Final
OCCURRENCE ASSESSMENT FOR
DISINFECTANTS AND DISINFECTION BYPRODUCTS
IN PUBLIC DRINKING WATER SUPPLIES
November 13, 1998
Prepared for:
U.S. Environmental Protection Agency
Office of Ground Water and Drinking Water
401 M Street, S.W.
Washington, D.C. 20460
Prepared by:
Science Applications International Corporation
mOGoodridgeDrive
McLean, Virginia 22102-3701
EPA Contract No. 68-C6-0059, Work Assignment 1-18
SAIC Project No. 01-0833-08-3554-041
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Occurrence Assessment for D/DBP in Public Drinking Water Supplies
Errata Sheet
I. Chapter 2, page 2-16
- Delete "Inc." from "Demers, Renner, Inc., 1992"
2. Chapter 4, page 4-54
- Replace (Gages, 1997) with (Gates, 1998)
- Sentence 3: Delete "Like the chlorite ion".
3. Chapter 4, page 4-56, para 2
- Replace "modified EPA method 300.0b", with "EPA method 300.0" here and in a few
other places in the text.
4. Chapter 7, page 7-7, section 7.5.2 chlorite.
- Replace "the 1994 proposed MCLG for chlorite was 0.08 mg/L", with "the 1998 final
MCLG for chlorite is 0.8 mg/L."
5. Appendix B, page B-4, para 1, SM 45000.C1O2E
- Replace "pH adjusted to 12" to "pH adjusted to 7".
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Occurrence Assessment for D/DBP in Public Drinking Water Supplies
ACKNOWLEDGMENTS
This document was prepared for the U.S. Environmental Protection Agency, Office of
Ground Water and Drinking Water (OGWDW) by Science Application International Corporation
(SAIC) (Contract No. 68-C6-0059). Overall planning and management for the preparation of
this document was provided by Maggie Javdan, and Mary Ellen Ley of OGWDW and Tom
Carpenter of SAIC.
EPA acknowledges the valuable contributions of those who wrote and reviewed this
document. They include; Dennis Borum, Michael Cox, Maggie Javdan, and Mary Ellen Ley of.
U.S. EPA; Tom Carpenter, Eric Michaels, Jennifer Cohen, and Kevin Skunda of SAIC. Special
thanks to Don Gates, PhD, and Stuart Krasner (Metropolitan Water District of Southern
California) for their valuable technical assistance. EPA also thanks the following external peer
reviewers for their excellent review and valuable comments on the draft manuscript: David A.
Reckhow, PhD, of University of Massachusetts, Amherst, Philip G. Singer, PhD, of University of
North Carolina, Chapel Hill, and James M. Symons, PhD, of University of Houston.
Final iii ' November 13, 1998
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Occurrence .\ssessmenifor D/DBP in Public Dnnkinq Water S
TABLE OF CONTENTS
- Page
ACKNOWLEDGEMENTS • iii
ACRONYM .AND .ABBREVIATION LIST . ix
EXECUTIVE SUMMARY '. ES-1
1. INTRODUCTION '. 1-1
1.1 OVERVIEW OF THE REGULATORY BACKGROUND l-l
1.2 PURPOSE OF THE DOCUMENT 1-4
1.3 DOCUMENT ORGANIZATION 1-7
2. USE OF DISINFECTANTS IN THE UNITED STATES
2. [ CHLORINE 2-3
2.1.1 Description of Chemistry 2-6
2.1.2 Use and Distribution 2-6
2.1.3 Advantages/Disadvantages 2-7
2.1.4 Dose Ranges 2-8
2.1.5 Byproducts 2-8
2.2 CHLORAMINES 2-9
2.2.1 Description of Chemistry 2-10
2.2.2 Use and Distribution 2-10
2.2.3 Advantages/Disadvantages 2-10
2.2.4 Dose Ranges 2-11
2.2.5 Byproducts 2-12
2'.3 CHLORINE DIOXIDE 2-12
2.3.1 Description of Chemistry 2-13
2.3.2 Use and Distribution 2-15
2.3.3 Advantages/Disadvantages 2-15
2.3.4 Dose Ranges • 2-16
2.3.5 Byproducts 2-17
2.4 OZONATION 2-18
2.4.1 Description of Chemistry 2-18
2.4.2 Use and Distribution 2-19
2.4.3 Advantages/Disadvantages 2-20
. 2.4.4 Dose Ranges 2-20
2.4.5 Byproducts 2-21
3. OCCURRENCE OF DBF PRECURSORS AND DISINFECTANTS 3-1
3.1 SUMMARY OF PRECURSOR OCCURRENCE DATA: TOTAL ORGANIC CARBON
AND BROMIDE ION 3-1
3.1.1 Total Organic Carbon Occurrence :. 3-1
3.1.2 Bromide Ion Occurrence 3-8
3.2 DISINFECTANTS ...' 3-11
3.2.1 Chlorine . 3-11
3.2.2 Chloramine 3-13
3.2.3 Chlorine Dioxide 3-14
Final iv November 13,1998
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'h\'urrence Assessment fi>r DfDBP in Public Dnnkinq Water Supplies
4.
4
4.
4
4.
4.
4.
4.
4.
4. OCCURRENCE OF DISINFECTION BYPRODUCTS 4-1
4.1 SOURCES OF 1994 DISINFECTION BYPRODUCT OCCURRENCE DATA 4-1
. 1 National Organics Reconnaissance Survey 4-2
.2 National Organics Monitoring Survey 4-2
.3 Rural Water Survey 4-2
.4 Community Water Supply Survey 4-3
.5 AWWARF National Trihalomethanes Survey 4-3
.6 EPAMMWA/CDHS Study (35 Utility Study) ' 4-3
.7 EPA Disinfection Byproduct Field Studies 4-3
.8 Water Industry Data Base (1991) 4-4
.9 AWWA 1991 Disinfection Survey 4-4
4.2 SOURCES OF POST-1994 DISINFECTION BYPRODUCT OCCURRENCE DATA .... 4-4
4.2.1 WaterStats 4-4
4.2.2 American Water Works Service Company Monitoring Data 4-5
4.2.3 State Compliance and Other Monitoring 4-5
4.2.4 Literature Search 4-5
4.3 DBP OCCURRENCE DATA 4-6
4.3.1 Chloroform . , 4-6
,4.3.2 Bromodichloromethane 4-23
4.3.3 Dibromochloromethane , 4-26
4.3.4 Bromoform 4-29
4.3.5 Total Trihalomethanes 4-31
4.3.6 Monochloroacetic Acid 4-38
4.3.7 Dichloroacetic Acid ' ; 4-39
4.3.8 Trichloroacetic Acid 4-40
4.3.9 Monobromoacetic Acid 4-42
4.3.10 Dibromoacetic Acid 4-43
4.3.11 Haloacetic Acids 5 . . . : 4-43
4.3.12 Chloral Hydrate 4-47
4.3.13 Bromate Ion , 4-49
4.3.14 Chlorite Ion 4-51
4.3.15 Chlorate Ion 4-54
5. NATIONAL OCCURRENCE ..;..... 5-1
5.1 DATA SOURCES 5-1
5.1.1 AWWA WaterStats 5-2
5.1.2 AWWSCo Monitoring Data 5-3
5.1.3 State Compliance Monitoring Data 5-3
5.2 TTHM DATA 5-3
5.3 HAAS DATA 5-6
5.4 CHLORITE AND BROMATE IONS 5-7
5.4.1 Bromate Ion 5-7
5.4.2 Chlorite Ion -. 5-7
6. SUMMARY OF EXPOSURE DATA FROM SOURCES OTHER THAN DRINKING WATER . 6-1
6.1 DISINFECTANTS 6-1
6.1.1 Chlorine, Hypochlorite Ion, and Hypochlorous Acid 6-1
6.1.2 Chloramines 6-2
6.1.3 Chlorine Dioxide ., 6-3
Final v November 13,1998
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\stewnent for D'DBP in Public Dnnkin'J
6 : DISINFECTION BYPRODUCTS ..'... 6-3
6.2.1 Chloroform 6-3
6.2.2 Bromodichloromethane 6-16
6.2.3 Dibromochloromethane 6-20
6.2.4 Bromoform 6-23
6 2.5 Total Tnhalomethanes 6-25
6.2.6 Monochloroacetic Acid - 6-26
6.2.7 Dichloroacetic Acid 6-26
6.2.8 tnchloroacetic Acid 6-26
6.2.9 Monobromoacetic Acid 6-27
6.2.10 Dibromoacetic Acid 6-27
6.2.11 Haloacetic Acids 5 6-28
6.2.12 Chloral Hydrate 6-28
6.2.13 Bromate . . / 6-29
6.2.14 Chlorate and Chlorite .- 6-29
7. RELATIVE SOURCE CONTRIBUTION EVALUATION 7-1
7.1 OVERVIEW OF THE RELATIVE SOURCE CONTRIBUTION APPROACH 7-1
7.2 CHOICE OF THE POPULATION OF CONCERN 7-3
. 7.3 ESTIMATION OF EXPOSURE FROM DRINKING WATER 7-3
7.4 ESTIMATION OF EXPOSURE FROM SOURCES OTHER THAN DRINKING WATER 7-4
7.5 RELATIVE SOURCE CONTRIBUTION VALUES CHOSEN FOR INDIVIDUAL
DISINFECTANTS AND DBPS 7-5
7.5.1 Disinfectants .../..... 7-5
7.5.2 Disinfection Byproducts . . . 7-6
APPENDDC A SUMMARY OF SURVEYS AND STUDIES A-1
APPENDIX B ANALYTICAL METHODS B-1
REFERENCES R-l
Final vi November 13,1998
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Occurrence Assessment for D/DBP in Public Drinking Water Supplies
LIST OF EXHIBITS
Exhibit l-I. Disinfectants and Compounds Regulated by the Stage I D/DBP Rule [-4
Exhibit 2-1. Number of Community Water Systems by Primary Water Source and Service
Population 2-2
Exhibit 2-2. Percent of Plants Applying Specific Disinfection Treatment for Primarily Surface
Water Systems . 2-4
Exhibit 2-3. Percent of Plants Applying Specific Disinfection for Primarily Groundwater Systems . 2-5
Exhibit 2-4. Chlorine Dose Ranges 2-8
Exhibit 2-5. Disinfection Byproducts of Chlorine 2-9
Exhibit 2-6. Suggested Doses of Ammonia 2-11
Exhibit 2-7. Observed Chlorine Dioxide Doses ' 2-17
Exhibit 2-8. Suggested Doses for Ozone 2-21
Exhibit 3-1. Disinfection Byproduct Precursor and Disinfectant Occurrence 3-2
Exhibit 3-3. Groundwater TOC Levels from the GWSS Reported in the 1994 Proposed Rule 3-5
Exhibit 3-2. TOC Occurrence Data from the WTDB in the 1994 Proposed Rule 3-5
Exhibit 3-5. Comparison of AWWA Survey TOC Data with WIDB Data .., 3-6
Exhibit 3-7. Pre-ICR Data from the State Of Utah (1994-1996) 3-8
Exhibit 3-8. Bromide Ion Occurrence by Source: 101 Utility Nationwide Study 3-9
Exhibit 3-9. Bromide Ion and TOC Occurrence in Source Water for Ozone Plants 3-10
Exhibit 3-10. Chlorine Dioxide Concentrations in Distribution Systems .. / 3-15
Exhibit 3-11. Chlorine Dioxide Concentrations at Charleston Plant and Customer Houses 3-16
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary " 4-7
Exhibit 4-2. Chloroform Concentration in Utah Plant Effluents (June 1990) 4-22
Exhibit 4-3. Bromodichloromethane Concentration in Thirty-Five Utah Plant Effluents 4-25
Exhibit 4-4. Dibromochloromethane Concentration in Utah Plant Effluents (June 1990) 4-28
Exhibit 4-5. Summary of Total Trihalomethane Concentrations from Public Water Systems in
Massachusetts (1994-1996) 4-3.3
Exhibit 4-6. Summary of Total Trihalomethane Concentrations from Public Water Systems in
Missouri (1996 - June 1997) 4-33
Exhibit 4-7. Summary of Total Trihalomethane Concentrations from New Jersey Public Water
Systems (1994-15(97) 4-34
Exhibit 4-8. Total Trihalomethane Concentrations from Public Water Systems in Oregon
Serving More Than 10,000 Persons (1994-1996) 4-34
Exhibit 4-9. Pennsylvania Compliance Monitoring Data for Total Trihalomethanes 4-35
Exhibit 4-10. Texas Compliance Monitoring Data for Total Trihalomethanes 4-36
Exhibit 4-11. Trihalomethane Concentration in Utah Water Treatment Plants Using Surface
Water (June 1990) 4-37
Exhibit 4-12. Seasonal Total Trihalomethane Variation in Utah Plant Effluents 4-37
Exhibit 4-13. Dichloroacetic Acid Concentrations from Six North Carolina Surface Water
Systems 4-40
Exhibit 4-14. Trichloroacetic Acid Concentrations from Six North Carolina Surface Water
Systems , - •. - 4-42
Exhibit 4-15. Haloacetic Acids 5 Concentrations in Missouri Water Treatment Plants (1/97-6/97) . 4-44
Exhibit 4-16. Haloacetic Acids Concentrations from Eight North Carolina Surface Water Plants .. 4-45
Exhibit 4-17. Haloacetic Acids 5 Concentration from Thirty-Five Utah Surface Water Systems . .. 4-46
Exhibit 4-18. Seasonal Analysis of Haloacetic Acids 5 Concentrations from Thirty-Five Utah
Surface Water Systems' Plant Effluents . 4-46
Final
vn
November 13,1998
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"cvurrfru'f
or D'DBP in Public
Exhibit--19 Chionte Ion Concentrations at Charleston Plant and Customer Houses 4-51
Exhibit-J-20 Occurrence of Chlorite Ion in Utilities Using Chlorine Dioxide 4-5!
Exhibit 4-21 , Chlorate Ion and Chlorite Ion Concentrations at Sixty-Five-Utilities Using
Chlorine Dioxide 4-53
Exhibit 4-22. Chlorate Ion Concentrations at Charleston Plant and Customer Houses 4-53
Exhibit 4-23. Occurrence of Chlorate Ion in Waters from Utilities Using Chlorine Dioxide 4-55
Exhibit 4-24 Occurrence of Chlorate Ion in Fifteen Utilities Using Hypochlorite Solution for
Disinfection , 4-55
Exhibit 5-1. Stage I D/DBP Rule MCLs ' '. 5-1
Exhibit 5-2. Summary Statistics on TTHM Based on WaterStats and AWWSCo 5-4
Exhibit 5-3. TTHM Compliance Monitoring Data (1994-1996): Surface and Groundwater
Systems Serving Greater Than 10,000'People ' 5-5
Exhibit 5-4. Comparison of State TTHM Data for Systems Servings Fewer Than 10.000 People . . 5-5
Exhibit 5-5. Comparison of HAAS Data for Systems Serving Greater Than 10.000 People 5-6
Exhibit 5-6. Available Data on Bromate Ion Occurrence in Drinking Water Supplies '. .. 5-6
Exhibit 5-7. Available Chlorite Ion Occurrence in Drinking Water Supplies 5-7
Exhibit 6-1. Chloroform Levels in Foods : 6-5
Exhibit 6-2. Mean Chloroform Concentrations in Samples Designated for Further Analysis 6-5
Exhibit 6-3. Chloroform Levels in Food 6-7
Exhibit 6-4. Chloroform Levels in Food 6-7
Exhibit 6-5. Chloroform Concentrations in Food and Beverages 6-7
Exhibit 6-6. Summary Statistics of Chloroform in Ambient Air of New Jersey and North Carolina
Subjects 6-9
Exhibit 6-7. Summary Statistics of Chloroform in Breath of New Jersey and North Carolina
Subjects 6-9
Exhibit 6-8. Chloroform in Personal Air Samples from the EPA TEAM Study 6-10
Exhibit 6-9. Chloroform in Outdoor Air Samples from the EPA TEAM Study 6-10
Exhibit 6-10. Exposure Levels of Chloroform Monitored in Air 6-12
Exhibit 6-11. Chloroform Exposure from Outdoor Air : 6-12
Exhibit 6-12. Chloroform Concentration in Indoor Air 6-13
Exhibit 6-13. Bromodichloromethane Levels in Food '. 6-17
Exhibit 6-14. Bromodichloromethane Concentrations in Food and Beverages 6-18
Exhibit 6-15. Summary Statistics of Bromodichloromethane in Ambient Air of New Jersey and
North Carolina Subjects 6-19
Exhibit 6-16. Summary Statistics of Bromodichloromethane in Breath of New Jersey and North
Carolina Subjects 6-19
Exhibit 6-17. Bromodichloromethane Occurrence and Exposure from Outdoor Air 6-20
Exhibit 6-18. Bromodichloromethane Occurrence and Exposure from Indoor Air 6-20
Exhibit 6-19. Dibromochloromethane Levels Found in Food 6-21
Exhibit 6-20. Dibromochloromethane Concentrations in Food and Beverages 6-21
Exhibit 6-21. Dibromochloromethane Occurrence from Outdoor Air 6-23
Exhibit 6-22. Dibromochloromethane Occurrence and Exposure from Indoor Air 6-23
Exhibit 6-23. Bromoform Levels Found in Food 6-23
Exhibit 6-24. Bromoform Occurrence and Exposure in Outdoor Air 6-25
Exhibit 6-25. Bromoform Occurrence and Exposure in Indoor Air . 6-25
Exhibit 6-26. Total Trihalomethanes Levels in Food 6-25
Exhibit 7-1 Relative Source Contribution for Disinfectants and Disinfection Byproducts 7-8
Final
Vill
November 13,1998
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Occurrence Assessment for D/DBP in Public Drinking Water
35 Utility Study
,AOC
ASTM
AWWA
AWWARF
AWWSCo
BDL
cr
Cl, '
CIO,
CKV
C1O,
CDSs
CWSS
D/DBP
DBF
DBPRAM
DPD
DSS
EPA
ESWTR
FACA
FACTS
FDA
FR
GAC
GC
GC/ECD
GC/MS
GWSS
HAA
HAA5
HC1
ICR
KG
L
LOAEL
M-DBP
MCLG
MCL
MDL
MG
MRDL
MRDLG
MRL
MTBE
N
Na '
ACRONYM AND ABBREVIATION LIST
EPA/AMWA/CDHS Study
Assimilable Organic Carbon
American Society for Testing and Materials
American Water Works Association
American Water; Works Association Research Foundation
American Water Works System Company
Below Detection Limit
Chloride
Trichloride
Chlorine Dioxide
Chlorite
Chlorate
Concentrations in Distribution Systems
Community Water Supply Survey
Disinfectant/Disinfection Byproducts
Disinfection Byproducts
Disinfection Byproduct Regulatory Assessment Model
N,N-Diethyl-P-Phenylenediamine
Distribution System Samples
U.S. Environmental Protection Agency
Enhanced Surface Water Treatment Rule
Federal Advisory Committee Act
Free (Available) Chlorine Test, Syringaldazine
U.S. Food and Drug Administration
Federal Register
Granular Activated Carbon
Gas Chromatograph
Gas Chromatography/Electron Capture Detection
Gas Chromatography/Mass Spectrometry
Groundwater Supply Service
Haloacetic Acid
Haloacetic Acid-Five
Hydrochloric Acid (
Information Collection Rule
Kilogram
Liter
Lowest Observed Adverse Effect Level
Microbial Disinfection Byproducts
Maximum Contaminant Level Goals
Maximum Contaminant Level
Method Detection Limit
Milligram
Maximum Residual Disinfectant Level
Maximum Residual Disinfectant Level Goal
Minimum Reporting Level
Methyl-Tert-Butyl Ether
Nitrogen
Sodium
Final
IX
November 13,1998
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tOccurrence Assessment fur O/DBP in Public Dnnkinq Water
N-\S
NCI
ND
NH,C1
NHC1,
NOAEL
N'OM
NOMS
NORS
O:
0,,^,
OGWDW
PAC
PPB
PPM
PWS
RfD
RSC
RWS
SDS
SDWA
SM
SMWA
SWTR
SPW
SUVA
TEAM
THM
TOC
TOX
TSD
TTHM
UNC
uv
voc
WIDE
National Academy of Sciences
National Cancer Institute
Not Detected
Monochloramine
Dichloramine
No Observed Adverse Effect Level
Natural Organic Matter
National Organic Monitoring Survey
National Organics Reconnaissance Survey
Oxygen
Aqueous Ozone
Office of Ground Water and Drinking Water
- Powdered Activated Carbon
parts per billion
parts per million
Public Water Systems
Reference Dose
Relative Source Contribution
Rural Water Survey
Simulated Distribution System
1974 Safe Drinking Water Act
Standard Method
Association of Metropolitan Water Agencies
Surface Water Treatment Rule
State Project Water
Specific Ultraviolet Absorbance
Total Exposure Assessment Methodology
Trihalomethanes
Total Organic Carbon
Total Organic Halides
Technical Support Division
Total Trihalomethane
University of North Carolina
Ultraviolet
Volatile Organic Compound
Water Industry Data Base
Microgram
Final
November 13,1998
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Occurrence \ssessment for D/DBP in Public Drinking Water
EXECUTIVE SUMMARY
The occurrence of disinfectants and DBFs in water intended for drinking has been documented in
a range of different disinfection treatments and for different source water, finished water, and ground water.
This document presents information from surveillance reports regarding occurrence of disinfectants and
DBFs. To develop this document literature searches were conducted using several research databases. EPA
notes that the occurrence data compiled in this document and the current national estimate of disinfectants
and DBF occurrence reflects existing data. Substantial additional information that will be used to strengthen
an estimate of national occurrence of disinfectants and DBF is currently being collected under the
Information Collection Rule (ICR). However, EPA believes that the information in this document is
sufficient to conclude that disinfectants and DBFs can and do occur in public water supplies at levels which
may pose a risk to human health.
The 1996 Amendments to the Safe Drinking Water Act require EPA to promulgate the Interim
Enhanced Surface Water Treatment Rule (EESWTR) and the Stage 1 Disinfectants and Disinfection
Byproducts Rule (DBPR) by November 1998 (Section 1412 (b)(2)(C)). EPA proposed these two regulations,
EESWTR (59 FR 38832) and Stage 1 DBPR (59 FR 38668), on July 29. 1994. The ESWTR was developed
to provide additional microbial protection beyond that which is prescribed in the Surface Water Treatment
Rule (54 FR 27486; June 29, 1989) and to control for Cryptosporidium. The Stage 1 DBPR was developed
to limit the levels of several disinfectants and disinfection byproducts resulting from their use. EPA believes
that the two rules need to be promulgated simultaneously to assure concurrent compliance and a balanced
risk-based implementation. The Stage I DBPR applies to community water systems and non-transient non-
community water systems that treat their water with a chemical disinfectant for either primary or residual.
treatment the EESWTR pertains to public water systems serving 10,000 people or greater.
The Agency has requested public comment regarding these rules on three occasions and has engaged
in several stakeholder meetings to discuss and share information pertaining to rule development. In February
1997. EPA established the Microbial and D/DBP Advisory Committee under the Federal Advisory
Committee Act (FACA) to collect, share and analyze new information and data, as well as to build a
consensus relating to the regulatory implications of this new information. As a result of these negotiations.
the Agency published Notice of Data Availability (NODA) for the ESWTR (59 FR 59486) and the Stage
I DBPR (62 FR 59388) in November 1997. An additional NODA for the Stage 1 DBPR was published in
Final ES-l November 13,1998
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Occurrence .\ssessmentfor D/DBP in Public Drinking Water Supplies
March 1998 which included new information and analyses that become available after the 1997 N'OD.A
<63 FR 15674).
The following document, "Occurrence Assessment for Disinfectants/Disinfection Byproducts in
Public Drinking Water", was developed to support the Stage I DBPR. The intent of this document is to
provide available information on the occurrence of disinfectants, disinfection byproducts, and source water
precursors to DBFs in surface and ground water as well as finished water supplies. The document provides
information on: drinking water treatment disinfection practices; occurrence of disinfect residuals and
disinfection byproducts in distribution systems, exposure to disinfectants and disinfection, byproducts.
analytical methodologies utilized to measure the contaminants, and populations potentially exposed to the
contaminants. The document emphasizes the occurrence of the regulated disinfectants and DBFs because a
large number of people are exposed to DBFs and because of the different potential risks(e.g. cancer and
adverse reproductive and developmental effects) that may result from exposure to DBFs.
The occurrence of disinfectants and DBFs in water intended for drinking has been documented in
a range of different disinfection treatments and for different source water, finished water, and ground water.
This document presents information from surveillance reports regarding occurrence of disinfectants and
DBFs. To develop this document literature searches were conducted using several research databases. EPA
notes that the occurrence data compiled in this document and the current national estimate of disinfectants
and DBF occurrence reflects existing data. Substantial additional information that will be used to strengthen
an estimate of national occurrence of disinfectants and DBF is currently being collected under the
Information Collection Rule (ICR). However, EPA believes that the information in this document is
sufficient to conclude that disinfectants and DBFs can and do occur in public water supplies at levels which
may pose a risk to human health.
Final ES-2 November 13, 1998
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i >i.\:trrtn<:e Av>vssm
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<>i\-urrence AiVfvvmeW f'ur D'DBP in Public DnitKiny
in November 1979. EPA promulgated an interim MCL for total mhalomeihanes iTTHM;>> of 0 10
mg/L as an annual averaae (44 FR 68624). This standard was based on the need to balance the requir'.-ment
for continued disinfection of water to lessen exposure to pathogenic microorganisms w hile simultaneously
lowering exposure to disinfection byproducts, which might be carcinogenic to humans. The interim TTHM
standard only applies to PWSs serving at least 10,000 people that add a disinfectant to drinking water during
any part of the treatment process. At their discretion, states may extend coverage to smaller PWSs.
In 1992. EPA initiated a negotiated rulemaking to develop a DBP rule. The Negotiating Committee
established for the. proposed D/DBP rule included representatives of state and local health and regulatory
agencies, public water systems, elected officials, consumer groups, and environmental groups. Early in the
process, the negotiators agreed that large amounts of information necessary to understand how to optimize
the use of disinfectants while minimizing microbial and D/DBP risk on a plant-specific basis were not
available. Nevertheless, the Negotiating Committee agreed to propose a D/DBP rule to extend coverage to
all community and nontransient noncommunity water systems that use disinfectants. This proposed D/DBP
rule would reduce the current MCL for TTHMs, regulate additional disinfection byproducts, set limits for
the use of disinfectants, and reduce the presence of organic compounds in source water that could react with
disinfectants to form byproducts.
The Negotiating Committee agreed to the development of three sets of rules: a two-staged D/DBP
rule, an ESWTR. and an ICR. EPA is currently developing the D/DBP rule and ESWTR in two stages. The
Stage 1 D/DBP and interim ESWTR were proposed in July 1994. EPA established a deadline of November
1998. as enacted in the 1996 amendments to the Safe Drinking Water Act. for the final promulgation of both
the Stage I D/DBP rule and interim ESWTR. The Stage I D/DBP rules apply to all systems", while the
interim ESWTR would only apply to systems serving 10,000 people or more. The Negotiating Committee
agreed that a long-term ESWTR would be needed for systems serving fewer than 10.000 people when the
results of more research and water quality monitoring became available. The long-term ESWTR could also
include additional refinements for larger systems.
The Negotiating Committee decided that additional field data were critical for developing a
reasonable set of rules and for understanding more fully the limitations of the current Surface Water
Treatment Rule (SWTR). EPA, therefore, promulgated the ICR on May 14, 1996 (61 FR 24354). The
purpose of the ICR is to collect occurrence and treatment information to evaluate the need for (I) possible
changes to the current SWTR and existing microbial treatment practices and (2) future regulation of
disinfectants and DBPs. The ICR will provide information necessary to determine the national occurrence
Final 1-2 November 13,1998
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Occurrence Aj^e'Vimt'if ;/>r O'DBP in Pubiu
of' DBP-^ in drinking'water Engineering data on how. PWSs currently control chemical and microbial
contaminants will also be collected under the ICR. This information will be used to assess the potential
health problems created by the presence of DBFs and pathogens in drinking water and to assess the extent
and severity of risk to assist the regulatory and public health decisions. The ICR data will be used for
developing the long-term ESWTR and the Stage 2 DBF rule.
EPA established the Microbial and D/DBP Advisory Committee under the Federal Advisory
Committee Act (FACA) on February 12. 1997, to collect, share, and analyze new information and data since
the 1994 proposed rule, as well as to build consensus on the regulatory implications of this new information
for the final Stage 1 D/DBP rule. The FACA Committee consisted of 20 members representing EPA, state
and local public health and regulatory agencies, local elected officials, drinking water suppliers, chemical
and equipment manufacturers, and public interest groups.
The compounds of concern under the Stage I D/DBP rule are listed in Exhibit 1-1. In the proposed
Stage I D/DBP rule, three Maximum Residual Disinfectant Levels (MRDLs) and four MCLs were proposed.
The proposed MDRL for chlorine and chloramines is 4.0 mg/L as CU and 0.8 mg/L as CIO, for chlorine
dioxide. Four MCLs were proposed for DBFs: TTHMs (0.08 mg/L), haloacetic acids-five (HAAS) (0.06
mg/L), chlorite (1.0 mg/L), and bromate (0.10 mg/L). TTHMs are the sum of the concentrations of
chloroform, bromodichloromethane, dibromochloromethane, and bromoform. HAA5 are the sum of the
concentrations of mono-, di-, and trichloroacetic acids and mono- and dibromoacetic acids. Although there
are nine HAAs. only five will be regulated under this rule based on occurrence data availability at this time.
EPA did not set an MCL for chloral hydrate because it is believed that the TTHM and HAAS MCLs and the
treatment technique (i.e., enhanced coagulation) for disinfection byproduct precursor removal will control
for chloral hydrate.
EPA will use information on drinking water plant design and operations obtained under the ICR.
as well as data and information from other sources, to develop, analyze, and assess options for proceeding
with the Stage n D/DBP rule and long-term ESWTR.
The future rulemaking activities will be:
• 2000—Promulgation of long-term 1 ESWTR in November .
• 2002—Promulgation of final long-term 2 ESWTR in November
• 2002—Promulgation of Final Stage 2 D/DBP rule in May.
Final 1-3 November 13, 1998
-------
Occurrence 4«%
-------
for D/DBP in Public Dnnking \\attr 'iuppiiti
• Occurrence e.-nrnates will be used to develop the exposure assessments and. subsequent!), the
contribution of drinking water, relative to other sources of exposure, to total intake for Betting
the maximum contaminant level goals (MCLG) for contaminants.
• Exposure information is used to estimate the baseline health impact assessment of current levels
and to evaluate the health benefits of the regulatory alternatives.
For the 1994 proposed rule. EPA developed the Disinfection Byproduct Regulatory Assessment
Model (DBPRAM) to provide simulated occurrence and DBF formation data for the D/DBP rule regulatory
impact analysis (RIA) (59 FR 38668). The SWTR. proposed enhanced SWTR. Total Coliform Rule, and
the Lead-Copper Rule were chosen for compliance standards for the DBPRAM simulation. These
assumptions allowed EPA to predict what levels would occur with these new and proposed rules. To account
for the disinfection requirements typical of surface water plants, the DBPRAM used total organic carbon
(TOO. bromide ion. and other water quality data from national surface water surveys to model DBP
formation in surface water systems that used filtration but did not soften. Actual water quality data were
used to simulate the DBP formation in occurrence values based on DBP empirical formation and disinfectant
decay equations.
The model predicted TTHM and HAA5 levels but not individual DBPs. because reliable equations
to predict the individual DBPs in a wide range of waters (e.g., high- and low-bromide ion concentration
waters) were not available. Empirical equations used in the model were based on numerous bench-, pilot-
and full-scale studies. Because analytical standards for bromochloroacetic acid. BDCAA, DBCAA, TBAA
were not available during development and validation of the predictive equations used in the model, they
were not included in the D/DBP Stage 1 HAA class of compounds. Any error that could result from this
omission is probably low, especially in low-bromide ion waters where the potential for forming
bromochloroacetic acids is low, but could be significant in high-bromide ion waters (Pourmoghaddas et al..
1993 and Singer 1996).
In addition to TTHM and HAA5 concentrations, the DBPRAM also predicted the following water
quality after individual treatment processes:
• TOC removal during alum coagulation, granular activated carbon (GAC) adsorption, and
nanofiltration
• Changes in alkalinity and pH resulting from chemical addition
• Disinfectant decay and residual chlorine and chlorarnine in plants and distribution systems.
Final 1-5 . November 13, 1998
-------
'ii\-urrrnce \isr D/DBP in Public Dnnktny
The D/DBP Technologies Work Group rescued the DBPRAM output during the negotiated
rulemaking process. The model was validated through comparison to real world data and engineering
judgment. The vai "".ation showed tendencies for both underpredictions and overpredictions. For example.
TTHM formation from source waters either low or high in bromide ion showed a 20 to 35 percent less than
what the models predicted. Conversely, the central tendency of the model was 5 to 10 percent over the
prediction of the TOC removal by alum coagulation. The D/DBP Technologies Work Group corrected the
outputs of the model according to the validation results.
Because the DBPRAM only provided occurrence data for surface water systems that use filtration
and do not soften, additional data were used to supplement the model. To develop values for the RIA for
systems not predicted in the model, data were used from case studies on numerous systems that either do not
filter.or filter and soften their water. These data were reviewed for compliance and predicted water qualities.
Water quality values for groundwater were derived from the Water Industry Database (WIDB) and the
Groundwater Supply Survey (GWSS) data. The 1994 proposed rule used the revised DBPRAM to identify
the potential percent lessening of TTHM and HAAS concentrations from waters treated by enhanced
coagulation for large systems that filter but do not soften.
At the February 1997 FACA meeting, new data were presented for comparison to the DBPRAM
projections used in the 1994 proposed rule. The data presented were occurrence data from treatment
facilities that pre-disinfected at various locations in the treatment process. The results indicated that DBP
formation could be reduced by continuing to pre-disinfect source water, but not to the same extent that could
be achieved by post-disinfection after DBP precursor removal. The complex equations needed to model the
application of pre-disinfection practices were not available to revise the DBPRAM. The presentation noted
that the DBPRAM did not provide data for all systems (i.e., systems that filter and do not soften), the model
could only provide limited empirical predictions, required revision against real world data to accurately
characterize DBP occurrence, and, most importantly, could not account for modified pre-disinfection
practices. Therefore, on advisement of the D/DBP Technologies Work Group, the D/DBP Advisory
Committee decided to rely on actual occurrence data to support the final rule rather than modifying the
DBPRAM.
To support the above regulatory processes and review the actual occurrence data an effort to collect.
review, and summarize occurrence and exposure data was undertaken by EPA. This document presents the
results of that effort. This document includes data from the document entitled Occurrence Assessment for
Disinfectants and Disinfection By-Products (Phase 6a) in Public Drinking Water (EPA, 1992a) and the
Final 1-6 November 13, 1998
-------
Occurrence \^n^sment for O/DBP in Public Dnnkiny \\aier )uppitf>
preamble to the 199-1 proposed D/DBP rule (59- FR 58668). Exposure estimates t'rom sources other than
drinking vvater will be used to establish the relative source contribution (RSC) for DBPs from drinking water.
The RSC will then be used to establish MCLGs or MRDL goals (MRDLGs).
1.3 DOCUMENT ORGANIZATION
The remainder of this document is organized into six sections and two Appendixes, highlighted in
the following list:
• Section 2 - Use of Disinfectants in the United States: This section provides information on
the four .most commonly used disinfectants: free chlorine, chioramine (combined chlorine).
chlorine dioxide, and ozone. The section briefly describes each disinfectant, including method
of application, use and distribution, advantages and disadvantages, dosage requirements, and
potential byproducts of disinfection. Special considerations for using the disinfectants in
groundwater and surface water systems and by system size are noted. Disinfection by ultraviolet
radiation is not discussed in this document.
• Section 3 - Occurrence of DBF Precursors and Disinfectants: This section summarizes
occurrence data available for the 1994 proposed rule and new data for disinfectants and the DBF
precursors: TOC and bromide ion. Two documents present the data available for the proposed
rule: Occurrence Assessment for Disinfectants and Disinfection By-Products (Phase 6a) in
Public Drinking Water (EPA. 1992) and the preamble to the 1994 proposed rule (59 FR 38668).
The new data were obtained from national surveys, preliminary ICR data, and peer-reviewed
journals.
• Section 4-Occurrence of Disinfection Byproducts: This section summarizes occurrence data
available for the 1994 proposed rule and new data for DBFs."Two documents provide the data
available for the proposed rule: Occurrence Assessment for Disinfectants and Disinfection By-
Products (Phase 6a) in Public Drinking Water (EPA. 1992) and the preamble to the 1994
proposed rule (59 FR 38668). The new data were obtained from national surveys, compliance
monitoring data from six states, and peer-reviewed journals.
• Section 5 - National Occurrence: This section addresses national occurrence of THMs and
HAA5. Unfortunately, national occurrence estimates of systems cannot be derived from the
limited available information. However, this section characterizes national occurrence based
on the available data and compares summary statistics.
• Section 6 - Summary of Exposure from Sources other than Drinking Water: This section
provides information on the potential exposure to DBPs via routes other than drinking water
(e.g., food and air). The majority of articles reviewed did not provide exposure data but rather
occurrence data for disinfectants and DBPs in food and ambient air.
• Section 7 - Relative Source Contribution Evaluation: The characterization of national
exposure to contaminants in drinking water involves assessing the population's intake from
drinking water.consumption and other routes of exposure. This section describes the .exposure
for persons consuming treated water and assesses exposure from other sources, such as food and
air.
Final 1-7 . " November 13, 1998
-------
or D'DBP :n Public
• Appendix A — Summary of Surveys and Studies: This appendix provides a summary of the
sup-evs and studies cited Sections 3 and 4 of the document. The summaries are more detailed
than those in the narrative of other sections and c :uss the sampling, analytical methods, and
the results of the surveys and summaries.
• Appendix B - Analytical Methods: This appendix briefly summarizes the approved analytical
methods for the Stage 1 rule and discusses the nationwide capacity of laboratory services to
perform these analytical methods. In addition, this appendix describes the approved analytical
methods for disinfectants and DBFs. The number of laboratories approved by EPA for (CR
analysis of drinking water monitoring is provided as an indicator of the laboratory capacity and
availability of analytical services.
Final 1-8 November 13, 1998
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Occurrence \ssewment for Of DBF in Public Drn*ri/i? ^ater •iuppitii'i
2. USE OF DISINFECTANTS IN THE UNITED STATES
The water treatment process removes and/or inactivates microorganisms in water, particularly
pathogens that can cause waterbome diseases. This function is especially important for surface supply
sources. In many cases, surface water supplies contain discharges from upstream wastewater treatment
plants, industrial facilities, stormwater runoff, and animal feed lots. In the treatment plant, some of the
treatment processes, such as sedimentation and filtration, will remove most, if not all. of the microorganisms
that cause waterbome diseases. However, filtration supplemented by disinfection is very important in the
treatment process for preventing waterbome diseases caused by pathogens.
The 1995 Community Water Systems Survey (EPA, 1997a) reports that in the United States.
99 percent of surface water systems provide some level of water treatment before distribution to customers,
and 99 percent of these treatment systems include disinfection as part of the treatment process. Disinfection
comprises specialized treatment for inactivating harmful organisms. Disinfection can be accomplished in
several ways: the most common process is the addition of a disinfectant to the water, which inactivates the
pathogenic microorganisms. The most commonly used disinfectants are chlorine and chloramines. Chloride
dioxide and ozone are also used somewhat for drinking water disinfection.
In addition to disinfection, these chemicals perform as oxidants and are used to treat drinking water
for the following additional purposes:
• To control Asiatic clams and zebra mussels
• To oxidize iron, manganese, and sulfides
• To prevent regrowth in the distribution system and maintain biological stability
• To remove taste and odors through chemical oxidation
• To improve coagulation and filtration efficiency
• To prevent algal growth in sedimentation basins and filters
• To oxidize organic micropollutants such as pesticides, volatile organic compounds, etc.
The majority of community groundwater and surface water systems disinfect drinking water supply.
More than 50,000 publicly and privately owned community water systems exist in the United States, not
including federal- or state-owned systems. Exhibit 2-1 categorizes the 50,288 community water systems by
water source (surface water, groundwater, and purchased water) and by service
Final 2-1 November 13, 1998
-------
N)
N»
Exhibit 2-1. Number of Community Water Systems by Primary Water Source and Service Population
Primary Water Source
Primarily' Groundwater
Primarily Surface Water
Primarily Purchased
Service Population Category (Number of Systems) .
100 or
Less
13.205
360
230
101-
500
13.140
820
1,463
501-
1,000
4,980
429
1.100
1,001-
3,300
4.769
1,135
. 1,090
3,301-
10,000
2,375
816
933
10,001-
50,000
1.370
891
318
50,001-
100,000
170
204
111
Greater than
100,000
94
207
78
Total number of Community Water Systems
Total Number
of Systems
40,103
4.862
5,323
50,288
Percent
of Systems
80
10
10
100
o
CO
'Primarily means system obtains all or highest percentage ol water from stated source.
Source: EPA, 1997a; EPA 1997b
I?
>T-
3
JQ
I
C
•o
•a
-------
Occurrence \ssessmerufiyr D/DBP :n Public Dnnxint; ^ater
population category Eightv percent of these communitv water systems provide water primarily trom
groundwater sources (i.e.. more than 50 percent of the water volume is from groundwater sources), while 10
percent provide waii-r pnmarily from surface water sources. Eighty-five percent of these community water
sv stems serve populations of less than 3.300 persons, while only two percent of these systems serve
populations greater than 50.000.
Exhibits-2-2 and 2-3 present the percentage of plants using a specific disinfection treatment method
for primary and secondary disinfection. During primary disinfection, disinfectants are added to raw water
as part of the treatment scheme. During secondary disinfection, disinfectants are added prior to the
distribution system to provide residual disinfection. Exhibits 2-2 and 2-3 do not represent the total
percentage of plants that disinfect because an overlap exists between plants that perform both primary and
secondary disinfection.
This section provides general information on the four common disinfectants. For each disinfectant.
the section describes the chemistry and method of application, use and distribution, advantages and
disadvantages, typical dosages needed, and potential byproducts.
2.1 CHLORINE
Chlorine is currently the most commonly used disinfectant in the United States. Through filtration
and chlorination, waterbome diseases, including typhoid and cholera, have been virtually eliminated in the
U.S. For example, in Niagara Falls, New York, between 1911 and. 1915. the number of typhoid cases
dropped from 185 deaths out of 100,000 to nearly zero following introduction of filtration and chlorination
(White, 1986). Today, 67.5 percent of all surface water treatment plants use chlorine as a residual
disinfectant (EPA, I997b).
Chlorine has four effects when added to water—oxidation, addition, substitution, and disinfection.
Chlorine will oxidize soluble iron, manganese, and sulfides that are typically found in groundwater sources.
The oxidized products are typically removed by clarification and filtration. When chlorine reacts with
natural organic matter in the water, it typically replaces or substitutes for a covalently bound atom in the
organic molecule and forms halogen-substituted organic byproducts (e.g., trihalomethanes. chlorophenols.
etc.), some of which have been shown to be possible human carcinogens. For disinfection, chlorine
hydrolyzes in water to form hypochlorous acid (HOC1) and hydrochloric acid (HC1). Hypochlorous acid
.contains the active form of chlorine that inactivates or kills pathogens of concern.
Final . 2-3 November 13, 1998
-------
•*)
i;
10
I
Exhibit 2-2. Percent of Plants Applying Specific Disinfection Treatment for Primarily Surface Water Systems
Treatment Type
Primary Disinfection
Chlorine
Chlorine Dioxide
Chloramines
Ozone
Primary Disinfection combinations
Secondary Disinfection
Chlorine
Chlorine Dioxide
Chloramines
Secondary Disinfection
Combinations
Service Population Category
100 Of
Less
59%
-0
4.6
0
0
49.7%
0
0
0
101-
500
73.9%
0
0
0
0
51.6%
0
0
0
501-
1,000
67.3%
0
1.1
0
2
80.6%
0
0
0
1,001-
3,300
66.3%
5
2.1
0
2.9
62.8%
0
2.9
2.1
3,301-
10,000
68.8%
4.7
0
0.3
0.6
77.9%
0.3
2.1
4
10,001-
50,000
58.6%
13.2
2.2
0
9.2
71.1%
•)';
15.6
3.9
50,001-
100,000
47.6%
14.2
15.5
5.4
5.1
73.8%
5.9
29.4
1.9
Greater than
100,000
57.1%
7.8
10.8
5.8
4.3
61.6%
1.6
24.4
11.2
Total
63.8%
6.3
31
0.9
3.5
67 5%
16
8.1
3
Percentages could exceed 100 percent because many plants ulilue different disinfectants lor the same objective.
Source. EPA, 1997a, EPA. 1997b.
CD
o-
a
"
I
I
-------
Exhibit 2-3. Percent of Plants Applying Specific Disinfection for Primarily Groundwater Systems
Treatment Type
Primary Disinfection
Chlorine
Chlorine Dioxide
Chloramines
Ozone
Primary Disinfection Combinations
Secondary Disinfection
Chlorine
Chlorine Dioxide
Chloramines
Secondary Disinfection Combinations
Service Population Category
100 or
Less
64.2%
1.3
0 ,
0
0.3
23%
0
0
0
101-
500
69.9%
0
0
0
0.5
23.4%
1
0
0
501-
1,000
56.7%
0
0
0
0
32.5%
0
0
0
1,001-
3,300
73.2%
0
0
0
0.7
28.3%
0
0
0
3,301-
10,000
60.6%
0
0
0
1
42.5%
0
0.1
01
10,001-
50,000
57.4%
0
0.6
0
2.6
41.9%
0.6
1.1
0.1
50,001-
100,000
36.2%
3.1
1.4
0
0
54.5%
0
3.9
0
Greater than
100,000
38.1%
0
0.7
0.6
0
65.8%
0
4.3
0
Total
63.9%
03
01
0
07
31.0% -
04
03
0
K>
Percentages could exceed 100 percent because many plants utilize different disinfectants for the same objective.
Source: EPA. 1997a; EPA 1997b.
$
-------
rtccurrence Assessment for D'DBP :n Public Dnnkinq Hater Supplies
2.1.1 Description of Chemistry
Disinfection with chlorine is simple, economical, efficient, measurable, and practical. Several t\pes
of chlorine are available for use as a disinfectant—chlorine gas. sodium hypochlorite (liquid), and calcium
hvpochlorite (tablet, granular, or powdered). Chlorine gas is often referred to as elemental chlorine.
Chlorine is produced, collected, purified, compressed, cooled, packaged, and shipped as a liquefied gas under
pressure.
Sodium hypochlorite is produced by reacting chlorine with sodium hydroxide. Typically, sodium
hypochlorite solutions are referred to as liquid bleach or Javelle water. Generally, the commercial or
industrial grade solutions produced have hypochlorite strengths of 10 to 16 percent. The stability of sodium
*
hypochlorite solution depends on the hypochlorite concentration, the storage temperature, the length of
storage (time), the impurities of the solution, and exposure to light. Decomposition of hypochlorite solution
over time can affect the feed rate and dosage, as well as produce undesirable byproducts such as chlorite or
chlorate ions (Gordon, et. al., 1995). Because of the storage problems, many systems are investigating onsite
generation of sodium hypochlorite in lieu of its purchase from a manufacturer or vendor. Low concentrations
(i.e., 5.25 percent or less) are supplied as common household bleach.
To produce calcium hypochlorite, hypochlorous acid is made by adding chlorine monoxide to water
and then neutralizing it with a lime slurry to create a solution of calcium hypochlorite. The water is removed
from the solution, leaving granulated calcium hypochlorite. Generally, the final product contains up to 70
percent available chlorine and 4 to 6 percent lime. Storage of calcium hypochlorite is a major safety
consideration. It should never be stored where it is subject to heat or allowed to contact any organic material
of an easily oxidized nature.
2.1.2 Use and Distribution .
For use in.treatment, chlorine gas feeders can be either direct feed or solution feed. Direct gas
feeders deliver the chlorine gas under pressure directly to the point of application. Because direct feeders
are less safe than solution feed chiorinators, solution feed is typically used. Chlorine gas is metered under
vacuum and mixed in an injector with water to produce a chlorine solution, which is injected at the
appropriate application point(s). With this type of system, the flow of chlorine gas is automatically shut off
on loss of vacuum, stoppage of the solution discharge line, or loss of operating solution water pressure.
Final 2-6 November 13. 1998
-------
Occtlrrence \ssessment for D/DBP in Public Dnnkiny Water
Sodium hvpochiontb. which is a dilute liquid chlonne solution, is normally fed directly with a motor-
driven diaphragm and plunger-type chemical metering pump(s) to the appropriate application ptintfs)..
Although unusual, feeding sbdium hypochlorite using a hydraulic injector or simple gravity flow is possible.
When calcium hypcrhlorite is used in a water treatment plant as a treatment process for continuous
disinfection, it is mixed wifi water to form a dilute liquid chlorine solution and fed in the same manner as
sodium hypochlorite. For spot disinfection, whether it be in a basin or pipe, calcium hypochlorite tablets are
deposited in the appropriate location, water is added, and the tablets allowed to dissolve to form a liquid
chlorine solution.
According to the 1«)95 Community Water Systems Survey (EPA, 1997a), most surface water and
groundwater systems use chorine for primary disinfection. Exhibit 2-2 provides the percentage of surface
water systems that use chlonne. Exhibit 2-3 lists the percentage of groundwater systems that use chlorine.
These exhibits also show that chlorine is the most widely used secondary disinfectant.
2.1.3 Advantages/Disadvantages
The following list p resents selected advantages and disadvantages of using chlorine as a disinfection
method for drinking water (IMasschelein, 1992; Process Applications, Inc., 1992).
• Advantages of chlorination may include:
- Chlorine oxidizes soluble iron, manganese, and sulfides.
- Chlorine enhances color removal.
- Chlorine controls taste and odor.
- Chlorine may enhance coagulation and filtration of paniculate contaminants.
- Chlorine is:an effective biocide.
- The use ofichlorine is the easiest and least expensive disinfection method, regardless of
system size.
- Chlorine is she most widely used disinfection method and, therefore, the most well known.
- Chlorine istavailable as calcium and sodium hypochlorite that are more advantageous for
smaller systems than chlorine gas because they are easier to use. are safer, and need less
equipment Compared to chlorine gas.
- Chlorine provides a residual.
• Disadvantages of chlorination may include:
- Chlorine m*y cause a deterioration in coagulation/filtration of dissolved organic substances.
- Chlorine fchns halogen-substituted byproducts.
- Finished water could have taste and odor problems, depending on the water quality and
dosage.
Final 2-7 November 13, 1998
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Occurrence Assessment for D'DBP in Public Dnnkin? ^ater iuppiits
Chlorine gas is a hazardous corrosive gas.
Special leak containment and scrubber facilities could be required for chlorine gas-
Tvnjcally. sodium and calcium hypochlorite are more expensive than chlorine gas.
S- Uium hypochlorite degrades over time and with exposure to light.
Sodium hypochlorite is a corrosive chemical.
Calcium hypochlorite must be stored in a cool, dry place because of its reaction with
moisture and heat.
A precipitate may form in a calcium hypochlorite solution because of impurities: therefore.
an antiscalant chemical may be needed.
Higher concentrations of hypochlorite solutions are unstabje and will produce chlorate as
a byproduct.
Chlorine is less effective at high pH.
