National Primary Drinking Water Regulations: Monitoring Requirements for Public Drinking Water Supplies; Final Rule

[Federal Register: May 14, 1996 (Volume 61, Number 94)]
[Rules and Regulations]
[Page 24353-24388]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[[Page 24353]]

Part II

Environmental Protection Agency

40 CFR Part 141

National Primary Drinking Water Regulations: Monitoring Requirements
for Public Drinking Water Supplies; Final Rule

[[Page 24354]]

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 141

[WH-FRL-5501-1]
RIN 2040-AC24

National Primary Drinking Water Regulations: Monitoring
Requirements for Public Drinking Water Supplies: Cryptosporidium,
Giardia, Viruses, Disinfection Byproducts, Water Treatment Plant Data
and Other Information Requirements

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

SUMMARY: Today, EPA is promulgating an information collection rule
(ICR) which establishes monitoring and data reporting requirements for
large public water systems (PWSs). This rule is intended to provide EPA
with information on the occurrence in drinking water of (1) chemical
byproducts that form when disinfectants used for microbial control
react with chemicals already present in source water (disinfection
byproducts (DBPs)) and (2) disease-causing microorganisms (pathogens),
including Cryptosporidium. Also, EPA will collect engineering data on
how PWSs currently control such contaminants. All data collected
pursuant to this rule will be available to the public via the Internet.
This information is being collected because a Regulatory
Negotiation on disinfectants and DBPs concluded that additional
information is needed to assess the potential health problem created by
the presence of DBPs and pathogens in drinking water and to assess the
extent and severity of risk in order to make sound regulatory and
public health decisions. These contaminants may have adverse human
health effects, including cancer, liver and kidney damage, and may
cause microbial disease such as cryptosporidiosis and hepatitis.
EPA will use information generated by this rule, along with
concurrent research, to determine whether revisions need to be made to
EPA's current drinking water filtration and disinfection rule and to
determine the need for new regulations for disinfectants and DBPs.
EPA has determined that the rule's objectives can be satisfied, and
sufficient information collected, by requiring only large PWSs to
collect the data. Surface water systems serving at least 100,000 people
and ground water systems serving at least 50,000 must monitor. EPA will
supplement this information with EPA-funded surveys that target smaller
PWSs. The specific information required is based on the number of
people served, the source of water (i.e., surface water or ground
water), and the type(s) of treatment used.
Although Cryptosporidium is an important drinking water pathogen,
it poses difficult measurement challenges. To ensure quality of data,
EPA has and will continue to take extraordinary steps. The first is to
continue an extensive method analysis and possible improvements. The
second is to establish stringent laboratory approval criteria to
increase Cryptosporidium data quality for developing a national
occurrence data base and conducting a national cost assessment of
possible future rules. Finally, EPA will supplement the collection of
Cryptosporidium data in this rule with a separate, EPA-funded survey.
EPA believes this combination of data collection activities will
produce the best data possible.

DATES: The effective date for this final rule is June 18, 1996. The
incorporation by reference of certain publications listed in the rule
is approved by the Director of the Federal Register as of June 18,
1996. This rule shall remain effective until December 31, 2000.
The information collection requirements contained in subpart M of
part 141 have not been approved by the Office of Management and Budget
(OMB) and are not effective until OMB has approved them. EPA will
publish a final rule announcing the effective date when OMB approves
the information collection requirements.

ADDRESSES: Copies of the public comments received, EPA responses, and
all other supporting documents (including references included in this
notice) are available for review at the U.S. Environmental Protection
Agency (EPA) Drinking Water Docket (MC-4101), 401 M Street SW,
Washington, DC 20460. For access to Docket materials, call (202) 260-
3027 between 9 am and 3:30 pm (Eastern) for an appointment. Copies of
major supporting documents cited in the reference section of this
notice are available for inspection at EPA's regional offices, listed
below. Copies of ``ICR Sampling Manual'', ``DBP/ICR Analytical Methods
Manual'', ``ICR Manual for Bench- and Pilot-scale Studies'', ``ICR
Microbial Laboratory Manual'', ``Reprints of EPA Methods for Chemical
Analyses under the Information Collection Rule'', and ``ICR Water
Utility Database System Users' Guide'' are available for a fee from the
National Technical Information Service (NTIS), U.S. Department of
Commerce, 5285 Port Royal Road, Springfield, VA 22161. The toll-free
number is 800-336-4700, local 703-487-4650. Copies of ``Standard
Methods for the Examination of Water and Wastewater'', 19th Ed., 1995,
are available from the American Public Health Association, 1015
Fifteenth Street, NW, Washington, DC 20005. Copies of ``Guidance Manual
for Compliance with the Filtration and Disinfection Requirements for
Public Water Systems using Surface Water Sources'', Appendices C and O,
1991, are available from American Water Works Association, 6666 West
Quincy Avenue, Denver, CO 80235.

FOR FURTHER 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. Since this rule will be directly implemented by EPA
rather than States, EPA recommends that inquiries be directed to EPA.
For technical inquiries, contact Tom Grubbs or Paul S. Berger, Ph.D.,
Office of Ground Water and Drinking Water (4603), U.S. Environmental
Protection Agency, 401 M Street SW, Washington, DC 20460, telephone
(202) 260-7270 (Grubbs) or (202) 260-3039 (Berger). For implementation
inquiries, contact Barbara Wysock, Technical Support Division, U.S.
Environmental Protection Agency, 26 West Martin Luther King Drive,
Cincinnati, OH 45268, telephone (513) 569-7906, or your EPA regional
office.

SUPPLEMENTARY INFORMATION:

EPA Regional Office Points of Contact for the Information Collection
Rule

I. Kevin Reilly, Water Supply Section, JFK Federal Bldg., Room 203,
Boston, MA 02203, (617) 565-3619
II. Michael Lowy, Water Supply Section, 290 Broadway, 24th Floor,
New York, NY 10007-1866, (212) 637-3830
III. Ghassan Khaled, Drinking Water Section (3WM41), 841 Chestnut
Building ,Philadelphia, PA 19107, (215) 597-8992
IV. David Parker, Water Supply Section, 345 Courtland Street,
Atlanta, GA 30365, (404) 347-2913 ext. 6493
V. Kimberly Harris, Water Supply Section, 77 W. Jackson Blvd.,
Chicago, IL 60604, (312) 353-2650
VI. Blake L. Atkins, Team Leader, Water Supply Section, 1445 Ross
Avenue, Dallas, TX 75202, (214) 665-2297
VII. Stan Calow, State Programs Section, 726 Minnesota Ave., Kansas
City, KS 66101, (913) 551-7410

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VIII. Bob Benson or Bob Clement, Public Water Supply Section (8WMDW),
999 18th Street, Suite 500, Denver, CO 80202-2466, (303) 312-
6243 (Benson), (303) 312-6079 (Clement)
IX. Barry Pollock, Water Supply Section, 75 Hawthorne Street, San
Francisco, CA 94105, (415) 744-1913
X. Wendy Marshall, Drinking Water Unit, 1200 Sixth Avenue (OW-136),
Seattle, WA 98101, (206) 553-1890

Regulated Entities

Entities potentially regulated by this action are public water
systems that treat surface water and serve at least 100,000 people and
public water systems that treat ground water and serve at least 50,000
people. Regulated categories and entities include:

Category Example of regulated entities

Public water systems......... Public water systems that treat surface

water and serve at least 100,000 people.
Public water systems that treat ground
water and serve at least 50,000 people.

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 public water system is regulated by this action, you should
carefully examine the applicability criteria in Sec. 141.141 of the
rule. If you have questions regarding the applicability of this action
to a particular entity, contact the person listed in the preceding FOR
FURTHER INFORMATION CONTACT section.

Table of Contents

I. Summary of Regulation
II. Statutory Authority
III. Regulatory Background
IV. Description of Today's Action
A. New Terms
B. General Applicability
C. Applicability of ICR Requirements to Specific Classes of PWSs
D. Disinfection Byproducts and Related Monitoring
E. Microbiological Monitoring Requirements
F. Disinfection Byproduct Precursor Removal Studies
G. Dates, Schedules, and Reporting Requirements
H. Summary
V. Significant Changes to the Proposed Rule
VI. State Implementation
VII. Cost of Rule
VIII. Other Statutory Requirements
A. Executive Order 12866
B. Regulatory Flexibility Act
C. Paperwork Reduction Act
D. Enhancing the Intergovernmental Partnership
E. Unfunded Mandates Reform Act
IX. References

Abbreviations Used in This Notice

deg.C--degrees Celsius
CFR--Code of Federal Regulations
CT--product of disinfectant residual concentration (C (mg/l)) and
contact time (T (minutes))
DBP--disinfection byproduct
D/DBPR--Disinfectants/Disinfection Byproducts Rule
DSE--distribution system equivalent
EPA--Environmental Protection Agency
ESWTR--Enhanced Surface Water Treatment Rule
equ--equivalents
ft--foot or feet
ft \2\--square feet
ft \3\--cubic feet
FR--Federal Register
GAC--granular activated carbon
gpd--gallons per day
GWUDI--ground water under the direct influence of surface water
HAA5--haloacetic acids (five)
HAA6--haloacetic acids (six)
HAN--haloacetonitriles
HK--haloketones
ICR--Information Collection Rule
MGD--million gallons per day
mg/l--milligrams per liter
nm--nanometers
OMB--Office of Management and Budget
PE--performance evaluation
psi--pounds per square inch
PWS--public water system
PWSID--public water system identification
RSSCT--rapid small-scale column test
SCFM--standard cubic feet per minute
SDS--simulated distribution system
THM4--trihalomethanes (four)
TOC--total organic carbon
TOX--total organic halides
TTHM--total trihalomethanes
<greek-m>m--micrometers
UFCTOX--Uniform formation conditions for total organic halides
U.S.C.--United States Code
WIDB--Water Industry Data Base

I. Summary of Regulation

Acting under the requirement of the Safe Drinking Water Act to
regulate additional contaminants that may cause adverse health effects,
EPA convened a regulatory negotiation in 1992 due to concerns over the
health effects of chemical byproducts (known as disinfection byproducts
(DBPs)). DBPs form in drinking water when disinfectants used for
microbial control react with organic and inorganic chemicals already
present in source water. The regulatory negotiation was convened to
determine how the risk-risk issue of controlling the level of DBPs in
drinking water on the one hand while controlling exposure to diseasecausing
microbes (pathogens) on the other hand is best addressed.
The Negotiating Committee, consisting of representatives of State
and local regulatory and public health agencies, local elected
officials, consumer groups, public water systems (PWSs), environmental
groups, and EPA, met for more than six months to develop a plan to
concurrently control DBPs and microorganisms. The Committee determined
that an important component of their plan would be to develop
additional information to better define the problem and better identify
possible solutions. To develop this information, the Committee agreed
that PWSs should be required to collect occurrence and treatment data
to characterize disinfectants, DBPs, and microorganisms in drinking
water. The Committee also decided that some PWSs should conduct
treatment studies to evaluate the use of granular activated carbon or
membranes to remove DBP precursors. The information collected, in
addition to concurrently conducted health effects and technology
research, will be used to evaluate the need for possible changes to the
current Surface Water Treatment Rule (SWTR) and to evaluate the need
for future regulations for disinfectants and DBPs. All data collected
pursuant to this rule will be available to the public via the Internet.
(See Section III below and the preamble to the proposed Information
Collection Rule (ICR) [59 FR 6332, February 10, 1994] for a more
detailed discussion of the regulatory negotiation process).
Today, EPA is promulgating an information collection rule (ICR)
which requires large PWSs to generate and provide the Agency with
specific monitoring data and other information characterizing their
water systems. There are three classes of PWSs affected, each somewhat
differently, by this rule. The three general classes are: (1) PWSs that
serve at least 100,000 people and use surface water; (2) PWSs that
serve at least 100,000 people, and use only ground water as the source;
and (3) PWSs that serve at least 50,000, but less than 100,000, people
and use ground water as the source. Throughout this rule and preamble,
requirements for

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PWSs or treatment plants that use ground water under the direct
influence of surface water as a source are the same as those for
surface water.
Table I-1 contains a summary of today's rule, which will appear in
subpart M to 40 CFR Part 141.

Table I-1.--General Subpart M Requirements \1\

Treatment Studies
Type of PWS \2\ DBP and related monitoring \3\ Microbial Monitoring \4\ \5\

PWS using surface water \6\ Yes--monthly for 18 months...................... Yes--monthly for 18 months...................... Yes.

serving <gr-thn-eq>100,000.

PWS using ground water serving Yes--monthly for 18 months...................... NA.............................................. Yes.

<gr-thn-eq>100,000.

PWS using ground water serving NA.............................................. NA.............................................. Yes.

50,000 to <100,000.

\1\ These are general requirements and do not include regulatory allowances for reduced monitoring and other specific provisions provided in the rule.
\2\ Population served will include both retail and wholesale populations. Specific instructions for calculating population served are included in the

rule.

\3\ DBP and related monitoring includes monitoring for DBPs and other parameters at specified locations throughout the treatment plant. Also, PWSs will
be required to characterize treatment processes in the treatment plant. Monitoring includes disinfectant residuals, trihalomethanes, haloacetic acids,
haloacetonitriles, haloketones, chloral hydrate, chlorite, chlorate, bromide, bromate, total organic halides (TOX), total organic carbon (TOC), and

general water quality parameters.

\4\ Microbiological monitoring includes monitoring for specific pathogens and microbial indicators: total culturable viruses, total coliforms, fecal

coliforms or E. coli, Giardia, and Cryptosporidium.

\5\ PWSs must conduct treatment study applicability monitoring and, unless avoidance criteria are met, bench- or pilot-scale treatment studies to
determine the effectiveness of granular activated carbon (GAC) or membranes in reducing the levels of precursors to the formation of disinfection

byproducts.
\6\ Includes PWSs using ground water under the direct influence of surface water.

A major issue with this rule is the adequacy of the protozoa
analytical method to generate meaningful occurrence information for
Cryptosporidium. The analytical method is relatively new and difficult
to conduct. Even experienced laboratories have had widely varying
results. EPA has worked over the last couple of years to improve the
method and evaluate its performance under field conditions. The most
recent round of testing showed laboratories recovering between 5and
2112f the Cryptosporidium known to be present. However, despite its
generally acknowledged limitations, this method is the best method
either currently available or anticipated to be available in the near
future and EPA is confident that data produced by approved laboratories
will enable the Agency to develop a reliable national occurrence data
base and national cost impact estimates for various scenarios of
regulations.
In making its determination whether the protozoa analytical method
is adequate to yield meaningful results, EPA focussed on how the data
were to be used. Specifically, the data generated under this rule will
be used to develop a national occurrence data base and national cost
impact estimates for various scenarios of regulations which could be
promulgated to reduce microbiological risk. Also, these data may be
used in conjunction with results of dose-response health effects
research to develop benefit estimates for regulatory options. ICR data
would not be used, except at the option of the PWS, to make compliance
determinations with future rules. At the national level, EPA will
aggregate data from PWS samples analyzed at different laboratories so
that the range of relative error is much smaller, nationally, than it
would be for a single PWS. EPA developed statistically based data
quality objectives which indicated that, even if Cryptosporidium
recovery averaged only 8, the range of uncertainty in cost estimates
would be no greater than with previously issued drinking water rules.
The reason the recovery rate can be this low is because of the large
number of PWSs (over 300) which would be generating data. With a much
smaller sample size, a higher range of recovery would be needed. With
such a large data base, EPA's independently evaluated statistical
analysis shows that an 8recovery rate can provide a reliable
adjustment factor from which to estimate national occurrence. EPA
believes that, with the stringent laboratory approval requirements
contained in this rule, recovery rates will meet this minimum
requirement. As added insurance that the data will be useful, EPA
intends to conduct a companion survey of 50 PWSs where the data are
analyzed by a single laboratory meeting even more stringent
requirements than those imposed in this rule. The results from this
survey will augment the ICR-generated data and improve their
statistical reliability.

