWA because
it does not produce a product. Therefore, EPA
considered certain additional factors that
specifically apply to centralized waste treatment
operations in its evaluation of how to establish
appropriate limitations and standards and
whether further subcategorization was warranted.
Additionally, EPA did not consider certain other
factors typically appropriate when
subcategorizing manufacturing facilities as
relevant when evaluating this industry. The
factors EPA considered in the subcategorization
of the centralized waste treatment industry
include:
• Facility age;
• Facility size;
• Facility location;
• Non-water quality impacts;
• Treatment technologies and costs;
• RCRA classification;
• Type of wastes received for treatment; and
• Nature of wastewater generated.
EPA concluded that certain of these factors
did not support further subcategorization of this
industry. The Agency concluded that the age of a
facility is not a basis for subcategorization as
many older facilities have unilaterally improved
or modified their treatment process over time.
EPA also decided that facility size was not an
appropriate basis for subcategorizing. EPA
identified three parameters as relative measures
of facility size: number of employees, amount of
waste receipts accepted, and wastewater flow.
EPA found that CWTs of varying sizes generate
similar wastewaters and use similar treatment
technologies. Furthermore, wastes can be treated
to the same level regardless of the facility size.
Likewise, facility location is not a good basis for
subcategorization. Based on the data collected,
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Chapter 5 Industry Subcategorization
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no consistent differences in wastewater treatment
technologies or performance exist because of
geographical location. EPA recognizes, however,
that geographic location may have an effect on
the market for CWT services, the cost charged for
these services, and the value of recovered
product. These issues are addressed in the
Economic Assessment Document.
While non-water quality characteristics
(solid waste and air emission effects) are of
concern to EPA, these characteristics did not
constitute a basis for subcategorization.
Environmental impacts from solid waste disposal
and from the transport of potentially hazardous
wastewater are a result of individual facility
practices and EPA could not identify any
common characteristics particular to a given
segment of the industry. Treatment costs were
not used as a basis for subcategorization because
costs will vary and are dependent on the
following waste stream variables: flow rates,
wastewater quality, and pollutant loadings.
Finally, EPA concluded that the RCRA
classification was not an appropriate basis for
subcategorization as the type of waste accepted
for treatment appears to be more important than
whether the waste was classified as hazardous or
non-hazardous.
EPA identified only one factor with primary
significance for subcategorizing the centralized
waste treatment industry — the type of waste
received for treatment or recovery. This factor
encompasses many of the other subcategorization
factors. The type of treatment processes used,
nature of wastewater generated, solids generated,
and potential air emissions directly correlate to
the type of wastes received for treatment or
recovery. For today's proposal, EPA reviewed its
earlier subcategorization approach and has
decided to retain it. It is still EPA's conclusion
that the type of waste received for treatment or
recovery is the only appropriate basis for
subcategorization of mis industry.
PROPOSED SUBCATEGORIES
5.2
Based on the type of wastes accepted for
treatment or recovery, EPA has determined that
there are three subcategories appropriate for the
centralized waste treatment industry:
• Subcategory A: Facilities which treat,
recover, or treat and recover metal, from
metal-bearing waste, wastewater, or used
material from off-site (Metals Subcategory);
• Subcategory B: Facilities which treat,
recover, or treat and recover oil, from oily
waste, wastewater, or used material from
off-site (Oils Subcategory); and
• Subcategory C: Facilities which treat,
recover, or treat and recover organics, from
other organic waste, wastewater, or used
material from off-site (Organics
Subcategory).
SUBCATEGORY DESCRIPTIONS 5.3
Metal-Bearing Waste Treatment
and Recovery Subcategory 5.3.1
The facilities in this Subcategory are those
treating metal-bearing waste received from
off-site and/or recover metals from off-site
metal-bearing wastes. Currently, EPA has
identified 59 facilities in this Subcategory.
Fifty-two facilities treat metal-bearing waste
exclusively, while another six facilities recover
metals from the wastes for sale in commerce or
for return to industrial processes. One facility
provides metal-bearing waste treatment in
addition to conducting a metals recovery
operation. The vast majority of these facilities
have RCRA permits to accept hazardous waste.
Types of wastes accepted for treatment include
spent electroplating baths and sludges, spent
anodizing solutions, metal finishing rinse water
and sludge, and chromate wastes.
The typical treatment process used for
metal-bearing waste is precipitation with lime or
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Chapter 5 Industry Subcategorization
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caustic followed by filtration. The sludge
generated is then landfilled in a RCRA Subtitle C
or D landfill depending on its content. Most
facilities that recover metals do not generate a
sludge that requires disposal. Instead, the sludges
are sold for metal content. In addition to treating
metal bearing wastestreams, many facilities in
this subcategory also treat cyanide wastestreams,
many of which are highly-concentrated and
complex. Since the presence of cyanide may
interfere with the chemical precipitation process,
these facilities generally pretreat to remove
cyanide and then commingle the pretreated
cyanide wastewaters with the other metal
containing wastewaters. EPA estimates that
nineteen of the metals facilities also treat cyanide
wastestreams.
Oily Waste Treatment.
and Recovery Subcategory
5.3.2
The facilities in this subcategory are those
that treat oily waste, wastewater, or used'material
received from off-site and/or recover oil from
off-site oily materials. Currently, EPA estimates
that there are 164 facilities in this subcategory.
Among the types of waste accepted for treatment
are lubricants, used petroleum products, used oils,
oil spill clean-up, bilge water, tank clean-out,
off-specification fuels, and underground storage
tank remediation waste. Many facilities in this
subcategory only provide treatment for oily
wastewaters while others pretreat the oily wastes
for contaminants such as water and then blend the
resulting oil residual to form a product, usually
fuel. Most facilities perform both types of
operations. EPA estimates that 53 of these
facilities only treat oily wastewaters and 36
facilities primarily recover oil for re-use. The
remaining 75 facilities both treat oily waste and
recover oil for re-use.
At the time of the original proposal, EPA
believed that 85 percent of oils facilities were
primarily accepting concentrated, difficult-
to-treat, stable, oil-water emulsions containing
more than 10 percent oil. However, during
post-proposal data collection, EPA learned that
many of the wastes treated for oil content at these
facilities were fairly dilute and consisted of less
than 10 percent oils. EPA now believes that,
while some facilities are accepting the more
concentrated wastes, the majority of facilities in
this subcategory are treating less concentrated
wastes.
Further, at the time of the original proposal,
only three of the facilities included in the data
base for this subcategory were identified as solely
accepting wastes classified as non-hazardous
under RCRA. The remaining facilities accepted
either hazardous wastes alone or a combination of
hazardous and non-hazardous wastes. In
contrast, based on more recent information, EPA
believes that the majority of facilities in this
subcategory only accept wastes that would be
classified by RCRA as non-hazardous.
The most widely-used treatment technology
in this subcategory is gravity separation and/or
emulsion breaking. One-third of this industry
only uses gravity separation and/or emulsion
breaking to treat oily wastestreams. One-third of
the industry also utilizes chemical precipitation
and one-quarter also utilizes dissolved air
flotation (DAF).
Organic Waste Treatment
and Recovery Subcategory
5.3.3
The facilities in this subcategory are those
that treat organic waste received from off-site
and/or recover organics from off-site organic
wastes. EPA estimates that there are 25 facilities
in this subcategory. The majority of these
facilities have RCRA permits to accept hazardous
waste. Among the types of wastes accepted at
these facilities are landfill leachate, groundwater
cleanup, solvent-bearing waste, off-specification
organic products, still bottoms, used antifreeze,
and wastewater from chemical product operations
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Chapter 5 Industry Subcategorization
Development Document for the CWT Point Source Category
and paint washes.
All of the organics facilities which discharge
to a surface water use equalization and some form
of biological treatment to handle the wastewater.
The vast majority of organics facilities which
discharge to a POTW primarily use equalization.
One third of all the organics facilities also use
activated carbon adsorption. Most of the
facilities in the organics subcategory have other
industrial operations as well, and the centralized
waste treatment wastes are mixed with these
wastewaters prior to treatment. The relatively
constant make-up of on-site wastewater can
support the operation of conventional, continuous
biological treatment processes, which otherwise
could be upset by the variability of the off-site
waste receipts.
MIXED WASTE SUBCATEGORY
CONSIDERATION
5.4
EPA has received numerous comments from
industry that the subcategorization scheme
developed for this rule is impractical for CWT
facilities which accept wastes in more than one
subcategory. These commenters are primarily
concerned about incoming waste receipts that
may be classified in more than one subcategory.
While CWTs can encourage their customers to
segregate their wastes, they argue that CWTs can
not require segregation of incoming waste
receipts. Additionally, commenters have
suggested that, for ease of implementation, mixed
waste subcategory limitations should be
developed for all facilities in multiple
subcategories. These commenters are primarily
concerned that permit writers may impose
additional and substantial record keeping burden
in order to classify wastes in each of the
subcategories. Commenters have suggested that
limitations for the mixed waste subcategory could
combine pollutant limitations from all three
subcategories, selecting the most stringent value
where they overlap.
While facilities have suggested developing a
mixed waste subcategory with limitations derived
by combining pollutant limitations from all three
subcategories (selecting the most stringent value
where they overlap), EPA does not believe
facilities have adequately considered the costs
associated with such an option. Assuming
facilities employ appropriate treatment rather
than dilution to meet these mixed waste
limitations, EPA compared the compliance cost
for facilities in multiple subcategories with the
mixed waste subcategory limitations as described
above to compliance costs for facilities meeting
the limitations for the three subcategories
separately. Costs were greater for the mixed
waste subcategory since EPA had to cost for
larger flows, more chemical addition, etc. EPA
chose nine representative facilities that treat
wastes in more than one subcategory to conduct
the comparisoa EPA found that, in all cases, the
costs of complying with the mixed waste
subcategory limitations were two to three times
higher than the costs associated with complying
with each of the subcategory limitations
separately. Since the market for these services is,
generally, very competitive and since many of
these facilities are small businesses, EPA believes
that few facilities would chose to meet the
limitations for the mixed waste subcategory.
The primary reason industry suggested the
development of a mixed waste subcategory was
their concern that waste receipts may be classified
in more than one subcategory. As detailed in
Chapter 13, EPA believes that the information
currently collected is sufficient to classify wastes
into each of the three subcategories. Using the
recommended subcategory determination
procedure, EPA is able to classify each waste
receipt identified by the industry during the
development of this rule in a single subcategory.
Therefore, EPA believes that mixed waste receipt
concern has been alleviated.
The second reason industry suggested the
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Chapter 5 Industry Subcategorization
Development Document for the CWT Point Source Category
development of a mixed waste subcategory was
to simplify implementation for mixed
subcategory facilities. EPA agrees with
commenters that developing appropriate
limitations for mixed waste facilities presents •
many challenges, but is concerned that mixed
wastes receive adequate treatment. In many
cases, facilities which accept wastes in multiple
subcategories do not have treatment in place to
provide effective treatment of all waste receipts.
While these facilities meet their permit
limitations, compliance is generally due to
dilution rather than treatment. As an example, a
facility may have a treatment system comprised
of equalization and biological treatment and
accepts wastes from the organics subcategory and
the metals subcategory (high concentrations of
metal pollutants). Only the organic subcategory
waste receipts would be treated effectively. The
"mixed waste subcategory" limitations described
above would not prevent ineffective treatment
and could actually encourage it. Therefore, based
on economic considerations as well as concerns
that EPA has about ensuring compliance with
effective treatment, rather than dilution, EPA is
not proposing a mixed waste subcategory.
5-5
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Chapter
6
POLLUTANTS OF CONCERN FOR THE
CENTRALIZED WASTE TREATMENT INDUSTRY
As discussed previously, wastewater receipts
treated at centralized waste treatment
facilities may have significantly different
pollutants and pollutant loads depending on the
customer and the process generating the waste
receipt. In fact, at many CWT facilities, the
pollutants and pollutant loads may vary daily and
from batch to batch. As a result, it is difficult to
characterize "typical" CWT wastewaters. In fact,
one of the distinguishing characteristics of CWT
wastewaters (as compared to traditional
categorical wastewaters) is that there is always
the exception to the rule. For example, at one
facility, EPA analyzed samples of wastewater
received for treatment from a single facility that
were obtained during three different, non-
consecutive weeks. EPA found that the weekly
waste receipts varied from the most concentrated
(in terms of metal pollutants) to one of the least
concentrated (in terms of metal pollutants).
METHODOLOGY
6.1
EPA determined pollutants of concern for the
CWT industry by assessing EPA sampling data
only. Industry has provided very little
quantitative data on the concentrations of
pollutants entering their wastewater treatment
systems. For the metals and organics
subcategory, EPA collected the data used to
determine the pollutants of concern at influent
points to the wastewater treatment systems. For
the oils subcategory, EPA collected the data
following emulsion breaking and/or gravity
separation. The pollutant concentrations at these
points are lower than the original waste receipt
concentrations as a result of the commingling of
a variety of waste streams, and, in the case of the
oils subcategory, as a result of pretreatment. In •
most cases, EPA could not collect samples from
individual waste shipments because of physical
constraints and excessive analytical costs.
EPA used two different analytical methods to
analyze samples for oil and grease during the
development of this guideline. EPA analyzed
samples collected prior to the 1995 proposal
using Method 413.1. This method uses freon and
is being phased out. EPA analyzed oil and grease
samples collected after the 1995 proposal using
the newly proposed EPA Method 1664. Method
1664 is used to measure oil and grease as hexane
extractable material (HEM) and to measure silica
gel treated-hexane extractable material (SGT-
HEM). EPA believes that oil and grease
measurements from Method 413.1 and Method
1664 are comparable and has used the data
interchangeably.
EPA collected influent sampling data over a
limited time span (generally two to five days).
The samples represent a snapshot of the receipts
accepted for treatment during the time the
samples were collected. Because waste receipts
may vary significantly from day to day, EPA
can't know if, in fact, the data are also
representative of waste receipts during any other
time period. If EPA had sampled at more
facilities or over longer periods of time, EPA
would expect to observe a wider range of flows,
pollutants, and pollutant concentrations in CWT
industry raw wastewater. This has complicated
6-1
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Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
the selection of pollutants of concern and
regulated pollutants, and the estimation of current
performance and removals associated with this
rulemaking. Historically, in developing
categorical limitations and standards, unlike the
case for CWT waste receipts, influent
wastestreams are generally consistent in strength
and nature.
To establish the pollutants of concern, EPA
reviewed the analytical data from influent
wastewater samples to determine the number of
times a pollutant was detected at treatable levels.
EPA set treatable levels at ten times the method
detection limit to ensure that pollutants detected
as only trace amounts would not be selected. For
most organic pollutants, the method detection
limit is 10 ug/L. Therefore, for most organic
parameters, EPA has defined treatable levels as
100 ug/L. For metals pollutants the method
detection limits range from 0.2 ug/L to 1000
ug/L. EPA then obtained the initial pollutants of
concern listing for each subcategory by
establishing which parameters were detected at
treatable levels in at least 10 percent of the
influent wastewater samples. Ten percent was
used to account for the variability of CWT
wastewaters. As mentioned previously in Section
2.3.3.2, after the initial two sampling episodes
EPA discontinued the analyses for dioxins/furans,
pesticides/herbicides, methanol, ethanol, and
formaldehyde, and as a result these parameters
were not included in the pollutants of concern
analysis. Figure 6-1 depicts the methodology
EPA used to select pollutants of concern for each
subcategory.
Tables 6-1 through 6-3 provide a listing of
the pollutants that were determined to be
pollutants of concern for each subcategory.
These tables list the pollutant name, CAS
number, the number of times the pollutant was
analyzed, the number of detects, the method
detection limit (MDL), the number of detects at
treatable levels, and the minimum and maximum
concentration detected. Tables 6-4 through 6-6
provide a listing of the pollutants that were not
considered to be pollutants of concern for each
subcategory and the reason they were not
' selected. While EPA generally uses the
parameters established as pollutants of concern to
estimate pollutant loadings and pollutant
removals, EPA only selected some of these
parameters for regulation. The regulated
pollutants are a subset of the pollutants of
concern and are discussed in Chapter 7. Chapter
12 discusses pollutant loading and removal
estimates.
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Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
/Total list of pollutants analyzed for each \
I influent sample at each sampling episode J
for a single subeategory /
Was the pollutant
ever detected in any sample?
Was the pollutant
detected at a concentration
10 times, the method
detection limit?
Was the
pollutant detected at a
concentrations 10 tones the method
detection limit in at least
10 % of the
pies?
Pollutant is not a POC for the
subeategory
Pollutant is not a POC for the
subeategory
Pollutant is not a POC for the
subeategory
Pollutant is 4 POC for the subeategory
Figure 6-1. Pollutant of Concern Methodology
6-3
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Chanter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-1. Pollutants of Concern for the Metals Subcategory
# Times
Cas No. Analyzed
MDL # Detects
# Detects (ug/1) >10xMDL
CLASSICALS OR CONVENTIONALS
Amenable Cyanide
Ammonia as Nitrogen
BOD 5-Day
COD
Chloride
Fluoride
Hexavalent Chromium
Nitrate/Nitrite
SGT-HEM
Total Cyanide
TDS
TOC
Total Phenols
Total Phosphorus
Oil & Grease
Total Sulfide
TSS
METALS
Aluminum
Antimony
Aiscnic
Barium
Bciyllium
Boron
Cadmium
Calcium
Chromium
Cobalt
Copper
Gallium
Indium
Iodine
Indium
Iron
Lead
Lithium
Magnesium
Manganese
Mercury
Molybdenum
Ncodymium
Nickel
Niobium
Osmium
Phosphorus
Potassium
Selenium
Silicon
Silver
Sodium
C-025
7664417
C-002
C-004
16887006
16984488
18540299
C-005
C-037
57125
C-010
C-012
C-020
14265442
C-007
18496258
C-009
7429905
7440360
7440382
7440393
7440417
7440428
7440439
7440702
7440473
7440484
7440508
7440553
7440746
7553562
7439885
7439896
7439921
7439932
7439954
7439965
7439976
7439987
7440008
7440020
7440031
7440042
7723140
7440097
7782492
7440213
7440224
7440235
21
51
49
50
12
51
39
51
6
26
12
51
46
46
43
46
51
51
51
51
51
51
51
51
51
51
51
51
26
25
25
25
51
51
26
51
51
51
51
24
51
26
24
25
26
51
26
51
51
15
51
42
50
12
51
28
50
5
22
12
49
41
45
37
16
51
48
33
35
36
25
50
49
51
51
39
51
9
10
10
13
51
50
16
44
50
39
51
7
51
6
11
21
25
24
24
42
51
20
10
2,000
5,000
1,000
100
10
50
5,000
20
1,000
50
10
5,000
1,000
4,000
200
20
10
200
5
100
5
. 5,000
10.
50
25
500
1,000
1,000
1,000
100
50
100
5,000
15
0
10
500
40
1,000
100
1,000
1,000
5
100
10
5,000
15
51
37
50
12
48
19
49
3
22
12
49
10
45
15
9
50
47
29
31
8
9
50
49
46
51
33
51
5
6
10
11
51
49
12
27
49
31
50
3
51
3
4
19
25
18
22
39
51
Minimum
Cone.
(mg/1)
0.00027
0.00040
0.00400
0.06800
0.26200
0.00012
0.00000
0.00030
0.00630
0.00030
13.00000
0.05500
0.00001
0.00030
0.00450
0.00008
0.01000
(ug/1)
723.0
29.0
17.0
7.1
1.7
1,300.0
83.0
6,630.0
661.0
49.0
756.0
1,125.0
800.0
23,800.0
400.0
3,140.0
208.0
129.0
9,330.0
84.0
1.3
14.0
480.0
6,190.0
600.0
149.0
1,730.0
15,100.0
10.0
111.0
13.0
469,500.0
Maximum
Cone.
(mg/1)
2.9000
1.0000
11.0000
86.0000
62.0000
28.0000
40.0000
40.0000
0.0430
8.4000
177.0000
19.0000
0.0029
15.0000
0.1430
1.1000
141.0000
(ug/1)
2,080,000.0
1,160,000.0
1,220,000.0
596,000.0
296.0
1,420,000.0
19,300,000.0
9,100,000.0
65,000,000.0
10,900,000.0
40,200,000.0
36,350.0
61,200.0
537,000.0
253,000.0
7,745,000.0
3,220,000.0
795,000.0
2,980,000.0
6,480,000.0
3,100.0
1,390,000.0
58,400.0
2,460,000.0
57,300.0
21,800.0
2,550,000.0
9,720,000.0
11,800.0
1,330,000.0
130,000.0
77,700,000.0
6-4
-------
Chapter 6 Pollutants of Concern for theCWT Industry
Development Document for the CWT Point Source Category
Table 6-1. Pollutants of Concern for the Metals Subcategory
Pollutant
Strontium
Sulfur
Tantalum
Tellurium
Thallium
Tin
Titanium
Vanadium
Yttrium
Zinc
Zirconium
ORGANICS
Benzoic Acid
Benzyl Alcohol
Bis(2-Ethylhexyl)Phthalate
Bromodichloromethane
Carbon Bisulfide
Chloroform
Dibromochloromethane
Hexanoic Acid
Methylene Chloride
N-Nitrosomorpholine
N,N-Dimelhylformamide
Pyridine
Tribromomethane
Trichloroethene
Tripropyleneglycol Methyl Ether
2-Butanone
2-Propanone
# Times
Cas No. Analyzed
7440246
7704349
7440257
13494809
7440280
7440315
7440326
7440622
7440655
7440666
7440677
65850
100516
117817
75274
75150
67663
124481
142621
75092
59892
68122
110861
75252
79016
20324338
78933.
67641
26
25
24
24
51
51
51
51
51
51
26
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
MDL # Detects Minimum
# Detects (ug/1) >10xMDL Cone.
17
25
7
4
17
44
42
31
38
50
11
13
5
7
3
2
5
3
7
11
3
5
5
3
4
3
4
13
100
1,000
500
1,000
10
30
5
50
5
20
100
50
10
10
10
10
10
10
10
10
10
10
10
10
10
99
50
50
12
25
3
3
11
43
40
22
29
50
5
12
4
6
2
2
3
3
6
8
2
3
3
2
3
2
3
11
202.0
157,000.0
1,270.0
11,700.0
14.0
145.0
36.0
22.0
3.0
2,512.0
200.0
(ug/0
193.0
13.0
18.0
90.0
186.0
161.0
105.0
99.0
11.0
50.0
126.0
140.0
72.0
122.0
147.0
65.0
105.0
Maximum
Cone.
16,300.0
33,300,000.0
20,000.0
182,000.0
275,000.0
15,100,000.0
7,500,000.0
364,000.0
900.0
16,400,000.0
4,860.0
(ug/0
36,756.0
7,929.0
1,063.0
704.0
449.0
731.0
723.0
1,256.0
734.0
167.0
301.0
1,684.0
338.0
360.0
3,212.0
7,826.0
54,083.0
6-5
-------
Chanter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-2. Pollutants of Concern for the Oils Subcategory
Pollutant
# Times
Cas No. Analyzed
# Detects
MDL # Detects Minimum
(ug/l)>10xMDL " Cone.
CLASSICALS OR CONVENTIONALS
Amenable Cyanide
Ammonia as Nitrogen
BOD 5-Day
BOD
COD
Chloride
Fluoride
Nitrate/Nitrite
SGT-HEM
Total Cyanide
IDS
TOC
Total Phenols
Total Phosphorus
Oil & Grease
TSS
METALS
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Calcium
Chromium
Cobalt
Copper
Germanium
Iron
Lead
Lutetium
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Phosphorus
Potassium
Selenium
Silicon
Silver
Sodium
Strontium
Sulfur
Tin
Titanium
Vanadium
Zinc
ORGANICS
Acenaphthene
C-025
7664417
C-002
C-003
C-004
16887006
16984488
C-005
C-037
57125
C-010
C-012
C-020
14265442
C-007
C-009
7429905
7440360
7440382
7440393
7440417
7440428
7440439
7440702
7440473
7440484
7440508
7440564
7439896
7439921
7439943
7439954
7439965
7439976
7439987
7440020
7723140
7440097
7782492
7440213
7440224
7440235
7440246
7704349
7440315
7440326
7440622
7440666
83329
3
24
19
9
28
14
24
24
14
13
18
28
24
24
28
28
28
28
28
28
28
28
28
28
28
28
28
19
28
28
19
28
28
28
28
28
17
19
28
19
28
28
19
17
28
28
28
28
28
3
24
19
9
28
14
23
23
14
12
18
28
24
24
28
28
26
20
26
28
7
28
22
28
28
18
27
2
28
27
3
28
28
20
24
27
17
19
15
19
15
27
13
17
16
16
17
28
6
20
10
2,000
2,000
5,000
1,000
100
50
5,000
20
1,000
50
10
5,000
4,000
200
20
10
200
5
100
5
5,000
10
50
25
500
100
50
100
5,000
15
0
10
40
1,000
1,000
5
100
10
5,000
100
1,000
30
5
50
20
10
1
24
19
9
28
14
19
23
14
5
18
28
24
24
28
26
22
7
18
11
3
28
19
23
19
14
21
2
27
18
3
17
28
14
23
18
16
19
12
19
3
27
8
17
13
14
3
25
6
(mg/1)
0.00003
0.02000
0.50000
3.60000
0.00140
0.01900
0.00012
0.00050
0.35400
0.00002
1.30000
0.29800
0.00280
0.00065
0.03800
0.03400
(ug/1)
213.0
27.0
46.0
33.0
0.8
2,170.0
8.6
27,700.0
9.2
8.5
11.0
10,250.0
494.0
34.0
1,165.0
4,910.0
535.0
0.3
15.0
77.0
4,033.0
23,550.0
11.0
1,862.0
8.0
219,000.0
128.0
90,600.0
127.0
29.0
14.0
34.0
(ug/0
105.0
Maximum
Cone.
(mg/1)
0.00025
1.90000
26.00000
20.00000
120.00000
6.20000
0.33000
0.10300
3.70000
0.00098
33.00000
157.00000
0.18500
19.00000
180.00000
22.00000
(ug/0
192,580.0
1,670.0
9,170.0
7,049.0
113.0
1,710,000.0
498.0
572,750.0
7,178.0
116,000.0
80,482.0
12,360.0
630,000.0
21,725.0
1,315.0
753,000.0
' 44,500.0
56.0
12,400.0
62,800.0
239,000.0
2,880,000.0
1,000.0
87,920.0
7,740.0
11,100,000.0
3,470.0
3,712,000.0
6,216.0
1,407.0
2,000.0
94,543.0
(ug/1)
13,418.0
6-6
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-2. Pollutants of Concern for the Oils Subcategory
Pollutant
Alpha-TerpineoI
Aniline
Anthracene
Benzene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzoic Acid
Benzyl Alcohol
Biphenyl
Bis(2-Ethylhexyl)Phthalate
Butyl Benzyl Phthalate
Carbazole
Carbon Disulfide
Chlorobenzene
Chlorofonn
Chrysene
Di-N-Butyl Phthalate
Dibenzofuran
Dibenzothiophene
Diethyl Phthalate
Diphenyl Ether
Ethylbenzene
Fluoranthene
Fluorene
Hexanoic Acid
M-Xylene
Methylene Chloride
N-Decane
N-Docosane
N-Dodecane
N-Eicosane
N-Hexacosane
N-Hexadecane
N-Octadecane
N-Tetracosane
N-Tetradecane
N,N-Dimethylformamide
Naphthalene
O+P Xylene
O-Cresol
P-Cresol
P-Cymene
Pentamethylbenzene
Phenanthrene
Phenol
Pyrene
Pyridine
Styrene
Tetrachloroethene
Toluene
# Times
Cas No. Analyzed
98555
62533
120127
71432
56553
50328
205992
207089
65850
100516
92524
117817
85687
86748
75150
108907
67663
218019
84742
132649
132650
84662
101848
100414
206440
86737
142621
108383
75092
124185
629970
112403
112958
630013
544763
593453
646311
629594
68122
91203
136777612
95487
106445
99876
700129
85018
108952
129000
110861
100425
127184
108883
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
# Detects
10
5
10
28
11
4
6
4
24
7
15
13 '
6
8
14
11
12
11
4
5
9
10
7
28
13
9
22
23
25
24
18
24
26
9
26
25
10
26
5
25
23
11
18
6
7
18
25
12
9
5
19
28
MDL # Detects
(ug/l)>10xMDL
10
10
10
10
10
10
10
10
50
10
10
10
10
20
10
10
10
10
10
10
10
10
10.
10
10
10
10
10
10
10
10
10
10
io
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
8
4
10
24
8
3
5
3
24
3
11
9
4
5
6
6
12
9
3
4
9
10
5
25
12
6
21
22
16
22
14
24
23
6
26
22
4
24
3
23
18
10
18
6
4
14
23
12
6
'5
18
26
Minimum
Cone.
57.0
142.0
110.0
70.0
67.0
65.0
38.0
38.0
3,458.0
40.0
36.0
33.0
118.0
48.0
11.0
12.0
160.0
88.0
104.0
117.0
128.0
145.0
149.0
14.0
47.0
73.0
56.0
24.0
13.0
62.0
17.0
125.0
58.0
16.0
160.0
47.0
18.0
78.0
83.0
152.0
14.0
142.0
220.0
232.0
116.0
12.0
1,351.0
113.0
14.0
289.0
24.0
51.0
Maximum
Cone.
2,245.0
367.0
18,951.0
20,425.0
6,303.0
6,670.0
5,752.0
5,752.0
163,050.0
783.0
10,171.0
838,450.0
49,069.0
1,459.0
2,335.0
326.0
1,828.0
8,879.0
1,262.0
13,786.0
5,448.0
9,309.0
13,751.0
18,579.0
28,873.0
15,756.0
90,080.0
32,639.0
10,524.0
579,220.0
15,354.0
472,570.0
319,080.0
9,561.0
1,367,970.0
901,920.0
10,289.0
2,560,460.0
803.0
53,949.0
16,584.0
8,273.0
2,382.0
4,452.0
11,186.0
49,016.0
48,640.0
22,763.0
1,280.0
843.0
12,789.0
99,209.0
6-7
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-2. Pollutants of Concern for the Oils Subcategory
Pollutant
Trichloroethene
Tripropyleneglycol Methyl Ether
1-Methylfluorene
l-Methy]phenanthrene
1,1-Dichloroethene
1,1, 1-Trichloroethane
1,2-Dichloroethane
1 ,2,4-Trichlorobenzene
1 ,4-Dichlorobenzene
1,4-Dioxane
2-Butanone
2-Methyinaphthalene
2-Phenylnaphthalene
2-Propanone
2,3-Benzofluorene
2,4-Dimethylphenol
3,6-Dimethylphenanthrene
4-Chloro-3-Methylphenol
4-Methvl-2-Pentanone
# Times
Cas No. Analyzed
79016
20324338
1730376
832699
75354
71556
107062
120821
106467
123911
78933
91576
612942
67641
243174
105679
1576676
59507
108101
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
28
# Detects
15
11
8
10
7
23
12
8
7
3
26
22
4
27
6
10
5
16
22
MDL # Detects
(ug/l)>10xMDL
10
99
10
10
10
10
10
10
10
10
50
10
10
50
10
10
10
10
50
9
9
6
8
6
19
9
8
7
3
24
16
3
27
5
7
5
14
14
Minimum
Cone.
18.0
1,495.0
42.0
92.0
11.0
10.0
14.0
359.0
454.0
189.0
57.0
80.0
30.0
974.0
162.0
76.0
114.0
460.0
199.0
Maximum
Cone.
7,125.0
383,151.0
5,803.0
7,111.0
1,968.0
14,455.0
713.0
18,899.0
2,334.0
1,323.0
178,748.0
46,108.0
543.0
2,099,340.0
2,755.0
2,171.0
2,762.0
. 83,825.0
20.489.0
6-8
-------
Chanter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-3. Pollutants of Concern for the Organics Subcategory
Pollutant
# Times
Cas No. Analyzed
MDL # Detects Minimum
# Detects (ug/L) >10 xMDL Cone.
CLASSICALS OR CONVENTIONALS
Amenable Cyanide
Ammonia as Nitrogen
BOD 5-Day
COD
Fluoride
Nitrate/Nitrite
Total Cyanide
TOC
Oil & Grease
Total Sulfide :
TSS
METALS
Aluminum
Antimony
Arsenic
Barium
Boron
Calcium
Chromium #
Cobalt
Copper
Iodine
Iron
Lead
Lithium
Manganese
Molybdenum
Nickel
Phosphorus
Potassium
Silicon
Sodium
Strontium
Sulfur
Tin
Titanium
Zinc
ORGANICS
Acetphenone
Aniline
Benzene
Benzole Acid
Bromodichlororrtethane
Carbon Disulfide
Chlorobenzene
Chloroform
Diethyl Ether
Dimethyl Sulfone
Ethane, Pentachloro-
Ethylenethiourea
Hexachloroethane
Hexanoic Acid
C-025
7664417
C-002
C-004
16984488
C-005
57125
C-012
C-007
18496258
C-009
7429905
7440360
7440382
7440393
7440428
7440702
7440473 '
7440484
7440508
7553562
7439896
7439921
7439932
7439965
7439987
7440020
7723140
7440097
7440213
7440235
7440246
. 7704349
7440315
7440326
7440666
98862
62533
71432
65850
75274
75150
108907
67663
60297
67710
76017
96457
67721
142621
5
5
5
' 5
5
5
5
5
5
5
5
5
5
5
5
5'
5
5
5
5
4
5
5
5
5
5
5
4
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
4
5
5
5
5
4
5
5
5
3
5
5
4
5
5
5
5
4
4
5
4-
5
4
5
5
5
5
4
5
5
5
5
5
4
5
5
4
2
5
2
5
4
4
4
4
3
2
2
2
3
20
10
2,000
5,000
100
50
20
1,000
5,000
1,000
4,000
200
20
10
200
100
5,000
10
50
25
1,000
100
50
100
15
10
40
1,000
1,000
100
5,000
100
1,000
30
5
20
10
10
10
50
10
10
10
10
10
20
20
10
10
3
5
5
5-
2
4
5
5
1
2
4
4
3
1
2
5
5
2
3
4
1
5
1
5
5'
4
4
1
5
5
5
5
5
.2
1
4
4
2
3
2
1
1
1
4
4
3
1
2
2
3
(mg/1)
0.00014
0.08300
0.79000
1.40000
0.00060
0.10000
0.00080
0.51000
0.00220
0.00400
0.03300
(ug/1)
148.0
146.0
8.3
1,030.0
2,950.0
1,025,000.0
63.0
253.0
7.0
3,800.0
2,360.0
109.0
1,100.0
179.0
33.0
55.0
3,000.0
383,000.0
1,500.0
2,470,000.0
3,900.0
12,800.0
200.0
9.0
40.0
(ug/1)
336.0
178.0
31.0
5,649.0
26.0
14.0
70.0
5,224.0
182.0
315.0
79.0
8,306.0
75.0
1,111.0
Maximum
Cone.
(mg/1)
0.00620
2.40000
7.60000
11.00000
0.00200
0.34000
0.00780
3.80000
0.04800
0.02400
3.70000
(ug/1)
7,660.0
1,540.0
152.0
136,000.0
4,320.0
1,410,000.0
274.0
731.0
2,690.0
15,100.0
6,430.0
687.0
18,750.0
513.0
6,950.0
2,610.0
15,900.0
1,240,000.0
3,600.0
6,390,000.0
14,000.0
1,990,000.0
2,530.0
64.0
1,210.0
(ug/1)
739.0
392.0
179.0
15,760.0
197.0
1,147.0
101.0
32,301.0
211.5
892.0
135.0
9,655.0
101.0
4,963.0
6-9
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-3. Pollutants of Concern for the Organics Subcategory
Pollutant
Isopborone
M-Xylene
Melhylene Chloride
N,N-Dimethylfomiamide
CH-PXylene
O-Cresol
P-Cresol
Pentachlorophenol
Phenol
Pyridinc
Tetrachloroethene
Tetrachloromethane
Toluene
Trans- 1 ,2-Dichloroethene
Trichloroethene
Vinyl Chloride
1,1-Dichloroethane
1,1-DichIoroethene
1,1,1-Trichloroethane
1,1,1,2-Tetrachloroethane
1 ,1 ,2-Trichloroethane
1,1,2,2-Tetrachloroethane
1,2-Dibromoethane
1 ,2-Dichlorobenzene
1,2-Dichloroethane
1,2,3-Trichloropropane
1,3-DichIoropropane
2-Butanone
2-Picoline
2-Propanone
2^-Dichloroaniline
2^,4,6-Tetrachlorophenol
2,4-DimethyIphenol
2,4,5-TrichIorophenol
2,4,6-Trichlorophenol
3,4,5-Trichlorocatechol
3,4-Dichlorophenol
3,4,6-Trichloroguaiacol
3,5-Dichlorophenol
3,6-Dichlorocatechol
4-Chlorophenol
4-Methyl-2-Pentanone
4,5-Dichloroguaiacol
4,5,6-Triehloroguaiacol
5-Chloroguaiacol
6-Chlorovanillin
# Times
Cas No. Analyzed
78591
108383
75092
68122
136777612
95487
106445
87865
108952
110861
127184
56235
108883
156605
79016
75014
75343
75354
71556
630206
79005
79345
106934
95501
107062
96184
142289
78933
. 109068
67641
608275
58902
105679
95954
88062
56961207
95772
60712449
591355
3938167
106489
108101
2460493
2668248
3743235
18268763
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
# Detects
2
5
4
3
5
4
4
5
4
5
4
5
5
5
4
5
5
5
5
5
5
1
5
1
4
5
1
5
3
5
3
• 5
1
5
5
2
4
3
3
1
1
5
1
2
1
1
MDL # Detects Minimum
(ug/L) >10xMDL Cone.
10
10
10
10
10
10
10
50
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
50
50
10
20
10
10
10
1
1
50
1
1
4
2
1
4
4
4
4
4
4
5
5
5
4
5
2
5
4
5
5
1
5
1
4
4
1
5
2
5
3
5
1'
4
4
1
4
1
3
4
1
60.0
45.0
• 2,596.0
23.0
13.0
7,162.0
220.0
25.0
483.0
29.0
2,235.0
1,862.0
148.0
1,171.0
3,551.0
290.0
23.0
112.0
74.0
249.0
776.0
8,602.0
297.0
479.0
855.0
100.0
286.0
894.0
54.0
1,215.0
109.0
594.0
683.0
50.0
50.0
0.002
0.070
0.007
0.040
0.010
7.800
290.000
0.010
0.004
2.400
0.040
Maximum
Cone.
141.0
310.0
87,256.0
225.0
113.0
14,313.0
911.0
677.0
9,491.0
444.0
19,496.0
16,126.0
2,053.0
5,148.0
23,649.0
1,226.0
108.0
461.0
320.0
2,573.0
6,781.0
8,602.0
6,094.0
479.0
5,748.0
839.0
286.0
5,063.0
187.0
12,435.0
636.0
2,698.0
683.0
289.0
546.0
0.050
0.470
0.020
0.170
0.010
7.800
4,038.000
0.010
0.060
2.400
0.040
6-10
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-4. Pollutants Not Selected as Pollutants of Concern for the Metals Subcategory
Pollutant
METALS
Bismuth
Cerium
Erbium
Europium
Gadolinium
Germanium
Gold
Hafnium
Holmium
Lanthanum
Lutetium
Palladium
Platinum
Praseodymium
Rhenium
Rhodium
Ruthenium
Samarium
Scandium
Terbium
Thorium
Thulium
Tungsten
Uranium
Ytterbium
Organics
Acenaphthene
Acenaphthylene
Acetophenone
Acrylonitrile
Adsorbable Organic Halides
Alpha-Terpineol
Aniline
Aniline, 2,4,5-Trimethyl
Anthracene
Aramite
Benzathrone
Benzene
Benzenethiol
Benzidine
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(ghi)perylene
Benzo(k)fluoranthene
Benzonitrile, 3,5-Dibromo-4-Hydroxy-
Beta-Naphthylamine
Biphenyl
Biphenyl, 4-Nitro
Bis(2-Chloroethoxy) Methane
Bis(2-Chloroethyl) Ether
Bis(2-Chloroisopropyl) Ether
Bromomethane
Butyl Benzyl Phthalate
Carbazole
Chloroacetonitrile
Cas No.
7440699
7440451
7440520
7440531
7440542
7440564
7440575
7440586
7440600
7439910
7439943
7440053
7440064
7440100
7440155
7440J66
7440188
7440199
7440202
7440279
7440291
7440304
7440337
7440611
7440644
83329
208968
98862
107131
59473040
98555
62533
137177
120127
140578
82053
71432
108985
92875
56553
50328
205992
191242
207089
1689845
91598
92524
92933
111911
111444
108601
74839
85687
86748
107142
Never
Detected
X
X
X
X
X
X
X
X
X
X
•X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Detected
<10xMDL
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Detected in <10%
of infuent samples
X
X
X
X
X
X
X
X
6-11
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-4. Pollutants Not Selected as Pollutants of Concern for the Metals Subcategory
Pollutant
Chlorobenzene
Chloroethane
Chloromethane
Chrysene
Cis-1 ,3-Dichloropropene
Crotonaldehyde
Crotoxyphos
Di-N-Butyl Phthalate
Di-N-Octyl Phthalate
Di-N-Propylnitrosamine
Dibenzo(a,h)anthracene
Dibenzofuran
Dibenzothiophene
Dibromomethane
Diethyl Ether
Diethyl Phthalate
Dimethyl Phthalate
Dimethyl Sulfone
Diphenyl Ether
Diphenylamine
Diphenyldisulfide
Ethane, Pentachloro-
Ethyl Cyanide
Ethyl Methacrylate
Ethyl Methanesulfonate
Ethylbenzene
Ethylenethiourea
Fluoranthene
Euorene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Hexachloropropene
Indeno(l,2,3-CD)pyrene
lodomethane
Isobutyl Alcohol
Isophorone
Isosafrole
Longifolene
M-Xylene
Malachite Green
Mestranol
Methapyrilene
Methyl Methacrylate
Methyl Methanesulfonate
N-Decane
NrDocosane
N-Dodecane
N-Eicosane
N-Hexacosane
N-Hexadecane
N-Nitrosodi-N-Butylamine
N-Nitrosodiethylamine
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
N-Nitrosomethylethylamine
Gas No.
108907
75003
74873
218019
10061015
4170303
7700176
84742
117840
621647
53703
132649
132650
74953
60297
84662
131113
67710
101848
122394
882337
76017
107120
97632
62500
100414
96457
206440
86737
118741
87683
77474
67721
1888717
193395
74884
78831
78591
120581
475207
108383
569642
72333
91805
80626
66273
124185
629970
112403
112958
630013
544763
924163
55185
62759
86306
10595956
Never
Detected
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
'
X
X
X
Detected Detected in <1 0%
<10 x MDL of infuent samples
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
6-12
-------
Chanter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-4. Pollutants Not Selected as Pollutants of Concern for the Metals Subcategory
Pollutant
N-Nitrosomethylphenylamine
N-Nitrosopiperidine
N-Octacosane
N-Octadecane
N-Tetracosane
N-Tetradecane
N-Triacontane
Naphthalene
Nitrobenzene
O+P Xylene
O-Anisidine
O-Cresol
O-Toluidine
O-Toluidine, 5-Chloro-
P-Chloroaniline
P-Cresol
P-Cymene
P-Dimethylaminoazobenzene
P-Nitroaniline
Pentachlorobenzene
Pentachlorophenol
Pentamethylbenzene
Perylene
Phenacetin
Phenanthrene
Phenol
Phenol, 2-Methyl-4,6-Dinitro-
Phenothiazine
Pronamide
Pyrene
Resorcinol
Safrole
Squalene
Styrene
Tetrachloroethene
Tetrachloromethane
Thianaphthene
Thioacetamide ,
Thioxanthe-9-One
Toluene
Toluene, 2,4-Diamino-
Trans-l,2-Dichloroethene
Trans- 1 ,3-Dichloropropene
Trans-l,4-Dichloro-2-Butene
Trichlorofluoromethane
Triphenylene
Vinyl Acetate
Vinyl Chloride
l-Bromo-2-Chlorobenzene
l-Bromo-3-Chlorobenzene
1 -Chloro-3-Nitrobenzene
1-Methylfluorene
1 -M ethy Iphenanthrene
1-Naphthylamine
1 -Pheny Inaphthalene
1 , 1 -Dichloroethane
1 , 1 -Dichloroethene
CasNo.
614006
100754 •
630024
593453
646311
629594
638686
91203
98953
136777612
90040
95487
95534
95794
106478
106445
99876
60117
100016
608935
87865
700129
198550
62442
85018
108952
534521
92842
23950585
129000
108463
94597
7683649
100425
127184
56235
95158
62555
492228
108883
95807
156605
10061026
110576
75694
217594
108054
75014
694804
108372
121733
1730376
832699
134327
605027
75343
75354
Never
Detected
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Detected
<10xMDL
X
X
X
X
X
X
X
X
X
X
X
Detected in <10%
of infuent samples
X
6-13
-------
Chanter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-4. Pollutants Not Selected as Pollutants of Concern for the Metals Subcategory
1,1,1-Trichloroethane
1,1,1,2-Tetrachloroethane
1,1,2-Trichloroethane
1,1,2,2-Tetrachloroethane
l,2-Dibromo-3-Chloropropane
1 ,2-Dibromoethane
1,2-Dichlorobenzene
1,2-Dichloroethane
1,2-Dichloropropane
1,2-Diphenylhydrazine
1,2,3-Trichlorobenzene
1,2,3-Trichloropropane
1,2,3-Trimethoxybenzene
1,2,4-Trichlorobenzene
1,2,4,5-Tetrachlorobenzene
l,2:3,4-Diepoxybutane
1,3-Butadiene, 2-Chloro
l,3-Dichloro-2-Propanol
1,3-Dichlorobenzene
1,3-Dichloropropane
1,3,5-Trithiane
1,4-Dichlorobenzene
1,4-Dinitrobenzene
1,4-Dioxane
1 ,4-Naphthoquinone
1,5-Naphthalenediamine
2-(Methylthio)Benzothiazole
2-Chloroethylvinyl Ether
2-Chloronaphthalene
2-Chlorophenol
2-Hexanone
2-Isopropylnatphthalene
2-Methylbenzothioazole
2-Methylnaphthalene
2-Nitroaniline
2-Nitrophenol
2-Phenylnaphthalene
2-Picoline
2-Propen-l-Ol
2-Propenal
2-Methyl-2-Propenenitrile
2,3-Benzofluorene
2,3-Dichloroaniline
2,3-Dichloronitrobenzene
2,3,4,6-Tetrachlorophenol
2,3,6-Trichlorophenol
2,4-Dichlorophenol
2,4-Dimethylphenol
2,4-Dinitrophenol
2,4-Dinitrotoluene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2,6-Di-Tert-Butyl-P-Benzoquinone
2,6-Dichloro-4-Nitroaniline
2,6-Dichlorophenol
2,6-Dinitrotoluene
3-Chloropropene
Cas No.
71556
630206
79005
79345
96128
106934
95501
107062
78875
122667
87616
96184
634366
120821
95943
1464535
126998
' 96231
541731
142289
291214
106467
100254
123911
130154
2243621
615225
110758
91587
95578
591786
2027170
120752
91576
88744
88755
612942
109068
107186
107028
126987
243174
608275
3209221
58902
933755
120832
105679
51285
121142
95954
88062
719222
99309
87650
606202
107051
Never Detected Detected in <10%
Detected <10 x MDL of infuent samples
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
6-14
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-4. Pollutants Not Selected as Pollutants of Concern for the Metals Subcategory
Pollutant
Cas No.
Never Detected
Detected <10 x MDL
Detected in <10%
of infuent samples
3-Methylcholanthrene
3-Nitroaniline
3,3'-Dichlorobenzidine
3,3'-Dimethoxybenzidine
3,6-Dimethylphenanthrene
4-Aminobiphenyl
4-Bromophenyl Phenyl Ether
4-Chloro-2-Nitroaniline
4-Chloro-3-Methylphenol
4-Chlorophenylphenyl Ether
4-Methyl-2-Pentanone
4-Nitrophenol
4,4-Methylene-Bis(2-Chloroaniline)
4,5-Methylene-Phenanthrene
5-Nilro-O-Toluidine
7,12-Dimethylbenz(a)anthracene
56495
99092
91941
119904
1576676
92671
101553
89634
59507
7005723
108101
100027
101144
203645
99558
57976
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
6-15
-------
Chanter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-5. Pollutants Not Selected as Pollutants of Concern for the Oils Subcategory
Pollutant
CLASSICALS OR CONVENTIONALS
Hexavalent Chromium
Total Sulfide
METALS
Bismuth
Cerium
Dysprosium
Erbium
Europium
Gadolinium
Gallium
Gold
Hafnium
Holmium
Indium
Iodine
Indium
Lanthanum
Lithium
Neodymium
Niobium
Osmium
Palladium
Platinum
Praseodymium
Rhenium
Rhodium
Ruthenium
Samarium ,
Scandium
Tantalum
Tellurium
Terbium
Thallium
Thorium
Thulium
Tungsten
Uranium
Ytterbium
Yttrium
Zirconium
ORGANICS
Acenaphthylene
Acetophenone
Acrylonitrile
Aniline, 2,4,5-Trimethyl
Aramite
Benzathrone
Benzenethiol
Benzidine
Benzo(ghi)perylene
Benzonitrile, 3,5-Dibromo-4-Hydroxy-
Beta-Naphthylamine
Biphenyl, 4-Nitro
Bis(2-Chloroethoxy) Methane
Bis(2-Chloroethyl) Ether
Never
Cas No. Detected
18540299
18496258
7440699
7440451
7429916
7440520
7440531
7440542
7440553
7440575
7440586
7440600
7440746
7553562
7439885
7439910
7439932
7440008
7440031
7440042
7440053
7440064
7440100
7440155
7440166
7440188
7440199
7440202
7440257
13494809
7440279
7440280
7440291
7440304
7440337
7440611
7440644
7440655
7440677
208968
98862
107131
137177
140578
82053
108985
92875
191242
1689845
91598
92933
111911
111444
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Detected Detected in <10%
<1 0 x MDL of infuent samples
X
X
X
X
X
X
X
X
X
X
X
X
X
,
X
X
X
X
X
6-16
-------
Chanter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-5 . Pollutants Not Selected as Pollutants of Concern for the Oils Subcategory
Pollutant
Bis(2-Chloroisopropyl) Ether
Bromodichloromethane
Bromomethane
Chloroacetonitrile
Chloroethane
Chloromethane
Cis-l,3-Dichloropropene
Crotonaldehyde
Crotoxyphos
Di-N-Ocryl Phthalate
Di-N-Propylnitrosamine •
Dibenzo(a,h)anthracene
Dibromochloromethane
Dibromomethane
Diethyl Ether
Dimethyl Phthalate
Dimethyl Sulfone
Diphenylamine
Diphenyldisulfide
Ethane, Pentachloro-
Ethyl Cyanide
Ethyl Methacrylate
Ethyl Methanesulfonate
Ethylenethiourea
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Hexachloropropene
Indeno(l,2,3-CD)pyrene
lodomethane
Isobutyl Alcohol
Isophorone
Isosafrole
Longifolene
M+PXylene
Malachite Green
Mestranol
Methapyrilene
Methyl Methacrylate
Methyl Methanesuifonate
N-Nitrosodi-N-Butylamine
N-Nitrosodiethylamine
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
N-Nitrosomethylethylamine
N-Nitrosomethylphenylamine
N-Nitrosomorpholine
N-Nitrosopiperidine
N-Octacosane
N-Triacontane
Nitrobenzene
O-Anisidine
O-Toluidine
O-Toluidine, 5-Chloro-
O-Xylene
Never Detected
CasNo. Detected <10xMDL
108601
75274
74839
107142
75003
74873
10061015
4170303
7700176
117840
621647
53703
124481
74953
60297
.131113
67710
122394
882337
76017
107120
97632
62500
96457
118741
87683
77474
67721
1888717
193395
74884
78831
78591
120581
475207
179601231
569642
72333
91805
80626
66273
924163
55185
62759
86306
10595956
614006
59892
100754
630024
638686
98953
90040
95534
95794
95476
X
X'
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
~
X
X
X
X
X
X
X
X
X
X
Detected in <10%
of infuent samples
X
X
X
X
X
X
X
X
6-17
-------
Chanter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-5. Pollutants Not Selected as Pollutants of Concern for the Oils Subcategory
Pollutant
P-Chloroaniline
P-Dimethylaminoazobenzene
P-Nitroaniline
Pentachlorobenzene
Pentachlorophenol
Perylene
Phenacetin
Phenol, 2-Methyl-4,6-Dinitro-
Phenothiazine
Pronamide
Resorcinol
Safrole
Squalene
Tetrachloromethane
Thianaphthene
Thioacetamide
Thioxanthe-9-One
Toluene, 2,4-Diamino-
Trans-l,2-Dichloroethene
Trans-l,3-Dichloropropene
Trans-l,4-Dichloro-2-Butene
Tribromomethane
Trichlorofluoromethane
Triphenylene
Vinyl Acetate
Vinyl Chloride
l-Bromo-2-Chlorobenzene
l-Bromo-3-Chlorobenzene
l-Chloro-3-Nitrobenzene
1 -Naphthylamine
1 -Phenylnaphthalene
1,1-Dichloroethane
1,1,1 ,2-Tetrachloroethane
1 , 1 ,2-Trichloroethane
1 , 1 ,2,2-Tetrachloroethane
l,2-Dibromo-3-Chloropropane
1,2-Dibromoethane
1,2-Dichlorobenzene
1,2-Dichloropropane
1 ,2-Diphenylhydrazine
1,2,3-Trichlorobenzene
1,2,3-Trichloropropane
1,2,3-Trimethoxybenzene
1,2,4,5-Tetrachlorobenzene
l,2:3,4-Diepoxybutane .
1,3-Butadiene, 2-Chloro
l,3-Dichloro-2-Propanol
1,3-Dichlorobenzene
1,3-Dichloropropane
1,3,5-Trithiane
1,4-Dinitrobenzene
1 ,4-Naphthoquinone
1,5-Naphthalenediamine
2-(Methylthio)Benzothiazole
2-Chloroethylvinyl Ether
2-Chloronaphthalene
Never Detected Detected in <10%
CasNo. Detected <10xMDL of infuent samples
106478
60117
100016
608935
87865
198550
62442
534521
92842
23950585
108463
94597
7683649
56235
95158
62555
492228
95807
156605
10061026
110576
75252
75694
217594
108054
75014
694804
108372
121733
134327
605027
75343
630206
79005
79345
96128
106934
95501
78875
122667
87616
96184
634366
95943
1464535
126998
96231
541731
142289
291214
100254
130154
2243621
615225
110758
91587
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
x •
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
6-18
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-5. Pollutants Not Selected as Pollutants of Concern for the Oils Subcategory
Pollutant
2-Chlorophenol
2-Hexanone
2-Isopropylnatphthalene
2-Methylbenzothioazole
2-Nitroaniline
2-Nitrophenol
2-Picoline
2-Propen-l-Ol
2-Propenal
2-Propenenitrile, 2-Methyl
2,3-Dichloroaniline
2,3-Dichloronitrobenzene
2,3,4,6-Tetrachlorophenol
2,3,6-Trichlorophenol
2,4-Dichlorophehol
2,4-Dinitrophenol
2,4-Dinitrotoluene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2,6-Di-Tert-Butyl-P-Benzoquinone
2,6-Dichloro-4-Nitroaniline
2,6-Dichlorophenol
2,6-Dinitrotoluene
3-Chloropropene
3-Methylcholanthrene
3-Nitroaniline
3,3'-Dichlorobenzidine
3,3-Dimethoxybenzidine
4-Amiriobiphenyl
4-Bromophenyl Phenyl Ether
4-Chloro-2-Nitroaniline
4-Chlorophenylphenyl Ether
4-Nitrophenol
4,4'-Methylene-Bis(2-Chloroaniline)
4,5-Methylene-Phenanthrene
5-Nitro-O-Toluidine
7, 1 2-Dimethylbenz(a)anthracene
Cas No.
95578
591786
2027170
120752
88744
88755
109068
107186
107028
126987 .
608275
3209221
58902
933755
120832
51285
121142
95954
88062
719222
99309
87650
606202
107051
56495
99092
91941
119904
92671
101553
89634
7005723
100027
101144
203645
99558
57976
Never
Detected
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Detected Detected in <1 0%
<10 x MDL of infuent samples
X
X
X
X
X
X
X
6-19
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-6. Pollutants Not Selected as Pollutants of Concern for the Organics Subcategory
Pollutant
CLASSICALS OR CONVENTIONALS
Hexavalent Chromium
Total Phenols
Total Phosphorus
METALS
Beryllium
Bismuth
Cadmium
Cerium
Dysprosium
Erbium
Europium
Gadolinium
Gallium
Germanium
Gold
Hafnium
Holmium
Indium
Indium
Lanthanum
Lutetium
Magnesium
Mercury
Neodymium
Niobium
Palladium
Platinum
Praseodymium
Rhenium
Rhodium
Ruthenium
Samarium
Scandium
Selenium
Silver
Tantalum
Tellurium
Terbium
Thallium
Thorium
Thulium
Tungsten
Uranium
Vanadium
Ytterbium
Yttrium
Zirconium
ORGANICS
Acenaphthene
Acenaphthylene
Acrylonitrile
Alpha-Terpineol
Aniline, 2,4,5-Trimethyl
Anthracene
Aramite
Cas No.
18540299
C-020
14265442
7440417
7440699
7440439
7440451
7429916
7440520
7440531
7440542
7440553
7440564
7440575
7440586
7440600
7440746
7439885
7439910
7439943
7439954
7439976
7440008
7440031
7440053
7440064
7440100
7440155
7440166
7440188
7440199
7440202
7782492
7440224
7440257
13494809
7440279
' 7440280
7440291
7440304
7440337
7440611
7440622
7440644
7440655
7440677
83329
208968
107131
98555
137177
120127
140578
Never
Detected
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Detected Detected in <10%
<1 0 x MDL of infuent samples
X
X
X
X
X
X
X
X
X
6-20
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-6. Pollutants Not Selected as Pollutants of Concern for the Organics Subcategory
Pollutant
Benzathrone
Benzenethiol
Benzidine
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Ben2»(ghi)perylene
Benzo(k)fluoranthene
Benzonitrile, 3,5-Dibromo-4-Hydroxy-
Benzyl Alcohol
Beta-Naphthylamine
Biphenyl
Biphenyl, 4-Nitro
Bis(2-Chloroethoxy) Methane
Bis(2-Chloroethyl) Ether
Bis(2-Chloroisopropyl) Ether
Bis(2-Ethylhexyl)Phthalate
Bromomethane
Butyl Benzyl Phthalate
Carbazole
Chloroacetonitrile
Chloroethane
Chloromethane
Chrysene
Cis-l,3-Dichloropropene
Crotonaldehyde
Crotoxyphos
Di-N-Butyl Phthalate
Dl-N-Octyl Phthalate
Di-N-Propylnitrosamine
Dibenzo(a,h)anthracene
Dibenzofuran
Dibenzothiophene
Dibromochloromethane
Dibromomethane
Diethyl Ether •
Diethyl Phthalate
Dimethyl Phthalate
Diphenyl Ether
Diphenylamine
Diphenyldisulfide
Ethyl Cyanide
Ethyl Methacrylate
Ethyl Methanesulfonate
Ethylbenzene
Fluoranthene
Fluorene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloropropene
Indeno(l,2,3-CD)pyrene
lodomethane
Isobutyl Alcohol
Isosafrole
Longifolene
Cas No.
82053
108985
92875
56553
50328
205992
191242
207089
1689845
100516
91598
92524
92933
111911
111444
108601
117817
74839
85687
86748
107142
75003
74873
218019
10061015
4170303
7700176
84742
117840
621647
53703
132649
132650
124481
74953
60297
84662
131113
101848
122394
882337
107120
97632
62500
100414
206440
86737
1 18741
87683
77474
1888717
193395
74884
78831
120581
475207
Never Detected Detected in <10%
Detected <10xMDL of infiient samples
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
. X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
6-21
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-6. Pollutants Not Selected as Pollutants of Concern for the Organics Subcategor>
Pollutant
Malachite Green
Mestranol
Methapyrilene
Methyl Methacrylate
Methyl Methanesulfonate
N-Decane
N-Docosane
N-Dodecane
N-Eicosane
N-Hexacosane
N-Hexadecane
N-Nitrosodi-N-Butylamine
N-Nitrosodiethylamine
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
N-Nitrosomethylethylamine
N-Nitrosomethylphenylarnine
N-Nitrosomorpholine
N-Nitrosopiperidine
N-Octacosane
N-Octadecane
N-Tetracosane
N-Tetradecane
N-Triacontane
Naphthalene
Nitrobenzene
O-Anisidine
O-Toluidine
O-Toluidine, 5-Chlorc-
P-Chloroaniline
P-Cymene
P-Dimethylaminoazobenzene
P-Nitroaniline
Pentachlorobenzene
Pentamethylbenzene
Perylene
Phenacetin
Phenanthrene
Phenol, 2-Methyl-4,6-Dinitro-
Phenothiazine
Pronamide
Pyrene
Resorcinol
Safrole
Squalene
Styrene
Tetrachlorocatechol
Tetrachloroguaiacol
Thianaphthene
Thioacetamide
Thioxanthe-9-One
Toluene, 2,4-Diamino-
Trans-l,3-Dichloropropene
Trans-l,4-Dichloro-2-Butene
Tribromomethane
Trichlorofluoromethane
Gas No.
569642
72333
91805
80626
66273
124185
629970
112403
1 12958
630013
544763
924163
55185
62759
86306
10595956
614006
59892
100754
630024
593453
646311
629594
638686
91203
98953
90040
95534
95794
106478
99876
60117
100016
608935
700129
198550
62442
85018
534521
92842
23950585
129000
108463
94597
7683649
100425
1198556
2539175
95158
62555
492228
95807
10061026
110576
75252
75694
Never Detected Detected in <10%
Detected <10xMDL of infuent samples
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X,
X
X
X
X
X
X
. X
X
X
X
X
X
X
X
X
X
X
X
X
X
6-22
-------
Chapter 6 Pollutants of Concern for the CWT Industry Development Document for the CWT Point Source Category
Table 6-6. Pollutants Not Selected as Pollutants of Concern for the Organics Subcategoiy
Pollutant
Trichlorosyringol
Triphenylene
Tripropyleneglycol Methyl Ether
Vinyl Acetate
1 -Bromo-2-Chlorobenzene
l-Bromo-3-Chlorobenzene
l-Chloro-3-Nitrobenzene
1-Methylfluorene
1-Methylphenanthrene
1-Naphthylamine
1 -Phenylnaphthalene
l,2-Dibromo-3-Chloropropane
1 ,2-Dichloropropane
1 ,2-Diphenylhydrazine
1 ,2,3-Trichlorobenzene
1,2,3-Trimethoxybenzene
1 ,2,4-Trichlorobenzene
1 ,2,4,5-Tetrachlorobenzene
l,2:3,4-Diepoxybutane
1,3-Butadiene, 2-Chloro
l,3-Dichloro-2-Propanol
1 ,3-Dichlorobenzene
1,3,5-Trithiane
1 ,4-Dichlorobenzene
1,4-Dinitrobenzene
1,4-Dioxane
1 ,4-Naphthoquinone
1,5-Naphthalenediamine
2-(Methylthio)Benzothiazole
2-Chloroethylvinyl Ether
2-Chloronaphthalene
2-Chlorophenol
2-Hexanone
2-Isopropylnatphthalene
2-Methylbenzothioazole
2-Methylnaphthalene
2-Nitroaniline
2-Nitrophenol
2-Phenylnaphthalene
2-Picoline
2-Propen-l-Ol
2-Propenal
2-Propenenitrile, 2-Methyl
2-Syringaldehyde
2,3-Benzofluorene
2,3-Dichloronitfobenzene
2,3,6-Trichlorophenol
2,4-Dichlorophenol
2,4-Dinitrophenol
2,4-Dinitrotoluene
2,6-Di-Tert-Butyl-P-Benzoquinone
2,6-Dichloro-4-Nitroaniline
2,6-Dichlorophenol
2,6-Dinitrotoluene
3-Chloropropene
3-Methylcholanthrene
Cas No.
2539266
217594
20324338
108054
694804
108372
121733
1730376
832699
134327
605027
96128
78875
122667
87616
634366
120821 .
95943
1464535
126998
96231
541731
291214
106467
100254
123911
130154
2243621
615225
110758
91587
95578
591786
2027170
120752
91576
88744
88755
612942
109068
107186
107028
126987
134963
243174
3209221
933755
120832
51285
121142
719222
99309
87650
606202
107051
56495
Never Detected Detected in <10%
Detected < 1 0 x MDL • of infuent samples
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X .
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
6-23
-------
Chanter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
Table 6-6. Pollutants Not Selected as Pollutants of Concern for the Organics Subcategory
Pollutant
3-Nitroaniline
3,3-Dichlorobenzidine
3,3'-Dimethoxybenzidine
3,4,5-Trichloroguaiacol
3,5-Dichlorocatechol
3,6-Dimethylphenanthrene
4-Aminobiphenyl
4-Bromophenyl Phenyl Ether
4-Chloro-2-NitroaniIine
4-Chloro-3-Methylphenol
4-Chloroguaiacol
4-Chlorophenylphenyl Ether
4-Nitrophenol
4J4'-Methylene-Bis(2-Chloroaniline)
4,5-Dichlorocatechol
4,5-Methylene-Phenanthrene
4,6-Dichloroguaiacol
5-Nitro-O-Toluidine
5,6-Dichlorovanillin
7,12-Dimethylbenz(a)anthracene
Gas No.
99092
91941
119904
57057837
13673922
1576676
92671
101553
89634
59507
16766306
7005723
100027
101144
3428248
203645
16766317
99558
18268694
57976
Never
Detected
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Detected Detected in <10%
<1 0 x MDL of infuent samples
X
X
X
POLLUTANTS OF CONCERN FOR
THE METALS SUBCATEGORY
6.2
Wastewaters treated at CWT facilities in the
. metals subcategory contain a range of
conventional, toxic, and non-conventional
pollutants. EPA analyzed influent samples for
320 conventional, classical, metal, and organic
pollutants. EPA identified 78 pollutants of
concern, including 43 metals, 17 organics, and 3
conventional pollutants as presented in Table 6-1.
EPA excluded 242 pollutants from further review
because they did not pass the pollutant of concern
criteria. Table 6-4 lists these pollutants, including
178 pollutants that were never detected at any
sampling episode, 54 pollutants that were
detected at a concentration less than ten times the
method detection limit, and 10 pollutants that
were present in less than ten percent of the
influent samples. EPA selected only 25 percent
of the list of pollutants analyzed as pollutants of
concern, and as expected, the greatest number of
pollutants of concern in the metals subcategory
were found in the metals group.
Facilities in the metals subcategory had the
highest occurrence and broadest range of metals
detected in their raw wastewater. The sampling
identified a total of 43 metals above treatable
levels, compared to 32 metals in the oils
subcategory, and 25 metals in the organics
subcategory. Maximum metals concentrations in
the metals subcategory were generally at least an
order of magnitude higher than metals in the oils
and organics subcategories, and were often two to
three orders of magnitude greater. Wastewaters
contained significant concentrations of common
non-conventional metals such as aluminum, iron,
and tin. In addition, given the processes
generating these Wastewaters, waste receipts in
this subcategory generally contained toxic heavy
metals. Toxic metals found in the. highest
concentrations were cadmium, chromium, cobalt,
copper, nickel, and zinc.
EPA detected three conventional pollutants
(BOD5, TSS, oil and grease) and fifteen classical
pollutants above treatable levels in the metals
subcategory, including hexavalent chromium,
which was not found in either the oils or organics
6-24
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWTPoint Source Category
subcategories. Concentrations for total and
amenable cyanide, chloride, fluoride,
nitrate/nitrite, TDS, TSS, and total sulfide were
significantly higher for metals facilities than for
facilities in the other subcategories.
While sampling showed organic pollutants at
selected facilities in the metals subcategory, these
were not typically found in wastewaters resulting
from this subcategory. Many metals facilities
have placed acceptance restrictions on the
concentration of organic pollutants allowed in the
off-site wastestreams. Of the 217 organic
pollutants analyzed in the metals subcategory,
EPA only detected 17 above treatable levels, as
compared to more than 72 in the oils subcategory
and 60 in the organics subcategory. However, of
the organic compounds detected in the metals
subcategory, three, specifically,
dibromochloromethane, tribromomethane, and n-
nitrosomorpholine were not detected in any other
subcategory. EPA sampling detected all other
organic pollutants in the. metals sufacategory at
relatively low concentrations, as compared to the
oils and organics subcategories.
POLLUTANTS OF CONCERN FOR
THE OILS SUBCATEGORY
6.3
As detailed in Chapters 2 and 12, EPA does
not have data to characterize raw wastewater for
the oils subcategory. Therefore, EPA based its
influent wastewater characterization for this
subcategory on an evaluation of samples obtained
following the initial gravity separation/emulsion
breaking step. EPA analyzed these samples for
322 conventional, classical, metal, and organic
pollutants. EPA identified 120 pollutants of
concern, including 72 organics, 32 metals, and 3
conventional pollutants presented in Table 6-2.
EPA eliminated 202 pollutants after applying its
traditional criteria for regulating pollutants.
Table 6-5 lists these pollutants, including 145
pollutants that were never detected at any
sampling episode, 31 pollutants that were
detected at a concentration less than ten times the
method detection limit, and 26 pollutants that
were present in less than ten percent of the
influent samples. EPA selected nearly 40 percent
of the list of pollutants analyzed as pollutants of
concern, the majority of which were organic
pollutants.
Facilities in the oils subcategory had the
broadest spectrum of pollutants of concern in
their raw wastewater with 3 conventional
pollutants, 13 classical pollutants, and more than
100 organics and metals. As expected, oil and
grease concentrations in this subcategory were
significantly higher than for the other.
subcategories, and varied greatly from one facility
to the next, ranging from 40 mg/L to 180,000
mg/L (see Table 6-2) after the first stage of
treatment. The concentrations of ammonia,
BOD5, COD, TOC, total phenols, and total
phosphorus were also higher for facilities in the
oils subcategory.
Wastewaters contained significant
concentrations of both non-conventional and
toxic metals such as aluminum, boron, cobalt,
iron, manganese, and zinc. EPA's sampling data
show most pollutant of concern metals were
detected at higher concentrations in the oils
subcategory than those found in the organics
subcategory, but at significantly lower
concentrations than those found in the metals
subcategory. Germanium .was the only metal
detected at a treatable level in the oils
subcategory but not in the other two
subcategories.
Of the 72 organic pollutants detected above
treatable levels in the oils subcategory, 40 were
not present in the other two subcategories.
Twenty four pollutants of concern organics were
common to both the oils and organics
subcategories, but more than half of these
organics were detected in oily wastewater at
concentrations two to three orders of magnitude
higher than those found in the organics
6-25
-------
Chapter 6 Pollutants of Concern for the CWT Industry
Development Document for the CWT Point Source Category
subcategory wastewaters. Organic pollutants
found in the highest concentrations were straight
chain hydrocarbons such as n-decane and n-
tetradecane, and aromatics such as naphthalene
and bis(2-ethylhexyl)phthalate. EPA also
detected polyaromatic hydrocarbons, such as
benzo(a)pyrene in the wastewaters of oils
facilities.
Some industry representatives questioned
EPA's sampling results and claimed that
benzo(a)pyrene would only be found at oils
facilities which treat hazardous wastes. EPA
reviewed the literature which confirmed that
benzo(a)pyrene may be present in any waste that
comes in contact with oil, coal tar, or petroleum
products. Tables 6-7 and 6-8 present
concentrations of benzo(a)pyrene in various
industrial products, some of which are likely to be
encountered at oils subcategory CWTs.
Though the concentration of benzo(a)pyrene
varies widely across the examined sources, the
information in the tables indicates that
carbonaceous combustion products are a source
of benzo(a)pyrene. Because many of these used
products are treated at both hazardous and non-
hazardous CWT oils facilities, benzo(a)pyrene
may be detected at either hazardous or non-
hazardous CWT facilities.
Table 6-7. Concentration of Benzo(a)pyrene in
Industrial Products (Osborae & Crosby, 1987)
Sample
Carbon black
Coal-tar pitch
Asphalt
Creosote
Regular gasoline
Premium gasoline
API Reference oils
Diesel oil
Fuel oil
Heavy lubricating oils
Light lubricating oils
Benzo(a)pyrene Content
2-40 ug/g
1.3-2.4%
0.1-27mg/kg
22mg/kg
0.21 mg/L
0.48 mg/L
0.6-44 mg/kg
0.03 mg/kg
0.03 mg/kg
1.2-4.2 mg/kg
6.0-7.0 mg/kg
Table 6-8. Concentration of Benzo(a)pyrene in Japanese Diesel Oils (Osborne & Crosby, 1987)
Oil Type
Aromatic Carbon
Content (%)
Boiling Range (°C)
Benzo(a)pyrene
Content (mg/L)
Commercial gas oil
Aromatic-rich gas oil
Coal-liquified oil
13.0
36.0
64
184-382
181-331
205-382
1.9
6.7
64.5
6-26
-------
Chapter 6 Pollutants of Concern, for the CWT Industry
Development Document for the CWT Point Source Category
POLLUTANTS OF CONCERN FOR
THE ORGANICS SUBCATEGORY
6.4
Wastewaters treated at CWT facilities in the
organics subcategory contain a range of
conventional, toxic, and non-conventional
pollutants. EPA analyzed influent samples for
336 classical, metal, and organic pollutants. EPA
identified 97 pollutants of concern, including 60
organic pollutants, 25 metals, and 3 conventional
pollutants presented in Table 6-3. EPA excluded
241 pollutants because they did not pass the
pollutant of concern criteria. Table 6-6 presents
these pollutants, including 214 pollutants that
were never detected at any sampling episode, and
27 pollutants that were detected at a
concentration less than ten times the method
detection limit. EPA determined that only 30
percent of the list of pollutants analyzed were
pollutants of concern.
As expected, wastewaters contained
significant concentrations of organic parameters,
many of which were highly volatile. However,
although EPA analyzed wastewater samples in
the organics subcategory for a more extensive list
of organics than samples in the metals or oils
subcategories, EPA selected only 20 percent of
those organic pollutants analyzed as pollutants of
concern. EPA selected a total of 60 organics
above treatable levels in the influent samples
analyzed. Thirty-six of these organics were
present in the organics subcategory but not in the
oils subcategory. EPA determined the remaining
24 organics were pollutants of concern for both
the organics and oils subcategories. EPA's
sampling detected only six of these organic
pollutants at higher concentrations at organics
facilities, specifically, chloroform, methylene
chloride, o-cresol, tetrachloroethene, trichloro-
ethene, and 1,2-dichloroethane. EPA found only
9 classical pollutants were pollutants of concern
in the organics subcategory, and most were
detected at lower concentrations than those found
in the metals and oils subcategories.
The sampling detected a total of 25 metals
above treatable levels, but these were present at
concentrations significantly lower than in the
metals subcategory. EPA's assessment showed
that only three pollutant of concern metals
(barium, calcium, and strontium) were detected at
concentrations above those found in the oils
subcategory.
REFERENCES
6.5
Osborne and Crosby, Cambridge Monographs on
Cancer Research: Benzopvrenes. Cambridge
University Press; New York, NY; 1987.
6-27
-------
-------
Chapter
7
POLLUTANTS SELECTED FOR REGULATION
Chapter 6 details the pollutants of concern
for each subcategory and the methodology
used in selecting the pollutants. As expected for
the CWT industry, these pollutants of concern
lists contain a broad spectrum of pollutants. EPA
has, however, chosen not to regulate all of these
parameters. This chapter details the pollutants of
concern which were not selected for regulation
under the proposed options and provides a
justification for eliminating these pollutants.
(The proposed options are detailed in Chapter 9.)
Additionally, Figures 7-1 and 7-2 illustrate the
procedures used to select the regulated pollutants
for direct and indirect dischargers.
TREATMENT CHEMICALS
7.1
EPA excluded all pollutants which may
serve as treatment chemicals: aluminum, calcium,
chloride, fluoride, iron, magnesium, phosphorus,
potassium, sodium, and sulfur. EPA eliminated
these pollutants because regulation of these
pollutants could interfere with their beneficial use-
as wastewater treatment additives.
NON-CONVENTIONAL BULK
PARAMETERS
7.2
EPA excluded many non-conventional bulk
parameters such as total dissolved solids (TDS),
chemical oxygen demand (COD), organic carbon
(TOC), nitrate/nitrite, total phenols, total
phosphorus, and total sulfide. EPA excluded
these parameters because it is more appropriate
to target specific compounds of interest rather
than a parameter which measures a variety of
pollutants for this industry. The specific
pollutants which comprise the bulk parameter
may or may not be of concern to EPA. EPA also
excluded amenable cyanide since the proposed
total cyanide limit would also control amenable
cyanide.
POLLUTANTS NOT DETECTED AT
TREATABLE LEVELS
7.3
EPA eliminated pollutants that were present
below treatable concentrations in wastewater
influent to the treatment system(s) selected as the
basis for effluent limitations. For a pollutant to
be retained, the pollutant: a) had to be detected in
the influent sample at treatable levels (ten times
the minimum analytical detection limit) in at least
fifty percent of the samples; or b) had to be
detected at any level in the influent samples at
least 50 percent of the time and the combined
mean of the influent samples for the entire
episode had to be greater than or equal to ten
tunes the minimum analytical detection limit.
EPA added the second condition to account for
instances where a slug of pollutant was treated
during the sampling episode. EPA added this
condition since the CWT industry's waste
receipts vary daily and EPA wanted to
incorporate these variations in the calculations of
long term averages and limitations. Pollutants
excluded from regulation for the selected
subcategory options because they were not
detected at treatable levels are presented in Table
7-1.
7-1
-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
POC List
Is POC a treatment
chemical?
IB POC a
non-conventional bulk
parameter?
Was POC
treated effectively at
selected BPT/BAT facilities upon
which the effluent
limitations are
ed?
asPO
'detected at treatable
a significant amount
f the time at selected BPT facilities
upon which the affluent
limitations are
d
Is POC a volatile
ollutant (see Figure 7-3)7
POC may be regulated for
Direct Dischargers
Yes
POC will not be regulated for the
subcategory
Yes
POC will not be regulated for the
subcategory
No
POC will not be regulated for the
subcategory
No
POC will not be regulated for the
subcategory
Yes
POC will not be regulated for the
subcategory
Figure 7-1. Selection of Pollutants That May Be Regulated for Direct Discharges for Each Subcategory
7-2
-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
Regulated Pollutants
for Direct Discharges
Does POC
pass through a POTW or cause
inhibition or
interference?
POC will be regulated for
Indirect Dischargeres
Yes
No
POC will not be regulated for
the subcategory
POC will not be regulated for
the subcategory
Figure 7-2. Selection of Pollutants to be Regulated for Indirect Discharges for Each Subcategory
7-3
-------
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-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
POLLUTANTS NOT TREATED
7.4
EPA excluded all pollutants for which the
selected technology option was ineffective (i.e.,
pollutant concentrations remained the same or
increased across the treatment system). For the oils
subcategory option 8, phenol and 2-propanone were
ineffectively treated, and for the oils subcategory
option 9, 2-propanone and 2,4-dimethylphenol were
not treated effectively. For the organics subcategory,
the selected treatment technology did not effectively
treat boron, chromium, lithium, nickel, and tin. For
the metals subcategory options, with the exception of
selenium (for Option 3), all pollutants of concern were
effectively treated.
VOLATILE POLLUTANTS
7.5
EPA detected volatile organic pollutants in the
waste receipts of all three subcategories. For this rule,
EPA defines a volatile pollutant as a pollutant which
has a Henry's Law constant in excess of 10"4 atm m3
mol"!. Table 7-2 lists the organic pollutants (those
analyzed using method 1624 or 1625) by subcategory
along with their Henry's Law constant. For pollutants
in the oils subcategory, the solubility in water was
reported in addition to the Henry's Law constant to
determine whether volatile pollutants remained in the
oil-phase or volatilized from the aqueous phase. If no
data were available on the Henry's Law constant or
solubility for a particular pollutant, then the pollutant
was assigned an average pollutant group value.
Pollutant groups were developed by combining
pollutants with similar structures. If no data were
available for any pollutant in the group, then all
pollutants in the group were not considered volatile.
The assignment of pollutant groups is discussed in
more detail in Section 7.6.2.
7-6
-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
I POC List for Oils Subcategoiy
Is (he pollutant organic?
Is the pollutant s
solubility in water & 10 MDL?
(«100ug/L)
Does the
pollutant have a Henry's Law
constant > 10"4
(atm*m3)/mol?
Pollutant is volatile
The pollutant is not volatile
Pollutant is in oily phase
and not volatile
Pollutant is not volatile
Figure 7-3. Determination of Volatile Pollutants for Oils Subcategor
7-7
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-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
As shown in Table 7-2, volatile pollutants
were regularly detected at treatable levels in
waste receipts from CWT facilities, particularly
in the oils and organics subcategory. However,
treatment technologies currently used at many of
these facilities, while removing the pollutants
from the wastewater, do not "treat" the volatiles.