Chlorine forms oxygenated byproducts that are biodegradable and which can enhance
subsequent biological growth if a chlorine residual is not maintained.
Because of the wide variation of system size, water quality, and dosages applied, some of these
advantages and disadvantages may not apply to a particular system.
2.1.4 Dose Ranges
The guideline for a typical dose range for chlorine used by the U.S. Environmental Protection
Agency (EPA) in review of the Public Water Systems' Initial Sampling Plans, which were required by the
Information Collection Rule (ICR), was based on dosages provided in engineering design manuals and
published articles. This range of doses, listed in Exhibit 2-4, includes both primary and secondary
disinfection. Note that these ranges represent the extreme upper and lower dose values. Normal doses fall
within these ranges.
Exhibit 2-4. Chlorine Dose Ranges
Chlorine Compound
Calcium hypochlorite
Sodium hypochlorite
Chlorine gas
Range of doses (mg/L)
0.5-5
0.2-2
1-16
Source: SAIC, 1996
2.1.5 Byproducts
Exhibit 2-5 lists identified disinfection byproducts associated with chlorine. Halogen-substituted
organic byproducts are formed when natural organic matter (NOM) reacts with free chlorine or free bromine.
Free chlorine is normally introduced into water directly as a primary or secondary disinfectant. Free bromine
Final 2-8 November 13, 1998
-------
Occurrence \sses±ment for D'DBP :n Pud/ic OnnKing
Supptirs
results from the oxidation bv chlorine of bromide ion in the water. Factors affecting the rate of formation
and concentration of halogen-substituted disinfection byproducts (DBFs) include type and concentration of
NOM. form of chlorine and dose. time, bromide ion concentration. pH. organic nitrogen concentration, and
temperature. Organic nitrogen significantly influences the formation of nitrogen containing DBFs, including
the haloacetomtnles. halopicrins. and cyanogen halides (Reckhow et al., 1990: Hoigne and Bader. 1988).
Exhibit 2-5. Disinfection Byproducts of Chlorine
Trihalomethanes
Haloacetic Acids
Haloacetonitriles
Chloroform
Bromodichloromethane
Dibrornochloromethane
Bromoform
Monochloroacetic acid
Dichloroacetic acid
Trichloroacetic acid
Monobromoacetic acid
Dibromoacetic acid
Dichloroacetonitrite
Bromochloroacetonitrile
Dibromoacetonitrile
Trichloroacetonitrile
Tribromoacetonitrile
Haloketones 1 , 1 -Oichloropropanone
1,1,1 -Trichloropropanone
Other Compounds Chlorophenols
2-Chlorophenol
2.4-Dichlorophenol
2,4,6-Trichlorophenol
Chloropicrin
Chloral Hydrate
Cyanogen Chloride
N-Organochloramines
MX*
'3-Chloro^-{dichloromethyl)-5-hydroxy-2(5H)-furanone
Source: Malcolm Pimie, 1992: Richardson et at., in press
2.2 CHLORAMINES
Early researchers identified the disinfectant potential of chlorine-ammonia compounds (i.e..
chloramines). The potential use of chloramines was considered after observing that when ammonia was
present, although free available chlorine dissipated, disinfection still occurred. The subsequent disinfection
was caused by inorganic chloramines.
Initially, chloramines were used for controlling taste and odor; however, chloramines were soon
recognized as being more stable than free chlorine in the distribution system and, consequently, were found
to be effective for controlling bacterial regrowth in the distribution system (Norton and LeChevallier. 1997).
As a result, chloramines were used regularly during the 1930s and 1940s for disinfection. Because of an
ammonia shortage during World War n, however, the popularity of chloramination declined. The recent
concern over halogen-substituted organics (trihalomethane [THM] and haloacetic acid [HAA] formation)
in water treatment and distribution systems increased interest in chloramines because they react differently
Final
2-9
November 13. 1998
-------
Occurrence Assessment for DiDBP in Public Dnnicint? \\ater
humic and remc acids than chlorine generally producing lower concentrations of DBFs (Symons et. al.. I998K
2.2.1 Description of Chemistry
Chloramines are formed by the reaction of ammonia with aqueous chlorine, [n aqueous solutions.
hypochlorous acid .from the chlorine reacts with ammonia to form inorganic chloramines in a series of
competing reactions. In these reactions, monochloramine (NH:C1), dichloramine (NHC1:). or nitrogen
trichloride (NCI,) are formed. These competing reactions (and several others) are primarily dependent on
pH and controlled to a large extent by the chlorine:ammonia nitrogen (C12:N) ratio. Temperature and contact
time also regulate this reaction. Monochloramine is predominately formed when the applied C1,:N ratio is
less than 5:1 by weight. As the applied C1::N ratio increases from 5:1 to 7.6:1, the breakpoint reaction
occurs, thereby reducing the residual chloramine and ammonia nitrogen level to a minimum. Breakpoint
chlorination results in the formation of nitrogen gas and nitrate. At C12:N ratios above 7.6: 1 . free chlorine
and nitrogen trichloride are present although being quite volatile the latter usually dissipates. To avoid
breakpoint reactions, utilities normally maintain a C12:N between 3: 1 and 5: 1 by weight. A ratio of 6: 1 is
actually optimum for disinfection because dichloramine predominates, but maintaining a stable operation
at that point in the breakthrough curve is difficult. Therefore as meritioned above, a CU:N ratio of 3: 1 to 5: 1
is typically accepted as optimal for chloramination.
2.2.2 Use and Distribution
Monochloramine can be formed by first adding ammonia and then chlorine, or concurrently adding
both reactants. Ammonia is added first where the formation of objectionable taste and odor compounds
caused by the reaction of chlorine and organic matter are a concern. Today, however, most drinking water
systems add chlorine first and then ammonia, in conformance with the EPA Surface Water Treatment Rule
disinfection requirements. Typically, the point of ammonia addition is selected to "quench" the free chlorine
residual after a target contact time has been achieved based on optimizing disinfection versus minimizing
DBF formation. Monochloramine is mainly used in water systems as a secondary disinfectant for
maintaining a residual in the distribution system.
2.23 Advantages/Disadvantages
The following list highlights selected advantages and disadvantages of using chloramines as a
disinfection method for drinking water (Masschelein, 1992).
Final 2-10 November 13, 1998
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Occurrence \ssessmen:/or D'DBP :n Public Dnnxine ^aler Supplies
• Advantages
Chlorarmnes are not as reactive with organics as free chlorine in forming DBFs.
- The monochloramine residual is more stable and longer lasting than free chlorine or chlonne
dioxide, thereby providing better protection against bacterial regrowth in systems with large
storage tanks and dead-end water mains.
- , Because chloramines do not tend to react with organic compounds, many systems will
experience less incidence of taste and odor complaints when using chloramines.
- Chloramines are inexpensive.
- Chloramines are easy to make.
• Disadvantages
- The disinfecting properties of chioramine are not as strong as other disinfectants, such as
chlorine, ozone, and chlorine dioxide.
- Chloramines cannot oxidize iron, manganese, and sulfides.
- When using chioramine as the secondary disinfectant, it may be necessary to periodically
, convert to free chlorine for biofilm control in the water distribution system.
- Excess ammonia in the distribution system may lead to nitrification problems, especially in
dead ends and other locations with low disinfectant residual.
- Monochloramine are less affective at high pH.
- Dichloramines have treatment and operation problems.
- Chloramines must be made on-site. ,
Because of the wide variation of system size, water quality, and dosages applied, some of these
advantages and disadvantages may not apply to a particular system.
2.2.4 Dose Ranges
The normal dose range for monochloramine is from 1.0 to 4.0 mg/L. The minimum dosage of
monochloramine in the distribution system is typically 0.5 mg/L (Texas Natural Resource Conservation
Commission, 1996). The range of ammonia doses, provided in Exhibit 2-6, includes doses for both primary
and secondary disinfection.
Exhibit 2-6. Suggested Doses of Ammonia Compounds for Chloramines
Chemical
Ammonium sulfate
Anhydrous ammonia
Ammonia hydroxide
Dosage (mg/L)
0.1-3.0
0.1-1.0
0.1-3.0
Sources: Masschelein, 1992; SAIC, 1996
Final 2-11 November 13, 1998
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Occurrence Assessment for D'DBP in Public Dnnkiny Viatfr Suppimi
2.2.5 Byproducts
The effectiveness of chloramines in controlling DBF production depends upon a variety of factors.
notably the chlorine to ammonia ratio, the point of addition of ammonia relative to that of chlorine, the extent
of mixing, and pH.
Direct reactions between monochloramine and organic matter in water produce very few halogen
substituted organic compounds, although some dichloroacetic acid can be formed, and cyanogen chloride
formation is greater than with free chlorine (Jacangelo et al., 1989; Topodurti and Haas. 1991; Smith et al..
1993: Cowman and Singer, 1994; Symons et al.. 1998). The inability to mix chlorine and ammonia
instantaneously allows the free chlorine to react before the complete formation of chloramines. In addition,
monochloramine slowly hydrolyzes to free chlorine in an aqueous solution. Therefore, halogen-substitution
reactions occur even when pre-formed monochloramine is used (Rice and Gomez-Taylor, 1986). The closer
the chlorine:ammonia ratio is to the breakpoint, the greater the formation of DBFs (Speed et al., 1987). As
this chlorine:ammonia reaction takes place, the chloramination results in lower concentrations of numerous
other halogen-substituted generated from free chlorine ((except in the cases of cyanogen chloride (Krasner
et al., 1989: Jacangelo et al., 1989)). Increased concentrations of cyanogen chloride are observed when
monochloramine is used as a secondary disinfectant instead of free chlorine.
The application of chloramines results in the formation of halogen-substituted organic material (i.e..
TOX). although it occurs to a much lesser degree than from an equivalent dose of free chlorine. Little is
known about the nature of these byproducts, except that they are more hydrophilic and larger in molecular
size than the organic halides produced from free chlorine (Jensen et al., 1985; Singer 1992; Symons et al.,
1998). Recent research has shown slow DBF formation when pre-formed chloramines were used in model
compound experiments (Topudurti and Hass 1991; DeLaat et al., 1982).
2.3 CHLORINE DIOXIDE
Chlorine dioxide is a powerful oxidant originally used by industry as a bleaching agent and
disinfectant. Chlorine dioxide was first used as a disinfectant for drinking water in 1944 at the Niagara Falls.
New York. Water Treatment Plant. Currently, the major use of chlorine dioxide is as a pre-oxidant to control
tastes and odors and to reduce THM formation in finished water (DeMers and Renner. 1992).
Final 2-12 . November 13. 199S
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h-currence \ssessment for D/DBP in Public Dnnkinq Wafer -i
2.3.1 Description of Chemistry
Chlorine dioxide (CIO,) is a neutral compound of cn.onne in the -t-FV oxidation state. CIO, exists
in a gaseous state at temperatures above 1 1-123C. It is a relatively small, volatile and highly energetic
molecule and is a free radical. It functions as a highly selective oxidant because of its unique, one-electron
transfer mechanism where it is reduced to chlorite (CIO,") (Hoehn et al.. 1996: Doerr. R.L. 1981). During
drinking water treatment, chlorite is the predominant reaction byproduct, with 50-70 percent of the reacted
chlorine dioxide being converted to chlorite and 30 percent to chlorate (C1O3") or chloride (Cl~) depending
on secondary disinfectant.
Although chlorine dioxide can be produced from sodium chlorate (NaClO3), most generators use
sodium chlonte (NaCIO,) as the predecessor chemical. Efficiency, conversion, and yield are used to describe
the generation of chlorine dioxide from sodium chlorite. These terms all relate to the purity of generated
chlorine dioxide. The proportion of chlorine dioxide relative to other oxychlorine compounds, including
chlorite, chlorate, or free chlorine, is important when chlorine dioxide is applied to the drinking water (Aieta
and Berg. 1986). Although a significant amount of chlorite ion can appear in drinking water from application
and subsequent reduction of chlorine dioxide, both unconverted precursor chlorite and over-oxidized chlorate
ions can be constituent contaminants in generated solutions. EPA recommends that utilities limit the
production of DBFs by maintaining high generator purity (i.e., more than 95-percent efficiency) and limiting
excess chlorine to 5 percent of the applied dose of chlorine dioxide.
For most potable water applications, chlorine dioxide is generated from sodium chlorite. Two feed
chemical combinations that generate chlorine dioxide yields in excess of 95 percent are (1) chlorine-sodium
chlorite and (2) acid-sodium hypochlorite-sodium chlorite.
Chlorine SolutionrCbJorite Solution. Chlorite ion (from dissolved sodium chlorite) will react in
aqueous solution with chlorine or hypochlorous acid to form chlorine dioxide:
[1]
Thus, two moles of chlorite ions will theoretically react with one mole of chlorine (i.e., as
hypochlorous acid) to produce two moles of chlorine dioxide. In order to fully utilize sodium chlorite
solution, the more expensive of the two ingredients, excess chlorine is often used, which lowers the pH and
drives the reaction further toward completion. The reaction is faster than the acid:chlorite solution method.
Final 2-13 November 13, 1991
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Occurrence Assessment for D/DBP in Public Onnkmy Water Supplier
but much slower than the other commercial methods described in the following discussion. Chlorine dioxide
production by this method is limited to about 1.000 pounds per day.
AcidiChlorite Solution. Chlorine dioxide can be generated by acidification of sodium chlorite
solution, and several stoichiometric reactions have been reported for such processes (Gordon et al.. 1972).
When chlorine dioxide is generated in this way, hydrochloric acid is generally preferred.
The sioichiometry expected for Hydrochloric acid activation of sodium chlorite is:
5CIO", + 4HC1 - 4C1O, + SCI' + 2H,O [2]
When catalyzed by the presence of chloride ion, acid activation of sodium chlorite has a maximum
possible yield of 80 percent of the quantity of chlorine dioxide that could be produced from reaction of the
same amount of sodium chlorite with chlorine (Pitochelli, 1995). The reaction is relatively slow, and
production rates using this method are practically limited to about 25 to 30 pounds per day, due to the
exothermic nature of the reactions.
Chlorine Gas:Chlorite Solution. Sodium chlorite solution can be "vaporized" and reacted under
vacuum with molecular gaseous chlorine. This process uses concentrated reactants and is much more rapid
than chlorine splution:chlorite solution methods (Pitochelli, 1995). If the chlorine and chlorite ion react
stoichiometrically, the resulting pH is close to 7. Production rates are virtually unlimited, and some installed
systems have reported producing more than 60,000 pounds per day.
[3]
Chlorine Gas:Solid Chlorite. This method reacts dilute, humidified chlorine gas with specially
processed solid sodium chlorite contained in sealed reactor cartridges:
2 NaC102(1) + C1M|) - 2Cl02(g, + 2NaCl(i) [4]
The reaction is rapid and produces high-purity chlorine dioxide gas inherently free of chlorine and
chlorate ions, because these ions will not carry into the- gas phase. Use of multiple cartridges in series
ensures an excess of the sodium chlorite; thus, all chlorine is reacted and the chlorine dioxide produced is
chlorine free. Because the chlorine dioxide production rate is a function solely of the chlorine gas feed rate.
Final 2- 14 November 13, 1998
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Occurrence Assessment for D/DBP in Public DnrtKinq VVaftr bupp/
generators that use chlorine 2as:sohd chlorite technology are capable of effectively infinite turndown u.e .
the chlonne dioxide production rate can be adjusted without requiring recalibration between settings)
(Pitochelli. 1995: Hoehn and Rosenblatt. 1996). The chlorine gas:chlonte solution method! production
capacities are limited to 2.000 pounds per day for practical reasons.
Besides the commercial processes discussed previously, other potential methods for generating
chlorine dioxide include electrolysis of sodium chlorite solution (with or without the use of membranes to
purify the chlorine dioxide product), irradiation of dilute sodium chlorite solution with UV light, and
reduction of sodium chlorate with concentrated sulphuric acid and 50 percent hydrogen peroxide. (Sodium
%
chlorate is neither an EPA nor Federal Insecticide, Fungicide, and Rodenticide Act-approved precursor for
chlorine dioxide production for drinking water treatment:)
2.3.2 Use and Distribution
Chlorine dioxide is almost never used commercially as a gas because it cannot be safely compressed
and shipped. For potable water treatment process, it is predominantly generated in aqueous solutions.
Because of the volatile nature of the gas, chlorine dioxide works extremely well in plug flow reactors, such
as pipe lines. It can be easily removed from dilute aqueous solution by aerated turbulence, such as in a rapid
mix tank or aerated cascade. For post disinfection, chlorine dioxide can be added before clearweils or
transfer pipelines.
Exhibit 2-2 shows thai chlorine dioxide is most frequently used in surface water systems serving
more than 10,000 persons. Today, an estimated 700 to 900 U.S. drinking water utilities use chlorine dioxide,
largely to oxidize iron and manganese, control taste and odor, and lower THM levels (Hoehn, 1992). Some
systems are looking to the higher disinfection efficacy of chlorine dioxide to assist in CT for
Cryptosporidium control.
2.3.3 Advantages/Disadvantages
The following.list highlights selected advantages and disadvantages of using chlorine dioxide as a
disinfection method for drinking water (Masschelein, 1992; DeMers and Renner, Inc., 1992; Gallagher, et al..
1994).
Final 2-15 November 13, 1998
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Occurrence Assessment fnr D/D8P in Public Dnnianq Water Supplies
• Advantages
Chlorine dioxide is more effective than chlorine and chloramines for inactivation of viruses.
Crypiosporidium. and Giardia.
- Chlorine dioxide oxidizes iron, manganese, and sulftdes.
- Chlorine dioxide may enhance the clarification process.
- Taste and odors resulting from algae and decaying vegetation, as well as phenolic
compounds, are controlled by chlorine dioxide.
Under proper generation conditions (i.e., no excess chlorine), halogen-substituted DBFs are
not formed.
- Chlorine dioxide is easy to generate.
- Biocidal properties are not influenced by pH.
- Chlorine dioxide provides residuals.
• Disadvantages
- The chlorine dioxide process forms the specific byproducts chlorite and chlorate.
- Generator inefficiency and optimization difficulty can cause excess chlorine to be fed at the
application point, which can potentially form halogen-substituted DBFs.
- Costs associated with training, sampling, and laboratory testing for chlorite and chlorate are
high. ' '
- Equipment is typically rented, and the cost of the sodium chlorite is high.
- Measuring a chlorine dioxide residual for determining disinfection credit is difficult.
- Chlorine dioxide gas is explosive, so it must be generated onsite.
- Chlorine dioxide decomposes in sunlight.
- Chlorine dioxide must be made on-site.
- Can lead to production of noxious odors in some systems.
Because of the wide variation of system size, water quality, and dosages applied, some of these advantages
and disadvantages may not apply to a particular system.
23.4 Dose Ranges
Before chlorine dioxide is selected, for use as a primary disinfectant, an oxidant demand study must
be completed. Ideally, this study should consider the seasonal variations in water quality, temperature, and
application points. EPA recommends that the combined residuals of chlorine dioxide, chlorate, and chlorite
not exceed 1.0 mg/L in finished water. This means that if the oxidant dosage is greater than about 1.4 mg/L.
chlorine dioxide cannot be used as a disinfectant because the chlorite/chlorate ions byproduct would already
be at the maximum level allowed. This range of doses, provided in Exhibit 2-7, includes both primary and
secondary disinfection. Note that these ranges represent the extremes; normal doses fall within these ranges.
Final 2-16 November 13. 1998
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Occurrence \sserssmtnt for D'DBP in Public Dnnkinq Hater iu
Exhibit 2-7. Observed Chlorine Dioxide Doses
Dose Range (mg/L)
06-10
0.5-1.5
0.07 - 2.0
0.5-2.0
2.0
Conditions
Finished water from lakes and streams
Two utilities with odor complains
As reported: four utilities
Five utilities
Two treatment plants, ferrous chloride reduction study
References
McGuire & Meadow, 1988
Hoehn, 1990
Boiyardetal., 1993
Gallagher etal.. 1994
Tarqum et al.. 1995
Source: Masschelein 1992, SAIC 1996.
2.3.5 Byproducts
The application of chlorine dioxide to water results in oxidation/reduction reactions that form two
inorganic DBFs in the treated drinking water: chlorite and chlorate (Rav Acha et al., 1984, Werdehoff and
Singer, 1987). However, the application of chlorine-free chlorine dioxide does not form THMs and produces
only a small amount of total organic halide (TOX) (Werdehoff and Singer, 1987) and other halogenated-
substituted compounds at very low concentrations (Richardson et al., 1998). Chlorite and chlorate frequently
are found as contaminants in chlorine dioxide feed streams, and chlorite is formed as a byproduct from
disinfection with chlorine dioxide (Griese et al., 1991). However, chlorine dioxide does not generate
bromine-substituted byproducts to the same extent as ozone in bromide-containing waters. Two principal
sources of chlorite occurs in finished drinking water:
• Unreacted chlorite during the chlorine dioxide generation process
• Redux formation upon application of chlorine dioxide to water.
Incomplete reaction or non-stoichiometric addition of the sodium chlorite and chlorine reactams can
result in unreacted chlorite or more likely chlorate in the chlorine dioxide feed stream. Upon application to
water, chlorine dioxide is fairly unstable and rapidly dissociates into chlorite and chlorate at pH above 10.
This dissociation is reversible with chlorite converting back to chlorine dioxide in the presence of free
chlorine, but only to a limited extent where residuals are greater than one percent. Chlorite ion is generally
the primary product of chlorine dioxide reduction. The distribution of chlorite and chlorate is influenced by
pH and sunlight. The efficiency of the chlorine dioxide generator and the decay of chlorine dioxide and free
available chlorine residual disinfectant concentrations also influence these distributions.
Final
2-17
November 13. 1998
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Occurrence Assessment for D/DBP in Public Dnnkinq Water Supplies
The quantity of chlorate produced during the chlorine dioxide generation process is greater with
excess chlorine addition. Likewise, low pH can increase the quantity of chlorate during the chlorine dioxide
generation process. The predominant source of chlorate ion in finished water: however, results from the
oxidation of chlonte (from the applied chlorine dioxide) by free available chlorine used as a final distribution
disinfectant iGallagheret al.. 1994). Consequently, the chlorate concentrations are expected to increase with
increasing contact time in water containing chlorite and chlorine. Once formed, chlorate is stable in finished
drinking water. Because chlorine dioxide does not hydrolyze in water, it exists as a dissolved gas as long
as the pH of the water ranges from 2 through 10. In strongly alkaline solutions (pH greater than 9 or 10),
however, formation rates of chlorite and chlorate increase with increasing concentrations of chlorine dioxide.
2.4 OZONATION
Ozone was first used for drinking water treatment in 1893 in the Netherlands. While used frequently
in Europe for disinfecting drinking water, ozonation was slow to transfer to the United States. In 1991,
approximately 40 water treatment plants serving more than 10,000 people in the United States used ozone
(Langlais et al., 1991). This number has grown to 201 in 1997 {Rice and Dimitrou, 1997). Most of these
facilities are small: 90 plants treat below I mgd and only 6 exceed 100 mgd, as of May 1997.
Ozone is used in water treatment for disinfection and oxidation. Early application of ozone was
primarily for non-disinfection purposes such as color removal or taste and odor control. Since implemen-
tation of the Surface Water Treatment Rule and in anticipation of the DBF and ESTWR rules, however.
ozone usage for disinfection has increased. Ozone is a powerful oxidant, second only to the hydroxyl free
radical among chemicals typically used in water treatment. Therefore,.it is capable of oxidizing many
organic and inorganic compounds in water.
2.4.1 Description of Chemistry
Ozone exists as a gas at room temperature. The gas is colorless with a pungent odor readily
detectable at concentrations as low as 0.01 to 0.05 ppm, which is below concentrations that will cause the
health problem. Ozone gas is highly corrosive and toxic.
Basic chemistry research (e.g., Hoigne and Bader, I983a; Hoigne and Bader. 1983b; Glaze, 1987)
has shown that ozone decomposes spontaneously in water treatment by a complex mechanism involving the
generation of hydroxyl radicals. The hydroxyl radicals are among the most reactive oxidizing agents in
water, with reaction rate constants for many compounds, as much as 10* times faster than that of ozone itself.
Final 2-18 November 13, 1998
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Occurrence Assessment for D/DBP in Public Dnnkinq Water
Ozone reacts in two modes in aqueous solution: (I) direct oxidation of compounds bv aqueous ozone tO-..wj
and (2) oxidation ot" compounds by hydroxyl radicals produced during the spontaneous decomposition of
ozone (Hoigne and Bader. 1977).
2.4.2 Use and Distribution
Ozone is used in drinking water treatment for various purposes:
• Disinfection
• Inorganic pollutant oxidation, including iron, manganese, and sulfide
• Organic micropollutant oxidation, including taste and odor compounds, phenolic pollutants, and
pesticides
• Organic macropollutant oxidation, including color removal, increasing the biodegradability of
organic compounds, THM and TOX precursor control, and destruction of chlorine demand
• Improvement of coagulation and filtration.
Ozone is an unstable molecule; therefore, it must be generated at the point of application. It is
generally formed by combining an oxygen atom with an oxygen molecule (O;). This reaction is endothermic
and requires a considerable input of energy. Ozone can be produced several ways, although one method.
corona discharge, predominates in the water industry. Ozone can also be produced by irradiating an oxygen-
containing gas with electrolytic reactions, ultraviolet light, or high-energy radiation. These are all processes
that produce free oxygen radicals from electron or photon energy input.
Corona discharge, also known as silent electrical discharge, consists of passing an oxygen-containing
gas through two electrodes separated by a dielectric and an air gap. A voltage is applied to the electrodes.
causing an electron flow across the air gap. These electrons provide the energy to dissociate the oxygen
cmolecules, leading to the formation of ozone.
For most applications, ozone is either fed to the source water or after some type of clarification and
clarification process. Turbidity and ozone demand (the amount of ozone required for all oxidation
requirements of the water) provide basic guidance on how to use ozone in the treatment process. By moving
the ozonation process further downstream, the ozone demand and production of oxidation byproducts are
reduced. The advantage of'placing ozone ahead of filtration is that, biodegradable organics produced during
Final 2-19 November 13.1998
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Occurrence \ssessment for D'DBP in Public Dnnktntf Uarer S
ozonation can be removed in the filters if they are operated biologically. Biological filtration is often a
necessity for waters with high levels of NOM.
2.4.3 Advantages/Disadvantages
The following list highlights selected advantages and disadvantages of using ozone as a disinfection
method for drinking water (Masschelien, 1992).
• Advantages
- Ozone is more effective than chlorine, chloramines, and chlorine dioxide for mactivation
of viruses, Cryptosporidium, and Giardia.
- Ozone oxidizes iron, manganese, and sulfides.
- Ozone can sometimes enhance the clarification process and turbidity removal.
- Ozone controls cojor, taste, and odors.
- One of the most efficient chemical disinfectants, ozone requires a very short contact time.
- In the absence of bromide, halogen-substituted DBFs are not formed.
- Upon decomposition, the only residual is dissolved oxygen.
- Biocidal actively not influenced by pH.
• Disadvantages
- DBFs are formed, particularly bromate and bromine-substituted DBFs, in the presence of
bromide, aldehydes, ketones, etc.
- The initial cost of ozonation equipment is high.
- The generation of ozone requires high energy and must be generated on-site.
- Ozone is highly corrosive and toxic.
- Biologically activated filters are needed for removing assimilable organic carbon and
biodegradable DBFs.
- Ozone decays rapidly at high pH and warm temperatures.
- Ozone provides no residual.
- .Ozone requires higher level of maintenance and operator skill.
Because of the wide variation of system size, water quality, and dosages applied, some of these advantages
and disadvantages may not apply to a particular system.
2.4.4 Dose Ranges
The typical dose range guideline for ozone that was used in EPA's review of the Public Water
Systems' Initial Sampling Plans that were required by the ICR was based on dosages provided in engineering
design manuals and published articles. This range of doses, provided in Exhibit 2-8, is for primary
disinfection only. Note that these ranges represent extremes; and normal values are in between these values.
Final 2-20 November 13, 1998
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Occurrence \ssessment for D/DBP in Public Drinking \later •iuppiini
Exhibit 2-8. Suggested Doses for Ozone
Wafer Source
Grounawater
Surface Water
Dosage (mg/L)
1.0 to 3.0
1.0 to 5.0 (normal)
1 .0 to 10.0 (extreme circumstances)
Sources: SAIC. 1996. Masschelein. 1992
2.4.5 Byproducts
A variety of organic and inorganic byproducts have been observed following ozonation of water.
Ozone itself does not form halogen-substituted DBFs when participating in oxidation/reduction reactions
with natural organic matter. If bromide is present in the source water, however, bromine-substituted DBFs
can be formed. The primary factors affecting the speciation and concentrations of bromine-substituted
byproducts are pH, and the ozone-to-bromide and total organic carbon-to-bromide ratios (Singer, 1992).
The principal benefit of using ozone for controlling THM formation is that ozone allows free
chlorine to be applied later in the treatment process after some of the precursors have been removed and at
lower doses, thereby reducing DBF formation potential. However, application of a secondary disinfectant
following ozonation requires special consideration for potential interaction between disinfectants. For
example, chloral hydrate formation has been observed to increase when using chlorine as a secondary
disinfectant after ozone (MeKnight and Reckhow, 1992; Logsdon et al., 1992). One byproduct of ozonation.
acetaldehyde, is a known precursor for chloral hydrate, a byproduct of chlorination. Enhancement of chloral
hydrate formation has not been observed when monochloramine is applied as the secondary disinfectant or
if biologically active filtration is used following ozonation and prior to chlorination (Singer. 1992).
Chloropicrin formation from free chlorine appears to be enhanced by pre-ozonation (Hoigne and Bader.
1988).
Oxidation byproducts, including aldehydes, ketones, aldo-acids. ketoacids, and AOC will be formed
upon ozonation of water. The primary aldehydes that have been measured are formaldehyde, acetaldehyde.
glyoxal. and methyl glyoxal (Glaze et al., 1991). Total aldehyde concentration in drinking water disinfected
with ozone ranges from less than 5 to 300"ug/L, depending on the TOC concentration and the applied ozone
to orgajiic carbon ratio (Van Hoof era!., 1985; Yarnada and Somiya, 1989; Glaze et al., 1989a; Krasher et
al.. 1989: Glaze et al., 1991; LeLacheur et al., 1991). Aldehydes with higher molecular weights have also
'Final
2-21
November 13, 1998
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< Occurrence \ssessment for D/DBP in Public Dnnkinq ^ater Supplier
been reported i Glaze et al..' 1989b). Insufficient data exist to determine the health impacts associated vuth
the mgestion of aldehvdes in drinking water.
Ozonation of a source water containing bromide can produce hydrobromic acid and. thus, bromine-
substituted byproducts, the brominated analogues of the chlorinated DBFs. These bromine-substituted
byproducts include bromine-substituted, bromoform, the bromine-substituted acetic acids and acetonitriles.
aldo-acids. bromopicnn. and cyanogen bromide. An ozone dose of 2 mg/L produced 53 ug/L of bromoform
and 17 ug/L ef dibromoacetic acid in a water containing 2 mg/L of bromide ion (McGuire et al.. 1990).
Ozonation of the same water spiked with 2 mg/L bromide ion showed cyanogen bromide formation of
10 ug/L (McGuire et al., 1990). Furthermore, ozone can react with the hypobromite ion to form bromate
(Siddiqui and Amy, 1993; Krasner et al., I993a: Amy et al., 1997). Bromate formation is affected by NOM,
pH. bromide ion concentrations, inorganic carbon, and ozone dose. NOM exerts a high demand on ozone
in competition with molecular ozone. This competition for molecular ozone is affected by the NOM
composition as well as concentrations. Additionally, decreasing pH (8.5 - 6.5) generally decreased bromate
formation. Higher bromide ion concentrations and high inorganic carbon concentrations were noted with
increased bromate ion formations (Amy et al., 1997). The amount of bromide incorporated into the measured
DBFs accounts for only one-third of the total source water bromide concentration. This indicates that other
bromine-substituted DBFs exist that are not-yet identified (McGuire et al., 1989; AWWARF, 1992).
Final 2-22 November 13. 1998
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Occurrence \aessmeni fur D'DBP .'/' Public Onnnimf
3. OCCURRENCE OF DBF PRECURSORS AND DISINFECTANTS
3.1 SUMMARY OF PRECURSOR OCCURRENCE DA I A: TOTAL ORGANIC CARBON "AND
BROMIDE ION
The 1994 DBF proposed rule provided data summarizing the occurrence of disinfectants, disinfection
byproducts (DBFs), and DBF precursors. Most of this information came from the 1992 occurrence
document. The 1992 occurrence document did not. however, address precursor occurrence data (EPA.
1992a). The 1994 proposed rule provided the only source of national occurrence data for total organic
carbon (TOC) and bromide ion. Precursor information discussed in the preamble is summarized below and
presented in Exhibit 3-1.
The majority of recent studies addressing DBP occurrence in the United States measured TOC and
bromide. These precursor data are included below. Descriptions of the major studies are located in
Section 4.1.
3.1.1 Total Organic Carbon Occurrence
The TOC level in source water is generally a good indication of the amount of DBP precursors in
the water (Singer and Chang, 1989). In the Water Industry Database (WIDB), 157 utilities provided TOC
data in 1991. Of the utilities reporting on groundwater systems, 57 of those facilities identified TOC values
ranging from below the detection limit (BDL = 0.05 mg/L to 15 mg/L). For these 57 groundwater systems.
the 50th and 75th percentiles were 0.84 and 1.9 mg/L.
TOC levels reported by 100 surface water systems ranged from BDL to 30 mg/L. For these waters.
the 25th. 50th. and 75th percentiles were 2.6,4.0, and 6.0 mg/L, respectively. The WIDB also identified the
number of utilities that did not have TOC data at the time. For surface water, 897 utilities did not provide
TOC values. Among the groundwater utilities, 854 did not provide TOC data. Exhibits 3-2 and 3-3 sum-
marize the data presented in Tables VI-1 and VI-2 of the proposed rule (56 FR 38716, 38721. July 29, 1994).
The Groundwater Supply Survey (GWSS) reported groundwater TOC occurrence data, by EPA
Region, for 945 utilities during 1980-1981. Sixty-nine percent of these utilities chlorinated their water, while
31 percent did not. When the TOC data were combined to present values for all groundwater systems, the
25th, 50th. and 75th percentiles were 0.3, 0.6, and 1.4 mg/L TOC, respectively, tables VI-3 A. B. and C
from the proposed rule presented these groundwater data, which are reproduced in Exhibit 3-3 (56 FR 38721.
July 29. 1994).
Final 3-1 . November 13, 1998
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Exhibit 3-1. Disinfection Byproduct Precursor and Disinfectant Occurrence
Survey (Year)
Location
Sample Information
(Number of Systems)
Concentration of Precursors in
Source Water (mg/L)
Range1
Mean
Median
Notes
Total Organic Carbon
WIOB (1989-1990)
GWSS (1980-1981)
Westricketal.(1983)
AWWA(1997)
AWWSCo(1991)
Arora et at. (1994)
Utah Pre-ICR Data (1996)
Bromide Ion
Glaze et al. (1993)
EPA/AMMWA/COHS
(1988-1989)
Krasneretal. (1989)
Amy etal. (1994)
Wesierhoffelal. (1994)
AWWSCo(1991)
Utah Pre-ICR Data (1996)
157 utilities nationwide
945 GW systems
198 ICR utilities, 50 states; Sept.. Oct.,
Nov. 1996
19 water utilities
2 sampling phases, 1991
20 water systems
7 SW> 100.000, 1994-1996
AWWA study - 7 lull-scale water systems
35 utilities nationwide
101 utilities nationwide,
October 1991-Apnl 1993
19 water utilities, 10 states
7 SW utilities > 100.000; 1994-1996
GW systems (57)
SW systems (100)
GW using CI2 (654)
GW not using CI, (291)
SW > 100,000 (668 samples, 329
plants)
GW > 50,000 (251 samples, 110
plants)
Source water
Source Waters:
River (8)
Reservoir (12)
Source water
9 Source water samples taken (10)
Groundwater/surtace water
Source Waters:
Lakes (34)
Rivers (29)
Groundwater (36)
Source water
Winter 1991
Summer 1991
Quarterly samples - source waters
BDL-15
BDL-30 •
Max. 14
Max. 18
BDL-22.7
BDL-13.0
0.44-8.7
1.3-8.7
0.4-7.8
0.37-13.0
BDL - 0.28
BDL-3.0
0.002-0.322
0.004-0.426
0.002-269
BDL -0.10
BDL - 0.37
BDL - 0.040
0.34
4.0
0.7
0.5
3.29
1.35
4.4
5.4
3.4
2.16
-
0.038
0.101
0.168
0.037
0.065
0010
-
_
2.77
0.76
3.9
-
1.93
-
0.1
0.023
0.063
0062
0.03
0.04
BOL
75mpercenlile^l.9
90"' percentile = fi 0
75°' percentile - 1 .4?
90"' percentile - 2.9
Sid. Dev = 2.2
Std. Dev. = 2.3
75" percenlile = 73
7581 percentile = 2.33
90" percenlile = 3. 10
DL = 001
Std. Dev.
0.054
0.115
0.428
75°' percenlile - 0"'«i
90"' percenlile = 0.(K«)
oo
•o
S
-o
ic
•3-
-------
Exhibit 3-1. Disinfection Byproduct Precursor and Disinfectant Occurrence (Continued)
SO
8
Survey (Year)
Location •
Sample Information
(Number of Systems)
Concentration of Precursors in
Source Water (mg/L)
Range1
Mean
Median
Notes
Chlorine ' > '
WIDB (1989-1990)
NORS (1975)
AWWARF(1987)
McGuire & Meadow
(1988)
EPA(1992b)
(1987-1989)
AWWA Disinfection
Survey (1991)
EPA/AMMWA/CDHS
(1988-1989)
Krasnerelal. (1989)
Large utilities nationwide
80 cities nationwide
National survey
Disinfection byproducts field studies
October 1987 -March 1989
283 utilities nationwide
35 water utilities nationwide
Residual chlorine at average customer
228 SW plants & 21 5 GW plants
Finished water at treatment plant SW
(64),GW(16)
Finished water from:
Lakes
Flowing streams
Groundwater
Mixed-supplies
Free chlorine sampled in distribution
system (45)
Finished water entering the
distribution system
Samples from clearwell effluent in lour
quarters (17)
BDL-3.5
BDL-5
BDL-2.8
BDL-3.2
0.07-5.0
0:3-5.2
0.94
088
-
0.7
1.10
1.5
0.80
033
0.5
1.0
Typical dosaqe
0.6 mg/L
Dose range: 0.1->20
mg/L
2.23
2.33
123
:.oj
90"' percenlile = 28
Chloramlne --
WIDB (1989-1990)
AWWARF (1987)
McGuire & Meadow
(1988)
EPA (1992b)
(1987-1989)
EPA/AMMWA/CDHS
(1988-1989)
Krasnerelal. (1989)
140 utilities nationwide
National survey
Disinfection byproducts field studies
35 water utilities nationwide
Distribution system average
chloramine
Finished water from:
Lakes (30)
Flowing streams (34)
At the plant (11)
Distribution system (8)
Samples from clearwell ettluenl,
lour quarters (13)
0.3-4.8
-
1.2-36
0.1-3.3
0.9 - 5.5
-
-
2.1
14
2.3
1.6
-
15
11
18
90" percenlile = 3 0
Dosaqe:
1.5 mg/L.
2.7mg/L
•
CO
•X)
-p
-------
Exhibit 3-1. Disinfection Byproduct Precursor and Disinfectant Occurrence (Continued)
Survey (Year)
Location
Sample Information
(Number of Systems)
Concentration of Precursors in
Source Water (mg/L)
Range1
Mean
Median
Notes
Chlorine Dioxide
AWWARF(1987)
McGuire & Meadow
(1988)
Gallagher etal. (1994)
Hoehnetal.(1990)
Nationwide plants using CI02
Charleston, WV
New Castle, PA
Gulf Coast Water Authority
Utility in Charleston, WV
-20 surface plants > 25.000
(lakes & streams)
Aug. 12-14, 1990(41)
July 25-28. 1990(33)
(111)
Below filter at plant (2)
Clearwell at plant (1)
Customer D (odor presenl)(2)
Customer E (no odor(1)
0.024-0.78
0.11-0.37
BDL -0.01
0.12
0.05-0.12
0.12
"
0.03
0.22
0.21
0.01
0.12
0.09
0.12
"
BDL
020
0.15
-
Typical CIO, dosage:
0.6 -1.0 mg/L
CIQ,f dosage:
2.05 mg/L
0.5 - 2.0 mg/L
CIQ? dosage:
2.0 mg/L
c
o>
T:
C
.1
a
1 Overall mean range.
2 Overall percentile for all systems.
3 Dosage.
4 Added only to half the plant, and the chlorine dioxide was monitored only in water from that treatment train.
5 Below MDL.
Abbreviations
AMWA Association of Metropolitan Water Agencies
AWWA American Water Works Association
AWWARF American Water Works Association Research Foundation
AWWSCo American Water Works Service Company
BDL Below Detection Limit
CDHS California Department ol Health Services'
DL Detection Limit
DS Distribution System
GW Ground Water
GWSS Ground Water Supply Survey
MDL Method Detection Limit
ND Not Detected
NORS National Organics Reconnaissance Survey
SW Surface Water
TSD Technical Services Division
WIDB Water Industry Data Base
-------
itci-urrfnce
i.jr D'DBP -n Public Dnnnim; Water i
Exhibit 3-2. TOC Occurrence Data from the WIDB in the 1994 Proposed Rule
Source
Grcunawater
Surface Water
Number of
Utilities
57'
. 100
Minimum
(mg/L)
BDL
BDL
Maximum
(mg/L)
15.0
30.0
Percentile (mg/L)
25th
BDL •
2.55
50th
0.84
4.0
75th
1.88
595
Source' 59 FR 38716. July 29. 1994
Exhibit 3-3. Groundwater TOC Levels from the GWSS Reported
in the 1994 Proposed Rule
Source
Groundwater - Chlorine
Groundwater - No Chlorine
All Utilities
Number of
Utilities
654
291
945
Maximum
(mg/L)
14
18
18
Percentile (mg/L)
25th
0.3
0.3
0.3
50th
0.7
0.5
0.6
75th
1.7 '
1.1
1.4
90th
3.3
. 2.2
2.9
Source: 59 FR 38721, July 29.1994
In January 1997, a survey of 298 Information Collection Rule (ICR) utilities was conducted by
McGuire Environmental Consultants for the American Water Works Association (AWWA) Survey. One
of the objectives was to gather TOC data for use in the Microbial Disinfection Byproducts (M-DBP)
stakeholder process to develop the final Stage I DBF rule. Data were requested from surface water systems
serving more than 100.000 people and groundwater systems serving more than 50.000 people in 50 states.
Two hundred seventy-five utilities provided three months of TOC data from September, October, and
November 199,6. Exhibit 3-4 presents results of the statistical analyses, grouped by groundwater (110
treatment plants) and surface water (329 treatment plants) sources (AWWA, 1997).
Exhibit 3-4. TOC in ICR Groundwater and Surface Water Plants:
September-November 1996
Source Water
Groundwater (110 plants)
Surface Water (329 plants)
Number of
Samples
251
888
Range
(mg/L)
0-12.9
0-22.7
Mean
(mg/L)
1.35
3.29
Median
(mg/L)
0.76
2.77
Standard
Deviation
2.312
2.197
Source: AWWA. 1997
Final
3-5
November 13,1998
-------
Occurrence AvSe-ssmcw for D'DBP in Public Dnnkiny V>ater Supplies
Exhibits 3-5 and 5-6 compare the TOC data from the AWWA survey to data used in the Stage 1 DBF
roposal (i.e.. the WIDE and the GW'SS). Groundwater TOC data from the AWWA surve> are consistent
iitn the GWSS. i - wever. the TOC levels in surface waters are significantly lower than those in the 1992
VIDB data. The AWWA survey samples were collected in September. October, and November, while the
VIDB samples were collected at different times over several years. A more accurate estimate of the national
fOC occurrence will be available when one vear of ICR data are collected.
Exhibit 3-5. Comparison of AWWA Survey TOC Data with WIOB Data1
100
90
40
30
20
10
—»—WIDB CI2
--•--WIDB NH2CI
---A---AWWA Survey
5 6
TOC (mg/L)
10
Source Water Data
In 1989, the American Water Works Service Company (AWWSCo) initiated a project to evaluate precursor
concentrations and the occurrence and formation of DBFs at approximately 20 of their 100 water systems.
the majority of which have surface water treatment plants. The systems are located in 10 states, nine of
which are located east of the Mississippi River. This project examined fewer systems in more detail than
did the project described in section 4.1 that monitored 90 systems.
Final
3-6
November 13. 1998
-------
Occurrence \ssessmeni fur D>DBP tn Public Unincmn \\ater <
Exhibit 3-6. Comparison of AWWA Survey TOC Data with GWSS Data'
•oo
30
30
70
t.'
f
£
o ^0
ff
40
30
20
10
n .
-/" — • — GWSS W Softening
0^ - -•- - GWSS v^o Softening
/ . A AWWA Survey
/ .
/
i
I
t
1 2 ' 3 4 5 6 78 9 10
TOC (mgfl.)
' Source Water Data
The data set used from the AWWSCo report was aggregated by sample location to provide a range
of statistics^or precursors and disinfection byproducts. The samples were collected in three phases: for
Phase I during fall 1989 from 16 water treatment facilities, for Phase n during winter 1991 from 19 treatment
facilities, and for Phase in from 21 facilities during summer 1991.
Samples from source waters (mostly surface waters), were analyzed for TOC concentrations in the
fall of. 1989, winter of 1991, and the summer of 1991 to observe seasonal differences. For the 19 source
waters averaged over the winter and summer of 1991, the TOC concentrations ranged from Q.44 to 8.7 and
averaged 4.4 mg/L TOC. The annual median was 3.9 and the 75th percentile-was 7.3 mg/L TOC. Exhibit
3-1 summarizes these statistics (Arora et al., 1994).
State Data
Data provided from a Pre-ICR survey from the state of Utah were aggregated by sample location to
provide a range of statistics for precursors and disinfection byproducts. Samples were taken from large
Final 3-7 November 13, 1998
-------
ce Assessment for DlDBP in Public Dnnkiny Hater
-------
Occurrence Assessment for O/DBP in Public Dnnkina Hater •j
analyzed tor bromide ion i Amy et al.. 1994. Westerhoff et al.. 1994/. Except for 10 utilities known to have
bromide ion-related problems, the utilities were randomly selected from the WIDB to obtain geographical
and pe diversity'. Exhibit 3-1. presented previously, provides these results.
The population-weighted averages for bromide ion concentrations for the randomly chosen large
utilities and randomly chosen small utilities were 0.078 and 0.006 mg/L. respectively. Lake and reservoir
sources were generally lower in concentration than rivers and groundwater. The I0th and 90th percentile
distribution values were 0.0055 and 0.102 mg/L, respectively, for bromide ion. The authors of the University
of Colorado Study suggested that connate seawater may occur ubiquitously and affect the distribution of
bromide ion in drinking water sources.
Seasonal variations in bromide concentrations were minimal. The concentration range across the
groundwater samples was higher, however, than across the samples from lakes and rivers, as shown in
Exhibit 3-8. When the data included the targeted samples (average of 0.210 mg/L), the overall average
increased to about 0.100 mg/L. Although the authors suggested that the values excluding the targeted
facilities were probably more representative of random sampling these data were not available (Amy et al.
1994).
Exhibit 3-8. Bromide Jon Occurrence by Source: 101 Utility Nationwide Study
Statistical Parameter
Number of Samples
Average (mg/L)
Median (mg/L)
Range (mg/L)
Standard Deviation (mg/L)
Lakes
34
0.038
0.023
0.002-0.322
0.054
Rivers
29
0.10.1
0.063
0.004-0.426
0.115 •
Groundwater
36
0.168
0.062
0.002.- 2.690
0.428
Source. Amy et al., 1994; Westemoft et al., 1994
The AWWSCo project also characterizes bromide ion occurrence as shown in Exhibit 3-1. This
project examined fewer systems in more detail than did the project described in Section 4.1 which monitored
90 systems. Samples for bromide were collected from source waters (mostly surface waters) throughout the
treatment train and in the distribution system to observe seasonal differences. These samples were collected
during fall 1989. winter 1991, and summer 1991. For the 19 source waters sampled in both winter and
summer 1991, the mean bromide concentrations were 0.037 and 0.065 mg/L, respectively. The winter
samples ranged from BDL to 0.10 mg/L bromide, while the summer samples ranged from BDL to 0.37 mg/L
Final
3-9
November 13, 1998
-------
Occurrence Assessment for O/DBP in Public Dnnkuit; ^aler
bromide. The median or the u inter samples was 0.03 mg/L and the median of the summer samples
0.0-t m/L.
Sample results for seven full-scale water systems across the country were1 discussed in an AWWA
report examining drinking water ozonation treatment plants. Glaze et al.. 1993 reported. A total of nine
samples were taken from two plants sampled on two separate occasions. Samples of source water were
collected and analyzed for bromide ion. The analytical method used was ion chromatography, which had
a detection level of 0.01 mg/L bromide ion. Exhibit 3-9 presents the results of this effort.
Exhibit 3-9. Bromide Ion and TOC Occurrence in Source Water for Ozone Plants
Plant/Source
Rocky Mount/Tar River
Pakn Beach Pilot Plant/GW
Belle Glade/Lake Okeechobee
Haworth/Oradall Reservoir -
Samte-Rose
N. Bay Regional/ N. Bay Aqueduct
Los Angeles/LA Aqueduct
Los Angeles/LA Aqueduct
El Sobrante/San Pablo Reservoir
Bull Run
State/Province
North Carolina
Florida
Florida
New Jersey
Quebec
California
California
California
California
Oregon
Date Sampled
5/26/90
7/30/90
7/31/90 ' .
8/19/91
2/19/91
10/2/91
7/23/90
• 9/10/91
10/15/91
1/29/91
Bromide Ion
(mg/L)
0.04
0.19
0.24
0.06
-BDL
0.05
0.28
0.22
0.02
BDL .
TOC
(mg/L)
5.76
11.55
25.9
3.89
6.11 ^
2.94
2.56
3.2
' 2.82
11.0
Source: Glaze et at., 1993 • .
Data provided from a Pre-ICR survey from the state of Utah were aggregated by sample location to
provide a range of statistics for precursors. Samples were taken from seven large surface water systems
serving more than 100,000 persons. Each of the treatment plants was sampled at four to six times between
October 1994 and September 1996. -
The TOC and bromide ion concentration results from the source water samples were analyzed using
all data points reported. Individual data points reporting less than the detection limit were converted to zero
and included in the analyses. The means, medians, ranges, and percentile concentrations of TOC and bromide
ion are shown in Exhibit 3-1, presented previously.
Final
3-10
November 13, 1998
-------
<.>ccurrence •Usfssmenr for DtDBP in Public DnnKinq '•'mur lup
3.2 DISINFECTANTS
3.2.1 Chlorine
Chlorine hydrolyzes in water to form hypochlorite and hypochlorous acid. Chlorine and
hypochlontes are used to disinfect drinking water, sewage and wastewater. and swimming pools. They have
also been used for general sanitation and control of bacterial odors in the food industry. In addition, chlonne
is used as a reagent in synthetic chemistry and in manufacturing chlorinated lime (a fabric bleach), detinning
and dezincing iron, and producing synthetic rubber and plastics. Much of the available information comes
from the addition and oxidation reactions with inorganic and organic compounds known to occur in aqueous
solutions. Such factors as reactant concentrations, pH, temperature, salinity, and sunlight influence these
reactions (Stevens and Symons, 1977; Merck Index, 1989; Johnson and Jensen. 1986; White. 1986).
