EPA-815-Z-98-008
Wednesday
December 16, 1998
I 1 J
Part IV
Environmental
Protection Agency
40 CFR Parts 9, 141, and 142
National Primary Drinking Water
Regulations: Disinfectants and
Disinfection Byproducts; Final Rule
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69390 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and .Regulations
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Parts 9,141, and 142
[WH-FRL-6199-8]
RIN 2040-AB82
National Primary Drinking Water
Regulations: Disinfectants and
Disinfection Byproducts
AGENCY: Environmental Protection
Agency (EPA).
ACTION: Final rule.
SUMMARY: In this document, EPA is
finalizing maximum residual
disinfectant level goals (MRDLGs) for
chlorine, chloramines, and chlorine
dioxide; maximum contaminant level
goals (MCLGs) for four trihalomethanes
(chloroform, bromodichloromethane,
dibromochloromethane, and
bromoform), two haloacetic acids
(dichloroacetic acid and trichloroacetic
acid), bromate, and chlorite; and
National Primary Drinking Water
Regulations (NPDWRs) for three
disinfectants (chlorine, chloramines,
and chlorine dioxide), two groups of
organic disinfection byproducts (total
trihalomethanes (TTHMs)—a sum of the
four listed above, and haloacetic acids
(HAAS)—a sum of the two listed above
plus monochloroacetic acid and mono-
and dibromoacetic acids), and two
inorganic disinfection byproducts
(chlorite and bromate). The NPDWRs
consist of maximum residual
disinfectant levels (MRDLs) or
maximum contaminant levels (MCLs) or
treatment techniques for these
disinfectants and their byproducts. The
NPDWRs also include monitoring,
reporting, and public notification
requirements for these compounds. This
document includes the best available
technologies (BATs) upon which the
MRDLs and MCLs are based. The set of
regulations promulgated today is also
know as the Stage 1 Disinfection
Byproducts Rule (DBPR). EPA believes
the implementation of the Stage 1 DBPR
will reduce the levels of disinfectants
and disinfection byproducts in drinking
water supplies. The Agency believes the
rule will provide public health
protection for an additional 20 million
households that were not previously
covered by drinking water rules for
disinfection byproducts. In addition, the
rule will for the first time provide
public health protection from exposure
to haloacetic acids, chlorite (a major
chlorine dioxide byproduct) and
bromate (a major ozone byproduct).
The Stage 1 DBPR applies to public
water systems that are community water
systems (CWSs) and nontransient
honcommunity water systems
(NTNCWs) that treat their water with a
chemical disinfectant for either primary
or residual treatment. In addition,
certain requirements for chlorine
dioxide apply to transient
noncommunity water systems
(TNCWSs).
EFFECTIVE DATE: This regulation is
effective February 16, 1999. Compliance
dates for specific components of the rule
are discussed in the Supplementary
Information Section. The incorporation
by reference of certain publications
listed in today's rule is approved by the
Director of the Federal Register as of
February 16, 1999.
ADDRESSES: Public comments, the
comment/response document,
applicable Federal Register documents,
other major supporting documents, and
a copy of the index to the public docket
for this rulemaking are available for
review at EPA's Drinking Water Docket:
401 M Street, SW., Washington, DC
20460 from 9 a.m. to 4 p.m., Eastern
Standard Time, Monday through Friday,
excluding legal holidays. For access to
docket materials, please call 202/260-
3027 to schedule an appointment and
obtain the room number.
FOR FURTHER INFORMATION CONTACT: For
general information contact, the Safe
Drinking Water Hotline, Telephone
(800) 426-4791. The Safe Drinking
Water Hotline is open Monday through
Friday, excluding Federal holidays,
from 9:00 am to 5:30 pm Eastern Time.
For technical inquiries, contact Tom
Grubbs, Office of Ground Water and
Drinking Water (MC 4607), U.S.
Environmental Protection Agency, 401
M Street SW, Washington, DC 20460;
telephone (202) 260-7270. For Regional
contacts see SUPPLEMENTARY
INFORMATION.
SUPPLEMENTARY INFORMATION: This
regulation is effective 60 days after
publication of Federal Register
document for purposes of the
Administrative Procedures Act and the
Congressional Review Act. Compliance
dates for specific components of the rule
are discussed below. Solely for judicial
review purposes, this final rule is
promulgated as of 1 p.m. Eastern Time
December 30, 1998, as provided in 40
CFR 23.7.
Regulated entities. Entities regulated
by the Stage 1 DBPR are community and
nontransient noncommunity water
systems that add a disinfectant during
any part of the treatment process
including a residual disinfectant. In
addition, certain provisions apply to
transient noncommunity systems that
use chlorine dioxide. Regulated
categories and entities include:
Category
Industry
State, Local, Tribal,
or Federal Gov-
ernments.
Examples of regulated entities
Community and nontransient
mary of residual treatment.
systems.
Same as above.
noncommunity water systems that treat their water with a chemical disinfectant for either pri-
In addition, certain requirements for chlorine dioxide apply to transient noncommunity water
This table is not intended to be
exhaustive, but rather provides a guide
for readers regarding entities likely to be
regulated by this action. This table lists
the types of entities that EPA is now
aware could potentially be regulated by
this action. Other types of entities not
listed in this table could also be
regulated. To determine whether your
facility is regulated by this action, you
should carefully examine the
applicability criteria in § 141.130 of this
rule. If you have questions regarding the
applicability of this action to a
particular entity, contact one of the
persons listed in the preceding FOR
FURTHER INFORMATION CONTACT section
or the Regional contacts below.
Regional Contacts
I. Kevin Reilly, Water Supply Section,
JFK Federal Bldg., Room 203, Boston,
MA 02203, (617) 565-3616
II. Michael Lowy, Water Supply Section,
290 Broadway 24th Floor, New York,
NY 10007-1866, (212) 637-3830
III. Jason Gambatese, Drinking Water
Section (3WM41), 1650 Arch Street,
Philadelphia, PA 19103-2029, (215)
814-5759
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Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations 69391
IV. David Parker, Water Supply Section,
345 Courtland Street, Atlanta, GA
30365, (404) 562-9460
V. Miguel Del Toral, Water Supply
Section, 77 W. Jackson Blvd., Chicago,
IL 60604, (312)886-5253
VI. Blake L. Atkins, Drinking Water
Section, 1445 Ross Avenue, Dallas,
TX 75202, (214) 665-2297
VII. Ralph Flournoy, Drinking Water/
Ground Water Management Branch,
726 Minnesota Ave., Kansas City, KS
66101, (913) 551-7374
VIII. Bob Clement, Public Water Supply
Section (8P2-W-MS), 999 18th Street,
Suite 500, Denver, CO 80202-2466,
(303) 312-6653
IX. Bruce Macler, Water Supply Section,
75 Hawthorne Street, San Francisco,
CA 94105, (415) 744-1884
X. Wendy Marshall, Drinking Water
Unit, 1200 Sixth Avenue (OW-136),
Seattle, WA 98101, (206) 553-1890
Abbreviations Used in This Document
AWWA: American Water Works
Association
AWWSCo: American Water Works
Service Company
BAT: Best available technology
BDCM: Bromodichloromethane
CDC: Centers for Disease Control and
Prevention
C.I.: Confidence Intervals
CMA: Chemicals Manufacturers
Association
CPE: Comprehensive performance
evaluation
CWS: Community water system
DBCM: D.ibromochloromethane
DBP: Disinfection byproducts
D/DBP: Disinfectants and disinfection
byproducts
DBPR: Disinfection Byproducts Rule
DBPRAM: Disinfection byproducts
regulatory analysis model
DCA: Dichloroacetic acid
DOC: Dissolved organic carbon
DWSRF: Drinking Water State Revolving
Fund
EC: Enhanced coagulation
EJ: Environmental justice
EPA: United States Environmental
Protection Agency
ESWTR: Enhanced Surface Water
Treatment Rule
FACA: Federal Advisory Committee Act
GAC10: Granular activated carbon with
ten minute empty bed contact time
and 180 day reactivation frequency
GAC20: Granular activated carbon with
twenty minute empty bed contact
time and 180 day reactivation
frequency
GDP: Gross Domestic Product
GWR: Groundwater rule
HAAS: Haloacetic acids
(five) (chloroacetic acid, dichloroacetic
acid, trichloroacetic acid, bromoacetic
acid, and dibromoacetic acid)
HAN: Haloacetonitriles
ICR: Information collection rule (issued
under section 1412(b) of the SDWA)
ILSI: International Life Sciences
Institute
IESTWR: Interim Enhanced Surface
Water Treatment Rule
LOAEL: Lowest Observed Adverse
Effect Level
LTIESTWR: Long-Term 1 Enhanced
Surface Water Treatment Rule
MCL: Maximum contaminant level
MCLG: Maximum contaminant level
goal
M-DBP: Microbial and Disinfectants/
Disinfection Byproducts
mg/L: Milligrams per liter
MRDL: Maximum residual disinfectant
level
MRDLG: Maximum residual disinfectant
level goal
NDWAC: National Drinking Water
Advisory Council
NIST: National Institute of Science and •
Technology
NOAEL: No Observed Adverse Effect
Level
NODA: Notice of Data Availability
NOM: Natural organic matter
NPDWR: National Primary Drinking
Water Regulation
NTNCWS: Nontransient noncommunity
water system
NTP: National Toxicology Program
NTTAA: National Technology Transfer
and Advancement Act
NTU: Nephelometric turbidity unit
OMB: Office of Management and Budget
PAR: Population attributable risk
PBMS: Performance based measurement
system
PE: Performance evaluation
POOR: Point of diminishing return
PQL: Practical quantitation limit
PWS: Public water system
QC: Quality control
Reg. Neg.: Regulatory Negotiation
RFA: Regulatory Flexibility Act
RfD: Reference dose
RIA: Regulatory impact analysis
RSC: Relative source contribution
SAB: Science Advisory Board
SBREFA: Small Business Regulatory
Enforcement Fairness Act
SDWIS: Safe Drinking Water
Information System
SUVA: Specific ultraviolet absorbance
SDWA: Safe Drinking Water Act, or the
"Act," as amended 1996
SWTR: Surface Water Treatment Rule
TC: Total coliforms
TCA: Trichloroacetic acid
TCR: Total Coliform Rule
TOC: Total organic carbon
TOX: Total organic halides
TTHM: Total trihalomethanes
(chloroform, bromdichloromethane,
dibromochloromethane, and
bromoform)
TNCWS: Transient noncommunity
water systems
TWG: Technical work group
UMRA: Unfunded mandates reform act
URTH: Unreasonable risk to health
WIDE: Water Industry Data Base
Table of Contents
I. Background
A. Statutory Requirements and Legal
Authority
B. Regulatory History
1. Existing Regulations
2. Public Health Concerns To Be
Addressed
3. Regulatory Negotiation Process
4. Federal Advisory Committee Process
5. 1997 and 1998 Notices of Data
Availability (NODA)
II. Summary of Final Stage 1 Disinfection
Byproduct Rule
A. Applicability
B. MRDLGs and MRDLs for Disinfectants
C. MCLGs and MCLs for TTHMs, HAAS,
Chlorite, and Bromate
D. Treatment Technique for Disinfection
Byproducts Precursors
E. BAT for Disinfectants, TTHMs, HAAS,
Chlorite, and Bromate
F. Compliance Monitoring Requirements
G. Analytical Methods
H. Laboratory Certification Criteria
I. Variances and Exemptions
J. State Recordkeeping, Primacy, Reporting
Requirements
K. System Reporting Requirements
L. Guidance Manuals
M. Regulation Review
III. Explanation of Final Rule
A. MCLGs/MRDLGs
1. MCLG for Chloroform
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
2. MCLG for Bromodichloromethane
(BDCM)
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
3. MCLG for Dibromochloromethane
(DBCM)
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
4. MCLG for Bromoform
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
5. MCLG for Dichloroacetic Acid (DCA)
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
6. MCLG for Trichloroacetic Acid (TCA)
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
7. MCLG for Chlorite and MRDLG for
Chlorine Dioxide
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
8. MCLG for Bromate
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
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69392 Federal Register /Vol. 63. No. 241/Wednesday, -December -16, 1998/Rules and Regulations.
9. MCLG for Chloral Hydrate
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
10. MRDLG for Chlorine
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
11. MRDLG for Chloramine
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
B. Epidemiology
1. Cancer Epidemiology
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
2. Reproductive and Developmental
Epidemiology
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
C. MCLs and BAT for TTHM. HAAS.
Chlorite, and Bromate; MRDLs and BAT
for Chlorine, Chloramlnes, and Chlorine
Dioxide
1. MCLs for TTHMs and HAAS
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
2. MCL for Bromate
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
3. MCL for Chlorite
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
4. MRDL for Chlorine
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
5. MRDL for Chloramines
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
6. MRDL for Chlorine Dioxide
a. Today's Rule
b. Background Analysis
c. Summary of Comments
D. Treatment Technique Requirement
1. Today's Rule
2. Background and Analysis
3. Summary of Comments
E. Predlslnfection Disinfection Credit
1. Today's Rule
2. Background and Analysis
3. Summary of Comments
F. Requirements for Systems to Use
Qualified Operators
G. Analytical Methods
1. Today's Rule
2. Background and Analysis
3. Summary of Comments
4. Performance Based Measurement
Systems
H. Monitoring Requirements
1. Today's Rule
2. Background and Analysis
3. Summary of Comments
I. Compliance Schedules
1. Today's Rule
2. Background and Analysis
3. Summary of Comments
J. Public Notice Requirements
1. Today's Rule
2. Background and Analysis
3. Summary of Comments
K. System Reporting and Record Keeping
Requirements
1. Today's Rule
2. Summary of Comments
L. State Recordkeeping, Primacy, and
Reporting Requirements
1. State Recordkeeping Requirements
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
2. Special Primacy Requirements
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
3. State Reporting Requirements
a. Today's Rule
b. Background and Analysis
c. Summary of Comments
M. Variances and Exemptions
1. Today's Rule
2. Background and Analysis
3. Summary of Comments
N. Laboratory Certification and Approval
1. Today's Rule
2. Background and Analysis
3. Summary of Comments
IV. Economic Analysis
A. Today's Rule
B. Background
1. Overview of RIA for the Proposed Rule
2. Factors Affecting Changes to the 1994
RIA
a. Changes in Rule Criteria
b. New Information Affecting DBP
Occurrence and Compliance Forecast
c. New Epidemiology Information
C. Cost Analysis
1. Revised Compliance Forecast
2. System Level Unit Costs
3. National Costs
D. Benefits Analysis
1. Exposure Assessment
2. Baseline Risk Assessment Based on
TTHM Toxicological Data
3. Baseline Analysis Based on
Epidemiology Data
4. Exposure Reduction Analysis
5. Monetization of Health Endpoints
E. Net Benefits Analysis
F. Summary of Comments
V. Other Requirements
A. Regulatory Flexibility Analysis
1. Today's Rule
2. Background and Analysis
3. Summary of Comments
B. Paperwork Reduction Act
C. Unfunded Mandates Reform Act
1. Summary of UMRA Requirements
2. Written Statement for Rules with Federal
Mandates of $ 100 million or More
a. Authorizing Legislation
b. Cost Benefit Analysis
c. Estimates of Future Compliance Costs
and Disproportionate Budgetary Effects
d. Macro-economic Effects
e. Summary of State, Local, and Tribal
Government and TheirConcerns
f. Regulatory Alternative Considered
3. Impacts on Small Governments
D. National Technology Transfer and
Advancement Act
E. Executive Order 12866: Regulatory
Planning and Review
F. Executive Order 12898: Environmental
Justice
G. Executive Order 13045: Protection of
Children from Environmental Health
Risks and Safety Risks
H. Consultation with the Science Advisory
Board, National Drinking Water
Advisory Council, and the Secretary of
Health and Human Services
I. Executive Order 12875: Enhancing the
Intergovernmental Partnership
J. Executive Order 13084: Consultation and
Coordination with Indian Tribal
Governments
K. Submission to Congress and the General
Accounting Office
L. Likely Effect of Compliance with the
Stage 1 DBPR on the Technical,
Financial, and Managerial Capacity of
Public Water Systems
VI. References
I. Background
A. Statutory Requirements and Legal
Authority
The Safe Drinking Water Act (SDWA
or the Act), as amended in 1986,
requires USEPA to publish a "maximum
contaminant level goal" (MCLG) for
each contaminant which, in the
judgement of the USEPA Administrator,
"may have any adverse effect on the
health of persons and which is known
or anticipated to occur in public water
systems" (Section 1412(b)(3)(A)).
MCLGs are to be set at a level at which
"no known or anticipated adverse effect
on the health of persons occur and
which allows an adequate margin of
safety'' (Section 1412 (b) (4)).
The Act was amended in August
1996. As a result of these Amendments,
several of these provisions were
renumbered and augmented with
additional language. Other sections
were added establishing new drinking
water requirements. These
modifications are outlined below.
The Act also requires that at the same
time USEPA publishes an MCLG, which
is a non-enforceable health goal, it also
must publish a National Primary
Drinking Water Regulation (NPDWR)
that specifies either a maximum
contaminant level (MCL) or treatment
technique (Sections 1401(1) and
1412(a)(3)). USEPA is authorized to
promulgate a NPDWR "that requires the
use of a treatment technique in lieu of
establishing a MCL," if the Agency finds
that "it is not economically or
technologically feasible to ascertain the
level of the contaminant"
As amended, EPA's general authority
to set a maximum contaminant level
goal (MCLG) and National Primary
Drinking Water Regulation (NPDWR)
applies to contaminants that may "have
an adverse effect on the health of
persons," that are "known to occur or
there is a substantial likelihood that the
contaminant will occur in public water
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systems with a frequency and at levels
of public health concern," and for
which "in the sole judgement of the
Administrator, regulation of such
contaminant presents a meaningful
opportunity for health risk reduction for
persons served by public water
systems" (SDWA Section 1412(b)(l)(A)).
The amendments, also require EPA,
when proposing a NPDWR that includes
an MCL or treatment technique, to
publish and seek public comment on an
analysis of health risk reduction and
cost impacts. In addition, EPA is
required to take into consideration the
effects of contaminants upon sensitive
subpopulations (i.e. infants, children,
pregnant women, the elderly, and
individuals with a history of serious
illness), and other relevant factors.
(Section 1412 (b)(3)(C)).
The amendments established a
number of regulatory deadlines,
including schedules for a Stage 1
Disinfection Byproduct Rule (DBPR), an
Interim Enhanced Surface Water
Treatment Rule (IESWTR), a Long-Term
Final Enhanced Surface Water
Treatment Rule (LTESWTR) affecting
Public Water Systems (PWSs) that serve
under 10,000 people, and a Stage 2
DBPR (Section 1412(b)(2)(C)). The Act
as amended also requires EPA to
promulgate regulations to address filter
backwash (Section 1412(b)(14)). Finally,
the Act requires EPA to promulgate
regulations specifying criteria for
requiring disinfection "as necessary" for
ground water systems (Section 1412
Finally, as part of the 1996 SDWA
Amendments, recordkeeping
requirements were modified to apply to
"every person who is subject to a
requirement of this title or who is a
grantee" (Section 1445 (a)(l)(A)). Such
persons are required to "establish and
maintain such records, make such
reports, conduct such monitoring, and
provide such information as the
Administrator may reasonably require
by regulation * * * ".
B. Regulatory History
1 . Existing Regulations
Surface Water Treatment Rule. Under
the Surface Water Treatment Rule
(SWTR) (54 FR 27486, June 29, 1989)
(EPA,1989a), EPA set maximum
contaminant level goals of zero for
Giardia lamblia, viruses, and Legionella;
and promulgated NPDWR for all PWSs
using surface water sources or ground
water sources under the direct influence
of surface water. The SWTR includes
treatment technique requirements for
filtered and unfiltered systems that are
intended to protect against the adverse
health effects of exposure to Giardia
lamblia, viruses, and Legionella, as well
as many other pathogenic organisms.
Briefly, those requirements include: (1)
requirements for a maintenance of a
disinfectant residual in the distribution
system; (2) removal and/or inactivation
of 3 logs (99.9%) for Giardia and 4 logs
(99.99%) for viruses; (3) combined filter
effluent performance of 5 nephelometric
turbidity unit (NTU) as a maximum and
0.5 NTU at 95th percentile monthly,
based on 4-hour monitoring for
treatment plants using conventional
treatment or direct filtration (with
separate standards for other filtration
technologies); and (4) watershed
protection and other requirements for
unfiltered systems.
Total Coliform Rule. The Total
Coliform Rule (TCR) (54 FR 27544; June
29, 1989) applies to all public water
systems (EPA, 1989b). This regulation
sets compliance with the MCL for total
coliforms (TC) as follows. For systems
that collect 40 or more samples per
month, no more than 5.0% of the
samples may be TC-positive; for those
that collect fewer than 40 samples, no
more than one sample may be TC-
positive. In addition, if two consecutive
samples in the system are TC-positive,
and one is also fecal coliform or E. coli-
positive, then this is defined as an acute
violation of the MCL. If a system
exceeds the MCL, it must notify the
public using mandatory language
developed by the EPA. The required
monitoring frequency for a system
depends on the number of people
served and, ranges from 480 samples per
month for the largest systems to once
annually for certain of the smallest
systems. All systems must have a
written plan identifying where samples
are to be collected.
If a system has a TC-positive sample,
it must test that sample for the presence
of fecal coliforms or E. coli. The system
must also collect a set of repeat samples,
and analyze for TC (and fecal coliform
or E. coli) within 24 hours of the first
TC-positive sample.
The TCR also requires an on-site
inspection every 5 years (10 years for
non-community systems using only
protected and disinfected ground water)
for each system that collects fewer than
five samples per month. This on-site
inspection (referred to as a sanitary
survey) must be performed by the State
or by an agent approved by the State.
Total Trihalomethane Rule. In
November 1979 (44 FR 68624) (EPA,
1979) EPA set an interim. MCL for total
trihalomethanes (TTHM) of 0.10
milligrams per liter (mg/L) as an annual
average. Compliance is defined on the
basis of a running annual average of
quarterly averages of all samples. The
value for each sample is the sum of the
measured concentrations of chloroform,
bromodichloromethane (BDCM),
dibromochloromethane (DBCM) and
bromoform.
The interim TTHM standard only
applies to community water systems
using surface water and/or ground water
serving at least 10,000 people that add
a disinfectant to the drinking water
during any part of the treatment process.
At their discretion, States may extend
coverage to smaller PWSs; however,
most States have not exercised this
option.
Information Collection Rule. The
Information Collection Rule OCR) is a
monitoring and data reporting rule that
was promulgated on May 14, 1996 (61
FR 24354) (EPA, 1996a). The purpose of
the ICR is to collect occurrence and
treatment information to help evaluate
the need for possible changes to the
current SWTR and existing microbial
treatment practices, and to help evaluate
the need for future regulation for
disinfectants and disinfection
byproducts (D/DBPs). The ICR will
provide EPA with additional
information on the national occurrence
in drinking water of (1) chemical
byproducts that form when disinfectants
used for microbial control react with
naturally occurring compounds already
present in source water and (2) disease-
causing microorganisms, including
Cryptosporidium, Giardia, and viruses.
The ICR will also provide engineering
data on how PWSs currently control for
such contaminants. This information is
being collected because the 1992
Regulatory Negotiating Committee
(henceforth referred to as the Reg. Neg.
Committee) on microbial pathogens and
disinfectants and DBFs concluded that
additional information was needed to
assess the potential health problem
created by the presence of DBFs and
pathogens in drinking water and to
assess the extent and severity of risk in
order to make sound regulatory and
public health decisions. The ICR will
also provide information to support
regulatory impact analyses for various
regulatory options, and to help develop
monitoring strategies for cost-effectively
implementing regulations.
The ICR pertains to large public water
systems serving populations at least
100,000; a more limited set of ICR
requirements pertain to ground water
systems serving between 50,000 and
100,000 people. About 300 PWSs
operating 500 treatment plants are
involved with the extensive ICR data
collection. Under the ICR, these PWSs
monitor for water quality factors
affecting DBF formation and DBFs
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69394 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
within the treatment plant and in the
distribution system monthly for 18
months. In addition, PWSs must
provide operating data and a description
of their treatment plan design and
surface water systems must monitor for
bacteria, viruses, and protozoa. Finally,
a subset of PWSs must perform
treatment studies, using either granular
activated carbon (GAG) or membrane
processes, to evaluate DBF precursor
removal and control of DBFs.
Monitoring for treatment study
applicability began in September 1996.
The remaining occurrence monitoring
began in July 1997.
One Initial intent of the ICR was to
collect pathogen occurrence data and
other Information for use in developing
the IESWTR and to estimate national
costs for various treatment options.
However, because of delays in
promulgating the ICR and technical
difficulties associated with laboratory
approval and review of facility sampling
plans, ICR monitoring did not begin
until July 1, 1997, which was later than
originally anticipated. As a result of this
delay and the new statutory deadlines
for promulgating the Stage 1 DBPR and
IESWTR in November of 1998 (resulting
from the 1996 SDWA amendments), ICR
data were not available in time to
support these rules. In place of the ICR
data, the Agency worked with
stakeholders to identify other sources of
data developed since 1994 that could be
used to support the development of the
Stage 1 DBPR and IESWTR. EPA will
continue to work with stakeholders in
analyzing and using the comprehensive
ICR data and research for developing
future Enhanced Surface Water
Treatment requirements and the Stage 2
DBPR.
2. Public Health Concerns to be
Addressed
EPA's main mission is the protection
of human health and the environment.
When carrying out this mission, EPA
must often make regulatory decisions
with less than complete information and
with uncertainties in the available
information. EPA believes it is
appropriate and prudent to err on the
side of public health protection when
there are indications that exposure to a
contaminant may present risks to public
health, rather than take no action until
risks are unequivocally proven.
In regard to the Stage 1 DBPR, EPA
recognizes that the assessment of public
health risks from disinfection of
drinking water currently relies on
inherently difficult and preliminary
empirical analysis. On one hand,
epidemiologic studies of the
populations in various geographic areas
are hampered by difficulties of study
design, scope, and sensitivity. On the
other hand, uncertainty is involved in
the interpretation of results using high
dose animal toxicological studies of a
few of the numerous byproducts that
occur in disinfected drinking water to
estimate the risk to humans from
chronic exposure to low doses of these
and other byproducts. Such studies of
individual DBFs is insufficient to
characterize risks from exposure to the
entire mixture of DBFs in disinfected
drinking water. While recognizing these
uncertainties, EPA continues to believe
that the Stage 1 DBPR is necessary for
the protection of public health from
exposure to potentially harmful DBFs.
A fundamental component in
assessing the risk for a contaminant is
the number of people that may be
exposed to the parameter of concern. In
this case, there is a very large
population potentially exposed to DBFs
through drinking water in the U.S. Over
200 million people are served by PWSs
that apply a disinfectant (e.g., chlorine)
to water in order to provide protection
against microbial contaminants. While
these disinfectants are effective in
controlling many microorganisms, they
react with natural organic and inorganic
matter in the water to form DBFs, some
of which may pose health risks. One of
the most complex questions facing
water supply professionals is how to
minimize the risks from DBFs and still
maintain adequate control over
microbial contaminants. Because of the
large number of people exposed to
DBFs, there is a substantial concern for
any risks associated with DBFs that may
impact public health.
Since the discovery of chlorination
byproducts in drinking water in 1974,
numerous toxicological studies have
been conducted. Results from these
studies have shown several DBFs (e.g.,
bromodichloromethane, bromoform,
chloroform, dichloroacetic acid, and
bromate) to be carcinogenic in
laboratory animals . Some DBFs (e.g.,
chlorite, BDCM, and certain haloacetic
acids) have also been shown to cause
adverse reproductive or developmental
effects in laboratory animals. Although
many of these studies have been
conducted at high doses, EPA believes
the studies provide evidence that DBFs
present a potential public health risk
that needs to be addressed.
In the area of epidemiology, a number
of epidemiology studies have been
conducted to investigate the
relationship between exposure to
chlorinated surface water and cancer.
While EPA cannot conclude there is a
causal link between exposure to
chlorinated surface water and cancer,
these studies have suggested an
association, albeit small, between
bladder, rectal, and colon cancer and
exposure to chlorinated surface water.
While there are fewer published
epidemiology studies that have been
conducted to evaluate the possible
relationship between exposure to
chlorinated surface water and
reproductive and developmental effects,
a recent study has suggested an
association between early term
miscarriage and exposure to drinking
water with elevated trihalomethane
levels. In addition to this study, another
new study reported a small increased
risk of neural tube defects associated
with consumption of drinking water
containing high levels of TTHMs.
However, no significant associations
were observed with individual THMs,
HAAs, and haloacetonitriles (HANs)
and adverse outcomes in this study. As
with cancer, EPA cannot conclude at
this time there is a causal link between
exposure to DBFs and reproductive and
developmental effects.
While EPA recognizes there are data
deficiencies in the information on the
health effects from the DBFs and the
levels at which they occur, the Agency
believes the weight-of-evidence
presented by the available
epidemiological studies on chlorinated
drinking water and toxicological studies
on individual DBFs support a potential
hazard concern and warrant regulatory
action at this time to reduce DBF levels
in drinking water. Recognizing the
deficiencies in the existing data, EPA
believes the incremental two-stage
approach for regulating DBFs, agreed
upon by the regulatory negotiation
process, is prudent and necessary to
protect public health and meet the
requirements of the SDWA.
In conclusion, because of the large
number of people exposed to DBFs and
the different potential health risks (e.g.,
cancer and adverse reproductive and
developmental effects) that may result
from exposure to DBFs, EPA believes
the Stage 1 DBPR is needed to further
prevent potential health effects from
DBFs, beyond that controlled for by the
1979 total trihalomethane rule. Both the
Reg. Neg. Committee for the 1994
proposed rule and the Microbial and
Disinfectants/Disinfection Byproducts
Advisory Committee (henceforth cited
as the M-DBP Advisory Committee)
formed in March 1997 under the Federal
Advisory Committee Act (FACA),
agreed with the need for the Stage 1
DBPR to reduce potential risks from
DBFs in the near term, while
acknowledging additional information
is still needed for the Stage 2 DBPR
(especially on health effects),
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3. Regulatory Negotiation Process
In 1992 EPA initiated a negotiated
rulemaking to address public health
concerns associated with disinfectants,
DBFs, and microbial pathogens. The
negotiators included representatives of
State and local health and regulatory
agencies, public water systems, elected
officials, consumer groups and
environmental groups. The Reg. Neg.
Committee met from November 1992
through June 1993.
Early in the process, the negotiators
agreed that large amounts of information
necessary to understand how to
optimize the use of disinfectants to
concurrently minimize microbial and
DBP risk on a plant-specific basis were
unavailable. Nevertheless, the Reg. Neg.
Committee agreed that EPA propose a
Stage 1 DBPR to extend coverage to all
community and nontransient
noncommunity water systems that use
disinfectants, reduce the current TTHM
MCL, regulate additional DBFs, set
limits for the use of disinfectants, and
reduce the level of organic precursor
compounds in the source water that
may react with disinfectants to form
DBFs.
EPA's most significant concern in
developing regulations for disinfectants
and DBFs was the need to ensure that
adequate treatment be maintained for
controlling risks from microbial
pathogens. One of the major goals
addressed by the Reg. Neg. Committee
was to develop an approach that would
reduce the level of exposure from
disinfectants and DBFs without
undermining the control of microbial
pathogens. The intention was to ensure
that drinking water is microbiologically
safe at the limits set for disinfectants
and DBFs and that these chemicals do
not pose an unacceptable health risk at
these limits. Thus, the Reg. Neg.
Committee also considered a range of
microbial issues and agreed that EPA
should also propose a companion
microbial rule (IESWTR).
Following months of intensive
discussions and technical analysis, the
Reg. Neg. Committee recommended the
development of three sets of rules: a
two-staged approach for the DBFs
(proposal: 59 FR 38668, July 29, 1994)
(EPA, 1994a), an "interim" ESWTR
(proposal: 59 FR 38832, July 29, 1994)
(EPA, 1994b), and an information
collection rule (proposal: 59 FR 6332,
February 10, 1994) (EPA, 1994c)
(promulgation: 61FR24354, May 14,
1996) (EPA, 1996a). The approach used
in developing these proposals
considered the constraints of
simultaneously treating water to control
for both microbial contaminants and D/
DBFs.
The Reg. Neg. Committee agreed that
the schedules for IESWTR and
LTESWTR should be "linked" to the
schedule for the Stage 1 DBPR to assure
simultaneous compliance and a
balanced risk-risk based
implementation. The Reg. Neg.
Committee agreed that additional
information on health risk, occurrence,
treatment technologies, and analytical
methods needed to be developed in
order to better understand the risk-risk
tradeoff, and how to accomplish an
overall reduction in health risks to both
pathogens and D/DBPs.
Finally the Reg. Neg. Committee
agreed that to develop a reasonable set
of rules and to understand more fully
the limitations of the current SWTR,
additional field data were critical. Thus,
a key component of the regulation
negotiation agreement was the
promulgation of the ICR previously
described.
4. Federal Advisory Committee Process
In May 1996, the Agency initiated a
series of public informational meetings
to provide an update on the status of the
1994 proposal and to review new data
related to microbial and DBP regulations
that had been developed since July
1994. In August 1996, Congress enacted
:the 1996 SDWA Amendments which
contained a number of new
requirements, as discussed above, as
well as specifying deadlines for final
promulgation of the IESWTR and Stage
1 DBPR. To meet these deadlines and to
maximize stakeholder participation, the
Agency established the M-DBP
Advisory Committee under FACA in
March 1997, to collect, share, and
analyze new information and data, as
well as to build consensus on the
regulatory implications of this new
information. The Committee consisted
of 17 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 M-DBP Advisory Committee met
five times in March through July 1997
to discuss issues related to the IESWTR
and Stage 1 DBPR. Technical support
for these discussions was provided by a
Technical Work Group (TWG)
established by the Committee at its first
meeting in March 1997. The
Committee's activities resulted in the
collection, development, evaluation,
and presentation of substantial new data
and information related to key elements
of both proposed rules. The Committee
reached agreement on a number of
major issues that were discussed in
Notices of Data Availability (NODA) for
the IESWTR (62 FR 59486, November 3,
1997) (EPA, 1997a) and the Stage 1
DBPR (62 FR 59388, November 3, 1997)
(EPA, 1997b). The major
recommendations addressed by the
Committee and in the NOD As were to:
(1) Maintain the proposed MCLs for
TTHM, HAAS, and bromate; (2) modify
the enhanced coagulation requirements
as part of DBP control; (3) include a
microbial benchmarking/profiling to
provide a methodology and process by
which a PWS and the State, working
together, assure that there will be no
significant reduction in microbial
protection as the result of modifying
disinfection practices in order to meet
MCLs for TTHM and HAAS; (4)
continue credit for compliance with
applicable disinfection requirements for
disinfection applied at any point prior
to the first customer, consistent with the
existing SWTR; (5) modify the turbidity
performance requirements and add
requirements for individual filters; (6)
establish an MCLG for Cryptosporidium;
(7) add requirements for removal of
Cryptosporidium; (8) provide for
mandatory sanitary surveys; and (9)
make a commitment to additional
analysis of the role of Cryptosporidium
inactivation as part of a multiple barrier
concept in the context of a subsequent
Federal Register microbial proposal. The
new data and analysis supporting the
technical areas of agreement were
summarized and explained at length in
EPA's 1997 NODAs (EPA, 1997a and
EPA, 1997b).
5. 1997 and 1998 Notices of Data
Availability
In November 1997 EPA published a
NODA (USEPA, 1997b) that
summarized the 1994 proposal;
described new data and information that
the Agency has obtained and analyses
that have been developed since the
proposal; provided information
concerning the July 1997
recommendations of the M-DBP
Advisory Committee on key issues
related to the proposal (described
above); and requested comment on these
recommendations, as well as on other
regulatory implications that flow from
the new data and information. The
Agency solicited additional data and
information that were relevant to the
issues discussed in the DBP NODA. EPA
also requested that any information the
Agency should consider as part of the
final rule development process
regarding data or views submitted to the
Agency since the close of the comment
period on the 1994 proposal, be
formally resubmitted during the 90-day
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69396 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
comment period unless already in the
underlying record in the docket for the
NODA.
In March 1998. EPA issued a second
DBF NODA (EPA. 1998a) that
summarized new health effects
information received and analyzed since
the November 1997 NODA and
requested comments on several issues
related to the simultaneous compliance
with the Stage 1 DBPR and the Lead and
Copper Rule. The 1998 NODA indicated
EPA was considering increasing the
MCLG for chloroform from zero to 0.3
mg/L and the proposed MCLG for
chlorite from 0.08 mg/L to 0.8 mg/L.
EPA also requested comment on
increasing the Maximum Residual
Disinfection Level Goal (MRDLG) for
chlorine dioxide from 0.3 mg/L to 0.8
mg/L. Today's final rule was developed
based on the outcome of the 1992 Reg.
Neg., the 1994 proposed rule, the 1997
FACA process, and both the 1997 and
1998 DBP NOD As, as well as a wide
range of technical comments from
stakeholders and members of the public.
A summary of today's rule follows.
II. Summary of Final Stage 1
Disinfection Byproduct Rule
A. Applicability
The final Stage 1 DBPR applies to
community water systems (CWSs) and
nontransient noncommunity water
systems (NTNCWs) that treat their water
with a chemical disinfectant for either
primary or residual treatment. In
addition, certain requirements for
chlorine dioxide apply to transient
noncommunity water systems
(TNCWSs).
B. MRDLGs and MRDLs for Disinfectants
EPA is finalizing the following
MRDLGs and maximum residual
disinfectant levels (MRDLs) for chlorine,
chloramines, and chlorine dioxide in
Table II-1.
TABLE 11-1.—MRDLGs AND MRDLs FOR DISINFECTANTS
Disinfectant residual
Chlorine
Chloramine
Chlorine Dioxide ,
MRDLG (mg/L)
4 (as CI2)
4 (as Clz)
0 8 (as ClOa)
MRDL (mg/L)
4 o (as Ch)
4 0 (as Ck)
0 8 (as ClOa)
C. MCLGs and MCLs for TTHMs, HAAS,
Chlorite, and Bromate
EPA is finalizing the MCLGs and
MCLs in Table II-2.
TABLE II-2.—MCLGs AND MCLs FOR DISINFECTION BYPRODUCTS
Disinfection byproducts
Total trihalomethanes (TTHM)1
— Chloroform . .
— Bromodichloromethane . ..
— Dibromochloromethane
— Bromoform
Haloacetic acids (five) (HAA5)2
— Dich!oroacetic acid
— Trichloroacetic acid
Chlorite
Bromate
MCLG (mg/L)
N/A
0
0
006
0
N/A
0
0.3
0.8
0
MCL (mg/L)
0080
0.060
1.0
0.010
N/A—Not applicable because there are no individual MCLGs for TTHMs or HAAs.
1 Total trihalomethanes is the sum of the concentrations of chloroform, bromodichloromethane, dibromochloromethane, and bromoform.
2 Haloacetio acids (five) is the sum of the concentrations of mono-, di-, and trichloroacetic acids and mono- and dibromoacetic acids.
D. Treatment Technique for Disinfection
Byproduct Precursors
Water systems that use surface water
or ground water under the direct
Influence of surface water and use
conventional filtration treatment are
required to remove specified
percentages of organic materials
(measured as total organic carbon) that
may react with disinfectants to form
DBFs as indicated in Table II-3.
Removal will be achieved through a
treatment technique (enhanced
coagulation or enhanced softening)
unless a system meets alternative
criteria discussed in Section III.D.
TABLE 11-3.—REQUIRED REMOVAL OF TOTAL ORGANIC CARBON BY ENHANCED COAGULATION AND ENHANCED SOFTENING
FOR SUBPART H SYSTEMS USING CONVENTIONAL TREATMENTa-b-c
Source Water TOG (mg/L)
Source Water Alkalinity (mg/L as
CaCO3) (percent)
>2.0-4.0
>4.0-8.0
0-60
35.0
45.0
>60-i20
250
35.0
>120
15.0
25.0
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TABLE 11-3.—REQUIRED REMOVAL OF TOTAL ORGANIC CARBON BY ENHANCED COAGULATION AND ENHANCED SOFTENING
FOR SUBPART H SYSTEMS USING CONVENTIONAL TREATMENTa.«>.°—Continued
Source Water TOG (mg/L)
>8.0
Source Water Alkalinity (mg/L as
CaCO3) (percent)
0-60
50.0
>60-120
40.0
>120
30.0
"Systems meeting at least one of the conditions in Section 141.135(a)(2) (i)-(vi) of the rule are not required to operate the removals in this
table.
b Softening systems meeting one of the two alternative compliance criteria in Section 141.135(a)(3) of the rule are not required to meet the re-
movals in this table.
c Systems practicing softening must meet the TOC removal requirements in the last column to the right.
E. BAT for Disinfectants, TTHMs,
HAAS, Chlorite, and Bromate
Under the SDWA, EPA must specify
the BAT for each MCL (or MRDL) that
is set. PWS that are unable to achieve an exemptions). Table II.4 includes the
MCL or MRDL may be granted a
variance if they use the BAT and meet
other requirements (see section III.M for
a discussion of variances and
BATs for each of the MCLs or MRDLs
that EPA is promulgating in today's
Stage 1 DBPR.
TABLE 11-4.—BAT FOR DISINFECTANTS AND DISINFECTION BYPRODUCTS
Disinfectant/DBP
Best available technology
Disinfectants
Chlorine residual
Chloramine residual
Chlorine dioxide residual
Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to
reduce disinfectant levels. ,
Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to
reduce disinfectant levels. .
Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to
reduce disinfectant levels.
Disinfection Byproducts
Total trihalomethanes
Total haloacetic acids
Chlorite
Bromate
Enhanced coagulation or enhanced softening or GAC10*, wjth chlorine as the primary and residual disinfectant.
Enhanced coagulation or enhanced softening or GAC10*, with chlorine as the primary and residual disinfectant.
Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to
reduce disinfectant levels.
Control of ozone treatment process to reduce production of bromate.
*GAC10 means granular activated carbon with an empty bed contact time of 10 minutes and reactivation frequency for GAC of no more than
six months.
F. Compliance Monitoring Requirements
Compliance monitoring requirements
are explained in Section III.H of today's
rule. EPA has developed routine and
reduced compliance monitoring
schemes for disinfectants and DBFs to
be protective from different types of
health concerns, including acute and
long-term effects.
G. Analytical Methods
EPA has approved five methods for
measurement of free chlorine, four
methods for combined chlorine, and six
for total chlorine. EPA has also
approved two methods for the
measurement of chlorine dioxide
residuals; three methods for the
measurement of HAAS; three methods
for the measurement of TTHMs; three
methods for the measurement of TOC/
Dissolved Organic Carbon (DOC); two
methods for the monthly measurement
of chlorite and one method for the daily
monitoring of chlorite; two methods for
bromide; one method for the
measurement of bromate; and one
method for the measurement of UV254.
Finally, EPA approved all methods
allowed in § 141.89(a) for measuring
alkalinity. These issues are discussed in
more detail in section III.G.
H. Laboratory Certification Criteria
Consistent with other drinking water
regulations, determinations of
compliance with the MCLs may only be
conducted by certified laboratories. EPA
is requiring that analyses can be
conducted by a party acceptable to EPA
or the State in those situations where
the parameter can adequately be
measured by someone other than a
certified laboratory and for which there
is a good reason to allow analysis at
other locations (e.g., for samples which
normally deteriorate before reaching a
certified laboratory, especially when
taken at remote locations). For a
detailed discussion of the lab
certification requirements, see section
III.N.
I. Variances and Exemptions
Variances and exemptions will be
permitted in accordance with existing
statutory and regulatory authority. For a
detailed discussion see section III.M.
J. State Recordkeeping, Primacy, and
Reporting Requirements
The Stage 1 DBPR requires States to
adopt several regulatory requirements,
including public notification
requirements, MCLs for DBFs, MRDLs
for disinfectants, and the requirements
in Subpart L. In addition. States are
required to adopt several special
primacy requirements for the Stage 1
DPBR. States are also required to keep
specific records in accordance with
existing regulations and additional
records specific to the Stage 1 DBPR.
Finally, the rule does not require any
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69398 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998,/Rules and Regulations
State additional reporting requirements
beyond those required under existing
regulations. These requirements are
discussed in more detail in Section III.L.
K. System Reporting Requirements
System are required to report
monitoring data to the State as
discussed in Section III.K.
L. Guidance Manuals
EPA is developing guidance for both
systems and States for the
implementation of the Stage 1 DBPR
and the IESWTR. The guidance manuals
include: Guidance Manual for Enhanced
Coagulation and Precipitative Softening;
Disinfection Benchmark Guidance
Manual; Turbidity Guidance Manual;
Alternative Disinfectants and Oxidants
Guidance Manual; M/DBP Simultaneous
Compliance Manual; Sanitary Survey
Guidance Manual; Unfiltered Systems
Guidance Manual; and Uncovered
Finished Water Reservoirs. Guidance
manuals will be available after the
publication of the Stage 1 DBPR.
M. Regulation Review
Under the provisions of the SDWA
(Section 1412(b)(9)), the Agency is
required to review NPDWRs at least
once every six years. As mentioned
previously, today's final rule revises,
updates, and supersedes the regulations
for total trihalomethanes, initially
published in 1979. Since that time,
there have been significant changes in
technology, treatment techniques, and
other regulatory controls that provide
for greater protection of human health.
As such, for today's rule, EPA has
analyzed innovations and changes in
technology and treatment techniques
that have occurred since promulgation
of the interim TTHM regulations. That
analysis, contained primarily in the cost
and technology document supporting
this rule, supports the changes in the
Stage 1 DBPR from the 1979 TTHM rule.
EPA believes that the innovations and
changes in technology and treatment
techniques that result in changes to the
1979 TTHM regulations are feasible
within the meaning of SDWA Section
1412(b).
III. Explanation of Final Rule
A. MCLGs/MRDLGs
MCLGs are set at levels at which no
known or anticipated adverse health
effects occur, allowing for an adequate
margin of safety. Establishment of an
MCLG for each specific contaminant is
based on the available evidence of
carcinogenicity or noncancer adverse
health effects from drinking water
exposure using EPA's guidelines for risk
assessment (see the proposed rule at 59
FR 38677 for a detailed discussion of
the process for establishing MCLGs).
The final Stage 1 DBPR contains
MCLGs for: four THMs (chloroform,
bromodichloromethane,
dibromochloromethane, and
bromoform); two haloacetic acids
(dichloroacetic acid and trichloroacetic
acid); bromate; and chlorite (see table
II-2 for final MCLG levels). These
MCLGs are the same as those proposed
in 1994 with the exception of chlorite,
which increased from 0.08 mg/L to 0.8
mg/L. The MCLG for chloral hydrate has
been dropped since EPA has concluded
that it will be controlled by the MCLs
for TTHM and HAAS and the enhanced
coagulation treatment technique.
The final Stage 1 DBPR contains
MRDLGs for chlorine, chloramines and
chlorine dioxide (see table II-1 for final
MRDLG levels). The MRDLGs are as the
same as those proposed in 1994, with
the exception of chlorine dioxide,
which increased from 0.3 mg/L to 0.8
mg/L.
The MRDLG concept was introduced
in the proposed rule for disinfectants to
reflect the fact that these substances
have beneficial disinfection properties.
As with MCLGs, MRDLGs are
established at the level at which no
known or anticipated adverse effects on
the health of persons occur and which
allows an adequate margin of safety.
MRDLGs are nonenforceable health
goals based only on health effects and
exposure information and do not reflect
the benefit of the addition of the
chemical for control for waterborne
microbial contaminants. By using the
term "residual disinfectant" in lieu of
"contaminant", EPA intends to avoid
situations in which treatment plant
operators are reluctant to apply
disinfectant dosages above the MRDLG
during short periods of time to control
for microbial risk.
EPA received numerous comments on
the use of the term MRDLG. The
majority of commenters agreed that the
term MRDLG was appropriate to use in
place of MCLG for disinfectants. Other
commenters agreed, but felt that the
language should more strongly reflect
that disinfectants are necessary and that
short-term exposure to elevated levels of
the disinfectants is not a health concern.
Some commenters suggested that
MRDLGs be extended to ozone,
potassium permanganate and iodine.
In response, EPA agrees with the
majority of commenters that the use of
the term MRDLG is appropriate and
therefore the final rule retains this term.
EPA believes the language on the
importance of disinfectants is adequate
in the rule and thus has not changed
this language. EPA does not agree that
the potential health effects from short-
term exposure to elevated levels of
disinfectants can be dismissed. Ozone
does not require an MRDLG because it
reacts so completely that it does not
occur in water delivered to consumers.
Finally, EPA believes the use of the
MRDLGs for other disinfectants or
oxidants would not be appropriate since
MRDLGs are developed for regulated
compounds controlled by MRDLs or
treatment techniques and EPA does not
allow these compounds to be used to
demonstrate compliance with
disinfection requirements.
The information EPA relied on to
establish the MCLGs and MRDLGs was
described in the 1994 proposal (EPA,
1994a), the 1997 DBF NODA (EPA,
1997b), and the 1998 NODA (EPA,
1998a). Criteria and assessment
documents to support the MCLGs and
MRDLGs are included in the docket
(EPA, 1993a; EPA, 1994 d-h; EPA,
1997c; EPA, 1998 b-f; and EPA, 1998p).
A summary of the occurrence and
exposure information for this rule are
detailed in "Occurrence Assessment for
Disinfectants and Disinfection
Byproducts in Public Drinking Water
Supplies' (EPA, 1998u). The discussion
of the data used to establish the MCLGs
and MRDLGs and a summary of the
major public comments for these
chemicals are included below. A more
detailed discussion is included below
for chloroform, DCA, chlorite, chloride
dioxide, and bromate than the other
disinfectants and DBFs. This is the case
because significant new data has
become available since the 1994
proposal for these four DBFs and one
disinfectant.
1. MCLG for Chloroform
a. Today's Rule. After careful
consideration of all public comments,
EPA has concluded at this time to
promulgate an MCLG for chloroform of
zero as proposed. This conclusion
reflects an interim risk-management
decision on the part of the Agency. The
Agency recognizes the strength of the
science in support of a non-linear
approach for estimating carcinogenicity
of chloroform. EPA received public
comments that questioned the
underlying basis and approach used to
reach the science judgment that the
mode of chloroform's carcinogenic
action supports a nonlinear approach.
Equally important are the policy and
regulatory issues raised by stakeholders
that touch on this issue. EPA believes
that it is essential to pursue a further
dialogue with stakeholders on the issues
raised in the public comments before
applying the substantial new data and
science on the mode of carcinogenic
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Federal Register'/Vol. 63, No. 241 /Wednesday, December 16, 1998/_Rules and Regulations 69399
action discussed in the 1998 NOD A to
the important decision of moving to a
non-linear cancer extrapolation
approach for drinking water
contaminants under the SDWA.
Moreover, EPA will complete additional
deliberations with the Agency's Science
Advisory Board (SAB) (open to
stakeholder presentations to the SAB)
on the analytical approach used to
evaluate and reach conclusions on mode
of action data, and the science basis for
the mode of carcinogenic action for
chloroform.
In evaluating how to proceed in the
development of an MCLG for
chloroform, the Agency believes two
additional factors must be taken into
consideration. First, as part of the 1996
SDWA amendments, Congress
mandated that the Stage 1 DBPR rule be
promulgated by November 1998. EPA
has concluded that it would be
impossible to complete the additional
deliberations noted above in time to
meet this statutory deadline. Second, as
explained below, the Agency has also
completed analysis indicating that
regardless of whether the MCLG is
based on a low-dose linear or non-linear
extrapolation approach, the MCL
enforceable standard for TTHMs of 0.08
mg/L will not be affected. In light of
these issues, EPA believes it is
appropriate and consistent with the
public health goals of the SDWA to
establish a zero MCLG for chloroform
based on a linear default extrapolation
approach until the Agency is able to
complete additional deliberations with
the Agency's SAB on the analytical
approach used to evaluate and reach
conclusions on mode of action data and
the science basis for the mode of
carcinogenic action for chloroform, and
complete the process of further public
dialogue on the important question of
moving to a non-linear cancer
extrapolation approach. EPA also notes
that its approach is consistent with
legislative history of the SDWA (see 56
FR 3533—EPA, 1991) and the 1996
SDWA Amendments.
b. Background and Analysis. As part
of its 1994 Stage 1 DBP proposal (EPA,
1994a), EPA requested comment on a
zero MCLG for chloroform. This was
consistent with information provided to
the 1992 Reg. Neg. Committee and was
based on data from a drinking water
study by Jorgensen et al. (1985)
indicating an increase of kidney tumors
in male rats in a dose-related manner.
However, at the time of the proposal
there was insufficient data to determine
the mode of carcinogenic action for
chloroform. Therefore, EPA based its
1994 proposal on a risk management
decision that a presumptive or low-dose
linear default (i.e, MCLG of zero) was
appropriate until more research became
available and there was an adequate
opportunity to work with stakeholders
and the scientific community to
evaluate and assess the technical as well
as policy and regulatory implications of
such new information. The 1994
proposal also reflected the Agency's
1986 Guidelines for Carcinogen Risk
Assessment (EPA, 1986) which
recommended reliance on the default
assumption of low-dose linearity in the
absence of substantial information on
the mechanism of carcinogenicity.
Since the 1994 proposal, over 30
toxicological studies have been
published on chloroform. These studies
were discussed in the November 1997
Stage 1 DBP NODA (EPA, 1997b). In
addition, EPA published a second DBP
NODA in March 1998 (EPA, 1998a)
which discussed recommendations and
findings from a 1997 International Life
Sciences Institute project (ILSI, 1997),
co-sponsored by EPA, on the cancer
assessment for chloroform. The ILSI
project included the analysis and
conclusions from an expert panel which
was convened and charged with
reviewing the available database
relevant to the carcinogenicity of
chloroform, and considering how end
points related to mode of action can be
applied in hazard and dose-response
assessment by using guidance provided
by the EPA's 1996 Proposed Guidelines
for Carcinogen Assessment (EPA,
1996b). The panel was made up of 10
internationally recognized scientists
from academia, industry, government,
and the private sector. Based on a
consideration of the ILSI panel findings
and an assessment of new data on
chloroform since 1994, EPA requested
comment in the 1998 NODA on the
Agency's science conclusion that
chloroform is a likely human carcinogen
and that available scientific analysis
supports a non-linear mode of action for
estimating the carcinogenic risk
associated with lifetime exposure from
ingesting drinking water.
As part of the 1998 NODA, EPA also
requested comment on a revised
chloroform MCLG of 0.30 mg/L. The
revised MCLG was premised on the
substantial new science noted above
that supports a non-linear mode of
action. In calculating the specific
MCLG, EPA relied upon data relating to
hepatoxicity in dogs (EPA, 1994a). This
hepatoxicity endpoint was deemed
appropriate given that hepatic injury is
the primary effect following chloroform
exposure; and that an MCLG based on
protection against liver toxicity should
be protective against carcinogenicity
given that the putative mode of action
understanding for chloroform involves
cytotoxicity as a key event preceding
tumor development. The MCLG of 0.3
mg/L was calculated using a relative
source contribution (RSC) of 80 percent.