II. Statutory Authority

The Safe Drinking Water Act (SDWA, or the Act), as amended in 1986,
requires EPA to publish maximum contaminant level goals (MCLGs) for
contaminants which may have an adverse effect on human health and are
known or anticipated to occur in PWSs. For such contaminants, EPA must
also promulgate national primary drinking water regulations (NPDWRs)
which specify either maximum contaminant levels (MCLs) or treatment
techniques (42 U.S.C. 300g-1). An MCL must be set as close to the MCLG
as feasible.
Under the Act, PWSs can be 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 to assist him in establishing regulations, [or] * * * in
evaluating the health risks of unregulated contaminants''. 40 U.S.C.
300j-4. This provision authorizes EPA to require systems to monitor and
provide the Agency with these data as well as other data characterizing
the systems, including source and treated water quality.
In addition, the Act defines NPDWRs to include ``criteria and
procedures to assure a supply of drinking water which dependably
complies with such maximum contaminant levels; including quality
control and testing procedures * * *''. 40 U.S.C. 300f(1)(D). This
provision authorizes EPA to require systems and laboratories to use
Agency-approved methods and quality assurance criteria for collecting
and analyzing water samples. EPA is using these information collection
authorities as the basis for promulgating the ICR.

III. Regulatory Background

EPA has issued two regulations intended to control pathogens in
public water supplies--the Total Coliform Rule (54 FR 27544, June 29,
1989) and the Surface Water Treatment Requirements (SWTR) (54 FR 27486,
June 29, 1989). A

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third regulation, the Groundwater Disinfection Rule, is currently under
development and will add further protection for systems using ground
water.
In addition to these regulations, EPA concluded that it was
necessary to address disinfectants and chemical byproducts that form
when disinfectants used for microbial control in drinking water react
with various organic and inorganic chemicals in the source water.
Chronic exposure to various DBPs may cause cancer, liver and kidney
damage, heart and neurological effects, and effects to unborn children.
In 1992, EPA instituted a formal regulatory negotiation (reg-neg)
process to develop the Disinfectants/Disinfection Byproducts Rule (D/
DBPR) (57 FR 53866, November 13, 1992). This negotiation was discussed
in the proposed rule.
In the course of the discussions, the Negotiating Committee
determined that insufficient data were available on DBPs to make
appropriate regulatory decisions. The Committee was concerned about the
risk from DBPs, on one hand, and microbial risk on the other. As
disinfectant use is decreased to decrease the formation of DBPs, the
risk of microbial illness increases. Microbes cause many diseases,
including giardiasis, cryptosporidiosis, dysentery, and hepatitis. For
individuals with weakened immune systems, these diseases can be fatal.
The Committee recommended that additional data be developed on
health effects, occurrence of and exposure to these contaminants, and
on the capabilities of treatment technologies to reduce levels of these
contaminants. Committee members were also concerned about limited data
available on microbial contaminants in water. (See preamble of proposed
ICR for a more detailed discussion of the need for additional data and
rationale for the proposed monitoring and reporting requirements. 59 FR
6332 (February 10, 1994).) The Committee agreed to proceed with the
proposal of regulatory actions but at the same time to initiate a
process for developing additional data for future regulatory decisions.
Accordingly, the Committee developed three proposed rules: (a) the
Information Collection Rule (ICR) (59 FR 6332, February 10, 1994), (b)
the ``interim'' Enhanced Surface Water Treatment Rule (ESWTR) (59 FR
38832, July 29, 1994), and (c) the D/DBPR (59 FR 38668, July 29, 1994).
It is the ICR that is the subject of this final rulemaking.
The Negotiating Committee's development of the three proposed rules
was based on: (1) the need to take prudent immediate steps by proposing
a Stage 1 D/DBP rule and an interim ESWTR and (2) the need to develop
additional data through monitoring and research for future regulatory
decisions that would support refinements to the proposed interim ESWTR,
and development of the long-term ESWTR and Stage 2 D/DBP rule.
The information collected under this rule will be used to determine
the most effective regulatory option(s) to reduce exposure to
pathogens, disinfectants, and DBPs. All can have adverse effects on
human health. Over 200 million people will benefit from these rules
once they are fully effective. Preliminary estimates of the annual
benefits of the rules could be the avoidance of many cases of disease,
including as many as several thousand cancer cases and 500,000 cases of
giardiasis, and control of the parasite Cryptosporidium. Accordingly,
today's final rule, which requires this additional information, meets
the direction and objectives of the Negotiating Committee.
The ICR is designed to obtain both microbial and DBP occurrence,
exposure, and treatment data for input into the ESWTR and Stage 2 D/DBP
rule, as outlined below, and is expected to require the expenditure of
an estimated $130 million over three years by a segment of PWSs. The
commitment by the public water supply community to support this
collection of additional data is linked to EPA's commitment to provide
(1) adequate quality control procedures for collecting and managing the
information obtained under the ICR and (2) additional funding,
especially on health effects research, for properly interpreting ICR
data.
The Negotiating Committee also agreed that more data, especially
monitoring data, should be collected under the ICR to assess possible
shortcomings of the SWTR and to develop appropriate remedies, if
needed, to prevent increased risk from microbial disease as systems
begin complying with the Stage 1 D/DBP Rule. It was also agreed that
EPA would propose an interim ESWTR for systems serving at least 10,000
people that included a wide range of regulatory alternatives. Data
gathered under the ICR will form the basis for developing the most
appropriate criteria among the options presented in the proposed
interim ESWTR. Eventually a long-term ESWTR would include possible
refinements to the interim ESWTR and be applicable to all system sizes.
The interim and long-term ESWTR rules would become effective
concurrently with the requirements of the Stage 1 D/DBP rule for the
respective different system sizes.
The Negotiating Committee also agreed that additional data on the
occurrence of disinfectants, DBPs, and potential surrogates for DBPs;
source water and within-treatment plant conditions affecting the
formation of DBPs; and bench- and pilot-scale information on the
removal of DBP precursors would be useful for developing Stage 2 D/DBP
regulatory criteria beyond those currently being considered for
proposal in Stage 1. Additional data will be developed on potential
consumer exposures, acute short-term health effects, and chronic health
effects through a concurrent EPA-sponsored research program. These data
will support important decisionmaking that will be required when
promulgating the Stage 2 D/DBPR.

IV. Description of Today's Action

This preamble briefly summarizes the background of the ICR, the
major elements of the regulations, and the major changes from the
proposal. The proposed ICR (59 FR 6332, February 10, 1994) includes a
detailed discussion of the lengthy regulatory negotiation process that
led to the development of the ICR and is an essential part of the
record for the decisions made in this final action. While the
discussions from the proposed ICR are not generally repeated here, this
preamble occasionally cites the proposed rule where such references are
useful.
The purpose of the ICR is to establish specific data collection
requirements for PWSs and to identify the exact manner in which the
data are to be collected and transmitted to the Agency. Most of the
requirements are presented in the rule in tabular format, because of
the diverse characteristics of the PWSs subject to the ICR. EPA also
concluded that technical manuals would be the most efficient way of
communicating the detailed requirements of the ICR to those who are
actually responsible for implementing the regulations. These technical
manuals are incorporated by reference into the ICR. These manuals will
be sent by EPA to those PWSs subject to the requirements of the rule.
These technical manuals can also be obtained through the National
Technical Information Service.

A. New Terms (Sec. 141.140)

EPA has developed new definitions to address specific issues raised
by the ICR and to respond to commenters' questions concerning
applicability and monitoring requirements. The definitions in
Sec. 141.140 apply only to

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the regulatory requirements of this rule (i.e., 40 CFR Part 141,
subpart M).

B. General Applicability

Notice of Applicability (Secs. 141.142(c)(2)(i) and
141.143(c)(3)(i))
In Appendix B of the proposed ICR, EPA included lists of PWSs that
it expected would have to comply with at least some of the proposed ICR
requirements, based on the Agency's own data system, on the Water
Industry Data Base (WIDB), or both. EPA requested comment on the
accuracy of these lists. Based on public comments and input from EPA
regions and States, the Agency developed an updated list of PWSs that
are expected to comply with subpart M requirements. Each of these PWSs
will receive a Notice of Applicability. Upon receiving a Notice of
Applicability, a PWS must reply within 35 days, specifically
identifying the subpart M requirements that apply to each treatment
plant operated by the PWS. A PWS that believes that it does not meet
applicability criteria must so indicate in its response to EPA's Notice
of Applicability.
Although EPA has expended considerable effort to identify all of
the PWSs subject to subpart M, it is possible that an affected PWS may
not have been identified. Failure to receive a Notice of Applicability
does not relieve a PWS of its responsibility for compliance. A PWS that
meets the applicability requirements, but does not receive an EPA
Notice of Applicability, must contact the ICR Utilities Coordinator,
TSD, USEPA, 26 West Martin Luther King Drive, Cincinnati, OH 45268, so
the Agency can send the necessary materials.
Applicability Determinations
In order to account for both retail and wholesale populations
served by treated water produced by a PWS, and to determine specific
monitoring requirements for each treatment plant operated by the PWS,
each PWS subject to this regulation must calculate the population
served by its entire system and by each of its plants. To make these
calculations, the PWS must complete Appendix A to Sec. 141.141(a). A
PWS that serves no retail population is required to use an EPAdeveloped
equation to calculate the wholesale population that it serves
and determine applicability (Cummins, 1987). This equation, included in
Appendix A, was developed from hundreds of data points showing the
relationship between flow and population served.
For the ICR, a treatment plant includes any site where a
disinfectant or oxidant is added to the water prior to the water
entering the distribution system (e.g., a chlorinator at a well). A PWS
that uses multiple wells drawing from the same aquifer and has no
central treatment plant is considered to have one treatment plant for
those wells and must monitor accordingly.

C. Applicability of ICR Requirements to Specific Classes of PWSs

The following discussion identifies the ICR requirements that are
applicable to each class of PWSs covered by this final rule. Sections
D-G explain each of these requirements in greater detail.

PWSs Serving at Least 100,000 People and Using Surface Water, or
Ground Water Under the Direct Influence of Surface Water, as a Source
a. Monitoring for DBPs and Related Parameters
All PWSs in this class must monitor for DBPs, DBP precursors, and
other chemical parameters at specific locations throughout each
treatment plant operated by the PWS on a monthly basis for a period of
18 months. Such PWSs also must characterize treatment processes (e.g.,
filtration or sedimentation) monthly for the 18 month period. The only
exception to this requirement is that PWSs receiving all of their water
from a supplier and not further disinfecting that water at the entrance
to their distribution system are not required to conduct such
monitoring.
In addition, for each treatment plant that uses chloramines,
hypochlorite solution, ozone, or chlorine dioxide for treatment or
disinfection residual maintenance, a PWS must conduct an analysis of
parameters related to those disinfectants, such as cyanogen chloride
for PWSs that use chloramines. This additional monitoring must also be
conducted by PWSs that disinfect finished water at the entrance to
their distribution system and receive that water from a PWS that
treated the water with chloramines, hypochlorite solution, ozone, or
chlorine dioxide.
b. Monitoring for Disease-causing Microorganisms and Microbial
Indicators
Unless a PWS meets the requirements for reduced monitoring (as
described in section E), all PWSs in this class must: (1) monitor their
source water at the intake of each treatment plant that treats surface
water for Cryptosporidium, Giardia, total culturable viruses, total
coliforms, and fecal coliforms or Escherichia coli (E. coli); and (2)
monitor their finished water for these microorganisms when
Cryptosporidium and Giardia exceed 10 per liter in the source water, or
when total culturable virus levels exceed one per liter in the source
water.
c. Treatment Studies
i. Treatment Study Applicability (Total Organic Carbon (TOC))
Monitoring
All PWSs must monitor for TOC to determine at which treatment
plants they must conduct treatment studies. PWSs must conduct TOC
monitoring at the following locations:

--At the influent of each treatment plant that treats surface water and
serves a population of 100,000 people or more.
--On finished water at each treatment plant serving a population of
100,000 people or more and using ground water as the source.
--For PWSs that serve at least 100,000 people but have no individual
treatment plant serving 100,000 or more, PWSs must conduct TOC
monitoring at the treatment plant serving the largest population. PWSs
must monitor for TOC at the influent of the treatment plant if it
treats surface water and must monitor finished water if it treats
ground water.
ii. Bench- and Pilot-scale Treatment Studies
Unless a PWS qualifies for one of the exceptions discussed in
section F of this preamble, PWSs in this class must conduct bench- and/
or pilot-scale treatment studies to determine the effectiveness of
granular activated carbon (GAC) or membranes in reducing the levels of
DBP precursors.
2. PWSs Serving at Least 100,000 People, Using Only Ground Water as a
Source
a. Monitoring for DBPs and Related Parameters
All PWSs in this class must monitor for DBPs, DBP precursors, and
other chemical parameters at specific locations throughout each
treatment plant operated by the PWS on a monthly basis for a period of
18 months. Such PWSs also must characterize treatment processes (e.g.,
aeration or ion exchange) monthly for the 18 month period. The only
exception to this requirement is that PWSs receiving all of their water
from a supplier and not further disinfecting that water at the entrance
to their distribution system are not required to conduct such
monitoring.
In addition, for each treatment plant that uses chloramines,
hypochlorite solution, ozone, or chlorine dioxide for treatment or
disinfection residual

[[Page 24359]]

maintenance, a PWS must conduct an analysis of parameters related to
those disinfectants. This additional monitoring must also be conducted
by PWSs that disinfect finished water at the entrance to their
distribution system and receive that water from a PWS that treated the
water with chloramines, hypochlorite solution, ozone, or chlorine
dioxide.
b. Treatment Studies
i. Treatment Study Applicability (TOC) Monitoring
All PWSs must monitor for TOC to determine at which treatment
plants they must conduct treatment studies. PWSs must conduct TOC
monitoring at the following locations:

--On finished water at each treatment plant serving a population of
100,000 people or more and using ground water as the only source.
--For PWSs that serve at least 100,000 people but have no individual
treatment plant serving 100,000 or more, PWSs must conduct TOC
monitoring on finished water at the treatment plant serving the largest
population.
ii. Bench- and Pilot-scale Treatment Studies
Unless a PWS qualifies for one of the exceptions provided in
section F of this preamble, PWSs in this class must conduct bench- and/
or pilot-scale treatment studies to determine the effectiveness of
granular activated carbon (GAC) or membranes in reducing the levels of
DBP precursors.
3. PWSs Serving at Least 50,000 People, But Less Than 100,000, and
Using Ground Water as a Source
PWSs serving at least 50,000, but less than 100,000, (with at least
50,000 served by ground water) are required to monitor for TOC in the
finished water at the treatment plant serving the largest population.
Subsequently, unless a PWS qualifies for one of the exceptions provided
in section F, PWSs in this class must conduct bench- and/or pilot-scale
treatment studies to determine the effectiveness of granular activated
carbon (GAC) or membranes in reducing the levels of DBP precursors.