The volatile pollutants are simply transferred to
the air. For example, in the metals subcategory,
wastewater treatment technologies are generally
based on chemical precipitation, and the removal
of volatile pollutants from wastewater following
treatment with chemical precipitation is due to
volatilization. Some CWT facilities recognize
that volatilization may be occurring and have
installed air stripping systems equipped with
emissions control to effectively remove the
pollutants from both the water and the air.
EPA evaluated various wastewater
treatment technologies during the development of
this rule. These technologies were considered
because of their efficacy in removing pollutants
from wastewater. Since EPA is concerned about
removing pollutants from all environmental
media, EPA also evaluated wastewater treatment
trains for the oils and organics subcategories
which included air stripping with emissions
control. .
EPA is not proposing to regulate" any
predominantly volatile parameters. The non-
regulated volatile parameters for the metals,
organics, and oils subcategory options that were
not already excluded as detailed in Sections 7.1,
7.2, 7.3, and 7.4 are presented in Table 7-3.
Unlike the metals and the organics subcategories,
for the oils subcategory, volatilization can not be
predicted using the Henry's Law constant only.
Henry's Law constants are established for
pollutants in an aqueous phase only. For other
non-aqueous single phase or two-phase systems
(such as oil-water), other volatilization constants
apply. Estimating these constants in oil-water
mixtures can lead to engineering calculations
which are generally based on empirical data.
EPA chose an approach which is depicted in
Figure 7-3 and discussed below.
First, EPA reviewed water solubility data to
estimate whether the organic pollutants would be
primarily in an oil phase or aqueous phase. For
pollutants which have a solubility less than ten
times the minimum analytical detection limit (the
same edit used to determine pollutants of concern
and long term averages), EPA assumed that the
amount of pollutants in the aqueous phase would
be negligible and that all of the pollutant would
be primarily in an oil phase. For pollutants which
have a solubility greater than ten times the
minimum analytical detection limit, EPA assumed
that the amount of pollutant in the oil phase
would be negligible and that all of the pollutant
would be primarily in an aqueous phase. For
pollutants determined to be in an aqueous phase,
EPA then reviewed the Henry's law constant in
the same manner as the other two subcategories.
For pollutants determined to be in an oil phase,
EPA assumed that volatilization would be
negligible (regardless of their volatility in the
aqueous phase) and has not categorized them as
volatile pollutants.
Even though EPA has not regulated volatile
pollutants through this rulemaking, EPA
encourages all facilities which accept waste
receipts containing volatile pollutants to
incorporate air stripping with overhead recovery
into their wastewater treatment systems. EPA
also notes that CWT facilities determined to be
major sources of hazardous air pollutants are
subject to maximum achievable control
technology (MACT) as promulgated for off-site
waste and recovery operations on July 1, 1996
(61FR34140) as 40 CFR Part 63.
7-13
-------
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-------
Chapter 7 goUvttants Selected for Regulation Development Document for the CWT Point Source Category
POLLUTANTS SELECTED FOR
PRETREATMENT STANDARDS AND
PRETREATMENT STANDARDS FOR NEW
SOURCES (INDIRECTDISCHARGERS) 7.6
Background 7.6.1
Unlike direct dischargers whose wastewater
will receive no further treatment once it leaves the
facility, indirect dischargers send their wastewater
streams to a POTW for further treatment.
Therefore, for indirect dischargers, before
proposing pretreatment standards, EPA examines
whether the pollutants discharged by the industry
"pass through" a POTW to waters of the U.S. or
interfere with the POTW operation or sludge
disposal practices. Generally, to determine if
pollutants pass through a POTW, EPA compares
the percentage of the pollutant removed by well-
operated POTWs achieving secondary treatment
with the percentage of the pollutant removed by
facilities meeting BAT effluent limitations. A
pollutant is determined to "pass through" a
POTW when the average percentage removed by
a well-operated POTW is less than the percentage
removed by direct dischargers complying with
BPT/BAT effluent limitations. In this manner,
EPA can ensure that the combined treatment at
indirect discharging facilities and POTWs is at
least equivalent to that obtained through
treatment by a direct discharger.
This approach to the definition of pass-
through satisfies two competing objectives set by
Congress: (1) that standards for indirect
dischargers be equivalent to standards for direct
dischargers, and (2) that the treatment capability
and performance of the POTW be recognized and
taken into account in regulating the discharge of
pollutants from indirect dischargers. Rather than
compare the mass or concentration of pollutants
discharged to the POTW with the mass or
concentration of pollutants discharged by a BAT
facility, EPA compares the percentage of the
pollutants removed by the facility with the
POTW removal. EPA takes this approach
because a comparison of the mass or
concentration of pollutants in a POTW effluent
with pollutants in a BAT facility's effluent would
not take into account the mass of pollutants
discharged to the POTW from non-industrial
sources, nor the dilution of the pollutants in the
POTW effluent to lower concentrations from the
addition of large amounts of non-industrial water.
For specific pollutants, such as volatile
organic compounds, EPA may use other means to
determine pass-through. Generally, for volatile
compounds, a volatile override test based on the
Henry's Law constant is used to determine pass-
through. The volatile override test is applied
where the overall percent removal estimated for a
well-operated POTW substantially includes
emission of the pollutant to the air rather than
actual treatment. Therefore, for volatile
pollutants, even though the POTW percent
removal data indicate that the pollutant would not
pass through, regulation of the pollutant is
warranted to ensure "treatment" of the pollutant.
As detailed in Section 7.5, fdr all three
subcategories, EPA selected technology options
which are not designed to control the emission of
volatile pollutants. Therefore, for the selected
options, removal of volatile pollutants from
wastewater is largely due to the emission of the
pollutant rather than treatment. As such, for this
rulemaking, EPA believes the volatile override
test is inappropriate and has determined pass-
through solely by comparing percent removals.
In selecting the regulated pollutants under
the pretreatment standards, EPA starts with the
pollutants regulated for direct dischargers under
BPT/BAT. For pretreatment standards, EPA
then excludes three conventional parameters,
BODS, total suspended solids (TSS), and oil and
grease (measured as HEM) from further
consideration without conducting the percent
removal comparison because POTWs are
designed to treat these parameters. Therefore, for
this rulemaking, EPA evaluated 23 pollutants for
7-15
-------
Chanter 7 Pollutants Selected for Regulation Development Document for the CWTPoint Source Category
metals option 3, 31 pollutants for metals option
4, 51 pollutants for oils option 9, and 23
pollutants for Organics Option 4 for possible
PSES and PSNS regulation. The following
sections describe the methodology used in
determining percent removals for the option
technologies, percent removals for a "well-
operated" POTW, and the results of EPA's pass-
through analysis.
Determination of Percent Removals
for Well-Operated POTWs
7.6.2
The primary source of the POTW percent
removal data was the "Fate of Priority Pollutants
in Publicly Owned Treatment Works" (EPA
440/1-82/303, September 1982), commonly
referred to as the "50-POTW Study". However,
the 50-POTW Study did not contain data for all
pollutants for which the pass-through analysis
was required. Therefore, EPA obtained
additional data from EPA's National Risk
Management Research Laboratory's (NRMRL)
Treatability Database (formerly called the Risk
Reduction Engineering Laboratory (RREL)
Treatability Database). These sources and their
uses are discussed below.
The 50-POTW Study presents data on the
performance of 50 well-operated POTWs
achieving secondary treatment in removing toxic
pollutants. The work performed with this
database included some data editing criteria.
Because the data collected for evaluating POTW
removals included influent levels that were close
to the detection limit, EPA devised the data
editing hierarchal rules to eliminate low influent
concentration levels, thereby minimizing the
possibility that low POTW removals might
simply reflect low influent concentrations instead
of being a true measure of treatment
effectiveness. The hierarchial data editing rules
for the 50-POTW Study were as follows: 1)
detected pollutants must have at least three pairs
(influent/effluent) of data points to be included,
2) average pollutant influent levels less than 10
times the pollutant minimum analytical detection
limit were eliminated, along with the
corresponding effluent values, and 3) if none of
the average pollutant influent concentrations
exceeded 10 times the minimum analytical
detection limit, then the average influent values
less than 20 ug/L were eliminated, along with the
corresponding effluent values. EPA then
calculated each POTW percent removal for each
pollutant based on its average influent and its
average effluent values. The POTW percent
removal used for each pollutant in the pass-
through test is the median value of all the POTW
pollutant specific percent removals.
EPA's NRMRL Treatability Database
provides information, by pollutant, on removals
obtained by various treatment technologies. The
database provides the user with the specific data
source and the industry from which the
wastewater was generated. EPA used the
NRMRL database to supplement the treatment
information provided in the 50-POTW Study
when there was insufficient information on
specific pollutants. For each of the pollutants of
concern not found in the 50-POTW database,
EPA obtained data from portions of .the NRMRL
database. EPA then edited these files so that only
treatment technologies representative of typical
POTW secondary treatment operations (activated
sludge, activated sludge with filtration, aerobic
lagoons) were used. EPA further edited these
files to include information pertaining only to
domestic or industrial wastewater. EPA used
pilot-scale and full-scale data only, and
eliminated any bench-scale data. EPA retained
data from papers in a peer-reviewed journal or
government report, but edited out lesser quality
references, such as reports which were not
reviewed. Zero and negative percent removals
were eliminated, as well as data with less than
two pairs of influent/effluent data points.
Finally, EPA calculated the average percent
7-16
-------
removal for each pollutant from the remaining
pollutant removal data.
EPA selected the final percent removal for
each pollutant based on a data hierarchy, which
was related to the quality of the data source. The
following data source hierarchy was used for
selecting a percent removal for a pollutant: 1) if
available, the median percent removal from the
50-POTW Study was chosen using all POTWs
data with influent levels greater than or equal to
10 times the pollutant minimum analytical
detection limit, 2) if not available, the median
percent removal from the 50-POTW Study was
chosen using all POTWs data with influent levels
greater than 20 ug/L, 3) if not available, the
average percent removal from the NRMRL
Treatability Database was chosen using only
domestic wastewater, 4) if not available, the
average percent .removal from the NRMRL
Treatability Database was chosen using domestic
and industrial wastewater, and finally 5) a
pollutant was assigned an average group percent
removal, or "generic" removal if no other data
was available. Pollutant groups were developed
by combining pollutants with similar chemical
structures. (A complete list of pollutants and
pollutant groupings are available in Appendix A).
EPA calculated the average group percent
removal by using all pollutants in the group with
selected percent removals from either the 50-
POTW Study or the NRMRL Treatability
Database. EPA then averaged percent removals
together to determine the average group percent
removal. Pollutant groups and generic removals
used in the pass-through analysis are presented in
Table 7-4. Only groups A, J, and CC are
presented in Table 7-4 since these are the only
groups for which EPA assigned a pollutant an
average group percent removal in its pass-
through analysis. The final POTW percent
removal assigned to each pollutant is presented in
Table 7-5, along with the source and data
hierarchy of each removal.
7-17
-------
hnntpr 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
Table 7.4 CWT Pass-Through Analysis Generic POTW Percent Removals
Pollutant
Group A: Metals
Barium
Beryllium
Cadmium
Chromium
Cobalt
Copper
Iridium
Lead
Lithium
Manganese
Mercury
Molybdenum
Nickel
Silver
Strontium
Thallium
Tin
Titanium
Vanadium
Yttrium
Zinc
Zirconium
Average Group Removal
Pollutant
Group J: Anilines
Aniline
Carbazole
Average Group Removal
Pollutant
Group CC: n-Paraffins
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Octadecane
n-Tetradecane
Average Group Removal
CAS NO.
7440393
7440417
7440439
7440473
7440484
7440508
7439885
7439921
7439932
7439965
7439976
7439987
7440020
7440224
7440246
7440280
7440315
7440326
7440622
. 7440655
7440666
7440177
CAS NO.
62533
86748
CAS NO.
124185
629970
112403
112958
630013
544763
593453
629594
% Removal
27.66
61.23
90.05
91.25
6.11
84.11
74.00
91.83
26.00
40.60
90.16
52.17
51.44
92.42
14.83
53.80
65.20
68.77
42.28
57.93
77.97
60.00
% Removal
62.00
62.00
% Removal
9.00
88.00
95.05
92.40
71.11
Source
50 POTW - 10 X NOMDL
.RREL 5 - (ALL WW)
50 POTW - 10 X NOMDL
50 POTW - 10 X NOMDL
50 POTW - 10 X NOMDL
50 POTW - 10 X NOMDL
RREL 5 - (ALL WW)
50 POTW - 10 X NOMDL
RREL 5 (ALL WW)
RREL 5 - (ALL WW)
50 POTW - 10 X NOMDL
RREL 5 - (DOM WW)
50 POTW - 10 X NOMDL
50 POTW - 10 X NOMDL
RREL 5 - (DOM WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
50 POTW - 10 X NOMDL
Average Group Removal
Source
RREL 5 - (ALL WW)
Average Group Removal
Source
RREL 5 - (ALL WW)
RREL 5- (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
Average Group Removal
Average Group Removal
Average Group Removal
Average Group Removal
7-18
-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
Table 7.5 Final POTW Percent Removals
Pollutant
CLASSICAL
Ammonia as N
BOD5
Hexavalent Chromium
Oil + Grease
Total Cyanide
Total Suspended Solids
METALS
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Chromium
Cobalt
Copper
Iridium
Lead
Lithium
Manganese
Mercury
Molybdenum
Nickel
Selenium
Silicon
Silver
Strontium
Thallium
Tin
Titanium
Vanadium
Yttrium
Zinc
Zirconium
ORGANICS
2-butanone
2-propanone
2,3-dichloroaniline
Metals
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Oils
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Organics
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
CAS NO.
766417
C-002
18540299
C-007
57125
C-009
7440360
7440382
7440393
7440417
7440428
7440439
7440473
7440484
7440508
7439885
7439921
7439932
7439965
7439976
7439987
7440020
7782492
7440213
7440224
7440246
7440280
7440315
7440326
7440622
7440655
7440666
7440677
78933
67641
608275
Percent
Removal
40.85
91.32
5.68
81.41
70.44
90.29
71.13
90.89
27.66
61.23
20.04
90.05
91.25
6.11
84.11
74.00
91.83
26.00
40.60
90.16
52.17
51.44
34.33
27.29
92.42
14.83
53.80
65.20
68.77
42.28
57.93
77.97
60.00
96.60
83.75
41.00
Source
50POTW-10XNOMDL
50POTW-10XNOMDL
50POTW-10XNOMDL
50POTW-10XNOMDL
50POTW-10XNOMDL
50POTW-10XNOMDL
50POTW-10XNOMDL
50 POTW - 10 X NOMDL
50POTW-10XNOMDL
REEL 5 - (ALL WW)
50 POTW - >20 PPB
50 POTW- 10 X NOMDL
50 POTW- 10 X NOMDL
50 POTW - >20 PPB
50 POTW- 10 X NOMDL
RREL 5 - (ALL WW)
50 POTW- 10 X NOMDL
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
50 POTW - 10 X NOMDL
RREL 5 - (DOM WW)
50 POTW - 10 X NOMDL
RREL 5 - (DOM WW)
RREL 5 - (ALL WW)
50 POTW - 10 X NOMDL
RREL 5- (DOM WW)
RREL 5- (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
50 POTW- 10 X NOMDL
Generic Removal-Group A
RREL 5 - (DOM WW)
RREL 5- (ALL WW)
RREL 5 - (ALL WW)
7-19
-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWTPoint Source Category
Table 7.5 Final POTW Percent Removals
Pollutant
2,4,6-trichlorophenol
4-chloro-3-methylphenol
Acenaphthene
Acetophenone
Alpha-terpineol
Aniline
Anthracene
Benzo (a) anthracine
Benzo (a) pyrene
Benzo (b) fluoranthene
Benzo (k) fluoranthene
Benzoic Acid
Bis(2-ethylhexyl) phthalate
Butyl benzyl phthalate
Carbazole
Chrysene
Diethyl phthalate
Di-n-butyl phthalate
Fluoranthene
Fluorene
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexadecane
n-Octadecane
n-Tetradecane
n,n-Dimethylformamide
o-Cresol
p-Cresol
Pentachlorophenol
Phenol
Pyrene
Pyridine
Metals Oils
X
X
X
X
X
X
X
X
X X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
• x x
Organics
X
X
X
X
X
X
X
X
X
X
CAS NO.
88062
,59507
83329
98862
988555
62533
120127
56553
50328
205992
207089
65850
117817
85687
86748
218019
84662
84742
206440
86737
124185
629970
112403
112958
544763
593453
629594
68122
95487
106445
87865
108952
129000
110861
Percent
Removal
65.00
63.00
98.29
95.34
94.40
62.00
95.56
97.50
95.20
95.40
94.70
80.50
59.78
94.33
62.00
96.90
59.73
79.31
42.46
69.85
9.00
88.00
95.05
92.40
71.11
71.11
71.11
84.75
52.50
71.67
13.88
95.25
83.90
95.40
Source
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
50 POTW - 1 0 X NOMDL
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
50 POTW- 10 X NOMDL
RREL 5 - (DOM WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
50 POTW - 10 X NOMDL
50 PO'TW - 10 X NOMDL
Generic Removal-Group J
RREL 5 - (DOM WW)
50 POTW - > 20 PPB
50 POTW - > 20 PPB
50 POTW - > 20 PPB
50 POTW - > 20 PPB
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
Generic Removal-Group CC
Generic Removal-Group CC
Generic Removal-Group CC
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
RREL 5 - (ALL WW)
50 POTW - >20 PPB
50 POTW- 10 X NOMDL
RREL 5 - (DOM WW)
RREL 5 - (ALL WW)
7-20
-------
Chanter 7 Pollutants Selected for Regulation Development Document for the CWTPoint Source Category
Methodology for Determining
Treatment Technology
Percent Removals
7.6.3
EPA calculated treatment percent removals
for each selected BAT option using the data used
to determine the option long term averages and
limitations. Therefore, the data used to calculate
treatment option percent removals was subjected
to the same data editing criteria as the data used
in calculating the long-term averages and
limitations as described in Section 10. This
editing included excluding the influent and
effluent data for pollutants that were not detected
in the influent at treatable levels, excluding data
for pollutants which were not treated by the
technology, and excluding data that were
associated with process upsets.
After the data were edited, EPA used the
following methodology to calculate percent
removal:
1) For each pollutant and each sampled
facility, EPA averaged the remaining
influent data and effluent data to give
an average influent concentration and
an average effluent concentration,
respectively.
2) EPA calculated percent removals for each
pollutant and each sampling episode from
the average influent and average effluent
concentrations using the following equation:
% Removal = CAvg Influent - Avg Effluent) x 100
Average Influent
3) EPA calculated the median percent removal
for each pollutant for each option from the
facility-specific percent removals.
Pass-Through Analysis Results 7.6.4
The results of the Pass-Through Analysis
are presented in Tables 7-6 through 7-9 by
subcategory and treatment option.
Pass-Through Analysis Results
for the Metals Subcategory 7.6.4.1
For metals subcategory option 3, pass-
through results are presented in Table 7-6. All
pollutants analyzed passed through and may be
regulated under PSES and PSNS. For metals
subcategory option 4, pass-through results are
presented in Table 7-7. All non-conventional
pollutants analyzed passed through, and all
metals passed through with the exception of
molybdenum and zirconium. However, for
organic pollutants analyzed, only benzoic acid
passed through. All pollutants that passed
through are regulated under PSES and PSNS.
7-21
-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWTPoint Source Category
Table 7.6 Final Pass-Through Results For Metals Subcategory Option 3
Pollutant Parameter
CLASSICALS
Hexavalent Chromium
METALS
Antimony
Arsenic
Beryllium
Boron
Cadmium
Chromium
Cobalt
Copper
Lead
Manganese
Mercury
Molybdenum
Nickel
Selenium
Silicon
Silver
Thallium
Tin
Titanium
Vanadium
Yttrium
Zinc
Option 3 Removal (%)
93.36
99.71
99.77
99.00
75.15
99.96
99.98
99.59
100.00
99.67
99.99
99.80
88.20
99.87
92.66
99.75
99.32
95.99
99.83
99.76
99.48
94.25
99.99
POTW Removal (%)
5.68
71.13
90.89
61.23
20.04
90.05
91.25
6.11
84.11
91.83
40.60
90.16
52.17
51.44
34.33
27.29
92.42
53.80
65.20
68.77
42.28
57.93
77.97
Pass-Through
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
7-22
-------
Chanter 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
Table 7.7 Final Pass-Through Results For Metals Subcategory Option 4
Pollutant Parameter
CLASSICALS
Hexavalent Chromium
Total Cyanide
METALS
Antimony
Arsenic
Boron
Cadmium
Chromium .
Cobalt
Copper
Iridium
Lead
Lithium
Manganese
Mercury
Molybdenum
Nickel
Selenium
Silicon
Silver
Strontium
Tin
Titanium
Vanadium
Yttrium
Zinc
Zirconium
ORGANICS
2-Butanone
2-Propanone
Benzoic Acid
n,n-Dimethylformamide
Pyridine
Option 4 Removal (%)
98.01
97.07
94.30
91.71
54.70
99.97
99.91
98.47
99.91
99.69
99.95
66.83
99.87
98.38
26.40
99.59
57.54
98.58
99.62
95.89
99.94
99.84
99.46
95.39
99.93
42.13
74.72
65.62
82.99
54.81
48.49
Median POTW Removal (%)
5.68
70.44
71.13
90.89
20.04
90.05
91.25
6.11
84.11
74.00
91.83
26.00
40.60
90.16
52.17
51.44
34.33
27.29
92.42
14.83
65.20
68.77
42.28
57.93
77.97
61.00
96.60
83.75
80.50
84.75
95.40
Pass-Through
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
no
yes
yes
yes
• yes
yes
yes
yes
yes
yes
yes
no
no
no
yes
no
no
7-23
-------
Pass-Through Analysis Results for the Oils Subcategory 7.6.4.2
The final pass-through analysis results for the oils subcategory option 9 are presented in Table 7-8.
Several metals and organic pollutants passed through, and therefore may be regulated under PSES an
PSNS.
Table 7.8 Final Pass-Through Results For Oils Subcategory Option 9
Pollutant Parameter
Option 9 Removal (%) Median POTW Removal (%) Pass-Through
CLASSICALS
Total Cyanide
64.38
70.44
no
METALS
.Antimony
Arsenic
Barium
Boron
Cadmium
Chromium
Cobalt
Copper
Lead
Manganese
Mercury
Molybdenum
Nickel
Selenium
Silicon
Strontium
Tin
Titanium
Zinc
87.99
57.64
91.91
33.01
88.08
86.24
52.20
93.85
88.26
46.03
77.43
53.73
41.24
36.94
42.07
50.68
90.78
89.99
78.25
71.13
90.89
27.66
20.04
90.05
91.25
6.11
84.11
91.83
40.60
90.16
52.17
51.44
34.33
27.29
14.83
65.20
68.77
77.97
yes
no
yes
yes
no
no
yes
yes
no
yes
no
yes
no
yes
yes
yes
yes
yes
yes
ORGANICS
2-Butanone 15.41
4-chloro-3-methylphenol 27.48
Acenapthene 96.75
Alpha-terpineol 94.77
Anthracene 96.67
Benzo (a) anthracene 95.70
Benzo (a) pyrene 96.27
Benzo (b) flouranthene 95.92
Benzo (k) fiuoranthene 95.89
96.60
63.00
98.29
94.40
95.56
97.50
95.20
95.40
94.70
no
no
no
yes
yes
no
yes
yes
yes
7-24
-------
Chapter 7 Pollutants Selected for Regulation Development Document for the C WTPoint Source Category
Benzole acid
Bis (2-ethylhexyl)
phthalate
Butyl benzyl phthalate
Carbazole
Chrysene
Di-n-butyl phthalate
Diethyl phthalate
Fluoranthene
Fluorene
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexadecane
n-Octadecane
n-Tetradecane
o-cresol
p-cresol
Phenol
Pyrene
Pyridine
19.32
94.09
92.60
81.09
97.22
88.07
63.97
96.43
92.86
94.98
96.87
96.50
95.54
96.53
97.20
96.85
21.08
34.88
14.88
97.63
21.45
80.50
59.78
94.33
62.00
96.90
79.31
59.73
42.46
69.85
9.00
88.00
95.05
92.40
71.11
71.11
71.11
52.50
71.67
95.25
83.90
95.40
no
yes
no
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
no
no
no
yes
no
7-25
-------
Chapter 7 Pollutants Selected for Regulation Development DocumentfQrJhe^WT_Point_Sgurce_Categor^_
Pass-Through Analysis Results for the Organics Subcategory 7.6.4.3
The results of the pass-through analysis for the organics subcategory option 3/4 are presented i
Table 7-9. Several metals and organic pollutants passed through, and therefore may be regulated under
PSES and PSNS.
Table 7.9 Final Pass-Through Results For Organics Subcategory Option 3/4
Pollutant Parameter
CLASSICALS
Total Cyanide
Option 3/4 Removal (%) Median POTW Removal (%) Pass-Through
33.46
70.44
no
METALS
Antimony
Cobalt
Copper
Manganese
Molybdenum
Silicon
Strontium
Zinc
33.27
17.31
38.04
4.22
57.10
4.71
59.51
60.51
71.13
6.11
84.11
40.60
52.17
27.29
14.83
77.97
no
yes
no
no
yes
no
yes
no
ORGANICS
2-butanone
2-propanone
2,3-dichloroaniline
2,4,6-trichlorophenol
Acetophenone
Aniline
Benzoic Acid
n,n-Dimethylfbrmamide
o-Cresol
p-Cresol
Pentachlorophenol
Phenol
Pyridine
69.20
68.57
80.45
45.16
92.44
92.88
94.29
89.26
98.39
85.38
23.19
87.08
61.69
96.60
83.75
41.00
65.00
95.34
62.00
80.50
84.75
52.50
71.67
13.88
95.25
95.40
no
no
yes
no
ho
yes
yes
yes
yes
yes
yes
no
no
7-26
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Chapter 7 Pollutants Selected for Regulation Development Document for the CWTPoint Source Category
FINAL LIST OF POLLUTANTS SELECTED FOR REGULATION
Direct Dischargers
7.7
7.7.1
After EPA eliminated pollutants of concern which were treatment chemicals, non-conventional bulk
parameters, not detected at treatable levels, not treated, or vqlatile, EPA still had a lengthy list of
pollutants which could be regulated — particularly in the oils subcategory. EPA further eliminated
pollutants that were identified during screening, but not analyzed in a quantitative manner1. These
pollutants are iridium, lithium, silicon, and strontium. EPA also eliminated pollutants that are not toxic
as quantified by their toxic weighting factor (TWF)2. A single pollutant, yttrium, has a TWF of zero
and was, therefore, eliminated. EPA also eliminated pollutants that were removed by the proposed
treatment technologies, but whose removal was not optimal. EPA eliminated pollutants that were
removed by less than 30% with the proposed technology options for the organics subcategory and by less
than 50% with the proposed technology options for the metals and oils subcategories. These pollutants
are listed in Table 7-10.
Table 7-10 Pollutants Eliminated Due to Non-Optimal Performance
Metals Option 4 Metals Option 3
BOD5 None
Molybdenum
Pyridine
Zirconium
Oils Option 8
BOD5
Boron
Manganese3
Nickel
Selenium
Benzoic Acid
p-Cres.ol
Phenol
Pyridine
2-butanone
Oils Option 9
BOD5
Boron
Manganese
Nickel
Selenium
Benzoic Acid
o-Cresol
p-Cresol
Phenol
Pyridine
2-butanone
4-methyl-2-pentanone
Organics Option 3/4
Cobalt
Manganese
Pentachlorophenol
Finally, EPA eliminated those pollutants for which the treatment technology forming the basis of
the option is not a standard method of treatment. For example, chemical precipitation systems are not
designed to remove BOD5. Table 7-11 lists these pollutants for each subcategory and option.
'Analyses for these pollutants were not subject to the quality assurance/quality control (QA/QC) procedur s.
required by analytical Method 1620.
eighting factors are derived from chronic aquatic life criteria and human health criteria established for the
consumption offish. Toxic weighting factors can be used to compare the toxiciry of one pollutant relative to another and
are normalized based on the toxicity of copper. TWFs are discussed in detail in the Cost Effectiveness Analysis Document.
Removals for this pollutant for option 8 were not less than 50%. However, since removals for this pollutant fo
option 9 (the BAT selected option) were less than 50%, for consistency, they were similarly eliminated for option 8.
7-27
-------
Chanter 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
Table 7-11. Pollutants Eliminated Since Technology Basis is Not Standard Method of Treatment
Metals Option 4
BOD5
Boron
Metals Option 3
Benzoic Acid
Boron
2-butanone
2-propanone
Oils Option 8/9
Total Cyanide
Organics Option 3/4
Total Cyanide
For the organics subcategory, EPA's final
list of regulated pollutants for direct discharging
CWT facilities was based on the previous edits.
For the metals subcategory, three pollutants,
beryllium, molybdenum, and thallium, remained
for metals option 3, but had been'eliminated for
metals option 4. For consistency, EPA also
eliminated these three pollutants for metals
option 3. EPA's final list of regulated pollutants
for direct discharges in the metals subcategory
was based on these additional edits.
However, for the organic pollutants in the
oils subcategory, EPA further reduced the number
of regulated pollutants as detailed in the
following paragraphs. EPA selected this
approach based on comments to the 1995
proposal.
Therefore, EPA organized the remaining
organic pollutants in the oils subcategory into
pollutant groups. As detailed in Section 7.6.2,
pollutant groups were developed by combining
pollutants of similar structures. The remaining
list of organics pollutants in the oils subcategory
are in four pollutant groups: n-paraffins,
polyaromatic hydrocarbons, phtalates, and
aliphatic alcohols. EPA reviewed the influent
characterization data from oils subcategory
facilities (including the additional data collected
at non-hazardous oils facilities) to determine
which pollutants in each structural group are
always detected together. If pollutants in a
structural group are always detected together,
then EPA can establish some (or one) pollutants
in each group as indicator pollutants. Since the
effectiveness of the treatment technologies which
form the basis of the proposed oils subcategory
limitations is similar for pollutants in each group,
EPA can be confident that regulation of the group
indicator pollutant(s) will ensure control of all the
group pollutants. This approach allows EPA to
reduce the list of regulated pollutants for the oils
subcategory substantially. Tables 7-12, 7-13,
and 7-14 summarize the da.ta for each structural
group. In these tables, an "X" indicates the
pollutant was detected at the sampled facility
while a "blank" indicates the pollutant was not
detected at the sampled facility.
Data for n-paraffins show that while n-
decane is usually detected in combination with
other n-paraffins, it was the sole n-paraffin
•detected at one facility. Therefore, no other n-
paraffins in this group can be used as an indicator
parameter for n-decane. Additionally, the data
show that n-decane is not an acceptable indicator
parameter for the other pollutants in this group.
The data also show that n-hexadecane, n-
octadecane and n-tetradecane were always
detected together and vice versa. Finally, the data
show that the other n-paraffins were also detected
with n-hexadecane, n-octadecane and n-
tetradecane, but that the reverse statement is not
always true. Therefore, along with n-decane,
EPA can select n-hexadecane, n-octadecane or n-
tetradecane as an indicator parameter for the
majority of the n-paraffins. EPA selected n-
octadecane.
Data for the polyaromatic hydrocarbons
show that fluroanthene and pyrene were always
detected together and vice-versa. Likewise, when
the other polyaromatic hydrocarbons were
detected, both fluoranthene and pyrene were
7-28
-------
Chantei^PollutantsSelecte^^
always detected. However, the reverse statement
is not true. Therefore, EPA can select either
fluoranthene or pyrene as an indicator parameter
for all of the polyaromatic hydrocarbons. EPA
selected fluoranthene since it was detected most
often. Data for the phthalate group show that
while bis-2-ethylhexylphthalate is usually
detected with other phthalates, it is sometimes the
only pollutant detected in this group. Therefore,
no other n-pollutant in this group can be used an
indicator parameter for bis-2-ethylhexylphthlate.
The data also show that butyl benzyl phlalate is
usually detected with other phlalates, but that it
was the only phthalate detected at one facility.
Therefore, no other n-pollutant in this group can
be used an indicator parameter for butyl benzyl
phthlate. Finally, the data show that
diethylphthalate and di-n-butylphthlate are
always detected with bis-2-ethylhexylphthlate.
As a result, EPA selected bis-2-
ethylhexylphthlate and butyl benzylphthlate for
regulation in the pthalate group.
Table 7-15 shows the final list of pollutants
selected for regulation for direct dischargers.
7-29
-------
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-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWTPoint Source Category
Table 7-15. Final List of Regulated Pollutants for Direct Discharging CWTs
Metals Subcategory
Option 4
(BPT, BAT)
Metals Subcategory
Option 3 (NSPS)
Oils Subcategory
Option 9
BPT, BAT, NSPS
Organics Subcategory
Option 3
BPT, BAT, NSPS
TSS
Oil and Grease
Antimony
Arsenic
Cadmium
Chromium
Cobalt
Copper
Hex chromium
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Tin
Titanium
Total cyanide
Vanadium
Zinc
TSS
Oil and Grease
Antimony
Arsenic
Cadmium
Chromium
Cobalt
Copper
Hex Chromium
Lead
Manganese
Mercury
Nickel
Silver
Tin
Titanium
Total cyanide
Vanadium
Zinc
Oil and Grease
TSS
Antimony
Arsenic
Barium
Cadmium
Chromium
Cobalt
Copper
Lead
Mercury
Molybdenum
Tin
Titanium
Zinc
Alpha-terpineol
Bis(2-ethylhexyl)
phthalate
Butylbenzyl phthalate
Carbazole
Fluoranthene
N-decane
N-octadecane
SGT-HEM 7
BOD5
TSS
Antimony
Copper
Molybdenum
Zinc
Acetophenone
Aniline
Benzoic Acid
o-Cresol
p-Cresol
Phenol
Pyridine
2-butanone
2-propanone
2,3-dichloroaniline
2,4,6-trichlorophenol
7EPA has not proposed regulating SGT-HEM. However, EPA has asked for comment on whether SGT-HEM
should be used as an indicator parameter for the organic analytes in this Subcategory.
7-33
-------
Chapter 7 Pollutants Selected for Regulation Development Document for the CWT Point Source Category
Indirect Dischargers 7.7.2
As detailed in Section 7.6, all pollutants regulated for direct dischargers which pass-through
well-operated POTWs are regulated for indirect dischargers. Table 7-16 shows the final list of
regulated pollutants for indirect dischargers selected by EPA.
Table 7-16.
Final List of Regulated Pollutants for Indirect Discharging CWT Facilities
Metals Subcategory
Option 4
PSES
Antimony
Arsenic
Cadmium
Chromium
Cobalt
Copper
Hex chromium
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Tin
Titanium
Total cyanide
Vanadium
Zinc
Metals Subcategory
Option 3
PSNS
Antimony
Arsenic
Cadmium
Chromium
Cobalt
Copper
Hex chromium
Lead
Manganese
Mercury
Nickel
Silver
Tin
Titanium
Total cyanide
Vanadium
Zinc
Oils Subcategory
Option 8 (PSES)
Option 9 (PSNS)
Antimony
Barium
Cobalt
Copper
Molybdenum
Tin
Titanium
Zinc
Alpha-terpineol
Bis-2-ethylhexyl
phthalate
Carbazole
Fluoranthene
N-decane
N-octadecane
SGT-HEM 8
Organics Subcategory
Option 3
PSES, PSNS
Molybdenum
Aniline
Benzoic Acid
o-Cresol
p-Cresol
2,3-dichloroaniline
8EPA has not proposed regulating SGT-HEM. However, EPA has asked for comment on whether SGT-HEM
should be used as an indicator parameter for the organic analytes in this Subcategory.
7-34-
-------
Chapter
8
WASTEWATER TREATMENT TECHNOLOGIES
This section discusses a number of
wastewater treatment technologies
considered by EPA for the development of these
guidelines and standards for the CWT Industry.
Many of these technologies are being used
currently at CWT facilities. This section also
reviews other technologies with potential
application in treating certain CWT pollutants of
concern.
Facilities in the CWT industry use a wide
variety of technologies for treating wastes
received for treatment or recovery .operations and
wastewater generated on site. The technologies
are grouped into the following five categories for
this discussion:
• Best Management Practices, section 8.2.1;
• Physical/Chemical/Thermal Treatment,
section 8.2.2;
• Biological Treatment, section 8.2.3;
• Sludge Treatment and Disposal, section
8.2.4; and
• Zero Discharge Options, section 8.2.5.
The processes reviewed here include both
those that remove pollutant contaminants in
wastewater and those that destroy them. Using a
wastewater treatment technology that removes,
rather than destroys, a pollutant will produce a
treatment residual. In many instances, this
residual is in the form of a sludge, that, typically,
a CWT further treats on site in preparation for
disposal. Section 8.2.4 discusses technologies for
dewatering sludges to concentrate them prior to
disposal. In the case of other types of treatment
residuals, such as spent activated carbon and
filter media, CWT facilities generally send those
off site to a vendor facility for management.
TECHNOLOGIES CURRENTLY IN USE
8.1
EPA obtained information on the treatment
technologies in use in the CWT industry from
responses to the Waste Treatment Industry (WTI)
Questionnaire, site visits, public comments to the
original proposal and the 1996 Notice of Data
Availability. As described in Section 4, of the
estimated 205 CWT facilities, EPA has obtained
detailed facility-specific technology information
for 116 of the direct and indirect discharging
CWT facilities. Although EPA has facility-
specific information for 145 facilities, only 116
of these facilities provided technology
information. The detail provided regarding the
technology information differs depending on the
source. Information for the 65 facilities that
completed the WTI Questionnaire was the most
explicit because the questionnaire contained a
detailed checklist of wastewater treatment
technologies, many of which are discussed in this
section. Technology information from other
sources, however, is much less descriptive.
Table 8-1 presents treatment technology
information by subcategory for the 116 indirect
and direct discharging CWT facilities for which
EPA has facility-specific treatment technology
information. The information in Table 8-1 has
not been scaled to represent the entire population
of CWT facilities. Responses to the WTI
Questionnaire provide the primary basis for the
technology information for the metals and the
organics subcategories. Comments to the 1996
Notice of Data Availability provide the primary
8-1
-------
Chapter 8 Wastewater Treatment Technologies Development Documentfoiithe^WTPoMt_Source_Categor^
source of the technology information for the oils
subcategory. It should be noted that a number of
facilities commingle different subcategory wastes
for treatment. EPA has attributed these treatment
technologies to all appropriate subcategories.
Table 8-1. Percent Treatment Ih-place by Subcategory and by Method of Wastewater Disposal
Number of Facilities with
Treatment Technology Data
Equalization4
Neutralization4
Flocculation
Emulsion Breaking
Gravity-Assisted Separation
Skimming4
Plate/Tube Separation4
Dissolved Air Flotation
Chromium Reduction4
Cyanide Destruction4
Chemical Precipitation
Filtration
Sand Filtration4
Mutimedia Filtration4
Ultrafiltration
Reverse Osmosis4
Carbon Adsorption
Ion Exchange4
Air Stripping
Biological Treatment
Activated Sludge
Sequencing Batch Reactors4
Vacuum Filtration4
Metals Subcategorv
Direct Indirect
91
78
89
44
11
89
22
0
22
33
33
78
44
11
11
0
11
22
0
0
56
33
0
11
67
41 '
68
73
51
29
61
27
10
5
76
46
88
32
15
5
0
0
12
2
7
2
0
2
17
61
Oils Subcategorv
Direct Indirect
31'2
100
100
100
33
100
100
0
33
0
100
0
33
0
0
0
0
67
0
0
100
100
0
100
100
80W
65
61
48
56
85
58
19
23
48
23
34
19
16
0
8
3
18
0
11
11
0
0
6
39
Oreanics Subcategorv
Direct Indirect
4;
75
100
75
25
100
25
0
50
0
25
25
25
0
0
0
0
0
0
0
100
100
0
25
75
141
71
57
57
50
64
57
21
0
57
29
64
21
21
7
0
0
21
0
0
7
0
7
7
36
JSum does not add to 116 facilities. Some facilities treat wastes in multiple subcategories.
*bf the 3 direct discharging oils facilities for which EPA has facility-specific information, only one completed the
WTI Questionnaire.
^Dfthe 80 indirect discharging oils facilities for which EPA has facility-specific information, only 31 completed
the WTI Questionnaire.
4Information for these technologies for the oils subcategory is based on responses to the WTI Questionnaire only.
8-2
-------
Chapter 8 Wastewater Treatment Technologies Development Document for the C WT Point Source Category
TECHNOLOGY DESCRIPTIONS
Best Management Practices
8.2
8.2.1
Physical/Chemical/
Thermal Treatment
Equalization
8.2.2
8.2.2.1
In addition to physical/chemical treatment
technologies, CWT facilities employ a number of
ancillary means to prevent or reduce the discharge
of pollutants. These efforts are termed "best
management practices. EPA believes that CWT
facilities should design best management
practices in the CWT industry with the following
objectives in mind:
• Maximize the amount of waste materials and
residuals that are recycled rather than
disposed as residuals, as wastewater, or as
waste material.
• Maximize recycling and reuse of wastewaters
generated on site.
• Minimize the introduction of uncontaminated
wastewaters into the treatment waste stream.
• Encourage waste generators to minimize the
mixing of different wastes.
• Segregate wastes for treatment particularly
where waste segregation would improve
treatment performance and maximize
opportunities for recycling.
Waste segregation is one of the most
important tools available for maximizing waste
recycling and improving treatment performance.
For example, separate treatment of wastes
containing different types of metals allows the
recovery of the individual metals from the
resultant sludges. Similarly, separate treatment
collection and treatment of waste oils will allow
recycling. Many oils subcategory facilities
currently practice waste oil recycling.
GENERAL DESCRIPTION
The wastes received at many facilities in the
CWT industry vary considerably in both strength
and volume. Waste treatment facilities often need
to equalize wastes by holding wastestreams in a
tank for a certain period of time prior to treatment
in order to obtain a stable waste stream which is
easier to treat. CWT facilities frequently use
holding tanks to consolidate small waste volumes
and to minimize the variability of incoming
wastes prior to certain treatment operations. The
receiving or initial treatment tanks of a facility
often serve as equalization tanks.
The equalization tank serves many functions.
Facilities use equalization tanks to consolidate
smaller volumes of wastes so that, for batch
treatment systems, full batch volumes are
available. For continuous treatment systems,
facilities equalize the waste volumes so that they
may introduce effluent to downstream processes
at a uniform rate and strength. This dampens the
effect of peak and minimum flows. Introducing
a waste stream with a more uniform pollutant
profile to the treatment system facilitates control
of the operation of downstream treatment units,
resulting in more predictable and uniform
treatment results. Equalization tanks are usually
equipped with agitators or aerators where mixing
of the wastewater is desired and to prevent
suspended solids from settling to the bottom of
the unit An example of effective equalization is
the mixing of acid and alkaline wastes. Figure 8-
1 illustrates an equalization system.
EPA does not consider the use of
equalization tanks for dilution as a legitemate
use. In this context, EPA defines dilution as the
mixing of more concentrated wastes with greater
volumes of less concentrated wastes in a manner
that reduces the concentration of pollutant in the
concentrated wastes to a level that enables the
facility to avoid treatment of the pollutant.
8-3
-------
Chanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Wastewater
Influent
Equalization Tank
Equalized
Wastewater
Effluent
Figure 8-1. Equalization System Diagram
8-4
-------
Chanter 8 Waste-water Treatment Technologies Development Document for the CWTPoint Source Category
INDUSTRY PRACTICE
EPA found equalization being used at
facilities in all of the CWT subcategories. Of the
65 CWT facilities in EPA's WTI Questionnaire
data base that provided information concerning
the use of equalization, 44 operate equalization
systems. Of these, approximately 44 percent
emply unstirred tanks and 56 percent use stirred
or aerated tanks.
The combining of separate waste receipts in
large receiving tanks provides for effective
equalization even though it is not necessarily
recognized as such. Nearly every facility visited
by EPA performed equalization, either in tanks
specifically designed for that purpose or in waste
receiving tanks. Consequently, EPA has
concluded that equalization is underreported in
the data base.
Neutralization
8.2.2.2
GENERAL DESCRIPTION
Wastewaters treated at CWT facilities have
a wide range of pH values depending on the types
of wastes accepted. Untreated wastewater may
require neutralization to eliminate either high or
low pH values prior to certain treatment systems,
such as biological treatment. Facilities often use
neutralization systems also in conjunction with
certain chemical treatment processes, such as
chemical precipitation, to adjust the pH of the
wastewater to optimize treatment efficiencies.
These facilities may add acids, such as sulfuric
acid or hydrochloric acid, to reduce pH, and
alkalies, such as sodium hydroxides, to raise pH
values. Many metals subcategory facilities use
waste acids and waste alkalies for pH adjustment.
Neutralization may be performed in a holding
tank, rapid mix tank, or an equalization tank.
Typically, facilities use neutralization systems at
the end of a treatment system to control the pH of
the discharge to between 6 and 9 in order to meet
NPDES and POTW pretreatment limitations.
Figure 8-2 presents a flow diagram for a
typical neutralization system.
INDUSTRY PRACTICE
EPA found neutralization systems in-place at
facilities identified in all of the CWT
subcategories. Of the 65 CWT facilities in EPA's
WTI Questionnaire data base that provided
information concerning the use of neutralization,
45 operate neutralization systems.
Flocculation/Coagulation
8.2.2.3
GENERAL DESCRIPTION
Flocculation is the stirring or agitation of
chemically-treated water to induce coagulation.
The terms coagulation and flocculation are often
used interchangeably. More specifically,
"coagulation" is the reduction of the net electrical
repulsive forces at particle surfaces by addition of
coagulating chemicals, whereas "flocculation" is
the agglomeration of the destabilized particles by
chemical joining and bridging. Flocculation
enhances sedimentation or filtration treatment
system performance by increasing particle size
resulting in increased settling rates and filter
capture rates.
Flocculation generally precedes
sedimentation and filtration processes and usually
consists of a rapid mix tank or in-line mixer, and
a flocculation tank. The waste stream is initially
mixed while a coagulant and/or a coagulant aid is
added. A rapid mix tank is usually designed for
a detention time of 15 seconds to several minutes.
After mixing, the coagulated wastewater flows to
a flocculation basin where slow mixing of the
waste occurs. The slow mixing allows the
particles to agglomerate into heavier, more
settleable/filterable solids. Either mechanical
paddle mixers or diffused air provides mixing.
Flocculation basins are typically designed for a
detention time of 15 to 60 minutes. Figure 8-3
presents a diagram of a clarification system
incorporating coagulation and flocculation.
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Chaoter 8 Wastewater Treatment Technologies Development Document for the CWTPoint Source Category
3
Wastewater i
Influent
n » T n
w.
/ control
H k
' NPI itraliypri
Neutralization Tank Wastewater
Effluent
Figure 8-2. Neutralization System Diagram
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWTPoint Source Category
Coagulant
Influent •
Clarifier
Rapid Mix Flocculating
Tank Tank
Effluent
*• Sludge
Figure 8-3. Clarification System Incorporating Coagulation and Flocculation
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antpr R
Treatment Technologies Develonment Document for the CWT Point Source Category
There are three different types of treatment
chemicals commonly used in
coagulation/flocculation processes: inorganic
electrolytes, natural organic polymers, and
synthetic polyelectrolytes. The selection of the
specific treatment chemical is highly dependent
upon the characteristics and chemical properties
of the contaminants. Many CWT facilities use
bench-scale jar tests to determine the appropriate
type and optimal dosage of coagulant/flocculent
for a given waste stream.
INDUSTRY PRACTICE
Chemical treatment methods to enhance the
separation of pollutants from water as a solid
residual may include both chemical precipitation
and coagulation/flocculation. Chemical
precipitation is the conversion of soluble
pollutants such as metals into an insoluble
precipitate and is described separately.
Flocculation is often an integral step in chemical
precipitation, gravity separation, and filtration.
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning the use of
coagulation/flocculation, 31 operate
coagulation/flocculation systems. However, due
to the integral nature of flocculation in chemical
precipitation and coagulation, and the
interchangeable use of the terminology, the use of
coagulation/flocculation at CWT facilities may
have been underreported.
Emulsion Breaking
8.2.2.4
GENERAL DESCRIPTION
One process used to treat emulsified oil/water
mixtures is emulsion breaking. An emulsion, by
definition, is either stable or unstable. A stable
emulsion is one where small droplets of oil are
dispersed within the water and are prevented from
coalescing by repulsive electrical surface charges
that are often a result of the presence of
emulsifying agents and/or surfactants. In stable
emulsions, coalescing and settling of the
dispersed oil droplets would occur very slowly or
not at all. Stable emulsions are often
intentionally formed by chemical addition to
stabilize the oil mixture for a specific application.
Some examples of stable emulsified oils are
metal-working coolants, lubricants, and
antioxidants. An unstable emulsion, or
dispersion, settles very rapidly and does not
require treatment to break the emulsion.
Emulsion breaking is achieved through the
addition of chemicals and/or heat to the
emulsified oil/water mixture. The most
commonly-used method of emulsion breaking is
acid-cracking where sulfuric or hydrochloric acid
is added to the oil/water mixture until the pH
reaches 1 or 2. An alternative to acid-cracking is
chemical treatment using emulsion-breaking
chemicals such as surfactants and coagulants.
After addition of the treatment chemical, the tank
contents are mixed. After the emulsion bond is
broken, the oil residue is allowed to float to the
top of the tank. At this point, heat (100 to 150°
F) may be applied to speed the separation
process. The oil is then skimmed by mechanical
means, or the water is decanted from the bottom
of the tank. The oil residue is then further
processed or disposed. A diagram of an emulsion
breaking system is presented in Figure 8-4.
INDUSTRY PRACTICE
Emulsion breaking is a common process in
the CWT industry. Of the 116 CWT facilities in
EPA's WTI Questionnaire and NOA comment
data base that provided information concerning
the use of emulsion breaking, 49 operate
emulsion breaking systems. Forty-six of the 83
oils subcategory facilities in EPA's data base use
emulsion-breaking. As such, EPA has concluded
that emulsion breaking is the baseline, current
performance technology for oils subcategory
facilities that treat emulsified oily wastes.
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWTPoint Source Category
Chemical
Addition
Oil
Residue
Wastewa
Influent
Treated
Effluent
Sludge
Figure 8-4. Emulsion Breaking System Diagram
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Chanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Gravity Assisted Separation
8.2.2.5
1. GRAVITY OIL/WATER SEPARATION
GENERAL DESCRIPTION
Like emulsion breaking, another in-place
treatment process primarily used to remove oil
and grease and related pollutants from oil/water
mixtures, is gravity separation. Unlike emulsion
breaking, gravity separation is only effective for
the bulk removal of free oil and grease. It is not
effective in the removal of emulsified or soluble
oils. Gravity separation is often used in
conjunction with emulsion breaking at CWT
facilities.
Gravity separation may be performed using
specially designed tanks or it may occur within
storage tanks. •During gravity oil/water
separation, the wastewater is held under quiescent
conditions long enough to allow the oil droplets,
which have a lower specific gravity than water, to
rise and form a layer on the surface. Large
droplets rise more readily than smaller droplets.
Once the oil has risen to the surface of the
wastewater, it must be removed. This is done
mechanically via skimmers, baffles, plates,
slotted pipes, or dip tubes. When treatment or
storage tanks serve as gravity separators, the oil
may be decanted off the surface or, alternately,
the separated water may be drawn off the bottom
until the oil layer appears. The resulting oily
residue from a gravity separator must then be
further processed or disposed.
Because gravity separation is such a widely-
used technology, there is an abundance of
equipment configurations available. A very
common unit is the API (American Petroleum
Institute) separator, shown in Figure 8-5. This
unit uses an overflow and an underflow baffle to
skim the floating oil layer from the surface.
Another oil/water gravity separation process
utilizes parallel plates which shorten the
necessary retention time by shortening the
distance the oil droplets must travel before
separation occurs.
INDUSTRY PRACTICE
Of the 116 CWT facilities in EPA's WTI
Questionnaire and NOA comment data base that
provided information concerning the use of
oil/water gravity separation, 16 operate skimming
systems, seven operate coalescing plate or tube
separation systems, and 42 operate oil/water
gravity separation systems. Oil/water separation
is such an integral step at oils subcategory
facilities that every oils subcategory facility
visited by EPA performed gravity oil/water
separation, either in tanks specifically designed
for that purpose or in waste receiving or storage
tanks.
2. CLARIFICATION
GENERAL DESCRIPTION
Like oil/water separators, clarification
.systems utilize gravity to provide continuous,
low-cost separation and removal of particulates,
flocculated impurities, and precipitates from
water. These systems typically follow wastewater
treatment processes which generate suspended
solids, such as chemical precipitation and
biological treatment.
In a clarifier, wastewater is allowed to flow
slowly and uniformly, permitting the solids more
dense than water to settle to the bottom. The
clarified wastewater is discharged by flowing
from the top of the clarifies over a weir. Solids
accumulate at the bottom of a clarifier and a
sludge must be periodically removed, dewatered
and disposed. Conventional clarifiers are
typically circular or rectaingular tanks. Some
specialized types of clarifiers additionally
incorporate tubes, plates, or lamellar networks to
increase the settling area. A circular clarification
system is illustrated in Figure 8-6.
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Chanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Oil Retention
Baffle
\
o
Wastewater
Influent
Diffusion Device 9"
(vertical baffle)
Skimmer
\
Scraper
Sludge
Hopper
Oil
Retention
Baffle
Treated
Effluent
Figure 8-5. Gravity Separation System Diagram
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nntpr s Wntfpwater Treatment Technolosies Develooment Document for the CWTPoint Source Category
Skimming Scraper
Overflow
Influent
Baffle
Effluent
Skimmings Removal
Sludge Removal
Figure 8-6. Clarification System Diagram
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Chapter 8 Waste-water Treatment Technologies Development Document for the CWT Point Source Category
INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning the use of clarification
systems, 39 pperate settling systems and seven
operate coalescing plate or tube separation
systems. EPA did not obtain detailed enough
treatment technology information from the Notice
of Data Availability comments for the oils
subcategory facilities to determine the presence or
absence of clarification systems. In general, oils
subcategory facilities are more likely to utilize
gravity oil/water separation. However, oils
facilities that also utilize solids generation
processes such as chemical precipitation or
biological treatment as part of their waste
treatment train will likely utilize clarification
systems.
3. DISSOLVED AIR FLOTATION
GENERAL DESCRIPTION
Flotation is the process of using fine bubbles
to induce suspended particles to rise to the
surface of a tank where they can be collected and
removed. Gas bubbles are introduced into the
wastewater and attach themselves to the particles,
thereby reducing their specific gravity and
causing them to float. Fine bubbles may be
generated by dispersing air mechanically, by
drawing them from the water using a vacuum, or
by forcing air into solution under elevated
pressure followed by pressure release. The latter,
called dissolved air flotation (DAF), is the
flotation process used most frequently by CWT
facilities and is the focus of the remaining
discussion.
DAF is commonly used to remove suspended
solids and dispersed oil and grease from oily
wastewater. It may effectively reduce the
sedimentation times of suspended particles that
have a specific gravity close to that of water.
Such particles may include both solids with
specific gravity slightly greater than water and
oil/grease particles with specific gravity slightly
less than water. Flotation processes are
particularly useful for inducing the removal of
oil-wet solids that may exhibit a combined
specific gravity nearly the same as water. Oil-wet
• solids are difficult to remove from wastewater
using gravity sedimentation alone, even when
extended sedimentation times are utilized. Figure
8-7 is a flow diagram of a DAF system.
The major components of a conventional
DAF unit include a centrifugal pump, a retention
tank, an air compressor, and a flotation tank. For
small volume systems, the entire influent
wastewater stream is pressurized and contacted
with air in a retention tank for several minutes to
allow time for the air to dissolve. The
pressurized water that is nearly saturated with air
is then passed through a pressure reducing valve
and introduced into the flotation tank .near the
. bottom. In larger units, rather than pressurizing
the entire wastewater stream, a portion of the
flotation cell effluent is recycled through the
pressurizing pump and the retention tank. The
recycled flow is then mixed with the
unpressurized main stream just prior to entering
the flotation tank.
As soon as the pressure is released, the
supersaturated air begins to come out of solution
in the form of fine bubbles. The bubbles attach
to suspended particles and become enmeshed in
sludge floes, floating them to the surface. The
float is continuously swept from the tank surface
and is discharged over the end wall of the tank.
Sludge, if generated, may be collected from the
bottom of the tank.
The mechanics of the bubble-particle
interaction include: (1) attachment of the bubbles
on the particle surface, (2) collision between a
bubble and a particle, (3) agglomeration of
individual particles or a floe structure as the
bubbles rise, and (4) absorption of the bubbles
into a floe structure as it forms. As such, surface
chemistry plays a critical role in the effective
performance of air flotation.
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fhanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Float Removal Device
Float
Wastewater
Influent
(Saturated
with Air)
Treated
Effluent
Baffle
Sludge (If Produced)
Figure 8-7. Dissolved Air Flotation System Diagram
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Other operating variables which affect the
performance of DAF include the operating
pressure, recycle ratio, detention time, the
air/solids ratio, solids and hydraulic loading rates,
and the application of chemical aids.
The operating pressure of the retention tank
influences the size of the bubbles released. If the
bubbles are too large, they do not attach readily to
the suspended particles. If the bubbles are too
fine, they will disperse and break up fragile floe.
Wastewater treatment textbooks generally
recommend a bubble size of 100 micrometers.
The most practical way to establish the proper
rise rate is to conduct experiments at various air
pressures.
The air-to-solids ratio in the DAF unit
determines the effluent quality and solids
concentration in the float. This is because
adequate air bubbles are needed to float
suspended solids to the surface of the tank.
Partial flotation of solids will occur if inadequate
or excessive amounts of air bubbles are present.
Researchers have demonstrated that the
addition of chemicals to the water stream is an
effective means of increasing the efficiencies of
DAF treatment systems. The use of coagulants
can drastically increase the oil removal efficiency
of DAF units. Three types of chemicals are
generally utilized to improve the efficiency of air
flotation units used for treatment of produced
water; these chemicals are surface active agents,
coagulating agents, and polyelectrolytes. The use
of treatment chemicals may also enhance the
removal of metals in air flotation units. EPA's
collection of data from the CWT industry has
shown that many facilities use DAF systems to
remove metals from their waste streams.
MDUSTRY PRACTICE
Of the 116 CWT facilities in EPA's WTI
Questionnaire and NOA comment data base that
provided information concerning use of DAF, 21
operate DAF systems.
Chromium Reduction
8.2.2.6
GENERAL DESCRIPTION
Reduction is a chemical reaction in which
electrons are transferred from one chemical to
another. The main reduction application at CWT
facilities is the reduction of hexavalent chromium
to trivalent chromium, which is subsequently
precipitated from the wastewater in conjunction
with other metallic salts. A low pH of 2 to 3 will
promote chromium reduction reactions. At pH
levels above 5, the reduction rate is slow.
Oxidizing agents such as dissolved oxygen and
ferric iron interfere with the reduction process by
consuming the reducing agent.
The use of strong reducing agents such as
sulfur dioxide, sodium bisulfite, sodium
metabisulfite, and ferrous sulfate also
promotesshexavalent chromium reduction. The
two most commonly used reducing agents in the
CWT industry are sodium metabisulfite or
sodium bisulfite and gaseous sulfur dioxide. The
remaining discussion will focus on chromium
reduction using these agents only. Figure 8-8 is
a diagram of a chromium reduction system.
Chromium reduction using sodium
metabisulfite (Na^S^) and sodium bisulfite
(NaHSO3) are essentially similar. The
mechanism for the reaction using sodium bisulfite
as the reducing agent is:
3NaHSO3 + 3H2SO4 + 2H2CrO4
- Cr2(SO4)3 + 3NaHSO4 + 5H2O
The hexavalent chromium is reduced to
trivalent chromium using sodium metabisulfite,
with sulfuric acid used to lower the pH of the
solution. The amount of sodium metabisulfite
needed to reduce the hexavalent chromium is
reported as 3 parts of sodium bisulfite per part of
chromium, while the amount of sulfuric acid is 1
part per part of chromium. The theoretical
retention time is about 30 to 60 minutes.
A second process uses sulfur dioxide (SO2)
as the reducing agent The reaction mechanism is
as follows:
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anter R Wastewater Treatment Technoloaies Development Document for the CWT Point Source Category
3S02 + 3H2O - 3H2SO3
3H2S03 + 2H2Cr04 - Cr2(SO4)3 + 5H2O
The hexavalent chromium is reduced to
trivalent chromium using sulfur dioxide, with
sulfuric acid used to lower the pH of the solution.
The amount of sulfur dioxide needed to reduce
the hexavalent chromium is reported as 1.9 parts
of sulfur dioxide per part of chromium, while the
amount of sulfuric acid is 1 part per part of
chromium. At a pH of 3, the theoretical retention
time is approximately 30 to 45 minutes.
INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning the use of chromium
reduction, 35 operate chromium reduction
systems. All of the 35 facilities are in the metals
subcategory. At these 35 facilities, there are four
sulfur dioxide processes, 21 sodium bisulfite
processes, and two sodium metabisulfite
processes. The remaining systems use various
other reducing agents.
Cyanide Destruction
8.2.2.7
GENERAL DESCRIPTION
Electroplating and metal finishing operations
produce the major portion of cyanide-bearing
wastes accepted at CWT facilities. EPA
observed three separate cyanide destruction
techniques during site visits at CWT facilities.
The first two methods are alkaline chlorination
with gaseous chlorine and alkaline chlorination
with sodium hypochlorite. The third method is a
cyanide destruction process, details of which the
generator has claimed are confidential business
information (CBI). The two alkaline chlorination
procedures are discussed here.
Alkaline chlorination can destroy free
dissolved hydrogen cyanide and can oxidize all
simple and some complex inorganic cyanides. It,
however, cannot effectively oxidize stable iron,
copper, and nickel cyanide complexes. The
addition of heat to the alkaline chlorination
process can facilitate the more complete
destruction of total cyanid.es. The use of an
extended retention time can also improve overall
cyanide destruction. Figure 8-9 is a diagram of
an alkaline chlorination system.
In alkaline chlorination using gaseous
chlorine, the oxidation process is accomplished
by direct addition of chlorine (C12) as the oxidizer
and sodium hydroxide (NaOH) to maintain pH
levels. The reaction mechanism is:
NaCN + C12 + 2NaOH
- NaCNO + 2NaCl + H2O
2NaCNO + 3C12 + 6NaOH
- 2NaHCO3 + N2 + 6NaCl + 2H2O
The destruction of the cyanide takes place in
two stages. The primary reaction is the partial
oxidation of the cyanide to cyanate at a pH above
9. In the second stage, the pH is lowered to a
range of 8 to 8.5 for the oxidation of the cyanate
to nitrogen and carbon dioxide (as sodium
bicarbonate). Each part of cyanide requires 2.73
parts of chlorine to convert it to cyanate and an
additional 4.1 parts of chlorine to oxidize the
cyanate to nitrogen and carbon dioxide. At least
1.125 parts of sodium hydroxide are required to
control the pH with each stage.
Alkaline chlorination can also be conducted
with sodium hypochlorite (NaOCl) as the
oxidizer. The oxidation of cyanide waste using
sodium hypochlorite is similar to the gaseous
chlorine process. The reaction mechanism is:
NaCN + NaOCl - NaCNO + NaCl
2NaCNO + 3NaOCl + H2O
- 2NaHCO3 + N2 + 3NaCl
In the first step, cyanide is oxidized to
cyanate with the pH maintained in the range of 9
to 11. The second step oxidizes cyanate to
carbon dioxide (as sodium bicarbonate) and
nitrogen at a controlled pH of 8.5. The amount of
sodium hypochlorite and sodium hydroxide
needed to perform the oxidation is 7.5 parts and
8 parts per part of cyanide., respectively.
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWTPoint Source Category
Su If uric
Acid
.V
pH Controller
Wastewater
Influent
Treatment
Chemical
V
A"
Chemical Controller
- Treated
Effluent
Reaction Tank
Figure 8-8. Chromium Reduction System Diagram
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Chanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Caustic Feed
Hypochlorite or Chlorine Feed
Wastewater
Influent •
Acid Feed
Treated
Effluent
First Stage
Second S
age
Figure 8.9 Cyanide Destruction by Alkaline Chlorination
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Chapter 8 Wastewater Treatment Technologies Development Document for the C WTPoint Source Cateeorv
INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning the use of cyanide
destruction, 22 operate cyanide destruction
systems. All of the 22 facilities are in the metals
subcategory. Of these 22 facilities, one is a
thermal unit, one is the CBI unit, and the rest are
chemical reagent systems.
Chemical Precipitation
8.2.2.8
GENERAL DESCRIPTION
Many CWT facilities use chemical
precipitation to remove metal compounds from
wastewater. Chemical precipitation converts
soluble metallic ions and certain anions to
insoluble forms, which precipitate from solution.
Chemical precipitation is usually performed in
conjunction with coagulation/flocculation
processes which facilitate the agglomeration of
suspended and colloidal material. Most metals
are relatively insoluble as hydroxides, sulfides, or
carbonates. Coagulation/flocculation processes
are used in conjunction with precipitation to
facilitate removal by agglomeration of suspended
and colloidal materials. The precipitated metals
are subsequently removed from the wastewater
stream by liquid filtration or clarification (or
some other form of gravity-assisted separation).
Other treatment processes such as equalization,
or chemical oxidation or reduction (e.g.,
hexavalent chromium reduction) usually precede
the chemical precipitation process. Chemical
interactions, temperature, pH, solubility of waste
contaminants, and mixing effects all affect the
performance of the chemical precipitation
process.
Chemical precipitation is a two-step process.
At CWT facilities, it is typically performed in
batch operations. In the first step, precipitants
are mixed with the wastewater, typically by
mechanical means, such as mixers, allowing the
formation of the insoluble metal precipitants.
The detention time in this step of the process is
specific to the wastewater being treated, the
treatment chemicals used, and the desired effluent
quality. In the second step, the precipitated
metals are removed from the wastewater,
typically through filtration or clarification. If
clarification is used,.a flocculent is sometimes
added to aid the settling process. The resulting
sludge from the clarifier or filter must be further
treated, disposed, or recycled. A typical chemical
precipitation system is shown in Figure 8-10.
Various chemicals may be used as
precipitants. These include lime, sodium
hydroxide (caustic), soda ash, sodium sulfide, and
ferrous sulfate. Other chemicals used in the
precipitation process for pH adjustment and/or
coagulation include sulfuric and phosphoric acid,
ferric chloride, and polyelectrolytes. Often,
facilities use a combination of these chemicals.
CWT facilities generally use hydroxide
precipitation and/or sulfide precipitation.
Hydroxide precipitation is effective in removing
metals such as antimony, arsenic, chromium,
copper, lead, mercury, nickel, and zinc. Sulfide
precipitation is used instead of, or in addition to,
hydroxide precipitation to remove specific metal
ions including lead, copper, silver, cadmium, zinc,
mercury, nickel, thallium, arsenic, antimony, and
vanadium. Both hydroxide and sulfide
precipitation are discussed in greater detail below.
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nf *«r s Wactpwatpr Treatment Technologies Development Document for the CWT Point Source Category
Treatment Chemical
\7
Wastewater
Influent
Chemical Controller
Chemical Precipitation Tank
Figure 8-10. Chemical Precipitation System Diagram
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Chanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Hydroxide precipitation using lime or caustic
is the most commonly-used means of chemical
precipitation at CWT facilities. Of these, lime is
used more often than caustic. The reaction
mechanism for each of these is as follows:
Ca(OH)2 - M(OH)2i + Ca^.
2NaOH - M(OH)2J + 2Na++
The chief advantage of lime over caustic is
its lower cost However, lime is more difficult to
handle and feed, as it must be slaked, slurried,
and mixed, and can plug the, feed system lines.
Lime also produces a larger volume of sludge
than caustic, and the sludge is generally not
suitable for reclamation due to its homogeneous
nature.
Sulfide precipitation is the next most
commonly-used means of chemical precipitation
at CWT facilities. It is used to remove lead,
copper, silver, cadmium, zinc, mercury, nickel,
thallium, arsenic, antimony, and vanadium from
wastewaters. An advantage of the sulfide process
over the hydroxide process is that it can reduce
hexavalent chromium to the trivalent state under
the same process conditions required for metals
precipitation. The use of sulfides also allows for
the precipitation of metals when chelating agents
are present. The two most common- sulfide
precipitation processes are the soluble sulfide
process and the insoluble sulfide (Sulfex)
process.
In the soluble sulfide process, either sodium
sulfide or sodium hydrosulfide, both highly
soluble, is added in high concentration either as a
liquid reagent or from rapid mix tanks using solid
reagents. This high concentration of soluble
sulfides results in rapid precipitation of metals
which then results in the generation of fine
precipitate particles and hydrated colloidal
particles. These fine particles do not settle or
filter well without the addition of coagulating and
flocculating agents to aid in the formation of
larger, fast-settling floe. The high concentration
of soluble sulfides may also lead to the generation
of highly toxic and odorous hydrogen sulfide gas.
To control this problem, the treatment facility
must carefully control the dosage and/or the
process vessels must be enclosed and vacuum
evacuated. The reaction mechanism for soluble
sulfide precipitation is:
+s" - MSI.
The basic principle governing the insoluble
sulfide process is that ferrous sulfide (FeS) will.
disassociate into ferrous and sulfide ions, as
predicted by its solubility, producing a sulfide
concentration of approximately 2 mg/1 under
normal conditions. In the insoluble sulfide
process, a slurry of freshly prepared FeS
(prepared by reactive FeSO4 and NaHS) is added
to the wastewater. As the sulfide ions are
consumed in precipitating the metal pollutants,
additional FeS will disassociate. This will
continue as long as other heavy metals with lower
equilibrium constants are present in solution.
Because most heavy metals have sulfides that are
less soluble than ferrous sulfate, they will
precipitate as metal sulfides. In addition, if given
enough time, any metal hydroxides present will
dissolve and precipitate out as sulfides. If the
operation is performed under alkaline conditions,
the released ferrous ion will precipitate out as a
hydroxide. The following reactions occur when
FeS is added to a solution that contains dissolved
metal and metal hydroxide:
FeS - Fe+,+ + S"
' M4"* +S" - MSI
M(OH)2- M++
Fe++ + 2(OH)--Fe(OH)2l
One advantage of the insoluble sulfide
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Chanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
process over the soluble sulfide process is that the
insoluble sulfide process generates no detectable
H2S gas odor. This is because the dissolved
sulfide concentration is maintained at a relatively
low concentration. Disadvantages of the insoluble
sulfide process include considerably higher than
stoichiometric reagent consumption and
significantly higher sludge generation than either
the hydroxide or soluble sulfide process.
Wastewater treatment facilities often choose
to combine hydroxide precipitation and sulfide
precipitation for optimal metals removal. A
common configuration is a two-stage process in
which hydroxide precipitation is followed by
sulfide precipitation with each stage followed by
a separate solids removal step. This will produce
the high quality effluent of the sulfide
precipitation process while significantly reducing
the volume of sludge generated and the
consumption of sulfide reagent.
In addition to the type of treatment chemical
chosen, another important operational variable in
chemical precipitation is pH. Metal hydroxides
are amphoteric, meaning they can react
chemically as acids or bases. As such, their
solubilities increase toward both lower and higher
pH levels. Therefore, there is an optimum pH for
hydroxide precipitation for each metal, which
corresponds to its point of minimum solubility.'
Figure 8-11 presents calculated solubilities of
metal hydroxides. For example, as demonstrated
in this figure, the optimum pH range where zinc
is the least soluble is between 8 and 10. The
solubility of metal sulfides is not as sensitive to
changes in pH as hydroxides and generally
decreases as pH increases. The typical operating
pH range for sulfide precipitation is between 7
and 9. Arsenic and antimony are" exceptions to
this rule and require a pH below 7 for optimum
removal. As such, another advantage of sulfide
precipitation over hydroxide precipitation is that
most metals can be removed to extremely low
concentrations at a single pH.
For wastewater contaminated with a single
metal, selecting the optimum treatment chemical
and treatment pH for .-precipitation simply
requires the identification of the treatment
chemical/pH combination that produces the
lowest solubility of that metal. This is typically
done using a series of bench-scale treatability
tests. However, when wastewater is
contaminated with more 1han one metal, as is
often the case for wastewaters at CWT facilities,
selecting the optimum treatment chemical and pH
for a single-stage precipitation process becomes
more difficult and often involves a tradeoff
between optimal removal of two or more metals.
In general, for wastewater contaminated with
multiple metals, EPA has concluded that a single-
stage precipitation process does not provide for
adequate treatment. In such cases, a series of
chemical treatment steps using different pH
values and/or different treatment chemicals may
be more appropriate. Each of these treatment
steps needs to be followed by a solids separation
step in order to prevent the resolubilization of
metal precipitates during the subsequent
treatment step.
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWT Point Sovrce Category
100
10-.
1 -
0.1 -
0.01 -
0.001 -
0.0001
0 2 4 6 8 10 12 14
PH
Figure 8-11. Calculated Solubilities of Metal Hydroxides
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Chanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
In order to take advantage of the effects of
pH and treatment chemical selection on metals
precipitation, a facility may hold its wastes and
segregate them by pollutant content for treatment.
This type of waste treatment management, called
selective metals precipitation, may be adopted in
order to optimize the recovery of specific metal
pollutants. In instances where the segregated
wastes contain several metals, the pH of the
precipitation process may be adjusted so that the
desired metal for recovery is precipitated in
greater proportion than the other metals.
Multiple precipitation steps are then performed in
series on a single waste stream using different pH
values, resulting in different metals being
selectively precipitated into separate sludges.
The production of specific sludges containing
only the target metals makes the sludges more
suitable for reclamation. If the sludge is to be
sold to a smelter for re-use, then hydroxide
precipitation using only caustic should be
performed. The calcium compounds from lime
would interfere with the smelting process.
Selective precipitation is advantageous
because the metals may be reclaimed and re-used
rather than disposed as a sludge in a landfill and
because it allows for optimal removal of the
metals of concern. However, selective metals
precipitation does have additional costs such as
those associated with the extra tanks and
operating personnel required for waste
segregation.
INDUSTRY PRACTICE
Of the 116 CWT facilities in EPA's WTI
Questionnaire and NOA comment data base that
provided information concerning the use of
chemical precipitation, 57 operate chemical
precipitation systems. Fifty-one of these facilities
treat metals subcategory wastewaters. As
discussed previously, a single facility may use
several chemical precipitation steps, depending
upon the type of waste being treated. Of the 51
chemical precipitation systems at metals
subcategory facilities, 13 operate secondary
precipitation processes, .four operate tertiary
precipitation processes, and one employs
selective chemical precipitation processes.
Filtration 8.2.2.9
Filtration is a method for separating solid
particles from a fluid through the use of a porous
medium. The driving force in filtration is a
pressure gradient caused by gravity, centrifugal
force, pressure, or a vacuum. CWT facilities use
filtration treatment processes to remove solids
from wastewaters after physical/chemical or
biological treatment, or as the primary source of
waste treatment. Filtration processes utilized in
the CWT industry include a broad range of media
and membrane separation technologies.
To aid in removal, the filter medium may be
precoated with a filtration aid such as ground
cellulose or diatomaceous earth. Polymers are
sometimes injected into the filter feed piping
downstream of feed pumps to enhance
flocculation of smaller floes to improve solids
capture. The following sections discuss the
various types of filtration in use at CWT
facilities.
1. SAND FILTRATION
GENERAL DESCRIPTION
Sand filtration processes consist of either a
fixed or moving bed of media that traps and
removes suspended solids from water passing
through the media. There are two types of fixed
sand bed filters: pressure and gravity. Pressure
filters contain media in an enclosed, watertight
pressure vessel and require a feed pump to force
the water through the media. A gravity filter
operates on the basis of differential pressure of a
static head of water above the media, which
causes flow through the filter. Filter loading rates
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Chapter 8 Waste-water Treatment Technologies Development Document for the CWT Point Source Category
for sand filters are typically between 2 to 6
gpm/sq ft.
Fixed media filters have influent and effluent
distribution systems consisting of pipes and
fittings. A stainless steel screen covered with
gravel generally serves as the tank bottom and
support for the sand. Dirty water enters the top
of the filter and travels downward.
Moving bed filters use an air lift pump and
draft tube to recirculate sand from the bottom to
the top of the filter vessel, which is usually open
at the top. Dirty water entering the filter at the
bottom must travel upward, countercurrently,
through the downward moving fluidized sand
bed. Particles are strained from the rising water
and carried downward with the sand. Due to the
difference in specific gravity, the lighter particles
are removed from the filter when the sand is
recycled through a separation box often located at
the top of the filter. The heavier sand falls back
into the filter, while the lighter particles are
washed over a weir to waste.
Both fixed media and moving bed filters
build up head loss over time. Head loss is a
measure of solids trapped in the filter. As the
filter becomes filled with trapped solids, the
efficiency of the filtration process falls off, and
the filter must be backwashed. Reversing the
flow will backwash filters so that the solids in the
media are dislodged and may exit the filter.
Sometimes air is dispersed into the sand bed to
scour the media.
Fixed bed filters may be automatically
backwashed when the differential pressure
exceeds a preset limit or when a timer starts the
backwash cycle. A supply of clean backwash
water is required. Backwash water and trapped
particles are commonly discharged to an
equalization tank upstream of the wastewater
treatment system's gravity separation system or
screen for removal. Moving bed filters are
continuously backwashed and have a constant
rate of effluent flow.
INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning use of sand filtration,
eight operate sand filtration systems.
2. MULTIMEDIA FILTRATION
GENERAL DESCRIPTION
CWT facilities may use multimedia, or
granular bed, filtration to achieve supplemental
removal of residual suspended solids from the
effluent of chemical and biological treatment
processes. In granular bed filtration, the
wastewater stream is sent through a bed
containing two or more layers of different
granular materials. The solids are retained in the
voids between the media particles while the
wastewater passes through the bed. Typical
media used in granular bed filters include
anthracite coal, sand, and garnet.
A multimedia filter is designed so that the
finer, denser media is at the bottom and the
coarser, less dense media at the top. A common
arrangement is garnet at the bottom of the bed,
sand in the middle, and anthracite coal at the top.
Some mixing of these layers occurs and is
anticipated. During filtration, the removal of the
suspended solids is accomplished by a complex
process involving one or more mechanisms such
as straining, sedimentation, interception,
impaction, and adsorption. The medium size is
the principal characteristic that affects the
filtration operation. If the medium is too small,
much of the driving force will be wasted in
overcoming the frictional resistance of the filter
bed. If the medium is too large, small particles
will travel through the bed, preventing optimum-
filtration.
By designing the filter bed so that pore size
decreases from the influent to the effluent side of
the bed, different size particles are filtered out at
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Chanter 8 Wastewater Treatment Technoloaies Development Document for the CWT Point Source Category
different depths (larger particles first) of the filter
bed. This helps prevent the build up of a single
layer of solids at the bed surface which can
quickly increase the pressure drop over the bed
resulting in shorter filter runs and more frequent
backwash cycles. Thus, the advantage of
multimedia filtration over sand filtration is longer
filter runs and less frequent backwash cycles.
The flow pattern of multimedia filters is
usually top-to-bottom. Upflow filters, horizontal
filters, and biflow filters are also used. Figure 8-
12 is a top-to-bottom multimedia filter. The
classic multimedia filter operates by gravity.
However, pressure filters are occasionally used.
The complete filtration process involves two
phases: filtration and backwashing. As the filter
becomes filled with trapped solids, the efficiency
of the filtration process falls off. Head loss is a
measure of solids trapped in the filter. As the
head loss across the filter bed increases to a
limiting value, the end of the filter run is reached
and the filter must be backwashed to remove the
suspended solids in the bed. During
backwashing, the flow through the filter is
reversed so that the solids trapped in the media
are dislodged and can exit the filter. The bed may
also be agitated with air to aid in solids removal.
Backwash water and trapped particles are
commonly discharged to an equalization tank
upstream of the wastewater treatment system's
gravity separation system or screen for removal.
An important feature in filtration and
backwashing is the underdrain. The underdrain is
the support structure for the filtration bed. The
underdrain provides an area for the accumulation
of the filtered water without it being clogged from
the filtered solids or the media particles. During
backwash, the underdrain provides even flow
distribution over the bed. This is important
because the backwash flowrate is set so that the
filter bed expands but the media is not carried out
with the backwashed solids. The media with
different densities then settle back down in
somewhat discrete layers at the end of the
backwash step.
INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning use of multimedia
filtration, four operate multimedia filtration
systems.
3. PLATE AND FRAME PRESSURE FILTRATION
GENERAL DESCRIPTION
Another filtration system for the removal of
solids from waste streams is a plate and frame
pressure filtration systems. Although plate and
frame filter presses are more commonly used for
dewatering sludges, they are also used to remove
solids directly from wastewater streams. The
liquid stream plate and frame pressure filtration
system is identical to the system used for the
sludge stream (section 8.4.1) with the exception
of a lower solids level in the influent stream. The
same equipment is used for both applications,
with the difference being the sizing of the sludge
and liquid units. See section 8.4.1 for a detailed
description of plate and frame pressure filtration.
No CWT facilities in EPA's database use plate
and frame filtration.