The RSC of 80 percent was based on the
assumption that most exposure to
chloroform is likely to come from
ingestion of drinking water. The 80
percent assumption for the RSC was
consistent with the calculations used to
derive the MCLGs for D/DBPs in the
1994 proposal. Based on information
received during the public comment
period for the 19,98 NODA, EPA is
considering revising its estimate of the
RSC for chloroform as discussed below.
Since the 1998 NODA, EPA has
reevaluated elements of the analysis
underlying a revised MCLG of 0.30 mg/
L. Considering recent information not
fully analyzed as part of the 1998
NODA, the Agency is considering
revising the assumption of an 80% RSC
from ingestion of drinking water in view
of data which indicates that exposure to
chloroform via inhalation and dermal
exposure may potentially contribute a
substantial percentage of the overall
exposure to chloroform depending on
the activity patterns of individuals.
Also, EPA is in the process of
developing a policy for incorporating
inhalation and dermal exposure into the
derivation of the RSC. Furthermore,
there is considerable uncertainty
regarding the potential exposure to
chloroform via the dietary route and
there is information which indicates
individuals who are frequent swimmers
may receive a large amount of
chloroform during swimming. There are
additional uncertainties regarding other
possible highly exposed sub-
populations, e.g., from use of
humidifiers, hot-tubs, and outdoor
misters. In conclusion, because there
may be a potential for exposure to
chloroform from other routes of
exposure than ingestion of drinking
water, EPA is considering using the 20
percent default floor to ensure adequate
public health protection. The 20 percent
has been used historically for drinking
water contaminants other than D/DBPs
when there is uncertainty in the
available exposure data. The use of the
20 percent RSC for chloroform would
produce a MCLG of 0.07 mg/L:
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69400 Federal "Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
MCLG for chloroform^0-01 mg/kg/dX70kgX°-2=0.07 mg/L
2L/d
In addition to its reassessment of
technical assumptions underlying the
revised MCLG, the Agency has also
reviewed and carefully considered in
detail a number of significant comments
on the 1998 NODA. These comments
reflect both substantial scientific
support as well as significant concerns
with a possible MCLG of 0.30 mg/L. As
outlined in more detail below, a number
of nationally recognized scientific
experts strongly affirmed the data and
technical rationale for relying upon a
non-linear mode of action for
chloroform. Other commenters,
however, highlighted several scientific
Issues they felt were not adequately
considered. These commenters also
emphasized their concern that the
policy, regulatory, and enforcement
Implications related to a revised MCLG
were not raised by EPA in either the
1992 or the 1997 regulatory negotiation
processes leading up to today's final
rule. Thus, these commenters felt that a
number of stakeholders who
recommended support for components
of the Stage 1 DBPR rule did so under
one set of conditions and assumptions
that the Agency subsequently changed
without providing a sufficient
opportunity for further debate and
discussion.
EPA believes that an adequate
opportunity for notice and comment
was provided as a result of the 1997 and
1998 DBP NOD As on the underlying
scientific data and technical issue of
moving to a non-linear extrapolation
approach based on an understanding of
the mode of carcinogenic action for
chloroform and recalculating the
chloroform MCLG to a nonzero number.
However, the Agency recognizes that
reliance on a non-linear mode of action
under the SDWA does represent a
significant and precedential, albeit
sound, application of new science to the
policy development and risk
management decision making process of
establishing appropriately protective
MCLGs. The Agency also recognizes
that although, as discussed below, a
revised MCLG for chloroform would not
affect the TTHM MCL under today's
rule, the precedential decision to utilize
a non-linear cancer extrapolation
approach clearly has important
implications for the development of
future MCLGs where there is also
adequate scientific research and data to
support such a non-linear analysis.
in reviewing the range of scientific,
policy, and regulatory analyses and
strongly held views associated with
development of the chloroform MCLG,
EPA notes that the one question not
fundamentally at issue is the
establishment of the 0.080 mg/L TTHM
MCL. The majority of commenters who
addressed the proposed TTHM MCL
continue to support it. This is
particularly important to EPA in light of
congressional action with regard to the
M-DBP process in the 1996 SDWA
Amendments. In enacting the
Amendments and particularly in
expressing congressional intent in the
conference Report, Congress was careful
to emphasize "that the new provisions
of this conference agreement not
conflict with the parties' agreement nor
disrupt the implementation of the
regulatory actions," (such as the current
agreement on an TTHM MCL of 0.080
mg/L). Both of these important elements
of the Congressional intent were
reflected in the statutory text. Section
1412(b)(2)(C) requires EPA to maintain
the M-DBP rule staggered promulgation
strategy agreed to by the negotiated
rulemaking; and Section 1412(b)(6)(C)
exempted the future M-DBP rules from
the new cost-benefit standard-setting
provision (1412(b)(6)(A)) but not from
the new risk-risk provision (1412(b)(5)),
because the latter was a part of the
negotiated rulemaking agreement but
the former was not.
The Agency, itself, also believes that
the underlying logic, data, and rationale
supporting establishment of a TTHM of
0.080 mg/L MCL is compelling, and this
is a critical factor in the Agency's
chloroform MCLG decision under
today's rule. Under either a low-dose
linear or non-linear extrapolation to
derive the MCLG, the final TTHM MCL
remains unaffected.
After thorough review of the data and
comments, EPA believes the nonlinear
cancer extrapolation approach is the
most appropriate means to establish an
MCLG for chloroform based on
carcinogenic risk. However, in light of
its own reconsideration of the
appropriate RSC for chloroform under
such an approach, considering the range
of policy, regulatory, and enforcement
issues raised as part of the public
comment period, recognizing the
importance of deliberations with SAB
before proceeding further and, yet,
recognizing that this cannot be
accomplished within the constraints of
meeting the statutory deadline for Stage
1 DBPR rule of November 1998, EPA has
determined that on balance the more
appropriate and prudent risk
management decision at this time is to
establish an MCLG for chloroform at the
proposed presumptive default level of
zero. As part of this decision, the
Agency will complete additional
deliberations with the Agency's SAB on
the analytical approach used to evaluate
and reach conclusions on mode of
action data, and the science basis for the
mode of carcinogenic action for
chloroform. The SAB's review will be
factored into the Agency's Stage 2 DBP
rulemaking process. EPA will also
include consideration of the regulatory,
policy, and precedential issues
involving chloroform in the Agency's
Round 2 M-BP stakeholder process.
EPA wishes to make clear that its
interim decision in today's rule to set an
MCLG of zero pending SAB review and
further stakeholder involvement is not
intended to prejudge the question of
what the appropriate MCLG should be
for purposes of regulatory decisions
under the Stage 2 DBPR. EPA may
decide to retain the zero MCLG for that
rule, or to revise it, depending on the
outcome of the SAB review, as well as
any new scientific evidence that may
become available. In regard to the
appropriate RSC factor, in case a non-
linear approach should ultimately be
adopted, the Agency requests that
stakeholders provide any data they man
have bearing on this determination.
The fundamental objective of the
SDWA is to establish protective public
health goals (MCLGs) together with
enforceable standards (MCLs or
treatment techniques) to move the water
treatment systems as close to the public
health goal as is technologically and
economically feasible. In the case of the
chloroform and TTHMs, this objective is
met with whichever extrapolation
approach (low dose linear versus
nonlinear) is relied upon.
c. Summary of Comments. EPA
received numerous comments on both
the 1994 proposed rule regarding the
MCLG of zero for chloroform and the
MCLG of 0.3 mg/L contained in the
1998 NODA. Some commenters were
supportive of the MCLG of zero, while
others were supportive of the 0.3 mg/L
MCLG. The major reason raised by
commenters for establishing a nonzero
MCLG (e.g., 0.3 mg/L) was that there
was convincing scientific evidence to
conclude that a nonlinear margin of
exposure approach for evaluating the
carcinogenic risk from chloroform is
warranted. Commenters who were
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Federal Register/Vol. 63, No. 241 / Wednesday, December 16, 1998/Rules and Regulations 69401
against establishing a nonzero MCLG for
chloroform presented policy and
scientific concerns. Scientific concerns
raised by commenters opposed to the
nonzero MCLG included their
perceptions that: there is insufficient
scientific evidence of a threshold for
chloroform; the threshold assumption is
also invalid because chloroform co-
occurs with other mutagenic
carcinogens; EPA ignored human data
in establishing the MCLG for
chloroform; the linkage between
cytotoxicity and regenerative
proliferation and kidney tumors is not
supported by the data; and the evidence
for genotoxicity is mixed and it would
be difficult if not impossible to
conclude that the evidence demonstrate
chloroform has no direct effect on DNA.
As detailed at greater length in the
docket, EPA does not agree with these
comments as a technical matter. The
Agency does agree with the commenters
view that further discussion of these
issues with both the SAB and as part of
additional public dialogue is
appropriate.
The policy issues raised by
commenters included their belief that: a
zero MCLG is required to comply with
provisions of the SDWA; EPA is
required to use the 1986 Cancer
Guidelines (EPA, 1986) until the 1996
Cancer Guidelines (EPA, 1996b) are
formally finalized, and under the 1986
guidelines the MCLG for chloroform
must be set at zero; EPA did not provide
sufficient opportunity for the members
of the FACA, established to assist in the
development of the Stage 1 DBF rule, to
properly consider the potential
implications of a nonzero MCLG; and
setting a MCLG for chloroform (0.3 mg/
L) above the MCL'for the TTHMs (0.08
mg/L) is illogical.
In response, EPA believes that the
underlying science for using a nonlinear
extrapolation approach to evaluate the
carcinogenic risk from chloroform is
well founded. As explained above,
because of the issues raised during the
public comment period, EPA believes
additional review and dialogue with
stakeholders is needed prior to
departing from a long-held EPA policy
of establishing zero MCLGs for known
or probable carcinogens. EPA will also
complete additional deliberations with
the Agency's SAB on the analytical
approach used to evaluate and reach
conclusions on mode of action data, and
the'science basis for the mode of
carcinogenic action for chloroform.
In response to the policy issues raised
by commenters, EPA, historically, has
established MCLGs of zero for known or
probable human carcinogens based on
the principle that any exposure to
carcinogens might represent some finite
level of risk and therefore an MCLG
above zero did not meet the statutory
requirement that the goal be set where
no known anticipated adverse effects
occur, allowing for an adequate margin
of safety (56 FR 3533; EPA, 1991).
However, if there is scientific evidence
that indicates there is a "safe threshold"
then a non-zero MCLG could be
established with an adequate margin of
safety (56 FR 3533; EPA, 1991)). Even
though EPA, as an interim matter, is
establishing an MCLG of zero for
chloroform in today's rule, it believes it
has the authority to establish nonzero
MCLGs for carcinogens if the scientific
evidence supports this finding.
In response to cdmmenter's concerns
with EPA using the proposed 1996
Guidelines for Carcinogen Risk
Assessment (EPA, 1996b) instead of the
Agency's 1986 guidelines, EPA believes
it is important to point out that the 1986
guidelines provide for departures from
default assumptions such as low dose
linear assessment. For example, the
1986 EPA guidelines reflect the position
of the OSTP (1985; Principle 26) "No
single mathematical procedure is
recognized as the most appropriate for
low-dose extrapolation in
carcinogenesis. When relevant
biological evidence on mechanisms of
action exists (e.g, pharmacokinetics,
target organ dose), the models or
procedure employed should be
consistent with the evidence." The 1986
guideline goes on to further state "The
Agency will review each assessment as
to the evidence on carcinogenesis
mechanisms and other biological or
statistical evidence that indicates the
suitability of a particular extrapolation
model." The EPA's 1996 Proposed
Guidelines for Carcinogen Risk
Assessment allow EPA to use other
default approaches to estimate cancer
risk than the historic, linearized
multistage default when there is an
understanding of an agent's mode of
carcinogenic action. EPA believes that
reliance on the 1986 guidance allows
EPA to reach the same conclusion on
the carcinogenic risk from chloroform as
if the 1996 guidelines were used. The
use of the best available science is a core
EPA principle and is statutorily
mandated by the SDWA amendments of
1996. The 1996 Proposed Guidelines for
Carcinogen Risk Assessment reflect new
science and are consistent with the
existing 1986 Guidelines for Carcinogen
Risk Assessment. EPA considered the
1996 proposed guidelines in assessing
the health effects data for chloroform
and the other contaminants discussed in
the 1998 March NODA.
EPA agrees with commenters that
additional review by the FACA of the
regulatory implications of a nonlinear
approach is appropriate for policy
reasons, and will initiate these
discussions in the context of the Stage
2 DBPR FACA deliberations. In light of
the November 1998 statutory deadline
to promulgate the Stage 1 DBF rule and
the steps necessary to complete a final
rule, EPA has concluded that there is
not enough time to meet with the SAB
and FACA, provide ample opportunity
for debate, resolve differing points of
views, and complete additional analysis
to meet stakeholders policy concerns in
the context of the Stage 1 DBF rule. EPA
notes, however, that regardless of the
MCLG for chloroform, the MCL for the
THMs remains at 0.08 mg/L. Since the
MCL is the enforceable standard that
water systems will be required to meet,
a nonlinear or low dose linear
extrapolation to derive the MCLG will
not have a direct impact on the
compliance obligations of public water
systems or on the levels of chloroform
allowed in public water systems,
although it may be relevant to
development of enforceable regulatory
limits established under future rules.
2. MCLG for Bromodichloromethane
(BDCM)
a. Today's Rule. The final MCLG for
BDCM is zero. The zero MCLG is based
on the classification of BDCM as a
probable human carcinogen. The MCLG
was determined in a weight-of-evidence
evaluation which considered all
relevant health data including
carcinogenicity and reproductive and
developmental toxicity animal data.
EPA believes the data are insufficient at
this time to determine the mode of
carcinogenic action for BDCM, and
therefore a low dose linear extrapolation
approach is used to estimate lifetime
cancer risk as a default.
b. Background and Analysis. In the
1994 Stage 1 DBPR proposal, the MCLG
of zero for BDCM was based on large
intestine and kidney tumor data from a
National Toxicology Program (NTP)
chronic animal study (NTP, 1987). Since
the proposal, several new studies have
been published on BDCM metabolism
(EPA, 1997c). In addition, several new
genotoxicity studies and short-term
toxicity studies including reproductive
evaluations were found for BDCM (EPA,
1997c). These new studies contribute to
the weight-of-evidence conclusions
reached in the 1994 proposal. Based on
this evidence, the final MCLG for BDCM
is zero based on sufficient evidence of
carcinogenicity in animals.
c. Summary of Comments. Several
commenters disagreed with the use of a
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69402 Federal Register/Vol. 63. No. 24II Wednesday, December 16, 1998/Rules and Regulations
corn oil gavage animal cancer study to
determine the MCLG for BDCM. Some
commenters agreed with the EPA
decision to use large intestine and
kidney tumor data from the corn oil
gavage study, but not liver tumor data
in the quantitative estimation of
carcinogenic risk. One commenter
agreed that a low-dose linear
extrapolation approach to dose-response
assessment was appropriate at this time
and consistent with EPA policy.
However, this commenter suggested that
EPA undertake chronic studies that
include a drinking water study of BDCM
and toxicokinetics. One commenter
disagreed with the EPA conclusion that
the evidence on the mutagenicity of
BDCM is adequate.
In response, EPA agrees with
commenters that a drinking water study
is preferable to a corn oil gavage study
to assess risk from DBPs in drinking
water. However, the NTP corn oil
gavage study is the best data available
on BDCM for a quantitative risk
estimation at this time. BDCM is
currently being tested for toxicokinetics
and cancer in a chronic BDCM drinking
water rodent study by the NTP. When
these data are available, EPA will
reassess the cancer risk of BDCM. EPA
believes that the animal data currently
available on BDCM are consistent with
EPA cancer guidelines on classifying
BDCM as a probable human carcinogen
given the evidence on mutagenicity and
given there was an increased incidence
of tumors at several sites in the animals.
Additionally, tumors were found in
both sexes of two rodent species.
Finally, there have been several new
studies on the genotoxicity of BDCM
that have supported a mutagenic
potential for BDCM (EPA, 1997c)
3. MCLG for Dibromochloromethane
(DBCM)
a. Today's Rule. The final MCLG for
DBCM is 0.06 mg/L. This MCLG is
based on a weight of evidence
evaluation of the cancer and noncancer
data which resulted in the classification
of DBCM as a possible human
carcinogen.
b. Background and Analysis. In the
1994 proposal, the MCLG of 0.06 mg/L
for DBCM was based on observed liver
toxicity from a subchronic study and
possible carcinogenicity {NTP, 1985).
EPA is not aware of any new
information that would change its
evaluation of DBCM since the proposal.
The final MCLG is therefore 0.06 mg/L.
c. Summary of Comments. Several
commenters disagreed with the
additional safety factor of 10 to account
for possible carcinogenicity that was
used in the MCLG calculation. One
commenter agreed with EPA's decision
to base the MCLG on noncarcinogenic
endpoints. Several commenters
disagreed with the use of a corn oil
gavage study to determine the MCLG for
DBCM.
In response, because the evidence of
carcinogenicity was limited on DBCM
(i.e., increased tumor response in only
one of the two species tested), EPA
classified DBCM as a possible human
carcinogen. The additional factor of 10
to account for possible carcinogenicity
follows EPA's science policy for
establishing MCLGs (EPA, 1994a). EPA
used liver effects from the NTP
subchronic corn oil gavage study as the
basis for the Reference Dose (RfD). EPA
agrees with the comment that this is an
appropriate basis for deriving the RfD
for DBCM. EPA agrees with commenters
that a drinking water study is preferable
to a corn oil gavage study to assess risk
from DBPs in drinking water. However,
the NTP corn oil gavage study is the best
data available on DBCM for derivation
of the MCLG at this time. EPA does not
plan to conduct additional chronic
studies for DBCM but is conducting
additional toxicokinetics and short term
drinking water studies on DBCM to
better understand the potential risk
associated with exposure through
drinking water.
4. MCLG for Bromoform
a. Today's Rule. The final MCLG for
bromoform is zero. The zero MCLG is
based on a weight-of-evidence
classification that bromoform is a
probable human carcinogen based on a
consideration of all relevant health data
including cancer and noncancer effects.
EPA believes the data are insufficient at
this time to determine the mode of
carcinogenic action for bromoform, and
therefore a low dose linear extrapolation
approach is used to estimate lifetime
cancer risk as a default.
b. Background and Analysis. The
proposed MCLG for bromoform was
zero. This MCLG was based on an NTP
chronic animal carcinogenicity study
(NTP, 1989). Since the proposal, new
studies on the genotoxicity of
bromoform were found. However, these
new studies do not support changing
the proposed MCLG of zero for
bromoform. The final MCLG for
bromoform is therefore zero.
c. Summary of Comments. Several
commenters agreed with EPA's
classification for bromoform as a
probable carcinogen. Other commenters
disagreed with this classification stating
that there was insufficient evidence
available because tumors were found in
only one species and the increased
number of tumors was small. These
commenters generally felt that EPA
should use an RfD approach in
quantifying the risk for bromoform.
Some commenters encouraged EPA to
conduct more experiments on
bromoform toxicity. Some commenters
were concerned with the use of a corn
oil gavage study to determine
carcinogenic risk.
In response, although the increase in
tumors was small, the increase was
considered significant because large
intestine tumors in both male and
female rats are rare and thus provides
sufficient evidence to classify
bromoform as a probable human
carcinogen. EPA does not plan on
conducting additional chronic testing
for bromoform at this time, but is
conducting toxicokinetic studies and
shorter term drinking water studies to
better understand the potential risk
associated with exposure to bromoform
in drinking water. EPA agrees with
commenters that drinking water studies
are preferable to a corn oil gavage study
to assess risk from DBPs in drinking
water. However, the NTP corn oil
gavage study is the best data available
on bromoform for derivation of the
MCLG.
5. MCLG for Dichloroacetic Acid (DCA)
a. Today's Rule. The final MCLG for
DCA is zero. EPA has developed a
weight-of-evidence characterization for
DCA in which it evaluated all relevant
health data (both cancer and noncancer
effects). The MCLG of zero is based on
sufficient evidence of carcinogenicity in
animals which indicates that DCA is a
probable human carcinogen (likely
under proposed cancer guidelines). EPA
believes the data are insufficient at this
time to determine the mode of
carcinogenic action for DCA and that
the data is insufficient to quantify the
potential cancer risk from DCA.
b. Background and Analysis. EPA
proposed an MCLG of zero for DCA.
This was based on classifying DCA as a
probable human carcinogen in
accordance with the 1986 EPA
Guidelines for Carcinogen Risk
Assessment (EPA, 1986). The DCA
categorization was based primarily on
findings of liver tumors in rats and
mice, which was regarded as
"sufficient" evidence in animals. No
lifetime risk calculation was conducted
at the time of the proposal because there
was insufficient data to quantify the risk
(EPA, 1994a).
As pointed out in the 1997 and 1998
DBP NODAs, several toxicological
studies have been identified for DCA
since the 1994 proposal (EPA, 1997c). In
addition, EPA co-sponsored an ILSI
project in which an expert panel was
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Federal Register/Vol. 63, No-. 241/.Wednesday, December 16, 1998/Rules and Regulations 69403
convened to explore the application of
the EPA's 1996 Proposed Guidelines for
Carcinogen Risk Assessment (EPA,
1996b) to the available data on the
potential carcinogenicity of chloroform
and DCA. The panel considered data on
DCA which included chronic rodent
bioassay data and information on
mutagenicity, tissue toxicity,
toxicokinetics, and other mode of action
information. The panel concluded that
the potential human carcinogenicity of
DCA "cannot be determined" primarily
because of the lack of adequate rodent
bioassay data (ILSI, 1997).
EPA prepared a new hazard
characterization regarding the potential
carcinogenicity of DCA in humans
(EPA, 1998b). One objective of this
report was to develop a weight-of-
evidence characterization using the
principles of the EPA's 1996 Proposed
Guidelines for Carcinogen Risk
Assessment (EPA, 1996b) which are •
consistent with the 1986 Guidelines.
Another objective of the report was to
consider new data since the 1994
proposal and to address the issues
raised by the 1997 ILSI panel report.
EPA agreed with the ILSI panel report
that the mode of action through which
DCA induces liver tumors in both rats
and mice cannot be reasonably
determined at this time. EPA disagrees
with the ILSI panel that the potential
human carcinogenicity cannot be
determined. Based on the
hepatocarcinogenic effects of DCA in
both rats and mice in multiple studies,
as well as other date, for example,
showing that DCA alters cell replication
and gene expression, EPA concludes
that DCA should be considered as a
"likely" (probable) cancer hazard to
humans (EPA, 1998b). Therefore, as in
the 1994 proposed rule, EPA believes
that the MCLG for DCA should remain
zero to assure public health protection.
c. Summary of Comments. Some
commenters agreed with the zero MCLG
for DCA based on positive carcinogenic
findings in two animal species. Several
commenters stated that a zero MCLG
was inappropriate due to evidence
which indicates a nongenotoxic mode of
action for DCA. The comment was
raised that the animal evidence was
insufficient to consider DCA a likely
(probable) human carcinogen, and that
DCA should be considered at most
suggestive of carcinogenicity.
In response, EPA concludes that DCA
should be considered as a probable
(likely under the 1996 proposed
guidelines) cancer hazard to humans
(EPA, 1998b) based on the
hepatocarcinogenic effects of DCA in
both rats and mice in multiple studies,
and mode of action related effects (e.g.,
mutational spectra in oncogenes,
elevated serum glucocorticoid levels,
alterations in cell replication and
death). EPA considers the mode of
action through which DCA induces liver
tumors in both rats and mice to be
unclear, and thus the likelihood of
human hazard associated with low
levels of DCA usually encountered in
the environment or in drinking water is
not sufficiently understood. EPA
acknowledges that a mutagenic
mechanism (i.e., direct DNA reactivity)
may not be an important influence on
the carcinogenic process at low doses.
EPA believes that the lack of
mutagenicity is not a sufficient basis to
depart from a low dose linear default
extrapolation approach for the cancer
assessment. There must be other
convincing evidence to explain how the
tumors are caused by the chemical. The
commenters have not presented such
evidence. Although DCA tumor effects
are associated with high doses used in
the rodent bioassays, there is
uncertainty regarding whether the mode
of tumorgenesis is solely through
mechanisms that are operative only at
high doses. Therefore, as in the 1994
proposed rule, EPA believes that the
MCLG for DCA should remain as zero to
assure public health protection. NTP is
implementing a new two year rodent
bioassay that will include full
histopathology at lower doses than
those previously studied. Additionally,
studies on the mode of carcinogenic
action are being done by various
investigators including the EPA health
research laboratory.
6. MCLG for Trichloroacetic Acid (TCA)
a. Today's Rule. The final MCLG for
TCA is 0.3 mg/L, as was proposed in
1994. This MCLG is based on
developmental toxicity and limited
evidence of carcinogenicity in animals.
fa. Background and Analysis. The
1994 proposed rule included a MCLG of
0.3 mg/L for TCA based on
developmental toxicity and possible
carcinogenicity based on limited
evidence in animal studies (i.e.,
hepatocarcinogenicity in mice). Since
the proposal, a 2-year carcinogenicity
study on TCA (DeAngelo et al., 1997)
found that TCA was not carcinogenic in
male rats. As was discussed in the 1997
DBF NODA (EPA, 1997b), there have
also been several recent studies
examining the mode of carcinogenic
action for TCA. These new studies
suggest that TCA does not operate via
mutagenic mechanisms. For a more in
depth discussion of this new data refer
to the 1997 DBF NODA (EPA, 1997b)
and related support documents (EPA,
1997c). This new information does not
alter the original assessment of the
health effects of TCA based on
developmental toxicity and limited
evidence of carcinogenicity. Therefore,
the MCLG will remain 0.3 mg/L.
c. Summary of Comments. Several
commenters agreed with the
classification of TCA as a possible
human carcinogen. One commenter felt
that toxicity data on TCA indicated a
threshold. Some commenters disagreed
with the study selected for estimating
the RfD (Smith et al. 1989). Some
commenters stated the uncertainty
factors used to establish the RfD were
too high.
In response, EPA acknowledges that a
DNA reactive mutagenic mechanism
may not be involved in TCA's mode of
carcinogenicity. Because an RfD was
used in lieu of a quantitative cancer
assessment for establishing the MCLG,
however, there was no need to evaluate
the mode of carcinogenic action for TCA
at this time. EPA believes that the Smith
et al. (1989) study is appropriate to use
in quantifying risk from TCA since
developmental toxicity was the most
critical effect. EPA believes that an
uncertainty factor of 3,000 is
appropriate to account for inter and
intraspecies differences (100), a lowest
observed adverse effects level (LOAEL)
(10), and lack of a two-generation
reproductive study (3) (EPA, 1994a).
These uncertainty factors are consistent
with current Agency science policy on
using uncertainty factors (EPA, 1994a).
7. MCLG for Chlorite and MRDLG for
Chlorine Dioxide
a. Today's Rule. The final MCLG for
chlorite is 0.8 mg/L and the final
MRDLG for chlorine dioxide is 0.8 mg/
L. The MCLG for chlorite was increased
from the proposed value of 0.08 mg/L to
0.8 mg/L based on a weight-of-evidence
evaluation of all health data on chlorite
including a recent two-generation
reproductive rat study sponsored by the
Chemical Manufactures Association
(CMA, 1996). The MRDLG for chlorine
dioxide was increased from the
proposed value of 0.3 mg/L to 0.8 mg/
L based on a weight-of-evidence
evaluation using all the health data on
chlorine dioxide including the
information on chlorite from the CMA
study. EPA believes that data on chlorite
are relevant to assessing the risks of
chlorine dioxide because chlorine
dioxide is rapidly reduced to chlorite.
Therefore, the findings from the CMA
study and previously described studies
in the 1994 proposal were used to assess
the risk for both chlorite and chlorine
dioxide.
fa. Background and Analysis. The
1994 proposal included an MCLG of
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69404 Federal Register/Vol. 63, No. 24 I.I Wednesday, December 16, 1998/Rules and Regulations
0.08 mg/L for chlorite. The proposed
MCLG was based on an RfD of 3 mg/kg/
d estimated from a lowest-observed-
adverse-effect-level (LOAEL) for
neurodevelopmental effects identified
in a rat study by Mobley et al. (1990).
This determination was based on a
weight of evidence evaluation of all the
available data at that time (EPA, 1994d).
An uncertainty factor of 1000 was used
to account for inter-and intra-species
differences in response to toxicity (a
factor of 100) and to account for use of
a LOAEL (a factor of 10).
The 1994 proposal included an
MRDLG of 0.3 mg/L for chlorine
dioxide. The proposed MRDLG was
based on a RfD of 3 mg/kg/d estimated
from a no-observed-adverse-effect-level
(NOAEL) for developmental
neurotoxicity identified from a rat study
(Orme et al., 1985; EPA, 1994d). This
determination was based on a weight of
evidence evaluation of all available
health data at that time (EPA, 1994a).
An uncertainty factor of 300 was
applied that was composed of a factor
of 100 to account for inter-and intra-
species differences in response to
toxicity and a factor of 3 for lack of a
two-generation reproductive study
necessary to evaluate potential toxicity
associated with lifetime exposure. To
fill this important data gap, the CMA
sponsored a two-generation
reproductive study in rats (CMA, 1996).
As described in more detail in the
1998 NODA (EPA. 1998a), EPA
reviewed the CMA study and completed
an external peer review of the study
(EPA, 1997d). In addition, EPA
reassessed the noncancer health risk for
chlorite and chlorine dioxide
considering the new CMA study (EPA,
1998d). This reassessment was also peer
reviewed (EPA, 1998d). Based on this
reassessment, EPA requested comment
In the 1998 NODA (EPA, 1998a) on
changing the proposed MCLG for
chlorite from 0.08 mg/L to 0.8 mg/L
based on the NOAEL identified from the
new CMA study which reinforced the
concern for neurodevelopmental effects
associated with short-term exposures.
EPA determined that the NOAEL for
chlorite should be 35 ppm (3 mg/kg/d
chlorite Jon, rounded) based on a
weight-of-evidence approach. The data
considered to support the NOAEL are
summarized in EPA (1998d) and
included the CMA study as well as
previous reports on developmental
neurotoxicity and other adverse health
effects (EPA. 1998d). EPA continues to
believe, as stated in the 1998 NODA
(EPA, 1998a), that the RfD for chlorite
should be 0.03 mg/kg/d (NOAEL of 3
mg/kg/d with an uncertainty factor of
100) and that a MCLG of 0.8 mg/L is
appropriate. EPA has concluded that the
RfD for chlorine dioxide should be 0.03
mg/L (NOAEL of 3 mg/kg/d with an
uncertainty factor of 100) and that a
MRDLG of 0.8 mg/L is appropriate.
c. Summary of Comments. EPA
received numerous comments on the
1994 proposal (EPA, 1994a) and 1998
NODA (EPA, 1998a). The major
comment from the 1994 proposal was
that reliance on the Mobley et al. (1990)
study for the MCLG for chlorite and the
Orme et al. (1985) study for chlorine
dioxide were inappropriate and that the
results from the CMA study must be
evaluated before any conclusions on the
MCLG for chlorite or chlorine dioxide
could be drawn. In relation to the 1998
NODA, several commenters supported
changing the MCLG for chlorite and
MRDLG for chlorine dioxide while
others were concerned that the science
did not warrant a change in these
values. The major comments submitted
against raising the MCLG and MRDLG
focused on several issues. First, one
commenter argued that the 1000-fold
uncertainty factor used for chlorite in
the proposal should remain in place
because the CMA study used to reduce
the uncertainty factor was flawed.
Second, several commenters indicated
that the LOAEL should be set at the
lowest dose level (35 ppm) because
certain effects at the lowest dose tested
may have been missed. Finally, some
commenters argued that an additional
safety factor should be included to
protect children and drinking water
consumption relative to the body weight
of children should be used instead of
the default assumption of 2 L per day
and 70 kg adult body weight.
EPA agrees with commenters on the
1994 proposal that the results from the
CMA should be factored into any final
decision on the MCLG for chlorite and
chlorine dioxide. As explained in more
detail in the 1998 DBP NODA (EPA,
1998a), EPA considered the findings
from the CMA study along with other
available data to reach its conclusions
regarding the MCLG and MRDLG for
chlorite and chlorine dioxide.
EPA disagrees with the commenter
who suggested that the 1000-fold
uncertainty factor for chlorite should
remain because the CMA study was
flawed. The study design for the
neurodevelopmental component of the
CMA study was in accordance with
EPA's testing guidelines at the time the
study was initiated. EPA had previously
reviewed the study protocol for the
CMA neurotoxicity component and had
approved the approach. While EPA
initially had some questions regarding
the design of the neurodevelopmental
component of the study (Moser, 1997),
subsequent information submitted by
the CMA provided clarification on
certain aspects of the study design
(CMA, 1998). EPA agrees that even with
the clarifications that there are some
limitations with the
neurodevelopmental component of the
CMA study. EPA believes that the
neuropathology components of the CMA
study were adequate. The functional
operation battery had some
shortcomings in that forelimb and
hindlimb grip strength and foot splay
were not evaluated. EPA believes the
results from the motor activity
component of the CMA study were
difficult to interpret because of the high
variability in controls. However, in its
evaluation of the MCLG for chlorite and
chlorine dioxide, EPA did not rely
solely on the CMA study, but used a
weight-of-evidence approach that
included consideration of several
studies. Thus, the shortcomings of one
study are offset by the weight from other
studies. EPA believes that the CMA
study contributes to the weight-of the-
evidence. The studies by Orme et al.
(1985), Mobley et al. (1990), and CMA
(1996) support a NOAEL of 3 mg/kg/d
based on neurodevelopmental effects
(e.g., decreased exploratory, locomotor
behavior, decreased brain weight).
Furthermore, the CMA study was
reviewed by outside scientists as well as
by EPA scientists. EPA's re-assessment
for chlorite and chlorine dioxide
presented in the 1998 March NODA was
reviewed internally and externally in
accordance with EPA peer-review
policy. The three outside experts who
reviewed the Agency's assessment
agreed with the NOAEL of 3 mg/kg/day
and the derived RfD.
Finally, EPA disagrees that an
additional safety factor should be
applied to provide additional protection
for children or that drinking water
consumption relative to the body weight
of children should be used in
developing the MCLG. The MCLG and
MRDLG presented for chlorite and
chlorine dioxide are considered to be
protective of susceptible groups,
including children, given that the RfD is
based on a NOAEL derived from
developmental testing, which includes a
two-generation reproductive study. A
two-generation reproductive study
evaluates the effects of chemicals on the
entire developmental and reproductive
life of the organism. Additionally,
current methods for developing RfDs are
designed to be protective for sensitive
populations. In the case of chlorite and
chlorine dioxide a factor of 10 was used
to account for variability between the
average human response and the
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Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules, and Regulations 69405
response of more sensitive individuals.
In addition, the important exposure is
that of the pregnant and lactating female
and the nursing pup. The 2 liter per day
water consumption and the 70 kg body
weight assumptions are viewed as
adequately protective of all groups.
Based .on a review of all the data and
public comments, EPA believes that the
MCLG for chlorite should be 0.8 mg/L
and the MRDLG for .chlorine dioxide
should be 0.8 mg/L. EPA believes the
MCLG and MRDLG are consistent with
the discussions during the regulatory
negotiations which recognized the need
for an acceptable two-generation
reproductive study prior to reducing the
uncertainty factors for chlorite and
chlorine dioxide. EPA believes the CMA
provided an acceptable two-generation
study with which to reduce the
uncertainty factors. In addition, EPA
believes potential health concerns in the
proposal with having a ;MCLG for
chlorite significantly below the MCL are
no longer relevant because the MCL for
chlorite in today's rule will remain at
J .0 mg/L while the MCLG has been
revised to 0.8 mg/L. Given the margin of
safety that is factored into the
estimation of the MCLG of 0.8 mg/L,
EPA believes that the MCL of 1.0 mg/
L will be protective of public health of
all groups, including fetuses and
children.
The MCLG for chlorite is based on an
RfD of 0.03 mg/kg/d using a NOAEL of
3 mg/kg/d and an uncertainty factor of
100 to .account for inter- and intra-
species differences. The MCLG for
chlorite is calculated to be 0.8 mg/L by
assuming an adult tap water
consumption of 2 L per day for a 70 kg
adult and using a relative source
contribution of 80% (because most
exposure to chlorite is likely to come
from ingestion of drinking water—
EPA,1998u). A more detailed discussion
of this assessment is included in the
public docket for this rule (EPA, 1998d).
A^r^r ui • 0.03 mg/kg/d x 70kg x 0.8 ....
MCLG for chlorite = §_=: § = Q.84 mg/L
2L/day
MCLG for chlorite = ,0.8 mg/L (Rounded)
For chlorine dioxide the MCLG is
based on a NOAEL of 3 mg/kg/d and
applying an uncertainty factor of 100 to
account for inter-and intra-species
differences in response to toxicity, the
revised MRDLG for chlorine dioxide is
calculated to be 0.8 mg/L. This MRDLG
takes into account an adult tap water
consumption of 2 L per day for a 70 kg
adult and applies a relative source
contribution of 80% (because most
exposure to chlorine dioxide is likely to
come from ingestion of drinking water-
EPA, 1998u). A more detailed
discussion of this assessment is
included in the public docket for this
rule (EPA, 1998d).
iv.fr,™ r* f ui • A- -A 0.03 mg/kg/d x70kgx0.8 no.
MRDLG for chlorine dioxide = 2—- — = 0.84 mg/L
2L/day &
MRDLG for chlorine dioxide = 0.8 mg/L (Rounded)
8. MCLG for Bromate
a. Today's Rule. The final MCLG for
bromate is zero. The zero MCLG is
based on a weight-of-evidence
evaluation of both the cancer and
noncancer effects which indicates there
is sufficient laboratory animal data to
conclude that bromate is a probable
(likely under the 1996 proposed cancer
guidelines) human carcinogen. EPA
believes the data are insufficient at this
time to determine the mode of
carcinogenic action for bromate, and
therefore a low dose linear extrapolation
approach is used to estimate lifetime
cancer risk as a default.
b. Background and Analysis. The
1994 proposed rule included a MCLG of
zero for bromate based on a
determination that bromate was a
probable human carcinogen. This
determination was based on results from
a two species rodent bioassay by
Kurokawa et al. (1986a and 1986b) that
found kidney tumors in rats. Since the
1994 proposed rule, EPA has completed
and analyzed a new chronic cancer
study in male rats and mice for
potassium bromate (DeAngelo et al.,
1998). EPA reassessed the cancer risk
associated with bromate exposure (EPA,
1998e), had this reassessment peer
reviewed (EPA, 1998e), and presented
its findings in the March 1998 NOD A
(EPA, 1998a). The new rodent cancer
study by DeAngelo et al. (1998)
contributes to the weight of the
evidence for the potential human
carcinogenicity of potassium bromate
and confirms the study by Kurokawa et
al. (1986a,b).
c. Summary of Comments. Several
commenters supported the zero MCLG
for bromate. Others believed the MCLG
of zero was not justified because there
is evidence of a carcinogenic threshold.
This evidence indicates that bromate
causes DNA damage indirectly via lipid
peroxidation, which generates oxygen
radicals which in turn induce DNA
damage. Other commenters argued that
even if there is no carcinogenic
threshold, EPA has overstated the
potency of bromate by using the
linearized multistage model and should
instead use the Gaylor-Kodell model.
In response, EPA disagrees with
commenters who believed that the zero
MCLG was inappropriate. At this time,
under the principles of both the 1986
EPA Guidelines for Carcinogen Risk
Assessment (EPA, 1986) and the draft
1996 EPA Proposed Guidelines for
Carcinogen Risk Assessment (EPA,
1996b) weight-of-evidence approach,
bromate is considered to be a probable
or likely human carcinogen. This weight
of evidence conclusion of potential
human carcinogenicity is based on
sufficient experimental findings that
include the following: tumors at
multiple sites in rats; tumor responses
in both sexes; and evidence for
mutagenicity including point mutations
and chromosomal aberrations in in vitro
genotoxicity assays. Furthermore, EPA
believes there is insufficient evidence at
this time to draw conclusions regarding
the mode of carcinogenic action for
bromate. EPA acknowledges there are
studies available showing that bromate
may generate oxygen radicals which
increase lipid peroxidation and damage
DNA. However, no data are available
that link this proposed mechanism to
tumor induction. Thus, EPA believes
that while there are studies which
provide some evidence to support the
commenters' claims, these studies are
insufficient at this time to establish
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69406 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and.Regulations
lipld peroxldation and free radical
production as key events responsible for
the induction of the multiple tumor
responses seen in the bromate rodent
bioassays (EPA, 1998e). Given the
uncertainty about the mode of
carcinogenic action for bromate, EPA
believes it is appropriate to use the
default assumption of low dose linearity
to estimate the cancer risk and establish
the MCLG of zero for bromate. EPA is
conducting additional studies
investigating the mode of action for
bromate.
EPA also disagrees with commenters
who suggested that the Gaylor-Kodell
model should be used for low-dose
extrapolation of the bromate data. In the
1998 NODA. a low dose linear
extrapolation of the DeAngelo et al.
(1998) data was conducted using a one-
stage Weibull time-to-tumor model. The
Weibull model was considered to be the
preferred approach to account for the
reduction in animals at risk that may be
due to the decreased survival observed
in the high dose group toward the end
of the study. The estimate of cancer risk
from the DeAngelo et al. (1998) study is
similar with the risk estimate derived
from the Kurokawa et al. (1986a) study
presented in the 1994 proposed rule.
Based on an evaluation of all the data
and after review and consideration of
the public comments, EPA believes the
MCLG for bromate should be zero.
9. MCLG for Chloral Hydrate
a. Today's Rule. EPA has decided to
not include an MCLG for chloral
hydrate in the Stage 1 DBPR. This
decision is based on an analysis of the
technical comments and on the fact that
chloral hydrate will be controlled by the
MCLs for TTHM and HAAs and by the
treatment technique of enhanced
coagulation.
b. Background and Analysis. The
1994 proposed rule included an MCLG
for chloral hydrate of 0.04 mg/L. This
was based on a 90-day mice study by
Sanders et al. (1982) which reported
liver toxicity. A RfD of 0.0016 mg/kg/d
was used (LOAEL of 16 mg/kg/d with an
uncertainty factor of 10,000). In the
1997 DBP NODA (EPA,1997b) and
supporting documents (EPA, 1997c),
additional studies on chloral hydrate
were discussed, however, these new
studies did not indicate a change in the
MCLG for chloral hydrate.
c. Summary of Comments. The
majority of commenters disagreed with
the MCLG of 0.04 mg/L for chloral
hydrate. Several commenters questioned
the need for an MCLG for chloral
hydrate. These commenters mentioned
its low toxic potential and the fact that
safe concentrations of chloral hydrate
are substantially greater than those
present in drinking water. Commenters
also questioned the need for an MCLG
for chloral hydrate because the MCLs for
THMs and HAAs and the treatment
technique of enhanced coagulation will
adequately control for chloral hydrate
and because there were no monitoring
provisions proposed. Other commenters
argued that the use of a 10,000
uncertainty factor and the selection of
the Sanders et al. (1982) study as a basis
for setting the MCLG were
inappropriate.
In response, EPA agrees with
commenters that an MCLG for chloral
hydrate is not needed. This is based on
the fact that the TTHM and HAA MCLs
and the treatment technique (i.e.,
enhanced coagulation/softening) will
control for chloral hydrate, as well as
other chlorination byproducts. In
addition, chloral hydrate does not serve
as an important indicator for other
chlorination byproducts. The final rule,
therefore, does not contain an MCLG for
chloral hydrate. In light of this decision,
EPA is not responding to comments on
the uncertainty factor used as the basis
for setting the MCLG.
10. MRDLG for Chlorine
a. Today's Rule. EPA is promulgating
an MRDLG of 4 mg/L for chlorine based
on a NOAEL from a chronic study in
animals.
b. Background and Analysis. EPA
proposed an MRDLG of 4 mg/L for
chlorine. The MRDLG was based on a
two-year rodent drinking water study in
which chlorine was given to rats at
doses ranging from 4 to 14 mg/kg/day
and mice at doses ranging from 8 to 24
mg/kg/day (NTP, 1990). Neither
systemic toxicity, nor effects on body
weight and survival were found. Thus,
the MRDLG was based on a NOAEL of
14 mg/kg/day and application of a 100
fold uncertainty factor to account for
inter- and intra-species differences
(EPA, 1994a). New information on
chlorine has become available since the
1994 proposal and was discussed in the
1997 DBP NODA and is included in the
public docket (EPA, 1997c). This new
information did not contain data that
would change the MRDLG. EPA has
therefore decided to finalize the
proposed MRDLG of 4 mg/L for
chlorine.
c. Summary of Comments. Several
commenters agreed with EPA's
conclusion that there is no animal
evidence of carcinogenicity for chlorine.
Some commenters also agreed with EPA
that 4 mg/L was the appropriate MCLG.
Several commenters agreed with the
proposed relative source contribution of
80 percent for chlorine. Some
commenters agreed with the uncertainty
factor of 100 while others felt that it was
too high. Some commenters encouraged
EPA to consider children in estimating
risk from chlorine.
In response, EPA believes that an
uncertainty factor of 100 is appropriate
when a NOAEL from a chronic animal
study is the basis for the RfD. Because
current methods for developing RfDs are
designed to be protective for sensitive
subpopulations, the uncertainty factor
of 100 is considered protective of
children. Furthermore, animal studies
indicate that chlorine is not a
developmental toxicant.
11. MRDLG for Chloramine
a. Today's Rule. EPA is promulgating
an MRDLG of 4 mg/L for chloramines
based on a NOAEL from a chronic
rodent study.
b. Background and Analysis. The
1994 proposed Stage I DBPR included
an MRDLG for chloramines at 4 mg/L
based on a NOAEL of 9.5 mg/kg/d for
lack of toxicity in chronic rodent
drinking water study and on application
of an uncertainty factor of 100 to
account of inter- and intra-species
differences (EPA, 1994h). New
information on chloramines has become
available since the 1994 proposal and
was included in the 1997 DBP NODA
and is included in the public docket
(EPA, 1997c). This new information did
not contain data that would change the
MRDLG. EPA has therefore decided to
finalized the proposed MRDLG of 4 mg/
L for chloramines.
c. Summary of Comments. Several
commenters agreed with the MRDLG of
4 mg/L for chloramine (as chlorine).
Some commenters felt that the MRDLG
was too low due to conservative
uncertainty factors. Many commenters
agreed with EPA's conclusion that there
is no animal evidence of carcinogenicity
for chloramines. Many commenters
agreed with the RSC of 80% for
chloramine while other believed that
the RSC should be higher.
In response, EPA believes that the
uncertainty factor of 100 in the MRDLG
calculation is appropriate to protect
public health including that of children
and sensitive subpopulations. EPA
believes that the 80 percent is an
appropriate ceiling for the RSC due to
lack of exposure data on other sources
of exposure.
B. Epidemiology
1. Cancer Epidemiology
a. Today's Rule. EPA has evaluated all
of the cancer epidemiology data and the
corresponding public comments
received on the 1994 proposal (EPA,
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Federal Register/Vol. 63, No. .241/Wednesday, December .16, 1998/Rules and Regulations 69407
1994a), 1997 NODA (EPA, 1997b), and
1998 NODA (EPA, 1998a). Based on this
evaluation, EPA believes that the cancer
epidemiology data provides important
information that contributes to the
weight-of-evidence evaluation on the
potential health risks from exposure to
chlorinated drinking water. At this time,
however, the cancer epidemiology
studies are insufficient to establish a
causal relationship between exposure to
chlorinated drinking water and cancer;
and are thus considered limited for use
in quantitative risk assessment. EPA's
weight-of-evidence evaluation of the
potential risk posed by chlorinated
drinking water is further discussed in
section IV of this preamble.
b. Background and Analysis. The
preamble to the 1994 proposed rule
discussed numerous cancer
epidemiology studies that had been
conducted over the past 20 years to
examine the relationship between
exposure to chlorinated water and
cancer (EPA, 1994a). At the time of the
regulatory negotiation, there was
disagreement among the members of the
Reg. Neg. Committee on the conclusions
that could be drawn from these studies.
Some members of the Committee felt
that the cancer epidemiology, data, taken
in conjunction with the results from
toxicological studies, provide ample and
sufficient weight-of-evidence to
conclude that exposure to DBFs in
drinking water could result in increased
cancer risk at levels encountered in
some public water supplies. Other
members of the Committee concluded
that the cancer epidemiology studies on
the consumption of chlorinated
drinking water to date were insufficient
to provide definitive information for the
regulation.
In the 1998 DBF NODA (EPA, 1998a),
EPA discussed several new
epidemiology studies that had been
published since the 1994 proposal. EPA
concluded in the 1998 NODA, based on
a review of all the cancer epidemiology
studies (including the more recent
studies), that a causal relationship
between exposure to chlorinated surface
water and cancer has not yet been
demonstrated. However, several studies
have suggested a weak association in
various subgroups. Results from recent
epidemiology studies continue to
support the decision to pursue
regulations to provide additional DBP
control measures as discussed in section
IV.D of this preamble.
c. Summary of Comments. Several
commenters agreed with EPA's
characterization that there was
insufficient evidence to conclude that
there was a causal relationship between
exposure to chlorinated surface water
and cancer. Other commenters
disagreed with this characterization
stating that they believed the evidence
did indicate there was a strong
association between exposure to
chlorinated water and cancer. Other
commenters stated that EPA had not
clearly articulated the basis for its
conclusions on the issue of causality.
In response, EPA continues to believe
that there is insufficient evidence, based
on the epidemiology data, to conclude
there is a causal association between
exposure to chlorinated waters and
cancer. EPA agrees, however, that the
basis for its conclusion on causality was
not clearly articulated. This judgement
of causality was based on evaluating the
existing cancer epidemiologic database
for the following criteria: strength of
association, consistency of the findings,
specificity of the association, as well as
other information concerning the
temporal sequence and presence of a
dose-response relationship, and
biological plausibility (Federal Focus,
1996; EPA, 1986; EPA 1996b).
EPA applied the criteria stated above
to assess the possible causality of cancer
using the best available cancer
epidemiology studies (Cantor et al.,
1985, McGeehin et al., 1993, King and
Marrett, 1996, Cantor etal., 1998,
Freedman et al., 1997, Hildesheim et al.,
1998, Doyle et al., 1997). These studies
found a weak association for bladder
cancer, although the findings were not
consistent within and among the
studies. The specificity of the
association, temporal association, and
dose response relationship remain
unknown. In addition, the biological
mode of action has not been
determined. Using the criteria for
causality, the present epidemiologic
data do not support a causal
relationship between exposure to
chlorinated drinking water and
development of cancer at this time. This
conclusion does not preclude the
possibility that a causal link may be
established at a later date by future
epidemiology and toxicology studies.
Some commenters argued that the
epidemiological evidence indicated an
increased risk for cancer by exposure to
chlorinated drinking water, while others
argued that the epidemiological
evidence does not support a health
effects concern. As stated above, EPA
believes that, at this time, a causal link
between exposure to chlorinated
drinking water and development of
cancer cannot be determined. However,
EPA believes that the epidemiological
evidence suggests a potential increased
risk for bladder cancer. It is therefore
prudent public health policy to protect
against this potential public health
concern in light of the uncertainties and
given the large population (over 200
million people) potentially exposed.
2. Reproductive and Developmental
Epidemiology
a. Today's Rule. EPA has evaluated all
of the reproductive and developmental
epidemiology data and the public
comments received on the 1994
proposal, 1997 NODA, and the 1998
NODA. Based on this evaluation, EPA
believes that the reproductive and
developmental epidemiology data
provides important information that
contributes to the weight-of-evidence
evaluation on the potential risks from
exposure to chlorinated drinking water.
However, the reproductive
epidemiology studies are insufficient to
establish a causal relationship between
exposure to chlorinated drinking water
and reproductive and developmental
effects and are limited for use in the
quantification of risk.
b. Background and Analysis. In the
preamble to the 1994 proposed DBPR,
EPA discussed several reproductive
epidemiology studies (EPA, 1994a). At
the time of the proposal, EPA concluded
that there was no compelling evidence
to indicate a reproductive and
developmental hazard due to exposure
to chlorinated water because the
epidemiologic evidence was inadequate
and the toxicological data were limited.
In 1993, an expert panel of scientists
was convened by the International Life
Sciences Institute to review the
available human studies for
developmental and reproductive
outcomes and to provide research
recommendations (EPA/ILSI, 1993). The
expert panel concluded that the
epidemiologic results should be
considered preliminary given that the
research was at a very early stage (EPA/
ILSI, 1993; Reif etal., 1996). The 1997
NODA and the supporting documents
(EPA, 1997c) presented several new
studies (Savitz et al., 1995; Kanitz et al.
1996; and Bove et al., 1996) that had
been published since the 1994 proposed
rule and the 1993 ILSI panel review.
Based on the new studies presented in
the 1997 NODA, EPA stated that the
results were inconclusive with regard to
the association between exposure to
chlorinated waters and adverse
reproductive and developmental effects
(EPA, 1997b).
In the 1998 DBP NODA (EPA, 1998a),
EPA included the recommendations
from an EPA convened expert panel in
July 1997 to evaluate epidemiologic
studies of adverse reproductive or
developmental outcomes that may be
associated with the consumption of
disinfected drinking water published
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69408 Federal Register/Vol. 63, No. 241/Wednesday, December 16. 1998/Rules and Regulations
since the 1993ILSI panel review. A
report was prepared entitled "EPA
Panel Report and Recommendations for
Conducting Epidemiological Research
on Possible Reproductive and
Developmental Effects of Exposure to
Disinfected Drinking Water" (EPA,
19980. The 1997 expert panel was also
charged to develop an agenda for further
epidemiological research. The 1997
panel concluded that the results of
several studies suggest that an increased
relative risk of certain adverse outcomes
may be associated with the type of water
source, disinfection practice, or THM
levels. The panel emphasized, however.
that most relative risks are moderate or
small and were found in studies with
limitations in design or conduct. The
small magnitude of the relative risk
found may be due to one or more
sources of bias, as well as to residual
confounding (factors not identified and
controlled). Additional research is
needed to assess whether the observed
associations can be confirmed. In
addition, the 1998 DBP NODA included
a summary of a study by Waller et al.
(1998) conducted in California and
another study by Klotz and Pyrch (1998)
conducted in New Jersey. EPA
concluded that while the Waller et al.
(1998) study does not prove that
exposure to THMs in drinking water
causes early term miscarriages, it does
provide important new information that
needs to be explored and that the study
adds to the weight-of-evidence which
suggests that exposure to DBFs may
have an adverse health effect on
humans. EPA indicated that the review
of the Klotz and Pyrch study (1998) had
not been completed in time for the 1998
NODA.
EPA has completed its review of the
Klotz and Pyrch (1998) study and
concluded that the results in the report
provide limited evidence to substantiate
the hypothesis that DBFs in drinking
water cause adverse reproductive or
developmental effects since the bulk of
the findings are inconclusive. There is,
however, a suggestion in the study that
total THMs or some other component of
surface water is associated with a small
increased risk of neural tube defects; no
significant associations, however, were
observed with individual THMs, HAAs
or other composite measures of
exposure.
c. Summary of Comments. Several
commenters agreed with EPA's
conclusions on the significance of the
reproductive and developmental effects
from the various studies. Others
believed EPA had not accurately
characterized the potential adverse
reproductive and developmental effects
from exposure to DBFs in drinking
water.