D. Disinfection Byproducts (DBPs) and Related Monitoring Requirements

General Monitoring (Secs. 141.141(c) and 141.142(a))
PWSs affected by this requirement must conduct monthly monitoring
for DBPs, DBP precursors, and other chemical parameters at each
treatment plant and in the distribution system. These PWSs will also be
required to characterize treatment processes (e.g., filtration and
sedimentation) in the treatment plant on a monthly basis for 18 months.
PWSs receiving all of their water from a supplier and not further
disinfecting that water at the entrance to the distribution system are
not required to conduct any monitoring under this rule.
Additional Monitoring Requirements for PWSs Using Chloramines,
Hypochlorite Solution, Ozone, or Chlorine Dioxide (Secs. 141.142(a)
(2)-(5))
For each treatment plant that uses chloramines, hypochlorite
solution, ozone, or chlorine dioxide for treatment or disinfection
residual maintenance, a PWS must also conduct an analysis of such
parameters as cyanogen chloride, chlorate, pH, temperature, free
residual chlorine, bromide, bromate, ammonia, and aldehydes. For
consecutive systems (i.e., PWSs receiving finished water from another
PWS), the receiving PWS must consult with the provider to ensure that
all such additional analyses are completed. For example, the rule
requires a PWS covered by the ICR that receives finished water that has
been treated with chlorine dioxide to conduct additional monitoring of
parameters such as chlorite, chlorate, chlorine dioxide residual, and
aldehydes. A PWS receiving finished water has the obligation to
determine whether the water it receives has been treated with
chloramines, chlorine dioxide, ozone, or hypochlorite solution and what
additional monitoring, if any, is required, and to conduct the
necessary monitoring.
Analytical Methods (Sec. 141.142(b))
For conducting the required analyses, PWSs are required to use the
methods specifically approved for subpart M. With the exception of
optional analyses for assimilable organic carbon (AOC) and
biodegradable organic carbon (BDOC), only results from laboratories
that have been approved by EPA to perform sample analyses for DBPs will
be acceptable. Laboratories may apply for approval under the provisions
of Sec. 141.142(b)(2).

E. Microbiological Monitoring Requirements

Monitoring (Secs. 141.141(d) and 141.143(a))
a. Source Water Monitoring
Microbiological monitoring requirements include monitoring for
disease-causing microorganisms, such as Cryptosporidium and Giardia,
total culturable viruses, and indicator organisms. To be eligible for
reduced monitoring, a PWS must notify EPA in its response to the EPA
Notice of Applicability of its plans to reduce monitoring, which is
available under the following provisions:

--A PWS may avoid the requirement to conduct finished water monitoring
of Cryptosporidium and Giardia (Sec. 141.143(a)(2)(iii)) by complying
instead with alternative monitoring requirements, including particle
counting at several locations within the treatment plant.
--A PWS may avoid virus monitoring (Sec. 141.143(a)(2)(iv)), if the PWS
has monitored for total coliforms, fecal coliforms, or E. coli in the
treatment plant influent for at least five days/week for any
consecutive six month period beginning January 1, 1994, and 90 percent
of all samples taken in that six-month period contain no greater than
100 total coliforms/100 milliliters (ml), or 20 fecal coliforms/100 ml,
or 20 E. coli/100 ml. For purposes of making this determination, PWSs
may use source water coliform data collected under the SWTR. EPA and
the Negotiating Committee agreed that raw waters that contained
densities of total coliforms, fecal coliforms, or E. coli lower than
the specified density value were unlikely to contain measurable levels
of viruses.
b. Finished Water Monitoring
PWSs must conduct finished water monitoring at any treatment plant
at which it detects, during the first 12 months of monitoring, 10 or
more Giardia cysts, or 10 or more Cryptosporidium oocysts, or one or
more total culturable viruses, per liter of water. The PWS must analyze
finished water samples for the same organisms analyzed for in source
water until 18 months of source water microbial monitoring are
completed.
c. Archiving
If either i or ii below occurs, PWSs must arrange to submit samples
of treatment plant influent and finished water to EPA for virus
archiving each month until the 18 months of microbial monitoring are
complete.
i. After the PWS learns that viruses were detected in any previous
sample of finished water.
ii. After the PWS learns that a density of at least 10 viruses per
liter was detected in any previous treatment plant influent sample.
2. Analytical Methods (Sec. 141.143(b))
PWSs are required to use the analytical methods approved for
subpart

[[Page 24360]]

M for pathogens and indicator organisms. In addition, systems are
required to use EPA-approved laboratories for analysis of Giardia,
Cryptosporidium, and total culturable viruses. As proposed, a PWS must
use laboratories certified for microbiology analyses under the EPA or
State drinking water program for the analysis of total coliforms, fecal
coliforms, and E. coli. Laboratory approval criteria for Giardia,
Cryptosporidium, and total culturable viruses are found in the ``ICR
Microbial Laboratory Manual'', EPA 600/R-95/178, April 1996.
Periodically, the Agency will update the list of EPA-approved
laboratories under this rule.

F. Disinfection Byproduct Precursor Removal Studies: Bench- and PilotScale
Treatment Studies and Treatment Study Applicability Monitoring

Determination of Treatment Study Requirements: Treatment Study
Applicability (TOC) Monitoring (Sec. 141.141(e) (2)-(3)
To determine which treatment plants will be required to conduct
bench- and/or pilot-scale testing, PWSs are required to conduct
treatment study applicability monitoring. Treatment study applicability
monitoring requires monitoring for TOC for 12 consecutive months. PWSs
must monitor for TOC in the influent of each treatment plant that
treats surface water and serves a population of 100,000 people or more.
For treatment plants serving a population of 100,000 people or more and
using ground water as the source, TOC monitoring must be conducted on
finished water. For PWSs that serve at least 100,000 people but have no
individual treatment plant serving 100,000 or more, TOC monitoring must
be conducted at the treatment plant serving the largest population.
PWSs serving at least 50,000, but fewer than 100,000 (with at least
50,000 served by ground water), are required to monitor finished water
TOC at the treatment plant serving the largest population. A PWS
operating multiple treatment plants using the same source is only
required to conduct one treatment study for those treatment plants.
Treatment Study Requirements (Sec. 141.144(b))
Treatment studies will consist of bench- and/or pilot-scale testing
systems for at least one of the two appropriate candidate technologies
(granular activated carbon (GAC) or membrane processes) for the
reduction of organic DBP precursors. The treatment studies must be
designed to yield representative performance data and to allow the
development of treatment cost estimates for different levels of organic
DBP control. To simulate the most likely treatment scenario, treatment
studies will need to be conducted with the effluent from the treatment
processes that are already in place to remove DBP precursors and TOC.
PWSs are required to conduct pilot-scale studies at treatment plants
serving 500,000 people or more and may conduct either bench- or pilotscale
studies at those serving fewer than 500,000.
a. Bench-scale Testing (Sec. 141.144(b)(1))
Bench-scale tests are continuous flow tests using the rapid small
scale column test (RSSCT) for GAC and either flat sheet or singleelement
bench test apparatus for membranes. Water to be used in benchscale
tests must be representative of water which would be applied to
the advanced treatment full-scale technology. The testing will include
the information specified in this rule and in the ``Manual for Benchand
Pilot-scale Treatment Studies'', EPA 814-B-96-003, April 1996. EPA
has provided utilities flexibility to select a bench-scale protocol
appropriate for its circumstances.
b. Pilot-scale Testing (Sec. 141.144(b)(2))
PWSs must conduct pilot-scale tests as continuous flow tests. For
GAC, the PWS must use GAC of a particle size representative of that
used in full-scale practice, a pilot GAC column with a minimum inner
diameter of 2.0 inches, and hydraulic loading rate (volumetric flow
rate/column cross-sectional area) representative of that used in fullscale
practice. For membranes, the PWS must use a staged array to
achieve a recovery of at least 75Pilot-scale testing must include
the information specified in this rule and in the ``Manual for Benchand
Pilot-scale Treatment Studies'', EPA 814-B-96-003, April 1996.
Treatment Study Exceptions (Secs. 141.141(e)(3) and
141.141(e)(7)(i))
PWSs that would otherwise be required to conduct a bench- and/or
pilot-scale treatment study are exempt from treatment study
requirements if they operate treatment plants that:

--Use chlorine as both the primary and residual disinfectant and have,
as an annual average, levels less than 40 micrograms per liter
(<greek-m>g/l) for THM4 and less than 30 <greek-m>g/l for HAA5. The
quarterly average is calculated by averaging results from all
individual distribution system samples taken during the quarter. The
annual average is calculated by averaging the four quarterly averages.
--Use surface water that does not exceed a TOC level of 4.0 milligrams
per liter (mg/l) in the treatment plant influent, when calculated by
averaging the 12 monthly TOC samples.
--Use ground water not under the direct influence of surface water that
does not exceed a TOC level of 2.0 mg/l in the finished water, when
calculated by averaging the 12 monthly TOC samples.
--Already use full-scale GAC or membrane technology. These PWSs must
submit full-scale plant data and data that show that the technology
effectively removes DBP precursors and must monitor the full-scale
process to comply with DBP and related monitoring requirements.
4. Joint Studies (Secs. 141.141(e)(4) and 141.141(e)(7)(ii))
PWSs that use common water resources and similar treatment trains
(e.g., conventional filtration treatment or softening) may conduct
joint treatment studies with other PWSs. A PWS operating more than one
treatment plant using similar treatment trains on the same source is
not required to conduct multiple studies. PWSs wishing to conduct joint
studies must submit a letter of intent to EPA signed by all PWSs
planning to participate in the study, as well as the additional
information specified in Sec. 141.141(e)(7)(ii) of the rule. Once all
applicability monitoring is complete, each PWS must formally apply for
EPA approval of a joint study. The minimum number and type of treatment
studies to be conducted in a joint study are specified in
Sec. 141.141(e)(4) of the rule.
5. Alternatives to Treatment Studies (Secs. 141.141(e)(5) and
141.141(e)(7)(iii))
In lieu of conducting a treatment study, a PWS may apply to EPA to
contribute funds to a cooperative research effort. The PWS must show in
its application to EPA that the treatment plant for which the waiver of
the treatment study is sought uses a common water resource which is
being studied by another PWS or a cooperative of PWSs. If EPA approves
the application, the PWS shall contribute funds for use in a dedicated
cooperative research program related to disinfectants, DBPs, and
enhanced surface water treatment. The mandatory contributions that must
be made under this option are as follows: $300,000 for a treatment
plant serving a population of 500,000 or more, and $100,000 for a
treatment plant serving a population of fewer than 500,000.

[[Page 24361]]

6. Grandfathered Studies (Secs. 141.141(e)(6) and 141.141(e)(7)(iv))
PWSs that have conducted studies of precursor removal using GAC or
membrane technology and which meet specified criteria may use the
results of those studies, if approved by EPA, in lieu of conducting
another treatment study. PWSs using grandfathered studies must submit
appropriate information on the earlier studies, such as data, study
description, equipment used, protocol, analytical methods, and
information to develop a full-scale cost estimate, and obtain EPA
approval.

G. Dates, Schedules and Reporting Requirements

EPA intends to notify PWSs that they are subject to this rule. PWSs
receiving a Notice of Applicability from EPA must respond within 35
days of receipt.

Sampling Plans (Sec. 141.141(f))
PWSs required to comply with subpart M requirements must submit
sampling plans to EPA for review and approval no later than eight weeks
after receiving sampling software and requirements from EPA. Once EPA
notifies the PWS that the plan has been approved, the PWS must begin
monitoring the following month.
Monitoring
PWSs must begin treatment study applicability monitoring (i.e., TOC
monitoring) no later than three months from the date the rule is
published in the Federal Register, regardless of whether the sampling
plan has been approved. For other applicable monitoring requirements, a
PWS must begin monitoring the month after receiving notice that the
PWS's sampling plan has been approved by EPA. If the PWS must conduct
both DBP and microbiological monitoring, the PWS must begin monitoring
for both in the same month.
Data Reporting (Secs. 141.142(c) and 141.143(c))
PWSs must submit monthly monitoring reports electronically on
diskettes in the format that EPA has prescribed and will be providing
to affected PWSs. This electronic reporting is necessary because of the
need for EPA to evaluate and manipulate the data.
Treatment Studies (Sec. 141.141(f)(4))
A PWS must begin treatment studies not later than 23 months from
the date that the ICR is published in the Federal Register. PWSs must
submit a report of each completed treatment study not later than 38
months after the final rule appears in the Federal Register.

H. Summary

Table IV-1 below provides a listing of the requirements contained
in today's rule cross-referenced to the section of the rule where each
requirement appears.

Table IV-1.--Summary of Subpart M Regulatory References

Subject DBP and related monitoring Microbiological monitoring Treatment studies

Definitions...................... Sec. 141.140......................... Sec. 141.140......................... Sec. 141.140
PWS applicability................ Sec. 141.141(b)...................... Sec. 141.141(b)...................... Sec. 141.141(b)

Treatment plant applicability.... Sec. 141.141 (b), (c)................ Sec. 141.141 (b), (d)................ Sec. 141.141 (b), (e)
Schedule......................... Sec. 141.141(f)(2)................... Sec. 141.141(f)(3)................... Sec. 141.141(f)(4)
Monitoring requirements.......... Sec. 141.142(a)...................... Sec. 141.143(a)...................... Sec. 141.144 (a), (b)

Analytical methods............... Sec. 141.142(b)...................... Sec. 141.143(b)...................... Sec. 141.144(c)
Reporting requirements........... Sec. 141.142(c)...................... Sec. 141.143(c)...................... Sec. 141.144(d)

V. Significant Changes to the Proposed Rule

In response to comments received during the public comment period,
EPA made many changes to the rule. All comments were evaluated, and EPA
has prepared a comment-response document that contains EPA's responses
to those public comments. That document, along with other documents
that support the rule, is available in the Drinking Water Docket. The
following sections provide a discussion of the most significant
comments considered.

A. Rule Applicability

The most far-reaching change in rule applicability was removing
PWSs serving 10,000 to 99,999 that use surface water from any ICR
requirements. EPA decided to take this action because the analytical
method for protozoan measurement had proven to be very complex and
difficult, and EPA was concerned about whether an adequate number of
laboratories would be able to meet the approval criteria, which include
passing a performance evaluation sample.
Many commenters noted that the DBP and related monitoring and
reporting required in the proposed rule were not applicable to their
PWS. These commenters believed that many of the proposed requirements
would not make sense based on the configuration or operational
practices of their PWS. During development of the ICR data system, EPA
held a number of public meetings with representatives of PWSs and
others to evaluate the applicability of the proposed requirements for
the universe of treatment plants. These meetings helped EPA to: (1)
Clarify the categories of PWSs that would appropriately be required to
meet the different requirements of the ICR and (2) clarify treatment
plant monitoring and data collection requirements. For example, the
Agency modified proposed rule language to include PWSs that sell or buy
large amounts of water in the appropriate applicability category. Also,
EPA has reorganized the rule to make it easier to find applicability
and monitoring requirements.
EPA has coordinated with the American Water Works Association
(AWWA) to form a group of technical experts that will be available to
PWSs to answer questions about this rule concerning applicability,
sampling plans, and monitoring. PWSs may contact these experts at 800-
200-0984 or on the Internet at 103327.2057@compuserve.com.

B. Data Quality Objectives

Several commenters noted that EPA did not clearly identify data
quality objectives for the large amount of data to be generated by this
rule. In response, EPA participated in several public workshops that
addressed this issue. During the workshops, statisticians, data
managers, scientists, and engineers reviewed the proposed requirements
to ensure that the data reporting is necessary and adequate to achieve
the goals of the rule. Also, EPA has developed a quality control
program to ensure that data used in modeling are appropriate for
regulatory development.