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Chapter 8 Waste-water Treatment Technologies Development'Document for the C WTPoint Source Category
Wastewater Influent
Coarse Media
Finer Media
Finest Media
Support
Underdrain Chamber
Backwash
Backwash
Treated Effluent
Figure 8-12. Multi-Media Filtration System Diagram
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4. MEMBRANE FILTRATION
GENERAL DESCRIPTION
Membrane filtration systems are processes
which employ semi-permeable membranes and a
pressure differential to remove solids in
wastestreams. Reverse osmosis and
ultrafiltration are two commonly-used membrane
filtration processes.
A. ULTRAFILTRATION
GENERAL DESCRIPTION
CWT facilities commonly use ultrafiltration
(UF) for the treatment of metal-finishing
wastewater and oily wastes. It can remove
substances with molecular weights greater than
500, including suspended solids, oil and grease,
large organic molecules, and complexed heavy
metals. UF can be used when the solute
molecules are greater than ten times the size of
the solvent molecules, and are less than one-half
micron. In the CWT industry, UF is applied in
the treatment of oil/water emulsions. Oil/water
emulsions contain both soluble and insoluble oil.
Typically the insoluble oil is removed from the
emulsion by gravity separation assisted by
emulsion breaking. The soluble oil is then
removed by UF. Oily wastewater containing 0.1
to 10 percent oil can be effectively treated by UF.
Figure 8-13 shows a UF system.
In UF, a semi-permeable microporous
membrane performs the separation. Wastewater
is sent through membrane modules under
pressure. Water and low-molecular -weight
solutes (for example, salts and some surfactants)
pass through the membrane and are removed as
"permeate. Emulsified oil and suspended solids
are rejected by the membrane and are removed as
concentrate. The concentrate is recirculated
through the membrane unit until the flow of
permeate drops. The permeate may either be
discharged or passed along to another treatment
unit. The concentrate is contained and held for
further treatment or disposal. An important
advantage of UF over reverse osmosis is that the
concentrate may be treated to remove the
concentrated solids and the separated water may
• then be retreated through the UF system.
The primary design consideration in UF is
the membrane selection. A membrane pore size
is chosen based on the size of the contaminant
particles targeted for removal. Other design
parameters to be considered are the solids
concentration, viscosity, and temperature of the
feed stream, pressure differential, and the
membrane permeability and thickness. The rate
at which a membrane fouls is also an important
design consideration.
INDUSTRY PRACTICE
Of the 116 CWT facilities in EPA's WTI
Questionnaire and NOA comment data base that
provided information concerning use of
ultrafiltration, six operate ultrafiltration systems.
B. REVERSE OSMOSIS
GENERAL DESCRIPTION
Reverse osmosis (RO) is a process for
separating dissolved solids from water. CWT
facilities commonly use RO in treating oily or
metal-bearing wastewater. RO is applicable
when the solute molecules are approximately the
same size as the solvent molecules. A
semi-permeable, microporous membrane and
pressure are used to perform the separation. RO
systems are typically used as polishing processes,
prior to final discharge of the treated wastewater.
Reverse osmosis systems have been demonstrated
to be effective in removing dissolved metals.
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Permeate (Treated Effluent)
Wastewater
Feed
Concentrate
Membrane Cross-section
Figure 8-13. Ultrafiltration System Diagram
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Chanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Osmosis is the diffusion of a solvent (such as
water) across a semi-permeable membrane from
a less concentrated solution into a more
concentrated solution. In the reverse osmosis
process, pressure greater than the normal osmotic
pressure is applied to the more concentrated
solution (the waste stream being treated), forcing
the purified water through the membrane and into
the less concentrated stream which is called the
permeate. The low-molecular-weight solutes (for
example, salts and some surfactants) do not pass
through the membrane. They are referred to as
concentrate. The concentrate is recirculated
through the membrane unit until the flow of
permeate drops. The permeate can either be
discharged or passed along to another treatment
unit. The concentrate is contained and held for
further treatment or disposal. Figure 8-14 shows
an RO system.
The performance of an RO system is
dependent upon the dissolved solids
concentration and temperature of the feed stream,
the applied pressure, and the type of membrane
selected. The key RO membrane properties to be
considered are: selectivity for water over ions,
permeation rate, and durability. RO modules are
available in various membrane configurations,
such as spiral-wound, tubular, hollow-fiber, and
plate and frame. In addition to the membrane
modules, other capital items needed for an RO
installation include pumps, piping,
instrumentation, and storage tanks. The major
operating cost is attributed to membrane
replacement A major consideration for RO
systems is the disposal of the concentrate due to
its elevated concentrations of salts, metals, and
other dissolved solids.
INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning use of reverse osmosis,
two operate reverse osmosis systems.
5. LANCY FILTRATION
GENERAL DESCRIPTION
The Lancy Sorption Filter System is a
patented method for the continuous recovery of
heavy metals. The Lancy sorption filtration
process may reduce metels not removed by
conventional waste treatment technologies to low
concentrations.
In the first stage of the Lancy filtration
process, a soluble sulfide is added to the
wastewater in a reaction tank, converting most of
the heavy metals to sulfides. From the sulfide
reaction tank, the solution is passed through the
sorption filter media. Precipitated metal sulfides
and other suspended solids are filtered out. Any
remaining soluble metals are absorbed by the
media. Excess soluble sulfides are also removed
from the waste stream.
The Lancy filtration process reportedly
reduces zinc, silver, copper, lead, and cadmium to
less than 0.05 mg/1 and mercury to less than 2
yug/l. In addition to the effective removal of
heavy metals, the system has a high solids
filtration capacity and a fully automatic,
continuous operation. The system continuously
recycles and reuses the same filter media thereby
saving on operating costs,. The system may be
installed with a choice of media discharge - slurry
or solid cake. Figure 8-15 illustrates the Lancy
Sorption Filtration System..
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Chapter S Wastewater Treatment Technologies Development Document for the CWTPoint Source Category
Permeate (Treated Effluent)
Waste water
Feed
Concentrate
Membrane Cross-section
Figure 8-14. Reverse Osmosis System Diagram
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Treated,
Wastewater
Influent
Media Discharge
Recycle
Tank
Figure 8-15. Lancy Filtration System Diagram
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INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning use of filtration systems,
only one operates the Lancy Sorption Filtration
System. This unit is used for polishing effluent
from a treatment sequence including chemical
precipitation, clarification, and sand filtration.
EPA obtained performance data for this system
during a sampling episode at one of the metals
subcategory facilities. The performance data
showed that some metals were reduced to the
target levels while the concentration of some
pollutants increased. This may not represent
optimal performance of the system, however,
because the facility reported that they were
experiencing operational problems throughout the
sampling episode.
Carbon Adsorption
8.2.2.10
GENERAL DESCRIPTION
Activated carbon adsorption is a
demonstrated wastewater treatment technology
that uses activated carbon to remove dissolved
organic pollutants from wastewater. The
activated carbon is made from many
carbonaceous sources including coal, coke, peat,
wood, and cpconut shells. The carbon source
material is "activated" by treating it with an
oxidizing gas to form a highly porous structure
with a large internal surface area. CWT facilities
generally use granular forms of activated carbon
(GAC) in fixed bed columns to treat wastewater.
However, some use powdered activated carbon
(PAC) alone or in conjunction with biological
treatment. Figure 8-16 presents a diagram of a
fixed-bed GAC collumn.
In a fixed bed system, the wastewater enters
the top of the unit and is allowed to flow
downward through a bed of granular activated
carbon. As the wastewater comes into contact
with the activated carbon, the dissolved organic
compounds adsorb onto the surface of the
activated carbon. In the upper area of the bed, the
pollutants are rapidly adsorbed. As more
wastewater passes through the bed, this rapid
adsorption zone moves downward until it reaches
the bottom of the bed. At this point, all of the
available adsorption sites are filled and the
carbon is said to be exhausted. This condition
can be detected by an increase in the effluent
pollutant concentration, and is called
breakthrough.
GAC systems are usually comprised of
several beds operated in series. This design
allows the first bed to go to exhaustion, while the
other beds still have the capacity to treat to an
acceptable effluent quality. The carbon in the
first bed is replaced, and the second bed then
becomes the lead bed. The GAC system piping
is designed to allow switching of bed order.
After the carbon is exhausted, it can be
removed and regenerated. Usually heat or steam
is used to reverse the adsorption process. The
light organic compounds are volatilized and the
heavy organic compounds are pyrolyzed. Spent
carbon may also be regenerated by contacting it
with a solvent which dissolves the adsorbed
pollutants. Depending on system size and
economics, some facilities may choose to dispose
of the spent carbon instead of regenerating it. For
very large applications, an on-site regeneration
facility is more economical. For smaller
applications, such as in the CWT industry, it is
generally cost-effective to use a vendor service to
deliver regenerated carbon and remove the spent
carbon. These vendors transport the spent carbon
to their centralized facilities for regeneration.
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Chanter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Fresh
Carbon
Fill
Collector/
Distributor
Spent
Carbon
Discharge
Wastewater
Influent
Backwash
Backwash
Treated
Effluent
Figure 8-16. Carbon Adsorption System Diagram
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Ctvaoter 8 Waste-water Treatment Technologies Development Document for the CWT Point Source Category
The carbon adsorption mechanism is
complicated and, although the attraction is
primarily physical, is a combination of physical,
chemical, and electrostatic interactions between
the activated carbon and the organic compound.
The key design parameter for activated carbon is
the adsorption capacity of the carbon. The
adsorption capacity is a measure of the mass of
contaminant adsorbed per unit mass of activated
carbon and is a function of the compound being
adsorbed, the type of carbon used, and the
process design and operating conditions. In
general, the adsorption capacity is inversely
proportional to the adsorbate solubility.
Nonpolar, high molecular weight organics with
low solubility are readily adsorbed. Polar, low
molecular weight organics with high solubilities
are more poorly adsorbed.
Competitive adsorption between compounds
has an effect on adsorption. The carbon may
preferentially adsorb one compound over another.
This competition could result in an adsorbed
compound being desorbed from the carbon. This
is most pronounced when carbon adsorption is
used to treat wastewater with highly variable
pollutant character and concentration.
INDUSTRY PRACTICE
Of the 116 CWT facilities in EPA's WTI
Questionnaire and NOA comment data base that
provided information concerning use of carbon
adsorption, 17 operate carbon adsorption
systems.
Ion Exchange
8.2.2.11
GENERAL DESCRIPTION
A common process employed to remove
heavy metals from relatively low-concentration
waste streams, such as electroplating wastewater,
is ion exchange. A key advantage of the ion
exchange process is that the metal contaminants
can be recovered and reused. Another advantage
is that ion exchange may be designed to remove
certain metals only, providing effective removal
of these metals from highly-contaminated
wastewater. A disadvantage is that the resins
may be fouled by some organic substances.
In an ion exchange system, the wastewater
stream is passed through a bed of resin. The
resin contains bound groups of ionic charge on its
surface, which are exchanged for ions of the same
charge in the wastewater. Resins are classified by
type, either cationic or anionic. The selection is
dependent upon the wastewater contaminant to be
removed. A commonly-used resin is polystyrene
copolymerized with divinylbenzene.
The ion exchange process involves four
steps: treatment, backwash, regeneration, and
rinse. During the treatment step, wastewater is
passed through the resin bed and ions are
exchanged until pollutant breakthrough occurs.
The resin is then backwashed to reclassify the bed
and to remove suspended solids. During the
regeneration step, the resin is contacted with
either an acidic or alkaline solution containing
high concentrations of the ion originally present
in the resin. This "reverses" the ion exchange
process and removes the metal ions from the
resin. The bed is then rinsed to remove residual
regenerating solution. The resulting
contaminated regenerating solution must be
further processed for reuse or disposal.
Depending upon system size and economics,
some facilities choose to remove the spent resin
and replace it with resin regenerated off-site
instead of regenerating the resin in-place.
Ion exchange equipment ranges from simple,
inexpensive systems such as domestic water
softeners, to large, continuous industrial
applications. The most commonly-encountered
industrial setup is a fixed-bed resin in a vertical
column, where the resin is regenerated in-place.
Figure 8-17 is a diagram of this type of system.
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These systems may be designed so that the
regenerant flow is concurrent or countercurrent to
the treatment flow. A countercurrent design,
although more complex to operate, provides a
higher treatment efficiency. The beds may
contain a single type of resin for selective
treatment, or the beds may be mixed to provide
for more complete deionization of the waste
stream. Often, individual beds containing
different resins are arranged in series, which
makes regeneration easier than in the mixed bed
system.
INDUSTRY PRACTICE
EPA is aware of only one CWT facility using
ion exchange.
Electrolytic Recovery
8.2.2.12
GENERAL DESCRIPTION
Another process for reclaiming metals from
wastewater is electrolytic recovery. It is a
common technology in the electroplating, mining,
and electronic industries. It is used for the
recovery of copper, zinc, silver, cadmium, gold,
and other heavy metals. Nickel is poorly
recovered due to its low standard potential.
The electrolytic recovery process uses an
oxidation and reduction reaction. Conductive
electrodes (anodes and cathodes) are immersed in
the metal-bearing wastewater, with an electric
potential applied to them. At the cathode, a metal
ion is reduced to its elemental form (electron-
consuming reaction). At the same time, gases
such as oxygen, hydrogen, or nitrogen form at the
anode (electron-producing reaction). After the
metal coating on the cathode reaches a desired
thickness, it may be removed and recovered. The
metal-stripped cathode can then be used as the
anode.
The equipment consists of an electrochemical
reactor with electrodes, a gas-venting system,
recirculation pumps, and a power supply. Figure
8-18 ia a diagram of an electrolytic recovery
system. Electrochemical reactors are typically
designed to produce high flow rates to increase
the process efficiency.
A conventional electrolytic recovery system
is effective for the recovery of metals from
relatively high-concentration wastewater. A
specialized adaptation of electrolytic recovery,
called extended surface electrolysis, or ESE,
operates effectively at lower concentration levels.
The ESE system uses a spiral cell containing a
flow-through cathode which has a very open
structure and therefore a lower resistance to fluid
flow. This also provides a larger electrode
surface. ESE systems are often used for the
recovery of copper, lead, mercury, silver, and
gold.
INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning use of electrolytic
recovery, three operate electrolytic recovery
systems.
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Wastewater
Influent
Used
Regenerant
Regenerant
Solution
Distributor
Support
Treated
Effluent
Figure 8-17. Ion Exchange System Diagram
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0 + 1/20
Deposited
Metal
Porous Insulating Separator
Figure 8-18. Electrolytic Recovery System Diagram
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Stripping
8.2.2.13
Stripping is a method for removing dissolved
volatile organic compounds from wastewater.
The removal is accomplished by passing air or
steam through the agitated waste stream. The
primary difference between air stripping and
steam stripping is that steam stripping is operated
at higher temperatures and the resultant off-gas
stream is usually condensed and recovered or
incinerated. The off-gas from air stripping
contains non-condenseable air which must be
either passed through an adsorption unit or
incinerated in order to prevent transfer of the
volatile pollutants to the environment. EPA is
not aware of any applications of steam stripping
technologies in the CWT industry.
1. AIR STRIPPING
GENERAL DESCRIPTION
r
Air stripping is effective in removing
dissolved volatile organic compounds from
wastewater. The removal is accomplished by
passing high volumes of air through the agitated
wastewater stream. The process results in a
contaminated off-gas stream which, depending
upon air emissions standards, usually requires air
pollution control equipment. Stripping can
be performed in tanks or in spray or packed
towers. Treatment in packed towers is the most
efficient application. The packing typically
consists of plastic rings or saddles. The two
types of towers that are commonly used, cross-
flow and countercurrent, differ in design only in
the location of the air inlets. In the cross-flow
tower, the air is drawn through the sides for the
total height of the packing. The countercurrent
tower draws the entire air flow from the bottom.
Cross-flow towers have been found to be more
susceptible to scaling problems and are less
efficient than countercurrent towers. Figure 8-19
is a countercurrent air stripper.
The driving force of the air stripping mass-
transfer operation is the difference in
concentrations between the air and water streams.
Pollutants are transferred from the more
concentrated wastewater stream to the less
concentrated air stream until equilibrium is
reached. This equilibrium relationship is known
as Henry's Law. The strippability of a pollutant
is expressed as its Henry's Law Constant, which
is a function of both its volatility or vapor
pressure and solubility.
Air strippers are designed according to the
strippability of the pollutants to be removed. For
evaluation purposes, organic pollutants can be
divided into three general strippability ranges
(low, medium, and high) according to their
Henry's Law Constants. The low strippability
group (Henry's Law Constants of 10"4 [mg/m3
air]/[mg/m3 water] and lower) are not effectively
removed. Pollutants in the medium (10"1 to 10"4)
and high(10'1 and greater) groups are effectively
stripped. Pollutants with lower Henry's law
constants require greater column height, more
trays or packing material, greater temperature,
and more frequent cleaning than pollutants with
a higher strippability.
The air stripping process is adversely
affected by low temperatures. Air strippers
experience lower efficiencies at lower
temperatures, with the possibility of freezing
within the tower. For this reason, depending on
the location of the tower, it may be necessary to
preheat the wastewater and the air feed streams.
The column and packing materials must be
cleaned regularly to ensure that low effluent
levels are attained. .
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Wastewater
Influent
Off-gas
Blower
Distributor
Support
Treated
Effluent
Figure 8-19. Air Stripping System Diagram
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Air stripping has proved to be an effective
process in the removal of volatile pollutants from
wastewater. It is generally limited to influent
concentrations of less than 100 mg/1 organics.
Well-designed and operated systems can achieve
over 99 percent removals.
INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning use of air stripping, 11
operate air stripping systems.
Liquid Carbon Dioxide Extraction 8.2.2.14
GENERAL DESCRIPTION
Liquid carbon dioxide (CO2) extraction is a
process used to extract and recover organic
contaminants from aqueous waste streams. A
licensed, commercial application of this
technology is utilized in the CWT industry under
the name "Clean Extraction System" (CES).
The process may be effective in the removal of
organic substances such as hydrocarbons,
aldehydes and ketones, nitriles, halogenated
compounds, phenols, esters, and heterocyclics. It
is not effective in the removal of some
compounds which are very water-soluble, such as
ethylene glycol, and low molecular weight
alcohols. It may provide an alternative in the
treatment of waste streams which historically
have been incinerated.
In liquid carbon dioxide extraction, the waste
stream is fed into the top of a pressurized
extraction tower containing perforated plates,
where it is contacted with a countercurrent stream
of liquefied CO2. The organic contaminants in
the waste stream are dissolved in the CO2; this
extract is then sent to a separator, where the CO2
is redistilled. The distilled CO2 vapor is
compressed and reused. The concentrated
organics bottoms from the separator can then be
disposed or recovered. The treated wastewater
stream which exits the extractor (raffinate) is
pressure-reduced and may be further treated for
residual organics removal if necessary to meet
discharge standards. Figure 8-20 is a diagram of
the CES is presented in.
INDUSTRY PRACTICE
EPA is aware of only one facility using this
technology in the CWT industry. Pilot-scale
information submitted to EPA by the CWT
facility showed effective removal for a variety of
organic compounds. EPA sampled this
commercial CWT CES unit during this
rulemaking effort. Performance was not optimal,
however, as the facility reported operational
problems with the unit throughout the sampling
episode.
Biological Treatment
8.2.3
A portion of the CWT industry accepts waste
receipts that contain organic pollutants, which are
often amenable to biological degradation. This
subset of CWT facilities is referred to as the
organics subcategory. In addition, a portion of
the facilities in the oils subcategory also use
biological treatment to treat wastewater separated
from oily wastes.
Biological treatment systems use microbes
which consume, and thereby destroy, organic
compounds as a food source. The microbes use
the organic compounds as both a source of
carbon and as a source of energy. These
microbes may also need supplemental nutrients
for growth, such as nitrogen and phosphorus, if
the waste stream is deficient in these nutrients.
Aerobic microbes require oxygen to grow,
whereas anaerobic microbes will grow only in the
absence of oxygen. Facultative microbes are an
adaptive type of microbe that can grow with or
without oxygen.
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Extract
Vapor CO2
Feed
Extractor
Liquid CO2
Separator
Makeup
CO,
I
Compressor
Water
Organics
Figure 8-20. Liquid CO2 Extraction System Diagram
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The success of biological treatment is
dependent on many factors, such as the pH and
temperature of the wastewater, the nature of the
pollutants, the nutrient requirements of the
microbes, the presence of inhibiting pollutants,
and variations in the feed stream loading. Certain
compounds, such as heavy metals, may be toxic
to the microorganisms and must be removed from
the waste stream prior to biological treatment.
Load variations are a major concern, especially in
the CWT industry, where waste receipts vary over
time in both concentration and volume.
There are several adaptations of biological
treatment These adaptations differ in three basic
ways. First, a system may be aerobic, anaerobic,
or facultative. Second, the microorganisms may
either be attached to a surface (as in a trickling
filter), or be unattached in a liquid suspension (as
in an activated sludge system). Third, the
operation may be either batch or continuous.
Of the 116 facilities in the WTI
Questionnaire and NOA comment data base that
responded to EPA's inquiry concerning the use of
biological treatment, 17 operate biological
treatment systems. There were no anaerobic
systems reported. Theses systems include
sequencing batch reactors, attached growth
systems (biotowers and trickling filters) and
activated sludge systems. With the exception of
trickling filters, EPA sampled at least one
application of each of the following biological
treatment technologies during the development of
these effluent guidelines.
Sequencing Batch Reactors
8.2.3.1
GENERAL DESCRIPTION
A sequencing batch reactor (SBR) is a
suspended growth system in which wastewater is
mixed with existing biological floe in an aeration
basin. SBRs are unique in that a single tank acts
as an equalization tank, an aeration tank, and a
clarifier. An SBR is operated on a batch basis
where the wastewater is mixed and aerated with
the biological floe for a specific period of time.
The contents of the basin are allowed to settle and
the supernatant is decanted. The batch operation
of an SBR makes it a useful biological treatment
option for the CWT industry, where the
wastewater volumes and characteristics are often
highly variable. Each batch can be treated
differently depending on waste characteristics.
Figure 8-21 shows an SBR.
The SBR has a four cycle process: fill, react,
settle, and decant. The fill cycle has two phases.
The first phase, called static fill, introduces the
wastewater to the system under static conditions.
This is an anaerobic period and may enhance
biological phosphorus uptake. During the second
phase of the fill cycle wastewater is mechanically
mixed to eliminate the scum layer and prepare the
microorganisms to receive oxygen. In the second
cycle, me react cycle, aeration is performed. The
react cycle is a time-dependent process where
wastewater is continually mixed and aerated,
allowing the biological degradation process to
occur. The third cycle, called the settling cycle,
provides quiescent conditions throughout the tank
and may accommodate low settling rates by
increasing the settling time. During the last or
decant cycle, the treated wastewater is decanted
by subsurface withdrawal from below the scum
layer. This treated, clarified effluent may then be
further treated or discharged.
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Process
Cycle
Fill
React
Settle
Decant
Figure 8-21. Sequencing Batch Reactor System Diagram
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When the quantity of biomass in the SBR
exceeds that needed for operation, the excess
biomass is removed. The sludge that is removed
from the SBR may be reduced in volume by
thickening and dewatering using any of the sludge
treatment processes discussed in section 8.2.4.
The dewatered sludge may be disposed in a
landfill or used as an agricultural fertilizer.
An SBR carries out all of the functions of a
conventional continuous flow activated sludge
process, such as equalization, biological
treatment, and sedimentation, in a time sequence
rather than a space sequence. Detention times
and loadings vary with each batch and are highly
dependent on the specific raw wastewater
loadings. Typically, an SBR operates with a
hydraulic detention time of 1 to 10 days and a
sludge retention time of 10 to 30 days. The
mixed liquor suspended solids (MLSS)
concentration is maintained at 3,500 to 10,000
mg/1. The overall control of the system may be
accomplished automatically by using level
sensors or timing devices. By using a single tank
to perform all of the required functions associated
with biological treatment, an SBR reduces land
requirements. It also provides for greater
operation flexibility for treating wastes with
viable characteristics by allowing the capability
to vary detention time and mode of aeration in
each stage. SBRs also may be used to achieve
complete nitrification/denitrification and
phosphorus removal.
INDUSTRY PRACTICE
EPA is aware of only one CWT facility that
uses an SBR. This facility is in the organics
subcategory, and its SBR unit was sampled
during the development of these effluent
guidelines.
Attached Growth Biological
Treatment Systems 8.2.3.2
Another system used to biodegrade the
organic components of a wastewater is the
attached growth biological treatment system. In
these systems, the biomass adheres to the
surfaces of rigid supporting media. As
wastewater contacts the supporting medium, a
thin-film biological slime develops and coats the
surfaces. As this film (consisting primarily of
bacteria, protozoa, and fungi) grows, the slime
periodically breaks off the medium and is
replaced by new growth. This phenomenon of
losing the slime layer is called sloughing and is
primarily a function of organic and hydraulic
loadings on the system. The effluent from the
system is usually discharged to a clarifier to settle
and remove the agglomerated solids.
Attached growth biological systems are
appropriate for treating industrial wastewaters
amenable to aerobic biological treatment. When
used in conjunction with suitable pre- and post-
treatment processes, attached growth biological
systems remove suspended and colloidal
materials effectively. The two major types of
attached growth systems used at CWT facilities
are trickling filters and biotowers. The following
section describes these processes.
l. TRICKLING FILTERS
GENERAL DESCRIPTION
Trickling filtration is an aerobic fixed-film
biological treatment process that consists of a
structure, packed with inert medium such as rock,
wood, or plastic. The wastewater is distributed
over the upper surface of the medium by either a
fixed spray nozzle system or a rotating
distribution system. The inert medium develops
a biological slime that absorbs and biodegrades
organic pollutants. Air flows through the filter by
convection, thereby providing the oxygen needed
to maintain aerobic conditions. Figure 8-22 is a
flow diagram of a trickling filter.
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Figure 8-22. Trickling Filter System Diagram
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Trickling filters are classified as low-rate or
high-rate, depending on the organic loading.
Typical design organic loading values range from
5 to 25 pounds and 25 to 45 pounds BOD5 per
1,000 cubic feet per day for low-rate and high-
rate, respectively. A low-rate filter generally has
a media bed depth of 1.5 to 3 meters and does not
use recirculation. A high-rate filter may have a
bed depth from 1 to 9 meters and recirculates a
portion of the effluent for further treatment.
INDUSTRY PRACTICE
EPA is aware of only one CWT facility that
uses a trickling filter. This facility is in the oils
subcategory.
2. BlOTOWERS
GENERAL DESCRIPTION
A variation of a trickling filtration process is
the aerobic biotower. Biotowers may be operated
in a continuous or semi-continuous manner and
may be operated in an upflow or downflow
manner. In the downflow mode, influent is
pumped to the top of a tower, where it flows by
gravity through the tower. The tower is packed
with plastic or redwood media containing the
attached microbial growth. Biological
degradation occurs as the wastewater passes over
the media. Treated wastewater collects in the
bottom of the tower. If needed, additional oxygen
is provided via air blowers countercurrent to the
wastewater flow. In the upflow mode, the
wastewater stream is fed into the bottom of the
biotower and is passed up through the packing
along with diffused air supplied by air blowers.
The treated effluent exits from the top of the
biotower.
Variations of this treatment process involve
the inoculation of the raw influent with bacteria
and the addition of nutrients. Wastewater
collected in the biotowers is delivered to a
clarifierto separate the biological solids from the
treated effluent. A diagram of a biotower is
presented in Figure 8-23.
INDUSTRY PRACTICE
EPA is aware of two biotowers in operation
in the CWT Industry. One system treats a waste
stream which is primarily composed of leachate
from an on-site landfill operation. The other
system treats high-TOC wastewater from a
metals recovery operation. EPA conducted
sampling at this facility during the development
of these effluent guidelines.
Activated Sludge
8.2.3.3
GENERAL DESCRIPTION
The activated sludge process is a
continuous-flow, aerobic biological treatment
process that employs suspended-growth aerobic
microorganisms to biodegrade organic
contaminants. In this process, a suspension of
aerobic microorganisms is maintained by
mechanical mixing or turbulence induced by
diffused aerators in an aeration basin. This
suspension of microorganisms is called the mixed
liquor. Figure 8-24 is a diagram of a
conventional activated sludge system.
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Inoculum
Nutrient
Solution
Wastewater
Influent
Treated
Effluent
Blower
Figure 8-23. Biotower System Diagram
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Wastewater
Influent
T
Aeration
Basin
Recycled Sludge
Secondary
Clarification
Waste
Excess
Sludge
Figure 8-24. Activated Sludge System Diagram
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Influent is introduced into the aeration basin
and is allowed to mix with the contents. A series
of biochemical reactions is performed in the
aeration basin, degrading organics and generating
new biomass. Microorganisms oxidize the
soluble and suspended organic pollutants to
carbon dioxide and water using the available
supplied oxygen. These organisms also
agglomerate colloidal and particulate solids.
After a specific contact period in the aeration
basin, the mixture is passed to a settling tank, or
clarifier, where the microorganisms are separated
from the treated water. A major portion of the
settled solids in the clarifier is recycled back to
the aeration system to maintain the desired
concentration of microorganisms in the reactor. •
The remainder of the settled solids is wasted and
sent to sludge handling facilities.
To ensure biological stabilization of organic
compounds in activated sludge systems, adequate
nutrient levels must be available to the biomass.
The primary nutrients are nitrogen and
phosphorus. Lack of these nutrients can impair
biological activity and result in reduced removal
efficiencies. Certain wastes may have low
concentrations of nitrogen and phosphorus
relative to the oxygen demand. As a result,
nutrient supplements (e.g., phosphoric acid
addition for additional phosphorus) have been
used in activated sludge systems at CWT
facilities.
The effectiveness of the activated sludge
process is governed by several design and
operation variables. The key variables are
organic loading, sludge retention time, hydraulic
or aeration detention time, and oxygen
requirements. The organic loading is described
as the food-to-microorganism (F/M) ratio, or
kilograms of BOD5 applied daily to the system
per kilogram of mixed liquor suspended solids
(MLSS). The MLSS in the aeration tank is
determined by the rate and concentration of
activated sludge returned to the tank. The organic
loading (F/M ratio) affects the BOD5 removal,
oxygen requirements, biomass production, and
the settleability of the biomass. The sludge
retention time (SRT) or sludge age is a measure
of the average retention time of solids in the
activated sludge system. The SRT affects the
degree of treatment and production of waste
sludge. A high SRT results in a high quantity of
solids in the system and therefore a higher degree
of treatment while also resulting in the production
of less waste sludge. The hydraulic detention
time determines the size of the aeration tank and
is calculated using the F/M ratio, SRT, and
MLSS. Oxygen requirements are based on the
amount required for biodegradation of organic
matter and the amount required for endogenous
respiration of the microorganisms. The design
parameters will vary with the type of wastewater
to be treated and are usually determined in a
treatability study.
Modifications of the activated sludge process
are common, as the process is extremely versatile
and can be adapted for a wide variety of
organically contaminated wastewaters. The
typical modification may include a variation of
one or more of the key design parameters,
including the F/M loading, aeration location and
type, sludge return, and contact basin
configuration. The modifications in practice have
been identified by the major characteristics that
distinguish the particular configuration. The
characteristic types and modifications are briefly
described as follows:
• Conventional. The aeration tanks are long
and narrow, with plug flow (i.e., little
forward or backwards mixing).
• Complete Mix. The aeration tanks are
shorter and wider, and the aerators, diffusers,
and entry points of the influent and return
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Chapter 8 Wastewater Treatment Technologies . Development.Document for the C WT Point Source Category
sludge are arranged so that the wastewater
mixes completely.
Tapered ^Aeration. A modification of the
conventional process in which the diffusers
are arranged to supply more air to the
influent end of the tank, where the oxygen
demand is highest.
Step Aeration. A modification of the
conventional process in which the wastewater
is introduced to the aeration tank at several
points, lowering the peak oxygen demand.
High Rate Activated Sludge. A modification
of conventional or tapered aeration in which
the aeration times are shorter, the pollutants
loadings are higher per unit mass of
microorganisms in the tank. The rate of
BOD5 removal for this process is higher than
that of conventional activated sludge
processes, but the total removals are lower.
Pure Oxygen. An activated sludge variation
in which pure oxygen instead of air is added
to the aeration tanks, the tanks are covered,
and the oxygen-containing off-gas is
recycled. Compared to normal air aeration,
pure oxygen aeration requires a smaller
aeration tank volume and treats high-strength
wastewaters and widely fluctuating organic
loadings more efficiently.
Extended Aeration. A variation of complete
mix in which low organic loadings and long
aeration times permit more complete
wastewater degradation and partial aerobic
digestion of the microorganisms.
Contact Stabilization. An activated sludge
modification using two aeration stages. In
the first, wastewater is aerated with the return
sludge in the contact tank for 30 to 90
minutes, allowing finely suspended colloidal
and dissolved organics to absorb to the
activated sludge. The solids are settled out in
a clarifier and then aerated in the sludge
aeration (stabilization) tank for 3 to 6 hours
before flowing into the first aeration tank.
• Oxidation Ditch Activated Sludge. An
extended aeration process in which aeration
and mixing are provided by brush rotors
placed across a race-track-shaped basin.
Waste enters the ditch at one end, is aerated
by the rotors, and circulates,
INDUSTRY PRACTICE
Because activated sludge systems are
sensitive to the loading and flow variations
typically found at CWT facilities, equalization is
often required prior to activated sludge treatment.
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning use of activated sludge,
four operate activated sludge systems.
Sludge Treatment and Disposal
8.2.4
Several of the waste treatment processes used
in the CWT industry generate a sludge. These
processes include chemical precipitation of
metals, clarification, filtration, and biological
treatment. Some oily waste treatment processes,
such as dissolved air flotation and centrifugation,
also produce sludges. These sludges typically
contain between one and five percent solids.
They require dewatering to concentrate them and
prepare them for transport and/or disposal.
Sludges are dewatered using pressure,
gravity, vacuum, or centrifugal force. There are
several widely-used, commercially-available
methods for sludge dewatering. Plate and frame
pressure filtration, belt pressure filtration, and
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vacuum filtration are the primary methods used
for sludge dewatering at CWT facilities. A plate
and frame filter press can produce the driest filter
cake of these three systems, followed by the belt
press, and lastly, the vacuum filter. Each of these
sludge dewatering methods are discussed below.
In some instances, depending upon the nature
of the sludge and the dewatering process used, the
sludge may first be stabilized, conditioned, and/or
thickened prior to dewatering. Certain sludges
require stabilization (via chemical addition or
biological digestion) because they have an
objectionable odor or are a health threat. Sludges
produced by the CWT industry usually do not fall
into this category. Sludge conditioning is used to
improve dewaterability; it can be accomplished
via the addition of heat or chemicals. Sludge
thickening, or concentration, reduces the volume
of sludge to be dewatered and is accomplished by
gravity settling, flotation, or centrifugation.
Plate and Frame Pressure Filtration 8.2.4.1
GENERAL DESCRIPTION
Plate and frame pressure filtration systems is
a widely used method for the removal of solids
from waste streams. In the CWT industry, plate
and frame pressure filtration system are used for
filtering solids out of treated wastewater streams
and sludges. The same equipment is used for
both applications, with the difference being the
solids level in the influent stream and the sizing
of the sludge and liquid units. Figure 8-25 is a
plate and frame filter press.
A plate and frame filter press consists of a
number of recessed filter plates or trays
connected to a frame and pressed together
between a fixed end and a moving end. Each
plate is constructed with a drainage surface on the
depressed portion of the face. Filter cloth is
mounted on the face of each plate and then the
plates are pressed together. The sludge is
pumped under pressure into the chambers
between the plates of the assembly while water
passes through the media and drains to the filtrate
outlets. The solids are retained in the cavities of
the filter press between the cloth surfaces and
form a cake that ultimately fills the chamber. At
the end of the cycle when the filtrate flow stops,
the pressure is released and the plates are
separated. The filter cake drops into a hopper
below the press. The filter cake may then be
disposed in a landfill. The filter cloth is washed
before the next cycle begins.
The key advantage of plate and frame
pressure filtration is that it can produce a drier
filter cake than is possible with the other methods
of sludge dewatering. In a typical plate and frame
pressure filtration unit, the filter cake may exhibit
a dry solids content between 30 and 50 percent.
It is well-suited for use in the CWT industry as it
is a batch process. However, its batch operation
results in greater operating labor requirements.
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T
Figure 8-25: Plate and Frame Filter Press System Diagram
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' INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning the use of pressure
filtration, 34 operate pressure filtration systems.
Of these34 facilities, 25 operate plate and frame
pressure filtration systems, three operate belt
pressure filtration systems, and six did not
specify the type of presure filtration systems
utilized.
Belt Pressure Filtration
8.2.4.2
GENERAL DESCRIPTION
A belt pressure filtration system uses gravity
followed by mechanical compression and shear'
force to produce a sludge filter cake. Belt filter
presses are continuous systems which are
commonly used to dewater biological treatment
sludge. Most belt filter installations are preceded
by a flocculation step, where polymer is added to
create a sludge which has the strength to
withstand being compressed between the belts
without being squeezed out. Figure 8-26 shows
a typical belt filter press.
During the press operation, the sludge stream
is fed onto the first of two moving cloth filter
belts. The sludge is gravity-thickened as the
water drains through the belt. As the belt holding
the sludge advances, it approaches a second
moving belt. As the first and second belts move
closer together, the sludge is compressed between
them. The pressure is increased as the two belts
travel together over and under a series of rollers.
The turning of the belts around the rollers shear
the cake which furthers the dewatering process.
At the end of the roller pass, the belts move apart
and the cake drops off. The feed belt is washed
before the sludge feed point The dropped filter
cake may then be disposed.
The advantages of a belt filtration system are
its lower labor requirements and lower power
consumption. The disadvantages are that the belt
filter presses produce a poorer quality filtrate, and
require a relatively large volume of belt wash
water.
Typical belt filtration applications may
dewater an undigested activated sludge to a cake
containing 15 to 25 perceni: solids. Heat-treated,
digested sludges may be reduced to a cake of up
to 50 percent solids.
INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning the use of pressure
filtration, 36 operate pressure filtration systems.
Of these 34 facilities, 25 operate plate and frame
pressure filtration systems, three operate belt
pressure filtration systems, and six did not
specify the type of presure filtration systems
utilized.
Vacuum Filtration
8.2.4.3
GENERAL DESCRIPTION
A commonly-used process for dewatering
sludge is rotary vacuum filtration. These filters
come in drum, coil, and belt configurations. The
filter medium may be made of cloth, coil springs,
or wire-mesh fabric. A typical application is a
rotary vacuum belt filter; a diagram of this
equipment is shown in Figure 8-27.
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Sludge
Influent
Drainage Compression
Zone Zone
Wash Water
Shear
Zone
Filter
Cake
Figure 8-26. Belt Pressure Filtration System Diagram
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Filter Cake
Discharge
Filter Media
Spray Wash
Figure 8-27. Vacuum Filtration System Diagram
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In a rotary vacuum belt filter, a continuous
belt of filter fabric is wound around a horizontal
rotating drum and rollers. The drum is perforated
and is connected to a vacuum. The drum is
partially immersed in a shallow tank containing
the sludge. As the drum rotates, the vacuum
which is applied to the inside of the drum draws
the sludge onto the filter fabric. The water from
the sludge passes through the filter and into the
drum, where it exits via a discharge port. As the
fabric leaves the drum and passes over the roller,
the vacuum is released. The filter cake drops off
of the belt as it turns around the roller. The filter
cake may then be disposed.
Vacuum filtration may reduce activated
sludge to a cake containing 12 to 20 percent
solids. Lime sludge may be reduced to a cake of
25 to 40 percent solids.
Because vacuum filtration systems are
relatively expensive to operate, they are usually
preceded by a thickening step which reduces the
volume of sludge to be dewatered. An advantage
of vacuum filtration is that it is a continuous
process and therefore requires less operator
attention.
1 INDUSTRY PRACTICE
Of the 65 CWT facilities in EPA's WTI
Questionnaire data base that provided
information concerning the use of vacuum
filtration, eight operate vacuum filtration systems.
Filter Cake Disposal 8.2.4.4
After a sludge is dewatered, the resultant
filter cake must be disposed. The most common
method of filter cake management used in the
CWT industry is transport to an off-site landfill
for disposal. Other disposal options are
incineration or land application. Land application
is usually restricted to biological treatment
residuals.
Zero or Alternate Discharge
Treatment Options
8.2.5
This section discusses zero discharge
wastewater treatment and disposal methods. In
this context, zero discharge refers to any
wastewater disposal method other than indirect
discharge to a POTW or direct discharge to a
surface water. A common zero discharge method
employed by CWT facilities that generate small
volumes of wastewater is transportation of the
wastewater to an off-site disposal facility such as
another CWT facility. Other methods discussed
below include deep well disposal, evaporation,
and solidification.
Deep well disposal consists of pumping the
wastewater into a disposal well, that discharges
the liquid into a deep aquifer. . Normally, these
aquifers are thoroughly characterized to insure
that they are not hydrogeologically-connected to
a drinking water supply. The characterization
requires the confirmation of the existence of
impervious layers of rock above and below the
aquifer. Pretreatment of the wastewater using
filtration is often practiced to prevent the
plugging of the face of the receiving aquifer.
Traditionally used as a method of sludge
dewatering, evaporation (or solar evaporation)
also can involve the discharge and ultimate
storage of wastewater into a shallow, lined, on-
site basin or ditch. Because the system is open to
the atmosphere, the degree of evaporation is
greatly dependent upon climatic conditions. This
option is generally available only to those
facilities located in arid regions.
Solidification is a process in which materials,
such as fly ash, cement, and lime, are added to the
waste to produce a solid. Depending on both the
contaminant and binding material, the solidified
waste may be disposed of in a landfill or
incinerated.
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWTPoint Source Category
INDUSTRY PRACTICE
EPA has information for 24 CWT facilities
not discharging directly to surface waters or
POTWs that employ zero and alternate discharge
methods. Of those 24 facilities, seven dispose of
wastewater by deep well injection, 13 transport
wastewater to an off-site commercial or intra-
company wastewater treatment facility, two
dispose of wastewater by evaporation, one
solidifies wastewater and landfills it on-site, and
one discharges wastewater to a privately-owned
treatment works.
REFERENCES
8.3
Standard Methods for Examination of Water and Wastewater. 15th Edition, Washington DC.
Henricks, David, Inspectors Guide for Evaluation of Municipal Wastewater Treatment Plants.
Culp/Wesner/Culp, El Dorado Hills, CA, 1979.
Technical Practice Committee, Operation of Wastewater Treatment Plants. MOP/11, Washington, DC,
1976.
Clark, Viesman, and Hasner, Water Supply and Pollution Control. Harper and Row Publishers, New
York, NY, 1977.
Environmental Engineering Division, Computer Assisted Procedure For the Design and Evaluation of
Wastewater Treatment Systems CCAPDET). U. S. Army Engineer Waterways Experiment Station,
Vicksburg, MS, 1981.
1991 Waste Treatment Industry Questionnaire. U.S. Environmental Protection Agency, Washington,
DC.
Osmonics, Historical Perspective of Ultrafiltration and Reverse Osmosis Membrane Development
Minnetonka, MN, 1984.
Organic Chemicals and Plastics and Synthetic Fibers fOCPSF) Cost Document SAIC, 1987.
Effluent Guidelines Division, Development Document for Effluent Limitations Guidelines & Standards
for the Metal Finishing. Point Source Category. Office of Water Regulation & Standards, U.S. EPA, .
Washington, DC, June 1983.
Effluent Guidelines Division, Development Document For Effluent Limitations Guidelines and
Standards for the Organic Chemicals. Plastics and Synthetic Fibers TOCPSFX Volume II, Point Source
Category, EPA 440/1-87/009, Washington, DC, October 1987.
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Chaoter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Engineering News Record (ENRX McGraw-Hill Co., New York, NY, March 30, 1992.
Comparative Statistics of Industrial and Office Real Estate Markets. Society of Industrial and Office
Realtors of the National Association of Realtors, Washington, DC, 1990.
Effluent Guidelines Division, Development Document for Effluent Limitations Guidelines & Standards
for the Pesticides Industry. Point Source Category, EPA 440/1-85/079, Washington, DC, October, 1985.
Peters, M., and Timmerhaus, K., Plant Design and Economics for Chemical Engineers. McGraw-Hill,
New York, NY, 1991.
Chemical Marketing Reporter. Schnell Publishing Company, Inc., New York, NY, May 10, 1993.
Palmer, S.K., Breton, M.A., Nunno, T.J., Sullivan, D.M., and Supprenaut, N.F., Metal/Cvanide
Containing Wastes Treatment Technologies. Alliance Technical Corp., Bedford, MA, 1988.
Freeman, H.M., Standard Handbook of Hazardous Waste Treatment and Disposal. U.S. EPA, McGraw-
Hill, New York, NY, 1989.
Corbitt, Robert, Standard Handbook of Environmental Engineering. McGraw-Hill Publishing Co., New
York, NY, 1990.
Perry, H., Chemical Engineers Handbook. 5th Edition. McGraw-Hill, New York, NY, 1973.
Development Document for BAT. Pretreatment Technology and New Source Performance Technology
for the Pesticide Chemical Industry. USEPA, April 1992.
Vestergaard, Clean Harbors Technology Corporation to SAIC - letter dated 10/13/93.
Brown and Root, Inc., "Determination of Best Practicable Control Technology Currently Available to
Remove Oil and Gas," prepared for Sheen Technical Subcommittee, Offshore Operators Committee,
New Orleans, (March 1974).
Churchill, R.L., "A Critical Analysis of Flotation Performance," American Institute of Chemical
Engineers, 290-299, (1978).
Leech, C.A., "Oil Flotation Processes for Cleaning Oil Field Produced Water," Shell Offshore, Inc.,
Bakersfield, CA, (1987).
Luthy, R.C., "Removal of Emulsified Oil with Organic Coagulants and Dissolved Air Flotation," Journal
Water Pollution Control Federation. (1978), 331-346.
Lysyj, I., et al., "Effectiveness of Offshore Produced Water Treatment," API et al., Oil Spill prevention,
Behavior Control and Clean-up Conference (Atlanta, GA) Proceedings, (March 1981).
Pearson, S.C., "Factors Influencing Oil Removal Efficiency in Dissolved Air Flotation Units," 4th
Annual Industrial Pollution Conference, Houston, TX, (1976).
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Chapter 8 Wastewater Treatment Technologies Development Document for the CWT Point Source Category
Viessman, W., And Hammer, M.J., Water Supply and Pollution Control. Harper Collins Publishers, New
York, NY, 1993.
Wyer, R.H., et al., "Evaluation of Wastewater Treatment Technology for Offshore Oil Production
Facilities," Offshore Technology Conference, Dallas, TX, (1975).
Eckenfelder, Welsey, Industrial Pollution Control. New York: McGraw-Hill, 1989.
Joint Task Force, Design of Municipal Wastewater Treatment Plants. MOP 8, Alexandria: Water
Environment Federation, 1991.
Tchobanoglous, George, Wastewater Engineering. 2nd Ed., New York: McGraw-Hill, 1979.
Development Document for the Proposed Effluent Limitations Guidelines and Standards for the
Landfills Point Source Category. USEPA, January, 1998.
Development Document for the Proposed Effluent Limitations Guidelines and Standards for Industrial
Waste Combustors. USEPA, December 1997.
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Chapter
9
REGULATORY OPTIONS CONSIDERED AND
SELECTED FOR BASIS OF REGULATION
This section presents the technology options
considered by EPA as the basis for the
proposed effluent limitations guidelines and
standards for the CWT industry. It also describes
the methodology for EPA's selection of the
proposed technology options. The limitations
and standards discussed in this section are Best
Practicable Control Technology Currently
Available (BPT), Best Conventional Pollutant
Control Technology (BCT), Best Available
Technology Economically Achievable (BAT),
New Source Performance Standards (NSPS),
Pretreatment Standards for Existing Sources
(PSES), and Pretreatment Standards for New
Sources (PSNS).
ESTABLISHMENT OF BPT
9.1
Section 304(b)(l)(A) requires EPA to
identify effluent reductions attainable through the
application of "best practicable control
technology currently available for classes and
categories of point sources." EPA determines
BPT effluent levels based upon the average of the
best existing performance by facilities of various
sizes, ages, and unit processes within each
industrial category or subcategory. However, in
industrial categories where present practices are
uniformly inadequate, EPA may determine that
BPT requires higher levels of control than any
currently in place if the technology to achieve
those levels can be practicably applied.
In addition, CWA Section 304(b)(l)(B)
requires a cost reasonableness assessment for
BPT limitations. In determining the BPT limits,
EPA must consider the total cost of treatment
technologies in relation to the effluent reduction
benefits achieved.
In balancing costs against the benefits of
effluent reduction, EPA considers the volume and
nature of expected discharges after application of
BPT, the general environmental effects of
pollutants, and the cost and economic impacts of
the required level of pollution control.
In assessing BPT for this industry, EPA
considered age, size, unit processes, other
' engineering factors, and non-water quality
impacts pertinent to the facilities treating waste in
each subcategory. For all subcategories, no basis
could be found for identifying different BPT
limitations based on age, size, process, or other
engineering .factors for the reasons previously
discussed. For a service industry whose service
is wastewater treatment, the pertinent factors for
establishing the limitations are cost of treatment,
the level of effluent reductions obtainable, and
.non-water quality effects.
EPA determined that, while some CWT
facilities are providing adequate treatment of all
wastestreatns, wastewater treatment at some
CWT facilities is poor. EPA has determined that
facilities which mix different types of highly
concentrated CWT wastes with non-CWT
wastestreams or with storm water are not
providing BPT treatment. In addition, while
some CWT facilities pretreat subcategory
wastestreams for optimal removal prior to
commingling, some facilities mix wastes from
different subcategories without pretreatment.
This practice essentially dilutes the waste rather
than treats the waste. As such, the mass of
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CHAPTER 9 Reg. Options Considered and Selected Development Document for the CWT Point Source Category
pollutants being discharged at some CWT
facilities is higher than that which can be
achieved, given the demonstrated removal
capacity of treatment systems that the Agency
reviewed. Many CWT facilities recognize that
commingling often leads only to dilution and have
encouraged their customers to segregate wastes as
much as possible. Waste minimization
techniques at most manufacturing facilities have
also led to increased waste stream segregation.
Comparison of EPA sampling data and CWT
industry-supplied monitoring information
establishes that, in the case of metal-bearing
wastestreams, virtually all the facilities are
discharging large amounts of heavy metals. As
measured by total suspended solids (TSS) levels
following treatment, TSS concentrations are
substantially higher than levels observed at
facilities in other industry categories employing
the very same treatment technology.
In the case of oil discharges, many facilities
are achieving low removal of oil and grease
relative to the performance required for other
point source categories. Many collect samples
infrequently to analyze for metal and organic
constituents in their discharge since these
parameters are not included in their discharge
permits. Further, facilities treating organic
wastes, while successfully removing organic
pollutants through biological treatment, fail to
remove metals associated with these organic
wastes.
The poor pollutant removal performance
observed for some direct discharging CWT
facilities is not unexpected. As pointed out
previously, some of these facilities are treating
highly concentrated wastes that, in many cases,
are process residuals and sludges from other
point source categories. EPA's review of permit
limitations for the direct dischargers show that, in
most cases, the dischargers are subject to "best
professional judgment" limitations which were
based primarily on guidelines for facilities
treating and discharging much more dilute
wastestreams. EPA has concluded that treatment
performance in the industry is often inadequate
and that the mass of pollutfants being discharged
is high, given the demonstrated removal
capability of treatment option that the Agency has
reviewed.
EPA's options to evaluate treatment systems
in place at direct discharging CWTs were
extremely limited since most of the facilities in
this industry are indirect dischargers. This is
particularly true of the melals and oils facilities.
Many indirect discharging CWTs are not required
to control discharges of conventional pollutants
because the receiving POTWs are designed to
achieve removal of conventional pollutants and
therefore, generally do nol: monitor or optimize
the performance of their treatment systems for
control of conventional pollutants. Because BPT
applies to direct dischargers, the data used to
establish limitations and standards are normally
collected from such facilities. For this rule, EPA
relied on information and data from widely
available treatment technologies in use at CWT
facilities discharging indirectly — so called
"technology transfer." EPA concluded that
certain technologies in place at indirect
discharging CWT facilities are appropriate for
use as the basis for regulation of direct
dischargers.
Rationale for Metals Subcategory
BPT Limitations
9.1.1
In developing BPT limitations for the metals
subcategory, EPA considered three regulatory
options (two previously assessed for the 1995
proposal as well as one new treatment option).
All rely on chemical precipitation to reduce the
discharge of pollutants from CWT facilities.
The three currently available treatment systems
for which EPA assessed performance for the
metals subcategory BPT are discussed below.
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CHAPTER 9 Reg. Options Considered and Selected
Development Document for the CWT Point Source Category
METALS SUBCATEGORY OPTION 2' - SELECTIVE
METALS PRECIPITATION. LIQUID-SOLID
SEPARATION. SECONDARY PRECIPITATION. AND
LIQUID-SOLID SEPARATION
The first treatment option (Option 2) that
EPA evaluated is based on "selective metals
precipitation." "Selective metals precipitation" is
a specialized metals removal technology that
tailors precipitation conditions to the metal to be
removed. The extent to which a metal is
precipitated from a solution will vary with a
number of factors including pH, temperature, and
treatment chemicals. Selective metals
precipitation adjusts these conditions sequentially
in order to provide maximum precipitation of
metals. Selective metals precipitation requires
segregation of incoming wastestreams and careful
characterization of the metals content of the
waste stream. Next, there are multiple
precipitations in batches at different pH levels in
order to achieve maximum removal of specific
metals. Selective metals precipitation results in
the formation of a metal-rich filter cake. This
treatment option requires numerous treatment
tanks and personnel to handle incoming
wastestreams, greater quantities of treatment
chemicals, and increased monitoring of the batch
treatment processes. One of the benefits of this
technology, however, is that it results in a metal-
rich filter cake that facilities employing this
treatment have the option of selling as feed
material for metal reclamation. For metal streams
which contain concentrated cyanide complexes,
achievement of the BPT limitations under this
option would require alkaline chlorination at
specific operating conditions prior to metals
lrThe numbering of options reflects the numbering
for the 1995 proposal. Options 2 and 3 were first
considered for that proposal. Option 4 is a new
technology EPA evaluated for this proposal. EPA is
no longer evaluating Option 1 as the treatment basis
for the proposed limitations and standards.
treatment. These BPT cyanide limitations are
discussed in greater detail below.
METALS SUBCATEGORY OPTION 3' - SELECTIVE
METALS PRECIPITATION. LIQUID-SOLID
SEPARATION. SECONDARY PRECIPITATION,
LIQUID-SOLID SEPARATION. TERTIARY
PRECIPITATION. AND CLARIFICATION
The second treatment option EPA evaluated
(Option 3) is the same as Option 2 with an
additional third precipitation step added for
increased pollutant removals. Again, for metals
streams which contain concentrated cyanide
complexes, like Option 2, BPT limitations for
Option 3 are also based on alkaline chlorination
at specific operating conditions prior to metals
precipitation.
METALS SUBCATEGORY OPTION 41 - BATCH
PRECIPITATION. LIQUID-SOLID SEPARATION.
SECONDARY PRECIPITATION. AND SAND
FILTRATION
The new technology EPA evaluated as the
basis of BPT for this regulation(Option 4) is a
two stage precipitation process. The first stage of
this technology is similar to the Option 1
chemical precipitation technology considered
(and rejected) for the earlier proposal and is
based on chemical precipitation, followed by
some form of solids separation and sludge
dewatering. In Option 4, however, a second
precipitation step is also performed followed by
sand filtration. Since most CWT metal facilities
utilize single-stage chemical precipitation only,
generally BPT limitations based on Option 4
would require facilities to use increased quantities
of treatment chemicals, perform additional
monitoring of batch processes, perform an
additional precipitation step, and add a sand
filtration step. Once again, for metals which
contain concentrated cyanide complexes, like
Options 2 and 3, alkaline chlorination at specific
operating conditions is also part of the Option 4
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CHAPTER 9 Reg. Options Considered and Selected Development Document for the CWT Point Source Category
treatment process that forms the basis for BPT
limitations.
The Agency is proposing to adopt BPT
limitations based on Option 4 for the metals
subcategory. EPA's decision to base BPT
limitations on Option 4 treatment reflects
primarily an evaluation of two factors: the degree
of effluent reductions attainable through this
technology and the total cost of the proposed
treatment in relation to the effluent reductions
benefits (These are detailed in Chapter 11 and
12). Option 4 technology is readily applicable to
all facilities that are treating metal-bearing
wastestreams. It is currently used at 25 percent
of the facilities in this subcategory. The adoption •
of this level of control would represent a
significant reduction in pollutants discharged into
the environment by facilities in this subcategory.
Option 4 would remove approximately 13.8
million pounds annually of conventional
pollutants now discharged to the Nation's waters.
The Agency also assessed the total cost of water
pollution controls likely to be incurred for
Option 4 in relation to the effluent reduction
benefits and determined these costs were
economically reasonable, less than $0.19 per
pound.
The Agency has decided not to propose BPT
limitations based on Option 3, selective metals
precipitation, for a number of reasons. First,
while both Option 3 and Option 4 provide
significant pollutant removals, are economically
achievable, and expected to result in non-water
quality benefits through increased recycling of
metals, Option 3 is nearly four times as costly as
Option 4. Furthermore, there is little, if any,
expected increase in total removals associated
with the Option 3 technology. (Total removals
associated with Option 3 are virtually identical to
those achieved by Option 4 ~ less than 1.25
percent greater.) Second, EPA has some concern
about whether selective metals precipitation could
be applied throughout the industry because
currently, only one facility is employing this
technology. Moreover, as noted above, the
effectiveness of selective: metals precipitation
depends, in part, on the separation and holding of
wastestreams in numerous treatment tanks. EPA
is aware that there may be physical constraints on
the ability of certain facilities to install the
additional, required treatment tanks. These and
other factors support EPA's determination not to
propose limitations based on the Option 3
technology.
The Agency used chemical precipitation
treatment technology performance data from the
Metal Finishing regulation (40 CFR Part 433) to
establish direct discharge limitations for TSS
because the facility from which the Option 4
limitations were derived is an indirect discharger
and the treatment system is not designed to
optimize removal of conventional parameters.
EPA has concluded that the transfer of this data
is appropriate given the absence of adequate
treatment technology for this pollutant at the only
otherwise well-operated BPT CWT facility.
Given the treatment of similar wastes with similar
TSS concentrations at both metal finishing and
centralized waste treatment facilities, use of the
data is warranted. Moreover, EPA has every
reason to believe that chemical precipitation
treatment systems will perform similarly when
treating TSS in waste in this subcategory.
Because CWT is based on additional chemical
precipitation and solid-liquid separation steps,
facilities should be able to meet the transferred
limit. Finally, since the metal finishing TSS
limitation was based on chemical precipitation
followed by clarification, EPA has costed all
direct discharging CWT facilities for a
clarification unit prior to the sand filtration unit.
EPA believes it is important to note that BPT
limitations established by Option 4 are based on
data from a single, well-operated system. In
reviewing technologies ciorrently in use in this
subcategory, however, EPA found that facilities
generally utilize a single stage chemical
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CHAPTERS Res. Ontions Considered and Selected
Development Document for the CWTPoint Source Category
precipitation step — not a technology calculated
to achieve significant metals removals for the
wastestreams observed at these operations. EPA
did identify a handful of facilities which utilize
additional metals wastewater treatment, generally
secondary chemical precipitation. Of these
facilities, EPA believes that only one accepts a
foil spectrum of waste, often with extremely high
metals concentrations and is, therefore, designed
and operated to achieve optimal performance for
a wide range of raw waste concentrations.
Consequently, EPA is proposing to adopt BPT
limitations based on performance data from this
one, well-designed and operated facility.
CYANIDE SUBSET
As discussed above, the presence of high
cyanide concentrations detrimentally affects the
performance of metal precipitation processes due
to the formation of metal-cyanide complexes.
Effective treatment of such wastes typically
involves a cyanide destruction step prior to any
metal precipitation steps. Consequently, in the
case of metal streams which contain concentrated
cyanide complexes, EPA based BPT limitations
on an additional treatment step to destroy cyanide
prior to metals precipitation. EPA considered the
following three regulatory options for the
destruction of cyanide.
CYANIDE SUBSET OPTION 1 - ALKALINE
CHLORINATION
The Option 1 technology, alkaline
chlorination, is widely used for cyanide
destruction in this industry as well as in others.
For this subset, it represents current performance.
CYANIDE SUBSET OPTION 2 - ALKALINE
CHLORINATION AT SPECIFIC OPERATING
CONDITIONS
The technology basis for Option 2 BPT
limitations is also alkaline chlorination. The
differences between the technology basis for
Option 1 and Option 2 cyanide destruction
treatment are specific operating conditions which
have been claimed confidential.
The oxidation of cyanide waste by alkaline
chlorination is a two step process. In the first
step, cyanide is oxidized to cyanate in the
presence of hypochlorite, and sodium hydroxide
is used to maintain a specific pH range. The
second step oxidizes cyanate to carbon dioxide
and nitrogen at a controlled pH. The application
of heat can facilitate the more complete
destruction of total cyanide.
CYANIDE SUBSET OPTION 3 - CONFIDENTIAL
CYANIDE DESTRUCTION
EPA evaluated a third technology which is
extremely effective in reducing cyanide.
Application of this technology resulted in cyanide
reductions of 99.8 percent for both amenable and
total cyanide. The Option 3 technology is also
claimed confidential.
For the 1995 proposal, the Agency proposed
limitations based on Cyanide Option 2 for the
cyanide subset of the metals subcategory. For
this proposal, this technology remains the basis
for the BPT limitations for metals streams with
concentrated cyanide complexes. Although
Option 3 provides greater removals than Option
2, the Agency has decided to reject Option 3 as a
basis for BPT limitations because the technology
is not publicly available. The cyanide destruction
system used at the one facility employing Option
3 is a proprietary process that does not employ
off-the-shelf technology. There are, in addition,
several reasons supporting the selection of
limitations based on Option 2. First, the facility
achieving Option 2 removals accepts a full
spectrum of cyanide waste. Consequently, the
treatment used by the Option 2 facility can be
readily applied to all facilities in the subset of this
subcategory. Second, adoption of this level of
control would represent a significant reduction in
pollutants discharged into the environment by
facilities in this subset. Finally, the Agency
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CHAPTER 9 Reg. Options Considered and Selected Development Document for the CWT Point Source Category
assessed the total cost for Option 2 in relation to
the effluent reduction benefits and determined
these costs were economically reasonable.
Rationale for Oils Subcategory
BPT Limitations
9.1.2
EPA has considered twelve technology
options in establishing BPT effluent reduction
levels for the oils subcategory during
development of this rule. The first four options
were evaluated at the time of the 1995 proposal
(60 FR 5478); the other eight options following
the 1995 proposal. The twelve technology
options considered are:
Option 1: emulsion breaking/gravity
separation
Option 2: emulsion breaking/gravity
separation and ultrafiltration
Option 3: emulsion breaking/gravity
separation, ultrafiltration, carbon
adsorption, and reverse osmosis
Option 4: emulsion breaking/gravity
separation, ultrafiltration, carbon
adsorption, reverse osmosis, and
carbon adsorption
Option 5: emulsion breaking/gravity
separation, ultrafiltration, and
chemical precipitation
Option 6: emulsion breaking/gravity
separation, dissolved air flotation,
and gravity separation
Option 7: emulsion breaking/gravity
separation, secondary gravity
separation, dissolved air flotation,
and biological treatment
Option 8: emulsion breaking/gravity
separation and dissolved air
flotation
Option 8v: emulsion breaking/gravity
separation, air stripping, and
dissolved air flotation
Option 9: emulsion breaking/gravity
separation, secondary gravity
separation, and dissolved air
flotation
Option 9v: emulsion breaking/gravity
separation, air stripping, secondary
gravity separation, and dissolved
air flotation
Option 10: emulsion breaking/gravity
separation and secondary gravity
separation
As detailed in the 1995 proposal, while
emulsion breaking/gravity separation (Option 1)
is widely used in this subcategory, EPA dropped
it from further consideration at the time of the
original proposal since emulsion breaking/gravity
separation did not adequately control the
pollutants of concern and, therefore, did not
represent a BPT technology. The Agency also
dropped the Option 4 technology (emulsion
breaking/gravity separation, ultrafiltration,
carbon adsorption, reverse osmosis, and carbon
adsorption) from consideration at the time of the
original proposal because EPA's analysis showed
that some pollutant concentrations actually
increased following the additional carbon
adsorption.
At the time of the 1995 proposal, the Agency
co-proposed BPT limitations based on emulsion
breaking/gravity separation and ultrafiltration as
well as emulsion breaking/gravity separation and
ultrafiltration with added carbon adsorption and
reverse osmosis to remove metal compounds
found at significant levels in this subcategory.
Because the costs associated with the latter
option were four times higher than ultrafiltration
alone, EPA was concerned about its impacts on
facilities in this subcategory. After the 1995
proposal, EPA collected additional information
on facilities in the oils subcategory and revisited
its conclusion about the size and nature of the oils
subcategory. EPA published a Notice of Data
Availability in 1996 describing the new
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CHAPTER 9 Res Ootions Considered and Selected
Development Document for the CWT Point Source Category
information and EPA's revised assessment of the
oils subcategory. Based on analyses presented in
the 1996 Notice, EPA determined it should no
longer consider emulsion breaking/gravity
separation and ultrafiltration with added
treatment steps (Option 3) as the basis for BPT
limitations because the projected total costs
relative to effluent reductions benefit were not
economically reasonable.
Based on comments to the 1995 proposal and
the 1996 Notice of Data Availability, EPA was
strongly encouraged to look at alternate
technology options to emulsion breaking/gravity
filtration and ultrafiltration. This concern was
driven in large measure by the fact that many of
the facilities in the oils subcategory are classified
as "small businesses" and the economic cost of
installing and operating ultrafiltration technology
was quite high. Additionally, many commenters
stated that ultrafiltration is a sophisticated
technology which would be difficult to operate
and maintain with the majority of these
wastestreams. Commenters also noted that the
Agency had failed to consider non-water quality
impacts adequately — particularly those
associated with the disposal of the concentrated
filtrate from these operations. As a result, based
on comments to the original proposal, the 1996
Notice of Data Availability, and additional site
visits, EPA identified several other treatment
options that were efficient, produced tighter oil
and grease limits, and were less expensive. As
such, EPA is no longer considering emulsion
breaking/gravity separation and ultrafiltration
(Option 2) as an appropriate technology for
limitations for the oils subcategory.
Following the 1995 proposal and the 1996
Notice of Data Availability, EPA preliminarily
considered Options 5 - 9v in establishing BPT
effluent reduction levels for this subcategory.
However, EPA dropped Options 5, 6, and 7 early
in the process. EPA dropped Option 5 since it
relied on ultrafiltration which, as described
previously, the Agency determined was
inappropriate for this subcategory. The Agency
dropped Option 6 since EPA is unaware of any
CWT facilities that currently use the Option 6
treatment technologies in the sequence
considered. Finally, EPA dropped Option 7
because EPA's sampling data showed little
additional pollutant reduction associated with the
addition of the biological treatment system.
Following the SBREFA panel, at the request
of panel members, EPA also examined another
option, Option 10, which is based on emulsion
breaking/gravity separation followed by a second
gravity separation step. The Agency has now
concluded that it should not propose BPT
limitations based on this technology.
EPA recognizes that a majority of the
industry currently employs primary emulsion
breaking/gravity separation (typically as a
pretreatment step prior to dissolved air flotation,
biological treatment, or chemical precipitation).
However, the data EPA has examined supports
the Agency's concerns that the performance of
emulsion breaking and/or gravity separation unit
operations are inadequate because they do not
achieve acceptable pollutant removals. For
example, one of the facilities in the oils
subcategory that EPA sampled discharged a
biphasic sample (oil and water) from the
emulsion breaking/gravity separation unit during
an EPA sampling visit. When EPA analyzed the
sample, the biphasic liquid stream had a relatively
small organic phase percentage, yet contained
extremely high overall concentrations of toxic
pollutants, especially priority, semi-volatile
organics (such as polynuclear aromatic
hydrocarbons, phthalates, aromatic hydrocarbons,
n-paraffins, and phenols). Hence, the Agency
believes that gravity separation systems without
further treatment provide inadequate removals
and, thus, do not represent BPT treatment for this
subcategory.
Therefore, the four new technology options
considered for the oils subcategory BPT
limitations are:
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CHAPTER 9 Reg. Options Considered and Selected Development Document for theCWT Point Source Category
Option 82: emulsion breaking/gravity
separation and dissolved air
flotation
Option Sv2: emulsion breaking/gravity
separation, air stripping, and
dissolved air flotation'
Option 92: emulsion breaking/gravity
separation, secondary gravity
separation, and dissolved air
flotation
Option 9v2: emulsion breaking/gravity
separation, air stripping, secondary
gravity separation, and dissolved
air flotation
Each of these are discussed below.
OILS SUBCATEGORY OPTION 82 - DISSOLVED AlR
FLOTATION
The technology basis for Option 8 is
dissolved air flotation (DAF). DAF separates
solid or liquid particles from a liquid phase by
introducing air bubbles into the liquid phase. The
bubbles attach to the particles and rise to the top
of the mixture. Often chemicals are added to
increase the removal of metal constituents.
Generally, BPT limitations based on Option 8
would require facilities with currently installed
DAF systems to perform better monitoring and.
operation of their system or to install and operate
a DAF system. For oils streams with significant
concentrations of metals, Option 8 would also
require increased quantities of treatment
chemicals to enhance metals removals.
As noted above, EPA is no longer considering
Oils Options 1- 4 proposed in 1995. During
development of today's proposal, EPA also
preliminarily considered seven other options
numbered 5 - 9v. EPA has chosen to focus its
attention on Options 8 through 9v.
OILS SUBCATEGORY OPTION 8 V2 -AlR STRIPPING
WITH EMISSIONS CONTROL AND DISSOLVED AIR
FLOTATION
The technology basis for Option 8v is the
same as Option 8 except air stripping with
emissions control is added to control the release
of volatile pollutants into the air. The wastewater
effluent limitations and standards are the same
for Options 8 and 8v.
OILS SUBCATEGORY OPTION 92 - SECONDARY
GRAVITY SEPARATION AND DISSOLVED AIR
FLOTATION
The technology basis for limitations based on
Option 9 is secondary gravity separation and
DAF. Secondary gravity separation involves
using a series of tanks to separate the oil and
water and then skimming the oily component off.
The resulting water moves: to the next step. The
gravity separation steps ure then followed by
DAF. As mentioned previously, EPA believes all
oils facilities currently utilize some form of
gravity separation, although most perform
primary gravity separation only. Generally, BPT
limitations based on Option 9 would require
facilities to perform additional gravity separation
steps, perform better monitoring and operation of
their DAF system, or install and operate a DAF
system. For oils streams with relatively high
concentrations of metals, Option 9 would also
require the use of increased quantities of
treatment chemicals to enhance the removal of
metals.
OILS SUBCATEGORY OPTION 9 v2 - AIR STRIPPING
WITH EMISSIONS CONTROL. SECONDARY
GRAVITY SEPARATION. AND DISSOLVED AIR
FLOTATION.
The technology basis for Option 9v is the
same as for Option 9 with the addition of air
stripping with emissions control to control the
release of volatile pollutants into the air. The
wastewater effluent limitations and guidelines are
the same for Options 9 and 9v.
9-8
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CHAPTER 9 Ree. Options Considered and Selected
Development Document for the CWT Point Source Category
The Agency is proposing BPT limitations for
the oils subcategory based on Option 9 (emulsion
breaking/gravity separation, secondary gravity
separation, and dissolved air flotation) for two
reasons. First, the adoption of this level of
control would represent a significant reduction in
pollutants discharged into the environment by
facilities in this subcategory. Second, the Agency
assessed the total costs of water pollution
controls likely to be incurred for this option in
relation to the effluent reduction benefits and
determined these costs were economically
reasonable.
EPA proposes to reject emulsion breaking/
gravity separation and DAF alone as the basis for
BPT limitations because the estimated costs of
complying with both options are equivalent and
the estimated removals associated with the added
gravity separation step are greater. Additionally,
BPT pollutant removals based on Option 8, for a
number of parameters (particularly oil and
grease), are much less stringent than current BPT
effluent limitations guidelines promulgated for
other industries. EPA believes that the vast
majority of DAF systems in use in this
subcategory are not performing optimally. As
mentioned earlier, all of the DAF systems studied
by EPA were used at facilities that discharge to
POTWs. As such, optimal control of oil and
grease is not required. Many do not even monitor
the oil and grease levels in the material entering
and, in some cases, leaving the DAF.
EPA has studied the performance of DAF
systems in other largely indirect discharging
industries and has found the same lack of optimal
performance. EPA believes that all facilities,
including indirect dischargers, should monitor the
levels of oil and grease entering and leaving the
DAF system. Even though oil and grease levels
are not of great concern for indirect dischargers,
removal of many organic compounds is directly
related to removal of oil and grease. As such, the
overall efficacy of the DAF system in removing
the vast majority of specific toxic parameters can
be improved by improving removals of oil and
grease.
The facilities that were sampled were not
required to optimize their oil and grease removals
because they discharge to POTWs that treat these
pollutants. Current POTW/local permit
limitations for oil and grease in this subcategory
range from 100 mg/L to 2,000 mg/L. Many have
no oil and grease limits at all. One of the systems
sampled was designed to remove oil and grease to
concentrations below 100 ug/L. Consequently,
EPA based the proposed oil and grease limitation
on data from this single facility.
EPA has also reviewed data from the
Industrial Laundries and the TECI rulemaking for
dissolved air flotation systems. For similar
influent oil and grease concentrations, these
systems removed oil and grease to levels well
below those achieved at the DAF systems
sampled for development of this regulation.
Table 9-1 shows average influent and effluent
concentrations of oil and grease and TPH at
sampled industrial laundry facilities with
chemical emulsion breaking or dissolved air
flotation. Given the similarities in the treated
waste, EPA is considering whether use of this
data is appropriate in determining CWT
limitations.
9-9
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CHAPTER 9 Reg. Options Considered and Selected Development Document for the CWTPoint Source Category
Table 9-1. Average Influent and Effluent Oil and Grease and Total Petroleum Hydrocarbon (TPH)
Concentrations at Sampled Industrial Laundry Facilities
Episode
Number
Treatment
Technology
5-Day Average Influent and Effluent
Concentrations When Sampled (mg/L)
Oil and
(measured
Influent
A
B
C
D
Dissolved Air Flotation
Dissolved Air Flotation
Chemical Emulsion
Breaking
Dissolved Air Flotation
777.2
1
1
1,
,530
,030
110*
Grease
as HEM)
Effluent
23.8
50.7
952
216*
(measured
Influent
308.6
681
159
245*
TPH
as SGT-HEM)
Effluent
10.4
15.7
164
41.4*
The pollutant loadings presented for this facility are based on 4-day average concentrations because a process
upset made the data for one day unusable
EPA projects additional pollutant removals
associated with the technology that is the basis
for the proposed limitations, has costed facilities
for the additional technology (a series of gravity
separation steps) associated with this option, and
has determined that it is economically achievable.
However, EPA believes that many CWT facilities
may be able to achieve these limitations using
emulsion breaking/gravity separation and DAF
only. As described above, EPA believes that
many DAF systems in this industry are not
performing optimally. Careful observations of
the influent and effluent of these systems would
allow facilities to better understand and control
the resulting effluent.
The Agency is not proposing BPT
limitations based on air stripping with overhead
recovery or destruction. While limitations based
on air stripping with overhead recovery or
destruction would seem to provide some
additional protection from volatile and semi-
volatile pollutants to all environmental media, no
substantial additional removal of volatile and
semi-volatile parameters from the water would be
achieved through these options. While gravity
separation systems and dissolved air flotation
systems are often effective in removing volatile
and semi-volatile pollutants from water, a large
portion of these volatile and semi-volatile organic
pollutants are emitted into the surrounding air.
Thus, while removing the pollutants from the
wastewater, these systems do not remove these
pollutants from the environment, but rather
transfer a large portion of them to another
environmental medium. The use of air stripping
coupled with emissions capture reduces or
eliminates the air emissions that otherwise would
occur by the air stripping of the volatile organic
pollutants in gravity separation and dissolved air
flotation systems. However, compliance with any
proposed limitation would not require installation
of such equipment.
EPA highly recommends that plants
incorporate air stripping with overhead recovery
or destruction into their wastewater treatment
systems for more complete environmental
protection. EPA also notes that CWT facilities
determined to be major sources of hazardous air
pollutants are currently subject to maximum
achievable control technology (MACT) as
promulgated for off-site waste and recovery
operations on July 1, 1996 (61 FR 34140).
9-10
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CHAPTER 9 Reg. Options Considered and Selected
Development Document for the CWT Point Source Category
Rationale for Organics Subcategory
BPT Limitations
9.1.3
In developing BPT limitations for the
organics subcategory, EPA re-examined the
treatment options considered for the 1995
proposal as well as assessed two new treatment
options. As a result of this re-examination, EPA
is no longer considering as a basis for BPT
limitations the two options considered earlier (60
FR 5479). The first treatment system EPA
examined as a basis for BPT limitations included
the following treatment steps: equalization, two
air strippers in series equipped with a carbon
adsbrption unit for control of air emissions,
biological treatment in the form of a sequential
batch reactor, and, finally, a multimedia filtration
unit. The second option was the same as the first,
but included a final carbon adsorption step.
For the previous proposal, the Agency
selected BPT limitations based on the first
treatment system, even though, theoretically, the
second system under consideration should have
provided greater removal of pollutants. EPA
selected the first system as the technology basis
since EPA's sampling data showed that,
following the carbon adsorption treatment step,
specific pollutants of concern actually increased.
Therefore, for today's proposal, EPA is no longer
considering the second system which includes the
final carbon adsorption unit as the basis for BPT
limitations. Additionally, EPA has concluded
that it should no longer consider the first system
(equalization, i air stripping, biological treatment,
and multimedia filtration) as the basis for BPT
limitations. The multimedia filtration step is
primarily included in the treatment train to protect
the carbon adsorption unit installed downstream
from high TSS levels. Since EPA rejected the
option which includes the carbon adsorption unit,
EPA similarly rejects the option which includes
the multimedia filtration step.
The two technology options considered for
the organics subcategory BPT are:
Option 3: equalization, air-stripping with
emissions control, and biological
treatment; and
Option 4: equalization and biological
treatment
Each of these are discussed below.
ORGANICS SUBCATEGORY OPTION 3 -
EQUALIZATION. AIR STRIPPING WITH EMISSIONS
CONTROL. AND BIOLOGICAL TREATMENT
Option 3 BPT effluent limitations are based
on the following treatment system: equalization,
two air-strippers in series equipped with a carbon
adsorption unit for control of air emissions, and
biological treatment in the form of a sequential
batch reactor (which is operated on a batch
basis).
Waste treatment facilities often need to
equalize wastes by holding wastestreams in a
tank for a certain period of time prior to treatment
in order to obtain a stable waste stream which is
easier to treat. CWT facilities frequently use
holding tanks to consolidate small waste volumes
and to minimize the variability of incoming
wastes prior to certain treatment operations. The
receiving or initial treatment tanks of a facility
often serve as equalization tanks.
Air stripping is effective in removing
dissolved volatile organic compounds from
wastewater. The removal is accomplished by
passing high volumes of air through the agitated
wastewater stream. The process results in a
contaminated off-gas stream which, depending
upon air emissions standards, usually requires air
pollution control equipment.
A sequencing batch reactor (SBR) is a
suspended growth system in which wastewater is
mixed with existing biological floe in an aeration
basin. SBRs are unique in that a single tank acts
as an equalization tank, an aeration tank, and a
clarifier. An SBR is operated on a batch basis
where the wastewater is mixed and aerated with
the biological floe for a specific period of time.
9-11
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CHAPTER 9 Ree. Options Considered and Selected Development Document for the CWT Point Source Category
The contents of the basin are allowed to settle and
the supernatant is decanted. The batch operation
of an SBR makes it a useful biological treatment
option for the CWT industry, where the
wastewater volumes and characteristics are often
highly variable. Each batch can be treated
differently depending'on waste characteristics.
An SBR carries out all of the functions of a
conventional continuous flow activated sludge
process, such as equalization, biological
treatment, and sedimentation, in a time sequence
rather than a space sequence. Detention times
and loadings vary with each batch and are highly
dependent on the specific raw wastewater
loadings. By using a single tank to perform all of
the required functions associated with biological
treatment, an SBR reduces land requirements. It
also provides for greater operation flexibility for
treating wastes with variable characteristics by
allowing the capability to vary detention time and
mode of aeration in each stage. SBRs also may
be used to achieve complete nitrification/
denitrification and phosphorus removal.
ORGANICS SUBCATEGORY OPTION 4 -
EQUALIZATION AND BIOLOGICAL TREATMENT
Option 4 BPT effluent limitations are based
on the same treatment system as Option 3
without the use of air strippers.
The Agency is proposing to adopt BPT
effluent limitations for the organics subcategory
based on the Option 4 technology. The Agency's
decision to select Option 4 is based primarily on
the pollutant reductions, the cost and impacts to
the industry, and non-water quality impacts.