In response, EPA continues to believe
that the available epidemiology data
along with the toxicological findings
suggest that exposure to DBFs may have
adverse effects on humans. However,
EPA believes the epidemiology evidence
is insufficient at this time to conclude
that there is a causal association
between exposure to DBFs and adverse
reproductive and developmental effects.
As noted in the 1998 NODA, EPA has
an epidemiology and toxicology
research program that is examining the
relationship between exposure to DBFs
and adverse reproductive and
developmental effects. In addition, EPA
is pursuing appropriate follow-up
studies to see if the observed association
in the Waller et al. (1998) study can be
replicated elsewhere. EPA will also be
working with the California Department
of Health Services to improve estimates
of exposure to DBFs in the existing
Waller et al. study population. EPA will
collaborate with the Centers for Disease
Control and Prevention (CDC) in a series
of studies to evaluate if there is an
association between exposure to DBFs
in drinking water and birth defects. EPA
is also involved in a collaborative
testing program with the NTP under
which several individual DBFs have
been selected for reproductive and
developmental laboratory animal
studies. This information will be used
in developing the Stage 2 DBPR.
C. MCLs and BAT for TTHM, HAAS,
Chlorite, and Bromate; MRDLs and BAT
for Chlorine, Chloramines, and Chlorine
Dioxide
MCLs are enforceable standards
which are established as close to the
MCLG as feasible. Feasible means with
the use of the best technology, treatment
techniques, and other means which the
Administrator finds available (taking
costs into consideration) after
examining for efficacy under field
conditions and not solely under '
laboratory conditions.
EPA is promulgating MCLs for two
groups of DBFs and two inorganic
byproducts. EPA is also promulgating
MRDLs for three disinfectants. EPA is
promulgating these MCLs and MRDLs at
the levels proposed in 1994. Systems
will determine compliance with the
MCLs and MRDLs in the same manner
as was proposed in 1994, except for
chlorite. EPA determined that
additional monitoring requirements for
chlorite were necessary based on the
findings from the CMA two-generation
reproductive and developmental study.
Along with introducing the concept of
the MRDLG in the proposed rule, EPA
also introduced the MRDL for the three
disinfectants (chlorine, chloramines,
and chlorine dioxide). The MRDLs are
enforceable standards, analogous to
MCLs, which recognize the benefits of
adding a disinfectant to water on a
continuous basis and to maintain a
residual to control for pathogens in the
distribution system. As with MCLs, EPA
has set the MRDLs as close to the
MRDLGs as feasible. The Agency has
also identified the BAT which is
feasible for meeting the MRDL for each
disinfectant.
EPA received similar comments on
the use of the term MRDL as with
MRDLG. The majority of commenters
agreed with the use of the term MRDL
for the disinfectants and therefore EPA
is using the term MRDL in the final rule.
1. MCLs for TTHMs and HAAS
a. Today's Rule. In today's rule, EPA
is promulgating an MCL for TTHMs of
0.080 mg/L. TTHM is the sum of
measured concentrations of chloroform,
bromodichloromethane,
dibromochloromethane, and
bromoform. EPA is also promulgating an
MCL for HAAS of 0.060 mg/L. HAA5 is
the sum of measured concentrations of
mono-, di-, and trichloroacetic acids,
and mono- and dibromoacetic acids. A
system is in compliance with these
MCLs when the running annual average
of quarterly averages of all samples
taken in the distribution system,
computed quarterly, is less than or
equal to the MCL. If the running annual
average computed for any quarter
exceeds the MCL, the system is out of
compliance. EPA believes that by
meeting MCLs for TTHMs and HAAS,
water suppliers will also control the
formation of other DBFs not currently
regulated that may also adversely affect
human health.
EPA has identified the best available
(BAT) technology for achieving
compliance with the MCLs for both
TTHMs and HAAS as enhanced
coagulation or treatment with granular
activated carbon with a ten minute
empty bed contact time and 180 day
reactivation frequency (GAG 10), with
chlorine as the primary and residual
disinfectant, as was proposed in 1994.
b. Background and Analysis. The
1994 proposal for the Stage 1 DBPR
included MCLs for TTHM and HAAS at
0.080 and 0.060 mg/L, respectively
(EPA, 1994a). In addition to the
proposed MCLs, subpart H systems—
utilities treating either surface water or
groundwater under the direct influence
of surface water—that use conventional
treatment (i.e., coagulation,
sedimentation, and filtration) or
precipitative softening would be
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required to remove DBF precursors by
enhanced coagulation or enhanced
softening. The removal of TOC would be
used as a performance indicator for DBF
precursor control.
As part of the proposed rule, EPA
estimated that 17% of PWSs would
need to change their treatment process
to alternative disinfectants (ozone or
chlorine dioxide) or advanced precursor
removal (GAC or membranes) in order
to comply with the Stage 1
requirements. This evaluation was
important to assist in determining
whether the proposed MCLs were
achievable and at what cost. This
evaluation required an understanding of
the baseline occurrence for the DBFs
and TOC being considered in the Stage
1 DBPR, an understanding of the
baseline treatment in-place, and an
estimation of what treatment
technologies systems would use to
comply with the Stage 1 DBPR
requirements.
In 1997, at the direction of the M-DBP
Advisory Committee, the TWG reviewed
MCL compliance predictions developed
for the 1994 proposal because of
concern by several Committee members
that modifications to the rule would
result in more PWSs not being able to
meet the new TTHM and HAAS MCLs
without installation of higher cost
technologies such as ozone or GAC.
Some members were concerned that
allowing disinfection inactivation credit
prior to precursor removal (by enhanced
coagulation or enhanced softening) in
order to prevent significant reductions
in microbial protection would result in
higher DBF formation and force systems
to install alternative disinfectants or
advanced precursor removal to meet the
1994 proposed TTHM and HAAS MCLs.
As discussed later in today's document
in Section III.E (Preoxidation CT Credit),
most PWSs can achieve significant
reduction in DBF formation through the
combination of enhanced coagulation
(or enhanced softening) while
maintaining predisinfection. The TWG's
analysis indicated that there would be a
decrease in the percentage of PWSs that
would need to install higher cost
technologies. This decrease was
attributed to changes in the proposed
IESWTR which altered the constraints
by which systems could comply with
the MCLs. The requirements of the
IESWTR would also prevent significant
reduction in microbial protection as
described in the 1997 NODA (EPA,
1997a) and elsewhere in today's Federal
Register. EPA has included a discussion
of the prediction of technology choices
in Section IV (Economic Analysis) of
today's rule and a more detailed
discussion in the RIA for this rule (EPA,
1998g). EPA continues to believe the
proposed MCLs are achievable without
large-scale technology shifts.
c. Summary of Comments. Several
commenters questioned whether the
TTHM MCL of 0.080 mg/L and the
HAAS MCL of 0.060 mg/L were set at a
level that would preclude the use of
chlorine as an effective disinfectant.
EPA does not believe the MCLs will
preclude the use of chlorine. While
there are currently systems that are
exceeding these MCLs, the Agency has
concluded that most systems will be
able to achieve compliance by relatively
low cost alternatives such as: improved
DBF precursor removal through
enhanced coagulation or enhanced
softening; moving the point of
disinfection to reduce the reaction
between chlorine and DBF precursors;
the use of chloramines for residual
disinfection instead of chlorine; or a
combination of these alternatives.
Many commenters also questioned the
need for a modified TTHM MCL and a
new MCL for HAAS. As discussed in
section I.B.2. of today's rule, EPA
believes the potential public health risks
do justify a reduction in exposure to
DBFs and hence a modification in the
MCL for TTHMs and a new MCL for
HAAS. Also as discussed in section IV
of this rule, EPA continues to believe
that the potential risks associated with
both TTHM and HAAS and unregulated
DBFs will be reduced by the
combination of these MCLs and DBF
precursor removal through enhanced
coagulation and enhanced softening.
While most commenters agreed with
EPA's definition of GAC 10 and GAC20
(GAC with a 10 and a 20 minute empty
bed contact time, respectively), several
commenters thought that designating
GAC as BAT meant that they would
have to install GAC. at their treatment
plant. EPA is required to designate a
BAT for any MCL that the Agency
promulgates; however, a system may
use any technology it wants to comply
with the MCL. However, a system must
install BAT prior to the State issuing a
variance to one of these MCLs.
Commenters also- questioned the use
of group MCLs for TTHM and HAAS,
instead of MCLs for the individual
DBFs, since a group MCL does not take
into account differing health effects and
potencies of individual DBFs. EPA
continues to believe that regulating
TTHMs and HAAs as group MCLs is
appropriate at this time for several
reasons. First, EPA does not have
adequate occurrence data for individual
trihalomethanes and haloacetic acids to
develop national occurrence estimates
which are needed for estimating the
potential costs and benefits of the rule
(although the Agency has an adequate
database of group occurrence). Second,
there is not an adequate understanding
of how water quality parameters (such
as pH, temperature, bromide, and
alkalinity) affect individual THM and
HAA formation. Third, EPA does not
have an adequate understanding of how
treatment technologies control the
formation of individual THMs and
HAAs to enable specifying appropriate
MCLs for individual TTHMs or HAAs at
this time. Finally, there are inadequate
health data to characterize the potential
health risks for several of the HAAs and
to then determine the potential benefits
from reduction in exposures. In
conclusion, EPA continues to believe
the most appropriate approach for
reducing the health risk from all DBFs
is by the combination of TTHM and
HAAS MCLs and DBF precursor
removal.
Some commenters stated that EPA
may have underestimated HAA
formation, especially in certain areas of
the country. The Agency was aware that
waters in particular regions of the
country would be more difficult to treat
in order to control for HAAS than for
TTHM. Based on additional data
received since the proposal, EPA
continues to believe that the HAAS MCL
can be met by most systems through the
same general low-cost strategies as used
for TTHM (e.g., improved DBF
precursor removal, moving the point of
disinfection, use of chloramines for
residual disinfection) rather than higher
cost alternatives (see section IV.C for
cost estimates of technology treatment
choices).
Many commenters also requested that
States be granted sufficient flexibility in
implementing this rule. While the State
must adopt rules that are at least as
stringent as those published in today's
rule, EPA has given the States and
systems much latitude in monitoring
plans (frequency and location),
allowable disinfectants, and other rule
elements. Much of this flexibility carries
over from the 1979 TTHM Rule (EPA,
1979).
Finally, some commenters stated that
requirements in this rule are
complicated. EPA acknowledges that
this rule is complicated, but that this
complexity is necessary in order to
adequately and economically address
the potential DBF risks. EPA was
required to consider a host of
complicating factors in developing
regulatory requirements: different
disinfectants, different health effects
(acute and chronic), different DBF
formation kinetics, different source
water types and qualities, different
treatment processes, and the need for
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69410 Federal Register/Vol. 63, No. 241/Wednesday, December 16,- 1998/Rules and Regulations
simultaneous compliance with other
rules such as the Total Coliform Rule,
Lead and Copper Rule, and Interim
Enhanced Surface Water Treatment
Rule. The Agency chose to evaluate all
these factors by developing
requirements that minimized impacts
on various classes of systems while
enabling States to implement the rule.
In addition to the further description of
the requirements in today's rule, EPA
will publish a State implementation
manual, a small system compliance
manual, and a series of guidance
manuals that will provide additional
information to systems and States in
implementing this rule.
EPA has reviewed all comments and
determined that the requirements
promulgated today are necessary to
control the occurrence of TTHM and
HAAS and are feasible to achieve. These
requirements take into account the
difficulties in simultaneously
controlling risks from DBFs and
pathogens, while appropriately
addressing implementation and
compliance issues.
2. MCL for Bromate
a. Today's Rule. In today's rule. EPA
is promulgating an MCL for bromate of
0.010 mg/L. Bromate is one of the
principal byproducts of ozonation in
bromide-containing source waters. The
proposed MCL for bromate was 0.010
mg/1. A system is in compliance with
the MCL when the running annual
average of monthly samples, computed
quarterly, is less than or equal to the
MCL. If the running annual average
computed for any quarter exceeds the
MCL, the system is out of compliance.
EPA has identified the BAT for
achieving compliance with the MCL for
bromate as control of ozone treatment
process to reduce formation of bromate,
as was proposed in 1994 (EPA, 1994a).
b. Background and Analysis. For
systems using ozone, a separate MCL
was proposed for the primary inorganic
DBP associated with ozone usage:
bromate. Although the theoretical 10~4
risk level for bromate is 0.005 mg/1, an
MCL of 0.010 mg/L was proposed
because available analytical detection
methods for bromate were reliable only
to the projected practical quantification
limit (PQL) of 0.01 mg/L (EPA. 1994a).
In the preamble to the proposed rule,
EPA requested comment on whether
there were ways to set (or achieve) a
lower MCL (i.e.. 0.005 mg/L [5 |ig/L])
and whether the PQL for bromate could
be lowered to 5 jig/L in order to allow
compliance determinations for a lower
MCL in Stage 1 of the proposed rule.
The proposed MCL of 0.010 mg/L for
bromate was based on a projected PQL
that would be achieved by improved
methods. The PQL of the revised
method is approximately 0.010 mg/L for
bromate, as discussed in Section III.G
(Analytical Methods). At the time of the
November 1997 NODA, EPA was not
aware of any new information that
would lower the PQL for bromate and
thus allow lowering the MCL. As a
result, EPA concluded that the proposed
bromate MCL was appropriate.
c. Summary of Comments. Several
commenters were concerned that the
bromate MCL may have been set at a
level that would preclude the use of
ozone. During the M-DBP Advisory
Committee discussions, the TWG
evaluated the feasibility of ozone for
certain systems that were predicted to
have problems in complying with the
TTHM and HAAS MCLs. While ozone
was not feasible for all systems, it was
feasible for many that did not have
elevated source water bromide levels to
react with ozone to form bromate. The
TWG predicted that most of the systems
not able to use ozone would be able to
switch to chlorine dioxide for primary
disinfection.
EPA has reviewed all comments and
determined that the requirements
promulgated today are necessary to
control the occurrence of bromate and
are feasible to achieve. For additional
discussion on the treatment
technologies for controlling bromate
formation and their costs see the Cost
and Technology Document for
Controlling Disinfectants and
Disinfection Byproducts (EPA, 1998k).
These requirements take into account
the difficulties in simultaneously
controlling risks from DBFs and
pathogens, while appropriately
addressing compliance and
implementation issues. In addition, the
Reg. Neg. Committee and the M-DBP
Advisory Committee supported these
conclusions.
3. MCL for Chlorite
a. Today's Rule. In today's rule, EPA
is promulgating an MCL for chlorite of
1.0 mg/L. EPA has modified the
monitoring requirements from the
proposed rule for the reasons discussed
in section III.A.7. The issue of
monitoring and MCL compliance
determinations as they relate to the
health effect of concern for chlorite were
discussed in the proposed rule (EPA,
1994a). CWSs and NTNCWSs using
chlorine dioxide for disinfection or
oxidation are required to conduct
sampling for chlorite both daily at the
entrance to the distribution system and
monthly (3 samples on the same day)
within the distribution system.
Additional distribution system
monitoring is required when the
chlorite concentration measured at the
entrance to the distribution system
exceeds a chlorite concentration of 1.0
mg/L. Distribution system monitoring
may be reduced if certain conditions are
met (described in section III.H of this
rule).
b. Background and Analysis. For
systems using chlorine dioxide, EPA
proposed a separate MCL for chlorite
associated with its usage in 1994. The
proposed chlorite MCL of 1.0 mg/L was
supported by the Reg. Neg. Committee
because 1.0 mg/L was the lowest level
considered practicably achievable by
typical systems using chlorine dioxide,
from both treatment and monitoring
perspectives. The MCLG was 0.08 mg/
L, due (in part) to data gaps that
required higher uncertainty factors in
the MCLG determination. The CMA
agreed to fund new health effects
research on chlorine dioxide and
chlorite—with EPA approval of the
experimental design—to resolve these
data gaps. EPA completed its review of
the study and published its findings in
a NODA in March 1998. Those findings
led to a chlorite MCLG of 0.8 mg/L and
support for an MCL of 1.0 mg/L.
c. Summary of Comments. Many
commenters requested that EPA not
modify the MCL for chlorite prior to
receipt and evaluation of the CMA
study, since lowering the MCL could
preclude the use of chlorine dioxide for
drinking water disinfection. EPA has
evaluated the CMA study and
concluded that the MCLG for chlorite
should be 0.8 mg/L. EPA believes the
proposed MCL of 1.0 mg/L, based on a
three sample average to determine
compliance, is appropriate because this
is the lowest level achievable by typical
systems using chlorine dioxide. In
addition, considering the margin of
safety that is factored into the estimate
of the MCLG, EPA believes the MCL
will be protective of public health. Once
the final MCLG was established, EPA
decided that the chlorite MCL should be
finalized at the level proposed which
was as close as economically and
technically feasible to the MCLG, and
modified the proposed requirements for
monitoirng and compliance in response
to the health concerns associated with
chlorite.
EPA has reviewed all comments and
determined that the requirements
promulgated today are necessary to
control the occurrence of chlorite and
are feasible to achieve. These
requirements take into account the
difficulties in simultaneously
controlling risks from DBFs and
pathogens, while appropriately
addressing compliance and
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implementation issues. In addition, the
Reg. Neg. Committee and the M-DBP
Advisory Committee supported these
conclusions.
4. MRDL for Chlorine
a. Today's Rule. Chlorine is a widely
used and highly effective water
disinfectant. In today's rule, EPA is
promulgating an MRDL for chlorine of
4.0 mg/L. As a minimum, CWSs and
NTNCWSs must measure the residual
disinfectant level at the same points in
the distribution system and at the same
time as total coliforms, as specified in
§ 141.21. Subpart H systems may use the
results of residual disinfectant
concentration sampling done under the
SWTR (§ 141.74(b)(6) for unfiltered
systems, § 141.74(c)(3) for systems that
filter) in lieu of taking separate samples.
Monitoring for chlorine may not be
reduced.
A system is in compliance with the
MRDL when the running annual average
of monthly averages of all samples,
computed quarterly, is less than or
equal to the MRDL. Notwithstanding the
MRDL, operators may increase residual
chlorine levels in the distribution
system to a level and for a time
necessary to protect public health to
address specific microbiological
contamination problems (e.g., including
distribution line breaks, storm runoff
events, source water contamination, or
cross-connections).
EPA has identified the best means
available for achieving compliance with
the MRDL for chlorine as control of
treatment processes to reduce
disinfectant demand, and control of
disinfection treatment processes to
reduce disinfectant levels.
b. Background and Analysis. The
1994 proposed Stage I DBPR included
an MRDL for chlorine at 4.0 mg/L (EPA,
1994a). The MRDL for chlorine is equal
to the MRDLG for chlorine. EPA
requested comment on a number of
issues relating to the calculation of the
MRDLG for chlorine. New information
on chlorine has become available since
the 1994 proposal and was discussed in
the 1997 NODA (EPA, 1997b). EPA
believes that no new information has
become available to warrant changing
the proposed MRDL. EPA has therefore
decided to promulgate the MRDL of 4.0
mg/L for chlorine.
c. Summary of Comments. Some
commenters expressed concern that the
MRDL for chlorine is too high. These
commenters were concerned that 4 mg/
L levels of chlorine would have a
detrimental effect on piping materials
and would cause taste and odor
problems. One commenter supported
the chlorine MRDL and the methods of
calculating compliance with the MRDL.
This commenter felt that 4.0 mg/L
appropriately allows for disinfection
under varying circumstances. One
commenter requested that EPA increase
the flexibility of utilities to meet the
MRDL for chlorine during periods when
chlorine levels in the distribution
systems may need to be raised to protect
public health.
EPA believes that the MRDL of 4.0
mg/L for chlorine is appropriate to
control for potential health effects
(MRDLG is 4.0 mg/L) from chlorine
while high enough to allow for control
of pathogens under a variety of
conditions. EPA also believes that
compliance based on a running annual
average of monthly averages of all
samples, computed quarterly is
sufficient to allow systems to increase
residual chlorine levels in the
distribution system to a level and for a
time necessary to protect public health
to address specific microbiological
contamination problems and still
maintain compliance. If a system has
taste and odor problems associated with
excess chlorine levels it can lower its
level of chlorine. Since there may not be
any health effects associated with taste
and odor problems, EPA does not have
a statutory requirement to address this
concern.
5. MRDL for Chloramines
a. Today's Rule. Chloramines are
formed when ammonia is added during
chlorination. In today's rule, EPA is
promulgating an MRDL for Chloramines
of 4.0 mg/L (measured as combined total
chlorine). As a minimum, CWSs and
NTNCWSs must measure the residual
disinfectant level at the same points in
the distribution system and at the same
time as total coliforms, as specified in
§ 141.21. Subpart H systems may use the
results of residual disinfectant
concentration sampling done under the
SWTR (§ 141.74(b)(6) for unfiltered
systems, § 141.74(c)(3) for systems that
filter) in lieu of taking separate samples.
Monitoring for Chloramines may not be
reduced.
A PWS is in compliance with the
MRDL when the running annual average
of monthly averages of all samples,
computed quarterly, is less than or
equal to the MRDL. Notwithstanding the
MRDL, operators may increase residual
chloramine levels in the distribution
system to a level and for a time
necessary to protect public health to
address specific microbiological
contamination problems (e.g., including
distribution line breaks, storm runoff
events, source water contamination, or
cross-connections).
EPA has identified the best means
available for achieving compliance with
the MRDL for chloramines as control of
treatment processes to reduce
disinfectant demand, and control of
disinfection treatment processes to
reduce disinfectant levels.
b. Background and Analysis. The
1994 proposed Stage 1 DBPR included
an MRDL for chloramines at 4.0 mg/L
(EPA, 1994a). The MRDL for
chloramines is equal to the MRDLG for
chloramines. EPA requested comment
on a number of issues relating to the
calculation of the MRDLG for
chloramines. New information on
chloramines has become available since
the 1994 proposal and was cited in the
1997 NODA and is included in the
public docket for this rule (EPA, 1997b).
This new information did not contain
data that would warrant changing the
MRDL. EPA has therefore decided to
promulgate the proposed MRDL of 4.0
mg/L for chloramines.
c. Summary of Comments. Some
commenters remarked that systems with
high concentrations of ammonia would
have difficulty meeting the MRDL for
chloramine of 4.0 mg/L and still
maintain adequate microbial protection.
One commenter felt that there should
not be a limit for chloramine residual
due to variations in parameters such as
distribution system configurations and
temperature. One commenter felt that
the MRDL for chloramines was too low
and should not be set at the same level
as the chlorine MRDL since chlorine is
a stronger disinfectant than
chloramines. This commenter felt that
limiting the chloramine residual would
reduce the capability to sustain high
water quality in the distribution system.
One commenter supported the
chloramine MRDL,and the methods of
calculating compliance with the MRDL.
This commenter felt that 4.0 mg/L
adequately allows for disinfection under
varying circumstances.
EPA believes that compliance based
on a running annual average of monthly
averages of all samples, computed
quarterly, is sufficient to allow systems
to increase residual chloramine levels in
the distribution system to a level and for
a time necessary to protect public health
to address specific microbiological
contamination problems and still
maintain compliance. The MRDL for
chloramine does not limit disinfectant
dosage but rather disinfectant residual
in the distribution system. EPA
therefore, believes that systems with
high levels of ammonia should be able
to comply with the MRDL. Systems that
have difficulty sustaining high water
quality in the distribution system
should consider modifying their
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69412 Federal Register/Vol. 63, No. 24IIWednesday, December 16, 1998ARules and Regulations
treatment or maintenance procedures to
reduce demand. Although chlorine is a
stronger disinfectant than chloramine,
EPA believes that an MRDL of 4.0 mg/
L is sufficient to provide adequate
microbial protection.
6. MRDL for Chlorine Dioxide
a. Today's Rule. Chlorine dioxide is
used primarily for the oxidation of taste
and odor-causing organic compounds in
water. It can also be used for the
oxidation of reduced iron and
manganese and color, and as a
disinfectant and algicide. Chlorine
dioxide reacts with impurities in water
very rapidly, and is dissipated quickly.
In today's rule, EPA is promulgating an
MRDL of 0.8 mg/L for chlorine dioxide.
Unlike chlorine and chloramines, the
MRDL for chlorine dioxide may not be
exceeded for short periods of time to
address specific microbiological
contamination problems because of
potential health concerns with short-
term exposure to chlorine dioxide above
the MCL.
CWSs and noncommunity systems
must monitor for chlorine dioxide only
if chlorine dioxide is used by the system
for disinfection or oxidation. Monitoring
for chlorine dioxide may not be
reduced. If monitoring is required.
systems must take daily samples at the
entrance to the distribution system. If
any daily sample taken at the entrance
to the distribution system exceeds the
MRDL, the system is required to take
three additional samples in the
distribution system on the next day.
Systems using chlorine as a residual
disinfectant and operating booster
chlorination stations after the first
customer must take three samples in the
distribution system: one as close as
possible to the first customer, one in a
location representative of average
residence time, and one as close as
possible to the end of the distribution
system (reflecting maximum residence
time in the distribution system).
Systems using chlorine dioxide or
chloramines as a residual disinfectant or
chlorine as a residual disinfectant and
not operating booster chlorination
stations after the first customer must
take three samples in the distribution
system as close as possible to the first
customer at intervals of not less than six
hours.
If any daily sample taken at the
entrance to the distribution system
exceeds the MRDL and if, on the
following day, any sample taken in the
distribution system also exceeds the
MRDL, the system will be in acute
violation of the MRDL and must take
immediate corrective action to lower the
occurrence of chlorine dioxide below
the MRDL and issue the required acute
public notification. Failure to monitor
in the distribution system on the day
following an exceedance of the chlorine
dioxide MRDL shall also be considered
an acute MRDL violation.
If any two consecutive daily samples
taken at the entrance to the distribution
system exceed the MRDL, but none of
the samples taken in the distribution
system exceed the MRDL, the system
will be in nonacute violation of the
MRDL and must take immediate
corrective action to lower the
occurrence of chlorine dioxide below
the MRDL. Failure to monitor at the
entrance to the distribution system on
the day following an exceedance of the
chlorine dioxide MRDL shall also be
considered a nonacute MRDL violation.
EPA has identified the best means
available for achieving compliance with
the MRDL for chlorine dioxide as
control of treatment processes to reduce
disinfectant demand, and control of
disinfection treatment processes to
reduce disinfectant levels.
b. Background and Analysis. EPA
proposed an MRDL for chlorine dioxide
of 0.8 mg/L in 1994. The MRDL was
determined considering the tradeoffs
between chemical toxicity and the
beneficial use of chlorine dioxide as a
disinfectant. The Reg. Neg. Committee
agreed to this MRDL with the
reservation that it would be revisited, if
necessary, after completion of a two-
generation reproductive study by CMA.
As discussed above for chlorite, a
two-generation reproductive study on
chlorite, which is relevant to health
effects of chlorine dioxide, was
completed by the CMA. EPA completed
its review of this study and published
its findings in a NOD A in March 1998
(EPA, 1998a). Based on its assessment of
the CMA study and a reassessment of
the noncancer health risk for chlorite
and chlorine dioxide, EPA concluded
that the MRDLG for chlorine dioxide be
changed from 0.3 mg/L to 0.8 mg/L.
Since this new MRDLG was equal to the
proposed MRDL for chlorine dioxide,
the MRDL will remain 0.8 mg/L.
c. Summary of Comments. A number
of commenters were concerned that the
MRDL for chlorine dioxide not be
lowered below the proposed level of 0.8
mg/L because this would preclude the
use of chlorine dioxide as a water
disinfectant. One commenter supported
the MRDL for chlorine dioxide based on
public health protection, adequate
microbial protection, and technical
feasibility. One commenter agreed that a
running annual average of samples for
compliance determination should not be
allowed for chlorine dioxide. One
commenter was concerned that the
chlorine dioxide MRDL was too high
and that EPA should consider children
and vulnerable populations in
establishing drinking water standards.
EPA has reassessed the health effects
data on chlorine dioxide, including the
new CMA two-generation study and
determined that the MRDL should
remain at 0.8 mg/L as proposed. EPA
believes that this MRDL is set at a
technically feasible level for the
majority of chlorine dioxide plants. This
is the case because EPA considered
children and susceptible populations in
its MRDLG determination (EPA, 1998h).
The MRDL is set as close to this MRDLG
as is technically and economically
feasible.
D. Treatment Technique Requirement
1. Today's Rule
Today's rule establishes treatment
technique requirements for removal of
TOC to reduce the formation of DBFs by
means of enhanced coagulation or
enhanced softening. The treatment
technique applies to Subpart H systems
using conventional filtration treatment
regardless of size. Subpart H systems are
systems with conventional treatment
trains that use surface water or ground
water under the influence of surface
water as their source. The treatment
technique requirement has two steps of
application. Step 1 specifies the
percentage of influent TOC a plant must
remove based on the raw water TOC and
alkalinity levels. The matrix in Table
III-l specifies the removal percentages.
TABLE 111-1.—REQUIRED REMOVAL OF TOTAL ORGANIC CARBON BY ENHANCED COAGULATION AND ENHANCED
SOFTENING FOR SUBPART H SYSTEMS USING CONVENTIONAL TREATMENT »-b
Source water alkalinity (mg/L as CaCOs)
>2.0-4.0
Source water TOC (mg/L)
0-60 (percent)
35.0
>60-1 20 (per-
cent)
25.0
>1 20° (per-
cent)
15.0
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Federal Register/Vol. 63. No. 241 / Wednesday, December 16, 19.98/Rules .and Regulations 69413
TABLE Ml-1.—REQUIRED REMOVAL OF TOTAL ORGANIC CARBON BY ENHANCED COAGULATION AND ENHANCED
SOFTENING FOR SUBPART H SYSTEMS USING CONVENTIONAL TREATMENT a-b—Continued
Source water TOC (mg/L)
>4.0-8.0
>8.0 .
Source water alkalinity (mg/L as CaCO3)
0-60 (percent)
45.0
50.0
>60-120 (per-
cent)
35.0
40.0
>120<: (per-
cent)
25.0
30.0
"Systems meeting at least one of the conditions in Section 141.135(a)(2) (i)-(vi) of the rule are not required to meet the removals in this table.
"Softening systems meeting one of the two alternative compliance criteria in Section 141.135(a)(3) of the rule are not required to meet the re-
movals in this table. .. , •
"Systems practicing softening must meet the TOC removal requirements in the last column to the right.
Step 2 provides alternate performance
criteria when it is technically infeasible
for systems to meet the Step 1 TOC
removal requirements. For systems
practicing enhanced coagulation, Step 2
of the treatment technique requirement
is used to set an alternative TOC
removal requirement (i.e. alternative
percent removal of raw water TOC) for
those systems unable to meet the TOC
removal percentages specified in the
matrix. The alternative TOC removal
percentage is determined by performing
jar tests on at least a quarterly basis for
one year. During the jar tests, alum or
an equivalent dose of ferric coagulant is
added in 10 mg/L increments until the
pH is lowered to the target pH value.
The target pH is the value the sample
must be at or below before the
incremental addition of coagulant can
be discontinued. For the alkalinity
ranges 0-60, >60-120, >120-240, and
>240 mg/L (as CaCO3), the target pH
values are 5.5, 6.3, 7.0, and 7.5,
respectively. Once the Step 2 jar test is
complete, the TOC removal (mg/L) is
then plotted versus coagulant dose (mg/
L). The alternative TOC removal
percentage is set at the point of
diminishing returns (POOR) identified
on the plot.
Today's rule defines the PODR as the
point on the TOC versus coagulant dose
plot where the slope changes from
greater than 0.3/10 to less than 0.3/10
and remains less than 0.3/10. After
identifying the PODR, the alternative
TOC removal percentage can be set. If
the TOC removal versus coagulant dose
plot does not meet the PODR definition,
the water is considered not amenable to
enhanced coagulation and TOC removal
is not required if the PWS requests, and
is granted, a waiver from the enhanced
coagulation requirements by the State.
Systems are required to meet the
alternative TOC removal requirements
during full-scale operation to maintain
compliance with the treatment
technique. For the technical reasons
outlined in the 1997 DBF NOD A (EPA
1997b), EPA has concluded that this
definition of the PODR is a reliable
indicator of the amount of TOC that is
feasible to remove.
Systems practicing enhanced
softening are not required to perform jar
testing under today's treatment
technique as part of a Step 2 procedure.
Rather, they are required to meet one of
three alternative performance criteria if
they cannot meet the Step 1 TOC
removal requirements. These criteria
are: (1) Produce a finished water with a
SUVA of less than or equal to 2.0 L/mg-
m; (2) remove a minimum of 10 mg/L
magnesium hardness (as CaC03); or (3)
lower alkalinity to less then 60 mg/L (as
CaCO3). All three of these alternative
performance criteria are measured
monthly and can be calculated quarterly
as a running annual average to
demonstrate compliance. As discussed
in the 1997 DBF NODA (EPA 1997b)
EPA has not been able, from a technical
and engineering standpoint, to identify
a Step 2 testing procedure at this time
that allows softening systems to set an
alternative TOC removal amount.
Enhanced softening systems unable to
meet the Step 1 TOC removal
requirements or any of the three
alternative performance criteria may
apply to the State for a waiver from the
treatment technique requirements. EPA
believes the three alternative
performance criteria listed above
provide assurance that softening
systems have maximized TOC removal
to the extent feasible.
Today's rule also provides alternative
compliance criteria—which are separate
and independent of the Step 2 enhanced
coagulation procedure and the
enhanced softening alternative
performance criteria—from the
treatment technique requirements
provided certain conditions are met.
These criteria are:
(1) the system's source water TOC is
<2.0 mg/L;
(2) the system's treated water TOC is
<2.0 mg/L;
(3) the system's source water TOC
<4.0 mg/L, its source water alkalinity is
>60 mg/L (as CaCO3), and the system is
achieving TTHM <40jig/L and HAAS
<30(ig/L (or the system has made a clear
and irrevocable financial commitment
to technologies that will meet the TTHM
and HAA level);
(4) the system's TTHM is <40ng/L,
HAA5 is <30u,g/L, and only chlorine is
used for primary disinfection and
maintenance of a distribution system
residual;
(5) the system's source water SUVA
prior to any treatment is < 2.0 L/fng-m;
and
:{6) the system's treated water SUVA is
< 2.0 L/mg-m.
Alternative compliance criteria 1, 2, 5,
and 6 are determined based on monthly
monitoring Calculated quarterly as a
funning annual average of all
measurements. Alternative compliance
criteria 3 is based on monthly
monitoring for TOC and alkalinity or
quarterly monitoring for TTHMs and
HAA5, calculated quarterly as a running
annual average of all measurements.
Alternative criteria 4 is determined
based on monitoring for TTHMs and
HAAS, calculated quarterly as a running
annual average of all measurements.
SUVA, an indicator of DBF precursor
removal treatability, is defined as the
UV-254 (measured in m-') divided by
the DOC concentration (measured as
mg/L).
2. Background and Analysis
The general structure of the 1994
proposed rule and today's final rule are
similar. The 1994 proposal included an
enhanced coagulation and enhanced
softening treatment technique
requirement for Subpart H systems. The
1994 proposed rule included a TOC
removal matrix for Step 1 TOC removal
requirements and it also provided for a
Step 2 jar test procedure for systems
practicing enhanced coagulation. The
PODR for the Step 2 procedure was
defined as a slope of .3/10 on the TOC
removal versus coagulant dose plot. The
Step 2 procedure included a maximum
pH value, now referred to as the "target
pH" for conducting the jar tests and it
also allowed systems to request a waiver
from the State if the PODR was never
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69414 Federal Register/Vol. 63, No. 241/.Wednesday,;December 16. 1998/Rules and Regulations
attained. The target pH values in the
1994 proposal were the same as those in
today's final rule. A Step 2 procedure
for enhanced softening systems was not
specified in the proposal.
The proposed rule also provided for a
number of exceptions to the enhanced
coagulation and enhanced softening
requirements, but it did not include use
of SUVA as an alternative compliance
criteria.
A major goal of the TOC removal
treatment technique requirements was
to minimize transactional costs to the
States both in terms of limiting the
number of systems seeking alternative
performance criteria and in providing
relatively simple methodologies for
determining alternative performance
criteria. In the 1997 DBF NODA (EPA
1997b), EPA presented new data and
analysis and the basis for modifying the
proposed criteria to those described in
today's final rule. The 1997 NODA also
solicited public comment on EPA's
intended changes to the proposal and
the recommendations of the M-DBP
Advisory Committee to EPA. An
overview of the key points in the 1997
NODA most pertinent to modifying the
treatment technique requirements are
presented below.
Data Supporting Changes in the TOC
Removal Requirements. The proposed
TOC removal percentages, which were
set with the intent that 90% of affected
systems would be able to achieve them,
were developed with limited data. Since
the proposal, several jar studies and
analyses of full-scale plant TOC removal
performance have been performed. They
were analyzed by EPA as part of the M-
DBP Advisory Committee process. This
data will not be thoroughly reviewed
here; instead, the major points salient to
development of the final regulation will
be summarized. See the 1997 DBF
NODA (EPA 1997b) to review EPA's
detailed analysis of the new data.
As discussed in greater detail in the
1997 DBP NODA, research by Singer et
al. (1995) indicated that a significant
number of waters, especially low-TOC,
high-alkalinity waters in the first row of
the proposed TOC removal matrix,
would probably not be able to meet the
TOC removal percentages and would
therefore need to use the Step 2 protocol
to establish alternative performance
criteria. The Singer et al. (1995)'study
raised concern regarding the number of
systems that might need to use the Step
2 procedure to set alternative
performance criteria. A study by
Malcolm Pirnie. Inc. and Colorado
University addressed this issue by
developing a nationally representative
database of 127 source waters and used
this data to develop a model to predict
enhanced coagulation's ability to
remove TOC from different source
waters (Edwards, 1997; Tseng &
Edwards, 1997; Chowdhury, 1997). The
model was subsequently used to analyze
the level or percentage of TOC removal
that is operationally feasible to achieve
for the boxes in the proposed TOC
removal matrix. Nine predictive
equations for TOC removal were
developed, one for each box of the TOC
removal matrix, to select TOC removal
percentages that could be "reasonably"
met by 90 percent of the systems
implementing enhanced coagulation.
The equations indicated that many
systems having source waters within the
low TOC boxes of the matrix (i.e. 2.0-
4.0 mg/L, the first row of the matrix)
would meet the Step 2 slope criterion
before meeting the required TOC
removal percentages. In other words,
less than 90 percent of the systems in
this row could achieve the proposed
TOC removal with reasonable coagulant
doses. The equations indicated that the
TOC removal percentages in the
medium and high TOC boxes (the
bottom two rows of the matrix) could be
met by approximately 90 percent of the
systems in these boxes. The research
team also examined 90th-percentile
SUVA curves, in conjunction with the
nine TOC removal curves, to predict
what TOC removal percentage is
appropriate for each of the nine boxes
of the matrix.
An analysis of full-scale TOC removal
has also been performed since 1994.
Data was obtained from 76 treatment
plants of the American Water Works
Service Company (AWWSCo) system,
plants studied by Randtke et al. (1994),
and plants studied by Singer et al.
(1995). These data represent a one-time
sampling at each plant under current
operating conditions when enhanced
coagulation was not being practiced.
This sampling is different from the
proposed compliance requirements
which would be based on an annual
average of monthly samples. Based on
current treatment at the plants in the
study, 83 percent of the systems treating
moderate-TOC, low-alkalinity water
removed an amount of TOC greater than
that required by the TOC removal
matrix, whereas only 14 percent of the
systems treating water with low TOC
and high alkalinity met the proposed
TOC removal requirements. The results
of the survey, coupled with the
information discussed in the preceding
paragraph, indicate that the proposed
TOC removal percentages in the top row
of the matrix might be too high for 90
percent of plants to avoid the Step 2
procedure, while the removal
percentages in the bottom two rows may
be reasonable and allow 90 percent of
plants to avoid the Step 2 procedure.
Therefore, the TOC removal percentages
in the first row have been lowered 5.0
percentage points to enable 90 percent
of plants to comply without
unreasonable coagulant dosage or
resorting to the Step 2 procedure.
Data Supporting the Use of SUVA as
an Exemption from Treatment
Technique Requirements. At the time of
the proposal, insufficient data on SUVA
was available to define precise criteria
for when enhanced coagulation would
not be effective for removing DBP
precursors. The M-DBP Advisory
Committee examined the role of SUVA
as an indicator of the amount of DBP
precursor material enhanced
coagulation is capable of removing. It
has been well established that
coagulation primarily removes the
humic fraction of the natural organic
matter (NOM) in water (Owen et al.,
1993). Furthermore, Edzwald and Van
Benschoten (1990) have found SUVA to
be a good indicator of a water's humic
content. The humic fraction of a water's
organic content significantly affects DBP
formation upon chlorination.
A study by White et al. (1997) showed
that waters with high initial SUVA
values exhibited significant reductions
in SUVA as a result of coagulation,
demonstrating a substantial removal of
the humic (and other UV-absorbing)
components of the organic matter,
whereas waters with low initial SUVA
values exhibited relatively low
reductions in SUVA. For all of the
waters examined, the SUVA tended to
plateau at high alum doses, reflecting
that the residual organic matter was
primarily non-humic and therefore
unamenable to removal by enhanced
coagulation. SUVA'S ability to indicate
the amount of humic matter present,
and enhanced coagulation's ability to
preferentially remove humic matter,
logically establishes SUVA as an
indicator of enhanced coagulation's
ability to remove humic substances from
a given water. The M-DBP Advisory
Committee therefore recommended that
a SUVA value < 2.0 L/mg-m be an
exemption from the treatment technique
requirement and that this SUVA value
also be added as a Step 2 procedure.
Effect of Coagulant Dose on TOC
Removal for Enhanced Softening. At the
time of proposal, limited data was
available on the effectiveness of TOC
removal by enhanced coagulation and
enhanced softening and on conditions
that define feasibility. Several studies
examined the relationship between
increased coagulant dose and TOC
removal (Shorney et al., 1996; Clark et
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Federal Register/Vol. 63, No. .241/Wednesday, December 16, 1998/Rules and Regulations 69415
al. 1994). These studies indicate some
improvement in TOC removal with
small doses of iron salts (5 mg/L ferric
sulfate), but no additional TOC removal
during softening occurred with
increased coagulant addition (up to 25
mg/L dose). Pilot testing by the City of
Austin's softening plant confirmed the
study's jar test results by showing that
increasing ferric sulfate doses beyond
the level required for turbidity removal
provided no additional TOC removal.
Multiple jar tests on various waters
performed by Singer et al. (1996)
examined the relationship between use
of lime and soda ash and TOC removal.
Only lime and soda ash (no coagulants)
were used in the tests. The study
showed the removal of 10 mg/L of
magnesium hardness would probably
have less of an impact on plant residual
generation than using a lime soda-ash
process. However, the amount of
residual material generated under both
scenarios could be substantial.
Step 2 Requirements for Softening
Systems. As stated above, the proposed
rule did not include a Step 2 procedure
for softening plants because of a lack of
data. The M-DBP Advisory Committee
examined new data that had been
collected since the proposal to
determine if a Step 2 procedure for
softening plants could be identified.
Data included the current TOC removals
being achieved by softening plants
covered by the ICR (49 plants). The data
were analyzed to find the appropriate
TOC removal levels for softening plants,
The results of plotting the average TOC
percent removals on a percentile basis
indicated that the relative impact of
meeting the TOC removal requirement
in the proposed rule would be greatest
in the low TOC group (>2-4 mg/L).
However, forcing a plant to increase pH
may require it to add soda ash (due to.
the decrease in alkalinity caused by
high lime dose necessary to raise the
pH). This would be a significant
treatment change due to the additional
solids generation and because
significant amounts of magnesium
hydroxide may precipitate at the higher
pH. Most softening plants are normally
operated without soda ash addition
because of the high cost of soda ash, the
additional sludge production, the
increased chemical addition to stabilize
the water, and the increased sodium
levels in the finished water (Randtke et
al., 1994 and Shorney et al., 1996). Due
to these difficulties, EPA does not
currently believe that a lime and soda-
ash softening process would be a viable
Step 2 procedure for softening systems.
The final rule instead specifies two
alternative compliance criteria,
mentioned earlier in this section, as a
Step 2 procedure for softening systems.
3. Summary of Comments
A large number of comments on the
1994 proposal questioned whether the
required TOC removal percentages
could be obtained by 90 percent of
affected systems. In response, since the
time of proposal, a large body of
additional data and analysis has been
developed to help address this question.
The analyses discussed above snowed
that the top row of the TOC removal
matrix needed to be lowered by 5.0
percentage points to enable 90 percent
of systems within the row to achieve the
required TOC removal without
unreasonable coagulant doses. Analysis
also showed the TOC removal
percentages contained in the two lower
rows of the TOC removal matrix
accurately reflected the TOC removal 90
percent of these systems could remove.
EPA believes the final TOC removal
matrix, which includes the adjustments
to the top row mentioned above,
accurately reflects the TOC removal that
90 percent of the systems affected by the
rule could practically achieve.
Commenters questioned why systems
that meet the DBP Stage 1 MCLs for
TTHM and HAAS must still practice
enhanced coagulation. The enhanced
coagulation treatment technique is
designed to remove DBP precursor
material to help reduce the risks posed
by DBPs. Also, EPA believes that
enhanced coagulation would reduce the
number of systems switching to
alternative disinfectants, which was a
goal of the Reg. Neg. Committee. EPA
believes that even if systems are meeting
the MCLs, an additional risk reduction
benefit can be achieved through removal
of DBP precursor material at a relatively
low cost to the system. Therefore,
systems that meet the MCLs must still
practice enhanced coagulation to
decrease the risks posed by DBPs in
general.
The Agency received numerous
comments on the 1994 proposal that
expressed doubt regarding the definition
of the POOR. Specifically, the
commenters stated that the accuracy of
the slope criterion (0.3 mg/L TOC
removed per 10 mg/L coagulant added)
for determining the POOR was not
supported with adequate data. The data
developed since trie-proposal and the
corresponding analysis demonstrate that
the slope criterion accurately predicts
the POOR. The analyses discussed
above showed that there is a particular
relationship between SUVA and the
slope criterion, namely, that they both
predict the POOR at the same point of
the TOC removal versus coagulant dose
curve. Since SUVA is a very good
predictor of the humic fraction of TOC,
which is the fraction preferentially
removed by enhanced coagulation, and
the POOR predicted by SUVA and the
slope criterion agree, EPA believes the
slope criterion of 0.3 mg/L TOC removal
per 10 mg/L of coagulant addition
accurately predicts the POOR.
The majority of commenters did not
support requiring the use of bench-scale
filtration as part of the Step 2 enhanced
coagulation procedure. The commenters
generally believed that using filtration at
bench scale is of limited value because
the great majority of TOC is removed via
sedimentation, not through filtration.
Additionally, some commentors felt that
attempting to replicate full-scale
filtration at bench scale can contain
inherent inaccuracy. EPA generally
agrees that a Step 2 filtration procedure
should not be required. The Agency
believes that most of the TOC removed
by conventional treatment plants is
removed in the sedimentation basin
rather than in the filters. Therefore,
requiring a bench-scale filtration
procedure as part of Step 2 testing will
not increase the accuracy of the
procedure or its value to the treatment
technique implementation. Accordingly,
today's final rule does not require the
use of a bench scale filtration procedure
during Step 2 enhanced coagulation
testing. Detailed guidance on
conducting the Step 2 testing will be
provided in the Guidance Manual for
Enhanced Coagulation and Enhanced
Precipatative Softening.
Commenters expressed varied
opinions regarding the frequency of
Step 2 testing. Several commenters
stated that the rule should not set a
minimum testing frequency, but that it
should be left to State discretion based
on source water characteristics. Other
commenters believed a minimum of
quarterly monitoring should be required
with a provision for more frequent
testing to address source water quality
events. EPA believes that Step 2 testing
frequency should be related to seasonal
and other variations in source water
quality as these variations may
influence the amount of TOC removal
the treatment plant can achieve.
Accordingly, EPA recommends that
systems utilizing the Step 2 procedure
for compliance perform Step 2 testing
quarterly for one year after the effective
data of the rule. The system may then
apply to the State to reduce testing to a
minimum of once per year. If the State
does not approve the request for
reduced testing frequency, the system
must continue to test quarterly.
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69416 Federal Register/Vol. 63, No. 24IIWednesday, December 16. 1998/Rules and Regulations
E, Predisinfection Disinfection Credit
1. Today's Rule
Today's rule does not impose any
constraints on the ability of systems to
practice predisinfection and take
mlcrobial inactivation credit for
predisinfection to meet the disinfection
requirements of the SWTR. Utilities are
free to take disinfection credit for
predisinfection, regardless of the
disinfectant used, for disinfection that
occurs after the last point the source
water is subject to surface water run-off
and prior to the first customer.
2. Background and Analysis
The 1994 proposed Stage 1 DBPR
(EPA.1994a) discouraged the use of
disinfectants prior to precursor
(measured as TOC) removal by not
allowing compliance credit for the
SWTR's disinfection requirements to be
taken prior to removal of a specified
percentage of TOC. The proposed
IESWTR options were intended to
include microbial treatment
requirements to prevent increases in
microbial risk due to the loss of
predisinfection credit. These options
were to be implemented simultaneously
with the Stage 1 DBPR. The purpose of
not allowing predisinfection credit was
to maximize removal of organic
precursors (measured as TOC) prior to
the addition of a disinfectant, thus
lowering the formation of DBFs.
Many drinking water systems use
preoxidation to control a variety of
water quality problems such as iron and
manganese, sulfides, zebra mussels,
Asiatic clams, and taste and odor. The
1994 proposed rule did not preclude the
continuous addition of oxidants to
control these problems. However, the
proposed regulation, except under a few
specific conditions, did not allow credit
for compliance with disinfection
requirements prior to TOC removal.
Analysis supporting the proposed rule
concluded that many plants would be
able to comply with the Stage 1 MCLs
for THMs and HAAS of 0.080 mg/L and
0.060 mg/L, respectively, by reductions
in DBF levels as a result of reduced
disinfection practice in the early stages
of treatment. Also, enhanced
coagulation and enhanced softening
were thought to lower the formation of
other unidentified DBFs as well. The
1994 proposal assumed that addition of
disinfectant prior to TOC removal
would initiate DBF formation through
contact of the chlorine with the TOC,
effectively eliminating the value of
enhanced coagulation for DBF
reduction. Finally, the analysis
underlying the 1994 proposed
elimination of the preoxidation credit
assumed that the addition of
disinfectant was essentially "mutually
exclusive" to the goal of reducing DBF
formation by the removal of TOC. As
discussed below, new data developed
since 1994 suggest this may not be the
case.
Reasons for Disinfectant Use. In order
to obtain information on the impact that
disallowing predisinfection would have
on utilities' disinfection practices, a
survey was sent out to ICR utilities to
obtain information on their current
predisinfection practices. The results of
the survey of 329 surface water
treatment plants indicated that 80
percent (263) of these plants use
predisinfection for one or more reasons.
The survey indicated that the majority
of the plants using predisinfection were
doing so for multiple reasons. However,
the main reason reported for
predisinfection was microbial
inactivation. Algae control, taste and
odor control, and inorganic oxidation,
in that order, were the next most
frequently cited reasons for practicing
predisinfection. Seventy-seven percent
of plants that predisinfected reported
that their current levels of Giardia
lamblia inactivation would be lowered
if predisinfection was discontinued and
no subsequent additional disinfection
was added to compensate for change in
practice. Eighty-one percent of plants
that predisinfected would have to make
major capital investments to make up
for the lost logs of Giardia lamblia
inactivation. For example, to maintain
the same level of microbial protection
currently afforded, construction to
provide for additional contact time or
use of a different disinfectant might be
needed if predisinfection credit was
eliminated.
In addition to the ICR mail survey,
results from EPA's Comprehensive
Performance Evaluations (CPE) from 307
PWSs (4 to 750 mgd) reported that 71%
of the total number of plants used
predisinfection and 93% of those that
predisinfected used two or three
disinfectant application points during
treatment.
Based on the above information, EPA
believes that predisinfection is used by
a majority of PWSs for microbial
inactivation, as well as other drinking
water treatment objectives. Therefore,
disallowing predisinfection credit could
influence systems to make changes in
treatment to comply with the
disinfection requirements of the SWTR
or to maintain current levels of
microbial inactivation.
Impact of Point of Chlorination on
DBF Formation. The results of a study
by Summers et al. (1997) indicate that
practicing enhanced coagulation, while
simultaneously maintaining
prechlorination, can still result in
decreased DBF formation (especially for
TOX and TTHM). Greater benefits are
realized by moving the point of
chlorination to post-rapid mixing or
further downstream for HAAS control,
and to mid-flocculation or post-
sedimentation for TOX and TTHM
control. These data show that the
assumption made in the 1994 proposal,
namely that application of any
disinfectant prior to TOC removal
would critically effect DBF formation,
was not accurate. The data indicate that
simultaneous employment of enhanced
coagulation and predisinfection does
not necessarily mean that DBF
formation cannot be substantially
controlled (see EPA 1997b for detailed
analysis).
Impact on Softening Plants. In order
to obtain additional information on the
current TOC removals being achieved
by softening plants, a survey was sent to
all the ICR softening utilities (49 plants)
requesting that they fill out a single page
of information with yearly average,
maximum and minimum values for
multiple operating parameters for each
softening plant. The survey showed that
in spite of the fact that 78 percent of
softening plants are using free chlorine
for at least a portion of their
disinfection, 90 percent of plants are
currently meeting an 80 |ig/L MCL level
for TTHMS. All the softening plants
reported average HAAS levels below 60
(ig/L. Without predisinfection credit,
these plants may have to provide
disinfection contact time after
sedimentation, which could mean
significantly increasing the free chlorine
contact time to make up for a shortened
detention time.
3. Summary of Comments
Most commenters stated that the
proposed elimination of predisinfection
would result in many plants not being
able to maintain existing levels of
disinfection or comply with the SWTR
disinfection requirements without
making significant compensatory
changes in their disinfection practice.
Commenters were concerned that
without predisinfection the level of
microbial risk their customers were
exposed to could significantly increase,
and that eliminating microbial
inactivation credit for predisinfection to
comply with the SWTR might influence
utilities to abandon predisinfection to
more easily comply with the TTHM and
HAAS MCLs. EPA agrees with this
concern and therefore the final rule has
been modified from the proposal to
allow predisinfection credit.
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Federal Register/VoL 63, No. 241/Wednesday,- December 16, 1998/Rules and Regulations 6Q417
F. Requirements for Systems to Use
Qualified Operators
EPA believes that systems that must
make treatment changes to comply with
requirements to reduce the
microbiological risks and risks from
disinfectants and disinfection
byproducts should be operated by
personnel who are qualified to
recognize and react to problems.