C. Data System

Commenters noted that EPA's data system for PWSs at the time of
proposal,

[[Page 24362]]

the Federal Reporting Data System (FRDS), was inadequate to handle and
manipulate the large amount of data that will be reported under this
rule. Commenters stated that the Agency needed to develop a new data
system that is able to receive, store, retrieve, manipulate, and
analyze data submitted by PWSs. Additionally, commenters noted that
once such a data system became available, EPA would have to test the
data system to ensure its smooth operation.
EPA used a contractor as the primary data systems developer for
this project. The contractor worked closely with EPA personnel and a
broad array of technical experts from drinking water suppliers and
other interested parties to understand the regulatory requirements,
develop data manipulation procedures and report capability, produce
adequate user instructions, and ensure the data system could perform
necessary data handling and manipulation.
The utility data system has undergone alpha, beta, and gamma
testing and revision and has been found to meet EPA's needs. Other data
systems, for laboratory quality assurance data and mainframe data
storage and manipulation, are undergoing similar testing and revision.
Testing and revision will be completed before data entry begins under
the rule.

D. Data Base Development

Many commenters stated that EPA, not PWSs, should fund the
development of a data base adequate to meet the objectives of the ICR
(i.e., determine what regulatory requirements are necessary for the
control of disinfectants, DBPs, and pathogens). Under section
1445(a)(1) of the Act, however, EPA is authorized to require PWSs to
conduct monitoring and provide information necessary to establish
drinking water regulations, including evaluating the health risks of
unregulated contaminants.
The information collected under this rule will enable EPA to
determine current occurrence levels and patterns for unregulated
contaminants. Because the ICR will provide EPA with detailed
information on what treatment PWSs already have in place and how well
such treatment processes work, the rule will also allow the Agency to
develop predictive models to evaluate the effect that various changes
in treatment will cause. Participants in the regulatory negotiation
process understood the importance of the data collection effort as it
relates to the objectives of the SDWA and agreed, as part of the
negotiation, to participate in the effort.

E. Protozoan Analytical Method

Many commenters expressed concern that EPA lacks an analytical
method to provide adequate quality data for Cryptosporidium. Also, some
commenters believed that the method that the Agency proposed was too
complex and difficult for reliable use by most laboratories. EPA has
taken several steps to address these concerns. The first was to
establish stringent laboratory approval criteria to assure adequate
quality analyses and ensure that data quality objectives are met. EPA
developed data quality objectives after consultation with outside
parties, including statisticians and microbiologists, to determine
minimum percentage recoveries and precision to meet data analytical
objectives (i.e., to characterize national occurrence of
Cryptosporidium for the purpose of conducting a regulatory impact
analysis). Based on performance evaluation testing of microbiological
laboratories, EPA believes that only laboratories that maintain high
standards will be able to comply with the EPA criteria.
In the ICR proposal, any PWS that treated surface water and served
a population of at least 10,000 would have been required to sample at
each treatment plant, with more sampling required for PWSs serving at
least 100,000. However, because only a small number of laboratories
would be available to analyze samples, EPA reduced the universe of PWSs
that must collect and analyze Cryptosporidium samples. In the final
rule, only PWSs that treat surface water and serve a population of at
least 100,000 are required to sample for Cryptosporidium. A PWS serving
fewer than 100,000 is not required to take any microbiological samples.
By reducing both the number of PWSs that are required to sample and the
number of samples that some of the remaining PWSs are required to take,
EPA expects that the number of laboratories who will qualify to conduct
testing will be able to handle the workload.
Since PWSs serving fewer than 100,000 people are no longer required
to conduct microbiological monitoring, EPA intends to conduct two
sample surveys to collect microbiological occurrence data at smaller
PWSs to determine the correlation with the data collected at PWSs
serving at least 100,000 people. These sample surveys will be conducted
at PWSs using surface water serving (1) 10,000 to 100,000 people and
(2) fewer than 10,000 people. A secondary purpose of these sample
surveys will be to collect occurrence data for areas where no PWSs will
be collecting microbiological occurrence data because there are no PWSs
serving at least 100,000 people that use surface water (e.g., the upper
Great Plains and Rocky Mountain area).
EPA has determined that the purposes of the ICR will not be
adversely affected by reducing the number of PWSs required to provide
data. In conjunction with requiring fewer samples, EPA has continued to
refine the analytical method and validate its accuracy and precision in
non-EPA laboratories. Results of field testing that used various source
waters in multiple laboratories indicate that a well-operated
laboratory will be able to exceed EPA's minimum recoveries. The field
testing results also indicate that well-operated laboratories will be
able to provide adequate data for deriving national occurrence data
that will be used in national cost estimates for evaluating different
ESWTR regulatory options. Depending on the criteria developed for the
interim ESWTR, data collected under the ICR may also be useful for
implementing the interim ESWTR. EPA further believes that analysis of
these data may aid in the identification of target indicators that
smaller PWSs using surface water can utilize for determining the level
of treatment needed for compliance with the ESWTR.
EPA believes that meaningful national occurrence data and
regulatory impact analyses for different ESWTR regulatory options can
be derived from ICR data if laboratories achieve, on average, greater
than an 8recovery for protozoan cysts. EPA simulation studies
indicated that if this laboratory performance is achieved, PWSs should
be able to detect and enumerate protozoa at least twice (among 18
monthly ICR raw water samples) at most sites where protozoa are
actually present. This level of occurrence, with use of a
statistically-derived adjustment factor for estimating true protozoan
concentrations from measured values, would enable EPA to estimate the
number of systems, nationally, that require different levels of
treatment to achieve a desired finished water concentration, as might
be prescribed under the ESWTR. Such an analysis, together with
treatment cost and performance information for various technologies,
would allow EPA to estimate national costs for different ESWTR
regulatory options. Also, samples in which Cryptosporidium are not
detected will help EPA evaluate the extent to which analyzable sample
volume and percent recovery affect the ability to quantify source water
protozoan concentrations. Such information will help EPA evaluate the

[[Page 24363]]

extent to which the protozoan method may need to be improved, or
special monitoring provisions adopted, to enable appropriate treatment
requirements to be prescribed for all systems under the ESWTR. For
example, depending upon the extent which better methods can be
developed for implementation of the ESWTR, utilities may be able to
increase the number of raw water samples collected (beyond the minimum
that may be required) to enable more sensitive quantification of source
water concentrations, and more accurate level of treatment requirement
estimates.
To provide for higher quality data to estimate national occurrence
and conduct a national regulatory impact analysis, EPA is prescribing
stringent laboratory approval criteria specific to the ICR. For a
laboratory to qualify for conducting protozoan analysis, it must (a)
conduct a comprehensive inventory to ensure the extensive equipment and
personnel requirements are met, (b) employ at least one principal
analyst (with previous experience of having analyzed at least 100
samples using the IFA procedure) to verify all microscopic counts, (c)
pass an on-site inspection that includes observation of the analysis
being performed by the laboratory, and (d) achieve sufficient recovery
and precision on PE samples provided by EPA. EPA does not normally
undertake the actions noted in (a) through (c) as part of laboratory
approval and will require more frequent PE samples (in d)) than usual.
EPA intends to provide technical assistance to laboratories during the
laboratory approval process to enhance laboratory performance.
While performance by ICR approved laboratories should be adequate
for conducting national regulatory impact analysis, EPA believes that
better method performance, and knowledge of how that performance varies
for specific water qualities, will be needed for individual PWSs to
comply with future rules. To address this issue, EPA is conducting
research to improve method performance. In the short term, EPA is
evaluating the extent to which the IFA method can be improved, focusing
mainly on the effects of different filters and smaller raw water sample
volumes. In the long term, as part of its five year research plan, EPA
is attempting to develop new methods that can achieve better recovery
and precision, and distinguish whether the oocysts that are detected
are alive or infectious to humans. Many researchers outside of EPA are
also involved with these efforts.
One shortcoming of PE samples is that they do not reproduce the
full range of sampling or water quality conditions of ICR monitoring.
To augment the ICR, EPA will conduct a sample survey of 50 PWSs serving
100,000 to measure Cryptosporidium under tightly controlled laboratory
conditions. Only those Cryptosporidium data from the ICR which meet
data quality objectives will be used, with EPA survey data, in a cost
analysis. EPA believes it appropriate to require Cryptosporidium data
under the ICR because: (1) the incremental cost of its inclusion is low
(since the same method and sample is used for Giardia), (2) a
sufficient number of laboratories are expected to meet the data quality
objectives, (3) the more experience laboratories have with the method,
the better their performance should be, and (4) through subsequent
testing, an adjustment factor can be generated to improve the utility
of ICR-generated protozoan data.

F. Other Changes

Other changes to the rule include requiring all systems taking
samples for microorganisms to also collect a full 18 months of virus
samples (with no provisions for reduced monitoring), unless a system
meets certain source water quality criteria. EPA is concerned about the
possibly significant variability in the virus density over time.
Therefore, the final rule eliminates the provision that allowed a PWS
to avoid further virus sampling if no viruses were found during the
first 12 months of sampling.
EPA decided not to include Clostridium perfringens and coliphage in
the list of microbial parameters to evaluate their potential use as
indicators. EPA was not confident that a valid laboratory approval and
performance evaluation process could be implemented and believes that
evaluation of indicators could be better accomplished under a separate
research project. EPA will allow particle counting in lieu of finished
water Cryptosporidium and Giardia monitoring, in order to develop data
to evaluate the usefulness of particle counting as a surrogate for
Cryptosporidium and Giardia removal.
The ICR also will require PWSs to submit treatment plant influent
and finished water samples for virus archiving under certain
conditions. EPA will use these samples to conduct research on
occurrence and treatment for specific viruses.
EPA has also added an additional analytical method (Standard Method
4500-Cl B) for determining free chlorine concentration in hypochlorite
stock solutions. A commenter pointed out that this method is able to
determine concentrations at much higher levels than the proposed
methods, reducing the need for large dilutions and their associated
potential for error. Because this method is not sensitive at
concentrations typically found in drinking water, its use is restricted
to analyses of hypochlorite solutions. Other approved analytical
methods may be used for any required free chlorine analyses, including
hypochlorite solutions.

G. Other Changes Considered

EPA also received comments on several other requirements that,
after evaluation, were not changed in the final ICR. One such comment
addressed the provision in the proposed rule to limit analyses of
cyanogen chloride and aldehyde to the EPA laboratory. Some commenters
disagreed with EPA's decision to limit cyanogen chloride and aldehyde
analyses to the EPA laboratory. Since EPA did not believe that it could
have developed performance evaluation samples and implemented a
laboratory approval program in the period of time that the Agency
believed it had available between proposal and promulgation, EPA's
laboratory will continue to be the only laboratory to analyze these
samples under the final rule. EPA believed that the following issues
could not be resolved in time: (1) the standard for cyanogen chloride
may not be stable for more than a few weeks and (2) the methods are not
simple (both require highly skilled analysts and must be analyzed
within 48 hours; aldehyde analysis is subject to contamination). The
EPA laboratory will provide sample containers and will not charge PWSs
for these analyses.

VI. State Implementation

The February 10, 1994, notice proposed that EPA, rather than
States, administer this rule. Many commenters believed that States
should be involved in the ICR and should be given primary enforcement
responsibility (primacy). Among their reasons were: States have more
experience with local conditions; administration of drinking water
rules by more than one party will cause confusion and contradictions
and would be cumbersome; it sends a message that the public water
system supervision program is not fully delegated; it would increase
noncompliance; it would not allow systems to use State waivers; State
administration would allow for local support and training and
facilitate corrective action; and EPA is not authorized to confer
partial primacy under the SDWA.
The rationale for proposing that EPA administer the ICR was that
this rule,

[[Page 24364]]

unlike other drinking water rules, is an information-gathering effort
of a limited duration, and the time constraints for implementing this
rule would strain State resources. The Negotiating Committee, including
the member representing State drinking water agencies, concurred on
this point during the regulatory negotiation. Some commenters agreed,
indicating that States should not administer the program. At least one
commenter remarked that States do not have the time or resources to
meet the ambitious ICR schedule.
EPA continues to believe that the short times involved with this
rule make it imperative that the Agency administer the rule. While some
States might be able to put all necessary mechanisms for rule
implementation (including regulatory authority and laboratory approval)
into place in the short-term (three months after promulgation), most
would not. EPA also believes that data such as these, which are to be
used for regulatory development (rather than for compliance) needs
national standardization to maximize the data's usefulness. To ensure
coordination with other implementation activities, EPA will be sharing
data with the States and will inform the States about any enforcement
actions the Agency intends to take to implement this rule.

VII. Cost of Rule

The ICR is estimated to result in national costs of $129 million,
with a range of $117 to $148 million, to be expended over a three year
period. Since this cost does not exceed $100 million per year, it does
not qualify as a ``major rule'' for purposes of Executive Order 12866,
or for the purposes of the Unfunded Mandate Reform Act of 1995. EPA has
prepared an economic impact analysis which establishes that this action
would not be a major rule within the meaning of the Executive Order. A
copy of this analysis is available in the docket. This analysis has
been submitted to the Office of Management and Budget for review. The
following is a summary of the cost estimates for implementation of this
rule.

A. Cost Estimates for Final ICR as Compared to the Proposed ICR

The range of the final total ICR cost estimates are exactly the
same as the range of cost estimates in the proposed rule. Comparisons
between the costs of the proposed rule and the costs of the final rule
are not straightforward, however, due to a number of factors. Some of
these factors resulted in higher cost estimates for some components of
the final rule, while other factors resulted in lower cost estimates
for various components of the final rule. The major factors which
resulted in changes to the final cost analysis include the following
items.

Decreases in the Final ICR Cost Estimates
The original cost estimates for DBP monitoring were found to have
been over-estimated in the proposed ICR due to a flawed assumption
regarding the number of treatment sites that systems using ground water
would be required to monitor. The proposed rule assumed that DBP
monitoring would be conducted at every treatment site within a ground
water system. The cost estimate in the final rule, however, more
realistically assumes that ground water systems will be required to
conduct DBP sampling at two treatment sites representing different
aquifers. This revised assumption reduced costs by $30 million. The
cost estimate for the final ICR also reflects the elimination of
microbial monitoring requirements for PWSs that serve fewer than
100,000 people.
Increases in the Final ICR Cost Estimates
The final rule cost estimates for DBP monitoring for surface water
systems show an increase of $11 million. This increase reflects a
number of revised assumptions including: changes regarding the number
of samples actually required by the monitoring requirements; a deeper
appreciation of the complexity of some treatment trains (an issue which
was brought to light during the development of the ICR data management
system); and the inclusion of some purchased water systems that redisinfect.

In addition, numerous unit cost assumptions within the analysis
were revised upwards to reflect public comments. Most notably, the
startup costs, microbial monitoring costs, and data reporting costs
were increased, taking into account information received from
commenters on the analysis accompanying the proposed rule.
3. Uncertainty
These national cost estimates have an inescapable range of
uncertainty associated with them. A sensitivity analysis performed in
response to public comments as part of the revised economic impact
analysis indicates that the greatest source of uncertainty is the cost
of the pilot- and bench-scale treatment studies. These studies were
estimated to cost $57 million in the proposed rule, with high and low
bounds of $76 and $45 million. In the final rule, EPA has retained the
original cost estimates and accompanying ranges for the cost of benchand
pilot-scale treatment studies. EPA has also finalized an option for
utilities to contribute to a research fund in lieu of conducting pilotand
bench-scale testing to reduce any possible duplication of effort
and possibly reduce costs to the PWS. The net effect of this option on
total costs is unpredictable. It is clear, however, that the pilot- and
bench-scale testing will remain the largest and most uncertain element
of the total cost.