Unlike the other BPT proposed limitations, the
adoption of limitations based on Option 4 would
not represent a significant reduction in pollutants
discharged into the environment by facilities in
this subcategory. EPA believes that all direct
discharging facilities in this subcategory currently
employ equalization and biological treatment
systems. EPA has assumed that all facilities
which currently utilize equalization and biological
treatment will be able to meet the BPT limitations
without additional capital or operating costs.
However, many of these facilities are not
currently required to monitor for organic
parameters or are only required to monitor one or
two times a year. The costs associated with
complying with BPT limitations for this
subcategory are, therefore, associated with
additional monitoring only. The Agency believes
the additional monitoring is warranted and will
promote more effective treatment at these
facilities.
The Agency proposes to reject Option 3.
BPT effluent limitations based on Option 3
treatment would be essentially the same as those
established by Option 4. The main difference
between Options 4 and 3 is that Option 3, which
includes air stripping with emissions control,
would be effective in reducing the levels of
volatile and semi-volatile organic pollutants in all
environmental media-not just the water. While
biological systems are often effective in removing
volatile and semi-volatile pollutants from water,
a large portion of these volatile and semi-volatile
organic pollutants are emitted by biological
systems into the surrounding air. Thus, while
' removing them from the wastewater, the typical
biological system does not remove these
pollutants from the environment but rather
transfers a large portion of them to another
environmental medium. The use of air stripping
with emissions control reduces or eliminates the
air emissions that otherwise would occur by the
volatilization of the volatile organic pollutants in
the biological system.
While EPA is concerned about volatile
pollutants, particularly for this subcategory, it
believes that the use of the CAA to address air
emissions from CWT wastewater is preferable.
EPA also notes that CWT facilities determined to
be major sources of hazardous air pollutants are
subject to . maximum achievable control
technology (MACT) as promulgated for off-site
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CHAPTER. 9 Ree. Options Considered and Selected
Development Document for the CWT Point Source Category
waste and recovery operations on July 1, 1996
(61 FR 34140) as 40 CFR Part 63.
The Agency used biological treatment
performance,data from the Thermosetting Resin
Subcategory of the OCPSF regulation to establish
direct discharge limitations for BOD5 and TSS,
because the facility from which Option 4
limitations were derived is an indirect discharger
and the treatment system is not operated to
optimize removal of conventional pollutants.
EPA has concluded that the transfer of these data
is appropriate given the absence of adequate
treatment technology for these pollutants at the
only otherwise well-operated BPT CWT facility.
Given the treatment of similar wastes at both
OCPSF and CWT facilities, use of the data is
warranted. Moreover, EPA has every reason to
believe that the same treatment systems will
perform similarly when treating the wastes in this
subcategory.
Once again, the selected BPT option is based
on the performance of a single facility. Many
facilities that are treating wastes that will be
subject to the organics subcategory effluent
limitations also operate other industrial processes
that generate much larger amounts of wastewater
than the quantity of off-site-generated organic
waste receipts. The off-site-generated CWT
organic waste receipts are directly mixed with the
wastewater from the other industrial processes for
treatment. Therefore, identifying facilities to
sample for limitations development was difficult
because the waste receipts and treatment unit
effectiveness could not be properly characterized
for off-site-generated waste. The treatment
system on which Option 4 is based was one of the
few facilities identified which treated organic
waste receipts separately from other on-site
industrial wastewater.
BEST CONVENTIONAL
TECHNOLOGY (BCT)
9.2
EPA is proposing BCT equal to BPT for the
conventional pollutants regulated under BPT for
all subcategories of the CWT industry. In
deciding whether to propose BCT limits, EPA
considered whether there are technologies that
achieve greater removals of conventional
pollutants than proposed for BPT, and whether
those technologies are cost-reasonable under the
standards established by the C WA. This is called
the "BCT Cost Test." For all three subcategories,
EPA identified no technologies that can achieve
greater removals of conventional pollutants than
those that are the basis for BPT that are also cost-
reasonable under the BCT Cost Test.
Accordingly, EPA is proposing BCT effluent
limitations equal to the proposed BPT effluent
limitations guidelines and standards.
BEST AVAILABLE TECHNOLOGY (BAT) 9.3
EPA is proposing BAT effluent limitations
for all subcategories of the CWT industry based
on the same technologies selected as the basis for
BPT for each subcategory. Therefore, the
proposed BAT limitations are the same as the
proposed BPT limitations. The proposed BAT
effluent limitations would control identified toxic
and non-conventional pollutants discharged from
facilities. As described in the BPT discussion, in
general, the adoption of this level of control
would represent a significant reduction in
pollutants discharged into the environment by
facilities in this subcategory. Additionally, EPA
has evaluated the economic impacts associated
with adoption of these limitations and found them
to be economically achievable.
With the exception of the metals subcategory,
EPA has not identified any more stringent
treatment technology option different from those
evaluated for BPT that might represent best
available technology economically achievable for
9-13
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CHAPTER 9 Ree. Options Considered and Selected
Development Document for theCWT Point Source Category
this industry. For the metals subcategory, EPA
did consider as BAT technology two treatment
technologies that it had evaluated for the 1995
proposal, Options 2 and 3, based on the use of
selective metals precipitation. However, the costs
to the industry for Option 2 and Option 3 are
more than four times greater than the cost of the
BPT option, Option 4, with no additional toxics
removal3. Given the comparable toxic removals,
EPA has concluded it should not adopt a more
costly option.
For the oils and organics subcategories, EPA
has evaluated treatment technologies for BAT
limitations which theoretically should provide
greater removal of pollutants of concern. For
example, EPA identified an add-on treatment
technology to technologies 'considered for
BPT-carbon adsorption-that should have further
increased removals of pollutants of concern.
However, EPA's data show increases rather than
decreases in concentrations of specific pollutants
of concern. Consequently, EPA is not proposing
BAT limitations based on this technology.
NEW SOURCE PERFORMANCE
STANDARDS (NSPS)
9.4
As previously noted, under Section 306 of
the Act, new industrial direct dischargers must
comply with standards which reflect the greatest
degree of effluent reduction achievable through
application of the best available demonstrated
control technologies. Congress envisioned that
new treatment systems could meet tighter controls
than existing sources because of the opportunity
to incorporate the most efficient processes and
treatment systems into plant design. Therefore,
EPA's data show that Option 4 would remove a
greater level of toxic pound-equivalents than Option 3.
Whether or not this is related to the small size of
EPA's sampling data set, EPA believes either option
would achieve comparable pound-equivalent
removals.
Congress directed EPA to consider the best
demonstrated process changes, in-plant controls,
operating methods and end-of-pipe treatment
technologies that reduce pollution to the
maximum extent feasible.
For the oils and the organics subcategories,
EPA is proposing NSPS that would control the
same conventional toxic and non-conventional
pollutants proposed for control by the BPT
effluent limitations. The technologies used to
control pollutants at existing facilities are fully
applicable to new facilities. Furthermore, EPA
has not identified any technologies or
combinations of technologies that are
demonstrated for new sources that are different
from those used to establish BPT/BCT/BAT for
existing sources. Therefore, EPA is establishing
NSPS oils and organic subcategories similar to
the oils and organics subcategories for existing
facilities and proposing NSPS limitations that are
identical to those proposed for BPT/BCT/BAT.
For the metals subcategory, however, EPA is
proposing NSPS effluent limitations based on the
technology proposed in 1995: selective metals
precipitation, liquid-solid separation, secondary
precipitation, liquid-solid separation, tertiary
precipitation, and clarification. This technology
provides the most stringent controls attainable
through the application of the best available
control technology.
In establishing NSPS, EPA is directed to take
into consideration the cost of achieving the
effluent reduction and any non-water quality
environmental impacts and energy requirements.
Option 3 provides the opportunity for the new
source to recover selected metals from the
wastestreams they accept, whereas Option 4 does
not provide this flexibility. (With Option 3, the
metals would be recovered and could be re-used,
but with Option 4 the metals would be collected
as a sludge and deposited in a landfill). EPA
believes that this technology is fully applicable to
all metal wastestreams in the CWT industry,
including those with high concentrations of total
9-14
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CHAPTER 9 Reg. Options Considered and Selected
Development Document for the CWT Point Source Category
dissolved solids (TDS). Commenters to the
original proposal had questioned whether the
level of TDS in wastewater would increase the
solubility of the metals and negatively affect the
ability of the Option 3 treatment technology to
perform optimally. As detailed in Chapter 2,
EPA has concluded that the evidence does not
support a direct relationship between TDS and
the solubility of metals in water. Finally, EPA
has concluded that there is no barrier to entry for
new sources to install, operate, and maintain
treatment systems that will achieve discharge
levels associated with these Option 3
technologies.
PRETREATMENT STANDARDS FOR
EXISTING SOURCES (PSES)
9.5
Indirect dischargers in the CWT industry, like
the direct dischargers, accept wastes for treatment
that contain many toxic and non-conventional
pollutants. Like direct dischargers, indirect
dischargers may be expected to discharge many
of these pollutants to POTWs at significant mass
and concentration levels. EPA estimates that
CWT indirect dischargers annually discharge
-8.5 million pounds of pollutants.
CWA Section 307(b) requires EPA to
promulgate pretreatment standards to prevent
pass-through of pollutants from POTWs to
waters of the United States or to prevent
pollutants from interfering with the operation of
POTWs. EPA is establishing PSES for this
industry to prevent pass-through of the same
pollutants controlled by BAT from POTWs to
waters of the United States. A detailed
description of the pass-through analysis
methodology and the results are presented in
Chapter 7.
PSES OPTIONS CONSIDERED
For the metals and organics subcategories,
the Agency is proposing to establish pretreatment
standards for existing sources (PSES) based on
the same technologies as proposed for BPT and
BAT. These standards would apply to existing
facilities in the metals or organics subcategories
of the CWT industry that discharge wastewater to
POTWs and would prevent pass-through of
pollutants and help control sludge contamination.
Based onEPA's pass-through analysis, all of the
BAT pollutants controlled by the metals
subcategory and half of the BAT pollutants
controlled by the organics subcategory would
pass-through and are proposed for PSES. As
detailed in Chapter 7, the pollutants in the
organics subcategory that were determined not to
pass-through are: antimony, copper, zinc,
acetophenone, pyridine, and 2,4,6-
trichlorophenol.
In establishing PSES, the Agency generally
sets the technology basis for PSES equivalent to
BAT and then conducts a pass-through analysis.
However, if the extent of the economic impacts is
questionable, the Agency also considers
alternative technology options. In developing
PSES for the oils subcategory, EPA carefully
considered several types of economic impacts: to
the CWT oils facilities, to the CWT oils firms,
and to specific segments of the CWT industry
such as small businesses. Early results from
these analyses supported basing PSES on Option
8 rather than Option 9 (the basis for the BAT
limitations) since the additional technology
associated with Option 9, while removing
additional pollutants, was associated with higher
costs and greater adverse economic impacts.
Therefore, EPA. preliminarily concluded that
Option 9 was not economically achievable for
indirect dischargers.
As explained in Chapter 2, EPA held a
number of discussions with the small business
community engaged in oils treatment operations.
EPA also convened a SBREFA review panel for
this proposal. The panel and the small entity
representatives provided many pertinent
discussions and insights on possible impacts of
this regulation to small businesses. Many
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CHAPTER 9 Ree. Ootions Considered and Selected
Development Document for the CWT Point Source Category
commented that even Option 8 was too
expensive. However, EPA believes that any
waste transferred to a CWT facility should be
treated to at least the same or similar level as that
required for the same wastes if treated on-site at
the manufacturing facility. Therefore, EPA has
concluded that Option 8 is economically
achievable even with the projected level of
impacts.
More recent results of the economic analysis
for this proposal (which include final cost
estimates, etc.) indicate that projected impacts for
Option 9, while greater than Option 8, were not
as high as originally projected in EPA's
preliminary analyses. However, while EPA
estimates that removals for Option 9 for indirect -
dischargers are approximately one percent higher
than removals for Option 8, EPA believes that
many facilities could actually achieve the Option
9 limitations with the Option 8 technology alone
if designed and operated efficiently.
Still, in estimating the economic impacts
associated with Option 9, EPA costed facilities
for the additional treatment technology associated
with the Option 9 technology basis. As such,
EPA estimates additional process closures and
impacts to small businesses associated with the
Option 9 technology basis.
Therefore, the proposed PSES standards for
the oils subcategory are based on the Option 8
technology — emulsion breaking/gravity
separation and DAF. Fifteen of the 20 BAT
pollutants controlled by the oils subcategory
would pass-through and are proposed for
regulation. As detailed in Chapter 7, the five
pollutants in the oils subcategory that were
determined not to pass-through are: arsenic,
cadmium, chromium, lead, and mercury.
PRETREATMENT STANDARDS FOR
NEWSOURCES (PSNS)
9.6
sources (PSNS) at the same time it promulgates
new source performance standards (NSPS). New
indirect discharging facilities, like new direct
discharging facilities, have the opportunity to
incorporate the best available demonstrated
technologies, including process changes, in-
facility controls, and end-of-pipe treatment
technologies.
As discussed in Chapter 7, EPA determined
that a broad range of pollutants discharged by
CWT industry facilities pass-through POTWs.
The same technologies discussed previously for
BAT, NSPS, and PSES are available as the basis
for PSNS.
EPA is proposing that PSNS be set equal to
NSPS for toxic and non-conventional pollutants
for all subcategories. Since the pass-through
analysis remains unchanged, the Agency is
proposing to establish PSNS for the same toxic
and non-conventional pollutants as are being
proposed for PSES. EPA considered the cost of
the proposed PSNS technology for new facilities.
EPA concluded that such costs are not so great as
to present a barrier to entry, as demonstrated by
the fact that currently operating facilities are
using these technologies.
Section 307 of the Act requires EPA to
promulgate pretreatment standards for new
9-16
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Chapter
10
LONG-TERM AVERAGES, VARIABILITY
FACTORS, AND LIMITATIONS AND STANDARDS
This chapter describes the data selected and
statistical methodology used by EPA in
calculating the long-term averages, variability
factors, and limitations. Effluent limitations and
standards1 for each subcategory are based on
long-term average effluent values and variability
factors that account for variation in treatment
performance within a particular treatment
technology over time. This chapter replaces the
discussion of how limitations were determined in
the 1995 statistical support document.2
FACILITY SELECTION
10.1
In determining the long-term averages and
limitations for each pollutant of concern and each
subcategory option, EPA first evaluated
information about individual facilities and the
analytical data from their treatment systems. As
a result of this evaluation, EPA selected only
those facilities that operated the model
.technology to achieve adequate pollutant
removals for use in calculating subcategory long-
term averages and limitations. EPA used data
from the appropriate influent and effluent sample
points to develop the long-term averages,
variability factors, and limitations. Table 10-1
identifies these facilities and sampling points for
the proposed options. The EPA sampling
episodes are identified with an '£' preceding the
!In the remainder of this chapter,
references to 'limitations' includes 'standards.'
Statistical Support Document For
Proposed Effluent Limitations Guidelines And
Standards For The Centralized Waste Treatment
Industry, EPA 821-R-95-005, January 1995.
facility's 4-digit number (for example, E4378).
Data supplied by the facilities ("self-monitoring
data") are not preceded by any alphabetic
character (for example, facility 602).. The table
includes some options that EPA did not use as the
basis for the proposed limitations. These are
included because the data are listed in Appendix
C and/or in items in the record for the proposed
rulemaking.
EPA selected some facilities for more than
one subcategory option if the facility treated its
wastes using more than one of the model
technologies. For example, EPA selected facility
4378 for both options 2 and 3 in the Metals
subcategory because the effluent from sample
point SP07 represents the option 2 model
technology and the effluent from SP09 represents
the option 3 model technology. For the Oils
subcategory, facilities 4814A, 4814B, and 701
had the model technology for option 8. The
model technology for option 9 is a combination of
the option 8 model technology and an additional
pretreatment step of gravity separation and are
based on facilities 4813, 4814A, 4814B, and
701. Even though the technology basis for
Option 9 is based on an additional treatment step,
EPA included the data from the option 8 facilities
to ensure that the limitations were based on
facilities which treat the full breadth of pollutants
and pollutant concentrations found in oils
subcategory wastes. Thus, EPA selected these
facilities to characterize both the model
technology for options 8 and 9.
If the concentration data from a facility was
collected over two or more distinct time periods,
EPA analyzed the data from each time period
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Chanter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
separately. In the documentation, EPA identifies
each time period with a distinct "facility"
identifier. For example, facilities 4378 and 4803
are actually one facility, but the corresponding
data are from two time periods. In effluent
guidelines for other industrial categories, EPA
has made similar assumptions for such data,
because data from different time periods
generally characterize different operating
conditions due to changes such as management,
personnel, and procedures.
Further, if EPA obtained the concentration
data from both an EPA sampling episode and
self-monitoring data provided by the facility,
EPA analyzed the data from each source
separately. Again, this is similar to assumptions
that EPA has made for effluent guidelines for
other industrial categories. The exception to this
general rule was for facility 701 in which EPA
combined data mat EPA and the facility collected
during overlapping time periods. The facility
provided effluent measurements collected on four
consecutive days by the control authority and
monthly effluent measurements collected by the
facility. EPA, however, only collected influent
and effluent measurements on one day. (In
Table 10-1, the data from the facility are
identified as '701.' The EPA sampling data is
identified as 'E5046.' In this document, the data
from the two sources are collectively identified as
'facility 701.') EPA believes that it is
inappropriate to include the effluent
measurements from E5046 in its calculations
because the sample was collected as a grab
sample rather than as a composite sample of the
continuous flow system at that sample point.
However, EPA retained the influent
measurements because influent measurements
were otherwise unavailable and this information
was crucial for determining if the facility accepted
wastes containing the pollutants that were
measured in the effluent. EPA also used this
influent information in evaluating the pollutant
removals for facility 701.
Although EPA collected the data for Episode
4814 during the same time period and from the
same facility, EPA has detennined that data from
facility 4814 should be used to characterize two
separate facilities.- Facility 4814 has two entirely
separate treatment trains which EPA sampled
separately. Because the systems were operated
separately and treated different wastes, EPA has
treated the data as if they were collected from two
different facilities (EPA has identified the
systems as 4814A and 4814B)
SAMPLE POINT SELECTION
Effluent Sample Point
10.2
10.2.1
For each facility, EPA determined the
effluent sample point representing wastewater
discharged by the model technology selected as
the basis for that subcategory option. For
example, the effluent discharged from sample
point SP09 at facility 4378 is the effluent
resulting from the model technology selected for
option 3 of the Metals subcategory.
Influent Sample Point
10.2.2
Influent data were available for all EPA
sampling episodes. However, relevant influent
data were not available for any of the self-
monitoring effluent data except for Facility 701
(as explained in section 10.1). As detailed
previously in Chapter 12, for the metals and
organics subcategories, this influent data
represent pollutant concentrations in "raw",
untreated wastes. For the oils subcategory,
however, influent data represent pollutant
concentrations following emulsion
breaking/gravity separation. Therefore, for each
facility, EPA determined the relevant influent
sample point for the waste entering the model
technology selected as the basis for that
subcategory option.
In some cases, EPA estimated influent
pollutant concentrations by combining pollutant
measurements from two or more influent sample
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Chanter 10 LT As, VFs, and Limitations and Standards
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points into a single flow-weighted value. For
example, in Option 3 of the metals subcategory,
EPA collected influent samples at five points
(SP01, SP03, SP05, SPOT, and SP10) during the
sampling episode at Facility 4803. EPA
calculated a single value from these five sampling
points representing the influent to the model
technology using the methodology described in
Section 10.4.3.3.
Special Cases
10.2.3
As detailed previously in Chapter 2, for
samples collected during EPA sampling episodes,
EPA did not analyze for the full spectrum of
pollutants at each sampling point. The specific
constituents analyzed at each episode and
sampling point varied and depended on the waste
type being treated and the treatment technology
being evaluated. For example, for the metals
subcategory,'EPA did not generally analyze for
organic pollutants in effluent from chemical
precipitation and clarification. Therefore, in
some cases, for specific pollutants, EPA selected
a different sample point to represent influent to
and effluent from the model treatment technology
than the sample point selected for all other
pollutants. For example, for Episode 4803 in
Metals Option 3, EPA selected sample point 15
to represent the effluent from the model
technology. Since EPA did not analyze the
wastewater collected at sample point 15 for oil
and grease, sgt-hem, total cyanide, and organic
constituents, for these pollutants only, EPA
selected sample point 16 to represent the effluent
point for Episode 4803 of Metals Option 3. EPA
believes this is appropriate since the treatment
step between sample point 15 and sample point
16 should not have affected the levels of these
pollutants in the wastewater.
DETERMINATION OF BATCH AND
CONTINUOUS FLOW SYSTEMS
10.3
For each influent and effluent sample point of
interest, EPA determined whether wastewater
flows were 'continuous'or 'batch.' At sample
points associated with continuous flow processes,
EPA collected composite samples for all analytes
except for oil and grease (for which the analytical
methods specify grab samples). At sample points
associated with batch flow processes, EPA
collected grab samples. For self-monitoring data,
EPA assumed the wastewater flow to be either
continuous or batch based on the type of
discharge at the facility (i.e., continuous or batch
discharge).
EPA made different assumptions depending
on the two types of flow processes. For a sample
point associated with a continuous flow process,
EPA aggregated all measurements within a day to
obtain one value for the day. This daily value
was then used in the calculations of long-term
averages, variability factors, and limitations. For
example, if samples were collected at the sample
point on four consecutive days, the long-term
average would be the arithmetic average of four
daily values. (Sections 10.4.2 and 10.5 discuss
data aggregation and calculation of long-term
averages, respectively.) In contrast, for a sample
point associated with a batch flow process, EPA
aggregated all measurements within a batch to
obtain one value for the batch process. This
batch value was then used as if it were a daily
value. For example, if one sample was collected
from each of 20 batches treated on four
consecutive days (i.e., a total of 20 samples
during a four day period), the long-term average
would be the arithmetic average of the 20 batch
values. For simplicity, the remainder of the
chapter refers to both types of aggregated values
(i.e., daily and batch values) as 'daily values.' In
addition, references to 'sampling day' or 'day'
mean either a sampling day at a continuous flow
facility or a batch from a batch flow facility. The
sample points followed by an asterisk in Table
10-1 are associated with batch flow systems.
EPA assumed all other sample points to be
associated with continuous flow systems.
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
Table 10-1 Facilities and Sample Points Used to Develop Long-term Averages and Limitations
Subcategory
Metals
Cyanide Subset
ofMetals
Subcategory
Oils
Option Facility
1A E1987
E4382
613
E4798
2 E4378
3 E4378
602
E4803
4 E4798
700
1 E4393
2 E4055
1C E4381
E4382
E4440
E4620
E4813
E4814A
E4814B
8/8v E4814A
E4814B
701 and
E5046 f
Pollutants
All
All
analytes that pass tests in
E4382
All
Total cyanide
Organics
All others
Total cyanide
Organics
All others
Analytes passing the tests
inE4378ORE4803
Oil and Grease,
SGT-HEM, total cyanide,
and organics
All others
All
Analytes passing the tests
inE4798
Total cyanide
Total cyanide
All •
All
All
All
Total cyanide
All others
All
All
All
All
AU
Effluent Sample
Point
SP03
SP12;
SP16*
SP03
SP07
SP07
SP07
SP09
SP09
SP09
SP01
SP16
SP15
SP05
SP01
SP07
SP03*
SP01*
SP11
SP06
SP02
SP06
SP05
SP07
SP08
SP09
SP10
SP01 from 701
Influent Sample Point
SP01, SP02
dav3 flows:
SP01=25()Ogal
SP02=1290gal
(on other days, samples weren't
collected at both sample points.)
SP07
none
SP02
SP06
SP08
SP01= 5,000 gal *
SP03=20,000 gal *
SP06
SP08
SP01= 5,000 gal
SP03=20,000 gal
none
SP12
SP01= 3,400 gal *
SP03=12,600 gal *
SP05=18,000 gal *
SP07= 8,000 gal *
SP10= 4,355 gal * J
SP02
none
SP06
SP02*
none
none
none
none
none
none
none
none
SP07
SP08
none from 701 and SP01 from
E5046
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Chapter 10 LTAs, VFs, and Limitations and Standards
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Table 10-1 Facilities and Sample Points Used to Develop Long-term Averages and Limitations
Subcategory
Oils (cont)
Organics
Option Facility
9/9v E4813
E4814A
E4814B
701 and
E5046 f
0 E4377
E4472
3/4 E1987
Pollutants
Total cyanide
All others
All others
All
All
All
All
All
Effluent Sample
Point
SP07
SP07
SP09
SP10
SP01 from 701
SP01
SP01
SP12
Influent Sample Point
SP06
SP05
SP07
SP08
none from 701 and SP01 from
E5046
none
none
SP07B
* Batch flow systems. All others are continuous flow systems.
J EPA collected samples from four separate batches at SP10. The flows associated with the four batches 10A,
10B, IOC, and 10D were 3500 gal, 5130 gal, 3500 gal, and 5130 gal, respectively. EPA used the average flow
of 4355 gal in flow-weighting SP10 with the four other sample points SP01, SP03, SP05, and SP07.
f These are identified as facility 701 in other tables in this document and in the record.
When multiple sample points are identified in this table, the data listing and data summaries identify the last sample
point. For example, for facility 4803 (metals subcategory, option 3), the influent sample point is identified as
'SP10.'
DATA SELECTION
10.4
EPA performed a detailed review of the
analytical data and sampling episode reports. As
a result, EPA corrected some errors in the
database. EPA also re-evaluated the bases for the
data exclusions and assumptions as used in
calculating limitations for the 1995 proposal.
EPA made some modifications to its approach for
this proposal after reviewing the assumptions it
used for excluding or modifying certain data.
These are discussed in this section. The database
was corrected and the corrected version has been
placed in the record to this proposed rulemaking.
Data Exclusions and Substitutions 10.4.1
In some cases, EPA did not use all of the data
detailed in Table 10-1 to calculate long-term
averages, variability factors and limitations. This
section details these data exclusions and
substitutions Other than the data exclusions and
substitutions described in this section and those
resulting from the data editing procedures
(described in section 10.4.3), EPA has used all
the data from the facilities and sample points
presented in Table 10-1.
Operational Difficulties 10.4.1.1
EPA excluded data that were collected while
the facility was experiencing operational
difficulties. For the data used in calculating long-
term averages and limitations, this occurred
during sampling at episode 4814 only. During
the second day of sampling, 9/17/96, the facility
was required to shut-down and re-start the
operation of both of their DAP systems due to
poor performance and equipment failures. As
such, EPA excluded all data collected on 9/17/97
associated with sample point 09 at facility 4814A
and sample point 10 at facility 4814B.
Treatment Not Reflective of
BPT/BCT/BAT Treatment 10.4.1.2
EPA reviewed the effluent data used to
develop the limitations and excluded any facility
data set where the long-term average did not
reflect the performance expected by
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BPT/BCT/BAT treatment. Other than excluding
mercury values from facility 602 in option 3 of
the metals subcategory, the other excluded facility
data sets were for conventional parameters (i.e.,
oil and grease, BODS, and TSS). In all cases,
these data sets were collected at facilities that are
indirect dischargers and that are not required to
optimize performance of their system for removal
of these pollutants. In most cases, the
conventional pollutants are not limited by the
POTW and the facility is not required to monitor
for these pollutants. These exclusions were for
oil and grease (facilities 4813, 4814A, and
4814B for option 93 of the oils subcategory),
BODS (facility 1987 for option 3/4 of the
organics subcategory), TSS (facility 1987 for
option 3/4 of the organics subcategory, and
facilities 4798 and 700 for option 4 of the metals
subcategory).
Similarly, in calculating long-term averages
for oils option 9, EPA excluded the TSS data for
facilities 4813, 4814A, and 4814B. However,
EPA used these data to calculate variability
factors for TSS for oils option 9 since EPA
believes that the data reflected the overall
variability associated with the model technology.
(Sections 10.5, 10.6, and 10.7 describe the
development of the long-term averages,
variability factors, and limitations, respectively.)
Exclusions to EPA Sampling Data
Based Upon the Availability of the
Influent and Effluent 10.4.1.3
For the data from the EPA sampling
episodes, EPA determined the availability of the
influent and effluent data for each sampling day.
Both influent and effluent levels are important in
evaluating whether the treatment system
efficiently removed the pollutants. In addition,
the pollutant levels in the influent indicate
3EPA did not similarly exclude data for
facilities 4814A and 4814B from the Option 8
calculations since EPA did not select this option as
the basis of the proposed BPT/BCT limitations.
whether the pollutants existed at treatable levels.
In most cases, influent and effluent data were
both available for a given day.
For the cases when effluent data were
unavailable for some days, but influent data were
available, EPA generally determined that the
influent data still provided useful information
about the pollutant levels and should be retained.
However, for the organic pollutants at facility
4378, the effluent data were only available for
one day while the influent data were available for
several days. In this case, EPA determined that
the influent levels on that single date should be
considered and the levels on the other dates
excluded.
When the effluent data were available but
influent data were unavailable, EPA determined
that the effluent data should be excluded from
further consideration. Without the influent data,
EPA could not evaluate the treatability of the
pollutants and the effectiveness of the treatment
system.
More Reliable Results Available 10.4.1.4
In some cases, EPA had. analytical data which
represent a single facility (and time period) that
were analyzed by two different laboratories or
using two different analytical methods. For two
of these cases, EPA determined that one
analytical result was more reliable than the other
and excluded the less reliable result. This section
describes these cases.
In limited instances, facility 700 provided
two analytical results for the same date from
different laboratories. For the total cyanide
effluent data collected on 1.1/6/96, the analytical
results from the two laboratories differed
considerably. The facility representative
considered the result generated by the off-site
laboratory to be more reliable than the result
generated by the facility's on-site laboratory and
recommended that EPA use the off-site data only.
EPA agrees with this suggestion and has used
only the value from the off-site laboratory.
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Some chlorinated phenolics in episode 1987
were analyzed by both method 85.01 and method
1625. Thus, for a given sample, there were two
results for a specific chlorinated phenolic. Of the
pollutants of concern, these compounds were
pentachlorophenol, 2,3,4,6-tetrachlorophenol,
2,4,5-trichlorophenol, and 2,4,6-trichlorophenol.
Where two results were provided for the same
pollutant in a sample, EPA used the analytical
result from Method 1625. This decision is based
on the knowledge that Method 1625 is an isotope
dilution GC/MS procedure, and therefore
produces more reliable results than Method
85.01.
Data from Facilities Which
Accepted Waste from More
than One Subcategory 10.4.1.5
EPA also excluded data that were collected
during time periods when the facility treated
wastes from more than one CWT subcategory.
For the oil and grease calculations for metals
option 4, EPA excluded all oil and grease values
greater than 143 mg/L since this was the highest
value of oil and grease measured in the influent
samples collected at any metals subcategory
facility. EPA believes that values of oil and
grease in the effluent above this level indicate
that the facility was also treating oils subcategory
wastes and has, therefore, excluded this data from
its calculations.
Substitution Using the
Baseline Values 10.4.1.6
In developing the pollutant long-term
averages and limitations, EPA compared each
laboratory-reported sample result to a baseline
value (defined in Chapter 15). For certain
pollutants, EPA substituted a larger value than
the measured value or sample-specific detection
limit in calculating the long-term averages and
limitations. These pollutants were measured by
Methods 1624 and 1625 (organic pollutants) and
Method 1664 (n-hexane extractable material
(HEM) and silica gel treated n-hexane extractable
material (sgt-hem)). For these pollutants, EPA
substituted the value of the minimum level (ML)
specified in the method and assumed that the
measurement was non-detected when a measured
value or sample-specific detection limit was
reported with a value less than the ML. For
example, if the ML was 10 ug/1 and the
laboratory reported a detected value of 5 ug/1,
EPA assumed that the concentration was non-
detected with a sample-specific detection limit of
10 ug/1. For all other pollutants, EPA used the
reported measured value or sample-specific
detection limit.
Data Aggregation
10.4.2
In some cases, EPA determined that two or
more samples had to be mathematically
aggregated to obtain a single value. In some
cases, this meant that field duplicates, grab
samples, and/or multiple daily observations were
aggregated for a single sample point. In other
cases, data from multiple sample points were
aggregated to obtain a single value representing
the influent to the model technology.
In all aggregation procedures, EPA
considered the censoring type associated with the
data. EPA considered measured values to be
detected. In statistical terms, the censoring type
for such data was 'non-censored' (NC).
Measurements reported as being less than some
sample-specific detection limit (e.g., <10 mg/L)
are censored and were considered to be non-
detected (ND). In the tables and data listings in
this document and the record for the proposed
rulemaking, EPA has used the abbreviations NC
and ND to indicate the censoring types.
The distinction between the two censoring
types is important because the procedure used to
determine the variability factors considers
censoring type explicitly. This estimation
procedure modeled the facility data sets using the
modified delta-lognormal distribution. In this
distribution, data are modeled as a mixture of two
distributions corresponding to different process
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conditions. Because this industry treats different
types of waste from day to day, EPA assumed
that the process conditions leading to
non-detected values are generally different than
process conditions leading to the detected values.
(For example, a facility may treat wastewater
with relatively high levels of organics and low
levels of metals and the next day treat wastes that
have high metals concentrations and non-
detectable levels of organics.) Thus, the
distinctions between detected and non-detected
measurements were important in estimating the
variability factors.
Because each aggregated data value entered
into the model as a single value, the censoring
type associated with that value was also
important. In many cases, a single aggregated
value was created from unaggregated data that
were all either detected or non-detected. In the
remaining cases with a mixture of detected and
non-detected unaggregated values, EPA
determined that the resulting aggregated value
should be considered to be detected because the
pollutant was measured at detectable levels.
This section describes each of the different
aggregation procedures. .They are presented in
the order that the aggregation was performed.
That is, field duplicates were aggregated first,
grab and multiple samples second, and finally
multiple streams. For example, if EPA has four
pairs of data (i.e., four influent samples and four
duplicate influent samples), then EPA aggregated
each of the four pairs to obtain four values — one
for each pair of data. These four values were then
aggregated to obtain one daily value for the
influent stream. As a further example, suppose
the same facility had two additional streams
entering into the treatment system. Thus, the
influent into the treatment system would be
characterized by the combination of the pollutant
levels of the three streams. To obtain one value
to characterize the influent, the pollutant levels in
the three streams would be 'flow-weighted' by
the wastewater flow in each stream. The
following three sections specify the procedures
used to aggregate field duplicates, grab samples
(and daily values), and multiple influent streams,
respectively.
Aggregation of Field Duplicates 10.4.2.1
During the EPA sampling episodes, EPA
collected a small number of field duplicates.
Generally, ten percent of the number of samples
collected were duplicated. Field duplicates are
two or more samples collected for the same
sampling point at approximately the same time,
assigned different sample numbers, and flagged
as duplicates for a single sample point at a
facility.- Because the analytical data from each
duplicate pair characterize the same conditions at
that time at a single sampling point, EPA
aggregated the data to obtain one data value for
those conditions. The data value associated with
those conditions was the arithmetic average of the
duplicate pair. In most cases, both duplicates in
a pair had the same censoring type. In these
cases, the censoring type of the aggregate was the
same as the duplicates. In the remaining cases,
one duplicate was a non-censored value and the
other duplicate was a non-detected value. In
these cases, EPA determined that the appropriate
censoring type of the aggregate was
'non-censored' because the pollutant had been
present in one sample. (Even if the other
duplicate had a zero value4, the pollutant still
would have been present if the samples had been
physically combined.) Table 10-2 summarizes
the procedure for aggregating the analytical
results from the field duplicates. This
aggregation step for the duplicate pairs was the
first step in the aggregation procedures for both
influent and effluent measurements.
4This is presented as a 'worst-case'
scenario. In practice, the laboratories cannot
measure 'zero' values. Rather they report that the
value is less than some level (see chapter 15).
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Table 10-2. Aggregation of Field Duplicates
If the field duplicates are:
Censoring type of Value of aggregate is:
average is:
Formulas for
aggregate value of
duplicates:
Both non-censored
Both non-detected
NC
ND
arithmetic average of
measured values
arithmetic average of sample-
(DL,+DL2)/2
One non-censored and one
non-detected
specific detection limits
NC arithmetic average of
measured value and sample-
specific detection limit
(NC + DL)/2
NC=non-censored (or detected) ND=non-detected
DL=sample-specific detection limit
Aggregation of Grab Samples
and Multiple Daily Values 10.4.2.2
This section describes the aggregation of
grab samples and multiple daily values for
effluent sample points associated with continuous
flow facilities (defined in section 10.3).
During the EPA sampling episodes, EPA
collected two types of samples: grab and
composite. Typically, for a continuous flow
system, EPA collected composite samples;
however, for oil and grease, the method specifies
that grab samples must be used. For that
pollutant, EPA collected four grab samples
during a sampling day at a sample point
associated with a continuous flow system. To
obtain one value characterizing the pollutant
levels at the sample point on a single day, EPA
mathematically aggregated the measurements
from the grab samples.
In the self-monitoring data, facilities
occasionally reported more than one value for a
single day. If the sample point was associated
with a continuous flow system, then EPA
mathematically aggregated the results to obtain
one daily value.
EPA used the same procedure for grab
samples and multiple daily values. The method
arithmetically averaged the measurements to
obtain a single value for the day. When one or
more measurements were non-censored, EPA
determined that the appropriate censoring type of
the aggregate was 'non-censored' because the
pollutant was present. Table 10-3 summarizes
the procedure.
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Chanter 10 LTAs, VFs, and Limitations and Standards Development Document for the CV\T Point Source Category
Table 10-3
Aggregation of Grab Samples and Daily Values
If the grab or multiple
samples are:
Censoring type of Daily value is:
Daily Value is:
Formulas for Calculating
Daily Value:
All non-censored
All non-detected
Mixture of non-censored
and non-detected values
(total number of
observations is n=k+m)
NC arithmetic average of measured
values
ND arithmetic average of sample-
specific detection limits
NC arithmetic*average of measured
values and sample-specific
detection limits
n
n
m
n
NC=snon-censored (or detected)
ND=non-detected
DL=sample-specific detection limit
Aggregation of Data Across
Streams ("Flow-Weighting") 10.4.2.3
After field duplicates and grab samples were
aggregated, the data were further aggregated
across sample points. This step was necessary
when more than one sample point characterized
the wastestream of concern. For example, this
situation occurred for facility 4803 where five
different wastestreams entered into the treatment
process. EPA sampled each of these
wastestreams individually at sample points SP01,
SP03, SP05, SPOT, and SP10. In aggregating
values across sample points, if one or more of the
values were non-censored, then the aggregated
result was non-censored (because the pollutant
was present in at least one stream). When all of
the values were non-detected, then the aggregated
result was considered to be non-detected. The
procedure for aggregating data across streams is
summarized in Table 10-4. The following
example demonstrates the procedure for
hypothetical pollutant X at a facility with three
streams entering into the treatment system.
Example of calculating an aggregated flow-weighted value:
Sample Point
SP33
SP34
SP35
Flow (gal)
10,000
20,000
5,000
Concentration (uefD
10
50
100
Censoring
ND
NC
ND
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Chapter 10 LTAs, VFs. and Limitations and Standard
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Calculation to obtain aggregated, flow-weighted value:
(10,000gal IQug/L) (20,000gal 50ug/L) (5,000gal IQOug/L)
10,000gal + 20,OOOgaJ + 5,OOOgaJ
= 45.7 ug/L
because one of the three values was non-censored, the aggregated value of 45.7 ug/L is no
censored.
Table 10-4
Aggregation of Data Across Streams
If the n observations are:
Censoring
type is:
Formulas for value of aggregate
All non-censored
NC
All non-detected
ND
/=r
1=1
Mixture of k non-censored and
m non-detected
(total number of observations is n=k+m)
NC
k
£
1=1
1=1
NC=non-censored (or detected) ND=non-detected
DL=sample-specific detection limit
Data Editing Criteria
After excluding some data (as detailed in
Section 10.4.1) and aggregating the data, EPA
applied data editing criteria to select facility data
sets from the EPA sampling episodes to use in
calculating the long-term averages and
limitations. These criteria were specified by the
'long-term average test' and 'percent removals
10.4.3 test.' In addition, the criteria for the self-
monitoring data depended upon the results of the
data editing criteria for the data that EPA
collected at the facilities. These data editing
criteria are described in the following sections.
When the influent data at a facility failed the
editing criteria, EPA excluded the effluent data
for the facility in calculating the long-term
averages and limitations for the corresponding
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option in the subcategory. For example, at
facility 1987, if the arsenic data from influent
sample point 07B failed any of the editing
criteria, then the effluent data at sample point
SP12 were excluded from calculating the long-
term averages and limitations for option 4 of the
organics subcategory. For each of the proposed
options and pollutants of concern evaluated for
long-term averages and limitations, Attachment
10-1 indicates whether the data failed the data
editing criteria, indicates when no data were
available for a pollutant at any of the facilities, or
provides the facility-specific long-term average
(calculated as described in section 10.5).
Long-Term Average Test 10.4.3.1-
EPA established the long-term average test
('LTA test') to ensure that the pollutants were
present in the influent at sufficient concentrations
to evaluate treatment effectiveness at the facility.
After the data aggregation described in section
10.4.2, EPA compared the daily values of the
influent and their long-term average to the
baseline values described in chapter 15. The
influent had to pass one of the following two
steps to pass the LTA test:
Step 1: Fifty percent of the influent
measurements had to be detected at
concentration levels equal to or greater
than ten times the baseline value for the
pollutant (these values are listed in
Attachment 15-1); or
Step 2: The influent long-term average had to be
equal to or greater than ten times the
baseline value and at least 50 percent of
the influent measurements had to be
detected (at any level). Section 10.5
describes the calculations for long-term
averages.
Percent Removal Test 10.4.3.2
If the influent data passed either step in the
LTA test, then EPA calculated the facility's
influent and effluent averages without all of the
data aggregation steps described in section
10.4.2. This is a deviation from the procedure
used to calculate the influent averages used in
LTA test (in section 10.4.3.1) and the effluent
long-term averages used in the limitations (in
section 10.7). For the percent removals, EPA
used a different aggregation procedure that
emphasized the detection of pollutant levels. In
this modified aggregation procedure, EPA
aggregated field duplicates using the procedure in
section 10.4.2.1 and flow weighted wastestreams
using the procedure in Section 10.4.2.3. EPA did
not aggregate batches, grabs, or multiple daily
values (other than duplicates) as an interim step
prior to obtaining one overall value for the
wastestream. For example, if a facility had five
influent measurements of which three were
batches from sample point 33 and the remaining
two were a duplicate pair at sample point 34,
EPA first aggregated the duplicate measurements
at sample point 34 to obtain one value for the
duplicate pair. EPA then arithmetically averaged
the three batches from sample point 33 without
considering the flows corresponding to each
batch. For the percent removals, the influent
average was then the flow-weighted average of
two values: one from sample point 33 and one
from sample point 34. In. contrast, the influent
average for the LTA test would have flow-
weighted the batches from sample point 33 using
the flows for each batch.
The percent removal test compared the
influent and effluent averages to determine if the
treatment associated with the effluent sample
point removed any of the pollutant. If the
removals were negative, then EPA excluded the
effluent data from developing the long-term
averages and limitations.
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Percent removal = Influent averaSe ~ Effluent averaSe x 100
Influent average
Evaluation of Self-Monitoring Data 10.4.3.3
EPA used self-monitoring data for effluent at
three facilities in developing the long-term
averages and limitations. These facilities were
602, 700, and 701. These facilities provided
concentration values for some of the pollutants
that EPA considered in developing the long-term
averages and limitations. However, the self-
monitoring data were for effluent only (i.e., no
influent data were provided). In its evaluation of
the data, EPA determined that influent data
provided critical evidence that the facility treated
wastes containing these pollutants. Thus, EPA
used influent data from its sampling episodes to
determine if the facility accepted wastes
containing these pollutants.
For facility 701, EPA collected influent
information during the same time period as the
effluent data provided by the facility. As
described in section 10.1, EPA used this influent
information .with the facility 701 effluent data.
For the remaining two facilities, 602 and 700,
EPA considered the pollutant levels in the
influent at the EPA sampling episodes. As
explained in section 10.1, different facility
numbers may refer to the same facility. For
example, for option 3 of the metals subcategory,
facilities 602, 4378, and 4803 are the same
facility. (Facilities 4378 and 4803 were EPA
sampling episodes.) If the influent data at facility
4378 or facility 4803 met the data editing criteria
(i.e., LTA test and percent removals test), then
EPA used the effluent data from facility 602 in
calculating the long-term averages and limitations
for the pollutant. If the influent data for the
pollutant at facility 4378 and facility 4803 did
not meet the criteria, then EPA excluded the data
from facility 602. In a similar manner, facilities
4798 and 700 for option 4 of the metals
subcategory were linked. If the influent data for
a pollutant at facility 4798 (an EPA sampling
episode at the same facility as facility 700) met
the data editing criteria, then EPA used the
effluent data from facility 700 in calculating the
long-term averages and limitations for the
pollutant. If the influent data for the pollutant at
facility 4798 did not meet the criteria, then EPA
excluded the data from facility 700.
DEVELOPMENT OF LONG-TERM
AVERAGES
10.5
In order to develop the long-term averages
and proposed limitations for the centralized waste
treatment industry, it was necessary to estimate
long-term averages and variability factors. This
section discusses the estimation of long-term
averages by facility ("facility-specific") and by
option ("pollutant-specific"). For each pollutant
of concern (see Chapter 7), EPA calculated long-
term averages for each regulatory option and each
subcategory. The long-term average represents
the average performance level that a facility with
well-designed and operated model technologies is
capable of achieving.
EPA calculated the long-term average for
each pollutant for each facility by arithmetically
averaging the pollutant concentrations. The
pollutant long-term average for an option was the
median of the long-term averages from selected
facilities with the technology basis for the option.
The following two subsections describe the
estimation of the facility-specific and pollutant-
specific long-term averages.
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Estimation ofFacility-Spectfic
Long-Term Averages
10.5.1
The facility-specific long-term average for
each pollutant for each facility is the arithmetic
average of the daily pollutant concentrations of
wastewater from the facility. EPA substituted the
sample-specific detection limit for each non-
detected measurement.
For example, for facility A, if the
concentration values for hypothetical pollutant X
are:
10 mg/1,
13 mg/1,
non-detect ("ND") with sample-specific detection
limit = 5 mg/1,
12 mg/1, and
15 mg/1
then the facility-specific long-term average is
calculated using the sample-specific detection
limit of 5 mg/1 for the non-detected measurement.
This facility-specific long-term average is equal
to the average of the five values:
(10 + 13 + 5 + 12 + 15)/5 mg/1 = 11 mg/1.
Estimation of Pollutant-Specific
Long-Term Averages
10.5.2
The pollutant-specific long-term average was
the median of the facility-specific long-term
averages from the facilities with the model
technologies for the option. The median is the
midpoint of the values ordered (i.e., ranked) from
smallest to largest. If there is an odd number of
values (with n=number of values), then the value
of the (n-H)/2 ordered observation is the median.
If there are an even number of values, then the
two values of the n/2 and [(n/2)+l] ordered
observations are arithmetically averaged to obtain
the median value.
For example, for subcategory Y option Z, if
the four (i.e., n=4) facility-specific long-term
averages for pollutant X are:
Facility Long-term average
A 20 mg/1
B 9 mg/1
C 16 mg/1
D 10 mg/1
then the ordered values are:
Order Facility Long-term average
1 B 9 mg/1
2 D 10 mg/1
3 C 16 mg/1
4 A 20 mg/1
And the pollutant-specific long-term average for
option Z is the median of the ordered values (i.e.,
the average of the 2nd and 3rd ordered values):
(10+16)/2 mg/1 = 13 mg/1.
The pollutant-specific long-term averages
were used in developing the limitations for each
pollutant within each proposed option.
Substitutions for
Long-Term Averages 10.5.3
Baseline Values Substituted,
for Long-Term Averages 10.5.3.1
After calculating the pollutant-specific long-
term averages for the proposed options, EPA
compared these values to the baseline values
provided in chapter 15. EPA performed this
comparison in response to comments on the 1995
proposal. These comments stated that it was not
possible to measure to the low levels required in
that proposal. If the long-term average was less
than the baseline value, EPA substituted the
baseline value for the pollutant-specific long-term
average. Table 10-5 identifies the pollutants for
options 3 and 4 in the Metals subcategory where
this situation occurs. (This situation did not
occur for the other subcategories.)
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Table 10-5 Metals Subcategory: Long-Term Averages Replaced by the Baseline Values
Option
3
4
. Pollutant
' "beryllium
manganese
silver
tin
titanium
vanadium
indium
vanadium
CAS number
7440417
7439965
7440224
7440315
7440326
7440622
7439885
7440622
Baseline Value Long-Term Average
(mg/L) (mg/L)
5
15
10
30
5
50
1000
50
1
12
5
28
4
11
500
12
Arsenic Long-Term Average for
Metals Subcategory Option 4 10.5.3.2
In developing the limitations for arsenic for
option 4 of the metals Subcategory, EPA used the
long-term average from option 1A. During the
EPA sampling episode, the influent
concentrations of arsenic were at levels less than
EPA's criteria for treatable levels (see
explanation of LTA test in section 10.4.3.1).
Thus, the data editing criteria excluded the
arsenic data from both facilities 4798 and 700.
However, the arsenic concentration at facilities in
. option 1A were at treatable levels. Because the
treatment technology in option 4 should provide
better removals than option 1 A, EPA expects that
facilities utilizing the option 4 technologies can
achieve arsenic effluent concentration levels at
least as low as the values from facilities using the
option 1A technologies. Thus, EPA has
transferred the long-term average from option 1A
to option 4.5
5Because the data for option 4 provided
group variability factors (see section 10.6.7) for the
semi-metals group (which includes arsenic), EPA
did not transfer develop variability factors using the
data from option 1 A. Because each group is
composed of pollutants with similar chemical
structure, EPA expects the variability of the model
technology in option 4 to be consistent for all
pollutants in the group and thus used the variability
factor from option 4.
DEVELOPMENT OF
VARIABILITY FACTORS
10.6
In developing the variability factors that were
used in calculating the limitations, EPA first
developed facility-specific variability factors
using the modified delta-lognormal distribution.
Second, EPA used these facility-specific
variability factors to develop the group-level
variability factors. (Chapter 7 describes the
assignment of pollutants to groups. Appendix A
provides a list of the groups and the associated
pollutants.) Third, EPA used the pollutant-
specific variability factors to develop the group-
level variability factors. For pollutants assigned
to groups, EPA then used the group variability
factors in calculating the limitations. For
pollutants that were not assigned to groups, EPA
used the pollutant-specific variability factor.
The following sections describe the modified
delta-lognormal distribution and the estimation of
the facility-specific, pollutant-specific, and
group-level variability factors.
Basic Overview of the Modified
Delta-Lognormal Distribution
10.6.1
EPA selected the modified delta-lognormal
distribution to model pollutant effluent
concentrations from the centralized waste
treatment industry in developing the variability
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factors. In this industry, wastewater is generated
from treating wastes from different sources and
industrial processes. A typical effluent data set
from a facility in this industry consists of a
mixture of measured (detected) and non-detected
values. Within a data set, gaps between the
values of detected measurements and the sample-
specific detection limits associated with non-
detected measurements may indicate that different
pollutants were present in the different industrial
wastes treated by a facility. Non-detected
measurements may indicate that the pollutant is
not generated by a particular source or industrial
process. The modified delta-lognormal
distribution is appropriate for such data sets
because it models the data as a mixture of
measurements that follow a lognormal
distribution and non-detect measurements that
occur with a certain probability. The model also
allows for the possibility that non-detect
measurements occur at multiple sample-specific
detection limits. Because the data appeared to fit
the modified delta-lognormal model reasonably
well, EPA believes that this model is the most
appropriate model of those evaluated for the
centralized waste treatment data.
The modified delta-lognormal distribution is
a modification of the 'delta distribution'
originally developed by Aitchison and Brown.6
The resulting mixed distributional model, that
combines a continuous density portion with a
discrete-valued spike at zero, is also known as the
delta-lognormal distribution. The delta in the
name refers to the proportion of the overall
distribution contained in the discrete
distributional spike at zero, that is, the proportion
of zero amounts. The remaining non-zero, non-
censored (NC) amounts are grouped together and
fit to a lognormal distribution.
6 Aitchison, J. and Brown, J.A.C. (1963)
The Lognormal Distribution. Cambridge University
Press, pages 87-99.
EPA modified this delta-lognormal
distribution to incorporate: multiple detection
limits. In the modification of the delta portion,
the single spike located at zero is replaced by a
discrete distribution made up of multiple spikes.
Each spike in this modification is associated with
a distinct sample-specific detection limit
associated with non-detected (ND) measurements
in the database.7 A lognorrnal density is used to
represent the set of measured values. This
modification of the delta-lognormal distribution
is shown in Figure 10-1.
The following two subsections describe the
delta and lognormal portions of the modified
delta-lognormal distribution in further detail.
Previously, EPA had modified the delta-
lognormal model to account for non-detected
measurements by placing the distributional "spike"
at the detection limit (i.e., a single positive value,
usually equal to the nominal method detection limit)
rather than at zero. For further details, see Kahn and
Rubin, 1989. This adaptation was used in
developing limitations and standards for the organic
chemicals, plastics, and synthetic fibers (OCPSF)
and pesticides manufacturing rulemakings. The
current modification was used in the pulp and paper
and pharmaceutical industry rulemakings.
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
Figure 10-1
Modified Delta -Lognormal Distribution
Censoring Type NC
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
Discrete Portion of the Modified Delta-Lognormal Distribution
10.6.2
In the discrete portion of the modified delta-lognormal distribution, non-detected values we e
associated with multiple values corresponding to the reported sample-specific detection limits.
Multiple spikes were then constructed and linked to the values of the k distinct sample-specific
detection limits observed in the facility data set for the pollutant. In the model, 8 represents the
proportion of non-detected values and is the sum of smaller fractions, 8;, each representing the
proportion of non-detected values associated with the distinct value of a particular sample-specific
detection limit. By letting D; equal the value of the 1th smallest distinct detection limit in the data set and
the random variable XD represent a randomly chosen non-detected measurement, the cumulative
distribution function of the discrete portion of the modified delta-lognormal model can be mathematically
expressed as:
(1)
(2)
The mean and variance of this discrete distribution can be calculated using the fallowing formulas
k k
= ^E E *,Wf -
2
(3)
Continuous Portion of the Modified Delta-Lognormal Distribution
10.6.3
This section describes the lognormal portion of the modified delta-lognormal distribution. The
continuous, lognormal portion of the modified delta-lognormal distribution was used to model the
detected measurements from the centralized waste treatment industry database.
The cumulative probability distribution of the continuous portion of the modified delta-lognormal
distribution can be mathematically expressed as
Pi(X
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CKanter 10 LT As, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
o2) (exp(o2) -
(5)
(6)
where
_
log(x)
t=i
~
(7)
measured value of the 1th detected
measurement
n = number of detected values
As shown in the next section, the continuous portion of the modified delta-lognormal distribution
combines tiie discrete and continuous portions to model data sets that contain a mixture of non-detected
and detected measurements.
Estimation Under the Modified Delta-Lognormal Distribution
10.6.4
It is possible to fit a wide variety of observed effluent data sets to the modified delta-lognormal
distribution. Multiple detection limits for non-detect measurements can be handled, as can measured
("detected") values. The same basic framework can be used even if there are no non-detected values in
the data set. Thus, the modified delta-lognormal distribution offers a large degree of flexibility in
modeling effluent data.
The modified delta-lognormal random variable U can be expressed as a combination of three other
independent variables, that is,
(8)
where XD represents a random non-detect from the discrete portion of the distribution, Xc represents a
random detected measurement from the continuous lognormal portion, and Iu is an indicator variable
signaling whether any particular random measurement is detected or not. Using a weighted sum, the
cumulative distribution function from the discrete portion of the distribution (equation 1) can be
combined with the function from the continuous portion (equation 4) to obtain the overall cumulative
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Chanter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
probability distribution of the modified delta-lognormal distribution as follows,
Pr(L7<;u) =
6, + (1 -S)$ [(log(u) -
6 +(1-8)$ [(log(u)-n)/o)]
if 0
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Estimation of Facility-Specific
Variability Factors
10.6.5
This section applies the methodology
described in the previous section to the estimation
of facility-specific variability factors for each
pollutant. EPA estimated the daily variability
factors by fitting a modified delta-lognormal
distribution to the daily measurements. In
contrast, EPA estimated monthly variability
factors by fitting a modified delta-lognormal
distribution to the monthly averages. These
averages were developed using the same number
of measurements as the assumed monitoring
frequency for the pollutant. EPA is assuming
that some pollutants such as organics will be
monitored weekly (approximately four times a
month) and others will be monitored daily
(approximately 20 times a month).8 Section
11.5.2 identifies these assumed monitoring
frequencies. The following sections describe the
facility data set requirements to be used in
estimating variability factors, and the estimation
of facility-specific daily and monthly variability
factors that were used in developing the
limitations. These facility-specific variability
factors are listed in Attachment 10-3.
Facility Data Set Requirements 10.6.5.1
Estimates of the necessary parameters for the
lognormal portion of the distribution can be
calculated with as few as two distinct detected
values in a data set (which may also include
non-detected measurements). EPA used the
facility data set for a pollutant if the data set
contained:
• three detected observations with two or more
distinct values.
Further, the each facility data set for a'pollutant
had to pass the data editing criteria described in
section 10.4.3.
In statistical terms, each measurement was
assumed to be independently and identically
distributed from the other measurements of that
pollutant in the facility data set.
Estimation of Facility-Specific
Daily Variability Factors 10.6.5.2
The facility-specific daily variability factor is
a function of the expected value, E(U), and
the 99th percentile., of the modified delta-
lognormal distribution fit to the daily
concentration values of the pollutant in the
wastewater from the facility. The expected
value, E(U), was estimated using equation 10.
The 99th percentile of the modified delta-
lognormal distribution fit to each data set was
estimated by using an iterative approach. First,
D0=0, 80=0, and Dk+1 = °° were defined as
boundary conditions where D; equaled the r*
smallest detection limit and 8; was the associated
proportion of non-detects at the r* detection limit.
Next, a cumulative distribution function, p, for
each data subset was computed as a step function
ranging from 0 to 1. The general form, for a
given value c, was:
four or more observations with two or more
distinct detected concentration values; or
Compliance with the monthly average
limitations will be required in the final rulemaking
regardless of the number of samples analyzed and
averaged.
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Chapter 10 LTAs. VFs, and Limitations and Standards Development Document for the CV/T Point Source Category
, D
(13)
where <& is the standard normal cumulative distribution function. The following steps were completed
to compute the estimated 99th percentile of each data subset:
Step 1 Using equation 13, k values of p at c=Dm, m=l,...,k were computed and labeled pm.
Step 2 The smallest value of m (m=l,...,k), such that pm > 0.99, was determined and labeled as PJ. If
no such m existed, steps 3 and 4 were skipped and step 5 was computed instead.
Step 3 Computed p* = PJ - 8j.
Step 4 If p* < 0.99, then P99 = Dj
else if p* > 0.99, then
P99=
exp
ft
\-l
0-99 -
i=0
(1-6)
where <&'* is the inverse normal distribution function.
Step 5 If no such m exists such that pm > 0.99 (m=l,...,k), then
6
(14)
P99=exp
;-i
0.99-6
(1-6)
(15)
The facility-specific daily variability factor, VF1, was then calculated as:
P99
VF1 =
E(U)
(16)
Estimation of Facility-Specific Monthly Variability Factors 10.6.5.3
EPA estimated the monthly variability factors by fitting a modified delta-lognormal distribution to
the monthly averages. EPA developed these averages using the same numberof measurements as the
assumed monitoring frequency for the pollutant EPA is assuming that some pollutants such as organics
will be monitored weekly (approximately four times a month) and others will be monitored daily
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(approximately 20 times a month).9 Section 11.5.2 identifies these assumed monitoring frequencies.
ESTIMAHON OF FACILITY-SPECIFIC 4-DAY VARIABILITY FACTORS
Variability factors based on 4-day monthly averages were estimated for pollutants with the
monitoring frequency assumed to be weekly (approximately four times a month). In order to calculate
the 4-day variability factors (VF4), the assumption was made that the approximating distribution of U4,
the sample mean for a random sample of four independent concentrations, was also derived from the
modified delta-lognormal distribution.10 To obtain the expected value of the 4-day averages, equation
10 is modified for the mean of the distribution of 4-day averages in equation 17:
E(U4) =
(17)
where (X4)D denotes the mean of the discrete portion of the distribution of the average of four
independent concentrations, (i.e., when all observations are non-detected values) and (X4)c denotes
the mean of the continuous lognormal portion (i.e., when all observations are detected).
First, it was assumed that the probability of detection (8) on each of the four days was independent
of the measurements on the other three days. (As explained in section_10.6.5.1, daily measurements were
also assumed to be independent.) Thus, 84 = 84 and because E(X^)D = E(XD), then equation 17
can be expressed as
6D
-^ + (l-84)exp(A4+0.5o24)
(18)
^^ A4 usmgequafionlSandbecause
- 0.562
1=1
(l-o4)
= E(U):
(19)
The expression for 524 was derived from the following relationship
9The attachments to this chapter (except Attachment 10-5 which provides the proposed limitations) sometimes
identify two monthly variability factors and monthly average limitations for a single pollutant in an option. These two
sets of variability factors and limitations correspond to monitoring four and twenty times a month. In developing the
limitations, EPA considered both monitoring frequencies. However, EPA is proposing only the monitoring frequencies
identified in section 11.5.2.
10This assumption appeared to be reasonable for the pulp and paper industry data that had percentages of non-
detected and detected measurements similar to the data sets for the centralized waste treatment industry. This conclusion
was based on the results of a simulation of 7,000 4-day averages. A description of this simulation and the results are
provided in the record for the proposed rulemaking.
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWTPoint Source Category
(20)
by substftuting the following
and
(21)
into equation 20. This substitution provides the following
which further simplifies to
(22)
«• (1 -84)exp(2A4 -^[expCd2,) -1]
46 (23)
£-i-
/=! o
Next, equation 24 results from solving for [exp(d24) -1 ] in equation 23.
exp(d24)-l =
-82(l-84]
4 I 1=1
(24)
Then solving for exp(p.4+0.5624) using equation 18 and substituting E(U4) = E(U) results in
>J (25)
exp(A4+0.5o24) =
k
1=1
k
£,
i=l
(1-84)
(1-84)
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Chanter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWTPoint Source Category
Letting
k
i=l
simplifies equation 25 to
(1-64)
Next, solving for O24 in equation 24 and using the substitution in equation 27 provides
* k
El
, _ 1=1 j=i
»t"V"4/
1
f
M (1-64);
-84)2
(26)
(27)
(28)
Finally, using the relationship Var(U4) = Var(U)/4 and rearranging terms:
6-24=log
4r|2
4r)2
(29)
Thus, estimates of p.4 and 624 in equations 19 and 29, respectively, were derived by using
estimates of 8j,...,8k (sample proportion of non-detects at observed sample-specific detection limits
D^.-.jDk),, E(U) from equation 10, and Var(U) from equation 12.
In finding the estimated 95th percentile of the average of four observations, four non-detects, not all
at the same sample-specific detection limit, can generate an average that is not necessarily equal to Dl5
D^..., or Dk. Consequently, more than k discrete points exist in the distribution of the 4-day averages.
For example, the average of four non-detects at k=2 detection limits, are at the following discrete points
with the associated probabilities:
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWTPoint Source Category
D*
8*,.
1
2
3
4
5
A
(3D1+D2)/4
. (2Di+2DJ/4
(D1+3D2)/4
A
V
48/8,
68/S,,2
461823
8,4
When all four observations are non-detected values, and when k distinct non-detected values exist,
the multinomial distribution can be used to determine associated probabilities. That is,
Pr
k
y^ U.D.
TJ j=l
I 4 4 J
4!
Ui!u2!-1
k
nsu/
giS '
(30)
where U; is the number of non-detected measurements in the data set with the D( detection limit. The
number of possible discrete points, k*, for k=l,2,3,4, and 5 are as follows:
k kl
1 1
2 5
3 15
4 35
5 70
To find the estimated 95th percentile of the distribution of the average of four observations, the same
basic steps (described in section 10.6.5.2) as for the 99th percentile of the distribution of daily
observations, were used with the following changes:
Step 1 Change P^ to P9S, and 0.99 to 0.95.
Step 2 Change Dm to Dm*, the weighted averages of the sample-specific detection limits.
StepS Change 6; to 6;*.
Step 4 Change k to k*, the number of possible discrete points based on k detection limits.
StepS Change the estimates of 8, & and * to estimates of 84, fl4, and 624, respectively.
Then, using J5(I74) = E(U), the estimate of the facility-specific 4-day variability factor, VF4, was
calculated as:
VF4 =
P95
to
(3D
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AUTOCORRELATION IN THE
DAILY MEASUREMENTS
Before estimating the facility-specific 20-day
variability factors, EPA considered whether
autocorrelation was likely to be present in the
effluent data. When data are said to be positively
autocorrelated, it means that measurements taken
at consecutive time periods are related. For
example, positive autocorrelation would be
present in the data if the final effluent
concentration of oil and grease was relatively
high one day and was likely to remain at similar
high values the next and possibly succeeding
days. Because EPA is assuming that some
pollutants (BOD5, TSS, oil and grease, metals,
and total cyanide) will be monitored daily, EPA
based the 20-day variability factors on the
distribution of the averages of 20
measurements.11 If concentrations measured on
consecutive days were positively correlated, then
the autocorrelation would have had an effect on
the estimate of the variance of the monthly
average and thus on the 20-day variability factor.
(The estimate of the long-term average and the
daily variability factor would not be affected by
autocorrelation.)
EPA believes that autocorrelation in any
significant amount is unlikely to be present in
daily measurements in wastewater from this
industry. Thus, EPA has not incorporated
autocorrelation into its estimates of the 20-day
variability factors. In many industries,
measurements in final effluent are likely to be
similar from one day to the next because of the
consistency from day-to-day in the production
processes and in final effluent discharges due to
1 ! In other rulemakings, EPA has used the
averages of 30 measurements when the assumed
monitoring frequency was daily measurements
throughout the month. However, many centralized
waste treatment facilities are closed on weekends.
Therefore, EPA assumed that 20 daily
measurements rather than 30 would be collected
each month.
the hydraulic retention time of wastewater in
basins, holding ponds, and other components of
wastewater treatment systems. Unlike these other
industries, where the industrial processes are
expected to produce the same type of wastewater
from one day to the next, the wastewater from
centralized waste treatment industry is generated
by treating wastes from different sources and
industrial processes. The wastes treated on a
given day will often be different than the waste
treated on the following day. Because of this,
autocorrelation would be expected to be absent
from measurements of wastewater from the
centralized waste treatment industry.
EPA believes that a statistical evaluation of
appropriate data sets would likely support its
assertion that autocorrelation is absent from daily
measurements in the centralized waste treatment
industry. However, the monitoring data that EPA
has received thus far are insufficient for the
purpose of evaluating the autocorrelation.12 To
determine autocorrelation in the data, many
measurements for each pollutant would be
required with values for every single day over an
extended period of time. Such data were not
available to EPA. In the preamble to the
proposal, EPA requests additional data that can
be used to evaluate autocorrelation in the data.
12In the 1995 statistical support document,
EPA included a discussion of the autocorrelation in
the effluent data from facility 602. The document
states that the facility provided 'sufficient amounts of
pollutant measurements.' That statement is not
correct. To have sufficient amounts of data, the data
set would need to include many more measurements
for every single day. In addition, in the 1995
document, the conclusions about statistical
significance were flawed due to an error in the
software.
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for ^CW^PointSourceCategory_
ESTIMATION OF FACILITY-SPECIFIC 20-DAY VARIABILITY FACTORS
Based upon the discussion on autocorrelation in the previous section, it was assumed that consecutive
daily measurements were independent of one another, and therefore
E(U20) = E(U) and Vai(U20) =
(32)
where E(U) and Var(L/) were calculated as shown in section 10.6.5.3.2 (see equations 10 and 12).
Finally, since tJ2ols approximately normally distributed by the Central Limit Theorem, the estimate of
the 95th percentile of a 20-day mean and the corresponding facility-specific 20-day variability factor
(VF20) were approximated by
P9520 = E(U20) + [<
By using the substitutions in equation 32, equation 33 simplified to
P9520 = E(U) + [*'
(33)
—Vai(U)
20
(34)
Then, the estimate of the facility-specific 20-day variability factor, VF20, was calculated using:
VF20 =
E(U)
because E(U20) = E(U)
(35)
where $"'(0.95) is the 95th percentile of the inverse normal distribution.
Evaluation of Facility-Specific
Variability Factors 10.6.5.4
Estimates of the necessary parameters for the
lognormal portion of the distribution can be
calculated with as few as two distinct measured
values in a data set (which may also include
non-detected measurements); however, these
estimates are likely to be unstable unless a more
sizable number of measured values is available.
As stated in section 10.6.5.1, EPA used the
modified delta-lognormal distribution to develop
facility-specific variability factors for data sets
that had a four or more observations with two or
more distinct measured concentration values or
three measured values with two or more distinct
values. Some variance estimates produced
unexpected results such as a daily variability
factor with a value less man 1.0 which would
result in a limitation with a value less than the
long-term average. This was an indication that
the estimate of " (the log standard deviation)
was unstable. To identify situations producing
unexpected results, EPA carefully reviewed all of
the variability factors and compared daily to
monthly variability factors. EPA determined that
when the facility's daily variability factor was
less than 1.0, the daily and monthly variability
factors for that pollutant should be excluded from
further consideration. Similarly, when the
facility's monthly variability factors for a
pollutant were greater than the daily variability
factor, EPA excluded the daily and monthly
variability factors from further consideration. If
the daily variability factor was greater than 10.5,
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Chanter 10 LTAs VFs and Limitations and Standards
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EPA reviewed the data in detail to determine if
one or more values were the result of process
upsets or data errors.
Estimation of Pollutant-Specific
Variability Factors
10.6.6
After the facility-specific variability factors
were estimated for a pollutant as described in
section 10.6.5, the pollutant-specific variability
factor was calculated. The pollutant-specific
daily variability factor was the mean of the
facility-specific daily variability factors for that
pollutant in the subcategory and option.
Likewise, the pollutant-specific monthly
variability factor was the mean of the facility-
specific monthly variability factors for that
pollutant in the subcategory and option. For
example, for option 4 of the Metals subcategory,
the cadmium daily variability factor was the mean
of the cadmium daily variability factors from
facilities 4798 and facility 700. A more detailed
example of estimating pollutant-specific monthly
variability factors is provided in section 10.7.2.
Attachment 10-213 lists the pollutant-specific
variability factors.
Estimation of Group-Level
Variability Factors
10.6.7
After the pollutant-specific variability factors
were estimated as described in section 10.6.6, the
13Attachments 10-2 through 10-7 include
some pollutants for which EPA has not proposed
limitations. In some cases, the data from these
additional pollutants were used to develop the group
variability factors (see section 10.6.7). For other
pollutants, at some point in developing the proposal,
EPA considered proposing limitations; however,
EPA later excluded them from the proposed
limitations (see chapter 7 for further explanation).
These attachments reflect the calculations prior to
transfers of limitations as described in section 10.8.
In addition, a revision to the TSS limitations for oils
• subcategory option 9 is not incorporated into these
attachments.
group-level variability factors were calculated.
Each group contained pollutants that had similar
chemical structure (e.g., the metals group
consisted of metal pollutants). For some
pollutants such as BOD5, EPA determined that
there were no other pollutants that could be
considered chemically similar for the purpose of
determining variability factors; therefore, these
pollutants were not assigned to a group.14 For the
pollutants (such as BOD5) that were not assigned
to a group, the pollutant-specific variability
factors were used in developing limitations.
However, in most cases, group-level variability
factors were used in developing limitations. (The
derivation of limitations is described in section
10.7.1.) Appendix A identifies the groups and
the pollutants assigned to them.
The group-level daily variability factor was
the median of the pollutant-specific daily
variability factors for the pollutants within the
group. Similarly for the monthly variability
factors, the group-level monthly variability factor
was the median of the pollutant-specific monthly
variability factors for the pollutants within the
group. Attachment 10-4 provides the group-level
daily and monthly variability factors that could be
calculated for the proposed options.
Transfers of Variability Factors
10.6.8
In some cases, EPA transferred variability
factors for pollutants when its associated group-
level variability factors could not be estimated.
In these cases, the facility data sets for that
pollutant and the other pollutants in the group
were excluded (section 10.4.1), did not meet the
data editing criteria (section 10.4.3), did not meet
the facility data set requirements
(section 10.6.5.1), or the facility-specific
variability factors were excluded (section
10.6.5.4).
14In some data listings, such cases are
sometimes identified with a group; however, the
group name and the pollutant name are the same.
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
EPA transferred variability factors for these
cases using other group-level variability factors in
the option for the subcategory.15 In developing
these transferred variability factors, EPA
calculated the transferred variability factors as the
median (i.e., mid-point value) of the group-level
variability factors from all groups except the
metals, semi-metals, and non-metals groups. For
example, for hypothetical subcategory X, suppose
its option 2 had five groups: TSS, oil and grease,
n-paraffins, aromatics, and metals. In addition,
suppose that group-level variability factors had
been calculated for all groups except n-paraffins,
then the transferred daily variability factor for the
pollutants in the n-paraffins group would be the
median of the group-level daily variability factors
from the TSS, oil and grease, and aromatics
group. (The daily variability factor from the
metals group would be excluded.) The
transferred monthly (4-day) variability factor
would be the 4-day variability factor from the
aromatics group, because 4-day variability factors
were not calculated for TSS and oil and grease
(because the monitoring frequency was assumed
to be 20 times per month.)
ISIn the 1995 proposal, EPA proposed
using fraction-level variability factors when group-
level variability factors were unavailable. EPA has
determined that more appropriate transfers are
available.
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWTPoint Source Category
Table 10-6 Cases where Variability Factors were Transferred
Subcategory
Metals
Oils
Organics
• Option Pollutant Transferred Variability Factors *
Daily Monthly
4 Hexavalent chromium 3.348 1.235
8/8v alpha-terpineol 2.907 1.467
carbazole
9/9v alpha-terpineol 3.434 1.682
carbazole
3/4 acetophenone 4.330 1.992
aniline
benzoic acid
/fonitoring Frequency
(days per month)
20
4
4
4
LIMITATIONS
10.7
The proposed limitations and standards are
the result of multiplying the long-term averages
by the appropriate variability factors. The same
basic procedures apply to the calculation of all
limitations and standards for this industry,
regardless of whether the technology is BPT,
BCT, BAT, NSPS, PSES or PSNS.
The proposed limitations for pollutants for
each option are provided as 'daily maximums'
and 'maximums for monthly averages.'
Definitions provided in 40 CFR 122.2 state that
the daily maximum limitation is the "highest
allowable 'daily discharge'" and the maximum
for monthly average limitation (also referred to as
the "monthly average limitation") is the "highest
allowable average of 'daily discharges' over a
calendar month, calculated as the sum of all 'daily
discharges' measured during a calendar month
divided by the number of 'daily discharges'
measured during that month." Daily discharges
are defined to be the '"discharge of a pollutant'
measured during a calendar day or any 24-hour
period that reasonably represents the calendar day
for purposes of samplings.".
EPA calculates the limitations based upon
percentiles chosen with the intention, on one
hand, to be high enough to accommodate
reasonably anticipated variability within control
of the facility and, on the other hand, to be low
enough to reflect a level of performance
consistent with the Clean Water Act requirement
that these effluent limitations be based on the
"best" technologies. The daily maximum
limitation is an estimate of the 99th percentile of
the distribution of the daily measurements. The
monthly average limitation is an estimate of the
95th percentile of the distribution of the monthly
averages of the daily measurements. EPA used
the 95th percentile rather than the 99th percentile
for monthly average limitations because the
variability of monthly averages is less than the
variability of individual daily measurements. The
percentiles for both types of limitations are
estimated using the products of long-term
averages and variability factors.
In the first of two steps in estimating both
types of limitations, EPA determines an average
performance level (the "long-term average"
discussed in section 10.7) that a facility with
well-designed and operated model technologies
(which reflect the appropriate level of control) is
capable of achieving. This long-term average is
calculated from the data from the facilities using
the model technologies for the option. EPA
expects that all facilities subject to the limitations
will design and operate their treatment systems to
achieve the long-term average performance level
on a consistent basis because facilities with well-
designed and operated model technologies have
demonstrated that this can be done.
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In the second step of developing a limitation,
EPA determines an allowance for the variation in
pollutant concentrations when processed through
extensive and well designed treatment systems.
This allowance for variance incorporates all
components of variability including shipping,
sampling, storage, and analytical variability. This
allowance is incorporated into the limitations
through the use of the variability factors
(discussed in section 10.6) which are calculated
from the data from the facilities using the model
technologies. If a facility operates its treatment
system to meet the relevant long-term average,
EPA expects the facility to be able to meet the
limitations. Variability factors assure that normal
fluctuations in a facility's treatment are accounted
for in the limitations. By accounting for these
reasonable excursions above the long-term
average, EPA's use of variability factors results
in limitations that are generally well above the
actual long-term averages.
After completing the data screening tests to
select the appropriate data sets, EPA calculated
the long-term averages for the limitations. For
some pollutants of concern, none of the facility
data sets with the technology basis for the option
met the data screening criteria; thus, these
pollutants of concern are not proposed to be
regulated for that option. These pollutants are
listed in Chapter 7, Table 7-1. Further, because
of these criteria, the options within a subcategory
may have slightly different lists of pollutants
proposed to be regulated. These data were used
to develop long-term averages and variability
factors, by pollutant and technology option, for
each subcategory. The limitations prior to
transfers are listed in Attachment 10-7.
Steps Used to Derive Limitations
10.7.1
This section summarizes the steps used to
derive the limitations. These steps were used
separately for the daily maximum limitation and
the monthly average limitation. Depending on the
assumed monitoring frequency of the pollutant,
either the 4-day variability factor or the 20-day
variability factor was used in deriving the
monthly average limitation.
Step 1 EPA calculated the facility-specific long-
term averages and variability factors for
all facilities that had the model
technology for the option in the
subcategory. EPA calculated variability
when the facility had four or more
observations with two or more distinct
detected values or three detected values
with two or distinct values. In addition,
the facility data set for the pollutant had
to meet the data screening criteria.
Step 2 For each option in the subcategory, EPA
calculated the median of the facility-
specific long-term averages and the
mean of the facility-specific variability
factors from the facilities with the model
technology to provide the pollutant-
specific long-term average and
variability factors for each pollutant.
Step 3 EPA calculated, the group-level
variability factor using the median of the
pollutant-specific variability factors for
the pollutants within each group.
Step 4 In most cases, EPA calculated the
limitation for a pollutant using the
product of the pollutant-specific long-
term average and the group-level
variability factor. If the group-level
variability factor could not be estimated
(because none of the pollutant-specific
variability factors in the group could be
estimated), then EPA transferred
variability factors (see section 10.6.8)
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Chapter 10 LTAs, VFs, and Limitations and Standards
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and the used pollutant-specific long-term
average in calculating the limitation. If
the pollutant was not assigned to a
group, then EPA calculated the
limitation using the product of the
pollutant-specific long-term average and
the pollutant-specific variability factors.
(See exceptions to step 4 described in
section 10.8.2.)
Example
10.7.2
This example illustrates the derivation of limitations using the steps described
above. In this example, four pollutants, A, B, C, and D all belong to hypothetical
group X. The facility-specific long-term averages and variability factors for the
pollutants are shown in Attachments 10-1 and 10-3, respectively (step 1). Table 10-7
shows the pollutant-specific long-term averages and variability factors calculated as
described in step 2. Then, using the procedure in step 3, the group-level variability
factor (see attachment 10-4 in Appendix E) is the median of the variability factors for
pollutants A, B, and C (D is excluded because facility-specific variability factors could
not be calculated for any of the facilities that provided data on pollutant D).
• The group-level daily variability factor for group X is 2.2 which is the median of
2.2 (pollutant A), 2.4 (pollutant B), and 2.1 (pollutant C).
• The group-level 4-day variability factor for group X is 1.4 which is the median of
1.5 (pollutant A), 1.4 (pollutant B), and 1.2 (pollutant C).