Therefore, in today's rule, the Agency is
requiring that all systems regulated
under this rule be operated by an
individual who meets State specified
qualifications, which may differ based
on size and type of the system. Subpart
H systems already are required to be
operated by qualified operators under
the provisions of the SWTR (40 CFR
141.70(c)). Current qualification or
certification programs developed by the
States should, in many cases, be
adequate to meet this requirement for
Subpart H systems. Also, States must
maintain a register of qualified
operators.
EPA encourages States which do not
already have operator certification
programs in effect to develop such
programs. The Reg. Neg. Committee and
TWG believed that properly trained
personnel are essential to ensure safer
drinking water. States with existing
operator certification programs may
wish to update their programs for
qualifying operators under the SWTR. In
these cases, States may wish to indicate
that their operator certification
programs are being developed in
accordance with EPA's new guidelines.
G. Analytical Methods
1. Today's Rule
Chlorine (Free, Combined, and Total).
Today's rule approves four methods for
measuring free, combined, and total
chlorine to determine compliance with
the chlorine MRDL (using either free or
total chlorine) and chloramines MRDL
(using either combined or total
chlorine): ASTM Method D1253-86
(ASTM, 1996), Standard Methods 4500-,
Cl D (APHA, 1995), 4500-C1 F (APHA,
1995), and 4500-C1 G (APHA, 1995).
Additionally, this rule approves two
methods for measuring total chlorine to
determine compliance with the chlorine
MRDL and chloramines MRDL:
Standard Methods 4500-C1 E (APHA,
1995) and 4500-C11 (APHA, 1995). The
rule also contains an additional method
for measuring free chlorine to determine
compliance with the chlorine MRDL:
Standard Method 4500-C1H (APHA,
1995).
Chlorine Dioxide. Today's rule
approves two methods for determining
compliance with the chlorine dioxide
MRDL: Standard Methods 4500-C1O2 D
(APHA, 1995) and 4500-C1O2 E (APHA
1995). EPA did not approve Standard
Method 4500-C1O2 C (APHA, 1995),
which was included in the 1994
proposed rule. The Agency determined,
in concurrence with the majority of
commenters on this issue, that Standard
Method 4500-C1O2 C is outdated and
inaccurate in comparison to chlorine
dioxide methods approved in today's
rule and is inadequate for compliance
monitoring.
TTHM. Today's rule approves three
methods for determining compliance
with the TTHM MCL: EPA Methods
502.2 (EPA, 1995), 524.2 (EPA, 1995),
and 551.1 (EPA, 1995).
HAAS. Today's rule approves three
methods for determining compliance
with the HAA5 MCL: EPA Methods
552.1 (EPA, 1992) and 552.2 (EPA,
1995) and Standard Method 625IB
(APHA, 1995).
Bromate. Today's rule approves a
method for determining compliance
with the bromate MCL: EPA Method
300.1 (EPA, 1997e). EPA has
demonstrated this method to be capable
of quantifying bromate at the MCL of 10
Hg/L under a wide range of solution
conditions. EPA did not approve EPA
Method 300.0 (EPA, 1993b) for bromate
analysis, although this method was
included for analysis of bromate in the
1994 proposed rule. As stated in the
proposed rule, EPA Method 300.0 is not
sensitive enough to measure bromate at
the MCL established in today's rule.
EPA Method 300.1 was developed
subsequent to the proposed rule in order
to provide a method with adequate
sensitivity to assess bromate
compliance.
Chlorite. Today's rule approves two
methods for determining compliance
with the chlorite MCL: EPA Methods
300.0 (EPA, 1993b) and 300.1 (EPA,
1997e). As described elsewhere in
today's rule, chlorite compliance
analyses are made on samples taken in ,
the distribution system during monthly
monitoring, or during additional
distribution system monitoring as
required. Today's rule establishes the
following method for daily monitoring
of chlorite: Standard Method 4500-C1O2
E.(APHA, 1995), amperometric titration.
As stated elsewhere in today's rule,
daily monitoring of chlorite is
conducted on samples taken at the
entrance to the distribution system.
Commenters supported the use of
amperometric titration as a feasible
method for daily monitoring of chlorite.
TOC. Today's Rule approves three
methods for TOC analysis: Standard
Methods 5310 B, 5310 C, and 5310 D,
as published in the Standard Methods
19th Edition Supplement (APHA, 1996).
EPA believes that all of these methods
can achieve the precision and detection
level necessary for compliance
determinations required in today's rule
when the quality control (QC)
procedures contained in the method
descriptions and this rule are followed.
However, while any of these methods
may be used, EPA advises that a
consistent method be employed for all
measurements in order to reduce the
impact of possible instrument bias.
In accordance with the concerns of
commenters, today's rule requires
certain QC procedures for TOC analyses
in addition to those contained in the
method descriptions. These additional
QC steps are designed to increase the
integrity of the analysis and have been
found to be effective in data collection
under the ICR. Filtration of samples
prior to TOC analysis is not permitted,
as this could result in removal of
organic carbon. Where turbidity
interferes with TOC analysis, samples
should be homogenized and, if
necessary, diluted with organic-free
reagent water. TOC samples must either
be analyzed or must be acidified to
achieve pH less than 2.0 by minimal
addition of phosphoric or sulfuric acid
as soon as practical after sampling, not
to exceed 24 hours. Samples must be
analyzed within 28 days.
SUVA (Specific Ultraviolet
Absorbance). Today's rule establishes
SUVA as an alternative criterion for
demonstrating compliance with TOC
removal requirements contained in
today's rule. SUVA is a calculated
parameter defined as the UV absorption
at 254 nm (UV2S4) (measured as m~J)
divided by the DOC concentration
(measured as mg/L). If the UV
absorption is first determined in units of
cm~', the SUVA equation is multiplied
by 100 to convert to m~', as shown
below:
SUVA = 100 (cm/m) [UV254 (cm-')/DOC
(mg/L)]
Two separate analytical methods are
necessary to make this measurement:
UV254 and DOC. Today's rule approves
three methods for DOC analysis:
Standard Methods 5310 B, 5310 C, and
5310 D, as published in the Standard
Methods 19th Edition Supplement
(APHA, 1996); and approves Standard
Method 5910 B (APHA, 1995) for UV2S4
analysis.
The final rule contains QC steps for
the SUVA analyses that are required in
addition to those mandated in the
method descriptions. These
requirements were developed in
response to comments solicited by EPA
in the 1997 DBF NODA (EPA, 1997b)
and are as follows:
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69418 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
—sample acquisition (DOC and UVz54
samples used to determine a SUVA
value must be taken at the same time
and at the same location. SUVA must
be determined on water prior to the
addition of disinfectants/oxidants.)
—sample preservation (DOC samples
must either be analyzed or must be
acidified to achieve pH less than 2.0
by minimal addition of phosphoric or
sulfurlc acid as soon as practical after
sampling, not to exceed 48 hours. The
pH of UVz54 samples may not be
adjusted.)
—holding times (DOC samples must be
analyzed within 28 days of sampling.
UVas4 samples must be analyzed as
soon as practical after sampling, not
to exceed 48 hours.)
-filtration (Prior to analysis, UVas4 and
DOC samples must be filtered through
a 0.45 \im pore-diameter filter. DOC
samples must be filtered prior to
acidification.)
-background concentrations in the
filtered blanks (Water passed through
the filter prior to filtration of the
sample must serve as the filtered
blank. This filtered blank must be
analyzed using procedures identical
to those used for analysis of the
samples and must meet the following
criteria: TOC <0.5 mg/L.)
Bromide. Today's rule approves the
following two methods for monitoring
bromide: EPA Methods 300.0 (EPA,
1993b) and 300.1 (EPA, 1997e).
Alkalinity. Today's rule approves
three methods for measuring alkalinity:
ASTM Method D1067-92B (ASTM,
1994), Standard Method 2320 B (APHA,
1995), and Method 1-1030-85 (USGS,
1989).
pH. Today's rule requires the use of
methods that have been previously
approved in § 141.23(k) for
measurement of pH.
Approved analytical methods are
summarized in Table III-2.
TABLE 111-2.—APPROVED ANALYTICAL METHODS
Analyte
Chlorine (frea, combined, total)
(Total)
(Free)
Chlorine Dioxide
TTHM
HAAS
Bromate
Chlorite (monthly)
(Daily)
TOC/DOC
UV234
Bromide
Alkalinity
oH
EPA method
5022
524.2
551.1
552 1
552.2
300.1
3000
300.1
3000
300.1
150 1
150.2
Standard method
4500-CI D
4500-CI F
4500-CI G
4500-CI E
4500-CI I
4500-CI H
4500-CIO2 D
4500-C!O2 E
625I B
4500-CIO2 E
5310 B
5310 C
5310 D
5910 B
2320 B
4500 H+B
Other
ASTM D 1253-8
ASTM D1067
92B.
USGS 1-1 030-
85.
ASTM D 1293-84
2, Background and Analysis
Chlorine (Free, Combined, and Total).
In the 1994 proposed rule, EPA
included all Standard Methods for
analysis of free, combined, and total
chlorine that were approved in today's
rule.
Chlorine Dioxide. The 1994 proposed
rule included the same three methods
for analyzing chlorine dioxide (C1O2)
that are approved under the SWTR and
ICR regulations. Two of these methods,
Standard Methods 4500.C1O2 C (APHA,
1992) and 4500.C1O2 E (APHA, 1992).
are amperometric methods. The third
proposed method was Standard Method
4500.C1O2 D (APHA, 1992). a
colorimetrlc test using the color
indicator N,N-diethyl-p-
phenylenediamine (DPD).
TTHM. The 1994 proposed rule
included three methods for the analysis
of TTHMs. They were EPA Methods
502.2, 524.2, and 551. In 1995, EPA
Method 551 was revised to EPA Method
551.1, rev. 1.0 (EPA, 1995), which was
approved for ICR monitoring under 40
CFR 141.142.
EPA Method 551.1 has several
improvements upon EPA Method 551.
The use of sodium sulfate is strongly
recommended over sodium chloride for
the MTBE extraction of DBFs. This
change was in response to a report
indicating elevated recoveries of some
brominated DBFs due to bromide
impurities in the sodium chloride (Xie,
1995). Other changes to EPA Method
551.1 include a buffer addition to
stabilize chloral hydrate, elimination of .
the preservative ascorbic acid, and
modification of the extraction procedure
to minimize the loss of volatile analytes.
The revised method requires the use of
surrogate and other quality control
standards to improve the precision arid
accuracy of the method.
HAAS. The 1994 proposed rule
included two methods for the analysis
of five haloacetic acids—EPA Method
552.1 (EPA, 1992) and Standard Method
6233B (APHA, 1992). Both methods use
capillary column gas chromatographs
equipped with electron capture
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detectors. The two methods differ in the
sample preparation steps. EPA Method
552.1 uses solid phase extraction disks
followed by an acidic methanol
derivitization. Standard Method 6233B
is a small volume liquid-liquid (micro)
extraction with methyl-t-butyl ether,
followed by a diazomethane
derivitization. Following the proposed
rule. Standard Method 6233B was
revised and renumbered 625IB (APHA,
1995) to include bromochloroacetic
acid, for which a standard was not
commercially available in 1994.
Recognizing these improvements, EPA
approved Standard Method 625IB for
analysis under the ICR (40 CFR Part 141
or ERA, 1996a). Several commenters
requested that the revised and
renumbered method, Standard Method
6251B, also be approved for the analysis
of haloacetic acids under the Stage 1
DBPR.
In 1995 EPA published a third
method for HAAs, EPA Method 552.2
(EPA, 1995), and subsequently approved
it for HAA analysis under the 1996 ICR
(40 CFR Part 141 or EPA, 1996a). EPA
Method 552.2 is an improved method,
combining the micro extraction
procedure of Standard Method 6233B
with the acidic methanol derivitization
procedure of EPA Method 552.1. It is
capable of analyzing nine HAAs.
Bromate. The 1994 proposed rule
required systems that use ozone to
monitor for bromate ion. EPA proposed
EPA Method 300.0. (EPA. 1993b) for the
analysis of bromate and chlorite ions.
However, at the time of the proposal,
EPA was aware that EPA Method 300.0
was not sensitive enough to measure
bromate ion concentration at the
proposed MCL of 10 ng/L. EPA
recognized that modifications to the
method would be necessary to increase
the method sensitivity. Studies at that
time indicated that changes to the
injection volume and the eluent
chemistry would decrease the detection
limit below the MCL. Many commenters
to the 1994 proposal agreed that EPA
Method 300.0 was not sensitive enough
to determine compliance with a MCL of
10 ng/L bromate ion, given that MCLs
are typically set at 5 times the minimum
detection levels (MDLs).
Following the proposal, EPA
improved EPA Method 300.0 and
renumbered it as EPA Method 300.1
(EPA, 1997b). EPA Method 300.1
specifies a new, high capacity ion
chromatbgraphy (1C) column that is
used for the analysis of all anions listed
in the method, instead of requiring two
different columns as specified in EPA
Method 300.0. The new column has a
higher ion exchange capacity that
improves chromatographic resolution
and minimizes the potential for
chromatographic interferences from
common anions at concentrations
10,000 times greater than bromate ion.
For example, quantification of 5.0 |ig/L
bromate is feasible in a matrix
containing 50 mg/L chloride.
Minimizing the interferences permits
the introduction of a larger sample
volume to yield method detection limits
in the range of 1-2 |J.g/L.
In the 1997 DBPR NODA (EPA,
1997b), EPA discussed EPA Method
300.1 and projected that by using it
laboratories would be able to quantify
bromate with the accuracy and
precision necessary for compliance
determination with an MCL of 10 jig/L.
Although there would be a limited
number of laboratories that would be
qualified to do such analyses, EPA
determined that there should be
adequate laboratory capacity for
bromate ion compliance monitoring by
the time the rule becomes effective.
Chlorite. The proposed rule required
systems using chlorine dioxide for
disinfection or oxidation to perform
monthly monitoring for chlorite ion in
the distribution system. EPA designated
EPA Method 300.0 (ion
chromatography) for chlorite analysis.
EPA considered other methods using
amperometric and potentiometric
techniques but decided that only the ion
chromatography method (EPA Method
300.0) would produce results with the
accuracy and precision needed for
determining compliance. Subsequent to
the proposed rule, EPA Method 300.0
was improved in order to achieve lower
detection limits for bromate ion and
renumbered as EPA Method 300.1.
TOC. To satisfy requirements of the
Stage 1 DBPR, the 1994 proposed rule
directed that a TOC analytical method
should have a detection limit of at least
0.5 mg/L and a reproducibility of ± 0.1
mg/L over a range of 2 to 5 mg/L TOC.
The proposed rule included two
methods for analyzing TOC: Standard
Methods 5310 C, which is the
persulfate-ultraviolet oxidation method,
and 5310 D, the wet-oxidation method
(APHA, 1992). These methods were
selected because, according to data
published in Standard Methods (APHA
1992), they could achieve the necessary
precision and detection limit. Standard
Method 5310 B, the high-temperature
combustion method, was considered but
not proposed because it was described
in Standard Methods (1992, APHA) as
having a detection limit of 1 mg/L. The
proposal stated that if planned
improvements to the instrumentation
used in Standard Method 5310 B were
successful, the next version would be
considered for promulgation. Revisions
of Standard Methods 5310 B, C, and D
were published in Standard Methods
19th Edition Supplement (APHA, 1996).
The revised version of Standard Method
5310 B recognized the capacity of
certain high temperature instruments to
achieve detection limits below 1 mg/L
using this method.
SUVA (Specific Ultraviolet
Absorbance). SUVA analytical methods
were not addressed in the 1994
proposed rule because SUVA had not
been developed and proposed as a
compliance parameter for TOC removal
requirements at that time. The analytical
methods and associated QC procedures
for DOC and UV2S4 approved in today's
rule are those on which the Agency
solicited comment in the 1997 DBPR
NODA (EPA, 1997b).
Bromide. The 1994 proposed rule
included EPA Method 300.0 for analysis
of bromide. EPA believed that the
working range of this method
adequately covered the requirements
proposed for bromide monitoring. As
described above, EPA developed
Method 300.1 for improved bromate
analysis subsequent to the proposed
rule. EPA Method 300.1 can also
effectively measure bromide at the
concentration of 50 (ig/L, required in
today's rule for reduced monitoring of
bromate.
Alkalinity. The proposed rule
included all methods approved by EPA
for measuring alkalinity. These methods
have all been approved in today's rule.
3. Summary of Comments
Following is a discussion of major
comments on the analytical methods
requirements of the Stage 1 DBPR.
Chlorine. A commenter to the 1994
proposal recommended approval of
ASTM method D1253-86. EPA
determined that this method is
equivalent to Standard Method 4500-C1
D, and has approved this method in
today's rule.
Chlorine Dioxide. EPA received
comments on the proposed rule
detailing weaknesses of the methods
selected to calculate C1O2. Commenters
pointed out that other halogenated
species, such as free chlorine,
chloramines, and chlorite, as well as
common metal ions (e.g. copper,
manganese, chromate) will interfere
with these methods. Additionally,
where these methods determine
concentrations by difference, they are
potentially inaccurate and subject to
propagation of errors. Commenters
specifically criticized Standard Method
4500-C1O2 C (APHA 1995),
amperometric method I, which was
characterized as outdated and
inaccurate, and stated that Standard
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Method 4500-C1O2 E (APHA 1995),
amperometric method II, is a
substantially better method.
Consequently, in the 1997 DBF NODA,
EPA requested comment on removing
Standard Method 4500-C1O2 C from the
list of approved methods for the
analysis of chlorine dioxide for
compliance with the MRDL.
Comments on the 1997 DBPR NODA
favored eliminating Standard Method
4500.C1O2 C as an approved method for
C102 compliance analysis. EPA does not
approve this method in today's rule.
EPA recognizes that the two methods
approved for C1O2 monitoring under
today's rule are subject to interferences.
However, EPA believes that these
methods can be used effectively to
indicate compliance with the C1O2
MRDL when the quality control
procedures contained in the method
descriptions are followed. Several
commenters also encouraged EPA to
approve a more sensitive and specific
method for C1O2 analysis, and suggested
alternative methods including Acid
Chrome Violet K. Lissamine Green B,
and Chlorophenol Red. While EPA
supports the development of improved
analytical methods for chlorine dioxide,
the Agency believes that at this time the
methods suggested by commenters have
not gone through the necessary
performance validation processes to
warrant their approval for compliance
monitoring.
Bromate. In the 1994 proposed rule,
EPA discussed the fact that the current
version of EPA Method 300.0 was not
sensitive enough to measure bromate
ion concentrations at the proposed MCL
and requested comment on
modifications to EPA Method 300.0 to
Improve its sensitivity. In the 1997
NODA, EPA presented EPA Method
300.1 and requested comment on
replacing EPA Method 300.0 with EPA
Method 300.1 for the analysis of
bromate.
Commenters agreed that EPA Method
300.1 is a more sensitive method than
EPA Method 300.0 for low level bromate
analysis and the majority suggested that
EPA Method 300.1 be the approved
method for bromate analysis. One
commenter requested that
interlaboratory round-robin testing be
conducted before EPA Method 300.1 is
accepted for Stage 1 DBPR compliance
monitoring. EPA considers
interlaboratory round-robin testing of
EPA Method 300.1 to be unnecessary
because this method is essentially an
Improvement of EPA Method 300.0
which is already approved. EPA Method
300.1 primarily makes use of a superior
analytical column to achieve increased
sensitivity for bromate analysis.
Moreover, the efficacy of EPA Method
300.1 in a wide range of sample
matrices is demonstrated by the
performance validation data contained
in the published method description.
Based on a review of all the public
comments, EPA is approving EPA
Method 300.1 for bromate analysis in
today's rule.
Chlorite. EPA solicited comment in
the 1997 DBPR NODA on approving
EPA Method 300.1, in addition to EPA
Method 300.0, for compliance analysis
of chlorite. The majority of commenters
on this issue favored approval of both
methods and today's rule establishes
both for determining compliance with
the chlorite MCL.
In the 1994 proposed rule, EPA
requested comment on changing
monitoring requirements for chlorite to
reflect concern about potential acute
health effects. Several commenters
stated that daily monitoring of chlorite
would be feasible if an amperometric
analytical method could be used.
Commenters suggested that daily
amperometric analyses for chlorite be
conducted on samples taken from the
entrance to the distribution system, and
that weekly or monthly analyses using
ion chromatography still be required as
a check, because ion chromatography is
a more accurate analytical method.
Commenters noted that daily
monitoring for chlorite would provide
improved operational control of plants
and reduce the likelihood of systems
incurring compliance violations.
Today's rule establishes amperometric
titration (Standard Method 4500-C1O2
E) for daily analyses of chlorite samples
taken at the entrance to the distribution
system, along with monthly (or
quarterly if reduced, or additional as
required), analyses by ion
chromatography (EPA Methods 300.0
and 300.1) of chlorite samples taken
from within the distribution system.
EPA believes that the ion
chromatography method, rather than the
amperometric method, should be used
for making chlorite compliance
determinations in the distribution
system due to its greater accuracy.
However, the amperometric method is
sufficient for the purposes of daily
monitoring at the entrance to the
distribution system, which are to
significantly aid in proper operational
control of a treatment plant and to
indicate when distribution system
testing is appropriate. For this reason,
only the ion chromatographic methods
(EPA Method 300.0 and 300.1), and not
the amperometric titration methods, are
approved in today's rule for determining
compliance with the chlorite MCL.
A minority of commenters on this
issue suggested that the DPD method
(Standard Method 4500-C1O2 D (APHA
1995)) be approved for daily monitoring
of chlorite ion levels. EPA has
determined that the accuracy and
precision of the DPD method (Standard
Method 4500-C1O2 D) in the
measurement of chlorite are
substantially worse than with Standard
Method 4500-C1O2 E, and are
insufficient for this method to be used
for daily monitoring of chlorite. As a
consequence, EPA has not approved the
DPD method for chlorite monitoring in
today's rule.
TOC. EPA received several comments
on the 1994 proposal requesting
approval of Standard Method 5310 B for
TOC compliance analysis. Commenters
stated that newer instrumentation could
achieve a detection limit of 0.5 mg/L
TOC using this method. Following the
publication of a revised version of
Method 5310 B in Standard Methods
19th Edition Supplement (APHA 1996)
which recognized the capacity of some
combustion based TOC analyzers to
achieve detection limits below 1 mg/L,
EPA requested comment on approving
Standard Method 5310 B, along with
Standard Methods 5310 C and 5310 D,
for the analysis of TOC in the 1997
DBPR NODA.
The majority of commenters on TOC
analysis urged EPA to approve all three
methods. Commenters were concerned,
though, that because these three
methods employ different processes to
oxidize organic carbon to carbon
dioxide, results from different TOC
analyzers could vary to a degree that is
of regulatory significance. Specifically,
the efficiency of oxidation of large
organic particles or very large organic
molecules such as tannins, lignins, and
humic acids may be lower with
persulfate based instruments (APHA
1996). Although available data
comparing different TOC methods is
limited, one study observed a persulfate
catalytic oxidation technique to
underestimate the TOC concentration
measured by a high temperature
catalytic oxidation technique by 3-6%
on stream water and soil water samples
(Kaplan, 1992). Standard Methods
recommends checking the oxidation
efficiency of the instrument with model
compounds representative of the sample
matrix, because many factors can
influence conversion of organic carbon
to carbon dioxide (APHA 1996).
EPA believes that the potential
regulatory impact of small disparities in
oxidation efficiencies between different
TOC analyzers is minor. Studies using
PE samples indicate that for instruments
calibrated in accordance with the
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Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations 69421
procedures specified in Standard
Methods (APHA, 1996), the magnitude
of measurement error due to analytical
discrepancies between instruments will
typically be less than the measurement
uncertainty attributed to a particular
instrument (EPA, 1994c). In addition,
EPA anticipates that most systems will
use a consistent method for TOC
analyses and that this will assist in
minimizing the importance of
instrument bias. This practice was
suggested by several commenters.
Commenters also suggested that EPA
implement a formal certification process
for laboratories measuring TOC. Some
commenters recommended that EPA
require a laboratory approval process for
TOC measurements under the Stage 1
DBPR that is similar to what is required
under the ICR. EPA requires that TOC
analyses be conducted by a party
approved by EPA or the State but not
that TOC measurements be subject to
the same laboratory certification
procedures required for the analysis of
DBPs. However, today's rule contains
QC requirements for TOC analyses
which are in addition to those in
Standard Methods. These additional QC
procedures pertain to sample
preservation and holding time, and have
been found to be effective for TOC
analyses under the ICR.
SUVA. In the 1997 DBPR NODA, EPA
solicited comment on a range of issues
dealing with the determination of SUVA
including: analytical methods,
sampling, sample preparation, filter
types, pH, interferences to UV, high
turbidity waters, quality control, and
other issues that should be addressed.
The Agency requested comment on
approving Standard Method 5910 B for
measuring UV2s4 and Standard Methods
5310 B, C, and D, for measuring DOC.
In requesting comment on filtration,
EPA noted that filtration is necessary
prior to both UV2s4 and DOC analyses in
order to eliminate particulate matter and
separate the operationally defined
dissolved organic matter (based on a
0.45 jim-pore-diameter cut-off).
However, filtration can also corrupt
samples through adsorption of
carbonaceous material onto the filter or
its desorption from it (APHA 1996). In
addition, EPA requested comment on
requiring that UV2s4 and DOC analyses
be measured from the same sample
filtrate.
The majority of commenters on SUVA
analytical methods recommended that
EPA approve Standard Methods 5310 B,
C, and D, for DOC analysis and Standard
Method 5910 B for UV254 analysis. EPA
has approved these methods in today's
rule. In addition, commenters stressed
the importance of sample preparation,
especially filtration, in the measurement
of DOC and observed that sufficient
washing of filters prior to filtration of
samples is critical to preventing
contamination of the samples by organic
carbon from the filters. Several
comments on the 1997 DBPR NODA
expressed opposition to a requirement
that UV254 and DOC analyses be made
on the same sample filtrate.
Commenters stated that this is
impractical because UV analyses are
often conducted at the treatment plant
while DOC analyses are typically run
off-site. Commenters also noted that
DOC samples should be acid preserved
whereas pH adjustment of samples for
UV254 analysis is improper.
Today's rule establishes that samples
for DOC and UV254 analyses must be
filtered through a 0.45 |im-pore-
diameter filter. EPA does not have
specific requirements on the type of
filter that is used, provided it has a 0.45
(Am pore-diameter, but will provide
guidance on this issue in the Guidance
Manual for Enhanced Coagulation. This
manual will be available for public
review after promulgation of the Stage 1
DBPR. Today's rule addresses filter
washing prior to analysis by requiring
that water passed through the filter prior
to filtration of the sample serve as the
filtered blank. The filtered blank must
be analyzed using procedures identical
to those used for analysis of the samples
and must meet the following criteria:
TOC < 0.5 mg/L. These criteria are the
maximum allowable background
concentrations specified for these
analyses under the ICR. In the Guidance
Manual for Enhanced Coagulation, EPA
will furnish instructions on sample
handling and filter washing to assist
systems in achieving acceptable field
reagent blanks.
Filtration of samples for DOC analysis
must be done prior to acid preservation,
as stipulated in today's rule. This is
necessary because acidification of the
sample to pH < 2 can cause substantial
precipitation of dissolved organic
species. Because biological activity will
rapidly alter the DOC of a sample that
has not been preserved, EPA requires
that DOC samples be acidified to pH <
2.0 within 48 hours of sampling.
Consequently, filtration of DOC samples
must be done within 48 hours in order
to allow acid preservation within this
time period. The pH of UV254 samples
may not be adjusted. Today's rule places
a maximum holding time from sampling
to analysis of 2 days for UV254 samples
and 28 days for DOC samples. These
holding times are the same as those
approved for ICR data collection.
Because the filtration procedures for
UV254 and DOC samples are largely
identical, EPA anticipates that most
systems will find it economical when
determining SUVA to filter one sample.
The filtrate would then be split into two
portions, one of which would be used
for UV analysis while the other would
be acid preserved and used for DOC
analysis. However, EPA has not
included a requirement that the DOC
and UV2S4 analyses used in the SUVA
determination be made on the same
sample filtrate. Instead, EPA requires
that DOC and UV2S4 samples used to
determine a SUVA value must be taken
at the same time and at the same
location.
In the 1997 DBPR NODA, EPA also
observed that because disinfectants/
oxidants (chlorine, ozone, chlorine
dioxide, potassium permanganate)
typically reduce UV254 without
substantially impacting DOC, raw water
SUVA should be determined on water
prior to the application of disinfectants/
oxidants. If disinfectants/oxidants are
applied in raw-water transmission lines
upstream of the plant, then raw water
SUVA should be based on a sample
collected upstream of the point of
disinfectant/oxidant addition. For
determining settled-water SUVA, if the
plant applies disinfectants/oxidants
prior to the settled water sample tap,
then settled-water SUVA should be
determined in jar testing. No
commenters were opposed to these
provisions and today's rule requires that
samples used for SUVA determinations
be taken from water prior to the
addition of any oxidants/disinfectants.
A few commenters stated that SUVA
should not be subject to rigorous
analytical procedures because the
application of SUVA in this rule is
based on a relationship which is largely
empirical (i.e. correlations between
SUVA and TOC removal by
coagulation). EPA recognizes the
empirical nature of this relationship and
the variance it has displayed in studies.
Regulations, however, must address
specific SUVA values if SUVA is to
serve as an alternative compliance
parameter. For compliance with these
regulations to be meaningful, SUVA
must be determined accurately.
Consequently, today's rule requires
certain QC procedures in the DOC and
UVM4 analyses that are used to calculate
SUVA.
Today's rule establishes the removal
of 10 mg/L magnesium hardness (as
CaCOS) as an alternative performance
criterion that systems practicing
enhanced softening can use to
demonstrate compliance with the
treatment technique requirement for
TOC removal. However, EPA did not
propose methods for the analysis of
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69422 Federal Register/Vol. 63,-No.,2417Wednesday, December. .16, 1998/Rules and Regulations
magnesium in drinking water and
therefore the final rule does not contain
any approved methods for magnesium.
EPA expects to propose magnesium
analytical methods to be used for
compliance monitoring under the Stage
!DBPRbytheendofl998.
4. Performance Based Measurement
Systems
On October 6.1997. EPA published a
Document of the Agency's intent to
Implement a Performance Based
Measurement System (PBMS) in all of
Its programs to the extent feasible (EPA,
1997f). The Agency is currently
determining the specifics steps
necessary to implement PBMS in its
programs and preparing an
implementation plan. Final decisions
have not yet been made concerning the
implementation of PBMS in drinking
water programs. However, EPA is
currently evaluating what relevant
performance characteristics should be
specified for monitoring methods used
in the drinking water programs under a
PBMS approach to ensure adequate data
quality. EPA would then specify
performance requirements in its
regulations to ensure that any method
used for determination of a regulated
analyte is at least equivalent to the
performance achieved by other
currently approved methods. EPA
expects to publish its PBMS
implementation strategy for water
programs in the Federal Register by the
end of calendar year 1998.
Once EPA has made its final
determinations regarding
implementation of PBMS in programs
under the Safe Drinking Water Act, EPA
would incorporate specific provisions of
PBMS into its regulations, which may
include specification of the performance
characteristics for measurement of
regulated contaminants in the drinking
water program regulations.
H. Monitoring Requirements
1. Today's Rule
Today's rule establishes monitoring
requirements to support implementation
of the enhanced coagulation and
enhanced softening treatment
technique, implementation of new
MCLs for TTHM, HAAS, bromate, and
chlorite, and implementation of MRDLs
for chlorine, chloramines, and chlorine
dioxide. Monitoring for DBFs,
disinfectant residuals, and TOC must be
conducted during normal operating
conditions. Failure to monitor in
accordance with the monitoring plan is
a monitoring violation. Where
compliance is based on a running
annual average of monthly or quarterly
samples or averages and the system's
failure to monitor makes it impossible to
determine compliance with MCLs or
MRDLs, this failure to monitor will be
treated as a violation.
Tables III-3 and III-4 below
summarize routine and reduced
monitoring requirements of today's rule.
TABLE 111-3.—ROUTINE MONITORING REQUIREMENTS'"
Requirement
(reference)
TOC and Alkalinity
(141.132(d)(1)).
TTHMs and HAAS
1 1 (ilVld CU IU tlr\f^*J
Bromate7
(141.132(b)(3)(i)).
Chlorite" (daily)
(141.132(b)(2)(l)(A)).
Chlorite8 (monthly)
141.132(b)(2)(i)(B)).
Chlorine and
chloramines
Chlorine dioxide8
(141.132(c)(2)(i)).
Location for sampling
Source Water^
Only required for
plants with conven-
tional filtration treat-
ment.
25% in dist sys at
max res time, 75%
at dist sys rep-
resentative loca-
tions.
Dist sys entrance
point.
Dist sys entrance
point.
Dist sys: 1 near first
oust, 1 in dist sys
middle, 1 at max
res time.
Same points as total
coliform in TCR.
Dist sys entrance
point.
Large surface sys-
tems2
1 sample/month/plant 3
4/plant/quarter
1/month/trt plant
using O3.
Daily/trt plant using
CIO2.
3 sample set/month ..
Same times as total
coliform in TCR.
Daily/trt plant using
CIO2.
Small surface sys-
tems2
1 sample/month/
plant3.
1/plant/quarter5
at maximum resi-
dence time.
if pop.<500, then 1/
plant/yr8.
during warmest
month.
1/month/trt plant
using O3.
Daily/trt plant using
CIO2.
3 sample set/month ..
Same times as total
coliform in TCR.
Daily/trt plant using
CIO2.
Large ground water
systems 3
NA
1/plant/quarter6
at maximum resi-
dence time.
1/month/trt plant
using Os.
Daily/trt/plant using
CIO2.
3 sample set/month ..
Same times as total
coliform in TCR.
Daily/trt plant using
CIO2.
Small ground water
systems3
NA.
1 /plant/year5-6
at maximum resi-
dence time.
during warmest
month.
1/month/trt plant
using O3.
3 sample set/month.
Same times as total
coliform in TCR.
Daily/trt plant using
CIO.
1 Samples must be taken during representative operating conditions. Provisions for reduced monitoring shown elsewhere.
2 Large surface (subpart H) systems serve 10,000 or more persons. Small surface (subpart H) systems serve fewer than 10,000 persons.
3 Large systems using ground water not under the direct influence of surface water serve 10,000 or more persons. Small systems using
ground water not under the direct influence of surface water serve fewer than 10,000 persons.
4 Subpart H systems which use conventional filtration treatment (defined in section 141.2) must monitor 1) source water TOC prior to any treat-
ment and 2) treated TOC at the same time; these two samples are called paired samples. Systems must take a source water alkalinity sample at
the same time.
5 If the annual monitoring result exceeds the MCL, the system must increase monitoring frequency to 1/plant/quarter. Compliance determina-
tions will be based on the running annual average of quarterly monitoring results.
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Federal Register/Vol. 63, No. 241/Wednesday, December .16, 1998 /Rules and ..Regulations 69423
6 Multiple wells drawing water from a single aquifer may, with State approval, be considered one treatment plant for determining the minimum
number of samples.
7 Only required for systems using ozone for oxidation or disinfection.
8 Only required for systems using chlorine dioxide for oxidation or disinfection. Additional chlorite monitoring required if daily sample exceeds
MCL. Additional chlorine dioxide monitoring requirements apply if any chlorine dioxide sample exceeds the MRDL.
TABLE 111-4.—REDUCED MONITORING REQUIREMENTS'"
Requirement
(reference)
Location for reduced
sampling
Reduced monitoring frequency and prerequisites2
TOG and Alkalinity
(141.132(d)(2)).
TTHMs and HAASs
Paired samples3
In dist sys at point with
max res time.
Bromate 5
(141.1
Chlorite6
Chlorine, chlorine diox-
ide 6, chloramines
(141.132(c)(2)(ii)and
Dist sys entrance point
Dist sys: 1 near first
cust, 1 in dist sys
middle, 1 at max res
time.
NA
Subpart H systems-reduced to 1 paired sample/plant/quarter if 1) avg TOG < 2.0 mg/l for 2
years or 2) avg TOG < 1.0 mg/l for 1 year.
Monitoring cannot be reduced if subpart H system source water TOC > 4.0 mg/l.
Subpart H systems serving 10,000 or more-reduced to 1/plant/qtr if 1) system has completed
at least 1 yr of routine monitoring and 2) both TTHM and HAAS running annual averages
are no more than 40 ng/l and 30 [ig/l, respectively.
Subpart H systems serving <10,000 and ground water systems4 serving 10,000 or more-re-
duced to 1/plant/yr if 1) system has completed at least 1 yr of routine monitoring and 2)
both TTHM and HAA5 running annual averages are no more than 40 ng/l and 30 (ig/l, re-
spectively. Samples must be taken during month of warmest water temperature. Subpart H
systems serving <500 may not reduce monitoring to less than 1/plant/yr.
Groundwater systems6 serving<10,000-reduced to 1/plant/3yr if 1) system has completed at
least 2 yr of routine monitoring and both TTHM and HAAS running annual averages are no
more than 40 jj.g/1 and 30 jig/I, respectively or 2) system has completed at least 1 yr of
routine monitoring and both TTHM and HAAS annual samples are no more than 20 p.g/1
and 15 ng/l, respectively. Samples must be taken during month of warmest water tempera-
ture.
1/qtr/trt plant using O3, if system demonstrates 1) avg raw water bromide <0.05 mg/l (based
on annual avg of monthly samples).
Systems may reduce routine distribution system monitoring from monthly to quarterly if the
chlorite concentration in all samples taken in the distribution system is below 1.0 mg/L for a
period of one year; 3 samples per quarter.
Monitoring may not be reduced.
1 Samples must be taken during representative operating conditions. Provisions for routine monitoring shown elsewhere.
2 Requirements for cancellation of reduced monitoring are found in the regulation.
3 Subpart H systems which use conventional filtration treatment (defined in Section 141.2) must monitor 1) source water TOC prior to any treat-
ment and 2) treated TOC before continuous disinfection (except that systems using ozone followed by biological filtration may sample after bio-
logical filtration) at the same time; these two samples are called paired samples.
4 Multiple wells drawing water from a single aquifer may, with State approval, be considered one treatment plant for determining the minimum
number of samples.
5 Only required for systems using ozone for oxidation or disinfection.
6 Only required for systems using chlorine dioxide for oxidation or disinfection.
The formation rate of DBFs is affected
by type and amount of disinfectant
used, water temperature, pH, amount
and type of precursor material in the
water, and the length of time that water
remains in the treatment and
distribution systems. For this reason,
today's rule specifies the points in the
distribution system (and, in some cases,
the time) where samples must be taken.
For purposes of this regulation, multiple
wells drawing raw water from a single
aquifer may, with State approval,-be
considered one plant for determining
the minimum number of samples.
TTHM and HAAS. Any system may
take samples in excess of the required
frequency. In such cases, at least 25
percent of all samples collected each
quarter must be taken at locations
within the distribution system that
represent the maximum residence time
of the water in the system. The
remaining samples must be taken at
locations representative of at least
average residence time in the
distribution system.
Subpart H Systems Serving 10,000 or
More People. Routine Monitoring: CWSs
and NTNCWSs using surface water (or
ground water under direct influence of
surface water) (Subpart H systems) that
treat their water with a chemical
disinfectant and serve 10,000. or more
people must routinely take four water
samples each quarter for both TTHMs
and HAAS for each treatment plant in
the system. At least 25 percent of the
samples must be taken at the point of
maximum residence time in the
distribution system. The remaining
samples must be taken at representative
points in the distribution system. This
monitoring frequency is the same as the
frequency required under the current
TTHM rule (§141.30). -
Reduced Monitoring: To qualify for
reduced monitoring, systems must meet
certain prerequisites (see Figure III-l).
Systems eligible for reduced monitoring
may reduce the monitoring frequency
for TTHMs and HAA5 to one sample per
treatment plant per quarter. Systems on
a reduced monitoring schedule may
remain on that reduced schedule as long
as the average of all samples taken in
the year is no more than 0.060 mg/L for
TTHM and 0.045 mg/L for HAAS.
Systems that do not meet these levels
must revert to routine monitoring in the
quarter immediately following the
quarter in which the system exceeded
0.060 mg/L for TTHM or 0.045 mg/L for
HAAS. Additionally, the State may
return a system to routine monitoring at
the State's discretion.
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69424 Federal Register /Vol. 63, No. 2417 Wednesday, December 16, 1998/Rules and Regulations
FIGURE III-1.—ELIGIBILITY FOR REDUCED TTHM AND HAA5 MONITORING: GROUND WATER SYSTEMS SERVING 10,000
OR MORE PEOPLE AND SUBPART H SYSTEMS SERVING 500 OR MORE PEOPLE
Ground water systems serving 10,000 or more people, and Subpart H systems serving 500 or more people, may reduce monitoring of TTHMs
and HAAS II they meet all of the following conditions:
—The annual average for TTHMs is no more than 0.040 mg/L.
—The annual average for HAAS is no more than 0.030 mg/L.
—At least one year of routine monitoring has been completed.
—Annual average source water TOC level is no more than 4.0 mg/L prior to treatment (applies to Subpart H systems only).
Compliance Determination: A public
water system (PWS) is in compliance
with the MCL when the running annual
arithmetic average of quarterly averages
of all samples, computed quarterly, is
less than or equal to the MCL. If the
running annual average computed for
any quarter exceeds the MCL, the
system is out of compliance.
Subpart H Systems Serving 500 to
9,999 People. Routine Monitoring:
Systems are required to take one water
sample each quarter for each treatment
plant in the system. Samples must be
taken at the point of maximum
residence time in the distribution
system.
Reduced Monitoring: To qualify for
reduced monitoring, systems must meet
certain prerequisites (see Figure III-l).
Systems eligible for reduced monitoring
may reduce the monitoring frequency
for TTHMs and HAAS to one sample per
treatment plant per year. Sample must
be taken at a distribution system
location reflecting maximum residence
time and during the month of warmest
water temperature. Systems on a
reduced monitoring schedule may
remain on that reduced schedule as long
as the average of all samples taken in
the year is no more than 0.060 mg/L for
TTHM and 0.045 mg/L for HAAS.
Systems that do not meet these levels
must revert to routine monitoring in the
quarter immediately following the
quarter in which the system exceeded
0.060 mg/L for TTHM or 0.045 mg/L for
HAAS. Additionally, the State may
return a system to routine monitoring at
the State's discretion.
Compliance Determination: A PWS is
in compliance with the MCL for TTHM
and HAAS when the annual average of
all samples, taken that year, is less than
or equal to the MCL. If the average for
these samples exceeds the MCL, the
system is out of compliance.
Subpart H Systems Serving Fewer
than 500 People. Routine Monitoring:
Subpart H systems serving fewer than
500 people are required to take one
sample per year for each treatment plant
in the system. The sample must be taken
at the point of maximum residence time
in the distribution system during the
month of warmest water temperature. If
the annual sample exceeds the MCL, the
system must increase monitoring to one
sample per treatment plant per quarter,
taken'at the point of maximum
residence time in the distribution
system.
Reduced Monitoring: These systems
may not reduce monitoring. Systems on
increased monitoring may return to
routine monitoring if the annual average
of quarterly samples is no more than
0.060 mg/L for TTHM and 0.045 mg/L
for HAAS.
Compliance Determination: A PWS is
in compliance when the annual sample
(or average of annual samples, if
additional sampling is conducted) is
less than or equal to the MCL. If the
annual sample exceeds the MCL, the
system must increase monitoring to one
sample per treatment plant per quarter.
If the running annual average of the
quarterly samples then exceeds the
MCL, the system is out of compliance.
Ground Water Systems Serving 10,000
or More People. Routine Monitoring:
CWSs and NTNCWSs using only ground
water sources not under the direct
influence of surface water that treat
their water with a chemical disinfectant
and serve 10,000 or more people are
required to take one water sample each
quarter for each treatment plant in the
system. Samples must be taken at points
that represent the maximum residence
time in the distribution system.
Reduced Monitoring: To qualify for
reduced monitoring, systems must meet
certain prerequisites (see Figure III-l).
Systems eligible for reduced monitoring
may reduce the monitoring frequency to
one sample per treatment plant per year.
Sample must be taken at a distribution
system location reflecting maximum
residence time and during the month of
warmest water temperature. Systems on
a reduced monitoring schedule may
remain on that reduced schedule as long
as the average of all samples taken in
the year is no more than 0.060 mg/L for
TTHM and 0.045 mg/L for HAAS.
Systems that do not meet these levels
must revert to routine monitoring in the
quarter immediately following the
quarter in which the system exceeded
0.060 mg/L for TTHM or 0.045 mg/L for
HAAS. Additionally, the State may
return a system to routine monitoring at
the State's discretion.
Compliance Determination: A PWS is
in compliance with the MCL when the
running arithmetic annual average of
quarterly averages of all samples,
computed quarterly, is less than or
equal to the MCL. If the running annual
average for any quarter exceeds the
MCL, the system is out of compliance.
Ground Water Systems Serving Fewer
than 10,000 People Routine Monitoring:
CWSs and NTNCWSs using only ground
water sources not under the direct
influence of surface water that treat
their water with a chemical disinfectant
and serve fewer than 10,000 people are
required to sample once per year for
each treatment plant in the system. The
sample must be taken at the point of
maximum residence time in the
distribution system during the month of
warmest water temperature. If the
sample (or the average of annual
samples if more than one sample is
taken) exceeds the MCL, the system
must increase monitoring to one sample
per treatment plant per quarter.
Reduced Monitoring: To qualify for
reduced monitoring, systems must meet
certain prerequisites (see Figure III-2).
Systems eligible for reduced monitoring
may reduce the monitoring frequency
for TTHMs and HAAS to one sample per
three-year monitoring cycle. Sample
must be taken at a distribution system
location reflecting maximum residence
time and during the month of warmest
water temperature. Systems on a
reduced monitoring schedule may
remain on that reduced schedule as long
as the average of all samples taken in
the year is no more than 0.060 mg/L for
TTHM and 0.045 mg/L for HAA5.
Systems that do not meet these levels
must resume routine monitoring.
Systems on increased monitoring may
return to routine monitoring if the
annual average of quarterly samples is
no more than 0.060 mg/L for TTHM and
0.045 mg/L for HAAS.
Compliance Determination: A PWS is
in compliance when the annual sample
(or average of annual samples) is less
than or equal to the MCL.
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Federal Register/Vol. 63, No. 241 /Wednesday, -December- 16, 1998/Rules and Regulations 69425
FIGURE III-2.—ELIGIBILITY FOR REDUCED TTHM AND HAA5 MONITORING: GROUND WATER SYSTEMS SERVING FEWER
THAN 10,000 PEOPLE
Systems using ground water not under the direct influence of surface water that serve fewer than 10,000 people may reduce monitoring for
TTHMs and HAA5 if they meet either of the following conditions:
1. The average of two consecutive annual samples for TTHMs is no more than 0.040 mg/L, the average of two consecutive annual samples for
HAAS is no more than 0.030 mg/L, and at least two years of routine monitoring has been completed.
2. The annual sample for TTHMs is no more than 0.020 mg/L, the annual sample for HAAS is no more than 0.015 mg/L, and at least one year
of routine monitoring has been completed.
Chlorite. Routine Monitoring: CWSs
and NTNCWSs using chlorine dioxide
for disinfection or oxidation are
required to conduct sampling for
chlorite both daily at the entrance to the
distribution system and monthly within
the distribution system. Additional
distribution system monitoring may be
required, and distribution system
monitoring may be reduced if certain
conditions are met. This monitoring is
described below.
Routine Monthly Monitoring—
Systems are required to take a three
sample set each month in the
distribution system. One sample must
be taken at each of the following
locations: (1) as close as possible to the
first customer, (2) in a location
representative of average residence time,
and (3) as close as possible to the end
of the distribution system (reflecting
maximum residence time in the
distribution system). As described
elsewhere in this document, all samples
taken in the distribution system must be
analyzed by ion chromatography
(Methods 300.0 and 300.1).
Routine Daily Monitoring—Systems
must take one sample each day at the
entrance to the distribution system. As
described elsewhere in this document
(section III.G), samples taken at the
distribution system entrance may be
analyzed by amperometric titration
(Method 4500-ClOa E). If the chlorite
MCL is exceeded at the entrance to the
distribution system, the system is not
out of compliance. However, the system
must carry out addition monitoring as
described in the following paragraph.
Additional Monitoring: On any day
when the chlorite concentration
measured at the entrance to the
distribution system exceeds the chlorite
MCL (1.0 mg/L), the system is required
to take a three sample set in the
distribution system on the following
day, at the locations specified for
routine monthly monitoring. If the
system is required to conduct
distribution system monitoring as a
result of having exceeded the chlorite
MCL at the entrance to the distribution
system, and the average of the three
samples taken in the distribution system
is below 1.0 mg/L, the system will have
satisfied its routine monthly monitoring
requirement for that month. Further
distribution system monitoring will not
be required in that month unless the
chlorite concentration at the entrance to
the distribution system again exceeds
1.0 mg/L.
Reduced Monitoring: Systems may
reduce routine distribution system
monitoring for chlorite from monthly to
quarterly if the chlorite concentration in
all samples taken in the distribution
system is below 1.0 mg/L for a period
of one year and the system has not been
required to conduct any additional
monitoring. Systems that qualify for
reduced monitoring must continue to
conduct daily monitoring at the
entrance to the distribution system. If
the chlorite concentration at the
entrance to the distribution system
exceeds 1.0 mg/L, the system must
resume routine monthly monitoring.
Compliance Determination: A PWS is
out of compliance with the chlorite
MCL when the arithmetic average
concentration of any three sample set
taken in the distribution system is
greater than 1.0 mg/L.
Bromate. Routine Monitoring: CWSs
and NTNCWSs using ozone for
disinfection or oxidation are required to
take at least one sample per month for
each treatment plant in the system using
ozone. The sample must be taken at the
entrance to the distribution system
when the ozonation system is operating
under normal conditions.
Reduced Monitoring: Systems may
reduce monitoring from monthly to
once per quarter if the system
demonstrates that the annual average
raw water bromide concentration is less
than 0.05 mg/L, based upon monthly
measurements for one year.
Compliance Determination: A PWS is
in compliance if the running annual
arithmetic average of samples,
computed quarterly, is less than or
equal to the MCL.
Chlorine. Routine Monitoring: As a
minimum, CWSs and NTNCWSs must
measure the residual disinfectant level
(as either free chlorine or total chlorine)
at the same points in the distribution
system and at the same time as total
coliforms, as specified in § 141.21.
Subpart H systems may use the results
of residual disinfectant concentration
sampling done under the SWTR
(§141.74(b) (6) (i) for unfiltered systems,
§ 141.74(c)(3)(i) for systems that filter)
in lieu of taking separate samples.
Reduced Monitoring: Monitoring for
chlorine may not be reduced.
Compliance Determination: A PWS is
in compliance with the MRDL when the
running annual arithmetic average of
monthly averages of all samples,
computed quarterly, is less than or
equal to the MRDL. Notwithstanding the
MRDL, operators may increase residual
chlorine levels in the distribution
system to a level and for a time
necessary to protect public health to
address specific microbiological
contamination problems (e.g., including
distribution line breaks, storm runoff
events, source water contamination, or
cross-connections).
Chloramines. Routine Monitoring: As
a minimum, CWSs and NTNCWSs must,
measure the residual disinfectant level
(as either total'chlorine or combined
chlorine) at the same points in the
distribution system and at the same time
as total coliforms, as specified in
§ 141.21. Subpart H systems may use the
results of residual disinfectant
concentration sampling done under the
SWTR (§ 141.74(b)(6) for unfiltered
systems, § 141.74(c)(3) for systems that
filter) in lieu of taking separate samples.
Reduced Monitoring: Monitoring for
chloramines may not be reduced.
Compliance Determination: A PWS is
in compliance with the MRDL when the
running annual arithmetic average of
monthly averages of all samples,
computed quarterly, is less than or
equal to the MRDL. Notwithstanding the
MRDL, operators may increase residual
chloramine levels in the distribution
system to a level and for a time
necessary to protect public health to
address specific microbiological
contamination problems (e.g., including
distribution line breaks, storm runoff
events, source water contamination, or
cross-connections).
Chlorine Dioxide Routine Monitoring:
CWSs, NTNCWSs. and TNCWSs must
monitor for chlorine dioxide only if
chlorine dioxide is used by the system
for disinfection or oxidation. If
monitoring is required, systems must
take daily samples at the entrance to the
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69426 Federal-Register/Vol. 63, No. 2417 Wednesday* .December 16, 1998 / Rules -and. .Regulations
distribution system. If the MRDL (0.8
mg/L) is exceeded, the system must
conduct additional monitoring.
Additional Monitoring: If any daily
sample taken at the entrance to the
distribution system exceeds the MRDL,
the system is required to take three
additional samples in the distribution
system on the next day. Samples must
be taken at the following locations.
Systems using chlorine as a residual
disinfectant and operating booster
chlorinatlon stations after the first
customer—These systems must take
three samples in the distribution
system: one as close as possible to the
first customer, one in a location
representative of average residence time,
and one as close as possible to the end
of the distribution system (reflecting
maximum residence time in the
distribution system).
Systems using chlorine dioxide or
chloramines as a residual disinfectant or
chlorine as a residual disinfectant and
not operating booster chlorinatlon
stations after the first customer—These
systems must take three samples in the
distribution system as close as possible
to the first customer at intervals of not
less than six hours.
Reduced Monitoring: Monitoring for
chlorine dioxide may not be reduced.
Compliance Determination: Acute
violations—If any daily sample taken at
the entrance to the distribution system
exceeds the MRDL and if, on the
following day, one or more of the three
samples taken in the distribution system
exceeds the MRDL, the system will be
in acute violation of the MRDL and
must issue the required acute public
notification. Failure to monitor in the
distribution system on the day following
an exceedance of the chlorine dioxide
MRDL shall also be considered an acute
MRDL violation.
Nonacute violations—If any two
consecutive daily samples taken at the
entrance to the distribution system
exceed the MRDL, but none of the
samples taken in the distribution system
exceed the MRDL, the system will be in
nonacute violation of the MRDL. Failure
to monitor at the entrance to the
distribution system on the day following
an exceedance of the chlorine dioxide
MRDL shall also be considered a
nonacute MRDL violation.
Important Note: Unlike chlorine and
chloramines, the MRDL for chlorine
dioxide may not be exceeded for short
periods of time to address specific
microbiological contamination
problems.
TOO. Routine Monitoring: CWSs and
NTNCWSs which use conventional
filtration treatment must monitor each
treatment plant water source for TOC on
a monthly basis, with samples taken in
both the source water prior to any
treatment and in the treated water no
later than the point of combined filter
effluent turbidity monitoring. At the
same time, systems must monitor for
source water alkalinity.
Reduced Monitoring: Subpart H
systems with an average treated water
TOC of less than 2.0 mg/L for two
consecutive years, or less than 1.0 ing/
L for one year, may reduce monitoring
for both TOC and alkalinity to one
paired sample per plant per quarter.
Compliance Determination:
Compliance criteria for TOC are
dependent upon a variety of factors and
is discussed elsewhere in this rule.
2. Background and Analysis
The monitoring requirements in
today's rule are the same as those in the
1994 proposed rule, with the exception
of requirements for bromide monitoring
and chlorite.