, In the disinfection treatment of drinking water, chlorine is added to water as chlorine gas (CU) or as
calcium or sodium hypochlorite. In water, the chlorine gas hydrolyzes to hypochlorous acid and hypochlorite
ion and is measured as free chlorine residual. Maintenance of a free chlorine residual throughout the
distribution system is important as an indicator for external contamination indicated by an absence of a
residual and for continual bacteria kill. Currently, maximum chlorine dosage is limited by taste and odor
constraints and. indirectly, by regulations on total trihalomethanes (TTHMs). Additionally, the
implementation of the Surface Water Treatment Rule (SWTR) will increase the number of systems using
chlorination and the degree of chlorine dosage due to contact time requirements.
The WIDB contains results from a survey conducted in 1989-90 of approximately 600 drinking water
systems serving more than 50,000 people in the United States. Estimates, based on data from the WIDB. are
that 51 percent of the surface water systems and 77 percent of the groundwater systems in the United States
that serve more than 10,000 people currently use chlonne for disinfection. For those community water
systems serving 25 to 10,000 people, 100 percent of the surface water systems and 50 percent of the ground
water systems use chlorine. Fifteen percent of the noncommunity groundwater systems use chlorine. It is
estimated that the population exposed to chlorine from the use of chlorination alone in community drinking
water systems is 70.3 million from surface water plants and 36 million from groundwater plants serving more
than 10.000 people and is 17.4 million and 16.1 million from surface water systems and groundwater plants
serving between 25 and 10,000 people (WIDB, 1990).
Final 3-11 November 13.1998
-------
<\-turrvnce lisessment fijr D/DBP in Public Drinking
National Surveys
The EPA's 1975 National Organic Reconnaissance Sur\e> iNORS) sampled the drinking water of
SO L'.S water supplies. Of these 80 supplies. 16 had groundwater sources and 64 had surface water sources.
According to survey results, chlorine residuals reportedly ranged from BDL to 2.8 mg/L. with an
approximate median concentration of 0.6 mg/L (Symons et al.. 1975). Exhibit 3-1. presented previously.
provides these results.
In 1987. the American Water Works Association Research Foundation (AWWARF) sponsored a
national survey of trihalomethanes (THMs) conducted by the Metropolitan Water District of Southern
California. As part of this survey, alternate treatment technologies were investigated that would lower THM
levels. According to survey results, typical chlorine dosage in drinking water was 2.2. 2.3, 1.2, and 1.0 mg/L
for systems using lakes, flowing streams, groundwater. and mixed-supplies, respectively, as their raw water
sources. Overall, doses ranged from 0.1 to more than 20 mg/L (McGuire and Meadow, 1988). Exhibit 3-1.
presented previously, provides these results.
EPA's Technical Support Division (TSD) has compiled a data base of its disinfection byproducts
field studies. The studies included a chlorination byproducts survey, conducted from October 1987 to March
1989. In this survey, free chlorine was sampled in finished water at the treatment plant and in the distribution
system. Among 71 finished water samples, concentrations ranged from 0.1 to 5.0 mg/L. with a mean of 1.7
mg/L and a median of 1.4 ug/L.. In the distribution system, the concentrations from 45 samples ranged from
0 to 3.2 mg/L, with a mean and median of 0.7 and 0.5 mg/L, respectively (EPA, I992b). Exhibit 3-1.
presented previously, provides these statistics.
Chlorine residual in drinking water for the average customer was determined using WTDB data from
228 surface water plants and 2IS groundwater plants. For surface water plants, the chlorine residual ranged
from 0 to 3.5 mg/L, with a mean of 0.94 mg/L and a median of 0.80 mg/L. For groundwater plants, values
ranged from 0 to 5 mg/L, with a mean of 0.88 mg/L and a median of 0.33 mg/L (WTDB, 1990). Exhibit 3-1.
presented previously, provides these results.
Five national surveys reported residual levels for free chlorine in U.S. drinking water. The AWWA's
1991 disinfection survey collected data from 283 utilities. Each facility was asked to respond to questions
involving disinfection and quality control. Survey results indicated that mean free chlorine residuals in
drinking water entering distribution systems were found to range from 0.07 to 5.00 mg/L, with a median of
Final 3-12 ' November 13, 1998
-------
• tccurrence A,\vvsmtw for D'DBP in Public L>nnitni>
1.10 mg'L i \\VU \. 1991). The "5th and 90th percentiles wre i .9 and 2.3 mg/L. respectively Residual
chlorine concentrations 97.6 percent of survey respondents was less than or equal to 4.0 mg/L.
3.2.2 Chloramine
Chloramme is used to disinfect drinking water and is formed as a byproduct of chlonnation when
source waters contain ammonia. It is also used as a primary or secondary disinfectant, usually with
chloramine being generated onsite by the addition of ammonia to water following treatment by chlonnation.
The use of chloramines has been shown to reduce the formation of certain byproducts, notably THMs.
relative to chlonnation alone. Chlonnation byproduct formation can be minimized when the ammonia is
added prior to or in combination with chlorine. Ammonia addition reduces the chlorine residual of the water
being treated. In some plants, however, ammonia may be added some time after the addition of chlorine.
allowing the chlorine residual to react with precursor chemicals (Bull and Kopfler, 1990; EPA. 1980: Cooper
et aL 1985).
It has been estimated from the WIDB that 29 percent of community surface water systems and 11
percent of community groundwater systems in the United States that serve more than 10.000 people use
chloramines for disinfection. Approximately 56.5 million people served by these surface water systems and
7.8 million people served by these groundwater systems are exposed to chloramines from disinfection
(WIDE, 1990), with this number increasing as more utilities convert to chloramines for secondary
disinfection in order to control DBF formation.
National Surveys
In 1987, AWWARF sponsored a national survey of THMs conducted by the Metropolitan Water
District of Southern California. According to survey results, typical chloramine concentrations in drinking
water were 1.5 mg/L for systems using lakes and 2.7 mg/L for systems using flowing streams as their raw
water sources (McGuire and Meadow, 1988). These results are presented in Exhibit 3-1.
EPA's TSD has compiled a data base of its disinfection byproducts field studies conducted from
October 1987 to March 1989. For the 11 samples collected at the plant, the data ranged from 1.2 to 3.6 mg/L
for chloramine residuals. The mean and median concentrations were 2.1 and 1.5 mg/L, respectively. For
the eight samples collected in the distribution system, the data ranged from 0.1 to 3.3 mg/L, while the mean
and median concentrations were 1.4 and 1.1 mg/L respectively (EPA, 1992b). Exhibit 3-1. presented
previously, provides these statistics.
Final 3-13 November 13,1998
-------
*>v
-------
<)<.currirncf
nt fur D'DBP in Public Dnnkinq Hater
OnMte analysis used amperometric ntration from Standard Methods for analysis of CIO- and it*
b> product concentrations in generator effluent. Reductive flow injection analysis with colorimetnc det? :tion
is uveful for the determjnation of chlorine dioxide and perhaps chlorite ion (C1O:").
Mo>t utilities that apply chlorine dioxide at dosages of 1 mg/L or slightly greater were able to meet
the currently recommended level of t mg/L for the sum of chlorine dioxide, chlorite ion. and chlorate
concentrations. Furthermore, most utilities were able to meet the maximum residual disinfectant level.
i.MRDL) for C1O; of 0.8 mg/L, which is the level EPA proposed in 1994 for chlorine dioxide.
Concentrations of C1O: in the range of 0.1 to 0.3 mg/L were not uncommon in systems where chlorine
dioxide had been added to source water and the finished water was dosed with free chlorine. During the
study, concentrations approaching 0.6 mg/L were observed in some clearwells after free chlorine had been
added. Exhibit 3-10 identifies the concentrations of C1O: at three utilities.
Exhibit 3*10. Chlorine Dioxide Concentrations in Distribution Systems
Location
Charleston, WV (August 12-14, 1990)
New Castle, PA (July 25-28. 1990)
Gulf Coast Water Authority
Number of
Samples
41
33
111
CIO; Dose
(mg/L)
2.0
- -
0.5-2.0
Concentration in the OS (mg/L)
Range
8DL' - 0.78
0.11-0.37
-
Mean
0.03
0.22
0.21
Median.
BDL .
0.20
0.15
•BDL = 0 1 mg/L.
Source: Gallagher etal., 1994
Local Studies
Hoehn et al. (1990) conducted a study to determine the contribution of drinking water disinfected
with chlorine dioxide to household odors reported at houses in Lexington, Kentucky, and Charleston, West
Virginia. Source waters at both plants were rivers, and samples were collected from the plants and from
houses. The Lexington treatment adds chlorine dioxide to source water at doses of 1.0 mg/L: the treatment
process in Charleston adds 2.0 mg/L of chlorine dioxide. Samples were analyzed using the amperometric
method of Aieta et al. and the flow injection analysis of Gordon et al. Exhibit 3-11 shows chlorine dioxide
concentrations in the Charleston treatment plant and distribution system. Results from sampling at Lexington
were not given.
Final
3-15
November 13. 1998
-------
rtncii \ssessment '"or D/DBP in Public Or:nxin
-------
Occurrence isstwnem !'<>r D'DBP :n Public Dnnifing Utiier Supplies
4. OCCURRENCE OF DISINFECTION BYPRODUCTS
4.1 SOURCES OF 1994 DISINFECTION BYPRODUCT OCCURRENCE DATA
A summary of the disinfection byproduct occurrence data available for the proposed Stage 1
disinfectant/disinfection byproducts rule (D/DBPR) is presented in Occurrence Assessment for Disinfectants
and Disinfection By-Products {Phase 6a) in Public Drinking Water (EPA, 1992). This section of the
document presents occurrence data for the 15 contaminants being considered for regulation under the
proposed rule. The U.S. Environmental Protection Agency (EPA) received comments on the occurrence
document and these"comments were incorporated in this section. The sources of data will be described first
followed by a discussion of the disinfection byproducts (DBPs) being considered in the D/DBPR.
This section briefly describes 10 pertinent data bases cited in the 1992 document and Exhibit 4-1
reports the corresponding results from analyses of the data bases. This exhibit is an extension of Exhibit 2-1
from the 1992 occurrence document and reflects corrections and clarifications in response to comments
received from the D/DBP Technologies Work Group of the Regulatory Negotiating Committee. Additional
regional and local studies were summarized in the 1992 document to further characterize the occurrence of
the Stage I D/DBPs; however, they are not addressed in this document. The most recent data identified in
literature searches, provided by commenters to the proposed rule (FR 59, 38668) and the Notices of Data
Availability (FR 62, 59388; FR 63, 156743) and by peer reviewers have been included in this section.
This section presents the occurrence data on the DBPs for the Stage I D/DBP rule. Although a
number of sources were available to characterize occurrence of DBPs, not all the sources were robust enough
to characterize a national occurrence. For the most recent national occurrence data on total trihalomethanes
(TTHMs) and haloacetic acids 5 (HAA5X a number of sources were available. These sources are
summarized in Section 5 of this document, the American Waterworks Association (AWWA) WaterStats and
the American Water Works Service Company (AWWSCo) datasets were selected for the Regulatory Impact
Analysis for the Disinfectants/Disinfection Byproduct Rule because they are national in scope, contain recent
data, and have a large sample size with sufficient accuracy. Additionally, state compliance monitoring data
are included in this section and in Section 5 to provide a sense of regional variability throughout the nation
for TTHMs and HAA5.
Prior to promulgation of a maximum contaminant level (MCL) of 100 ug/L total trihalomethanes
(TTHMs) in 1979, EPA performed two surveys to obtain information on the occurrence of trihalomethanes
Final 4-1 November 13,1998
-------
re/ite 4j'»'fvsm
-------
f>ccurrenta \ssessment fur D'DBP in Public Drinking ^attr
4.1.4 Community Water Supply Survey
EPA conducted-the Community Water Supply Survey (CWSS) in 1978. The survey examined 1100
drinking water samples provided by 452 systems, including 388 utilities serving populations of less than
10.000. These samples were collected at the treatment plants and in the distribution systems. The survey
included analyses for chloroform, bromofoim. bromodichloromethane. and dibromochloromethane. It should
be noted the samples were one to two years old prior to analysis.
4.1.5 AWWARF National TriHalomethanes Survey
In 1987, the American Water Works Association Research Foundation (AWWARF) partially funded
a grant awarded to the Metropolitan Water District of Southern California (MWD), to perform a national
survey of THMs. The purpose of the THM survey was to determine the extent and costs of compliance with
the THM MCL. Questionnaires were completed by 910 utilities, each serving greater than 10.000 people.
Seven hundred and twenty-seven utilities reported THM data for one or more quarters for the years 1984
through 1986. Data on source water, treatment chemicals used, and populations served were also provided.
The survey involved data collected from more than 67 percent of the population represented by water utilities
serving greater than 10.000 customers.
4.1.6 EPA/AMWA/CDHS Study (35 Utility Study)
In 1987. EPA funded a cooperative agreement with the Association of Metropolitan Water Agencies
(AMWA) to study the formation and control of DBPs in drinking water systems. Thirty-five utilities
nationwide participated in the study performed by the MWD and James M. Montgomery Consulting
Engineers. Inc. (JMM). The California Department of Health Services (CDHS) also contracted with the
MWD to include 10 California utilities in the baseline phase of the study. The study provided data for seven
groundwater systems, six that served greater than 50,000, and 28 surface water systems, 19 served greater
than 50.000. Samples of plant influent and clearwell effluent were collected from each utility, on a quarterly
basis during 1988-89. The clearwell effluent samples were analyzed for chlorine residuals, surrogate
parameters, and several chlprination DBPs, including: THMs, chloral hydrate, dichloroacetic acid, and
trichloroacetic acid. Appropriate dechlorinating agents were added to all samples at the time of collection.
4.1.7 EPA Disinfection Byproduct Field Studies
The Technical Support Division (TSD) of the Office of Groundwater and Drinking Water has
conducted several DBP field studies. A study of chlorination byproducts was performed from October 1987
Final 4-3 November 13, 1998
-------
iv \ssessmeni for D'DBP in Public Dnnkiny Ujter *>uppiitf>
to March I9S9. Samples of source water, plant effluent, and water from a far point in the distribution svstem
were collected from 21 community water supplies. Dismtection processes and concentrations of the- "our
indisidual THMs. chloral hydrate, dichloroacetic acid, and trichloroacetic acid were characterized.
4.1.8 Water Industry Data Base (1991)
The Water Industry Data Base (WIDE) was developed through a joint effort by the American Water
Works Association (AWWA) and the AWWARF. The study, conducted between 1989 and 1990, surveyed
approximately 1.300 drinking water systems serving more than 10.000 people in the United States. A wide
spectrum of information was covered in the survey, including utility characteristics and finances, surface and
groundwater treatments, water quality monitoring, and water distribution characteristics. The WIDB
provides a large data set of annual average TTHM data, free chlorine, and combined chlorine residuals.
Estimates of these levels, based on the professional judgment of utility personnel, were compiled. Because
of the comprehensive nature of the WIDB. the Regulatory Negotiating Committee used this data set in their
regulatory impact analysis.
4.1.9 AWWA 1991 Disinfection Survey
The Disinfection Committee of AWWA's Water Quality Division conducted the AWWA 1991
Disinfection Survey. A total of 283 utilities participated in this study, responding to questions pertaining
to disinfection and quality control, including: control methodology, chlorine demand, filtration, chlorine
dose, contact times, and TTHM levels.
4.2 SOURCES OF POST-1994 DISINFECTION BYPRODUCT OCCURRENCE DATA
Section 4.2 describes occurrence data reviewed by EPA since the 1994 proposed rule. This section
provides data from national surveys, five states' compliance monitoring data, and summarized articles from
current scientific literature.
4.2.1 WaterS tats
The WIDB was replaced by the WaterStats data base in 1996 and is currently maintained by the
AWWA. WaterStats was developed to support the regulatory and legislative efforts of AWWA. assist
AWWA in focusing research activities, and support educational endeavors of AWWA and interested parties.
The 1996 study surveyed 3,162 public drinking water systems in the United States. Of the 956 respondents.
460 systems reported annual TTHM estimates, and 146.systems reported haloacetic acid (HAA) estimates.
Final 4-4 . November 13, 1998
-------
i><.\'urrence Ajsessmenr fur D/DBP in Public Dnnx:ng
The-^e systems were in the L'nited States and also reponed the size of the population ser\ed The >ur\e\
covered a wide spectrum ot" information, including utilip. characteristics and finances, surface and
groundwater treatr--nts. water quality monitoring, and water distribution characteristics. Data from
WaterStats form the basis of the regulatory impact analysis because they are considered the most
representative, comprehensive data on DBFs and precursors.
4.2.2 American Water Works Service Company Monitoring Data
The AWWSCo. the largest investor-owned water utility in the United States, owns and operates more
than 100 water systems. The systems are located in 10 states, 9 of which are east of the Mississippi River.
AWWSCo collected information on the occurrence of DBFs in their distribution systems (Arora et al.. 1994,
1997). AWWSCo provided EPA with a summary of TTHM and haloacetic acids 5 (HAAS) data for
approximately 52 systems for 1991 and 1992. Information, on source water and population served was also
provided.
4.2.3 State Compliance and Other Monitoring
EPA requested all available TTHM compliance monitoring data and HAA data from nine state
agencies. These agencies were selected to provide comparisons to the nationafestimates of occurrence
generated from WaterStats. Five agencies submitted TTHM data on systems serving less than 10,000 people
in addition to their data for systems serving 10,000 or more people. Data from the states of Massachusetts.
Missouri, New Jersey, Oregon, Pennsylvania, and Texas were analyzed and presented. The state of Utah
submitted "pre-Information Collection Rule (ICR) Data." which consisted of monitoring results consistent
with ICR requirements, beginning in October 1994.
More detailed summaries of the national and state data are provided in the following sections on each
of the disinfectants, DBPs, and DBF precursors. More detailed summaries on the surveys and summaries
are provided in Appendix A. Exhibit 4-1, presented previously, summarizes the occurrence data from these
sources. Additional sources of occurrence data were identified during a review of the scientific literature.
Information from these sources are summarized in the'following sections.
4.2.4 , Literature Search
During a literature search, appropriate articles and studies were identified using keywords, including
drinking water, contaminant names, or the Chemical Abstract Service Registry Number for specific
disinfectants and DBPs. The literature searches were performed on several bibliographic services to ensure
Final 4-5 November 13,1998
-------
for D/DBP :n Public Dnnkinq <-\aier iuppiie'i
dentit'ication or' the most available data. In order to focus on the most recent data, only articles published
;ince 1985. and not previously summarized in the documents supporting the proposed rule, were reviewed.
A total of 113 articles were identified from'these searches. Studies conducted in the United States
that best represent national occurrence of a contaminant were selected for this document. If national studies
or monitoring projects were not available for a contaminant, then regional or local studies were cited.
The following information was extracted and summarized from each article: the type of public water
system (e.g.. size, source water, and disinfection process); the analytical methods used and any modifications
to standard methods: occurrence information for disinfectants and DBFs, including range of detections and
means, medians, and percentile rankings of detections; and any conclusions presented in the articles. Some
authors provided additional data from their studies for inclusion in this document.
4.3 DBF OCCURRENCE DATA
4.3.1 Chloroform
Chloroform, the most prevalent THM in drinking water, occurs in public water systems as a result
of drinking water chlonnation and source water contamination. Chloroform is a byproduct of the
chlorination of naturally occurring organic matter in raw water. Several water quality factors such as total
organic carbon (TOC), pH, and temperature affect the formation of chloroform. Surface water systems have
higher frequencies of occurrence and higher concentrations of chloroform than groundwater systems because
humic and fulvic acids are found primarily in surface water sources and since groundwater is a relatively
protected source. Since residual chlorine levels are maintained in water distribution systems for disinfection
purposes, the formation of chloroform continues throughout the distribution system (Stevens and Symons.
1977: EPA. 1980).
Different treatment practices also affect the formation of chloroform. Chloroform levels can be
reduced, although not eliminated, when chloramines are used to disinfect. The reduction is less, however,
when chloramination involves a pre-chlorination step in which a free chlorine residual is maintained through
a portion of the water treatment process prior to the addition of ammonia. Pre-ozonation followed by
chloramination substantially reduces the formation of chloroform. In addition, the use of chlorine dioxide.
rather than chlorine, produces lower levels of chloroform than chlorine (EPA, 1980, Singer, et al.. 1989).
Final 4-6 . Novtmbtr 13, 1998
-------
•*!
I
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary
Survey (Year)"
Location
Sample Information
(No. of Samples)
Concentration in OS (ug/L)
Range
Mean
Median
Chloroform
NORS (1975)
Symonsetal. (1975)
NOMS (1976-1977)
Bull&Kop(!er(1990)
CWSS(1978)
Brass etal. (1981)
RWS (1978-1980)
EPA/AMWA/CDHS
(1988-1989)
Krasner etal. (1989)
EPA(1992b)
(1987-1989)
Arora etal. (1994.
1997)
Niemenski et al.
(1993)
Pre-ICR data (1996)
80 cities nationwide
80%SW.20%GW
1 13 community water supplies
92 SW, 21 GW
450 water supply systems
>600 rural systems
(>2,000 households)
35 Water utilities nationwide
(10 located in California)
Disinfection byproducts field
studies
2 sampling phases 1991
20 water systems
Finished surface water from 35
Utah treatment utilities
State of Utah, 1994-1996
7 SW utilities >100,000 .
Finished water at treatment plant
Finished water at treatment plants'
Finished water (1,1 00):
Surface water
Groundwater
Drinking water from:
Surface water (154)
Groundwater (494)
Samples from clearwell
effluent for 4 quarters
Distribution Systems (56):
SW, 10,000 (39)
SW<10,000(11)
GW< 10,000 (5)
Phase ii:winter 1991 (19 facilities)
Phase iii: summer 1991(21 facilities)
Plant effluent from:
14 utilities >10,000 (SDS Samples)
21 utilities < 10,000 (OS Samples)
Average distribution system samples
Max. 311
Max. 540
-
-
Max. 130
BDL -340
BDL- 111.0
10.22-
39.52
0.51-91.10
2.70-69.80
-
-
90"
8.91
84'
8.91
—
57
58.7
77.2
3.6
38.52
22.24
27.47
23.0
23
22-54.5"
60
BDL
57
BDL
96-15k
14 (overall)
42
27.70
17.24
1970
22.40
Notes
(Pre-THM rule)
Pos detections
92%- 100%'
Pos detections.
97%' SW
34%' GW
Pos. detections:
8T%' SW
17%'GW
75% ol data was below
33
Pos. detections: 98%
90" percenlile
141.0
110.0
9.4
75lhpercentile=54 78
90"' percenlile=94 90
Std. Dev =21
CHCL/TTHM=0 79
75"' percenlile^ 31 93
90'"percenlile=37 18
c
6
CO
-o
O
3
^-
2
-------
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
oo
i
Survey (Year)3
Location
Sample Information
(No. of Samples)
Concentration in DS (ug/L)
Range
Mean
Median
Chloroform (cont'd)
Singer etal. (1995)
Finished surface water from 8
North Carolina treatment plants
Distribution system samples (42)
(June 1991- February 1992)
8-91
41
38
Notes
CHCI/TTHM 079
Bromodichtoromethane
NQRS(1975)
Symons et al. (1975)
NOMS (1976-1977)
Bull AKopfler (1990)
CWSS(1978)
Brass etal. (1981)
RWS (1978-1980)
EPA/AMWA/CDHS
(1988-1989)
Krasner etal. (1989)
EPA (1992b)
(1987-1989)
Arora etal. (1994,
1997)
Niemenskieta!.(1993)
80 Cities nationwide
80%SW,20%GW
1 1 3 community water supplies
(92 SW. 21 GW)
450 water supply systems
>600 rural systems
>2,000 households)
35 Water utilities nationwide
(10 located in California)
(Spring 1988- winter 1989)
Disinfection byproducts field
studies
October 1987 -March 1989
2 sampling phases 1991
20 water systems
Finished surface water from 35
Utah treatment plants
Finished water at treatment plant -
Finished water at treatment plants9
Finished water (1,100):
Surface water
Groundwater
Drinking water from:
Surf ace water (154)
Groundwater (494) .
Samples from clearwell
Effluent for 4 quarters
Distribution Systems (56)
SW> 10,000(39)
SW<10,000(11)
GW< 10,000 (5)
Phase ii: winter 1991 (19 facilities)
Phase iii: summer 1991(21 facilities)
Plant effluent from:
14 plants >10,000 (SDS Samples)
21 plants <10,000 (DS Samples)
Max. 100
Max. 183
-
-
Max. 82
BDL - 100
BDL- 36.00
1.03-14.0
0.10-200
-
-
12'
58'
IT1
7.7'
—
17
17.4
24.8
2.2
11.94
5.08-
5.01
2
5.9-14"
6.8
BDL
11
BDL
6.6 (overall)
4.1 -10"
15
9.25
4.25
4.73
Pos. detections: 90%
Pos. detections 90%
Pos. detections
94%' SW
33%' GW
Pos. detections:
76%' SW
13%'GW
75% of data was below
14
Positive detects 96%'
SW
8,98%'GW
90"' oercentile
35.3
51.0
2.6 & 5.4
75" percenlile= 16.00
90"'percenlile=24.80
-------
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
Survey (Year)"
Location
Sample Information
(No. of Samples)
Concentration In DS (ug/L)
Range
Mean
Median
Notes
Bromodlchloromethane (cont'd)
Singer et al. (1995)
Pre-ICR data (1996)
Finished surface water from 8
North Carolina treatment plants
State of Utah, 1994-1996
7 SW utilities >100,000
Distribution system samples (42)
Average distribution system samples
3-21
1.30-60
6.6
6.73
8.1
6.70
BDCM/TTHM=0 19
Mean TOC-5 25 mg/L
75Ulpercenlile=9l5
90°'percentile=1091
Dibrdmochloromethane
NORS (1975)
Symonsetal. (1975)
NOMS (1976-1977)
Bull &Kopfler (1990)
CWSS (1978)
Brass etal. (1981)
RWS (1978-1980)
EPA/AMWA/CDHS
(1988-1989)
Krasner etal., 1989
EPA (1992b)
(1987-1989)
Arora et al. (1994,
1997)
80 cities nationwide
80%SW,20%GW
1 13 community water supplies
92 SW, 21 GW
450 water supply systems
>600 rural systems
>2,000 households)
35 water utilities nationwide
Disinfection byproducts field
studies
2 sampling phases 1991
20 water systems
Finished water at treatment plant
Finished water at treatment plants'
Finished water (1,100):
Surface water
Groundwater
Drinking water from:
Surf ace water (154)
Groundwater (494)
Samples from clearwell
effluent for 4 quarters
(Spring 1988- winter 1989)
Distribution Systems (56):
SWi 10,000(39)
SW<10,000(11)
GW< 10,000 (5)
Phase h: winter 1991 (19 facilities)
Phase in: summer 1991(21 facilities)
Max. 100
Max. 280
-
-
Max. 63
BDL-41
BDL-26.0
-
-
5.0 •
6.61
8.5'
9.91
—
6.6
6.3
10.4
1.8
3.04
2
BDL - 3"
1.5
BDL
0.8
BDL
3.6 (overall)
2.6-4.5"
3.4
1.60
Pos. detections. 90%'
Pos. detections: 73%'
Pos detections.
67%'
34%'
Pos detections:
56%'
13%'
75% ol data was below
9.1
Pos. detections.92% &
93%
90" percentile
17.3
350
3.6
75"'percentile=315
90"'percenlile=GOO
D
6
CO
a
j-
Hi
JO
£
-------
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
£
o
1
(\
*n
I
Survey (Year)"
Location
Sample Information
(No. of Samples)
Concentration in OS (pg/L)
Range
Mean
Median
Notes
Dibr omochlor omelhane (conl'd)
Niemenski et al.
(1993)
Pre-ICR data (1996)
Singer et al. (1995)
Finished surface water from 35
Utah treatment plants
State of Utah, 1994-1996
7 SW utilities >100,000
Finished surface water from 8
North Carolina treatment plants
Plant effluent from:
14 plants >10,000 (SOS samples)
21 plants <10,000 (OS samples)
Average distribution system samples
Distribution system samples (42)
0.49-10.0
0.20-16.0
BDL-5.90'
-
2.03
0.99 •
1.5
-
0.82
0.83
1.30
-
OBCM/TTHM. o.U4
75mpercenlile=2.70
90"percentile=3.60
DBCM/TTHM<0.02
Bromoform
NORS (1975)
Symonsetal. (1975)
NOMS (1976-1977)
Bull &Kopfler (1990)
CWSS(1978)
Brass etal. (1981)
HWS (1978-1 980)
EPA/AMWA/CDHS
(1988-1989)
Krasner etal. (1989)
EPA (1992b)
(1987-1989)
80 cities nationwide
80%SW,20%GW
113 community water supplies
92 SW (OS samples), 21 GW
450 water supply systems
>600 rural systems
>2.000 households')
35 water utilities nationwide
(10 located in California) .
Disinfection byproducts field
studies
Finished water at treatment plant
Finished water at treatment plants8
Finished water (1.100):
Surface water
Groundwater
Drinking water from:
Surface water '(154)
Groundwater (494)
Samples from clearwell effluent lor 4
quarters
Spring 1988 - winter 1989
Distribution systems (56):
SW> 10.000(39)
SW<10,000(11)
GW< 10.000 (5)
Max. 92
Max. 280
-
-
Max. 72
BDL-10
-
-
2.1'
11'
8.7'
121
"
1.0
0.8
1.4
2.3
BDL
BDL(all 3
phases)
BDL
BDL
BDL
BDL
0.33-0.88k
0.57 (overall)
BDL
DL=0.3
Pos. detections.
13%'SW
26%8 GW
Pos. detections:
18%' SW
12%" GW
75% ot data was below
2.8
Pos. deleclions.45% &
48%
90"1 percenlile
3.1
5.1
39
O
a
£•
s
K:
-------
"»]
I
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
I
Survey (Year)'
Location
Sample Information
(No. of Samples)
Concentration in OS (ug/L)
Range
Mean
Median
Notes
Bromoform (cont'd)
Aroraetal. (1994,
1997)
Niemenski et al.
(1993)
Pre-ICR data (1996)
Singer elal. (1995)
2 sampling phases 1991
20 water systems
Finished surface water from 35
Utah treatment plants
State of Utah, 1994-1996
7 SW utilities > 100. 000 .
Finished surface water from 8
North Carolina treatment plants
Phase ii: winter 1991 (19 facilities)
Phase iii: summer 1991(21 facilities)
Plant effluent from:
14 plants >10,000 (SDS samples)
21 plants <1 0,000 (OS samples)
Average distribution system samples
Distribution system samples (42)
June 1991 -February 1992
BDL-17.0
Max. 0.38
BDL-1.20
-
0.75
—
0.03
-
0.00
—
0.00
-
75"' percenlile^ BDL
90"' percenlile^ 0 90
No detects lor < 10,000
75lhpercentile=BDL
90"percentile=BDL
CHBr/TTHM = BDL
Total Trihalomethanes
NORS (1975)
Symonsetal. (1975)
NOMS (1976-1977)
Bull AKopfler (1990)
RWS (1978-1980)
Brass (1980)
AWWARF (1987)
McGuire & Meadow
(1988)
USEPA/AMWA/CDHS
(1988-1989)
Krasneretal. (1989)
Aroraetal. (1994,
1997)
AWWA(1996)
80 cities nationwide
80%SW,20%GW
1 13 community water supplies
92SW.21GW
677 cities nationwide < 10,000 pop.
154SW.494GW
727 cities nationwide that serve
> 10,000 people
35 utilities nationwide
(10 located in California)
2 sampling phases 1991
20 water systems
460 water utilities
Finished water at treatment plant
Finished water at treatment plant9
Finished water samples (800)
Quarterly mean of finished water
73%SW,27%GW
Samples Irom clearwell effluent lor 4
quarters
Spring 1988- winter 1989
Phase ii: winter 1991(19 facilities)
Phase HI: summer 1991(21 facilities)
Distribution system samples
Max. 482
Max. 784
Max. 313
Max. 360
•*
BDL-142
BDL - 96.0
68
84
36
42
—
55.14
43.2
41
55
18
39
36 (overall)
30-44"
43.0
44.0
go^percenlile^O
90th percenlile-60
90m percenlile=95
75"' percentile=86 00
90"'percenlile=11900
O
O
ce
a-
-------
•>!
I
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
£
N)
Survey (Year)'
Location
Sample Information
(No. of Samples)
Concentration in OS (ug/L)
Range
Mean
Median
Notes
Total Trihakmethanes (cont'd)
Massachusetts
compliance monitoring
data
(1994-1996)
Missouri compliance
monitoring data
(1996-1997)
New Jersey
compliance monitoring
data
(1994-1996)
Oregon compliance
monitoring data
(1994-1996)
Statewide
111 systems reporting
Statewide
Statewide
SW< 10.000 (3)
SW* 10.000(21)
GW> 10.000 (8)
Mixed < 10,000 (2)
Mixed > 10,000 (19)
SW< 10.000 (81)
SW> 10,000 (11)
GW< 10,000(1)
GW> 10,000 (14)
SW< 10.000 (5)
SW> 10.000 (23)
GW< 10,000 (37)
GW> 10.000 (86)
SW> 10,000 (27)
GW> 10.000 (7)
15-75
2-502
BDL-207
2-104
BDL-524
BOL-541
0.7-165
0.6-134
21.86-
88.97
2.31-87.44
BDL- 47.98
BDL- 70.37
7-76
5-31
41
54
46
28
50
118
44.5
14.5
48.0
41.8
6.84
8.93
29
16
37
50
44
12
45
102
37.3
2.8
27.3
38.5
2.59
2.73
-
90"' percentile
71
90
89
83
90
90" percenlile
206
82.5
Single result 48. 7 pg/L
45.6
90" percentile
83.6
70.6
169
31.3
90* percentile
42
28
o
CD
-o
o
0
VO
3
-------
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
Survey (Year)"
Location
Sample Information
(No. of Samples)
Concentration in OS (jig/L)
Range
Mean
Median
Notes
Total Trihatomethanes (cont'd)
Pennsylvania
compliance monitoring
data
(1994-1996)
Texas compliance
monitoring data
(1994-1996)
Singer et al. (1995)
Niemenski et al.
(1993)
Pre-ICR data (1996)
223 systems statewide
(63 purchased SW)
227 systems statewide
(48 purchased SW)
Finished water from Surface water
in 8 North Carolina utilities
Finished water from 35 surface
water utilities in Utah
State of Utah, 1994-1996
7 SW utilities >100,000
Quarterly samples, distributions system
samples
SW < 10,000 (54 systems; 1,676
samples)
SW > 10,000 (1 19 systems; 7,345
samples)
GW < 10,000 (25 systems; 306
samples)
GW> 10.000 (25 systems; 985
samples)
Quarterly samples
SW> 10.000 (114 systems; 2,521
samples)
GW>10,000 (102 systems; 1427
samples)
GW <10,000 (1 1 systems; 32 samples)
Distribution samples (42)
January 1991 -February 1992
14 plants > 10,000 (SOS samples)
21 plants <1 0,000 (dist. samples)
All plants
Average distribution system samples
BDL-162
0.64-113
BDL-159
0.40-40.8
8.05-
135.41
BDL-
121.02
BDL-
120.58
39-82"
28.8-81.6
2.33-215
2.33-215
5.20-87.4
46.0 '
40.0
14.1
8.01
41.10
23.72
26.21
51
50.7
66.2
60.0
31.3
44.5
42.0
2.42
5.47
36.88
14.59
18.85
46
518
62.9
821
32.1
90"' percentile
837
63.8
35.8
17.3
90" percentile
70.35
60.33
52.00
Avg. TTHM/TOX=015
75"' percenlile=40 4
90"' percentile=46.8
00
o
a
I
-------
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
Survey (Year)'
Location
Sample Information
(No. ol Samples)
Concentration in OS (ug/L)
Range
Mean
Median
Notes
Monochloroacetic Acid
Aroraelal. (1994,
1997)
Pre-ICR data (1996)
2 sampling phases 1991
20 water systems
State of Utah, 1994-1996
7 SW utilities >100.000
Phase ii: winter 1991(19 facilities)
Phase iii: summer 1991(21 facilities)
Average distribution system samples
BDL-3.98
BDL-3.80
1.38
0.08
1.19
BDL
90" peicenlile=2.65
90°' percenlile^BDL
Dlchtoroacetlc Acid
EPA/AMWA/CDHS
(1988-1989)
Krasner et al. (1989)
EPA(1992b)
(1987-1989)
Aroraelal. (1994,
1997)
Singer et al. (1995)
Pre-ICR data (1996)
35 water utilities nationwide
(10 located in California)
Disinfection byproducts field
studies
2 sampling phases 1991
20 water systems
Finished Surface water from 8
North Carolina treatment plants
State ol Utah, 1994-1996
7 SW utilities > 100,000
Samples from clearwell effluent for 4
quarters
Spring 1988-winter 1989
Distribution systems (56):
SWi 10,000 (39)
SW<10,000(11)
GW< 10.000 (5)
Phase ii: winter 1991(19 facilities)
Phase iii: summer 1991(21 facilities)
Distribution system samples (42)
Distribution system samples
Max. 46
BDL-75
BDL - 45.2
9-60
BDL -45.23
—
22
28
1.9
17.3
30
17.28
5.0-7.3"
6.4 (overall)
17.0
28
17.00
75% ol data was below
12
DL=0.6
PCS. dejections- 96%
Wpercenlile
48.0
41.0
4.7
75"1percenlile= 15.75
90mpercentile=35.6
75" percenlile=24 24
90" perce.nlile=35.59
Trichtoroacetlc Acid
EPA/AMWA/CDHS
(1988-1989)
Krasner etal. (1989)
35 water utilities nationwide
(10 located in California)
Samples from clearwell effluent for 4
quarters
-
_
4.0-5.8k
5.5 (all)
75% ol data was below
15.3
DL=0.6
o
00
TJ
a
*-
5
19
I
-------
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
Survey (Year)'
Location
Sample Information
(No. of Samples)
Concentration in DS (ug/L)
Range
Mean
Median
Notes
Trtehloroacetjc Acid (cont'd)
EPA(1992b)
(1987-1989)
Aroraetal. (1994,
1997)
Singer etal. (1995)
Pre-lCR data (1996) .
Disinfection byproducts field
studies
2 sampling phases 1991
20 water systems
Finished surface water from 8
North Carolina treatment plants
State of Utah, 1994-1996
7 SW utilities > 100,000
Finished water systems (69):
SW> 10,000 (42)
SW< 10,000 (20)
GW< 10,000 (7)
Distribution systems (55):
SW, 10,000(39)
SW< 10,000 (11)
GW< 10,000 (5)
Phase ii: winter 1991(19 facilities) •
Phase iii: summer 1991(21 facilities)
Distribution system samples (42)
Average distribution system samples
BDL - 54
BDL-77
BDL -83.07
12-79
BDL - 32.20
14.4
14.8
19
17
16.6
1.1
19.79
36
14.18
11
15
16.74
37
14.50
90°'percenlil.'
287
30.4
10.7
Pos. detections 90% &
91%
90"percenlile
306
2B.9
4.2
75* percenlile=:24 98
90" percenlile=37 93
75th percentile; i 6
90"' percentile-;^ JO
Monobromoacetlc Acid ,
Aroraetal. (1994,
1997)
Pre-lCR data (1996)
2 sampling phases 1991
20 water systems
State of Utah, 1994-1996
•7 SW utilities >100,000
Phase n: winter 1991(19 facilities)
Phase iii: summer 1991(21 facilities)
Average distribution system samples
BDL - 4.55
BDL -2.40
0.77
0.10
0.40
BDL
90" percentile=2 48
90"'puicenlile=BDL
Dlbromoacetic Acid
Aroraetal. (1994.
1997)
Pre-lCR data (1996)
2 sampling phases 1991
20 water systems
State of Utah, 1994-1996
7 SW utilities > 100,000
Phase ii: winter 1991(19 facilities)
Phase iii: summer 1991(21 facilities)
Average distribution system samples
BDL - 20.0
BDL -4.70
1.41
0.71
0.58
BDL
90°1percenlile=2.16
90"1 percentile=2,5.5
o
6
CD
-o
a
-o
O
-------
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
Survey (Year)'
Location
Sample Information
(No. of Samples)
Concentration in DS (ug/L)
Range
Mean
Median
Notes
HaloaceticAcids(5)(HAA5)"
EPA/AMWA/CDHS
(1988-1989)
Krasnerelal. (1989)
Arora et al. (1994,
1997)
Missouri compliance
monitoring data (1997)
Singer et al. (1995)
Niemenski et al.
(1993)
Pre-ICR data (1996)
35 water utilities nationwide
(10 located in California)
2 sampling phases 1991
20 water systems
106 systems reporting
January-June 1997
Finished surface water from 8
North Carolina treatment plants
Finished water from 35 surface
water utilities in Utah
State of Utah. 1994-1996
7 SWutyities>1 00,000
Chloral Hydrate
EPA/AMWA/CDHS
fiSUffirOMB)
EPA(1992t>)
(1987-1989)
Arora etal. (1994.
1997)
35 water utilities nationwide
(10 located in California)
Disinfection byproducts field
studies
2 sampling phases 1991
20 water systems
Samples Irom clearwell effluent for 4
quarters
Phase ii: winter 1991(19 facilities)
Phase iii: summer 1991(21 facilities)
SW< 10,000 (81)
SW> 10,000 (11)
GW> 10,000 (14)
All systems (106)
Distribution system samples (42)
Distribution samples (35)
>10.000 (14) (SDS samples)
<10,000 (21) (DS samples)
Average distribution system samples
~
4.69-134.3
0.1-284
0)1-95.8
0.1-43.2
0.1-284
36-106
1.00-89.8
8.06-51.5
1.00-89.8
1.50-57.40
~
41.35
88.0
284
6.8
69.2
77
30.0
19.0
37.3
25.87
4.0-5.8"
5.5(overall)
37.04
80.4
24.1
3.2
56.3
81
20.1
17.7
42.2
47.1
75% ol dala was below
15.3
DU0.6
75" peicen!ile=52.27
90°' percentile=72.35
90" percenlile
165
63.0
17.1
150.4
HAAs4
High TOC, Low Br
75°1percentile=34.40
90"percentile=47.18
Samples from clearwell effluent tor 4
quarters
Finished water:
At the plant (67)
Distribution systems (53)
Phase ii: winter 1991 (19 facilities)
Phase iii: summer 1991(21 facilities)
Max. 22
BDL-25
BDL-30
BDL- 27.33
50
7.8
6.27
1.7-3.0"
2.1 (overall)
2:5
44
4.35
75% ol dala was below
4.1"
DU 0.02(1 si quartet )&
0.01 (thereafter)
Pos. detections:
90%
91%
75"'percentile=8.88
90Blpercenlile= 14.08
a
"0
O
-------
•*]
1
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
Survey (Year)"
Location
Sample Information
(No. of Samples)
Concentration in OS (ug/L)
Range
Mean
Median
Notes
Chloral Hydrate (cont'd)
Niemenski et al.
(1993)
Pre-ICR data (1996)
Finished SW from 6 Utah treatment
plants > 10.000
State of Utah. 1994-1996
7 SW utilities >100,000
SOS samples in June 1990 (4)
Average distribution system samples
0.7 - 3.76 '
BDL-8.60
-
3.43
-
3.35
75mpercenti!e=533
90"'percenlile=6.34
Bromate Ion
Krasnerelal. (1992)
Sorrel), Hautman
(1992)
Grammith (1993)
North American pilot- and full-
scale studies
9 surface waters
MWO demonstration plant
(5.5 MGO)
10 utilities, pilot- and full-scale ozonation
facilities
Finished water plants using ozone (9)
Ozonation sampled at contactor effluent
BDL-20
BDL-6.3
BDL->10
2.5
•
0.75
Oj dose=0.94 - 9 3 mg/L
Br =BDL - 0 33
pH=5.6 - 9.9
MRL=5; 10
TOC=09-26mg/L
MDL=0.4
2 samples BDL
O.,dose=0.75-20mg/l
Br =017-0.5mg/L
pH=7.6 - 8 4
MRL=3
Chlorite Ion
Hoehnelal. (1990)
Bolyardelal. (1993)
2 houses (WV), November 3-4,
1988
4 sites using CI02
Finished water
Below filter at plant (2)
Clearwell at plant (1)
Customer D with odor problems (2)
Customer E with no odor (1)
1 sample in 1990, 4 samples in 1991 (5)
mg/L
1.67-1.04
0.71
0.90-0.31
093
mg/L
0.052-0.74
mq/L
1.36
0.71
0.61
0.93
moA
031
mg/L
mq/L
017
ClOjDoselmo/U
2.0b
CIO., Dose (mq/Ll
0.07 - 2.0
-------
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
.£»
oo
I
Survey (Year)'
Location
Sample Information
(No. of Samples)
Concentration in OS (ug/L)
Range
Mean
Median
Notes
Chlorite Ion (conl'd)
Gallagher etal. (1994)
CMAdatasel(1997)
Charleston, WV
New Castle, PA
Gulf Coast Water Authority, TX
Skagit, WA
Columbus, GA .
65 utilities nationwide using CIO,
August 12-14, 1990 (15)c
July 22-24. 1991(54)
June 1989- April 1991 (40)
September 24-25, 1990(6)
February 19-21, 1991 (4)
October 18, 1991 (9)
Monthly samples
1995-1997(855)
mq/L
0.51-2.41
BDL-0.1
0.1-3.4
0.36-0.38
0.16-0.44
0.16-0.41
rng/L
0.01-2.60"
mg/L
1.0
0.03
0.66
0.37
0.30
0.33
mg/L
0.58
mg/L
0.75
0.03
0.54
0.37
0.31
0.37
mg/L
0.52
CIO, Dose (mg/L)
20?
0.75-1.1
0.5 - 2.0
07
0.5,1.0
0.5,1.0
75th percentile= 0.69
go^percenlile^M?
Chlorate Ion
Hoehn. etal. (1990)
Bolyard etal. (1993)
Gallagher etal. (1994)
CMA data set (1997)
Gordon etal. (1995)
2 houses (WV), November 3-4
4 sites using CIO.,
15 sites using hvpochlorination
Charleston, WV
New Castle, PA
Gulf Coast Water Authority. TX
Skagit. WA
Columbus, GA
65 utilities nationwide using CIO,,
1 1 1 systems using hypochlorination
Finished water
Below filter at plant (2)
Clearwell at plant (1)
Customer D with odor problems (2)
Customer E with no odor ( 1 )
1 sample in 1990, 4 in 1991 (5)
1991 (16)
August 12-14. 1990(16)
July 22-24, 1991(54)
June 1989-April 1991 (40)
September 24-25, 1990 (6)
February 19-21 ,1991 (4)
October 18, 1991 (9)
Monthly samples
1995-1997(855)
,1993-1995(111)
mg/L
0.14-BDL"
BDL*
0.28-0.22
0.28
mg/L
0.02-0.33
0.01-0.66
mg/L
0.08-1.52
0.30-0.58
0.15-1.50
0.09-0.10
0.11-0.23
0 10-0.24
mg/L
0.01-2.401
mg/L
BDL -918
mg/L
0.14
0.25
0.28
mg/L ,
0.18
0.16
6mg/L
024
0.39
0.22
0.10
0.16
0.20
mg/L
0.40
mq/L
049
mg/L
mg/L
0.14
0.08
mg/L
0.14
0.39
0.17
o.to
015
0.22
mg/L
0.23
mg/L
0.16
CIO?dose(mq/L) •
2.0"
CIO, dose (mo/1.)
0.07 - 2.0
NA
CIO, dose (mg/L)
2.0"
0.75-1.1
05-2.0
0.7
0.5, 1.0
0.5,1.0
75"' percentile= 0.38
90"'peicentile-).20
NA
CD
-o
o-
-------
Exhibit 4-1. Disinfection Byproduct Drinking Water Summary (Continued)
Footnotes:
i
a. Dates in parentheses indicate period of sample collection.
b. Chlorine dioxide is added to one of the two treatment trains in the plant with unequal blending of water.
c. One point in three days sampling was an outlier = 3.49 mg/L
d. One point from 855 samples was 5.36 mg/L, which potentially has been a yield sample.
e. Sample interference during analysis-no valid data.
f. One point from 855 samples was 4.42 mg/L, which potentially has been a yield sample.
g. Sampled over three phases.
h. Median concentrations of the three phases.
I. Of systems sampled.
j. Mean of the positives.
k. Range of median for individual quarters.
I. Detection limit was 0.02 u g/L in the first quarter and 0.1 u g/L, thereafter.
m. In the 35 Utility Study, chloral hydrate had a good correlation with chloroform occurrence (r=0.85), while chloral hydrate had a poor correlation with bromolorm levels ® - -0 24)
In one water sample with a low level of bromide ions, chloral hydrate was detected in the distribution system up to 20 ug/L, but for another, bromide levels varied from 0.14 io
0.79 mg/L, resulting in chloral hydrate concentrations of 3.3 to 0.38 ug/L. Xie and Rechow (1992) identified brominated trihaloacelaldehydes in ozonated and chlorinated lluvic
acid solutions containing inorganic bromide ion. However, the formation of these in chlorinated drinking water has not been investigated (Reference Xie, Y and Reckhow, 1992)
n. Range of plants' medians.
o. includes DBAA, DCAA. MBAA. MCAA, and TCAA.
Abbreviations:
AMWA Association of Metropolitan Water Agencies
AWWA American Water Works Association
AWWARF American Water Works Association Research Foundation
BDCM Bromodichloromethane
BOL Below Detection Limit
CDHS California Department of Health Services
CHBr, Bromoform
CHCIj Chloroform
CIO, Chlorine dioxide
CMA Chemical Manufacturer Association
CWSS. . . Community Water Supply Survey
DBCM Dichlorobromomethane
DL Detection Limit
DS Distribution System
GW Groundwater
GWSS Groundwater Supply Survey
ICR Information Collection Rule
JMM James M. Montgomery Engineers, Inc.
MDL Minimum Detection Limit
MGD Million gallons per day
MRL Minimum Reporting Limit
MWD Metropolitan Water District of Southern California
NA Not Applicable
ND Not Detected
NOMS National Organics Monitoring Survey
NORS National Organics Reconnaissance Survey
0, Ozone
RWS Rural Water Survey
SDS Simulated Distribution System
SW Surface Water
TOC Total Organic Carbon
TOX Total Organic Hahde
TSD Technical Services Division
WIDB Water Industry Data Base
c
6
CO
O
-------
occurrence Aivfssme/u fur D'DBP :n P'tblic Dnnkinn ^'iur tuopli
-------
Occurrence isse'ismem for 0/D8P in Public £>n;t»::ntf '^
r'rom 9 6 to 15 ug/L. The maximum detected xalue was 130 ug/L Seventy-five percent ot" the data was
below 53 ug/L for all four quarters (Krasner et al.. 1989: EPA -nd AMW'A. 1989). No samples were taken
from the distribution system.
»
TSD compiled a data base using the results from its chlorination byproducts survey, which was
conducted from October 1987 to March 1989 along with several other EPA DBP field studies. In the
distribution system, the mean chloroform concentrations were 58.7 and 77.2 ug/L for plants serving above
and below 10.000. respectively, with a 90th percentile concentration of 141.0 and 110.0 ug/L for 39 samples
and 11 samples, respectively (EPA, 1992b). The groundwater systems serving less than 10,000 had a mean
chloroform concentration of 3.6 ug/L for five observations, with a 90th percentile of 9.4 ug/L (EPA. 1992b).