In this example, the limitations are calculated using the pollutant-specific long-term
averages and the group-level variability factors in the following way:
Daily maximum limitation
= pollutant-specific long-term average
* group-level daily variability factor
For each pollutant, the daily maximum limitation is:
Pollutant A: 15 mg/1 * 2.2 = 33 mg/1
Pollutant B: 14 mg/1 * 2.2 = 31 mg/1
Pollutant C: 22 mg/1 * 2.2 = 48 mg/1
Pollutant D: 20 mg/1 * 2.2 = 44 mg/1
Monthly average limitation
= pollutant-specific long-term average
* group-level 4-day variability factor
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
For each pollutant, the monthly average limitation is:
Pollutant A: 15 mg/1 * 1.4 = 21 mg/1
Pollutant B: 14 mg/1 * 1.4 = 20 mg/1
Pollutant C: 22 mg/1 * 1.4 = 31 mg/1
Pollutant D: 20 mg/1 * 1.4 = 28 mg/1
Table 10-7. Long-Term Averages and Variability Factors Corresponding to Example for Hypothetical
Group X
Pollutant
A
B
C
D
Facility
Al
A2
A3
A4
AS
Pollutant-specific
Bl
B2
B3
B4
Pollutant-specific
Cl
C2
C3
Pollutant-specific
Dl
D2
D3
Pollutant-specific
Long-term
Average (mg/1)
10
12
15
20
26
15
(median)
17
16
10
12
14
(median)
22
24
12
22
(median)
20
22
14
20
(median)
Daily Variability
Factor
2.1
2.3
. 2.0
1.8
2.8
2.2
(mean)
2.7
2.2
2.3
*
2.4
(mean)
1.9
*
2.3
2.1
(mean)
*
*
*
*
4-day Variability
Factor
1.4
1.5
1.4
1.3
1.9
1.5
(mean)
1.7
1.2
1.3
*
1.4
(mean)
1.1
*
1.3
1.2
(mean)
*
*
*
*
* could not be estimated (i.e., the data set did not contain four or more observations with two
or more distinct detected values or three detected values with two or more distinct values.)
TRANSFERS OF LIMITATIONS
10.8
In some cases, EPA was either unable to
calculate a limitation using the available data for
an option or determined that the treatment
provided by facilities employing the option did
not represent BPT/BCT/BAT treatment. In these
cases, EPA transferred limitations from another
option or from another industrial category. The
following sections describe each case where the
limitations were transferred.
Transfer of Oil and Grease
Limitation for Metals Subcategory
Option 4 to Option 3 10.8.1
Because of the relatively low levels of oil and
grease in the influent of the facilities with the
model technology for Metals subcategory option
3, application of the LTA test to the influent data
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Chapter 10 LTAs, VFs, and Limitations and Standards
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(described in section 10.4.3.1) resulted in
excluding the effluent data. EPA believes that
this parameter should be regulated for all options
in this subcategory. EPA based the oil and grease
limitations upon data from facilities with the
option 4 model technology. In effect, EPA has
transferred the limitations from option 4 to option
3 for oil and grease. EPA has concluded that
transfer of this data is appropriate given that the
technology basis for metals option 3 includes
additional treatment steps than the technology
basis for metals option 4. As such, EPA has
every reason to believe that facilities employing
the option 3 technology could achieve the
limitations based on the option 4 technology.
Transfers of Limitations from Other
Rulemakings to CWT Industry
10.8.2
In some cases, the model technology did not
optimally remove BOD5 and TSS for an option in
a subcategory. EPA believes this occurred
because the limitations are largely based on
indirect discharging facilities that are not required
to control or optimize their treatment systems for
the removal of conventional parameters. Thus,
EPA transferred the BPT/BCT limitations (for
direct dischargers data) from effluent guidelines
from other industries with similar wastewaters
and treatment technologies. In one case, EPA
proposes the transfer of the BPT/BCT TSS
limitations from the Metal Finishing rulemaking
to the Metals subcategory BPT/BCT limitations
(option 4). In the other case, EPA proposes the
transfer of the BPT/BCT BOD5 and TSS
limitations from the Organic Chemical, Plastics,
and Synthetic Fibers (OCPSF) rulemaking to the
Organics subcategory BPT/BCT limitations
(option 3/4). EPA used different procedures
from the one discussed in section 10.7.1 to
develop the proposed limitations for BOD5 and
TSS for the organics subcategory and TSS for
option 4 in the Metals subcategory. The
following sections describe these different
procedures.
Transfer ofBOD5 and TSS
for the Organics Subcategory 10.8.2.1
EPA based the transferred limitations of
BOD5 and TSS for the organics subcategory on
biological treatment performance data used to
develop the limitations for the thermosetting
resins subcategory in the Organic Chemicals,
Plastics, and Synthetic Fibers (OCPSF) industry
rulemaking. As described in the preamble to the
proposed rulemaking, EPA determined that the
transfer of the data was warrarrted because
facilities in the organics subcategory treat wastes
similar to wastes treated by OCPSF facilities.
For the organics subcategory of the
centralized waste treatment industry, the
proposed daily maximum limitations for BOD5
and TSS were transferred directly from the
OCPSF rulemaking. No modifications were
required before transferring these daily maximum
limitations.
Some modifications of the OCPSF monthly
average limitations were required before the
values could be transferred to the centralized
waste treatment industry. The OCPSF limitations
for BODS and TSS were based on assumptions of
a monitoring frequency of 30 days and the
presence of autocorrelation in the measurements.
In the proposed rulemaking for the centralized
waste treatment industry, the monthly limitations
for BODS and TSS were based on an assumed
monitoring frequency of 20 days and no
autocorrelation (see section 10.6.5.3.2 for a
discussion of the absence of autocorrelation in the
centralized waste treatment data). Therefore, the
following conversion steps were necessary to
convert the OCPSF 30-day variability factors to
20-day variability factors.
The following formula was used in the
OCPSF rulemaking to calculate the 30-day
variability factors. This formula incorporates
autocorrelation between measurements on
adjacent days (i.e., the lag-1 autocorrelation).
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Chanter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
VF3Q = 1+1.645.
(eq2-l)/30(p,o)
30
(36)
where the function f30(p,tf) represents the additional variability attributable to autocorrelation, and is
given by
9 29
f30(p,o) = 1+ £(30-£)(epo -1) (37)
30(e°2- l)*=i
The above two formulas can be generalized to estimate n-day variability factors. These formulas are:
VFn = 1+1.645.
(e0-l)fn(p,0)
m.2
(38)
n
where
4(p>°) =
(39)
For the proposed limitations, the autocorrelation, p, has been assumed to be absent; thus, the value of
p is set equal to zero. Therefore, the value of fn(0,o) is equal to 1, and equation 38 becomes:
VF = 1+1.645
(6°
n
(40)
Because all of the values were detected (i.e., there were no non-detected measurements) in the OCPSF
data base for BOD5 and TSS, the delta-lognormal distribution of these data is the same as the lognormal
distribution (i.e., the delta portion does not apply because it is used to model non-detect measurements).
Therefore, an estimate of o2 was obtained from the daily variability factor from the lognormal
distribution by using the following equation:
Wl = e
c4>-'(0.99)- —
(41)
where $'1(0.99) is the 99th percentile of the inverse normal distribution. (The value of 4>'I(0.99) is
2.326.) By solving this equation using maximum likelihood estimation for a and substituting it into
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
equation 40, an estimate of VFn may be obtained. Finally, the n-day limitation is given by:
(42)
Limit° - m
The expected value, E(X) can be estimated by solving for E(X) in the following equation for the daily
maximum limitation (which is the same for both the OCPSF, and centralized waste treatment industries):
E(X)
(43)
to obtain
E(X) =—4
Limit
(44)
Then, equation 40 (using the estimate of a2 from equation 41) and equation 44 can be substituted into
equation 42 to obtain:
"**• -
Limit
1+1.645,
e° -1
n
(45)
In particular, for the monthly average limitation based on assuming daily monitoring (i.e.,
approximately 20 times a month), the limitation is
Limit20 =
VK
1 + 1.645,
20
(46)
Table 10-8 provides the values of the BOD5 and TSS limitations and other parameters for the
thermosetting resins subcategory from the OCPSF industry and the organics subcategory in the
centralized waste treatment industry.
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
Table 10-8 BOD, and TSS Parameters for Organics Subcategory
Parameter
a
Long-Term Average (mg/1)
VF,
VF30
VF20
Daily Maximum Limitation (mg/1)
Monthly Average Limitation (mg/1)
OCPSF: Thermosetting Resins
Subcategory
BOD,
0.6971
41
3.97
1.58
n/a
163
61
TSS
0.8174
45
4.79
1.45
n/a
216
67
Centralized Waste Treatment:
Organics Subcategory
BOD,
0.
41
3.
n/a
1.
163
53.
6971
97
29
0
TSS
0.8174
45
4.79
n/a
1.36
216
61.3
Transfer of TSS for Option 4 of
the Metals Subcategory 10.8.2.2
For TSS for option 4 of the metals
Subcategory, EPA transferred the proposed
limitations directly from the Metal Finishing
rulemaking (see Table 10-9). EPA based the
Metal Finishing monthly average limitation for
TSS upon an assumed monitoring frequency of
ten days per month and the absence of
autocorrelation in the measurements. EPA has
also assumed an absence of autocorrelation in
TSS for the centralized waste treatment industry.
However, EPA assumed a monitoring frequency
of 20 measurements a month for TSS for the
centralized waste treatment industry, rather than
the ten measurements assumed in the metal
finishing rulemaking. EPA will consider whether
it should adjust the monthly average limitation
from the metal finishing rulemaking for the
increase in monitoring frequency. This
adjustment would result in a monthly average
limitation with a slightly lower value than
presented in the proposal. (The monitoring
frequency does not effect the value of long-term
averages and daily maximum limitations.)
Table 10-9 TSS Parameters: for Metal Finishing
Metal Finishing TSS Values
TSS (mg/L)
Long-Term Average (mg/1) 16.8
Daily variability factor 3.59
Monthly Variability Factor 1.85
Assumed monitoring frequency 10/month
Daily Maximum Limitation (mg/1) 60.0
Monthly Average Limitation (mg/1) 31.0
EFFECT OF GROUP AND
POLLUTANT VARIABILITY
FACTORS ON LIMITATIONS
10.9
In the preamble to the proposed rulemaking,
EPA solicited comment on using pollutant (or
'pollutant-specific') variability factors rather than
group (or 'group-level') variability factors in
calculating the limitations. For the 1995
proposed limitations and in today's proposed
limitations, EPA generally used the product of the
group variability factor and the pollutant long-
term average in calculating each pollutant
limitation. For today's re-proposal, EPA
alternatively considered using the pollutant
variability factor instead of the group variability
factor. (Group and pollutant variability factors
are listed in Attachment 10-6.) For pollutants
where pollutant variability factors could not be
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Chapter 10 LTAs, VFs. and Limitations and Standards Development Document for the CWT Point Source Category
calculated (due to data constraints), EPA .would
continue to use the group variability factor. >
Using the group variability factor eliminates
the extremely low and high pollutant variability
factors. Thus, limitations for some pollutants
would be more stringent and for others less
stringent. Attachment 10-7 provides a listing of
the limitations calculated using both methods.
EPA believes that the variability of the
pollutants with similar chemical structures would
behave similarly in treatment systems; thus, EPA
believes that using a single group variability
factor may be appropriate for those pollutants. In
the preamble to the proposed rulemaking, EPA
solicited comment on whether the pollutant or
group variability factors or some combination
should be used in calculating the limitations to
accurately reflect the variability of the pollutants
discharged by the centralized waste treatment
industry.
ATTACHMENTS
10.10
Attachments 10.1 through 10.7 to this chapter
are located in Appendix E at the end of the
document
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Chapter 10 LTAs, VFs, and Limitations and Standards Development Document for the CWT Point Source Category
REFERENCES
10.11
Aitchison, J. and J.A.C. Brown. 1963. The Lognormal Distribution. Cambridge University Press, New
York.
Barakat, R. 1976. "Sums of Independent Lognormally Distributed Random Variables." Journal
Optical Society of America, 66: 211-216.
Cohen, A. Clifford. 1976. Progressively Censored Sampling in the Three Parameter Log-Normal
Distribution. Technometrics, 18:99-103.
Crow, E.L. and Shimizu. 1988. Lognormal Distributions: Theory and Applications. Marcel Dekker,
Inc., New York.
Engineering and Analysis Division, EPA. "Comment Response Document (Volume VI)." Record
Section 30.11, DCN 14497 in the Pulp and Paper Phase I Rulemaking Docket.
Engineering and Analysis Division, EPA. "Statistical Support Document for the Pulp and Paper
Industry: Subpart B." November 1997, Record Section 22.5, DCN 14496 in the Pulp and Paper
Phase I Rulemaking Docket.
Fuller, W.A. 1976. Introduction to Statistical Time Series. John Wiley & Sons;, New York.
Kahn, HD., and M.B. Rubin. 1989. "Use of Statistical Methods in Industrial Water Pollution Control
Regulations in the United States." Environmental Monitoring and Assessment. Vol. 12:129-148.
Owen, WJ. and T.A. DeRouen. 1980. Estimation of the Mean for Lognormal Data Containing Zeroes
and Left-Censored Values, with Applications to the Measurement of Worker Exposure to Air
Contaminants. Biometrics, 36:707-719.
U.S. Environmental Protection Agency, Effluent Guidelines Division. 1983. Development Document
for Effluent Limitations Guidelines and Standards for the Metal Finishing Point Source Category:
Final. EPA 440/1-83/091. Pages A-l to A-7, A-l 1, A-12, and VII-260 to VII-262.
U.S. Environmental Protection Agency, Industrial Technology Division. 1987. Development Document
for Effluent Limitations Guidelines and Standards for the Organic Chemicals. Plastics, and Synthetic
Fibers Point Source Category. Volume I, Volume II. EPA 440/1-87/009.
U.S. Environmental Protection Agency, Office of Water. 1993. Statistical Support Document for
Proposed Effluent Limitations Guidelines and Standards for the Pulp. Paper, and Paperboard Point
Source Category. EPA-821-R-93-023.
U.S. Environmental Protection Agency, Office of Water. 1995. Statistical Support Document for
Proposed Effluent Limitations Guidelines and Standards for the Centralized Waste Treatment
Industry. EPA 821-R-95-005.
10-40
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Chapter
11
COST OF TREATMENT TECHNOLOGIES
In this chapter, EPA presents the costs
estimated for compliance with the proposed
CWT effluent limitations guidelines and
standards. Section 11.1 provides a general.
description of how the individual treatment
technology and regulatory option costs were
developed. In sections 11.2 through 11.4, EPA
describes the development of costs for each of the
wastewater and sludge treatment technologies.
In section 11.5, EPA presents additional
compliance costs to be incurred by facilities,
which are not technology specific. These
additional items are retrofit costs, monitoring
costs, RCRA permit modification costs, and land
costs.
In Section 11.6, EPA presents some
examples of capital and O&M cost calculations
for CWT facilities using this methodology.
Finally, Section 11.7 summarizes, by
subcategory, the total capital expenditures and
annual O&M costs for implementing the
proposed regulation. Appendix D contains, by
subcategory,'the facility-specific capital, O&M,
land, RCRA, and monitoring cost estimates for
each facility to comply with the proposed
limitations and standards.
COSTS DEVELOPMENT
Technology Costs
11.1
11.1.1
EPA obtained cost information for the
technologies selected from the following sources:
• the data base developed from the 1991 Waste
Treatment Industry (WTI) Questionnaire
responses (This contained some process cost
information, and was used wherever
possible.),
• technical information developed for EPA
rulemaking efforts such as the guidelines and
standards for: the Organic Chemicals,
Plastics, and Synthetic Fibers (OCPSF)
category, Metal Products and Machinery
(MP&M) category, and Industrial Laundries
industries category,
• engineering literature,
• the CWT sampling/model facilities, and
• vendors' quotations (used extensively in
. estimating the cost of the various
technologies).
The total costs developed by EPA include the
capital costs of investment, annual O&M costs,
land requirement costs, sludge disposal costs,
monitoring costs, RCRA permit modification
costs, and retrofit costs. Because 1989 is the
base year for the WTI Questionnaire, EPA scaled
all of the costs either up or down to 1989 dollars
using the Engineering News Record (ENR)
Construction Cost Index.
EPA based the capital costs for the
technologies primarily on vendors' quotations.
The standard factors used to estimate the capital
costs are listed in Table 11-1. Equipment costs
typically include the cost of the treatment unit and
some ancillary equipment associated with that
technology. Other investment costs in addition to
the equipment cost include piping,
instrumentation and controls, pumps, installation,
engineering, delivery, and contingency.
EPA estimated certain design parameters for
costing purposes. One such parameter is the flow
rate used to size many of the treatment
technologies. EPA used the total daily flow in all
cases, unless specifically stated. The total daily
flow represents the annual flow divided by 260,
.11-1
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Categor
the standard number of operating days for a CWT
per year.
EPA derived the annual O&M costs for the
various systems from vendors' information or
from engineering literature, unless otherwise
statedl The annual O&M costs represent the
costs of maintenance, taxes and insurance, labor,
energy, treatment chemicals (if needed), and
residuals management (also if needed). Table 11-
2 lists the standard factors EPA used to estimate
the O&M costs.
Sections 11.2 through 11.4 present cost
equations for capital costs, O&M costs, and land
requirements for each technology and option. For
most technologies, EPA also developed capital
cost upgrade and O&M cost upgrade equations.
EPA used these equations for facilities which
already have the treatment technology forming
the basis of the option (or some portion of the
treatment technology) in place. EPA also presents
the flow rate ranges recommended for use in each
equation. EPA is confident the equations are
representative of costs for such facilities within
these ranges. Outside these ranges, the equations
become extrapolations. EPA does not believe
these equations, however, yield representative
results below the recommended low flow rate.
Table 11-1. Standard Capital Cost Algorithm
Factor
Capital Cost
Equipment Cost
Installation
Piping
Instrumentation and Controls
Technology-Specific Cost
25 to 55 percent of Equipment Cost
31 to 66 percent of Equipment Cost
6 to 30 percent of Equipment Cost
Total Construction Cost
Equipment + Installation + Piping
+ Instrumentation and Controls
Engineering
Contingency
15 percent of Total Construction Cost
15 percent of Total Construction Cost
Total Indirect Cost
Engineering + Contingency
Total Capital Cost
Total Construction Cost + Total Indirect Cost
Option Costs
11.12
EPA developed engineering costs for each of
the individual treatment technologies which
comprise the CWT regulatory options. These
technology-specific costs are broken down into
capital, O&M, and land components. To
estimate the cost of an entire regulatory option, it
is necessary to sum the costs of the individual
treatment technologies which make up that
option. In a few instances, an option consists of
only one treatment technology; for those cases,
the option cost is obviously equal to the
technology 'cost. The CWT subcategory
technology options are shown in Table 11-3. The
treatment technologies included in each option are
listed, and the subsections which contain the
corresponding cost information are indicated.
EPA generally calculated the capital and
O&M costs for each of the individual treatment
technologies using a flow rate range of 1 gallon
per day to five million gallons per day. However,
the flow rate ranges recommended for use in the
equations are in a smaller range and are presented
for each cost equation in Sections 11.2 to 11.4.
Land Requirements and Costs 11.1.2.1
EPA calculated land requirements for each
piece of new equipment based on the equipment
dimensions. The land requirements include the
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Chapter 11 Cost of Treatment Technologies Development Document for the CWTPoint Source Cat&gor
total area needed for the equipment plus
peripherals (pumps, controls, access areas, etc.).
Additionally, EPA included a 20-foot perimeter
around each unit. In the cases where adjacent
tanks or pieces of equipment were required, EPA
used a 20-foot perimeter for each piece of
equipment, and configured the geometry to give
the minimum area requirements possible. The
land requirement equations for each technology
are presented in the tables throughout sections
11.2 to 11.4. EPA then multiplied the land
requirements by the corresponding land costs (as
detailed in 11.5.4) to obtain facility specific land
cost estimates.
Operation and Maintenance Costs 11.1.2.2
EPA based O&M costs on estimated energy
usage, maintenance, labor, taxes and insurance,
and chemical usage cost. With the principal
exception of chemical usage and labor costs, EPA
calculated the O&M costs using a single
methodology. This methodology is relatively
consistent for each treatment technology, unless
specifically noted otherwise.
EPA's energy usage costs include electricity,
lighting, and controls. EPA estimated electricity
requirements at 0.5 Kwhr per 1,000 gallons of
wastewater treated. EPA assumed lighting and
controls to cost $1,000 per year and electricity
cost $0.08 per Kwhr. Manufacturers'
recommendations form the basis of these
estimates.
EPA based maintenance, taxes, and insurance
on a percentage of the total capital cost as
detailed in Table 11-2.
Chemical usage and labor requirements are
technology specific. These costs are detailed for
each specific technology according to the index
given in Table 11-3.
Table 11-2. Standard Operation and Maintenance Cost Factor Breakdow
Factor
O&M Cost (1989 $/year)
Maintenance
Taxes and Insurance
Labor
Electricity
Chemicals:
Lime (Calcium Hydroxide)
Polymer
Sodium Hydroxide (100 percent solution)
Sodium Hydroxide (50 percent solution)
Sodium Hypochlorite
Sulfuric Acid
Aries Tek Ltd Cationic Polymer
Ferrous Sulfate
Hydrated Lime
Sodium Sulfide
Residuals Management
4 percent of Total Capital Cost
2 percent of Total Capital Cost
$30,300 to $31,200 per man-year
$0.08 per kilowatt-hour
$57 per ton .
$3.38 per pound
$560 per ton
$275 per ton
$0.64 per pound
$80 per ton
$1.34 per pound
$0.09 per pound
$0.04 per pound
$0.30 per pound
Technology-Specific Cost
Total O&M Cost
Maintenance + Taxes and Insurance + Labor
+ Electricity + Chemicals + Residuals
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
Table 11-3. CWT Treatment Technology Costing Index - A Guide to the Costing Methodology Sections
Subcategory/
Option
Metals 2
Metals 3
Metals 4
Metals -
Cyanide Waste
Pretreatment
Oils 8
Oils 8v
Oils 9
Oils 9v
Organics 4
Organics 3
Treatment Technology
Selective Metals Precipitation
Plate and Frame Liquid Filtration
Secondary Chemical Precipitation
Clarification
Plate and Frame Sludge Filtration
Filter Cake Disposal
Selective Metals Precipitation
Plate and Frame Liquid Filtration
Secondary Chemical Precipitation
Clarification
Tertiary Chemical Precipitation and pH Adjustment
Clarification
Plate and Frame Sludge Filtration
Filter Cake Disposal
Primary Chemical Precipitation
Clarification
Secondary (Sulfide) Chemical Precipitation
Secondary Clarification (for Direct Dischargers Only)
Multi-Media Filtration
Plate and Frame Sludge Filtration^
Cyanide Destruction at Special Operating Conditions
Dissolved Air Flotation
Dissolved Air Flotation
Air Stripping
Secondary Gravity Separation
Dissolved Air Flotation
Secondary Gravity Separation
Dissolved Air Flotation
Air Stripping
Equalization
Sequencing Batch Reactor
Equalization
Sequencing Batch Reactor
Air Stripping
Section
11.2.1.1
11.2.2.1
11.2,1.2
11.2.2.2
11.4.1
11.4.2
11.2.1.1
11.2.2.1
11.2.1.2
11.2.2.2
11.2.1.3
11.2.2.2
11.4.1
11.4.2
11.2.1.4
11.2.2.2
11.2.1.5
11.2.2.2
11.2.5
11.4.1
11.2.6
11.2.8
11.2.8
11.2.4
11.2.7
11.2.8
11.2.7
11.2.8
11.2.4
11.2.3
11.3.1
11.2.3
11.3.1
11.2.4
'Metals Option 4 sludge filtration includes filter cake disposal.
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
PHYSICAL/CHEMICAL WASTEWATER
TREATMENT TECHNOLOGY COSTS 11.2
Chemical Precipitation 11.2.1
Wastewater treatment facilities widely use
chemical precipitation systems to remove
dissolved metals from wastewater. EPA
evaluated systems that utilize sulfide, lime, and
caustic as the precipitants because of their
common use in CWT chemical precipitation
systems and their effectiveness in removing
dissolved metals.
Selective Metals Precipitation-Metals
Option 2 and Metals Option 3 11.2.1.1
The selective metals precipitation equipment
assumed by EPA for costing purposes for Metals
Option 2 and Metals Option 3 consists of four
mixed reaction tanks, each sized for 25 percent of
the total daily flow, with pumps and treatment
chemical feed systems. EPA costed for four
reaction tanks to allow a facility to segregate its
wastes into small batches, thereby facilitating
metals recovery and avoiding interference with
other incoming waste receipts. EPA assumed
that these four tanks would provide adequate
surge and equalization capacity for a metals
subcategory CWT. EPA based costs on a four
batch per day treatment schedule (that is, the sum
of four batch volumes equals the facility's daily
incoming waste volume).
As shown in Table 11-3, plate and frame
liquid filtration follows selective metals
precipitation for Metals Options 2 and 3. EPA
has not presented the costing discussion for plate
and frame liquid filtration in this section (consult
section 11.2.3.2). Likewise, EPA has presented
the discussion for sludge filtration and filter cake
disposal in sections 11.4.1 and 11.4.2,
respectively.
CAPITAL COSTS
Because only one facility in the metals
subcategory has selective metals precipitation in-
place, EPA included selected metals precipitation
capital costs for all facilities (except one) for
Metals Options 2 and 3.
EPA obtained the.equipment capital cost
estimates for the selective metals precipitation
systems from vendor quotations. These costs
include the cost of the mixed reaction tanks with
pumps and treatment chemical feed systems. The
total construction cost estimates include
installation, piping and instrumentation, and
controls. The total capital cost includes
engineering and contingency at a percentage of
the total construction cost plus the total
construction cost (as explained in Table 11-1).
The equation for calculating selective metals
precipitation capital costs for Metals Option 2
and Option 3 is presented in Table 11-4 at the
end of this section.
CHEMICAL USAGE AND LABOR
REQUIREMENT COSTS
EPA based the labor requirements for
selective metals precipitation on the model
facility's operation. EPA estimated the labor cost
at eight man-hours per batch (four treatment
tanks per batch, two hours per treatment tank per
batch).
EPA estimated selective metals precipitation
chemical costs based on stoichiometric, pH
adjustment, and buffer adjustment requirements.
For facilities with no form of chemical
precipitation in-place, EPA based the
stoichiometric requirements on the amount of
chemicals required to precipitate each of the
metal and semi-metal pollutants of concern from
the metals subcategory average raw influent
concentrations to current performance levels (See
Chapter 12 for a discussion of raw influent
concentrations and current loadings). The
chemicals used were caustic at 40 percent of the
required removals and lime at 60 percent of the
required removals. (Caustic at 40 percent and
lime at 60 percent add up to 100 percent of the
stoichiometric requirements.) These chemical
11-5
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
dosages reflect the operation of the selective
metals precipitation model facility. Selective
metals precipitation uses a relatively high
percentage of caustic because the sLudge resulting
from caustic precipitation is amenable to metals
recovery. EPA estimated the pH adjustment and
buffer adjustment requirements to be 40 percent
of the stoichiometric requirement EPA added an
excess of 10 percent to the pH and buffer
adjustment requirements, bringing the total to 50
percent. EPA included a 10 percent excess
because this is typical of the operation of the
CWT facilities visited and sampled by EPA.
EPA estimated selective metals precipitation
upgrade costs for facilities that currently utilize
some form of chemical precipitation. Based
on responses to the Waste Treatment Industry
Questionnaire, EPA assumed that the in-place
chemical precipitation systems use a dosage ratio
of 25% caustic and 75% lime and achieve a
reduction of pollutants from "raw" to "current"
levels. The selective metals precipitation upgrade
would require a change in the existing dosage mix
to 40% caustic and 60 % lime. Therefore, the
selective metals precipitation upgrade for
facilities with in-place chemical precipitation is
the increase in caustic cost (from 25 % to 40%)
minus the lime credit (to decrease from 75% to
The O&M cost equation for selective metals
precipitation is presented in Table 11-4 along
with the O&M upgrade cost equation for
facilities with primary and secondary chemical
precipitation in-place.
Table 11-4. Cost Equations for Selective Metals Precipitation in Metals Options 2 and 3
Description
Equation
Recommended
Flow Rate Range
(MOD) .
Capital.cost
ln(Yl) = 14.461 + 0.5441n(X) + 0.0000047(ln(X))2 1.0 E -6 to 5.0
O&M cost forfacilities with no chemical ln(Y2) = 15.6402 + l.OOlln(X) + 0.04857(ln(X))2 3.4 E -5 to 5.0
precipitation treatment in-place
O&M upgrade cost for facilities with
precipitation in-place
Land requirements
ln(Y2) = 14.2545 + 0.80661n(X) + 0.04214(ln(X))2 7.4 E -5 to 5.0
ln(Y3) = -0.575 + 0.4201n(X) + 0.025(ln(X))2
1.6 E-2 to 4.0
Yl = Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 - Land Requirement (Acres)
X = Flow Rate (million gallons per day)
Secondary Precipitation — Metals
Option 2 and Metals Option 3 11.2.1.2
The secondary precipitation system in the
model technology for Metals Option 2 and Metals
Option 3 follows selective metals precipitation
and plate and frame liquid filtration. This
secondary chemical precipitation equipment
consists of a single mixed reaction tank with
pumps and a treatment chemical feed system,
which is sized for the full daily batch volume.
As shown in Table 11-3, clarification follows
secondary chemical precipitation for Metals
Options 2 and 3. The costing discussion for
clarification following secondary precipitation is
presented in section 11.2.2.2. The discussions
for sludge filtration and the; associated filter cake
disposal are presented in sections 11.4.1, and
11.4.2, respectively.
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Chapter 11 Cost of Treatment Technologies
Development Document for the CWT Point Source Category
Many facilities in the metals subcategory
currently have chemical precipitation units in-
place. For these facilities, cost upgrades may be
appropriate. EPA used the following set of rules
to decide whether a facility's costs should be
based on a full cost equation or an upgrade
equation for the secondary chemical precipitation
step of metals Options 2 and 3:
• Facilities with no chemical precipitation la-
place should use the full capital and O&M
costs.
• Facilities with primary chemical precipitation
in-place should assume no capital costs, no
land requirements, but an O&M upgrade cost
for the primary step.
• Facilities with secondary chemical
precipitation currently in-place should
assume no capital costs, no land
requirements, and no O&M costs for the
secondary step.
CAPITAL COSTS
For facilities that have no chemical
precipitation in-place, EPA calculated capital cost
estimates for the secondary precipitation
treatment systems from vendor quotations.
EPA estimated the other components (i.e.,
piping, instrumentation and controls, etc.) of the
total capital cost by applying the same factors
and additional costs as detailed for selective
metals precipitation (see Section 11.2.1.1 above).
The capital cost equation for secondary
precipitation in Metals Option 2 and Option 3 is
shown in Table 11-5 at the end of this section.
For the facilities that have at least primary
chemical precipitation in-place, EPA assumed
that the capital cost for the secondary
precipitation treatment system would be zero.
The in-place primary chemical precipitation
systems would serve as secondary precipitation
systems after the installation of upstream
selective metals precipitation units.
CHEMICAL USAGE AND LABOR
REQUIREMENT COSTS
EPA developed O&M cost estimates for the
secondary precipitation step of Metals Option 2
and 3 for facilities with and without chemical
precipitation currently in-place. For facilities
with no chemical precipitation in-place, EPA
calculated the amount of lime required to
precipitate each of the metals and semi-metals
from the metals subcategory current performance
concentrations (achieved with the previously
explained selective metals precipitation step) to
the Metals Option 2 long-term average
concentrations. EPA then added a ten percent
excess dosage factor and based the chemical
addition costs on the required amount of lime
only, which is based on the operation of the
model facility for this technology. EPA assumed
the labor cost to be two hours per batch, based on
manufacturers' recommendations.
For facilities with chemical precipitation in-
place, EPA calculated an O&M upgrade cost. In
calculating the O&M upgrade cost, EPA assumed
that there would be no additional costs associated
with any of the components of the annual O&M
cost, except for increased chemical costs.
Since. EPA already applied credit for
chemical costs for facilities with primary
precipitation in estimating the selective metals
precipitation chemical costs, the chemical
upgrade costs for facilities with primary
precipitation are identical to facilities with no
chemical precipitation in-place.
Since EPA assumed that facilities with
secondary precipitation would achieve the metals
option 2 long term average concentrations with
their current system and chemical additions (after
installing the selective metals precipitation
system), EPA assumed these facilities would not
incur any additional chemical costs. In turn, EPA
also assumed that facilities with secondary
precipitation units in-place would incur no O&M
upgrade costs.
11-7
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Chanter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
Table 11-5. Cost Equations for Secondary Chemical Precipitation in Metals Options 2 and 3
Description
Equation
Recommended Flow
Rate Range (MOD)
In (Yl) = 13.829 + 0.5441n(X) + 0.00000496(ln(X)r
In (Y2) = 11.6553 + 0.483481n(X) + 0.02485(ln(X))2
Capital cost
O&M cost for facilities with no
chemical precipitation in-place
O&M upgrade cost for facilities In (Y2) = 9.97021 + 1.001621n(X) + 0.00037(ln(X))2
with primary precipitation in-place
Land requirements
In (Y3) = -1.15 + 0.4491n(X) + 0.027(ln(X))2
1.0 E-6 to 5.0
6.5 E-5 to 5.0
5.0 E-4 to 5.0
4.0 E-3 to 1.0
Yl - Capital Costs (1989 $)
Y2 - Operation and Maintenance Costs (1989 $ /year)
Y3 = Land Requirement (Acres)
X » Flow Rate (million gallons per day)
Tertiary Precipitation andpH
Adjustment- Metals Option 3 11.2.1.3
The tertiary chemical precipitation step for
Metals Option 3 follows the secondary
precipitation and clarification steps. This tertiary
precipitation system consists of a rapid mix
neutralization tank and a pH adjustment tank. In
this step, the wastewater is fed to the rapid mix
neutralization tank where lime slurry is added to
raise the pH to 11.0. Effluent from the
neutralization tank then flows to a clarifier for
solids removal. The clarifier overflow goes to a
pH adjustment tank where sulfuric acid is added
to achieve the desired final pH of 9.0. This
section explains the development of the cost
estimates for the rapid mix neutralization tank
and the pH adjustment tank. The discussions for
clarification, sludge filtration, and associated
filter cake disposal are presented in Sections
11.2.2.2, 11.4.1, and 11.4.2, respectively.
CAPITAL COSTS
EPA developed the capital cost estimates for
the rapid mix tank assuming continuous flow and
a 15-minute detention time, which is based on the
model facility's standard operation. The
equipment cost includes one tank, one agitator,
and one lime feed system.
EPA developed the capital cost estimates for
the pH adjustment tank assuming continuous
flow and a five-minute detention time, also based
on the model facility's operation. The equipment
cost includes one tank, one agitator, and one
sulfuric acid feed system.
EPA estimated the other components (i.e.,
piping, instrumentation and controls, etc.) of the
total capital cost for both the rapid mix and pH
adjustment tank by applying the same factors and
additional costs as detailed for selective metals
precipitation (see Section 11.2.1.1 above). The
capital cost equations for the rapid mix and pH
adjustment tanks are presented in Table 11-6 at
the end of this section.
CHEMICAL USAGE AND LABOR
REQUIREMENT COSTS
EPA did not assign O&M costs, and in turn,
chemical usage and labor requirement costs for
tertiary precipitation and pH adjustment to the
few facilities which have tertiary precipitation
(and pH adjustment) systems in-place. For those
facilities without tertiary precipitation (and pH
adjustment) in-place, EPA estimated the labor
requirements at one man-hour per day for the
rapid mix and pH adjustment tanks. EPA based
this estimate on the model facility's typical
operation.
EPA estimated chemical costs for the rapid
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Chanter 11 Cost of Treatment Technologies .Development Document for the CWT Point Source Category
mix tank based on lime addition to achieve the
stoiehiometric requirements of reducing the
metals in the wastewater from the Metals Option
2 long-term averages to the Metals Option 3
long-term averages, with a 10 percent excess.
EPA estimated the chemical requirements for the
pH adjustment tank based on the addition of
sulfuric acid to lower the pH from 11.0 to 9.0,
based on the model facility's operation. The
O&M cost equations for the rapid mix tank and
pH adjustment tank are presented in Table 11-6.
Table 11-6. Cost Equations for Tertiary Chemical Precipitation in Metals Option 3
Description
Equation
Recommended
Flow Rate Range
(MOD)
Capital cost for rapid mix tank
Capital cost for pH adjustment tank
O&M cost for rapid mix tank
O&M cost for pH adjustment tank
Land requirements for rapid mix tank
Land requirements for pH adjustment tank
ln(Yl) = 12.318 + 0.5431n(X) - 0.000179(ln(X))2 1.0 E -5 to 5.0
ln(Yl) = 11.72,1 + 0.5431n(X) + 0.000139(ln(X))2 1.0 E -5 to 5.0
ln(Y2) = 9.98761 + 0.375141n(X) + 0.02124(ln(X))2 1.6 E -4 to 5.0
ln(Y2) = 9.71626 + 0.332751n(X) + 0.0196(ln(X))2 2.5 E -4 to 5.0
ln(Y3) = -2.330 + 0.3521n(X) + 0.019(ln(X))2 1.0 E -2 to 5.0
ln(Y3) = -2.67 + 0.301n(X) + 0.033(ln(X))2 1.0 E -2 to 5.0
Yl = Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 = Land Requirement (Acres)
X = Flow Rate (million gallons per day)
Primary Chemical Precipitation -
Metals Option 4 11.2.1.4
The primary chemical precipitation system
equipment for the model technology for Metals
Option 4 consists of a mixed reaction tank with
pumps, a treatment chemical feed system, and an
unmixed wastewater holding tank. EPA designed
the system to operate on a batch basis, treating
one batch per day, five, days per week. The
average chemical precipitation batch duration
reported by respondents to the WTI
Questionnaire was four hours. Therefore, a one
batch per day treatment schedule should provide
sufficient time for the average facility to pump,
treat, and test its waste. EPA also included a
holding tank, equal to the daily waste volume, up
to a maximum size of 5,000 gallons (equivalent
to the average tank truck receipt volume
throughout the industry), to allow facilities
flexibility in managing waste receipts. (The
Metals Option 4 model facility utilizes a holding
tank.)
As shown in Table 11-3, clarification follows
primary chemical precipitation for metals Option
4. The costing discussion for clarification
following primary precipitation in Metals Option
4 is presented in section 11.2.2.2. The
discussions for sludge filtration and the
associated filter cake disposal are presented in
sections 11.4.1, and 11.4.2, respectively.
CAPITAL COSTS
EPA developed total capital cost estimates
for the Metals Option 4 primary chemical
precipitation systems. For facilities with no
chemical precipitation units in-place, the
components of the chemical precipitation system
included a precipitation tank with a mixer,
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Chanter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
pumps, and a feed system. In addition, EPA
included a holding tank equal to the size of the
precipitation tank, up to 5,000 gallons. EPA
obtained these cost estimates from
manufacturer's recommendations.
EPA estimated the other components (i.e.,
piping, instrumentation and controls, etc.) of the
total capital cost for both the rapid mix and pH
adjustment tank by applying the same factors and
additional costs as detailed for selective metals
precipitation (see Section 11.2.1.1 above).
For facilities that already have any chemical
precipitation (treatment in-place), EPA included
as capital expense only the cost of a holding tank.
The capital cost equations for primary chemical
precipitation and the holding tank only for Metals '
Option 4 are presented in Table 11-7.
LABOR AND CHEMICAL COSTS
EPA approximated the labor cost for primary
chemical precipitation in Metals Option 4 at two
hours per batch, one batch per day. EPA based
this approach on the model facility's operation.
EPA estimated chemical costs based on
stoichiometric, pH adjustment, and buffer
adjustment requirements. For facilities with no
chemical precipitation in-place, EPA based the
stoichiometric requirements on the amount of
chemicals required to precipitate each of the
metal pollutants of concern from the metals
subcategory average raw influent concentrations
to Metals Option 4 (Sample Point-03)
concentrations. Metals Option 4, Sample Point-
OS concentrations represent the sampled effluent
from primary chemical precipitation at the model
facility. The chemicals used were lime at 75
percent of the required removals and caustic at 25
percent of the required removals, which are based
on the option facility's operation. EPA estimated
the pH adjustment and buffer adjustment
requirements to be 50 percent of the
stoichiometric requirement, which includes a 10
percent excess of chemical dosage. The O&M
cost equation for primary chemical precipitation
in Metals Option 4 for facilities with no treatment
in-place is presented in Table 11-7.
For facilities which already have chemical
precipitation treatment in-place, EPA estimated
an O&M upgrade cost. EPA assumed that
facilities with primary chemical precipitation in-
place have effluent concentrations exiting the
primary precipitation/solid-liquids separation
system equal to the metals subcategory primary
precipitation current loadings. Similarly, EPA
assumed that facilities with secondary chemical
precipitation in place have effluent concentrations
exiting the secondary precipitation/solid-liquids
separation system equal to metals subcategory
secondary precipitation current loadings (see
chapter 12 for a detailed discussion of metals
subcategory primary and secondary chemical
precipitation current loadings).
For the portion of the O&M upgrade
equation associated with energy, maintenance,
and labor, EPA calculated the percentage
difference between the primary precipitation
current loadings and Metals Option 4 (Sample
Point-03) concentrations. For facilities which
currently have primary precipitation systems this
difference is an increase of approximately two
percent. Therefore, EPA calculated the energy,
maintenance, and labor components of the O&M
upgrade cost for facilities with primary chemical
precipitation in-place at two percent of the O&M
cost for facilities with no chemical precipitation
in-place.
For the portion of the O&M upgrade
equation associated with energy, maintenance,
and labor, EPA calculated the percentage
difference between secondary precipitation
current loadings and Metals Option 4 (Sample
Point-03) concentrations. For secondary
precipitation systems, this difference is also an
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Chapter 11 Cost of Treatment Technologies
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increase of, approximately two percent1.
Therefore, EPA calculated the energy,
maintenance, and labor components of the O&M
upgrade cost for facilities with secondary
chemical precipitation in-place at two percent of
the O&M cost for facilities with no chemical
precipitation in-place.
For the chemical cost portion of the O&M
upgrade, EPA also calculated upgrade costs
depending on whether the facility had primary
precipitation or secondary precipitation currently
in-place. For facilities with primary precipitation,
EPA calculated chemical upgrade costs based on
current-to-Metals Option 4 (Sample Point-03)
removals. Similarly for facilities with secondary
precipitation, EPA calculated chemical upgrade
costs based on secondary precipitation removals
to Metals Option 4 (Sample Point -03) removals.
In both cases, EPA did not include costs for pH
adjustment or buffering chemicals since these
chemicals should already be used in the in-place
treatment system. .Finally, EPA included a 10
percent excess of chemical dosage to the
stoichiometric requirements of the precipitation
chemicals.
EPA then combined the energy, maintenance
and labor components of the O&M upgrade with
the chemical portion of the O&M upgrade to
develop two sets of O&M upgrade equations for
the primary chemical precipitation portion of
Metals Option 4. These cost equations for
Metals Option 4 (primary chemical precipitation
O&M upgrade costs) for facilities with primary
and secondary treatment in place are presented
Table 11-7.
1 While pollutant concentrations resulting
from secondary chemical precipitation are generally
lower than those resulting from primary chemical
precipitation, the percentage increase (when
rounded) for primary and secondary precipitation are
the same.
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
Table 11-7. Cost Equations for Primary Chemical Precipitation in Metals Option 4
Description
Equation
Recommended Flow
Rate Range (MOD)
1.0E-6to5.0
1.0 E-6 to 0.005
Capital cost for primary precipitation ln(Yl) = 14.019 + 0.4811n(X) - 0.00307(ln(X))2
and no treatment in-place
Capital cost for holding tank only - ln(Yl) = 10.671 - 0.0831n(X) - 0.032(ln(X))2
used for facilities with chemical
precipitation currently in-place.
O&M cost for primary precipitation ln(Y2) = 15.3086 + 1.083491n(X) + 0.04891(ln(X))2 1.7 E -5 to 5.0
and no treatment in-place
O&M upgrade for facilities with
primary precipitation in-place
O&M upgrade for facilities with
secondary precipitation in-place
Land requirements
ln(Y2) = 11.4547 + 1.043371n(X) + 0.04575(ln(X))2 2.0 E -5 to 5.0
ln(Y3) = 10.9647 + 0.98525In(X) + 0.04426(ln(X))2 1.7 E -5 to 5.0
ln(Y3) = -1.019 + 0.299m(X) + 0.015(ln(X))2
Land requirements (associated with ln(Y3) = -2.866 - 0.023m(X) - 0.006(ln(X))2
holding tank only) ;
Yl = Capital Costs (1989 $)
Y2 » Operation and Maintenance Costs (1989 $ /year)
Y3 - Land Requirement (Acres)
X - Flow Rate (million gallons per day)
6.7 E-5 to 1.0
1.0 E-5 to 0.5
Secondary (Sulfide) Precipitation
for Metals Option 4 11.2.1.5
The Metals Option 4 secondary sulfide
precipitation system follows the primary metals
precipitation/clarification step. This equipment
consists of a mixed reaction tank with pumps and
a treatment chemical feed system, sized for the
full daily batch volume. For direct dischargers,
the overflow from secondary sulfide precipitation
would carry on to a clarifier and then multi-media
filtration. For indirect discharges, the overflow
would go immediately to the filtration unit,
without clarification. Cost estimates for the
clarifier are discussed in section 11.2.2.2 of this
document. Cost estimates for multi-media
filtration are presented in section 11.2.5.
For costing purposes, EPA assumed that
facilities either have secondary precipitation
currently in-place and attributes no additional
capital and O&M costs to these facilities, or EPA
assumes that facilities do not have secondary
sulfide precipitation in-place and, consequently,
EPA developed costs for Ml O&M and capital
costs. Therefore, EPA has not developed upgrade
costs associated with secondary precipitation in
Metals Option 4.
CAPITAL COSTS
EPA developed capital cost estimates for the
secondary sulfide precipitation systems in Metals
Option 4 from vendor's quotes. EPA estimated
the other components (i.e., piping,
instrumentation, and controls, etc.) of the sulfide
precipitation system by applying the same
methodology, factors and additional costs as
outlined for the primary chemical precipitation
system for Metals Option 4 (see Section 11.2.1.4
above). The capital cost equation for Metals
Option 4 secondary sulfide precipitation is
presented in Table 11-8 at the end of this section.
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
LABOR AND CHEMICAL COSTS
For facilities with no secondary precipitation
systems in-place, EPA estimated the labor
requirements at two hours per batch, one batch
per day. EPA based this estimate on standard
operation at the Metals Option 4 model facility.
For secondary sulfide precipitation in Metals
Option 4, EPA did not base the chemical cost
estimates on stoichiometric requirements.
Instead, EPA estimated the chemical costs based
on dosage rates for the addition of polymer and
ferrous sulfide obtained during the sampling of
the Metals Option 4 model plant with BAT
performance. The O&M cost equation for the
Metals Option 4, secondary sulfide precipitation
is presented in Table 11-8.
Table 11-8. Cost Equations for Secondary (Sulfide) Precipitation for Metals Option 4
Description
Equation
Recommended
Flow Rate Range
(MOD)
Capital cost for secondary precipitation In (Yl) = 13.829 + 0.544ln(X) + 0.00000496(ln(X))2 1.0 E -6 to 5.0
and no treatment in-place
O&M cost for secondary precipitation In (Y2) = 12.076 + 0.634561n(X) + 0.03678(ln(X))2
and no treatment in-place
Land requirements
In (Y3) = -1.15 + 0.4491n(X) + 0.027(ln(X))2
1.8 E-4 to 5.0
2.5 E-4 to 1.0
Yl = Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 = Land Requirement (Acres)
X = Flow Rate (million gallons per day)
Plate and Frame Liquid
Filtration and Clarification
11.2.2
Clarification systems provide continuous,
low-cost separation and removal of suspended
solids from water. Waste treatment facilities use
clarification to remove particulates, flocculated
impurities, and precipitants, often following
chemical precipitation. Similarly, waste
treatment facilities also use plate and frame
pressure systems to remove solids from waste
streams. As described in this section, these plate
and frame filtration systems serve the same
function as clarification and are used to remove
solids following chemical precipitation from
liquid wastestreams. The major difference
between clarification systems and plate and frame
liquid filtration systems is that the sludge
generated by clarification generally needs to be
processed further prior to landfilling, whereas, the
sludge generated by plate and frame liquid
filtration does not.
EPA costed facilities to include a plate and
frame liquid filtration system following selective
metals precipitation in Metals Options 2 and 3.
The components of the plate and frame liquid
filtration system include: filter plates, filter cloth,
hydraulic pumps, control panel, connector pipes,
and a support platform. Since EPA costed all
metals facilities for selective metals precipitation
systems for metals Options 2 and 3 (except the
one facility which already utilizes this
technology), EPA also costed all metals facilities
for plate and frame liquid filtration systems.
Consequently, EPA did not develop any upgrade
costs associated with the use of plate and frame
liquid filtration.
EPA also costed facilities to include a
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Chanter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
clarifier following secondary precipitation for
Metals Option 2 and following both secondary
and tertiary precipitation for Metals Option 3.
For Metals Option 4, EPA costed facilities to
include a clarifier following primary chemical
precipitation and following secondary
precipitation (for direct dischargers only). EPA
designed and costed a single clarification system
for all options and locations in the treatment
train. The components of this clarification
system include a clarification unit, flocculation
unit, pumps, motor, foundation, and accessories.
Plate and Frame Liquid
Filtration Following Selective
Metals Precipitation
112.2.1
CAPITAL COSTS
The plate and frame liquid filtration
equipment following the selective metals
precipitation step for the model technology in
Metals Option 2 and 3 consists of two plate and
frame liquid filtration systems. EPA assumed
that each system would be used to process two
batches per day for a total of four batches. EPA
costed the plate and frame liquid filtration
systems in this manner to allow facilities to
segregate their wastes into smaller batches,
thereby facilitating selective metals recovery.
EPA sized each of the units to process a batch
consisting of 25 percent of the daily flow and
assumed that the influent to the plate and frame
filtration units would consist of 96 percent liquid
and four percent (40,000 mg/1) solids (based on
the model facility). EPA based the capital cost
equation for plate and frame liquid filtration for
Metals Options 2 and 3 on information provided
by vendors. This capital cost equation is listed in
Table 11-9.
CHEMICAL USAGE AND LABOR REQUIREMENTS
EPA estimated that labor requirements for
plate and frame liquid filtration for Metals
Options 2 and 3 would be 30 minutes per batch
per filter press (based on the metals Options 2
and 3 model facility). There are no chemicals
associated with the operation of the plate and
frame filtration systems. EPA estimated the
remaining components of O&M using the factors
listed in Table 11-2. The: O&M equation for
plate and frame liquid filtration is listed in Table
11-9.
Even though the metal-rich sludge generated
from selective metals precipitation and plate and
frame liquid filtration may be recycled and re-
used, EPA additionally included costs associated
with disposal of these sludges in a landfill. The
discussion for filter cake disposal is presented
separately in Section 11.4.2. These disposal
costs are additional O&M costs which must be
added to the O&M costs calculated above to
obtain the total O&M costs associated with plate
and frame liquid filtration for Metals Options 2
and 3.
Clarification for Metals
Options 2,3, and 4
11.2.2.2
CAPITAL COSTS
EPA obtained the capital cost estimate for
clarification systems from vendors. EPA
designed the clarification system assuming an
influent total suspended solids (TSS)
concentration of 40,000 mg/L (four percent
solids) and an effluent TSS concentration of
200,000 mg/L (20 percent solids). In addition,
EPA assumed a design overflow rate of 600
gpd/ft2. EPA estimated the influent and effluent
TSS concentrations and overflow rate based on
the WTI Questionnaire response for
Questionnaire ID 105. The: capital cost equation
for clarification is presented in Table 11-9 at the
end of this section. As detailed earlier, the same
capital cost equation is used for all of the
clarification systems for all of the metals options
regardless of its location in the treatment train.
EPA did not develop capital cost upgrades for
facilities which already have: clarification systems
in-place. Therefore, facilities which currently
have clarifiers have no land or capital costs.
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Chapter XI Cost of Treatment Technologies
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CHEMICAL USAGE AND LABOR REQUIREMENTS
EPA estimated the labor requirements for the
clarification systems for Metals Options 2 and 3
following secondary precipitation and Metals
Option 4 following primary and secondary (for
direct dischargers only) precipitation at three
hours per day for low-flow clarifiers and four to
six hours per day for high-flow clarifiers. Based
on manufacturers recommendations, EPA
selected the flow cut-off between high-flow and
low-flow systems to be 1000 gallons per day.
For the clarifier following tertiary precipitation in
Metals Option 3 only, EPA estimated the labor
requirement at one hour per day (based on the
operation of the Metals Option 3 model facility).
For all clarifiers for all metals options and
treatment train locations, EPA estimated a
polymer dosage rate of 2.0 mg per liter of
wastewater (for the flocculation step) based on
the MP&M industry cost model. EPA estimated
the remaining components of O&M using the
factors listed in Table 11-2. The two cost
equations developed for clarification are listed in
Table 11-9. One equation is used for the clarifier
following the tertiary precipitation step of Metals
Option 3 and the other equation is used for all
other Metals options and locations in the
treatment train.
As shown in Table 11-3, sludge filtration
follows clarification for the secondary
precipitation step of Metals Options 2 and 3 and
the primary and secondary (direct dischargers
only) of Metals Option 4. The costing discussion
and equations for sludge filtration and the
associated filter cake disposal are presented in
Section 11.4.1 and 11.4.2, respectively.
For facilities which already have clarification
systems or plate and frame liquid filtration
systems in-place for each option and location in
the treatment train, EPA estimated clarification
upgrade costs. EPA assumed that in-place
clarification systems and in-place plate and frame
liquid filtration systems are equivalent.
Therefore, if a facility has an in-place liquid
filtration system which can serve the same
purpose as a clarifier, EPA costed this facility for
an up-grade only and not a new clarification
system.
For the clarification step following secondary
precipitation in Metals Options 2 and 3, in order
to quantify the O&M increase necessary for the
O&M upgrade, EPA compared the difference
between secondary precipitation current
performance concentrations and the Metals
Option 2 long- term averages. EPA determined
facilities would need to increase their current
removals by 3 percent. Therefore, for in-place
clarification systems (or plate and frame liquid
filtration systems) which could serve as the
clarifier following secondary chemical
precipitation for Metals Option 2 and 3, EPA
included an O&M cost upgrade of three percent
of the O&M costs for a brand new system (except
for taxes, insurance, and maintenance which are
a function of the capital cost). The O&M
upgrade equations for clarification following
secondary chemical precipitation for Metals
Option 2 and 3 (one for facilities which currently
have a clarifier and one for facilities which
currently have a plate and frame liquid filtration
system) are listed in Table 11-9.
For facilities which already have clarifiers or
plate and frame liquid filtration systems in-place
which could serve as the clarifier following the
tertiary chemical precipitation of Metals Option
3, EPA did not estimate any O&M upgrade costs.
EPA assumed the in-place technologies could
perform as well as (or better) than the technology
costed by EPA.
For facilities which already have clarifiers or
plate and frame liquid filtration systems in-place
which could serve as the clarifier following the
primary chemical precipitation of Metals Option
4, EPA compared the difference between primary
precipitation current loadings and the long-term
averages for Metals Option 4, Sample Point 03
(Sample Point 03 follows primary precipitation
and clarification at the Metals Option 4 model
facility). EPA determined that facilities would
need to increase their removals by 2%.
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
Therefore, for in-place clarification systems (or
plate and frame liquid filtration systems) which
could serve as the clarifier following primary
chemical precipitation for Metals Option 4, EPA
included an O&M cost upgrade of two percent of
the O&M costs for a brand new system (except
for taxes, insurance, and maintenance which are
a function of the capital cost). The O&M
upgrade equations for clarification following
primary chemical precipitation for Metals
Option4 (one for facilities which currently have a
clarifier and one for facilities which currently
have a plate and frame liqiuid filtration system)
are listed in Table 11-9.
EPA did not calculate an O&M upgrade
equation for the clarification step following
secondary chemical precipitation (direct
dischargers only) of Melials Option 4. EPA
costed all direct discharging facilities for a new
clarification system following secondary chemical
precipitation for Metals Option 4 since none of
the direct discharging metals facilities had
treatment in-place for this step.
Table 11-9. Cost Equations for Clarification and Plate and Frame Liquid Filtration in Metals Option 2,3,4
Description
Equation
Recommended
Flow Rate
Range (MOD)
Capital cost for plate and frame liquid filtration for ln(Yl) =
Metals Options 2 and 31
Capital Cost for Clarification for Metals Options ln(Yl) =
2,3, and 4
O&M cost for plate and frame liquid filtration for ln(Y2) =
Metals Options 2 and 31
14.024 + 0.8591n(X) + 0.040(ln(X)r
11.552 + 0.4091n(X) + 0.020(ln(X))2
13.056 + 0.1931n(X) + 0.00343(ln(X))2
O&M cost for Clarification for Metals Options ln(Y2) = 10.673 + 0.2381n(X) + 0.013(ln(X))2
2,33,and4
O&M cost for clarification for Metals Option 34 ln(Y2) = 10.294 + 0.3621n(X) + 0.019(ln(X))2
O&M upgrade for Clarification for Metals' ln(Y2) = 7.166 + 0.2381n(X) + 0.013(ln(X))2
Options 2 and 3 — facilities which currently have
clarification in-place5
O&M upgrade for Clarification for Metals ln(Y2) = 8.707 + 0.3331n(X) + 0.012(ln(X)f
Options 2 and 3 — facilities which currently have .
plate and frame liquid filtration in-place
1.0 E-6 to 1.0
4.0 E-5 to 1.0
1.0 E-6 to 1.0
1.2 E-4 to 1.0
8.0 E-5 to 1.0
7.0 E-5 to 1.0
1.0 E-6 to 1.0
O&M upgrade for Clarification for
Metals Option 46
Land requirements for plate and frame liquid
filtration for Metals Options 2 and 3
Land requirements for clarification
ln(Y2) = 6.8135 + 0.33151n(X) + 0.0242(ln(X))2
ln(Y3) = -1.658 + 0.1851n(X) + 0.009(ln(X))2
ln(Y3) = -1.773 + 0.5131n(X) + 0.046(ln(X))2
1.2 E -3 to 1.0
1.0 E -6 to 1.0
1.0 E -2 to 1.0
Yl = Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 = Land Requirement (Acres)
X = Flow Rate (million gallons per day)
'Follows selective metals precipitation
3For metals option 3, this equation is used for clarification following secondary chemical precipitation only
''This equation is used for clarification following tertiary precipitation only.
5For Metals Option 3, this equation is used for clarification following secondary precipitation only. No O&M
upgrade costs included for tertiary precipitation.
^This equation is used for clarification following primary precipitation only. No facilities require O&M upgrades
for clarification following secondary chemical precipitation.
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Chapter 11 Cost of Treatment Technologies
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Equalization
11.2.3
To improve treatment, facilities often need to
equalize wastes by holding them in a tank. The
CWT industry frequently uses equalization to
minimize the variability of incoming wastes
effectively.
EPA costed an equalization system which
consists of a mechanical aeration basin based on
responses to the WTI Questionnaire. EPA
obtained the equalization cost estimates from the
1983 U.S. Army Corps of Engineers' Computer
Assisted Procedure for Design and Evaluation of
Wastewater Treatment Systems (CAPDET).
EPA originally used this program to estimate
equalization costs for the OCPSF Industry.
Tablell-10 lists the default design parameters
that EPA used in the CAPDET program. These
default design parameters are reasonable for the
CWT industry since they reflect values seen in
the CWT industry. For example, the default
detention time (24 hours) is appropriate since
this was the median equalization detention time
reported by respondents to the WTI
Questionnaire.
Tablell-10. Design Parameters Used for
Equalization in CAPDET Program
Aerator mixing requirements = 0.03 HP per
1,000 gallons';
Oxygen requirements = 15.0 mg/1 per hour;
Dissolved oxygen in basin = 2.0 mg/1;
Depth of basin = 6.0 feet; and
Detention time = 24 hours.
facilities would perform as well as (or better than)
the system costed by EPA.
CAPITAL COSTS
The CAPDET program calculates capital
costs which are "total project costs." These
"total project costs" include all of the items
previously listed in Table 11-1 as well as
miscellaneous nonconstruction costs, 201
planning costs, technical costs, land costs,
interest during construction , and laboratory
costs. Therefore, to obtain capital costs for the
equalization systems for this industry, EPA
calculated capital costs based on total project
costs minus: miscellaneous nonconstruction
costs, 201 planning costs, technical costs, land
costs, interest during construction, and laboratory
costs. The resulting capital cost equation for
equalization is presented in Table 11-11 at the
end of this section.
OPERATION AND MAINTENANCE COSTS .
EPA obtained O&M costs directly from the
initial year O&M costs produced by the
CAPDET program. The O&M cost equation for
equalization systems is presented in Table 11-11.
LAND REQUIREMENTS
EPA used the CAPDET program to develop
land requirements for the equalization systems.
EPA scaled up the requirements to represent the
total land required for the system plus peripherals
(pumps, controls, access areas, etc.). The land
requirement equation for equalization systems is
also presented in Table 11-11.
EPA did not calculate capital or O&M
upgrade equations for equalization. If a CWT
facility currently has an equalization tank in-
place, the facility received no costs associated
with equalization. EPA assumed that the
equalization tanks currently in-place at CWT
11-17
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
Table 11-11. Summary of Cost Equations for Equalization
Description
Equation
Recommended Flow Rate
Range (MOD)
Capital cost for equalization
O&M cost for equalization
Land requirements
ln(Yl) = 12.057 + 0.4331n(X) + 0.043(ln(X))2 6.6 E -3 to 5.0
ln(Y2)= 11.723 + 0.3111n(X) + 0.019(ln(X))2 3.0E-4to5.0
ln(Y3) = -0.912 + 1.1201n(X) + 0.01 l(ln(X))2 1.4 E-2 to 5.0
Yl - Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 - Land Requirement (Acres)
X - Flow Rate (million gallons per day)
Air Stripping
11.2.4
Air stripping is an effective wastewater
treatment method for removing dissolved gases
and volatile compounds from wastewater streams.
The technology passes high volumes of air
through an agitated gas-water mixture. This
promotes volatilzation of compounds, and,
preferably capture in air pollution control
systems.
The air stripping system costed by EPA
includes transfer pumps, control panels, blowers,
and ancillary equipment. EPA also included
catalytic oxidizers as part of the system for air
pollution control purposes.
If a CWT facility currently has an air.
stripping system in-place, EPA did not assign the
facility any costs associated with air stripping.
EPA assumed that the air stripping systems
currently in-place at CWT facilities would
perform as well as (or better than) the system
costed by EPA.
CAPITAL COSTS
EPA's air stripping system is designed to
remove pollutants with medium to high
volatilities. EPA used the pollutant 1,2-
dichloroethane, which has a Henry's Law
Constant of 9.14 E -4 atm*L/mol, as the design
basis with an influent concentration of 4,000
ug/L and an effluent concentration of 68 ug/L.
EPA based these concentration on information
collected on the model facility's operation. EPA
used the same design basis for the air stripping
systems costed for the option 8v and 9v in the
oils subcategory.
EPA obtained the equipment costs from
vendor quotations. The capital cost equation for
air stripping systems is presented in Table 11-13
at the end of this section.
OPERATION AND MAINTENANCE COSTS
For air stripping, O&M costs include
electricity, maintenance, labor, catalyst
replacement, and taxes and insurance. EPA
obtained the O&M costs from the same vendor
which provided the capital cost estimates.
EPA based the electricity usage for the air
strippers on the amount of horsepower needed to
operate the system and approximated the
electricity usage for the catalytic oxidizers at 50
percent of the electricity use:d for the air strippers.
EPA based both the horsepower requirements and
the electricity requirements for the catalytic
oxidizer on vendor's recommendations. EPA
estimated the labor requirement for the air
stripping system at three hours per day, which is
based on the model facility's operation. EPA
assumed that the catalyst beds in the catalytic
oxidizer would require replacement every four
years based on the rule of thumb (provided by the
vendor) that precious metal catalysts have a
11-18
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Chapter 11 Cost of Treatment Technologies
Development Document for the CWT Point Source Category
lifetime of approximately four years. EPA
divided the costs for replacing the spent catalysts
by four to convert them to annual costs. As is the
standard used by EPA for this industry, taxes and
insurance were estimated at 2 percent of the total
capital cost. The resulting O&M cost equation
for air stripping systems is presented in Table 11-
12.
Table 11-12. Cost Equations for Air Stripping
Description
Equation
Recommended Flow Rate
Range(MGD)
Capital cost for air stripping
O&M cost for air stripping
Land requirements
ln(Yl) = 12.899 + 0.4861n(X) + 0.03 l(ln(X))2 4.0 E -4 to 1.0
ln(Y2) = 10.865 + 0.2981n(X) + 0.021(ln(X))2 8.5 E -4 to 1.0
ln(Y3) = -2.207 + 0.5361n(X) + 0.042(ln(X))2 0.1 to 1.0
Yl = Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 = Land Requirement (Acres)
X = Flow Rate (million gallons per day)
Multi-Media Filtration
11.2.5
Filtration is a proven technology for the
removal of residual suspended solids from
wastewater. The multimedia filtration system
costed by EPA for this industry is a system which
contains sand and anthracite coal, supported by
gravel.
EPA based the design for the model
multimedia filtration system on the TSS effluent
long- term average concentration for Metals
Option 4 —'15 mg/L. EPA assumed that the
average influent TSS concentration to the
multimedia filtration system would range from 75
to 100 mg/L. EPA based the influent
concentration range on vendor's
recommendations on realistic TSS concentrations
resulting from wastewater treatment following
chemical precipitation and clarification.
EPA did not calculate capital or O&M
upgrade equations for multi-media filtration. If a
CWT facility currently has a multimedia filter in-
place, EPA assigned the facility no costs
associated with multi-media filtration. EPA
assumed that the multi-media filter currently in-
place at CWT facilities would perform as well as
(or better than) the system costed by EPA.
CAPITAL COSTS
EPA based the capital costs of multi-media
filters on vendor's recommendations. The
resulting capital cost equation for multi-media
filtration systems is presented in Table 11-13.
CHEMICAL USAGE AND LABOR
REQUIREMENT COSTS
EPA estimated the labor requirement for the
multi-media filtration system at four hours per
day, which is based on manufacturer's
recommendations. There are no chemicals
associated with the operation of a multimedia
filter. The O&M cost equation for the multi-
media filtration system is presented in Table 11-
13.
11-19
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Categor
Table 11-13. Cost Equations for Multi-Media Filtration
Description
Equation
Flow Rate Range
(MOD)
Capital cost for multi-media filtration
O&M cost for multi-media filtration
Land requirements
ln(Yl) = 12.0126 + 0.480251n(X) + 0.04623(m(X))2 5.7 E -3 to 1.0
ln(Y2) = 11.5039 + 0.724581n(X) + 0.09535(ln(X))2 2.3 E -2 to 1.0
ln(Y3) = -2.6569 + 0.193711n(X) + 0.02496(ln(X))2 2.4 E -2 to 1.0
Yl = Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 = Land Requirement (Acres)
X - Flow Rate (million gallons per day)
Cyanide Destruction
11.2.6
Many CWTs achieved required cyanide
destruction by oxidation. These facilities
primarily use chlorine (in either the elemental or
hypochlorite form) as the oxidizing agent in this
process. Oxidation of cyanide with chlorine is
called alkaline chlorination.
The oxidation of cyanide waste using sodium
hypochlorite is a two step process. In the first
step, cyanide is oxidized to cyanate in the
presence of hypochlorite, and sodium hydroxide
is used to maintain a pH range of 9 to 11. The
second step oxidizes cyanate to carbon dioxide
and nitrogen at a controlled pH of 8.5. The
amounts of sodium hypochlorite and sodium
hydroxide needed to perform the oxidation are
8.5 parts and 8.0 parts per part of cyanide,
respectively. At these levels, the total reduction
occurs at a retention time of 16 to 20 hours. The
application of heat can facilitate the more
complete destruction of total cyanide.
The cyanide destruction system costed by
EPA includes a two-stage reactor with a retention
time of 16 hours, feed system and controls,
pumps, piping, and foundation. The two-stage
reactor includes a covered tank, mixer, and
containment tank. EPA designed the system
based on a total cyanide influent concentration of
4,633,710 ug/L and an effluent concentration of
total cyanide of 135,661 ug/L. EPA based these
influent and effluent concentrations on data
collected during EPA's sampling of cyanide
destruction systems.
Because the system used by the facility which
forms the basis of the proposed cyanide limitation
and standards uses special operation conditions,
EPA assigned full capital and O&M costs to all
facilities which perform cyanide destruction.
CAPITAL COSTS
EPA obtained the capital costs curves for
cyanide destruction systems with special
operating conditions from vendor services. The
capital cost equation is presented in Table 11-14.
CHEMICAL USAGE AND LABOR
REQUIREMENT COSTS
In estimating chemical usage and labor
requirements, EPA assumed the systems would
treat one batch per day. EPA based this
assumption on responses to the WTI
Questionnaire. Based on vendor's
recommendations, EPA estimated the labor
requirement for the cyanide destruction to be
three hours per day. EPA determined the amount
of sodium hypochlorite and sodium hydroxide
required based on the stochiometric amounts to
maintain the proper pH and chlorine
concentrations to facilitate the cyanide
destruction as described earlier. The O&M cost
equation for cyanide destruction is presented in
Table 11-14.
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a^ter 11 Cost of Treatment Technologies
Development Document for the CWTPoint Source Categor
Table 11-14. Cost Equations for Cyanide Destruction
Description
Equation
Recommended Flow
Rate Range (MOD)
Capital cost for cyanide destruction
O&M cost for cyanide destruction
Land requirements
ln(Yl) = 13.977 + 0.5461n(X) + 0.0033(ln(X))2 1.0 E -6 to 1.0
ln(Y2) = 18.237 + 1.3181n(X) + 0.04993(ln(X))2 1.0 E-5 to 1.0
ln(Y3) = -1.168 + 0.4191n(X) + 0.021(ln(X))2 1.0 E -4 to 1.0
Yl = Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 = Land Requirement (Acres)
X = Flow Rate (million gallons per day)
Secondary Gravity Separation
11.2.7
Primary gravity separation provides oil and
grease removal from oily wastewater. During
gravity separation, the wastewater is held in tanks
under quiescent conditions long enough to allow
the oil droplets to rise and form a layer on the
surface, where it is skimmed.
Secondary gravity separation .systems
provide additional oil and grease removal for oily
wastewater. Oily wastewater, after primary
gravity separation/emulsion breaking, is pumped
into a series of skimming tanks where additional
oil and grease removal is obtained before the
wastewater enters the dissolved air flotation unit.
The secondary gravity separation equipment
discussed here consists of a series of three
skimming tanks in series. The ancillary
equipment for each tank consists of a mix tank
with pumps and skimming equipment.
In estimating capital and O&M cost
associated with secondary gravity separation,
EPA assumed that facilities either currently have
or do not have secondary gravity separation.
Therefore, EPA did not develop any secondary
gravity separation upgrade costs.
CAPITAL COSTS
EPA obtained the capital cost estimates for
the secondary gravity separation system from
vendor quotes. The capital cost equation for
secondary gravity separation is presented in
Table 11-15 at the end of this section.
CHEMICAL USAGE AND LABOR
REQUIREMENT COSTS
, EPA estimated the labor requirement to
operate secondary gravity separation to be 3 to 9
hours per day depending on the size of the
system. EPA obtained this estimate from one of
the model facilities for Oils Option 9. There are
no chemicals associated with the operation of the
secondary gravity separation system. The O&M
Cost equation for the secondary gravity
separation system is presented in Table 11-15.
Table 11-15. Cost Equations for Secondary Gravity Separation
Description
Equation
RecommendedFlow
Rate Range (MOD)
Capital cost for secondary gravity separation ln(Yl) = 14.3209 + 0.387741n(X) - 0.01793(ln(X))2 5.0 E -4 to 5.0
ln(Y2) = 12.0759 + 0.44011n(X) + 0.01544(ln(X))2 5.0 E -4 to 5.0
1.0 E-6 to 1.0
O&M cost for secondary gravity separation
Land reauirements
ln(Y3) = -0.2869 + 0.313871n(X) + 0.01191(ln(X))2
Yl = Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 = Land Requirement (Acres)
X = Flow Rate (million gallons per day)
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Categor
Dissolved Air Flotation
11.2.8
Flotation is the process of inducing
suspended particles to rise to the surface of a tank
where they can be collected and removed.
Dissolved Air Flotation (DAF) is one of several
flotation techniques employed in the treatment of
oily wastewater. DAF is commonly used to
extract free and dispersed oil and grease from oily
wastewater.
CAPITAL COSTS
EPA developed capital cost estimates for
dissolved air flotation systems for the oils
subcategory Options 8 and 9. EPA based the
capital cost estimates for the DAF units on'
vendor's quotations. EPA assigned facilities with
DAF units currently in-place no capital costs.
For facilities with no DAF treatment in-place, the
DAF system consists of a feed unit, a chemical
addition mix tank, and a flotation tank. EPA also
included a sludge filtration/dewatering unit. EPA
developed capital cost estimates for a series of
flow rates ranging from 25 gpm (0.036 MOD) to
1000 gpm (1.44 MOD). EPA was unable to
obtain costs estimates for units with flows below
25 gallons per minute since manufacturers do not
sell systems smaller than those designed for flows
below 25 gallons per minute.
The current DAF system capital cost
estimates include a sludge filtration/dewatering
unit For facilities which do not have a DAF unit
in-place, but have other treatment systems that
produce sludge (i.e. chemical precipitation and/or
biological treatment), EPA assumed that the
existing sludge filtration unit could accommodate
the additional sludge produced by the DAF unit.
For these facilities, EPA did not include sludge
filtration/dewatering costs in the capital cost
estimates. EPA refers to the capital cost equation
for these facilities as "modified" DAF costs. The
resulting total capital cost equations for the DAF
and modified DAF treatment systems are
presented in Table 11-17 at the end of this
section.
Because the smallest design capacity for
DAF systems that EPA could obtain from
vendors is 25 gpm and since more than 75
percent of the oils subcategory facilities have
flow rates lower than 25 gpm, EPA assumed that
only facilities with flow rates above 20 gpm
would operate their DAF systems everyday (i.e.
five days per week). EPA assumed that the rest
of the facilities could hold their wastewater and
run their DAF systems from one to four days per
week depending on their flowrate. Facilities that
are not operating their DAF treatment systems
everyday would need to install a holding tank to
hold their wastewater until treatment.
Therefore, for facilities which do not currently
have DAF treatment in place and which have flow
rates less than 20 gallons per minute, EPA
additionally included costs for a holding tank. For
these facilities, EPA based capital costs on a
combination of DAF cosls (or modified DAF
costs) and holding tank costs. Table 11-16A lists
the capacity of the holding tank costed for various
flowrates.
Table 11-16A. Estimate Holding Tank
Capacities for DAF Systems
Flowrate Holding Tank Capacity
(GPM) (gallons)
<5
5-10
10-15
15-20
>20
7,200
14,400
21,600
28,800
none
The resulting capital cost equation for the holding
tank associated with the DAF and modified DAF
systems is presented in Table 11-17 at the end of
this section.
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of Treatment XecKnolosies
Development Document for the CWTPoint Source Category
CHEMCAt USAGE AND LABOR
REQUIREMENT COSTS
EPA estimated the labor requirements
associated with the model technology at four
hours per day for the small systems to eight hours
per day for the large systems, which is based on
the average of the Oils Options 8 and 9 model
facilities. EPA used the same labor estimate for
DAF and "modified" DAF systems.
As discussed in the capital cost section, EPA
has assumed that facilities with flow rates below
20 gpm will not operate the DAF daily.
Therefore, for these lower flow rate facilities,
EPA only included labor to operate the DAF (or
"modified" DAF) systems for the days the system
will be operational. Table 11-16B lists the
number of days per week EPA assumed these
lower flow facilities would operate their DAF
systems-
Table 11-16B. Estimate Labor Requirements
for DAF Systems
Flowrate Labor Requirements
(GPM) , (days/week)
<5
5-10
10-15
15-20
>20
1
2
3
4
5
As detailed earlier, however, EPA also
assumed that facilities with flow rates below 20
gpm, would also operate a holding tank.
Therefore, for facilities with flow rates below 20
gallons per minute, EPA included additional labor
to operate the holding tank.
EPA calculated chemical cost estimates for
DAF and "modified" DAF systems based on
additions of aluminum sulfate, caustic soda, and
polymer. EPA costed for facilities to add 550
mg/L alum, 335 mg/L polymer and 1680 mg/L of
NaOH. EPA also included costs for perlite
addition at 0.25 Ibs per Ib of dry solids for
sludge conditioning and sludge dewatering
operations (for DAF, not "modified" DAF
systems). EPA based the chemical additions on
information gathered from literature, the database
for the proposed Industrial Laundries Industry
guidelines and standards, and sampled facilities.
For a special set of facilities—referred to as
"group 5 facilities" in the oils subcategory
current performance modeling estimates — EPA
estimated the chemical additions at 760 mg/L
alum, 460 mg/L polymer, and 2300 mg/L NaOH.
EPA costed these facilities for additional
chemicals because the concentration of metal
analytes assigned to the group 5 facilities was
significantly higher than the metal concentrations
assigned to the facilities in the other modeling
groups (See Chapter 12). Hence, it would be
necessary to use larger dosages of flocculent
chemicals to remove the higher metals
concentrations associated with these group 5
facilities. Therefore, in addition to the four O&M
equations developed for DAF and modified DAF
systems with flowrates above and below 20 gpm,
EPA additionally developed four O&M equations
for these group 5 facilities
Finally, similar to the labor requirements
shown in table 11-16B, EPA based chemical
usage cost estimates for the DAF and modified
DAF systems assuming five days per week
operation for facilities with flowrates greater than
20 gpm and from one to four days per week for
facilities with flowrates of 5 to 20 gpm.
The eight equations relating the various types
of O&M costs developed for DAF treatment for
facilities with no DAF treatment in-place are
presented in Table 11-17 at the end of this
section.
For facilities with DAF treatment in-place,
EPA estimated O&M upgrade costs. These
facilities would need to improve pollutant
removals from their current DAF current
11-23
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Chapter 11 Cost of Treatment Technologies
Development Document for the CWT Point Source Category
performance concentrations to the Oils Option 8
and Option 9 long-term averages. As detailed in
Chapter 12, EPA does not have current
performance concentration data for the majority
of the oils facilities with DAF treatment in-place.
EPA does, however, have seven data sets which
represent effluent concentrations from emulsion
breaking/gravity separation. While the pollutant
concentrations in wastewater exiting emulsion
breaking/gravity separation treatment are higher
(in some cases, considerably higher) than the
pollutant concentrations in wastewater exiting
DAF treatment, EPA has, nevertheless, used the
emulsion breaking/gravity separation data sets to
estimate DAF upgrade costs. For each of the
seven emulsion breaking/gravity separation data
sets, EPA calculated the percent difference
between these concentrations and the Option 8
and Option 9 long-term averages. The median of
these seven calculated percentages is 25 percent.
Therefore, EPA estimated the energy, labor,
and chemical cost components of the O&M
upgrade cost as 25 percent of the full O&M cost
of anew system. EPA assumed that maintenance,
and taxes and insurance would be zero since they
are functions of the capital cost (that is, there is
no capital cost for the upgrade). EPA developed
two separate O&M upgrade cost equations for
facilities which currently have DAF treatment in
place — one for facilities with flowrates up to 20
gpm and one for facilities with flow rates greater
than 20 gpm. Similarly, EPA developed two
separate O&M upgrade equations — one for
facilities which currently have DAF treatment in-
place and were assigned Group 5 concentrations
in the first step of EPA's current performance
modeling procedure and one for facilities which
currently have DAF treatment in-place and were
assigned concentrations from one of the other six
groups in the first step of EPA's current
performance modeling procedure. The four
equations representing O&M upgrade costs for
facilities with DAF treatment in-place are
presented in Table 11-17.
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Chapter 11 Cost of Treatment Technologies
Development Document for the CWTPoint Source Category
Table 11-17. Cost Equations for Dissolved Air Flotation (DAF) in Oils Options 8 and9
Description
Equation
Recommended Flow
Rate Range (MOD)
Total capital cost for DAF
Total capital cost for modified DAF
Holding tank capital cost for DAF and
modified DAF'
O&M cost for DAF with flowrate above
20gpm
O&M cost for modified DAF with
flowrate above 20 gpm
O&M cost for DAF with flowrate below
20 gpm
O&M cost for modified DAF with
flowrate below 20 gpm
O&M cost for group 5, DAF with flowrate
above 20 gpm
O&M cost for group 5, modified DAF
with flowrate above 20 gpm
O&M cost for group 5, DAF with flowrate
below 20 gpm
O&M cost for group 5, modified DAF
with flowrate below 20 gpm
O&M upgrade for DAF with flowrate
below 20 gpm
O&M upgrade for DAF with flowrate
above 20 gpm
O&M upgrade for group 5, DAF with
flowrate below. 20 gpm
O&M upgrade for group 5, DAF with
flowrate above 20 gpm
Land required for holding tank'
Land required for DAF and modified DAF
ln(Yl) = 13.9518 + 0.294451n(X) - 0.12049(ln(X))2
ln(Yl) = 13.509 + 0.294451n(X) - 0.12049(ln(X))2
ln(Yl) = 13.4616 + 0.54421m(X) + 0.00003(ln(X))2
14.5532 + 0.964951n(X) + 0.01219(ln(X))2
14.5396 + 0.976291n(X) + 0.0145 l(ln(X))2
21.2446 + 4.148231n(X) + 0.36585(ln(X))2
21.2005 + 4.074491n(X) + 0.34557(ln(X))2
14.8255 + 0.97411n(X) + 0.01005(ln(X))2
14.8151 + 0.982861n(X) + 0.01176(ln(X))2
21.8136 + 4.252391n(X) + 0.36592(ln(X))2
21.6503 + 4.119391n(X) + 0.33896(ln(X))2
19.0459 + 3.55881n(X) + 0.25553(m(X))2
13.1281 + 0.997781n(X) + 0.01892(ln(X))2
19.2932 + 3.509231n(X) + 0.23946(ln(X))2
ln(Y2)
In(Y2)
ln(Y2)
ln(Y2)
ln(Y2)
m(Y2)
ln(Y2)
ln(Y2)
ln(Y2)
ln(Y2)
ln(Y2)
ln(Y2)
= 13.4098 + 0.999251n(X) + 0.01496(ln(X))2
ln(Y3) = -1.5772 + 0.359551n(X) + 0.02013(ln(X))2
ln(Y3) = -0.5107 + 0.512171n(X) - 0.01892(ln(X))2
0.036 to 1.44
0.036 to 1.44
5.0 E-4 to 0.05
0.036 to 1.44
0.036 to 1.44
7.2 E -3 to 0.029
7.2 E-3 to 0.029
0.036 to 1.44
0.036 to 1.44
7.2 E-3 to 0.029
7.2 E -3 to 0.029
7.2 E -3 to 0.029
0.036 to 1.44
7.2 E -3 to 0.029
0.036 to 1.44
5.0 E-4 to 0.05
0.036 to 1.44
Yl = Capital Costs (1989 $)
Y2 = Operation and Maintenance Costs (1989 $ /year)
Y3 = Land Requirement (Acres)
X = Flow Rate (million gallons per day)
'Only facilities with flow rates below 20 gpm receive holding tank costs.