Bromide Monitoring for Reduced
Bromate Monitoring. The 1994 proposal
included a provision for reduced
bromate monitoring for utilities with
source water bromide concentrations
less than 0.05 mg/L. EPA believes there
is a very small likelihood that systems
using ozone will exceed the bromate
MCL if source water bromide
concentrations are below this level. The
provision did not specify a bromide
monitoring frequency, however. Today's
rule allows utilities to reduce bromate
monitoring from monthly to once per
quarter if the system demonstrates,
based on representative monthly
samples over the course of a year, that .
the average raw water bromide
concentration is less than 0.05 mg/L.
Chlorite Monitoring. The proposed
rule required treatment plants using
chlorine dioxide to monitor for chlorite
ion by taking a three sample set in the
distribution system, once per month,
and to analyze these samples using ion
chromatography. However, the proposal
states that after the Negotiating
Committee had agreed to the above
monitoring scheme for chlorite at its last
meeting in June, 1993, EPA's Reference
Dose Committee met and determined a
different toxicological endpoint for
chlorite, based on the identification of
neurobehavioral effects. In light of this
finding, EPA asserted that it did not
believe the proposed monthly
monitoring requirement for chlorite was
sufficiently protective of public health.
Following the proposed rule, EPA
acquired additional information on
chlorite toxicity, including the results of
a two-generation study sponsored by the
CMA. This additional information,
discussed elsewhere in this document
(III.A.7), supported EPA's finding of
neurobehavioral health effects resulting
from chlorite, along with the rationale
for daily monitoring at the entrance to
the distribution system as a trigger for
further compliance monitoring in the
distribution system.
3. Summary of Comments
TOC. Many commenters expressed
confusion regarding the raw and
finished water TOC monitoring scheme
and their relationship to compliance
calculations. Commenters noted,
correctly, that changes in alkalinity and
TOC level can move the utility to a
different box of the TOC removal
matrix, and questioned whether this
would affect requisite monitoring. As in
the proposal, moving to a different box
of the matrix will not affect monitoring
requirements. Utilities are required to
take a minimum of one paired (raw and
finished water) TOC sample per month.
Commenters were also concerned that
the TOC monitoring provisions would
limit their ability to take additional TOC
samples for operational control. This
concern is unfounded; EPA
recommends in the Enhanced
Coagulation and Enhanced Precipitative
Softening Guidance Manual that
utilities take as many TOC samples as
necessary to maintain proper
operational control. EPA also
recommends that TQC compliance
samples, as opposed to operational
samples, be taken on a constant
schedule or be identified one month
prior to the samples being taken. This
will allow utilities to take numerous
operational samples and still provide for
unbiased compliance sampling. Systems
may use their sampling plans for this
purpose.
Chlorite. In the proposal, EPA
solicited comment on changing the
frequency and location of chlorite
monitoring in consideration of potential
acute health effects. Commenters stated
that daily monitoring of chlorite would
be feasible if amperometric titration
were allowed as an analytical method.
Commenters recommended that daily
amperometric analyses for chlorite be
conducted on samples taken from the
entrance to the distribution system, and
that weekly or monthly analyses using
ion chromatography still be required as
a check since ion chromatography is a
more accurate analytical method.
Several comments stated that daily
monitoring for chlorite would improve
operational control of plants and
decrease the probability of a PWS
exceeding the chlorite MCL in the
distribution system. However,
commenters requested that if daily
monitoring for chlorite were to be
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Federal Register/Vol. 63,' No. 241/Wednesday, December 16K1998/Rules and.Regulations 69427
required, a provision for reduced
chlorite monitoring be included as well.
In response to these comments,
today's rule requires treatment plants
using chlorine dioxide to conduct daily
monitoring for chlorite by taking one
sample at the entrance to the
distribution system. This sample may be
measured using amperometric titration
(Standard Method 4500-C1O 2 E).
Treatment plants are also required to
take a three sample set from the
distribution system once per month, as
was proposed in 1994. In addition,
today's rule requires that on any day
that the concentration of chlorite
measured at the distribution system
entrance exceeds the MCL, the
treatment plant must take a three
sample set in the distribution system on
the following day. All samples taken in
the distribution system must be
analyzed by ion chromatography
(Method 300.0 or 300.1).
EPA recommends that treatment
plants keep chlorite levels below 1.0
mg/L and believes that if treatment
plants exceed the MCL in finished
water, immediate distribution system
testing is warranted to ensure that
chlorite levels are below 1.0 mg/L. EPA
has not, however, changed the
compliance determination for chlorite
from the 1994 proposed rule.
Compliance is still based on the average
of three sample sets taken in the
distribution system. The results of daily
monitoring do not serve as a compliance
violation; rather, they can only trigger
immediate distribution system
monitoring. Moreover, if the treatment
plant is required to take distribution
system samples by the results of daily
monitoring and the average chlorite
concentration in the three distribution
system samples is below the MCL, then
that sampling will meet the treatment
plant's requirement for routine monthly
monitoring in the distribution system
for that month. Today's rule also
includes a provision for reduced
chlorite monitoring. Treatment plants
may reduce routine distribution system
monitoring for chlorite from monthly to
quarterly if the chlorite concentration in
all samples both at the entrance to the
distribution system and within the
distribution system are below 1.0 mg/L
for a period of one year.
In summary, after review of all public
comments and associated data, EPA
believes that these provisions for
chlorite monitoring will be both feasible
for treatment plants and provide a level
of protection to public health
commensurate with the toxic effects
associated with chlorite.
/. Compliance Schedules
1. Today's Rule
Today's action establishes revised
compliance deadlines for States to adopt
and for public water systems to
implement the requirements in this
rulemaking. Central to the
determination of these deadlines are the
principles of simultaneous compliance
between the Stage 1 DBPR and the
corresponding rules (Interim Enhanced
Surface Water Treatment Rule, Long
Term Enhanced Surface Water
Treatment Rule, and Ground Water
Rule) to ensure continued microbial
protection, and minimization of risk-
risk tradeoffs. These deadlines also
reflect new legislative provisions
enacted as part of 1996 SDWA
amendments. Section 1412 (b)(10) of the
SDWA as amended provides PWSs must
comply with new regulatory
requirements 36 months after
promulgation (unless EPA or a State
determines that an earlier time is
practicable or that additional time up to
two years is necessary for capital
improvements). In addition, Section
1413(a)(l) provides that States have 24
instead of the previous 18 months from
promulgation to adopt new drinking
water standards.
Applying the 1996 SDWA
Amendments to today's action, this
rulemaking provides that States have
two years from promulgation to adopt
and implement the requirements of this
regulation. Simultaneous compliance
will be achieved as follows.
Subpart H water systems covered by
today's rule that serve a population of
10,000 or more generally have three
years from promulgation to comply with
all requirements of this rule. In cases
where capital improvements are needed
to comply with the rule, States may
grant such systems up to an additional
two years to comply. These deadlines
were consistent with those for the
IESWTR.
Subpart H systems that serve a
population of less than 10,000 and all
ground water systems will be required
to comply with applicable Stage 1 DBPR
requirements within five years from
promulgation. Since the Long Term
Enhanced Surface Water Treatment Rule
(LT1) requirements that apply to
systems under 10,000 and the Ground
Water Rule are scheduled to be
promulgated two years after today's rule
or in November 2000, the net result of
this staggered deadline is that these
systems will be required to comply with
both Stage 1 DBPR and LT1/GWR
requirements three years after
promulgation of LT1/GWR at the same
end date of November 2003. For reasons
discussed in more detail below, EPA
believes this is both consistent with the
requirements of section 1412(b)(10) as
well as with legislative history affirming
the Reg. Neg. objectives of simultaneous
compliance and minimization of risk-
risk tradeoff.
2. Background and Analysis
The background, factors, and
competing concerns that EPA
considered in developing the
compliance deadlines in today's rule are
explained in detail in both the Agency's
IESWTR and Stage 1 DBPR November
1997 NOD As. As explained in those
NODAs, EPA identified four options to
implement the requirements of the 1996
SDWA Amendments. The requirements
outlined above reflect the fourth option
that EPA requested comment upon in
November 1997.
By way of background, the SDWA
1996 Amendments affirmed several key
principles underlying the M-DBP
compliance strategy developed by EPA
and stakeholders as part of the 1992
regulatory negotiation process. First,
under Section 1412(b)(5)(A), Congress
recognized the critical importance of
addressing risk/risk tradeoffs in
establishing drinking water standards
and gave EPA the authority to take such
risks into consideration in setting MCL
or treatment technique requirements.
The technical concerns and policy
objectives underlying M/DBP risk/risk
tradeoffs are referred to in the initial
sections of today's rule and have
remained a key consideration in EPA's
development of appropriate compliance
requirements. Second, Congress
explicitly adopted the phased M-DBP
regulatory development schedule
developed by the Negotiating
Committee. Section 1412(b)(2)(C)
requires that the M/DBP standard
setting intervals laid out in EPA's
proposed ICR rule be maintained even
if promulgation of one of the M-DBPRs
is delayed. As explained in the 1997
NODA, this phased or staggered
regulatory schedule was specifically
designed as a tool to minimize risk/risk
tradeoff. A central component of this
approach was the concept of
"simultaneous compliance", which
provides that a PWS must comply with
new microbial and DBF requirements at
the same time to assure that in meeting
a set of new requirements in one area,
a facility does not inadvertently increase
the risk (i.e., the risk "tradeoff) in the
other area.
A complicating factor that EPA took
into account in developing today's
deadlines is that the SDWA 1996
Amendments changed two statutory
provisions that elements of the 1992
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69428 Federal Register/Vol. 63, No. 241/.Wednesday, December. 16, 1998/Rules and. Regulations
Negotiated Rulemaking Agreement were
based upon. The 1994 Stage 1 DBPR and
ICR proposals provided that 18 months
after promulgation large PWS would
comply with the rules and States would
adopt and implement the new
requirements. As noted above, Section
1412(b)(10) of the SDWA as amended
now provides that drinking water rules
shall become effective 36 months after
promulgation (unless the Administrator
determines that an earlier time is
practicable or that additional time for
capital improvements is necessary—up
to two years). In addition, Section
1413(a)(l) now provides that States have
24 Instead of the previous 18 months to
adopt new drinking water standards that
have been promulgated by EPA.
Today's compliance deadline
requirements reflect the principle of
simultaneous compliance and the
concern with risk/risk tradeoffs. Subpart
H systems serving a population of at
least 10,000 will be required to comply
with the key provisions of this rule on
the same schedule as they will be
required to comply with the parallel
requirements of the accompanying
IESWTR that is also included in today's
Federal Register.
With regard to subpart H systems
serving fewer than 10,000, EPA believes
that providing a five year compliance
period under Stage 1 DBPR is
appropriate and warranted under
section 1412(b)(10), which expressly
allows five years where necessary for
capital improvements. As discussed in
more detail in the 1997 IESWTR NODA,
capital improvements require, of
necessity, preliminary planning and
evaluation. An essential prerequisite of
such planning is a clear understanding
of final compliance requirements that
must be met. In the case of the staggered
M/DBP regulatory schedule established
as part of the 1996 SDWA Amendments,
LT1 microbial requirements for systems
under 10,000 are required to be
promulgated two years after the final
Stage 1 DBPR. As a result, small systems
will not even know what their final
combined compliance obligations are
until promulgation of the LT 1 rule.
Thus, an additional two year period
reflecting the two year Stage 1 DBPR/LT
1 regulatory development interval
established by Congress is required to
allow for the preliminary planning and
design steps which are inherent in any
capital improvement process.
In the case of ground water systems,
the statutory deadline for promulgation
of the GWR is May 2002. However. EPA
intends to promulgate this rule by
November 2000, in order to allow three
years for compliance and still ensure
simultaneous compliance by ground
water systems with the Stage 1 DBPR
and the GWR. As in the case of subpart
H systems serving fewer than 10,000,
system operators will not know until
November 2000 what the final
compliance requirements for both rules
are. EPA thus believes it appropriate to
grant the additional two years for
compliance with the Stage 1 DBPR
allowed by the statute.
EPA has been very successful in
meeting all of the new statutory
deadlines and is on track for the LT1
Rule and GWR. While EPA fully intends
to meet the schedule discussed earlier,
if those rules are delayed the Agency
will evaluate all available options to
protect against unacceptable risk-risk
trade-offs. Part of this effort is the
extensive outreach to systems already
underway to fully inform water supplies
of the likely elements in the upcoming
rules. In addition, EPA would consider
including provisions for streamlined
variance and/or exemption processing
in these rules if they were delayed, in
order to enhance State flexibility in
ensuring that compliance with the Stage
1 DBPR is not required before the
corresponding microbial protection rule.
Under today's Stage 1 DBPR, EPA has
already provided small subpart H
systems and ground water systems the
two-year extension for capital
improvements since these systems will
not know with certainty until November
2000 if capital improvements will be
needed for simultaneous compliance
with the Stage 1 DBPR and LT1/GWR.
States considering whether to grant a
two-year capital improvement extension
for compliance with the GWR or LT1
will also need to consider the impact of
such extensions on compliance with
today's rule, given that a similar
extension for capital improvement has
already been provided in the initial
compliance schedule for the Stage 1
DBPR. EPA believes, however/that
these systems will generally not require
extensive capital improvements that
take longer than three years to install to
meet Stage 1 DBPR, GWR, and LT1
requirements, or will require no capital
improvements at all. However if needed,
EPA will work with States and utilities
to address systems that require time
beyond November 2003 to comply. This
strategy may include exemptions.
In addition, EPA will provide
guidance and technical assistance to
States and systems to facilitate timely
compliance with both DBF and
microbial requirements. EPA will
request comment on how best to do this
when the Agency proposes the
LTESWTR and GWR.
3. Summary of Comments
Commenters were in general
agreement that the compliance deadline
strategy contained in the fourth option
of the 1997 NODA did the best job of
complying with the requirements to
1996 SDWA Amendments and meeting
the objectives of the 1993 Reg. Neg.
Agreement that Congress affirmed as
part of the 1996 Amendments.
Nonetheless, a number of commenters
expressed concern about the ability of
large surface water systems that had to
make capital improvements to comply
with all requirements of the Stage 1
DBPR and IESWTR. They pointed out
that capital improvements include more
than just the construction, but also
financing, design, and approval.
EPA believes that the provisions of
Section 1412(b)(10) of the SDWA as
amended allow systems the flexibility
needed to comply. As noted earlier in
this section, States may grant up to an
additional two years compliance time
for an individual system if capital
improvements are necessary. Moreover,
as both of these rules have been under
negotiation since 1992, proposed in
1994 and further clarified in 1997, EPA
believes that most systems have had
substantial time to consider how to
proceed with implementation and to
initiate preliminary planning. Several
commenters also supported delaying the
promulgation of the Stage 1 DBPR for
ground water systems until the GWR is
promulgated, in order to ensure
simultaneous compliance with both
rules. EPA believes that this option
would not be consistent with the reg-
neg agreement, as endorsed by Congress,
because the agreement specifies that the
Stage 1 DBPR will apply to all
community and nontransient
noncommunity water systems.
Moreover, EPA has committed to the
LT1 and GWR promulgation schedule
oudined above precisely to address this
issue.
In conclusion EPA believes that the
compliance deadlines outlined above
for systems covered by this rule are
appropriate and consistent with the
requirements of the 1996 SDWA
amendments. The Agency notes,
however, that some elements of Option
4 outlined in the 1997 NODA apply to
systems that may be covered by future
Long Term Enhanced and Ground Water
rules. EPA intends to follow the
deadline strategy outlined in Option 4
for these future rules. However, as
today's action only relates to the Stage
1 DBPR, the Agency will defer final
action on deadlines associated with
future rules until those rules,
themselves, are finalized.
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J. Public Notice Requirements
1. Today's Rule
Today's action addresses public
notification by promulgating public
notification language for the regulated
compounds in 40 CFR Section 141.32
(e). EPA takes this opportunity to note
that the 1996 amendments to the SDWA
require the Agency to make certain
changes to the public notice regulations.
EPA intends to propose changes to the
public notice requirements in the
Federal Register shortly after
promulgation of the Stage 1 DBPR.
Applicable changes in the public notice
requirements, when they become
effective, will supersede today's
provisions. In general, the public
notification for the Stage 1 DBPR is not
substantially changed from that
included in the 1994 Proposed Stage 1
DBPR (EPA, 1994a).
2. Background and Analysis
Under Section 1414(c)(l) of the Act,
each owner or operator of a public water
system must give notice to the persons
served by the system of (1) any violation
of any MCL, treatment technique
requirement, or testing provision
prescribed by an NPDWR; (2) failure to
comply with any monitoring
requirement under section 1445 (a) of
the Act; (3) existence of a variance or
exemption; (4) failure to comply with
the requirements of a schedule
prescribed pursuant to a variance or
exemption; and (5) notice of the
concentration level of any unregulated
contaminant for which the
Administrator has required public
notice.
EPA promulgated the current
regulations for public notification on
October 28, 1987 (52 FR 41534—EPA,
1987). These regulations specify general
notification requirements, including
frequency, manner, and content of
notices, and require the inclusion of
EPA-specified health effects information
in each public notice. The public
notification requirements divide
violations into two categories (Tier 1
and Tier 2) based on the seriousness of
the violations, with each tier having
different public notification
requirements. Tier 1 violations include
violations of an MCL, treatment
technique, or a variance or exemption
schedule. Tier 1 violations contain
health effects language specified by EPA
which concisely and in non-technical
terms conveys to the public the adverse
health effects that may occur as a result
of the violation. States and water
utilities remain free to add additional
information to each notice, as deemed
appropriate for specific situations. Tier
2 violations include monitoring
violations, failure to comply with an
analytical requirement specified by an
NPDWR, and operating under a variance
or exemption.
Today's final rule contains specific
health effects language for the
contaminants which are in today's
rulemaking. EPA believes that the
mandatory health effects language is the
most appropriate way to inform the
affected public of the potential health
implications of violating a particular
EPA standard.
3. Summary of Comments
EPA received comments on the topic
of the public notification language for
TTHM, HAAS, chlorine, chloramines,
chlorine dioxide, and enhanced
coagulation. Some commenters noted
that the language in 141.32 (e) (79) is
satisfactory. One commenter requested
that the language for DBFs be modified
to recognize that disinfectants react with
naturally occurring organic and
inorganic matter to form DBFs. Some
commenters did not support the use of
the same public notification language
for both DBP MCL and enhanced
coagulation treatment technique
violations. Several commenters
suggested that the content of the notices
for chlorine, chloramine, and chlorine
dioxide should reflect that disinfection
is an essential step in surface water
treatment. One commenter suggested
that the language for chlorine dioxide
acute effects should be deleted. Other
commenters felt that the notice to
consumers of chlorine dioxide
violations at the treatment facility
which do not result in violations in the
distribution system (nonacute
violations) should not require public
notification.
In response, EPA has modified the
public notification language for DBFs to
indicate that disinfectants react with
naturally occurring organic and
inorganic matter to form DBFs. EPA
believes it is appropriate to use the same
public notification language for the
enhanced coagulation treatment
technique violation as for violations for
the TTHM and HAAS MCLs, since
enhanced coagulation is meant to limit
exposure to DBFs. EPA believes the
current language in the public
notification language is appropriate to
reflect that disinfection is an essential
step in water treatment. EPA believes
that since the potential health effects
from.chlorine dioxide are short-term
that it is appropriate to maintain the
acute effects language to protect the
fetus, infants, and children. In general,
the public notification requirements for
the Stage 1 DBPR will not substantially
change from that included in the 1994
Proposed Stage 1 DBPR (EPA, 1994a).
K. System Reporting and Record
Keeping Requirements
1. Today's Rule
The Stage 1 DBPR, consistent with the
current system reporting regulations
under 40 CFR 141.31, requires PWSs to
report monitoring data to States within
ten days after the end of the compliance
period. In addition, systems are required
to submit the data required in § 141.134.
These data are required to be submitted
quarterly for any monitoring conducted
quarterly or more frequently, and within
10 days of the end of the monitoring
period for less frequent monitoring.
Systems that are required to do extra
monitoring because of the disinfectant
used have additional reporting
requirements specified. This applies to
systems that use chlorine dioxide (must
report chlorine dioxide and chlorite
results) and ozone (must report bromate
results).
Subpart H systems that use
conventional treatment are required to
report either compliance/
noncompliance with DBP precursor
(TOC) removal requirements or report
which of the enhanced coagulation/
enhanced softening exemptions they are
meeting. There are additional
requirements for systems that cannot
meet the required TOC removals and
must apply for an alternate enhanced
coagulant level. These requirements are
included in § 141.134(b).
Calculation of compliance with the
TOC removal requirements is based on
normalizing the percent removals over
the most recent four quarters, since
compliance is based on that period.
Normalization, which would prescribe
equal weight to the data collected each
month, is necessary since source water
quality changes may change the percent
TOC removal requirements from one
month to another. EPA has developed a
sample reporting and compliance
calculation sheet that will be available
in the enhanced coagulation guidance
manual to assist utilities in making
these calculations.
2. Summary of Comments
There were no significant comments
on the system reporting and
recordkeeping requirements and
therefore EPA is finalizing the
requirements as proposed.
L. State Recordkeeping, Primacy, and
Reporting Requirements
The SDWA provides that States and
eligible Indian Tribes may assume
primary enforcement responsibilities.
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69430 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
Fifty-four out of fifty-six State and
territorial jurisdictions have applied for
and received primary enforcement
responsibility (primacy) under the Act.
No Tribes have received primacy. To
obtain primacy for the federal drinking
water regulations, States must adopt
their own regulations which are at least
as stringent as the federal regulations.
This section describes the regulations
and other procedures and policies that
States must adopt to implement the
final Stage 1 DBPR.
To Implement the final rule, States are
required to adopt the following
regulatory requirements:
—Section 141.32, Public Notification;
—Section 141.64, MCLs for Disinfection
Byproducts;
—Section 141.65. MRDLs for
Disinfectants;
—Subpart L, Disinfectant Residuals,
Disinfectant Byproducts, and
Disinfection Byproduct Precursors.
In addition to adopting regulations no
less stringent than the federal
regulations. States must adopt certain
requirements related to this regulation
in order to have their program revision
applications approved by EPA. This rule
also requires States to keep specific
records and submit specific reports to
EPA.
On April 28. 1998, EPA amended its
State primacy regulations at 40 CFR
142,12 to incorporate the new process
Identified in the 1996 SDWA
amendments for granting primary
enforcement authority to States while
their applications to modify their
primacy programs are under review (63
FR 23362; EPA. 1998i). The new process
grants Interim primary enforcement
authority for a new or revised regulation
during the period in which EPA is
making a determination with regard to
primacy for that new or revised
regulation. This interim enforcement
authority begins on the date of the
primacy application submission or the
effective date of the new or revised State
regulation, whichever is later, and ends
when EPA makes a final determination.
However, this interim primacy authority
is only available to a State that has
primacy for every existing national
primary drinking water regulation in
effect when the new regulation is
promulgated.
As a result. States that have primacy
for every existing NPDWR already in
effect may obtain interim primacy for
this rule, beginning on the date that the
State submits its complete and final
primacy application for this rule to EPA,
or the effective date of its revised
regulations, whichever is later. In
addition, a State which wishes to obtain
interim primacy for future NPDWRs
must obtain primacy for this rule.
1. State Recordkeeping Requirements
a. Today's Rule. The current
regulations in § 142.14 require States
with primacy to keep various records,
including analytical results to determine
compliance with MCLs, MRDLs, and
treatment technique requirements;
system inventories; State approvals;
enforcement actions; and the issuance of
variances and exemptions. The Stage 1
DBPR requires States to keep additional
records of the following, including all
supporting information and an
explanation of the technical basis for
each decision:
(1) Records of determinations made
by the State when the State has allowed
systems additional time to install GAC
or membrane filtration. These records
must include the date by which the
system is required to have completed
installation;
(2) Records of systems that are
required to meet alternative minimum
TOC removal requirements or for whom
the State has determined that the source
water is not amendable to enhanced
coagulation. These records must include
the results of testing to determine
alternative limits and the rationale for
establishing the alternative limits;
(3) Records of subpart H systems
using conventional treatment meeting
any of the enhanced coagulation or
enhanced softening exemption criteria;
(4) Register of qualified operators;
(5) Records of systems with multiple
wells considered to be one treatment
plant for purposes of determining
monitoring frequency;
(6) Records of the sampling plans for
subpart H systems serving more than
3,300 persons must be keep on file at
the State after submission by the system;
(7) A list of laboratories that have
completed performance sample analyses
and achieved the quantitative results for
TOC, TTHMs, HAAS, bromate, and
chlorite; and
(8) A list of all systems required to
monitor for disinfectants and DBFs
under subpart L.
b. Background and Analysis. In
addition to requesting comments on the
requirements (1) through (5), and (7)
and (8) listed above, EPA also requested
comments on whether States should be
required to keep the monitoring plan
submitted by systems serving more than
3,300 people on file at the State after
submission to make it available for
public review.
c. Summary of Comments. There were
several commenters who suggested that
EPA should keep in mind State budget
constraints when requiring specific
additional recordkeeping requirements.
Other commenters stated that they
believed the requirements were
necessary. EPA understands
commenters concerns with requiring
recordkeeping requirements that are
unnecessary, but believes this
information is important to conduct
effective State program oversight,
including the review of State decisions
and their basis. After further review,
EPA has decided to eliminate the
requirement in the proposal that States
must keep records of systems that apply
for alternative TOC performance
criteria. EPA is more concerned with the
systems that are required to meet
alternative TOC performance criteria,
not the systems that have applied for the
alternative performance criteria. In
addition, EPA has added three
recordkeeping requirements, two of
which were originally in the reporting
requirements section and one for which
EPA requested comment.
The first additional requirement will
require States to keep lists of all systems
required to monitor for various
disinfectants and DBPs (#8 above). The
second additional requirement will
require States to maintain a list of
laboratories that have completed
performance sample analyses and
achieved the quantitative results for
TOC, TTHMs, HAAS, bromate, and
chlorite (#6 above). EPA believes both of
these recordkeeping requirements are
necessary to ensure adequate EPA
program oversight. As discussed below,
these two requirements are no longer in
the State reporting requirements as EPA
has decided that the requirements in the
proposal on State reporting
requirements are not needed on a
regular basis, but are needed for
program oversight. The third additional
requirement pertains to the request for
comment in the proposal on
maintaining the monitoring plans
submitted by systems (#6 above).
Several commenters supported this
additional requirement stating that it
was a necessary element for
implementing the final rule. Others
believed it was not necessary to keep
this on file because the public could
request this information from the system
or the State as normal public records.
EPA believes that it is important for
States to review, and keep on file the
systems monitoring plan to ensure that
the PWS is monitoring and calculating
compliance in accordance with the
plan. This will also enable the public to
view the plan. Thus, EPA is adding this
requirement to the final recordkeeping
requirements. In conclusion, based on a
review of all public comments the final
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Federal Register/Vol."-63. No. 241/Wednesday, December 16, 1998/Rules, and Regulations 69431
rule contains eight State recordkeeping
requirements in addition to those
required under current regulations in
§142.14.
2. Special Primacy Requirements
a. Today's Rule. To ensure that a State
program includes all the elements
necessary for an effective and
enforceable program under today's rule,
a State application for program revision
approval must include a description of
how the State will:
(1) Determine the interim treatment
requirements for systems granted
additional time to install GAG and
membrane filtration under 141.64(b)(2).
(2) Qualify operators of community
and nontransient noncommunity water
systems subject to this regulation under
141.130(c). Qualification requirements
.established for operators of systems
subject to 40 CFR Part 141 Subpart H
(Filtration and Disinfection) may be
used in whole or in part to establish
operator qualification requirements for
meeting subpart L requirements if the
State determines that the subpart H
requirements are appropriate and
applicable for meeting subpart L
requirements.
(3) Approve DPD colorimetric tests
kits for free and total chlorine
measurements under 141.131 (c) (2).
State approval granted under subpart H
(§ 141.74(a)(2)) for the use of DPD
colorimetric test kits for free chlorine
testing would be considered acceptable
approval for the use of DPD test kits in
measuring free chlorine residuals as
required in subpart L.
(4) Approve parties to conduct
analyses of water quality parameters
under 141.132(a)(2) (pH, alkalinity,
bromide, and residual disinfectant
concentration measurements). The
State's process for approving parties
performing water quality measurements
for systems subject to subpart H
requirements may be used for approving
parties measuring water quality
parameters for systems subject to
subpart L requirements, if the State
determines the process is appropriate
and applicable..„_
(5) Define criteria to use in
determining if multiple wells are being
drawn from a single aquifer and
therefore can be considered as a single
source under 141.132 (a) (2): Such
criteria will be used in determining the
monitoring frequency for systems using
only ground water nox under the direct
influence of surface waier.
(6) Approve alternative TOG removal
levels as allowed under 141.135 (b).
b. Background and Analysis. As
discussed above, EPA included several
special primacy requirements to ensure
that State programs contain all the
essential elements for an effective
program. Specifically, EPA believes the
special requirements are important to
ensure that the process or approach
used by the State for evaluating whether
the interim treatment in place for
systems granted additional time to
install GAG or membranes or alternative
enhanced coagulation levels will be
protective of public health. The
requirement to have qualified operators
is important because the treatment
technologies used to comply with the
Stage 1 DBPR and the IESWTR
simultaneously are complex and will
require a certain level of expertise. The
requirement to approve parties for
conducting analyses of specific water
quality parameters is important because
each of the parameters required to be
tested is critical to a specific component
of the final rule (e.g., bromide ion is
important because for bromate it is
possible to reduce monitoring from
monthly to once per quarter, if a system
demonstrates that the average raw water
bromide concentration is less than 0.05
mg/L based upon representative
monthly measurements for one year).
Finally, it is important to define the
criteria used to determine if multiple
wells are to be considered a single
source as this could have significant
implications for monitoring.
c. Summary of Comments. There were
no significant comments on the primacy
requirements. The only change from the
proposal was to delete the requirement
that States must have approved parties
to perform temperature evaluations.
This requirement was included in the
proposed rule because of the need to
have accurate measurements as a part of
the process for not allowing
predisinfection credit. Since the final
rule allows credit for compliance with
applicable disinfection requirements
consistent with the SWTR, the
temperature requirement was removed.
3. State Reporting Requirements
a. Today's Rule. EPA currently
requires in § 142.15 that States report to
EPA information such as violations,
variance and exemption status, and
enforcement actions. The Stage 1 DBPR
does not add any additional reporting
requirements.
b. Background and Analysis. The
preamble to the proposed rule included
six State reporting requirements. These
included:
(1) A list of all systems required to
monitor for various disinfectants and
disinfection byproducts;
(2) A list of all systems for which the
State has granted additional time for
installing GAG or membrane technology
and the basis for the additional time;
(3) A list of laboratories that have
completed performance sample analyses
and achieved the quantitative results for
TOG, TTHMs, HAAS, bromate, and
chlorite;
(4) A list of all systems using multiple
ground water wells which draw from
the same aquifer and are considered a
single source for monitoring purposes;
(5) A list of all Subpart H systems
using conventional treatment which are
not required to operate with enhanced
coagulation, and the reason why
enhanced coagulation is not required for
each system; and
(6) A list of all systems with State-
approved alternate performance
standards (alternate enhanced
coagulation levels).
c. Summary of Comments. Several
commenters stated that the reporting
requirements were not necessary to
operate an oversight program and that
these reports could be made available
for EPA review during annual audits.
EPA agrees with commenters that the
reports are not necessary to operate an
oversight program, and that if needed
EPA could request this information from
the States. However, EPA does believe
it is important that States maintain this
information in their records. In
conclusion, based on commenters
concerns and for the reasons cited
above, the final rule contains no
additional State reporting requirements
other than those required by 142.15.
M. Variances and Exemptions
1. Today's Rule
Variances may be granted in
accordance with section 1415(a)(l)(A) of
the SDWA and in accordance with
1415 (e) and EPA's regulations.
Exemptions may be granted in
accordance with section 1416 (a) of the
SDWA and EPA's regulations.
2. Background and Analysis
Variances. The SDWA provides for
two types of variances—general
variances and small system variances.
Under section 1415 (a) (1) (A) of the
SDWA, a State which has primary
enforcement responsibility (primacy), or
EPA as the primacy agency, may grant
variances from MCLs to those public
water systems of any size that cannot
comply with the MCLs because of
characteristics of the water sources. The
primacy agency may grant general
variances to a system on condition that
the system install the best available
technology, treatment techniques, or
other means, and provided that
alternative sources of water are not
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69432 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
reasonably available to the system. At
the time this type of variance is granted,
the State must prescribe a compliance
schedule and may require the system to
implement additional control measures.
Furthermore, before EPA or the State
may grant a general variance, it must
find that the variance will not result in
an unreasonable risk to health (URTH)
to the public served by the public water
system.
Under section 1413(a)(4), States that
choose to issue general variances must
do so under conditions, and in a
manner, that are no less stringent than
section 1415. Of course, a State may
adopt standards that are more stringent
than the EPA standards. EPA specifies
BATs for general variance purposes.
EPA may identify as BAT different
treatments under section 1415 for
variances other than the BAT under
section 1412 for MCLs. EPA's section
1415 BAT findings may vary depending
on a number of factors, including the
number of persons served by the public
water system, physical conditions
related to engineering feasibility, and
the costs of compliance with MCLs. In
this final rule. EPA is not specifying
different BAT for variances under
section 1415(a). Section 1415(e)
authorizes the primacy Agency (EPA or
the State) to issue variances to small
public water systems (those serving less
than 10,000 persons) where the system
cannot afford to comply with an MCL
and where the primacy agency
determines that the terms of the
variances ensure adequate protection of
public health (63 FR 1943-57; EPA,
1998)). These variances also may only
be granted where EPA has identified a
variance technology under Section
1412(b)(15) for the contaminant, system
size and source water quality in
question.
Prior to the 1996 SDWA amendments,
EPA was required to set the MCL for a
contaminant as close to the MCLG as is
feasible. Section 1412(b)(4)(D) of the
SDWA states that "the term "feasible"
means with the use of the best
technology, treatment techniques and
other means which the Administrator
finds, after examination for efficacy
under field conditions and not solely
under laboratory conditions, are
available (taking cost into
consideration)."
The cost assessment for the feasibility
determinations have historically been
based upon Impacts to regional and
large metropolitan water systems
serving populations greater than 50,000
people. Since large systems served as
the basis for the feasibility
determinations, the technical and/or
cost considerations associated with
these technologies often were not
applicable to small water systems.
While EPA will continue to use
feasibility for large systems in setting
NPDWRs, the 1996 amendments to the
SDWA specifically require EPA to make
small system technology assessments for
both existing and future regulations.
The 1996 amendments to the SDWA
identifies three categories of small
public water systems that need to be
addressed: (1) those serving a
population between 3301 to 10,000; (2)
those serving a population of 501—
3300; and (3) those serving a population
of 26—500. The SDWA requires EPA to
make determinations of available
compliance technologies and, if needed,
variance technologies for each size
category. A compliance technology is a
technology that is affordable and that
achieves compliance with the MCL and/
or treatment technique. Compliance
technologies can include point-of-entry
or point-of-use treatment units. Variance
technologies are only specified for those
system size/source water quality
combinations for which there are no
listed compliance technologies.
EPA has completed an analysis of the
affordability of DBF control
technologies for each of the three size
categories included above. Based on this
analysis, multiple affordable
compliance technologies were found for
each of the three system sizes (EPA,
1998q and EPA, 1998r) and therefore
variance technologies were not
identified for any of the three size
categories. The analysis was consistent
with the methodology used in the
document "National-Level Affordability
Criteria Under the 1996 Amendments to
the Safe Drinking Water Act" (EPA,
1998s) and the "Variance Technology
Findings for Contaminants Regulated
Before 1996" (EPA, 1998t).
Exemptions. Under section 1416(a),
EPA or a State may exempt a public
water system from any requirements
related to an MCL or treatment
technique of an NPDWR, if it finds that
(1) due to compelling factors (which
may include economic, factors such as
qualification of the PWS as serving a
disadvantaged community), the PWS is
unable to comply with the requirement
or implement measure to develop an
alternative source of water supply; (2)
the exemption will not result in an
unreasonable risk to health; and; (3) the
PWS was in operation on the effective
date of the NPWDR, or for a system that
was not in operation by that date, only
if no reasonable alternative source of
drinking water is available to the new
system; and (4) management or
restructuring changes (or both) cannot
reasonably result in compliance with
the Act or improve the quality of
drinking water.
If EPA or the State grants an
exemption to a public water system, it
must at the same time prescribe a
schedule for compliance (including
increments of progress or measures to
develop an alternative source of water
supply) and implementation of
appropriate control measures that the
State requires the system to meet while
the exemption is in effect. Under section
1416(b)(2)(A), the schedule prescribed
shall require compliance as
expeditiously as practicable (to be
determined by the State), but no later
than 3 years after the effective date for
the regulations established pursuant to
section 1412(b)(10). For public water
systems which do not serve more than
a population of 3,300 and which need
financial assistance for the necessary
improvements, EPA or the State may
renew an exemption for one or more
additional two-year periods, but not to
exceed a total of 6 years, if the system
establishes that it is taking all
practicable steps to meet the
requirements above.
A public water system shall not be
granted an exemption unless it can
establish that either: (1) the system
cannot meet the standard without
capital improvements that cannot be
completed prior to the date established
pursuant to section 1412(b)(10); (2) in
the case of a system that needs financial
assistance for the necessary
implementation, the system has entered
into an agreement to obtain financial
assistance pursuant to section 1452 or
any other Federal or state program; or
(3) the system has entered into an
enforceable agreement to become part of
a regional public water system.
3. Summary of Comments on Variance
and Exemptions
In the 1994 proposal, EPA requested
comment on whether exemptions to the
rule should be granted if a system could
demonstrate to the State that due to
unique water quality characteristics it
could not avoid, through the use of
BAT, the possibility of increasing total
health risk to its consumers by
complying with the Stage 1 regulations.
The Agency requested information
under which such a scenario may
unfold. Several commenters supported
granting exemptions provided a system
could demonstrate that installation of
BAT will increase die total health risk.
After additions! consideration, EPA
believes it is not appropriate, for several
reasons, to granf exemptions based on a
demonstration that the use of BAT
could increase (he total health risk by
complying wittfthe Stage 1 DBPR. First,
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EPA does not believe the analytical
tools and methodologies are currently
available that would allow a
determination of whether the total
health risk from the installation of BAT
would increase. Second, at the time of
proposal there was concern that in
waters with high bromide
concentrations it may be possible to
increase the concentrations of certain
brominated DBFs when using precursor
removal processes even though the
concentrations of the TTHMs and HAAS
may decrease. Also, at the time of
proposal, the health risks associated
with many of the brominated DBFs was
unknown, and it was unclear whether
the benefits of lowering the
concentrations of chlorinated DBFs
outweigh the possible downside risks of
increasing certain brominated DBFs.
Since the proposal, some additional
health effects research has been
completed evaluating the toxicity of
brominated DBFs. However, this
research is still preliminary and no
conclusions can be drawn on the
potential for increased risks from the
brominated DBFs. In addition, it is
unclear to what extent the use of
precursor removal processes will change
the concentrations of certain brominated
DBFs. The ICR data should provide
some additional information that may
be helpful in this area along with
additional ongoing research. This
information will be available for
consideration in the Stage 2 rule
deliberations. Based on the reasons
stated above, EPA does not believe it is
appropriate to allow exemptions to the
rule based on a finding that the
installation of BAT would increase the
total risk from DBFs.
N. Laboratory Certification and
Approval
1. Today's Rule
EPA recognizes that the effectiveness
of today's regulations depends on the
ability of laboratories to reliably analyze
the regulated disinfectants and DBFs at
the MRDL or MCL, respectively.
Laboratories must also be able to
measure the trihalomethanes and
haloacetic acids at the reduced
monitoring trigger levels, which are
between 25 and 50 percent of the MCLs
for these compound classes. EPA has
established State primacy requirements
for a drinking water laboratory
certification program for the analysis of
DBFs. States must adopt a laboratory
certification program as part of primacy.
[40 CFR 142.10(b)]. EPA has also
specified laboratory requirements for
analyses of DBF precursors and
disinfectant residuals which must be
conducted by approved parties. [40 CFR
141.89 and 141.74]. EPA's "Manual for
the Certification of Laboratories
Analyzing Drinking Water", EPA 815-
B-97-001—(EPA, 1997g), specifies the
criteria for implementation of the
drinking water laboratory certification
program.
In today's rule, EPA is promulgating
MCLs for TTHMs, HAAS, bromate, and
chlorite. Today's rule requires that only
certified laboratories be allowed to
analyze samples for compliance with
the proposed MCLs. For the
disinfectants and certain other
parameters in today's rule, which have
MRDLs or monitoring requirements,
EPA is requiring that analyses be
conducted by a party acceptable to the
State.
Performance evaluation (PE) samples,
which are an important tool in the
SDWA laboratory certification program
(laboratories seeking certification) may
be obtained from a PE provider
approved by the National Institute of
Science and Technology (NIST). To
receive and maintain certification, a
laboratory must use a promulgated
method and, at least once per year,
successfully analyze an appropriate PE
sample. In the drinking water PE
studies, NIST-approved providers will
provide samples for bromate, chlorite,
five haloacetic acids, four
trihalomethanes, free chlorine, and
alkalinity. The NIST-approved PE
providers will provide total chlorine
and TOC samples in the wastewater PE
studies and have the potential to
provide these samples for drinking
water studies. Due to the lability of
chlorine dioxide, EPA does not expect
a suitable PE sample can be designed for
chlorine dioxide measurements.
PE Sample Acceptance Limits for
Laboratory Certification. Historically,
EPA has set minimum PE acceptance
limits based on one of two criteria:
statistir^illy derived estimates or fixed
acceptance limits. Statistical estimates
are based on laboratory performance in
the PE study. Fixed acceptance limits
are ranges around the true concentration
of the analyte in the PE sample. Today's
rule combines the advantages of these
approaches by specifying statistically-
derived acceptance limits around the
study mean, within specified minimum
and maximum fixed criteria.
EPA believes that specifying
statistically-derived PE acceptance
limits with upper and lower bounds on
acceptable performance provides the
flexibility necessary to reflect
improvement in laboratory performance
and analytical technologies. The
acceptance criteria maintain minimum
data quality standards (the upper
bound) without artificially imposing
unnecessarily strict criteria (the lower
bound). Therefore, EPA is establishing
the following acceptance limits for
measurement of bromate, chlorite, each
haloacetic acid, and each
trihalomethane in a PE sample.
EPA is defining acceptable
performance for each chemical
measured in a PE sample from estimates
derived at a 95% confidence interval
from the data generated by a statistically
significant number of laboratories
participating in the PE study. However,
EPA requires that these acceptance
criteria not exceed ±50% nor be less
than ±15% of the study mean. If
insufficient PE study data are available
to derive the estimates required for any
of these compounds, the acceptance
limit for that compound will be set at
±50% of the study true value. The true
value is the concentration of the
chemical that EPA has determined was
in the PE sample.
EPA recognizes that when using
multianalyte methods, the data
generated by laboratories that are
performing well will occasionally
exceed the acceptance limits. Therefore,
to be certified to perform compliance
monitoring using a multianalyte
method, laboratories are required to
generate acceptable data for at least 80%
of the regulated chemicals in the PE
sample that are analyzed with the
method. If fewer than five compounds
are included in the PE sample, data for
each of the analytes in that sample must
meet the minimum acceptance criteria
in order for the laboratory to be
certified.
Approval Criteria for Disinfectants
and Other Parameters. Today's rule
establishes MRDLs for the three
disinfectants—chlorine, chloramines,
and chlorine dioxide. In addition, EPA
has established monitoring
requirements for TOC, alkalinity, and
bromide; there are no MCLs for these
parameters. In previous rules [40 CFR
141.28, .74, and .89], EPA has required
that measurements of alkalinity,
disinfectant residuals, pH, temperature,
and turbidity be made with an approved
method and conducted by a party
approved (not certified) by the State. In
today's rule, EPA requires that samples
collected for compliance with today's
requirements for alkalinity, bromide,
residual disinfectant, and TOC be
conducted with approved methods and
by a party approved by the State.
Other Laboratory Performance
Criteria. For all contaminants and
parameters required to be monitored in
today's rule, the States may impose
other requirements for a laboratory to be
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69434 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules .and Regulations
certified or a party to be approved to
conduct compliance analyses.
2, Background and Analysis
The laboratory certification and
approval requirements that today's rule
establishes are unchanged from those
proposed by EPA in 1994.
3. Summary of Comments
EPA received few comments on
laboratory certification and approval.
Commenters requested clarification of
the use of the ±50% upper bound and
±15% lower bound, along with the use
of statistically derived limits. EPA
believes that statistically derived limits
provide flexibility to allow laboratory
certification standards to reflect
improvement in laboratory performance
and analytical technologies. As
laboratories become more proficient in
conducting these analyses, statistically
derived acceptance limits may drop.
However, to prevent the exclusion of
laboratories capable of producing data
of sufficient quality for compliance
purposes, EPA has established a lower
bound for acceptance limits of ±15%.
EPA is imposing an upper bound on
acceptable performance to establish
minimum data quality standards.
Results outside of this range have
unacceptable accuracy for compliance
determinations. These upper and lower
bounds were not determined
statistically; they are the data quality
objectives the Agency has determined as
acceptable.
IV. Economic Analysis
Under Executive Order 12866,
Regulatory Planning and Review, EPA
must estimate the costs and benefits of
the Stage 1 DBPR in a Regulatory Impact
Analysis (RIA) and submit the analysis
to Office of Management and Budget
(OMB) in conjunction with publishing
the final rule. EPA has prepared an RIA
to comply with the requirements of this
Order. This section provides a summary
of the information from the RIA for the
Stage 1 DBPR (USEPA 1998g).
A, Today's Rule
EPA has estimated that the total
annualized cost, for implementing the
Stage 1 DBPR is $701 million in 1998
dollars (assuming a 7 percent cost of
capital). This estimate includes
annualized treatment costs to utilities
(S593 million), start-up and annualized
monitoring costs to utilities ($91.7
million), and startup and annualized
monitoring costs to states ($17.3
million). Annualized treatment costs to
utilities includes annual operation and
maintenance costs ($362 million) and
annualized capital costs assuming 7
percent cost of capital ($230 million).
The basis for these estimates, and
alternate cost estimates using different
cost of capital assumptions are
described later in this section. While the
benefits of this rule are difficult to
quantify because of the uncertainty
associated with risks from exposure to
DBFs (and the resultant reductions in
risk due to the decreased exposure from
DBFs), EPA believes that there is a
reasonable likelihood that the benefits
will exceed the costs. Various
approaches for assessing the benefits are
considered and described in the benefits
and net benefits sections of this
preamble.
B. Background
1. Overview of RIA for the Proposed
Rule
In the RIA for the 1994 proposed
Stage 1 DBPR (EPA, 19941) EPA
estimated the national capital and
annualized utility costs (sum of
amortized capital and annual operating
costs, assuming 10% cost of capital) for
all systems at $4.4 billion and $1.04
billion, respectively. The cost and
reduction in DBF exposure estimates of
the 1994 RIA were derived using a
Disinfection Byproduct Regulatory
Analysis Model (DBPRAM). The
DBPRAM consisted of a collection of
analytical models which used Monte
Carlo simulation techniques to produce
national forecasts of compliance and
exposure reductions for different
regulatory scenarios. The TWG,
representing members of the Reg. Neg.
Committee, used the best available
information at the time as inputs to the
DBPRAM, and for making further
adjustments to the model predictions.
The Stage 1 DBPR compliance and
exposure forecasts were affected by
constraints imposed by the 1994
proposed IESWTR option which would
have required systems to provide
enough disinfection, while not allowing
for disinfection credit prior to TOC
removal by enhanced coagulation, to
achieve a 10_4 annual risk of infection
from Giardia (EPA, 1994a). The
compliance forecast assumed that a
substantial number of systems would
need to install advanced technologies to
meet the Stage 1 DBPR because of
needing to achieve the 10_4 annual risk
level from Giardia while no longer being
allowed disinfection credit prior to TOC
removal.
Predicted benefits for the proposed
Stage 1 DBPR were derived assuming a
baseline risk ranging from 1 to 10,000
cancer cases per year (based on analysis
of available toxicological and
epidemiological data) and assuming
reductions in the cancer risks were
proportional to reductions in TTHM,
HAAS, or TOC levels (predicted from
compliance forecasts). Negotiators
agreed that the range of possible risks
attributed to chlorinated water should
consider both toxicological data and
• epidemiological data, including the
Morris et al. (1992) estimates. No
consensus, however, could be reached
on a single likely risk estimate.
Therefore, the predicted benefits for the
proposal ranged from one to several
thousands cases of cancer being avoided
per year after implementation of the
Stage 1 DBPR. Despite, the uncertainty
in quantifying the benefits from the
Stage 1 DBPR, the Reg. Neg. Committee
recognized that risks from chlorinated
water could be large, and therefore
should be reduced. The Reg. Neg.
Committee also recommended that the
proposed Stage 1 DBPR provided the
best means for reducing risks from DBFs
until better information become
available.
For a more detailed discussion of the
cost and benefit analysis of the 1994
proposed DBPR refer to the preamble of
the proposed rule (EPA, 1994a) and the
RIA for the proposed rule (EPA, 19941).
2. Factors Affecting Changes to the 1994
RIA
a. Changes in Rule Criteria. Based on
the new data reflecting the feasibility of
enhanced coagulation, as discussed
previously, the enhanced coagulation
requirements were modified by
decreasing the percent TOC removal
requirements by 5 percent for systems
with low TOC level waters (i.e., 2-4 mg/
L TOC). These new percent TOC
removal requirements were used with
new source and finished water TOC
occurrence data to revise the estimates
for the number of systems requiring
enhanced coagulation.
The IESWTR was revised from the
proposal to allow inactivation credit for
disinfection prior to and during stages
of treatment for precursor removal.
Also, the proposed IESWTR was revised
to include disinfection benchmark
criteria, in lieu of requiring treatment to
an acceptable risk level, to prevent
increases in microbial risk while
systems complied with the Stage 1
DBPR. These two rule changes were
considered in revising the forecasts of
compliance and changes in exposure
resulting from the Stage 1 DBPR.
b. New Information Affecting DBF
Occurrence and Compliance Forecasts.
Since the rule was proposed, new
sources of data have become available
that were used to update the 1994 RIA.
The new data includes:
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Federal Register/Vol. 63. No. 2417 Wednesday, December 16, 1998/Rules and Regulations 69435
• Updated costs for different
treatment technologies (e.g.,
membranes) used in the DBF Cost and
Technology Document, (EPA, 1998k);
• 1996 data from the AWWA Water
Industry Data Base on TOC, TTHM and
HAAS occurrence, and disinfection
practices;
• Plant schematics of treatment
processes for ICR utilities;
• Research data from numerous
sources regarding the efficacy of
enhanced coagulation for precursor
removal and resultant DBF formation
(Krasner, 1997; and EPA, 1997b);
• New research results produced in
jar tests by TWG members documenting
the effect of moving the point of
predisinfection under varying
conditions (Krasner, 1997 and EPA,
1997b).
This new information has been
described in the 1997 DBF NOD A (EPA,
1997b). Public comments received in
1997, supported using the above
information in revising the decision tree
analysis. Discussion on the decision tree
changes are in section IV.C of this
preamble.
c. New Epidemiology Information.
Since the proposal, EPA has completed
an reassessment of the Morris et al.
(1992) meta-analysis (Poole, 1997).
Review of the meta-analysis indicated
that the estimate of cancer cases had
limited utility for risk assessment
purposes for methodological reasons
(EPA, 19981 and EPA, 1998m). EPA has
decided not to use the Morris et al.
(1992) meta-analysis to estimate the
potential benefits from the Stage 1
DBPR. EPA has considered new
epidemiology studies conducted since
the time of proposal and completed an
assessment of the potential number of
bladder cancer cases that could be
attributed to exposure from chlorinated
surface waters. Based on this assessment
of epidemiological studies, EPA
estimates that between 1100-9300
bladder cancer cases per year could be
attributed to exposure to chlorinated
surface waters (EPA, 1998c). Due to the
wide uncertainty in these estimates, the
true number of attributable cases could
also be zero. The basis for these bladder
cancer case estimates and potential
reductions in risk resulting from the
Stage 1 DBPR is discussed further in the
benefits and net benefits sections that
follow.
C. Cost Analysis
National cost estimates of compliance
with the Stage 1 DBPR were derived
from estimates of utility treatment costs,
monitoring and reporting costs, and
start-up costs. Utility treatment costs
were derived using compliance forecasts
of technologies to be used and unit costs
for the different technologies.
1. Revised Compliance Forecast
The TWG, supporting the M-DBP
Advisory Committee, used the 1996
AWWA Water Industry Data Base
(WIDE) to reevaluate the compliance
decision tree used in the RIA for the
1994 proposal. The WIDE provided
occurrence data on TOC level in raw
water and finished water, TTHM and
HAAS levels within distribution
systems, and information on
predisinfection practices.
The above information was used to
predict treatment compliance choices
that plants would likely make under the
Stage 1 DBPR. Table IV-1 illustrates
how the compliance forecast changed
for large systems using surface water
since the time of proposal.
TABLE IV-1 .—COMPARISONS OF COMPLIANCE FORECASTS FOR SURFACE WATER SYSTEMS SERVING >10,000
POPULATION FROM THE 1994 PROPOSAL AND FINAL RULE
Treatment
(A) No Further Treatment ....
(B) Chlorine/Chloramines ....
(C) Enhanced Coagulation +
(D) Enhanced Coagulation +
(E) Ozone, Chlorine Dioxide,
Total*
Chloramines
Chlorine
Granular Activated Carbon, Membranes
1994
* systems
386
41
136
600
232
1,395
% systems
27.7
2.9
9.7
43.0
16.6
100
1998
* systems
544
231
265
265
90
1,395
% systems
39.0
16.6
19.0
19.0
6.5
100
*May not add to total due to independent rounding.
Notable is that the percentage of systems
predicted to use advanced technologies
(ozone, chlorine dioxide, GAC, or
membrane) dropped from 17 percent to
6.5 percent since proposal, and the
percentage of systems not affected by
the rule increased from 28 percent to 39
percent. This shift in predicted
compliance choices is mainly attributed
to less stringent disinfection
requirements under the IESWTR which
would reduce the formation of DBFs
and reduce the number of systems
requiring treatment to meet the Stage 1
DBPR. It also appears that a substantial
number of systems may have already
made treatment changes to comply with
the 1994 proposed rule.
Table IV-2 illustrates how the
compliance forecast changed for small
systems using surface water since the
time of proposal. As for large systems,
the percentage of systems predicted to
use advanced technologies dropped
substantially, from 17 percent to 6.5
percent. This drop in use of advanced
technology (i.e., ozone/chloramines and
membrane technologies) is attributed to
the change in the IESWTR (as described
above) from the time of proposal.
However, unlike for large systems, the
overall percentage of systems predicted
to require treatment modifications did
not change. A higher percentage of
small systems (70 percent) are predicted
to be affected than large systems (61
percent) because previously smaller
systems did not have to comply with a
TTHM standard.