Investigators collected samples in the fall 1989, winter 1991, and summer 1991 to observe seasonal
differences for the AVVWSCo project. THM analyses were conducted with EPA Method 501.1. Monitoring
;
data from winter and summer 1991 were used to make statistical estimates. The mean and median
chloroform concentrations in the distribution systems were 38.52 and 27.70 ug/L. respectively (Arora et al..
1994. 1997). Values ranged from BDL to 111.0 ug/L of chloroform. The 90th percentile concentration was
94.90 ug/L (Arbra et al.. 1994, 1997).
State Studies
Utah. Nieminski et al. (1993), from the Utah Department of Environmental Quality and the Utah
Department of Health, studied DBFs in surface water treatment facilities in Utah. All plants used chlorine
for primary and secondary disinfection. The study analyzed treated water for individual THMs. HAAs. and
other halogenated DBFs. Samples were collected from 35 water utilities, including 14 serving more than
10.000 people and 21 serving fewer than 10,000 people. No significant differences in DBP occurrence were
observed in large versus small utilities.
At the 14 larger systems, testing for DBFs was conducted quarterly to observe seasonal variations.
These samples were collected at locations just prior to distribution and held for various periods to simulate
conditions in the distribution system samples. At the small plants, samples were collected annually from the
plant effluents and at the end of the distribution systems.
Samples were collected during three stages of DBP formation: immediately, after a period of time
simulating distribution system detention time and after a seven-day holding time. The first set of samples
Final 4-21 November 13,1998
-------
occurrence ^ssessment for DfDBP in Public Dnnxiny Mater
r'rom each r"acilit> uas presen-ed using 4.6 mg ammonium chloride to 40 mL uater to quench che free
chlorine. The second set of samples from 14 facilities was -tored at a terr.per-ature and time simulating
distribution system conditions to allow free chlorine to react with the precursors. At the end of this period.
the chlorine residual was measured. The third set was held for seven days before quenching and was then
analyzed. EPA Method 551 using a methyl-tert-butyl ether (MTBE) extraction was used rather than pentane
to analyze individual THMs.
In a representative large plant, chloroform was the major THM compound detected, representing 77
percent THMs by weight. The authors provided EPA with analytical results of individual THM species from
the plant effluents not published in the article. Exhibit 4-2 presents the mean, median, and range of plant
effluent chloroform concentrations calculated from these data. It should be noted that concentrations in the
distribution system were up to 40 percent greater than concentrations in the plant effluents.
Exhibit 4-2. Chloroform Concentration in Utah Plant Effluents (June 1990)
Population
>io.ooo '
< 10.000
Number of Systems
14
21
Chloroform (ug/L)
Range
10.2 - 39.5
0.5-91.1
Mean
22.2
27.5
Median
17.2
19.7 '
Source: Nieminski et al., 1993
Utah Pre-ICR Data. Data provided from a pre-ICR survey from the state of Utah were aggregated
by sample location to provide a range of statistics for precursors and disinfection byproducts. Samples were
taken from seven large surface water systems serving more than 100,000 persons. Water was collected from
each treatment plant at several locations within the treatment process and in distribution system four to six
times between October 1994 and September 1996.
The individual and total THM results from two average distribution system samples were analyzed.
Monitoring results from all sampling events were used. Data points reporting below the detection limit
(BDL) were converted to zeros and included in the analyses. The mean and median chloroform
concentrations in the distribution systems were 23,0 and 22.4 ug/L, respectively. Values ranged from 2.7
to 69.8 ug/L of chloroform, and the 90th percentile concentration was 37.2 ug/L.
Final
4-22
November 13, 1998
-------
il'.'currenc? Ai'.veifmffjf for O'DBP :n Public Ori^-.
North Carolina. Drinking water from MX North Carolina utilities u-as evaluated to assess the
occurrence of DBFs in the state (Singer et al.. 1995). Eight water treatment plants provide water for the six
utilities. Because North Carolina has a relatively high TOC concentration in surface water sources of
drinking water (average of 5 mg/L TOC in systems serving populations greater than 50.000), DBF levels
were expected to be higher than levels reported in other studies. Source waters were characterized as
relatively low in bromide ion levels. All plants used chlorine for disinfection; most plants applied chlorine
to the settled water prior to filtration. Sample sets were collected three times from each utility between June
1991 and February 1992 to encompass high- and low-temperature periods. A total of 93 samples were
collected from representative locations in the distribution systems and analyzed for four THMs. four HAAs.
and other DBFs. The sampling locations were those used for THM compliance monitoring.
The average chloroform concentrations in the plant effluents and the distribution systems were 32
and 41 ug/L. respectively. The 42 distribution system samples had a median of 38 ug/L chlo^form. with
a range of 8 to 91 ug/L of chloroform. The average chloroform/TTHM ratio was 0.79, indicating that
chloroform represented 79 percent of the TTHMs measured.
4.3.2 Bromodichloromethane
Bromodichloromethane occurs in public water systems that chlorinate water which contains humic
and fulvic acids and bromide that can enter source waters through natural and anthropogenic means.
Bromide enters source water from several water quality factors such as TOC, pH. and temperature affect the
j
formation of bromodichloromethane. Surface water systems generally have higher frequencies of occurrence
and higher concentrations of bromodichloromethane than groundwater systems since groundwater is a more
protected source. Because residual chlorine is used in water distribution systems for disinfection purposes,
the formation of bromodichloromethane continues throughout the distribution system (Stevens and Symons.
1977; Cooper et al., 1985; EPA, 1980).
Different treatment practices affect the formation of bromodichloromethane. The levels of
bromodichloromethane can be lessened, but not eliminated, when chloramines are used to disinfect. The
reduction is less, however, when chloraminatioh involves a pre-chlorination step in which a free chlorine
residual is maintained through a portion of the water treatment process prior to the addition of ammonia. Pre-
ozonation followed by chloramination substantially controls the formation of bromodichloromethane, but
ozonation prior to chiorination could increase the formation of bromodichloromethane. In addition, the use
Final 4-23 Sovember 13,1998
-------
Occurrence \isetsmenifor D'DBP in Public Dnnxing \\aier >u0
ot'chlorine dioxide rather than chlorine has been shown to produce louer le\els of bromodichloromethane
(Cooper etal.. 1985: EPA. 1980b).
National Surveys
Bromodichloromethane was detected ir, 98 percent of the systems sampled for NORS. The survey
also reported a median concentration of 8 ug/L and a maximum detected value of 116 ug/L. NORS was
performed prior to the 1979 TTHM regulation; therefore, these results are expected to be higher than current
levels (Symons etal.. 1975).
NOMS used two analytical methods to measure bromodichloromethane concentrations at the time
of sampling and to measure the maximum bromodichloromethane concentrations due to the reaction of all
the chlorine residual. Bromodichloromethane was detected during the three phases in more than 90 percent
of the systems sampled. The median concentrations of the three phases ranged from 5.9 to 1.4 ug/L. The
maximum detected value was 183 ug/L (Bull and Kopfler, 1990).
Ninety-four percent of the surface water samples collected for the CWSS detected
j
bromodichloromethane. Bromodichloromethane was detected in thirty-three percent of the groundwater
supplies . For the surface water supplies, the mean and the median were 12 and 6.8 ug/L, respectively. For
the groundwater supplies, the mean was 5.8 ug/L, and the median was below the minimum reporting limit
of 0.5 ug/L( Brass etal., 1981). ' •
RWS detected bromodichloromethane in 76 percent of the surface water supplies and in 13 percent
of the groundwater supplies. For these surface water supplies, the mean and the median concentrations were
17 and 11 ng/L. respectively. For the groundwater supplies detecting bromodichloromethane, the mean was
7.7 ug/L. and the overall median was below the minimum reporting limit of 0.5 ug/L (Brass, 1981).
In the nationwide 35 Utility Study, clearwell effluent samples were analyzed for bromodichloro-
methane. The overall median for all four quarters was 6.6 ug/L, with the medians of the individual quarters
ranging from 4.1 to 10 ug/L. The maximum detected value was 82 ug/L. For all four quarters, 75 percent
of the data was below 14 ug/L (Krasner et al., 1989; EPA and AMWA, 1989).
The TSD has compiled a data base from the results of its disinfection byproducts field studies. The
studies included a chlorination byproducts survey, which was conducted from October 1987 to March 1989.
Final 4-24 November 13,1998
-------
tiir D'DBP in Public Dnnkiny ^aier ~>
In the distribution Astern, the mean was 17.4 and 24.3 ug/'L for plants serving above and below 10.000.
respectively, with 90th percentile bromodichloromethane concentrations of 35.3 and 51.0 ng/L for 3^ and
1 1 10,000
<1 0,000
Number of
Systems
14
21
Bromodichloromethane (ug/L)
Range
1.0-14.1
0.1-20.0
Mean
5.1
5.0
Median
4.3
4.7
Source: Nieminski et al., 1993
Utah Pre-ICR Data. Data provided from a pre-ICR survey from the state of Utah were aggregated
by sample location to provide a range of statistics for precursors and disinfection byproducts. Samples were
Final
4-25
Novtmber 13, 1998
-------
Occurrence Avfe-ssm^n/ for D'DBP in Public Dnnkint; V>ater
iaken t'rom -e\en larse ^urt'ace water systems serving more than 100.000 persons. Each treatment plant ^ js
Campled at several locations in the treatment process and distribution system four to six times between.
October 1994 and September 1996.
The individual and total THM results from two average distribution system samples were analyzed.
Monitoring results from all sampling events were used. Data points reporting below the detection limit were
converted to zeros and included in the analyses. The mean and median bromodichloromethane
concentrations in the distribution systems were 6.7 and 6.7 ug/L. respectively. Values ranged from 1.3 to
16 ug/L. and the 90th percentile concentration was 10.9 ug/L.
North Carolina. Drinking water from six North Carolina utilities was evaluated to assess the
occurrence of DBFs in the state (Singer et al.. 1995). All plants used chlorine for disinfection. Sampling
procedures and analytical methods are the same as those discussed in Section 4.3.1. The average
bromodichloromethane concentrations in the plant effluents and the distribution systems were 7.2 and
8.8 ug/L. respectively. The 42 distribution system samples had a median of 8.1 ug/L, with a range of 3 to
21 ug/L of bromodichloromethane.
4.3.3 Dibromochloromethane
Dibromochloromethane occurs in public water systems that chlorinate water containing humic and
fulvic acids and bromide that can enter source waters through natural and anthropogenic means. Water
quality factors such as TOC, pH, and temperature affect the formation of dibromochloromethane. Surface
water systems have higher frequencies of occurrence and higher concentrations of dibromochloromethane
than groundwater systems because humic and fulvic material are contained primarily in surface water
sources. Since chlorine is used as a residual in water distribution systems for disinfection purposes, the
formation of dibromochloromethane continues throughout the distribution systems (Stevens and Symons.
1977; EPA. 1980; Cooper et al.. 1985).
Different treatment practices affect the formation of dibromochloromethane in drinking water. The
levels of dibromochloromethane can be lessened, although not eliminated, when chloramines are used to
disinfect. The reduction is less, however, when chloramination involves a pre-chlorination step in which a
free chlorine residual is maintained through a portion of the water treatment process prior to the addition of
ammonia. Pre-ozonation followed by chloramination substantially controls the formation of
dibromochloromethane, but ozonation prior to chlorination could increase the formation of
Final . 4-26 - November 13,1998
-------
'>(.•>.• urreru.e 4>wumtw fijr D'OBP in PttPlt<: Dnnkini;
dibromochloromethane. in addition, the use of chlorine dioxide rather than chlorine is expected to produce
lower le\els of dtbromochloromethane (EPA. 1980: Cooper et al.. 1985).
National Surveys
Dibromochloromethane was detected in 90 percent of the systems sampled for the NORS study. This
study also reported a median concentration of 2 ug/L and a maximum level of 100 ug/L for
dibromochloromethane. NORS was performed prior to the 1979 TTHM regulation: therefore, these results
could be higher than current levels (Symons et al.. 1975).
NOMS used two analytical methods to measure dibromochloromethane concentrations at the time
of sampling and to measure the maximum dibromochloromethane concentrations due to the reaction of all
the chlorine residual. Dibromochloromethane was detected during all three phases in 73 percent of the
systems sampled. The median concentrations of the three phases ranged from BDL to 3 ug/L. The maximum
detected value was 280 ug/L (Bull and Kopfler, 1990).
In the CWSS, 67 percent of the surface water supplies and 34 percent of the groundwater supplies
contained dibromochloromethane. For the surface water supplies, the mean supplies that detected
dibromochloromethane and the overall median were 5.0 and 1.5 ug/L, respectively. For the groundwater
supplies, the mean of the positives was 6.6 ug/L, and the overall median was below the minimum reporting
limit of 0.5 ug/L (Brass et al., 1981).
In the RWS, 56 percent of the surface water supplies and 13 percent of the groundwater supplies
detecting dtbromochloromethane. For the surface water supplies containing dibromochloromethane, the
mean of the positives and the overall median concentrations were 8.5 and 0.8 ug/L, respectively. For the
groundwater supplies, the mean of the positives was 9.9 ug/L, and the overall median was below the
minimum reporting limit of 0.5 ug/L (Brass, 1981)
In the nationwide 35 Utility Study, clearwell effluent samples were analyzed for dibromochloro-
methane. The median concentration for all four quarters was 3.6 ug/L, with the medians of the individual
quarters ranging from 2.6 to 4.5 ug/L. The maximum value detected was 63 ug/L. For all four quarters, 75
percent of the data was below 9.1 ug/L (Krasner et al., 1989; EPA and AMWA, 1989).
Finat . 4-27 November 13,1998
-------
Occurrence Assessment for O/DBP in Public Dnnkittz
iuppliei
Dibromochloromethane was sampled for finished water at the treatment plant and in the distribution
>>-tem for the TSD survey. For surface water systems, the distribution system mean was 6.3 and 10.4 iix/L
for plants 10,000
<1 0,000
Number of
Systems
14
21
Dibromochloromethane (ug/L)
Range
0.5-10.0
0.2-16.0
Mean
2.0
1.0
Median
0.8
0.8
Source: Nieminski et al., 1993
Utah Pre-lCR Data. The individual and total THM results from two average distribution system
samples were analyzed for the pre-ICR survey. Monitoring results from all sampling events were used. Data
points reporting below the detection limit were converted to zeros and included in the analyses. The mean
and median dibromochlbromethane concentrations in the distribution systems were 1.5 and 1.3 ug/L.
Final
4-28
November 13. 1998
-------
ihcurrenct \>;ettm*/i; '.or D'OBP :n Public Dnnkins ^ater
re>pecti\el> The data ranged from BDL to 5 9 ug/L of dibromochloromethane. and the 90th percennle
concentration was 3 6 ug/L. Exhibit 4-1 presented previously, summarizes these statistics.
, North Carolina. Distribution system samples collected between June 1991 and February 1992 were
analyzed for dibromochloromethane and had very small quantities (i.e.. less than two percent) of TTHMs
(Singer et al.. 1995). The authors attributed these low levels to the relatively low bromide ion concentrations
in the source waters.
4.3.4 Bromoform
Bromoform occurs in public water supplies that chlorinate drinking water containing humic and
fulvic acids and bromide that can enter source waters through natural and anthropogenic means. Bromide
ion enters source water from geological formations and from saltwater intrusion. In addition, bromide ion
enters the environment from the agricultural use of methyl bromide and the presence of ethylene dibrorrude
in leaded gasoline. Several water quality factors including TOC. pH. and temperature affect the formation
of bromoform. Surface water systems are expected to have higher frequencies of occurrence and higher
concentrations of THMs than groundwater systems due to the presence of organic material: however, the
levels of bromoform in groundwater supplies may be the same or higher than the levels in surface water
supplies due to the,potentially higher occurrence of bromide ion in certain groundwater sources. Because
free chlorine is used as a residual disinfectant in water distribution systems for disinfection purposes, the
formation of bromoform continues throughout the distribution system (Stevens and Symons, 1977: Cooper
etal.. 1985).
Different treatment practices affect the formation of bromoform in drinking water. The levels of
bromoform can be lessened, although not eliminated, when chloramines are used to disinfect. The reduction
is less, however, when chloramination involves a pre-chlorination step in which a free chlorine residual is
maintained through a portion of the water treatment process prior to the addition of ammonia. Pre-ozonation
followed by chloramines substantially controls the formation of bromoform, but ozonation prior to
chlorination could increase the formation of bromoform. In addition, the use of chlorine dioxide is expected
to produce lower levels of bromoform than chlorine (Cooper et al., 1985).
Final 4-29 November 13,1998
-------
Occurrence \s*ie
-------
n,.Ltirrent:e \*'i'e*sment for D/DBP in Public DnnKint?
- - Investigators collected Camples in fall 1989. winter 1991. and summer 1991 to observe se
differences in bromoform concentration for the AWWSCo stu> . THM analyses were conducted with EPA
Method 501 1. Monitoring data from winter and summer 1991 were used to make statistical estimates. The
mean and median bromoform concentrations in the distribution systems were 0.8 ug/L and BDL. respectively
(Arora et al.. 1994. 1997). The data ranged was from BDL to 17ug/L bromoform. and the 90th percentile
concentration was BDL.
State Studies
Utah. Niemi'nski et al. (1993) reported limited data for bromoform. The sample procedures and
analytical methods are the same as those described in Section 4.3.1. Bromoform was only detected in the
systems serving more than 10,000 people. According to the authors, bromoform was only detected in trace
levels, with a maximum detected value of 0.38 ug/L. This comprised one percent of the total THMs detected
at a single representative plant.
Utah Pre-ICR Data. The individual and total THM results from two average distribution system
samples were analyzed. Monitoring results from all sampling events were used. Data points reporting below
the detection limit were converted to zeros and included in the analyses. The mean and median bromoform
concentrations in the distribution systems were 0.03 ug/L and BDL, respectively. The range was BDL to
1.20 ug/L of bromoform, and the 90th percentile concentration was BDL.
North Carolina. Distribution system samples collected between June 1991 and February 1992 were
analyzed for bromoform and had very small quantities (i.e., less than two percent) of TTHMs (Singer et al..
1995). The authors attributed these low levels to the relatively low bromide ion concentrations in the source
waters. '
4.3.5 Total Trihalomethanes
National Surveys
NORS reported a mean and median TTHM concentration of 68 and 41 ug/L. respectively. The
maximum detected value was 482 ug/L. NORS was performed prior to the 1979 TTHM regulation:
therefore, these results are likely to be higher than current levels for systems that disinfect and serve more
than 10.000 (Symons et al., 1975).
Final 4-31 SovemKer 13, 1998
-------
Occurrence Itse-isment fur O'DBP tn Public Dnn»:/it?
NOMS reported mean and median TTHM concentrations of 84 and 55 ug/L. reipecmeK The
maximum detected value was 784 ug/L. N'OMS was conducted before the enactment of the 1979 TTHM
regulation, therefore, these results are likely to be higher than current levels in systems that disinfect and
serve more than 10.000 (Bull and Kopfler. 1990).
The RWS reported mean and median TTHM concentrations of 36 and 18 ug/L. respectively. The
maximum detected value was 313 pg/L. The RWS was conducted before the enactment of the 1979 TTHM
regulation: therefore, these results are expected to be higher than current levels in systems that disinfect and
serve more than 10.000 (Brass. 1981).
In the AWWARF National THMs Survey (McGuire and Meadows. 1988), 727 utilities serving more
than 10.000 people reported TTHM data for one or more quarters for the years 1984 through 1986. Twenty-
seven percent of the utilities used groundwater as their source of drinking water: the remaining 73 percent
used surface water sources. The survey reflected that greater than 67 percent of the population was
represented by water utilities serving more than 10.000 customers. The overall mean and median TTHM
levels were 42 and 39 ug/L. respectively, with a maximum detected value of 360 ug/L.
In the nationwide 35 Utility Study, clearwell effluent samples were analyzed for the four THMs.
The.overall median TTHM for all four quarters was 36 ug/L, with the medians of the individual quarters
ranging from 30 to 44 ug/L (Krasner et al., 1989; EPA and AMWA. 1989).
The AWWSCo study reported that the mean and median TTHM concentrations in the distribution
systems were 55.1 and 43.0 ug/L, respectively (Arora et al., 1994, 1997). The data ranged from BDL to
142 ug/L of TTHM, and the 90th percentile concentration was 119 ug/L. Exhibit 4-1. presented previously.
summarizes these statistics.
The most recent version of Water Stats (AWWA. 1997) provided TTHM data for 460 systems. The
mean value was 43 ug/L. The median and 90th percentile were 44 and 72 ug/L. respectively.
State Compliance Monitoring
Community water systems that serve populations of 10,000 or more and use disinfectants are
required to monitor their drinking water distribution system for TTHMs. The four individual THM species
Final 4-32 Sovtmber 13, 1998
-------
•<>/• D>DBF :n Pupiic
are measured individually, added together, and reported to the state. Many states only track the total of the
four for compliance purposes.
In surface water systems, samples are collected quarterly from one or more points in the distribution
system. Groundwater systems, that serve populations of more than 10,000 and use a disinfectant, initially
collect four quarterly samples, however, these systems could be permitted to reduce sampling to one sample
per year if the measured sample is less than the maximum TTHM potential. EPA requested information
about the results of their TTHM monitoring data for the period between January I. 1994. and December 31.
1996. from nine state agencies. EPA also asked these state agencies to provide available data on
concentrations of individual THMs (i.e.. chloroform, bromodichloromethane. dibromochloromethane. and
bromoform), disinfectant residuals, total and individual HAAs, TOC in raw and finished water, and bromide
ion in raw water. These data were not readily available. However, five states submitted TTHM data for
systems that serve fewer than 10.000 and that disinfect. Non-detect values were calculated as zero for the
averages, which is consistent with the method of determining compliance with the MCL.
Massachusetts. The state of Massachusetts compiled quarterly TTHM data from groundwater and
surface water systems for the period between January 1994 and December 1996. Average TTHM
concentrations and median values were calculated for systems serving populations of less than and greater
than 10.000 persons. Exhibit 4-5 presents the concentrations.
Exhibit 4-5. Summary of Total Trihalomethane Concentrations
from Public Water Systems in Massachusetts (Jan. 1994-Dec. 1996)
Population
Served
Number of
Systems
Number of
Samples
TTHM (ug/L)
Mean
Median
Surface Water
> 10,000
< 10,000
21
3
54
41
"50
37
Range
1-502
1-75
Groundwater (no systems serving <1 0,000)
>1 0,000
8
46
44
BDL-207
Surface Water and Groundwater (mixed)
>10,000
< 10,000
19
2
50
28
45
12
BDL-524
1-104
Source: Massachusetts compliance data
Final
4-33
November 13,1998
-------
' iccurrence
;nr D'DBP :n Puhlic
Missouri. The State of Missouri compiled quarterK TTHM data from grounduater and surface
s> stems for 1996 and 1997. Exhibit 4-6 provides average TTHM concentrations and median -.Jues
calculated for sysiJ ns serving populations of less than and greater than 10.000 persons. Data from four
systems that purchase water were provided but were not included in this summary.
Exhibit 4-6. Summary of Total Trihalomethane Concentrations
from Public Water Systems in Missouri (1996-1997)
Population
Served
Number of
Systems
TTHM (ug/L)
Mean
Median
Range
Surface Water
>10,000
<1 0.000
11
81
44
118
. 37
102
1-165' •
BDL-541
Groundwater
>10,000
<1 0,000
14
1
1.5
49
. 3
-
•1-134
-
Source: Missouri compliance data
New Jersey. The New Jersey Department of Environmental Protection provided compliance
monitoring data for average TTHM concentrations at public water systems for 1994-1996. Exhibit 4-7
presents the average and median concentrations.
Exhibit 4-7. Summary of Total Trihalomethane Concentrations
from New Jersey Public Water Systems (1994-1996)
Population
Served
Number of
Systems
TTHM (ug/L)
Mean
Median
Range
Surface Water
> 10,000 •
<1 0,000
23
5
42
48
39
27
1-87
1^89
Groundwater
>1 0,000
<1 0,000
86
37
9
7
3
3
BDL-70
BDL-48
Source: New Jersey compliance data
Final
4-34
November 13, 1998
-------
\sse^^ment for D/DBP in Public Dnnkiny Uaitr
Oregon. TTHM data for Oregon's public water systems include only er\mg more than
IO.QOO persons. Quarter!;, average TTHM concentrations for each water system were provided fora trree-
year period 11994-1996). Exhibit 4-8 presents the range of average values reported for each system and the
overall average TTHM value that was calculated for eroundwater and surface water svstems.
Exhibit 4-8. Total Trihalomethane Concentrations from Public Water Systems
in Oregon Serving More Than 10,000 Persons (1994-1996)
Source Water
Surface Water
Groundwater
Number of
Systems
27
7
TTHM (ug/L)
Mean
29
16
Median
26
16 •
Range
7-76
5-31
Source: Oregon compliance data
Pennsylvania. The state of Pennsylvania provided compliance monitoring data characterizing
TTHM concentrations in 223 surface water, purchased water, and groundwater treatment systems between
1994 and 1996. Samples were collected quarterly. The data set was limited to samples collected in the
distribution system. Data were aggregated by source and the population being served by the public water
supply. Data from systems using purchased water were included with surface water systems and aggregated
by population served. Exhibit 4-9 presents the mean, median, and ranges of TTHM by water source for
systems serving more than and less than 10,000 persons.
Exhibit 4-9. Pennsylvania Compliance Monitoring Data for Total Trihalomethanes
Population
Served
Number of
Systems
Number of
Samples
TTHM (ug/L)
Mean
Median
Range
Surface Water
>10,000a
<1 0,000° '
119
54
7,345
1 ,676
40
46
42
45
1-113
BDL-162
Groundwater
> 10,000
<1 0.000
25
' 25
985
306
8
14
, 5
2"
BDL-41
BDL-159
Source: Pennsylvania compliance data
a 24 systems using purchased surface water are included.
D 39 systems using purchased surface water are included.
Final
4-35
Sovember 13.1998
-------
' i<:t.urrgni.i
'if fur O'OBP :n Public Onnicny
v/00<.'f>
Texas. The ^uie or' Texas provided compliance monitoring data characterizing TTHM
concentrations in 227 surface water, purchased water, and grpundwater treatment systems between the vears
1994 and 1996. Samples were collected quarterly. Data were aggregated by source and the population being
served b> the public water supply. In the analysis. 47 systems using purchased water were considered
surface uater systems. Systems using groundwater reported data for actual TTHM or potential TTHM
values. Exhibit 4-10'provides the mean, median, and range by water source for systems serving more than
and less than 10.000 persons.
Exhibit 4-10. Texas Compliance Monitoring Data for Total Trihalomethanes
Population
Served
Number of
Systems
Number of
Samples
TTHM 1 0,000*
114
2.521
41
37
8-135
Groundwater4
>1 0.000°
<1 0,000°
102
11
1,427
32
24
26
15
19
BDL-121
BDL-120
Source: Texas compliance data <
a. This class includes 48 systems using purchased surface water.
b. Forty-six systems reported formation potentials.
c. Seven systems reported formation potentials.
State Studies
North Carolina. The TTHM samples were quenched with ammonium chloride at collection and
analyzed by liquid-liquid or pentane extraction and capillary column gas chromatpgraphy/electron capture
detection (GC/ECD) (Singer et al., 1995). The DBF analytes (i.e., THMs, haloacetonitriles, haloketones.
and chloropicrin) were extracted into pentane after saturation with sodium sulfate. THM data resulted in a
mean of 40 |jg/L and a median of 35 ug/L for plant effluent. The distribution system mean and median were
51 and 46 ug/L, respectively. TTHMs in these six utilities constituted an average of 15 percent of the total
organic halides (TOX) concentration, the same percentage as HAAS. The mean TTHM concentration in
North Carolina utilities serving more than 10.000 from 1987 through 1989 was reported as 64 ug/L (Haws
and Singer, 1989).
Final
4-36
November 13,1998
-------
Asi'tfsjmenr fur D'DBP in Public Dnniiing ^ater Nup
Ltah. The sampling and analuical methods used were the same as those discussed in Section - 3 I
i Nieminski et al.. 1993). Exhibit 4-11 provides the ranges, means, and medians of plant effluent and
distribution system TTHM concentrations for samples collected in June 1990.
Exhibit 4-11. Trihalomethane Concentration in Utah Water Treatment Plants
Using Surface Water (June 1990)
System Size
Number of
Samples
TTHM (ug/L)
Range
Mean
Median
Plant Effluent
All Systems
> 10.000
<1 0.000
35
14
21
1.4-97.2
16.2-59.1
1.4-97.2
31.3
28.8
33.0
22.4
21.6
25.4
Distribution System
All Systems
> 10.000*
< 10,000
35
14
21
2.3-215.4
28.8-81.5
2.3-215.4
60.0
50.7
66.2
82.1
51.8
62.9
Source: Nieminski et al., 1993
* SOS samples
TTHMs accounted for 64 percent by weight of all Utah's identified DBFs. In June 1990. the average
TTHM concentration in the 35 plant effluents was 31.3 ug/L, while the average TTHM concentration in the
distribution system was 60.0 ug/L. Seasonal variations at many of the plants were also summarized. Mean
and median values were calculated from data provided for 14 plants. Exhibit 4-12 provides seasonal ranges.
Exhibit 4-12. Seasonal Total Trihalomethane Variation in Utah Plant Effluents
Date
June 1990
September 1990
November 1990
March 1991
Number of
Samples
14
14
11
8
TTHM (ug/L)
Range
16.2-59.1
11.0-55.1
7.0 - 37.5
7.7 - 33.4
Mean
28.8
30.9
20.9
16.6
Median
21.6
32.4
15.9
15.9
Source: Nieminski et al., 1993
Final
4-37
Sovember 13, 1998
-------
Occurrence Aj? Cample location to provide a range of statistics for precursors and disinfection byproducts. Samples ^ere
taken from seven large surface water systems serving more than 100.000 persons. Each treatment plant was
Campled at several locations in the treatment process and distribution system four to six times between
October 1994 and September 1996.
The individual and total THM results from two average distribution system samples were analyzed.
Monitoring results from all sampling events were used. Data points reporting below the detection limit were
converted to zeros and included in the analyses. The mean and median TTHM concentrations in the
distribution systems were 31.3 and 32.1 ug/L respectively. The range was 5.20 to 87.4 ug/L TTHM. and the
90th percentile concentration was 46.8 ug/L. Exhibit 4-1. presented previously, summarizes these statistics.
4.3.6 Monochloroacetic Acid
Monochloroacetic acid occurs in drinking water as a byproduct of disinfection. Monochloroacetic
acid has been found to occur as a disinfection byproduct in public water systems that chlorinate water
containing natural organic material. Similar to other chlorination byproducts, such as THMs. monochloro-
acetic acid levels can be lessened, although not eliminated, when chloramines are used to disinfect. The
reduction is less, however, when chloramination involves a pre-chlorination step in which a free chlorine
residual is maintained through a portion of the water treatment process prior to the addition of ammonia. In
industry, monochloroacetic acid is used as a herbicide, in the synthesis of synthetic caffeine and as a
preservative.
National Surveys , .
The AWWSCo study included monochloroacetic acid analysis. Monitoring data from winter and
summer 1991 were used to make statistical estimates. The mean and median monochloroacetic acid
concentrations in the distribution systems were 1.38 and 1.19 ug/L, respectively (Arora et al., 1994. 1997).
The data ranged from BDL to 3.98 ug/L and the 90th percentile concentration was reported as 2.65 ug/L.
Exhibit 4-1, presented previously, summarizes these statistics.
State Studies
Utah Pre-ICR Data. Data provided from a pre-ICR survey from the state of Utah were aggregated
by sample location to provide a range of statistics for precursors and disinfection byproducts. The individual
Final 4-38 .Vovembtr 13,1998
-------
Occurrence AjVe-vsmen/ f,tr
and total HAA results came t'rom two average distribution s\stem samples Monitoring results r'rom all
sampling events were used. Data points reporting below the detection limit were convened to zeros and
included in the analyses. The mean and median monochloroacetic acid concentrations in the distribution
systems were 0.08 ug/L and BDL. respectively. The data ranged from BDL to 3.80 ug/L monochloroacetic
acid, and the 90th percentile concentration was BDL.
4.3.7 Dichloroacetic Acid
Dichloroacetic acid occurs in drinking water as a byproduct of disinfection. In industry.
dichloroacetic acid is used as a chemical intermediate and in the manufacture of Pharmaceuticals and has
been used as an agricultural fungicide, and as a topical astringent. The medical uses of dichloroacetic acid
include experimental treatment of diabetes and hypercholesterolemia and it is being investigated for possible
use as a hypoglycemic, hypolactemic, and hypolipidemic agent (Merck Index. 1989).
Dichloroacetic acid occurs as a disinfection byproduct in public water systems that chlorinate water
containing humic and fulvic acids. Although dichloroacetic acid levels can be lessened, when chloramines
are used to disinfect byproduct formation is not controlled. The reduction is less, however, when
chloramination involves a pre-chlorination step in which a free chlorine residual is maintained through a
portion of the water treatment process prior to the addition of ammonia.
National Surveys
In the nationwide 35 Utility Study, clearwell effluent samples were analyzed for dichloroacetic acid.
The overall median for the quarterly sampling was 6.4 ug/L, with the medians of the individual quarters
ranging from 5.0 to 7.3 ug/L. The maximum detected value was 46 ug/L. The detection limit for the survey
was 0.6 ug/L. Overall, 75 percent of the data was detected below 12 ug/L (Krasner et al., 1989; EPA and
AMWA. 1989).
Dichloroacetic acid was sampled in finished water at the treatment plant and in the distribution
system for the TSD survey. For surface water systems, the mean concentration in finished water for systems
serving more than and less than 10,000 people was 20.7 and 21.8 ug/L, respectively, with the 90th percentile
of 33.4 and 50.0 ug/L for 42 samples and 20 samples, respectively. In the distribution system, the mean was
22.1 and 27.7 ug/L for plants serving more than and less than 10,000, respectively, with a 90th percentile
concentration of 48.0 and 41.0 ug/L for 39 samples and 11 samples, respectively. The groundwater systems
serving less than 10,000 had a mean dichloroacetic acid concentration in finished water samples and
Final 4-39 November 13.1998
-------
^Sffssmtnt f/>r D'DBP in Public Drinking
distribution >>^tem samples of 2.7 and I 9 ug/L. respectively, for seven and five obser\ations. with a 90th
percentile of 12.5 and 4 7 ua/L. respectively. For systems serving more than 10.000. dichloroacetic acid was
not detected in single samples taken at the plant and from the distribution system based on a detection limit
ot'0.-iug/L
-------
A>s«"rs/7ternr/r)r D/DBP in Publit. Dnrtkinv ^ater -m
protein; Tnchloroaceth: acid is also used in the medical field as a peeling agent for damaged skin, cervical
d\splasia. and tattoo removal (Pringle et al.. 1975: Merck Inc^x. 1990).
Tnchloroacetic acid occurs in public watersystems that chlorinate water containing hurruc and fulvic
acids. Similar to other chlorination byproducts, such as the THMs. trichloroacetic acid levels can be
lessened, although not eliminated, when chloramines are used to disinfect. The reduction is less, however.
when chloramination involves a pre-chlorination step in which a free chlorine residual is maintained through
a portion of the water treatment process prior to the addition of ammonia. In addition, the formation of
trichloroacetic acid is lessened substantially at high pH levels (i.e.. approximately pH 9) (Stevens et al..
1989).
National Surveys
In the nationwide 35 Utility Study, clearwell effluent samples were analyzed for trichloroacetic acid.
The overall median for the four quarters was 5.5 ug/L, with the medians of the individual quarters ranging
from 4.1 to 5.8 )Jg/L. The detection limit for the survey was 0.6 ug/L. Seventy-five percent of the data was
reported below 15.3 ug/L (Krasner et al., 1989;, EPA and AMWA, 1989).
% |
The TSD survey sampled for trichloroacetic acid in finished water at the treatment plant and in the
distribution system. For surface water systems, the mean concentration in finished water for systems serving
more than and less than 10.000 people was 14.4 and 14.8 ug/L- respectively, with the 90th percentile of 28.7
and 30.4 ug/L for 42 samples and 20 samples, respectively. In the distribution system, the mean was 17.0
and 16.6 ug/L for plants serving more than and less than 10,000 people, respectively, with the 90th percentile
concentration of 30.6 and 28.9 ug/L for 39 samples and 11 samples, respectively. The groundwater systems
serving less than 10,000 people had a mean trichloroacetic acid concentration in finished water samples and
distribution system samples of 1.9 and 1.1 ug/L, respectively, for seven observations and five observations.
with the 90th percentile of 10.7 and 4.2 ug/L. For systems serving more than 10,000 people, trichforoacetic
acid was not detected in single samples taken at the plant and from the distribution system based on a
detection limit of 0.4 ug/L (EPA, I992b).
. The AWWSCo study reported mean and median trichloroacetic acid concentrations in the
distribution systems of 19.79 and 16.74 ug/L, respectively (Arora et al., 1994, 1997). The data ranged was
from BDL to 83.07 ug/L of trichloroacetic acid with a 90th percentile concentration of 37.93 ug/L (Arora
et al.. 1994, 1997). Exhibit 4-1, presented previously, summarizes these statistics.
Final 4-41 November 13, 1998
-------
t'.'currrnce 4»it'«mfrt/ ;'.ir D'DBP m Public Dnnk>.iu> Water ^uoo
State Studies
North Carolina. Drinking water from six North •' • .rolina utilities was evaluated to assess the
occurrence of DBFs in the state (Singer et al.. 1995). Samples were collected and analyzed as described in
Section 4.3.7. In the distribution system, the mean and median trichloroacetic acid concentrations were 36
and 37 ug/L . respectisely. The 42 distribution system samples ranged from 12 to 79 ug/L of trichloroacetic
acid. Exhibit 4-14 presents the means, medians, and ranges for the plant effluents and distribution systems.
Exhibit 4-14. Trichloroacetic Acid Concentrations from Six North Carolina
Surface Water Systems
Sampling
Location
Plant Effluent
Distribution
System
Number of
Samples
24 -
42
Trichloroacetic Acid (ug/L)
Range
8-58
12-79
Mean
28
36
Median
28
37
Source: Singer et al., 1995
Utah Pre-ICR Data. The mean and median trichloroacetic acid concentrations in the distribution
systems were 14.2 and 14.5 ug/L, respectively. The data ranged from BDL to 32.2 ug/L of trichloroacetic
acid, and the 90th percentile concentration was 25.3 ug/L.
' , i
4.3.9 Monobromoacetic Acid
National Surveys
The AWWSCo study reported mean and median monobromoacetic acid concentrations in the
distribution systems of 0.77 and 0.40 ug/L. respectively (Arora et al., 1994, 1997). The data ranged from
BDL to 4.55 ug/L of rnonobromoacetic acid, and the 90th percentile concentration was 2.48 ug/L (Arora et
al.. 1994. 1997). Exhibit 4-1, presented previously, summarizes these statistics.
State Studies '
Utah Pre-ICR Data. The mean and median rnonobromoacetic "acid concentrations in the
distribution systems were 0.10 ug/L and BDL, respectively. The data ranged from BDL to 2.40 ug/L of
rnonobromoacetic acid, and the 90th percentile concentration was reported as BDL. Exhibit 4-1. presented
previously, summarizes these statistics.
Final
4-42
November 13, 1998
-------
h currenca Isfetsmtnr for D'DBP in Public
4.3.10 Dibromoacetic Acid
National Surveys
The AWWSCo study reported mean and median dibromoacetic acid (DBAA) concentrations in the
distribution systems of 1.41 and 0.58 ug/L. respectively. The data ranged from BDL to 20.0 ug/L of DBAA.
and the 90th percentile concentration was 2.16 ug/L (Aroraet al.. 1994. 1997).
State Studies
Utah Pre-IGR Data. The individual and total HAA results came from two average distribution
system samples. Monitoring results from all sampling events were used. Data points reporting below the
detection limit were convened to zeros and included in the analyses. The mean and median dibromoacetic
acid concentrations in the distribution systems were 0.71 ug/L and BDL. respectively. The data ranged from
BDL to 4.70 ug/L of DBAA, and the 90th percentile concentration was 2.55 ug/L. Exhibit 4-1. presented
previously, summarizes these statistics.
4.3.11 Haloacetic Acids 5
HAAs occur in drinking water as byproducts of disinfection along with the presence of chlorine or
bromide ions in the system. HAA formation tends to decrease with increasing pH, the opposite formation
from THMs (Singer, et al.. 1996). There are nine chloride and bromide containing HAAs: however.
occurrence data are only provided for five of these compounds, including monochloroacetic acid.
dichloroacetic acid, tnchloracetic acid, monobromoacetic acid, and dibromoacetic acid. HAAS refer to the
sum of the concentrations of these five compounds.
Summers et al. (1997) reported that HAA5 formation decreased when chlorination was moved
further downstream in the coagulation, flocculation, and sedimentation process. This allowed for additional
natural organic matter removal before chlorine could react to form DBFs. Similar to other chlorinated
byproducts, such as THMs, HAA5 can be lessened when chloramines are used to disinfect. Known effects
of HAA5 on humans include reduced blood glucose, reduced plasma levels, reduced plasma cholesterol
levels, and reduced triglyceride levels (EPA, 1994b).
National Surveys
In the nationwide 35 Utility Study, clearwell effluent samples were analyzed for HAAs. The overall
median for all four quarters was 5.5 ug/L, with the medians of the individual quarters ranging from 4.1 to
Final 4-43 Hovember 13,1998
-------
ce \*si Public OnnKing Half 'supplier
?.} ui stems were 41.3 and 37.0 ug/L. respectively. The data ranged was from 4.7 to 134.3 ug/L for HAAS and
the 90th percentile concentration was 72.3 ug/L (Aroraet al.. 1994. 1997). Exhibit 4-1 summarizes these
statistics.
The most recent version of Water Stats (AWAA, 1997) provide HAAS data for 146 systems. The
mean value was 28.1 ug/L. The median value was 25 ug/L. The values ranged from BDL to 91 ug/L.
State Studies
Missouri. The only state to provide HAAS data was Missouri. Exhibit 4-15 presents HAAS data
by source water for systems serving greater than 10,000 and fewer than 10,000 people, respectively. In
January 1997, the State of Missouri Department of Natural Resources initiated quarterly monitoring of
HAAS at all surface water systems and groundwater systems serving 10,000 or more people. Results from
the first two quarters of data are presented in Exhibit 4-15. The means and medians ranged from 32 to
46, ug/L and 29 to 42 ug/L, respectively. As expected, the concentrations of HAAS in groundwater systems
serving greater than 10.000 people were substantially lower. Limited data was available for HAAS in small
systems. In surface water systems serving over 10,000 people, the state of Missouri had mean and median
levels of HAAS of 28 and 24 ug/L, respectively. The state of Missouri also reported HAAS data from
surface water systems serving fewer than 10,000 people. For 81 public water systems, the mean and median
HAAS concentrations were 88 and »0 ug/L HAA5 respectively. The range of HAAS values for these 81
systems was 0.1 to 284 ug/L. The nigh levels are attributed to high source water TOC levels and the fact that
these small systems are not required to comply with the TTHM MCL.
Final 4-44 November 13. 1998
-------
Occurrence \\te\sment lor D'DBP in Public DrnKiny
Exhibit 4-15. Haloacetic Acids 5 Concentrations in Missouri Water Treatment Plants
(1/97-6/97)
System Type and Size
Surface Water Systems
>10.000
Surface Water Systems
<1 0.000
Groondwater Systems
>1 0.000
All Systems
Number of
Systems
11
81
14
' 106
HAAS (\ig/L)
Range
0.1 -95.8
0.1 -284
0.1 -43.2
0.1 -284
Mean
28
88
7
69
Median
24
80
3
56
90th
Percentile
63
165
17
150
Source: Missouri compliance data
North Carolina. Samples were collected and analyzed as described in Section 4.3.7 (Singer et al..
1995). A total of 93 samples were analyzed for four HAAs: chloroacetic acid, dichloroacetic acid,
trichloroacetic acid and bromoacetic acid. Dibromoacetic acid was not analyzed because it was assumed that
it would not be formed to any significant degree with the low-bromide ion source waters. This was indeed
the case with bromoacetic acid, whose concentrations were barely above the detection limits in all samples
analyzed.
Exhibit 4-16 presents results from the HAA analyses. The authors noted that the mean and median
dichloroacetic acid and trichloroacetic acid concentrations were almost as high as the corresponding
chloroform concentrations, unlike other studies in other regions where HAAs were approximately half of the
TTHM concentrations. The HAAs, consisting mostly of dichloroacetic acid and trichloroacetic acid.
comprised an average of 15 percent of the TOX on a chlorine equivalent basis, the same percentage as
TTHMs.
Exhibit 4-16. Haloacetic Acids Concentrations from Eight North Carolina
Surface Water Plants
Sampling
Location
Plant Effluent
Distribution •
System
Number of
Samples
24
42
HAA4(ng/L)
Range
39-80
36-106
Mean
63 -
77
Median
64
81
Source: Singer et al., 1995
Final
4-45
November 13, 1998
-------
\ •isestment for D/DBP in Public Drinking
Utah. Nieminbki et al. (1993) studied DBFs. including HAAs. in water treatment facilities in Utah.
Samples uere collected from 35 water utilities. 14 of" which serve at least 10.000 people and 2! that serve
less than 10.000 people. About 30 percent of all DBFs detected in Utah waters were HAAs. The HAAs were
anaKzed using a micro extraction method similar to that developed by Metropolitan Water District (now
Standard Methods) and EPA Method 552.
HAA5 concentrations were reported for the mean, median, and 25th and 75th percentiles. The mean
plant concentration for the 35 utilities was 17.3 ug/L. with a median concentration of 13.2 ug/L of HAA5.
The 25th and 75th percentiles were 7.13 and 22.60 ng/L HAA5. respectively. The authors noted that
monochloroacetic acid and trichloroacetic acid were the major HAAs detected in the distribution systems.
HAA concentrations reported were somewhat lower than nationwide medians, and the authors attributed
reduced medians to the lower TOC in Utah waters. The statistics were calculated from data provided by the
authors for plant effluent and distribution systems and are presented in Exhibit 4-17.
The authors also noted that although seasonal variation was seen in the results from the 14 large
. plants, no season was significantly lower or higher than the other seasons. Exhibit 4-18 presents data from
the seasonal analysis.
Exhibit 4-17. Haloacetic Acids 5 Concentrations from Thirty-Five Utah
Surface Water Systems
System Size
Number of
Systems
HAAS (ug/L)
Range
Mean
Median
Plant Effluent
All Systems
Medium and Large
Systems
Small Systems
35
14
21
0.3 - 60.6
5.0-24.3
0.3 - 60.6
17.3
12.6
20.5
13.2
'11.3
14.6
Distribution System
All Systems
Medium and Large
Systems
Small Systems
35
14
21
1.0-89.8
8.1-51.5
• 1.0-89.8
29.8
18.6
37.3
20.8
17.7
.42.2
Source: Nieminski et al.. 1993
Final
4-46
Novtmbtr 13,1998
-------
>ccurrence lisetsment fur D'DBP'in Public DnnKinii Hater -i
Exhibit 4-18. Seasonal Analysis of Haloacetic Acids 5 Concentrations
from Thirty-Five Utah Surface Water Systems' Plant Effluents
Date
June 1990
September 1990
November 1990
Marcri 1991
HAAS (M9/L)
Range
6.9-24.3
6.9-42.1
2.1-22.0
4.0-18.8
Mean
12.6
21.1
11.9
11.9
Median
11.3
15.5
14.3
12.9
Source: Nieminski et al.. 1993
The mean and median values were calculated from the data presented in the report.
. \
Utah Pre-ICR Data. Data provided from a pre-ICR survey from the state of Utah were aggregated
by sample location to provide a range of statistics for precursors and disinfection byproducts. Samples were
taken from seven large surface water systems serving more than 100.000 persons. Each treatment plant was
sampled at several locations in the treatment process and distribution system four to six times between
October 1994 and September 1996.
The individual and HAA5 results came from two average distribution system samples. Monitoring
results from all sampling events were used. Data points reporting below the detection limit were converted
to zeros and included in the analyses. The mean and median HAAS concentrations in the distribution
systems were 25.87 and 47.1 ug/L, respectively. The range was from 1.5 to 57.4 ug/L of HAA5, and the 90th
percentile concentration was 47.2 ug/L.
4.3.12 Chloral Hydrate
Chloral hydrate, also known as trichloroacetaldehyde monohydrate, is used as a hypnotic or sedative
drug in humans and in the manufacture of DDT. Chloral hydrate occurs as a disinfection byproduct in public
water systems that chlorinate water containing humic and fulvic acids. Ozonation prior to chlorination
increases the levels of chloral hydrate compared to chlorine disinfection alone. In addition, pre-ozonation
followed by chloramines produces levels of chloral hydrate below that of chlorine disinfection (Jacangelo
et al.. 1989; Merck Index, 1989).
Final
4-47
November 13,1998
-------
u<.\'ur~'>nce ijs^vsme/i/ > 2 occurrence document, two studies described the occurrence of chloral hydrate iri the
nation's drinking water. In the 35 Utility Study, clearv/ell effluent samples were analyzed for chloral hydrate
for 4 quarters (spring, summer, and fall 1988 and winter 1989). The overall median for the quarterly samples
i.vas 2.1 ug/L. with the medians of the individual quarters ranging from 1.7 to 3.0 ug/L. The maximum
t
detected value was 22 ug/L. For all four quarters. 75 percent of the chloral hydrate levels were below 4.1
Ug/L. The detection limits for the survey were 0.02 ug/L in the first quarter and 0.1 ug/L thereafter (Krasner
et al.. 1989: EPA and AMWA, 1989).
In the TSD survey, finished waters at the treatment plant and distribution system waters were
sampled and tested for chloral hydrate. Concentrations ranged from less than 0.2 to 25 ug/L. with a mean
of 5.0 ug/L and a median of 2.5 ug/L for the 67 finished water samples. For the 53 distribution system
samples, concentrations ranged from less than 0.2 to 30 ug/L. with a mean and median of 7.8 and 4.4 ug/L.
respectively (EPA. 1992b).
Chloral hydrate analyses were conducted with EPA Method 551 for the AWWSCo study. The mean
and median chloral hydrate concentrations in the distribution systems were 6.3 and 4.4 ug/L. respectively
f Arora et al.. 1994. 1997). The data ranged was from BDL to 27.3 ug/L of chloral hydrate, and the 90th
percentile concentration was 14.1 ug/L. Exhibit 4-1, presented previously, summarizes these statistics.
*
State Studies
Utah. Nieminski et al. (1993) studied DBFs in water treatment facilities in Utah. Samples were
collected from six large water utilities in Utah (serving more than 10,000 people). The first set of samples
from each facility was preserved using 4.6 mg ammonium chloride to 40 mL water to quench the free
chlorine. The second set of samples from all facilities .was stored at a temperature and time simulating
distribution system conditions to allow free chlorine to react with the precursors. At the end of this period,
the chlorine residual was measured. The third set was held for seven days before quenching and then was
analyzed. Chloral hydrate concentrations between 0.7 and 3.8 ug/L were reported from the four samples
collected in June 1990.