BIOLOGICAL WASTEWATER
TREATMENT TECHNOLOGY COSTS 11.3
Sequencing Batch Reactors 11.3.1
A sequencing batch reactor (SBR) is a
suspended growth system in which wastewater is
mixed with retained biological floe in an aeration
basin. SBR's are unique in that a single tank acts
as an equalization tank, an aeration tank, and a
clarifier.
The SBR system costed by EPA for the
model technology consists of a SBR tank, sludge
handling equipment, feed system and controls,
pumps, piping, blowers, and valves. The design
parameters that EPA used for the SBR system
were the average influent and effluent BOD5,
ammonia, and nitrate-nitrite concentrations. The
average influent concentrations were 4800 mg/L,
995 mg/L, and 46 mg/L for BOD5, ammonia, and
nitrate-nitrite, respectively. The average effluent
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
BOD5, ammonia, and nitrate-nitrite
concentrations used were 1,600 mg/1, 615 mg/1,
and 1.0 mg/1, respectively. EPA obtained these
concentrations from the sampling data at the SBR
model facility. EPA assumed that all
existing biological treatment systems in-place at
organics subcategory facilities can meet the
limitations of this proposal without incurring
cost. This includes facilities which utilize any
form of biological treatment — not just SBRs.
Therefore, the costs presented here only apply to
facilities without biological treatment in-place.
EPA did not develop SBR upgrade costs for
either capital or O&M.
CAPITAL COSTS
EPA estimated the capital costs for the SBR
systems using vendor quotes which include
installation costs. The SBR. capital cost equation
is presented in Table 11-18 at the end of this
section.
OPERATION AND MAINTENANCE COSTS
The O&M costs for the SBR system include
electricity, maintenance, labor, and taxes and
insurance. No chemicals are utilized in the SBR
system. EPA assumed the labor requirements for
the SBR system to be four hours per day and
based electricity costs on horsepower
requirements. EPA obtained the labor and
horsepower requirements from vendors. EPA
estimated maintenance, taxes, and insurance
using the factors detailed in Table 11-2. The
SBR O&M cost equation is presented in Table
11-18.
Table 11-18. Cost Equations for Sequencing Batch Reactors
Description
Equation
Recommended
Flow Rate
Range(MGD)
Capital cost for sequencing batch reactors
O&M cost for sequencing batch reactors
Land requirements
ln(Yl) = 15.707 + 0.5121n(X) + (K0022(ln(X))2
ln(Y2) = 13.139 + 0.5621n(X) + 0.020(ln(X))2
ln(Y3) = -0.531 + 0.9061n(X) + 0.072(ln(X))2
1.0 E -7 to 1.0
3.4 E -7 to 1.0
1.9 E-3 to 1.0
Yl - Capital Costs (1989 $)
Y2 - Operation and Maintenance Costs (1989 $ /year)
Y3 - Land Requirement (Acres)
X - Flow Rate (million gallons per day)
SLUDGE TREATMENT AND
DISPOSAL COSTS
Plate and Frame Pressure
Filtration — Sludge Stream
11.4
11.4.1
Pressure filtration systems are used for the
removal of solids from waste streams. This
section details sludge stream filtration which is
used to treat the solids removed by the clarifiers
in the metals options.
The pressure filtration system costed by EPA
for sludge stream filtration consists of a plate and
frame filtration system. The components of the
plate and frame filtration system include: filter
plates, filter cloth, hydraulic pumps, pneumatic
booster pumps, control panel, connector pipes,
and a support platform. For design purposes,
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Ckaoter 11 Cost of Treatment Technologies
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EPA assumed the sludge stream to consist of 80
percent liquid and 20 percent (200,000 mg/1)
solids. EPA additionally assumed the sludge
stream to be 20 percent of the total volume of
wastewater treated. EPA based these design
parameters on CWT Questionnaire 105.
In costing for sludge stream treatment, if a
facility does not have sludge filtration systems in-
place, EPA estimated capital costs to add a plate
and frame pressure filtration system to their on-
site treatment train2. If a facilty's treatment train
includes more than one clarification step in its
treatment train (such as for Metals Option 3),'
EPA only costedthe facility for a single plate and
frame filtration system. EPA assumed one plate
and frame filtration system could be used to
process the sludge from multiple clarifiers.
Likewise, if:a facility already had a sludge
filtration system in-place, EPA assumed that the
in-place system would be sufficient and did not
estimate any sludge filtration capital costs for
these facilities.
CAPITAL COSTS
EPA developed the capital cost equation for
plate and frame sludge filtration by adding
installation, engineering, and contingency costs to
vendors' equipment cost estimates. EPA used the
same capital cost equation for the plate and frame
sludge filtration system for all of the metals
options. The plate and frame sludge filtration
system capital cost equation is presented in Table
11-19.
2If a facility only had to be costed for a
plate and frame pressure filtration system to process
the sludge produced during the tertiary chemical
precipitation and clarifications steps of metals
Option 3, EPA did not cost the facility for a plate
and frame pressure filtration system. Likewise, EPA
assumed no O&M costs associated with the
treatment of sludge from the tertiary chemical
precipitation and clarification steps in Metals Option
3. EPA assumed that the total suspended solids
concentration at this point is so low that sludge
stream filtration is unnecessary.
OPERATION AND MAINTENANCE COSTS
METALS OPTION 2 AND 3
The operation and maintenance costs for
metals option 2 and 3 plate and frame sludge
filtration • consist of labor, electricity,
maintenance, and taxes and insurance. EPA .
approximated the labor requirements for the plate
.and frame sludge filtration system to be thirty
minutes per batch based on the Metals Option 2
and 3 model facility. Because no chemicals are
used with the plate and frame sludge filtration
units, EPA did not include costs for chemicals.
EPA estimated electricity, maintenance, and taxes
and irisurance using the factors listed in Table 11-
2. The resulting plate and frame sludge filtration
O&M cost equation is listed in Table 11-19.
For facilities which already have a sludge
filtration system in-place, EPA included plate and
frame filtration O&M upgrade costs. Since the
sludge generated from the secondary precipitation
and clarification steps in metals option 2 and 3 is
the sludge which requires treatment for these
options, these facilities would be required to
improve pollutant removals from their secondary
precipitation current performance concentrations
to the long term averages for Metals Options 2.
Therefore, EPA calculated the percent difference
between secondary precipitation current
performance and the Metals Option 2 long-term
averages. EPA determined this percentage to be
an increase of three percent.
As such, for facilities which currently have
sludge filtration systems in place, for metals
option 2 and 3, EPA included an O&M upgrade
cost which is three percent of the O&M costs of
a new system (except for taxes and insurance,
which are a function of the capital cost). The
O&M upgrade cost equation for sludge filtration
in Metals Option 2 and Option 3 is presented in
Table 11.19.
OPERATION AND MAINTENANCE COSTS
METALS OPTION 4
The operation and maintenance costs for
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
metals option 4 consists of labor, chemical
usage, electricity, maintenance, taxes, and
insurance, and filter cake disposal. The O&M
plate and frame sludge filtration costing
methodology For Metals Option 4 is very similar
to the one discussed previously for Metals Option
2 and 3. The primary differences in the
methodologies are the estimation of labor, the
inclusion of filter cakedisposal, and the O&M
upgrade methodology.
EPA approximated the labor requirement for
Metals Option 4 plate and frame sludge filtration
systems at 2 to 8 hours per day depending on the
size of the system. As was the case for metals
option 2 and 3, no chemicals are used in the plate
and frame sludge filtration units for metals
Option 4, and EPA estimated electricity,
maintenance and taxes and insurance using the
factors listed in Table 11-2. EPA also included
filter cake disposal costs at $0.74 per gallon of
filter cake. A detailed discussion of the basis for
the filter cake disposal costs is presented in
Section 11.4.2. The O&M cost equation for
sludge filtration for Metals Option 4 is presented
in Table 11-19.
Table 11-19. Cost Equations for Plate and Frame Sludge Filtration in Metals Option 2,3 and 4
Description
Equation
Recommended Flow
Rate Range (MOD)
Capital costs for plate and fiame sludge ln(Yl) = 14.827 + 1.0871n(X) + 0.0050(ln(X))2 2.0 E -5 to 1.0
filtration
O&M costs for sludge filtration for Metals ln(Y2) = 12.239 + 0.3881n(X) + 0.016(ln(X))2 2.0 E -5 to 1.0
Option 2 and 3 u
O&M costs for sludge filtration for Metals ln(Y2)= 15.9321 + 1.1771n(X) + 0.04697(ln(X))2 1.0E-5to 1.0
Option 44
O&M upgrade costs for sludge filtration for ln(Y2) = 8.499 + 0.33 lln(X) + 0.013(ln(X))2 2.0 E -5 to 1.0
Metals Option 2,3J'3
O&M upgrade cost for sludge filtration for ln(Y2)= 12.014+ 1.178461n(X) + 0.050(ln(X))2 1.0E-5to 1.0
Metals Option 4*
Land requirements for sludge filtration ln(Y3) = -1.971 + 0.2811n(X) + 0.018(ln(X))2 1.8 E -3 to 1.0
Yl «= Capital Costs (1989 $)
Y2 - Operation and Maintenance Costs (1989 $ /year)
Y3 - Land Requirement (Acres)
X ~ Flow Rate (million gallons per day)
^Following secondary chemical precipitation/clarification only. EPA assumed the sludge generated from tertiary
precipitation/clarification would not produce a significant quantity of sludge.
*This equation does not include filter cake disposal costs.
''This equation includes filter cake disposal costs.
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Chapter 11 Cost of Treatment Technologies
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For facilities which already have a sludge
filtration system in-place, EPA included sludge
stream filtration O&M upgrade costs. For Metals
Option 4, EPA included these O&M upgrade
costs for processing the sludge generated from
the primary precipitation and clarification steps3.
These facilities would need to improve pollutant
removals from their primary precipitation current
performance concentrations to Metals Option 4
(Sample Point-03) concentrations. This sample
point represents the effluent from the liquid-
solids separation unit following primary chemical
precipitation at the Metals Option 4 model
facility. Therefore, EPA calculated the percent
difference between primary precipitation current
performance concentrations and Metals Option 4
(Sample Point 03) concentrations. EPA
determined that there was an increase of two
percent.
As such, for facilities which currently have
sludge filtration systems in place, for metals
option 4, EPA included an O&M cost upgrade of
two percent of the total O&M costs (except for
taxes and insurance, which are a function of the
capital cost). The O&M upgrade cost equation
for sludge filtration for Metals Option is
presented in Table 11-19.
Filter Cake Disposal
11.4.2
The liquid stream and sludge stream pressure
filtration systems presented in Sections 11.2.3
and 11.4.1, respectively, generate a filter cake
residual. There is an annual O&M cost that is
associated with the disposal of this residual. This
cost must be added to the pressure filtration
equipment O&M costs to arrive at the total O&M
3 EPA did not include O&M upgrade costs
for the sludge generated from the secondary
precipitation and clarification step (direct
dischargers only).
costs for pressure filtration operation4.
To determine the cost of transporting and
disposing filter cake to an off-site facility, EPA
performed an analysis on a subset of
questionnaire respondents in the WTI
Questionnaire response database. This subset
consists of metals subcategory facilities that are
direct and/or indirect dischargers and that
provided information on contract haul and
disposal cost to hazardous (Subtitle C) and non-
hazardous (Subtitle D) landfills. From this set of
responses, EPA tabulated two sets of costs —
those reported for Subtitle C contract haul and
disposal and those reported for Subtitle D
contract haul and disposal, the reported costs for
both the Subtitle C and Subtitle D contract
haul/disposal. EPA then edited this information
by excluding data that was incomplete or that was
not separated by RCRA classification.
EPA used the reported costs information in
this data set to determine the median cost for both
the Subtitle C and Subtitle D disposal options,
and then calculated the weighted average of these
median costs. The average was weighted to
reflect the ratio of hazardous (67 percent) to
nonhazardous (33 percent) waste receipts at these
Metals Subcategory facilities. The final disposal
cost is $0.74 per gallon of filter cake.
EPA calculated a single disposal cost for
filter cake using both hazardous and non-
hazardous landfilling costs. Certain facilities will
incur costs, however, that, in reality, are higher
and others will incur costs that, in reality, are
lower. Thus, some low revenue metals
subcategory facilities that generate non-
hazardous sludge may show a higher economic
burden than is representative. On the other hand,
some low revenue metals subcategory facilities
that generate hazardous sludge may show a lower
4Note that these costs have already been
included in the O&M equation for plate and frame
sludge filtration for Metals Option 4.
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Chanter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
economic burden than is representative. EPA has
concluded that in the end, these over- and under
estimates will balance out to provide a
representative cost across the industry.
The O&M cost equation for filter cake
disposal for Metals Option 2 and Option 3 is
presented in Table 11-20. Table 11-20
additionally presents an O&M upgrade for filter
cake disposal resulting from Metals Option 2 and
Option 3 for facilities that already generate filter
cake as part of their operation.
This upgrade is 3 percent of the cost of the
O&M upgrade for facilities that do not already
generate filter cake as a part of their operation.
EPA used 3 percent because this was the same
percentage calculated for plate and frame sludge
filtration for these same options.
Table 11-20. Cost Equations for Filter Cake Disposal for Metals Options 2 and 31
Description
Equation
Recommended Flow
Rate Range (GPM)
O&M cost for filter cake disposal
O&M upgrade for filter cake disposal
Z = 0.109169 + 7,695,499.8(X)
Z = 0.101 186 + 230,879.8(X)
1.0 E -6 to 1.0
1.0 E -6 to 1.0
Z « Filter Cake Disposal Cost (1989 $ / year)
X » Flow Rate (million gallons per day)
'Filter cake disposal costs for Metals Option 4 are included in the sludge filtration equations.
ADDITIONAL COSTS
Retrofit Costs
11.5
11.5.1
EPA assigned costs to the CWT Industry on
both an option- and facility-specific basis. The
option-specific approach estimated compliance
cost for a sequence of individual treatment
technologies, corresponding to a particular
regulatory option, for a subset of facilities defined
as belonging to that regulatory subcategory.
Within the costing of a specific regulatory option,
EPA assigned treatment technology costs on a
facility-specific basis depending upon the
technologies determined to be currently in-place
at the facility.
Once EPA determined that a treatment
technology cost should be assigned to a particular
facility, EPA considered two scenarios. The first
was the installation of a new individual treatment
technology as a part of a new treatment train. The
full capital costs presented in Subsections 11.2
through 11.4 of this document apply to this
scenario. The second scenario was the
installation of a new individual treatment
technology which would have to be integrated
into an existing in-place treatment train. For
these facilities, EPA applied retrofit costs. These
. retrofit costs cover such items as piping and
structural modifications which would be required
in an existing piece of equipment to
accommodate the installation of a new piece of
equipment prior to or within an existing treatment
train.
For all facilities which received retrofit costs,
EPA added a retrofit factor of 20 percent of the
total capital cost of the newly-installed or
upgraded treatment technology unit that would
need to be integrated into an existing treatment
train. These costs are in addition to the specific
treatment technology capital costs calculated with
the technology specific equations described in
earlier sections.
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Chapter 11 Cost of Treatment Technologies
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Monitoring Costs
11.5.2
CWT facilities that discharge process
wastewater directly to a receiving stream or
indirectly to a POTW will have monitoring costs.
EPA regulations require both direct discharge
with NPDES permits and indirect dischargers
subject to categorical pretreatment standards to
monitor their effluent.
EPA used the following generalizations to
estimate the CWT monitoring costs:
1. EPA included analytical cost for parameters
at each subcategory as follows:
• TSS, O&G, Cr+6, total CN, and foil
metals analyses for the metals subcategory
direct dischargers, and Cr+6, total CN, and
full metals analyses for the metals
subcategory indirect dischargers;
• TSS, O&G, and foil metals and semi-
volatiles analyses'for the oils subcategory
option 8 and 9 direct dischargers, and foil
metals, and semi-volatiles for oils
subcategory options 8 and 9 indirect
dischargers;
• TSS, O&G, and foil metals, volatiles and
semi-volatiles analyses for the oils
subcategory direct dischargers, and foil
metals, volatiles, and semi-volatiles for
oils subcategory option 8V and 9V indirect
dischargers;
• TSS, BOD5, O&G, 6 individual metals,
volatiles, and semi-volatiles analyses for
the organics subcategory option 3 direct
dischargers, and 6 individual metals,
volatiles, and semi-volatiles analyses for
the organics subcategory option 3 indirect
dischargers; and
• TSS, BOD5, O&G, 6 individual metals,
and semi-volatiles analyses for the
organics subcategory option 4 direct
dischargers, and 6 individual metals and
semi-volatiles analyses for the organics
subcategory option 4 indirect dischargers.
EPA notes that these analytical costs may be
overstated for the oils and the organics
subcategories because EPA's final list of
pollutants proposed for regulation for these
subcategories do not include all of the parameters
included above.
2. The monitoring frequencies are listed in
Table 11-21 and are as follows:
Table 11-21. Monitoring Frequency Requirements
Parameter
Conventional*
Total Cyanide and Cr+6
Metals
Semi- Volatile Organics
Volatile Organics
Monitoring Frequency (samples/month)
Metals Subcategory
20
20
20
~
Oils Subcategory
20
4
4
4**
Organics Subcategory
20
4
4
4**
*Conventioiial monitoring for direct dischargers only.
**Volatile organics monitoring for oils option 8V and 9V and organics option 3 only.
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
3. For facilities in multiple subcategories, EPA
applied full multiple, subcategory-specific
monitoring costs.
4. EPA based the monitoring costs on the
number of outfalls through which process
wastewater is discharged. EPA multiplied
the cost for a single outfall by the number of
outfalls to arrive at the total costs for a
facility. For facilities for which this
information is not available, EPA assumed a
single outfall per facility.
5. EPA did not base monitoring costs on flow
rate.
6. EPA did not include sample collection costs
(labor and equipment) and sample shipping
costs, and
7. The monitoring cost (based on frequency and
analytical methods) are incremental to the
monitoring currently being incurred by the
CWT Industry. EPA applied credit to
facilities for current monitoring-in-place
(MP). For facilities where actual monitoring
frequencies are unknown, EPA estimated
monitoring frequencies based on other
subcategory facilities with known monitoring
frequencies.
The cost of the analyses needed to determine
compliance for the CWT pollutants are shown
below in Table 11-22. EPA obtained these costs
from actual quotes given by vendors and
converted to 1989 dollars using the ENR's
Construction Cost Index.
Table 11-22. Analytical Cost Estimates
Analyses
Cost
($1989)
BOD5 • $20
TSS $10
O&G $32
Cr+6 $20
Total CN $30
Metals: $335
Total (27 Metals) $335
Per Metal1 $35
Volatile Organics (method 1(524)2 $285
Semi-volatile Organics (method 1625)2 $615
'For 10 or more metals, use the foil metals analysis
cost of $335.
2There is no incremental cost per compound for
methods 1624 and 1625 (although there may be a
slight savings if the entire scan does not have to be
reported). Use the foil method cost, regardless of
the actual number of constituent parameters.
required.
RCRA Permit Modification Costs
11.5.3
Respondents to the WTI Questionnaire who
indicated that their RCRA Part B permits were
modified were asked to report the following
information pertaining to the: cost of obtaining the
modification:
• Legal fees;
• Administrative costs;
• Public relations costs;
• Other costs; and
• Total costs.
EPA also requested the reason for the permit
modification. Table 11-23 lists the RCRA permit
modification costs reported for installation of new
units, installation of new technology, and
modifications to existing equipment. As shown,
the average cost for these permit modifications is
$31,400. EPA anticipates that many CWT
facilities with RCRA Part B permits will be
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Civsoter 11 Cost o€Treatrtvent Technologies
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required to modify their permits to include the
upgrade of existing equipment and/or the
installation of new treatment technologies to
achieve the proposed CWT effluent limitations
and standards. Therefore, for all RCRA B
facilities, EPA additionally included a one-time
cost of $31,400 to modify their permit.
Table 11-23. RCRA Permit Modification Costs Reported in WTI Questionnaire
Modification
New Units
New Technology
Modify Existing
Equipment
Average
QID
081
255
081
090
402
-
Year
1990
1990
1990
1990
1991
-
Total Cost
(reported $)
26,000
7,000
82,000
6,300,000*
14,080
-
Total Cost
(1989 $)
25,357
6,827
79,793
6,144,231*
13,440
31,400
This cost includes equipment and installation costs; no cost breakdown is given.
Therefore, this data was not used in calculating the average cost.
Land Costs
11.5.4
An important factor in the calculation of
treatment technology costs is the value of the land
needed for the installation of the technology. To
determine the amount of land required for costing
purposes, EPA calculated the land requirements
for each treatment technology for the range of
system sizes. EPA fit these land requirements to
a curve and calculated land requirements, in
acres, for every treatment system costed. EPA
then multiplied the individual land requirements
by the corresponding state land cost estimates to
obtain facility-specific cost estimates.
EPA used different land cost estimates for
each state rather than a single nationwide average
since land costs may vary widely across the
country. To!estimate land costs for each state,
EPA obtained average land costs for suburban
sites for each state from the 1990 Guide to
Industrial and Real Estate Office Markets survey.
EPA based these land costs on "unimproved
sites" since, according to the survey, they are the
most desirable.
The survey additionally provides land costs
broken down by size ranges. These are zero to 10
acres, 10 to 100 acres, and greater than 100 acres.
Since CWT facilities fall into all three size ranges
(based on responses to the WTI Questionnaire),
EPA averaged the three size-specific land costs
. for each state to arrive at the final land costs for
each state.
The survey did not provide land cost
estimates for Alaska, Idaho, Montana, North
Dakota, Rhode Island, South Dakota, Utah,
Vermont or West Virginia For these states, EPA
used regional averages of land costs. EPA
determined the states comprising each region also
based on the aforementioned survey since the
survey categorizes the states by geographical
region (northeast, north central, south, and west).
In estimating the regional average costs for the
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
western region, EPA did not include Hawaii since
Hawaii's land cost is high and would have
skewed the regional average.
Table 11-24 lists the land cost per acre for
each state. As Table 11-24 indicates, the least
expensive state is Kansas with a land cost of
$7,042 per acre and the most expensive state is
Hawaii with a land cost of $1,089,000 per acre.
Table 11-24. State Land Costs for the CWT Industry Cost Exercise
State Land Cost per Acre (1989$) State Land Cost per Acre (1989$)
Alabama
Alaska*
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho*
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana*
22,773
81,105
46,101
15,899
300,927
43,560
54,232
54,450
63,273
72,600
1,089,000
81,105
36,300
21,078
8,954
7,042
29,040
56,628
19,602
112,530
59,895
13,649
21,054
13,068
39,930
81,105
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota*
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island*
South Carolina
South Dakota*
Tennessee
Texas
Utah*
Vermont*
Virginia
Washington
West Virginia*
Wisconsin
Wyoming*
Washington DC
24,684
36,300
52,998
89,443
26,929
110,013
33,880
20,488
14,578
24,321
50,820
32,307
59,822
21,296
20,488
20,873
47,674
81,105
59,822
39,930
63,670
47,345
17,424
81,105
174,240
* No data available for state, used regional average.
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Chapter 11 Cost of Treatment Technologies
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EXAMPLE 11-1:
Costing exercise for direct discharging metals subcategory facility with treatment in-place.
Example Facility Information:
Current Treatment In-Place:
Primary Chemical Precipitation + Clarification + Plate and Frame Sludge Filtration
Daily. Flow = 0.12196 MOD (Million Gallons/Day)
[NOTE: Daily Flow = X in costing equations]
Treatment Upgrades To Be Costed:
Primary Chemical Precipitation Upgrade + Clarifier Upgrade + Sludge Filtration Upgrade
Full Treatment Technologies To Be Costed:
Secondary Chemical Precipitation + Secondary Clarification + Multimedia Filtration
Section 11.2.1.4
Section 1 1.2.2
Section 11.2.1.3
1
Primary
Chemical
Precipitation
i
^
Clar
\
>
>
iQgj. Secondary
/ Precipitation
>
f Secoi
\Clai
Section 11.2.2
r • \
f
idary
Lfierx1
t
Sludge Multimedia
Filter Filter
Section 11. 4. 1.1
>
Section 11.2.6
f >
f
Figure 11-1. Metals Option 4 Model Facility Diagram
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Chapter 1 1 Cost of Treatment Technologies Development Document for the CWT Point Source Category
EXAMPLE 11-1. CONTINUED:
Capital Costs:
• Primary chemical precipitation upgrade, from Table 1 1-7, Section 1 1 .2. 1 .4.
The maximum size holding tank to be costed for a primary chemical precip.
upgrade is 0.005 MOD. In addition, there is a 20% retrofit cost for the upgrade.
ln(Yl) = 10.671 - 0.083*ln(X) - 0.032*(ln(X))2
= 10.671 - 0.083 *ln(0.005) - 0.032*(ln(0.005))2
= 10.212
.-. Yl = $27,240.25 * 1.2 = $32,688.30 *
• Clarification capital cost upgrade, following primary precipitation = $0.00 +
• Sludge filtration capital cost upgrade = $0 .00 •»
• Secondary chemical precipitation, full capital costs, from Table 11-8, Section 1 1 .2. 1 .5
ln(Yl) = 13.829 + 0.544*ln(X) + 4.96E-6*(ln(X))2
= 12.68441
.-. Yl =$322,678.63*
• Clarification, following secondary chemical precipitation, from Table 11-9, Section
11.2.2.2
ln(Yl) = 1 1 .552 + 0.409*ln(X) + 0.020*(ln(X))2
= 10.77998
.-. Yl = $48,049.17 «•
• Multi-media filtration capital costs, from Table 11-13, Section 11.2.5
ln(Yl) = 12.0126 + 0.48025*ln(X) + 0. 04623 *(ln(X))2
= 11.20679
.-. Yl =$73,628.54*
• Total capital cost (TCC)
TCC = £ (Individual Capital Costs)
.-. TCC = $477,045 •
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Chaotet \ 1 Cost of Treatment Technologies Development Document for the CWT Point Source Category
EXAMPLE 11-1. CONTINUED:
Operation and Maintenance Costs:
• Primary chemical precip. O&M upgrade, from Table 11 -7, Section 11.2.1.4
ln(Y2) = 11.4547 + 1.04337*ln(X) + 0.04575*(ln(X))2
= 11.4547 + 1.04337*ln(0.12196) + 0.04575*(ln(0.12196))2
= 9.46192
.-. Y2 = $12,860.60 «•
• Clarification O&M upgrade, following primary chemical precipitation, from Table 11-9,
Section 11.2.2
ln(Y2) = 6.81347 + 0.33149*ln(X) + 0.0242*(ln(X))2
= 6.22313
.-. Y2 = $504.28 4-
• Sludge filtration O&M upgrade, from Table 11-19, Section 11.4.1
ln(Y2) = 12.014 + 1.17846*In(X) + 0.05026*(ln(X))2
= 9.75695
/. Y2 = $17,273.90 > (which includes filter cake disposal costs)
• Secondary chemical precip. O&M costs, from Table 11-8, Section 11.2.1.5
ln(Y2) = 12.076 + 0.63456*ln(X) + 0.03678*(ln(X))2
= 10.9037
.-. Y2 = $54,375.79 «•
• Clarification O&M costs, following secondary chemical precipitation, from Table 11-9,
Section 11.2.2.2
ln(Y2) = 10.673 + 0.238*ln(X) + 0.013*(ln(X))2
= 10.22979
.-. Y2 =$27,716.56*
Multimedia Filtration O&M Costs, from Table 11-13, Section 11.2.5
ln(Y2) = 11.5039 + 0.72458*ln(X) + 0.09535*(ln(X))2
= 10.40146
.-. Y2 = $32,907.65 «•
Total Operation and Maintenance Cost (O&MTot)
O&MTot = £ (Individual O& M Costs)
O&MTot = $145,640 •
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
EXAMPLE ll-l. CONTINUED:
Land Requirements:
• Primary chemical precipitation upgrade land requirement associated with capital cost
upgrade (Table 11-7, section 11.2.1.4). The maximum size holding tank to be
costed for a primary chemical precipitation upgrade is 0.005 MGD.
ln(Y3) = -2.866 - 0.0231n(X) - 0.006(ln(X))2
= -2.866 - 0.0231n(0.005) - 0.006(ln(0.005))2
= -2.913
.'. Y3 = 0.054 acre *
• Clarifier, following primary chemical precip., land requirement = 0.0 acre *
• Sludge filtration unit land requirement = 0.0 acre *
• Secondary chemical precipitation land requirement, from Table 11-8, Section 11.2.1.5
ln(Y3) = -1.15 + 0.449*ln(X) + 0.027*(ln(X))2
--1.975
.-. Y3 =0.139 acre*
• Clarification, following secondary chemical precipitation, land requirement, from Table 11-
9, Section 11.2.2.2
ln(Y3) =-1.773+0.513*ln(X) + 0.046*(ln(X))2
= -2.6487
.-. Y3 =0.071 acre*
• Multimedia filtration land requirement, from Table 11-13, Section 11.2.5
ln(Y3) = -2.6569 + 0.1937*ln(X) + 0.02496*(ln(X))2
= -2.95396
.-. Y3 =0.0521 acre*
• Total land requirement (TLR)
TLR = £ (Individual Land Requirement)
.-. TLR = 0.316 acre •
11-38
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Chapter 11 Cost of Treatment Technologies
Development Document for the CWT Point Source Category
EXAMPLE 11-2:
Costing exercise for a direct discharging oils subcategory facility with only emulsion
breaking/gravity separation in-place.
Example Facility Information:
Current Treatment In-Place:
Primary Emulsion Breaking/Gravity Separation
Daily Flow = 0.0081 MOD (Million Gallons/Day) [= 5.63 gpm]
[NOTE: Daily Flow = X in costing equations]
Treatment Upgrades To Be Costed:
None
Full Treatment Technologies To Be Costed:
Secondary Gravity Separation + Dissolved Air Flotation (DAF)
Section 11.2.8
>.
Secondary
Gravity
\Separadon/
/
>fc
•
Section 11.2.9
Dissolved Air
Flotation
Direct Discharge
>„
"
Figure 11-2. Treatment Diagram For Oils Option 9 Facility Improvements
11-39
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Chanter 11 Cost of Treatment Technoloaies
Development Document for the CWTPoint Source Category
EXAMPLE 11-2. CONTINUED:
Capital Costs:
Secondary gravity separation, from Table 11-15, Section 1 1 .2.7
ln(Yl) = 14.3209 + 0.38774*ln(X) - 0.01793*(ln(X))2
= 14.3209 - 0.38774*ln(0.0081) - 0.01793*(ln(0.0081))2
= 12.0377
Yl =$169,014.42*'
Dissolved air flotation costs, from Table 11-17, Section 11.2.8
ln(Yl) = 13.9518 + 0.29445*ln(X) - 0.1 2049 *(ln(X))2
= 11.6415
Yl =$113,720.41*
Holding tank for dissolved air flotation (flow < 20 gpm, hence holding tank is sized),
from Table 11-17, Section 1 1 .2.8
ln(Yl) = 13.4616 + 0.54421*ln(X) + 0.00003*(ln(X))2
= 10.8414
Yl =$51,094.88*
Total capital cost (TCC)
TCC = £ (Individual Capital Costs)
TCC = $333,830 •
11-40
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
EXAMPLE 11-2. CONTINUED:
Operation and Maintenance Costs:
• Secondary gravity separation, from Table 11-15, Section 11.2.7
ln(Y2) = 12.0759 + 0.4401*ln(X) + 0.01594*(ln(X))2
= 12.0759 + 0.4401*ln(0.0081) + 0.01594*(ln(0.0081))2
= 10.3261
Y2 = $30,519.46 +
• Dissolved air flotation (flow < 20 gpm), from Table 11-17, Section 11.2.8
ln(Y2) = 21.2446 + 4.14823*ln(X) + 0.36585*(ln(X))2
= 9.7523
Y2 = $17,193.12 «•
• Total Operation and Maintenance Cost (O&MTot)
O&MTot = £ (Individual O& M Costs)
O&MTot =$47,713 •
11-41
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
EXAMPLE 11-2. CONTINUED:
Land Requirements:
• Secondary gravity separation, Table 11-15, Section 11.2.7
ln(Y3) =-0.2869 + 0.31387*ln(X) + 0.01191*(ln(X))2
= -0.2869 + 0.31387*ln(0.0081) + 0.01191*(ln(0.0081))2
= -1.5222
Y3 =0.218 acre*
• Dissolved air flotation (sized at 25 gpm, the minimum available), from Table 11-17,
Section 11.2.8
ln(Y3) = -0.5107 + 0.51217*ln(X) - 0.01892*(ln(X))2
= -2.4224
Y3 =0.089 acre*
Holding tank, from Table 11-17, Section 11.2.8
ln(Y3) = -1.5772 + 0.35955*ln(X) + 0.02013*(ln(X))2
= -2.8419
Y3 =0.058 acre*
• Total land requirement (TLR)
TLR = £ (Individual Land Requirement)
TLR = 0.365 acre •
11-42
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Chanter 11 Cost of Treatment Technologies
Development Document for the CWT Point Source Category
REFERENCES
11.6
Standard Methods for Examination of Water and Wastewater. 15* Edition, Washington, DC.
Henricks, David. Inspectors Guide for Evaluation of Municipal Wastewater Treatment Plants, Culp/Wesner/Culp,
El Dorado Hills, CA, 1979.
Technical Practice Committee, Operation of Wastewater Treatment Plants. MOP/11, Washington, DC, 1976.
Clark, Viesman, and Hasner, Water Supply and Pollution Control. Harper and Row Publishers, New York, NY,
1977.
1991 Waste Treatment Industry Questionnaire Respondents Data Base. U. S. Environmental Protection Agency,
Washington, DC.
Osmonics, Historical Perspective of Ultrafiltration and Reverse Osmosis Membrane Development Minnetonka,
MN, 1984.
Organic Chemicals and Plastics and Synthetic Fibers fOCPSF') Cost Document SAIC, 1987.
Effluent Guidelines Division, Development Document For Effluent Limitations Guidelines and Standards for the
Organic Chemicals. Plastics and Synthetic Fibers COCPSFX Volume n, Point Source Category, EPA 440/1-87/009,
Washington, DC, October 1987.
Engineering News Record (ENR). McGraw-Hill, New York, NY, March 30,1992.
Comparative Statistics of Industrial and Office Real Estate Markets. Society of Industrial and Office Realtors of
the National Association of Realtors, Washington, DC, 1990.
Peters, M., and Timmerhaus, K., Plant Design and Economics for Chemical Engineers. McGraw-Hill, New York,
NY, 1991.
Chemical Marketing Reporter. Schnell Publishing Company, Inc., New York, NY, May 10,1993.
Palmer, S.K., Breton, M.A., Nunno, T.J., Sullivan, D.M., and Supprenaut N.F., Metal/Cyanide Containing Wastes
Treatment Technologies. Alliance Technical Corporation, Bedford, MA, 1988.
Freeman, H.M, Standard Handbook of Hazardous Waste Treatment and Disposal. U.S. Environmental Protection
Agency, McGraw-Hill, New York, NY, 1989.
Development Document for the Proposed Effluent Limitations Guidelines and Standards for the Metal Products
and Machinery Phase 1 Point Source Category. U.S. Environmental Protection Agency, EPA 821-R-95-021, April
1995.
Control and Treatment Technology for the Metal Finishing Industry. Sulfide Precipitation. Summary Report EPA
625/8-80-003, April 1980.
11-43
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Chapter 11 Cost of Treatment Technologies Development Document for the CWT Point Source Category
SUMMARY OF COST OF
TECHNOLOGY OPTIONS
11.7
This section summarizes the estimated
capital and annual O&M expenditures for CWT
facilities to achieve each of the proposed effluent
limitations and standards. All cost estimates in
this section are expressed in terms of 1997
dollars.
BPT Costs
11.7.1
BPT costs apply to all CWT facilities
that discharge wastewater to surface waters
(direct dischargers). Table 11-25 summarizes, by
subcategory, the total capital expenditures and
annual O&M costs for implementing BPT.
Table 11-25. Cost of Implementing BPT Regulations [in 1997 dollars]
Subcategory Number of Facilities
Metals Treatment and Recovery
Oils Treatment and Recovery
Organics Treatment
Combined Regulatory Option
9
5
4
14
1 Total Capital Costs
3,069,500
931,600
75,600
4,076,700
Annual O&M Costs
1,532,100
176,700
59,600
1,768,500
'There are 14 direct dischargers. Because some direct dischargers include operations in more than one
subcategory, the sum of the facilities with operations in any one subcategory exceeds the total number of facilities.
EPA notes that this BPT cost summary
does not include the additional capital costs of the
second clarifier that may.be associated with the
transferred TSS limitations for the metals
subcategory. EPA will re-visit its BPT costs
estimates for this subcategory prior to
promulgation.
BCT/BAT Costs
11.7.2
The Agency estimated that there
would be no incremental cost of compliance for
implementing BCT/BAT, because the technology
used to develop
BCT/BAT limitations is identical to BPT and the
costs are included with BPT.
PSES Costs
11.7.3
The Agency estimated the cost for
implementing PSES applying, the same
assumptions and methodology used to estimate
cost of implementing BPT. The major difference
is that the PSES costs are applied to all CWT
facilities that discharge wastewater to a POTW
(indirect dischargers). Table 11-26 summarizes,
by subcategory, the capital expenditures and
annual O&M costs for implementing PSES.
11-44
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Chapter 11 Cost of Treatment Technologies
Development Document for the CWT Point Source Category
Table 11-26. Cost of Implementing PSES Regulations [in of 1997 dollars]
Subcategory Number of Facilities2
Metals Treatment and Recovery
Oils Treatment and Recovery -
Organics Treatment
Combined Regulatory Option
41
123
14
147
Total Capital Costs
7,209,100
17,778,400
11,084,600
36,072,000
Annual O&M Costs
2,822,500
6,531,900
1,149,900
10,505,400
JThere are 147 indirect dischargers. Because some indirect dischargers include operations in more than one
subcategory, the sum of the facilities with operations in any one subcategory exceeds the total number of facilities.
11-45
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-------
Chapter
12
POLLUTANT LOADING AND REMOVAL ESTIMATES
INTRODUCTION
12.1
This chapter presents annual pollutant
loading and removal estimates for the CWT
industry associated with each of the subcategories
and regulatory options considered by EPA in
developing the proposed effluent limitations and
pretreatment standards. EPA estimated the
pollutant loadings and removals from CWT
facilities to evaluate the effectiveness of different
treatment technologies and to evaluate how costly
these regulatory options were in terms of
pollutant removals. EPA also used this
information in analyzing potential benefits from
the removal of pollutants discharged to surface
waters directly or indirectly through publicly
owned treatment works (POTWs). EPA
estimated raw, current, and post-compliance
pollutant loadings and pollutant removals for the
industry using data collected from the industry
throughout development of the proposed rule.
This assessment uses the following definitions for
raw, current, and post-compliance pollutant
loadings:
• Raw loadings - For the metals and organics
subcategory, raw loadings represent CWT
waste receipts, that is, typically untreated
wastewater as received from customers. For
the oils subcategory, raw loadings represent
the effluent from the initial processing of oil
bearing, CWT waste receipts, that is, effluent
from emulsion breaking and/or gravity
separation.
• Current loadings — These are the pollutant
loadings in CWT wastewater that are
currently being discharged to POTWs and
surface waters. These loadings account for
wastewater treatment currently in place at
CWTs.
• Post-compliance loadings — These are the
pollutant loadings in CWT wastewater that
would be discharged to POTWs and surface
waters if the proposed rule is promulgated.
EPA calculated these loadings assuming that
all CWTs would achieve treatment at least
equivalent to that which may be achieved by
employing the technology option selected as
the basis of the limitations or standards.
The following information is presented in this
chapter:
• Section 12.2 summarizes the data sources
used to estimate pollutant loadings and
removals;
Section 12.3 discusses the methodology used
to estimate current loadings;
• Section 12.4 discusses the methodology used
to estimate post-compliance pollutant
loadings;
• Section 12.5 discusses the methodology used
to estimate pollutant removals;
• Section 12.6 presents the pollutant loadings
and removals for each regulatory option,
including current and post-compliance
pollutant loadings.
DATA SOURCES
12.2
As previously explained in Chapter 2,
EPA primarily relied on three data sources to
estimate pollutant loadings and removals:
industry responses to the 1991 Waste Treatment
Industry Questionnaire, industry responses to the
Detailed Monitoring Questionnaire, and
wastewater sampling data collected by EPA.
12-1
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Chapter 12 Pollutant Loading and Removal Estimates
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Chapter 2 of this document discusses each of
these data sources in detail.
Current Loadings Estimates for
the Metals Subcategory
12.3.1
METHODOLOGY USED TO DEVELOP
CURRENT LOADINGS ESTIMATES
12.3
EPA calculates current loadings for a
specific facility from the effluent flow rate of the
facility and the concentration of pollutants in its
effluent obtained from effluent monitoring data.
EPA does not have data for every facility in the
database to calculate current loadings. For some,
EPA has no effluent monitoring data, while for
others, EPA may have only limited monitoring
data for a few parameters. In many cases, EPA
has effluent monitoring data, but the data do not
represent CWT wastewaters only. As discussed
previously, most CWT facilities commingle CWT
wastewaters with non-CWT wastewaters such as
industrial wastestreams or stormwater prior to
monitoring for compliance. Most CWT facilities
with waste receipts in more than one subcategory
commingle CWT wastestreams prior to
monitoring for performance. Some facility
supplied data, therefore, is insufficient for
estimating current loadings.
When possible, EPA determined current
loadings for an individual facility based on
information reported by that facility. For most
CWT facilities, however, EPA had to develop
estimated current loadings. EPA's methodology
differs depending on the subcategory of CWT
facilities and individual facility characteristics.
Factors that EPA took into account in estimating
current loadings include: 1) the analytical data
available for the subcategory; 2) the
characteristics of the facilities in the subcategory;
and 3) the facility's treatment train. For facilities
in multiple subcategories, EPA estimated
loadings for that portion of the wastestream in
each subcategory and subsequently added them
together. The sections that follow discuss the
current loadings methodologies for each
subcategory.
EPA calculated current loadings for the
metals subcategory facilities by assigning
pollutant concentrations based on the type of
treatment currently in-place at each facility. EPA
placed in-place treatment for this subcategory in.
one of five classes:
1) raw, or no metals treatment;
2) primary precipitation with solids-liquid
separation;
3) primary precipitation with solids-liquid
separation plus secondary precipitation with
solids-liquid separation;
4) primary precipitation with solids-liquid
separation plus secondary precipitation with
solids-liquid separation followed by multi-
media filtration (EPA based the
BAT/BPT/PSES proposed limitations and
standards for this subcategory on this
technology); and
5) selective metals precipitation with solids-
liquid separation plus secondary precipitation
with solids-liquid separation plus tertiary
precipitation with solids-liquid separation
(EPA based the NSPS/PSNS proposed
limitations and standards on this
technology).
Table 12.1 shows the current loadings estimates
for each classification and the following five
sections (12.3.1.1 through 12.3.1.5) detail the
estimation procedure for each classification.
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Chanter 12 Pollutant Loading and Removal Estimates
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Table 12.1. Metals Subcategory Pollutant Concentration Profiles for Current Loadings
Pollutant of Concern
CONVENTIONALS
Oil and Grease 2
Total Suspended Solids (TSS)
PRIORITY METALS
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
NON-CONVENTIONAL METALS
Aluminum
Barium
Boron
Cobalt
Iridium
Iron
Lithium
Manganese
Molybdenum
Silicon
•Strontium
Tin
Titanium
Vanadium
Yttrium
Zirconium
CLASSICAL PARAMETERS
Chemical Oxygen Demand (COD)
Hexavalent Chromium
Ammonia as N
Cyanide
Raw
Treatment
(ug/L)
685,300
27,957,052
116,714
1,790
44,629
1,186",645
1,736,413
211,044
300
374,739
328
1,105
461
978,167
378,955
941
153,726
25,809
51,231
588,910
114,438
26,157
48,403
284,693
7,605
1,337,924
795,623
38,570
96
1,477
13,963,394
1,923,560
216,097
12,285
BAT Selective
Primary Secondary Option Metals
Precipitation Precipitation Technology Precipitation
(ug/L) (ug/L) (ug/L) (ug/L)
143,160
840,000
7,998
84
21
387
448
393
50
2,787
514
91
26
3,900
5,580
N/A;
31,730
254
3,283
15,476
53,135
245
3,403
2,590
3,561
1,026
239
37
26
N/A'
10,628,000
4,114
120,790
763
93,348
833,266
768
280
63
671
800
356
6
1,968
433
70
240
3,550
27,422
221
32,131
200
3,500
8,018
976
2,195
2,690
1,238
1,223
552
45
85
48
762
4,537,778
361
89,997
1,910
56,279
113,197
170
143
45
1,177
581
117
1
1,070
347
23
N/A;
422
856
N/AJ
8,403
115
500
6,803
1,927
49
1,747
1,447
100
90
57
12
5
1,287
1,333,333
800
15,630
82
< 5,000
9,250
21
11
82
40
169
55
0
270
210
5
21
206
73 '
WA1
66,951
57
N/AJ
387
N/A'
12
528
356
N/AJ
28
4
11
5
N/AJ
108,802
43
9,123
N/A'
'Concentration values for certain pollutants were not available for some classifications.
2EPA determined that the oil and grease concentration listed for raw loadings includes data from a facility (4382)
which commingles oils subcategory waste receipts with metals subcategory receipts. The recalculated raw loadings
oil and grease concentration is 27,589 ug/L, after excluding the data from the facility 4382. EPA will incorporate
this change into the overall loadings and removals calculations between proposal and promulgation.
12-3
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Chapter 12 Pollutant Loading and Removal Estimates
Development Document for the CWT Point Source Category
Raw Loadings for the
Metals Subcategory 12.3.1.1
EPA classified metals subcategory facilities
with no chemical precipitation in the "raw" class
(even if they had other treatment in place, such as
activated carbon). EPA assigned the "raw"
current loadings estimates to three facilities in the
metals subcategory. EPA based its estimates for
raw wastewaters on data from eight sample
points at five sampling episodes (refer to Table
12-2 for sample episode and sample point
identifiers). The data from these episodes include
composite samples from continuous systems and
grab samples from batch systems. In order to
compare and use continuous and batch system
data interchangeably, EPA calculated a daily'
average value for the batch systems by averaging
sample measurements from all batches for a
single day. Therefore, if the facility treated nine
batches during a four day
sampling episode, EPA calculated four daily
averages for the episode. EPA incorporated non-
detect measurements at the sample-specific
detection levels. The Agency averaged duplicate
batch samples together first, and then included
the averaged value in the daily average
calculation.
Once EPA calculated daily averages for the
batch systems, EPA then averaged the batch daily
averages with the daily composite values to
obtain raw pollutant concentrations. As an
illustrative example, Table 12-2 shows the data
used to obtain the raw wastewater estimation for
aluminum: 378,955 ug/L. Table 12-2 shows that
this estimation comes from twenty-nine daily
averages (some from continuous systems and
some from batch systems) from fifty-nine
analyses. Raw wastewater estimations for other
pollutants were calculated in a similar manner.
Table 12-2. Example of Metals Subcategory Influent Pollutant Concentration Calculations7
Sample Point
Episode 4378-01
Episode 4378-03
Episode 4055-01
Episode 1987-01
Episode 1987-02
Episode 4393-01
Episode 4382-07
Episode 4393-05
Raw Aluminum Daily Averages (ug/L)
389,338 189,223
2,080,000 2,090,000
31,800 838,275
839,000 792,000
577,500 53,400
3,730 29,400
84,400 139,000
72,400 3,765
3,128
745,000
260,000
859,000
171,000
6,150
8,376
91,700 130,000
145,000 330,000
15,900 11,200
# of measurements
23 (2 duplicate values)
1 1 (2 duplicate values)
5
3
3(1 duplicate value)
2(1 non-detect value)
6 (1 duplicate value)
6(1 duplicate and
1 non-detect value)
'The Raw Aluminum Concentration is 378,955 ug/L — the average of sample values in the table.
Primary Precipitation with Solids-
Liquid Separation Loadings 12.3.1.2
EPA estimated pollutant concentrations
resulting from primary precipitation and solids-
liquid separation using data from EPA sampling
episodes and industry supplied effluent
monitoring data. EPA used data from three
sampling episodes and one facility's effluent
monitoring data submissions to represent the
current loadings for 32 of the metals subcategory
facilities. The episodes used are detailed
monitoring questionnaire 613 (industry supplied
effluent monitoring data),. sample point 16;
episode 4382, sample point 12; episode 1987,
sample point 3; and episode 4798, sample point
3. The facility supplied effluent monitoring data
was collected as grab samples from batch
systems. For each day, EPA averaged the batch
12-4
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Chanter 12 Pollutant Loading and Removal Estimates
Development Document for the CWTPoint Source Category
samples together to obtain a daily average.
Conversely, the EPA sampling episode data came
from continuous systems. Regardless of the
sample type, the analysis averaged the daily
average values from a facility together to give a
facility average, then combined the four facility
averages to give a pollutant concentration
average. Table 12.1 shows the concentrations
representing primary precipitation for the relevant
pollutants of concern.
Secondary Precipitation with Solids-
Liquid Separation Loadings 12.3.1.3
EPA estimated current loadings for facilities
with secondary chemical precipitation using data
from three sampling points at three separate
episodes. These are episode 4393, sample point
13; episode 4382, sample point 12; and episode
4798, sample point 05 (which represents the
technology basis for the proposed metals
subcategory BPT/BAT/PSES option). EPA then
averaged the facility average effluent values from
liquid-solids separation following secondary
chemical precipitation to give concentrations for
the relevant pollutants of concern. Table 12-1
summarizes these average values.'
Technology Basis for the Proposed
BPT/BAT/PSES Option 4 Loadings . 12.3.1.4
EPA used the long-term averages from
Metals Option 4 — batch primary precipitation
with solids-liquid separation plus secondary
precipitation with solids-liquid separation
followed by multi-media filtration - to represent
current loadings at three facilities in the metals
subcategory: The facility sampled by EPA that
employs the technology basis for the
BPT/BAT/PSES Option, obviously, is assigned
its current loadings. EPA modeled the loadings
for two facilities that utilize tertiary precipitation
with the BPT/BAT/PSES option current loadings.
EPA believes that facilities utilizing tertiary
precipitation will not need to alter their system to
meet the proposed pretreatment standards and
limitations. By assigning current loadings
estimates based on the Option 4 technology basis
to the tertiary systems, EPA may have
overestimated current loadings at these two
facilities.' However, EPA does not estimate any
post-compliance pollutant reductions at these
facilities.
Selective Metals Precipitation (NSPS/
PSNSProposed Option 3) Loadings 12.3.1.5
Only one facility in the metals subcategory
utilizes selective metals precipitation. EPA
sampled this facility during development of this
rule. Therefore, the current loadings pollutant
concentrations for this facility are not estimates,
but measured data. Table 12.1 summarizes these
pollutant concentrations.
Current Loadings Estimates
for the Oils Subcategory
12.3.2
Based on questionnaire responses and site
visits, EPA found that all facilities which treat
oily wastewaters, for which EPA has data,
currently employ emulsion breaking and/or
gravity separation. If emulsions are present in the
incoming waste receipts, the facility first makes
use of emulsion breaking. If not, the waste
receipts generally bypass emulsion breaking and
.the facility processes the waste through a gravity
separation step for gross separation of the water
and the oil phase. A facility may often follow up
these pretreatment steps by other wastewater
treatment technologies. Therefore, EPA believes
that, at a minimum, it may characterize current
loadings for oils subcategory discharges by
analyzing samples obtained from the effluent of
emulsion breaking/gravity separation.
EPA has seven data sets which represent
effluent from emulsion breaking/gravity
separation systems. EPA collected these seven
data sets during EPA sampling episodes at
various types of oily waste facilities. Six of these
seven data sets represent facilities that treat oily
12-5
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Chapter 12 Pollutant Loading and Removal Estimates
Development Document for the C\VT Point Source Category
wastewater and recover/process used oil. One
facility, which primarily accepts bilge water,
performs oily wastewater treatment only. The '
annual volume of treated oily wastewater
discharged at these facilities ranges from 174,000
gallons/year to 35 million gallons/year. Two of
the data sets represent facilities that only accept
non-hazardous wastes, while the other five data
sets represent facilities which are permitted by
RCRA to additionally accept hazardous wastes.
For each pollutant of concern, each of the
seven emulsion breaking/gravity separation data
sets contains the mean concentration of the data
collected over the sampling episode (usually a
duration of .five days). This mean includes
measured (detected) and non-detected values.
The value substituted for each non-detected
measurement was either 1) the sample-specific
detection limit or 2) the average of the measured
(detected) values across all seven data sets.
Section 12.3.2.1 discusses EPA's representation
of non-detect values for this analysis. Section
12.3.2.1 further discusses EPA's representation
of the one biphasic sample. Table 12-7 presents
a compiled summary of these seven data sets.
For each episode and each pollutant, the table
presents the mean concentration of the data
collected over the sampling episode. Figure 12-1
shows the procedure EPA used to estimate the
mean concentration data over the seven sampling
episodes.
EPA has facility-specific information in its
database for 84 oils subcategory facilities. Of
these 84 facilities, EPA has sampling data for
seven. For the remainder of the facilities, EPA
does not have current loadings data. EPA does,
however, have facility-specific information on the
volume of wastewater being discharged and the
treatment train currently in use. EPA evaluated
several ways to associate one of the seven
emulsion breaking/gravity separation data sets to
each of the facilities for which EPA needed to
estimate current performance. EPA, therefore,
reviewed the seven emulsion breaking/gravity
separation data sets to determine if there was a
relationship between the concentration of
pollutants, and facility flow, but found no
evidence of relationship.
Consequently, EPA randomly assigned one
of the seven data sets to each of the facilities that
required current loadings estimates. For facilities
which only employ emulsion breaking/gravity
separation, EPA estimated current loadings for
each pollutant using values in the randomly
assigned data set. For facilities which use
additional treatment after that step, EPA further
reduced the pollutant loadings for certain
pollutants (or all pollutants depending on the
technology) in the randomly assigned data set to
account for the additional treatment-in-place at
the facility.
TREATMENT-IN-PLACE
As mentioned previously, there are many
configurations of treatment trains in this
subcategory. While EPA does not have sampling
data representing each of these treatment
configurations, EPA does have sampling data
representing each of the individual treatment
technologies currently in place at oily waste
facilities. While EPA collected all of the data at
CWT facilities, EPA collected some of the data it
used to develop treatmerit-in-place credits at
facilities in other CWT subcategories. For some
technologies, EPA has sampling data from a
single facility, while for others, EPA has
sampling data from multiple CWT facilities.
In order to estimate the current pollutant
reductions due to additional treatment-in-place at
oils facilities, for each technology, EPA compiled
and reviewed all CWT sampling data for which
EPA collected influent and effluent data. EPA
subjected the influent data to a similar screening
process as the one used in determining long-term
averages. For each episode, EPA retained
influent and effluent data for a specific pollutant
12-6
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Chapter 12 Pollutant Loading and Removal Estimate
Develophient Document for the CWT Point Source Categor
only if the pollutant was detected in the influent
at treatable levels (10 times the baseline value1)
at least 50 percent of the time. For each facility,
EPA then calculated an "average" percent
removal for metals (averaging the percent
removal for each metal), an "average" percent
removal for organics, and an "average" percent
removal for BOD5 TSS, and oil and grease. EPA
rounded the averages to the nearest 5 percent.
When the "average" percent removal for more
than one third of the pollutants in a compound
class (i.e., metals, organics, BOD5 TSS, and oil
and grease) was zero or less, EPA set the
"average" percent removal for the class of
compounds equal to zero. EPA recognizes that
treatment technologies are not equally effective in
reducing all metals and/or all organics from
wastewater, but believes this provides a
reasonable estimate. The result is that, for some
pollutants, .EPA believes it may have
underestimated the removals associated with the
additional treatment-in-place, while for other
pollutants, EPA may have overestimated the
removals.
Table 12-3 shows the percent removal
credited to each technology. For technologies
that EPA evaluated at more than one CWT
facility, the value for each class of compounds
represents the lowest value at the facilities. For
example, EPA sampled at two facilities that use
multimedia filtration. The average percent
removal of metal pollutants at facility 1 and
facility 2 is 60 percent and 30 percent,
respectively. Table 12-3 shows that EPA used 30
percent to estimate metals removal in multimedia
filtration systems. EPA believes that using the
lower percent removal of the "best" performers
provides a reasonable estimate of the percent
removals of these technologies for the rest of the
industry and may even overstate the percent
'Defined in chapter 15.
removals for some facilities that may not be
operating the treatment technologies efficiently.
For some classes of compounds and some
technologies, EPA does not have empirical data
from the CWT industry to estimate percent
removals. For these cases, EPA assumed percent
removals based on engineering judgement. EPA
assumed that air stripping is only effective for the
removal of volatile and semi-volatile organic
pollutants. EPA also assumed that chemical
precipitation is ineffective for the treatment of
organic pollutants. Finally, EPA assumed a 50
percent reduction in organic CWT pollutants
through carbon adsorption treatment. EPA
recognizes that carbon adsorption, given the
correct design and operating conditions can
achieve much higher pollutant removals.
However, for this industry, EPA believes that the
complex matrices, variability in waste receipts,
and high loadings would compromise carbon
adsorption performance.
12-7
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Chapter 12 Pollutant Loading and Removal Estimates
Development Document for the CVCT Point Source Categor
Examine the data
from the 7 facilities
sampled by EPA
For each pollutant,
examine the data
from each sample
No
Use EPA method to
obtain one value for
each pollutant
Calculate
MNC = mean
of detected values
from all 7 facilities
Compare each
sample-specific
detection limit (DL)
to MNC
Is
treatment
system batch or
ntinuous?
Calculate pollutant
LTA for the facility
as mean of its daily
values
Calculate pollutant
LTA for the facility
as mean of its batch
values
Figure 12-1 Calculation of Current Loadings for Oils Subcategor
12-8
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Chapter 12 Pollutant Loading and Removal Estimates
Development Document for the CWT Point Source Category
Table 12-3. Treatment-in-Place Credit Applied to Oils Facilitie
Pollutant
Group
BOD5
Oil and
Grease
TSS
Metals
Organics
Treatment Technology
Chemical
Precipitation
0
45
85
75
0*
Carbon
Adsorption
0
45
0
0
50*
Air
Stripping
0*
0*
0*
0*
70
Ultra
filtration
55
85
100
75
85
Biological
50
65
50
15
75
Multi-
media/
Sand
Filtration
10
0
55
30
0
DAF
10
60
80
50
40
Secondary
Separtion
5
30
0
0
50
* Value is based on engineering judgement.
In determining current loadings for facilities
with additional treatment-in-place, EPA then
reduced the current loadings concentrations
established for the facility with gravity
separation/emulsion breaking alone by the
appropriate percent removal as defined above.
For facilities with multiple treatment technologies
in their treatment train, EPA credited each of the
treatment technologies in the order that the
process occurs in their treatment train.
Issues Associated with Oils
Current Performance Analyses 12.3.2.1
This section describes four issues associated
with estimating the current performance of the
oils subcategory. The first issue is the dilution
required in analyses of some highly concentrated
samples representing the baseline technology
(emulsion breaking/gravity separation). The
second issue is the appropriate procedure for
incorporating the concentrations of a biphasic
sample into the estimates of current performance.
The third issue is the appropriateness of various
substitution methods for the non-detected
measurements, especially of diluted samples. The
fourth issue discussed is EPA's approach to
assigning the seven emulsion breaking/gravity
separation data sets randomly to oils facilities.
DILUTION OF SAMPLES DURING
LABORATORY ANALYSIS
Effluent from emulsion breaking/gravity
separation operations may be highly
concentrated, which may present difficulties in
analyzing such effluent. Consequently, in its
analysis of some samples, EPA needed to dilute
the samples in order to reduce matrix difficulties
(such as interference) to facilitate the detection or
quantitation of certain target compounds. For
some organic compounds, moreover, EPA also
had to dilute samples where a highly concentrated
sample could not be concentrated to the method-
specified final volume.
If EPA diluted a sample for analytical
purposes, EPA adjusted the particular pollutant
measurement to correct for the dilution. For
example, if a sample was diluted by 100 and the
measurement was 7.9 ug/L, the reported value
was adjusted to 790 ug/L (i.e., 7.9 ug/L * 100).
In general, the sample-specific detection limits
(DLs) for a pollutant were equal to or greater
than the nominal quantitation limit described in
Chapter 15. Dilution generated sample-specific
DLs greater than the nominal quantitation limit.
Because wastes generated using the proposed
technologies will be less concentrated than
emulsion breaking/gravity separation operations,
EPA does not believe effluent samples collected
12-9
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Chapter 12 Pollutant Loading and Removal Estimates
Development Document for the CWT Point Source Category
to demonstrate compliance with the proposed
limitations and standards will necessitate dilution
and therefore result in effluent values with large
sample-specific DLs. Further, a laboratory can
overcome potential analytical interferences using
procedures such as those suggested in Guidance
on the Evaluation, Resolution, and
Documentation of Analytical Problems
Associated with Compliance Monitoring (EPA
821-B-93-001). Thus, in demonstrating
compliance, EPA would not allow dilution of a
sample to a sample-specific DL greater than the
limitation or standard.
DIPHASIC SAMPLES
EPA used a number of different analytical
methods to determine the pollutant levels in the
effluent samples from facilities that employ
chemical emulsion breaking/gravity separation
for treating oily wastewater. Each method is
specific to a particular analyte or to structurally
similar chemical compounds such as volatile
organics (analyzed by Method 1624) and
semivolatile organics (analyzed by Method
1625). In developing the laboratory procedures
described in Method 1625, EPA included a
procedure for analyzing aqueous samples and
another procedure for analyzing biphasic
samples. Some effluent samples from emulsion
breaking/gravity separation were biphasic. That
is, each sample separated into two distinct layers,
an aqueous layer and an organic one. In these
instances, if the phases could not be mixed, EPA
analyzed each phase (or layer) separately. Thus,
each pollutant in a sample analyzed by Method
1625 had two analytical results, one for the
organic phase and the other for the aqueous
phase. There were three such samples in the oils
subcategory. Only sample number 32823
(episode 4814B), however, represents oily wastes
following emulsion breaking/gravity separation.
This sample is part of one of the seven data sets
representing emulsion breaking/gravity
separation randomly assigned to facilities without
concentration data. For this sample, EPA
combined the two concentration values into a
single value for each pollutant analyzed using
Method 1625. The discussion below describes
the procedures for combining the two
concentration values and Table 12-4 summarizes
these procedures. Table 12-5 provides examples
of these procedures. DCN* 23.13
If the pollutant was detected in the organic
phase, EPA adjusted the analytical results to
account for the percent of the sample in each
phase. For sample 32823, 96 percent of the
sample volume was aqueous and the remaining 4
percent was organic. Thus, EPA multiplied the
aqueous value (detected value or sample-specific
DL) by 0.96 and the organic value by 0.04. EPA
then summed the two adjusted values to obtain
the total concentration value for the pollutant in
the sample.
If the pollutant was not detected in the
organic phase, EPA used several different
procedures depending on the pollutant and its
concentration in the aqueous phase. A factor
which complicated EPA;is analysis was that
sample-specific DLs for pollutants in the organic
phase were 10003 times greater than the
minimum levels for Method 1625. When a
measurement result indicates that a pollutant is
not detected, then the reported sample-specific
DL is an upper bound for the actual concentration
of the pollutant in the sample. When some
sample-specific DLs for the organic phase (which
were 1000 times the minimum level) were
2 Items identified with document control
numbers (DCN) are located in the record to the
proposed rulemaking.
Because the volume of'the organic phase was
small, the organic phase sample required dilution
(by 1000) for analysis. In contrast, the aqueous
phase had sufficient amount so that it was not
diluted.
12-10
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Chapter 12 Pollutant Loading and Removal Estimates
Development Document for the CWT Point Source Category
multiplied by 0.04, the adjusted non-detected
values were greater than the measured amount in
the aqueous phase. EPA concluded that
substituting the sample-specific DL for the non-
detected results in the organic phase in these
circumstances might over-estimate the amount of
pollutant in the sample. Thus, EPA applied one
of the two alternative substitution procedures
described below for the sample-specific DLs
resulting from the organic phase.
First, if EPA did not detect the pollutant in
either phase, EPA considered the sample to be
non-detect at the sample-specific DL of the
aqueous phase. This value for the aqueous phase
was equal to the minimum level specified in
Method 1625.
Second, if the pollutant was detected in the
aqueous phase (and non-detected in the organic
phase), EPA used a procedure that compared the
non-detected organic values to the detected
aqueous value adjusted by a partition ratio (550).
EPA determined this partition ratio using the
average of the ratios of the detected organic phase
concentrations to the detected aqueous phase
concentrations for the pollutants that had detected
values in both phases. There were twenty-two
pollutants that were used to calculate this value of
550. These pollutants are in four structural
groupings of organic pollutants: chlorobenzenes,
phenols, aromatic ethers, and polynuclear
aromatic hydrocarbons. The ratios were similar
in each of the structural groupings; consequently,
EPA determined that a single value for the
partition ratio was appropriate. EPA then
multiplied the aqueous phase concentration value
by this partition ratio of 550. If this value was
less than the sample-specific DL of the pollutant
in the organic phase, EPA substituted this value
for the organic phase sample-specific DL.
Otherwise, EPA used the organic phase sample-
specific DL. EPA then multiplied the values for
the aqueous and organic phases by the relative
volume amounts (0.96 and 0.04, respectively)
and summed them to obtain one value for the
sample.
Table 12-4. Diphasic Sample Calculations (Summary of rules for combining aqueous/organic phase cones.)
Censoring types (i.e., detected or non-detected)
Aqueous phase
NC .
ND
ND
NC
Organic phase
NC
NC
ND
ND (DL>550*AQ)
ND (DL<=550*AO1)
Combined result
(same as aqueous)
NC
ND
ND
NC
Method for obtaining
combined value
0.96*AQ + 0.04*ORG
0.96* AQ (use DL) + 0.04*ORG
AQ (use DL)
0.96*AQ + 0.04*(550*AQ)
0.96* AO + 0.04*ORG ("use DL)
AQ = value for aqueous phase
ORG = value for organic phase
NC = non-censored (detected)
ND = non-detected DL = sample-specific detection limit
12-11
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Chapter 12 Pollutant Loading and Removal Estimates
Development Document for the CWT Point Source Category
Table 12-5. Examples of Combining Aqueous and Organic Phases for Sample 32823
Pollutant
Accnaphthene
Benzo(a)pyrene
4,5-Methylene
Phcnanthrene f
Aniline
1-phenyl
-naphthalene f
Reported Cones. (ug/L)
Aqueous Phase
668.6
158.4
ND(10)
ND (10)*
10.49
Organic Phase
319,400
162,950
118,330
ND (10,000)
ND (10,000)
Concentration for Calculation for Sample
Sample (ug/L)
13,418
6,670
ND (4,743)
ND(10)
240.9
(0.96*668.6 ug/L)
+ (0.04*3 19,400 ug/L)
(0.96* 158.4 ug/L)
+ (0.04* 162,950 ug/L)
(0.96*10 ug/L)
+ (0.04* 11 8,330 ug/L)
(0.96* 10.49 ug/L)
+(0.04*550*10.49 ug/L)
Comment
Concentrations are
weighted by relative
amounts of the
sample volume in
each phase: 96%
aqueous and 4%
organic
no calculation
necessary
The sample-specific
DL of 10,000 ug/L
Alpha-
Terpineol
1,885.8 ND (10,000)
for the organic phase
is greater than 5570
ug/L (i.e., 550 times
10.49 ug/L)
2,210 (1,885.8 ug/L*0.96) The sample-specific
+ (10,000 ug/L*0.04) DL of 10,000 ug/L
for the organic phase
is less than 1,037,190
(i.e., 550 times
1885.8 ug/L)
* ND=non-detected measurement. The sample-specific DL is provided in the parentheses.
t None of measurements of the pollutants of concern from this sample resulted in a non-detected measurement
for the aqueous phase with a detected measurement for the organic phase. This analyte is shown for demonstration
purposes.
JNone of measurements of the pollutants of concern from this sample resulted in a detected measurement for the
aqueous phase with a sample-specific DL for the organic phase that was greater than 550 times the measurement
from the aqueous phase. This analyte is shown for demonstration purposes.
NON-DETECT DATA IN COMPLEX SAMPLES
EPA included values for measurements
reported as "non-detected" when it calculated the
mean for each pollutant of concern in the seven
emulsion breaking/gravity separation data sets.
In some instances, the measurements reported as
non-detected had sample-specific detection limits
that were well in excess of the minimum
analytical detection limits. The high sample-
specific detection limits occurred because the
samples contained many pollutants which
interfered with the analytical techniques. EPA
considered several approaches for handling these
sample-specific non-detected measurements
because, by definition, if a pollutant is 'not
detected', then the pollutant is either not present
at all (that is, the concentration is equal to zero)
or has a concentration values somewhere between
zero and the sample-specific detection limit (DL).
EPA considered the following five
approaches to selecting a value to substitute for
non-detected measurements:
1. Assume that the pollutant is not present in
the sample and substitute zero for the non-
detected measurement (that is, ND=0).
2. Assume that the pollutant is present in the
sample at a concentration equal to the
minimum analytical level (that is,
12-12
-------
Chapter 12 Pollutant Loading and Removal Estimates
Development Document for the CWT Point Source Category
ND=minimum analytical detection limit
(MADL)).
3. Assume that the pollutant is present at a
concentration equal to half the sample-
specific DL (that is, ND=DL/2). (In general,
the values of the sample-specific DLs are
equal to or greater than the values of the
minimum analytical detection limits used in
the second approach.)
4. Assume that the pollutant is present at a
concentration equal to the sample-specific
DL (that is, ND=DL). This is the
substitution approach that was used in the
1995 proposal, for the influent pollutant
loadings for the other two subcategories, and
for the proposed limitations and standards
for all three subcategories.
5. Assume that the pollutant is present at a
concentration equal to either the sample-
specific DL or the mean of the detected (or
non-censored) values (MNC) of the
pollutant4 EPA used the lower of the two
values (that is, ND=minimum of DL or
MNC).
EPA ultimately selected the approach
described in 5. because Agency concluded that it
provided the most realistic estimate of current
performance in these data sets.
Table 12-6A shows how EPA applied the
five substitution approaches to data for
hypothetical pollutant X for seven facilities. The
example shows the types of calculations EPA
performed in comparing the five approaches. The
example includes facilities that treat wastes on a
batch and continuous basis. It also includes a
mixture of detected and non-detected
measurements as well as duplicate samples. For
each facility, the table lists the analytical results
reported by the laboratory for pollutant X. If the
reported value is non-detected, then this
analytical result is identified in the table as "ND"
with the reported sample-specific DL in the
parenthesis. If the value is detected, the
analytical (measured) result is shown in the table
and is identical in all five approaches because the
substitutions apply only to non-detected values.
Finally, for each of the seven facilities, the table
shows five long-term averages for pollutant X~
one for each of the five substitution approaches.
4For each pollutant, EPA calculated the mean
(or average) of the detected (or non-censored)
values (MNC) using all detected values in the seven
data sets except for the biphasic sample. The
substitutions were only applied to non-detected
measurements observed in aqueous samples because
the non-detected measurements in the biphasic
sample were evaluated separately as described in the
previous section. While EPA believes that biphasic
samples can result from some wastes in this
subcategory after processing through emulsion
breaking/gravity separation, EPA believes that it is
appropriate to use only detected measurements from
aqueous samples in calculating the mean that will be
compared to each sample-specific DL in aqueous
samples.
12-13
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Chanter 12 Pollutant Loading and Removal Estimates
Development Document for the CWT Point Source Category
Table 12-6A. Example of Five Substitution Methods for Non-Detected Measurements of
Hypothetical Pollutant X
Facility
A
B
C
D
E
F
G
Sampling Day Reported
or Batch
Number
Batch 1
Batch 1
Batch 2
Batch 3
Batch 4
Dayl
Day 2
Dayl
Day 2
Day 3
Dayl
Day 2
(duplicate)
Day 2
(duplicate)
Day 3
Dayl
Day 2
Day 3
Day 4
DayS
Dayl
Day 2
DayS
Day 4
DayS
Dayl
Day 2
DayS
Day 4
MNC
Values
(ug/L)
99
95
ND (300)*
84
258
A:LTA
ND (100)
ND (1000)
B:LTA
57
84
26
C:LTA
73
ND (100)
ND(10)
62
D:LTA
411
257
79
ND
(1000)
ND (220)
E: LTA
ND (300)
320
44
47
180
F:LTA
1234
855
661
1377
G:LTA
= 315
Approach Approach 2
1
ND=0
99
95
0
84
258
122
0
0
0
57
84
26
56
73
0
0
62
45
411
257
79
0
0
149
0
320
44
47
180
118
1234
855
661
1377
1032
(MNC =
ND=MADL f
(MADL=10 ug/L)
99
95
10
84
258
125
10
10
10
57
84
26
56
73
. 10
10
62
48
411
257
79
10
10
153
10
320
44
47
180
120
1234
855
661
1377
1032
Approach
3
ND=DL/2
99
95
150
84
258
160
50
500
275
57
84
26
56
73
50
5
62
54
411
257
79
500
110
271
150
320
44
47
180
148
1234
855
661
1377
1032
Approach
4
ND=DL
99
95
300
84
258
197
100
1000
550
57
84
2.6
56
73
100
10
62
613
411
257
79
1000
220
393
300
320
44
47
180
178
1234
855
661
1377
1032
Approach 5
ND=
min(DL,MNC)
99
95
300
84
258
197
100
315
208
57
84
26
56
73
100
10
62
63
411
257
79
315
220
256
300
320
44
47
180
178
1234
855
661
1377
1032
mean of detected values from all seven facilities)
* ND=non-detected measurement. The sample-specific detection limit is provided in the parentheses.
f MADL=minimum analytical detection level
12-14
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Chapter 12 Pollutant Loading and Removal Estimates
Development Document for the CWT Point Source Category
While Table 12-6A provides an example
using the five approaches, DCN 23.8 shows the
results of the substitution values under the first
four approaches to the actual seven concentration
data sets from the seven facilities with emulsion
breaking/gravity separation. DCN 23.21 shows
the results of using the fifth approach. After
evaluating the five approaches, EPA prefers
Approach 5 because it tends to minimize the
effect of large detection levels on the long-term
averages while providing reasonable estimates of
the actual concentrations. Furthermore, EPA
feels that Approach 5 is superior to the other four
approaches. In particular, the first and second
approaches (substitutions of zero or the MADL,
respectively, for non-detects) are poor choices
because they are likely to provide unrealistically
low estimates of the analyte concentrations in
samples with high sample-specific detection
limits, especially when all detected values are
substantially greater than zero and the MADL. In
addition, the third and fourth approaches
(substitution of the sample-specific DL or DL/2,
respectively) are poor choices because the
substitutions could exceed the detected values in
some cases, and thus, possibly could over
estimate the concentrations in non-detected
measurements. EPA's analyses also show that
there is little or no difference in the averages
between using the sample-specific DL or half the
sample-specific DL for many of the
facility/analyte data sets. Thus, EPA has
followed the approach outlined in 5 above
because it concluded that this approach provides
reasonable estimates of the actual concentrations
because the substituted values are neither
unrealistically low nor exceed the greatest
detected value.
Table 12-7 shows the pollutant concentration
data sets for the seven facilities (identified as A,
B, etc.) using the "Originial" approach (that is,
Approach 1: sample-specific DL substituted for
non-detected measurements) and the 'Replaced'
approach (that is, Approach 5). Each set
provides the overall mean (i.e., the average of all
values — detected and non-detected), the mean of
the detected values, and the mean of the NDs (i.e.,
the mean of the substituted values). Both provide
the same detected mean value because, unlike the
non-detected measurements, no substitutions
were made for detected measurements. In
contrast, the overall mean and the mean of the
NDs vary when one or more values in a facility
data set exceed the mean detected value for the
pollutant.
Table 12-6B shows the relative effects of
EPA's preferred approach in comparison to
Approach 1 on the estimates of priority,
conventional, and non-priority pollutant
concentrations for baseline loadings and the total
removals changes for toxic weighted pollutants.
In comparison to Approach 1 (EPA's 'original
method), EPA's preferred (or 'replaced')
approach (that is, Approach 5) had little
noticeable effect on the baseline loadings for the
oils subcategory. In other words, the current
loadings are approximately the same using either
approach. There is, however, a significant
decrease in toxic pound-equivalent removals with
EPA's preferred approach. Hence, overall toxic
pound-equivalent removal estimates using EPA's
preferred approach decreased by approximately
34% from those calculated using its original
approach (that is, substituting the sample-specific
detection limit for all non-detected
measurements). The cost effectiveness document
provides more information on toxic pound-
equivalent removals.
Table 12-6B. Difference in Oils Subcategory Loadings After Non-Detect Replacement Using EPA Approach
Priority Metals & Organics Non-Priority Metals &
Current Loading (percent Organics Current Loading
change) (percent change)
-5
+ 1
Conventional Pollutant
Current Loading
(percent change)
0
Pound-Equivalent
Net Removals
(percent change)
-34
12-15
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-------
Chapter 12 Pollutant Loading and Removals Estimates
Development Document for the CWT Point Source Category
Random Assignment of Seven
Emulsion Breaking/Gravity
Separation Data Sets 12.3.2.2
While EPA's assignment of one of the seven
emulsion breaking/gravity separation data sets to
each oils facility for which EPA needed to
estimate current performance was random, the
SBREFA Panel raised the concern that this
approach may not have resulted in a
representative assignment of loadings.
The following explains EPA's procedure. To
obtain estimates of current pollutant loadings
associated with emulsion breaking/gravity
separation, EPA developed estimates of the
pollutant loadings at each of the 84 facilities
identified as having wastestreams in the oils
subcategory. To obtain estimates of pollutant
loadings, EPA needed concentration and flow
information for each facility. EPA had flow
information from all facilities, but had data on
pollutant .concentrations from only seven
facilities where EPA had sampled the emulsion
breaking/gravity separation operations. Section
12.3.2.1 describes these seven concentration data
sets. To obtain concentration estimates for the
remaining facilities in the oils subcategory, EPA
assigned one of the seven available concentration
data sets to each of those 77 facilities without
pollutant concentration data at random. EPA
assigned each set to no more than 11 facilities.
Then, EPA estimated each facility's pollutant
loadings as the product of the total oils
wastewater flow at the facility and the pollutant
concentrations in its assigned data set. Figure 12-
2 shows this procedure.
EPA assigned the seven data sets to each of
the 77 oil subcategory facilities for which there
was no actual concentration data. EPA assigned
the data sets randomly. Thus, EPA did not
weight some data sets more heavily than others.
After this assignment of the data sets, however,
EPA determined that there was one additional
facility that would fall within the scope of the
proposed oils subcategory, and one facility that
was no longer in-scope. EPA removed from the
data base the one facility and selected actual
concentration data for the newly included facility
randomly. The result of this procedure is that
each of the seven data sets represented data for
11, 12, or 13 facilities. EPA then calculated
pollutant loadings for the total of 84 facilities.
While EPA had randomly assigned the
concentration data, EPA reexamined its
procedure to assure itself that the results were, in
fact, statistically random and concluded they were
(see DCNs 23.5, 23.6, and 23.31). Further
review of the data established that two of the
facilities sampled by EPA had large wastewater
flows as compared to all CWT oils subcategory
facilities. Of the 84 oils subcategory facilities,
flows for these two facilities represented the sixth
and second highest wastewater flows. Total
flows and total loadings for any groups of
facilities that included these facilities would exert
influence regardless of the random assignment of
the concentration data for facilities for which
none was available. In addition, the sampled
facility with the highest toxic loadings was
assigned to the group with only a total of 11
facilities (the smallest number of facilities in any
group).