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69436 Federal'Register/Vol. 63, No. 241 /Wednesday, December 16, 1998/Rules and Regulations
TABLE IV-2.—COMPARISON OF COMPLIANCE DECISION TREE FOR SURFACE WATER SYSTEMS SERVING <10,000
POPULATION FROM THE 1994 PROPOSAL AND FINAL RULE
Numbsr of Affoctsd Systems •
Treatment:
Membranes
1£
* systems
1,549
3,615
155
2,169
465
258
258
310
)94
% systems
30
70
3.0
42.0
9.0
5.0
5.0
6.0
19
* systems
1,549
3,615
826
1,983
465
184
0
157
98
% systems
30
70
16.0
38.4
9.0
3.6
0
3.0
ground water systems are anticipated to
need treatment changes (12 percent)
than large ground water systems (15
percent) because the use of disinfectants
Table IV-3 Illustrates the compliance
forecast for ground water systems. This
forecast did not change from the time of
proposal. A smaller percentage of small
TABLE IV-3.—COMPLIANCE DECISION TREE FOR ALL GROUND WATER SYSTEMS
is more prevalent in large versus small
ground water systems.
Treatment:
Membranes
Systems <1 0,000
# systems
59,847
8,324
5,403
0
2,921
% systems
88
12
8
0
4
Systems >1 0,000
# systems
1,122
198
119
26
53
% systems
85
15
9
2
4
2. System Level Unit Costs
Tables IV-4 and IV-5 present the unit cost estimates in 1998 dollars that were utilized for each of the different
treatment technologies in each system size category. Unit costs are presented in $ per 1000 gallons which includes
operation and maintenance costs and amortized5 capital costs (using a 7% discount rate and a 20 year amortization
period). One dollar per thousand gallons equates to approximately $100 per household per year as an average for
communities in the U.S. More detailed information on these unit costs is available from the EPA s Cost and Technology
Document (EPA, 1998k).
TABLE IV-4.—SURFACE WATER SYSTEMS COSTS FOR DBF CONTROL TECHNOLOGIES ($/KGAL) AT 7% COST OF CAPITAL
Enhanced Coagulation (EC)
EC+Ozone, Chloramlna
EC+GAC10
EC+GAC20
Mombranos
Population size category
25-100
0.71
0.15
0.87
12.67
12.82
6.24
14.11
24.33
3.40
100-500
0.19
0.13
0.32
3.21
3.34
2.43
5.87
5.73
3.47
500-1 K
0.06
0.12
0.18
1.05
1.17
1.21
3.45
1.65
3.39
1-3.3K
0.03
0.11
0.14
0.52
0.63
0.81
2.45
0.64
2.65
3.3-1 OK
0.03
0.09
0.12
0.38
0.47
0.59
1.87
0.24
1.72
10-25K
0.02
0.08
0.09
0.23
0.30
0.46
1.48
0.11
0.96
25-50K
0.01
0.07
0.08
0.13
0.20
0.37
1.05
0.07
0.96
50-75K
0.01
0.07
0.08
0.10
0.17
0.35
1.00
0.07
0.87
75-1 OOK
0.01
0.07
0.08
0.08
0.15
0.29
0.90
0.06
0.87
100K-
500K
0.01
0,07
0.07
0.06
0.13
0.24
0.64
0.05
0.87
500K-1M
0.01
0.06
0.07
0.04
0.11
0.19
0.48
0.04
0.87
>1M
0.01
0.06
0.07
0.04
0.10
0.16
0.41
0.04
0.87
TABLE IV-5.—GROUND WATER SYSTEMS COSTS FOR DBF CONTROL TECHNOLOGIES ($/KGAL) AT 7% COST OF CAPITAL
Membranes
Population size category
25-100
0.72
12.67
3.41
100-500
0.19
3.21
3.47
500-1 K
0.06
1.05
3.39
1-3.3K
0.03
0.52
2.65
3.3-1 OK
0.03
0.38
1.72
10-25K
0.02
0.23
0.96
25-50K
0.01
0.13
0.96
50-75K
0.01
0.10
0.87
75-1 OOK
0.01
0.08
0.87
100K-
500K
0.01
0.06
0.87
500K-1M
0.01
0.04
0.87
>1M
0.01
0.04
0.87
3. National Costs
by OMB for bendS^T anatyses" of ^overrTment programs and regulations. The 3 percent and 10 percent rates are
nrovldpd as a sensitivity analysis to snow different alsumptions about the cost of capital that would affect estimated
provided as a sensitivity analysis
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Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations 69437
costs. The 10 percent rate also provides a link to the 1994 Stage 1 DBPR cost analysis which was based on a 10
percent rate. EPA believes that the cost estimates presented in Table IV-6 are probably within +/-30 percent. Uncertainty
around the cost estimates pertain to compliance forecast estimates, unit cost estimates for the different technologies
as they may pertain to individual sites, and estimated costs associated with monitoring.
TABLE IV-6.—SUMMARY OF COSTS UNDER THE STAGE 1 DBPR ($000)
Utilities Costs
Surface water systems
Small
Large
Total
Ground water systems
Small
Large
Total
All systems
Summary of Costs at 3 Percent Cost of Capital
Treatment Costs
Total Capital Costs
Annual O&M
Annualized Capital Costs .. .
Annual Utility Treatment Costs
Monitoring and Reporting Cost:
Start-Up Costs
Annual Monitoring
State Costs:
Start-Up Costs
Annual Monitoring
Total Annual Costs at 3 Percent
Cost of Capital
242 652
23068
16326
39 394
59
10,867
554 564
201 308
37 161
238 469
28
14619
797 216
224376
53 487
277 863
87
25 486
997 537
83 910
67 287
151 197
674
38 803
528 539
54243
V^ R1R
89 861
26
26 326
1 "Wfi f)7fi
WmT
1 H9 Qn^.
940 fVifl
ynn
fi1! 1P
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69438 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
water. Because DBFs are formed in
drinking water by the reaction of
disinfectants with natural organic and
inorganic matter, the population at risk
is Identified as the population served by
drinking water systems that disinfect.
The population served by each of four
system categories, taken from recent
Safe Drinking Water Act Information
System data (SDWIS) is estimated in
Table IV-7. Based on recent information
from SDWIS, it was assumed that all
surface water systems disinfect and a
portion of ground water systems
disinfect (95 percent by population
among large systems and 83 percent by
population among small systems).
Approximately 239 million persons are
estimated to be served by water systems
that disinfect and are potentially
exposed to DBFs. This widespread
exposure represents over 88 percent of
the total U.S. population (270 million).
The route of exposure is through
drinking disinfected tap water.
TABLE IV-7.—POPULATION POTENTIALLY EXPOSED TO DBPs
Large Surface Water: >10,000 persons
Small Surfaco Water: <10,000 persons
Largo Ground Water >10 000 persons
Small Ground Water < 10 000 persons
Tola!
Population
served
141,297,000
17,232,000
56,074,000
32,937,000
% of popu-
lation receive
ing disinfected
water
100
100
95
83
Population
served by sys-
tems that dls-
• infect
141,297,000
17,232,000
53,270,300
27,337,710
239,137,010
In general, little data are available on
the occurrence of DBPs on a national
basis. Although there is sufficient
occurrence data available for THMs in
large water systems to develop a
national occurrence distribution for that
subset of systems, data are limited for
small water systems. Similarly, some
occurrence data for HAAS are available
for large surface water systems, but not
small surface water and groundwater
systems.
2. Baseline Risk Assessment Based on
TTHM Toxicological Data
EPA performed a quantitative risk
assessment using the dose-response
information on THMs. This assessment,
however, captures only a portion of the
potential risk associated with DBPs in
drinking water. It is not possible, given
existing toxicological and exposure
data, to gauge how much of the total
cancer risk associated with the
consumption of chlorinated drinking
water is posed by TTHMs alone. An
assessment of THMs, however, provides
some estimation of the potential human
risk, albeit limited.
Performing the risk assessment based
on TTHM toxicological data requires
making several assumptions and
extrapolations (from a nonhuman
species to humans, from high doses in
the laboratory study to lower
environmental exposures, and from a
nondrinking water route to the relevant
route of human exposure). Assumptions
are also made about the occurrence of
TTHMs and the individual DBPs. EPA
estimated the pre-Stage 1 DBPR TTHM
concentration levels by calculating a
weighted average (based on populations
receiving disinfected waters) of TTHM
levels among the different system type
categories described in Table IV-7.
TTHM levels among systems serving
greater than 10,000 people were
estimated based on average
concentrations among systems in
AWWA's WIDB. TTHM levels in
systems serving less than 10,000 people
were estimated through modeling.
Modeling consisted of applying TTHM
predictive equations to estimates of DBF
precursor levels and treatment
conditions. The mean weighted average
baseline TTHM concentrations among
all the system type categories was 44 (ig/
L.
Occurrence data from an EPA DBF
field study indicate that chloroform is
the most common THM (in general,
about 70 percent of total THMs), with
bromoform being the least common (1
percent). Bromodichloromethane has an
occurrence of approximately 20 percent
of the total THMs, with
dibromochloromethane comprising the
final 8 percent of the total THMs. In the
absence of more detailed occurrence
data, these proportions are used to
divide the average TTHM concentration
into the concentration for the four
individual compounds.
Two estimates of risk factors were
used to estimate the cancer incidence.
The first set of lifetime unit risk factors
represent the upper 95 percent
confidence limit of the dose-response
function. The second estimate of
lifetime unit risk is the maximum
likelihood estimate used in the 1994
analysis that represents the central
tendency of the dose-response function
(Bull, 1991). The annual unit risk is
calculated by dividing the lifetime risk
by a standard assumption of 70 years
per lifetime. To calculate the annual
incidence of cancer due to consumption
of TTHMs in drinking water, the annual
drinking water unit risk is multiplied by
the number of units, in this case the
concentration of TTHMs in |ig/L, broken
out into individual THMs based on the
proportions presented above. Based on
these cancer risk estimates derived from
laboratory animal studies, the annual
95th percentile upper bound number of
cancer cases attributable to TTHMs is
approximately 100. This means that
there is a 95 percent chance that the
annual number of cases are less than or
equal to 100. Using the maximum
likelihood or "best" estimates, the
annual number of cancer cases is about
2.
3. Baseline Analysis Based on
Epidemiology Data
Epidemiological studies can be used
to assess the overall population risk
associated with a particular exposure.
Since the late 1970s, epidemiological
investigations have attempted to assess
whether chlorinated drinking water
contributes to the incidence of bladder,
colon, rectal, and other cancers. Several
studies have reported a weak
association between bladder cancer and
exposure to chlorinated drinking water,
but a causal relationship has not been
confirmed (Freedman, et al., 1997).
Several cancer epidemiological
studies examining the association
between exposure to chlorinated surface
water and cancer were published
subsequent to the 1994 proposed rule
and the 1992 meta-analysis. In general,
these new studies are better designed
than the studies published prior to the
1994 proposal. The new studies include
incidence of disease, interviews with
the study subjects, and better exposure
assessments. More evidence is available
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Federal Register/Vol. 63, No. 241 /Wednesday, December 16, 1998/Rules and Regulations 69439
on bladder cancer for a possible
association to exposure to chlorinated
surface water than other cancer sites.
Because of the limited data available for
other cancer sites such as colon and
rectal cancer, the RIA focuses on
bladder cancer.
Based on the best studies, a range of
potential risks was developed through
the use of the population attributable
risk (PAR) concept. Epidemiologists use
PAR to quantify the fraction of disease
burden in a population (e.g., bladder
cancer) that could be eliminated if the
exposure (e.g., chlorinated drinking
water) was absent. PAR (also referred to
as attributable risk, attributable portion,
or etiologic fraction) provides a
perspective on the potential magnitude
of risks associated with various
exposures under the assumption of
causality. For example, the National
Cancer Institute estimates that there will
be^54,500 new cases of bladder cancer
in 1997. If data from an epidemiological
study analyzing the impact of
consuming chlorinated drinking water
reports a PAR of 1 percent, it can be
estimated that 545 (54,500 x .01)
bladder cancer cases in 1997 may be
attributable to chlorinated drinking
water.
Under the Executive Order #12866
that requires EPA to conduct a RIA, EPA
has chosen to estimate an upper bound
bladder cancer risk range for chlorinated
drinking water using the PAR. EPA
suggested this approach in the 1998
NODA (EPA, 1998a). While EPA
recognizes the limitations of the current
epidemiologic data base for making
these estimates, the Agency considers
the data base reasonable for use in
developing an upper bound estimate of
bladder cancer risk for use in the RIA.
In light of the toxicological evidence,
EPA recognizes that the risks from
chlorinated drinking water may be
considerably lower than those derived
from the currently available
epidemiological studies. EPA selected
studies for inclusion in the quantitative
analysis if they contained the pertinent
data to perform a PAR calculation and
met all three of the following criteria:
1. The study was a population-based,
case-control, or cohort study conducted
to evaluate the relationship between
exposure to chlorinated drinking water
and incidence of cancer cases, based on
personal interviews; (all finally selected
studies were population-based, case-
control studies)
2. The study was of high quality and
well designed (e.g., adequate sample
size, high response rate, adjusted for
known confounding factors); and, .
3. The study had adequate exposure
assessments (e.g., residential histories,
actual THM data).
Using the above criteria, five bladder
cancer studies were selected for
estimating the range of PARs.
• Cantor, etal., 1985;
• McGeehin, et al., 1993;
• King and Marrett, 1996;
• Freedman, etal., 1997; and
• Cantor, etal., 1998.
The PARs from the five bladder
cancer studies ranged from 2 percent to
17 percent. These values were derived
from measured risks (Odds Ratio and
Relative Risk) based on the number of
years exposed to chlorinated surface
water. Because of the uncertainty in
these estimates, it is possible that the
PAR could also be zero. The
uncertainties associated with these PAR
estimates are large due to the common
prevalence of both the disease (bladder
cancer) and exposure (chlorinated
drinking water).
In order to apply these PAR estimates
to the U.S. population to estimate the
number of bladder cancer cases
attributable to DBFs in drinking water,
a number of assumptions must be made.
These include: (1) that the study
populations selected for each of the
cancer epidemiology studies are
reflective of the entire population that
develops bladder cancer; (2) that the
percentage of those cancer cases in the
studies exposed to chlorinated drinking
water are reflective of the bladder
cancer cases in the U.S.; (3) that DBFs
were the only carcinogens in these
chlorinated surface waters; and (4) that
the relationship between DBFs in
chlorinated drinking water exposure
and bladder cancer is causal.
The last of these assumptions is
perhaps the most open to question. As
noted in the March 1998 NODA, the
results of the studies are inconsistent. In
light of these concerns, the Agency
agrees that causality between exposure
to chlorinated water and bladder cancer
has not been established and that the
number of cases attributable to such
exposures could be zero.
Based on the estimate of 54,500 new
bladder cancer cases per year nationally,
as projected by the National Cancer
Institute for 1997, the numbers of
possible bladder cancer cases per year
potentially associated with exposures to
DBFs in chlorinated drinking water
estimated from the five studies range
from 1,100 (0.02 x 54,500) to 9,300 (.17
x 54,500) cases. As noted above, due to
• the uncertainty in these estimates, the
number of cases could also be zero. In
making these estimates it is necessary to
assume that these bladder cancer cases
are attributed to DBFs in chlorinated
surface water, even though the studies
examined the relationship between
chlorinated surface water and bladder
cancer. This derived range is not
accompanied' by confidence intervals
(C.Is), but the C.Is. are likely to be very
wide. EPA believes that the mean risk
estimates from each of the five studies
provides a reasonable estimate of the
potential range of risk suggested by the
different epidemiological studies. Table
IV-8 contains a summary of the risk
estimates from the 1994 draft RIA and
the estimates derived from the more
recent analysis.
A related analysis based on odds
ratios was conducted to derive a range
of plausible estimates for cancer
epidemiologic studies (EPA, 1998n).
This analysis was also based on bladder
cancer studies (the five studies cited
above in addition to Doyle et al. 1997).
For the purpose of this exercise, the
annual U.S. expected number of 47,000
bladder cancers cited by Morris et
al.(1992) was used to calculate estimates
of the cancers prevented. The number of
cancers attributable to DBF exposure
was estimated not to exceed 2,200-
9,900 per year and could include zero.
As would be expected from related
analysis performed in the same data,
this range is similar to the 1,100-9300
PAR range. EPA has used the 1100-9300
PAR range for the RIA.
TABLE IV-8.—NUMBER OF CANCER CASES ATTRIBUTABLE TO DBFs: COMPARISON OF ESTIMATES IN 1994 AND 1998
1994 estimates
1998 estimates
Number of New Bladder Cancer Cases/Year
Number of Estimated Deaths Due to Bladder Cancer/Year,
Attributable to DBPs in Drinking Water
Data Source
Causality
Percent Attributable to DBPs
Approx. 50,000
Did not state ....
>15 studies ..
No
Did not state
54,500.
12,500.
5 studies that meet specific criteria.
No.
2% to 17%.
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69440 Federal Register/Vol. 63, No. 2417Wednesday, December 16, 1998/Rules and Regulations
TABLE IV-8.—NUMBER OF CANCER CASES ATTRIBUTABLE TO DBFs: COMPARISON OF ESTIMATES IN 1994 AND 1998—
Continued
Number of Cancer Cases Attributable to DBFs:
Estimated Usino Toxicological Data
Estimated Using Epidemiological Data
1994 estimates
Less than 1*
Over 10,000***
1 998 estimates
Zero to 100.**
Zero to 9,300.****
* Based on maximum likelihood estimates of risk from THMs.
"* Based on IRIS 95th percent C.I. estimates of risk from THMs.
*** Indicates rectal and bladder cancer cases.
**" Indicates only bladder cancer cases.
The current benefits analysis is
structured in roughly the same manner
as that presented in the 1994 RIA. The
baseline cancer risks could lie anywhere
from zero to 100 cases per year based on
toxicological data; and zero to 9,300
cases per year based on epidemiological
data. Consequently, the task is to assess
the economic benefit of the final Stage
1 DBPR in the face of this broad range
of possible risk.
4. Exposure Reduction Analysis
EPA predicted exposure reductions
due to the current Stage 1 DBPR relative
to the present baseline. EPA used the
concentration of TTHMs as a marker to
measure the exposure to the range of
DBFs because data are available on the
baseline occurrence and formation of
TTHMs. There are limited data on the
total mix of byproducts in drinking
water. Therefore, the reduction in
TTHMs is assumed to reflect the
reduction in exposure to all DBFs. To
determine the change in exposure, it is
necessary to estimate the pre-Stage 1
baseline average TTHM concentration
and the post Stage 1 average TTHM
concentration. The difference in the pre-
and post-Stage 1 TTHM concentrations
reflect the potential reduction in
TTHMs and thus in DBFs.
As described previously, the
estimated pre-Stage 1 TTHM weighted
average concentration is 44 u,g/L for all
system sizes and types of systems. The
post Stage 1 TTHM concentrations for
each system category were estimated
based on the technology compliance
forecasts previously discussed and
estimated reductions in TTHM levels
depending upon technology. The post-
Stage 1 TTHM weighted average
concentration is estimated at 33 u,g/L.
This represents a 24 percent reduction
in TTHM levels resulting from the Stage
1 DBPR. Further details of the above
analysis is described in the RIA for the
Stage 1 DBPR (USEPA, 1998g).
5. Monetizatlon of Health Endpoints
The range of potential benefits from
the Stage 1 DBPR can be estimated by
applying the monetary values for fatal
and nonfatal bladder cancer cases with
the estimate of the number of bladder
cancer cases reduced by the rule. The
following assumptions are used to
estimate the range of potential benefits:
• An estimate of the number of
bladder cancer cases attributable to
DPBs in drinking water ranging from 0
to 9,300 annually.
• A 24 percent reduction in exposure
to TTHMs due to the Stage 1 DBPR (75
percent CI of 19 to 30 percent) will
result in an equivalent reduction in
bladder cancer cases
• A value per statistical life saved for
fatal bladder cancers represented by a
distribution with a mean of $5.6 million
• A willingness to pay to avoid a
nonfatal case of bladder cancer
represented by a distribution with a
mean of $587,500
Using the low end of the risk range of
0 bladder cancer cases attributable to
DBPs results in a benefits estimate of $0.
To calculate the high end of the range,
the 9,300 estimate of attributable cases
is multiplied by the percent reduction
in exposure to derive the number of
bladder cancer cases reduced (9,300 x
.24 = 2,232 bladder cancer cases
reduced). This assumes a linear
relationship between reduction in
TTHMs concentrations and reduction in
cancer risk (e.g., 24 percent reduction in
TTHMs concentration is associated with
a 24 percent reduction in cancer risk).
Assuming 23 percent of the bladder
cancer cases end in fatality and 77
percent are nonfatal, the number of fatal
bladder cancer cases reduced is 513
(2,232 x .23) and the number of nonfatal
bladder cancer cases is 1,719 (2,232 x
.77). Based on the valuation
distributions described above, the
estimate of benefits at the mean
associated with reducing these bladder
cancer cases is approximately $4 billion.
It should be noted that these estimates
do not include potential benefits from
reducing other health effects (e.g, colon/
rectal cancer and reproductive
endpoints) that cannot be quantified at
this time. As a result, EPA believes that
the potential benefits discussed in
today's rule may be a substantial
underestimate of potential benefits that
will be realized as a consequence of
today's action. While the low end of the
range cannot extend below $0, it is
possible that the high end of the range
could extend beyond $4 billion if the
other reductions in risk could be
quantified and monetized. No discount
factor has been applied to these
valuations, although there is likely to be
a time lag between compliance with the
rule and the realization of benefits.
Given this wide range of potential
benefits and the uncertainty involved in
estimating the risk attributable to DBPs,
EPA undertook five different
approaches to assessing the net benefits
of the Stage 1 DBPR. These approaches
are described in the net benefits section
and should be considered both
individually and in the aggregate.
E. Net Benefits Analysis
The potential economic benefits of the
Stage 1 DBPR derive from the increased
level of public health protection and
associated decreased level of risk. The
quantification of the benefits resulting
from DBP control is complicated by the
uncertainty in the understanding of the
health risks. Epidemiological studies,
referred to previously, suggest an
association between bladder cancer and
exposure to chlorinated surface water;
however, these risks are uncertain. The
lowest estimate in the selected
epidemiological studies of the number
of new bladder cancer cases per year
attributable to chlorinated surface water
is 1,100 cases, while the highest is 9,300
cases. EPA recognizes that while these
risks may be real, they also could be
zero. Assessment of risks based only on
toxicological data for THMs, indicate a
much lower risk (2 cancer cases per year
at the most likely estimate, to about 100
cases per year using the 95 percent
confidence level upper bound), but
THMs represent only a few of the many
DBPs in drinking water.
EPA explored several alternative
approaches for assessing the benefits of
the Stage 1 DBPR: Overlap of Benefit
and Cost Estimates; Minimizing Total
Social Losses; Breakeven Analysis;
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Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations 69441
Household Costs; and Decision-Analytic
Model. A summary of the analysis of
each approach is presented below. More
detailed descriptions are described in
theRIA (USEPA, 1998g).
Overlap of Benefit and Cost Estimates.
One method to characterize net benefits
is to compare the relative ranges of
benefits and costs. Conceptually, an
overlap analysis tests whether there is
enough of an overlap between the range
of benefits and the range of costs for
there to be a reasonable likelihood that
benefits will exceed costs. In a
theoretical case where the high end of
the range of benefits estimates does not
overlap the low end of the range of cost
estimates, a rule would be difficult to
justify based on traditional benefit-cost
rationale.
For the Stage 1 DBPR, the overlap
analysis (Figures IV-la and IV-Ib)
show that there is substantial overlap in
the estimates of benefits and costs. The
range of quantified benefits extends
from zero to over $4 billion. The zero
end of the range of estimated benefits
represents the possibility that there is
essentially no health benefit from
reducing exposure to DBFs. The other
end of the range assumes there are 9,300
bladder cancer cases per year
attributable to DBFs and there is a 24
percent annual reduction in exposure
with the promulgation of the rule,
resulting in avoidance of 2,232 cases.
Assuming that number of avoided cases,
approximately 513 would have been
fatalities and would result in a cost
savings of approximately $3 billion
(each avoided fatality results in a cost
savings of $5.6 million). Additionally,
1,719 non-fatal cases avoided would
result in a cost savings of approximately
$1 billion (each avoided non-fatal case
results in a cost savings of $0.6 million).
The sum of the cost savings is
approximately $4 billion. The high end
of the benefits range could potentially
be higher if other health damages are
avoided. The range of cost estimates is
significantly smaller, ranging from $500
million to $900 million annually.
Although these cost estimates have
uncertainty, the degree of uncertainty is
of little consequence to the decisions
being made given the scale of the
uncertainty for the benefits.
Figure IV-lb, on the other hand,
indicates that while the quantified
benefits could exceed the costs, there is
the possibility that there could be
negative net benefits if there were no
health benefits.
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69442 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
Figure IV-la Overlap of Estimated
Benefits and Costs of the Stage 1 DBPR
Figure IV-Ib Overlap of the Ranges of
the Estimated Benefits and Costs of the
Stage 1 DBPR
Figure IV-la Overlap of Estimated Benefits and Costs of the Stage 1 DBPR
Costs
$500M-$900M
Figure IV-lb Overlap of the Ranges of the Estimated Benefits and Costs
of the Stage 1 DBPR
-2
-1 0
Range of Estimated Co its
Range of Estimated Benefits
\ Rang: of Estimated Net Benefits
1 2 3
S Billions
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Minimizing Total Social Losses
Analysis. Minimizing Total Social
Losses analysis, sometimes called
"minimizing regrets" analysis, is a
decision-aiding tool that is suited for
use in situations where it is impossible
to pin down the exact nature and extent
of a risk. The basic premise of
Minimizing Total Social Losses analysis
is to estimate total social costs for policy
alternatives over a range of plausible
risk scenarios. The actual, or "true" risk
is unknowable, so instead this analysis
asks what range and level of risks could
be true, and then evaluates the total
costs to society if particular risk levels
within that range turned out to be the
"true" value. Total social costs include
both the cost to implement the policy
option, plus costs related to residual
(i.e., remaining) health damages at each
risk level after implementation of the
policy option.
Under this analysis the "total social
costs" (water treatment costs plus costs
of health damages still remaining after
treatment) are calculated for three
regulatory alternatives (No Action, Stage
1, and Strong Intervention—otherwise
known as the proposed Stage 2
requirements of the 1994 proposal)
across a range of risk scenarios (< 1; 100;
1,000; 2,500; 5,000; 7,500; and 10,000
attributable bladder cancer cases
annually). Total social costs for each
regulatory alternative for different risk
assumptions are presented in Table IV-
9. The results indicate that the Stage 1
DBPR has the least social cost among
the three alternatives analyzed across
the range of risks from 2,500 through
7,500 attributable bladder cancer cases
annually.
Total "social loss" for each risk
scenario are also indicated in Table IV-
9. The "social loss" is the cost to society
of making a wrong choice among the
regulatory alternatives. It is computed as
the difference between the total social
cost (water treatment cost plus
remaining health damages) of an
alternative at a given risk scenario and
the total social cost of the best
alternative (least total social cost
alternative for that risk scenario). The
regulatory alternatives across the
different risk levels can also be
compared to see which alternative
minimizes the maximum potential loss.
The best alternative, by this "mini-max"
criteria, would be the one in which the
upper bound of potential losses is
smallest.
BILLING CODE 6560-50-U
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69444 Federal Register/Vol. 63, No. 24IIWednesday, December 16, 1998/Rules and Regulations
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Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations 69445
Under the Stage 1 DBPR alternative,
the worst loss that could happen would
occur if the lowest end of the risk range
is true. This would result in total social
losses of $0.7 billion per year. It is
concluded that the maximum potential
loss of the Stage 1 alternative is smaller
than that of No Action ($4.1 billion) by
a factor of 6 and smaller than that of
Strong Intervention ($2.9 billion) by a
factor of 4. Thus, the Stage 1 DBPR is
the best of the 3 alternatives at
minimizing the maximum social loss.
The 1994 Reg. Neg. and 1997 M-DBP
Advisory Committees implicitly applied
this type of "minimizing maximum
loss" framework when developing and
evaluating the DBF regulatory options.
In the face of large uncertainty regarding
risk from DBFs, they decided that a
moderate response, relying on the more
cost-effective of the available treatment
methods was appropriate as an interim
step until more information on risk
becomes available.
Break Even Analysis. Breakeven
analysis represents another approach to
assessing the benefits of the Stage 1
DBPR given the scientific uncertainties.
Breakeven is a standard benchmark of
cost effectiveness and economic
efficiency, and is essentially the point
where the benefits of the Stage 1 DBPR
are equal to the costs. Normally, the
benefits and costs of an option are
calculated separately and then
compared to assess whether and by
what amount benefits exceed costs. In
the case of the Stage 1 DBPR,
independently estimating benefits is
difficult, if not impossible, because of
the 10,000-fold uncertainty surrounding
the risk. Instead, the breakeven analysis
works backwards from those variables
that are less uncertain. In this case,
implementation costs for the rule and
the monetary value associated with the
health endpoints are used to calculate
what baseline risk and risk reduction
estimates are needed in order for the
benefits, as measured in avoided health
damages associated with bladder cancer,
to equal the costs.
Two important concepts for this
analysis are the cost of illness measure
and the willingness-to-pay measure. The
cost of illness measure includes medical
costs and lost wages associated with
being unable to work as a result of
illness. In comparison, willingness-to-
pay measures how much one would pay
to reduce the risk of having all the
discomfort and costs associated with
nonfatal cancer if such an option
existed. The main difference between
these two methods is that willingness-
to-pay incorporates pain and suffering,
as well as changes in behavior into the
valuation, while cost of illness does not.
EPA has estimated the cost of a non-
fatal case of bladder cancer at $121,000
using the cost of illness method, and at
$587,500 using the willingness-to-pay
approach.
Assuming an annual cost of $701
million and assumptions about the
monetary value of preventing both fatal
and nonfatal bladder cancer cases, the
Stage 1 DBPR would need to reduce' 438
bladder cancer cases per year using the
willingness-to-pay measure for nonfatal
cancers or 574 cases per year using the
cost of illness measure. If exposure is
reduced by 24 percent, the baseline
number of bladder cancer cases
attributable to DBFs in chlorinated
drinking water required to break even
would need to range from 1,820 to 2,390
new cases annually. Although these
values are well above the range
indicated by existing toxicological data
for THMs alone, they fall within the
attributable risk range suggested by the
epidemiological studies.
Household Cost Analysis. A fourth
approach for assessing the net benefits
of the Stage 1 DBPR is to calculate the
costs pe • household for the rule.
Household costs provide a common
sense test of benefit/cost relationships
and are another useful benchmark for
comparing the willingness-to-pay to
, reduce the possible risk posed by DBFs
in drinking water. It is essentially a
household level breakeven analysis. It
works backwards from the cost to ask
whether the implied amount of benefits
(willingness-to-pay) needed to cover
costs is a plausible amount.
About 115 million households are
located in service areas of systems
affected by the Stage 1 DBPR. Of these
households, 71 million (62 percent) are
served by large surface water systems.
Approximately 4.2 million (4 percent)
are served by small surface water
systems. Large ground water systems
served 24 million households (21
percent) and small ground water
systems serve 15.7 million households
(14 percent).
All of the households served by
systems affected by the Stage 1 DBPR
will incur some additional costs (e.g.,
monitoring costs), even if the system
does not have to change treatment to
comply with the proposed rule. The
costs calculated below include both
monitoring and treatment costs.
The cumulative distribution of
household costs for all systems and by
each system type is displayed in Figures
IV-2a, IV-2b, IV-2c. The distributions
show that the large percentage of
households will incur small additional
costs, with a small portion of systems
facing higher costs. At the highest end
of the distribution, approximately 1,400
households served by surface water
systems in the 25-100 size range
switching to membrane technology will
face an average annual cost increase of
$400 per year ($33 per month).
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69446 Federal Register/Vol. 63. No. 2417Wednesday, December 16. 1998/Rules and Regulations
Figure IV-2a
Cumulative Distribution of Annual Household Costs under the Stage 1 DBPR
Cumulative Percent of Households
90%
80%
70%
i^_ ^— -— . $10 per month (99th percentile)
|\
1
1 $1 per month (95th percentile)
I
60% 1
50%
40%
30%
20%
10%
n%
$- $50 $100 $150 $200 $250 $300 $350 $400 $450
Annual Cost per Household
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The households have been sorted into
three cost categories for the ease of
comparison (Table IV-10). The first
category includes households with a
cost increase of less than $12 per year,
less than $1 per month. The second
category contains households with costs
greater than $ 12 per year, but less than
$120 per year ($10 per month). The
third category includes households with
cost increases greater than $120 per year
to $400 per year ($33 per month).
Across all system categories (see
Figure IV-2a), 95 percent of the
households (110.1 million) fall within
the first category and will incur less
than $1 per month additional costs due
to the Stage 1 DBPR. An additional 4
percent (4.4 million) are in the second
category at between $1 and $10 per
month cost increase and 1 percent (1.0
million) are in the highest category
($10-$33.40 per month).
For households served by large
surface water systems (Figure IV-2b), 98
percent will incur less than $ 1 per
month, 2 percent will incur between $ 1
and $10 per month, and 0.03 percent
will incur greater than $10 per month.
The highest cost ($125 annually, $10.40
monthly) is faced by households served
by systems in the 10,000 to 25,000 size
range implementing membrane
technology.
For households served by small
surface water systems (Figure IV-2c), 71
percent will incur less than $ 1 per
month, 28 percent will incur between
$1 and $10 per month, and 1 percent
will incur greater than $10 per month.
The highest cost ($400 annually, $33
monthly) is faced by households served
by systems in the 25-100 size range
implementing membrane technology.
For households served by large
ground water systems (Figure IV-2b), 95
percent will incur less than $1 per
month, 4 percent will incur between $ 1
and $10 per month, and 1 percent will
incur greater than $ 10 per month. The
highest cost ($125 annually, $10.40
monthly) is faced by households served
by systems in the 10,000 to 25,000 size
range implementing membrane
technology.
For households served by small
ground water systems (Figure IV-2c), 91
percent will incur less than $ 1 per
month, 5 percent will incur between $ 1
and $ 10 per month, and 4 percent will
incur greater than $10 per month. The
highest cost ($357 annually, $29.75
monthly) is faced by households served
by systems in the 25-100 size range
implementing membrane technology.
BILLING CODE 656O-50-U
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69448 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
Table IV-10
Summary of the Number of Households and Percentage of Total Households in Each Cost Category
Total
Large Ground Water
Small Ground Water
All Systems
# Households
115,490,000
71,378,000
4.267,000
24,174,000
15,671,000
% Total
100%
61.8%
3.7%
20.9%
13.6%
$0- $12 per Year
Cost/Household
# Households
110,093,000
69,870,000
3.009.000
22,969,000
14.245,000
% Total
95%
60%
3%
20%
12%
$12.01 -$120 per Year
Cost/Household
# Households
4,387,000
1,489,000
1.204,000
939,000
755,000
% Total
4%
1%
1%
0.8%
0.7%
$120.01 -$400 per Year
Cost/Household
# Households
1,011,000
20,000
54,000
266,000
671,000
% Total
1%
0.02%
0.05%
0.2%
1%
Summary of the Number of Households and Percentage of Households in Each Cost Category by System Type
Total
Lame Surface Water
Small Surface Water
All Systems
# Households
115.490,000
71.378,000
4.267,000
24,174,000
15.671,000
% System
Category
100%
100%
100%
100%
100%
$0- $12 per Year
Cost/Household
# Households
110.093.000
69,870,000
3.009,000
22,969,000
14,245,000
% System
Category
95%
98%
71%
95%
91%
$12.01 -$120 per Year
Cost/Household
# Households
4,387,000
1,489,000
1,204,000
939,000
755,000
% System
Category
4%
2%
28%
4%
5%
$120.01 - $400 per Year
Cost/Household
# Households
1,011,000
20,000
54,000
266,000
671,000
% System
Category
1%
0.03%
1%
1%
4%
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Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations 69449
Figure IV-2b: Cumulative Distribution of Annual Costs per Household for Large Surface
and Ground Water Systems
Large Surface Water Systems
100%
90%
$- $50 $100 $150 $200 $250 $300 $350 $400 $450
Annual Cost per Household
Large Ground Water Systems
•im% A .,
90%
80%
5 70%
1 60%
£ 50%.
1 40%
£ 30%
J 20%
| 10% .
° 0%
• -^~ ~*~~-~ $10 per nwnth(100th percentile)
\
SI per month (%m pencennle)
$- $50 $100 $150 $200 $250 $300 $350 $400 $450
Annual Cost Derrbusehdd
100%
99%
96%
fj 97%
1 93%
•g 95%
§ 94%
£ 93%
S 92%
§ 91%
90%
$
S
$20 $40 $80 $80 $100 $120 $140 $1
Annual Cost per Household
60
100%
$20 $40 $60 $80 $100
Annual Cost per (ixsehoM
$120 $140
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69450 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
Figure IV-2c Cumulative Distribution of Annual Costs per Household for Small Surface
and Ground Water Systems
Small Surface Water Systems
Small Ground Water Systems
$- $50 $100 $150 $200 $250 $300 $350 $400 $450
Annual Cost per Household
x $10 per month (97th penxntile)
$1 per month (91st percennle)
$50 $100 $150 $200 $250 $300 $350 $400 $450
AnraalOoatpBrrbisehold
$30$100$15b$200$290$300$360$«)$«0
AmrfCbstperHwsehoW
10CP/0
560 $100 $150 $200 $250 $300 $390 $400
AndCGetparHMBehol
BILLING CODE 6560-50-C
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Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations 69451
In the small proportion of systems
where household costs are shown to be
much greater—up to several hundreds
of dollars per year—these results are
driven by the assumption that
membrane technologies will be the
selected treatment, as noted above.
Additionally, two points must be made:
(1) a number of these systems may find
less expensive means of compliance
(e.g., selection of alternative source
water, purchased water, or
consolidation with other systems); and
(2) if these systems do install
membranes, they may receive additional
water quality and/or compliance
benefits beyond those associated with
DBFs. For example, because membranes
are so effective, systems that install
membranes are likely to incur lower
compliance costs for future
rulemakings.
Given the uncertain nature of the risks
associated with DBFs, household costs
provide a common sense estimate of
willingness-to-pay to reduce the risks:
Would the average household (95
.percent of households) be willing to pay
less than $1 per month ($12 per year) to
reduce the potential risks posed by
DBFs?
Willingness to pay studies are not
available to directly answer this
question. Taking the $ 1 per month
figure as a measure of implied public
health benefit at the household level, it
is useful to ask what benefits can be
identified that could balance a $ 1 per
month expenditure. First, it is entirely
possible that there is much more than a
dollar-a-month's worth of tangible
health benefit based on reduced risk of
bladder cancer alone. Second, the broad
exposure to DBFs and the possible
health effects involved offer the
possibility that there are significant
additional health benefits of a tangible
nature. However, the agency recognizes
that in the small percentage of situations
where the costs per household is
between $120 to $400 per year, this may
indeed be a difficult financial burden to
meet (e.g., may exceed household
willingness-to-pay).
Finally, the preventive weighing and
balancing of public health protection
also provides a margin of safety—a
hedge against uncertainties. Recent
survey research conducted in the
drinking water field provides
compelling empirical evidence that the
number one priority of water system
customers is the safety of their water.
Although definitive economic research
has not been performed to investigate
the extent of household willingness-to-
pay for such a margin of safety, there is
strong evidence from conventional
customer survey research implying a
demand for this benefit.
Decision Analytical model. The RIA
also discusses a fifth type of analysis in
which probability functions are used to
model the uncertainty surrounding
three variables (rule cost, exposure
reduction, and attributable bladder '''
cancer risk) in order to derive a
probability distribution function for
annual net benefit of the Stage I rule.
Because there is little actual data on
these probability functions, this
approach should be considered
illustrative only. It is not discussed
further here, but is discussed in Chapter
6 of the RIA for the Stage 1 DBPR (EPA.
1998g).
While any one of the above analytical
approaches by itself may not make a
definitive case for the benefit-cost
effectiveness for the Stage 1 DBPR,
taken collectively EPA believes they
indicate that the Stage 1 DBPR benefits
to society will exceed the costs. The
monetized benefits in the five
alternatives represent only a portion of
total potential benefits. Benefits
associated with other cancer sites (rectal
and colon) and other health endpoints
(such as developmental and
reproductive effects) could not be
quantified at this time, and while they
could be nil, they also could be quite
large. Based on a careful weighing of the
projected costs against the potential
quantified and non-quantified benefits,
EPA has determined that the benefits of
the rule justify its costs.,
F. Summary of Comments
Many commenters expressed concern
about the wide range of benefits given
the high national cost of the rule. EPA
has revised the benefits analysis; and
while the associated uncertainties
remain large, EPA believes the benefits
of the Stage 1 DBPR justify its costs.
Other commenters expressed concern
with using the data from Morris et al.
(1992) for quantifying benefits. They
believed that the studies used in the
meta-analysis were different in design
and thus not appropriate to use in meta-
analysis. In addition the commenters
believed that potential confounding
factors or bias may not have been
adequately controlled in the selected
studies. Others believed there was
utility in using the meta-analysis to
provide a perspective on the potential
cancer risks. Several commenters were
supportive of the Poole (1997)
evaluation of the Morris etal. (1992)
meta-analysis stating that they
concurred that the Morris analysis
should not be used for estimating
benefits for the Stage 1 DBPR. Other
commenters suggested a better use of
the resources used to complete the
Poole report would have been to
complete a new meta-analysis using the
more recent studies that have come out
since the Morris etal. (1992) meta-
analysis and that the Poole evaluation
did not advance the science in this area.
"Several commenters were critical of the
PAR analysis (described in EPA, 1998a)
used to characterize the potential
baseline bladder cancer cases per year
that could be attributable to exposure to
chlorinated drinking water. They
present several arguments including:
questioning whether such an analysis is
warranted given the inconsistencies in
the studies used to complete the
analysis; stating that the use of the term
upper bound of any suggested risk of
cancer is inappropriate because this
does not include the potential risks from
other cancer sites such as colon and
rectal; using the assumption of causality
is not warranted given the
inconsistencies in the studies used to
complete the PAR analysis; and the PAR
analysis should include a lower bound
estimate of zero.
EPA agrees that the use of the Morris
etal. (1992) meta-analysis for estimating
benefits is not appropriate for the
reasons cited by commenters (e.g.,
studies of different designs and
discussed in more detail in the 1998
DBF NODA). EPA is currently
considering whether a new meta-
analysis that uses the most recent
epidemiology studies would be useful
for the Stage 2 rulemaking. The Poole
(1997) report considered a meta analysis
of the available data. Poole used several
techniques to evaluate the data and
included several new studies that were
available at the time of his analysis.
Poole concluded that the cancer
epidemiology data considered in his
evaluation should not be combined into
a single summary estimated and that the
data had limited utility for risk
assessment purposes. More recent
studies by Cantor et al. (1998), Doyle et
al. (1997) and Freedman et al. (1997)
were not available at the time of his
evaluation.
EPA understands commenters
concerns with the PAR analysis,
especially concerns with assuming
"causality" in the PAR evaluation when
it is stated in other sections of the
preamble that EPA does not believe
causality has been established. Even
though causality has not been
established, EPA is required to estimate
the potential impacts of major
regulations such as the DBP Stage 1
rule. The Agency believes it is
appropriate to conduct the PAR analysis
as described in the 1998 DBP NODA
(EPA, 1998a), to provide estimates of the
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6945? Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
potential risk that may need to be
reduced. EPA agrees that the use of the
term "upper bound of any suggested
risk" is not appropriate because there
are other potential risks that have not
been quantified that may contribute to
the overall risk estimates. In addition,
EPA agrees that the estimates of the
potential cancer cases should include
zero as this is a possibility given the
uncertainties in the data. EPA agrees
that several assumptions are made in
the analysis regarding the national
extrapolation of the results and that
there is insufficient information at this
time to validate these assumptions.
However, given the need to develop
national estimates of risk, EPA believes
It is appropriate to make these
assumptions in order to provide a
perspective on the potential risks from
exposure to chlorinated surface waters.
Commenters expressed concerns with
the high costs associated with systems
that must adopt alternative advanced
technologies, especially for small
systems. Since the 1994 proposal, the
projected national costs for the Stage 1
DBPR have dropped significantly (as
discussed above). This is mainly due to
the revised compliance forecast and
lower membrane technology costs. In
the revised compliance forecast, fewer
systems using surface water will need
advanced technologies to comply. This
shift to lesser use of advanced
technologies to comply with the Stage 1
DBPR also pertains to small systems
(those serving less than 10,000 people).
Commenters expressed concern for
the high costs associated with the Stage
2 DBPR and whether EPA would obtain
enough information to adequately
understand the risks that might be
avoided to justify such a rule. EPA
agrees that additional health effects
Information is needed before
reproposing the Stage 2 DBPR and will
address this issue in the next round of
FACA deliberations. Based on new data
generated through research, EPA will
reevaluate the Stage 2 regulations and
re-propose, as appropriate.
V. Other Requirements
A, Regulatory Flexibility Act
1. Today's Rule
Under the Regulatory Flexibility Act,
5 U.S.C. 601 ef seg. (RFA), as amended
by the Small Business Regulatory
Enforcement Fairness Act, EPA
generally is required to conduct a
regulatory flexibility analysis describing
the impact of the regulatory action on
small entities as part of rulemaking.
However, under section 605 (b) of the
RFA, if EPA certifies that the rule will
not have a significant economic impact
on a substantial number of small
1 entities, EPA is not required to prepare
a regulatory flexibility analysis.
Throughout the 1992-93 negotiated
rulemaking process for the Stage 1
DBPR and IESWTR and in the July 1994
proposals for these rules, a small PWS
was defined as a system serving fewer
than 10,000 persons. This definition
reflects the fact that the original 1979
standard for total trihalomethanes
applied only to systems serving at least
10,000 people. The definition thus
recognizes that baseline conditions from
which systems serving fewer than
10,000 people will approach
disinfection byproduct control and
simultaneous control of microbial
pathogens is different than that for
systems serving 10,000 or more persons.
EPA again discussed this approach to
the definition of a small system for these
rules in the 1998 DBF NODA (EPA,
1998a). EPA is continuing to define
"small system" for purposes of this rule
and the IESWTR as a system which
serves fewer than 10,000 people.
The Agency has since proposed and
taken comment on its intent to define
"small entity" as a public water system
that serves 10,000 or fewer persons for
purposes of its regulatory flexibility
assessments under the RFA for all future
drinking water regulations. (See
Consumer Confidence Reports Rule, 63
FR 7620, Feb. 13, 1998.) In that
proposal, the Agency discussed the
basis for its decision to use this
definition and to use a single definition
of small public water system whether
the system was a "small business",
"small nonprofit organization", or
"small governmental jurisdiction." EPA
also consulted with the Small Business
Administration on the use of this
definition as it relates to small
businesses.-Subsequently, the Agency
has used this definition in developing
its regulations under the Safe Drinking
Water Act. This approach is virtually
identical to the approach used in the
Stage 1 DBPR and IESWTR. Since, EPA
is not able to certify that the final Stage
1 DBPR will not have a significant
economic impact on a substantial
number of small entities, EPA has
completed a final RFA and will publish
a small entity compliance guidance to
help small entities comply with this
regulation.
2. Background and Analysis
The Regulatory Flexibility Act
requires EPA to address the following
when completing a final RFA: (1) state
succinctly the objectives of, and legal
basis for, the final rule; (2) summarize
public comments on the initial RFA, the
Agency's assessment of those
comments, and any changes to the rule
in response to the comments; (3)
describe, and where feasible, estimate
the number of small entities to which
the final rule will apply; (4) describe the
projected reporting, record keeping, and
other compliance requirements of the
rule, including an estimate of the classes
of small entities that will be subject to
the requirements and the type of
professional skills necessary for
preparation of reports or records; and (5)
describe the steps the Agency has taken
to minimize the impact on small
entities, including a statement of the
reasons for selecting the chosen option
and for rejecting other options which
would alter the impact on small entities.
EPA has considered and addressed all
the above requirements in the
Regulatory Impact Analysis (RIA) for the
Stage 1 DBPR (EPA 1998g). The
following is a summary of the RFA.
The first requirement is discussed in
section I of today's rule. The second,
third and fifth requirements are
summarized below. The fourth
requirement is discussed in V.B
(Paperwork Reduction Act) and the
Information Collection Requirement.
Number of Small Entities Affected.
EPA estimates that 69,491 groundwater
systems will be affected by the Stage 1
DBPR, with 68,171 (98%) of these
systems serving less than 10,000
persons. Of the 68,171 small systems
affected, EPA estimates that 8,323 (12%)
will have to modify treatment to comply
with the Stage 1 DBPR. Of these, 5,403
systems (8%) will use chloramines to
comply and 2,921 systems (4.3%) will
use membranes to comply. Use of these
technologies by small groundwatfer
systems will result in total capital costs
of $998 million and an annualized
treatment cost of $180 million.
EPA estimates that 6,560 surface
water systems will be affected by the
Stage 1 DBPR, with 5,165 (79%) of these
systems serving less than 10,000
persons. It is estimated that 3,616 (70%)
of these small systems will have to
modify treatment to comply with the
Stage 1 DBPR and 3,459 (67%) of these
systems will use a combination of
enhanced coagulation, chloramines, and
ozone, while another 157 systems (3%)
will use membranes. Use of these
technologies by small surface water
systems will result in total capital costs
of $243 million and an annualized
treatment cost of $46 million.
EPA has included several provisions
which will reduce the economic burden
of compliance for these small systems.
These requirements, discussed in
greater detail in the RIA (EPA, 1998g),
include:
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Federal Register/Vol. 63, No. 241 / Wednesday, December 16, 1998/Rules and Regulations B9453
—Less routine monitoring. Small
systems are required to monitor less
frequently for such contaminants as
TTHMs and HAAS. Also, ground
water systems (the large majority of
small systems) are required to monitor
less frequently than Subpart H
systems (surface water systems and
groundwater under the direct
influence of surface water) of the
same size.
—Extended compliance dates. Systems
that use only ground water not under
the direct influence of surface water
serving fewer than 10,000 people have
60 months from promulgation of this
rule to comply. This is in contrast to
large Subpart H systems which have
36 months to comply. These extended
compliance dates will allow smaller
systems to learn from the experience
of larger systems on how to most cost
effectively comply with the Stage 1
DBPR. In addition, larger systems will
generate a significant amount of
treatment and cost data from the ICR
and in their efforts to achieve
compliance with the Stage 1
requirements. EPA intends to
summarize this information and make
it available through guidance manuals
(i.e., the Small Entities Guidance
Manual). EPA believes this
information will assist smaller
systems in achieving compliance with
the Stage 1 DBPR.
3. Summary of Comments
Several commenters expressed
concern with the significant economic
burden that the Stage 1 DBPR would
place on small systems. Other
commenters suggested more flexibility
be given for small systems and that a
longer compliance period for small
systems should be included in the final
Stage 1 DBPR. 'Several commenters
suggested small systems should not be
included in the final Stage 1 DBPR
because the costs for implementing the
rule would exceed the potential benefits
for these systems.
EPA understands commenters'
concerns with the potential significant
economic burden on small systems.
Because of this potential significant
impact, EPA has provided several
requirements which will reduce the
burden on these systems. These
requirements which are discussed above
and also in greater detail in the RIA
(EPA, 1998g) include: (1) less routine
monitoring; and (2) extended
compliance dates. EPA also believes
small systems can reduce their
economic burden by; (1) consolidation
with larger systems; (2) using money
from the State revolving fund loans; and
(3) using variances and exemptions
when needed. EPA considered an
option in the development of the final
rule for large systems to have MCLs of
80 ug/L for TTHMs and 60 ug/L for
HAAs and for small systems to have a
simple TTHM standard of 100 ug/L.
This option was rejected because
allowing small systems to comply with
a different MCL level would not
adequately protect the health of the
population served by these systems.
EPA did not consider excluding small
systems from the Stage 1 DBPR; because
these systems do not currently have any
standards for DBFs and the Agency
believed there was a public health
concern that needed to be addressed.
For a more detailed description of the
alternatives considered in the
development of the final rule see the
final RIA (EPA, 1998g) or the final
Unfunded Mandates Reform Act
Analysis for the Stage 1 DBPR (EPA,
1998o).
B. Paperwork Reduction Act
The Office of Management and Budget
(OMB) has approved the information
collection requirements contained in
this rule under the provisions of the
Paperwork Reduction Act, 44 U.S.C.
3501 et seq. and has assigned OMB
control number 2040-0204.
The information collected as a result
of this rule will allow the States and the
EPA to evaluate PWS compliance with
the rule. For the first three years after
promulgation of the Stage 1 DBPR, the
major information requirements pertain
to preparation for monitoring activities,
and for compliance tracking. Responses
to the request for information are
mandatory (Part 141). The information
collected is not confidential.
EPA is required to estimate the
burden on PWS for complying with the
final rule. Burden means the total time,
effort, or financial resources expended
by persons to generate, maintain, retain,
qr disclr-se or provide information to or
for a Federal agency. This includes the
time needed to review instructions;
develop, acquire, install, and utilize
technology and systems for the purposes
of collecting, validating, and verifying
information, processing and
maintaining information, and disclosing
and providing information; adjust the
existing ways to comply with any
previously applicable instructions and
requirements; train personnel to be able
to respond to a collection of
information; search data sources;
complete and review the collection of
information; and transmit or otherwise
disclose, the information.
EPA estimates that the annual burden
on PWS and States for reporting and
recordkeeping will be 314,471 hours.
This is based on an estimate that there
will be 4,631 respondents on average
per year who will need to provide about
9,449 responses and that the average
response will take 33 hours. The annual
labor cost is estimated to be about $12
million. In the first 3 years after
promulgation of the rule, only labor
costs are incurred. The costs are
incurred for the following activities:
reading and understanding the rule;
planning; and training.
An Agency may not conduct or
sponsor, and a person is not required to
respond to a collection of information
unless it displays a currently valid OMB
control number. The OMB control
numbers for EPA's regulations are listed
in 40 CFR Part 9 and 48 CFR Chapter
15. EPA is amending the table in 40 CFR
Part 9 of currently approved ICR control
numbers issued by OMB for various
regulations to list the information
requirements contained in this final
rule. This ICR was previously subject to
public notice and comment prior to
OMB approval. As a result, EPA finds
that there is "good cause" under section
553 (b)(B) of the Administrative
Procedures Act (5 U.S.C. 553 (b) (B)) to
amend this table without prior notice
and comment. Due to the technical
nature of the table, further notice and
comment would be unnecessary.
C. Unfunded Mandates Reform Act
1. Summary of UMRA Requirements
Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for
Federal agencies to assess the effects of
their regulatory actions on State, local,
and tribal governments and the private
sector. Under UMRA section 202, EPA
generally must prepare a written
statement, including a cost-benefit
analysis, for proposed and final rules
with "Federal mandates" that may
result in expenditures to State, local,
and tribal governments, in the aggregate,
or to the private sector, of $ 100 million
or more in any one year. Before
promulgating an EPA rule, for which a
written statement is needed, section 205
of the UMRA generally requires EPA to
identify and consider a reasonable
number of regulatory alternatives and
adopt the least costly, most cost-
effective or least burdensome alternative
that achieves the objectives of the rule.