B. Total Cost and Burden Estimates for the Final ICR

The total estimated cost of $129 million for the final ICR is
indicated in the third column of Table VII-1. The following five
elements contribute to the total cost:

BILLING CODE 6560-50-P

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Start-up Activities (Sec. 141.141)
Start-up activities are estimated to cost a total of $7.6 million.
This estimate has been revised upward from the original cost estimate
of $515,000 in the proposed ICR to reflect public comments. Start-up
activities consist of reading and understanding the requirements of the
rule, determining applicability and evaluating treatment plants to
determine specific sampling requirements for each treatment plant,
preparing sampling plans, and installing and learning to operate
computer software to report monitoring results. Start-up costs will be
spread across an estimated 422 community water systems, resulting in an
average cost of $18,000 per system.
Microbiological Monitoring (Sec. 141.143)
Microbial monitoring, which is estimated to apply to 440 plants in
233 community surface water systems serving at least 100,000 people, is
estimated to cost $17.2 million. The average cost per plant is
estimated to be $39,000.
DBP and Related Monitoring (Sec. 141.142)
DBP monitoring is estimated to apply to 292 surface and ground
water community water systems that purchase none, or only a portion, of
their water and serve at least 100,000 people. DBP monitoring is also
estimated to apply to an additional 24 community water systems that
purchase all their finished water and disinfect that water prior to
distribution, and serve at least 100,000 people. DBP monitoring is
estimated to cost $37.5 million nationally, resulting in average costs
of $50,000 per treatment site for ground water systems and $69,000 per
treatment site for surface water systems.
This estimate is approximately $20 million less than the estimate
presented in the preamble to the proposed rule due to a flawed
assumption (discussed above) regarding the number of treatment sites
that PWSs using ground water would be required to monitor. The analysis
accompanying the proposed rule assumed that DBP monitoring would be
conducted at every treatment site within a ground water system (a total
of 1,295 sites in 59 ground water systems). The present analysis,
however, more realistically assumes DBP sampling at two treatment sites
per system (a total of 118).
Electronic Data Reporting (Secs. 141.143 and 141.142)
The ICR requires monthly electronic reporting of microbial
monitoring results and DBP monitoring results along with various
process parameters of water treatment processes related to microbial
treatment and DBP formation. The total cost is estimated to be $9.4
million nationally, with an average cost of $14,000 per treatment
plant. This estimate compares to $3.9 million estimated in the proposed
rule.
TOC Monitoring and Bench- and Pilot-Scale Treatment Studies
(Sec. 141.144)
Required TOC monitoring and bench- and pilot-scale treatment
studies are estimated to have a total national cost of $57 million,
with a range of $45 million to $75 million. For each treatment study,
costs are estimated to range from $150,000 to $750,000. This
requirement applies, with some exceptions, to all surface water
treatment plants serving at least 100,000 persons (or the largest
treatment plant in the PWS if no single treatment plant serves at least
100,000) that have an influent TOC concentration greater than 4 mg/l.
It also applies to all ground water treatment plants serving at least
100,000 persons (or the largest treatment plant in the PWS if no single
treatment plant serves at least 100,000) that have a finished water TOC
concentration greater than 2 mg/l, or to the largest ground water
treatment plant in PWSs serving 50,000 to 99,999 (with at least 50,000
served by ground water), if that treatment plant has a finished water
TOC concentration greater than 2 mg/l.

VIII. Other Statutory Requirements

A. Executive order 12866

Under Executive Order 12866, (58 FR 51735, October 4, 1993) 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 or entitlements, grants,
user fees, or loan programs or the rights and obligations of the
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'' within
the meaning of the Executive Order. 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.

B. Regulatory Flexibility Act

The Regulatory Flexibility Act requires EPA to explicitly consider
the effect of proposed regulations on small entities. The Act requires
EPA to consider regulatory alternatives if a rule has a significant
economic impact on a substantial number of small entities. The Small
Business Administration defines a small water utility as one which
serves fewer than 3,300 people.
This Final Rule is consistent with the objectives of the Regulatory
Flexibility Act because it will not have any economic impact on any
small entities. The rule only applies to PWSs serving more than 50,000
people; thus, PWSs serving fewer than 50,000 people would not be
affected. Therefore, pursuant to section 605(b) of the Regulatory
Flexibility Act, 5 U.S.C. 605(b), the Administrator certifies that this
rule will not have a significant economic impact on a substantial
number of small entities.

C. Paperwork Reduction Act

The information collection requirements in this rule have been
submitted for approval to the Office of Management and Budget (OMB)
under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An
Information Collection Request document has been prepared by EPA (ICR
No. 270.35) and a copy may be obtained from Sandy Farmer, OPPE
Regulatory Information Division, U.S. Environmental Protection Agency
(2136), 401 M Street SW., Washington, DC 20460 or by calling (202) 260-
2740. The information requirements are not effective until OMB approves
them.
Public burden for this collection of information is estimated to
total 1,344,146 hours, about 200,794 more than estimated in the
proposed rule, reflecting public comments on the previous analysis.
There are five elements contributing to the total burden estimate, as
detailed in Table VII-1. The total burden associated with start-up
activities is estimated to be 188,700 hours. The total burden
associated with microbial monitoring is estimated to be 175,923 hours
(Sec. 141.143). Total burden for DBP monitoring is estimated to be
291,209

[[Page 24367]]

hours (Sec. 141.142). Total burden for the process data reporting
requirement is estimated to be 308,677 hours (Secs. 141.142 and
141.143). Total burden associated with the bench- and pilot-scale
treatment study requirement is estimated to be 379,636 hours
(Sec. 141.144).
The annual public reporting and recordkeeping burden for this
collection of information is estimated to average 1.42 hours per
response and 1,062 hours per respondent. This estimate 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 respond to a collection of
information; search existing data sources; complete and review the
collection of information; and transmit or otherwise disclose the
information.
No person is 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 displayed in 40 CFR Part 9.
Send comments regarding the burden estimate or any other aspect of
this collection of information, including suggestions for reducing this
burden to Director, OPPE Regulatory Information Division, U.S.
Environmental Protection Agency (2136), 401 M Street SW., Washington,
DC 20460; and to the Office of Information and Regulatory Affairs,
Office of Management and Budget, 725 17th Street NW., Washington, DC
20503, marked ``Attention: Desk Officer for EPA.'' Include the ICR
number in any correspondence.

D. Enhancing the Intergovernmental Partnership

As described in greater detail in the preamble to the proposed ICR,
EPA used a negotiated rulemaking process to develop the regulatory
approach to the problems associated with disinfection. The Negotiating
Committee included representatives of:

--Local public health, drinking water supply, and elected officials;
and
--State public health, regulated utilities commissioners, and drinking
water program officials.

Committee members were supported by other program and financial
officials and Washington-based association directors (e.g., Association
of State Drinking Water Administrators, National League of Cities) both
during meetings and between meetings of the Committee. Also, EPA made
documents publicly available and associations distributed them to
interested members.
During evaluation of public comments and development of the final
requirements, EPA held several public meetings to discuss monitoring
requirements, the data management system, applicability, and data
quality objectives.

E. Unfunded Mandates Reform Act

Section 201 of the Unfunded Mandates Reform Act of 1995 (``Unfunded
Mandates Act''), signed into law on March 22, 1995, requires each
agency, unless prohibited by law, to assess the effects of federal
regulations on State, local, and tribal governments and the private
sector. Under Section 202 of the Unfunded Mandates Act, EPA must
prepare an unfunded mandate statement to accompany any proposed rule
where the estimated costs to State, local, or tribal governments, or to
the private sector, will be $100 million or more in any one year. Under
Section 205, EPA must select the most cost-effective or least
burdensome alternative that achieves the requirements for actions
covered by Section 202, or explain why this was not possible. Section
203 requires EPA to establish a plan for informing and advising any
small governments that may be significantly affected by the rule.
The unfunded mandate statement under Section 202 must include: (1)
A citation of the statutory authority under which the rule is proposed,
(2) an assessment of the costs and benefits of the rule and the federal
resources available to defray the costs, (3) where feasible, estimates
of future compliance costs and disproportionate impacts upon particular
geographic or social segments of the nation or industry, (4) where
relevant, an estimate of the effect on the national economy, and (5) a
description of EPA's prior consultation with State, local, and tribal
officials.
Since this rule is not estimated to impose annual costs of $100
million or more on either State, local, or tribal governments, or on
the private sector, EPA is not required to prepare an unfunded mandate
statement. Because the rule only applies to PWSs serving at least
50,000 persons, no small governments are affected.

F. Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA)

For the purposes of Congressional review, OMB has determined that
this rule is not major under SBREFA. Therefore, this rule is effective
35 days after publication.

IX. References

APHA. 1995. American Public Health Association. ``Standard methods for
the examination of water and wastewater'' (19th ed.). Washington, DC.
AWWA. 1991. ``Guidance manual for compliance with the filtration and
disinfection requirements for public water systems using surface water
sources.'' American Water Works Association, Denver, CO.
Cummins, Michael D. Memorandum to Stephen Clark titled ``Average Flow
and Design Capacity for Technologies and Cost Documents.'' October 5,
1987.
EPA. U.S. Environmental Protection Agency. April 1996. ``ICR Comment
Response Document'', EPA 811-R-96-001.
EPA. U.S. Environmental Protection Agency. April 1996. ``ICR Sampling
Manual'', EPA 814-B-96-001.
EPA. U.S. Environmental Protection Agency. April 1996. ``DBP/ICR
Analytical Methods Manual'', EPA 814-B-96-002.
EPA. U.S. Environmental Protection Agency. April 1996. ``ICR Microbial
Laboratory Manual'', EPA 600/R-95/178.
EPA. U.S. Environmental Protection Agency. April 1996. ``ICR Manual for
Bench- and Pilot-scale Treatment Studies'', EPA 814-B-96-003.
EPA. U.S. Environmental Protection Agency. April 1996. ``Reprints of
EPA Methods for Chemical Analyses under the Information Collection
Rule'', EPA 814-B-96-006.
EPA. U.S. Environmental Protection Agency. April 1996. ``ICR Water
Utility Database System Users' Guide'', EPA 814-B-96-004.

List of Subjects in 40 CFR Part 141

Administrative practice and procedure, Analytical methods,
Chemicals, Incorporation by reference, Intergovernmental relations,
Microorganisms, Monitoring, National Primary Drinking Water
Regulations, Reporting and recordkeeping requirements, Water supply.

Dated: May 1, 1996.
Carol M. Browner,
Administrator.

For the reasons set out in the preamble, part 141 of title 40 of
the Code of Federal Regulations is amended as follows:

[[Page 24368]]

PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS

The authority citation for part 141 continues to read as
follows:

Authority: 42 U.S.C. 300f, 300g-1, 300g-2 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9.

2. Section 141.2 is amended by adding ``or PWS'' to the definition
for ``Public water System'' to read as follows:

Sec. 141.2 Definitions.

* * * *
Public water system or PWS * * *
* * * *
Section 141.6 is amended in paragraph (a) by revising the
reference ``(a) through (h)'' to read ``(a) through (i)'' and by adding
paragraph (i) to read as follows:

Sec. 141.6 Effective dates.

* * * *
(i) Regulations for information collection requirements listed in
Subpart M are effective August 14, 1996, and shall remain effective
until December 31, 2000.
A new Subpart M is added consisting of Secs. 141.140 through
141.144 to read as follows:

Subpart M--Information Collection Requirements (ICR) for Public
Water Systems

Sec.
141.140 Definitions specific to subpart M.
141.141 General requirements, applicability, and schedule for
information collection.
141.142 Disinfection byproduct and related monitoring.
141.143 Microbial monitoring.
141.144 Disinfection byproduct precursor removal studies.

Subpart M--Information Collection Requriements (ICR) for Public
Water Systems

Sec. 141.140 Definitions specific to subpart M.

The following definitions apply only to the requirements of subpart
M of this part and are arranged alphabetically.
Distribution system means the components of a PWS that are under
the control of that PWS located after the point where the finished
water sample is taken and that provide distribution, storage, and/or
booster disinfection of finished water.
Distribution System Equivalent (DSE) sample means a sample
collected from the distribution system for the purpose of comparing it
with the ``simulated distribution system (SDS) sample''. The DSE sample
shall be selected using the following criteria:
(1) No additional disinfectant added between the treatment plant
and the site where the DSE sample is collected;
(2) Approximate detention time of water is available; and
(3) There is no blending with finished water from other treatment
plants.
Entry point to distribution system means a location following one
or more finished water sample points but prior to the beginning of the
distribution system.
Finished water means water that does not undergo further treatment
by a treatment plant other than maintenance of a disinfection residual.
Haloacetic acids (five) (HAA5) means the sum of the concentration
in micrograms per liter of the haloacetic acids mono-, di-, and
trichloroacetic acid; mono-, and di-, bromoacetic acid, rounded to two
significant figures.
Haloacetic acids (six) (HAA6) means the concentration in micrograms
per liter of the haloacetic acids mono-, di-, and trichloroacetic
acid; mono-, and di- bromoacetic acid; and bromochloroacetic acid,
rounded to two significant figures.
Haloacetonitriles (HAN) means the concentration in micrograms per
liter of the haloacetonitriles dichloro-, trichloro-, bromochloro-, and
dibromo- acetonitrile, rounded to two significant figures.
Haloketones (HK) means the concentration in micrograms per liter of
the haloketones 1,1-dichloropropanone and 1,1,1- trichloropropanone,
rounded to two significant figures.
Intake means the physical location at which the PWS takes water
from a water resource. Thereafter, the water is under the control of
that PWS.
Notice of applicability means a notice sent by EPA to a PWS that
indicates that EPA believes that the PWS must comply with some or all
requirements of subpart M. The PWS is required to reply to this notice
by providing information specified in the notice (e.g., retail and
wholesale population served, types of water sources used, volume of
water treated) by the date provided in subpart M.
Process train means some number of unit processes connected in
series starting from the treatment plant influent and ending with
finished water. A particular unit process may be in more than one
process train.
Purchased finished water means finished water purchased by one PWS
from another PWS (the wholesaler). Purchased finished water includes
both purchased finished water that is redisinfected and purchased
finished water that is not.
Simulated distribution system (SDS) sample means a finished water
sample incubated at the temperature and detention time of a ``DSE
sample'' collected from the distribution system. Analytical results of
the SDS sample will be compared with the DSE sample to determine how
well the SDS sample predicts disinfection byproduct formation in the
actual distribution system sample.
Total finished water means the flow (volume per unit of time) of
finished water obtained from all treatment plants operated by a PWS and
includes purchased finished water. This flow includes water entering
the distribution system and water sold to another PWS.
Treatment plant means the PWS components that have as their
exclusive source of water a shared treatment plant influent and that
deliver finished water to a common point which is located prior to the
point at which finished water enters a distribution system or is
diverted for sale to another PWS. For these components of the PWS to be
considered part of one treatment plant, the PWS must be able to collect
one representative treatment plant influent sample, either at a single
sample point or by a composite of multiple influent samples, and there
must exist a single sampling point where a representative sample of
finished water can be collected. For the purpose of subpart M, a
treatment plant is considered to include any site where a disinfectant
or oxidant is added to water prior to the water entering the
distribution system. Facilities in which ground water is disinfected
prior to entering a distribution system, and facilities in which
purchased finished water has a disinfectant added prior to entering a
distribution system, are considered treatment plants.
Treatment plant influent means water that represents the water
quality challenge to a particular plant.
Treatment system means all treatment plants operated by one PWS.
Trihalomethanes (four) (THM4) means the sum of the concentration in
micrograms per liter of the trihalomethanes chloroform,
bromodichloromethane, dibromochloromethane, and bromoform, rounded to
two significant figures.
Unit process means a component of a treatment process train which
serves any treatment purpose such as mixing or sedimentation for which
design and operating information is requested in Sec. 141.142(a), Table
6c, of this subpart.
Water resource means a body of water before it passes through an
intake structure. Examples of a water resource

[[Page 24369]]

include a river, lake, or aquifer. For a PWS which purchases finished
water, the water resource is the wholesale PWS which supplies the
purchased finished water. Generally water resources are not under the
direct control of a PWS.
Watershed control practice means protection of a water resource
from microbiological contamination prior to the water entering an
intake. These protective measures might include, but are not limited
to, a watershed control program approved under Sec. 141.71(b)(2) of
this part, or land use restrictions.