Utah Pre-ICR Data. The chloral hydrate results came from two average distribution system
samples. Monitoring results from all sampling events were used. Data points reporting below the detection
limit were converted to zeros and included in the analyses. -The mean and median chloral hydrate
Final 4-48 November 13,1998
-------
' >ccurry/u-f Aisfssmenr ;,ir D/DRP :n Public Onnxiny
iConcentrations in the distribution systems were 3.4 and 3.4 ug/'L. respective!}.. The data ranged t'rom BDL
to 8 6 ug/L of chloral hydrate, and the 90th percentile concentration was 6.3 (Jg/L. Exhibit 4-1. presented
previously, summarizes these statistics.
4.3.13 Bromate Ion
Bromate ion and organobromine compounds occur in public water systems that treat raw water
containing bromide ion and ozone. Bromide ion occurs in raw waters due to both natural and anthropogenic
sources. Bromide ion can be oxidized to bromate ion or hypobromous acid: however, in the presence of
excess ozone, bromate ion is the principal product (von Gunten and Hoigne. 1994). In laboratory studies.
the rate and extent of bromate ion formation depend on the ozone concentration used in disinfection. pH. and
contact time. Bromate ion can also be produced during chlorihation reactions. However, its formation is
expected to be limited under conditions normally found in drinking water (Glaze, 1988: Singer. 1988; Cooper
et ah. 1985). Bromate has been found as a contaminant in sodium hypochlorite and can therefore also be
found in low bromide waters treated with sodium hypochlorite.
A 1995 review of the conditions for bromate ion formation was conducted by Siddiqui et ah (1995)
to summarize the global occurrence of bromate ion, methods for quantification, chemical formation
pathways, and treatment conditions conducive to bromate ion formation. This review also focused on
identifying methods of minimizing bromate ion formation in drinking water supplies. Bromate ion forms
through reactions'with molecular ozone, which contributes 30 to 80 percent of the overall bromate ion
formation in waters containing natural organic matter. Siddiqui referenced three articles that reported normal
water treatment conditions bromate ion can form in ranges from I to 150 ug/L during the ozonation of
natural waters containing bromide ion (Krasner et al.; Siddiqui and Amy; and Daniel, et ah). Section 3.1.2
summarizes the occurrence of bromide ion. Although bromate ion occurrence data are limited by analytical
detection limits and no comprehensive surveys have been conducted, the data identified" are presented below
(Singer. 1998).
National Surveys
In 1990, the University of North Carolina conducted AWWARF sponsored pilot-plant and full-scale
studies at 10 utilities that treat surface and groundwater with ozone to produce drinking water (Krasner et
ah, 1989; Glaze, 1993). The purpose was to survey ozonation facilities to determine the occurrence and
control of DBFs, including aldehydes, bromate ion, and chlorinated DBFs.
Final 4-49 ' November 13,1998
-------
'h\-urreice Usfvsmtnf for D'DBP :n Public
The 10 full-->caie utilities surveyed provided a matnx of bromide ion levels, ozone dosages. pH
:ve!>. and ammonia concentrations. Bromate ion was analyzed by ion chromatographv. Over the course
t" the srudv the minimum reporting level (MRL) was lowered from 10 to 5 ug/L. For four of the six utilities
. ith background levels of bromide ion of at least 0.06 mg/L. bromate ion was not detected above the MRL
alue at the ozone dosages investigated. For the other two low-bromide ion detection was inconsistent over
pace and time. Values ranged from 5 to 8 ug/L (Krasner et al.. 1989).
Bromate ion concentrations of 5 to 20 ug/L were observed when ozonation (0.94 to 9.3 mg/L) was
:onducted at ambient pH (5.6 to 9.9), bromide ion (less than 0.01 to 0.33), and TOC (0.9 to 26 mg/L) levels.
Dzone dose was determined to be critical in bromate ion formation, although appropriate staging of ozone
hrough two to three contractors can minimize ozone residual and bromate ion formation while still meeting
roncentration time (CT) criteria. Ozone oxidizes bromide ion to hypobromous acid that dissociates into
hypbromite. that, in rum. is oxidized by ozone to bromate ion. Hydrogen peroxide acts as a reducing agent
reducing hypobromous acid, thus preventing the formation of hybromate ion and bromate ion (Symons and
Zheng, 1997). The highest levels of bromate ion correlated with high bromide ion levels and high ozone
doses. As the pH of ozonation was lowered, the required ozone dose dropped, and less bromate ion was
produced.
Bromate ion testing was conducted on state project water (SPW) at MWD's 5.5 million gallons per
day (MOD) demonstration plant in September and October 1992 and April and May 1993 (Grammith et al..
1993). The formation of bromate ion was evaluated for ambient and spiked bromide ion levels (0.17 to 0.49
mg/L). pH levels of 6 to 8.4 and ozone doses ranging from 0.75 to 2 mg/L. Samples for bromate ion were
collected at the contactor effluent. At ambient pH (7.6 to 8.4), ozonation of SPW containing high levels of
bromide ion (0.3 to 0.5 mg/L) produced bromate ion concentration greater than 10 Mg/L. When bromide ion
levels were 0.2 to 0.3 mg/L bromate ion formation ranged from 5 to 10 ug/L. At bromide ion levels below
0.2 mg/L, less than 5 ug/L bromate ion was detected. When the pH of ozonation was lowered to 6.0. bromate
ion levels were below 5 ug/L for all bromide ion concentrations. Higher bromate ion occurrence correlated
with higher ozone doses.
Sorrell and Hautman (1992) developed a concentration technique for analyzing bromate ion at low
levels in drinking water. This procedure used a rotovap.to concentrate drinking water samples, followed by
ion chromatography. Bromate ion was detected with a combination of suppressed conductivity and
ultraviolet absorbance. A minimum detection level of 0.4 ug/L was achieved. This rotary evaporator
Final • 4-50 November 13. 1998
-------
foment for D/DBP in Public Dnivan?
concentration technique '.*.as applied to several surface drinking water sources before and after ozonation.
Bromate ion levels ranged from less than 0.4 to 6.3 ug/L after ozonation. No ozone dosages or bromide ion
levels uere reported.
State Studies
N'iemmski et al. (1993) studied DBFs in water treatment facilities in Utah. Although analyses for
bromate ion were conducted, the authors noted that bromate ion was not detected above the detection level
of 7 ug/L from any of the 35 water utilities plants that use liquid chlorine (sodium hypochlorite). None of
the systems characterized in the study used ozonation. typically a major source of bromate ion.
4.3.14 Chlorite Ion
Chlorine dioxide (C1O:), commonly used as a disinfectant for drinking water purposes since it does
not form THMs. is a good oxidant. and treats taste and odors. However, its use is restricted because of the
potential health risks associated with its presence and the presence of its byproducts, chlorite and chlorate
ions in finished water. The main health effects associated with CIO,, and its byproducts include oxidative
damage to red blood cells, delayed neurodevelopment and decreased thyroxine hormone levels (EPA. 1994).
Chlorite ion (CICv) is formed as an end-product of oxidation-reduction reactions when CIO: reacts
with organic matter and reduced iron and manganese (Gallagher et al., 1994). C1O: concentrations can,
however, be potentially controlled through the addition of a ferrous iron or remove it through the use of
powdered activated carbon (PAC) or granular activated carbon (GAC). CIGy has the potential to form C1O;
or chlorate ion (C1O3") when it reacts with free chlorine in the distribution system (Gallagher et al., 1994)
Chlorite (as the sodium salt) has been used by industry as a bleaching agent and in the manufacture of
shellacs, waxes, and varnishes (EPA, 1994).
National Surveys
Hoehn et al. (1990) conducted a study to determine the role that drinking water disinfected with
chlorine dioxide played in contributing to household odors reported at houses located in Lexington.
Kentucky, and Charleston. West Virginia. The Lexington plant adds chlorine dioxide to the raw water at
doses of approximately 1.0 mg/L. Three customer houses were sampled during the Lexington visit, but. the
sampling results were sampled were not discussed. Two customer houses were sampled during the
Charleston visit: the results are discussed here. The Charleston plant is divided into two identical treatment
trains. Chlorine dioxide can be added to raw water on one side of-the treatment plant, typically at 2.0 mg/L.
Final 4-51 November 13, 1998
-------
ur D'DBP in PuhUc Dnnkinq Mater
Chlorine i^ then added on the other side and. after filtration, the water from each side of the treatment plant
i> blended in a common clearwell. Exhibit 4-19 pro\ides the /hlorite ion results from the two Charleston
houses and the distribution system.
Exhibit 4-19. Chlorite Ion Concentrations at Charleston Plant and Customer Houses
Oxidant
Species
Chlorite Ion
Below Filter
at Plant
November 3
1.67
November 4
1.04
Clearwell
at Plant
November 3
0.71 -
Customer D
November 3
0.90
November 4
0.31
Customer E
November 3
0.93
Source: Hoehn et al., 1990
Bolyard et al. (1993) reported the occurrence of chlorite ion in source water and finished water from
four utilities that use chlorine dioxide. Exhibit 4-20 presents data from systems that use chlorine dioxide.
These data show a wide range of concentrations for chlorite ion. The study concluded that chlorine dioxide
is the source of inorganic contaminants in these sites since the source water for these systems did not contain
measurable concentrations of chlorite and chlorate ions and because gaseous chlorine was used for
chlonnation. The estimated chlorine dioxide varied from 0.07 to 2.0 mg/L. Additional gaseous chlorine was
also added to provide a residual disinfectant level in the distribution system. The concentrations of chlorite
ion in the finished water ranged from 0.02 to 0.74 mg/L.
Exhibit 4-20. Occurrence of Chlorite Ion in Utilities Using Chlorine Dioxide
Utility ID
Number
37
37
44
62
80
Date
9/90
9/91
8/91
8/91
9/91
Source Water
Stream
Stream0
Reservoir5
Stream6
Mixedc
Chlorine Dioxide Dose
-------
Occurrence \ssessment f.ir O'OBP in Public Orirnana H
Gallagher et al. i 1994) evaluated chlorine dioxide byproduct ichlorue ion and chlorate ioni
\vithm the water treatment plant and the distribution systems of six utilities in the United States. Only five
of the utilities were sampled in the distribution system and that data is presented in Exhibit 4-1. The chemical
composition of the chlorine dioxide generator effluents was closely monitored, and the effects of generator
optimization on byproduct residuals within the treatment plants and distribution systems were determined.
The study also evaluated different analytical methods and sample preservation techniques. The resulting data
provide an indication of chlorine dioxide and its byproducts concentrations in water treated with chlorine
dioxide.
Most utilities'that apply chlorine dioxide at dosages of 1.0 mg/L or slightly greater were able to meet'
the currently recommended level of'1.0 mg/L for the sum of chlorine dioxide, chlorite ion. and chlorate ion
concentrations. The level of chlorite ions that appears following chlorine dioxide treatment can be as much
as 70 percent of the applied chorine dioxide dose. During the study, the median concentration of chlorite ion
in the distribution system at locations where the dosage of chlorine dioxide to the raw water was 1.0 mg/L or
less ranged from 0.03 to 0.78 mg/L. The highest levels were observed at a location where the dosage was 2.0
mg/L but was applied to only one-half of the plant flow. Incomplete mixing between the water treated with
chlorine dioxide and the other half of the plant flow was responsible for higher chlorite ion concentrations.
Exhibit 4-21 presents the range and mean concentrations of chlorite in distribution systems.
Exhibit 4-21. Chlorite Ion Concentrations in Water Treatment Plant
and Generator Effluents
Plant/Date
Skagit, WA 1990
Columbus, GA 1 991
Newcastle, PA 1990
Range in Plant Effluent (mg/L)
0.35-0.40
0.21-0.40
BDL-0.11
Mean CIO2 in Plant Effluent
(mg/L)
0.4
0.3
0.04
The Chlorine Dioxide Panel of the Chemical Manufacturer Association (CMA) provided EPA with
data for chlorite ion occurrence at 65 water treatment facilities that are serviced by one generation company.
CMA estimates that the 65 facilities represent between five to 10 percent of the facilities nationwide that use
chlorine dioxide treatment. Greater than 50 percent of the 65 facilities are located in the state of Texas. The
rest of the facilities are located in the states of Kentucky, Missouri, Rhode Island, Georgia, South Dakota.
Oklahoma, and Kansas.
Final 4-53 November 13, 1998 _
-------
' >-::urrence \>v«s/n?n» fur D'DBP in Public Dnnkinv
or these facilities provided monthly monitoring results collected betueen Januar. 1995 and
Januar\ 199". The double blinded data set did not indicate exact sample locations, source u'ater
characteristics, nor .'.lorine dioxide dosages or residuals. EPA Method 300.0 was used to determine chlorite
ion concentrations. The practical quantitation level is 10 ug/L. and the method detection limit is
approximately 1.0 ug/L for chlorite ion. Exhib'r 4-22 presents the data.
Exhibit 4-22. Chlorate Ion and Chlorite Ion Concentrations at Sixty-Five Utilities
Using Chlorine Dioxide
DBF Contaminant
Chlorate Ion
Chlorite. Ion
Concentrations (mg/L)
Range
0.01 -4.42
0.01 -5.36
Mean
0.40
0.58
Median
0.23-
0.52
90th Percentile
1.07
1.02
Source: CMA dataset, 1997
4.3.15 Chlorate Ion
Not only is chlorate ion (C1O3") a byproduct of the inefficient generation of chlorine dioxide and
oxidation reactions between CIO," and the free chlorine residual in the distribution system, it may also be
present as a contaminant in liquid sodium hypochlorite solutions (Gallagher et ai., 1994: Gages. 1997).
Chlorate ion can not readily be moved from the water once it is produced. Like the chlorite ion. chlorate (as
the sodium salt) has been used by industry as a-herbicide, to tan leather, and in the manufacture of dyes.
matches, and explosives (EPA, 1994). v
National Surveys
As mentioned in Section 4.2.14, Hoehn et al. (1990) evaluated the role that chlorine dioxide played
in contributing to household odors reported at houses in Lexington, Kentucky, and Charleston, West Virginia.
Exhibit 4-23 presents the chlorate ion results from the two Charleston houses and the distribution system.
Final
4-54
\ovember 13, 1998
-------
i >f.\"jr'ifrJCg
\r>r D'DBP :n Public Dnnmny M<
Exhibit 4-23. Chlorate Ion Concentrations (mg/L) at Charleston Plant and Customer
Houses
Oxidant
Species
Chlorate Ion
Below Filter
at Plant
November 3
0.14
November 4
*
Clearwell
at Plant
November 3
*
Customer 0
November 3
0.28
November 4
0.22
Customer E
November 3 .
0.28
Source: Hoehn et al.. 1990
"Sample interference during analysis - no valid data.
As reported in Section 4.2.14. Bolyard et al. (1993) reported the occurrence of chlorate ion in source
water and finished water from four utilities that use chlorine dioxide and 15 sites that use hypochlorination
(Cl: + HOC1). Analyses for chlorate ions were performed by direct injection into an ion chromatograph with
suppressed conductivity detection.
Exhibit 4-24 presents data from systems that use chlorine dioxide. These data show a wide range of
concentrations for chlorate ions in these waters. The estimated doses of chlorine dioxide varied from 0.07
to 2.0 mg/L. Additional gaseous chlorine was also added to provide a residual disinfectant level in the
distribution system. The concentrations of chlorate ions in the finished water ranged from 0.02 to 0.33 mg/L.
The concentration of chlorate tons was much higher than the concentration of chlorite ions in the finished
water collected from sites 44 and 62. Both systems use chlorine dioxide as a pre-oxidant. At site 62. the
water is chlorinated before the secondary sedimentation basins and passed through granular activated carbon
(GAC) filters after sedimentation. Powdered activated carbon (PAC), added to the raw water at site 44, is in
contact with the water throughout the sedimentation basins. When PAC acts in a manner similar to GAC.
chlorite ions and excess chlorine from the chlorite ion generator or free available carbon, there is the potential
to form high concentrations of chlorate ions. This may have attributed to the chlorate ion concentration at
site 44. The creation of chlorate ions was higher than would be predicted from the chlorine dioxide dosage
for this site, suggesting that the estimated dosage may be low.
Final
4-55
November 13,1998
-------
Occurrence Aj'svssmenf fur D'OBP in Public Drinking
Exhibit 4-24. Occurrence of Chlorate Ion in Waters from Utilities Using Chlorine Dioxide
Utility ID
Number
37
37
44
62
80
Date
9/90
9/91
. 8/91
8/91
9/91
Source Water
Stream
Stream"
Reservoir
Streanv
Mixed0
Chlorine Dioxide Dose
(mg/tr
2
1
0.1 -0.2
1
0.07
Plant Effluent Chlorite
(mg/L)°
0.11
0.14
0.33
0.31
0.02
Source: Bolyard et al.. 1993
a. Chlorine dioxide dosage was calculated based on feed rates of raw materials, plant'flow on day of sampling, and approximate punty of ieed
material. Dosage is only an estimate, since these data were obtained from the utilities several months after the samples collection.
b. The samples were assumed to have no detectable chlonne dioxide residual on the basis of information from utility personnel. Therefore, the
samples were not purged with an inert gas to remove chlonne dioxide. All samples contained 50 mg EDA/L as a preservative.
c. Source water was analyzed for chlonte ion ana chlorate ion and none was detected above the 10 u,g/L reporting limit.
Exhibit 4-25 presents occurrence data for 15 utilities for 11 systems that use hypochlorination as a
source of chlorine for disinfection. The levels of chlorate ions detected in these Finished waters are generally
in the same range as those for systems that use chlorine dioxide during treatment. The levels of chlorate ions
in the finished water from sites 77 and 87 were much higher than the rest, but the significance of this is not
known because of the limited number of samples analyzed. In two sites, 82 and 83. chlorate ions were present
in the source water. In both case.s. however, higher levels were present in the finished water.
Onsite analysis used amperometric titration from standard methods for analysis of chlorine dioxide
and its byproducts concentrations in generator effluent. Ion chromatography (modified EPA Method 300.0b)
is recommended for the analysis of chlorate at levels as low as those expected in the distribution system when
dosages of chlorine dioxide are in the range of 0.5 to 1.0 mg/L. Preservation with sodium oxalate or ethylene
diamide stabilized samples during shipping and storage for one week. Carbonate and borate effluents were
used to provide better separation of ion chromatography peaks.
As reported in Section 4.2.14, Gallagher et al. (1994) evaluated chlorine dioxide byproducts (chlorite
ion and chlorate ion) levels within the water treatment plant and the distribution systems of five utilities in
the United States.
Final
4-56
November 13, 1998
-------
(Acurrence Assessment ;or D'DBP in Public
Exhibit 4-25. Occurrence of Chlorate Ion in Fifteen Utilities
Using Hypochlorite Solution for Disinfection
Utility 10 Number
(Date)
57
72(7/91)
72(9/91)
73
74
75
76
77 .
78
81
82
83
84
' 85
86
87
Water Source
Stream •
Stream
Stream
Stream
Ground
Stream
Reservoir
Stream
Reservoir
Ground
Ground
Ground
Ground
Ground
Ground
Reservoir
Chlorate Ion Concentration mg/L
Source Water
BDL
NA*
BDL
BDL
BDL
BDL
BDL
BDL
BDL
BDL
0.019
0.023
BDL
BDL
BDL
BDL
Plant Effluent
0.05
0.06
0.04
0.09
0.05
• 0.10
0.13 -
0.63
0.32
0.19 •
0.04
0.08
0.01
0.13
0.01
0.66
Source: Bolyard et al., 1993
* No sample was collected at this sampling point.
The median concentrations for the observed distribution systems ranged from O.I to 0.39 mg/L. A
substantial source of chlorate ions during this project was the chlorine dioxide generator; reactions between
residual chlorite ions and free chlorine most often can be expected to produce the majority of chlorate ions.
These reactions can occur rather rapidly after post-chlorination. Concentrations of chlorate ions in the
distribution systems monitored during this project were not appreciably greater than those in the dearwells
at the treatment plants. Exhibit 4-26 presents the chlorate concentrations collected at three plants.
Final
4-57
November 13.1998
-------
\isessmentf-ir D'DBP in Public Dnnxme ^aier
-------
fiir O'DBP >n
5. NATIONAL OCCURRENCE OF DBFs
The purpose of this section is to characterize the national occurrence of the disinfection byproducts
I DBFs) for the Stage I Disinfectant/Disinfection Byproduct (D/DBP) rule which will be promulgated by
November 1998. Occurrence assessments are required in the regulatory development process for
contaminants with proposed Maximum Contaminant Levels (MCLs). In the proposed Stage I D/DBP rule
(59 FR 38668), MCLs and Maximum Contaminant Level Goals (MCLGs) were proposed for the following
contaminants:
Exhibit 5-1. Stage I D/DBP Rule MCLs
Contaminants
Total trihalomethanes (4)
Haioacetic acids (5)
Bromate ion
Chlorite ion
MCL
0.080 mg/L
0.060 mg/L
0.010 mg/L
1.0 mg/L
MCLG
-
--
0.0 mg/L
0.8 mg/L
For the most recent national occurrence data on total trihalomethanes (TTHMs) and haloacetic
acids 5 (HAAS), a number of sources were available. Of these sources, which are summarized in Section
4 of this document, the American Waterworks Association (AWWA) WaterStats and the American Water
Works Service Company (AWWSCo) datasets were selected for the Regulatory Impact Analysis for the
Stage I Disinfectants/Disinfection Byproduct Rule because they are national in scope, contain recent data.
and have a large sample size with sufficient accuracy. These datasets are used in Chapter 4 of the Regulatory-
Impact Analysis for the Stage 1 Disinfectant/Disinfection Byproducts Rule document to estimate pre-
regulatory baseline concentrations, which factor into the national costs of complying with the new MCLs
and treatments are calculated.
<
State compliance monitoring data are included .here to provide a sense of regional variability
throughout the nation for TTHMs and HAA5 and to provide supplementary occurrence data since no true
comprehensive DBF survey has been done. The state datasets contain information of excellent quality. They
are not, however, national in scope. Sufficient data were not available to characterize the national occurrence
of chlorite ion or bromate ion. The available data are presented in this section for comparison.
Final
5-1
November 13,1998
-------
i\'£urrtnce \ife\wnent tor DiDBP in Public Dnnkin% ^attr
5.1 DATA SOURCES
Summary information and sumrnar. statistics were generated tor the AWWA WaterStats. AWWSCo
compliance data, and state compliance monitoring data for TTHM and HAA5. Information regarding the
data sources, including purpose, objective, and scope, are summarized below. Information for chlorate ion
and bromate ion. although not national in scope, are also summarized. Sections 4.2.13 and 4.2.14 also
discuss the bromate ion and chlorate ion data, respectively.
5.1.1 AWWA WaterStats
WaterStats was initiated through a joint effort by the AWWA and the AWWA Research Foundation
(AWWARF). The purpose of this database is to support the regulatory and legislative efforts of AWWA.
assist AWWA in focusing research activities, and support the educational endeavors of AWWA and
interested parties. In 1996. AWWA surveyed approximately 3.162 drinking water systems serving
populations exceeding 10,000 in the United States. The response rate was better than 30 percent, resulting
in TTHM. HAA5. and population-served information for approximately 300 systems in the United States.
The survey covered a wide spectrum of information, including utility characteristics and finances, surface
and groundwater treatments, water quality monitoring, and water distribution characteristics. The data
gathered in this survey comprise WaterStats.
The data in WaterStats characterize distribution system concentrations for TTHM and HAA5. These
distribution system data were also characterized by source water and the population served. The data
represented annual averages based on quarterly sampling for TTHMs and HAA5 in systems that chlorinate.
WaterStats was examined for data consistency and outliers, assumptions associated with the data, and
possible analysis methods. The WaterStats data base was assumed to be a representative sample of the water
systems in the United States serving greater than 10,000 people.
i
Many systems in WaterStats had multiple records for an individual plant. The data were presented
as plant concentration values. The samples, however, were taken from the distribution systems. The values
for shared distribution systems were presented for each plant contributing to the finished water. TTHM data
for all plants within a single distribution system were compared. This comparison showed that TTHM and
HAAS data were the same among all plants within a single distribution system. Therefore, system data were
. extracted from the database and the analyses were conducted on a system, not a plant, level.
Final 5-2 November /J, 1998
-------
fur DiDBP in P'tpiu Dr/i^iny -l-j/vr
Funher examination of the data showed that several TTHM and HAA5 values were reported a.s zero.
These values were excluded from the analysis because they were believed to represent data entry error and
not to be reflective of detection lirruts. In addition, obviously incorrect data points, systems outside the
L'mted States, and systems with .incomplete data were excluded from the analysts. After applying these
restrictions to the data. 460 systems with valid TTHM data and 146 systems with valid HAA5 data were
available for analysis. 4
5.1.2 A WWSCo Monitoring Data
AWWSCo, the largest investor-owned water utility in the United States, owns and operates more
than 100 water systems in 21 states. The utility generated a system-wide summary of DBFs in the
distribution systems of their water treatment plants. Upon request, AWWSCo provided a summary to EPA
of TTHM and HAA5 data for approximately 92 systems 1991 and 1992. For many of these systems.
AWWSCo also provided source water and population information. The data for TTHM and HAA5 were
reviewed for source water and population information. In the complete data set. 92 systems had TTHM data
and 85 systems had HAA5 data. Only 52 surface water systems, however, provided both TTHM and HAAS
data and the corresponding population and source water data. The data from these systems are used to
characterize TTHM and HAAS occurrence. These data were summarized by Arora et al. (1994 and 1997).
5.1.3 State Compliance Monitoring Data
EPA requested TTHM compliance monitoring data and HAAS data, if available, from nine states.
These states were selected to provide regional, demographic, and source type diversity. THM monitoring
is required in all surface water plants serving 10,000 or more people. The same is true for groundwater
systems that add a disinfectant in the treatment process. Section 4 includes summary reviews of the state
data.
The states of Massachusetts, Missouri, New Jersey, Oregon, Pennsylvania, and Texas submitted
quarterly or annual TTHM sample results, Public Water Supply Identification Numbers, populations served.
source water types and sample collection dates for the 3-year period between January 1994 and December
1996. The state of Missouri provided the same information for January 1996 through June 1997. Although
TTHM monitoring at systems serving fewer than 10,000 people is discretionary, the states of Massachusetts.
Missouri. New Jersey, Pennsylvania, and Texas submitted TTHM results from smaller systems that disinfect.
Compliance with the TTHM MCL may or may not be required in these states for systems serving fewer than
10,000 people. Missouri is the only state that has provided HAA5 data.
Final 5-3 November 13, 1998
-------
i><-*urrem-e
ijr OiDBP in Public
5.2 TTHM DATA
TTHNt daca were asailable from seseral sources repr. enting various cross sections of the nation.
WaterStats. a national survey of public and private water systems, represents data from across the countv
The AWWSCo data, representing the largest private water utility in the nation, were compiled from water
s> stems from approximately 18 states. Exhibit 5-2 presents the mean, median, and 90th percentile of the
occurrence data. A discussion and comparison of the TTHM results from these two datasets appears in
Chapter 4 of the Stage I Regulatory Impact Analysis for the Stage I Disinfectant/Disinfection Byproducts
Rule.
Exhibit 5-2. Summary Statistics on TTHM Based on WaterStats and AWWSCo
Data Source
WaterStats 1996
AWWSCo 1991
AWWSCo 1992
Number of Systems
• 308
52 '
52
TTHM (ug/L)
Mean
44
54 .
64
Median
45
59
65
90th Percentile
72
83
87
In addition to the data in WaterStats and AWWSCo, state monitoring data, including information
from many small systems, were collected from six states. For comparison purposes. Exhibits 5-3 and 5-4
present the assembled TTHM data by source water and population served. In Exhibit 5-3, which focuses on
surface water and groundwater systems serving more than 10,000 people, the TTHM means and medians
ranged from 29 to 64 ug/L and 26 to 65 ug/L, respectively for surface waters. The 10th percentiles from all
of the different data sets ranged from 13 to 35 ug/L, and the 90th percentiles ranged from 42 to 89ug/L. As
expected, the TTHM concentrations for groundwater systems serving more than 10,000 people were
substantially lower. The ranges of means and medians were 8 to 44ug/L and 3 to 15 ug/L, respectively. The
1 Oth percentiles dropped to. a range of 0 to 2 ug/L. and the range of 90th percentiles fell to 17 to 60 ug/L.
For systems serving fewer 10,000 people (Exhibit 5^*), large sample sets of TTHM data were
available only from state monitoring data. For surface water systems, the states of Missouri and North
Carolina had means of 118 and 64 ug/L, respectively. Missouri exhibited high TTHM values for small
systems with a median of 102 ug/L and a 90th percentile of 206 ug/L. Because these systems are not
required to comply with the TTHM MCL, the concentrations are much higher than in large surface water
systems. The small'systems in North Carolina, however, had TTHM levels similar to the large systems with
a !0th percentile of 18.3 ug/L, a median of 43.8 ug/L, and a 90th percentile of 89.6 ug/L.
Final
5-4
November 13. 1998
-------
• OBP :n
Exhibit 5-3. TTHM Compliance Monitoring Data (1994-1996):
Surface and Groundwater Systems Serving Greater Than 10,000 People
Source
Number of
Systems
Mean (ug/L)
Percentiie(ug/L)*
10
20
50
80 | 90
Surface Water
Massacniisens
Missouri
New Jersey
Oregon
Pennsylvania
Texas •
Waterstats. 1996
AWWSCo. 1991-
AWWSCo. 1992
21
11
23
27
119
114 .
308
52
52
54
45
42
29
40
41
44
57
64
18
• 13
15
17
15
15
17
28
35
27
21
21
19
20 -
22
24
39
47
50
37
39
26
42
37
45
59
, 65
75
68
61
40
58
56
64
74
83
89
83
71
42
64
70
72
83
87
Groundwater
Massachusetts
Missouri
New Jersey
Oregon
Pennsylvania
Texas
8 •
14
86
7
25
102
44
14
9
16
8
24
-
1
0
-
1
2
-
2
1
-
2
,5
-
3
3
-
6
15
-
27.
11
-
9
39
- .
46
•31
-
17
60
'Percentiles were not calculated for sources reporting less than 10 systems for a category.
Final
5-5
November 13, 1998
-------
\s^essment for DiDBP in Puhiic OmiKing \\aur
Exhibit 5-4. Comparison of State TTHM Data for Systems
Servings Fewer Than 10,000 People
Source
Number of
Systems
Mean (pg/l)
Percentile (ug/L)*
50
90
Surface Water
Massachusetts
Missouri
North Carolina
New Jersey
Pennsylvania
3
81
66
5
54
42
118
64
48
46
-
102
44
-
45
-
206
90
-
84
Groundwater
Missouri
North Carolina
New Jersey
Pennsylvania
Texas
1
1.217
37
25
11
49
8
7
14
26
-
2
. 3
2
- 19
-
18
16
36
52
'Percentiles were not calculated for sources reporting fewer than 10 systems for a category.
The groundwater TTHM levels for small systems in New Jersey and North Carolina exhibited
TTHM levels lower than those for medium and large groundwater systems. The mean and median TTHM
values for New Jersey were 6.8 and 2.6 ug/L, respectively. The mean and median TTHM values for North
Carolina were 7.8 and 2.0 ug/L. respectively.
5.3 HAAS DATA
HAA5 data were also available in the WaterStats and the AWWSCo data. The only state to provide
HAAS data was Missouri. Exhibit 5-5 presents HAA5 data by source water for systems serving greater than
10.000 people. In January 1997, the state of Missouri Department of Natural Resources initiated quarterly
monitoring of HAAS at all surface water systems and groundwater systems serving 10,000 or more people.
Exhibit 5-6 presents results from the first 2 quarters of data. The means and medians ranged from 32 to 46
(jg/L and 29 to 42 ug/L, respectively. As expected, the concentrations of HAAS in groundwater systems
serving greater than 10.000 people were substantially lower than the concentrations in surface water systems.
Final
5-6
Novtmber 13, 1998
-------
Exhibit 5-5. Comparison of HAAS Data for Systems Serving Greater,Than 10.000 People
Source
Number of
Systems
Mean (ug/L)
Percentile (pg/L)'
10
20
Surface Water
Missouri, 1997
WaterStats. 1996
AWWSCo. 1991
AWWSCo. 1992
11
78
52
52
28
32
46
41
9
11
19
18
11
18
24
21
50
80
9G
«*
24
29
42
34
45
50
56
56
63
60
88
79
Groundwater
Missouri
14
7
1
2
3
11
•7
'Percentiles were not calculated for Sources reporting less than 10 systems for a category.
Exhibit 5-6. Available Data on Bromate Ion Occurrence in Drinking Water Supplies
Study
Sorrell, Hautman. 1992
Krasneretal.,1992
Grammith, 1993
Range (ug/L)
< 0.4 -6.3
<5-20
<5->10
Mean (ug/L)
2.5
-
--
Comments
Median = 0.75 pg/L
Pilot-plant and full-scale studies of six utilities
*
• No information.
Limited data were available for HAA5 in small systems. Only the state of Missouri has collected
HAA5 data from systems serving fewer than 10,000 people. For 81 public water systems (< 10.000) that use
surface water, the mean and median HAA5 concentrations were 88 and 80 u.g/L HAAS, respectively. The
range of HAAS values for these 81 systems was 0.1 to 284 ug/L. The high levels are attributed to high
source water total organic carbon levels and because these small systems are not required to comply with the
TTHMMCL.
5.4 CHLORITE AND BROMATE IONS
Characterizations of national occurrence were not generated for the chlorite ion and bromate ion
because of the lack of nationally representative data sets. For these DBFs, a discussion of their occurrence
in various studies and surveys is provided. This discussion summarizes the available anecdotal occurrence
data for chlorite ion and bromate ion. Additionally, the commentary identifies typical concentrations of these
DBFs in public water supplies based on the available studies, where possible.
Final
5-7
Sovember 13,1998
-------
1/1 Puhlic Ur-.
5.4.1 Bromate (on
Seseral studies were summarized m Section 4 of this document and in the 1992 Occurrence
document addressing the occurrence of bromate ion in public drinking water supplies. Exhibit 5-6 identifies
the ranges of bromate ion concentrations found in these studies.
Bromide ion levels in the range of 50 to 180 ug/L may yield measurable levels of bromate ion
(Krasneret aL 1993c). Low levels of bromide ion concentrations may yield bromate ion concentrations of
less than 5 (ag/L. A lowering of pH levels to 6 has lessened bromate ion formation fourfold in pilot studies.
Staging of ozone addition through the use of multiple ozone contractors may also reduce bromate ion
formation. • ^
5.4.2 Chlorite Ion
Section 4 of this document and the 1992 occurrence document summarized several studies addressing
the occurrence of chlorite ion in public drinking water supplies. Exhibit 5-7 identifies the ranges of chlorite
ion concentrations found in these.
Exhibit 5-7. Available Chlorite Ion Occurrence in Drinking Water Supplies
Study
Gallagher et al.. 1994
Bolyardetal.. 1993
Hoehnetal., 1990
CMADataset.,1997
Range (mg/L)
' 0 - 2.41
0.052-0.74
0.31-0.93
0.01-2.60
Comments
Five water treatment plants using CI02
Four sites using CI02
Two houses, same surface water treatment plant
Mean = 0.58 mg/L; n = 855, 65 utilities
Final
•5-8
November 13. 1998
-------
iX-currence Assessment for D'DBP tn Public Dnnkinq Hater
6. SUMMARY OF EXPOSURE DATA FROM SOURCES
OTHER THAN DRINKING WATER .
This section provides information gathered from published articles about potential exposure to
D/DBPs from routes other than drinking water through food and air via processes such as showering, bathing.
cooking, washing dishes, eating, washing clothes, or swimming. The majority of the reviewed articles did
not provide exposure data that directly indicates the concentration of disinfectants or DBFs with which an
individual could come in contact. The articles typically provided data on the occurrence of disinfectants and
DBFs in ambient air and food. Any relevant occurrence and/or exposure information for these non-drinking
water sources can be used to establish the relative source contribution (RSC) for drinking water. The RSC
can then be used in setting the maximum contaminant level goal (MCLG) or maximum residual disinfection
level goal (MRDLG). as described in Section 7. Any adequate occurrence data for individual chemicals can
be used, with standard assumptions about the amount of food and air an individual would ingest or inhale,
to estimate exposure to disinfectants and DBFs from these non-drinking water sources. THMs are the only
volatile DBF compounds, therefore they are the only 'DBFs expected to be found in any significant
concentrations in air.
6.1 DISINFECTANTS
Of the four disinfectants considered for this report, chlorine, chioramines, and chlorine dioxide can
remain in process water, food, and air after disinfection. Ozone residuals do not remain in the water after
disinfection due to their short half-lives.
6.1.1 Chlorine, Hypochlorite Ion, and Hypochlorous Acid
Dietary Intake
\
Based on the literature reviewed, little information is available concerning the occurrence of
chlorine, hypochlorite ion, and hypochlorous acid in food in the United States. The U.S. Food and Drug
Administration (FDA) does not analyze for these chemicals in foods. Chlorine is used extensively in the
food production industry to: sanitize food processing equipment and food containers that convey raw and
uncooked vegetables, cool heat-sterilized canned foods, wash meats and nuts, and process seafoods, poultry,
and red meats. According to the FDA, chlorine is widely used in the poultry industry (DiNovi. 1997).
Whole birds are placed in "chiller" tanks, where they soak in water containing 50 to 100 ppm of chlorine.
This chlorine soak can add an additional 12 percent to the bird's body weight while in the tank, however.
neither the FDA nor the U.S. Department of Agriculture has analyzed chlorine concentrations in poultry
Final 6-1 . November 13, 1998
-------
Occurrence Itsessmenc/or D/DBP in Public Dnnkinq Uaier iuppti
products i DiNoM. 199'). In addition, chlonne is used in chlorinating water at soda and beer bottling plants
and for oxidizing and bleaching flour (Wei et al.. 1985: Borum. 1991). Therefore, the dietary exposure to
chlonne and its hydrolysis products is possible due to its use in food production.
Air Intake
Based on the literature reviewed, no information has.been found concerning the occurrence of
chlorine in ambient or indoor air or at swimming pools in the United States. The Air Division of the U.S.
Environmental Protection Agency's (EPA's) Office of Air and Radiation is not actively studying the ambient
effects of chlorine. However, chlorine volatilization from tap water can contribute to exposure in air.
Volatile chlorine gas exists in water, but only at pH values well below those found in finished drinking water.
It is likely that other chlorinated organic's (e.g., chlorine monoxide) volatilize and become potential airborne
exposure compounds. Furthermore, Shaw et al. (1982) indicates thai road salting with sodium chloride can
also lead to volatilization of reduced chlorine (i.e., chloride -1 oxidation state) in air.
6.1.2 Chloramines
Dietary Intake
t
Based on a review of the published literature, no information is currently available on chloramine
occurrence in food in the United States. Currently, the FDA does not analyze for chloramine concentrations
in foods and is not aware of any specific uses in foods, either direct or indirect. Therefore, it is assumed that
exposure to chloramines through food consumption is negligent.
Air Intake
Only one of the reviewed studies discussed chloramine concentrations with regards to air intake.
The study measured chloramine concentrations in the atmosphere surrounding 13 swimming pools (Hery et
al.. 1995). A two-day pollution measurement campaign was carried out at all of the pools, with three
exceptions: one pool where the assessment was restricted to one day, and two other pools where spring and
autumn campaigns were carried out instead. A total of 309 samples were taken from the pools on the first
day. The mean concentration of chloramines was 0.43 mg/m3. The second day, a total of 317 samples were
collected from the swimming pools and the mean chloramine concentration was 0.40 mg/m3. Chloramine
concentration from both days ranged from below the detection limit (BDL) to 1.49 mg/m3.
Final 6-2 November 13. 1998
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Occurrence Assessment for D'DBP in Pueiic Dnnxiny ^ater
6.1.3 Chlorine Dioxide
Dietary Intake
Based on a review of the published literature, no information is currently available on the occurrence
of chlorine dioxide, chlorate, and chlorite in food products in the United States. Currently, the FDA does
not analyze for chlorine dioxide, chlorate, or chlorite m foods. However, the FDA is aware of uses of
chlorine dioxide in food processing (DiNovi, 1997). Various vegetables including sugar beets, lima beans.
corn, carrots, peas, potatoes, and tomatoes, are disinfected with chlorine dioxide, followed by a potable water
rinse. In addition, the use of chlorine dioxide is approved for flour bleaching. A current proposal would
replace the poultry industry's use of chlorine with chlorine dioxide. Sodium chlorite has generally been
considered safe for use in bleaching cherries.
/ /
Chlorine dioxide is a highly reactive chemical and is likely to transform readily to chlorite and
chlorate during contact with food (DiNovi, 1997). The FDA requires that fruits and vegetables that come
into contact with chlorite and chlorate must undergo further processing. The FDA acknowledged that some
raw vegetables can be exposed to chlorite and chlorate and is currently conducting an analysis on residual
amounts in these vegetables (DiNovi, 1997).
Air Intake
Based on a review of the published literature, no information is currently available on the occurrence
of chlorine dioxide in air in the United States. However, chlorine dioxide is used as a sanitizer in air ducts.
thus ambient air concentrations are possible where this sanitation method is practiced (Borum, 1991).
6.2 DISINFECTION BYPRODUCTS
/
This section discusses thirteen disinfection byproducts and their potential occurrence in food- and/or
air. These byproducts may remain in process water, food, and air after disinfection.
6.2.1 Chloroform
Dietary Intake
No exposure estimates were found for chloroform in food; however, seven studies analyzed foods
for chloroform content. This section summarizes these seven studies, data collected for six studies reported
in a 1993 Department of Health and Human Services (DOHHS) toxicology profile document, and data
collected for four studies reported in an EPA drinking water criteria'document (EPA, 1994d). Given the use
Final 6-3 November 13, 1998
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Occurrence \ssessment for D/DBP in Public Dnnkiny filter
of chlonne in processes such as the one pre\iousl> described by the poultn. industry, chloroform formation
v
and the formation of other halogenated DBFs is possible and. therefore, so is exposure to this compound.
The possibility of exposure remains unquantified. however, due to the lack of analysis.
In accordance with the FDA's Total Diet Study program. Entz et al. (1982) purchased 39 different
food items at retail markets in three geographical areas (i.e., Elizabeth. New Jersey; Chapel Hill. North
Carolina: and Washington, D.C.). Twenty food composites representing four different food groups (i.e..
dairy, meats, oils and fats, and beverages) were analyzed. Chloroform was detected in one dairy composite
at 17 ppb. one oils and fats composite at trace levels (less than 12-ppb), and four beverage composites at
concentrations of 6,^12,'12. and 32 ppb. Subsequent analysis of individual food items detected chloroform
in four cola soft drink samples (178, 22,9, and 36 ppb). two non-cola soft drink samples (32 and 14.5 ppb).
milk (17 ppb), ice cream (23 ppb), processed American cheese (17 ppb). natural cheese (15 ppb), butter (56
ppb), and mayonnaise (34 ppb).
Wallace et al. (1984) analyzed chloroform levels of the air. water, and food for nine volunteers from
New Jersey and three volunteers from North Carolina over a six-month period between June and December,
\
1980. This study was conducted to study seasonal variations. Volunteers were visited three different times
during the monitoring period for three days at a time. Food samples from community grocery stores were
analyzed to determine if exposure through food was sufficiently important to collect individual food sample's.
About 40 food items were collected from stores in New Jersey and North Carolina on four occasions.
Composites of dairy, meats, fatty foods, and beverages were taken and analyzed for THMs. Chloroform was
detected in all beverage composites at concentrations of 32 and 12 ppb in the North Carolina samples and
at 10 and 6 ppb in the New Jersey samples.
Heikes (1987) analyzed 19 table-ready food items (including drinking water), which were
representative of the 234 items in the FDA Total Diet Study. Fifty-three percent of the sampled foods tested
positive for chloroform. The results of this analysis are presented in Exhibit 6-1.
Those items shown to be high in volatile halocarbons (i.e.. butter and margarine, cheese, ready-to-eat
cereal, peanut butter, and highly processed foods) were designated for further analysis. Samples of
individual food items, which were representative of two or three regions of the country, were analyzed.
These results are presented in Exhibit 6-2.
Final 6-4 November 13, 1998
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'ccurrence \ssessment /4>r D'DBP in Public Dnnmnn
Exhibit 6-1. Chloroform Levels in Foods
Food Product
Chocolate chip cookies
Plain granola
Cheddar cheese
Butter
Peanut butter
Fried breaded shrimp
Scalloped potatoes
Cream style corn
Frozen fried chicken dinner
High meat baby food dinner
Chloroform Level (ppb)
22
57
80
670
29
24
7.1
6.1
29
17
Source: Heikes, 1987
Exhibit 6-2. Mean Chloroform Concentrations in Samples
Designated for Further Analysis
Food Product
14 butter and margarine samples
8 samples of four types of cheeses
1 1 samples of ready-to-eat cereal products
7 samples of peanut butter
12 samples of highly processed foods
Mean Chloroform
Concentration (ppb)
364
182
60
51.3-
122
Source: Heikes, 1987
Uhler and Daichenko (1987) sampled food products from 15 food processing plants located in nine
different states as part of a FDA study. Plants were chosen from areas where the presence of chloroform in
the process water would be most probable. Results of analysis indicated that out of 39 food items tested.
chloroform was present in 13 samples ranging from 2.3 to 31.2 ng/g: two samples of clear sodas, 2.3 and
15.6 ng/g; one sample of dark cola, 12.3 ng/g; four samples of cheese, ranging from 2.4 to 10.9 ng/g; and six
samples of ice cream, ranging from 4.6 to 31.2 ng/g.
Final
, 6-5
November 13, 1998
-------
' Vcu/renee \ssessment for D/DBP in Public Dnniciny Hafer
Daft ( 19S~-89i anaKzed foods in three different studies, the most recent and comprehensive of which
unalszed 549 food items. Foods were chosen from the FDA'* ~otal Diet Study program list and were made
table-ready (e.g.. cooking, peeling) prior to analysis. Chloroform was detected in 302 of the food items
(about 55 percent), with concentrations ranging from 2 to 830 ng/g with a mean of 71 ng/g (Daft. 1989). The
1988 study analyzed 231 food items obtained from the FDA's Total Diet Study collection. Chloroform was
detected in 94 food items (about 17 percent) with a mean concentration of 52 ng/g and a range of 4 to
312 ng/g. In the 1987 study, chloroform was detected in five samples collected as part of a 100-sample grain
survey. Chloroform was also detected in seven samples of a combined study that included fortified split
peas, seasoned salt, sugar, grapefruit, lime, coffee grounds, coffee beans, spaghetti, flour, bread, two cereals.
and crackers.
The Total Exposure Assessment Methodology (TEAM) study measured chloroform in five composite
food sample collections from New Jersey, North Carolina, and Washington. D.C. (Wallace. 1988). Four of
the composite samples showed measurable levels of chloroform in soft drinks, tea, and coffee. One of the
composite samples contained chloroform in dairy products. Cola soft drinks had an average concentration
of 50 ug/L. non-cola soft drinks had an average concentration of 10 ug/L. and milk had an average
concentration of 4 ug/L.
The DOHHS document, entitled, A Toxicological Profile for Chloroform, summarizes the results
of six studies involving chloroform concentrations in food (DOHHS, 1993). The results of these studies are
presented in Exhibit 6-3. The Heikes (1987) includes results from further analysis conducted on foods
containing high levels of volatile hydrocarbons.
EPA's Office of Science and Technology prepared a document entitled, Drinking Water Criteria
Document on Trihalomethanes, that summarizes the results of a study exploring the occurrence of
disinfection byproducts in air and food (EPA, 1994d). This document presents study results discussed
previously in this document. The studies were conducted by Daft (1987-89), Entz et al. (1982), Heikes
(1987), and Uhler and Daichenko (1987). Exhibit 6-4 summarizes the chloroform levels detected in food
by four other studies also discussed in this document.
Final 6-6 . - November 13, 1998
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Occurrence Assessment fijr D/DBP :n Public Dr-.nK-.nii ^aier
Exhibit 6-3. Chloroform Levels in Food
Reference
Abaei-Ranman. 1982; Heikes. 1987; Entz et al.. 1982:
Graham and Robertson. 1988; Heikes and Hopper,
1986: Lovegren et al.. 1979
Heikes. 1987 . .
Food
Soft drinks/beverages
Dairy products
Oils and fats
Dried legumes '
Grams/milled gram products
Butter
Mixed cereal
Infant/junior food
Cheddar cheese
Chloroform Level
2.7-1 78 ug/'L
3-1.110ppb
< 12ppb
6.1 -572ug/kg
1.4- 3.000 ug/kg
1.100ppb
220 ppb
230 ppb
80 ppb
Source: DOHHS. 1993
Exhibit 6-4. Chloroform Levels in Food
Reference
Abdel-Rahman. 1982
Entz and Daichenko. 1988 (cited in Wallace, 1992)
Kroneld and Reunanen, 1990
Toyodaetal., 1990
Food
Colas
Clear soft drinks
37 samples
Pasteurized milk
90 samples - summer
90 samples • winter
Chloroform Level
9-6.1MQ/L
2.7-1 0.9 pg/L
15-150ng/g
BDL-3.1pg/L
3.6-1 06.8 ng/g
2.6 - 80.9 ng/g
Sources: Listed in exhibit
McNeal et al. (1995) purchased foods from local markets in the Washington. D.C.. area and analyzed
the products for total trihalomethanes (TTHMs) with EPA Method 524.2 using gas chromatography and
electron capture detection. The researchers observed that the same products from different lots (i.e..
produced on different dates) had significantly different contaminant concentrations. Of the individual THMs.
chloroform was detected most often in these samples. Exhibit 6-5 summarizes the results for chloroform.
The detection limit for chloroform was 0.02 ng/g.
Air Intake
This section summarizes twelve studies that reported chloroform levels in air. Some of these studies
measured chloroform concentrations in the breath of individuals. In addition, this section summarizes data
from five studies reported in the DOHHS toxicology profile document (DOHHS, 1993), data from six studies
reported in an EPA drinking water criteria document (EPA, I994d), and data from a 1997 literature review
document on human exposure to chloroform and other THMs, compiled by Wallace. Singh et al. (1981)
Final
6-7
November U, 1998
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Occurrence \ssessmentfor D/DBP tn Public Dnnkinz Hater
Exhibit 6-5. Chloroform Concentrations in
Food and Beverages
. Food Analyzed*
Spring water
Mineral water
Flavored sparkling water
Dry beer A
Dry beer B
Apple juice A
Fruit drink A
Fruit drink B
Sport drink
Cola A (3 samples)
Diet orange soda (4 samples)
Diet white grape soda
Diet lemon lime soda
Diet raspberry soda
Diet cherry berry soda
Diet grapefruit soda
Diet tangerine soda
Pizza sauce (canned)
Green beans (vegetable water)
Sweet com (vegetable water)
Duck sauce
Beef extract
Lite syrup product
CHCh (ng/g)
1
1
38
1
1
1
21
1
'12
36-94
10-65
50
38
57
23
56
49
50
1
1
3
3
2 •
Source: McNealetal. (1995)
' Letters for food products designate different brands
reported results from field studies conducted in three cities: Los Angeles, California; Oakland. California;
and Phoenix, Arizona. Ambient air samples were collected at each site over a two-week period in 1979 and
analyzed for chloroform. Results of the analysis indicated that for the Los Angeles area, the mean
concentration was 88.2 ppb and the range was 24.3 to 223.5 ppb. In Phoenix, a mean of 111.4 ppb and range
of 27.1 to 514.0 ppb were reported, while Oakland had a mean of 32.1 ppb and a range of 13.1 to 60.1 ppb.