The provisions of section 205 do not
apply when they are inconsistent with
applicable law. Moreover, section 205
allows EPA to adopt an alternative other
than the least costly, most cost effective
or least burdensome alternative if the
Administrator publishes with the final
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69454 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
rule an explanation on why that
alternative was not adopted.
Before EPA establishes any regulatory
requirements that may significantly or
uniquely affect small governments,
including tribal governments, it must
have developed, under section 203 of
the UMRA. a small government agency
plan. The plan must provide for
notification to potentially affected small
governments, enabling officials of
affected small governments to have
meaningful and timely input in the
development of EPA regulatory
proposals with significant Federal
intergovernmental mandates; and
Informing, educating, and advising
small governments on compliance with
the regulatory requirements.
2. Written Statement for Rules With
Federal Mandates of S100 Million or
More
EPA has determined that this rule
contains a Federal mandate that may
result in expenditures of $100 million or
more for State, local, and tribal
governments, in the aggregate, and the
private sector in any one year.
Accordingly, EPA has prepared, under
section 202 of the UMRA, a written
statement addressing the following
areas: (1) authorizing legislation; (2)
cost-benefit analysis including an
analysis of the extent to which the costs
to State, local and Tribal governments
will be paid for by the federal
government; (3) estimates of future
compliance costs and disproportionate
budgetary effects; (4) macro-economic
effects; and (5) a summary of EPA's
consultation with State, local, and
Tribal governments, and a summary of
their concerns, and a summary of EPA's
evaluation of their concerns. A more
detailed description of this analysis is
presented in EPA's Unfunded Mandates
Reform Act Analysis for the Stage 1 DBP
Rule (EPA, 1998o) which is included in
the docket for this rule.
a. Authorizing Legislation. Today's
rule is promulgated pursuant to Section
1412(b)(2) of the 1996 amendments to
the SDWA; paragraph C of this section
establishes a statutory deadline of
November 1998 to promulgate this rule.
This rule supersedes the TTHM Rule
(EPA. 1979). In addition, the Stage 1
DBP rule is closely integrated with the
IESWTR, which also has a statutory
deadline of November 1998.
b. Cost Benefit Analysis. Section IV
discusses the cost and benefits
associated with the Stage 1 DBP rule.
Also, the EPA's Regulatory Impact
Analysis of the Stage 1 Disinfectants/
Disinfection Byproducts Rule (EPA,
1998g) contains a detailed cost benefit
analysis. Today's rule is expected to
have a total annualized cost of
approximately $701 million using a 7
percent cost of capital. The analysis
includes both qualitative and monetized
benefits for improvements to health and
safety. Because of scientific uncertainty
regarding the exposure assessment and
the risk assessment for DBFs, the
Agency has used five analytical
approaches to assess the benefits of the
Stage 1 DBP. These analyses were based
on the quantification of bladder cancer
health damages avoided. However, this
rule may also reduce colon and rectal
cancers, as well as decrease adverse
reproductive and developmental effects.
This would further increase the benefits
of this rule.
Various Federal programs exist to
provide financial assistance to State,
local, and Tribal governments in
complying with this rule. The Federal
government provides funding to States
that have primary enforcement
responsibility for their drinking water
programs through the Public Water
Systems Supervision Grants program.
Additional funding is available from
other programs administered either by
EPA or other Federal agencies. These
include the Drinking Water State
Revolving Fund (DWSRF) and Housing
and Urban Development's Community
Development Block Grant Program. For
example, SDWA authorizes the
Administrator of the EPA to award
capitalization grants to States, which in
turn can provide low cost loans and
other types of assistance to eligible
public water systems. The DWSRF
assists public water systems with
financing the costs of infrastructure
needed to achieve or maintain
compliance with SDWA requirements.
Each State will have considerable
flexibility to determine the design of its
program and to direct funding toward
its most pressing compliance and public
health protection needs. States may
also, on a matching basis, use up to ten
percent of their DWSRF allotments for
each fiscal year to assist in running the
State drinking water program.
c. Estimates of Future Compliance
Costs and Disproportionate Budgetary
Effects. To meet the UMRA requirement
in section 202, EPA analyzed future
compliance costs and possible
disproportionate budgetary effects. The
Agency believes that the cost estimates,
indicated above and discussed in more
detail in Section IV of this rule,
accurately characterize future
compliance costs of the rule.
In regard to the disproportionate
impacts, EPA considered available data
sources in analyzing the
disproportionate impacts upon
geographic or social segments of the
nation or industry. This analysis was
difficult because impacts will most
likely depend on a system's source
water characteristics and this data is not
available for all systems. However, it
should be noted that the rule uniformly
protects the health of all drinking water
system users regardless of the size or
type of system. Further analysis
revealed that no geographic or social
segment patterns were likely for this
rule. One observation is that the
historical pattern of development in this
country led most large cities to be
developed near rivers and other bodies
of water useful for power,
transportation, and drinking water. To
the extent that this rule affects surface
water, it in most ways reflects the
distribution of population and
geography of the nation. No rationale for
disproportionate impacts by geography
or social segment was identified. This
analysis, therefore, developed three
other measures: reviewing the impacts
on small systems versus large systems;
reviewing the costs to public versus
private water systems; and reviewing
the household costs of the final rule.
First, the national impacts on small
systems (those serving fewer than
10,000 people) versus large systems
(those serving 10,000 people or more) is
indicated in Table V-l. The higher cost
to the small ground water systems is
mostly attributable to the large number
of these types of systems (i.e. there are
68,171 small ground water systems,
1,320 large ground water systems, 5,165
small surface water systems, and 1,395
large surface water surface water
systems).
TABLE V-1 .—ANNUAL COST OF COMPLIANCE FOR SMALL AND LARGE SYSTEMS ($000)*
Surface Water Systems (All)
Small systems
(population
< 10,000)
$56,804
Large systems
(population
> 10,000)
$278,321
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Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations 69455
TABLE V-1 .—ANNUAL COST OF COMPLIANCE FOR SMALL AND LARGE SYSTEMS ($000)*—Continued
Ground Water System (All)
Total
Small systems
(population
< 10,000)
Q"\Q nfio
274,866
Large systems
(population
>. 10,000)
H QH CCH
408,972
* Costs calculated at a 7 percent cost of capital and include one time start-up costs.
The second measure of
disproportionate impact evaluated is the
relative total costs to public versus
private water systems, by size. EPA
believes the implementation of the rule
affects both public and private water
systems equally, with the variance in
total cost by system size merely a
function of the number of affected
systems.
The third measure, household costs,
can also be used to gauge the impact of
a regulation and to determine whether
there are disproportionately high
impacts in particular segments of the
population. A detailed analysis of
household cost impacts by system size
and system type are presented in
Section IV.E. In summary, for large
surface water systems EPA estimates
that 98 percent of households will incur
costs of less than $1 per month while
0.3 percent of households will incur
costs greater than $10 per month. For
large groundwater systems, EPA
estimates that 95 percent of households
will incur costs of less than $ 1 per
month while 1.0 percent of households
will incur costs greater than $10 per
month. For small surface water systems
EPA estimates the 71 percent of
households will incur costs of less than
$ 1 per month while 1 percent of
households will incur costs of greater
than $10 per month. For small
groundwater systems EPA estimates that
91 percent of households will incur
costs of less than $1 per month while 4
percent of households will incur costs
of greater than $10 per month.
The household analysis tends to
overestimate the costs per household
because of the structure and
assumptions of the methodology. For
example, the highest per-household cost
would be incurred in a system using
membrane technology. These systems,
conversely, might seek less costly
alternatives such as point-of-use
devices, selection of alternative water
sources, or connecting into a larger
regional water system. The overall effect
is that costs are higher in smaller
systems, and a higher percentage of
those systems are publicly owned.
Smaller systems, however, represent a
larger portion of systems that are not in
compliance with existing regulations.
EPA believes that smaller systems
incurring the highest household costs
may also incur the highest reduction in
risk. This is because smaller systems
have not had to previously comply with
a TTHMs standard of 100 ug/L. In the
RIA, EPA estimates that on average,
small systems will achieve about twice
as much reduction in risk as achieved
by larger systems (EPA, 1998g).
Based on the analysis above, EPA
does not believe there will be
disproportionate impacts on small
systems, public versus private systems,
or generally by household. A more
detailed description of this analysis is
presented in the EPA's Unfunded
Mandates Reform Act Analysis for the
Stage 1 DBP Rule (EPA, 1998o).
d. Macro-economic Effects. As
required under UMRA Section 202, EPA
is required to estimate the potential
macro-economic effects of the
regulation. Macro-economic effects tend
to be measurable in nationwide
econometric models only if the
economic impact of the regulation
reaches 0.25 percent to 0.5 percent of
Gross Domestic Product (GDP). In 1997,
real GDP was $7,188 billion so a rule
would have to cost at least $18 billion
to have a measurable effect. A regulation
with a smaller aggregate effect is
unlikely to have any measurable impact
unless it is highly focused on a
particular geographic region or
economic sector. The macro-economic
effects on the national economy from
the Stage 1 DBPR should be negligible
based on the fact that the total annual
costs are about $701 million per year (at
a 7 percent cost of capital) and the costs
are not expected to be highly focused on
a particular geographic region or sector.
e. Summary of EPA's Consultation
with State, Local, and Tribal
Governments and Their Concerns.
Under UMRA section 202, EPA is to
provide a summary of its consultation
with elected representatives (or their
designated authorized employees) of
affected State, local and Tribal
governments in this rulemaking.
Although this rule was proposed before
UMRA became a statutory requirement,
EPA initiated consultations with
governmental entities and the private
sector affected by this rule through
various means. This included
participation on a Regulatory
Negotiation Committee chartered under
the Federal Advisory Committee Act
(FACA) in 1992-93 that included
stakeholders representing State and
local governments, public health
organizations, public water systems,
elected officials, consumer groups, and
environmental groups.
After the amendments to SDWA in
1996, the Agency initiated a second
FACA process, similarly involving a
broad range of stakeholders, and held
meetings during 1997 to address the
expedited deadline for promulgation of
the Stage 1 DBPR in November 1998.
EPA established the M-DBP Advisory
Committee to collect, share, and analyze
new data reviewed since the earlier Reg.
Neg. process and also to build a
consensus on the regulatory
implications of this new information.
The M-DBP Advisory Committee
established a technical working group to
assist them with the many scientific
issues surrounding this rule. The
Committee included representatives
from organizations such as the National
League of Cities, the National
Association of City and County Health
Officials, the Association of
Metropolitan Water Agencies, the
Association of State Drinking Water
Administrators, and the National
Association of Water Companies. In
addition, the Agency invited the Native
American Water Association to
participate in the FACA process to
develop this rule. Although they
eventually decided not to take part, the
Association continued to be informed of
meetings and developments through a
stakeholders mailing list.
Stakeholders who participated in the
FACA processes, as well as all other
interested members of the public, were
invited to comment on the proposed
rule and NODAs. Also, as part of the
Agency's Communication Strategy, EPA
sent copies of the proposed rule and
NODAs to many stakeholders, including
six tribal associations.
In addition, the Agency notified
governmental entities and the private
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69456 Federal Register/Vol. 63, No. 241/Wednesday, December 16. 1998/Rules and Regulations
sector of opportunities to provide input
on this Stage 1 DBPR in the Federal
Register on July 29, 1994 (59 FR
38668—EPA, 1994A), November 3, 1997
(62 FR 59485—EPA, 1997b), and on
March 31, 1998 (63 FR 15974—EPA,
1998a). Additionally, EPA extended the
comment period for the March 31, 1998
NODA and announced a public meeting
to address new information. EPA
received approximately 213 written
comments on the July 29, 1994 notice,
approximately 57 written comments on
the November 3, 1997 notice, and
approximately 41 written comments on
the March 31. 1998 notice. Of the 213
comments received concerning the 1994
proposed rule, 11% were from States
and 41% were from local governments.
Also, one comment on the 1994
proposal was from a tribal group that
represented 43 tribes. Of the 57
comments received concerning the 1997
Notice of Data Availability, 18% were
from States and 37% were from local
governments. Of the 41 comments
received on the 1998 Notice of Data
Availability prior to the close of the
comment period, 5% were from States
and 15% were from local governments.
The public docket for this rulemaking
contains all comments received by the
Agency and provides details about the
nature of State, local, and tribal
government's concerns. State and local
governments raised several concerns
including: the need for the Stage 1
DBPR; the high costs of the rule in
relation to the uncertain benefits; the
belief that not allowing predisinfection
credit would increase the microbial risk;
and the need for flexibility in
implementing the Stage 1 DPBR and
IESWTR to insure the rules are
implemented simultaneously. The one
tribal comment noted that compliance
would come at a cost of diverting funds
away from other important drinking
water needs such as maintaining
drinking water infrastructure.
EPA understands the State, local, and
tribal governments concerns with the
costs of the rule and the need to provide
additional public health protection for
the expenditure. The Agency believes
the final Stage 1 DPBR will provide
public health benefits to individuals by
reducing their exposures to DBPs, while
not requiring excessive capital
expenditures. As discussed above, the
majority of households will incur
additional costs of less than SI per
month. As discussed in section III.E, the
final rule maintains the existing
predisinfection credit. Finally, in the
1997 DBP NODA (EPA, 1997b), EPA
requested comment on four alternative
schedules for complying with the Stage
1 DBPR. Most State and local
commenters preferred the option which
provides the maximum flexibility
allowed under the SDWA for systems to
comply with the Stage 1 DBPR, and this
is the option EPA selected for the final
rule.
f. Regulatory Alternatives Considered.
As required under Section 205 of the
UMRA, EPA considered several
regulatory alternatives developed by the
Reg Neg Committee and M-DBP
Advisory Committee and suggested by
stakeholders.
The Reg Neg Committee considered
several options including a proposed
TTHMs MCL of 80 |ig/L and HAAS MCL
of 60 ng/L for large systems (and a
simple standard of 100 p.g/1 for small
systems). Another option called for the
use of precursor removal technology to
reduce the level of total organic carbon
with alternative levels ranging from 4.0
to 0.5. Other options evaluated included
a 80 ng/L for TTHMs, 60 ng/L for HAA5,
and 4.0 for TOC. Finally, an option was
evaluated of a 80 |ig/L for TTHMs, 60
Hg/L for HAAS, and 5.0 for TOC. The
final consensus included a combination
of MCLs which would be equal for all
system size categories and a target TOC
level. Allowing small systems to comply
with a different MCL levels was rejected
because the rule would not adequately
protect the health of the population
served by these systems. A more
detailed description of these alternatives
is discussed in the document Unfunded
Mandates Reform Act Analysis for the
Stage 1 DBPR Rule which can be found
in the docket (EPA, 1998o).
Other regulatory alternatives were
considered by the M-DBP Advisory
Committee and these alternatives had
the overall effect of reducing the cost of
the final rule. For example, the M-DBP
Advisory Committee recommended
maintaining the predisinfection credit
after reviewing data which suggested
that many systems could probably meet
the proposed MCLs for DBPs while
maintaining current disinfection
practices. This decision was important
because systems would have had to
incur large capital costs to remain in
compliance with disinfection
requirements if predisinfection credits
were disallowed. Thus by allowing
predisinfection, the overall cost of the
rule was lowered.
Also, the Committee recommended
exempting systems for the enhanced
coagulation requirements based on their
raw water quality. For example, systems
with raw-water TOC of less than or
equal to 2.0 mg/L and raw-water SUVA
of less than or equal to 2.0 L/mg-m
would be exempt from the enhanced
coagulation requirements. This
exclusion was intended to promote cost-
effective enhanced coagulation (i.e.,
obtaining efficiencies of TOC removal
without excessive sludge production
and associated costs).
In conclusion, EPA believes that the
alternative selected for the Stage 1 DBPR
is the most cost-effective option that
achieves the objectives of the rule. For
a complete discussion of this issue see
EPA's Regulatory Impact Analysis of the
Stage 1 Disinfectants/Disinfection
Byproducts Rule (EPA,1998g).
3. Impacts on Small Governments
The 1994 Stage 1 DBPR proposal was
done without the benefit of the UMRA
requirements. However, in preparation
for the final rule, EPA conducted
analysis on small government impacts
and included small government officials
or their designated representatives in
the rule making process. The FACA
processes gave a variety of stakeholders,
including small governments, the
opportunity for timely and meaningful
participation in the regulatory
development process. Representatives of
small government organizations were on
both the Reg. Neg. Committee and the
M-DBP Advisory Committee and their
representatives attended public
stakeholder meetings. Groups such as
the National Association of City and
County Health Officials and the
National League of Cities participated in
the rulemaking process. Through such
participation and exchange, EPA
notified potentially affected small
governments of requirements under
consideration and provided officials of
affected small governments with an
opportunity to have meaningful and
timely input into the development of
regulatory proposals.
In addition, EPA will educate, inform,
and advise small systems including
those run by small government about
DBPR requirements. One of the most
important components of this process is
the Small Entity Compliance Guide, as
required by the Small Business
Regulatory Enforcement Fairness Act of
1996. This plain-English guide will
explain what actions a small entity must
take to comply with the rule. Also, the
Agency is developing fact sheets that
concisely describe various aspects and
requirements of the DBPR.
D. National Technology Transfer and
Advancement Act
Under section 12(d) of the National
Technology Transfer and Advancement
Act (NTTAA), the Agency is required to
use voluntary consensus standards in its
regulatory activities unless to do so
would be inconsistent with applicable
law or otherwise impractical. Voluntary
consensus standards are technical
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standards (e.g., materials specifications,
test methods, sampling procedures,
business practices, etc.) that are
developed or adopted by voluntary
consensus standards bodies. Where
available and potentially applicable
voluntary consensus standards are not
used by EPA, the Act requires the
Agency to provide Congress, through
OMB, an explanation of the reasons for
not using such standards.
EPA's process for selecting the
analytical test methods is consistent
with section 12(d) of the NTTAA. EPA
performed literature searches to identify
analytical methods from industry,
academia, voluntary consensus
standards bodies, and other parties that
could be used to measure disinfectants,
DBPs, and other parameters. In addition,
EPA's selection of the methods
benefited from the recommendations of
an Advisory Committee established
under the FACA Act to assist the
Agency with the Stage 1 DBPR. The
Committee made available additional
technical experts who were well-versed
in both existing analytical methods and
new developments in the field.
The results of these efforts form the
basis for the analytical methods in
today's rule which includes: eight
methods for measuring different DBPs,
of which five are EPA methods and
three are voluntary consensus
standards; nine methods for measuring
disinfectants, all of which are voluntary
consensus standards; three voluntary
consensus methods for measuring TOC;
two EPA methods for measuring
bromide; one voluntary consensus
method for measuring UV254, and both
governmental and voluntary consensus
methods for measuring alkalinity.
Where applicable voluntary consensus
standards were not approved, this was
due to their inability to meet the data
quality objectives (e.g. accuracy,
sensitivity, quality control procedures)
necessary for demonstration of
compliance with the relevant
requirement.
In the 1997 NODA, EPA requested
comment on voluntary consensus
standards that had not been addressed
and which should be considered for
addition to the list of approved
analytical methods in the final rule. No
additional consensus methods were
suggested by commenters.
E. Executive Order 12866: Regulatory
Planning and Review
Under Executive Order 12866, (58 FR
41344—EPA, 1993c) the Agency must
determine whether the regulatory action
is "significant" and therefore subject to
OMB review and the requirements of
the Executive Order. The Order defines
"significant regulatory action" as one
that is likely to result in a rule that may:
1. Have an annual effect on the
economy of $ 100 million or more or
adversely affect in a material way the
economy, a sector of the economy,
productivity, competition, jobs, the
environment, public health or safety, or
State, local, or tribal governments or
communities;
2. Create a serious inconsistency or
otherwise interfere with an action taken
or planned by another agency;
3. Materially alter the budgetary
impact of entitlement, grants, user fees,
or loan programs or the rights and
obligations of recipients thereof; or
4. Raise novel legal or policy issues
arising out of legal mandates, the
President's priorities, or the principles
set forth in the Executive Order.
Pursuant to the terms of Executive
Order 12866, it has been determined
that this rule is a "significant regulatory
action" because it will have an annual
effect on the economy of $ 100 million
or more. As such, this action was
submitted to OMB for review. Changes
made in response to OMB suggestions or
recommendations are documented in
the public record.
F. Executive Order 12898:
En vironmen tal Justice
Executive Order 12898 establishes a
Federal policy for incorporating
environmental justice into Federal
agency missions by directing agencies to
identify and address disproportionately
high and adverse human health or
environmental effects of its programs,
policies, and activities on minority and
low-income populations. The Agency
has considered environmental justice
related issues concerning the potential
impacts of this action and has consulted
with minority and low-income
stakeholders.
Two aspects of today's rule comply
with the Environmental Justice
Executive Order which requires the
Agency to consider environmental
justice issues in the rulemaking and to
consult with Environmental Justice (EJ)
stakeholders. They can be classified as
follows: (1) the overall nature of the
rule, and (2) the convening of a
stakeholder meeting specifically to
address environmental justice issues.
The Stage 1 DBPR applies to community
water systems and nontransient
noncommunity water systems that treat
their water with a chemical disinfectant
for either primary or residual treatment.
Consequently, the health protection
benefits this rule provides are equal
across all income and minority groups
within these communities.
Finally, as part of EPA's
responsibilities to comply with E.O.
12898, the Agency held a stakeholder
meeting on March 12, 1998 to address
various components of pending
drinking water regulations; and how
they may impact sensitive sub-
populations, minority populations, and
low-income populations. Topics
discussed included treatment
techniques, costs and benefits, data
quality, health effects, and the
regulatory process. Participants
included national, state, tribal,
municipal, and individual stakeholders.
EPA conducted the meetings by video
conference call between eleven cities.
This meeting was a continuation of
stakeholder meetings that started in
1995 to obtain input on the Agency's
Drinking Water Programs. The major
objectives for the March 12, 1998
meeting were:
• Solicit ideas from EJ stakeholders
on known issues concerning current
drinking water regulatory efforts;
• Identify key issues of concern to EJ
stakeholders; and
• Receive suggestions from EJ
stakeholders concerning ways to
increase representation of EJ
communities in OGWDW regulatory
efforts.
In addition, EPA developed a plain-
English guide specifically for this
meeting to assist stakeholders in
understanding the multiple and
sometimes complex issues surrounding
drinking water regulation.
Overall, EPA believes this rule will
equally protect the health of all minority
and low-income populations served by
systems regulated under this rule from
exposure to DBPs.
G. Executive Order 13045: Protection of
Children From Environmental Health
Risks and Safety Risks
Executive Order 13045 applies to any
rule initiated after April 21, 1997, or
proposed after April 21, 1998, that (1) is
determined to be "economically
significant" as defined under E.O. 12866
and (2) concerns an environmental
health or safety risk that EPA has reason
to believe may have a disproportionate
effect on children. If the regulatory
action meets both criteria, the Agency
must evaluate the environmental health
or safety effects of the planned rule on
children, and explain why the planned
regulation is preferable to other
potentially effective and reasonably
feasible alternatives considered by the
Agency.
The final Stage 1 DBPR is not subject
to the Executive Order because EPA
published a notice of proposed
rulemaking before April 21, 1998.
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However, EPA's policy since November
1, 1995, Is to consistently and explicitly
consider risks to infants and children in
all risk assessments generated during its
decision making process including the
setting of standards to protect public
health and the environment.
EPA's Office of Water has historically
considered risks to sensitive
populations (including fetuses, infants,
and children) in establishing drinking
water assessments, advisories or other
guidance, and standards (EPA, 1989c
and EPA, 1991). The disinfection of
public drinking water supplies to
prevent waterborne disease is the most
successful public health program in U.S.
history. However, numerous chemical
byproducts (DBPs) result from the
reaction of chlorine and other
disinfectants with naturally occurring
organic and inorganic material in source
water, and these may have potential
health risks. Thus, maximizing health
protection for sensitive subpopulations
requires balancing risks to achieve the
recognized benefits of controlling
waterborne pathogens while minimizing
risk of potential DBF toxicity. Human
experience shows that waterborne
disease from pathogens in drinking
water is a major concern for children
and other subgroups (elderly, immune
compromised, pregnant women)
because of their greater vulnerabilities
(Gerba et al., 1996). Based on animal
studies, there is also a concern for
potential risks posed by DBPs to
children and pregnant women (EPA,
1994a;EPA, 1998a).
In developing this regulation, risks to
sensitive subpopulations (including
fetuses and children) were taken into
account in the assessments of
disinfectants and disinfection
byproducts. A description of the data
available for evaluating risks to children
and the conclusions drawn can be found
in the public docket for this rulemaking
(EPA, 1998h). In addition, the Agency
has evaluated alternative regulatory
options and selected the option that will
provide the greatest benefits for all
people including children. See the
regulatory impact analysis for a
complete discussion of the different
options considered. It should also be
noted that the IESTWR, which
accompanies this final rule, provides
better controls of pathogens and
achieves the goal of increasing the
protection of children.
H. Consultations With the Science
Advisory Board, National Drinking
Water Advisory Council, and the
Secretary of Health and Human Services
In accordance with section 1412 (d)
and (e) of the Act. the Agency submitted
the proposed Stage 1 DBF rule to the
Science Advisory Board, National
Drinking Water Advisory Council
(NOWAC), and the Secretary of Health
and Human Services for their review.
EPA has evaluated comments received
from these organizations and considered
them in developing the final Stage 1
DBP rule.
I. Executive Order 12875: Enhancing the
Intergovernmental Partnership
Under Executive Order 12875, EPA
may not issue a regulation that is not
required by statute and that creates a
mandate upon a State, local or tribal
government, unless the Federal
government provides the funds
necessary to pay the direct compliance
costs incurred by those governments, or
EPA consults with those governments. If
EPA complies by consulting, Executive
Order 12875 requires EPA to provide to
the Office of Management and Budget a
description of the extent of EPA's prior
consultation with representatives of
affected State, local and tribal
governments, the nature of their
concerns, copies of any written
communications from the governments,
and a statement supporting the need to
issue the regulation. In addition,
Executive Order 12875 requires EPA to
develop an effective process permitting
elected officials and other
representatives of State, local and tribal
governments "to provide meaningful
and timely input in the development of
regulatory proposals containing
significant unfunded mandates."
EPA has concluded that this rule will
create a mandate on State, local, and
tribal governments and that the Federal
government will not provide all of the
funds necessary to pay the direct costs
incurred by the State, local, and tribal
governments in complying with the
mandate. In developing this rule, EPA
consulted with State and local
governments to enable them to provide
meaningful and timely input in the
development of this rule. EPA also
invited the Native American Water
Association to participate in the FACA
process to develop this rule, but they
decided not to take part in the
deliberations.
As described in Section V.C.2.e, EPA
held extensive meetings with a variety
of State and local representatives, who
provided meaningful and timely input
in the development of the proposed
rule. State and local representatives
were also part of the FACA committees
involved in the development of this
rule. Summaries of the meetings have
been included in the public docket for
this rulemaking. See section V.C.2.e for
summaries of the extent of EPA's
consultation with State, local, and tribal
governments; the nature of the
government concerns; and EPA's
position supporting the need to issue
this rule.
/. Executive Order 13084: Consultation
and Coordination With Indian Tribal
Governments
Under Executive Order 13084, EPA
may not issue a regulation that is not
required by statute, that significantly or
uniquely affects the communities of
Indian tribal governments, and that
imposes substantial direct compliance
costs on those communities, unless the
Federal government provides the funds
necessary to pay the direct compliance
costs incurred by the tribal
governments, or EPA consults with
those governments. If EPA complies by
consulting, Executive Order 13084
requires EPA to provide to the Office of
Management and Budget, in a separately
identified section of the preamble to the
rule, a description of the extent of EPA's
prior consultation with representatives
of affected tribal governments, a
summary of the nature of their concerns,
and a statement supporting the need to
issue the regulation. In addition,
Executive Order 13084 requires EPA to
develop an effective process permitting
elected officials and other
representatives of Indian tribal
governments "to provide meaningful
and timely input in the development of
regulatory policies on matters that
significantly or uniquely affect their
communities."
EPA has concluded that this rule will
significantly affect communities of
Indian tribal governments. It will also
impose substantial direct compliance
costs on such communities, and the
Federal government will not provide all
the funds necessary to pay the direct
costs incurred by the tribal governments
in complying with the rule. In
developing this rule, EPA consulted
with representatives of tribal
governments pursuant to both Executive
Order 12875 and Executive Order
13084. EPA's consultation, the nature of
the governments' concerns, and EPA's
position supporting the need for this
rule are discussed above in the
preamble section that addresses
compliance with Executive Order
12875. Specifically in developing this
rule, the Agency invited the Native
American Water Association to
participate in the FACA process to
develop this rule. Although they
eventually decided not to take part, the
Association continued to be informed of
meetings and developments through a
stakeholders mailing list. As described
in Section V.C.2.6 of the discussion on
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Federal Register/Vol. 63. No. 241/Wednesday, December 16, 1998/Rules and Regulations 69459
UMRA, EPA held extensive meetings
that provided the opportunity for
meaningful and timely input in the
development of the proposed rule.
Summaries of the meetings have been
included in the public docket for this
rulemaking.
K. Submission to Congress and the
General Accounting Office
The Congressional Review Act, 5
U.S.C. 801 et seq., as added by the Small
Business Regulatory Enforcement
Fairness Act of 1996, generally provides
that before a rule may take effect, the
agency promulgating the rule must
submit a rule report, which includes a
copy of the rule, to each House of the
Congress and to the Comptroller General
of the United States. EPA will submit a
report containing this rule and other
required information to the U.S. Senate,
the U.S. House of Representatives, and
the Comptroller General of the United
States prior to publication of the rule in
the Federal Register. A major rule
cannot take effect until 60 days after it
is published in the Federal Register.
This rule is a "major rule" as defined by
5 U.S.C. 804(2). This rule will be
effective February 16, 1999.
L. Likely Effect of Compliance With the
Stage 1 DBPR on the Technical,
Financial, and Managerial Capacity of
Public Water Systems
Section 1420(d)(3) of the SDWA as
amended requires that, in promulgating
a NPDWR, the Administrator shall
include an analysis of the likely effect
of compliance with the regulation on
the technical, financial, and managerial
capacity of public water systems. The
following analysis has been performed
to fulfill this statutory obligation.
Overall water system capacity is
defined in EPA guidance (EPA 816-R-
98-006) as the ability to plan for,
achieve, and maintain compliance with
applicable drinking water standards.
Capacity has three components:
technical, managerial, and financial.
Technical capacity is the physical and
operational ability of a water system to
meet SDWA requirements. Technical
capacity refers to the physical
infrastructure of the water system,
including the adequacy of source water
and the adequacy of treatment, storage,
and distribution infrastructure. It also
refers to the ability of system personnel
to adequately operate and maintain the
system and to otherwise implement
requisite technical knowledge. A water
system's technical capacity can be
determined by examining key issues
and questions, including:
• Source water adequacy. Does the
system have a reliable source of
drinking water? Is the source of
generally good quality and adequately
protected?
• Infrastructure adequacy. Can the
system provide water that meets SDWA
standards? What is the condition of its
infrastructure, including well(s) or
source water intakes, treatment, storage,
and distribution? What is the
infrastructure's life expectancy? Does
the system have a capital improvement
plan?
• Technical knowledge and
implementation. Is the system's operator
certified? Does the operator have
sufficient technical knowledge of
applicable standards? Can the operator
effectively implement this technical
knowledge? Does the operator
understand the system's technical and
operational characteristics? Does the
system have an effective operation and
maintenance program?
Managerial capacity is the ability of a
water system to conduct its affairs in a
manner enabling the system to achieve
and maintain compliance with SDWA
requirements. Managerial capacity refers
to the system's institutional and
administrative capabilities.
Managerial capacity can be assessed
through key issues and questions,
including:
• Ownership accountability. Are the
system owner(s) clearly identified? Can
they be held accountable for the system?
• Staffing and organization. Are the
system operators) and manager(s)
clearly identified? Is the system
properly organized and staffed? Do
personnel understand the management
aspects of regulatory requirements and
system operations? Do they have
adequate expertise to manage water
system operations? Do personnel have
the necessary licenses and
certifications?
• Effective external linkages. Does the
system interact well with customers,
regulators, and other entities? Is the
system aware of available external
resources, such as technical and
financial assistance?
Financial capacity is a water system's
ability to acquire and manage sufficient
financial resources to allow the system
to achieve and maintain compliance
with SDWA requirements.
Financial capacity can be assessed
through key issues and questions,
including:
• Revenue sufficiency. Do revenues
cover costs? Are water rates and charges
adequate to cover the cost of water?
• Credit worthiness. Is the system
financially healthy? Does it have access
to capital through public or private
sources?
• Fiscal management and controls.
Are adequate books and records
maintained? Are appropriate budgeting,
accounting, and financial planning
methods used? Does the system manage
its revenues effectively?
There are 76,051 systems affected by
this rule. Of these, 12,998 will have to
modify their treatment process and
undertake disinfectant and DBP
monitoring and reporting. Some of this
smaller group may also be required to
do DBP precursor monitoring and
reporting. The other 63,063 systems will
need to do disinfectant and DBP
monitoring and reporting, but will not
need to modify their treatment process.
Some of this larger group may also be
required to do DBP precursor
monitoring and reporting.
Systems not modifying treatment are
not generally expected to require
significantly increased technical,
financial, or managerial capacity to
comply with these new requirements.
Certainly some individual facilities may
have weaknesses in one or more of these
areas but overall, systems should have
or be able to obtain the capacity needed
for these activities.
Systems needing to modify treatment
will employ one or more of a variety of
steps. The steps expected to be
employed by 50% or more of subpart H
systems and by eight percent or more of
ground water systems covered by the
rule include a combination of low cost
alternatives, including switching to
chloramines for residual disinfection,
moving the point of disinfectant
application, and improving precursor
removal. EPA estimates that less than
seven percent of systems in any category
will resort to higher cost alternatives,
such as switching to ozone or
chloramines for primary disinfection or
using GAC or membranes for precursor
removal. These higher cost alternatives
may also provide other treatment
benefits, so the cost may be somewhat
offset by eliminating the need for
technologies to remove other
contaminants. Some of these systems
may choose nontreatment alternatives
such as consolidation with another
system or changing to a higher quality
water source.
Furthermore, there are a number of
actions that are expected to be taken
disproportionately by smaller sized
systems (that is to say, a greater
percentage of smaller sized systems will
undertake than will larger sized
systems). These steps include increased
plant staffing and additional staff
training to understand process control
strategy. Small systems will be required
to do this since larger systems have
already undertaken these changes to
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69460 Federal Register/Vol. 63, No. 241/Wednesday, December 16. 1998/Rules and Regulations
some extent for compliance with the
1979 TTHM rule.
For many systems serving less than
10,000 persons which need to make
treatment modifications, an
enhancement of technical, financial,
and managerial capacity may likely be
needed. As the preceding paragraph
makes clear, these systems will be
making structural improvements and
enhancing laboratory and staff capacity.
Larger sized systems have typically
already made these improvements as
part of normal operations. Meeting the
requirements of the Stage 1 DBPR wjll
require operating at a higher level of
sophistication and in a better state of
repair than some plants serving less
than 10,000 people have considered
acceptable in the past.
Certainly there will be exceptions in
systems serving both below 10,000
persons and above. Some larger plants
will doubtless find their technical,
managerial, and financial capacity taxed
by the new requirements. Likewise,
some plants serving less than 10,000
persons will already have more .than
adequate technical, financial, and
managerial capacity to meet these
requirements, ^owever, in general, the
systems serving less than 10,000
persons needing to make treatment
modifications will be the ones most
needing to enhance their capacity.
VI. References
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72. U.S. EPA. 1994a. National Primary
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73. U.S. EPA. 1994b. National Primary
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74. U.S. EPA. 1994c. National Primary
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84. U.S. EPA. 1997a. National Primary
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Notice of Data Availability; Proposed
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59557. (Novembers, 1997).
85. U.S. EPA. 1997b. National Primary
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59388-59484. (Novembers. 1997).
86. U.S. EPA. 1997c. Summaries of New
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October 1997.
87. U.S. EPA. 1997d. External Peer Review of
CMA Study -2- Generation, EPA
Contract No. 68-C7-0002, Work
Assignment B-14. The Cadmus Group,
Inc., October 9, 1997.
88. U.S. EPA. 1997e. Method 300.1.
Determination of Inorganic Anions in
Drinking Water by Ion Chromatography.
Revision 1.0. USEPA National Exposure
Research Laboratory, Cincinnati OH.
89. U.S. EPA. 1997f. Performance Based
Measurement System. Notice of Intent.
Federal Register, October 6, 1997. Vol.
62, No. 193., 52098-52100.
90. U.S. EPA. 1997g. Manual for the
Certification of Laboratories Analyzing
Drinking Water, Fourth Edition, Office of
Water Resource Center (RC-4100), EPA
815-B-97-001. March 1997.
91. U.S. EPA. 1998a. National Primary
Drinking Water Regulations;
Disinfectants and Disinfection
Byproducts; Notice of Data Availability;
Proposed Rule. Fed. Reg., 63 (No. 61):
15606-15692. (March 31, 1998).
92. U.S. EPA. 1998b. Dichloroacetic acid:
Carcinogenicity Identification
Characterization Summary. National
Center for Environmental Assessment—
Washington Office. Office of Research
and Development. March 1998. EPA
815-B-98-010.PB 99-111387.
93. U.S. EPA. 1998c. Quantification of
Bladder Cancer Risk from Exposure to
Chlorinated Surface Water. Office of
Science and Technology, Office of Water.
November 9, 1998.
94. U.S. EPA. 1998d. Health Risk
Assessment/Characterization of the
Drinking Water Disinfection Byproduct
Chlorine Dioxide and the Degradation
Byproduct Chlorite. Office of Science
and Technology, Office of Water.
October 15, 1998. EPA 815-B-98-008.
PB 99-111361.
95. U.S. EPA. 1998e. Health Risk
Assessment/Characterization of the
Drinking Water Disinfection Byproduct
Bromate. Office of Science and
Technology, Office of Water. September
30, 1998. EPA 815-B-98-007. PB 99-
111353.
96. U.S. EPA. 1998f. Panel Report and
Recommendation for Conducting
Epidemiological Research on Possible
Reproductive and Developmental Effects
of Exposure to Disinfected Drinking
Water. Office of Research and
Development. February 12, 1998.
97. U.S. EPA. 1998g. Regulatory Impact
Analysis of Final Disinfectant/
Disinfection By-Products Regulations.
Washington, D.C. EPA Number 815-B-
98-002. PB 99-111304.
98. U.S. EPA. 1998h. Health Risks to Fetuses,
Infants, and Children (final Stage 1 DBF
Rule). Office of Science and Technology.
Office of Water. November 19, 1998. EPA
815-B-98-009. PB 99-111379.
99. U.S. EPA. 19981. Revisions to State
Primacy Requirements To Implement
Safe Drinking Water Act Amendments:
Final Rule. Federal Register, Tuesday,
April 28, 1998, Vol. 63, No.81, 23362-
23368.
100. U.S. EPA. 1998j. Revision of Existing
Variance and Exemption Regulations to
Comply with Requirements of the Safe
Drinking Water Act; Final Rule. Federal
Register, Vol 63, No. 157. Friday, Aug.
14, 1998. pp. 43833-43851.
101. U.S. EPA. 1998k. Cost and Technology
Document for Controlling Disinfectants
and Disinfection Byproducts. Office of
Ground Water and Drinking Water.
Washington, DC. EPA 815-R-98-014. PB
99-111486.
102. U.S. EPA. 19981. Synthesis of the Peer-
Review of Meta-analysis of
Epidemiologic Data on Risks of Cancer
from Chlorinated Drinking Water.
National Center for Environmental
Assessment, Office of Research and
Development, February 16, 1998.
103. U.S. EPA. 1998m. NCEA Position Paper
Regarding Risk Assessment Use of the
Results from the Published Study: Morris
et al. Am J Public Health 1992:82:955-
963. National Center for Environmental
Assessment, Office of Research and
Development, October 7, 1997.
104. U.S. EPA. 1998n. A Suggested Approach
for Using the Current Epidemiologic
Literature to Estimate the Possible
Cancer Risk from Water Chlorination, for
the Purposes of the Regulatory Impact
Analysis. ORD, National Center for
Environmental Assessment. August 27,
1998.
105. U.S. EPA. 1998o. Unfunded Mandates
Reform Act Analysis for the Stage 1
Disinfectant and Disinfection Byproduct
Rule. Office of Groundwater and
Drinking Water.
106. U.S. EPA. 1998p. Health Risk
Assessment/Characterization of the
Drinking Water Disinfection Byproduct
Chloroform. Office of Science and
Technology, Office of Water. November
4, 1998. EPA 815-B-98-006. PB 99-
111346.
107. U.S. EPA. 1998q. Small System
Compliance Technology List for the
Stage 1 DBF Rule. Office of Groundwater
and Drinking Water. EPA 815-R-98-017.
PB 99-111510.
108. U.S. EPA. 1998r. Technologies and Costs
for Point-of-Entry (POE) and Point-of-Use
(POU) Devices for Control of Disinfection
Byproducts. Office of Groundwater and
Drinking Water. EPA 815-R-98-016. PB
99-111502.
109. U.S. EPA. 1998s. National-Level
Affordability Criteria Under the 1996
Amendments to the Safe Drinking Water
Act. Office of Groundwater and Drinking
Water. August 19, 1998.
110. U.S. EPA. 1998t. Variance Technology
Findings for Contaminants Regulated
Before 1996. Office of Water. September
1998. EPA 815-R-98-003.
111. U.S. EPA. 1998u. Occurrence
Assessment for Disinfectants and
Disinfection Byproducts in Public
Drinking Water Supplies. Office of
Groundwater and Drinking Water. EPA
815-B-98-004. November 13, 1998. PB
99-111320.
112. USGS. 1989. Method 1-1030-85.
Techniques of Water Resources
Investigations of the U.S. Geological
Survey. Book 5, Chapter A-l, 3rd ed.,
U.S. Government Printing Office.
113. Waller K., Swan S. H., DeLorenze G.,
Hopkins B., 1998. Trihalomethanes in
drinking water and spontaneous
abortion. Epidemiology. 9(2):134-140.
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Federal Register/Vol. 63, No. 241 / Wednesday, December 16, 1998/Rules and Regulations 69463
114. White, M. C., Thompson, D., Harrington,
G. W., and P.S. Singer. 1997. Evaluating
Criteria for Enhanced Coagulation
Compliance. AWWA, 89:5:64.
115. Xie, Yuefeng. 1995. Effects of Sodium
Chloride on DBF Analytical Results,
Extended Abstract, Division of
Environmental Chemistry, American
Chemical Society Annual Conference,
Chicago, IL, Aug. 21-26, 1995.
List of Subjects
40 CFR Part 9
Environmental protection, Reporting
and recordkeeping requirements.
40 CFR Parts 141 and 142
Analytical methods, Drinking water,
Environmental protection, Incorporation
by reference, Intergovernmental
relations, Public utilities, Reporting and
recordkeeping requirements, Utilities,
Water supply.
Dated: November 30, 1998.
Carol M. Browner,
Administrator.
• For the reasons set out in the
preamble, title 40, chapter I of the Code
of Federal Regulations is amended as
follows:
PART 9—[AMENDED]
1. The authority citation for part 9
continues to read as follows:
Authority: 7 U.S.C. 135 etseq., 136-136y;
15 U.S.C. 2001, 2003, 2005, 2006, 2601-2671-
21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33
U.S.C. 1251 etseq., 1311, 1313d, 1314, 1318
1321, 1326, 1330, 1342, 1344, 1345 (d) and
(e), 1361; E.O. 11735, 38 FR 21243, 3 CFR,
1971-1975 Comp. p. 973; 42 U.S.C. 241,
242b, 243, 246, 300f, 300g, 300g-l, 300g-2
300g-3, 300g-4, 300g-5, 300g-6, SOOj-l,
300J-2, SOOj-3, SOOj-4, 300J-9, 1857 etseq
6901-6992k, 7401-7671q, 7542, 9601-9657
11023, 11048.
2. In § 9.1 the table is amended by
adding under the indicated heading: the
new entries in numerical order to read
as follows:
§9.1 OMB approvals under the Paperwork
Reduction Act.
40 CFR citation
OMB con-
trol No.
National Primary Drinking
Water Regulations
141.130-141.132 2040-0204
141.134-141.135 2040-0204
PART 141—NATIONAL PRIMARY
DRINKING WATER REGULATIONS
3. The authority citation for part 141
continues to read as follows:
Authority: 42 U.S.C. 300f, 300g-l, 300g-2,
300g-3, 300g-4, 300g-5, 300g-6, 3001-4,
SOOj-9, and300j-ll.
4. Section 141.2 is amended by
adding the following definitions in
alphabetical order to read as follows:
§141.2 Definitions.
Enhanced coagulation means the
addition of sufficient coagulant for
improved removal of disinfection
byproduct precursors by conventional
filtration treatment.
***'**
Enhanced softening means the
improved removal of disinfection
byproduct precursors by precipitative
softening.
* * * * *
GAC10 means granular activated
carbon filter beds with an empty-bed
contact time of 10 minutes based on
average daily flow and a carbon
reactivation frequency of every 180
days.
*****
Haloacetic acids (five) (HAAS) mean
the sum of the concentrations in
milligrams per liter of the haloacetic
acid compounds (monochloroacetic
acid, dichloroacetic acid, trichloroacetic
acid, monobromoacetic acid, and
dibromoacetic acid), rounded to two
significant figures after addition.
*****
Maximum residual disinfectant level
(MRDL) means a level of a disinfectant
added for water treatment that may not
be exceeded at the consumer's tap
without an unacceptable possibility of
adverse health effects. For chlorine and
chloramines, a PWS is in compliance
with the MRDL when the running
annual average of monthly averages of
samples taken in the distribution
system, computed quarterly, is less than
or equal to the MRDL. For chlorine
dioxide, a PWS is in compliance with
the MRDL when daily samples are taken
at the entrance to the distribution
system and no two consecutive daily
samples exceed the MRDL. MRDLs are
enforceable in the same manner as
maximum contaminant levels under
Section 1412 of the Safe Drinking Water
Act. There is convincing evidence that
addition of a disinfectant is necessary
for control of waterborne microbial
contaminants. Notwithstanding the
MRDLs listed in § 141.65, operators may
increase residual disinfectant levels of
chlorine or chloramines (but not
chlorine dioxide) in the distribution
system to a level and for a time
necessary to protect public health to
address specific microbiological
contamination problems caused by
circumstances such as distribution line
breaks, storm runoff events, source
water contamination, or cross-
connections.
* * * * *
Maximum residual disinfectant level
goal (MRDLG) means the maximum
level of a disinfectant added for water
treatment at which no known or
anticipated adverse effect on the health
of persons would occur, and which
allows an adequate margin of safety.
MRDLGs are nonenforceable health
goals and do not reflect the benefit of
the addition of the chemical for control
of waterborne microbial contaminants.
*****
Subpart H systems means public
water systems using surface water or
ground water under the direct influence
of surface water as a source thatare
subject to the requirements of subpart H
of this part.
*****
SUVA means Specific Ultraviolet
Absorption at 254 nanometers (nm), an
indicator of the humic content of water.
It is a calculated parameter obtained by
dividing a sample's ultraviolet
absorption at a wavelength of 254 nm
(UV254) (in m=1) by its concentration of
dissolved organic carbon (DOC) (in mg/
Total Organic Carbon (TOC) means
total organic carbon in mg/L measured
using heat, oxygen, ultraviolet
irradiation, chemical oxidants, or
combinations of these oxidants that
convert organic carbon to carbon
dioxide, rounded to two significant
figures.
*****
5. Section 141.12 is revised to read as
follows:
§141.12 Maximum contaminant levels for
total trihalomethanes.
The maximum contaminant level of
0.10 mg/L for total trihalomethanes (the
sum of the concentrations of
bromodichloromethane,
dibromochloromethane,
tribromomethane (bromoform), and
trichloromethane (chloroform)) applies
to subpart H community water systems
which serve a population of 10,000
people or more until December 16,
2001. This level applies to community
water systems that use only ground
water not under the direct influence of
surface water and serve a population of
10,000 people or more until December
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69464 Federal Register/Vol. 63, No. 241 /Wednesday, December 16, 1998/Rules and Regulations
16, 2003. Compliance with the
maximum contaminant level for total
trihalomethanes is calculated pursuant
to § 141.30. After December 16, 2003,
this section is no longer applicable.
6. Section 141.30 is amended by
revising the the first sentences in
paragraphs (d) and (f) and adding
paragraph (h) to read asfbllows:
§141.30 Total trihalomethanes sampling,
analytical and other requirements.
*****
(d) Compliance with § 141.12 shall be
determined based on a running annual
average of quarterly samples collected
by the system as prescribed in
paragraph (b)(l) or (2) of this
section. * * *
*****
(f) Before a community water system
makes any significant modifications to
its existing treatment process for the
purposes of achieving compliance with
§ 141.12, such system must submit and
obtain State approval of a detailed plan
setting forth its proposed modification
and those safeguards that it will
Implement to ensure that the
bacteriological quality of the drinking
water served by such system will not be
adversely affected by such
modification. * * *
*****
(h) The requirements in paragraphs (a)
through (g) of this section apply to
subpart H community water systems
which serve a population of 10,000 or
more until December 16, 2001. The
requirements in paragraphs (a) through
(g) of this section apply to community
water systems which use only ground
water not under the direct influence of
surface water that add a disinfectant
(oxidant) in any part of the treatment
process and serve a population of
10,000 or more until December 16, 2003.
After December 16, 2003, this section is
no longer applicable.
7. Section 141.32 is amended by
revising the heading in paragraph (a)
introductory text, the first sentence of
paragraph (a)(l)(iii) introductory text,
and the first sentence of paragraph (c),
and adding paragraphs (a) (1) (ill) (E) and
(e) (76) through (81), to read as follows:
§141.32 Public notification.
*****
(a) Maximum contaminant levels
(MCLs), maximum residual disinfectant
levels (MRDLs). * * *
m* * *
(iii) For violations of the MCLs of
contaminants or MRDLs of disinfectants
that may pose an acute risk to human
health, by furnishing a copy of the
notice to the radio and television
stations serving the area served by the
public water system as soon as possible
but in no case later than 72 hours after
the violation. ***
*****
(E) Violation of the MRDL for chlorine
dioxide as defined in § 141.65 and
determined according to § 141.133(c)(2).
*****
(c) * * * The owner or operator of a
community water system must give a
copy of the most recent public notice for
any outstanding violation of any
maximum contaminant level, or any
maximum residual disinfectant level, or
any treatment technique requirement, or
any variance or exemption schedule to
all new billing units or new hookups.
prior to or at the time service begins.
*****
(e) * * *
(76) Chlorine. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that chlorine is a health
concern at certain levels of exposure.
Chlorine is added to drinking water as
a disinfectant to kill bacteria and other
disease-causing microorganisms and is
also added to provide continuous
disinfection throughout the distribution
system. Disinfection is required for
surface water systems. However, at high
doses for extended periods of time,
chlorine has been shown to affect blood
and the liver in laboratory animals. EPA
has set a drinking water standard for
chlorine to protect against the risk of
these adverse effects. Drinking water
which meets this EPA standard is
associated with little to none of this risk
and should be considered safe with
respect to chlorine.
(77) Chloramines. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that chloramines are a
health concern at certain levels of
exposure. Chloramines are added to
drinking water as a disinfectant to kill
bacteria and other disease-causing
microorganisms and are also added to
provide continuous disinfection
throughout the distribution system.
Disinfection is required for surface
water systems. However, at high doses
for extended periods of time,
chloramines have been shown to affect
blood and the liver in laboratory
animals. EPA has set a drinking water
standard for chloramines to protect
against the risk of these adverse effects.
Drinking water which meets this EPA
standard is associated with little to none
of this risk and should be considered
safe with respect to chloramines.
(78) Chlorine dioxide. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that chlorine dioxide is
a health concern at certain levels of
exposure. Chlorine dioxide is used in
water treatment to kill bacteria and
other disease-causing microorganisms
and can be used to control tastes and
odors. Disinfection is required for
surface water systems. However, at high
doses, chlorine dioxide-treated drinking
water has been shown to affect blood in
laboratory animals. Also, high levels of
chlorine dioxide given to laboratory
animals in drinking water have been
shown to cause neurological effects on
the developing nervous system. These
neurodevelopmental effects may occur
as a result of a short-term excessive
chlorine dioxide exposure. To protect
against such potentially harmful
exposures, EPA requires chlorine
dioxide monitoring at the treatment
plant, where disinfection occurs, and at
representative points in the distribution
system serving water users. EPA has set
a drinking water standard for chlorine
dioxide to protect against the risk of
these adverse effects.
Note: In addition to the language in this
introductory text of paragraph (e)(78),
systems must include either the language in
paragraph (e)(78)(i) or (e)(78)(ii) of this
section. Systems with a violation at the
treatment plant, but not in the distribution
system, are required to use the language in
paragraph (e) (78) (i) of this section and treat
the violation as a nonacute violation.
Systems with a violation in the distribution
system are required to use the language in
paragraph (e)(78)(ii) of this section and treat
the violation as an acute violation.
(i) The chlorine dioxide violations
reported today are the result of
exceedances at the treatment facility
only, and do not include violations
within the distribution system serving
users of this water supply. Continued
compliance with chlorine dioxide levels
within the distribution system
minimizes the potential risk of these
violations to present consumers.
(ii) The chlorine dioxide violations
reported today include exceedances of
the EPA standard within the
distribution system serving water users.
Violations of the chlorine dioxide
standard within the distribution system
may harm human health based on short-
term exposures. Certain groups,
including pregnant women, infants, and
young children, may be especially
susceptible to adverse effects of
excessive exposure to chlorine dioxide-
treated water. The purpose of this notice
is to advise that such persons should
consider reducing their risk of adverse
effects from these chlorine dioxide
violations by seeking alternate sources
of water for human consumption until
such exceedances are rectified. Local
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Federal Register/Vol. 63, No. 241/Wednesday. December 16, 1998/Rules and Regulations 69465
and State health authorities are the best
sources for information concerning
alternate drinking water.
(79) Disinfection byproducts and
treatment technique for DBFs. The
United States Environmental Protection
Agency (EPA) sets drinking water
standards and requires the disinfection
of drinking water. However, when used
in the treatment of drinking water,
disinfectants react with naturally-
occurring organic and inorganic matter
present in water to form chemicals
called disinfection byproducts (DBFs).
EPA has determined that a number of
DBFs are a health concern at certain
levels of exposure. Certain DBPs,
including some trihalomethanes (THMs)
and some haloacetic acids (HAAs), have
been shown to cause cancer in
laboratory animals. Other DBPs have
been shown to affect the liver and the
nervous system, and cause reproductive
or developmental effects in laboratory
animals. Exposure to certain DBPs may
produce similar effects in people. EPA
has set standards to limit exposure to
THMs, HAAs, and other DBPs.
(80) Bromate. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that bromate is a health
concern at certain levels of exposure.