Sec. 141.141 General requirements, applicability, and schedule for
information collection.

(a) General requirements. (1) The purpose of subpart M is to
collect specified information from certain PWSs for a limited period of
time. Accordingly, subpart M is of limited duration and is effective
for a defined period (see Sec. 141.6 (i) and Sec. 141.141(e) of this
part). Since subpart M does not establish continuing obligations, a PWS
that has completed all of its requirements at the required duration and
frequency may discontinue its information collection efforts even if
subpart M is still in effect.
(2) For the purpose of this subpart, a PWS shall make applicability
determinations based on completion of data gathering, calculations, and
treatment plant categorization specified in Appendix A to paragraph (a)
of this section.
(3) For the purpose of this subpart, a PWS that uses multiple wells
drawing from the same aquifer and has no central treatment plant is
considered to have one treatment plant for those wells and shall
conduct required monitoring under this specification. A PWS with
multiple wells in one or more aquifers that are treated in the same
treatment plant is considered to have one treatment plant for those
wells and shall conduct required monitoring under this specification.
(i) To the extent possible, the PWS should sample at the well with
the largest flow and at the same well each month for the duration of
required monitoring.
(ii) A PWS must report information from Sec. 141.142(a) Tables 6a
through 6e of this subpart for each well that the PWS sampled.
(4) For the purpose of this subpart, a PWS shall treat ground water
sources that have been classified by the State as under the direct
influence of surface water by May 14, 1996, as surface water sources. A
PWS shall treat ground water sources that either have not been
classified by the State (as under the direct influence of surface water
or not) or have been classified by the State as ground water, by May
14, 1996, as ground water sources.

Appendix A to 40 CFR 141.141(a)

Purpose. The purpose of this appendix is to enable the PWS to
assign proportional amounts of its retail and wholesale population
served to specific treatment plants. The PWS shall then use these
values to determine which specific requirements in subpart M that it
must comply with and on what schedule.
Period of applicability determination. For the purpose of this
appendix, a PWS shall make applicability determinations based on
population calculated as annual averages based on PWS records of
treatment system or treatment plant operation during calendar year
1995.

--If a natural disaster made a treatment system or treatment plant
inoperable for one or more calendar months in 1995, the
applicability determination will be based on those months in 1995
during which the treatment system or treatment plant was in
operation, plus the calendar months from 1994 that are
representative of those months of 1995 during which the treatment
system or treatment plant was inoperable. The total time period
shall be 12 months.
--If the treatment system or treatment plant was not in operation
during one or more calendar months during 1995 due to a seasonal
reduction in demand for finished water, the months that the
treatment system or treatment plant was not in operation are to be
included in the 12 months of applicability determination with zero
flow indicating no operation.
--If the treatment system or treatment plant was not in operation
for one or more calendar months in 1995 due to construction and/or
maintenance, the applicability determination will be based on those
months in 1995 during which the treatment system or treatment plant
was in operation, plus the calendar months from 1994 that correspond
to those months of 1995 during which the treatment system or
treatment plant was inoperable. The total time period shall be 12
months.
--Treatment systems or treatment plants whose total operational
lifetime is fewer than 12 calendar months as of December 1995 are
not required to comply with subpart M requirements.
--PWSs that purchase all their water from one or more other PWSs and
do not further treat any of their water are not required to comply
with subpart M requirements.

Applicability determination. To determine applicability, the PWS
is required to collect certain operational data and perform
specified mathematical operations. All operational data and
calculated values will be expressed as either ``F'' (for flow) or
``P'' (for population), with a one or two character subscript. Table
A-1 contains a more detailed explanation.

Table A-1.--: Appendix A Subscript Identification Protocol

General.

``F'' indicates a flow value. The PWS must use million gallons per
day (MGD) to express the flow throughout its calculations.
``P'' indicates a population value, expressed as a number of people.
Subscripts.
``P<INF>R'' is retail population, ``F<INF>W'' is wholesale flow, and ``F<INF>N'' is
purchased finished water that is not further treated.
Each ``F'' value (in Table A-2) or ``P'' value (in Table A-4) will
have a two character designator.
a. The first character in the subscript indicates the source type.
Possible entries are ``S'' (for surface water or ground water under
the direct influence of surface water), ``G'' (for ground water not
under the direct influence of surface water), ``P'' (for finished
water purchased from another PWS and further treated at the
entrance to the distribution system, such as by redisinfection),
and ``C'' (for combined, or the sum of all water treated by the
PWS, including purchased water that is further treated at the
entrance to the distribution system).
b. The second character in the subscript indicates the specific
identification of the treatment plant. This will be a number (e.g.,
1, 2, 3, * * *, with # being a non-specific designator) and ``T''
(for a Total).

[[Page 24370]]

Data from operational records. The PWS shall determine the
following information based on operational records.
--P<INF>R=Retail population served by the PWS
=________ (number of people)
--F<INF>N=treated water bought from one or more other PWSs and not
further treated at the entry point to the distribution system
=________ (MGD)
--F<INF>W= finished water sold to one or more other PWSs, regardless
of whether buying PWSs further treat the finished water
=________ (MGD)

--Flows from specific water resources to specific treatment plants.
For each treatment plant operated by the PWS, the PWS must determine
the flow from each water resource that provides water to the
treatment plant. In the following table, the PWS must enter flow
from each type of water resource into the appropriate block, using
the subscript identification protocol in Table A-1.

--F<INF>S#=surface water treated at treatment plant ``#''
=________ (MGD) (enter into Table A-2)
--F<INF>G#=ground water treated at treatment plant ``#''
=________ (MGD) (enter into Table A-2)
--F<INF>P#=treated water bought from one or more other PWSs and
further treated at treatment plant ``#'' prior to the entry point to
the distribution system
=________ (MGD) (enter into Table A-2)

Table A-2.--Treated Flow Values

Sources of treated water (FLOW)
------------------------------------------------------------------------------
Water resources (by type source) Treatment plants
------------------------------------------------------------------------------
#1 #2 #3 #4

Surface water (S)................ (F<INF>S1) (F<INF>S2) (F<INF>S3) (F<INF>S4)
Ground water (G)................. (F<INF>G1) (F<INF>G2) (F<INF>G3) (F<INF>G4)
Purchased finished water that is (F<INF>P1) (F<INF>P2) (F<INF>P3) (F<INF>P4)

further treated (P).

Combined (C)..................... (F<INF>C1) (F<INF>C2) (F<INF>C3) (F<INF>C4)

Note: The F<INF>C# value is calculated by adding the F<INF>S#, F<INF>G#, and F<INF>P# values in the column above.

--F<INF>CT=finished water produced in all of the PWS's treatment
plants (calculated by adding the combined flows from each treatment
plant (<greek-S> (F<INF>C#)).
=________ (MGD)

Calculated values. The PWS must calculate the following values.

--Population equivalents. Divide the flow values in Table A-2 by the
conversion factor K below (a PWS-specific per capita finished water
usage rate) and enter in the corresponding box in Table A-3 below.
For each treatment plant operated by the PWS, the PWS must determine
the population served by each type of water resource that provides
water to the treatment plant.

Conversion factor=K=(F<INF>CT+F<INF>N-F<INF>W)/P<INF>R=________
For Table A-3, P=F/K, using F values from Table A-2 (e.g.,
P<INF>S1=F<INF>S1/K).

Table A-3: Population Served Values

Population served by treated water (number of people)
------------------------------------------------------------------------------
Water resources (by type source) Treatment plants
------------------------------------------------------------------------------
#1 #2 #3 #4

Surface water (S)................ (P<INF>S1) (P<INF>S2) (P<INF>S3) (P<INF>S4)
Ground water (G)................. (P<INF>G1) (P<INF>G2) (P<INF>G3) (P<INF>G4)
Purchased finished water that is (P<INF>P1) (P<INF>P2) (P<INF>P3) (P<INF>P4)

further treated (P).

Combined (C)..................... (P<INF>C1) (P<INF>C2) (P<INF>C3) (P<INF>C4)

Note: The P<INF>C# value is calculated by adding the P<INF>S#, P<INF>G#, and P<INF>P# values in the column above.

--P<INF>CT=number of people served by finished water produced in all
of the PWS's treatment plants (calculated by adding the combined
populations served by each treatment plant (<greek-S> (P<INF>C#)))
=________ (people)
Note: A PWS that sells all its finished water and thus has no
retail population must calculate the population served by the PWS by
raising the PWS's average treated flow (in MGD) to the 0.95 power
and multiplying the result by 7,700. As an equation, this would
appear as:

PWS population served=7,700 (PWS's average treated flow in
MGD)0.95

The PWS may then calculate the population served by each of its
treatment plants by multiplying the PWS population served times the
average treated flow from the treatment plant divided by the average
treated flow for the PWS. As an equation, this would appear as:
[GRAPHIC] [TIFF OMITTED] TR14MY96.001

Treatment plant categorization. A PWS must categorize its
treatment plants to determine its specific compliance requirements
by reviewing Table A-4 below.

[[Page 24371]]

Table A-4.--Treatment Plant Categories

Treatment plant category P<INF>CT P<INF>C# P<INF>S# P<INF>G#

A.............................. <gr-thn-eq>100,00 <gr-thn-eq>100,000.... <gr-thn-eq>1..... NA.

B.............................. <gr-thn-eq>100,00 <gr-thn-eq>100,000.... Zero............. NA.

C.............................. <gr-thn-eq>100,00 P<INF>C# is <100,000 and is <gr-thn-eq>1..... NA.

0. largest P<INF>C# in PWS.

D.............................. <gr-thn-eq>100,00 P<INF>C# is <100,000 and is Zero............. NA.

0. largest P<INF>C# in PWS.

E.............................. <gr-thn-eq>100,00 <100,000 and is not <gr-thn-eq>1..... NA.

0. largest P<INF>C# in PWS.

F.............................. <gr-thn-eq>100,00 <100,000 and is not Zero............. NA.

0. largest P<INF>C# in PWS.

G.............................. 50,000-99,999 and NA.................... NA............... Largest P<INF>G#.

P<INF>GT <gr-thn-eq>
50,000.

NA--not applicable.

(b) Applicability.
(1) Table 1 of this paragraph is a summary of treatment plant
categorization under the provisions of Appendix A to paragraph (a)
of this section.

Table 1.--Treatment Plant Categories

Treatment plant Treatment plant Treatment plant

Treatment plant category PWS combined combined population surface water ground water

population served served population served population served

A.............................. <gr-thn-eq>100,00 <gr-thn-eq>100,000.... <gr-thn-eq>1..... NA.

B.............................. <gr-thn-eq>100,00 <gr-thn-eq>100,000.... zero............. NA.

C.............................. <gr-thn-eq>100,00 Plant serves <100,000 <gr-thn-eq>1..... NA.

0. and is largest plant.

D.............................. <gr-thn-eq>100,00 Plant serves <100,000 zero............. <100,000.

0. and is largest plant.

E.............................. <gr-thn-eq>100,00 Plant serves <100,000 <gr-thn-eq>1..... NA.

and is not largest
plant in PWS.
F.............................. <gr-thn-eq>100,00 Plant serves <100,000 zero............. <100,000.
and is not largest
plant in PWS.
G.............................. 50,000-99,999 and NA.................... NA............... Largest ground
<gr-thn-eq> water plant.
50,000 served by
ground water.

NA-not applicable.

(2) Table 2 of this paragraph specifies applicability for
requirements contained in Secs. 141.142, 141.143, and 141.144 of
this part, based on treatment plant categorization determined under
the provisions of Appendix A to paragraph (a) of this section.

Table 2--Subpart M Applicability

Categories of treatment plants1

Subpart M Requirements -------------------------------------------------------------------------------------------------

A B C D E F G

Sec. 141.142.--DBP and Related Monitoring

Table 1a and 1b....................................... X X X X X X ............
Table 22.............................................. X X X X X X ............
Table 32.............................................. X X X X X X ............
Table 4a and 4b2...................................... X X X X X X ............
Table 5a and 5b2...................................... X X X X X X ............
Table 6............................................... X X X X X X ............

Sec. 141.143--Microbiological Monitoring

Treatment plant influent monitoring................... X ............ X ............ X ............ ............
Finished water monitoring3............................ X ............ X ............ X ............ ............

Sec. 141.144--Applicability Monitoring and Treatment Studies

Treatment study applicability monitoring.............. X X X X ............ ............ X
Pilot-scale treatment studies4........................ X X ............ ............ ............ ............ ............
Bench- or pilot-scale treatment studies4.............. X X X X ............ ............ X

1 As determined by Appendix A to paragraph (a) of this section.

2 Table 2 required only for treatment plants using chloramines. Table 3 required only for treatment plants using hypochlorite solution. Table 4a and 4b

required only for treatment plants using ozone. Table 5a and 5b required only for treatment plants using chlorine dio xide.

[[Page 24372]]

3 Only required for a PWS that, during any of the first twelve months of monitoring at the treatment plant influent, detects 10 or more Giardia cysts,
or 10 or more Cryptosporidium oocysts, or one or more total culturable viruses in one liter of water; or calculates a numerical value of the Giardia
or Cryptosporidium concentration equal to or greater than 1000 per 100 liters or virus concentration equal to or greater than 100 per 100 liters; or
detects no pathogens in the sample and calculates a numerical value of the detection limit for Giardia or Cryptosporidium concentration equal to or

greater than 1000 per 100 liters or virus concentration equal to or greater than 100 per 100 liters.

4 Pilot-scale treatment studies are required for treatment plants that serve a population of 500,000 or greater. Bench- or pilot-scale treatment studies

are required for treatment plants that serve a population of fewer than 500,000.

(c) Disinfection Byproduct and Related Monitoring. A PWS must
comply with the monitoring requirements in Sec. 141.142 of this
subpart for treatment plants in treatment plant categories A, B, C,
D, and E listed in Table 1 in paragraph (b)(1) of this section. The
PWS shall monitor monthly for 18 consecutive months at each
treatment plant, even if a treatment plant was not used for one or
more calendar months. When the treatment plant is not operating, the
PWS shall file the report required under Sec. 141.142(c) of this
subpart to indicate zero flow, and need only conduct treatment plant
influent monitoring under the provisions of Sec. 141.142 of this
subpart. A PWS must comply with the monitoring requirements in
Sec. 141.142 of this subpart for treatment plants in treatment plant
categories F listed in Table 1 in paragraph (b)(1) of this section
monthly for 18 consecutive months at each treatment plant, except if
a treatment plant was not used for one or more calendar months. When
the treatment plant is not operating, the PWS shall file the report
required under Sec. 141.142(c) of this subpart to indicate zero
flow, and is not required to conduct treatment plant influent
monitoring under the provisions of Sec. 141.142 of this subpart.
(d) Microbiological Monitoring. A PWS must comply with the
monitoring requirements in Sec. 141.143 of this subpart for
treatment plants in treatment plant categories A, C, and E listed in
Table 1 in paragraph (b)(1) of this section and Table 3 of this
paragraph. The PWS shall conduct 18 consecutive months of
microbiological monitoring at each treatment plant, even if it is
not operated each calendar month.