Final
6-8
November 13, 1998
-------
tor D-OBP :n Pubiic
From November 1982 to December 1985. ambient air samples at four urban/industrial site- i the
California South Coast air basin were surveyed for the presence of halogenated hydrocarbons iShikiya ?t ul..
1984). Chloroform was detected above the quantitation limit of 0.02 ppb in 96 percent of the'samples.
Concentrations generally increased in the summer months equally throughout the sites, but the highest value
of 3.0 ppb vvas recorded for downtown Los Angeles. Los Angeles also reported the highest monthly mean
of 0.78 ppb and the highest composite mean of 0.13 ppb.
Wallace et al. (1984) analyzed the air. water, and food of nine volunteers from New Jersey and three
volunteers from North Carolina over a six month period between June and December 1980 to study seasonal
variations in chloroform exposure. The New Jersey subjects were expected to have occupational exposure
to volatile organic compounds; the North Carolina subjects were not. Subjects were monitored during
different times of the day. during six weekdays and three weekend days. Air samples were analyzed using
a purge and trap method, followed by gas chromatography/mass spectrometry (GC/MS) techniques. The
detection limit was 0.01 (ig/m3. Exhibit 6-6 summarizes the monitoring results.
Exhibit 6-6. Summary Statistics of Chloroform in Ambient Air
of New Jersey and North Carolina Subjects (ug/m3)
Location
New Jersey
North Carolina
Number of
Samples
165
59
Number of
Samples Below
Detection Limit
• 31
9
Number of
Samples at
Trace Levels
2
0
Median
2.1
3.4
Range
0.03-129.00
0.09-17.60
Source: Wallace et a)., 1984
Wallace et al. (1984) also analyzed breath samples of these same individuals. Samples were collected
using a specially designed spirometer. Samples were analyzed using a purge and trap method, followed by
GC/MS techniques. The detection limit was 0.01 ng/m3. Exhibit 6-7 summarizes the monitoring results.
Exhibit 6-7. Summary Statistics of Chloroform in Breath
of New Jersey and North Carolina Subjects (M9/m3)
Location
New Jersey
North Carolina
Number of
Samples
49
17
Number of
Samples Betow
Detection Umit
7
. 1
Number of
Samples at Trace
2
0
Median
3.5
50
Range
0.09-53.00
0.11-685.00
Source: Wallace et al.. 1984
Final
6-9
November 13, 1998
-------
Occurrence Assessment for D/DBP in Public Drtnxins ^ater ^up
Several studies
-------
Occurrence ^ssessmtn[ lor D'DBP in Public Dnnking Water ^
ot" three household compartments were calculated by using a 1 ma-L of tap water concentration. Chloroform
concentrations in the shower air averaged 2.0 *• \Q'~ mg/L. Average concentrations in the bathroom air and
household air were .-.8 * 10"3 mgfL and 1.2 x 10J mg'L. respectively. This model, along with data on water
use in the L'.S. homes, and a range of exposure parameters, were used to estimate reference and upper-bound
lifetime daily equivalent human dose. The calculated doses for all the VOCs, except for DBCP were 0.04
and 0.2 (mg'kg.d)/(mg/L). Based on these dose factors, the author suggested that, for a 70 kg adult indoor
inhalation exposures to contaminated tap water can be between 1.5 and 6.0 times the exposure from ingesting
2 liters of tap water a day. Calculated doses for chloroform were comparable to the measured values
obtained by Wallace et al. for the non-bathroom pathway in studies published in 1984 and 1986.
Jo et al. (1990a) conducted a study to determine the chloroform dose to an individual based on
exhaled breath analysis. This study team also demonstrated that chloroform is absorbed by the body as a
result of dermal exposure during showering (Jo et al, 1990b). The researchers quantified a person's mean
absorbed chloroform dose for a 10-minute shower as being 0.47 ug/kg/day. A chloroform absorption
efficiency rate of 0.77 was used for inhalation to conduct the analysis.
McKone (1993) developed a model to estimate chloroform concentrations in breath samples from
individuals exposed to this chemical during showering through both inhalation and dermal routes and
inhalation only. This model combined two dermal uptake models, the McKone-Howd model and the EPA.
model (1992); and a revised PBPK. model. Model predictions were evaluated against previously reported
ratios of air and breath concentrations to tap water concentrations. The resulting ratio ranged from 0.25 to
0.66 mg per mg/L. Effective permeability of the skin during a ten-minute shower was between 0.16 and
0.42 cm/hr. The model also allowed for the calculation of the ratio between dermal and inhalation exposure
to the metabolized dose in the liver. This ratio of metabolized dose to water concentration was
0.41 mg/mg/L, at conditions of linear metabolism.
Wallace (1992) reported the results of a 1983 study conducted by Singh et al. in which 2.577 short-
term measurements of ambient air in 10 cities were collected between 1979 and 1981. The 25th percentile.
median, and 75th percentile values were 0.14,0.20, and 0.78 ug/mj, corresponding to exposures of 2.8. 4.0.
and 16 mg/day, respectively, for these measurements.
Although TEAM studies do not collect breath samples during showers, attempts have been made to
measure the contribution of shower water to airborne chloroform levels. Wallace (1992) reported results
from a 1987 EPA study that indicated that chloroform levels increased from 2 to 100 ppb (about 10 to
Final 6-11 November 13. 1998
-------
Occurrence Issessment for D/DBP in Public Dnnkinq Hater -i
500 ug'm > during a !0-minute shower with chlorinated water. Furthermore, these studies have shov^n that
50 percent of the chloroform present in water is expected to volatilize from water during showers.
Exhibit 6-10 presents the results of five studies of exposure to chloroform monitored in air
«
summarized m a lexicological Profile for Chloroform (DOHHS. 1993).
Exhibit 6-10. Exposure Levels of Chloroform Monitored in Air
Study
Class and Ballschmidter. 1986
Singh etal., 1982
Brodzmsky and Singh, 1982
Barkiey etal.. 1980
Wood and Porter. 1987
Sampling Location
Northern Atlantic' ocean ranges
Seven U.S. cities between 1 980 and 1 981
U.S. cities between 1980 and 1981
Source dominated areas in U.S. between 1977 and 1980
Outside houses in Love Canal, New York in 1978*
20 California Class II nontoxic municipal landfills
Exposure Level
25 - 50 ppt
Maximum: 5.1 x 10° ppm
Background: 2.0xiO'5ppm
Mean: 2x 10'5-2 x 10°
ppm
Median: 8.2 x 10"* ppm
1,000-1 10,000 ng/mj
Maximum: 0.61 ppm
Sources: Listed in exhibit .
' It should be noted that these samples were collected in an area underlain by a previous toxic chemical dump.
The Drinking Water Criteria Document on Trihalomethanes summarizes study results for occurrence
and exposure of disinfection byproducts in air and food (EPA, 1994d). This document presents previously
discussed study results, conducted by Shikiyaet aJ. (1984) and Singh et al. (1981). Exhibit 6-11 presents the
results of chloroform exposure from outdoor air for four studies, and Exhibit 6-12 summarizes the results
of chloroform occurrence in indoor air reported by three studies.
Exhibit 6-11. Chloroform Exposure from Outdoor Air
Study
Singh etal., 1983
(cited in Wallace, 1992)
Shikiya etal., 1994
Singh etal. 1986
Armstrong and Golden, 1986
Sampling Location
10 cities
California South
Los Angeles and Oakland, California,
Phoenix, Arizona
Outdoor pools
Chloroform Exposure
Median: 4.0pg/mJ
Maximum: 14.0ug/day
3.7-1 0.5 pg/day
Maximum: 1 ug/m3
Sources: Listed in exhibit
Final
6-12
November 13. 1998
-------
Occurrence Assessment for DiDBP in Public Dnnking Hater
Exhibit 6-12. Chloroform Concentration in Indoor Air
Study
Joetai.. 1990
Wallace. 1992
Armstrong and Golden. 1986
Sampling Location
Shower - with individual
House after washing clothes and dishes - "
Indoor pools
Hot tubs
Chloroform Concentration
(M9/mJ)
119-313.4
BDL-44
Mean: 90
Mean: 12
Sources: tistea in exmbit
Andelman (1985a) compared chloroform concentrations in outdoor and indoor air, previously
reported in field studies. The range of means for outdoor air was 81-900 ppt, and the range for indoor air
was 14-730 ppt. Background chloroform concentration was 20 ppt at remote sites. These values showed that
indoor concentrations are considerably higher than background concentrations, but are similar to outdoor
measurements. The author concluded that indoor volatilization of chloroform and other chemicals, and
inhalation exposure, especially during bathing and showering, should be of concern as water supplies become
increasingly contaminated.
In another study, Andelman et al (1986) studied the extent to which chloroform is volatilized in a
laboratory bath-shower system, and the factors affecting the volatilization process. The authors continuously
injected known concentrations of chloroform into this system for a period of one hour, while effluent air and
water samples were monitored. Results demonstrated that an increase in the water temperature, the
chloroform concentration in the water, and the diameter of the shower head hole are all factors that increased
the rate of chloroform volatilization. During the injection period, chloroform air concentrations were much
lower in the bath than in the shower, due to the larger surface area of the shower droplets resulting in a larger
rate of volatilization. However, after injection stopped, the rate of decay of air concentration was much
greater in the shower mode. While only residual chloroform was present in the water from the shower, the
bath water volume contained chloroform concentrations that could volatilize. The authors concluded that
in this study, chloroform volatilization was approximately 50 percent, and suggested that inhalation exposure
could be potentially greater than that from ingestion.
Andelman (198Sb) used the single compartment air model to analyze maximum indoor air chemical
concentrations resulting from the volatilization of the chemicals from tap water brought to a home. Taking
an adult man with a daily respiratory volume of 20 m3 and a daily water intake of 2 liters, the author
concluded that the air exposure to chloroform is higher than that from water by a factor of 6. This calculation
indicates that inhalation exposure is substantial if compared to exposure attributed to the ingestion route.
Final 6-13 November 13. 1998
-------
(Occurrence \isessmem far DiDBP in Public Dnnicing Hater Supplies
Researchers in Canada (Le'vesque et al.. 1994) studied 11 male shimmers to quantif> their exposure
to chloroform from the indoor air of a swimming pool. Water from the indoor ambient air at the pool and
exhaled breath (alveolar air) were sampled. Data were collected over seven days in the pool area. Exhaled
breath data were collected over five days from the subjects, ages 19 to 38 years (median age = 23 years)
during and after 55-minute swimming workouts. The detection limit was 10 ppb. The mean alveolar air
concentration was 52.6 ppb (0 to 200 ppb. standard deviation 50.8 ppb) because of air contamination in the
locker room. Mean chloroform body burden (concentration of chloroform in the air of the lungs) after 35
minutes of exercise ranged from 100 to 950 ppb. Mean chloroform body burden after 55 minutes of exercise
ranged from. 103.9 to 1093.6 ppb.
Weisel and Shepard (1994) studied chloroform occurrence and exposure in swimming pools
disinfected with sodium hypochlorite. Breath samples were taken from one individual following 30 minutes
of exposure during five separate visits to an indoor pool in New Brunswick, New Jersey. During three of
the visits, the individual swam for the 30-minute period and remained at rest in the water. During the other
two visits, the individual remained three meters from the pool edge but out of the water. Breath samples
were taken within five minutes after leaving the pool area and compared to a pre-exposure breath sample.
prior to entry in the pool. Water samples were analyzed by purge and trap coupled with GC/MS. Air
samples were collected on an adsorbent trap filled with 0.5 g Tenax GC.
Chloroform concentrations in the swimming pool water ranged between 32 and 150 ug/L. w'th a
mean of 85 ug/L. Air samples revealed chloroform concentrations ranging from 23 to 120 ug/mj. with a
mean of 87 ug/m3. The pre-exposure breath concentrations were less than 0.5 ug/m3 on all but one day, when
a value of 1.6 ug/m3 was measured. Initial concentrations of chloroform in breath increased immediately
after the 30 minute swimming and resting period and generally declined as more time passed. Chloroform
concentrations in breath were higher after swimming than after resting. Chloroform concentrations in breath
ranged from 0.76 to 26.5 jig/m3.
Using these concentrations, the authors made a conservative estimate of chloroform exposure due
to swimming and from ingesting chlorinated drinking water. The inhalation exposure to an adult who swims
one hour/day, three days/week, in a pool with a chloroform air concentration of 100 ug/m3 and assuming a
respiration rate of one mYh would be 300 ug. The respiration rate used in this study is higher than the EPA
standard of 20 mVday (0.833 mj/h) and results in a more conservative internal dose than if the EPA standard
was used. These assumptions would result in an internal chloroform dose of 210 ug. The same person who
Final 6-14 November 13, 1998
-------
I),
:currence \ssessmentfor D'DBP in Public Dnnkinq Hater S
dail\ ingests tv,o liters of water with a chloroform concentration of 25 ug/L would have a weekl> exposure
from mgestion of 350 ug. assuming 100-percent absorption.
Lindsrrom et al. (1997) assessed the exposure of collegiate swimmers to chloroform during a two-
hour training session in an indoor natatorium at the University of Montana. Alveolar breath samples from
one female and one male were collected before, during, and three hours after the swimming session. A total
of fifty samples were obtained by using the single breath canister technique. Six whole-air grab samples and
two pool water samples were collected to obtain background concentration data. Pool water chloroform
concentrations were 68 and 73 ug/L. Chloroform concentration in the air was 145 ug/m3 during the exposure
period.
Chloroform concentrations in pre-exposure breath samples ranged from 3.07 to 3.46 ug/m3. At two
and at eight minutes of exposure, breath concentrations rapidly increased to 71.2 and 160 ug/m3, respectively,
peaking 371 ug/m3 at ninety minutes. This peak concentration was more than two times the maximum
concentration possible (i.e., 145 ug/m3) considering an inhalation route only, suggested the importance of
the dermal exposure route. Body burden of chloroform during the three hours following the exposure period
showed breath levels more than five times higher than pre-exposure levels.
Based on the post-exposure results, the authors used a three-compartment model, which allowed
estimation of compartmental half-lives, resulting minimum bloodborae dose, and an approximation of the
duration of elevated body burden. The authors concluded that at an air chloroform concentration of 145
ug/nr and a 0.33 steady state breath/environmental equilibrium ratio, the inhalation exposure route alone
should contribute about 48 ug/m3 to the final breath concentration at the end of the exposure period. The
dermal exposure route was considered to be the dominant estimated to account for 80 percent of the blood
chloroform concentration.
Weisel and Jo (1996) collected and analyzed time series samples of expired alveolar breath to
evaluate changes in concentrations of chloroform being expired after showering. Analyses of chloroform
in expired breath were used to determine uptake from tap water by inhalation and dermal exposure. Each
route of exposure contributed to the total exposure of these compounds from, daily water use. The
chloroform concentrations in the exhaled breath were elevated in each subject after both inhalation and
dermal exposures during showering and bathing. Chloroform concentrations in the water ranged from 10
to 50 ug/L for the inhalation exposure experiments and from BDL to 41 ug/L for the dermal exposure
experiments. The bath water ranged from 11 to IS'pgfL for the dermal exposure experiments. Expired
Final 6-15 November 13,1998
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Occurrence \ssetsmentfnr D/DBP in Public Dnnkins Water
breath concentrations ranged from 0.02 to 0.05 ug for the inhalation-only exposure. 0.02 to 0. 1 3 ug for the
derrnal-onl> shower exposure, and from 0.33 to 0.56 ug after ^.e dermal bathing study. The larger amount
expired after bathing is due to the longer exposure time (60 minutes for a bath versus 10 minutes for a
Wallace (1997) summarized existing information on human integrated exposure to chloroform
(i.e.. exposure through drinking water, diet, indoor air. inhalation from shower, and dermal absorption from
shower). The author found that each of these exposures provides chloroform amounts ranging from 10 to
40 ug/d to an individual whose water supply is chlorinated, for a total chloroform intake of 100 to 150 ug/d
for an adult. . . ,
Another exposure route is dermal absorption from swimming in indoor pools. According to studies
reviewed by Wallace (1997) and carried out by Weisel and Shepard (1994), Levesque et al. (1994), and
Lindstrom et al. (1995), 25 percent to 50 percent of the total chloroform exposure in swimming pools comes
from the dermal exposure route. Additionally, Weisel and Shepard calculated that for an adult swimming
for a period of one hour a day, three days a week, in a pool water with chloroform air concentration of 100
jig/m3. the weekly dose from inhalation would be 210 ug. They also estimated a similar inhalation and
dermal dose from showering and a similar ingestion dose per week for the same individual.
Wallace (1997) reported the results of a 1979 study conducted by Krotoszynski et al. (1977, 1979)
in which measurements of the pulmonary elimination of chloroform through the exhaled breath in 54
individuals revealed a geometric mean of 23.3 iig/m3, and a range of 7.4 to 73.7- ug/m3.
6.2.2 BromodichJoromethane
Dietary Intake .
No exposure estimates were found for bromodichloromethane in food: however, five studies
analyzed foods for bromodichloromethane content. This section summarizes these studies, as well as data
collected for an EPA drinking water criteria document. Given the use of chlorine in processes such as the
ones used by the poultry industry, bromodichloromethane formation is possible and, therefore, exposure from
such sources is also possible. However, exposure remains unqualified due to the lack of analysis.
Entz et al. ( 1982) analyzed food samples from Elizabeth, New Jersey; Chapel Hill, North Carolina;
and Washington, D.C., for bromodichloromethane. A total of 39 different food items from each city were
Final 6-16 November 13. 1998
-------
i >ccurrgnt:e tjs
-------
Occurrence Assessment for D'DBP in Public Dnnkinq Hater 'iupplie-,
NtcNeal et al. i 19951 purchased foods from local markets in the Washington. D.C.. area and analyzed
the products for THMs using EPA Method 524.2. The detection lirrut for bromodichloromethane was 0 05
ng/g. The researchers observed that the same products from different lots (i.e.. produced on different dates)
had significantly different contaminant concentrations. Exhibit 6-14 summarizes the bromodichloromethane
concentrations detected in the food and beverages. Bromodichloromethane was not detected in six types of
noncarbonated bottled waters, two types of beer, two types of apple juice, one sport drink sample, three
different canned tomato and pizza sauces, one vegetable juice, three different vegetable waters, and three
other foods.
Exhibit 6-14. Bromodichloromethane Concentrations in Food and Beverages
Food Analyzed*
Flavored sparkling water
Fruit drink A
Cola A (3 samples)
Diet orange A soda (4 samples)
Diet white grape soda
Diet lemon lime soda
Diet raspberry soda
Diet cherry berry soda
Diet grapefruit soda
Diet tangerine soda
CHBrCh (ng/g)
38
5
2-4
2-12
2
1
3
2
' 3
2
Source: McNealeta)., 1995
'Different letters for the same food indicate different brands
Air Intake
This section summarizes four studies that reported bromodichloromethane levels in air. Some of
these studies measured bromodichloromethane concentrations in the breath of individuals. In addition, this
section presents data from one study reported in an EPA drinking water criteria document (EPA, 1994d).
In a pilot study designed to field test personal air quality monitoring methods, Wallace et al. (1982)
collected personal air samples from students at two universities: Lamar University, Texas, which is located
near petroleum refineries, and the University of North Carolina (UNC), which is located in a
nonindustrialized area in Chapel Hill, North Carolina. In personal air samples collected from 11. Lamar
students, bromodichloromethane was detected in 64 percent of the samples, with a mean of 1.23 pg/m3. a
Final . 6-18 November 13,1998
-------
nce \isessment far D'DBP in Public Dnnkint;
median of 1 ug/rrr. and a range )f 0.12 to'3 ~2. ug/m-. At l~N'C 17 percent of the samples from six students
had detectable levels of bromcrdichloromethane. Concentrations ranged from 0.12 to 4.36 ug/nr:. . -th a
mean of 0.83 ug/m- and a median of 0.12 jjg/m-'.
Another study conducted by Wallace et al. (1984) analyzed the air. water, and food of nine
individuals from New Jersey an i three individuals from North Carolina over three seasons. The New Jersey
subjects were expected to havesoccupationai exposure to. volatile organic compounds: the North Carolina
subjects were not. Subjects went monitored during different times of the day, over a period of six weekdays
and three weekend days. Air simples were analyzed using a purge and trap method, followed by GC/MS
techniques. The detection limit was 10 ug/m3. Exhibit 6-15 summarizes the monitoring results.
Exhibit 6-15. Summary Statistics of Bromodichloromethane in Ambient Air
of New* Jersey and North Carolina Subjects (ug/m3)
Location
New Jersey •
North Carolina
Number of
Samples :
164
60
Number Below
Detection Limit
136 ,
48
Number of
Samples at
Trace Levels
16
7
Median
0.44
-
Range
0.10-13.40
0.10-3.66
Source: Wallace eta)., 1984
Wallace et al. (1984) also analyzed breath samples of the same individuals. Breath samples were
collected using a specially desgned spirometer. Samples were analyzed using a purge and trap method.
followed by GC/MS technique;. The detection limit was 10 ug/m3. Exhibit 6-16 presents the monitoring
results.
Exhibit 6-16. Suynmary Statistics of Bromodichloromethane in Breath
of New Jersey and North Carolina Subjects (mg/m3)
Location
New Jersey
North Carolina
Number of
Samples:
49
17
Number Below
Detection Limit
49
' 17
Number of
Samples at
Trace Levels
0
0
Median
0.17
Range
0.17-2.20
0.14-2.20 •
Source: Wallace et al.. 1984
From November 1982 io December 1983, ambient air samples at four urban/industrial sites in the
California South Coast air basin were surveyed for the presence of halogenated hydrocarbons (Shikiya et al..
1984). Thirty-five percent of tpe samples detected bromodichloromethane above the quamitation limit of
Final
6-19
November 13, 1998
-------
r D/DBP in Public Dnnkinif Water V
0.01 ppb. Peaks in the concentration of bromodichloromethane uere observed at the various >ites in June
and July, uith downtown Los Angeles and Dominguez registering the highest monthly means of 0.03 ppb.
The maximum reported value was 0.04 ppb. while the composite means ranged from 0.02 to 0.1.
Howard (1990) reported the results of a 1982 study conducted by Brodzinsky and Singh. Ambient
air samples from Magnolia, Arizona: El Dorado, Arkansas: Chapel Hill. North Carolina: and Beaumont.
Texas, were measured.. Bromodichloromethane was detected at mean concentrations of 0.76.. 1.4. 120. and
180 ppt. respectively.
In Drinking Water Criteria Document on Trihalomethanes, EPA summarized study results for the
occurrence of disinfection byproducts in air and food (EPA. I994d). The criteria document presents results
of outdoor air studies already discussed in this document. The studies were conducted by Brodinsky and
Singh (1983) and Shikiya et ai. (1984). In addition, the document summarizes a study by Armstrong and
Golden (1986), which presents both occurrence and exposure data. Exhibits 6-17 and 6-18 present the
bromodichloromethane concentrations and exposure from outdoor air and indoor air, respectively, reported
by Armstrong and Golden.
Exhibit 6-17. Bromodichloromethane Occurrence and Exposure from Outdoor Air
Study
Armstrong and Golden, 1986
Location
Outdoor swimming pool
Bromodichloromethane
Concentration (mo/m3)
1-72
Bromodichloromethane
Exposure (ug/day)
0.12-26
Source; Armstrong and Golden, 1986
Exhibit 6-18. Bromodichloromethane Occurrence and Exposure from Indoor Air
Study
Armstrong and Golden, 1986
Location
Indoor swimming pool
Hot tubs
Bromodichloromethane
Concentration (ug/L)
1-90
BDL-105
Bromodichloromethane
Exposure (ug/day)
0.12-26
0.12-26
Source: Armstrong and Golden, 1986
6.2.3 Dibromochloromethane
Dietary Intake
No exposure estimates were found for dibromochloromethane in food. The FDA does not analyze
for dibromochloromethane in foods, however, chlorine is used for several purposes (e.g., disinfection of
chicken in poultry plants, as described previously) and for the chlorination of water at soda and beer bottling
Final
6-20
November 13, 1998
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Occurrence \isessmentfor D'DBP in Public Dnnkinq
plants i Borum. 199!). Therefore, dietary exposure is possible from the byproducts of chlonnation in food
production. This section summarizes data from two studies reported in an EPA drinking water criteria
document (EPA. 1 -94d) and two other studies that reported dibromochloromethane in food products.
EPA's Drinking Water Criteria Document on Trihalomethanes summarizes study results for
occurrence and exposure of disinfection byproducts in air and food (EPA. 1994d). Exhibit 6-19 presents the
results of two studies analyzing dibromochloromethane occurrence in food.
Exhibit 6-19. Dibromochloromethane Levels Found in Food
Study
Toyodaetal., 1990
Kroneld and Reunanen, 1990
Food Item
90 food samples - summer
90 food samples - winter
Pasteurized milk
Dibromochloromomethane
Concentration
BDL - 0.5 ng/g
BDL - 0.7 ng/g
8DL-0.3Mg/L
Sources: Listediin exhibit
Graham and Robertson (1988) reported the results of THM analysis on soft drinks.
Dibromochloromethane concentrations ranged from BDL to 5 ug/L in the sampled soft drinks.
McNeal et al. (1995) purchased foods from local markets in the Washington, D.C., area and analyzed
the products for TTHMs using EPA Method 524.2. The detection limit for dibromochloromethane was
0.05 ng/g. The researchers observed that the same products from different lots (i.e., produced on different
dates) had significantly different contaminant concentrations. Dibromochloromethane was detected in five
of the 37 food samples analyzed. Exhibit 6-20 presents these results. Dibromochloromethane was not
detected in six types of noncarbonated bottled waters, two types of beer, five different flavored
noncarbonated beverages, nine of the 13 types of soft drinks, three different canned sauces, seven types of
canned vegetables and vegetable juices, and three other foods.
Exhibit 6-20. Dibromochloromethane Concentrations in Food and Beverages
Food Analyzed
Flavored sparkling water
Diet orange soda (3 samples)
Diet white grape soda
CHBriCI (ng/g)
1
1-2
0-5
Source: McNeal etal.. 1995
Final
6-21
November 13, 1998
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Occurrence \isessment for D/DBP in Public Dnnkinq Water Supplief
Air Intake
Limited information is available concerning dibromochloromethane levels in air. This section
summarizes four studies that reported dibromochloromethane levels in air. Some of these studies measured
dibromochloromethane concentrations in the breath of individuals. In addition, this section summarizes data
from a-study reported in an EPA drinking water criteria document {EPA. I994d).
Wallace et al. (1982) conducted a pilot study designed to field test personal air quality monitoring
methods. Personal air samples were collected from students of two universities: Lamar University, which
is located near petroleum refineries, and UNC, which is located in a non-industrialized area.
Dibromochloromethane was not detected above 0.12 jjg/m3.
In a another study (Shikiya et al.. 1984), ambient air samples were collected from November 1982
to December 1983 at four urban/industrial sites in the California South Coast air basin and analyzed for
halogenated hydrocarbons. Dibromochloromethane was detected above the quantitation limit of 0.01 ppb
in 17 percent of the samples. The maximum reported value, highest monthly mean, and highest mean
composite were 0.29,0.28, and 0.05 ppb, respectively, all of which were recorded in downtown Los Angeles
in July. Mean concentrations ranged from BDL to 0.05 ppb.
Howard (1990) reported the results of a 1982 study conducted by Brodzinsky and Singh.
Dibromochloromethane levels were reported in ambient air samples from Magnolia and El Dorado, Arizona:
Chapel Hill, North Carolina, Beaumont, Texas; and Lake Charles, Louisiana, at concentrations of 0. 0.48,
14, 14, and 19 ppt, respectively.
In another study (Atlas and Schauffler, 1991), replicate air samples were collected at various
locations on the island of Hawaii during a month-long field experiment to test an analytical method for
determining halocarbons in ambient air. Dibromochloromethane was detected at a mean of 0.27 ppt on the
island.
The EPA Office of Science and Technology's Drinking Water Criteria Document on Trihalo-
methanes summarizes study occurrence results for disinfection byproducts in air and food (EPA. 1994d).
This document presents the results of outdoor air studies discussed previously in this document. The studies
were conducted by Brodzinsky and Singh (1983)t Shikiya et al. (1984), and Atlas and Schauffler (1991). In
addition, the document summarizes a study by Armstrong and Golden (1986) which presents both occurrence
Final 6-22 . November 13, 1998
-------
Occurrence Assessment for D/D8P in Public Dnnktny Hater i'
and exposure results. Exhibits 6-21 and 6-22 present the results of'dibromochloromethane occurrence from
outdoor air and occurrence and exposure t'rom indoor air. respectively, from the Armstrong and Golden
studv.
Exhibit 6-21. Dibromochloromethane Occurrence from Outdoor Air
Study
Armstrong and Golden, 1986
Location
Outdoor swimming pool
Dibromochloromethane
Occurrence (ug/ma)
BDL-8
Source: Armstrong and Golden, 1986
Exhibit 6-22. Dibromochloromethane Occurrence and Exposure from Indoor Air
Study
Armstrong and Golden, 1986
Location
Indoor swimming pools
Hot tubs
Dibromochloromethane
Occurrence (pg/L)
0.3-30
BDL-48
Dibromochloromethane
Exposure (ug/day)
0.18-94
0.18-94
Source: Armstrong and Golden, 1986
6.2.4 Bromoform
Dietary Intake
Based on a review of the literature reviewed, one study concerning the occurrence of bromoform in
food was available. This section includes the results of this study which is summarized in an EPA drinking
water criteria document (EPA, 1994d). The FDA does not analyze for bromoform in foods, however.
chlorine is used for several purposes in food production (e.g., disinfection of chicken in poultry plants, as
described previously) and for the chlorination of water at soda and beer bottling plants (Borum. 1991).
Therefore, dietary exposure is possible from the byproducts of chlorination in food processing. However.
exposure from foods has not been extensively quantified.
EPA's Drinking Water Criteria Document on Trihalomethanes summarizes the results of one study
of bromoform levels found in food (EPA, 1994d). Exhibit 6-23 summarizes the results of this study.
Exhibit 6-23. Bromoform Levels Found in Food
Study
Toyodaetal., 1990
Food Item
90 food samples - summer
90 food sample -winter
Bromoform Concentration(ng/g)
BDL-3.1
BDL-8.1
Source: Toyodaetal., 1990
Final
6-23
November 13. 1998
-------
Occurrence \ssessment /or D'DBP in Public Dnnmng ^aler -j
Air Intake
Brominated THMs are usually found in air at low concentrations. This section summarizes three
studies that reported bromoform levels in air. as well as data from one study reported in an EPA drinking
water criteria document (EPA, 1994d).
;
From November 1982 to December 1983, ambient air samples at four urban/industrial sites in the
California South Coast air basin were surveyed for the presence of halogenated hydrocarbons (Shikiya et al..
1984). Thirty-one percent of the samples detected bromoform above the quamitation limit of 0.01 ppb.
Peaks in the concentration of bromoform were observed at the various sites in May and June, with the
downtown Los Angeles site registering the highest composite mean of 0.04 ppb and the highest monthly
mean of 0.31 ppb in June 1983.
EPA (1989, 1991) reported the results of a 1983 Brodzinsky and Singh study of ambient air
concentrations for several urban locations across the United States. From 1976 to 1977 in El Dorado,
Arizona, bromoform was detected in 76 percent of 46 samples at a mean of 0.81 ng/m3, with a range from
\
BDL to 2.7 ng/m3. In samples from Lake Charles, Louisiana, bromoform was detected in all four samples.
with a mean of 50 ng/m3 and a range from 6.6 to 71 ng/m3 in 1978. In 1977, bromoform was detected in 89.3
percent of 28 ambient air samples collected from Magnolia, Arizona. Concentrations ranged from BDL to
8.3 ng/m3, and the mean was 1.5 ng/m3. Overall, the average bromoform concentration was 37 ng/m3.
In a third study, replicate air samples were collected at various locations on the island of Hawaii
during a month-long field experiment to test an analytical method for determining halocarbons in ambient
air. Bromoform was detected at a mean concentration of 1.9 ppt (Atlas and Schauffler, 1991).
EPA's Drinking Water Criteria Document on Trihalometnanes summarizes study results for the
occurrence of disinfection byproducts in air and food (EPA, 1994d). This document presents the results of
outdoor air studies, discussed previously. The studies were conducted by Brodzinsky and Singh (1983).
Shikiya et al. (1984), and Atlas and Schauffler (1991). In addition, the EPA document discusses a study
presenting both occurrence and exposure results. Exhibits 6-24 and 6-25 summarize the bromoform
concentrations and exposure from outdoor and indoor air reported by Armstrong and Golden (1986).
Final 6-24 November 13,1998
-------
Occurrence Assessment for D/DBP in Public Dnnkinq \\ater Supplies
Exhibit 6-24. Bromoform Occurrence and Exposure in Outdoor Air
Study
Armstrong and Golden, 1986
Location
Outdoor swimming pools
Rromoform
Occurrence (ug/L)
BDL
Bromoform
Exposure (ug/day)
0.42 - 70
Source: Armstrong and Golden. 1986
Exhibit 6-25. Bromoform Occurrence and Exposure in Indoor Air
Study
Armstrong and Golden. 1986
Location
Indoor swimming pools
Hot tubs
Bromoform
Occurrence (ug/L)
BDL -20
BDL -62
Bromoform
Exposure (ug/day)
0.42 - 70
0.42 - 70
Source: Armstrong and Golden,'1986
6.2.5 Total Trihalomethanes
Dietary Intake
Based on a review, of the published literature, one study concerning the occurrence of total
trihalomethanes in food in the United States was available. Currently, the FDA does not analyze for total
trihalomethanes in foods. Studies with information on these individual THMs were discussed previously.
but only one reference was found that contained information about the total group of THMs. As previously
stated, given the use of chlorine in such processes as those used by the poultry industry, the formation of
trihalomethanes is possible and, therefore, so is exposure from these sources. However, these possibilities
remain unquantified.
Toyoda et al (1990) analyzed the daily intakes of TTHMs in Japanese housewives. Exhibit 6-26
presents these results.
Exhibit 6-26. Total Trihalomethanes Levels in Food
Food Item
90 food samples - summer
90 food samples • winter
Total Trihalomethanes Concentration (ng/g)
3.8-108.2
1.6-81.0
Source: Toyoda etai., 1990
Air Intake
No information is available concerning the occurrence of total trihalomethanes in air; however,
individual compounds have been discussed in previous sections.
Final
6-25
November 13,1998
-------
Occurrence issessmtnc for D'DBP in Public Dnnkinq Viattr Supplies
6.2.6 Monochloroacetic Acid
Dietary Intake
Based on a review of the.published literature, no information is available on the occurrence of
monochloroacetic acid in food in the United States. Currently, the FDA does not analyze for
monochloroacetic acid in foods. However, chlorine is used for several purposes in food production (e.g..
disinfection of chicken in poultry plants) and the chlorination of water at soda and beer bottling plants.
Therefore, dietary exposure is possible from the byproducts of chlorination in food products. Also.
monochloroacetic acid has a limited use as a herbicide (Borum, 1991).
Air Intake
Based on a review of the published literature, no information is available concerning the occurrence
of monochloroacetic acid in air.
6.2.7 Dichloroacetic Acid
Dietary Intake
Based on a review of the published literature, no information is available on the occurrence of
dichloroacetic acid in food in the United States. Currently, the FDA does not analyze for dichloroacetic acid
in foods. However, chlorine is used for several purposes in food production (e.g., disinfection of chicken
in poultry plants) and for the chlorination of water at soda and beer bottling plants. Therefore, dietary
exposure is possible from the byproducts of chlorination in food products. In addition, dichloroacetic acid
has a limited use as a herbicide (Borum, 1991).
Air Intake
Based on a review of the published literature, no information is available concerning the occurrence
of dichloroacetic acid in air.
6.2.8 Trichloroacetic Acid
Dietary Intake
Based on a review of the published literature, no information is available concerning the occurrence
of trichloroacetic acid in food in the United States. The FDA does not analyze for trichloroacetic acid in
foods. However, chlorine is used for several purposes in food production (e.g., disinfection of chicken in
Final 6-26 November 13,1998
-------
Occurrence Assessment for D'DBP in Public Dnnkinq Water Supplier
poultry plants) and for the chlonnanon of water at soda and beer botiling p.lants. Therefore, dietary exposure
is possible from the byproducts of chionnation in food products. 'In addition, trichlbroacetic acid has a
limited use as a herbicide (Borem. 1991).
Air Intake
No information is identified in the review of published literature concerning the occurrence of
trichloroacetic acid in ambient or indoor air in the United States (Borum, 1991).
6.2.9 Monobromoacetic Acid
Dietary Intake
Based on a review of the published literature, no information is available on the occurrence of
monobromoacetic acid in food in the United States. Currently, the FDA does not analyze for
monobromoacetic acid in foods. However, chlorine is used for several purposes in food production (e.g.,
disinfection of chicken in poultry plants) and for the chionnation of water at soda and beer bottling plants.
Therefore, dietary exposure is possible from the byproducts of chlorination in food products. In addition.
monobromoacetic acid has a limited use as a herbicide (Borum, 1991).
Air Intake
Based on a review of the published literature, no information is available concerning the occurrence
of monobromoacetic acid in air.
6.2.10 Dibromoacetic Acid
Dietary Intake
No information in the published literature is available on the occurrence of dibromoacetic acid in
food in the United States. Currently, the FDA does not analyze for dibromoacetic acid in foods. However.
chlorine is used for several purposes in food production (e.g., disinfection of chicken in poultry plants) and
for the chlorination of water at soda and beer bottling plants. Therefore, dietary exposure is possible from
the byproducts of chlorination in food products. In addition, dibromoacetic acid has a limited use as a
herbicide (Borum, 1991).
Final 6-27 November 13,1998
-------
Occurrence Assessment for DiDBP in Public Drinkint? Water Supplies
Air Intake
Based on n review of the published literature, no information is available concerning the occurrence
ofdibromoacetic acid in air.
6.2.11 Haloacetic Acids 5
Dietary Intake
Based on a review of the published literature, no information is available on the occurrence of total
haloacetic acids in food in the United States. Currently, the FDA. does not analyze for dibromoacetic acid
in foods: however, chlorine in food production (e.g., disinfection of chicken in poultry plants) and for the
chlorination of water at soda arid beer bottling plants. Therefore, dietary exposure is possible from the
byproducts of chlorination in food products. In addition, each of the haloacetic acids has a limited use as
a herbicide (Borum, 1991) .
Air Intake
Based on a review of the published literature, no information is available concerning the occurrence
of haloacetic acids in air.
6.2.12 Chloral Hydrate
Dietary Intake
Based a review of the published literature, no information is available on the occurrence of chloral
hydrate in food in the United States. The FDA does not analyze for chloral hydrate in foods. However,
chlorine is used for several purposes in food production, including sanitizing equipment and containers.
conveying vegetables, cooling heat-sterilized foods, washing meats and nuts, processing seafoods and poultry
and red meats, oxidizing and bleaching flour and for the chlorination of water at soda and beer bottling plants
(Wei et al., 1985; Borum, 1991). Therefore, dietary exposure to chloral hydrate is possible as a result of its
formation as a result of chlorination in food products.
Air Intake
No information in the published literature is available concerning the occurrence of chloral hydrate
in ambient or indoor air in the United States. However, chlorine volatilization from tap water may contribute
to chloral hydrate exposure in air (Borum, 1991).
Final . 6-28 November 13. 1998
-------
Occurrence Assessment fur DfDBP :rt Public Dnnkuiq Water supplies
6.2.13 Bromate
Dietary Intake.
Based on a review of the published literature, no information is available concerning the occurrence
•>
of bromate levels in food in the United States. Currently, the FDA does not analyze for bromate in foods.
However, bromate has been used as a maturing agent in malted beverages, as a dough conditioner, and in
confectionery products. Therefore, exposure to bromate is possible through ingestion of foods processed
using bromate (Borum. 1991). According to the FDA, American beer producers have stopped using bromates
in the manufacturing process (DiNovi. 1977). However, bromate can still be used for malting barley in
imported beers and is used as a preservative by the bakery industry.
Air Intake
Based on the studies reviewed, no information is available concerning the occurrence of bromate in
air in the United States. Bromate is not a volatile compound and therefore is not expected to be found in high
concentrations in air.
6.2.14 Chlorate and Chlorite
Based on a review of the published literature, no information is available on the occurrence of
chlorate or chlorite in food in the United States. Currently, the FDA does not analyze for chlorine dioxide
in foods. However, the FDA is aware of uses of chlorine dioxide in food processing (DiNovi. 1997).
Various vegetables including sugar beets, lima beans, corn, carrots, peas, potatoes, and tomatoes, are
disinfected with chlorine dioxide, followed by a potable water rinse. In addition, the use of chlorine d'ioxide
is approved for flour bleaching. A current proposal would replace the poultry industry's use of chlorine with
chlorine dioxide. Sodium chlorite has generally been considered safe for use in bleaching cherries.
Chlorine dioxide is a highly reactive chemical and is likely to transform readily to chlorite and
chlorate during contact with food (DiNovi, 1997). FDA regulations are written such that fruits and
vegetables in contact with chlorite and chlorate are required to undergo further processing. The FDA
acknowledged that some raw vegetables' could be exposed to chlorite and chlorate and is currently conducting
an analysis on residual amounts in these vegetables (DiNovi, 1997). Cooking processes convert chlorite and
chlorate to chloride; therefore, exposure to these chemicals is not anticipated after cooking.
Final 6-29 November 13,1998
-------
Occurrence Assessment/or D/DBP in Public Dnnxintj U-
Air Intake
Based on a review of the published literature, no r/ormation is available on the occurrence of"
chlorate or chlorite in air in the United States. However, chlorine dioxide is used as a sanitizer in air ducts.
thus ambient air concentrations are possible where this sanitation method is practiced (Borum, 1991). Due
to the chemical and physical properties of chlorite and chlorate, it is not anticipated that these two
compounds will occur in a gaseous form and. therefore, air intake of these two compounds should be
nonexistent.
Final 6-30 November 13, 1998
-------
Occurrence Assessment fur D/DBP in Public DnnKtn% Hater iaapi^i
7. RELATIVE SOURCE CONTRIBUTION EVALUATION
The occurrence and exposure data for drinking water and other sources presented in Sections 3
through 6 can be used to develop maximum residual disinfectant level goals (MRDLGs) and maximum
contaminant level goals (MCLGs) using a relative source contribution (RSC) approach. This section
describes the RSC approach and the types of exposure assumptions that would be used with occurrence data
(when adequate occurrence data are available) to estimate exposure. In addition, this section presents the
RSCs chosen for each disinfectant and disinfection byproduct for which the RSC approach is applicable.
7.1 OVERVIEW OF THE RELATIVE SOURCE CONTRIBUTION APPROACH
The RSC is the fraction of total exposure attributable to a given environmental source. The portion
of total exposure attributable to drinking water (the RSC for drinking water) is multiplied by the reference
dose for noncarcinogens to set the MCLG or MRDLG. The rationale for using the RSC approach to set the
MRDLG or MCLG is based on the idea that an individual's jotal exposure to a chemical should not exceed
the reference dose (RfD) established for noncarcinogens (or, more recently, th6 dose reflecting the chosen
margin of exposure for nonlinear carcinogens). The reference dose for noncarcinogens is formally defined
as "an estimate (with uncertainty spanning approximately an order of magnitude) of a daily exposure to the
human population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious
effects over a lifetime" (EPA, 1988). The RfD is estimated by dividing the experimental no observed adverse
effect level (NOAEL) or the lowest observed adverse effect level (LOAEL) by an appropriate uncertainty
factor. The NOAEL is the highest experimental dose at which there is no biologically or statistically
significant increase in the frequency or severity of a critical effect in an exposed group occurred when
compared with an appropriate control group. If all doses in the available data resulted in adverse effect.
thereby precluding the determination of a NOAEL, the RfD may be determined from the LOAEL. The
NOAEL or the LOAEL is then divided by an uncertainty factor (UF). The UF is based on the data set and
variability in sensitivity among humans, uncertainty in extrapolating effects data collected on animals to
effects in humans, uncertainty associated with extrapolating chronic levels from exposure levels from studies
using less than chronic exposure, uncertainty in extrapolating from LOAELs, and uncertainty in the
lexicological data. The resulting value (NOAEL or LOAEL / UF) is the RfD.
The RSC is employed to establish a MCLG or MRDLG for Category n and m compounds using
EPA's three-category approach. As described in the 1994 proposed rule, the three-category approach
classifies compounds as carcinogens (Category I) or noncarcinogenic compounds '(Category HO based on
evidence of carcinogenicity, pharmacokinetics, potency, and exposure. Compounds that exhibit carcinogenic
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Occurrence Assessment for D'DBP in'Public Dnnkiny Hater Supplies
endpoints. but have limited evidence, and exhibit noncarcinogenic endpoints are classified as Category II
compounds. The assessment of carcinogenic health effects is based on EPA's five-tiered general
carcinogenic classification scheme (EPA. 1986). The MCLG or MRDLG for Category I compounds is set
at zero because it is assumed, in the absence of other data, that there is no threshold dose for carcinogenicity.
For Category H compounds, the MCLG or MPOLG is established using one of two options. The first option
uses the RfD and then applies an additional safety factor of 1 to 10 to establish the MCLG or MRDLG. This
accounts for the possible carcinogenicity of the compound. The second option sets the MCLG or MRDLG
using a theoretical lifetime excess cancer risk of 10'5 to 10"6 using a conservative mathematical extrapolation
model. EPA generally uses the first option to establish MCLG or MRDLG values. However, EPA uses the
second option when valid noncarcinogenic data are not available to calculate the RfD and adequate
experimental data are not available to quantify the cancer risk.
The RSC approach used in setting drinking water standards involves several general steps. First, the
population of concern to be protected by the MCLG or MRDLG is chosen. Next, data on the occurrence of
the pollutant in each medium are used (if available) with assumptions about the intake of water, food, and
air for the chosen population to estimate exposure levels from these environmental sources. These estimated
exposure levels are then used to estimate total exposure to a given disinfectant or disinfection byproduct.
As noted above, the fraction of total exposure attributable to drinking water (the RSC) is then multiplied by
the reference dose for the chemical and is used in the following equation to set the MCLG or MRDLG for
noncarcinogenic chemicals:
MCLG or MRDLG =
WC
where:
RfD = Reference dose for noncarcinogens (mg/kg per day),
BW = Body weight of the individual to be protected (kg), and
WC = Water consumption (L/d).
RSC = Fraction attributed to drinking water.
When adequate exposure data from drinking water and other sources are available and the data
indicate that drinking water exposure contributes between 20 and 80 percent of the total exposure, EPA uses
the actual percentage contributed by drinking water exposure to determine the RSC for drinking water
(59 FR. 38668). When data indicate that the exposure from.drinking water is between zero and 20 percent
Final 7-2 November 13,1998
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Occurrence \ssessmem for D/DBP in Public Drinking Water >u
or 80 and 10) percent. EPA uses a floor and ceiling value of 20 percent or 80 percent, respectively. When
adequate exposure data for the chemical are not available, EPA typically uses a 20 percent default as the RSC
for drinking water exposure (59 FR. 38668). However, the 1994 proposed rule used the 80 percent default
value to set the RSC for all relevant disinfectants and disinfection byproducts (DBPs)-because. based on
available information, the drinking water source was anticipated to contribute the vast majority of overall
exposure.
12 CHOICE OF THE POPULATION OF CONCERN
Exposure to disinfectants and DBFs possibly may have different effects on the subpopulations being
served by the water treatment system. Thus, assessments of the exposure to disinfectants and DBPs should
consider sensitive subpopulations. Some common sensitive subpopulations include infants, the elderly,
pregnant women, people with cardiovascular disease, malnourished individuals, enzyme deficient
individuals, and immune-compromised individuals. The health effects from disinfectants and DBPs have
been generally characterized as long-term exposure illnesses and are assumed to pose limited additional risk
to most subpopulations. Based on these considerations, the population of concern for exposure from
disinfectants and DBPs was characterized as adults with long-term exposure.
7.3 ESTIMATION OF EXPOSURE FROM DRINKING WATER
The RSC approach uses central tendency estimates of occurrence and exposure when estimating the
contribution of exposure from drinking water for an average adult. However, it is also important to note that
exposure to disinfectants and DBPs in drinking water may vary according to regional water quality and
disinfection practices and also with residual disinfection concentrations is also important . Residual
disinfectant concentrations decrease from the point of entry to the terminal portions of the distribution system
(Haas, 1990). The formation of most DBPs increases with time in the distribution system (Stevens and
Symons, 1977). The inverse relationship of residual disinfectant and most halogen-substituted DBP
concentrations creates a range of exposures within a distribution system. Consumers closer to the treatment
plant may have higher exposures to disinfectants and lower exposure to DBPs, while populations at the
terminal sections of the distribution system may be exposed to higher concentrations of DBPs and lower
concentrations of disinfectants.
EPA believes that the 2 L/d assumption is representative of a majority of the population over the
course of a lifetime. This assumption has been used in numerous drinking water regulations and also with
the human health methodology for setting ambient water quality criteria. Although a policy decision, 2 L/d
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Occurrence Assessment far D/DBP in Public Dnnkinq Water Supplies
is a reasonable and protective determination that represents the intake of most water consumers m the general
population according to available drinking water studies, as discussed below.
The National Academy of Sciences (NAS) specifically undertook a study to meet the needs
expressed in the 1974 Safe Drinking Water Act (SDWA). Under the SDWA. EPA was required to establish
federal standards for protection from harmful contaminants in the drinking water supplies of the nation.
Congress directed EPA to arrange with NAS to study the adverse effects on health attributable to
contaminants in drinking water. In 1977, NAS produced a multivolume study entitled, Drinking Water and
Health.. In this study, 2 L were taken as the average amount of water consumed per day. While the average
per capita water consumption, as calculated from a survey of nine different literature sources, was 1.63 L/d
NAS adopted 2 L/d as better representation of the intake of the majority of water consumers. EPA adopted
2 L/d as the drinking water exposure for its human health criteria methodology, understanding that it included
a margin of safety that would ensure that most water consumers would be protected.
Another significant and more recent study by the National Cancer Institute (NCI) estimated intake
from tapwater using data from the USDA's National Food Consumption Survey (Ershow and Canter, 1989).
For 11,700 adults aged 20 to 64 years, this study reports the 50th, 75th, and 90th percentile tapwater intakes
to be 1.3, 1.7, and 2.3 L/d, respectively. This study indicates that 2 L/d is the 84th percentile value.
Because EPA's purpose in selecting a higher than statistical average value is to provide a margin of
s
safety sufficient to protect most people, a finding that 2 L is representative of 84 percent of the population
is consistent with EPA's approach in setting human health criteria. EPA is also aware that certain individuals
who work or exercise in hot climates may consume water at rates significantly higher than 2 L/d. EPA still
believes that the 2 L/d assumption continues to represent an appropriate risk management decision. If
occurrence data ace adequate, the estimate of 2 L can be combined with occurrence data to estimate the daily
amount of a chemical from drinking water to which an adult is exposed.
7.4 ESTIMATION OF EXPOSURE FROM SOURCES OTHER THAN DRINKING WATER
As noted previously, occurrence data for sources other than drinking water can be used to develop
exposure levels that are then used in the development of MRDLGs and MCLGs. Only limited data on
occurrence in sources other than drinking water were available for the disinfectants and disinfection
byproducts considered in this document. When adequate data are available to estimate exposure, however.