12-31
-------
Chapter 12 Pollutant Loading and Removals Estimates
Development Document for the CWT Point Source Category
Each facility provides flow
information
Each sampled faclty fe
assigned its own
concentration data set
Randomly assign 1 of 7
concentration data sets to
facSity
L
J
Calculate loading using
assigned concentration data
set and faciJt/s flow
Doos facility
have treatment h-place
that provides better removals than
chemical emulsion/gravity
separation?
Incorporate appropriate
reductions into facH/s
badings
Loadings remain the same
Figure 12-2. Methodology for Current Loadings Estimates in Oils Subcategory
12-32
-------
Chapter 12 Pollutant Loading and Removals Estimates
Development Document for the CWT Point Source Category
Organics Subcategory
Current Loadings
12.3.3
EPA had limited available data from the
organics subcategory and very little data which
represent organic subcategory CWT wastewater
only. The vast majority of organic facilities
commingle large quantities of non-CWT
wastewater prior to the point of discharge.
Therefore, EPA estimated current loadings based
on the treatment technologies in place except for
the two facilities for which EPA has analytical
data representing organic subcategory wastewater
. only.
Based on a review of technologies currently
used at organic subcategory facilities, EPA placed
in-place treatment for this subcategory in one of
five classes:
1) raw;
2) filtration only;
3) carbon adsorption;
4) biological treatment; and
5) biological treatment and multimedia
filtration.
The discussion below describes the
methodology EPA used to estimate current
loadings for each classification. Table 12-8 lists
the current performance estimates for each
classification. This table does not include current
loadings estimates for all pollutants of concern in
the organics subcategory. EPA excluded the non-
conventional bulk parameters, such as chemical
oxygen demand, many pollutants which serve as
treatment chemicals, and all pollutants not
detected at treatable levels in the wastewater
influent to the treatment system selected as the
basis for effluent limitations.
EPA used the first classification ("raw") for
seven organic subcategory facilities with no
reported treatment in place for the reduction of
organic constituents. EPA based its current
loadings estimate for "raw wastewater" on EPA
sampling data at two organic facilities. These
were Episode 1987, sample points 07A and 07B
and Episode 44725, sample point 01. For each
pollutant of concern and each facility, EPA
calculated a long-term average or mean. This
mean includes measured (detected) and non-
detected values. For non-detected values, EPA
used the sample-specific detection limit. Once
EPA had calculated the long-term average or
mean for each facility and each pollutant of
concern, EPA then calculated the mean of the
long-term averages from the two facilities for
each pollutant of concern to estimate the "raw"
current loadings concentrations reported in Table
12-8.
EPA classified in the second category
("filtration only") three organic subcategory
facilities which only had multi-media or sand
filtration as the on-site treatment technology for
the organic waste stream. For these facilities,
EPA adjusted the "raw wastewater"
concentrations to account for 55 percent removal
of TSS, 30 percent removal of metal parameters,
10 percent removal of BOD5 and no removal of
other classical or organic pollutants. EPA
estimated the percent reductions for facilities in
this group using the procedure previously
described in Section 12.3.2.
EPA placed in the third category two organic
subcategory facilities with carbon adsorption
(usually preceded by sand or multi-media
filtration). EPA adjusted the "raw wastewater"
concentrations to account for 50 percent removal
of organic pollutants, 45 percent removal of oil
and grease, and no removal of all other pollutants.
Again, EPA also estimated the percent removals
2After further review, EPA determined that data
from one episode (4472) represented a combination of
organics and oils subcategory wastewater. EPA will
re-visit its current loadings estimates classifications
prior to promulgation and incorporate the following
changes to the oil and grease loadings concentrations:
29,875 ug/L for raw treatment, 29,875 ug/L for
filtration only; 19,419 ug/L for carbon adsorption,
5,440 ug/L for biological treatment, and 5,290 ug/L
for biological treatment plus multimedia filtration.
12-33
-------
Chanter 12 Pollutant Loading and Removals Estimates
Development Document for the CWI Point Source Category
for facilities in this category using the procedure
previously described in Section 12.3.2.
EPA based the current loadings
concentrations for the fourth and fifth
classification on EPA sampling data collected at
Episode 1987. EPA calculated the current
loadings estimates for each pollutant of concern
using a similar procedure to that described above
for the "raw" organics subcategory current
performance. EPA based the: percent removals for
five organic subcategory facilities in the fourth
classification (biological treatment) on analytical
data collected at sample point 12. For the two
organic subcategory facilities in the fifth
classification (biological treatment and
multimedia filtration) EPA based removals on
analytical data collected at sample point 14.
Table 12-8. Current Loadings Estimates for the Organics Subcategory (units = ug/L)
Pollutant
CONVENTIONAL POLLUTANTS
BODS
Total Cyanide
Oil and Grease
TSS
METAL POLLUTANTS
Aluminum
Antimony
Boron
Chromium
Cobalt
Iron
Lithium
Manganese
Molybdenum
Nickel
Phosphorus
Silicon
Strontium
Sulfur
Tin
Zinc
ORGANIC POLLUTANTS
Acetophenone
Aniline
Benzene
Benzoic Acid
Chloroform
Dimethyl Sulfone
Ethylene-thiourea
Hexanoic Acid
M-xylene
Methylene Chloride
N,N-dimethylformamide
O-cresol
RawJ
22,027,643
3,270
176,649
1,454,857
56,363
456
48,098
553
277
32,175
11,888
710
1,337
1,426
6,925
2,813
5,088
1,601,750
984
1,402
1,528
1,367
2,776
10,469
4,449
1,449
5,150
2,240
1,206
1,962,725
32,846
7,339
Filtration
Only
19,824,879
3,270
176,649
654,686
39,454
319
33,668
387
194
22,522
8,321
497
936
998
4,848
1,969
3,561
1,121,225
689
981
1,528
1,367
2,776
10,469
4,449
1,449
5,150
2,240
1,206
1,982,725
32,846
7,339
Carbon
Adsorption
22,027,643
3,270
97,157
1,454,857
56,363
456
48,098
553
277
32,175
11,888
710
1,337
1,426
6,925
2,813
5,088
1,601,750
984
1,402
764
684
1,388
5,234
2,224
724
2,575
1,120
603
981,362
16,423
3,699
Biological Biological
Treatment* Treatment and
Multimedia
Filtration
2,440,000
2,176
17(5,649
480,000
2,474
569
48,098
553
437
3,948
11,888
227
943
1,426
6,925
2,680
2,060
1,370,000
984
382
36
10
10
320
73
158
4,400
64
10
204
11
185
1,564,000
2,120
3,900
399,000
2,474
569
48,098
553
437
3,948
11,888
227
943
1,426
6,925
2,680
2,060
1,370,000
984
382
36
10
10
320
73
158
4,400
64
10
204
11
185
12-34
-------
Chapter 12 Pollutant Loading and Removals Estimates
Development Document for the CWT Point Source Category
Table 12-8. Current Loadings Estimates for the Organics Subcategory (units = ug/L)
Pollutant
P-cresol
Pentachlorophenol
Phenol
Pyridine
Tetrachloroethene
Tetrachloromethane
Toluene
Trans- 1 ,2-dichloroethene
Trichloroethene
Vinyl chloride
1 , 1 -dichloroethane
1 , 1 -dichloroethene
1,1,1 -trichloroethane
1,1,1 ,2-tetrachloroethane
1 , 1 ,2-trichloroethane
1 ,2-dibromoethane
1 ,2-dichloroethane
1 ,2,3-trichloropropane
2-butanone
2-propanone
2,3-dichloroaniline
2,3 ,4,6-tetrachlorophenol
2,4,5-trichlorophenol
2,4,6-trichlorophenol
4-methyl-2-pentanone
Raw;
3,367
6,968
6,848
3,881
2,382
1,706
746,124
1,228
4,645
691
544
579
1,444
121
1,191
2,845
4,713
575
59,991
6,849,320
1,349
3,340
1,365
1369
3479
Filtration
Only
3,367
6,968
6,848
3,881
2,382
1,706
746,124
1,228
4,645
691
544
579
1,444
121
1,191
2,845
4,713
575
59,991
6,849,320
1,349
3,340
1,365
1369
3479
Carbon Biological Biological
Adsorption Treatment* Treatment and
Multimedia
Filtration
1,683
3,484
3,424
1,940
1,191
853
373,062
614
2,323
345
272
290
722
364
595
1,422
2,357
288
29,996
3,424,660
675
1,670
683
684
1739
66
791
362
116
112
14
10
22
69
10
10
10
10
10
13
10
10
10
878
2,061
23
629
97
86
146
66
791
362
116
112
14
10
22
69
10
10
10
10
10
13
10
10
10
878
2,061
23
629
97
86
146
* Current performance estimates for biological treatment and biological treatment with multimedia filtration are
equal for metal and organic constituents because EPA only analyzed for conventional parameters at Episode 1987,
sample point 14.
1 EPA used sampling data from Episodes 1987 and 4472 to estimate these "raw" concentrations. After reviewing
the data further, EPA determined that data collected at Episode 4472 did not represent "raw" organic subcategory
wastewater only and will re-visit between proposal and promulgation.
METHODOLOGY USED TO ESTIMATE
POST-COMPLIANCE LOADINGS
12A
Post-compliance pollutant loadings for each
regulatory option represent the total industry
wastewater pollutant loadings after
implementation of the proposed rule. For each
proposed option, EPA determined an average
performance level (the "long-term average") that
a facility with well designed and operated model
technologies (which reflect the appropriate level
of control) is capable of achieving. In most cases,
EPA calculated these long-term averages using
data from CWT facilities operating model
technologies. For a few parameters, EPA
determined that CWT performance was uniformly
inadequate and transferred effluent long-term
averages from other sources.
To estimate post-compliance pollutant
loadings for each facility for a particular option,
EPA used the long-term average concentrations,
the facility's annual wastewater discharge flow,
and a conversation factor in the following
equation:
12-35
-------
Chanter 12 Pollutant Loading and Removals Estimates Development Document for the CWI'Point Source Category
Postcompliance long-term average concentration
(mg/L)
Facility annual discharge flow x 1 Ib
453,600 mg
- Facility postcompliance annual loading
(Ibs/yr)
EPA expects that all facilities subject to the
effluent limitations and standards will design and
operate their treatment systems to achieve the
long-term average performance level on a
consistent basis because facilities with well-
designed and operated model technologies have
demonstrated that this can be done. Further, EPA
has accounted for potential treatment system
variability in pollutant removal through the use of
variability factors. The variability factors used
to calculate the proposed limitations and
standards were determined from data for the same
facilities employing the treatment technology
forming the basis for the proposal.
Consequently, EPA has concluded that the
standards and limitations take into account the
level of treatment variation well within the
capability of an individual CWT to control. If a
facility is designed and operated to achieve the
long-term average on a consistent basis, and if the
facility maintains adequate control of treatment
variation, the allowance for variability provided
in the limitations is sufficient.
Table 12-9 presents the long-term averages
for the selected option for each subcategory. The
pollutants for which data is presented in Table
12-9 represent the pollutants of concern at
treatable levels at the facilities which form the
basis of the options. The pollutants selected for
regulation are a much smaller subset.
12-36
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-------
Chapter 12 Pollutant Loading and Removals Estimates
Development Document for the CWT Point Source Category
METHODOLOGY USED TO ESTIMATE
POLLUTANT REMOVALS
12.5
POLLUTANT LOADINGS
AND REMOVALS
12.6
For each regulatory option, the difference
between baseline loadings and post-compliance
loadings represent the pollutant removals. For
direct discharging CWT facilities, this represents
removals of pollutants being discharged to
surface waters. For indirect, dischargers, this
represents removals of pollutants being
discharged to POTWs less the removals achieved
by POTWs. EPA calculated the pollutant
removals, for each facility using the following
equation:
Baseline Loadings - Postcompliance Loadings
= Pollutant Removals
EPA used the following methodology to
estimate pollutant removals:
1) If the post-compliance loading of a pollutant
was higher than the baseline loading, EPA
set the removal to zero;
2) If EPA did not identify a particular pollutant
in the wastewater of a facility at baseline and
that pollutant was present at baseline in the
wastewater of a facility used as the basis for
determining limitations and standards
associated with one of the regulatory options,
EPA set the removal to zero.);
3) If EPA did not calculate a long-term average
for a pollutant for a technology option (i.e.,
the post-compliance loading for the pollutant
could not be calculated), EPA set the removal
to zero; and
4) For indirect dischargers, EPA additionally
reduced the pollutant removal estimate by the
POTW removal percentage. Therefore, the
pollutant removal estimates for indirect
dischargers only account for pollutant
removals over and above the POTW
removals.
EPA estimated annual baseline and post-
compliance loadings for each of the subcategories
and the respective regulatory options using the
methodology described in Sections 12.3 through
12.5 of this document. For the oils subcategory,
EPA extrapolated the facility-specific loadings
and removals from the 84 in-scope discharging
facilities to provide estimates of an estimated
total population of 141 discharging oils facilities.
Facilities with no wastewater discharge ("zero
dischargers") have no pollutant loadings or
removals.
Tables 12-10 through 12-13 present the total
baseline and post-compliance loadings and the
pollutant removals for the facilities in each
subcategory.
12-41
-------
Chapter 12 Pollutant Loading and Removals Estimates Development Document for the CWTPoint Source Category
Table 12-10. Summary of Pollutant Loadings and Removals for the CWT Metals Subcategory1
Pollutant of Concern
Current Wastewater
Pollutant Loading
(Ibs/vr)
Direct Indirect
Discharges Discharges
Post-Compliance Wastewater
Pollutant Loading
flbs/vr)
Direct Indirect
Discharges Discharges
Post-Compliance Pollutant
Reductions
(Ibs/vr)
Direct Indirect
Discharges Discharges
CONVENTIONALS
Biochemical Oxygen
Demand 5-Day (BODS)
Oil and Grease (measured as HEM)
Total Suspended Solids (TSS)
PRIORITY METALS
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
TOTAL PRioRrrYMETALs
NON-CONVENTIONAL METALS
Aluminum
Barium
Boron
Cobalt
Indium
Iron
Lithium
Manganese
Molybdenum
Silicon
Strontium
Tin
Titanium
Vanadium
Yttrium
Zirconium
TOTAL NON-CONVENTIONAL
METALS
CLASSICAL PARAMETERS
Chemical Oxygen Demand (COD)
Hexavalent Chromium
Ammonia as N
Cyanide
8,366,557
519,480
6,109,653
34,215
676
5,380
140,366
205,011
26,012
164
52,686
1,838
421
347
127,400
594,516
82,842
308
168,406
3,865
17,288
114,752
146,215
5,645
16,864
41,066
10,831
159,531
93,683
4,686
122
857
866,961
32,170,276
235,527
411,874
5,295
N/A
N/A
N/A
7,504
37
16
289
669
139
16
5,024
1,226
24
82
3,359
18,385
3,455
64
92,315
885
3,122
9,248
125,992
1,007
5,863
6,810
10,106
1,856
586
119
43
223
261,694
N/A
15,106
N/A
1,046
570,816
74,445
64,680
608
301
125
1,727
1,811
441
4
3,917
1,346
80
347
1,605
12,312
3,042
308
34,766
435
3,499
24,042
5,884
175
6,445
5,100
350
330
188
150
21
835
85,570
4,733,770
2,431
60,506
304
N/A
N/A
N/A
184
29
9
147
278
36
1
1,945
854
6
82
347
3,918
377
64
25,153
401
953
4,329
5,056
107
3,126
3,876
319
116
64
81
8
223
44,253
N/A
2,660
N/A
96
7,795,741
445,035
6,044,973
33,607
375
5,255
138,639
203,200
25,571
160
48,769
492
341
0
125,795
582,204
79,800
0
133,640
3,430
13,789
90,710
140,331
5,470
10,419
35,966
10,481
159,201
93,495
4,536 '
101
22
781,391
27,436,506
233,096
351,368
4,991
N/A
N/A
N/A
7,320
8
7
142
391
103
15
3,079
372
18
0
3,012
14,467
3,078
0
67,162
484
2,169
4,919
120,936
900
2,737
2,934
9,787
1,740
522
38
35
0
217,441
N/A
12,446
N/A
950
'All loadings and reductions take into account the removals by POTWs for indirect discharges.
HEM - Hexane extractable material
12-42
-------
Chanter 12 Pollutant Loading and Removals Estimates
Development Document for the CWT Point Source Category
Table 12-11. Summary of Pollutant Loadings and Removals for the CWT OHs Subcategory*
Pollutant of Concern
Current Wastewater
Pollutant Loading
flbs/vr)
Direct Indirect
Discharges Discharges
Post-Compliance Wastewater
Pollutant Loading
flbs/vrt
Direct Indirect
Discharges Discharges
Post-Compliance Pollutant
Reductions
flbs/vr)
Direct Indirect
Discharges Discharges
CONVENTIONALS
Biochemical Oxygen
Demand 5-Day (BODS)
Oil and Grease (measured as HEM)
Total Suspended Solids (TSS)
PRIORITY ORGANICS
1,1,1-Trichloroethane
1,2,4-Trichlorobenzene
1,4-Dichlorobenzene
1,1-Dichloroethene
1,2-Dichloroethane
2,4-Dimethylphenol
Acenapthene
Anthracene
Benzene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Bis(2-ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Chlorobenzene
Chloroform
Chrysene
Diethyl Phthalate
Di-ii-butyl Phthalate
Ethylbenzene
Fluoranthene
Fluorene
Methylene Chloride
Naphthalene
Phenanthrene
Phenol
Pyrene
Tetrachloroethene
Toluene
Trichloroethene
TOTAL PRIORITY ORGANICS
NON-CONVENTIONAL ORGANICS
l-Methylfluorene
1-Methylphenanthrene
2,3-Benzofluorene
2-Butanone
2-Methylnaphthalene
2-Phenylnaphthalene
2-Propanone
3,6-Dimethylphenanthrene
4-Chloro-3-methylphenol
4-Methyl-2-pentanone
«-Terpineol
Benzoic Acid
Benzyl Alcohol
Biphenyl
Carbazole
Carbon Disulfide
Dibenzofuran
Dibenzothiopene
Diphenyl Ether
1,099,760
324,206
291,300
38
12
8
4
3
19
10
14
166
11
9
8
8
24
13
2
5
15
13
3
129
12
10
26
. 52
50
393
35
11
677
7 '
1,787
12
29
14
392
45
4
4,313
14
207
51
8
875
8
37
5
5
10
16
105
N/A
N/A
N/A
80S
723 •
1,012
185
66
1,088
80
242
562
60
123
100
122
126,764
576
14
396
102
1,902
171
794
4,514
1,459
3,616
2,319
933
2,020
1,309
823
2,122
308
155,313
384
592
236
1,508
. 13,986
90
62,551
236
18,504
2,158
196
18,858
287
189
209
141
101
414
201
845,531
4,840
4,214
13
10
7
4
3
19
10
12
84
9
6
6
5
7
4
2
5
8
13
3
36
2
10
26
39
"13
393
10
11
314
7
1,091
5
8
9
392
26
2
4,313
8
61
51
4
875
8
20
5
4
10
10
94
N/A
N/A
N/A
71
56
230
112
61
1,088
13
42
117
15
19
18
20
287
18
11
303
16
1,304
62
107
812
348
3,353
328
196
1,598
135
303
574
179
11,796
48
76
236
1,144
5,581
90
62,551
236
18,504
1,894
17
13,631
287
19
109
26
14
90
201
254,229
319,366
287,086
25
2
1
0
0
0
0
2
82
2
3
2
3
17
9
0
0
7
0
0
93
10
0
0
13
37
0
25
0
363
0
696
7
21
5
0
19
2
0
6
146
0
4
0
0
17
0
1
0
6
11
N/A
N/A
N/A
737
667
782
73
5
0
67
200
445
45
104
82
102
126,477
558
3
93
86
598
109
687
3,702
1,111
263
1,991
737
422
1,174
520
1,548
129
143,517
336
516
0
364
8,405
0
0
0
0
264
179
5,227
0
170
100
115
87
324
0
12-43
-------
Chapter 12 Pollutant Loading and Removals Estimates Development Document for the CWTPoint Source Category
Table 12-11. Summary of Pollutant Loadings and Removals for the CWT Oils Subcategory;
Pollutant of Concern
HexanoicAcid
ro-Xylene
n-Dccane
Ji-Docosane
n-Dodecane
n-Ecosane
n-Hexadccane
n-Octadecane
n-Tetradecane
o-Cresol
o-&p-Xylene
p-Cresol
p-Cymene
Pentamethylbenzene
Pyridine
Styrene
Tripropyleneglycol Methyl Ether
TOTAL NON-CONVENTIONAL
ORGANICS
PRIORITY METALS
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Zinc
TOTAL PRIORITY METALS
NON-CONVENTIONAL METALS
Aluminum
Barium
Boron
Cobalt
Iron
Manganese
Molybdenum
Silicon
Strontium
Tin
Titanium
TOTAL NON-CONVENTIONAL METALS
CLASSICAL PARAMETERS
Chemical Oxygen Demand
-------
Chapter 12 Pollutant Loading and Removals Estimates
Development Document for the CWT Point Source Category
Table 12-12. Summary of Pollutant Loadings and Removals for the CWT Organics Subcategory7
Pollutant of Concern
Current Wastewater
Pollutant Loading
(lbs/vr)
Direct Indirect
Discharges Discharges
Post-Compliance Wastewater
Pollutant Loading
(Ibs/vr)
Direct Indirect
Discharges Discharges
Post-Compliance Pollutant
Reductions
(Ibs/vrt
Direct Indirect
Discharges Discharges
CONVENTIONALS
Biochemical Oxygen Demand
5-Day (BOD5)
Oil and Grease (measured as HEM)
Total Suspended Solids (TSS)
PRIORITY ORGANICS
1,1,1-Trichloroethane
1,1,2-Trichloroethane
1,1-Dichloroehtane
1,1-Dichloroethene
1,2-DichIoroethane
Benzene
Chloroform
Methylene Chloride
Pentachlorophenol
Phenol
Tetrachloroethene
Toluene
Trichloroethene
Vinyl Chloride
TOTAL PRIORITY ORGANICS
NON-CONVENTIONAL ORGANICS
1,1,1,2-Tetrachloroethane
1,2,3-Trichloropropane
1,2-Dibromoethane
2,3,4,6-Tefrachlorophenol
2,3-Dichloroaniline
2,4,5-Trichlorophenol
2,4,6-TrichlorophenoI
2-Butanone
2-Propanone
4-Methyl-2-pentanone
Acetophenone
Aniline
Benzoic Acid
Diethyl Ether
Dimethyl Sulfonone
Ethylenethiourea
Hexanoic Acid
m-Xylene
N,N-Dimethylformamide
o-Cresol
Pyridine
p-Cresol
Tetrachloromethane
Trans-l,2-Dichloroehtene
TOTAL NON-CONVENTIONAL
ORGANICS
PRIORITY METALS
Antimony
Chromium
Copper
Nickel
Zinc
5,366
23,062
5,888
1
2
1
1
1
1
9
27
103
47
15
1
9
1
219
1
1
1
82
3
13
11
115
269
19
5
1
42
0
21
574
8
1
1
24
15
9
2
3
N/A
N/A
N/A
154
463
48
183
314
109
631
258,747
1,779
54
368
7,722
211
110
270,893
1,312
1,576
1,926
661
' 243
292
140
2,432
361,967
1,028
21
151
594
7,640
22
750
108
638
4,957
1,019
53
280
165
400
5,366
23,062
5,888
1
2
1
1
1
1
9
27
103
47
15
1
9
1
219
1
1
1 .
82
3
13
11
115
269
19
5
1
42
0
21
574
8
1
1
24
15
9
2
3
N/A
N/A
N/A
0
1
1
1
0
1
6
40
243
3
7
0
2
0
305
4
4
5
140
7
26
10
26
146
8
1
1
19
24
2
648
5
2
2
31
2
7
1
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
N/A
N/A
N/A
154
462
47
182
314
108
625
258,707
1,536
51
361
7,722
209
110
270,588
1,308
1,572
1,921
521
236
266
130
2,406
361,821
1,020
20
150
575
7,616
20
102
103
636
4,955
988
51
273
164
398
1,221
388,375
1,221
1,094
387,252
74
72
92
186
50
40
13
29
351
96
74
72
92
186
50
40
5
29
351
34
0
0
0
0
0
0
8
0
0
62
12-45
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Chanter 12 Pollutant Loadine and Removals Estimates
Development Document for the CWT Point Source Category
Table 12-12. Summary of Pollutant Loadings and Removals for the CWT Organics SubcategoryJ
Pollutant of Concern
Current Wastewater
Pollutant Loading
flbs/vr)
Direct Indirect
Post-Compliance Wastewater
Pollutant Loading
flbs/vnrt
Direct Indirect
P ost-Compliance Pollutant
Reductions
flbs/vr)
Direct Indirect
nischarpps nisrharces
TOTAL PRIORTTY METALS
NON-CONVENTIONAL METALS
Aluminum
Boron
Calcium
Iodine
Iron
Lithium
Magnesium
Manganese
Molybdenum
Phosphorus
Potassium
Silicon
Sodium
Strontium
Sulfur
Tin
TOTAL NON-CONVENTIONAL
METALS
CLASSICAL PARAMETERS
Total Cvanide
474
323
6,279
0
0
515
1,552
0
30
123
904
0
350
0
269
178,861
128
189,334
285
529
15,395
5,535
0
1,982
1,847
3,911
0
219
204
751
0
893
0
1,723
496,299
147
528,906
352
474
323
6,279
0
0
515
1,552
0
30
123
904
0
350
0
269
178,861
128
189,334
285
459
854
545
0
0
292
3,911
0
68
161
0
0
858
0
803
0
147
7,639
260
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
70
14,541
4,990
0
1,982
1,555
0
0
151
43
751
0
35
0
920
496,299
0
521,267
92
'All loadings and reductions take into account the removals by POTWs for indirect discharges.
HEM - Hexane extractable material
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Chapter 12. Pollutant Loading and Removals Estimates
Development Document for the CWTPointSource Category
Table 12-13. Summary of Pollutant Loadings and Removals for the Entire CWT Industry'
Pollutant of Concern
CONVENTIONALS2
TOTAL PRIORITY ORGANICS
Current Wastewater
Pollutant Loading
flbs/vr)
Direct Indirect
Discharges Discharges
Post-Compliance Wastewater
Pollutant Loading
(lbs/vr)
Direct Indirect
Discharges Discharges
Post-Compliance Pollutant
Reductions
flbs/vr)
Direct Indirect
Discharges Discharges
16,225,792 N/A 1,524,397 N/A 14,701,395 N/A
2,006 426,206 1,310 12,101 696 414,105
TOTAL NON-CONVENTIONAL
ORGANICS
TOTAL PRIORITY METALS
TOTAL NON-CONVENTIONAL
METALS
13,463
601,238
1,502,013
68,604
1,079,386 1,343,796
8,865
13,232
285,287
136,032
11,748
407,104
4,598
588,006
794,099
1,365,951
56,856
936,692
JA11 loadings and reductions take into account the removals by POTWs for indirect discharges.
HEM - Hexane extractable material
2Oil and grease loadings and removals for the metals subcategory are not included in this table.
12-47
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Chapter
13
NON-WATER QUALITY IMPACTS
Sections 304(b) and 306 of the Clean Water
Act provide that non-water quality
environmental impacts are among the factors
EPA must consider in establishing effluent
limitations guidelines and standards. These
impacts are the environmental consequences not
directly associated with wastewater that may be
associated with the regulatory options considered.
For this rule, EPA evaluated the potential effect
of the proposed options on air emissions, solid
waste generation, and energy consumption.
This section quantifies the non-water quality
impacts associated with the options evaluated for
this proposal. Cost estimates for the impacts, and
the methods used to estimate these costs are
discussed in Chapter 11 of this document.. In all
cases, the costs associated with non-water quality
impacts were included in EPA's cost estimates
used in the economic evaluation of the proposed
limitations and standards.
AIR POLLUTION
13.1
CWT facilities receive and produce
wastewaters that contain significant
concentrations of organic compounds, some of
which are listed in Title 3 of the Clean Air Act
Amendments (CAAA) . of 1990. These
wastewaters often pass through a series of
collection and treatment units. These units are
open to the atmosphere and allow wastewater
containing organic compounds to contact ambient
air. Atmospheric exposure of the organic-
containing wastewater may result in significant
water-to-air transfers of volatile organic
compounds (VOCs).
The primary sources of VOCs in the CWT
industry are the wastes treated in the oils and the
organics subcategory. In general, CWT facilities
have not installed air or wastewater treatment
technologies designed to control the release of
VOCs to the atmosphere. Additionally, most
CWT facilities do not employ best management
practices designed to control VOC emissions
(such as covering their treatment tanks).
Therefore, as soon as these VOC-containing oil
and organic subcategory wastewaters contact
ambient air, volatilization will begin to occur.
Thus, volatilization of VOCs and HAPs from
wastewater may begin immediately on receipt, as
the wastewater enters the CWT facility, or as the
wastewater is discharged from the process unit.
Emissions can also occur from wastewater
collection units such as process drains, manholes,
trenches, sumps, junction boxes, and from
wastewater treatment units such as screens,
settling basins, equalization basins, biological
aeration basins, dissolved air flotation systems,
chemical precipitation systems, air or steam
strippers lacking air emission control devices, and
any other units where the wastewater is in contact
with the air. In some cases, volatilization will
begin at the facility and continue as the
wastewaters are discharged to the local river or
POTW.
EPA believes air emissions from existing
CWT facilities would be similar before or after
implementation of any of the proposed options.
This is due primarily to the nature of VOCs, the
failure of CWT facilities to equip their
wastewater treatment systems with emissions
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Chapter 13 Non-Water Quality Impacts
Development Document for the CWT Point Source Category
controls, and the lack of best management
practices designed to control the emissions of
volatile pollutants. While EPA does not project
any net increase in air emissions as a result of the
implementation of the proposed effluent
guidelines and standards, EPA does project a
shift in the location of the VOC emissions.
Table 13-1 provides information on
incremental VOC emissions resulting from
implementation of the proposed rule at CWT oils
and organics facilities. EPA has not provided
information for the metals subcategory, but
believes these emissions would be negligible. For
this analysis, EPA defined a volatile pollutant as
described in Chapter 7 and calculated volatile
pollutant baseline and post-compliance loadings
and reductions as described in Chapter 12. EPA
additionally assumed that 80% of the volatile
pollutant reduction would be due to volatilization.
EPA selected 80% based on an assessment of
information developed during the development of
OCPSF guidelines (see pages 275-285 of the
October 1987 "Development Document for
Effluent Limitations Guidelines and Standards
for the OCPSF Point Source Category (EPA
440/1-87/009)). EPA believes the information
presented in Table 13-1 represents a "worst-case"
scenario in terms of incremental volatile air
emissions, since the analysis assumes no
volatilization of pollutants at baseline. As
explained earlier, EPA believes that the majority
of these pollutants are already being volatilized in
the absence of additional treatment technologies.
Table 13-1 also shows that, for this worst-
case scenario, the sum of the annual VOC air
emissions at CWT facilities would not exceed
400 tons of HAPs. Under the Clean Air Act,
major sources of pollution by HAPs are defined
as having either: (1) a total emission of 25
tons/year or higher for the total HAPs from all
emission points at a facility; or (2) an emission of
10 tons/year or higher from all emission points at
a facility. Based on these criteria, incremental air
emissions from this worst-case scenario analysis
of the proposed BPT/BAT/PSES organics
subcategory options would cause three facilities
to be classified as major sources. For the oils and
metals subcategories, EPA. does not project any
major sources due to incremental removals. Since
EPA believes that the three organics subcategory
CWT facilities classified as major sources would
be classified as such in the absence of the
implementation of the proposed options, EPA has
determined that air emission impacts from the
proposed options are acceptable.
Finally, while this proposal is not based on
technology that uses air stripping with emissions
control to abate the release of volatile pollutants,
EPA encourages all facilities which accept waste
containing volatile pollutants to incorporate air
stripping with overhead recovery or destruction
into their wastewater treatment systems.
Additionally, EPA also notes that CWT sources
of hazardous air pollutants are subject to
maximum achievable control technology
(MACT) as promulgated for off-site waste and
recovery operations on July 1, 1996 (61 FR
34140) as 40 CFR Part 63.
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Chapter 13 Non-Water Quality Impacts
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Table 13-1. Projected Air Emissions at CWT Facilities
Subcategory
Oils
Organics
VOCs Emitted
(tons/yr)
69
329
Priority VOCs
Emitted
(tons/yr)
32
323
Number of Projected
MACT* Facilities
0
3
Major Constituents
Toluene
Methylene Chloride
and Toluene
* MACT requires 25 tons of volatile emissions for a facility to be a major source or 10 tons of a single
pollutant at a single facility.
SOLID WASTE
13.2
Solid waste will be generated by several of
the proposed treatment technologies EPA.
evaluated. These wastes include sludges from
biological treatment, chemical precipitation and
clarification, gravity separation, and dissolved air
flotation systems.
To estimate the incremental sludge generated
from the proposed options, EPA subtracted the
volume of sludge currently being generated by the
CWTs from the estimated volume of sludge that
would be generated after implementation of the
options. EPA-calculated the volume of sludge
currently being generated by CWT facilities for
all sludge-generating technologies currently being
operated at CWT facilities. EPA then calculated
the volume of sludge that would be generated by
CWT facilities after implementation of the
proposed options. Table 13-2 presents the
estimated increase in volumes of filter cake
generated by CWT facilities that would result
from implementation of the proposed limitations
and standards.
The precipitation and subsequent separation
processes proposed as the technology basis for
the metals subcategory will produce a metal-rich
filter cake. In most instances, the resulting filter
cake will require disposal in Subtitle C and D
landfills. EPA estimates that the annual increase
in filter cake generated by the metals subcategory
facilities will be 3.71 million gallons. In
evaluating the economic impact of sludge
disposal, EPA assumed that all of the sludge
generated would be disposed in a landfill. This
assumption does not take into consideration the
fact that an undetermined portion of the generated
filter cake may be recovered in secondary metals
manufacturing processes rather than being
disposed in a landfill.
The dissolved air flotation system and
additional gravity separation step proposed as the
technology basis for the oils subcategory will
produce a filter cake with varying solids and oil
content. This filter cake may be either disposed
in Subtitle C and D landfills or in some cases
through incineration. EPA estimates that the
annual increase in filter cake generated by the oils
subcategory facilities will be 22.68 million
gallons. These estimates are based on
implementation of option 8 technology for
indirect dischargers (PSES) and option 9 for
direct dischargers (BPT/BAT). EPA applied a
scale-up factor to include the estimated volume of
filter cake generated by the NOA non-
respondents. In evaluating the economic impact
of sludge disposal, EPA assumed that all of the
sludge generated would be disposed in a landfill.
Biological treatment proposed as the
technology basis for the organics subcategory will
produce a filter cake that consists primarily of
biosolids. This filter cake can be disposed by a
variety of means including disposal at Subtitle C
and Subtitle D landfills, incineration, composting,
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Chapter 13 Non-Water Quality Impacts
Development Document for the CWT Point Source Category
and land application. However, contaminants
contained in the sludges may limit the use of
composting and land application. EPA estimates
that the annual increase in filter cake generated by
the organics subcategory facilities will be 4.31
million gallons. In evaluating the economic
impact of sludge disposal, EPA assumed that all
of the sludge generated would be disposed in a
landfill.
Table 13-3 presents the percentage of the
national volume of hazardous and non-hazardous
waste sent to landfills represented by the increase
for each regulatory option. The information
presented in this table represents the tonnage of
waste accepted by landfills in 1992 and was
based on information .collected during the
development of the proposed Landfills Point
Source Category (see pages 3-32 of the January
1998 "Development Document for Proposed
Effluent Limitations Guidelines and Standards
for the Landfills Point Source Category" (EPA-
821-R-97-022)). Based on this analysis, EPA
has determined that the solid waste impacts of the
proposed regulatory options are acceptable.
Table 13-2. Projected Incremental Filter Cake Generation at CWT Facilities
CWT
Subcategory
Metals
Oils
Organics
Total
Filter Cake Generated (million gal/yr)
Option
4
8
9
4
-
Indirect
0.
10
2.
13
80
.04
89
.73
Hazardous
Direct
1.68
_
0
0
1.68
Total
2.48
10.04
0
2.89
15.41
Non-Hazardous
Indirect Direct Total
0.40
12.28
-
1.42
14.1
0.83
_
0.36
0
1.19
1.23
12.28
0.36
1.42
15.29
Table 13-3. National Volume of Hazardous and Non-hazardous Waste Sent to Landfills
CWT
Subcategory
Metals
Oils
Organics
Total
Option
4
8
9
4
Percentage of Annual Tonnage of Waste
Disposed in National Landfills
Hazardous
0.032
0.093
0
0.024
0.149
Non-hazardous
0.004
0.028
0.001
0.003
0.036
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Chapter 13 Non-Water Quality Impacts
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ENERGY REQUIREMENTS
13.3
EPA estimates that the attainment of the
proposed options will increase energy
consumption by a small increment over present
industry use. The projected increase in energy
consumption is primarily due to the incorporation
of components such as pumps, mixers, blowers,
lighting, and controls. Table 13-4 presents the
estimated increase in energy requirements that
would result from the implementation of the
proposed limitations and standards. The
estimated total increase in energy consumption of
7.51 million kilowatt hours per year that would
result from compliance with the proposed
regulation equates to 4,209 barrels of oil per day.
According to the United States Department of
Energy-Energy Information Administration
website (http ://www.eia.doe.gov/pub/energy/
overview/aer), the United States currently
consumes 18.3 million barrels of oil per day.
Therefore, EPA has determined that energy
impacts from the proposed rule would be
acceptable.
LABOR REQUIREMENTS
13.4
The installation of new wastewater treatment
equipment along with improvements in the
operation of existing equipment for compliance
with the proposed limitations and standards
would result in increased operating labor
requirements for CWT facilities. It is estimated
that compliance with the CWT regulations would
result in industry-wide employment gains. Table
13-5 presents the estimated increase in labor
requirements for the CWT industry.
Table 13-4. Projected Energy Requirements for CWT Facilities
Energy Usage (kwh/yr)
CWT Subcategory Option
Metals 4
Cyanide Waste ^
Pretreatment
Oils 8
Organics 4
Total
Indirect
Dischargers
1,805,369
129,000
3,336,584
505,175
5,776,128
Direct
Dischargers
1,551,195
18,046
137,061
24,069
1,730,371
Total
3,356,564
147,046
3,336,584
137,061
529,244
7,506,499
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Chapter 13 Non-Water Quality Impacts
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Table 13-5. Projected Labor Requirements for CWT Facilities
Operating Labor Requirements
Q ,CWT Option
Subcategory
Indirect Dischargers
(Hours/yr) (Men/yr)
Direct Dischargers
(Hours/yr) (Men/yr)
Total
(Hours/yr) (Men/yr)
Metals
Cyanide
Waste
Pretreatment
Oils
Organics
4
2
8
9
4
85,448 42.7
16,425 8.2
57,825 25.9
29,042 14.5
27,105
2,190
2,496
936
13.6 112,553 56.3
1.1 18,615
1.2
0.5
57,825
2,496
29,978
9.3
25.9
1.2
15
Total
188,740 91.3
32,727
16.4
221,467
107.7
13-6
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Chapter
14
IMPLEMENTATION
Implementation of a regulation is a critical step
in the regulatory process. If a regulation is not
effectively implemented, the removals and
environmental benefits estimated for the
regulation may not be achieved. Likewise,
ineffective implementation could hinder the
facility's operations without achieving the
estimated environmental benefits. In discussions
with permit writers and pretreatment authorities
many stated that close communication with C WT
facilities is important for effective
implementation of discharge permits. Control
authorities need to have a thorough understanding
of a CWT's operations to effectively implement
this rule. Likewise, CWT facilities must maintain
close communication with the waste generators in
order to accurately characterize and treat the
incoming waste streams.
APPLICABLE WASTE STREAMS
14.1
Chapter 5 describes the sources of
wastewater for the CWT industry, which include
the following:
Off-site-generated wastewater:
• Waste receipts via tanker truck,
trailer/roll-off bins, and drums.
On-site-generated wastewater:
• Equipment/area washdown
• Water separated from recovered/recycled
materials
• Contact/wash water from recovery and
treatment operations
• Transport container washdown
• Solubilization water
• Laboratory-derived wastewater
• Air pollution control wastewater
• Incinerator wastewater from on-site
incinerators
• Landfill wastewater from on-site landfills
• Contaminated stormwater.
All of these waste streams should be classified as
process wastewater and are thus subject to the
appropriate subcategory discharge standards.
EPA believes that uncontaminated stormwater
should not be mixed with waste receipts prior to
complete treatment of the waste receipts since
this arrangement may allow discharge standards
to be met by dilution rather than proper
treatment. However, EPA is concerned that only
contaminated stormwater (i.e. stormwater whic
comes in contact with waste receipts and waste
handling and treatment areas) be classified as a
process wastewater. During site visits at CWT
facilities, EPA observed many circumstances in
which uncontaminated stormwater was
commingled with the CWT wastewaters prior t
treatment or was added after treatment prior to
effluent discharge monitoring. EPA believes that
permit writers and pretreatment authorities
should be responsible for determining which
stormwater sources warrant designation as
process wastewater. Additionally, control
authorities should require facilities to monitor and
meet their CWT discharge requirements
following wastewater treatment and prior to
combining these treated CWT wastewaters with
non-process wastewaters. If a control authority
allows a facility to combine treated CWT
wastewaters with non-process wastewaters prior
to compliance monitoring, the control authori y
should ensure that the non-contaminated
stormwater dilution flow is factored into the
facility's permit limitations.
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Chapter 14 Implementation
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EPA has also observed situations where
stormwater, contaminated and uncontaminated,
was recycled as process water (e.g., as
solubilization water for wastes in the solid phase
to render the wastes treatable). In these
instances, dilution is not the major source of
pollutant reductions (treatment). Rather, this
leads to reduced wastewater discharges. Permit
writers and pretreatment authorities should
investigate opportunities for use of such
alternatives and encourage such practices
wherever feasible.
DESCRIPTION OF SUBCATEGORY 14.2
One of the most important aspects of
implementation is the determination of which
subcategory's limitations are applicable to a
facility's operations). As detailed in Chapter 5,
EPA established a subcategorization scheme
based on the character of the wastes being treated
and the treatment technologies utilized. The
subcategories are as follows:
Subcategory A: Metals Subcategory:
Facilities which treat, recover, or treat and
recover metal, from metal-bearing waste,
wastewater, or used material received from
offsite;
Subcategory B: Oils Subcategory:
Facilities which treat, recover, or treat and
recover oil, from oily waste, wastewater, or
used material received from offsite; and
Subcategory C: Organics Subcategory:
Facilities which treat, recover, or treat
and recover organics, from other organic
waste, wastewater, or used material
received from offsite;
The determination of a Subcategory is
primarily based on the type of process generating
the waste, the characteristics of the waste, and the
type of treatment technologies which would be
effective in treating the wastes. It is important to
note that various pollutants were detected in all
three subcategories. That is,, organic constituents
were detected in metal Subcategory wastewater
and vice versa. The following sections provide a
summary description of the wastes in each of the
three subcategories; a more detailed presentation
is in Chapter 5.
Metals Subcategory Description
14.2.1
Waste receipts classified in the metals
subcategory include, but are not limited to: spent
electroplating baths and sludges, spent anodizing
solutions, air pollution control water and sludges,
incineration wastewaters, waste liquid mercury,
metal finishing rinse water and sludges, chromate
wastes, cyanide-containing wastes, and waste
acids and bases. The primary concern with
metals subcategory waste streams is the
concentration of metal constituents, and some
form of chemical precipitation with solid-liquid
separation is essential. These raw waste streams
generally contain few organic consituents and
have low oil and grease levels. The range of oil
and grease levels in metal subcategory
wastestreams sampled by EPA was 5 mg/L (the
minimum analytical detection limit) to 143 mg/L.
The average oil and grease level measured at
metals facilities by EPA was 39 mg/L. As
expected, metal concentrations in wastes from
this subcategory were generally high in
comparison to other subcategories. In general,
wastes that contain significant quantities of
inorganics and/or metals should be classified in
the metals subcategory.
Oil Subcategory Description
14.2.2
Waste receipts classified in the oils
subcategory include, but are not limited to:
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Chapter 14 Implementation
Development Document for the CWT Point Source Categor
lubricants, used petroleum products, used oils, oil
spill clean-up, interceptor wastes, bilge water,
tank cleanout, off-specification fuels, and
underground storage tank remediation waste.
Based on EPA's sampling data, oil and grease
concentrations in these streams following
emulsion breaking and/or gravity separation
range from 23 mg/L to 180,000 mg/L. The
facility average value is 5,976 mg/L. Based on
information provided by industry, oil and grease
content in these waste receipts prior to emulsion
breaking and/or gravity separation varies between
0.1% and 99.6% (1,000 mg/L to 996,000 mg/L).
Additionally, as measured after emulsion
breaking and/or gravity separation, these oily
wa.stewaters generally contain a broad range of
organic and metal constituents. Therefore, while
the primary concern is often a reduction in oil and
grease levels, oils subcategory wastewaters
require treatment for metal constituents and
organic constituents also. In general, wastes that
do not contain a recoverable quantity of oil
should not be classified as being in the oils
subcategory. The only exception to that would be
wastes contaminated with gasoline or other
hydrocarbon fuels.
Organics Subcategory Description 14.2.3
Waste receipts classified in the organics
subcategory include, but are not limited to:
landfill leachate, contaminated groundwater
clean-up, solvent-bearing waste, off-specification
organic product, still bottoms, used glycols,
wastewater from adhesives and epoxies, and
wastewater from chemical product operations and
paint washes. These wastes generally contain a
wide variety and concentration of organic
compounds, low concentrations of metal
compounds'(as compared to waste receipts in the
metals subcategory), and low concentrations of
oil and grease. The concentration of oil and
grease in organic subcategory samples measured
by EPA ranged from 2mg/L to 42 mg/L with an
average value of 22 mg/L. The primary concern
for organic wastestreams is the reduction in
organic constituents which generally requires
some form of biological treatment. In general,
wastes that do not contain significant quantities
of inorganics, metals, or recoverable quantities of
oil or fuel should be classified as belonging to the
organics subcategory.
FACILITY SUBCATEGORIZATION
IDENTIFICATION
14.3
EPA believes that the paperwork and
analyses currently performed at CWT facilities as
part of their waste acceptance procedures (as
outlined in Chapter 4) are generally sufficient for
making a subcategory determination. EPA has
strived to base its recommended
subcategorization determination procedure on
information generally obtained during these waste
acceptance and confirmation procedures. EPA
discourages permit writers and pretreatment
authorities from requiring additional monitoring
or paperwork solely for the purpose of
subcategory determinations. In most cases, as
detailed below, EPA believes the subcategory
determination can be made on the type of waste
receipt, e.g., metal-bearing sludge, waste oil,
landfill leachate. EPA believes that all CWT
facilities should, at a minimum, collect
information from the generator on the type of
waste receipt since this is the minimum
information required by CWT facilities to
effectively treat off-site wastes.
To determine an existing facility's
subcategory classifications), the facility should
review its incoming waste receipt data for a
period of one year. The facility should first use
Table 14-1 below to classify each of its waste
receipts for that one year period into a
subcategory. Finally, the facility should
determine the relative percent of off-site wastes
accepted in each subcategory (by volume).
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Chapter 14 Implementation
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Table 14-1 Waste Receipt Classification
Metals Subcategory
spent electroplating baths and/or sludges;
metal finishing rinse water and sludges;
chromate wastes;
air pollution control water and sludges;
incineration wastewaters;
spent anodizing solutions;
waste liquid mercury;
cyanide-containing wastes (>136 mg/L); and
waste acids and bases with or without metals.
Oils Subcategory
used oils;
oil-water emulsions or mixtures;
lubricants;
coolants;
contaminated groundwater clean-up from petroleum sources;
used petroleum products;
oil spill clean-up;
bilge water;
rinse/wash wasters from petroleum or oily sources;
interceptor wastes;
off-specification fuels;
underground storage remediation waste; and
tank clean-out from petroleum or oily sources
Organics Subcategory
landfill leachate;
contaminated groundwater clean-up from non-petroleum sources
solvent-bearing wastes;
off-specification organic product;
still bottoms;
used glycols;
wastewater from paint washes;
wastewater from adhesives and/or epoxies;
wastewater from chemical product operations; and
tank clean-out from organic, non-petroleum sources
If the waste receipt is listed above, the
Subcategory determination is made solely from
the information provided in Table 14-1. If,
however, the waste receipt is unknown or not
listed above, the facility should use the following
hierarchy to determine the appropriate
subcategory:
1). If the waste receipt contains oil and
grease at or in excess of 100 mg/L, the
waste receipt should be classified in
the oils subcategory;
' 2). If the waste receipt contains oil and
grease <100 mg/L, and has either
cadmium, chromium, copper, or nickel
concentrations in excess of the values
listed below, the waste receipt should
be classified in the metals subcategory.
cadmium 0.2 mg/L
chromium 8.9 mg/L
copper 4.9 mg/L
nickel 37.5 mg/L
3). If the waste receipt contains oil and
grease < 100 mg/L, and does not have
concentrations of cadmium, chromium,
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copper, or nickel above any of the
values listed above, the waste receipt
should be classified in the organics
subcategory.
This process is also illustrated in Figure 14-1.
Members of the CWT industry have
expressed concern that wastes may be received
from the generator as a "mixed waste", i.e., the
waste may be classified in more than one
subcategory. Based on the information collected
during the development of this rule, using the
subcategorization procedure recommended in this
section, EPA is able to classify each waste receipt
identified by the industry into the appropriate
subcategory. Therefore, EPA believes that these
"mixed waste receipt" concerns have been
addressed in the current subcategorization
procedure.
Once the facility's subcategory
determination has been made, the facility should
not be required to make an annual determination.
However, if a single subcategory facility alters
their operation to accept wastes from another
subcategory or if a mixed waste facility alters its
annual operations to change the relative
percentage of waste receipts in one subcategory
by more than 20 percent, the facility should notify
the appropriate permit writer or pretreatment
authority and the subcategory determination
should be re-visited. EPA also recommends that
the subcategory determination be re-evaluated
whenever the permit is re-issued.
For new CWT facilities, the facility should
estimate the percentage of waste receipts
expected in each subcategory. Alternatively, the
facility could compare the treatment technologies
being installed to the selected treatment
technologies for each subcategory. After the
initial year of operation, the permit writer or
pretreatment authority should re-visit the CWT's
subcategory determination and follow the
procedure outlined for existing facilities.
Some facilities, such as those located near
auto manufacturers, claim that their waste
streams vary significantly for very limited time
spans each year, and that they would be unable to
meet limitations based on their annual waste
receipts during these time periods. In these cases,
one set of limits or standards may not be
appropriate for the permit's entire period. EPA
recommends that a tiering approach be used in
such situations. In tiered permits, the control
authority issues one permit for "standard"
conditions and another set which take effect when
. there is a significant change in the waste receipts
accepted. EPA's Industrial User Permitting
Guidance Manual (September 1989) recommends
that tiered permits should be considered when
production'rate varies by 20 percent or greater.
Since this rule is not production based, EPA
recommends that for the CWT industry, tiered
permits should be considered when the
subcategory determination varies for selected
time periods by more than 20 percent. An
example when a tiered approach may be
appropriate in the CWT industry would be if a
CWT facility's major customer (in terms of flow)
does not operate for a two week period in
December. The CWT facility would not be
receiving waste receipts from the generating
facility during their two week closure which could
greatly alter the relative percent of waste accepted
by the CWT facility for the two week period only.
As explained previously, many facilities
have waste streams that vary on a daily basis.
EPA cautions that the tiering approach should
only be used for facilities which have limited,
well-defined, "non-standard" time periods. A
tiered permit should only be considered when the
control authority thoroughly understands the
CWTs operations and when a substantial change
in the relative percentages of waste in each
subcategory would effect permit conditions.
Additionally, a tiered permit is never required if
compliance is measured on a subcategory basis
after each treatment system.
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Is the waste receipt listed
ia Table 14-1?
No
. Does the receipt contain
oil and grease at or in
excess of 100 mg/L?
Does it have any of the
following metals in
concentrations exceeding:
Cadmium: 0.2 mg/L?
Chromium: 8.9 mg/L?
Copper: 4.9 mg/L?
Nickel: 37.5 mg/L?
No
The waste receipt is in the
organics subcategory
Yes
Consult Table 14-1 for
subcategorization
Yes
The waste receipt is in the
oils subcategory
Yes
The waste receipt is in the
metals subcategory
Figure 14-1. Waste Receipt Subcategory Classification Diagra
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ON-SITE GENERATED WASTEWATER
SUBCATEGORY DETERMINATION
14.4
Section 14.3 details the subcategory
determination for off-site waste receipts. For
other on-site generated wastewater sources such
as those described in Section 14.1, wastewater
generated in support of, or as the result of,
activities associated with each subcategory should
be classified in that subcategory. For facilities
that are classified in a single subcategory, the
facility should generally classify on-site
wastewater in that subcategory. For facilities that
are classified in more than one subcategory,
however, the facility should apportion the on-site
generated wastewater to the appropriate -
subcategory. Certain waste streams may be
associated with more than one subcategory such
as stormwater, equipment/area washdown, air
pollution control wastewater, etc. For these
wastewater sources, the volume generated should
be apportioned to each associated subcategory.
For example, for contaminated stormwater, the
volume can be apportioned based on the
proportion of the surface area associated with
operations in each subcategory. Equipment/area
washdown may be assigned to a subcategory
based on the volume of waste treated in each
subcategory. Alternatively, control authorities
may assign the on-site wastestreams to a
subcategory based on the appropriateness of the
selected subcategory treatment technologies.
On-site Industrial Waste Combustors,
Landfills, and Transportation
Equipment Cleaning Operations 14.4.1
As noted previously, wastewater from
on-site industrial waste combustors, landfills, and
transportation equipment and cleaning operations
that is commingled with CWT wastewater for
treatment shall be classified as CWT process
wastewater. Like the off-site waste receipts, the
subcategory determination of these wastewaters
should be based on the characteristics of the
wastewater and the appropriateness of the
application of treatment technologies associated
with each subcategory.
For wastewater associated with industrial
waste combustors, the wastewater should be
classified as a metals subcategory wastestream.
This reflects the treatment technology selected in
the recently proposed rule for Industrial Waste
Combustors (63 FR 6392-6423). For landfill
wastewater, the wastewater should be classified
as an organics subcategory wastestream. This
also reflects the treatment technology selected in
the recently proposed rule for Landfills (63 FR
6426-6463)1. For wastewaters associated with
transportation equipment cleaning, these
wastestreams should be classified in a manner
similar to that used for off-site waste receipts.
SUBCATEGORY DETERMINATION IN EPA
QUESTIONNAIRE DATA BASE 14.5
In order to estimate the quantities of
wastewater being discharged, current pollutant
loads, pollutant reductions, post compliance
costs, and environmental benefits for each
subcategory, EPA developed a methodology to
classify waste streams for CWT facilities in the
EPA Waste Treatment Industry Questionnaire
database into each of the proposed subcategories.
The following is a list of the rules used by EPA in
the subcategory .determination of the wastes
reported in 308 Questionnaires. The rules rely
primarily on Waste Form Codes (where
available) plus RCRA wastes codes. Table 14-2
lists the waste form codes utilized in this
classification.
•'•For leachate generated at Subtitle C
landfills (hazardous), the selected technology basis
is chemical precipitation and biological treatment.
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Table 14-2. RCRA and Waste Form Codes Reported by Facilities in 198
RCRA COPES
D001 Ignitable Waste
D002 Corrosive Waste
D003 Reactive Waste
D004 Arsenic
D005 Barium
D006 Cadmium
DO 07 Chromium
D008 Lead
D009 Mercury
DO 10 Selenium
DO 11 Silver
D012 Endrin(l,2)3,4,10,10-hexachlorc-lJ7-epoxy-l,4,4a,5,6,7,8,8a-octahydro-l,4-endo-5,8-dimeth-ano
napthalene)
D017 2,4,5-TP Silvex (2,4,5-trichlorophenixypropionic acid)
D035 Methyl ethyl ketone
FOO1 The following spent halogenated solvents used in degreasing: tetrachloroethylene; Irichloroethane; carbon
tetrachloride and chlorinated fluorocarbons and all spent solvent mixtures/blends used in degreasing
containing, before use, a total of 10 percent or more (by volume) of one or more of the above halogenated
solvents or those solvents listed in F002, F004, and F005; and still bottoms from the recovery of these spent
solvents and spent solvent mixtures
F002 The following spent halogenated solvents: tetrachloroethylene; 1,1,1-trichloroetharie; chlorobenzene; 1,1,2-
trichloro-1,2,2- trifluoroethane; ortho-dichlorobenzene; trichloroethane; all spent solvent mixtures/blends
containing, before use, a total of 10 percent or more (by volume) of one or more of the above halogenated
solvents or those solvents listed in F001, F004, and F005; and still bottoms from the recovery of these spent
solvents and spent solvent mixtures
F003 The following spent nonhalogenated solvents: xylene, acetone, ethyl acetate, ethyl benzene, ethyl ether,
methyl isobutyl ketone, n-butyl alcohol, cyclohexanone, and methanol; all spent solvent mixtures/blends
containing, before use, one or more of the above nonhalogenated solvents, and a toial of 10 percent or more
(by volume) of one or more of those solvents listed in F001, F002, F004, and F005-1 and still bottoms from
the recovery of these spent solvents and spent solvent mixtures.
F004 The following spent nonhalogenated solvents: cresols, cresylic acid, and nitrobenzene; and the still bottoms
from the recovery of these solvents; all spent solvent mixtures/blends containing before use a total of 10
percent or more (by volume) of one or more of the above nonhalogenated solvents or those solvents listed in
F001, F002, and F005; and still bottoms from the recovery of these spent solvents and spent solvent mixtures
F005 The following spent nonhalogenated solvents: toluene, methyl ethyl ketone, carbon disulfide, isobutanol,
pyridine, benzene, 2-ethoxyethanol, and 2-nitropropane; all spent solvent mixtures/blends containing, before
use, a total of 10 percent or more (by volume) of one or more of the above nonhalogenated solvents or those
solvents listed in F001, F002, or F004; and still bottoms from the recovery of these spent solvents and spent
solvents mixtures
F006 Wastewater treatment sludges from electroplating operations except from the following processes: (1)
sulfuric acid anodizing of aluminum; (2) tin plating on carbon steel; (3) zinc plating (segregated basis) on
carbon steel; (4) aluminum or zinc-aluminum plating on carbon steel: (5) cleaning/stripping associated with
tin, zinc, and aluminum plating on carbon steel; and (6) chemical etching and milling of aluminum
F007 Spent cyanide plating bath solutions from electroplating operations
F008 Plating bath residues from the bottom of plating baths from electroplating operations in which cyanides are
used in the process
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Table 14-2. RCRA and Waste Form Codes Reported by Facilities in 1989
F009 Spent stripping and cleaning bath solutions from electroplating operations in which cyanides are used in the
process
F010 Quenching bath residues from oil baths from metal heat treating operations in which cyanides are used in the
process
FO11 Spent cyanide solutions from slat bath pot cleaning from metal heat treating operations
FO12 Quenching waste water treatment sludges from metal heat treating operations in which cyanides are used in
the process
FO 19 Wastewater treatment sludges from the chemical conversion coating of aluminum
F039 Multi-source leachate
KOO1 Bottom sediment sludge from the treatment of wastewater from wood preserving processes that use creosote
and/or pentachlorophenol
KOI 1 Bottom stream from the wastewater stripper in the production of acrylonitrile
KO13 Bottom stream from the acetonitrile column in the production of acrylonitrile
KOI 4 Bottoms from the acetonitrile purification column in the production of acrylonitrile
KOI 5 Still bottoms from the distillation of benzyl chloride
KOI 6 Heavy ends or distillation residues from the production of carbon tetrachloride
K031 By-product salts generated in the production of MSMA and cacodylic acid
K035 Wastewater treatment sludges generated in the production of creosote
K044 Wastewater treatment sludges from the manufacturing and processing of explosives
K045 Spent carbon from the treatment of wastewater containing explosives K048 air flotation (DAF) float from the
petroleum refining industry K049 Slop oil emulsion solids from the petroleum refining industry
K050 Heat exchanger bundle cleaning sludge from the petroleum refining industry
K051 API separator sludge from the petroleum refining industry
K052 Tank bottoms (leaded) from the petroleum refining industry
K061 Emission control dust/sludge from the primary production of steel in electric furnaces
K064 Acid plant blowdown slurry/sludge resulting from the thickening of blowdown slurry from primary copper
production
K086 Solvent washes and sludges, caustic washes and sludges, or water washes and sludges from cleaning tubs and
equipment used in the formulation of ink from pigments, driers, soaps, and stabilizers containing chromium
and lead
K093 Distillation light ends from the production of phthalic anhydride from ortho-xylene
K094 Distillation bottoms from the production of phthalic anhydride from ortho-xylene
K098 Untreated process wastewater from the production of toxaphene
K103 Process residues from aniline extraction from the production of aniline K104 Combined wastewater streams
generated from nitrobenzene/aniline production
P011 Arsenic pentoxide (t)
PO12 Arsenic (III) oxide (t) Arsenic trioxide (t)
P013 Barium cyanide
P020 Dinoseb, PhenoI,2,4-dinitro-6-(l-methylpropyl)-
P022 Carbon bisulfide (t)
Carbon disulfide (t)
P028 Benzene, (chloromethyl)
-Benzyl chloride
P029 Copper cyanides
P030 Cyanides (soluble cyanide salts), not elsewhere specified (t)
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Table 14-2. RCRA and Waste Form Codes Reported by Facilities in 1989
P040 0,0-diethyl 0-pyrazinyl phosphorothioate
Phosphorothioic acid, 0,0-diethyl 0-pyrazinyl ester
P044 Dimethoate (t)
Phosphorodithioic acid,
0,0-dimethyl S-[2-(methylamino)-2-oxoethyl]ester (t)
P048 2,4-dinitrophenol
Phenol,2,4-dinitro-
P050 Endosulfan
5-norbornene-2,3-dimethanol,
l,4,5,6,7,7-hexachloro,cyclic sulfite
P063 Hydrocyanic acid
Hydrogen cyanide
P064 Methyl isocyanate
Isocyanic acid, methyl ester
P0<39 2-methyllactonitrile
Propanenitrile,2-hydroxy-2-methyl-
P071 0,0-dimethyl 0-p-nitrophenyl phosphorothioate
Methyl parathion
P074 Nickel (E) cyanide
Nickel cyanide
P078 Nitrogen (TV) oxide
Nitrogen dioxide
P087 Osmium tetroxide
Osmium oxide
P089 Parathion (t)
Phosphorothiotic acid,0,0-diethyl 0-(p-nitrophenyl) ester (t)
P098 Potassium cyanide
P104 Silver cyanide
PI06 Sodium cyanide
P121 Zinc cyanide
PI23 Toxaphene
Camphene,octachloro-
U002 2-propanone (i)
Acetone (i)
U003 Ethanenitrile (i,t)
Acetonitrile (i,t)
U008 2-propenoic acid (i)
Acrylic acid (i)
U009 2-propenenitrile
Acrylonitrile
UO12 Benzenamine (i,t)
Aniline (i,t)
U019 Benzene (i,t)
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Table 14-2. RCRA and Waste Form Codes Reported by Facilities in 1989
U020 Benzenesulfonyl chloride (c,r)
Benzenesulfonic acid chloride (c,r)
U031 l-butanol(i)
N-butyl alcohol (i)
U044 Methane, trichloro-
Chloroform
U045 Methane,chloro-(i,t)
Methyl chloride (i,t)
U052 Cresylicacid
Cresols
U057 Cyclohexanone (i)
U069 Dibutyl phthalate
1,2-benzenedicarboxylic acid, dibutyl ester
U080 Methane,dichloro-
Methylene chloride
U092 Methanamine, N-methyl-(i)
Dimethylamine (i)
U098 Hydrazine, 1,1-dimethyl-
1,1 -dimethylhy drazine
U105 2,4-dinotrotoluene
Benzene, l-methyl-2,4-dinitro-
U106 2,6-dinitrotoluene
Benzene, l-methyl-2,6-dinitro
U107 Di-n-octyl phthalate
1-2-benzenedicarboxylic acid, di-n-octyl ester
U113 2-propenoic acid, ethyl ester (i)
Ethyl acrylate (i)
Ul 18 2-propenoic acid, 2-methyl-, ethyl ester
Ethyl methacrylate
U122 Formaldehyde
Methylene oxide
U125 Furfural (i)
2-furancarboxaldehyde (i)
Ul 34 Hydrogen fluoride (c,t)
Hydrofluoric acid.(c,t)
U135 Sulfur hydride
Hydrogen sulfide
U139 Ferric dextran
Iron dextran
U140 1 -propanpl, 2-methyl- (i,t)
Isobutyl alcohol (i,t)
U150 Melphalan
Alanine, 3-[p-bis(2-chloroethyl)amino] phenyl-,L-
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Table 14-2. RCRA and Waste Form Codes Reported by Facilities in 1989
U151 Mercury
U154 Methanol(i)
Methyl alcohol (i)
Ul 59 Methyl ethyl ketone (i,t)
2-butanone (i,t)
U161 4-methyl-2-pentanone (i)
Methyl isobutyl ketone (i)
U162 2-propenoic acid,2-methyl-,methyl ester (i,t)
Methyl methacrylate (i,t)
U188 Phenol
Benzene, hydroxy-
U190 Phthalic anhydride
1,2-benzenedicarboxylic acid anhydride
U205 Selenium disulfide (r,t)
Sulfur selenide (r,t)
U210 Tetrachloroethylene
Ethene, 1,1,2,2-tetrachloro
U213 Tetrahydrofuran (i)
Furan, tetrahydro- (i)
U220 Toluene
Benzene, methyl-
U226 1,1,1-trichloroethane
Methylchloroform
U228 Trichloroethylene
Trichloroethene
U239 Xylene(i)
Benzene, dimethyl- (i,t)
WASTE FORM CODES
BOO 1 Lab packs of old chemicals only
B101 Aqueous waste with low solvent
B102 Aqueous waste with low other toxic organics
BIOS Spent acid with metals
Bl 04 Spent acid without metals
B105 Acidic aqueous waste
B106 Caustic solution with metals but no cyanides
B107 Caustic solution with metals and cyanides
BIOS Caustic solution with cyanides but no metals
B109 Spent caustic
B110 Caustic aqueous waste
Bill Aqueous waste with reactive sulfides
B112 Aqueous waste with other reactives (e.g., explosives)
B113 Other aqueous waste with high dissolved solids
B114 Other aqueous waste with low dissolved solids
B115 Scrubber water
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Table 14-2. RCRA and Waste Form Codes Reported by Facilities in 1989
B116 Leachate
B117 Waste liquid mercury
B119 Other inorganic liquids
B201 Concentrated solvent-water solution
B202 Halogenated (e.g., chlorinated) solvent
B203 Nonhalogenated solvent
B204 Halogenated/Nonhalogenated solvent mixture
B205 Oil-water emulsion or mixture
B206 Waste oil
B207 Concentrated aqueous solution of other organics
B208 Concentrated phenolics
B209 Organic paint, ink, lacquer, or varnish
B210 Adhesive or epoxies
B211 Paint thinner or petroleum distillates
B219 Other organic liquids
B305 "Dry" lime or metal hydroxide solids chemically "fixed"
B306 "Dry" lime or metal hydroxide solids not "fixed"
B307 Metal scale, filings, or scrap
B308 Empty or crushed metal drums or containers
B309 Batteries or Battery parts, casings, cores
B310 Spent solid filters or adsorbents
B312 Metal-cyanides salts/chemicals
B313 Reactive cyanides salts/chemicals
B315 Other reactive salts/chemicals
B316 Other metal salts/chemicals
B319 Other waste inorganic solids
B501 Lime sludge without metals
B502 Lime sludge with metals/metal hydroxide sludge
B504 Other wastewater treatment sludge
B505 Untreated plating sludge without cyanides
B506 Untreated plating sludge with cyanides
B507 Other sludges with cyanides
B508 Sludge with reactive sulfides
B510 Degreasing sludge with metal scale or filings
B511 Air pollution control device sludge (e.g., fly ash, wet scrubber sludge)
B513 Sediment or lagoon dragout contaminated with inorganics only
B515 Asbestos slurry or sludge
B519 Other inorganic sludges
B601 Still bottoms of halogenated (e.g., chlorinated) solvents or other organic liquids
B603 Oily sludge
B604 Organic paint or ink sludge
B605 Reactive or polymerized organics
B607 Biological treatment sludge
B608 Sewage or other untreated biological sludge
B609 Other organic sludges •
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Wastes Classified in the Metals Subcategory - Questionnaire Responses
14.5.1
The wastes that EPA classified in the metals subcategory include the following:
All wastes reported in Section G, Metals Recovery, of the 308 Questionnaire; and
All wastes with Waste Form Codes and RCRArodes meeting the criteria specified in Table 14-3
Table 14-3. Waste Form Codes in the Metals Subcategory
All Inorganic
Liquids
All Inorganic
Solids
All Inorganic
Sludges
Waste Form Codes
B101-B119
Waste Form Codes
B301-B319
Waste Form Codes
B501-B519
Exceptions:
Waste Form Codes Bl 16, and BIO I, B102, Bl 19
when combined with RCRA Codes:
F001-F005 and other organic F, K, P, and U Codes
Exceptions:
Waste Form Code B301
when combined with RCRA Codes::
F001-F005 and other organic F, K, P, and U Codes
*
Exceptions:
Waste Form Code B512
when combined with RCRA Codes::
F001-F005 and other organic F, K, P, and U Codes
* These exceptions were classified as belonging in the organics subcategory
Wastes Classified in The Oils Subcategory - Questionnaire Responses 14.5.2
The wastes EPA classified in the oils subcategory include the following:
• All wastes reported in Section E, Waste Oil Recovery, of the 308 Questionnaire;
• All wastes reported in Section H, Fuel Blending Operations, of the 308 Questionnaire that
generate a wastewater as a result of the fuel blending operations; and
• All wastes with Waste Form Codes and RCRA codes meeting the criteria in Table 14-4.
Table 14-4. Waste Form Codes in the Oils Subcategory
Organic Liquids
Organic Sludge
Waste Form Codes
B205, B206
Waste Form Code
B603
Exceptions:
None
Exception!!:
None
Wastes Classified in the Organics Subcategory - Questionnaire Responses
14.5.3
The wastes EPA classified in the organics subcategory include the following:
• All wastes with Waste Form Codes and RCRA codes meeting the criteria specified in Table 14-5
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Table 14-5. Waste Form Codes in the Organics Subcategory
Organic Liquids
Organic Solids
Organic Sludges
Inorganic Liquids
Waste Form Codes
B201-B204, B207-B219
Waste Form Codes
B401-B409
Waste Form Codes
B601.B602, B604-B609
Waste Form Codes
B101,B102,B116,B119
Exceptions:
None
Exceptions:
None
Exceptions:
None
when combined with RCRA Codes:
F001-F005 and other organic F, K, P, and U
Codes
Inorganic Solids Waste Form-Code B301
Inorganic Sludges Waste Form Code B512
when combined with RCRA Codes:
F001-F005 and other organic F, K, P, and U
Codes
when combined with RCRA Codes:
F001-F005 and other organic F, K, P, and U
Codes
For wastes that can not be easily classified
into a subcategory such as lab-packs, the
subcategory determination was based on other
information provided such as RCRA codes and
descriptive comments. Therefore, some
judgement was required in assigning some waste
receipts to a subcategory.
ESTABLISHING LIMITATIONS AND
STANDARDS FOR FACILITY DISCHARGES 14.6
In establishing limitations and standards for
CWT facilities, it is important for the permit
writer or pretreatment authority to ensure that the
CWT facility has an optimal waste management
program. First, the control authority should
verify that the CWT facility is identifying and
segregating waste streams to the extent possible
since segregation of similar waste streams is the
first step in obtaining optimal mass removals of
pollutants from industrial wastes. Next, the
control authority should verify that the CWT
facility is employing treatment technologies
designed and operated to optimally treat all off-
site waste receipts. For example, biological
treatment is inefficient for treating concentrated
metals waste streams like those found in the
metals subcategory or wastestreams with oil and
grease compositions and concentrations like those
found in the oils subcategory. In fact,
concentrated metals streams and high levels of oil
and grease compromise the ability of biological
treatment systems to function. Likewise,
emulsion breaking/gravity separation, and/or
dissolved air flotation is typically insufficient for
treating concentrated metals wastewaters or
wastewaters containing organic pollutants which
solubilize readily in water. Finally, chemical
precipitation is insufficient for treating organic
wastes and waste streams with high oil and grease
concentrations.
Once the control authority has established
that the CWT facility is segregating its waste
receipts and has appropriate treatment
technologies for all off-site waste receipts, the
permit writer or pretreatment authority can then
establish limitations or standards which ensure
that the CWT facility is operating its treatment
technologies optimally. Available guidance in
calculating NPDES categorical limitations for
direct discharge facilities can be found in the U.S.
EPA NPDES Permit Writers' Manual (December
1996, EPA-833-B-96-003). Sources of
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information used for calculating Federal
pretreatment standards for indirect discharge
facilities include 40 CFR Part 403.6, the
Guidance Manual for the Use of Production-
Based Pretreafrnent Standards and the Combined
Waste Stream Formula (September 1985), and
EPA's Industrial User Permitting Guidance
Manual (September 1989). However, as
illustrated in the next section, for the CWT point
source category, only 40 CFR Part 403.6 and
EPA's Industrial User Permitting Guidance
Manual should be used as a source of information
for calculating Federal CWT pretreatment
standards for indirect dischargers.
Existing Guidance for Multiple
Subcategory Facilities 14.6.1
Direct Discharge Guidance 14.6.1.1
For instances where a direct discharge
facility's operations are covered by multiple
subcategories, the NPDES permit writer must
apply the limits from each subcategory in
deriving the technology-based effluent limits for
the facility. If all wastewaters regulated by the
effluent guidelines are combined prior to
treatment or discharge to navigable waters, then
the permit writer would simply combine the
allowable pollutant loadings for each subcategory
to arrive at a single, combined set of technology-
based effluent limits for the facility - the
"building block" approach (pages 60 & 61, U.S.
EPA NPDES Permit Writers' Manual. December
1996), In those circumstances when the limits for
one subcategory regulate a different set of
pollutants than the limits applicable to another
subcategory, the permit writer must ensure proper
application of the guidelines. If one subcategory
wastestream that does not limit a particular
pollutant is combined with another wastestream
that limits the pollutant, then the permit writer
must ensure that the non-regulated pollutant
stream does not dilute the regulated pollutant
stream to the point where the pollutant is not
analytically detectable. If this circumstance
occurs, then the permit writer is authorized to
establish internal monitoring points, as allowed
under 40 CFR § 122.45(h).
The methodology for developing "building
block" daily maximum limits for selected
pollutants for a hypothetical CWT facility is
illustrated in Example 14-1.
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Example 14-1
Facility A accepts wastes in all three CWT subcategories with separate subcategory
treatment systems and a combined end-of-pipe outfall. This facility treats 20,000
I/day of metal-bearing wastes, 10,000 I/day of oily wastes, and 45,000, I/day of
organic wastes.
Metals Waste
20,000 L/day
Oils Waste
10,000 L/day
I
Metals
Treatment
Oils
Treatment
Organics Waste
45,000 L/day
Organics
Treatment
Discharge
75,000 L/day
Figure 14-2. Facility Accepting Waste in All Three Subcategories With Treatment in Each.
For this example, EPA has proposed chromium and lead BAT limits for the metals and
oils subcategories; fluoranthene limits for only the oils subcategory; and 2,4,6-
trichlorophenol limits for only the organics subcategory. Table 14-6 shows the proposed
daily maximum limits for these pollutants.
Table 14-6. Proposed BAT Daily Maximum Limits for Selected Parameters
Pollutant
Chromium
Lead
Flouranthene
2,4,6-trichlorophenol
Metals Daily
Maximum Limit, mg/1
2.9
0.29
none
none
Subcategory
Oils Daily Maximum
Limit, mg/1
0.65
0.35
.045
none
Organics Daily
Maximum Limit, mg/1
none
none
none
0.16
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The flow-weighted building block daily maximum limits for the combined outfall
for chromium are calculated using equation 14-1:
Cr Limit = £
•*-'
of subcategory L x
Total How
Qf subcat L
(14-1)
20,000
Cr limit =
day
20,000 — + 10,000 — + 45,000 -£-
day day day
10,000 —
day
20,000 — + 10,000 Jl- + 45,000 -±-
day day day
45,000 -£-
x o.65
20,000 — + 10,000 — + 45,000
day day day
x 0.0
L
Cr limit = 0.77 —- + 0.09 — + 0 -- = 0.86 —
L L JL L,
Table 14-7 additionally shows the calculations and calculated limits for lead,
fluoranthene, and 2,4,6-trichlorophenol.
Table 14-7. "Building Block Approach" Calculations for Selected Parameters for Example 14-1
Pollutant Equation Combined Daily
Maximum Limit
Lead [(20,000 L/day)/(75,000 L/day) x 0.29 mg/L] + 0.12 mg/L
[(10,000 L/day)/(75,000 L/day) x 0.35 mg/L] +
[(45,000 L/day)/(75,000 L/day) x 0 mg/L] =
Fluoranthene [(20,OOOL/day)/(75,000 L/day) x Omg/L] + 0.006 mg/L
[(10,000 L/day)/(75,000 L/day) x 0.045 mg/L] +
[(45,000 L/day)/(75,000 L/day) x 0] =
2,4,6-trichlorophenol [(20,OOOL/day)/(75,000 L/day) x 0 mg/L] + 0.096 mg/L
[(10,000 L/day)/(75,000 L/day) x 0 mg/L] +
[(45,000 L/day)/(75,000 L/day) x 0.16 mg/L] =
EPA notes that in this example, the calculated daily maximum limit for fluoranthene
for the combined outfall, 0.006 mg/L, is below the minimum analytical detection level
(0.01 mg/L). Therefore, this facility would be required to demonstrate compliance with the
fluoranthene limit for the oils subcategory prior to commingling at the outfall.
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Indirect Discharge Guidance 14.6.1.2
If Facility A in Example 14-1 discharged to
a POTW, the control authority would apply the
combined wastestream formula (40 CFR §
403.6(e)). The combined wastestream formula
(CWF) is based on three types of wastestreams
that can exist at an industrial facility: regulated,
unregulated, and dilute. As defined (40 CFR
403), a regulated wastestream is a wastestream
from an industrial process that is regulated by a
categorical standard for pollutant x. An
unregulated wastestream is a wastestream that is
not covered by categorical pretreatment standards
and not classified as dilute, or one that is not
regulated for the pollutant in question although it
is regulated for others. A dilute wastestream is'
defined to • include sanitary wastewater,
noncontact cooling water and boiler blowdown,
and wastestreams listed in Appendix D to 40
CFR 403. Since the CWT industry accepts a
wide variety of wastestreams, for this point
source category, Appendix D does not apply and
the only dilute wastestreams are those specifically
defined in 40 CFR 403.
Therefore, as described in 40 CFR 403, the
combined waste stream formula is
(14-2)
where CT =
the alternate concentration
limit for the combined
wastestream;
the categorical pretreatment
standard concentration limit
for a pollutant in the
regulated stream i;
the average daily flow of
stream i;
the average daily flow from
dilute wastestreams as
defined in 40 CFR 403; and
Fr = the total daily average flow.
For the example 14-1 facility, there are no
dilution flows. Therefore, the CWF equation
reduces in the following manner:
Fr-0
(14-3)
N
i=l
I
""* F = F
^ri rT
A F,
which is equivalent to the "building block"
equation (equation 14-1).
Therefore, as described in 40 CFR Part
403 and in EPA's Industrial User Permitting
Guidance Manual, the methodology for
developing combined wastestream formula daily
maximum limits would be essentially the same as
the methodology for the "building block"
approach used for direct dischargers. For
instances where an indirect discharge facility's
operations are covered by multiple subcategories,
the control authority must apply the pretreatment
standards from each subcategory in deriving the
technology-based pretreatment standards for the
facility. If all wastewaters regulated by the
pretreatment standards are combined prior to
treatment or discharge to the POTW, then the
control authority would simply combine the
allowable pollutant loadings for each subcategory
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to arrive at a single, combined set of technology-
based pretreatment standards for the facility. In
those circumstances when the standards for one
subcategory regulate a different set of pollutants
than the standards applicable to another
subcategory, the control authority must ensure
proper application of the pretreatment standards.
If one subcategory wastestream that does not
limit a particular pollutant is combined with
another wastestream that limits the pollutant, then
the control athority must ensure that the non-
regulated pollutant stream does not dilute the
regulated pollutant stream to the point where the
pollutant is not analytically detectable. If this
occurs, then the control authority will most likely
need to establish internal monitoring points, as
allowed under 40 CFR § 403.6(e)(2) and (4).