Table 3.--Microbiological Monitoring Requirements for Subpart M

Treatment plant category
---------------------------------------
A, C and E

Microbial sample ---------------------------------------

Treatment plant
influent Finished water \1\

Total culturable viruses........ 1/month \2\....... 1/month.
Total coliforms................. 1/month........... 1/month.
Fecal coliforms or E. coli...... 1/month........... 1/month.
Giardia......................... 1/month........... 1/month.\3\
Cryptosporidium................. 1/month........... 1/month.\3\

\1\ Only required for a PWS that, during any of the first twelve months
of monitoring at the treatment plant influent, detects 10 or more
Giardia cysts, or 10 or more Cryptosporidium oocysts, or one or more
total culturable viruses in one liter of water; or calculates a
numerical value of the Giardia or Cryptosporidium concentration equal
to or greater than 1000 per 100 liters or virus concentration equal to
or greater than 100 per 100 liters; or detects no pathogens in the
sample and calculates a numerical value of the detection limit for
Giardia or Cryptosporidium concentration equal to or greater than 1000
per 100 liters or virus concentration equal to or greater than 100 per
100 liters. The PWS shall collect one sample of finished water during
each month that the treatment plant is operated at each such treatment
plant beginning in the first calendar month after the PWS learns of
such a result. A PWS shall continue finished water monitoring monthly
until 18 months of treatment plant influent monitoring has been

completed.

\2\ A PWS may avoid virus monitoring if the PWS has monitored total
coliforms, fecal coliforms, or E. coli in the source water for at
least five days/week for any period of six consecutive months
beginning after January 1, 1994, and 9012f all samples taken in that
six-month period contained no greater than 100 total coliforms/100 ml,

or 20 fecal coliforms/100 ml, or 20 E. coli/100 ml.

\3\ A PWS may avoid the requirement for finished water monitoring of
Giardia and Cryptosporidium if the PWS notifies EPA that it will
comply with the alternative monitoring requirements in Sec.
141.143(a)(2)(iii). The PWS must still conduct finished water
monitoring for all other microorganisms, except that Giardia and
Cryptosporidium monitoring in the finished water is not required.

(e) Disinfection Byproduct Precursor Removal Studies (Treatment
Studies).
(1) A PWS shall comply with treatment study applicability
monitoring in paragraph (e)(2) of this section at each treatment
plant in treatment plant categories A, B, C, D, and G listed in
Table 1 in paragraph (b)(1) of this section. A PWS shall comply with
the treatment study requirements in Sec. 141.144 of this subpart at
each such treatment plant, except for those treatment plants:
(i) Meeting the source water quality, disinfection practice, or
disinfection byproduct precursor removal practice criteria in
paragraph (e)(3) of this section, for which no treatment study is
required; or
(ii) Meeting the common water resource criteria in paragraph
(e)(4) of this section, for which several PWSs may conduct treatment
studies jointly, in lieu of separately; or
(iii) Meeting the common water resource criteria in paragraph
(e)(5) of this section, for which a PWS may contribute funds towards
research, in lieu of conducting a treatment study; or
(iv) At which a previous treatment study that meets the criteria
in paragraph (e)(6) of this section has already been conducted, for
which a PWS may use the results of this previous treatment study, in
lieu of conducting another treatment study; or
(v) Operated by the PWS that use the same water resource, as
classified by the procedure in paragraph (e)(4) of this section. The
PWS is not required to conduct more than one treatment study for
those treatment plants. If both pilot-scale and bench-scale
treatment studies would otherwise be required for treatment plants
on the same water resource, the PWS shall conduct a pilot-scale
study. A PWS with multiple water resources shall conduct treatment
studies for each treatment plant that uses different water
resources.
(2) Treatment study applicability monitoring.
(i) PWSs shall monitor total organic carbon (TOC) monthly for 12
months. Treatment plants using surface water shall monitor treatment
plant influent. Treatment plants using ground water shall monitor
finished water.
(ii) Treatment study applicability monitoring for THM4 and HAA5
is only required by a PWS that intends to qualify for avoiding a
treatment study under the provisions of paragraph (e)(3)(i) of this
section.
(iii) Total organic halides formed under the uniform formation
conditions (UFCTOX) monitoring is only required by a PWS that
intends to qualify for a joint treatment study under the provisions
of paragraph (e)(4)(i)(A)(2) of this section or for the alternative
to conducting a treatment study under the provisions of paragraph
(e)(5) of this section.
(3) Criteria under which no treatment study is required. A PWS
identified in paragraph (e)(1) of this section is not required to
conduct a treatment study at any treatment plant that satisfies any
criteria in paragraphs (e)(3) (i) through (iv) of this section,
provided that the PWS has also complied with the requirements in
paragraph (e)(7)(i) of this

[[Page 24373]]

section and EPA has approved the PWS's request to avoid the
treatment study.
(i) Treatment plants that use chlorine as both the primary and
residual disinfectant and have, as an annual average of four
quarterly averages, levels of less than 40
<greek-m>g/l for THM4 and less than 30 <greek-m>g/l for HAA5. Quarterly
averages are the arithmetic average of the four distribution system
samples collected under the requirements of Sec. 141.142(a)(1) of this
subpart.
(ii) Treatment plants using surface water that do not exceed a
TOC annual average of 4.0 mg/l in the treatment plant influent,
measured in accordance with Secs. 141.141(f)(4) and 141.144(a) of
this subpart and calculated by averaging the initial 12 monthly TOC
samples.
(iii) Treatment plants using only ground water not under the
direct influence of surface water that do not exceed a TOC annual
average of 2.0 mg/l in the finished water, measured in accordance
with Secs. 141.141(f)(4) and 141.144(a) of this subpart and
calculated by averaging the initial 12 monthly TOC samples.
(iv) Treatment plants that already use full scale membrane or
GAC technology. For a treatment plant that already uses full-scale
GAC or membrane technology capable of achieving precursor removal, a
PWS shall conduct monitoring and submit full-scale plant data
required for disinfection byproduct and related monitoring by
Sec. 141.142(a) of this subpart, ensuring that the GAC or membrane
processes are included in the process train being monitored. For a
treatment plant to be considered to have membrane technology to
achieve precursor removal, the PWS shall have used nanofiltration or
reverse osmosis membranes. GAC capable of removing precursors is
defined as GAC with an empty bed contact time (EBCT) of 15 minutes
or greater, with a time between carbon reactivation or replacement
of no more than nine months. PWSs that operate treatment plants that
use GAC with either an EBCT of less than 15 minutes or a replacement
or reactivation frequency for GAC longer than nine months may submit
a request to avoid treatment studies under the provisions of
paragraph (e)(7)(i) of this section by including data demonstrating
effective DBP precursor removal.
(4) Criteria under which joint treatment studies are allowed.
(i) PWSs that use common water resources and have similar treatment
trains may conduct joint treatment studies. A common water resource
for all types of surface water resources requires the mean treatment
plant influent TOC or UFCTOX of each of the cooperating treatment
plants to be within 1012f the average of the mean treatment plant
influent TOCs or UFCTOX of all the cooperating treatment plants. A
common water resource for all types of ground water resources
requires the mean treatment plant finished water TOC or UFCTOX of
each of the cooperating treatment plants to be within 1012f the
average of the mean treatment plant finished water TOCs or UFCTOX of
all the cooperating treatment plants. The mean is calculated from
the monthly TOC or UFCTOX monitoring data for the initial twelve
months of monitoring under Sec. 141.144(a) of this subpart. Similar
treatment trains means that, for example, softening plants may not
conduct joint studies with conventional treatment plants. In
addition, the applicable requirements in paragraphs (e)(4)(i) (A)
through (C) of this section shall be met for the water resource to
be considered a common water resource. If otherwise eligible, a PWS
may choose to either perform a joint treatment study with other
eligible systems or contribute funds to a cooperative research
program, as described in paragraph (e)(5) of this section, as an
alternative to conducting a treatment study.
(A) River sources. Treatment plants with river intakes are
considered to have a common water resource if the PWS meets either
criteria in paragraphs (e)(4)(i)(A) (1) or (2) of this section.
(1) The intakes are no more than 20 river miles apart and TOC at
each treatment plant influent is within 1012f the mean TOC of all
the treatment plant influents.
(2) The intakes are at least 20, but no more than 200, river
miles apart and the PWS demonstrates that the mean water resource
UFCTOX is within 1012f the mean UFCTOX of all the treatment plant
influents, based on UFCTOX analytical results of the same 12
consecutive months for all cooperating treatment plants.
(B) Lake/reservoir. Treatment plants with lake or reservoir
intakes are considered to have a common water resource if the same
lake or reservoir serves all the cooperating treatment plants and
TOC at each treatment plant influent is within 1012f the mean TOC
of all the treatment plant influents.
(C) Ground water not under the direct influence of surface
water. Treatment plants with intakes from a single aquifer are
considered to have a common water resource if treatment plant
finished water TOC at each treatment plant is within 1012f the mean
finished water TOC of all the treatment plants.
(ii) PWSs that meet the requirements of paragraph (e)(4)(i) of
this section shall conduct at least the number and type of joint
studies noted in the following tables. Joint studies shall only be
conducted among treatment plants in the same size category, i.e. a
population served of either <gr-thn-eq>500,000 or of <500,000. The
maximum number of treatment plants with a population served
<gr-thn-eq>500,000 persons allowed to join together to conduct a
study is three. The maximum number of treatment plants with a
population served <500,000 persons allowed to join together to
conduct a study is six.

Joint Studies Requirement for Treatment Plants With a Population Served

of <500,000

Number of plants Minimum studies to be conducted

2............................. 1 pilot (GAC or membrane).
3............................. 1 pilot and 1 bench (GAC or membrane).
4............................. 2 pilots (GAC and/or membrane).
5............................. 2 pilots (GAC and/or membrane), 1 bench

(GAC or membrane).

6............................. 2 pilots and 2 bench (GAC and/or

membrane).

Joint Studies Requirement For Treatment Plants With a Population Served

of <gr-thn-eq>500,000

Number of plants Minimum studies to be conducted

2............................. 1 pilot (GAC or membrane), 2 bench (GAC

and/or membrane).

3............................. 2 pilots (GAC and/or membrane).

(5) Criteria under which an alternative to conducting a
treatment study is allowed. In lieu of conducting the required
treatment study, a PWS may apply to EPA to contribute funds to a
cooperative research effort. The PWS shall submit an application to
EPA Technical Support Division, ICR Precursor Removal Studies
Coordinator, 26 W. Martin Luther King Drive, Cincinnati, OH 45268.
The application shall show that the treatment plant for which the
waiver of the treatment study is sought uses a common water
resource, as described in paragraph (e)(4) of this section, that is
being studied by another PWS or cooperative of PWSs operating
treatment plants in the same size category. A PWS operating
treatment plants serving a population of fewer than 500,000 may also
contribute to this fund if there is a common water resource (as
defined in paragraph (e)(4) of this section) treatment plant serving
500,000 or more conducting a treatment study. If EPA approves the
application, the PWS shall contribute funds in the amount specified
in paragraph (e)(5)(i) of this section to the Disinfection
Byproducts/Microbial Research Fund, to be administered by the
American Water Works Association Research Foundation (AWWARF) under
the direction of an independent research council, for use in a
dedicated cooperative research program related to disinfectants,
disinfection byproducts, and enhanced surface water treatment.
(i) The PWS shall contribute $300,000 for a treatment plant with
a population served of 500,000 or more. The PWS shall contribute
$100,000 for a treatment plant with a population served of fewer
than 500,000.
(ii) The PWS shall send the contribution to the address
specified in EPA's approval letter not later than 90 days after EPA
approves the PWS application for waiver of the treatment study.
(6) Criteria under which a previous treatment study is
acceptable (grandfathered studies). A PWS that has conducted studies
of precursor removal that meet all the criteria in paragraphs
(e)(6)(i) and (ii) of this section may use the results of that study
in lieu of conducting another treatment study.

[[Page 24374]]