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Occurrence \ssessmem for D/D8P in Public Dnnkinq Vtater Supplies
the amount of food an adult eats per day and the amount of air an individual breathes are used with
occurrence data from nondnnking water sources to estimate 'ntake from these sources.
7.5 RELATIVE SOURCE CONTRIBUTION VALUES CHOSEN FOR INDIVIDUAL
DISINFECTANTS AND DBFS
The RSC approach is used only for those disinfectants and disinfection byproducts that are not
evaluated as carcinogens and that have sufficient toxicity data to establish an MCLG or MRDLG. The
following sections describe whether the RSC approach is applicable to the chemical described, based on
whether the chemical is a carcinogen and whether adequate toxicity data were available at the time of the
1994 proposed rule to set an MCLG or MRDLG for the chemical.
r Of the chemicals that are not carcinogens and that have sufficient toxicity data to establish an MCLG
or MRDLG, the available data on occurrence and exposure were reviewed for the chemical for potential use
in estimating the RSC for the chemical. Data were available for only two noncarcinogenic chemicals,
chloramines and chlorodibromomethane, regarding concentrations in sources other than drinking water. The
data for these two chemicals were determined to be too limited to use in estimating the RSC. Therefore, for
all disinfectants and disinfection byproducts for which the MRDLG and the MCLG were based on
noncarcinogenic endpoints, the RSC was set at 80 percent (see Section 7.1).
7.5.1 Disinfectants
Chlorine
The U!S. Food and Drug Administration (FDA) does not currently analyze for this compound in
food. Although chlorine is used extensively in food preparation, no monitoring data are available to
adequately characterize exposure. Limited additional data were identified for chlorine since the 1994
proposed rule. Exposure to chlorine from the inhalation of ambient or indoor air is also insufficient to
develop an RSC based on available data. Although EPA requested additional data-on nondnnking water
exposure in the 1994 proposed rule, no comments were received. Because no additional information are
available to estimate exposure, the RSC will remain at 80 percent.
Chloramines
The 1994 proposed rule set the RSC for chloramine at 80 percent exposure from drinking water.
Little information on dietary or ambient air intake exposures was published since the proposed rule.
Although EPA requested additional data on nondnnking water exposure in the 1994 proposed rule, no
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Occurrence \ssfssment for DtOBP in Public Dnnkint; Water Supplies
additional data uere received in response to the request. Data characterizing exposure to chloramme t'rom
dietary intake and inhalation of ambient or indoor air are insufficient to develop an RSC. Therefore, the RSC
will remain at 80 percent.
Chlorine Dioxide
Little information is available on the occurrence of chlorine dioxide in food in the United States.
However, the FDA. anticipates that no typical exposure to chlorine'dioxide in foods will occur because of
its reactive nature. Although chlorine dioxide is approved for use as a sanitizer in air ducts (Borum. 1991),
insufficient information exists to develop an RSC based on the data. The RSC was set at 80 percent in the
proposed rule, and no comments were received from the proposed rule request for additional data on
nondrinking water exposure. Therefore, the RSC will remain at 80 percent for chlorine dioxide.
7.5.2 Disinfection Byproducts
Total Trihalomethanes
The lexicological data for bromodichloromethane, bromoform, and chloroform supported a Category
I classification for these compounds as carcinogens. Therefore, EPA proposed MCLGs of zero for these
compounds. RSCs are not necessary for these carcinogenic compounds.
In the 1994 proposal, the RSC for chlorodibromomethane was set at 80 percent because there were
no significant levels detected in ambient air. Although, the EPA requested additional information in the 1994
proposed rule, no additional information was received. Limited additional data on nondrinking water
exposure have been identified for chlorodibromomethane since the 1994 proposed rule. Therefore, the RSC
will remain at 80 percent for chlorodibromomethane;
Haloacetic Acids 5
The five haloacetic acids include mono-, di-, and trichloroacetic acid and mono- and dibromoacetic
acids. EPA proposed MCLGs for two of these compounds, dichloroacetic acid and trichloroacetic acid. EPA
proposed zero for dichloroacetic acid and 0.3 mg/L for trichloroacetic acid. Dichloroacetic acid was
classified as a Category I carcinogenic compound, and no RSC was necessary.
The MCLG for trichloroacetic acid was based on an RSC of 80 percent. Little additional information
has been identified for trichloroacetic acid since the 1994 proposed rule. Although the proposed rule
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5
'Occurrence \ssessmerttfor D'DBP in Public DnriKini; Water -suppi:*
requested additional data on the concentration of tnchloroacetic acid in food, water, and air. no additional
studies or data were received. Therefore, the RSC will remain at 80 percent for tnchloroacetic acid.
Chloral Hydrate
The proposed MCLG of 0.04 mg/1 for chloral hydrate was based on an RSC of 80 percent. Although
the proposed rule requested additional data on the concentration of chloral hydrate in water, food, and air,
no additional studies or data were received. Only limited information on the exposure to chloral hydrate has
been identified'since the 1994 proposed rule. Therefore, the RSC will remain at 80 percent for chloral
hydrate.
Chlorite
The 1994 proposed MCLG for chlorite was 0.08 mg/L. EPA based this MCLG on an RSC of 80
percent. Although EPA requested additional information in the proposed rule and NODA, no additional data
on non-drinking water exposure were submitted and no additional information was identified in the literature
searches. Therefore, the RSC will remain at 80 percent for chlorite.
Bromate
EPA proposed an MCLG of zero for brpmate based on a Category I classification as a carcinogen.
Therefore, an RSC is not necessary.
Exhibit 7-1 summarizes the RSCs for disinfectants and DBPs. Note that RSCs are not developed
for class 1 carcinogens and are not provided in the exhibit.
Final 7-7 November 13,1998
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Occurrence Assessment for D/DBP in Public Dnnkiny Wafer )uppli
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APPENDIX A
Summary of Surveys and Studies
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Occurrence \ssessmem for D'DBP tn Public DnnKinq
SUMMARY OF SURVEYS AND STUDIES
This appendix provides summaries of the major surveys and studies cited in Sections 3 and 4 of this
occurrence assessment document. The summaries extract details from the published literature on sampling,
'analytical methods, and the evaluations of the data. It should be noted that these data may have a wide
degree of validity. For example data from some of the surveys were provided by public water systems
(PWSs) in response to requests for data from the Agency or associations funding the survey. Data from the
monitoring compliance reports and local studies may have received a more thorough degree of quality
assurance. The summaries are organized in alphabetical order by author for studies and by title for surveys.
American Water Works Association Disinfection Survey, 1991: The Disinfection Committee of
AWWA's Water Quality Division conducted the AWWA's 1991 Disinfection Survey and collected data
from 283 utilities. Each facility was asked to respond to questions involving disinfection and quality control,
including: control methodology, chlorine demand, filtration, chlorine dose, contact times, and TTHM levels.
The survey results indicated that mean free chlorine residuals in drinking water entering distribution systems
ranged from 0.07 to 5.00 mg/L, with a median of 1.10 mg/L.
American Water Works Association, 1997: This survey for the American Water Works
Association (AWWA) Survey was conducted in January 1.997 by McGuire Environmental Consultants. The
survey includes data from 298 Information Collection Rule (ICR) utilities. One of the objectives was to
gather TOC data for use in the Microbial Disinfection Byproducts (M-DBP) stakeholder process to develop
the final Stage 1 DBF rule. For this study, data were requested from surface water systems serving more than
100,000 people and groundwater systems serving more than 50,000 people in 50 states. Two hundred
seventy-five utilities provided 3 months of TOC data from September, October, and November 1996.
American Water Works. Association Research Foundation, 1987; McGuire and Meadow, 1988:
In 1987, the American Water Works Association Research Foundation (AWWARF) sponsored a national
survey of trihalomethanes (THMs) conducted by the Metropolitan Water District of Southern California.
As part of this survey, alternate treatment technologies were investigated that would lower THM levels.
According to survey results, typical chlorine dosage in drinking water was 2.2,2.3, 1.2, and 1.0 mg/L
for systems using lakes, flowing streams, groundwater, and mixed-supplies, respectively, as their raw water
sources. Overall, doses ranged from 0.1 to more than 20 mg/L. Typical chloramine concentrations in
drinking water were 1.5 mg/L for systems using lakes and 2.7 mg/L for systems,using flowing streams as
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Occurrence \ssessment for D/DBP in Public Dnnkiny ^ater -sup
their raw, uater sources. Typical chlorine dioxide dosage used in drinking water was 0.6 mg/L for systems
using lakes and 1.0 mg/L for systems using flowing streams as their raw water sources (McGuire and
Meadow. 1988).
.American Water Works Service Companies, 1991. The American Water Works System Company
(AWWSCo) is the largest investor-owned water utility in the United States. It owns and operates more than
100 water systems in 21 states. In 1989, AWWSCo initiated a project to evaluate the occurrence and
formation of DBFs at approximately 20 of their 100 water systems (the majority of which have surface water
treatment plants) and to observe seasonal differences in these occurrences. Investigators collected samples
in three phases: phase I in the fall of 1989 for 16 systems; phase II in the winter of 1991 for 16 systems; and
phase three summer'1991 for 21 systems. Overall, sampling represented systems in 10 slates, 9 of which are
located east of the Mississippi River. In this study, AWWSCo characterizes TOC and bromide ion
occurrence in raw water. For dibromochloromethane and cloral hydrate sampling, waterwas collected from
source waters (mostly surface waters) throughout the treatment train and in the distribution system; chloral
hydrate analyses were conducted with EPA Method 551.
AWWSCo provided EPA with a summary of TTHM and haloacetic acid 5 (HAA5) data for
approximately 52 systems for 1991 and 1992. For many of these systems, information on source water and
population was also provided. For the purpose of this occurrence assessment, precursor and disinfection by
product data were aggregated by sample location to obtain a range of statistics.
Amy et al., 1994; Westerhoff et ah, 1994: This is a study from the University of Colorado on
bromide ion occurrence. Source water samples from 101 drinking water utilities across the United States
were collected from October 1991 to April 1993 and analyzed for bromide ion. Except for 10 utilities known
to have bromide ion-related problems, the utilities were randomly selected from the Water Industry Database
to obtain geographical and source type diversity.
•
The population-weighted averages for bromide ion for the randomly chosen large utilities and
randomly chosen small utilities were 0.078 and 0.006 mg/L, respectively. Lake and reservoir sources were
generally lower in concentration than rivers and groundwater. The 10th and 90th percentile distribution
values were 0.0055 and 0.102 mg/L, respectively, for bromide ion. The authors of the University of
Colorado Study suggested that connate seawater may occur ubiquitously and affect the distribution of
bromide ion in drinking water sources.
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Ozcurrtnct Assessment for D/DBP in Public Drinking H ater iupptits
Seasonal variations m bromide concentrations were minimal. The concentration range across the
groundwater samples was higher, however, than across the samples from lakes and rivers. When the data
included the targeted samples (average of 0.210 mg/L), the overall average increased to about 0.100 mg/L.
The authors suggested that the values excluding the targeted facilities were probably more representative of
random sampling.
Arora et al., 1994: This survey analyzed water samples from 20 utilities (mostly surface waters)
in the fall of 1989, winter of 1991, and the summer of 1991 to observe seasonal differences in TOC and
THM. THM analyses were conducted by EPA Method 501.1. Monitoring data from winter and summer
1991 were used to make statistical estimates.
Bolyard et al., 1993: Bolyard et al. (1993) reported the occurrence of chlorite ion in source water
and finished water from four utilities that use chlorine dioxide and 15 sites that use hypochlorination.
Analyses for chlorate ions were performed by direct injection into an ion chromatograph with suppressed
conductivity detection. Because the source water for these systems did not contain measurable
concentrations of chlorite ion and chlorate ion and because gaseous chlorine was used for chlorination.
chlorine dioxide is the source of DBF contaminants in these sites. The estimated dose of c'hlorine dioxide
doses varied from 0.07 to 2.0 mg/L. Additional gaseous chlorine was also added to provide a residual
disinfectant level in the distribution system. The concentrations of chlorite ion in the finished water ranged
from 0.015 to 0.740 mg/L.
Results for chlorate ions in these waters show a wide range of concentrations. The estimated doses
of chlorine dioxide varied from 0.07 to 2.0 mg/L. Additional gaseous chlorine was also added to provide
a residual disinfectant level in the distribution system. The concentrations of chlorate ions in the finished
water ranged from 0.021 to 0.330 mg/L. The concentration of chlorate ions was much higher than the
concentration of chlorite ions in the finished water from two specific sites (sites 44 and 62). Both systems
use chlorine dioxide as a pre-oxidant. At site 62, the water is chlorinated before the secondary sedimentation
basins and passes through granular activated carbon (GAC) filters after sedimentation. Powdered activated
carbon (PAC), added to the raw water at site 44, is in contact with the water through the sedimentation
basins. If PAC acts in a manner similar to GAC, chlorite ions and excess chlorine from the chlorite ion
generator or free available chlorine as the residual disinfectant probably react to form the high concentration
of chlorate ions detected in the finished water at site 44. The creation of chlorate ions was higher than would
be predicted from the chlorine dioxide dosage for this site, suggesting that the estimated dosage may be low.
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Occurrence Assessment for D/DSP in Public Drinking V,ater Supplies
Data for 1 I $>stems I 15 sites) that use hypochlorination as a source of chlorine for disinfection
demonstrates that the levels of chlorate ions detected in these finished waters are generally in the same range
as those for systems that use chlorine dioxide during treatment. The levels of chlorate ions in the finished
water from sites 77 and 87 were much higher than the rest, but the significance of this is not known because
of the limited number of samples analyzed. In two sites. 82 and 83. chlorate ions were present in the source
water. In both cases, however, higher levels were present in the finished water.
Chemical Manufacturers Association Dataset, 1997: The Chlorine Dioxide Panel of the Chemical
Manufacturer Association (CMA) provided EPA with data for chlorite ion occurrence at 65 water treatment
facilities that are serviced by one generation company. CMA estimates that the 65 facilities represent
between 5 to 10 percent of the facilities nationwide that use chlorine dioxide treatment. More than
50 percent of the 65 facilities are located in the states of Texas, Kentucky, Missouri, and Rhode Island: with
a few in Georgia. South Dakota, Oklahoma, and Kansas.
Many facilities provided monthly monitoring results between January 1995 and January 1997. The
double blinded data set did not indicate exact sample locations, source water characteristics, nor chlorine
dioxide dosages or residuals. EPA Method 300.0 was used to determine chlorite ion concentrations. The
practical quantitation level is 10 ug/L, and the method detection limit is approximately 1 ug/L for chlorite
ion. Data showed a range for chlorate ion concentration from 0.01 to 4.42 mg/L and a range for chlorite ion
that varies from 0.01 to 5.36 mg/L. Mean values for chlorate and chlorite ions were of 0.40 and 0.58 mg/L.
respectively.
Community Water System Survey, 1978 (Brass et aL, 1981): The U.S. EPA conducted the
Community Water Supply Survey (CWSS) in 1978. Drinking water samples provided by 452 systems.
including 388 utilities serving populations of less than 10,000, were taken at the treatment plants and in the
distribution systems. The survey included analyses for chloroform, bromoform. bromodichloromethane. and
dibromochloromethane. It should be noted the samples were 1 to 2 years old prior to analysis.
The CWSS results show that 97 percent of the surface water supplies and 34 percent of the
groundwater supplies were positive for chloroform. For the surface water supplies, the mean of the positives
and the overall median were 90 and 60 Mg/L, respectively. For the groundwater supplies, the mean of the
positives was 8.9 ug/L, and the overall median was below the minimum reporting limit of 0.5 ug/L. The
CWSS was conducted before the enactment of the total trihalomethane regulation; therefore, these results
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Occurrence \ssessment for D/D8P in Public Onnxini; Hater .iuppu
rru> be higher than current levels in systems that disinfect and serve more than 10.000 people < Brass et al..
1981).
EPA/AMWA/CDHS (35 utility study), 1988-1989; (Krasner et al., 1989): In 1987, EPA funded
a cooperative agreement with the Association of Metropolitan Water Agencies (AMWA) to study the
formation and control of disinfection byproducts (DBPs) in drinking water systems. Twenty-five utilities
nationwide participated in the study performed by the Metropolitan Water District of Southern California
and James M. Montgomery Consulting Engineers, Inc. The California Department of Health Services also
contracted with Metropolitan Water District of Southern California to include 10 California utilities in the
baseline phase of the study. Samples of plant influent and clearwell effluent were collected from each utility
on a quarterly basis during 1988-89. The clearwell effluent samples were analyzed for chlorine residuals;
surrogate parameters; and several chlorination DBPs, including THMs, chloral hydrate, dichloroacetic acid,
and trichloroacetic acid. Appropriate dechlorinating agents were added to all samples at the time of
collection.
Krasner et al. (1989) reported bromide ion levels in the 35 utility nationwide DBP study. Bromide
ion concentrations in groundwater and surface water samples ranged from less than 0.1 to 3.0 mg/L. with a
median of O.I mg/L. High levels may have been due to saltwater intrusion or connate waters. In addition.
clearwell effluent samples were analyzed for chloroform. Samples were taken for 4 quarters (spring,
summer, and fall 1988 and winter 1989). The median for all 4 quarters was 14 ng/L, with the medians of
the individual quarters ranging from 9.6 to 15 ug/L. The maximum value detected was 130 ng/L. For all
4 quarters, 75 percent of the data was below 33 Mg/L (Krasner et al., 1989; EPA and AMWA, 1989).
Gallagher et al., 1994: In an AWWARF report Gallagher et al. (1994) evaluated chlorine dioxide
byproduct (chlorite ion and chlorate ion) levels within the waste water treatment plant and the distribution
systems of five utilities in the United States. These included Charleston, WV; New Castle, PA; Gulf Coast
Water Authority; Skagit, WA; and Columbus, GA. At each utility, the chemical composition of the chlorine
dioxide generator effluents was closely monitored, and the effects of generator optimization on byproduct
residuals within the treatment plants and distribution systems were determined. The study also evaluated
different analytical methods and sample preservation techniques. The resulting data provide an indication
of chlorine dioxide and its byproducts concentrations in water treated with chlorine dioxide.
Onsite analysis used amperometric titration from standard methods for analysis of chlorine dioxide
and its byproducts concentrations in generator effluent. Ion chromatography (modified EPA Method 300.0b)
Final A-5 November 13,1998
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Occurrence \sseismtfnt for D/DBP in Public Dnnkinq Water S
is recommended for the anahsis of chlorite and chlorate ions at levels as low as those expected in the
distribution system when dosages of chlorine dioxide are in the range of 0.5 to 1.0 mg/L. Preservation with
sodium dxalate or ethylene diamine stabilized samples during shipping and storage for 1 week. Carbonate
and borate eluants were used to provide better separation of ion chromatography peaks. Reductive flow
injection analysis with colorometric detection is useful in determining levels of chlorine dioxide and chlorite
ion. was accomplished using a Tecator 5020 analyzer with a Tecator Chemifold n manifold.
Most utilities that apply chlorine dioxide at dosages of 1 mg/L or slightly greater were able to meet
the currently recommended level of 1 mg/L for the sum of chlorine dioxide, chlorite ion, and chlorate
concentrations. Furthermore, most utilities were able to meet the maximum disinfectant residual level
(MRDL) of 0.8 mg/L, which is the level EPA proposed in 1994 for chlorine dioxide. Concentrations of CIO:
in the range of 0.1 to 0.3 •mg/L were not uncommon in systems where chlorine dioxide had been added to raw
water and the finished water was dosed with free chlorine. During the study, concentrations approaching
0.6 mg/L were observed in some clearwells after free chlorine had been added. Exhibit 3-10 identifies the
concentrations of C1O2 at three utilities.
During the study, the median concentration of chlorite ion in the distribution system at locations
where the dosage of chlorine dioxide to the raw water was 1.0 mg/L or less ranged from 0.03 to 0.78 mg/L.
The highest levels were observed at a location where the dosage was 2.0 mg/L but was applied to only one-
half of the plant flow. Incomplete mixing between the water treated with chlorine dioxide and the other half
of the plant flow was responsible for higher chlorite ion concentrations. • Exhibit 4-1 presented previously,
gives study results.
The median concentrations for the observed distribution systems ranged from 0.1 to 0.39 mg/L. A
substantial source of chlorate ions during this project was the chlorine dioxide generator; reactions between
residual chlorite tons and free chlorine most often can be expected to produce the majority of chlorate ions.
These reactions can occur rather rapidly after post-chlorination. Concentrations of chlorate ions in the
distribution systems monitored during this project were not appreciably greater than those in the clearwells
at the treatment plants. Exhibit 4-20, presented previously, gives study results.
Glaze et al., 1993: Glaze et al. (1993) reported sample results for seven full-scale water systems
across the country in an AWWA report that discusses drinking water ozonation treatment plants. A total of
nine samples were taken from two plants sampled on two separate occasions. Samples oftaw water were
Final A-6 November 13, 1998
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Occurrence Assessment for D/DBP in Public DnnKinq V-ater
collected and analyzed for bromide ion. The analytical method used was ion chromatography. which had
a detection level of 0.01 mg/L bromide ion.
Gordon et al., 1993 This 1991 study evaluated the concentration chlorate ion as a disinfection
byproduct for in 16 systems using hypochlorination. Twenty-five samples showed a residual chlorate ion
concentration ranging from 0.08 to 0.30 mg/L and a median of 0.12 mg/L. The 25 and 75 percentiles were
0.08 and 0.18 mg/L, respectively.
!
Gordon et al., 1995a: From 1993 to 1995, Gordon et al. collected and analyzed water samples from
111 systems using hypochlorination. The objective was to evaluate disinfection byproduct concentrations.
specifically of chlorate ion, in the drinking water samples. Results demonstrated a residual chlorate ion
concentration in the distribution system varying from <0.01 mg/L to 9.18 mg/L and mean and median
concentrations of 0.49 and 0.16 mg/L, respectively.
Grammith, 1993: In this study, Grammith evaluated bromate concentrations in water samples from
a MWD demonstration plant of 5.5 MGD. Ozonation water sampling was performed at contactor effluent.
Results showed a residual bromate concentration range in the distribution system varying from <5 to
>10Mg/L.
Groundwater Supply Survey 1980-1981: The Groundwater Supply Survey (GWSS) is an EPA
national study on groundwater TOC occurrence. It reports data by EPA Region for 945 utilities. GWSS is
not applicable to the occurrence of chloroform in distribution systems...
GWSS data presented in this ocurrence assessment indicates that sixty-nine percent of these utilities
or 654 chlorinated their water, while 31 percent or 291 utilities did not. When the TOC data were combined
to present values for all groundwater systems, the 25th, 50th, and 75th percentiles were 0.3,0.6, and 1.4 mg/L
TOC, respectively. These results were presented in Tables VI-3 A, B, and C from the 1994 D/DBP proposed
rule.
• . *
Hoehn, 1990: Hoehn et al. (1990) conducted a study to determine the contribution of drinking water
disinfected with chlorine dioxide to household odors reported at houses, in Lexington, Kentucky (three
houses, samples not specified), and in Charleston, West Virginia.. Source waters at both plants were rivers,
and samples were collected from the plants and from houses. The Lexington treatment adds chlorine dioxide
Final A-7 November 13,1998
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Occurrence Assessment for D/DBP in Public Drinking Uaier Supplies
to rau. water at doses of 1.0 mg/L: the treatment process in Charleston adds 2.0 mg/L of chlorine dioxide.
Samples were analyzed using the amperometric method of Aieta et al. and the flow injection analysis of
Gordon et al. Chlorine dioxide concentrations in the Charleston treatment plant and distribution system, and
chlorite and chlorate ion results from two houses and'the distribution system were examined. Results from
sampling at Lexington were not specified.
Massachusetts Compliance Monitoring Data: During the period from. 1994 to 1996, the State of
Massachusetts collected data on total trihalomethanes (TTHMs) from statewide drinking water systems that
used groundwater, surface water, and mixed water as the source. A total of 53 samples were analyzed for
TTHM. Results indicate that the highest TTHM concentrations were for the 21 samples from those systems
using surface water as the source and serving more than 10,000 people, with*values ranging from 2 to
502 ug/L and mean and median values of 54 and 50 ug/L, respectively. These TTHM concentrations were
followed by those from 19 samples in systems using mixed water as a source and serving more than 10.000
people, which showed values varying from 0 to 524 ug/L and mean and median values of 50 and 45 ug/L,
respectively. The lowest TTHM concentrations were found in systems serving less than 10,000 people in
systems using surface water and mixed water as the source. Two samples from the smaller systems (serving
less than 10,000 people), that use mixed water as the source, showed the lowest TTHM mean value. 28 Mg/L,
and median value, 12 ug/L.
Missouri Compliance Monitoring Data: The State of Missouri evaluated the concentrations of
total trihalomethanes (TTHM) reported for 107 groundwater and surface water systems statewide during
1996 and 1997. Surface water samples comprised 86 percent of the 107 samples, and groundwater samples
the other 14 percent. Results indicate the highest average TTHM concentrations for those systems serving
less than 10,000 people, regardless of their source. Eighty-one samples from surface water systems serving
less than 10,000 people showed the highest average and mean TTHM concentrations, 118 and 102 ug/L,
respectively. Fourteen groundwater systems (> 10,000 people) demonstrated an average TTHM concentration
of 15 ug/L and a median TTHM concentration of 3 ug/L. These were the lowest values reported.
New Jersey Compliance Monitoring Data: The New Jersey Department of Environmental
Protection provided compliance monitoring data for average TTHM concentrations at 151 public water
i
systems from 1994 through 1996, the majority (123 systems) of these being groundwater systems. Data
reported from surface water systems, regardless of population served, showed the highest average and mean
TTHM concentrations, varying from 42 to 48 ug/L and from 27 to 39 Mg/L, respectively. Groundwater
Final A-8 November 13,1998
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Occurrence \ssessmenl for D/DBP th Public Dnnking Water Supplm-i
average TTHM concentrations were lower than those form surface water. 9 ug/L for small «10.000 people
served), and 7 |ug/L for large systems (>10.000 people served).
Nieminski et al., (1993): The Utah Department of Environmental Quality and the Utah Department
of Health studied DBFs in surface-water treatment facilities in Utah. All plants used chlorine for primary
and secondary disinfection. The study analyzed treated water for individual THMs, HAAs, and other
halogenated DBFs. Samples were collected from 35 water utilities, including 14 serving more than 10.000
people and 21 serving fewer than 10,000 people.
At the 14 larger systems, testing for DBFs was conducted quarterly to observe seasonal variations.
These samples were collected at locations just prior to distribution and held, for various periods to simulate
conditions in the distribution system samples (SDSs). At the small plants, samples were collected annually
from the plant effluents and at the end of the distribution system. All samples were collected in triplicate.
Three sets of samples were collected: plant effluent, distribution system or SDS samples and 7-day
formation potential. The first set of samples from each facility was preserved using 4.6 mg ammonium
chloride to 40 mL water to quench the free chlorine. The second set of samples from 14 facilities was stored
at a temperature and time simulating distribution system conditions to allow free chlorine to react with the
precursors. At the end of this period, the chlorine residual was measured. The third set was held for 7 days
before quenching and then was analyzed. EPA Method 551 with a methyl-tert-butyl ether (MTBE) extraction
rather than the pentane was used to analyze individual THMs.
The HAAs were analyzed using a micro extraction method similar to that developed by Metropolitan
Water District (now Standard Methods) and EPA Method 552. To prevent MTBE from boiling over; the
method was modified. The water was shaken for 20 seconds after the addition of the acid, and then the
MTBE was added after another 5 to 10 seconds. Copper sulfate was not added, because it contained
impurities that interfered with chromatography of monochloroacetic acid. Only 6 grams of sodium sulfate
was added (not 12 as per the method) to avoid caking.
Results showed no significant differences in DBP occurrence in large versus small utilities. The
authors also noted that although seasonal variation was seen in the results from the 14 large plants, no season
was significantly lower or higher than the other seasons. In a representative large plant, chloroform was the
major THM compound detected, representing 77 percent THMs by weight. The authors provided EPA with
analytical results of individual THM species from the plant effluents not published in the article. It should
Final A-9 November 13, 1998
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Occurrence \isessmentfor DlDBP in Public Drinking \\ater
be noted that concentrations'in the distribution system were up to 40 percent greater than concentrations in
the plant effluents.
Total HAA concentrations were reported for the mean, median, and 25th and 75th percentiles. The
mean plant concentration for the 35 plants was 17.3 ug/L, with a median concentration of 12.8 ug/L of
HAAS. The 25th and 75th percentiles were 7.13 and 22.60 ug/L HAAS, respectively. The authors noted
that monochloroacetic acid and trichloroacetic acid were the major HAAs detected in the distribution
systems. HAA concentrations reported were somewhat lower than nationwide medians, and the authors
attributed reduced medians to the lower TOC in Utah waters. The statistics were calculated from data
provided by the authors for plant effluent and distribution systems.
i
Chloral hydrate concentrations between 0.7 and 3.76 ug/L were reported from the four samples
collected in June 1990. Although analyses for bromate ion were conducted, the authors noted that bromate
ion was not detected above the detection level of 7 ug/L from any of the 35 water utilities plants that use
liquid chlorine. However, none of the systems characterized in the study used ozonatibn, the major source
of bromate ion.
National Organics Monitoring Survey, 1976-1977 ( Bull and Kopfler, 1990): The National
Organics Monitoring Survey (NOMS) is one of two surveys performed by EPA to obtain information on the
occurrence of trihalomethanes (THMs) and other organic compounds in the United States prior to the
promulgation of the maximum contaminant level (MCL) of 0.10 mg/L for total trihalomethanes (TTHMs)
in 1979.
EPA conducted the National Organics Monitoring Survey from March 1976 to January 1977 to
identify sources and frequency of occurrence of organics and inorganics in drinking water supplies. NOMS
was conducted in three phases: Phase I - March to April 1976, Phase n - May to July 1976, and Phase HI -
November 1976 to January 1977. NOMS involved sampling and analyzing finished water from 113 public
water supplies across the United States.
Results show that surface water was the major source for 92 of the systems, and groundwater was
the major source, for the remaining 21 systems. Two analytical methods were used to measure chloroform
concentrations at the time of sampling and to measure the maximum chloroform concentrations due to the
reaction of all the chlorine residual. During the three phases, chloroform was detected in 92 to 100 percent
of the systems sampled. The median concentrations of the maximum chloroform in the three phases ranged
Final A-10 November 13,1998
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Occurrence Assessment for D/D8P in Public Dnnkinq Water Supplier
'from 22 to 54 5 ug/L. The maximum value detected was 540 u.g/L. NOMS was conducted before the
enactment of the total trihalomethane regulation: therefore, these results may be higher than current levels
in systems that disinfect and serve populations of more than 10.000 people (Bull and Kopfler. 1990).
National Organics Reconnaissance Survey, 1975; (Symons et ah, 1975): The National Organics
Reconnaissance Survey is one of two surveys performed by EPA to obtain information on the occurrence
of trihalomethanes (THMs) and other organic compounds in the United States prior to the promulgation of
the maximum contaminant level (MCL) of 0.10 mg/L for total trihalomethanes ([THMs) in 1979. The
NORS primary objective was to characterize the extent and presence of TTHMs in the United States.
The NORS collected drinking water samples from 80 cities nationwide, geographically distributed
and representing a wide variety of raw water sources and treatment technologies. This survey sampled for
several organics, including THMs, at the water treatment facilities. Results indicated chlorine residuals
ranging from 0 to 2.8 mg/L, with an approximate median concentration of 0.6 mg/L (Symons et al., 1975).
In addition, it was found that eighty percent of the systems had surface water sources, and the remaining 20
percent had groundwater sources. The median concentration for chloroform was 23 ug/L, and the maximum
level detected was 311 yg/L.
The NORS no longer represents occurrence of THMs in water systems serving more than 10.000
people, because of changes in disinfection practices required in the Surface Water Treatment Rule, which
became effective in 1993. However, data could be indicative of THM occurrence in small systems. NORS
was performed prior to the 1979 total trihalomethane regulation; therefore, these results may be higher than
current levels for systems that disinfect and serve more than 10,000 (Symons et al., 1975).
Oregon Compliance Monitoring Data: Information reported by the State of Oregon from 1994
to 1996 included TTHM data for 34 Oregon's public water systems serving more than 10,000 people. Of
these systems, 27 are surface water and 7 are groundwater. Results indicate that the mean TTHM
concentration in surface water systems is 29 ug/L, approximately twice of that found in groundwater systems.
16 ug/L. Ranges for surface water and groundwater systems are 7-76 ug/L and 5-31 ug/L, respectively.
Pennsylvania Compliance Monitoring Data: The State of Pennsylvania provided compliance
monitoring results, including TTHM concentration data for 223 systems statewide for the years 1994 through
1996. Surface water systems, a total of 173, comprised the majority of the systems studied. Of these, 63
Final A-11 November 13. 1998
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Assessment for D/DBP in Public Dnnkin? Wafer
purchase surt'ace water. A total of 10.312 samples were collected t'rom the distribution system only
on a quarterly basis and analyzed using EPA Methods 551, 502.2. and 524 2. The results showed h.jher
TTHM concentrations in samples collected from surface water systems than those in groundwater systems.
TTHM concentrations from surface water systems serving more than 10.000 people ranged from 1 to
113 ng/L. with a 90th percemile of 64 (jg/L. Surface water systems showed a TTHM concentration range
of 0-162 ug/L. and a 90th percentile of 84 ug/L. In groundwater systems. TTHM concentrations ranged from
0-41 ug/L in systems serving more than 10,000 people, and 0-158 ug/L in those serving less than 10.000.
Their 90th percentiles were 17 and 36 ug/L, respectively.
Rural Water Survey, 1978-1980: The Rural Water Survey (RWS), conducted by EPA between
1978 and 1980, assessed the occurrence of organic compounds in public water supplies from rural areas
serving less than 10.000 people. The samples were collected from more than 2,000 households, representing
more than 600 rural water supply systems. Data collected showed that most of the systems (i.e., 494)
sampling for TTHMs used groundwater as their source water, and 154 used surface water. Of the 2,655
samples obtained, 800 were analyzed for purgeable halocarbons, including the four THMs. It should be
noted that some samples were up to 27 months old prior to analysis.
The RWS sample analyses demonstrated that 82 percent of the surface water supplies and 17 percent
of the groundwater supplies were positive for chloroform. For the surface water supplies, the mean of the
positives and the overall median concentrations were 84 and 57 ug/L, respectively. For the groundwater
supplies, the mean of the positives was 8.9 ug/L, and the overall median was below the minimum reporting
limit of 0.5 ug/L (Brass, 1981).
«
Singer et al., 1995: This study evaluates the occurrence of DBFs in drinking water from six North-
Carolina utilities. Eight water treatment plants provide water for the six utilities. Because North Carolina
has a relatively high TOC concentration in surface water sources of drinking water (average of 5 mg/L TOC
in systems serving populations greater than 50,000), DBF levels were expected to be higher than levels
reported in other studies. Source waters were characterized as relatively low in bromide ion levels. All
plants used chlorine for disinfection; most plants applied chlorine to the settled water'prior to filtration.
Sample sets were collected three times from each utility between June 1991 and February 1992 to encompass
high- and low-temperature periods. A total of 93 samples were collected from representative locations in
the distribution systems and analyzed for four THMs, four HAAs, and other DBFs. The sampling locations
were those used for THM compliance monitoring. DBF analysis was performed by liquid-liquid extraction
and capillary column gas chromatography with electron capture detection.
Final A-12 November 13,1998
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Occurrence Assessment for DiDBP '" Public Onniiine
The a\erage chloroform concentrations tn the plant effluents and the distribution systems 'Aere 32
and 41 ug/L. respectively. The 42 distribution system samples had a median of 38 ug/L chloroform, with
a range of 8 to 91., ug/L of chloroform. The average chloroform/TTHM ratio was 0.79, indicating that
chloroform represented 79 percent of the TTHMs measured.
Sorrell and Hautman, 1992: In their 1992 study, Sorrell and Hautman report on the development
of a concentration technique for analyzing bromate ion at low levels in drinking water. This procedure used
a rotovap to concentrate drinking water samples, followed by ion chromatography. Bromate ion was detected
with a combination of suppressed conductivity and ultraviolet. A minimum detection level of 0.4 ug/L was
achieved. This rotary evaporator concentration technique was applied to several drinking water surface water
sources before and after ozonation. Bromate ion levels ranged from less than 0.4 to 6.3 ug/L in samples from
nine surface water plants using ozone. No ozone dosages or bromide ion levels were reported. .
Technical Support Division, 1992: The Technical Support Division (TSD) of the U.S. EPA Office
of Ground water and Drinking Water conducted a water chlorination byproduct field study from October 1987
to March 1989 and compiled a database with the information collected. Twenty-one community water
supplies provided samples of source water, plant effluent, and water from a far point in the distribution
system. Disinfection processes and concentrations of the four individual THMs (i.e., chloral hydrate.
dichloroacetic acid, and trichloroacetic acid) were characterized.
In the distribution system, the mean chloroform concentration was 58.7 and 77.2 ug/L for plants
serving above and below 10,000, respectively, with the 90th percentile concentration of 141.0 and 110.0 ug/L
for 39 samples and II samples, respectively (EPA, 1992b). The groundwater systems serving less than
10.000 had a mean chloroform concentration of 3.6 ug/L for five observations, with the 90th percentile of
9.4 ug/L (EPA, 1992b).
Texas Compliance Monitoring Data: Between the years 1994 and 1996, the State of Texas
provided compliance monitoring data characterizing TTHM concentrations in 227 water treatment systems,
114 surface water and 113 groundwater systems^ In this analysis, 47 systems using purchased water were
considered surface water systems. Fifty-three groundwater systems or roughly half of the groundwater
systems reported their TTHM results as formation potentials. Samples were collected quarterly and analyzed
using EPA Methods 551,502.2, and 524.2. Data were aggregated by source and the population being served
by the public water supply. Actual TTHM results and TTHM results reported as formation potentials were
Final A-13 November 13, 1998
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Occurrence \ssessment for DlDBP in Public Onnking Water Supplies
combined for the purposes of this analysis. The analysis results showed that surface water systems have a
slightly higher range, mean, median and 90th percentile than those from groundwater systems. A range of
8-135 ug/L and a 90th percentile of 70 ug/L were obtained for 2.521 surface water system samples. Results
from the groundwater system samples indicate that 113 systems serving more than or less than 10.000 people
have similar means, medians, and ranges for TTHM concentrations. Large systems showed mean, median
and range values of 24, 15 and 0-121 ug/L, while small systems reported 26, 19 and 0-120 ug/L for the same
statistics. The 90th percentile in for those serving more than 10,000 people is 60 ug/L and 52 ug/L for
smaller systems.
Utah Pre-ICR data, 1996: The state of Utah conducted a survey between October 1994 and
September 1996 on seven large surface water treatment plants serving more, than 100,000 persons. This
survey provides data for disinfection precursors (TOC and bromide ion), and byproducts (individual and total
THMs and HAAs). Samples for this study were taken at several locations in the treatment process and
distribution system four to six times between October 1994 and September 1996. EPA Method 551 with a
methyl-ten-butyl ether (MTBE) extraction rather than the pentane was used to analyze individual THMs.
The HAAs were analyzed using a micro extraction method similar to that developed by Metropolitan Water
District (now Standard Methods) and EPA Method 552.
For the occurrence assessment, Utah Pre-ICR survey data were aggregated by sample location to
provide a range of statistics for precursors and disinfection byproducts. Disinfection precursor and by
* i
product data points reporting less than the detection limit were converted to zeros and included in the
analyses. The TOC and bromide ion results from the raw water samples were analyzed using all data points
reported. Individual and total HAA results came from two average distribution system samples. Chloral
hydrate results came from two average distribution system samples. Monitoring results from all total HAA
and chloral hydrate samples were used.
WaterStats 1996: WaterStats was initiated through a joint effort by the AWWA and the AWWA
Research Foundation (AWWARF)- The purpose of this database is to support the regulatory and legislative
efforts of AWWA, assist AWWA in focusing research activities, and support the educational endeavors of
AWWA and interested parties. In 1996, AWWA surveyed approximately 3,162 drinking water systems
serving populations exceeding 10,000 in the United States. The response rate was better than 30 percent,
resulting in TTHM, HAAS, and population-served information for approximately 300 systems in the United
States. The survey covered a wide spectrum of information, including utility characteristics and finances,
Final A-14 November 13, 1998
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ce \ssessmem for D/DBP in Public Drinking Water
and aroundwater treatments, water quality monitoring, and water distribution characteristics. The
•data gathered in this survey comprise W'aterStats.
The data in WaterStats characterize distribution system concentrations for TlHM and HAAS. These
distribution system data were also characterized by source water and the population served. The data
represented annual averages based on quarterly sampling for TTHMs and HAAS in systems that chlorinate.
WaterStats was examined for data consistency and outliers, assumptions associated with the data, and
possible analysis methods. The WaterStats data base was assumed to be a representative sample of the
universe of systems .serving greater than 10,000 people.
Water Industry Database 1989-1990: The Water Industry Data Base (WIDE) is a joint effort by
the American Water Works Association (AWWA) and the American "Water Works Association Research
Foundation (AWWARF). The study, conducted between 1989 and 1990, surveyed approximately 1,300
drinking water systems serving more than 10,000 people in the United States. Sampling was conducted at
different times over several years and other water system data were collected based on the professional
judgement of utility personnel. The WIDB includes information on utility characteristics and finances,
surface and groundwater treatments and disinfection methods, water quality monitoring, and water
distribution characteristics. In addition, it provides a large data set of annual average TTHM data, free
chlorine, and combined chlorine residuals. Because of the comprehensive nature of the WIDB. the
Regulatory Negotiating Committee used this data set in their regulatory impact analysis.
For the occurrence assessment, data on TOC levels from 157 utilities was extracted-from the WIDB
to analyze TOC occurrence data in groundwater (57 systems) and surface water (100) systems. The
ocurrence study used the WIDE to identify the number of utilities that did not provide TOC data; 854
groundwater utilities and 897 surface water utilities did not provide TOC data. Also, it studied the residual
chlorine at average consumer from 228 surface water plants and 215 groundwater plants and distribution
system average chloramine from 140 utilities nationwide. Other estimates based on WTBD data included the
usage of chlorine dioxide for disinfection, chlorine residual in drinking water and population exposed to
chlorine residual in drinking water.
Final A-15 November 13, 1998
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APPENDIX B
ANALYTICAL METHODS
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Occurrence 'Assessment for D/'DBP in Public Dnnn-.ng Hater
ANALYTICAL METHODS
Analytical methods are an important factor in water quality monitoring. When interpreting and
comparing data on the occurrence of contaminants, knowing that different studies have used similar methods
with comparable precision, accuracy, and sensitivity is useful. Many of the analytical methods used for
• disinfection byproducts (DBFs) have been improved significantly during the 1990s; hence, the quality of
occurrence data has improved as well.
For the disinfectant/disinfection byproduct (D/DBP) rule, the levels of precursors in the source water
will determine the extent of treatment required. The quantities of DBFs must remain below the maximum
levels specified in the regulation. All of the measurements must be accurate to ensure a safe water supply
while avoiding unnecessary treatment.
Appendix B briefly summarizes the approved analytical methods for the Stage I D/DBP rule and
discusses the nationwide capacity of laboratories to perform these analytical methods. This section describes
the approved analytical methods for the disinfectants or DBFs. The number of laboratories approved by the
U.S. Environmental Protection Agency (EPA) for monitoring under the Information Collection Rule (ICR)
are used to estimate the laboratory capacity and availability of analytical services.
Each of the methods described in this section has an associated method detection limit( MDL). By
definition, the MDL is specific to the analyte, method, and laboratory. For example, EPA Method 524.2
provides four tables of MDL values. The MDL values are dependent on how the instrument is set up matrix,
and analyte. The MDLs provided in this .section represent the most sensitive value available for each method
from the published methods, not an exhaustive analysis of MDL data that is being collected for the ICR.
Under this effort each laboratory approved to work under the ICR ran MDL studies for the analytes and
reported all the results. Method detection limits for each of the methods summarized in this section are
presented in exhibits following each class of analyte.
DISINFECTANTS
Free and Total Residual Chlorine
Standard Method (SM) 4500-C1 D (APHA, 19%) is an amperometric method for detecting chlorine
and chloramines with a detection limit of 2 mg/L. Free residual chlorine is measured by adjusting the pH
of the sample to 6.5 to 7.5 and titrating to the endpoint with a phenyl arsine oxide reducing solution. Total
Final B-l November 13,1998
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•Occurrence Assessment for OiDBP '" Public Dnnkinq ^aier su
residual chlorine is measured by adding potassium iodide to the sample, adjusting the pH to 3.5 to 4.5. and
titrating with phenyl arsine oxide to the endpoint. Microamperometry detects the endpoints in each titration.
SM 4500-C1 E (APHA, 1996) is a low-level amperometric method for detecting chlorine and
chloramines measured as total residual chlorine. This method has a detection limit of 10 ug/L and utilizes
the same principles as the amperometric titration method (4500-C1 D). This method modifies SM 4500-C1 D
by using a more dilute concentration of phenyl arsine oxide titrant and a graphical procedure to determine
the endpoint. Use of this method is recommended when the total residual chlorine is less than or equal to
0.5 mg/L as chlorine. A positive bias will be shown if other oxidizing reagents.are present in the water
sample.
SM 4500-C1 F (APHA, 1996) uses N,N-diethyl-p-phenylenediamine (DPD) as an indicator with
ferrous ammonium sulfate titrimetric method for detecting chlorine and chloramines with a detection limit
of 18 ug/L Cl as C12. When the proper pH is chosen, this method can differentiate between free chlorine and
monochloramine, dichioramine, and total chlorine. The color produced by the reaction of the chlorine
species with DPD dye slowly disappears as the sample is titrated with ferrous ammonium sulfate. The
amount of titrant corresponds to the concentration of the chlorine species being measured. This method is
approved .for determinating free, combined, and total residual chlorine.
c'
SM 4500-C1 G (APHA, 1996) is a DPD colorimetric method for detecting chlorine and chloramines.
This method has a detection limit of 10 ug/L and utilizes the same principles as the DPD ferrous titrimetric
method (SM 4500-C1 F), except that the color produced is read by a colorimeter, and the concentration of
free and total chlorine are calculated after standardization. Combined residual chlorine is the sum of the
monochloramine and dichioramine measurements. Total residual is the sum of free and combined residual
chlorine. This method is used for determining free, combined, and total residual chlorine.
SM 4500-C1H (APHA, 1996) is a detects free available chlorine test, syringaldazine (FACTS) which
is sensitive to free chlorine concentrations of 0.1 mg/L or less. The reagent, syringaldazine, is oxidized by
free chlorine on a 1:1 basis to produce a color that is determined colorimetrically. The pH of the sample
must be maintained at approximately 6.7 to stabilize the color formed. This method is used for determining
free residual chlorine.
SM 4500-C1 I (APHA, 1996) is an iodimetric electrode technique for detecting chlorine and
chloramines. This method involves the direct potentiometric measurement of iodine released when
Final B-2 November 13, 1998
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Occurrence \siessmeni for D/DBP in Public Dnnkinq
potassium iodide is added to an acidified sample containing chlonne. A platinum-silver, platinum-platinum.
or platinum-copper electrode pair is used in combination to measure the liberated iodine. This method is
used for determining total residual chlonne.
Chlorine Dioxide Residual
SM 4500-C1O; C (APHA. 1996) is an amperometric titration method which is an extension of the
amperometric method used for chlorine (SM 4500-C1 D). It consists of four successive titrations using
phenylarsine oxide (PAO) in order to determine the concentrations of free chlorine, chloramines. chlorite.
and chlorine dioxide. The cell current changes as the titrant reacts with the oxyhalogen as chlorine, or with
iodine formed by the addition of iodide to the solution prior to the titration. The four titrations are done
using different pretreatment steps, primarily involving pH adjustment and potassium iodide (KI) addition,
in order to differentiate between the species. The concentrations of the analytes are calculated through
mathematical manipulation of the titration results. Error in one titration step can potentially be propagated
to affect multiple analyte determinations. In this method, chlorine dioxide is determined by subtracting the
concentration of total available chlorine from the sum of total available chlorine plus one-fifth available
chlorine dioxide. Consequently, error in the measurement of chlorine dioxide increases at higher relative
concentrations of total available chlorine. This method is also subject to interferences from chloramines.
manganese, copper, and nitrite. In addition, loss of chlorine dioxide due to volatilization during sample
pretreatment and titrations can be problematic. USEPA removed SM 4500-C1O, C from its list of approved
methods for monitoring chlorine dioxide to determine compliance with the MRDL.
SM 450Q-C1O2 D (APHA 1996) is a colorimetric titration that involves successive titrations with
ferrous ammonium sulfate (FAS) to reduce the color formed upon reaction of oxychlorine species with N,N-
diethyl-p-phenylenediamine (DPD). The method is an extension of the standard DPD method used for
determination of free chlorine and chloramines in water. Oxychlorine species produce a red color upon
reaction with the DPD indicator. As with SM 4500-C1O2 C; a series of titrations is carried out using different
pretreatment steps in order to quantitate free and combined chlorine, chlorine dioxide, and chlorite. Glycine
is added to convert free chlorine to nonreactive chloroaminoacetic acid which allows determination of
chlorine dioxide at neutral pH. Titration of a separate sample along with successive additions of potassium
iodide yields free available chlorine and mono- and dichloramine. Chlorite is determined through acidifying
and then neutralizing a sample prior vto titration. Oxidized manganese, copper, and chromate are
interferences in this method, although these can be suppressed by addition of EDTA or corrected by
subtraction of the background color of a reagent blank. Monochloramine reacts with the DPD indicator to
Final B-3 November 13,1998
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Occurrence \ssessment for D/DBP in Public Dnnkinq \\ater
form a colored product and. thereby, interferes with analysis of other oxychlorine species when present in
high concentration. EDTA is added to suppress iron activation of chlorite by FAS.
SM 4500-C1O, E (APHA 1996) is an amperometric titration much like 4500-C1O, C except that the
pH is adjusted to 12 and a gaseous purge step to physically remove chlorine dioxide are added, [t uses
successive titrations of combinations of chlorine species, followed by calculations to determine the
concentration of each species. Either phenylarsine oxide (PAO) or sodium thiosulfate can be used as the
titrant. Residual chlorine and one-fifth of available C1O2 are titrated at pH 7. The sample pH is then lowered
to 2 and the remaining four-fifths of available C1O2 plus the chlorite are determined. A separate sample is
purged with nitrogen gas to remove CIO, and titrated for non-volatilized chlorine after adding KI. The
sample is then acidified to pH 2 and titrated to measure chlorite ion. In a final step employing highly acidic
conditions, all the oxidized chlorine species, including chlorate ion, are measured.
In this method, the concentration of chlorine dioxide is calculated by subtracting the concentration
of chlorite from the sum of chlorite plus four-fifths of available C1O2. This procedure typically allows
quantitation of C1O2 with far less error than when using 4500-CIO2 C. Standard Methods (APHA 1996)
recommends that the total mass of oxidants should be no greater than 15 mg equivalents of iodine and that
all analyses be made in triplicate. The method is also recommend for assessing chlorine dioxide purity as
j
the PQLs are 0.1 mg/L for chlorine dioxide and chlorite and 0.2 mg/L for chlorate. ,
Exhibit 8-1. Method Detection Limits for Disinfectants.