However, as detailed in the Guidance
Manual for the Use of Production-Based
Prefreatment Standards and the Combined Waste
Stream Formula, the CWF approach is applied
differently. Unregulated wastestreams are
presumed, for purposes of using the CWF, to
contain pollutants of concern at a significant
level. In effect, the CWF "gives credit" for
pollutants which might be present in the
unregulated wastestream. Rather than treating
the unregulated flow as dilution, which would
result in lowering the allowable concentration of
a pollutant, the guidance allows the pollutant to
be discharged in the unregulated wastestream at
the same concentration as the standard for the
regulated wastestream that is being discharged.
This is based on the assumption that if pollutants
are present in the unregulated wastestream, they
will be treated to the same level as in the
regulated wastestream. In many cases, however,
unregulated wastestreams may not actually
contain pollutants of concern at a significant
level. Regardless of whether the pollutants are
present in significant levels or not, they are still
considered unregulated when applying, the
formula (Pages 3-3 to 3-7, Guidance Manual for
the Use of Production-Based Pretreatment
Standards and the Combined Waste Stream
Formula (September 1985)).
Table 14-8 shows the proposed daily
maximum pretreatment standards for Facility A
in Example 14-1 for chromium, lead,
fluoranthene, and 2,4,6-trichlorophenol. Table
14-9 shows the combined outflow calculations
using the CWF as described in EPA's Industrial
User Permitting Guidance Manual (and in 40
CFR 403) and Table 14-10 shows the
calculations using the CWF as described in
Guidance Manual for the Use of Production-
Based Pretreatment Standards and the Combined
Waste Stream Formula. Note that, in this
example, since there are no proposed daily
maximum pretreatment standards for 2,4,6-
trichlorophenol in any subcategory, there are no
pretreatment standards for this pollutant for the
combined outfall.
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Table 14-8. Proposed Daily Maximum Pretreatment Standards for Selected Parameters
Pollutant
Subcategory
Metals Daily Maximum Oils Daily Maximum Organics Daily Maximum
Pretreatment Standard, Pretreatment Standard, Pretreatment Standard,
mg/1 mg/1 . mg/1
Chromium
Lead
Flouranthene
2,4,6-trichlorophenol
2.9
0.29
none
none
none
none
0.611
none
none
none
none
none
Using the first CWF approach (Table 14-
9), EPA is proposing standards for chromium and
lead in the metals subcategory, standards for
fluoranthene in the oils subcategory, and no
standards in any subcategory for 2,4,6-
trichlorophenol. After
applying equation 14-3, the CWF daily maximum
standards for the combined outfall are shown to
be 0.77,0.08, and 0.08, for chromium, lead, and
fluoranthene, respectively.
Table 14-9. CWF Calculations for Selected Parameters for Example 14-1 Using 40 CFR 403 and
Guidance in EPA's Industrial User Permitting Guidance Manual
Pollutant
Equation
Combined Daily
Maximum Limit, mg/1
Chromium [(20,0001/day)/(75,000 I/day) x 2.9 mg/1] +
[(10,000 l/day)/(75,000 I/day) x 0 mg/1] +
[(45,000 l/day)/(75,000 I/day) x 0 mg/1] =
Lead [(20,0001/day)/(75,000 I/day) x 0.29 mg/1] +
[(10,000 l/day)/(75,000 I/day) x 0 mg/1] +
[(45,000 yday)/(75,000 I/day) x 0 mg/1] =
Fluoranthene [(20,0001/day)/(75,000 I/day) x Omg/1] +
[(10,000 l/day)/(75,000 I/day) x 0.61 lmg/1] +
[(45,000 l/day)/(75,000 I/day) x 0 mg/1] =
0.77
0.08
0.08
However, under the second CWF
approach (Table 14-10), the metals subcategory
chromium and lead standards extend to the oils
and organics subcategories, the anthracene
standard for the oils subcategory extend to the
metals and organics subcategories, and 2,4,6-
trichlorophenol is not limited for any
subcategory. The CWF daily maximum
standards for the combined outfall are 2.9, 0.290,
and 0.611 mg/1 for chromium, lead, and
anthracene, respectively.
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Table 14-10. CWF Calculations for Selected Parameters in Example 14-1 Using the Guidance Manual for
Use of Production-Based Pretreatment Standards and Combined Waste Stream Formula
Pollutant
Equation
Combined Daily
Maximum Limit, mg/1
Chromium [(20,0001/day)/(75,000 I/day) x 2.9 mg/1] +
[(10,000 l/day)/(75,000 I/day) x 2.9 mg/1] +
[(45,000 l/day)/(75,000 I/day) x 2.9 mg/1] =
Lead [(20,0001/day)/(75,000 I/day) x 0.29 mg/1] +
[(10,000 l/day)/(75,000 I/day) x 0.29 mg/1] +
[(45,000 l/day)/(75,000 I/day) x 0.29 mg/1] =
Fluoranthene [(20,0001/day)/(75,000 I/day) x 0.61 lmg/1] +
[(10,000 l/day)/(75,000 I/day) x 0.611mg/l] +
[(45,000 l/day)/(75,000 I/day) x 0.611 mg/1] =
2.9
0.29
0.611
Table 14-11 lists the daily maximum pretreatment standards for the selected parameters calculated
using the two different approaches. For comparison purposes, the table also lists the "building block
approach" BAT daily maximum limitations.
Table 14-11: Daily Maximum Limits and Standards for Example 14-1
Pollutant
Direct Dischargers
"Building Block"
Indirect Dischargers
CWF-I1
Indirect Dischargerst
CWF-22
Chromium
Lead
Fluoranthene
2,4,6-trichlorphenol
0.86 mg/1
0.12 mg/1
0.006 mg/1
0.096 mg/1
0.77 mg/1
0.08 mg/1
0.08 mg/1
no standard
2.9 mg/1
0.29 mg/1
0.6 11 mg/1
no standard
1 Using 40 CFR Part 403 and EPA's Industrial User Permitting Guidance Manual
2 Using the Guidance Manual for the Use of Production-Based Pretreatment Standards and the Combined Waste
Stream Formula
The table shows that if the example facility
were to discharge indirectly using the CWF
approach detailed in the Guidance Manual for the
Use of Production-Based Pretreatment Standards
and the Combined Waste Stream Formula (CWF-
2), its pretreatment standards would be 337,242,
and over 10,000 percent higher than its direct
discharge BAT limitations, for chromium, lead,
and fluoranthene, respectively. As such, for the
CWT Point Source Category, control authorities
should not apply the CWF as described in the in
Guidance Manual for the Use of Production-
Based Pretreatment Standards and the Combined
Waste Stream Formula.
The example 14-1 calculation using the
CWF as described in EPA's Industrial User
Permitting Guidance Manual (CWF-1) also
illustrates a problem with this approach. Since
there are no proposed pretreatment standards for
chromium and lead, the daily maximum standards
under this CWF approach for chromium and lead
would be lower than the direct discharge BAT
limitations. In order to alleviate this problem, for
the CWT point source category, EPA would
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define an individual parameter as having a
"regulated flow" if the pollutant is limited
through BAT. Therefore, the flow for a pollutant
with no established BAT limit would be included
as a dilution flow and the flow for a pollutant
with an established BAT limit would be included
as an allowance.
For the metals and organics
subcategories, since the proposed limits and
standards are based on identical technologies, the
CWF allowance would be determined based on
the BAT limit. For the oils subcategory,
however, since the proposed limitations and
standards are based on different technologies, the
CWF allowance would be determined based on
the PSES limit if one had been proposed. For the
metals subcategory, all proposed BAT pollutants
pass through and were, therefore, proposed for
PSES. Tables 14-12 and 14-13 list the CWF
allowances for the oils and organics
subcategories, respectively.
Table 14-12. Allowances for Use in Applying the Combined Waste Stream Formula for CWT Oils
Subcategory Flows (PSES or PSNS)
Pollutant
Daily Maximum Allowance, Monthly Average Allowances, mg/1
mg/1
Arsenic
Cadmium
Chromium
Lead
Mercury
butyl benzyl phthalate
1.81
0.024
0.584
0.314
0.010
0.127
1.08
0.012
0.283
0.152
0.005
0.075
Table 14-13. Allowances for Use in Applying the Combined Waste Stream Formula for CWT
Organics Subcategory Flows
Pollutant Daily Maximum Allowance, mg/1
Antimony
Copper
Zinc
2-butanone
2-propanone
2,4,6-trichlorphenol
acetophenone
phenol
pyridine
0.97
0.85
0.46
8.83
20.7
0.155
0.155
3.70
0.370
Monthly Average Allowances, mg/1
0.691
0.752
0.408
2.62
6.15
0.106
0.072
1.09
0.182
For example 14-1, using the proposed CWF approach with allowances, the combined end-of-
pipe standards for chromium, lead, and fluoranthene would be 0.85 mg/1,0.12 mg/1, and 0.08 mg/1,
respectively. Table 14-14 shows the calculations.
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Table 14-14 CWF Calculations for Example 14-1 Including Allowances
Pollutant
Equation
Combined Daily
Maximum Limit, mg/I
Chromium [(20,0001/day)/(75,000 I/day) x 2.9 mg/1] +
[(10,000 I/day)/(75,000 I/day) x 0.58 mg/1] +
[(45,000 l/day)/(75,000 I/day) x 0 mg/1] =
Lead [(20,0001/day)/(75,000 I/day) x 0.29 mg/1] +
[(10,000 l/day)/(75,000 I/day) x 0.31 mg/1] +
[(45,000 l/day)/(75,000 I/day) x 0 mg/1] =
Fluoranthene [(20,0001/day)/(75,000 I/day) x Omg/1] +
[(10,000 l/day)/(75,000 I/day) x 0.611mg/l] +
[(45,000 l/day)/(75,000 I/day) x 0 mg/1] =
0.85
0.12
0.08
EPA has taken this approach, even for indirect dischargers, since a pollutant may pass the pass-
through test and not be regulated at PSES, but still provide a significant contribution of that pollutant
5n the combined wastestream as in the case of chromium and lead in the example. By adopting this
approach for the CWT point source category, EPA can ensure that standards for indirect dischargers are
equivalent to limitations for direct dischargers, but still allow for any contribution by these pollutants
to the combined wastestream.
Example 14-2 further illustrates the use of the CWF, as proposed, for the CWT point source
category.
Example 14-2: Facility Which Accepts Wastes in Multiple Subcategories and
Treats the Wastewater Sequentially
Facility B accepts waste in the oils and metals subcategory. The total volume of
wastewater discharged to the local POTW is 100,000 liters per day and the relative
percentage of oils and metal subcategory flows are 30% and 70% respectively. The facility
segregates oils and metals waste receipts and first treats the oils waste receipts using
emulsion breaking/gravity separation and dissolved air flotation. (See Figure 14-3) The
facility then commingles this wastewater with metal subcategory waste receipts and treats
the combined wastestreams using primary and secondary chemical precipitation and
solid/liquid separation followed bymutlimedia filtration.
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Metals Waste
70,000 L/day
Oils Waste
30,000 I/day
w
W
Oils
Treatment
\
f
w
Metals
Treatment
Discharge
100,000 I/day
Figure 14-3. Facility Which Accepts Wastes in Multiple Subcatgories and Treats Separately
For this example, both the oils and metals subcategory wastewaters are regulated
process flows. Looking only at chromium, lead, fluoranthene, and 2,4,6-trichlorophenol again,
EPA has proposed chromium (2.9 mg/1) and lead (0.29 mg/1) PSES daily maximum standards
for the metals subcategory only; and fluoranthene (0.611 mg/1) daily maximum standards for
only the oils subcategory. EPA has also provided an allowance for chromium (0.58 mg/1) and
lead (0.31 mg/1) in the oils subcategory. EPA has not proposed daily maximum standards or
daily maximum BAT limits for 2,4,6-trichlorophenol in either subcategory.
Even though EPA has not proposed daily maximum standards for chromium and lead
in the oils subcategory, their contribution would not be set to zero. In applying the CWF, the
control authority would determine the contribution for chromium and lead in the oils
subcategory based on Table 14-2. Therefore, the chromium daily maximum standard would be
(0.7 x 2.9) + (0.3 x 0.58) = 2.2 mg/1; and the lead daily maximum standard would be (0.7 x.
0.29) + (0.3 x 0.31) = 0.29 mg/1. The fluoranthene calculation, however, illustrates the case
where a pollutant's contribution in a regulated, wastestream would be zero. Since EPA has not
proposed BAT daily maximum limits for fluoranthene in the metals subcategory, the
contribution for flouranthene in the metals subcategory would be considered a dilution flow and
set to zero. Therefore, the fluoranthene daily maximum standard would be (0.7 x 0) + (0.3 x
0.611) = 0.18 mg/1. The control authority would not establish a daily maximum limitation for
2,4,6-trichlorophenol since EPA has not proposed regulating it for either subcategory.
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CWT Facilities Also Covered
By Another Point Source Category
14.6.2
As detailed in Chapter 3, some
manufacturing facilities, which are subject to
existing effluent guidelines and standards, may
also be subject to provisions of this rule. In all
cases, these manufacturing facilities accept waste
from off-site for treatment and/or recovery which
are generated from a different categorical process
as the on-site generated wastes. EPA is
particularly concerned that these facilities
demonstrate compliance with all applicable
effluent guidelines and pretreatment standards --
including this rule. Example 14-3 illustrates the
daily maximum limitations calculations for a
CWT facility which is also subject to another
effluent guideline.
Example 14-3 Categorical Manufacturing Facility Which Also Operates as a
CWT Facility
Facility Cisa manufacturing facility currently discharging wastewater to the local
river under the OCPSF point source category. Facility C also performs CWT operations and
accepts off-site metal-bearing wastes for treatment. Facility C commingles the on-site
wastewater and the off-site wastewater together for treatment in an activated sludge system.
The total volume of wastewater discharged at Facility C is 100,000 liters per day. The total
volume of wastewater contributed by the off-site wastewater is 10,000 liters per day.
On-Site OCPSF
Wmstes
90,000 L/day
Organic*
Treatment
Discharge
100,000 L/day
Off-Site CWT
Metals Wastes
10,000 L/d*y
Figure 14-4. Categorical Manufacturing Facility Which Also Operates as a CWT
Facility C would be required to monitor and demonstrate that it has complied with the
CWT metals BAT limitations. Since Facility C commingles the wastestreams and has no
treatment in place for the metals wastestreams, Facility C would be unable to demonstrate
compliance with the BAT limits through treatment rather than dilution. Therefore, Facility C
would not be able to commingle the CWT metals wastestreams and on-site OCPSF
wastestreams for treatment.
If Facility C chose to install metals treatment for the off-site wastewater and wanted to
commingle the effluent from the metals treatment and the biological treatment at a single
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discharge point (See Figure 14-5), the permit writer would use the building block approach to
determine the limitations. Using lead and chromium, for the metals subcategory, EPA has
. proposed BAT limits of 2.9 mg/L for chromium and 0.29 mg/L for lead. Since the OCPSF
facility has no limits for chromium and lead, the contribution for the OCPSF wastewaters would
be zero. Therefore, the chromium daily maximum limit would be ( 0.1 x 2.9) + (0.9 x 0) = 0.29
mg/1 and the lead daily maximum limit would be (0.1 x 0.29) x (0.9 x 0) = 0.029 mg/1. Since
the daily maximum limit for lead is below the minimum analytical detection level (.050 mg/1),
the facility would be required to demonstrate compliance with the lead limit for the CWT metals
subcategory prior to commingling at the outfall. The daily maximum limitations for other
pollutants would be calculated in a similar manner. Since EPA has not proposed any BAT
limits for organic pollutants under the metals subcategory of the CWT point source category,
the contribution for these pollutants would be zero.
Off-Site
CWT Metals Wastes
10,000 L/day
On-Site OCPSF
Wastes
90,000 L/day
Metals
Treatment
Organics.
Treatment
Discharge
100,000 L/day
Figure 14-5. Facility that Commingles Wastestreams after Treatment.
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Chapter
15
ANALYTICAL METHODS AND BASELINE VALUES
INTRODUCTION
15.1
This chapter describes the analytical methods
that EPA used to analyze the samples
collected during EPA's data gathering efforts at
a number of facilities. (These sampling efforts
are described in section 2). It also discusses how
EPA treated the results of its sample analysis for
purpose of determining the loadings and
proposed limitations and standards.
EPA compared each laboratory-reported
analytical result for each pollutant to a baseline
value in order to determine whether to use the
value as reported in determining the loadings and
proposed limitations and standards. In most
cases, the baseline value was the "nominal
quantitation limit"1 stipulated for the specific
method used to measure a particular pollutant. In
general, the term "nominal quantitation limit" is
used here to describe the smallest quantity of an
analyte that can be measured reliably. In some
cases, however, EPA used a value lower than the
nominal quantitation limit as the baseline value
because data demonstrated that reliable
measurements could be obtained for at a lower
level. In a few instances, EPA has concluded that
the nominal quantitation limit for a specified
method was less than that level that laboratories
could reliably achieve. For those pollutants, EPA
modified the nominal quantitation limit upward
and used a higher value as the baseline value.
Sections 15.3 and 15.4 provide further
1 In other chapters in this document and in
the preamble to the proposed rulemaking, EPA uses
the term "minimum analytical detection limit" when
it refers to nominal quantitation limit or the baselin
value.
explanation of nominal quantitation limits and
baseline values. Table 15-1 sets forth the
analytical methods and baseline values used for
each pollutant in developing the loadings and
proposed limitations and standards.
ANALYTICAL RESULTS
15.2
The laboratories expressed the result of the
analysis either numerically or as "not
quantitated"2 for a pollutant in a sample. When
the result is expressed numerically, then the
pollutant was quantitated3 in the sample. For
example, for a hypothetical pollutant X, the result
would be reported as "15 ug/L" when the
laboratory quantitated the amount of pollutant X
in the sample as being 15 ug/L. For the non-
quantitated results, for each sample, the
laboratories reported a "sample-specific
quantitation limit." For example, for the
hypothetical pollutant X, the result would be
reported as "<10 ug/L" when the laboratory could
not quantitate the amount of pollutant X in the
sample. That is, the analytical result indicated a
value less than the sample-specific quantitation
limit of 10 ug/L. The actual amount of pollutant
X in that sample is between zero (i.e., the
pollutant is not present) and 10 ug/L. The
2Elsewhere in this document and in the
preamble to the proposed rulemaking, EPA refers to
pollutants as "not .detected" or "non-detected." This
chapter uses the term "not quantitated" or "non-
quantitated" rather than non-detected.
Elsewhere in this document and in the
preamble to the proposed rulemaking, EPA refers to
pollutants as "detected." This chapter uses the term
"quantitated" rather than detected.
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sample-specific quantitation limit for a particular
pollutant is generally the smallest quantity in the
calibration range that may be measured reliably in
any given sample. If a pollutant is reported as not
quantitated in a particular wastewater sample,
this does not mean that the pollutant is not
present in the wastewater, merely that analytical
techniques (whether because of instrument
limitations, pollutant interactions or other
reasons) do not permit its measurement at levels
below the sample specific quantitation limit. In
a few instances, some of the laboratories reported
numerical results for specific pollutants detected
in the samples as "right-censored." Right-
censored measurements are those, that were
reported as being greater than the largest
calibration value of the analysis (e.g., >1000
ug/L).
In calculating pollutant loadings, long-term
averages and limitations, EPA generally
substituted the value of the reported sample-
specific quantitation limit for each non-
quantitated result. In a few cases when the
sample-specific quantitation limit was less than
the baseline value, EPA substituted the baseline
value for the non-quantitated result In a few
instances when the quantitated value was below
the baseline value, EPA substituted the baseline
value for the measured value. EPA further
determined that these values should be considered
non-quantitated in the statistical analyses. For
the rare instances when the laboratory reported a
measurement as right-censored, EPA used the
largest calibration value in its calculations.
NOMINAL QUANTTTATION LIMITS
15.3
Protocols used for determination of nominal
quantitation limits in a particular method depend
on the definitions and conventions that EPA used
at the time the method was developed. The
nominal quantitation limits associated with the
methods addressed in the following sections fall
into three general categories. The first category
includes Methods 1613, 1624, 1625, and 1664,
which used the minimum level (ML) definition as
the lowest level at which the entire analytical
system must give a recognizable signal and an
acceptable calibration point for the analyte. The
second category pertains specifically to Method
1620, and is explained in detail in section 15.5.3.
The third category pertains, to the remainder of
the methods (i.e., Method 85.01 and the classical
wet chemistry methods), in which a variety of
terms are used to describe: the lowest level at
which measurement results! are quantitated. In
some cases (especially with the classical wet
chemistry analytes) the methods are older (1970s
and 1980s) and different concepts of quantitation
apply. These methods typically list a
measurement range or lower limit of
measurement. The terms differ by method and,
as discussed in subsequent sections, the levels
presented are not always representative of the
lowest levels laboratories can achieve currently.
For those methods associated with a calibration
procedure, the laboratories demonstrated through
a low point calibration standard that they were
capable of reliable quarttitation at method-
specified (or lower) levels. In such cases these
nominal quantitation limits are operationally
equivalent to the ML (though not specifically
identified as such in the methods). In the case of
titrimetric or gravimetric methods, the laboratory
adhered to the established lower limit of the
measurement range published in the methods.
Details of the specific methods are presented in
the following sections.
BASELINE VALUES
15.4
In developing the pollutant loadings and
limitations, EPA compared each analytical result
(i.e., quantitated value or sample-specific
quantitation limit for a non-quantitated value) to
a baseline value for the pollutant. (Section 10.4
15-2
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Chapter IS Analytical Methods and Baseline Values
Development Document for the CWT Point Source Category
describes this comparison.) For example, if a
facility data set had five values for oil and grease
of which two were non-quantitated with sample-
specific quantitation limits of 10 mg/L and the
remaining three values were quantitated with
measurements of 20 mg/L, 25 mg/L, and 50
mg/L, then all five values (10 mg/L, 10 mg/L, 20
mg/L, 25 mg/L, and 50 mg/L) were compared to
the baseline value of 5 mg/L for oil and grease.
In most cases, the detected values and sample-
specific quantitation limits were equal to or
greater than the baseline values.
In general, the baseline value was equal to the
nominal quantitation limit identified for the
method. For example, for total cyanide, the
baseline value was 0.02 mg/L which is the same '
as the nominal quantitation limit of 0.02 mg/L for
total cyanide in method 335.2.
EPA made several exceptions to this general
rule when EPA determined that the baseline value
should differ from the nominal quantitation limit
as specified in the method for a pollutant. For
example, EPA determined that the baseline value
for COD by!method 410.1 should be 5 mg/L
rather than the nominal quantitation limit of 50
mg/L. (Section 15.5.7 explains this decision.)
EPA made exceptions to the general rule based
upon EPA's knowledge about the methods,
experiences with laboratories using those
methods, and the need for a single baseline value
for each pollutant. For example, EPA selected a
baseline value to be less than a nominal
quantitation limit when the laboratories
demonstrated through calibration or other quality
control (QC) data that reliable measurements of
the pollutant could be made at a lower level. For
these pollutants, the nominal quantitation limits
reported in the methods are underestimates of
what laboratories can reliably achieve and, the
baseline values were adjusted downwards.
Another example is when EPA selected baseline
values greater than the nominal quantitation
limits because the nominal quantitation limits
could not be reliably achieved. A third example
is when EPA selected a single baseline value
when the pollutant was measured by two or more
methods, each with a different nominal
quantitation limit.
The following section provides a brief
description of the analytical methods and explains
any differences between the nominal quantitation
limits and the baseline values.
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Chapter 15 Analytical Methods and Baseline Values
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Table 15-1 Analytical Methods and Baseline Values
Method
D4658
160.1
160.2
1613
1620
1624
1625
1664
1664
209F
218.4
335.2
350.1
3500D
353.2
365.2
376.1
405.1
410.1
410.1
410.2
410.4
413.1
415.1
420.2
85.01
Analyte
Total Sulfide
Total Dissolved Solids
Total Suspended Solids
Dioxins
Metals Compounds
Organic Compounds
Organic Compounds
HEM
SGT-HEM
Total Solids
Hexavalent Chromium
Total Cyanide
Ammonia as Nitrogen
Hexavalent Chromium
Nitrate/Nitrite
Total Phosphorus
Total Sulfide
BODS
COD
D-COD
COD
COD
Oil and Grease
Total Organic Carbon
Total Phenols
Chlorinated Phenolics
CAS Nominal
Number Quantitation
Value
18496258
C010
C009
*
*
*
*
C036
C037
COOS
18540299
57125
7664417
18540299
COOS
14265442
18496258
COOS
C004
C004D
C004
C004
C007
C012
C020
*
0.04
10.0
4.0
5.0
5.0
10.0
0.01
0.02
0.01
0.1
0.05
0.01
1.0
2.0
50.0
50.0
5.0
3.20
5.0
1.0
0.01
Baseline
Value
1.0
10.0
4.0
5.0
5.0
10.0
0.01
0.02
0.01
0.1
0.05
0.01
1.0
2.0
5.0**
5.0**
5.0
5.0
5.0
1.0
0.05
Unit
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
MG/L
Assumption for
Reported Values <
Baseline Value
used reported value
n/a
n/a
. n/a
used reported value
modified
modified
modified
modified
n/a
n/a
used reported value
n/a
n/a
used reported value
n/a
used reported value
n/a
n/a
n/a
n/a
n/a
n/a
n/a
used reported value
n/a
* The method analyzed a number of pollutants. Attachment 15-1 identifies the all pollutants of concern and thei
baseline values. In general, the baseline values are equal to the nominal quantitation limits
**The baseline value was adjusted to reflect the lowest nominal quantitation limit of the titrimetric procedures (i.e.,
410.1 and 410.2). See Section 15.5.7 for a detailed explanation.
n/a: none of the data used for the pollutant loadings and limitations were reported below the baseline value.
15-4
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Chapter IS Analytical Methods and Baseline Values
Development Document for the CWT Point Source Category
ANALYTICAL METHODS
15.5
Table 15-1 provides a summary of the
analytical methods, the associated pollutants
measured by the method, the nominal quantisation
levels, the baseline levels, and the assumptions
for values reported below the baseline levels.
Attachment 15-1 to this chapter provides a more
complete list of the pollutants and their baseline
values. The following subsections provide
additional information supporting the summary in
Table 15-1.
If a measured value or sample-specific
quantisation limit was reported with a value less
than the ML specified in a method, EPA
substituted the value of the ML and assumed that
'the measurement was non-quantitated. For
example, if the ML was 10 ug/L and the
laboratory reported a quantitated value of 5 ug/L,
EPA assumed that the concentration was non-
quantitated with a sample-specific7 quantisation
limit of 10 ug/L.
Method 413.1 (Oil and Grease)
15.5.2
Methods 1613,1624,1625,1664
(Dioxins, Organics, HEM)
15.5.1
As stated earlier, Method 1613 for dioxins,
Methods 1624 and 1625 for organic compounds,
and Method 16644 for n-hexane extractable
material (HEM) and silica gel treated n-hexane
extractable material (SGT-HEM)5 use the
minimum level concept for quantisation of the
pollutants measured by the methods. The ML is
defined as the lowest level at which the entire
analytical system must give a recognizable signal
and an acceptable calibration point for the
analyte. When an ML is published in a method,
the Agency has demonstrated that the ML can be
achieved in at least one well-operated laboratory,
and when that laboratory or another laboratory
uses that method, the laboratory is required to
demonstrate, through calibration of the
instrument or analytical system, that it can make
measurements at the ML. For these methods,
EPA used the minimum levels as the baseline
values.
4See proposal at 61 Federal Register 1730,
January 23, 1996.
5SGT-HEM measures non-polar material
(i.e., n-hexane extractable material that is not
absorbed by silica gel). Method 1664 measures
both oil and grease and non-polar material.
Method 413.1 was used in early sampling
episodes to measure pollutant concentrations of
oil and grease. Because this method requires
freon, an ozone depleting solvent, to perform the
analysis, EPA developed and recently
promulgated Method 1664 to replace the
procedures currently approved at 40 CFR 136.
The same nominal quantisation limit applies to
both methods for measuring oil and grease and
HEM. In calculating the pollutant loadings and
limitations, the data used from this method were
all greater than the nominal quantisation limit of
5mg/L.
Method 1620
15.5.3
Method 1620, which measures the amounts
of specific metals in samples, uses the concept of
an instrument detection limit (IDL) which is
defined as "the smallest signal above background
noise that an instrument can detect reliably."6
IDLs are determined on a quarterly basis by each
analytical laboratory participating in the data
gathering efforts by EPA's Engineering and
Analysis Division (BAD) and are, therefore,
laboratory-specific and time-specific. Data
6Keith, L.H., W. Crummett, J. Deegan,
R.A. Libby, J.K. Taylor, G. Wentler (1983).
"Principles of Environmental Analysis," Analytical
Chemistry, Volume 55, Page 2217.
15-5
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Chapter 15 Analytical Methods and Baseline Values
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reporting practices for Method 1620 analysis
follow conventional metals reporting practices
used in other EPA programs, in which values are
reported at or above the IDL. Though Method
1620 does contain minimum levels (MLs), these
MLs pre-date EPA's recent refinement of the
minimum level concept. The ML values
associated with Method 1620 are based on a
consensus opinion reached between EPA and
laboratories during the 1980s regarding levels
that could be considered reliable quantitation
limits when using Method 1620. These limits do
not reflect advances in technology and
instrumentation since the 1980s. Consequently,
the IDLs were used as the baseline for reporting
purposes, with the general understanding that '
reliable results can be produced at or above the
DDL.
The Method 1620 ML values were used as
the baseline values in the data screening, with the
exception of two analytes: boron and lead. Based
on laboratory feedback years ago, it was
determined that the boron ML of 10 ug/L
specified in Table 9 of Method 1620 could not be
reliably achieved. Consequently, for the purposes
of EAD's data gathering under the metals
contracts, the ML for boron was adjusted to 100
ug/L. In the case of lead, which has an ML of 5
ug/L associated with graphite furnace atomic
absorption (GFAA) spectroscopy analysis, BAD
determined that it was not necessary to measure
down to such low levels, and that lead could be
analyzed by inductively coupled plasma atomic
emission (ICP) spectroscopy instead.
Consequently, the ML requirement was adjusted
to 50 ug/L.
Though the baseline values were derived
from the MLs (or adjusted MLs) in Method 1620,
EPA used the laboratory reported values, which
captured concentrations down to the IDLs, in
calculating the pollutant loadings and limitations.
If the long-term average for a pollutant was less
than the baseline value, however, EPA substituted
the ML for the long-term average and re-
calculated the limitation using this revised long-
term average and the group variability factor.
Method 85.01
15.5.4
NCASI Method 85.01 was used to analyze
some samples associated with the organics
subcategory for chlorinated phenolics. This gas
chromatography/electron capture detector
(GC/ECD) method predates; EPA Method 1653
for chlorinated phenolics determination, and was
only used for analysis of samples under one CWT
sampling episode (Episode 1987, collected in
1990). Method 1653 is an isotope dilution gas
chromatography/mass spectrometry (GC/MS)
method. EPA intends to use this method, rather
than Method 85.01, for any subsequent data
gathering for analyses of chlorinated phenolics
not included in semiivolatiles organics
Method 1625.
Some chlorinated phenolics in Episode 1987
were analyzed by both Method 85.01 and Method
1625. Thus, for a given sample, there were two
results for a specific cMorinated phenolic
compound. Of the pollutants of concern, these
compounds were pentachlorophenol, 2,3,4,6-
tetrachlorophenol, 2,4,5-trichlorophenol, and
2,4,6-trichlorophenol. Where two results were
provided for the same pollutant in a sample, EPA
used the analytical result from Method 1625.
This decision is based on the knowledge that
Method 1625 is an isotope dilution GC/MS
procedure, and therefore produces more reliable
results than Method 85.01.
For the remaining chlorinated phenolics
analytes that were determined by Method 85.01,
EPA used the laboratory-specific quantitation
limits as the baseline values (see Table 15-2
below). In all cases, the data used to calculate the
pollutant loadings were greater than or equal to
the baseline value associated with the pollutant.
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Chapter 15 Analytical Methods and Baseline Values
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Table 15-2 Baseline values for Method 85.01
Analyte
3,4-dichlorophenol
3,4,5-trichlorocatechol
3,4,6-trichloroguaiacol
3,5-dichlorophenol
3,6-dichlorocatechol
4-chlorophenol
4,5-dichloroguaiacol
4,5,6-trichloroguaiacol
5-chloroguaiacpl
6-chlorovanillin
CAS Number
95772
56961207
60712449
591355
3938167
106489
2460493
2668248
3743235
18268763
Minimum
Level
(mg/L)
0.0008
0.0008
0.0008
0.0008
0.0008
0.24
0.0008
0.0008
0.16
0.0008
Methods D4658 and 376.1
(Total SulBde)
15.5.5
Total sulfide was analyzed by Methods
376.1 and D4658, each of which have different
nominal quantisation limits. Method 376.1 has a
nominal quantitation limit of 1 mg/L, while
Method D4658 has a nominal quantitation limit
of 0.04 mg/L. Rather than use two different
baseline values for the same pollutant, EPA used
the maximum of the two values (i.e., 1 mg/L) as
the baseline value.
In some cases, the reported value was lower
than the nominal quantitation limits identified in
the method. EPA used these values as reported in
calculating the pollutant loadings. (EPA has not
proposed limitations for total sulfide.)
Methods 410J, 410.2, and 410.4
(CODandD-COD)
15.5.6
Methods 410.1,410.2, and 410.4 were used
to measure COD concentrations. In addition,
Method 410.1 was used to measure the D-COD
concentrations in Episode 1987.
Methods 410.1 and 410.2 are titrimetric
procedures that follow identical analytical
protocols, with the exception of the concentration
level of the reagents used for the titration.
Method 410.1 is designed to measure "mid-level"
concentrations greater than 50 mg/L for chemical
oxygen demand (COD) and D-chemical oxygen
demand (D-COD). Method 410.2 is designed to
measure "low-level" concentrations of those
parameters in the range of 5-50 mg/L. When one
of the participating laboratories analyzes a
sample, they are required to measure down to the
lowest quantitation limit possible.
Consequently, if the laboratory analyzes a
sample using Method 410.1 and obtains a non-
quantitated result, it must reanalyze the sample
using Method 410.2. Therefore, the quantitation
limit reported for non-quantitations will be equal
to 5 mg/L, unless sample dilutions were required
because of matrix complexities.
Method 410.4 is a colorimetric procedure
with a measurement range of 3-900 mg/L for
automated procedures and measurement range of
20-900 mg/L for manual procedures.
For all COD data, EPA used the baseline
value of 5 mg/L that is associated with the lower
quantitation limit for the titrimetric procedures
because most of the data had been obtained by
the titrimetric procedures (i.e., Methods 410.1 or
410.2). Regardless of the method used to analyze
COD and D-COD, all values used to calculate the
pollutant loadings were greater than the nominal
quantitation limit of 5 mg/L. . (EPA is not
proposing limitations for COD.)
Method 420.2 (Total Phenols)
15.5.7
Method 420.2 was used to analyze for total
phenols. The method reports two "working
ranges"; one with a lower range limit of 0.002
mg/L and the other with a lower range limit of
0.01 mg/L. In this case, EPA's experience with
the laboratories has indicated that some can meet
the lower limits of the method-specified range
and others cannot. Consequently, EPA
15-7
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Chapter 15 Analytical Methods and Baseline Values
Development Document for the CWT Point Source Category
determined that the baseline value should be 0.05
mg/L, which reflects that quantitation limit that
all participating laboratories were capable of
achieving.
In some cases, the reported value was lower
than the baseline value of 0.05 mg/L. Because
some laboratories have demonstrated that they
can quantitate to lower levels, EPA used these
values as reported in calculating the pollutant
loadings. (EPA has not proposed limitations for
total phenols.)
Method 218.4 and 3500D
(Hexavalent Chromium)
15.5.8
Hexavalent chromium was determined by
Methods 218.4 and 3500D. Because most of the
samples were analyzed using Method 218.4, its
baseline value of 0.01 mg/L was used for all
hexavalent chromium results. None of the
quantitated values and sample-specific
quantitation limits were reported with values less
than this baseline value.
Methods 335.2 and 353.2
(Total Cyanide and Nitrate/Nitrate)
15.5.9
Samples were analyzed for total cyanide and
nitrate/nitrate using Methods 335.2 and 353.2,
respectively. Within each method, the nominal
quantitation limit and the baseline value were the
same.
In some cases, the reported value was lower
than the baseline value for the pollutant. Because
some laboratories have demonstrated that they
can quantitate to lower levels, EPA used these
values as reported in calculating the pollutant
loadings and limitations.
Remaining Methods
15.5.10
The previous subsections in section 15.5
identify many of the methods used to analyze the
wastewater samples. The remaining methods
were: 160.1 (total dissolved solids), 160.2 (total
suspended solids), 209F (total solids), 350.1
(ammonia as nitrogen), 365.2 (total phosphorus),
405.1 (5-day biochemical oxygen demand), and
415.1 (total organic carbon)'. For these methods,
the nominal quantitation limits and the baseline
values were equal. In addition, none of the values
were reported below the nominal quantitation
limits.
Of the pollutants measured by these
methods, EPA proposed limitations for total
suspended solids (TSS) and 5-day biochemical
oxygen demand (BOD5).
ANALYTICAL METHOD
DEVELOPMENT EFFORTS
15.6
Section 304(h) of the Clean Water Act
directs EPA to promulgate guidelines establishing
test procedures for the analysis of pollutants.
These methods allow the analyst to determine the
presence and concentration of pollutants in
wastewater, and are used for compliance
monitoring and for filing applications for the
NPDES program under 40 CFR 122.21, 122.41,
122.44 and 123.25, and for the implementation of
the pretreatment standards under 40 CFR 403.10
and 403.12. To date, EPA has promulgated
methods for all conventional and toxic pollutants,
and for some nonconventional pollutants. EPA
has identified five pollutants pursuant to section
304(a)(4) of the CWA defined as "conventional
pollutants" (See 40 CFR 401.16). Table I-B at
40 CFR 136 lists the analytical methods
approved for these pollutants. EPA has listed
pursuant to section 307(a) of the Act, 65 metals
and organic pollutants and classes of pollutants
as "toxic pollutants" at 40 CFR 401.15. From
the list of 65 classes of toxic pollutants, EPA
identified a list of 126 "Priority Pollutants." This
list of Priority Pollutants is; shown, for example,
at 40 CFR Part 423, Appendix A. The list
includes non-pesticide organic pollutants, metal
pollutants, cyanide, asbestos, and pesticide
15-8
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Chapter 15 Analytical Methods and Baseline Values
Development Document for the CWT Point Source Category
pollutants.
Currently approved methods for metals and
cyanide are included in the table of approved
inorganic test procedures at 40 CFR 136.3, Table
I-B. Table I-C at 40 CFR 136.3 lists approved
methods for measurement of non-pesticide
organic pollutants, and Table I-D lists approved
methods for the toxic pesticide pollutants and for
other pesticide pollutants. Dischargers must use
the test methods promulgated at 40 CFR Part
136.3 or incorporated by reference in the tables,
when available, to monitor pollutant discharges
from the centralized waste treatment (CWT)
industry, unless specified otherwise in Part 437 or
by the permitting authority.
Table I-C does not list 11 CWT semivolatile
organic pollutants and two CWT volatile organic
pollutants (2-butanone and 2-propanone).
However, the analyte list for EPA Method 1624
contains both volatile organic pollutants and the
analyte list for EPA Method 1625 contains four
of the semivolatile organic pollutants. EPA
promulgated both of these methods for use in
Clean Water Act measurement programs at 40
CFR 136, Appendix A. As a part of this
rulemaking, EPA is proposing to allow the use of
EPA Method 1624 for the determination of the
CWT volatile organic pollutants and modified
versions of EPA Methods 625 and 1625 for the
determination of all CWT semivolatile organic
pollutants. The proposed modifications to EPA
Methods 625 and 1625 have been included in the
Docket for this rulemaking. The modified
versions of Methods 625 and 1625 will allow the
analysis of all CWT semivolatile organic
pollutants by each method. If EPA adopts these
proposed modifications, the following pollutants
will be added to their respective analyte lists:
Additions to EPA Method 1625 and Method 625
Pollutant CASRN
acetophenone 98-86-2
aniline 62-53-3
benzoic acid 65-85-0
2,3-dichloroaniline 608-27-5
o-cresol 95-48-7
p-cresol 160-44-5
pyridine 110-86-1
Additions to EPA Method 625
Pollutant CASRN
alpha-terpineol 98-55-5
carbazole 86-74-8
n-decane 124-18-5
n-octadecane 593-45-3
These pollutants were found in CWT industry
wastewaters in EPA's data gathering. The
modifications to Methods 625 and 1625 consist
of text, performance data, and preliminary quality
control (QC) acceptance criteria for the additional
analytes, if available. This information will allow
a laboratory to practice the methods with the
additional analytes as an integral part. The QC
acceptance criteria for the additional analytes to
be added to Method 1625 have been validated in
single-laboratory studies. EPA plans further
validation of these method modifications by use
in subsequent data gathering for the final rule and
plans to promulgate these method modifications
for monitoring at 40 CFR part 437 (see 40 CFR
401.13) or at 40 CFR part 136 in the final rule
for this rulemaking.
On March 28,1997, EPA proposed a means
to streamline the method development and
approval process (62 FR 14975) and on October
6, 1997, EPA published a notice of intent to
implement a performance-based measurement
system (PBMS) in all of its programs to the
extent feasible (62 FR 52098). The Agency is
15-9
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Chanter 15 Analytical Methods and Baseline Values
Development Document for the CWT Point Source Category
currently determining the specific steps necessary
to implement PBMS in all of its regulatory
programs and has approved a plan for
implementation of PBMS in the water programs.
Under PBMS, regulated entities will be able to
modify methods without prior approval and will
be able to use new methods without prior EPA
approval provided they notify the regulatory
authority to which the data will be reported. EPA
expects a final rule implementing PBMS in the
water programs by the end of calendar year 1998.
When the final rule takes effect, regulated entities
in the CWT industry will be able to select
methods for monitoring other than those
approved at 40 CFR parts 136 and 437 provided
that certain validation requirements are met.
Many of the details were provided at proposal (62
FR 14975) and will be finalized in the final
PBMS rule.
15-10
-------
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LIST OF DEFINITIONS
Administrator - The Administrator of the U.S. Environmental Protection Agency.
Agency - The U.S. Environmental Protection Agency.
Average Monthly Discharge Limitation - The highest allowable average of "daily discharges" over
a calendar month, calculated as the sum of all "daily discharges" measured during the calendar month
divided by the number of "daily discharges" measured during the month.
B
BAT - The best available technology economically achievable, applicable to effluent limitations to b
achieved by July 1, 1984, for industrial discharges to surface waters, as defined by Sec. 304(b)(2)(B)
of the CWA.
BCT - The best conventional pollutant control technology, applicable to discharges of conventional
pollutants from existing industrial point sources, as defined by Sec. 304(b)(4) of the.CWA.
BPT - The best practicable control technology currently available, applicable to effluent limitations to
be achieved by My 1,1977, for industrial discharges to surface waters, as defined by Sec. 304(b)(l) of
the CWA.
Centralized Waste Treatment Facility - Any facility that treats and/or recovers or recycles any
hazardous or non-hazardous industrial waste, hazardous or non-hazardous industrial wastewater, and/or
used material from off-site.
Centralized Waste Treatment Wastewater - Wastewater generated as a result of CWT activities.
CWT wastewater sources may include, but are not limited to: liquid waste receipts, solubilization water,
used oil emulsion-breaking wastewater, tanker truck/drum/roll-off box washes, equipment washes, air
pollution control scrubber blow-down, laboratory-derived wastewater, on-site industrial waste combustor
wastewaters, on-site landfill wastewaters, and contaminated stormwater.
Clean Water Act (CWA) - The Federal Water Pollution Control Act Amendments of 1972 (33 U.S.C.
Section 1251 et seq.X as amended by the Clean Water Act of 1977 (Pub. L. 95-217), and the Water
Definitions-1
-------
Quality Act of 1987 (Pub. L. 100-4).
Clean Water Act (CWA) Section 308 Questionnaire - A questionnaire sent to facilities under the
authority of Section 308 of the CWA, which requests information to be used in the development of
national effluent guidelines and standards.
Commercial Facility - A CWT facility that accepts off-site generated wastes, wastewaters or used
material from other facilities not under the same ownership as this facility. Commercial operations are
usually made available for a fee or other remuneration.
Contaminated Storm Water - Storm water which comes in direct contact with the waste or waste
handling and treatment areas.
Conventional Pollutants - Constituents of wastewater as determined by Sec. 304(a)(4) of the CWA,
including, but not limited to, pollutants classified as biochemical oxygen demand, total suspended solids,
oil and grease, fecal coliform, and pH.
CWT - Centralized Waste Treatment.
n
Daily Discharge - The discharge of a pollutant measured during any calendar day or any 24-hour period
that reasonably represents a calendar day.
Detailed Monitoring Questionnaire (DMQ) - Questionnaires sent to collect monitoring data from 20
selected CWT facilities based on responses to the Section 308 Questionnaire.
Direct Discharger - A facility that discharges or may discharge treated or untreated wastewaters into
waters of the United States.
E
Effluent Limitation - Any restriction, including schedules of compliance, established by a State or the
Administrator on quantities, rates, and concentrations of chemical, physical, biological, and other
constituents which are discharged from point sources into navigable waters, the waters of the contiguous
zone, or the ocean. (CWA Sections 301(b) and 304(b).)
Existing Source- Any facility from which there is or may be a discharge of pollutants, the construction
of which is commenced before the publication of the proposed regulations prescribing a standard of
performance under Sec. 306 of the CWA.
Definitions-2
-------
Facility - All contiguous property owned, operated, leased or'under the control of the same person or
entity
Fuel Blending - The process of mixing waste, wastewater, or used material for the purpose of
regenerating a fuel for re-use.
H
Hazardous Waste - Any waste, including wastewater, defined as hazardous under RCRA, TSCA, or
any state law.
High Temperature Metals Recovery (HTMR) - A metals recovery process in which solid forms of
metal containing materials are processed with a heat-based pyrometallurgical technology to produce
remelt alloy which can then be sold as feed material in the production of metals.
In-scope - Facilities and/or wastewaters that EPA proposes to be subject to this guideline.
Indirect Discharger - A facility that discharges or may discharge wastewaters into a publicly-owned
treatment works.
Intercompany - Facilities that treat and/or recycle/recover waste, wastewater, and/or used material
generated by off-site facilities not under the same corporate ownership. These facilities are also referred
to as "commercial" CWTs.
Intracompany Transfer - Facilities that treat and/or recycle/recover waste, wastewater, and/or used
material generated by off-site facilities under the same corporate ownership. These facilities are also
referred to as "non-commercial" CWTs.
LTA - Long-Term Average. For purposes of the effluent guidelines, average pollutant levels achieved
over a period of time by a facility, subcategory, or technology option. LTAs were used in developing
the limitations and standards in today's proposed regulation.
M
Marine-generated Waste - Waste, wastewater, and/or used material generated as part of the normal
maintenance and operation of a ship, boat, or barge operating on inland, coastal, or open waters.
Definitions-3
-------
Metal-bearing Wastes - Wastes and/or used materials that contain metal pollutants from manufacturing
or processing facilities or other commercial operations. These wastes may include, but are not limited
to, the following: process wastewater, process residuals such as tank bottoms or stills, and process
wastewater treatment residuals such as treatment sludges.
Minimum Level - the lowest level at which the entire analytical system must give a recognizable signals
and an acceptable calibration point for the analyte.
Mixed Commercial/Non-commercial Facility - Facilities that treat and/or recycle/recover waste,
wastewater, and/or used material generated by off-site facilities both under the same corporate ownership
and different corporate ownership.
H
National Pollutant Discharge Elimination System (NPDES) Permit - A permit to discharge
wastewater into waters of the United States issued under the National Pollutant Discharge Elimination
system, authorized by Section 402 of the CWA.
New Source- Any facility from which there is or may be a discharge of pollutants, the construction of
which is commenced after the proposal of regulations prescribing a standard of performance under
section 306 of the Act and 403.3(k).
Non-commercial Facility - Facilities that accept waste from off-site for treatment and/or recovery from
generating facilities under the same corporate ownership as the CWT facility.
Non-contaminated Stormwater - Storm water which does not come into direct contact with the waste
or waste handling and treatment areas.
Non-conventional Pollutants - Pollutants that are neither conventional pollutants nor priority pollutants
listed at 40 CFR Section 401.
Non-detect Value - the analyte is below the level of detection that can be reliably measured by the
analytical method. This is also known, in statistical terms, as left-censoring.
Non-water Quality Environmental Impact - Deleterious aspects of control and treatment technologies
applicable to point source category wastes, including, but not limited to air pollution, noise, radiation,
sludge and solid waste generation, and energy used.
NSPS - New Sources Performance Standards, applicable to industrial facilities whose construction is
begun after the publication of the proposed regulations, as defined by Sec. 306 of the CWA.
Definitions-4
-------
o
OCPSF - Organic chemicals, plastics, and synthetic fibers manufacturing point source category. (40
CFRPart414).
Off Site - Outside .the boundaries of a facility.
Oily Wastes - Wastes and/or used materials that contain oil and grease from manufacturing or
processing facilities or other commercial operations. These wastes may include, but are not limited to,
the following: spent lubricants, cleaning fluids, process wastewater, process residuals such as tank
bottoms or stills and process wastewater treatment residuals, such as treatment sludges.
Oligopoly - A market structure with few competitors, in which each producer is aware of his
competitors' actions and has a significant influence on market price and quantity.
On Site - The same or geographically contiguous property, which may be divided by a public or private
right-of-way, provided the entrance and exit between the properties is at a crossroads intersection, and
access is by crossing as opposed to going along the right-of-way. Non-contiguous properties owned by
the same company or locality but connected by a right-of-way, which it controls, and to which the public
does not have access, is also considered on-site property.
Organic-bearing Wastes - Wastes and/or used materials that contain organic pollutants from
manufacturing or processing facilities or other commercial operations. These wastes may include, but
are not limited to, process wastewater, process residuals such as tank bottoms or stills and process
wastewater treatment residuals, such as treatment sludges.
Outfall - The mouth of conduit drains and other conduits from which a facility effluent discharges into
receiving waters.
Out-of-scope - Out-of-scope facilities are facilities which only perform centralized waste treatment
activities which EPA has not proposed to be subject to provisions of this guideline.' Out-of-scope
operations are centralized waste treatment operations which EPA has not proposed to be subject to
provisions of this guideline. .
Pipeline - "Pipeline" means an open or closed conduit used for the conveyance of material. A pipeline
includes a channel, pipe, tube, trench, ditch or fixed delivery system.
Pass Through - A pollutant is determined to "pass through" a POTW when the average percentage
removed by an efficiently operated POTW is less than the average percentage removed by the industry's
direct dischargers that are using well-defined, well-operated BAT technology.
Definitions-5
-------
Point Source - Any discemable, confined, and discrete conveyance from which pollutants are or may
be discharged.
Pollutants of Concern (POCs) - Pollutants commonly found in centralized waste treatment
wastewaters. For the purposes of this guideline, a POC is a pollutant that is detected three or more
times above a treatable level in influent wastewater samples from centralized wasite treatment facilities.
Additionally, a CWT POC must be present in at least ten percent of the influent wastewater samples.
Priority Pollutant - One hundred twenty-six compounds that are a subset of the 6 5 toxic pollutants and
classes of pollutants outlined in Section 307 of the CWA. The priority pollutants are specified in the
NRDC settlement agreement (Natural Resources Defense Council et al v. Train, 8 E.R.C. 2120 [D.D.C.
1976], modified 12 E.R.C. 1833 [D.D.C. 1979]).
Product Stewardship - A program practiced by many manufacturing facilities which involves taking
back spent, used, or unused products, shipping and storage containers with product residues, off-
specification products and waste materials from use of products.
PSES - Pretreatment standards for existing sources of indirect discharges, under Sec. 307(b) of the
CWA.
PSNS - Pretreatment standards for new sources of indirect discharges, under Sec. 307(b) of the CWA.
Publicly Owned Treatment Works (POTW) - Any device or system, owned by a state or municipality,
used in the treatment (including recycling and reclamation) of municipal sewage or industrial wastes of
a liquid nature that is owned by a state or municipality. This includes sewers, pipes, or other
conveyances only if they convey wastewater to a POTW providing treatment (40 CFR 122.2),
R
RCRA - The Resource Conservation and Recovery Act of 1976 (RCRA) (42 U.S.C. Section 6901 et
geq.), which regulates the generation, treatment,, storage, disposal, or recycling of solid and hazardous
wastes.
Re-refining - Distillation, hydrotreating, and/or other treatment employing acid, caustic, solvent, clay
and/or chemicals of used oil in order to produce high quality base stock for lubricsmts or other petroleum
products.
SIC - Standard Industrial Classification (SIC). A numerical categorization system used by the U.S.
Department of Commerce to catalogue economic activity. SIC codes refer to the products, or group of
products, produced or distributed, or to services rendered by an operating establishment. SIC codes are
used to group establishments by the economic activities in which they are engaged. SIC codes often
denote a facility's primary, secondary, tertiary, etc. economic activities.
Definitions-6
-------
Small-business - Businesses with annual sales revenues less than $6 million. This is the Small Business
Administration definition of small business for SIC code 4953, Refuse Systems (13 CFR Ch.l, §
121.601) which is being used to characterize the CWT industry.
Solidification - The addition of sorbents to convert liquid or semi-liquid waste to a solid by means of
adsorption, absorption or both. The process is usually accompanied by stabilization.
Stabilization - A waste process that decreases the mobility of waste constituents by means of a chemical
reaction. For the purpose of this rule, chemical precipitation is not a technique for stabilization.
V
Variability Factor - used in calculating a limitation (or standard) to allow for reasonable variation in
pollutant concentrations when processed through extensive and well designed treatment systems.
Variability factors assure that normal fluctuations in a facility's treatment are accounted for in the
limitations. By accounting for these reasonable excursions above the long-term average, EPA's use of
variability factors results in limitations that are generally well above the actual long-term averages.
w
Waste Receipt - Wastes, wastewater or used material received for treatment and/or recovery. Waste
receipts can be liquids or solids.
Zero or Alternative Discharge - No discharge of pollutants to waters of the United States or to a
POTW. Also included in this definition are disposal of pollutants by way of evaporation, deep-well
injection, off-site transfer, and land application.
Definitions-?
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-------
LIST OF ACRONYMS
A
AMSA: Association of Municipal Sewage
Authorities
API: American Petroleum Institute
B
BAT: Best Available Technology
(Economically Achievable)
BCT: Best Conventional (Pollutant Control
Technology
BDAT: Best Demonstrated Available
(Treatment) Technology
BOD: Biological Oxygen Demand
BPJ: Best Professional Judgement
BPT:
c
CBI:
Best Practicable (Control) Technolog
(Currently Available)
Confidential Business Information
CERCLA: Comprehensive Environmental
Response, Compensation, and
Liability Act
CMA: Chemical Manufacturers Association
COD: Chemical Oxygen Demand
CWA: Clean Water Act
CWT: Centralized Waste Treatment
D
DAF: Dissolved Air Flotation
DL: Detection Limit
DMQ: Detailed Monitoring Questionnaire
E
EAD: Engineering and Analysis Division
ELG: Effluent Limitations Guidelines
ENR: Engineering News Record
EPA: Environmental Protection Agency
F
F/M: Food-to-microorganism (ratio)
G
GAC: Granular Activated Carbon
GC/ECD: Gas Chromatography/Electron
Capture Detector
GFAA: Graphite Furnace Atomic Absorption
H
HAP: Hazardous Air Pollutant
HEM: Hexane-Extractable Material
HSWA: Hazardous and Solid Waste
Amendments
HTMR: High Temperature Metals Recovery
Acronyms-1
-------
I
ICP: Inductively Coupled Plasma (Atomic
Emission Spectroscopy)
IDL: Instrument Detection Limit
L
LDR: Land Disposal Restriction
LTA: Long-term Average
MACT: Maximum Achievable Control
Technology
MADL: Minimum Analytical Detection Limit
MGD: Million Gallons per Day
MIP: Monitoring-in-place
ML: Minimum Level
MLSS: Mixed Liquor Suspended Solids
MNC: Mean Non-censored (Value)
JV
ND: Non-detected
NOA: Notice of (Data) Availability
NORA: National Oil Recyclers Association
NPDES: National Pollutant Discharge
Elimination System
NRDC: Natural Resources Defense Council
NRMRL: National Risk Management
Research Laboratory; formerly
RREL
NSPS: New Source Performance Standards
NSWMA: National Solid Waste Management
Association
o
O&M: Operation and Maintenance
OCPSF: Organic Chemicals, Plastics, and
Synthetic Fibers
OMB: Office of Management and Budget
£
PAC:
POC:
POTW:
PSES:
Powdered Activated Carbon
Pollutant of Concern
Publicly Owned Treatment Works
PSNS:
Pretreatment Standards for Existing
Sources
Pretreatment Standards for New
Sources
Q
QC: Quality Control
R
RCRA:
Resource Conservation and Recovery
Act
RO: Reverse Osmosis
RREL:
Risk Reduction Engineering
Laboratory; now known as NRMRL
SBA: Small Business Administration
SBR: Sequencing Batch Reactor
SBREFA: Small Business Regulatory
Flexibility Act
Acronyms-2
-------
SGT-HEM: Silica Gel-Treated Hexane-
Extractable Material
SIC: Standard Industrial Code
SRT: Sludge Retention Time
I
TDS: Total Dissolved Solids
TEC: Transportation Equipment Cleaning
TOC: Total Organic Carbon •
TSDF: • Treatment, Storage, and Disposal
Facility
TSS: Total Suspended Solids
TWF: Toxic Weighting Factor
u
UF: Ultrafiltration
UIC: Underground Injection Control
UTS: Universal Treatment Standards
Y
VOC: Volatile Organic Compound
w
WTI: Waste Treatment Industry
Acronyms-3
-------
-------
INDEX
A
Activated Sludge: 7-16, 8-2, 8-43, 8-45, 8-47, 8-49, 8-50, 8-51, 8-54, 8-57, 9-12,14-26
Alternate Discharge Methods: 8-57, 8-58
Analytical Costs: 6-1,11-31
Analytical Methods: 2-5, 2-7, 2-8, 2-9, 6-1,10-6,11-32,15-1,15-2,15-3,15-4,15-5,15-8
Applicability - Facilities subject to 40 CFR (Parts 400 to 471): 3-1
Grease Trap/Interceptor Wastes: 3-14
High Temperature Metals Recovery. 3-10
Industrial Waste Combustors: 3-11,3-12
Landfill Wastewaters: 3-11
Marine Generated Wastes: 3-13,3-14
Pipeline Transfers (Fixed Delivery Systems): 3-4
Product Stewardship: 3-5, 3-6, 3-7
Publicly Owned Treatment Works (POTWs): 3-8,3-9
Re-refining. 3-12,3-13
Sanitary Wastes: 3-8
Silver Recovery Operations from Used Photographic & X-Ray Materials: 3-9, 3-10
Solids, Soils, and Sludges: 3-7
Solvent Recycling/Fuel Blending: 3-12
Stabilization: 3-14
Transporters and/or Transportation Equipment Cleaner : 3-8
Used Oil Filter Recycling: 3-13
Attached Growth Biological Treatment System: 8-45
B
BAT: 1-2,1-3,1-5,3-9,3-10,7-15, 7-21, 7-27, 7-33, 8-59, 9-1, 9-13, 9-14, 9-15, 9-16,10-5,10-6,
10-31,10-34
Batch: 2-5, 2-10, 2-11, 4-5, 6-1, 8-2, 8-3, 8-19,8-43,8-44, 8-45,8-52, 9-3, 9-11, 9-12,10-3,10-5,
11-4,11-5,11-6,11-7,11-9,11-10,11-12,11-13,11-14,11-20,11-25,11-26,11-27
BCT: 1-2,1-5, 9-1, 9-13, 9-14,10-5,10-6,10-31,10-34,10-35,11-44
Belt Pressure Filtration: 8-51, 8-54, 8-55
Index-1
-------
Index
Development Document for the CWT Point Source Category
Benzo(a)pyrene: 2-9, 6-7, 6-11, 6-21, 6-26, 7-9, 7-20, 7-24, 7-31,12-12,12-18,12-37,12-43,
15-11
Best Management Practices: 8-1, 8-3
Biological Treatment: 1-6, 2-10, 2-11, 5-4, 5-5, 8-1, 8-2, 8-5, 8-10, 8-13, 8-24, 8-25, 8-41,
8-43, 8-45, 8-47, 8-51, 8-54, 8-57, 9-2, 9-6,9-7, 9-11, 9-12, 9-13,10-35,
11-22,11-26,12-33,12-34,12-35,13-3,14-3,14-7,14-13,14-15,14-27
Biotowers: 8-43, 8-45,8-47, 8-48
BOD: 1-2,2-7,6-4,6-6,6-9,6-24, 6-25, 7-15, 7-19, 7-27, 7-28, 7-33,8-47,8-50, 8-51, 9-13,10-6,
10-27, 10-29, 10-35, 10-37, 10-38,11-25, 11-26, 11-31, 11-32, 12-7, 12-9, 12-33, 12-42,
12-43,12-45
Boron: 2-8, 6-4, 6-6, 6-9, 6-26, 7-6, 7-19, 7-22, 7-23, 7-24, 7-27, 7-28,12-3,12-19,12-34,12-37,
12-42,12-44,12-46,15-6,15-11
BPT: 1-1, 1-2, 1-5,1-6, 7-15, 7-33, 9-1, 9-2, 9-3, 9-4, 9-5, 9-6, 9-7, 9-8, 9-9, 9-10, 9-11, 9-12,
9-13, 9-14, 9-15,10-5,10-6,10-31,10-34,10-35,11-44,12-2,12-5,12-37,12-38, 12-39,
12-40
Capital Costs: 11-1, 11-2, 11-5, 11-6, 11-7, 11-8, 11-9, 11-10, 11-12, 11-13, 11-14, 11-16,
11-17, 11-18, 11-19, 11-20, 11-21, 11-21, 11-22, 11-25, 11-26, 11-27, 11-28,
11-30,11-36,11-40,11-44,11-45
Carbon Adsorption: 1-6, 2-11, 5-4, 8-2,8-33,8-34, 8-35, 9-6, 9-11, 9-14,12-7,12-33
Chemical Precipitation: 2-14, 5-3, 7-13, 7-27, 8-2, 8-5, 8-8, 8-10, 8-13, 8-19, 8-20, 8-21,
8-22,8-24,8-51,9-2, 9-3, 9-4, 9-5, 9-6, 9-7,10-3,11-4, 11-5,11-6,11-7,
11-8,11-9,11-10,11-11,11-12,11-13,11-15,11-16,11-19,11-22,
11-27,11-28,11-35,11-36,11-37,11-38
Chromium Reduction: 8-2,8-15, 8-16, 8-17, 8-19
Clarification: 2-3, 2-10, 3-7, 3-8, 3-11, 4-1, 8-5, 8-7, 8-10, 8-12, 8-13, 8-19, 8-33, 8-51, 9-3, 9-4,
9-14,10-3,11-4,11-6,11-8,11-9,11-12,11-13, 11-14,11-15, 11-16, 11-19, 11-27,
11-28,11-29,11-35,11-36,11-37, 11-38
Coagulation: 2-11, 8-5,8-7, 8-8, 8-15, 8-19, 8-21, 8-59
Continuous: 1-1, 1-2, 2-5, 2-8, 2-9, 2-10, 3-3, 3-4, 5-4, 8-3, 8-10, 8-13, 8-21, 8-25, 8-30,
Index-2
-------
Index
Development Document for the CWT Point Source Category
8-35, 8-43,8-45,8-47, 8-54,8-57, 9-12,10-2, 10-3, 10-5, 10-9,10-16,10-18, 10-19,
10-20,10-23,10-39,11-8,11-13,12-4,12-5,12-8,12-13
Conventional Pollutants: 6-24, 6-25, 6-27, 9-2, 9-13, 9-15,10-6,12-34,15-8
Cyanide: 1-6,2-7, 2-8, 2-10, 5-3, 6-4, 6-6, 6-9, 6-12, 6-25, 7-1, 7-4, 7-19, 7-23, 7-24, 7-26, 7-28,
7-33, 7-34, 8-2, 8-16, 8-18, 8-19, 8-59, 9-3, 9-5, 10-3, 10-4, 10-5, 10-6, 10-27, 11-4,
11-20,11-21,11-31,11-43,12-3,12-16,12-34,12-37,12-42,12-44,12-46,13-5,13-6,
14-2,14-4,14-8,14-9,14-10,14-12,14-13,15-3,15-4,15-8,15-9,15-15
Cyanide Destruction: 8-2, 8-16, 8-18, 8-19, 9-5,11-4,11-20,11-21
D
Dissolved Air Flotation: 1-6,2-10,2-11,5-3,8-2,8-13,8-14,8-51,8-59, 9-6, 9-7,9-8, 9-9, 9-10,
11-4, 11-21,11-22,11-25,11-39,11-40,11-41,11-42, 13-1, 13-3,
14-15,14-24
as "DAF": 5-3,8-13, 8-15,9-8, 9-9, 9-10, 9-16,10-5,11-22,11-23,11-24,11-25,
11-39,12-9,14-9
E
Electrolytic Recovery: 8-36, 8-38
Emulsion Breaking: 2-10, 2-11, 3-1,4-4, 5-3, 6-1, 6-25, 8-2, 8-8, 8-9, 8-10, 8-28, 9-6, 9-7, 9-8,
9-10,9-16,10-2,11-21,11-24,11-39,12-1,12-5,12-6,12-9, 12-10,12-12,
12-13, 12-16, 12-17, 12-18, 12-19, 12-20, 12-21, 12-22, 12-23, 12-24,
12-25,12-26,12-27,12-28,12-29,12-30,12-31,14-3,14-15,14-24
Emulsion Breaking/Gravity Separation: 3-1,8-10,9-6,9-7,9-10,9-16,10-2,11-24,11-39,12-5,
12-6,12-9,12-10,12-12,12-13,12-16,12-17,12-18,
12-19,12-20,12-21,12-22,12-23,12-24,12-25,12-26,
12-27,12-28,12-29,12-30,12-31,14-15,14-24
Equalization: 1-6,5-4,5-5,8-2,8-3,8-4, 8-5,8-19, 8-25, 8-26, 8-43, 8-45, 8-51, 9-11, 9-12,11-4,
11-5,11-17,11-18,11-25
Index-3
-------
Index
Development Document for the CWT'Point Source Category
Filter Cake Disposal: 8-57,11-4,11-5,11-6,11-8,11-9,11-14,11-15,11-28,11-29,11-30,11-37
Filtration - Belt Pressure Filtration: 8-51,8-54, 8-55
Lancy Filtration: 8-30,8-32
Liquid Filtration: 8-19,11-4,11-5,11-6,11-13,11-14,11-15,11-16
Membrane Filtration: 8-28
Multimedia Filtration: 1-6,2-11,8-25,8-26,8-27,9-11,11-4,11-12,11-19,11-20,
11-35,11-36,11-37,11-38,12-5,12-7,12-33,12-34, 12-35
Plate and Frame Filtration: 8-26, 8-30, 8-51, 8-52, 8-53, 8-54,11-4,11-5,11-6
11-13, 11-14, 11-15, 11-16, 11-26, 11-27, 11-28,
11-29,11-30,11-35
Reverse Osmosis: 1-6, 2-10,8-2,8-28, 8-30, 8-31, 8-58, 9-6., 11-43
Sand Filtration: 8-2,8-24, 8-25, 8-26, 8-33, 9-3, 9-4,12-9,12-33
Sludge Filtration: 11-4,11-5,11-6,11-8,11-9,11-15,11-22,11-27,11-28,11-29,
11-30,11-35,11-36,11-37,11-38
Ultrafiltration: 1-6, 2-10,8-2, 8-28, 8-29, 8-58, 9-6, 9-7,11-43
Vacuum. Filtration: 8-2, 8-52,8-54, 8-56, 8-57
Fixed Delivery Systems: 3-4
Flocculation: 2-11,8-2, 8-5, 8-7, 8-8, 8-10, 8-19, 8-21,8-24, 8-54,11-13,11-14,11-15,11-23
Flocculation/Coagulation: 8-5
Q.
Gravity Separation:
2-10,3-1,3-13,4-4,5-3,6-25, 8-8, 8-10, 8-11, 8-25, 8-26, 8-10, 8-11, 8-25,
8-26, 8-28, 9-6, 9-7, 9-8, 9-9, 9-10, 9-16, 10-1, 10-2, 11-4, 11-21, 11-24,
11-39, 11-40, 11-41, 11-42, 12-5, 12-6, 12-9, 12-10, 12-12, 12-13, 12-15,
12-16, 12-17,12-18, 12-19, 12-20, 12-21, 12-22, 12-23, 12-24, 12-25,
12-26,12-27,12-28,12-29,12-30,12-31,13-3,14-3,14-15,14-24
Secondary Gravity Separation: 9-6,9-8,11-4,11-21,11-39,11-40,11-41,
11-42
Index-4
-------
Index
Development Document for the CWT Point Source Category
H
Hexane Extractable Material:
as "HEM":
6-1,10-7,12-42,12-44,12-46,12-47,15-5,15-12
6-1, 7-15, 9-10,12-42,12-43,12-44,12-45,12-46,12-47,15-4,
15-5
Ion Exchange: 8-2, 8-35, 8-36, 8-37
Land Costs: 11-3,11-17,11-33,11-34
Land Disposal Regulations (as LDR): 1-3,1-4,1-5
Land Requirements: 8-45,9-12,11-2,11-6,11-7,11-8,11-9,11-12,11-13,11-16,11-17,11-18,
11-19,11-20,11-21,11-26,11-28,11-33,11-38,11-42
Landfills: 1-4, 2-1, 2-3, 3-1, 3-11, 4-4, 4-5, 5-3, 8-24, 8-45, 8-47, 8-52, 8-57, 8-58, 8-60, 9-14,
11-13,11-14,11-29,13-3,13-4,14-1,14-3,14-4,14-7
Limitations: 1-1, 2-6, 5-1, 5-4, 5-5, 9-1, 9-2, 9-3, 9-4, 9-5, 9-6, 9-7, 9-8, 9-9, 9-10, 9-11, 9-12,
9-13, 9-14, 9-15, 9-16, 10-1, 10-3, 10-4, 10-5, 10-6, 10-7, 10-11, 10-12, 10-13,
10-14,10-15,10-16,10-21,10-23,10-29,10-31,10-32,10-33,10-34,10-35,10-36,
10-37,10-38,10-39,14-15,14-22,14-23,14-24,14-25,14-26,14-27
Liquid Carbon Dioxide Extraction: 8-41
Long-Term Average: 10-1,10-3,10-5,10-11,10-12,10-13,10-14,10-15,10-27, 10-28, 10-31,
10-32,10-33,10-38
as "LTA ": 2-6,10-12,10-13,10-15,10-34,12-8,12-14
M
Metals Subcategory: 2-10, 2-14, 3-7, 3-9, 4-4, 5-2, 5-5, 6-4, 6-5, 6-11, 6-12, 6-13, 6-14, 6-15,
6-24, 6-25, 6-27, 7-6, 7-13, 7-21, 7-22, 7-23, 7-28, 7-33, 7-34, 8-2, 8-5,
8-16, 8-24, 9-2, 9-3, 9-5, 9-13, 9-14, 10-1, 10-2, 10-3, 10-4, 10-5, 10-6,
10-7,10-13,10-14,10-15,10-29, 10-34,10-35, 10-38, 11-5,11-7,11-10,
Index-5
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Index
Development Document for the CWT Point Source Category
11-29,11-31,11-35,11-44,12-2,12-3,12-4,12-5, 12-42,12-47, 13-2,13-3,
14-2,14-3,14-4,14-7,14-14,14-15,14-21,14-23,14-24,14-25,14-27
Cyanide Subset of Metals Subcategory. 9-5,10-4
Monitoring Frequency: 10-21,10-22,10-23,10-27,10-30,10-31,10-32,10-35,10-38,11-31
N
Neutralization: 8-2,8-5, 8-6,11-8
Non-detect: 10-1, 10-2,10-3,10-4, 10-5,10-6,10-7,10-8, 10-9,10-10, 10-11, 10-12, 10-13,
10-14, 10-16,10-19, 10-36,12-4,12-6,12-8, 12-11,12-12, 12-15,12-16,12-17,
12-18,12-19,12-20,12-21,12-22,12-23,12-24,12-25,12-26,12-27,12-28,12-29,
12-30
Non-detect Replacement: 12-15,12-16,12-17, 12-18,12-19,12-20,12-21,12-22,12-23,12-24,
12-25,12-26,12-27,12-28,12-29,12-30
a
Oil and Grease:
1-2, 2-7, 6-1, 6-4, 6-6, 6-9, 6-24, 6-25, 7-4, 7-5, 7-15, 7-19, 7-33, 8-10, 8-28,
9-2,9-9,9-10,10-3,10-4,10-6,10-7,10-9,10-27,10-30, 10-34,10-35,11-21,
11-22,12-3,12-7,12-9,12-16,12-33,12-34,12-37,12-42, 12-43,12-45,12-47,
14-2,14-3,14-4,14-15,15-3,15-4,15-5,15-15
Option -
Metals Option 2:
Metals Option 3:
Metals Option 4:
Oils Option 8:
Oils Option 8v.
Oils Option 9:
Oils Option 9v.
Organics Option 3:
Organics Option 4:
7-16,11-5,11-6,11-7,11-14,11-15,11-27,11-28, 11-30
7-4, 7-5,7-14,7-16, 7-27, 7-28, 9-4,10-3,10-35,11-5,11-6,11-8,
11-9,11-14,11-15,11-16,11-27
7.4, 7.5, 7-14, 7-27, 7-28,10-7,10-35,11-4,11-9, 11-10,11-11,
11-12, 11-13,11-14,11-15,11-16,11-19,11-27,11-28,11-29,
11-30,11-35,12-5
7-4, 7-5, 7-14, 7-27, 7-28,11-24
9-6,9-8,11-18,11-31
7-4, 7-5, 7-14, 7-16, 7-27,10-6,11-21,11-39
9-6, 9-8
7-4, 7-5, 7-14, 7-2-7, 7-28,11-31
7-4, 7-5, 7-14, 7-16, 7-27, 7-28
Oils Subcategory: 1-6, 2-10, 2-11, 2-12, 2-13, 3-14, 4-4, 5-2, 6-1,6-6, 6-7, 6-8, 6-17, 6-18, 6-19,
6-24,6-25, 6-26, 6-27, 7-6, 7-7, 7-13, 7-24, 7-27, 7-28, 7-30, 7-31, 7-32, 7-33,
7-34,8-2,8-3,8-8, 8-10, 8-41, 9-6, 9-7, 9-8,9-15, 9-16,10-1,10-2,10-6,10-7,
Index-6
-------
Index
Development Document for the CWT Point Source Category
11-18,11-22,11-23, 11-31,11-39,12-1,12-3,12-5,12-6,12-9,12-10,12-15,
12-16, 12-17, 12-18,12-19,12-20,12-21,12-22,12-23,12-24,12-25,12-26,
12-27, 12-28, 12-29, 12-30, 12-31, 12-32, 12-33, 12-41, 12-43, 12-44, 13-3,
14-2,14-3,14-4,14-14,14-15,14-17,14-19,14-21,14-23,14-25
Operation and Maintenance (O&M) Costs: 11-1, 11-2,11-3,11-7,11-8,11-12 ,11-14,11-15,
11-16, 11-17,11-18, 11-20,11-23, H-26, 11-27,
11-28, 11-29,11-37,11-41,11-44, 11-45
Organic Subcategory: 5-5,12-33,12-34,12-35,13-1,14-3
Out-of-scope: 2-13
Phenanthrene: 2-9, 6-7, 6-13, 6-22, 7-11, 7-14,12-26,12-39,12-43,15-14
Pipeline: 1-5, 2-3, 2-4, 3-4, 3-5
POTW Removals: 7-15, 7-22, 7-23, 7-24, 7-26,12-41
Priority Pollutants: 1-2,1-3, 2-1, 2-13, 7-16,15-8
Publicly Owned Treatment Works: 1-1,1-3,2-13,3-8,4-6,7-16
' as "POTW": 1-1,1-3,2-13,3-4,3-8,3-9,4-5,4-6, 5-4, 7-15, 7-16, 7-17,
7-18, 7-19, 7-20, 7-22, 7-23, 7-24, 7-26, 7-34, 8-5, 8-57,
8-58,9-2,9-9,9-15,9-16,10-6,11-31,11-44,12-1,12-41,
12-42,12-44,12-46,12-47,13-1,14-19,14-24
R
RCRA: 1-3, 1-4, 2-12, 4-1, 4-2, 4-3, 4-6, 5-1, 5-2, 5-3, 11-1,11-29, 11-32, 11-33,12-6, 14-7,
14-8,14-9,14-10,14-11,14-12,14-13,14-14,14-15
Sample-specific [Non-detect Values]: 10-7,10-9,10-10,10-11,10-14,10-16,10-18,10-20,10-25,
10-26,12-4,12-6,12-8,12-9,12-10,12-11,12-12,12-13,
12-14, 12-15, 12-16, 12-17, 12-18,12-19, 12-20, 12-21,
12-22, 12-23, 12-24, 12-25, 12-26, 12-27, 12-28, 12-29,
Index-7
-------
Index Development Document for the CWT Point Source Category
12-30,12-33,15-1,15-2,15-5,15-8
Sampling: 2-1,2-3,2-4,2-5,3-7,4-4,4-7, 6-1,6-11, 6-12, 6-13, 6-14, 6-15, 6-16, 6-17, 6-18, 6-19,
6-20, 6-21, 6-22, 6-23, 6-24, 6-25, 6-26, 6-27, 7-1, 7-21, 7-28, 7-30, 7-31, 7-32, 8-33,
8-41,8-43,8-45,8-47,9-2,9-7,9-9,9-10, 9-11, 9-13, 9-14,10-1,10-2,10-3,10-4,10-5,
10-6,10-7,10-8,10-9,10-10,10-11,10-12,10-13,10-14,10-15,10-16,10-18,10-20,
10-21,10-23,10-25,10-26,10-32,10-40,11-1,11-6,11-10,11-11,11-13,11-15,11-20,
11-23, 11-26,11-29,11-31,11-32,12-1,12-4,12-5, 12-6,12-7,12-8,12-9,12-10,
12-11,12-12, 12-13,12-14, 12-15, 12-16, 12-17, 12-18, 12-19, 12-20, 12-21, 12-22,
12-23,12-24, 12-25, 12-26,12-27, 12-28, 12-29, 12-30,12-31, 12-33, 12-34, 12-35,
14-2,14-3
Scope: see Applicability
Sequencing Batch Reactors: 8-2,8-43, 8-44, 9-11,11-4,11-25,11-26
as "SBR ": 8-43, 8-44,8-45, 9-11, 9-12,11-25,11-26
Silica-gel-treated Hexane Extractable Material: 6-1,10-7,15-5
as "SGT-HEM": 6-4,6-6,7-4,7-33,7-34,9-10,10-3,10-4,10-7,
12-16,12-37,15-4,15-5,15-14
Sludge Treatment and Disposal: 8-1,8-51,11-26
Stripping: 1-6,2-10,2-11,7-13,8-2,8-36,8-39,8-40,8-41, 9-6, 9-8, 9-10, 9-11, 9-12,11-4,11-18,
11-19,12-7,12-9,13-2,14-8,14-9
Air Stripping: 1-6, 2-10, 2-11, 7-13, 8-2,8-39, 8-40,8-41, 9-6, 9-8, 9-10, 9-11, 9-12,
11-4,11-18,11-19,12-7,13-2
I
Total Dissolved Solids: 2-10, 2-13, 7-1,12-16,12-37,12-44,15-4,15-8,15-15
as "IDS": 2-7, 2-10, 2-13, 2-14, 6-4,6-6, 6-25, 7-1, 9-15
Total Suspended Solids (as "TSS"): 1-1,1-2,2-7,6-4,6-6,6-9, 6-24, 6-25, 7-15, 7-33, 9-2, 9-4,
9-11,9-13,10-6,10-27,10-29,10-30,10-35,10-36,10-37,
10-38,11-14,11-19,11-31,11-32,11-44,12-3,12-7,12-9,
12-33,12-34,12-37,12-42,12-43, 12-45,15-8
Treatment-in-place: 5-5, 8-2, 11-6,11-10,11-11,11-12,11-13,11-16,11-22,11-23,11-24,
11-26,11-35,11-39,12-4,12-6,12-7,12-9,12-33,14-26
Index-8
-------
Index
Development Document for the CWT Point Source Category
Trickling Filters: 8-43, 8-45, 8-47
V
Variability Factor: 10-1,10-2, 10-5, 10-6,10-7, 10-8,10-13,10-15,10-20, 10-21, 10-22, 10-23,
10-27, 10-28, 10-29, 10-30, 10-31, 10-32, 10-33, 10-34, 10-35, 10-36,
10-38,10-39,12-36
Zero Discharge: 3-13, 3-14,8-1, 8-57
Index-9
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