Bromate is formed as a byproduct of
ozone disinfection of drinking water.
Ozone reacts with naturally occurring
bromide in the water to form bromate.
Bromate has been shown to produce
cancer in rats. EPA has set a drinking
water standard to limit exposure to
bromate.
(81) Chlorite. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that chlorite is a health
concern at certain levels of exposure.
Chlorite is formed from the breakdown
of chlorine dioxide, a drinking water
disinfectant. Chlorite in drinking water
has been shown to affect blood and the
developing nervous system. EPA has set
a drinking water standard for chlorite to
protect against these effects. Drinking
water which meets this standard is
associated with little to none of these
risks and should be considered safe
with respect to chlorite.
*****
8. Subpart F is amended by revising
the subpart heading and adding
§§ 141.53 and 141.54 to read as follows:
Subpart F—Maximum Contaminant
Level Goals and Maximum Residual
Disinfectant Level Goals
§ 141.53—Maximum contaminant level goals
for disinfection byproducts.
MCLGs for the following disinfection
byproducts are as indicated:
Disinfection byproduct
Chloroform
Bromodichloromethane
Bromoform
Bromate
Dichloroacetic acid
Trichloroacetic acid
Chlorite
Dibromochloromethane
MCLG
(mg/L)
Zero
Zero
Zero
Zero
Zero
03
0 8
006
§ 141.54 Maximum residual disinfectant
level goals for disinfectants.
MRDLGs for disinfectants are as
follows:
Disinfectant residual
Chlorine
Chloramines
Chlorine dioxide
MRDLG(mg/L)
4 (as Cl 2)
4 (as Cl 2)
0.8 (as CIC>2)
9. Subpart G is amended by revising
the subpart heading and adding
§§ 141.64 and 141.65 to read as follows:
Subpart G—National Revised Primary
Drinking Water Regulations: Maximum
Contaminant Levels and Maximum
Residual Disinfectant Levels
§ 141.64 Maximum contaminant levels for
disinfection byproducts.
(a) The maximum contaminant levels
(MCLs) for disinfection byproducts are
as follows:
Disinfection byproduct
Total trihalomethanes (TTHM)
Haloacetic acids (five) (HAAS)
Bromate
Chlorite
MCL
(mg/L)
0.080
0.060
0010
1 0
(b) Compliance dates. (1) CWSs and
NTNCWSs. Subpart H systems serving
10,000 or more persons must comply
with this section beginning December
16, 2001. Subpart H systems serving
fewer than 10,000 persons and systems
using only ground water not under the
direct influence of surface water must
comply with this section beginning
December 16, 2003.
(2) A system that is installing GAC or
membrane technology to comply with
this section may apply to the State for
an extension of up to 24 months past the
dates in paragraphs (b) (1) of this section,
but not beyond December 16, 2003. In
granting the extension, States must set
a schedule for compliance and may
specify any interim measures that the
system must take. Failure to meet the
schedule or interim treatment
requirements constitutes a violation of a
National Primary Drinking Water
Regulation.
(c) The Administrator, pursuant to
Section 1412 of the Act, hereby
identifies the following as the best
technology, treatment techniques, or
other means available for achieving
compliance with the maximum
contaminant levels for disinfection
byproducts identified in paragraph (a) of
this section:
Disinfec-
tion by-
product
TTHM ...
HAAS ....
Bromate
Chlorite
Best available technology
Enhanced coagulation or en-
hanced softening or GAC10,
with chlorine as the primary and
residual disinfectant
Enhanced coagulation or en-
hanced softening or GAC10,
with chlorine as the primary and
residual disinfectant.
Control of ozone treatment proc-
ess to reduce production of bro-
mate.
Control of treatment processes to
reduce disinfectant demand and
control of disinfection treatment
processes to reduce disinfectant
levels.
§ 141.65 Maximum residual disinfectant
levels.
(a) Maximum residual disinfectant
levels (MRDLs) are as follows:
Disinfectant residual
Chlorine
Chloramines
Chlorine dioxide
MRDL (mg/L)
4 o (as Cb)
4.0 (as CI2)
0 8 (as CIC>2)
(b) Compliance dates.
(1) CWSs and NTNCWSs. Subpart H
systems serving 10,000 or more persons
must comply with this section
beginning December 16, 2001. Subpart
H systems serving fewer than 10,000
persons and systems using only ground
water not under the direct influence of
surface water must comply with this
subpart beginning December 16, 2003.
(2) Transient NCWSs. Subpart H
systems serving 10,000 or more persons
and using chlorine dioxide as a
disinfectant or oxidant must comply
with the chlorine dioxide MRDL
beginning December 16, 2001. Subpart
H systems serving fewer than 10,000
persons and using chlorine dioxide as a
disinfectant or oxidant and systems
using only ground water not under the
direct influence of surface water and
using chlorine dioxide as a disinfectant
or oxidant must comply with the
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69466 Federal Register/Vol. 63, No. 241 /Wednesday, December 16, 1998/Rules and Regulations
chlorine dioxide MRDL beginning
December 16, 2003.
(c) The Administrator, pursuant to
Section 1412 of the Act, hereby
identifies the following as the best
technology, treatment techniques, or
other means available for achieving
compliance with the maximum residual
disinfectant levels identified in
paragraph (a) of this section: control of
treatment processes to reduce
disinfectant demand and control of
disinfection treatment processes to
reduce disinfectant levels.
10. A new subpart L is added to read
as follows:
Subpart L—Disinfectant Residuals,
Disinfection Byproducts, and
Disinfection Byproduct Precursors
Sec.
141.130 General requirements.
141.131 Analytical requirements.
141.132 Monitoring requirements.
141.133 Compliance requirements.
141.134 Reporting and recordkeeplng
requirements.
141.135 Treatment technique for control of
disinfection byproduct (DBF) precursors.
§141.130 General requirements.
(a) The requirements of this subpart L
constitute national primary drinking
water regulations.
(1) The regulations in this subpart
establish criteria under which
community water systems (CWSs) and
nontransient, noncommunity water
systems (NTNCWSs) which add a
chemical disinfectant to the water in
any part of the drinking water treatment
process must modify their practices to
meet MCLs and MRDLs in §§ 141.64 and
141.65, respectively, and must meet the
treatment technique requirements for
disinfection byproduct precursors in
§141.135.
(2) The regulations in this subpart
establish criteria under which transient
NCWSs that use chlorine dioxide as a
disinfectant or oxidant must modify
their practices to meet the MRDL for
chlorine dioxide in § 141.65.
(3) EPA has established MCLs for
TTHM and HAAS and treatment
technique requirements for disinfection
byproduct precursors to limit the levels
of known and unknown disinfection
byproducts which may have adverse
health effects. These disinfection
byproducts may include chloroform;
bromodichloromethane;
dlbromochloromethane; bromoform;
dichloroacetic acid; and trichloroacetic
acid.
(b) Compliance dates. (1) CWSs and
NTNCWSs. Unless otherwise noted,
systems must comply with the
requirements of this subpart as follows.
Subpart H systems serving 10,000 or
more persons must comply with this
subpart beginning December 16, 2001.
Subpart H systems serving fewer than
10,000 persons and systems using only
ground water not under the direct
influence of surface water must comply
with this subpart beginning December
16, 2003.
(2) Transient NCWSs. Subpart H
systems serving 10,000 or more persons
and using chlorine dioxide as a
disinfectant or oxidant must comply
with any requirements for chlorine
dioxide and chlorite in this subpart
beginning December 16, 2001. Subpart
H systems serving fewer than 10,000
persons and using chlorine dioxide as a
disinfectant or oxidant and systems
using only ground water not under the
direct influence of surface water and
using chlorine dioxide as a disinfectant
or oxidant must comply with any
requirements for chlorine dioxide and
chlorite in this subpart beginning
December 16, 2003.
(c) Each CWS and NTNCWS regulated
under paragraph (a) of this section must
be operated by qualified personnel who
meet the requirements specified by the
State and are included in a State register
of qualified operators.
(d) Control of disinfectant residuals.
Notwithstanding the MRDLs in § 141.65,
systems may increase residual
disinfectant levels in the distribution
system of chlorine or chloramines (but
not chlorine dioxide) to a level and for
a time necessary to protect public
health, to address specific
microbiological contamination problems
caused by circumstances such as, but
not limited to, distribution line breaks,
storm run-off events, source water
contamination events, or cross-
connection events.
§ 141.131 Analytical requirements.
(a) General. (1) Systems must use only
the analytical method(s) specified in
this section, or otherwise approved by
EPA for monitoring under this subpart,
to demonstrate compliance with the
requirements of this subpart. These
methods are effective for compliance
monitoring February 16, 1999.
(2) The following documents are
incorporated by reference. The Director
of the Federal Register approves this
incorporation by reference in
accordance with 5 U.S.C. 552(a) and 1
CFR part 51. Copies may be inspected
at EPA's Drinking Water Docket, 401 M
Street, SW, Washington, DC 20460, or at
the Office of the Federal Register, 800
North Capitol Street, NW, Suite 700,
Washington DC. EPA Method 552.1 is in
Methods for the Determination of
Organic Compounds in Drinking Water-
Supplement II, USEPA, August 1992,
EPA/600/R-92/129 (available through
National Information Technical Service
(NTIS), PB92-207703). EPA Methods
502.2, 524.2, 551.1, and 552.2 are in
Methods for the Determination of
Organic Compounds in Drinking Water-
Supplement III, USEPA, August 1995,
EPA/600/R-95/131. (available through
NTIS, PB95-261616). EPA Method
300.0 is in Methods for the
Determination of Inorganic Substances
in Environmental Samples, USEPA,
August 1993, EPA/600/R-93/100.
(available through NTIS, PB94-121811).
EPA Method 300.1 is titled USEPA
Method 300.1, Determination of
Inorganic Anions in Drinking Water by
Ion Chromatography, Revision 1.0,
USEPA, 1997, EPA/600/R-98/118
(available through NTIS, PB98-169196);
also available from: Chemical Exposure
Research Branch, Microbiological &
Chemical Exposure Assessment
Research Division, National Exposure
Research Laboratory, U.S.
Environmental Protection Agency,
Cincinnati, OH 45268, Fax Number:
513-569-7757, Phone number: 513-
569-7586. Standard Methods 4500-C1 D.
4500-C1 E, 4500-C1 F, 4500-C1G, 4500-
Cl H, 4500-C11, 4500-C1O2 D, 4500-C1O2
E, 6251 B, and 5910 B shall be followed
in accordance with Standard Methods
for the Examination of Water and
Wastewater, 19th Edition, American
Public Health Association, 1995; copies
may be obtained from the American
Public Health Association, 1015
Fifteenth Street, NW, Washington, DC
20005. Standard Methods 5310 B, 5310
C, and 5310 D shall be followed in
accordance with the Supplement to the
19th Edition of Standard Methods for
the Examination of Water and
Wastewater, American Public Health
Association, 1996; copies may be
obtained from the American Public
Health Association, 1015 Fifteenth
Street, NW, Washington, DC 20005.
ASTM Method D 1253-86 shall be
followed in accordance with the Annual
Book of ASTM Standards, Volume
11.01, American Society for Testing and
Materials, 1996 edition; copies may be
obtained from the American Society for
Testing and Materials, 100 Barr Harbor
Drive, West Conshohoken, PA 19428.
(b) Disinfection byproducts. (1)
Systems must measure disinfection
byproducts by the methods (as modified
by the footnotes) listed in the following
table:
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Federal Register/Vol. 63. No. 241/Wednesday, December 16, 1998/Rules and Regulations 69467
APPROVED METHODS FOR DISINFECTION BYPRODUCT COMPLIANCE MONITORING
Methodology2
P&T/GC/EICD & PID
P&T/GC/MS
LLE/GC/ECD
LLE/GC/ECD
SPE/GC/ECD
LLE/GC/ECD
Amperometric Titration
1C
1C
EPA meth-
od
3502.2
524.2
551.1
552.1
552.2
300.0
300.1
Standard method
6251 B
4500-CIO2 E
Byproduct measured 1
TTHM
X
X
X
HAAS
X
X
X
Chlorite4
X
X
X
Bromate
X
mass soec-
P
o IM^UIUU 10 a^yiuvcu iui iiieasuiuiy specmea aisimeciion Dyproauct
e and trap; GC = gas chromatography; EICD = electrolytic conductivity detector; PID = photoionization detector- MS
3 = liqu1d/l1quid extraction; ECD = electron capture detector; SPE = solid phase extractor; 1C = ion chromatography
a If TTHMs are the only analytes being measured in the sample, then a PID is not required uinaiuyidpny.
nllttri0nhmay te ustd f°r ?Ktine ^ monitorin9 °f chlorite at the entrance to the distribution system, as prescribed in
m°nthly m°nil0ring °f Chl°rite and addi
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69468 Federal Register/Vol. 63, No. 2417Wednesday. December 16, 1998/Rules and Regulations
5310 D (Wet-Oxidation Method). Prior
to analysis, DOC samples must be
filtered through a 0.45 u.m pore-diameter
filter. Water passed through the filter
prior to filtration of the sample must
serve as the filtered blank. This filtered
blank must be analyzed using
procedures identical to those used for
analysis of the samples and must meet
the following criteria: DOC < 0.5 mg/L.
DOC samples must be filtered through
the 0.45 urn pore-diameter filter prior to
acidification. DOC samples must either
be analyzed or must be acidified to
achieve pH less than 2.0 by minimal
addition of phosphoric or sulfuric acid
as soon as practical after sampling, not
to exceed 48 hours. Acidified DOC
samples must be analyzed within 28
days.
(ii) Ultraviolet Absorption at 254 nm
(UVaso). Method 5910 B (Ultraviolet
Absorption Method). UV absorption
must be measured at 253.7 nm (may be
rounded off to 254 nm). Prior to
analysis, UVas4 samples must be filtered
through a 0.45 (im pore-diameter filter.
The pH of UV254 samples may not be
adjusted. Samples must be analyzed as
soon as practical after sampling, not to
exceed 48 hours.
(5) pH. All methods allowed in
§ 141.23(k)(l) for measuring pH.
§141.132 Monitoring requirements.
(a) General requirements. (1) Systems
must take all samples during normal
operating conditions.
(2) Systems may consider multiple
wells drawing water from a single
aquifer as one treatment plant for
determining the minimum number of
TTHM and HAAS samples required,
with State approval in accordance with
criteria developed under § 142.16(f) (5)
of this chapter.
(3) Failure to monitor in accordance
with the monitoring plan required
under paragraph (f) of this section is a
monitoring violation.
(4) Failure to monitor will be treated
as a violation for the entire period
covered by the annual average where
compliance is based on a running
annual average of monthly or quarterly
samples or averages and the system's
failure to monitor makes it impossible to
determine compliance with MCLs or
MRDLs.
(5) Systems may use only data
collected under the provisions of this
subpart or subpart M of this part to
qualify for reduced monitoring.
(b) Monitoring requirements for
disinfection byproducts. (1) TTHMs and
HAAS, (i) Routine monitoring. Systems
must monitor at the frequency indicated
in the following table:
ROUTINE MONITORING FREQUENCY FOR TTHM AND HAAS
Type of system
Minimum monitoring frequency
Sample location in the distribution system
Subpart H system serving at least
10,000 persons.
Subpart H system serving from
500 to 9,999 persons.
Subpart H system serving fewer
than 500 persons.
System using only ground water
nol under direct influence of sur-
face water using chemical dis-
infectant and serving at least
10,000 persons.
System using only ground water
not under direct influence of sur-
face water using chemical dis-
infectant and serving fewer than
10,000 persons.
Four water samples per quarter
per treatment plant.
One water sample per quarter per
treatment plant.
One sample per year per treat-
ment plant during month of
warmest water temperature.
One water sample per quarter per
treatment plant2.
One sample per year per treat-
ment plant2 during month of
warmest water temperature.
At least 25 percent of all samples collected each quarter at locations
representing maximum residence time. Remaining samples taken at
locations representative of at least average residence time in the
distribution system and representing the entire distribution system,
taking into account number of persons served, different sources of
water, and different treatment methods.1
Locations representing maximum residence time.1
Locations representing maximum residence time.1 If the sample (or
average of annual samples, if more than one sample is taken) ex-
ceeds MCL, system must increase monitoring to one sample per
treatment plant per quarter, taken at a point reflecting the maximum
residence time in the distribution system, until system meets re-
duced monitoring criteria in paragraph" (c) of this section.
Locations representing maximum residence time.1
Locations representing maximum residence time.1 If the sample (or
average of annual samples, if more than one sample is taken) ex-
ceeds MCL, system must increase monitoring to one sample per
treatment plant per quarter, taken at a point reflecting the maximum
residence time in the distribution system, until system meets criteria
in paragraph (c) of this section for reduced monitoring.
system elects to sample more frequently than the minimum required, at least 25 percent of all samples collected each quarter (including
ihoRRnken In excess of the reauired frequency) must be taken at locations that represent the maximum residence time of the water in the dis-
ributon system^ Thl remaininTsamples must ^ £ken at locations representative 0*1 at least average residence time in the distribution system
2Multlp?ei wSls drawingTwatir from a single aquifer may be considered one treatment plant for determining the minimum number of samples
required; with State approval in accordance with criteria developed under § 142.16(f)(5) of this chapter.
(ii) Systems may reduce monitoring,
except as otherwise provided, in
accordance with the following table:
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Federal Register/Vol. 63. No. 241/Wednesday. December 16, 1998/Rules and Regulations 69469
Reduced Monitoring Frequency for TTHM and HAAS
If you are a ...
You may reduce monitoring if you
have monitored at least one year
and your . . .
To this level
Subpart H system serving at least
10,000 persons which has a
source water annual average
TOG level, before any treatment,
<4.0 mg/L.
Subpart H system serving from
500 to 9,999 persons which has
a source water annual average
TOC level, before any treatment,
^4.0 mg/L.
System using only ground water
not under direct influence of sur-
face water using chemical dis-
infectant and serving at least
10,000 persons.
System using only ground water
not under direct influence of sur-
face water using chemical dis-
infectant and serving fewer than
10,000 persons.
TTHM annual average <0.040 mg/
L and HAAS annual average
<0.030 mg/L.
TTHM annual average S0.040 mg/
L and HAAS annual average
<0.030 mg/L.
TTHM annual average <0.040 mg/
L and HAAS annual average
<0.030 mg/L.
TTHM annual average <0.040 mg/
L and HAAS annual average
<0.030 mg/L for two consecutive
years OR TTHM annual average
<0.020 mg/L and HAAS annual
average <0.015 mg/L for one
year.
One sample per treatment plant per quarter at distribution system lo-
cation reflecting maximum residence time.
One sample per treatment plant per year at distribution system loca-
tion reflecting maximum residence time during month of warmest
water temperature. NOTE: Any Subpart H system serving fewer
than 500 persons may not reduce its monitoring to less than one
sample per treatment plant per year.
One sample per treatment plant per year at distribution system loca-
tion reflecting maximum residence time during month of warmest
water temperature
One sample per treatment plant per three year monitoring cycle at
distribution system location reflecting maximum residence time dur-
ing month of warmest water temperature, with the three-year cycle
beginning on January 1 following quarter in which system qualifies
for reduced monitoring.
(iii) Systems on a reduced monitoring
schedule may remain on that reduced
schedule as long as the average of all
samples taken in the year '(for systems
which .must monitor quarterly) or the
result of the sample (for systems which
must monitor no more frequently than
annually) is no more than 0.060 mg/L
and 0.045 mg/L for TTHMs and HAAS,
respectively. Systems that do not meet
these levels must resume monitoring at
the frequency identified in paragraph
(b)(l)(i) of this section in the quarter
immediately following the quarter in
which the system exceeds 0.060 mg/L
and 0.045 mg/L for TTHMs and HAAS,
respectively.
(iv) The State may return a system to
routine monitoring at the State's
discretion.
(2) Chlorite. Community and
nontransient noncommunity water
systems using chlorine dioxide, for
disinfection or oxidation, must conduct
monitoring for chlorite.
(i) Routine monitoring. (A) Daily
monitoring. Systems must take daily
samples at the entrance to the
distribution system. For any daily
sample that exceeds the chlorite MCL,
the system must take additional samples
in the distribution system the following
day at the locations required by
paragraph (b)(2)(ii) of this section, in
addition to the sample required at the
entrance to the distribution system.
(B) Monthly monitoring. Systems must
take a three-sample set each month in
the distribution system. The system
must take one sample at each of the
following locations: near the first
customer, at a location representative of
average residence time, and at a location
reflecting maximum residence time in
the distribution system. Any additional
routine sampling must be conducted in
the same manner (as three-sample sets,
at the specified locations). The system
may use the results of additional
monitoring conducted under paragraph
(b) (2) (ii) of this section to meet the
requirement for monitoring in this
paragraph.
(ii) Additional monitoring. On each
day following a routine sample
monitoring result that exceeds the
chlorite MCL at the entrance to the
distribution system, the system is
required to take three chlorite
distribution system samples at the
following locations: as close to the first
customer as possible, in a location
representative of average residence time,
and as close to the end of the
distribution system as possible
(reflecting maximum residence time in
the distribution system).
(iii) Reduced monitoring. (A) Chlorite
monitoring at the entrance to the
distribution system required by
paragraph (b)(2)(i)(A) of this section
may not be reduced.
(B) Chlorite monitoring in the
distribution system required by
paragraph (b)(2)(i)(B) of this section may
be reduced to one three-sample set per
quarter after one year of monitoring
where no individual chlorite sample
taken in the distribution system under
paragraph (b) (2) (i) (B) of this section has
exceeded the chlorite MCL and the
system has not been required to conduct
monitoring under paragraph (b)(2)(ii) of
this section. The system may remain on
the reduced monitoring schedule until
either any of the three individual
chlorite samples taken quarterly in the
distribution system under paragraph
(b)(2)(i)(B) of this section exceeds the
chlorite MCL or the system is required
to conduct monitoring under paragraph
(b)(2)(ii) of this section, at which time
the system must revert to routine
monitoring.
(3) Bromate. (i) Routine monitoring.
Community and nontransient
noncommunity systems using ozone, for
disinfection or oxidation, must take one
sample per month for each treatment
plant in the system using ozone.
Systems must take samples monthly at
the entrance to the distribution system
while the ozonation system is operating
under normal conditions.
(ii) Reduced monitoring. Systems
required to analyze for bromate may
reduce monitoring from monthly to
once per quarter, if the system
demonstrates that the average source
water bromide concentration is less than
0.05 mg/L based upon representative
monthly bromide measurements for one
year. The system may remain on
reduced bromate monitoring until the
running annual average source water
bromide concentration, computed
quarterly, is equal to or greater than 0.05
mg/L based upon representative
monthly measurements. If the running
annual average source water bromide
concentration is >0.05 mg/L, the system
must resume routine monitoring
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69470 Federal Register/Vol. 63, No. 241 / Wednesday, December 16. 1998/Rules and Regulations
required by paragraph (b)(3)(i) of this
section.
(c) Monitoring requirements for
disinfectant residuals. (1) Chlorine and
chloramlnes. (i) Routine monitoring.
Systems must measure the residual
disinfectant level at the same points in
the distribution system and at the same
time as total coliforms are sampled, as
specified in § 141.21. Subpart H systems
may use the results of residual
disinfectant concentration sampling
conducted under § 141.74(b)(6)(i) for
unfiltered systems or § 141.74(c)(3)(i) for
systems which filter, in lieu of taking
separate samples.
(ii) Reduced monitoring. Monitoring
may not be reduced.
(2) Chlorine dioxide, (i) Routine
monitoring. Community, nontransient
noncommunity, and transient
noncommunity water systems that use
chlorine dioxide for disinfection or
oxidation must take daily samples at the
entrance to the distribution system. For
any daily sample that exceeds the
MRDL, the system must take samples in
the distribution system the following
day at the locations required by
paragraph (c)(2)(li) of this section, in
addition to the sample required at the
entrance to the distribution system.
(ii) Additional monitoring. On each
day following a routine sample
monitoring result that exceeds the
MRDL, the system is required to take
three chlorine dioxide distribution
system samples. If chlorine dioxide or
chloramlnes are used to maintain a
disinfectant residual in the distribution
system, or if chlorine is used to
maintain a disinfectant residual in the
distribution system and there are no
disinfection addition points after the
entrance to the distribution system (i.e.,
no booster chlorination), the system
must take three samples as close to the
first customer as possible, at intervals of
at least six hours. If chlorine is used to
maintain a disinfectant residual in the
distribution system and there are one or
more disinfection addition points after
the entrance to the distribution system
(i.e., booster chlorination), the system
must take one sample at each of the
following locations: as close to the first
customer as possible, in a location
representative of average residence time,
and as close to the end of the
distribution system as possible
(reflecting maximum residence time in
the distribution system).
(ill) Reduced monitoring. Chlorine
dioxide monitoring may not be reduced.
(d) Monitoring requirements for
disinfection byproduct precursors
(DBPP). (1) Routine monitoring. Subpart
H systems which use conventional
filtration treatment (as defined in
§ 141.2) must monitor each treatment
plant for TOC no later than the point of
combined filter effluent turbidity
monitoring and representative of the
treated water. All systems required to
monitor under this paragraph (d) (1)
must also monitor for TOC in the source
water prior to any treatment at the same
time as monitoring for TOC in the
treated water. These samples (source
water and treated water) are referred to
as paired samples. At the same time as
the source water sample is taken, all
systems must monitor for alkalinity in
the source water prior to any treatment.
Systems must take one paired sample
and one source water alkalinity sample
per month per plant at a time
representative of normal operating
conditions and influent water quality.
(2) Reduced monitoring. Subpart H
systems with an average treated water
TOC of less than 2.0 mg/L for two
consecutive years, or less than 1.0 mg/
L for one year, may reduce monitoring
for both TOC and alkalinity to one
paired sample and one source water
alkalinity sample per plant per quarter.
The system must revert to routine
monitoring in the month following the
quarter when the annual average treated
water TOC >2.0 mg/L.
(e) Bromide. Systems required to
analyze for bromate may reduce bromate
monitoring from monthly to once per
quarter, if the system demonstrates that
the average source water bromide
concentration is less than 0.05 mg/L
based upon representative monthly
measurements for one year. The system
must continue bromide monitoring to
remain on reduced bromate monitoring.
(f) Monitoring plans. Each system
required to monitor under this subpart
must develop and implement a
monitoring plan. The system must
maintain the plan and make it available
for inspection by the State and the
general public no later than 30 days
following the applicable compliance
dates in § 141.130(b). All Subpart H
systems serving more than 3300 people
must submit a copy of the monitoring
plan to the State no later than the date
of the first report required under
§ 141.134. The State may also require
the plan to be submitted by any other
system. After review, the State may
require changes in any plan elements.
The plan must include at least the
following elements,
(1) Specific locations and schedules
for collecting samples for any
parameters included in this subpart.
(2) How the system will calculate
compliance with MCLs, MRDLs, and
treatment techniques.
(3) If approved for monitoring as a
consecutive system, or if providing
water to a consecutive system, under the
provisions of § 141.29, the sampling
plan must reflect the entire distribution
system.
§ 141.133 Compliance requirements.
(a) General requirements. (1) Where
compliance is based on a running
annual average of monthly or quarterly
samples or averages and the system's
failure to monitor for TTHM, HAAS, or
bromate, this failure to monitor will be
treated as a monitoring violation for the
entire period covered by the annual
average. Where compliance is based on
a running annual average of monthly or
quarterly samples or averages and the
system's failure to monitor makes it
impossible to determine compliance
with MRDLs for chlorine and
chloramines, this failure to monitor will
be treated as a monitoring violation for
the entire period covered by the annual
average.
(2) All samples taken and analyzed
under the provisions of this subpart
must be included in determining
compliance, even if that number is
greater than the minimum required.
(3) If, during the first year of
monitoring under § 141.132, any
individual quarter's average will cause
the running annual average of that
system to exceed the MCL, the system
is out of compliance at the end of that
quarter.
(b) Disinfection byproducts. (1)
TTHMs and HAAS, (i) For systems
monitoring quarterly, compliance with
MCLs in § 141.64 must be based on a
running annual arithmetic average,
computed quarterly, of quarterly
arithmetic averages of all samples
collected by the system as prescribed by
§ 141.132 (b) (1). If the running annual
arithmetic average of quarterly averages
covering any consecutive four-quarter
period exceeds the MCL, the system is
in violation of the MCL and must notify
the public pursuant to § 141.32, in
addition to reporting to the State
pursuant to § 141.134. If a PWS fails to
complete four consecutive quarters'
monitoring, compliance with the MCL
for the last four-quarter compliance
period must be based on an average of
the available data.
(ii) For systems monitoring less
frequently than quarterly, compliance
must be based on an average of samples
taken that year under the provisions of
§ 141.132 (b) (1). If the average of these
samples exceeds the MCL, the system
must increase monitoring to once per
quarter per treatment plant.
(iii) Systems on a reduced monitoring
schedule whose annual average exceeds
the MCL will revert to routine
monitoring immediately. These systems
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Federal Register/Vol. 63. No. 241/Wednesday. December 16, 1998/RuIes and Regulations 69471
will not be considered in violation of
the MCL until they have completed one
year of routine monitoring.
(2). Bromate. Compliance must be
based on a running annual arithmetic
average, computed quarterly, of monthly
samples (or, for months in which the
system takes more than one sample, the
average of all samples taken during the
month) collected by the system as
prescribed by § 141.132 (b) (3). If the
average of samples covering any
consecutive four-quarter period exceeds
the MCL, the system is in violation of
the MCL and must notify the public
pursuant to § 141.32, in addition to
reporting to the State pursuant to
§ 141.134. If a PWS fails to complete 12
consecutive months' monitoring,
compliance with the MCL for the last
four-quarter compliance period must be
based on an average of the available
data.
(3) Chlorite. Compliance must be
based on an arithmetic average of each
three sample set taken in the
distribution system as prescribed by
§141.132(b)(2)(i)(B)and •
§ 141.132(b)(2)(ii). If the arithmetic
average of any three sample set exceeds
the MCL, the system is in violation of
the MCL and must notify the public
pursuant to § 141.32, in addition to
reporting to the State pursuant to
§141.134.
(c) Disinfectant residuals. (1) Chlorine
and chloramines. (i) Compliance must
be based on a running annual arithmetic
average, computed quarterly, of monthly
averages of all samples collected by the
system under § 141.132(c)(l). If the
average of quarterly averages covering
any consecutive four-quarter period
exceeds the MRDL, the system is in
violation of the MRDL and must notify
the public pursuant to § 141.32, in
addition to reporting to the State
pursuant to §141.134.
(ii) In cases where systems switch
between the use of chlorine and
chloramines for residual disinfection
during the year, compliance must be
determined by including together all
monitoring results of both chlorine and
chloramines in calculating compliance.
Reports submitted pursuant to § 141.134
must clearly indicate which residual
disinfectant was analyzed for each
sample.
(2) Chlorine dioxide, (i) Acute
violations. Compliance must be based
on consecutive daily samples collected
by the system under § 141.132(c)(2). If
any daily sample taken at the entrance
to the distribution system exceeds the
MRDL, and on the following day one (or
more) of the three samples taken in the
distribution system exceed the MRDL,
the system is in violation of the MRDL
and must take immediate corrective
action to lower the level of chlorine
dioxide below the MRDL and must
notify the public pursuant to the
procedures for acute health risks in
§ 141.32(a)(l)(iii)(E). Failure to take
samples in the distribution system the
day following an exceedance of the
chlorine dioxide MRDL at the entrance
to the distribution system will also be
considered an MRDL violation and the
system must notify the public of the
violation in accordance with the
provisions for acute violations under
.
(ii) Nonacute violations. Compliance
must be based on consecutive daily
samples collected by the system under
§ 141.132(c)(2). If any two consecutive
daily samples taken at the entrance to
the distribution system exceed the
MRDL and all distribution system
samples taken are below the MRDL, the
system is in violation of the MRDL and
must take corrective action to lower the
level of chlorine dioxide below the
MRDL at the point of sampling and will
notify the public pursuant to the
procedures for nonacute health risks in
§ 141.32(e)(78). Failure to monitor at the
entrance to the distribution system the
day following an exceedance of the
chlorine dioxide MRDL at the entrance
to the distribution system is also an
MRDL violation and the system must
notify the public of the violation in
accordance with the provisions for
nonacute violations under
§141.32(e)(78).
(d) Disinfection byproduct precursors
(DBPP). Compliance must be
determined as specified by § 141.135(b).
Systems may begin monitoring to
determine whether Step 1 TOC
removals can be met 12 months prior to
the compliance date for the system. This
monitoring is not required and failure to
monitor during this period is not a
violation. However, any system that
does not monitor during this period,
and then determines in the first 12
months after the compliance date that it
is not able to meet the Step 1
requirements in § 141.135(b)(2) and
must therefore apply for alternate
minimum TOC removal (Step 2)
requirements, is not eligible for
retroactive approval of alternate
minimum TOC removal (Step 2)
requirements as allowed pursuant to
§ 141.135(b)(3) and is in violation.
Systems may apply for alternate
minimum TOC removal (Step 2)
requirements any time after the
compliance date.
§ 141.134 Reporting and recordkeeping
requirements.
(a) Systems required to sample
quarterly or more frequently must report
to the State within 10 days after the end
of each quarter in which samples were
collected, notwithstanding the
provisions of § 141.31. Systems required
to sample less frequently than quarterly
must report to the State within 10 days
after the end of each monitoring period
in which samples were collected.
(b) Disinfection byproducts. Systems
must report the information specified in
the following table:
If you are a...
monitoring for TTHM and HAA5 under the requirements of
.132(b) on a quarterly or more frequent basis.
System monitoring for TTHMs and HAA5 under the requirements of
§§ 141.132(b) less frequently than quarterly (but at least annually).
™, f°r TTHMs and' HAA5 under tne requirements of
§141.132(b) less frequently than annually.
You must report...1
(•1) The number of samples taken during the last quarter.
(2) The location, date, and result of each sample taken during the last
quarter.
(3) The arithmetic average of all samples taken in the last quarter.
(4) The annual arithmetic average of the quarterly arithmetic averaqes
of this section for the last four quarters.
(5) Whether the MCL was exceeded.
(1) The number of samples taken during the last year.
(2), The location, date, and result of each sample taken during the last
quarter.
(3) The arithmetic average of all samples taken over the last year
(4) Whether the MCL was exceeded.
(1) The location, date, and result of the last sample taken.
(2) Whether the MCL was exceeded.
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69472 Federal Register/Vol. 63. No. 241/Wednesday. December 16, 1998/Rules and Regulations
If you are a...
You must report...1
System monitoring for chlorite under the requirements of § 141.132(b)
System monitoring for bromate under the requirements of § 141.132(b)
(1) The number of samples taken each month for the last 3 months.
(2) The location, date, and result of each sample taken during the last
quarter.
(3) For each month in the reporting period, the arithmetic average of all
samples taken in the month.
(4) Whether the MCL was exceeded, and in which month it was ex-
ceeded.
(1) The number of samples taken during the last quarter.
(2) The location, date, and result of each sample taken during the last
quarter.
(3) The arithmetic average of the monthly arithmetic averages of all
samples taken in the last year.
(4) Whether the MCL was exceeded.
(c) Disinfectants. Systems must report
the information specified in the
following table:
If you are a...
You must report...1
System monitoring for chlorine or chloramines under the requirements
of §141.132(c).
System monitoring for chlorine dioxide under the requirements of
§141.132(c).
(1) The number of samples taken during each month of the last quar-
ter.
(2) The monthly arithmetic average of all samples taken in each month
for the last 12 months.
(3) The arithmetic average of all monthly averages for the last 12
months.
(4) Whether the MRDL was exceeded.
(1) The dates, results, and locations of samples taken during the last
quarter.
(2) Whether the MRDL was exceeded.
(3) Whether the MRDL was exceeded in any two consecutive daily
samples and whether the resulting violation was acute or nonacute.
iThe State may choose to perform calculations and determine whether the MRDL was exceeded, in lieu of having the system report that infor-
mation.
(d) Disinfection byproduct precursors
and enhanced coagulation or enhanced
softening. Systems must report the
information specified in the following
table:
If you are a
You must report.
System monitoring monthly or quarterly for TOC under the require-
ments of §141.132(d) and required to meet the enhanced coagula-
tion or enhanced softening requirements in §141.135(b)(2) or (3).
System monitoring monthly or quarterly for TOC under the require-
ments of §141.132(d) and meeting one or more of the alternative
compliance criteria in §141.135(a)(2) or (3).
(1) The number of paired (source water and treated water, prior to con-
tinuous disinfection) samples taken during the last quarter.
(2) The location, date, and result of each paired sample and associ-
ated alkalinity taken during the last quarter.
(3) For each month in the reporting period that paired samples were
taken, the arithmetic average of the percent reduction of TOC for
each paired sample and the required TOC percent removal.
(4) Calculations for determining compliance with the TOC percent re-
moval requirements, as provided in §141.135(c)(1).
(5) Whether the system is in compliance with the enhanced coagula-
tion or enhanced softening percent removal requirements in
§141.135(b) for the last four quarters.
(1) The alternative compliance criterion that the system is using.
(2) The number of paired samples taken during the last quarter.
(3) The location, date, and result of each paired sample and associ-
ated alkalinity taken during the last quarter.
(4) The running annual arithmetic average based on monthly averages
(or quarterly samples) of source water TOC for systems meeting a
criterion in §§141.135(a)(2)(i) or (iii) or of treated water TOC for sys-
tems meeting the criterion in § 141.135(a)(2)(ii).
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Federal Register/Vol. 63. No. 241 / Wednesday, December 16, 1998/Rules and Regulations 69473
If you are a .
You must report.
(5) The running annual arithmetic average based on monthly averages
(or quarterly samples) of source water SUVA for systems meeting
the criterion in §141.135(a)(2)(v) or of treated water SUVA for sys-
tems meeting the criterion in § 141.135(a)(2)(vi).
(6) The running annual average of source water alkalinity for systems
meeting the criterion in § 141.135(a)(2)(iii) and of treated water alka-
linity for systems meeting the criterion in §141.135(a)(3)(i).
(7) The running annual average for both TTHM and HAAS for systems
meeting the criterion in §141.135(a)(2)(iii) or (iv).
(8) The running annual average of the amount of magnesium hardness
removal (as CaCO3, in mg/L) for systems meeting the criterion in
(9) Whether the system is in compliance with the particular alternative
compliance criterion in §141.135(a)(2) or (3).
1hannformlt?orTy Ch°°Se
Perf°rm calculations and determine whether the treatment technique was met, in lieu of having the system report
§ 141.135 Treatment technique for control
of disinfection byproduct (DBF) precursors.
(a) Applicability. (1) Subpart H
systems using conventional filtration
treatment (as defined in § 141.2) must
operate with enhanced coagulation or
enhanced softening to achieve the TOC
percent removal levels specified in
paragraph (b) of this section unless the
system meets at least one of the
alternative compliance criteria listed in
paragraph (a) (2) or (a) (3) of this section.
(2) Alternative compliance criteria for
enhanced coagulation and enhanced
softening systems. Subpart H systems
using conventional filtration treatment
may use the alternative compliance
criteria in paragraphs (a)(2)(i) through
(vi) of this section to comply with this
section in lieu of complying with
paragraph (b) of this section. Systems
must still comply with monitoring
requirements in § 141.132(d).
(i) The system's source water TOC
level, measured according to
§ 141.131(d)(3), is less than 2.0 mg/L,
calculated quarterly as a running annual
average.
(ii) The system's treated water TOC
level, measured according to
§ 141.131 (d)(3), is less than 2.0 mg/L,
calculated quarterly as a running annual
average.
(iii) The system's source water TOC
level, measured as required by
§ 141.131 (d)(3), is less than 4.0 mg/L,
calculated quarterly as a running annual
average; the source water alkalinity,
measured according to § 141.131 (d) (1),
is greater than 60 mg/L (as CaCO3),
calculated quarterly as a running annual
average; and either the TTHM and
HAAS running annual averages are no
greater than 0.040 mg/L and 0.030 mg/
L, respectively; or prior to the effective
date for compliance in § 141.130(b), the
system has made a clear and irrevocable
financial commitment not later than the
effective date for compliance in
§ 141.130 (b) to use of technologies that
will limit the levels of TTHMs_and
HAAS to no more than 0.040 mg/L and
0.030 mg/L, respectively. Systems must
submit evidence of a clear and
irrevocable financial commitment, in
addition to a schedule containing
milestones and periodic progress reports
for installation and operation of
appropriate technologies, to the State for
approval not later than the effective date
for compliance in § 141.130(b). These
technologies must be installed and
operating not later than June 16, 2005.
Failure to install and operate these
technologies by the date in the approved
schedule will constitute a violation of
National Primary Drinking Water
Regulations.
(iv) The TTHM and HAAS running
annual averages are no greater than
0.040 mg/L and 0.030 mg/L,
respectively, and the system uses only
chlorine for primary disinfection and
maintenance of a residual in the
distribution system.
(v) The system's source water SUVA,
prior to any treatment and measured
monthly according to § 141.131 (d) (4), is
less than or equal to 2.0 L/mg-m,
calculated quarterly as a running annual
average.
(vi) The system's finished water
SUVA, measured monthly according to
§ 141.131 (d) (4), is less than or equal to
2.0 L/mg-m, calculated quarterly as a
running annual average.
(3) Additional alternative compliance
criteria for softening systems. Systems
practicing enhanced softening that
cannot achieve the TOC removals
required by paragraph (b)(2) of this
section may use the alternative
compliance criteria in paragraphs
(a)(3)(i) and (ii) of this section in lieu of
complying with paragraph (b) of this
section. Systems must still comply with
monitoring requirements in
§141.132(d).
(i) Softening that results in lowering
the treated water alkalinity to less than
60 mg/L (as CaCO3), measured monthly
according to § 141.131 (d) (1) and
calculated quarterly as a running annual
average.
(ii) Softening that results in removing
at least 10 mg/L of magnesium hardness
(as CaCO3), measured monthly and
calculated quarterly as an annual
running average.
(b) Enhanced coagulation and
enhanced softening performance
requirements. (1) Systems must achieve
the percent reduction of TOC specified
in paragraph (b)(2) of this section
between the source water and the
combined filter effluent, unless the State
approves a system's request for alternate
minimum TOC removal (Step 2)
requirements under paragraph (b)(3) of
this section.
(2) Required Step 1 TOC reductions,
indicated in the following table, are
based upon specified source water
parameters measured in accordance
with § 141.131 (d). Systems practicing
softening are required to meet the Step
1 TOC reductions in the far-right
column (Source water alkalinity >120
mg/L) for the specified source water
TOC:
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69474 Federal Register/Vol. 63, No. 241/Wednesday, December 16, 1998/Rules and Regulations
STEP 1 REQUIRED REMOVAL OF TOG BY ENHANCED COAGULATION AND ENHANCED SOFTENING FOR SUBPART H
SYSTEMS USING CONVENTIONAL TREATMENT1-2
Source-water TOO, mg/L
^A A_Q n •
>8.0
Source-water alkalinity, mg/L as CaCO3
0-60 (percent)
35.0
45.0
50.0
<60-120 (per-
cent)
25.0
35.0
40.0
>1203 (per-
cent)
15.0
25.0
30.0
1 Systems meeting at least one of the conditions in paragraph (a)(2)(i)-(vi) of this section are not required to operate with enhanced coagula-
^Soflenlng systems meeting one of the alternative compliance criteria in paragraph (a)(3) of this section are not required to operate with en-
3 Systems praciicing softening must meet the TOG removal requirements in this column.
(3) Subpart H conventional treatment
systems that cannot achieve the Step 1
TOC removals required by paragraph
(b)(2) of this section due to water quality
parameters or operational constraints
must apply to the State, within three
months of failure to achieve the TOC
removals required by paragraph (b)(2) of
this section, for approval of alternative
minimum TOC (Step 2) removal
requirements submitted by the system.
If the State approves the alternative
minimum TOC removal (Step 2)
requirements, the State may make those
requirements retroactive for the
purposes of determining compliance.
Until the State approves the alternate
minimum TOC removal (Step 2)
requirements, the system must meet the
Step 1 TOC removals contained in
paragraph (b)(2) of this section.
(4) Alternate minimum TOC removal
(Step 2) requirements. Applications
made to the State by enhanced
coagulation systems for approval of
alternative minimum TOC removal
(Step 2) requirements under paragraph
(b)(3) of this section must include, as a
minimum, results of bench- or pilot-
scale testing conducted under paragraph
(b)(4)(i) of this section and used to
determine the alternate enhanced
coagulation level.
(i) Alternate enhanced coagulation
level Is defined as coagulation at a
coagulant dose and pH as determined by
the method described in paragraphs
(b)(4)(i) through (v) of this section such
that an incremental addition of 10 mg/
L of alum (as aluminum) (or equivalent
amount of ferric salt) results in a TOC
removal of 5 0.3 mg/L. The percent
removal of TOC at this point on the
"TOC removal versus coagulant dose"
curve is then defined as the minimum
TOC removal required for the system.
Once approved by the State, this
minimum requirement supersedes the
minimum TOC removal required by the
table in paragraph (b)(2) of this section.
This requirement will be effective until
such time as the State approves a new
value based on the results of a new
bench- and pilot-scale test. Failure to
achieve State-set alternative minimum
TOC removal levels is a violation of
National Primary Drinking Water
Regulations.
(ii) Bench- or pilot-scale testing of
enhanced coagulation must be
conducted by using representative water
samples and adding 10 mg/L increments
of alum (as aluminum) (or equivalent
amounts of ferric salt) until the pH is
reduced to a level less than or equal to
the enhanced coagulation Step 2 target
pH shown in the following table:
ENHANCED COAGULATION STEP 2
TARGET PH
Alkalinity (mg/L as CaCO3)
0-60
>60 120
>120 240
>240
Target pH
5.5
6.3
7.0
7.5
(iii) For waters with alkalinities of
less than 60 mg/L for which addition of
small amounts of alum or equivalent
addition of iron coagulant drives the pH
below 5.5 before significant TOC
removal occurs, the system must add
necessary chemicals to maintain the pH
between 5.3 and 5.7 in samples until the
TOC removal of 0.3 mg/L per 10 mg/L
alum added (as aluminum) (or
equivalant addition of iron coagulant) is
reached.
(iv) The system may operate at any
coagulant dose or pH necessary
(consistent with other NPDWRs) to
achieve the minimum TOC percent
removal approved under paragraph
(b)(3) of this section.
(v) If the TOC removal is consistently
less than 0.3 mg/L of TOC per 10 mg/
L of incremental alum dose (as
aluminum) at all dosages of alum (or
equivalant addition of iron coagulant),
the water is deemed to contain TOC not
amenable to enhanced coagulation. The
system may then apply to the State for
a waiver of enhanced coagulation
requirements.
(c) Compliance calculations. (1)
Subpart H systems other than those
identified in paragraph (a) (2) or (a) (3) of
this section must comply with
requirements contained in paragraph
(b)(2) of this section. Systems must
calculate compliance quarterly,
beginning after the system has collected
12 months of data,, by determining an
annual average using the following
method:
(i) Determine actual monthly TOC
percent removal, equal to:
(1—(treated water TOC/source water
TOC)) x 100
(ii) Determine the required monthly
TOC percent removal (from either the
table in paragraph (b)(2) of this section
or from paragraph (b) (3) of this section).
(iii) Divide the value in paragraph
(c) (1) (i) of this section by the value in
paragraph (c)(l)(ii) of this section.
(iv) Add together the results of
paragraph (c) (1) (iii) of this section for
the last 12 months and divide by 12.
(v) If the value calculated in
paragraph (c) (1) (iv) of this section is less
than 1.00, the system is not in
compliance with the TOC percent
removal requirements.
(2) Systems may use the provisions in
paragraphs (c)(2)(i) through (v) of this
section in lieu of the calculations in
paragraph (c)(l)(i) through (v) of this
section to determine compliance with
TOC percent removal requirements.
(i) In any month that the system's
treated or source water TOC level,
measured according to § 141.131 (d) (3),
is less than 2.0 mg/L, the system may
assign a monthly value of 1.0 (in lieu of
the value calculated in paragraph
(c)(l)(iii) of this section) when
calculating compliance under the
provisions of paragraph (c) (1) of this
section.
(ii) In any month that a system
practicing softening removes at least 10
mg/L of magnesium hardness (as
CaCO3), the system may assign a
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Federal Register/Vol. 63. No. 241/Wednesday. December 16, 1998/Rules and Regulations 69475
monthly value of 1.0 (in lieu of the
value calculated in paragraph (c) (1) (iii)
of this section) when calculating
compliance under the provisions of
paragraph (c)(l) of this section.
(iii) In any month that the system's
source water SUVA, prior to any
treatment and measured according to
§ 141.131(d)(4). is <2.0 L/mg-m, the
system may assign a monthly value of
1.0 (in lieu of the value calculated in
paragraph (c)(l)(iii) of this section)
when calculating compliance under the
provisions of paragraph (c)(l) of this
section.
(iv) In any month that the system's
finished water SUVA, measured
according to § 141.131(d)(4), is <2.0 L/
mg-m, the system may assign a monthly
value of 1.0 (in lieu of the value
calculated in paragraph (c)(l)(iii) of this
section) when calculating compliance
under the provisions of paragraph (c)(l)
of this section.
(v) In any month that a system
practicing enhanced softening lowers
alkalinity below 60 mg/L (as CaCO3), the
system may assign a monthly value of
1.0 (in lieu of the value calculated in
paragraph (c)(l)(iii) of this section)
when calculating compliance under the
provisions of paragraph (c)(l) of this
section.
(3) Subpart H systems using
conventional treatment may also
comply with the requirements of this
section by meeting the criteria in
paragraph (a) (2) or (3) of this section.
(d) Treatment technique requirements
for DBF precursors. The Administrator
identifies the following as treatment
techniques to control the level of
disinfection byproduct precursors in
drinking water treatment and
distribution systems: For Subpart H
systems using conventional treatment,
enhanced coagulation or enhanced
softening.
11. Section 141.154 is amended by
adding paragraph (e) to read as follows:
§ 141.154 Required additional health
information.
*****
(e) Community water systems that
detect TTHM above 0.080 mg/1, but
below the MCL in § 141.12, as an annual
average, monitored and calculated
under the provisions of § 141.30, must
include health effects language
prescribed by paragraph (73) of
appendix C to subpart O.
PART 142—NATIONAL PRIMARY
DRINKING WATER REGULATIONS
IMPLEMENTATION
12. The authority citation for part 142
continues to read as follows:
Authority: 42 U.S.C. 300f, 300g-l, 300g-2
300g-3, 300g-4, 300g-5, 300g-6, 300J-4, 300j-
9, and300j-ll.
13. Section 142.14 is amended by
adding new paragraphs (d)(12), (d)(13),
(d)(14). (d)(15). and (d)(16) to read as
follows.
§ 142.14 Records kept by States.
*****
(d) * * *
(12) Records of the currently
applicable or most recent State
determinations, including all supporting
information and an explanation of the
technical basis for each decision, made
under the following provisions of 40
CFR part 141, subpart L for the control
of disinfectants and disinfection
byproducts. These records must also
include interim measures toward
installation.
(i) States must keep records of
systems that are installing GAC or
membrane technology in accordance
with § 141.64(b)(2) of this chapter.
These records must include the date by
which the system is required to have
completed installation.
(ii) States must keep records of
systems that are required, by the State,
to meet alternative minimum TOC
removal requirements or for whom the
State has determined that the source
water is not amenable to enhanced
coagulation in accordance with
§ 141.135(b)(3) and (4) of this chapter,
respectively. These records must
include the alternative limits and
rationale for establishing the alternative
limits.
(iii) States must keep records of
subpart H systems using conventional
treatment meeting any of the alternative
compliance criteria in § 141.135 (a) (2) or
(3) of this chapter.
(iv) States must keep a register of
qualified operators that have met the
State requirements developed under
§142.16(f)(2).
(13) Records of systems with multiple
wells considered to be one treatment
plant in accordance with § 141.132 (a) (2)
of this chapter and § 142.16(f)(5).
(14) Monitoring plans for subpart H
systems serving more than 3,300
persons in accordance with § 141.132(0
of this chapter.
(15) List of laboratories approved for
analyses in accordance with
§ 141.131 (b) of this chapter.
(16) List of systems required to
monitor for disinfectants and
disinfection byproducts in accordance
with part 141, subpart L of this chapter.
The list must indicate what
disinfectants and DBFs, other than
chlorine, TTHM, and HAA5, if any, are
measured.
* * * * *
14. Section 142.16 is amended by
adding paragraph (h) to read as follows.
§ 142.16 Special primacy requirements.
*****
(h) Requirements for States to adopt
40 CFR part 141, subpart L. In addition
to the general primacy requirements
elsewhere in this part, including the
requirement that State regulations be at
least as stringent as federal
requirements, an application for
approval of a State program revision
that adopts 40 CFR part 141, subpart L,
must contain a description of how the
State will accomplish the following
program requirements:
(1) Section 141.64(b)(2) of this chapter
(interim treatment requirements).
Determine any interim treatment
requirements for those systems electing
to install GAC or membrane filtration
and granted additional time to comply
with § 141.64 of this chapter.
(2) Section 141.130(c) of this chapter
(qualification of operators). Qualify
operators of public water systems
subject to 40 CFR part 141, subpart L.
Qualification requirements established
for operators of systems subject to 40
CFR part 141, subpart H—Filtration and
Disinfection may be used in whole or in
part to establish operator qualification
requirements for meeting 40 CFR part
141, subpart L requirements if the State
determines that the 40 CFR part 141,
subpart H requirements are appropriate
and applicable for meeting subpart L
requirements.
(3) Section 141.131(c)(2) of this
chapter (DPD colorimetric test kits).
Approve DPD colorimetric test kits for
free and total chlorine measurements.
State approval granted under
§ 141.74(a)(2) of this chapter for the use
of DPD colorimetric test kits for free
chlorine testing is acceptable for the use
of DPD test kits in measuring free
chlorine residuals as required in 40 CFR
part 141, subpart L.
(4) Sections 141.131(c)(3) and (d) of
this chapter (State approval of parties to
conduct analyses). Approve parties to
conduct pH, bromide, alkalinity, and
residual disinfectant concentration
measurements. The State's process for
approving parties performing water
quality measurements for systems
subject to 40 CFR part 141, subpart H
requirements in paragraph (b) (2) (i) (D) of
this section may be used for approving
parties measuring water quality
parameters for systems subject to
subpart L requirements, if the State
determines the process is appropriate
and applicable.
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69476 Federal Register/Vol. 63, No. 241 / Wednesday, December 16, 1998/Rules and Regulations
(5) Section 141.132(a)(2) of this
chapter (multiple wells as a single
source). Define the criteria to use to
determine if multiple wells are being
drawn from a single aquifer and
therefore be considered a single source
for compliance with monitoring
requirements.
(6) Approve alternate minimum TOC
removal (Step 2) requirements, as
allowed under the provisions of
§ 141.135 (b) of this chapter.
[FR Doc. 98-32887 Filed 12-15-98; 8:45 am]
BILLING CODE 6560-50-U
vvEPA
United States
Environmental Protection Agency
(4607)
Washington, DC 20460
Official Business
Penalty for Private Use
$300
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