Analyte
Method
MDL
Disinfectants
Free and Total Residual Chlorine
Chlorine Dioxide
SM 4500-CI D
SM 4500-CI E
SM 4500-CI F
SM 4500-CI G
SM 4500-CI H
SM 4500-CIO2 C
SM 4500-CIO2 D
SM 4500-CIO2 E
< 0.2 mg/L
< 0.01 mg/L
- 18ugClasCl2/L
- 10ugClasCI2/L
0.1 mg/L or less
0.1 mg/L
> 0.1 mg/L
0.1 mg/L
Final
B-4
November 13, 1998
-------
Occurrence \ssessment for D/DBP in Public DnnKine
DISINFECTION BYPRODUCTS
Trihalomethanes
EPA Method 502.2 (EPA. 1995) is used for determining the amount of volatile organic compounds
(VOCs). including the four trihalomethanes (THMS). EPA Method 502.2 is a purge and trap gas
chromatography method utilizing a photoionization detector in series with an electrolytic conductivity
detector. The method detection limits range from 0.01 to 3.0 ug/L for concentrations between 0.02 to
200.0 ug/L. Air purged samples are trapped in a tube with sorbent material. The sorbent material in the tube
is then heated and backflushed with helium to thermally desorb trapped sample components. Identification
of the individual THM species is based on comparison of retention times; concentrations are quantified by
standard calibration.
EPA Method 524.2 (EPA, 1995) uses the same purge and trap procedures as EPA Method 502.2;
however, this method employs a capillary column gas chromatograph and mass spectrometer quantitate
analytes. .The method detection limits range from 0.02 to 1.6 ug/L and depend on the sample matrix and
analyte. The specific method detection limits are listed in Table 4 of the method.
EPA Method 551.1 (EPA, 1996) is used for determining chlorination disinfection byproducts.
chlorinated solvents, and halogenated pesticides/herbicides in drinking water using liquid-liquid extraction
and gas chromatpgraphy/electron capture detection (GC/ECD). This method is used to determine 12
commonly observed chlorination DBPs. Method 551.1. offers significant improvements over previous
methods for THMs.
In EPA Method 551.1, the ionic strength of a 35- to 50-mL drinking water sample is adjusted using
sodium chloride, and the sample is extracted with 2 mL of methyl-tert-butyl ether (MTBE). If only THMs
are being measured, pentane can be used as an extraction solvent. Prior to sample analysis, the THM
formation reaction must be halted by the addition of a reagent that removes all free chlorine from the sample.
Sodium sulfate is used as an extraction salt instead of sodium chloride, which can have trace bromide
impurities. Following extraction, 2 uL of the extract is injected into a GC equipped with a fused silica
capillary column and linearized electron capture detector for separation and analysis. Gas chromatography/
mass spectrometry (GC/MS) can be used to confirm the presence of the compounds.
Final B-5 November 13,1998
-------
Occurrence Assessment for D/DBP in Public Dnnkinq Water Supplies
Haloacetic Acids
EPA Methods 552.1 and 552.2 (EPA. 1995) and SM 625 IB (APHA. 1996) are methods that use gas
chromatographic instrumentation to determine the presence of haloacetic acid in drinking water.
groundwater. raw water, and water at any intermediate treatment stage. The analytical procedures in these
three methods are equivalent and very similar.
EPA Method 552.1 and SM 625IB both use capillary column gas chromatographs with electron
capture detectors. The two methods differ in the sample preparation steps. Method 552.1 uses solid phase
extraction disks, followed by an acidic methanol derivitization. MDLs, which vary according to analyte, are
listed in Table 2-of the method. SM 625IB is a small-volume micro liquid-liquid extraction with MTBE.
followed by a diazomethane derivitization. Following the extraction procedures, the concentration extracts
are convened to methyl esters, which are partitioned into the MTBE phase. The convened esters are
identified, and capillary column gas chromatography is used for quanitification.
EPA Method 552.2 uses capillary column gas chromatography with electron capture detection and
combines the micro extraction procedure of SM 625 IB with the acidic methanol derivitization procedure of
EPA Method 552.1. Following the extraction procedure, this method follows the similar process of
converting the concentration extracts to methyl esters for identification and using capillary column gas
chromatography for quantification.
Chloral Hydrate
EPA Method 551.1 (EPA. 1996) is used for determining chlorination disinfection byproducts,
chlorinated solvents, and halogenated pesticides/herbicides in drinking water "using liquid-liquid extraction
and gas chromatography/electron capture detection (GC/ECD). This method is used to determine. 12
commonly observed chlorination DBFs. Method 551.1 offers significant improvements over previous
methods for chloral hydrate.
EPA Method 551.1,. the,ionic strength of a 35- to 50-mL drinking water sample is adjusted using
sodium chloride, and the sample is extracted with 2 ttiL of methyl-tert-butyl ether (MTBE). Prior to sample
analysis, the DBP formation reaction must be halted by the addition of a reagent that removes all free
chlorine from the sample.. Sodium sulfate is used as an extraction salt instead of sodium chloride,.which can
have trace bromide impurities. Following extraction, 2 uL of the extract is injected into a GC equipped with
Final B-6 . November 13, 1998
-------
Occurrence Assessment for D/DBP in Public DnnKins> ^ater
Exhibit 8-2. Disinfection Byproduct Method Detection Limit
Analyte
Method
MDL
Disinfection Byproducts
Chloroform
t
BDCM
DBCM
Bromoform
i
Monochloroacetic acid
Monobromoacetic acid
Dichloroacetic acid
Trichloroacetic acid
Dibromoacetic acid
Bromide Ion
Chlorite Ion
Bromate Ion
EPA 502.2
EPA 524.2
EPA 551
EPA 551.1
EPA 502.2
EPA 524.2
EPA 551
EPA 551.1
EPA 502.2
EPA 524.2
EPA 551
EPA 551.1
EPA 502.2
EPA 524.2
EPA 551
EPA 551.1
SM 6233B '
EPA 552.1
EPA 552.2
SM 6233B
EPA 552.1
EPA 552.2
SM 6233B
EPA 552.1
EPA 552.2
SM 6233B
EPA 552. r
EPA 552.2
SM 6233B
EPA 552.1
EPA 552.2
EPA 300.0
EPA 300.0
EPA 300.0
0.02 ug/L
0.03 ug/L
0.002 ug/L
0.075 ug/L
0.02 ug/L
0.08 ug/L
0.006 ug/L
0.005 ug/L
0.3 ug/L
0.05 ug/L
0.01 2 ug/L
0.007 ug/L
1.6 ug/L
01 2 ug/L
0.01 2 ug/L
0.006 ug/L
0.082 ug/L
0.21 ug/L
0.60 ug/L
0.087 ug/L
0.24 ug/L
0.20 ug/L
0.054 ug/L
0.45 ug/L
0.24 ug/L
0.054 ug/L
0.07 ug/L
0.20 ug/L
0.065 ug/L
0.10 ug/L
0.25 ug/L
0.1 mg/L
0.01 mg/L
0.02 mg/L
Final
B-7
November 13,1998
-------
Occurrence \isessment fur D/D8P in Public Dnnking Water Supplies
a fused silica capillary column and linearized electron-capture detector for separation and analvsis. Gas
chromatoeraphy/mass spectrometry (GC/MS) can be used to confirm the presence of the compounds.
Chlorite Ion, Bromide Ion, and Bromate Ion
EPA Method 300.1 (EPA. 1996) is an improved method used for determining inorganic anions by
ion chromatography. This method covers the determination of several inorganic ions in a variety of liquid
matrices, including drinking water. The laboratory method detection limit for chlorite and bromide ions is
0.01 mg/L. The MDL for bromate is expected to be 2 ug/L. The MDL for a specific matrix can differ.
depending upon the nature of the samples.
Analysis of the sample occurs by introducing approximately 2 to 3 mL of sample into an ion
chromatograph. The anions of interest are separated and measured using a system comprising a guard
column, analytical column, suppressor device, and conductivity detector. Method 300.1 consists of two pans
(i.e., A and B). The part used depends on the anion of concern.
WATER QUALITY PARAMETERS
Total Organic Carbon
EPA has approved three methods for analyzing total organic carbon (TOC). SM 53IOB (APHA.
1996) was not originally approved; however, improvements in instrumentation have increased the sensitivity
to an acceptable level. SM 53IOB, High-Temperature Combustion Method, is suitable for samples with high
levels of TOC that would require dilution using the persulfate methods. A sample is injected into a heated
reaction chamber packed with an oxidative catalyst. The organic carbon is oxidized to carbon dioxide and
is detected with a non-dispersive infrared analyzer. Because both inorganic and organic carbon are detected,
the inorganic carbon must be removed prior to detection or measured separately and subtracted from the total
carbon measurement.
SM 53 IOC (APHA, 1996) is a persulfate-ultraviolet oxidation method that measures organic carbon
via infrared absorption of the carbon dioxide gas that is produced when the organic carbon in the sample is
simultaneously reacted with a persulfate solution and irradiated with ultraviolet light. Inorganic carbon is
removed from the sample prior to analysis by acidification using phosphoric or sulfuric acid and purging
with nitrogen gas. Chloride and low sample pH can impede the analysis. The MDL is 0.05 mg/L.
Final B-8 Novtmbtr 13,1998
-------
Occurrence \ssessment for D'DBP tn Public Dnnianq Water Suppiie•>
SM 53IOD (APHA. 1996) is a wet-oxidation method with a detection limit of 0.10 mg/L. This
method is subject to the same interferences as the persulfate-ultraviolet method. Inorganic carbon is re.moved
from the sample prior to analysis by acidification using phosphoric acid or sulfuric acid and purging with
nitrogen gas. The purged sample is sealed in an ampule and combusted in an oven for 4 hours, causing the
persulfate to oxidize organic carbon to carbon Hjoxide. The ampule is opened inside the TOC analyzer, and
carbon dioxide is measured using a non-dispersive infrared analyzer.
UV 254 run
SM 5910 (APHA, 1996) uses the ultraviolet (UV) light absorbing characteristic of constituents in
the water. Data derived using SM 5910 are an aggregate measure of the organic content base where
absorbance is proportional to concentration. This method requires filtration to remove particles that create
absorbance interference. Results from the spectrophotometric analysis of samples at 254 nm correlate to the
concentrations of dissolved organic material in the sample. Note that the correlation between UV absorbance
and organic content is site specific and may not be comparable to absorbance values from other sites.
The UV absorbance at 254 nm can be used to further characterize precursors in source water. The
specific ultra violet absorbance (SUVA) is a calculated value that is a good indicator of the humic content
of water. SUVA is defined as the UV (measured in m') divided by the dissolved organic carbon
concentration (measured as mg/L). Typically, SUVA values <3L/mg-m are representative of largely
nomhumic material, while values in the 4-5L/mg-m represent mainly humic material.
pH
EPA Methods 150.1 and 150.2 are used to determine the hydrogen ion activity with potentiometnc
measurement using a standard hydrogen electrode and reference electrode. SM 4500-HB and American
Society for Testing and Materials (ASTM) D1293-84 are also approved methods for determining pH (ASTM.
1994). All of these methods are relatively free of interference. However, interference may be attributed to
sodium interference at pH of more than 10. These methods require two point calibration and standard
temperature (e.g., 25 °.C).
Alkalinity
SM 2320B (APHA, 1996) is the approved method for alkalinity. Total alkalinity is measured by
titration of the sample to an electrochemically determined endpoint and reported as milligrams per liter as
calcium carbonate. The method ascribes the entire alkalinity concentrations to the equivalent sum of
Final B-9 November 13, 1998
-------
Occurrence 4.ssessmenr far D/DBP in Public Dnnkinq Hater Supplies
carbonate, bicarbonate, and hydroxide concentrations and assumes an absence of other alkalinity contributing
compounds.
Exhibit B-3. Precursor Method Detection Limits.
Analyte
Total Organic Carbon
UV Absorbance at 254 nm
Method
SM5310B
SM5310C
SM5310D
SM5910
MOL
1 mg carbon/L
0.05 mg organic carbon/L
0.10 mg organic carbon/L
- 1 mg/L
NATIONAL LABORATORY CAPACITY
This section estimates the number of laboratories that are capable of conducting analyses for the
D/DBP rule. It also estimates the number of samples those laboratories can analyze, which is referred to as
the laboratory capacity.
Because the ICR requires that DBF testing be conducted by approved laboratories, the number of
laboratories approved for ICR analyses may be the best indicator of the national laboratory capacity for DBF
monitoring. The ICR laboratory approval process confirms a laboratory's ability to produce data of known
accuracy and precision for both DBFs and their precursors. The ICR approval process tracks the number of
laboratories that have applied for approval in this program and the number of laboratories that have been
approved. Exhibit B-4 lists the number of laboratories that applied and were approved for each analyte. ICR
laboratories use the methods summarized previously. Laboratories may have applied for approval of more
than one analyte and may be counted in multiple categories. Therefore, Exhibit B-4 should not be used to
provide the total number of ICR-approved laboratories.
Each of the 384 ICR laboratory application forms submitted by applying laboratories was examined
to determine the laboratory sample capacity for each method. In this approval process, laboratories were
required to provide data on their ability to perform each analytical method and estimate the weekly total of
analyses performed.
National Capacity for Disinfectant and Precursor Measurements
The Stage I D/DBP rule does not require analyses for disinfectants (i.e., chlorine, chloramine,
chlorine dioxide) by a certified laboratory. Many of the methods must be performed immediately onsite
Final B-10 November 13, 1998
-------
Occurrence \ssessment fur D/DBP in Public Dnnkinq liorer
Exhibit B-4. Laboratories Applying and Approved for Certification in the ICR Program
Analyte
Free Chlorine'
Total Chlorine*
Chlorine Dioxide'
Total Tnhalomethanes
Haloacetic Acids 5
Chlorite Ion
Bromate Ion
Bromide Ion*
TOG'
UV 254 nm'
Alkalinity
PH'
Laboratories Applied
328
324
36
204
103
57
'57
57
181
163
324
359.
Laboratories Approved
318
312
29
203
88
48
48
48
175
158
314
355
Percent Approved
97
96
81
99
. 85
84
84
84
97
97
99
99
'Certification is not federally mandated for these parameters under the Stage ID/D8P rule. •
because of the short holding time of the samples. Analyses can be performed by trained operators; therefore.
!
laboratory capacity is not an issue for these parameters.
Similarly, certification is not required for TOC or for specific ultraviolet absorbance (SUVA) - LTV
absorbance/TOC. A greater degree of skill is necessary to conduct these tests than disinfectant analysis, and
state drinking water programs may require certification. Exhibit B-5 provides estimates of the number of
samples analyzed per week for TOC and SUVA by method. The overall average was 119 TOC samples per
laboratory per week, and the reported average for SUVA was 103 samples per week per laboratory.
National Capacity for Total Trihalomethane Measurements
Since 1979, the Safe Drinking Water Act has required analyses for TTHMs for public water supplies
that serve at least 10,000 people and add a disinfectant to their water. Additionally, the methods for VOCs
include the four TTHMs. All community and nontransient, noncommunity water supplies are required to
analyze for VOCs. Because numerous.commercial, state, and municipal laboratories are certified for TTHM
and VOC testing, laboratory capacity is considered adequate for the Stage I DBF rule. Laboratories that
applied for ICR approval were not asked to provide laboratory capacity for TTHMs.
Final
B-ll
November 13, 1998
-------
Occurrence Assessment for D/DBP in Public Dnnkinq Uaier
Exhibit B-5. Laboratory Sample Capacity
Analyt?
Tnnaiomethanes
Haloacetic Acids 5
Chlorite. Bromide, or Bromate
Total Organic Carbon
UV Absorbance at 254 nm
Method
EPA 502.2
EPA 524.2
EPA 551
EPA 551.1
EPA 552.1
EPA 552.2
SM6233B&6251B
EPA 300.0
SM5310B
SM5310C
SM5310D
SM5910
Lab Approved
156
47
17
41
26
48
57
94
16
158
Sample Capacity
per Week
Not Provided
i.713
940
1,783
1,550
7,208
7.373
10,669
1,860
14,250
Average Samples
per Lab per Week
-
-
55
43
60
106
129
114
116
103
National Capacity for Haloacetic Acids
The ICR was the first EPA regulation requiring analyses for HAAs from about 600 water treatment
plants. Prior to the ICR, few laboratories performed HAA analyses. In the ICR laboratory application
process, laboratories submitted information on the maximum number of samples that they could analyze per
week. Exhibit B-5 lists the number of laboratories approved for HAA analyses under the ICR. The exhibit
also shows the number of samples per week for each method employed.
A total of 88 laboratories are approved for analyzing HAAs. These laboratories estimated that they
could process a maximum of 4,273 samples per week, or an average of 51 HAA samples per laboratory per
week. For the D/DBP Stage I rule, up to 50 percent additional, capacity may be expected from State
laboratories not involved in ICR testing and from laboratories that applied for ICR approval but failed.
National Capacity for Bromate and Chlorite
EPA approved 57 laboratories for the analyses of bromide, bromate, and chlorite using Method
300.0. These laboratories estimated that they could process a.maximum of 7,208 samples per week, or an
average of 106 samples per laboratory per week. Not all laboratories will update their instruments as
required in the revised method. Method 300.1; however, additional capacity is expected from state
laboratories.
Final
B-12
November 13, 1998
-------
Occurrence Assessment far D/DBP.tn Public Drinking Water Supplies
REFERENCES
Abdel-Rahman. M.S. 1982. "The presence of trihalomethanes in soft drinks." In: Journal of
Applied Toxicology, 2 (3). .
/
Abdel-Rahman, M.S.; Couri, D.; Bull, RJ. 1982. "Metabolism and pharmoklnetics of alternate
drinking water disinfectants." In: Environ. Health Perspective, 16: 19-23.
Aieta, E.M.; Berg, J.D. 1986. "A review of chlorine dioxide in drinking water treatment. In:
Journal of American Water Works Association, 78 (6): 64-72.
American Society for Testing and Materials. 1994. Annual Book ofASTM Standards. Volumes
11.01 and 11.02. Philadelphia, PA.
Amy, G.; Siddiqui, M.; Zhai, W.; DeBroux, J.; Odem, W. 1994. Survey of Bromide in Drinking
Water and Impacts on DBP Formation. American Water Works Association.
Amy, G.L.; Minear, R.A.; Westeroff, R.; Sony, R. 1997. Formation and Control of Brominated
ozone Byproducts. CAT No. 90714. American Water Works Association. Denver, CO. 72
PP-
Andelman J.B. 1985a. Human Exposures to Volatile Halogenated Organic Chemicals from Indoor
and Outdoor Air. Evironmental Health Perspectives. 62 : 313-318
Andelman, J.B. 1985b. 'Inhalation exposure in the home to Volatile Organic contaminants in
Drinking Water. Science of the Total Environemnt. 47:443-460.
Andelman, J.B., Meyers, S.M., and Wilder, L.C. 1986. Volatilization of Organic Chemicals from
Indoor Uses of Water. In: Chemicals in the Environment. pp323-330. Lester JN, Perry R
and SterrittRM Eds). Seleper Ltd, London, UK
Armstrong, D.W.; Golden, T. 1986. "Determination of distribution and concentration of
trihalomethanes in aquatic recreational and therapeutic "facilities by electron capture GC."
In: LC-GC, 4:652-655.
Arora, H.; LeChevalier, M.; Moser, R. 1994. Disinfection By-Products B American System Survey
of Occurrence, Control, and Fate. American Water Works Service Company, Inc.
November.
Arora, H.; LeChevalier, M.; Dixon, K. 1997. "DBP occurrence study." In: Journal of American
Water Works Association, 89(6).
Atlas, E.; Schauffler, S. 1991. "Analysis of alkyl nitrates and selected halocarbons in the ambient
atmosphere using a charcoal preconcentration technique." In: Environ. Sci. Technol.,25(\):
. 61-67.
Final R-l November 13,1998
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Occurrence \ssessmentfor D/DBP in Public Drinking Water Supplies
AWWA. [991. American Water Works Association Disinfection Survey. WDDB Database.
o
AWWA. 1996. American Water Works Association Disinfection Survey. Water Stats Database.
AWWA. 1997. Analysis of Fax Survey Results. Washington. D.C. January.
AWWARF and Lyonnaise des Eaux. 1987\ "Identification and treatment of tastes and odors in
drinking water. American Water Works Association. Denver.
AWWARF. 1992. "Pilot scale evaluation of ozone and peroxone." American Water Works
Association. Denver, CO.
' j
Barkley, J., J. Bunch; J.T. Bursey, N. Castillo, S.D. Cooper, J.M. Davis, M.D. Erickson, B.S.H.
Harris, M. Kirkpatrick, L.C. Michael, S.P. Parks, E.D. Pellizzari, M. Ray, D. Smith, B.
Tomer, R. Wagner, and R.A. Zweidinger. 1980. "Gas chromatography mass spectrometry
computer analysis of volatile halogenated hydrocarbons in man and his environment - a
.multimedia environmental study." In: Biomedical Mass Spectrometry,! (4): 139-147. April.
Bolyard, M.; Fair, P.S.; Hautman, D.P. 1993. "Sources of chlorate ion in U.S. drinking water." In:
Journal of American Water Works Association, (September): 81-88.
Borum, D. 1991. OGWDW, U.S. Environmental Protection Agency, Washington. D.C. Phone
Conversation with Jeff Mosher, Wade Miller Associates, Arlington, Virginia; December 17,
1991.
Brass, H.J. 1981. "Rural water surveys organics data," Drinking Water Quality Assessment
Branch, Technical Support Division, Office of Drinking Water, U.S. Environmental
Protection Agency. Memo to Hugh Hanson, Science and Technology Branch, CSD, ODW.
U.S. Environmental.Protection Agency.
Brass, H.J.; Weisner, M.J.; Kingsley, B.A. 1981. "Community Water Supply Survey: Sampling
and analysis for purgeable organics and total organic carbon (draft)." American Water
Works Association Annual Meeting, Water Quality Division; June 9, 1981.
Brodinsky, R.; Singh, H.B. 1982. "Volatile organic chemicals in the atmospher: an assessment of
available data." Atmospheric Science Center, SRI International, Menlo Park, CA. Contract
68-02-3452.
Bull, R.J.; Kopfler, F.C. 1990. "Health effects of disinfectants and disinfection by-products."
Prepared for: AWWA Research Foundation, August.
Class, T.; Ballschmidter, K. 1986. "Chemistry of organic traces in air." In: Fresenius Z Anal
Chem. 325: 1-7.,
Class, T.; Kohnle, R.; Ballschmidter, K. 1986. "Chemistry of organic traces in air VII: bromo- and
bromochloromethanes in air over the Atlantic ocean." In: Chemosphere, 15(4): 429-436.
Final R-2 November 13,1998
-------
ikcurrence \^e^smtntlor D/DBP in Public Dr.nkinn
Cooper. \V J. 1990. "Bromide ion: oxidant chemistry in drinking water: A review." Preprint
extended abstract. 200th Amer. Chem. Soc. Nat. Mtg. Div. of Environ. Chem.. Washinaton.
D.C.. pp. 224-225. "
Cooper. W.J.: Zika. R.G.; Steinhauer, M.S. 1985. "Brqmide-oxidant interactions and THM
formation: A literature review." In: Journal of American Water Works Association, (April):
,116-121.
Couri. D.: Abdel-Rahman, M.S.; Bull, R.J. 1982. "Toxicological effects of chlorine dioxide.
chlorite and chlorate." In: Environ. Health Perspective." 46: 13-17.
Cowman, G.A.; Singer, P.C. 1994. "Effect of bromide ion on haloacetic acid speciation resulting
from chlorination and chloramination of humic extracts." In: Proceedings, American Water
Works Association Annual Conference, American Water Works Association.
Daft, J.L. 1987. "Determining multifumigams in whole grains and legumes, milled and low-fat-
grain products, spices, citrus fruits, and beverages." In: Jour. Assoc. Off. Anal. Chem.,
70(4): 734-739.
Daft. J.L. 1988. "Rapid determination of fumigant and industrial chemical residues in food." In:
Jour. Assoc. Off. Anal. Chem., 71(4): 748-760.
Daft, J.L. 1989. "Determination of fumigants in fatty and nonfatty foods." In: Jour. Agric. Food
Chem. ,31'(2): 560-564.
DeMers. L.O., Renner, R. 1992. Alternative Disinfectant Technologies for Small Drinking Water
Systems. AWWA Research Foundation.
DOHHS, Agency for Toxic Substance and Disease Registry. 1993. Toxological Profile for
Chloroform,\J.S. Department of Commerce, pub., Springfield, VA, PB93-182426.
Dinovi, M. 1997. Center for Food Safety and Applied Nutrition, FDA, Phone conversations with
Denis Borum, Office of Ground Water and Drinking Water, U.S. Environmental Protection
Agency, Washington, D.C. August.
Doerr, R.L. 1981 "Reactions of Chlorine, Chlorine Dioxide and Mixtures thereof with Humic Acid."
In: Water Chlorination, Environmental Input and Health, Vol. 2. Edited by R. C. Jolley, Ann
Arbor, MI, Ann Arbor Science Publishing, Inc.
Entz, R.C.; Daichenko, G.W. 1988. "Residues of volatile hydrocarbons in margarines." In: Food
Add. Contam., 5:267-276.
Entz, R.C.; Thomas, K.W.; Diachenko, G.W. 1982. "Residues of volatile halocarbons in foods
using headspace gas chromatography." In: Jour. Agric. Food Chem., 30(5): 846-849.
EPA. 1978. National Organics Monitoring Survey (NOMS). Technical Support Division,U.S.
Environmental Protection Agency, Office of Drinking Water, Cincinnati, OH. September.
Final R-3 November 13,1998
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Occurrence Assessment for D'DBP in Public Dnnking Water Supplies
EPA. •-1980. "Humics. chJormation. and drinking water quality: A report to Congress." Office of
Drinking Water. U.S. Environmental Protection Agency. Washington. D.C. September.
EPA. 1985. Health and Environmental Effects Profile for Bromodichloromethanes. Criteria and
Assessment Office, Office of Health and Environmental Assessment, U.S. Environmental
Protection Agency, Cincinnati. OH, June. 1985.
EPA. 1986. Risk Assessment Guidelines of 1986. EPA/600/8-87/045. NTIS PB88-123997.
EPA. 1988. Reference Dose (RfD): Description and use in Health Risk Assessments. Integrated
Risk Information System (IRIS). Intra-Agency Reference Dose (RfD) Work Group, Office
of Health and Environmental Criteria and Assessment Office, U.S. Environmental Protection
Agency, Cincinnati, OH. February.
EPA and AMWA. 1989. '.'Final report for disinfection by-products in United States drinking
waters." Prepared by Metropolitan Water District of Southern California and James M.
Montgomery Engineers, Inc. Prepared for U.S. Environmental Protection Agency and
Association of Metropolitan Water Agencies. November, pp. ES-1 to ES-15 and 5-1 to 5-
35.
EPA. 1991. Guidance Manual For Compliance With the Filtration and Disinfection Requirements
for Public Water Systems Using Surface Water Resources. Office of Drinking Water, U.S.
Environmental Protection Agency, Washington, DC.
EPA. 1992a. Occurrence Assessment for Disinfectants and Disinfection By-Products (Phase 6a)
in Public Drinking Water, U.S. Environmental Protection Agency, June 1992.
EPA. 1992b. Technical Support Division Disinfection By-Products Field Study Data Base.
Technical Support Division (TSD), Office of Ground Water and Drinking Water, U.S.
Environmental Protection Agency. Communication with Patricia Fair, TSD, Cincinnati,
Ohio; February 14, 1992.
EPA. 1994a. National Primary Drinking Water Regulations; Disinfectants and Disinfection
Byproducts; Proposed Rule. Federal Register 59-145:38668. July 24.
EPA. 1994b. Drinking Water Health Criteria Document for Chlorinated Acetic Acids, Alcohols,
Aldehydes and Ke tones.
EPA. 1994c. Final Draft for the Drinking Water Criteria Document on Chlorinated Acids/Aldehydes/
Ketones/Alcohols. Office of Science and Technology, Office of Water. Washington, D.C. March.
EPA. 1994d. Final Draft for the Drinking Water Criteria Document on Trihalomethanes. Office
of Science and Technology, U.S. Environmental Protection Agency, Washington, DC.
EPA. 1995. Methods for the Determination of Organic Compounds in Drinking Water B
Supplement III. EPA-600/R-95-131. National Technical Information Service (NTIS), U.S.
Department of Commerce, Springfield, Virginia. PB95-261616.
Final R-4 November 13,1998
-------
Occurrence Assessment for D/DBP in Public Drinking Water Supplies
EPA. 1996. Reprints of EPA Methods for Chemical Analysis under the Information Collection
Rule. Office of Water. U.S. Environmental Protection Agency. Washington. DC. EPA 814-
B-96-006, April.
EPA. I997a. Community Water System Survey B Volume I. Overview. U.S. EPA 815-R-97-
OOla, January 1997.
EPA. 1997b. Community Water System Survey B Volume Q. Detailed Survey Result Tables and
Methodology Report. U.S. EPA 8l5-R-97-001b, January 1997.
Gallagher, D.L.; Hoehn, R.C.; Dietrich, A.M. 1994. Sources, Occurrence, and Control of Chlorine
Dioxide Byproduct Residuals in Drinking Water.. American Water Works Research
Foundation, Denver, CO.
Glaze, W.H.; et al. 1987. "The chemistry of water treatment processes involving ozone, hydrogen
peroxide, and ultraviolet radiation." In: Ozone: Science & Engineering, 9(4): 335.
Glaze, W.H. 1988. "Summary of workshop on ozonation by-products." UCLA School of Public
Health's Workshop on Ozonation By-Products. January 13-15, 1988; Los Angeles,
California; March 18, 1988.
Glaze, W.H.; Koga, M.; Cancilla, D. 1989a. "Ozonation byproducts. 2. Improvement of an
aqueous-phase derivatization method for the detection of formaldehyde and other carbonyl
compounds formed by the ozonation of drinking water." In: Environmental Science and
Technology, 23(7): 838.
Glaze, W.H.; Kpga, M.; Cancilla, D., et al. 1989b. "Evaluation of ozonation" byproducts from two
California surface waters." In: Journal of American Water Works Association, 1(8): 66.
Glaze, W.H., Weinberg, H.S., Krasner, S.W., Sclimenti, M.J. 1991. 'Trends in Aldehyde
Formation and Removal Through Plants Using Ozonation and.Biological Active Filters."
In: Proceedings American Water Works Association, American Water Works Association.
pp. 913-943, Philadelphia, PA, June 22-27.
Glaze, W.H.; Weinberg, H.S. 1993. "Identification and occurrence of ozonation by-products in
drinking water." Report for AWWARF, American Water Works Association.
Gordon, G.; Kieffer, R.G.; Rosenblatt, D.H. 1972. "The chemistry of chlorine dioxide." S.J.
Lippard (Ed.) Dr Progress of Inorganic Chemistry, Vol XV, J. Wiley & Sons, New York.
pp. 202-286.
Gordon, G.; Adam, L.; Bubnis, B.; Hoyt, B.; Gillette, S.; Wilczak, A. 1995. Minimizing the
Chlorate Ion Formation in Drinking Water when Hypochlorite Ion is the Chlorinationg
Agent. American Water Works Research Foundation, Denver, Colorado.
Final R-5 November 13,1998
-------
Occurrence \ssessmem for D/D8P in Public Dnnkinq Water Supplies
Gordon. G.: Bubnis. B. 1996. "Chlorine dioxide: Chemistry and technology". In: Proceedings
of First European Symposium on Chlorine Dioxide and Disinfection. Rome. -,taly.
November 7-8. 1996.
Graham. R.C.: Robertson, J.K. 1988. "Analysis of trihalomethanes in soft drinks." In: Journal of
Chemical Education. 65(8): 735-737. August.
Gramith. J.T.; Coffey, B.M.; Krasner, S.W.; Kuo, C; Means, E.G. 1993. "Demonstration-scale
formation of bromate formation and control strategies." In: Proceedings, American Water
Works Association Annual Conference. American Water Works Association, San Antonio,
Texas.
Griese, M.H.: Hauser, K.; Berkemeier, M.; Gordon, G. 1991. "Using reducing agents to eliminate
chlorine dioxide and chlorite ion residuals in drinking water." In: Journal of American
Water Works Association, 83(5): 56.
Haas. Charles N. 1990. "Disinfection." In: Water Quality and Treatment: A Handbook of
Community Water Supplies. American Water Works Association. New York, NY: McGraw
Hill.
Haws, B.C.; Singer, P.C. 1989. 'Trihalomethanes in North Carolina drinking waters: An
assessment." In: Proceedings, AWWA North Carolina Section Meeting, American Water
Works Association, Raleigh, NC. Cited in Singer, et al. 1995.
Heikes, D.L. 1987. "Purge and trap method for determination of volatile halocarbons and carbon
disulfide in table-ready foods." In: Jour. Assoc. Off. Anal. Chem, 70(2): 215-26.
Heikes, D.L.; Hopper, M.L. 1986. "Purge and trap method for determination of fumigants in whole
grains, milled grains products, and intermediate grain-based foods." In: Jour. Assoc. Off.
Anal. Chem, 69(6): 990-998.
Heikes, D.L.; Jensen, S.R.; Fleming-Jones, M.E. 1995. "Purge and trap extractions with GC-MS
determination of volatile organic compounds in table-ready foods." In: Journ. Agric. Food
Chem, 43(11): 2869-2875.
Hery, M.; Gerber, M.; Gendre, G.; Hecht, G.; Hubert, G.; Rebuffaud, J. 1995. "Exposure to
chloramines in the atmosphere of indoor swimming pools." In: Ann. Occup. Hyg., 39(4):
427-439.
Hoehn, R.C.; Dietrich, A.M.; Farmer, W.S.; Orr, M.P.; Lee, R.G.; Aieta, E.M.; Wood, D.W.;
Gordon, G. 1990. "Household odors associated with the use of chlorine dioxide." In:
Journal of American Water Works Association, (June): 166-172.
Hoehn, R.C., Rosenblatt, A.A., and D.J. Gates. 1992. "Considerations for Chlorine Dioxide
Treatment of Drinking Water." Presented at: AWWA Water Technology Conference, Boston,
MA, November, 1006.
Final R-6 November 13,1998
-------
'Occurrence \ssessmem for D/DBP in Public Dnnking Vi'ater Supplies
Hoehn. R.C.; Rosenblatt. A. A.: Gates. D.J. 1996. "Considerations for chlorine dioxide treatment
of drinking water." Presented at: AWWA Water Technology Conference. Boston. MA.
November.
Hoehn. R.C.; Rosenblatt, A.A. 1996. "Full-scale, high-performance chlorine dioxide gas
generator." Poster presented at: American Water Works Association, Engineering and
Construction Conference. Denver. CO.
Hoigne, J.; Bader, H. 1977. "The role of hydroxyl radical reactions in ozonation processes in
aqueous solutions." In: Water Research, 10: 377-386.
Hoigne, J.; Bader, H. 1983a. "Rate constants of reaction of ozone with organic and inorganic
compounds in water B I. Non-dissociating organic compounds." In: Water Research, 17:
173-183.
Hoigne, J.; Bader, H. 1983b. "Rate constants of reaction of ozone with organic and inorganic
compounds in water B n. Dissociating organic compounds." In: Water Research, 17: 185-
-194.
Hoigne, J.; Bader, H. 1988. "The formation of trichloronitromethane (chloropicrin) and chloroform
in a combined ozonation/chlorination treatment of drinking water." In: Water Resources,
22(3): 313.
Howard, P.H. 1990. "Handbook of environmental fate and exposure data for organic chemicals."
Lewis Publishers, Chelsea, ML 2: 40-47.
Jacangelo, J.G.; Patania, N.L.; Reagan, K.M.; Aieta, E.M.; Krasner, S.W.; McGuire. M.J. 1989:
"Ozonation: Assessing It's Role In the Formation and Control of Disinfection By-products."
In: Journal of American Water Works Association, 81(8): 74.
Jensen, J.N.; Johnson, J.D.; St. Aubin, J.J; Christman, R.F. 1985. "Effect of Monochloramine on
Isolated Fulvic Acid." fa: Org. Geochem. 8:1:71.
Jo, W.K.; Weisef, C.P; Lioy, P.J. 1990a. "Chloroform exposure and the health risk associated with
multiple uses of chlorinated tap water." In: RiskAnalysis, 10(4): 581-585.
Jo, W.K.; Weisel, C.P; Lioy, P.J. 1990b. "Routes of chloroform exposure and body burden from
showering with chlorinated tap water." In: Risk Analysis, 10(4): 575-580.
Johnson, J.D.; Jensen, J.N. 1986. "THM and TOX formation: Routes, rates, and precursors." In:
Journal of'American Water Works Association, (April): 156-162.
Krasner, S.W.; McGuire, M.J.; Jacangelo, J.J. 1989. "The occurrence of disinfection byproducts
in U.S. drinking water." In: Journal of American Water Works Association, 81(8): 41.
Final R-7 November 13,1998
-------
Occurrence Assessment for D/DBP in Public Drinking Uaier Supplies
Krasner. S.W.; et aJ. 1992. "Formation and control of bromate during ozonation of waters
containing bromide." In: Proceedings. Pan American Committee Conference of the
International Ozone Assn., Pasadena, CA. March 1992. ' '
Krasner. S.W.; Sclimenti. M.J.; Means. E.G.; Symons, J.M.: Simms, L. 1993b. "The impact of
chlorine dose, residual chlorine, bromide, and organic carbon on trihalomethane speciation."
In: Proceedings, Water Qualify Technology Conference, Volume n. 1745-59.
Krasner, S.W.; Glaze, W.H.; Weinberg, H.S. I993a. "Formation of control of bromate during
ozonation of water containing bromide." In: Journal of American Waterworks Association,
85(5): 62. ~
Krasner, S.W.; Glaze, W.H.; Weinberg, H.S.; Daniel, P.A.; Najm, I.N. 1993c. "Formation and
control of bromate during ozonation of water containing bromide." In: Journal of American
Water Works Association, 85(1): 73.
Kroneld. R.; Reunanen, M. 1990. "Determination of volatile pollutants in human and animal milk
by GC-MS." In: Bull. Environ. Contam. Toxic. 44:917-923.
Langlais, B.; Reckhow, D.A.; Brink, D.R. (Editors). 1991. Ozone in Drinking Water Treatment:
Application and Engineering. AWWARF and Lewis Publishing, Chelsea. MI.
LeLacheur, R.M.; Singer, P.C.; Charles, M.J. 1991. "Disinfection byproducts in New Jersey
drinking waters." In: Proceedings, American Water Works Association Annual Conference,
American Water Works Association, Denver, CO,,pp. 791-805.
Levesque, B.; Ayotte, P.; LeBlanc, A; Dewailly, E.; Prud'Homme, D.; Lavoie, R. Allaire, S.,
Levallois, P. 1994. "Evaluation of dermal and respiratory chloroform exposure in humans."
In: Environmental Health Perspectives, 102(12): 1082-1087.
Lindstrom, A.B., Pleil, J.D., and Berkoff, D.C. 1997. Alveolar Breath Sampling and Analysisto
Assess Trihalomethane Exposures During Copetitive Swimming Training. Environmental
Health Perspectives. 105(6)636-642
Logsdon, G.S.; Foellmi, S.; Long, B. 1992. "Filtration pilot plant studies for Greater Vancouver
water supply." In: Proceedings, American Water Works Association Annual Conference,
American Water Works Association, Denver CO.
Lovegren, N.V.; Fisher, G.S.; Lehendre, M.G.; et al. 1979. "Volatile constituents of dried legumes."
In: Joum. Agric. Food Chem. 27:851-853.
•
Malcolm Pimie, Inc. 1992. Technologies and Costs for Control of Disinfection Byproducts. Office
of Ground Water and Drinking Water, U.S. Environmental Protection Agency.
Masschelein, W.J. 1992. Unit Processes in Drinking Water Treatment. New York, NY: Marcel
Dekker, Inc.
Final R-8 November 13,1998
-------
Occurrence Assessment for D/DBP in Public Dnnking Water Supplies
McGuire. M.J.: Meadow. R.G. 1988. "AWWARF trihalomethane survey." In: Journal of
American Water Works Association. 80(1): 61-68.
McGuire. M.J.: Krasner, S.W.; Reagan. K.M: Aieta. E.M.; Jacangelo, J.G.; Patania, N.L.; Gramith.
K.M. '1989. "Final report for disinfection by-products in United States drinking waters.
Vol. 1." U.S. Environmental Protection Agency and California Dept. of Health Services.
Cited in Bull and Kopfler, 1990.
McGuire. M.J.; Krasner. S.W.; Gramith, J.T. 1990. Comments on Bromide Levels in State Project
Water and Impacts on Control of Disinfection Byproducts.
McKnight, A.; Reckhow, D.A. 1992. "Reactions of ozonation byproducts with chlorine and
chloramines." In: Proceedings, American Water Works Assocication Annual Conference,
. American Water Works Association, Denver, CO.
McKone, T.E. 1987. -Human Exposure to Volatile Organic Compounds in Household Tap Water:
the Indoor Inhalation Pathway. Environmental Science and Technology. 21 1194-1201.
McKone. T.E. 1993. Linking a PBPK model for Chloroform with Measured Breath Concentrations
in Shower: Implications for Dermal exposure models. Journal of Exposure and Analytical
Environmental Epidemiology 3(3):339-365.
McNeal, T.; Hollifield, H.C.; Diachenko, G.W. 1995. "Survey of trihalomethanes and other volatile
chemical contaminants in processed foods by purge-and-trap capillary gas chromatography
with mass selective detection." In: Journal ofAOAC International, 78(2): 391-395.
Merck Index. 1989. Budavari, S., Ed.; 11th Edition; Merck & Co., Inc., Rahway, N.J.
Nieminski, E.G.; Chaudhuri, S.; Lamoreaux, T. 1993. "The occurrence of DBPs in Utah drinking
waters." In: Journal of American WaterWorks Association, 85(9): 98-105.
Petochelli, A. 1995. "Chlorine dioxide generation chemistry." In: Proceedings of the Third
International Symposium. Chlorine Dioxide: Drinking Water, Process Water, and
Wastewater Issues. September 14-15. New Orleans, LA.
Pourmoghaddas, H.; Stevens, A.A.; Kinman, R.N.; Dressman, R.C.; Moore, L.A.; Ireland, J.C.
1993. "Effect of bromide ion on formation of HAAs during chlorination." In: Journal of
American Water Works Association, (January): 82-87.
Pringle, J.C., Demint, R.J., Hatrup, A., Bruns, V.F., Frank, P.A. 1975. Residues in Crops Irrigated
with Water Containing Trichloroacetic Acid," In: Journal of Agriculture, Food, and
Chemistry. Vol 23, 1 p. 81.
Process Applications, Inc. 1992. Alternative Disinfection Technologies for Small Drinking Water
Systems. Denver, CO: AWWA Research Foundation.
Final R-9 . November 13,1998
-------
i)ccurrence Assessment for D/DBP in Public Drinking Water Supplier
Rav-Acha. C.-: Serri. A.: Choshen. E.: Limoni. B. 1984. "Disinfection of drinking water rich in
bromide with chlorine and chlorine dioxide, while minimizing the formation of undesirable
byproduc-. " In: Water Science and Technology. 17; 611.
Rechhow. D.A.: Singer. P.C.; Malcolm, R.L. 1990. "Chlorination of humic materials: Byproduct
formation and chemical interpretations." In: Environmental Science and Technology.
24(11): 1655. -.
Rice. R.G.; Dimitrou, M.A. 1997. "Ozone matures in U.S. drinking water treatment: Impacts of
the 1996 Safe Drinking Water Act Amendments." Presented at: Annual Conference of the
International Ozone Association (IOA), Lake Tahoe, N V.August 17-20.
Rice, R.G. and Gomez-Taylor, M. 1986. "Occurrence of By-Products of Strong Oxidants Reacting
with Drinking Water Contaminants B Scope of the Problem." In: Environmental Health
Perspectives, Vol. 69, p. 31.
Richardson, S.D. 1998. "Drinking Water Disinfection By-Products" in the Encyclopedia of
Environmental Analysis and Remediation. Vol 3, pp. 1398-1421. Ed. Robert A. Meyers,
John Wiley and Sons, NY.
SAIC. 1996. In development of ICR sampling plan review guidance.
Shaw, R.W.; Binkowski, F.S.; Courtney, W.J. 1982. "Aerosols of high chlorine concentration
transported into central and eastern United States." In: Nature, 296(5854): 229-231.
Shikiya, J.; Tsou, G.; Kowalski, J.; Leh, F. 1984. "Ambient monitoring of selected halogenated
. hydrocarbons and benzene in the California south coast air basin." In: Proceedings of APCA
77th Annual Meeting, 1: 84-111.
Siddiqui, M.S.; Amy, G.L.; Rice, R.G. 1995. "Bromate ion formation: A critical review." In:
Journal of American Water Works Association, (October): 58-70.
Siddiqui, M.S.; Amy, G.L. 1993. "Factors affecting DBP formation during ozone-bromide
reactions." In: Journal of American Water Works Association, 85(1): 63.
Singer, P.C. 1988. "Assessment of Ozonation Research in Drinking Water." AWWA Research
Foundation Denver, CO.
Singer, P.C.; Chang, S.D. 1989. "Correlations between trihalomethanes and total organic halides
formed during water treatment." In: Journal of American Water Works Association,
(August): 61-65.
Singer, P.C. 1992. "Formation and characterization of disinfection byproducts. Presented at: First
International Conference on the Safety of Water Disinfection: Balancing Chemical and
Microbial Risks.
Final RrlO November 13,1998
-------
Occurrence \ssessmenl for D/DBP :n Public Drinking Water Supplies
Singer. P.C.: Obolensky, A.: Grenier. A. 1995. "DBFs in chlorinated North Carolina drinking
waters.". In: Journal of American Water Works Association. (October): 83-92.
Singh. H.B.; Salas.- L.J.: Smith, A.J.; Shigeishi. H. 1981. "Measurements of some potentially
hazardous chemicals in urban environments." In: Atmos. Environ., 15(4): 601-12.
Singh. H.B.: Salas. L.J.: Stiles. R.E. 1982. "Distribution of selected gaseous organic mutagens and
suspect carcinogens in ambient air." In: Environmental Science and Technology. 16:872-
880.
Singh, H.B.; Salas. L.J.; Stiles, R.; Shigeishi, H. 1983. "Measurements of some potentially
hazardou chemicals in the ambient atmosphere." U.S. Environmental Protection Agency,
Research Triangle Parl, NC. EPA 600/S3-83-002.
Smith. M.E.; Cowman, G.A.; Singer, P.C. 1993. "The impact of ozonation and coagulation on DBP
formation in raw waters." In: Proceedings, American Water Works Association Annual
Conference.
Sorrell, R.K., Hautman, D.W. 1992. "A simple concentration technique for the analysis of bromate
at low levels in drinking water" In: AWWA WQTC Proceedings, Toronto, Ontario, Canada.
pp.281 ,
Speed. M.A.; et al. 1987. 'Treatment alternatives for controlling chlorinated organic contaminants
in drinking water." EPA/60012-87/011, U.S. Environmental Protection Agency, Washington
DC-
Stevens. A.A.; Symons, J.M. 1977. "Measurement of trihalomethane and precursor concentration
changes." In: Journal of American Water Works Association, (October): 546-554.
Summers, R.S., G. Solarik, V..A. Hatcher, R.S. Isabel, and J.F. Stile. 1997. "Analyzing the Impacts
of Predisinfection Through Jar Testing." In: Proceedings, AWWA Water Quality Technology
Conference, Denver, CO.
Symons, J.M.; Bellar, T.A.; Carswell, J.K.; DeMarco, J.; Kropp, K.L.; Robeck, G.G.; Seeger, D.R.;
Slocum, C.J.; Smith, B.L.; Stevens, A.A, 1975. "National Organics Reconnaissance Survey
for halogenated organics." In: Journal of American Water Works Association, 67( 11): 634-
647.
Symons, M.; Krasner, S:W.; Simms, L.A.; Sclimenti, M. *1993. "Measurement of THM and
precursor concentrations revisisted: the effect of the bromide ion." In: Journal of AWWA.
. January.
Symon, J.M., M.C.H. Zheng. 1997. "Does Hydroxl readical oxicize Bromide to Bromate?" Journal
of AWWA, 89(6): 106-109.
Symons etal. 1998. "Factors Affecting Disinfection Byproduct Formation During Chloramination."
Report No. 90728 American Water Works Association. Denver, CO. 316 pp. In press.
Final R-l 1 November 13,1998
-------
Occurrence \ssessment for D/D8P in Public Dnnking Hater
Tarquin. A.: Hansel. G.: Rittmann D. 1995. "Reduction of chlorite concentrations of potable water
with ferrous chloride." In: Water Engineering and Management. (February): 35-37.'
Texas Natural Resource Conservation Commission. 1996. Rules and Regulations for Public Water
Supplies Systems.
Toyoda. M.: Takagi. K.: Tsurumizu, A.; S
-------
Occurrence Assessment for D'DBP in Public Dnnkint? Hater Supplies
26 volatile compounds in air and'drinking water of 188 residents of Los Angeles. Antioch.
and Pittsburgh, CA." In: Annas. Environ.. 22(10): 2141-63.
Wallace. L. A. 1992= Human exposure and body burden for chloroform and other trihalomethanes.
U.S. Environmental Protection Agency, Office of Research and Development, Warrenton.
Virginia. July 28, 1992.
Wei. C.I.: Cook. D.L.; Kirk, J.R. 1985. "Use of chlorine compounds in the food industry." In:
- Food Technology, 39(1): 107-115. Weisel and Jo, 1996.
Weisel, C.P.: Shepard, T.A. 1994. "Chloroform exposure and the body burden associated with
swimming in chlorinated pools." In: Water Contamination and Health, Integration of
Exposure Assessment, Toxicology, and Risk Assessment. R. Wang, Ed., 135-148.
Weisel, C.P.; and Jo, W.K. 1996. "Ingestion, inhalation, and dermal exposures to chloroform and
trichloroethene from tap water." In: Environ. Health Perspectives, 104 (1): 48-51.
January.
Werdehoff, K.S.; Singer, P.C. 1987. "Chlorine dioxide effects on THMFP, TOXJrP and the
formation of inorganic by-products." In: Journal of American Water Works Association,
79(9): 107.
Westerhoff, P.; Siddiqui, M.; DeBroux, J.; Zhai, W.; Ozekin, K.; Amy, G. 1994. "Nation-wide
bromide occurrence and bromate formation potential in drinking water supplies." In:
Critical Issues in Water and Wastewater Treatment. National Conference on
Environmental Engineering, July 11-13, 1994; New York: American Society of Civil
Engineers, pp. 670-677.
Westrick, J.J.; Mello, J.W.; Thomas, R.F. 1983. "The Ground Water Supply Survey summary of
volatile organic contaminant occurrence data." Technical Support Division, Office of
Drinking Water and Office of Water, U.S. Environmental Protection Agency, Cincinnati,
Ohio; January.
White, G.C. 1986. Handbook of chlorination. Van Nostrand Reinhold Company, Inc.: New York,
New York. .
o-
WIDE. 1990. Water Industry Data Base, American Water Works Association. Database.
Wood, J.A.; Porter, M.L. 1987. "Hazardous pollutants in class II landfills." In: Intern. Journ. of
Air Pollution Control and Hazardous Waste Management. 37(5): 609-615.
t
Yamada. H. and Somiya, I 1989. "The Determination of Carbonyl Compounds in Ozonated Water
By the PFBOA Method." In: Ozone Sci. Engin., Vol. 11, No. 2, p. 127.
Final R-13 November 13,1998
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