(i) The PWS used analytical methods specified in Table 7 of
Sec. 141.142(b)(1) of this subpart and used the analytical and
quality control procedures described in ``DBP/ICR Analytical Methods
Manual'', EPA 814-B-96-002.
(ii) The PWS followed a protocol similar to that specified and
supplies the data specified in ``ICR Bench- and Pilot-scale
Treatment Study Manual'' (EPA 814-B-96-003, April 1996).
(7) Process for a PWS to obtain EPA approval of criteria
applicability. A PWS wanting to avoid the requirements for a
treatment study under the provisions of paragraphs (e)(3) through
(6) of this section shall submit the applicable information in
paragraphs (e)(7)(i) through (iv) of this section and in ``ICR
Bench- and Pilot-scale Treatment Study Manual'' (EPA 814-B-96-003,
April 1996) and all monitoring data required under Secs. 141.142(a)
and 141.143(a) of this subpart to EPA, Technical Support Division,
ICR Precursor Removal Studies Coordinator, 26 W. Martin Luther King
Drive, Cincinnati, OH 45268.
(i) Approval of request to avoid treatment studies. A PWS that
believes it qualifies to avoid the requirements for a treatment
study under the provisions of paragraph (e)(3)(i) through (iii) of
this section shall submit the information showing the applicable
criterion for not conducting the study has been met not later than
November 14, 1997. A PWS wanting to avoid the requirements for a
treatment study under the provisions of paragraph (e)(3)(iv) of this
section shall submit the supporting information, including any
pilot- or full-scale data showing effective precursor removal, not
later than November 14, 1997. A PWS that applies to avoid a
treatment study under the provisions of paragraph (e)(4) through (6)
of this section and subsequently qualifies to avoid a treatment
study under the provisions of paragraph (e)(3)(i) through (iii) of
this section may elect to avoid a treatment study under the
provisions of paragraph (e)(3)(i) through (iii) of this section. If
the PWS elects to avoid a treatment study under the provisions of
paragraph (e)(3)(i) through (iii) of this section, the PWS shall
notify all PWSs that were associated with the application to avoid a
treatment study under the provisions of paragraph (e)(4) through (6)
of this section.
(ii) Approval of request to conduct joint studies. A PWS that
believes it qualifies to avoid the requirements for a treatment
study under the joint study provisions of paragraph (e)(4) of this
section shall submit a letter of intent to EPA with the information
in paragraphs (e)(7)(ii)(A) through (F) of this section for all
treatment plants to be included in the joint study not later than
May 14, 1997. The letter shall be signed by all PWSs planning to
participate in the joint study. All PWSs shall submit a combined
application for joint studies approval to EPA (including 12 months
of treatment plant influent TOC or finished water TOC results or
UFCTOX results, as appropriate, for each treatment plant to be
included in the joint study) not later than November 14, 1997.
(A) Data to support their common water resource designation.
(B) Information to demonstrate that treatment plants have
similar treatment trains.
(C) Information that treatment plants are in the same size
category.
(D) The treatment plant influent TOC or finished water TOC
results, or UFCTOX results, as appropriate, from the first six
months of monitoring.
(E) What studies will be conducted (i.e., combination of bench/
pilot and GAC/membrane).
(F) Any additional supporting data.
(iii) Approval of request for alternative to treatment studies.
A PWS that believes it qualifies to avoid the requirements for a
treatment study under the provisions for an alternative in paragraph
(e)(5) of this section shall submit a letter of intent expressing
its intention to contribute funds to the cooperative research effort
not later than May 14, 1997. The letter shall identify the other
treatment plants using the same water resource which will be
conducting studies. Each PWS shall submit an application for
approval of alternative to treatment studies to EPA (including 12
months of treatment plant influent TOC or finished water TOC results
or UFCTOX results, as appropriate) not later than November 14, 1997.
EPA shall notify the PWS whether a treatment study is required
(because there is no other appropriately sized treatment plant using
the same water resource conducting a treatment study) or if the PWS
can avoid the study by contributing funds to the cooperative
research effort specified in paragraph (e)(5) of this section.
(iv) Approval of request to use grandfathered studies. A PWS
that believes it qualifies to avoid the requirements for a treatment
study under the grandfathered study provisions of paragraph (e)(6)
of this section shall submit the following information not later
than February 14, 1997: a description of the study, the equipment
used, the experimental protocol, the analytical methods, the quality
assurance plan, and any reports resulting from the study. EPA shall
review the information and inform the PWS whether or not the prior
study meets the ICR requirements. Not later than November 14, 1997,
the PWS must submit study data in the format specified in ``ICR
Manual for Bench- and Pilot-scale Treatment Studies'', EPA 814-B-96-
003, April 1996. An approved grandfathered study can be
justification for common water resource PWSs contributing to the
cooperative research effort under the provisions of paragraph (e)(5)
of this section, but may not be used as joint treatment studies
unless it incorporates the requirements listed in Sec. 141.141(e)(4)
of this section and the PWS submits written concurrence of the PWS
which conducted the study.
(f) Effective dates. (1) A PWS shall respond to the Notice of
Applicability sent by EPA within 35 calendar days of receipt of that
notice. The PWS's response to the Notice shall indicate what
requirements in subpart M apply to each treatment plant operated by
the PWS. If a PWS meets the applicability criteria in paragraph (b)
of this section and has not received a Notice of Applicability from
EPA by June 28, 1996, that PWS must request a Notice of
Applicability from EPA by contacting the ICR Utilities Coordinator,
TSD, USEPA, 26 West Martin Luther King Drive, Cincinnati, OH 45268,
not later than July 15, 1996.
(2) A PWS required to monitor under both paragraphs (c) and (d)
of this section shall begin monitoring to comply with the provisions
of Sec. 141.142 (Disinfection Byproduct and Related Monitoring) and
Sec. 141.143 (Microbiological Monitoring) of this subpart in the
same month. The PWS must submit the sampling plans required by
Secs. 141.142(c)(2)(ii) and 141.143(c)(3)(ii) of this subpart at the
same time.
(3) Disinfection Byproduct and Related Monitoring. A PWS
operating a treatment plant required to comply with Sec. 141.142 of
this subpart shall begin monitoring in the calendar month following
approval of the DBP and related monitoring sampling plan submitted
under the provisions of Sec. 141.142(c)(2)(ii) of this subpart. Once
a PWS has begun monitoring, it shall continue to monitor for 18
consecutive months.
(4) Microbiological Monitoring. A PWS operating a treatment
plant identified in paragraph (d) of this section shall begin
monitoring under the provisions of Sec. 141.143 of this subpart in
the calendar month following approval of the sampling plan submitted
under the provisions of Sec. 141.143(c)(3)(ii) of this subpart. Once
a PWS has begun monitoring, it shall continue to monitor for 18
consecutive months.
(5) DBP precursor removal studies. (i) TOC, UFCTOX, THM4, and
HAA5 monitoring. A PWS required to comply with Sec. 141.144 of this
subpart shall begin TOC, UFCTOX, THM4, and HAA5 monitoring specified
in paragraph (e)(2) of this section not later than August 14, 1996
and continue this monitoring for 12 consecutive months for TOC and
UFCTOX and four consecutive quarters for THM4 and HAA5.
(ii) A PWS required to conduct a disinfection byproduct
precursor removal study (treatment study) under the provisions of
paragraph (e)(1) of this section shall begin conducting such
treatment studies not later than April 14, 1998 and submit the
report(s) of the completed study to EPA not later than July 14,
1999.

Sec. 141.142 Disinfection byproduct and related monitoring.

(a) Monitoring requirements. Samples taken under the provisions of
this section shall be taken according to the procedures described in
the ``ICR Sampling Manual,'' EPA 814-B-96-001, April 1996. If a
treatment plant configuration results in two required sampling points
from any table in this section when in fact it is a single location,
duplicate analyses are not required for the same location and time. A
PWS that uses purchased finished water shall determine whether any
monitoring of treatment plant influent is required under paragraphs
(a)(2) through (5) of this section because of certain treatment (e.g.,
use of hypochlorite or chlorine dioxide) of the water provided by the
selling PWS.

[[Page 24375]]

(1) A PWS shall obtain a complete set of samples at the frequency
and location noted in Tables 1a and 1b of this section for treatment
plants required to test under Sec. 141.141(b) of this subpart. Samples
shall be taken according to the sampling plan approved under the
provisions of paragraph (c)(2)(ii) of this section.
(i) Samples of finished water shall be collected at a point after
which all treatment processes for a particular treatment plant are
complete (including the clearwell and final point of chlorination) and
before the distribution system begins. A PWS that purchases finished
water shall collect a sample before additional disinfectant is added to
the purchased finished water. A PWS shall collect a sample of purchased
finished water only if the PWS redisinfects the purchased finished
water. A sample of finished water is a sample representing the final
product water from a particular treatment plant.
(ii) A sample of treatment plant influent for a PWS that treats
untreated water shall be taken at a location at the upstream end of a
treatment plant where waters from all intakes are blended prior to any
treatment or chemical addition. For treatment plants that have multiple
intakes and add chemicals at the intake, the sample of treatment plant
influent shall be a flow proportional composite of intake samples
collected before chemical addition and before pretreatment. If the
intakes are expected to have the same source water quality, one
representative intake sample may be taken. If a disinfectant is added
at or before the intake (e.g., for zebra mussel control), the sample
shall be taken in the vicinity of the intake so that the sample is not
contaminated by the disinfectant. A sample of treatment plant influent
for a PWS that treats purchased finished water is taken at a location
just before the purchased finished water is treated. An intake sample
is collected after the intake but before blending with waters from
other intakes and before addition of chemicals or any treatment.

Table 1a.--Monthly Monitoring Requirements for Treatment Plants

Sampling point Monthly analyses 1

Treatment plant influent for pH, Alkalinity, Turbidity, Temperature,
non-finished water. Calcium and Total Hardness, TOC, UV <INF>254,

Bromide, Ammonia.

Treatment plant influent for pH, Alkalinity, Turbidity, Temperature,
purchased finished water 2. Calcium and Total Hardness, TOC, UV <INF>254,

Disinfectant residual 3.
Before first point of oxidant Chlorine demand test.
addition.

Washwater return between pH, Alkalinity, Turbidity, Temperature,
washwater treatment plant Calcium and Total hardness, TOC, UV <INF>254,
and point of addition to Bromide, Ammonia, Disinfectant residual
process train 4. 3 if disinfectant is used.
Additional water sources pH, Alkalinity, Turbidity, Temperature,
added to process train after Calcium and Total hardness, TOC, UV <INF>254,
treatment plant influent. Bromide, Ammonia, Disinfectant residual
The sample point is before 3 if disinfectant is used.

additional water is blended
with the process train.

Before Filtration............ pH, Alkalinity, Turbidity, Temperature,

Calcium and Total Hardness, TOC, and UV
<INF>254.

After Filtration............. pH, Alkalinity, Turbidity, Temperature,

Calcium and Total Hardness, TOC, and UV
<INF>254.

Before each Point of pH, Alkalinity, Turbidity, Temperature,
Disinfection 5. Calcium and Total Hardness, TOC, and UV

<INF>254.

After every unit process that Disinfectant Residual 3.

is downstream from the
addition of chlorine or
chloramines.

Finished water sample point pH, Alkalinity, Turbidity, Temperature,
(Plant effluent). Calcium and Total Hardness, TOC, UV <INF>254,

Disinfectant Residual 3.

Entry point to distribution pH, Alkalinity, Turbidity, Temperature,

system 6. Calcium and Total Hardness, TOC, UV <INF>254,
Disinfectant Residual 3.

\1\ TOC: total organic carbon. UV <INF>254: absorbance of ultraviolet light

at 254 nanometers.

\2\ Samples of purchased finished water shall be taken prior to addition

of any more disinfectant.

\3\ Free chlorine residual and total chlorine residual shall be measured
in treatment systems using free chlorine. Total chlorine residual, but
not free chlorine residual, shall be measured in treatment systems

using chloramines as the residual disinfectant.

\4\ Washwater return shall be sampled prior to blending with the process

train.

\5\ For utilities using ozone or chlorine dioxide, Tables 4 and 5,
respectively, of this section, show additional monitoring requirements
at this sampling point. Addition of ammonia for the purpose of
converting free chlorine to chloramines is considered a point of
disinfectant addition. PWSs that disinfect just before filtration may
use the ``before filtration'' sampling point analytical results to

meet the monitoring requirement for this point.

\6\ Entry point to distribution system only required for treatment
plants that blend finished water with finished water from other
treatment plant(s) prior to entry point of distribution system. For
most treatment plants, the finished water sample point and the entry

point to the distribution system are the same.

Table 1b.--Quarterly Monitoring Requirements for Treatment Plants

Sampling point Quarterly analyses1

Treatment plant influent for TOX.
non-finished water.

Treatment plant influent for THM4, HAA67, HAN, CP, HK, CH, TOX.

purchased finished water.
Washwater Return between TOX.
washwater treatment plant
and point of addition to
process train.

After filtration if THM4, HAA67, HAN, CP, HK, CH, TOX.

disinfectant is applied at
any point in the treatment
plant prior to filtration.

Finished water sample point THM4, HAA67, HAN, CP, HK, CH, TOX.

(Plant Effluent).

Entry point to distribution THM4, HAA67, HAN, CP, HK, CH, TOX.

system2.

SDS3......................... THM4, HAA67, HAN, CP, HK, CH, TOX, pH,

Alkalinity, Turbidity, Temperature,
Calcium and Total Hardness, Disinfectant
Residual5.

[[Page 24376]]

Four monitoring points in THM4, HAA67, HAN, CP, HK, CH, TOX, pH,
distribution system4,6. Alkalinity, Turbidity, Temperature,

Calcium and Total Hardness, Disinfectant
Residual5.

\1\ TOC: total organic carbon. THM4: trihalomethane (four). HAA6:
haloacetic acids (six). HAN: Haloacetonitriles. CP: chloropicrin. HK:
haloketones. CH: chloral hydrate. TOX: total organic halide. For THM4,
HAA6, HAN, and HK, analytical results for individual analytes shall be

reported.

\2\ Entry point to distribution system only required for treatment
plants that blend finished water with finished water from other
treatment plant(s) prior to entry point of distribution system. For
most treatment plants, the finished water sample point and the entry

point to the distribution system are the same.

\3\ Simulated Distribution System (SDS) sample shall be collected at the
finished water sampling point (or entry point to distribution system
if finished water from two or more plants are blended prior to
entering the distribution system) and analyzed using the method
specified in Sec. 141.142. PWSs using purchased finished water are
not required to take an SDS sample at treatment plants that use only

purchased finished water.

\4\ For each treatment plant, one distribution system equivalent sample
location (known as DSE) shall be chosen to correspond to the SDS
sample, one sample location shall be chosen to be representative of
maximum residence time for the treatment plant, and the remaining two
sample locations shall be representative of the average residence time
in the distribution system for the treatment plant. PWSs using
purchased finished water shall take three samples representing the
average residence time in the distribution system for the treatment
plant and one representing the maximum residence time for the

treatment plant (no DSE sample required).

\5\ Free chlorine residual and total chlorine residual shall be measured
in treatment systems using free chlorine. Total chlorine residual, but
not free chlorine residual, shall be measured in treatment systems

using chloramines as the residual disinfectant.

\6\ A PWS may use TTHM compliance monitoring locations and analytical
results under Sec. 141.30 of this part to the extent that such
locations and analytical results are consistent with the requirements

of this section.

\7\ PWSs are encouraged to also analyze for the additional haloacetic
acids bromodichloro-, chlorodibromo-, and tribromo-acetic acid, and
report the results as part of the reports specified in paragraph

(c)(1) of this section.

(2) Additional requirements for PWSs using chloramines. For each
treatment plant that uses chloramines for treatment or disinfection
residual maintenance, a PWS shall also conduct the additional sampling
identified in Table 2 of this section. A PWS shall send samples of
cyanogen chloride taken under the provisions of this paragraph for
analysis to EPA, following the procedures contained in the ``ICR
Sampling Manual,'' EPA 814-B-96-001, April 1996.

Table 2.--Additional Quarterly Monitoring for Treatment Plants Using

Chloramines

Sampling point Quarterly analyses

Treatment plant influent for purchased Cyanogen Chloride\2\.

finished water \1\.

Finished water sample point (plant Cyanogen Chloride\2\.

effluent).

Distribution system sample point Cyanogen Chloride\2\.

representing a maximum residence time
in distribution system relative to the
treatment plant.

\1\ Applicable only when wholesale water provider is using chloramines.
\2\ EPA shall provide all analytical results to the PWS. The PWS shall

report all results in its monthly report.

(3) Additional requirements for PWSs using hypochlorite solutions.
For each treatment plant that uses hypochlorite solutions for treatment
or disinfection residual maintenance, a PWS shall also conduct the
additional sampling identified in Table 3 of this section.

Table 3.--Additional Quarterly Monitoring for Treatment Plants Using

Hypochlorite Solutions

Sampling point Quarterly analyses

Treatment plant influent for non- Chlorate.
finished water.
Treatment plant influent for purchased Chlorate.
finished water \1\.

Hypochlorite Stock Solution............ pH, Temperature, Free Residual

Chlorine, Chlorate.
Finished Water Sample Point (Plant Chlorate.
Effluent).

\1\ Applicable only when wholesale water provider is using hypochlorite

solutions.

(4) Additional requirements for PWSs using ozone. For each
treatment plant that uses ozone for treatment, a PWS shall also conduct
the additional sampling identified in Tables 4a and 4b of this section.
A PWS shall collect samples for bromate taken under the provisions of
this paragraph in duplicate, with the PWS analyzing one aliquot and
submitting the other aliquot for analysis to EPA, following the
procedures contained in the ``ICR Sampling Manual,'' EPA 814-B-96-001,
April 1996. A PWS shall submit samples for aldehydes taken under the
provisions of this paragraph for analysis to EPA, following the
procedures contained in the ``ICR Sampling Manual,'' EPA 814-B-96-001,
April 1996.

Table 4a.--Additional Monthly Monitoring for Treatment Plants Using

Ozone

Sampling point Monthly analyses

Ozone Contactor Influent............... Bromide, bromate 2,3, and

ammonia.

[[Page 24377]]

Each Ozone Contact Chamber Effluent \1\ Ozone residual.

Ozone Contactor Effluent............... Bromate\2\.
Finished Water Sample Point (Plant Bromate\2\.
Effluent).

\1\ Each ozone contactor can be subdivided into its contact chambers.
Measure ozone residual in effluent of all contact chambers until <0.05

mg/l is measured in two consecutive chambers.

\2\ EPA shall provide all analytical results to the PWS. The PWS shall

report all results in its monthly report.

\3\PWSs are not required to analyze a bromate sample at this location.
However, PWSs are still required to submit a sample to EPA for

analysis.

Table 4b.--Additional Quarterly Monitoring for Treatment Plants Using

Ozone

Sampling point Quarterly analyses

Ozone Contactor Influent............... Aldehydes \1\ and AOC/BDOC \2\.
Ozone Contactor Effluent............... Aldehydes \1\ and AOC/BDOC \2\.
Finished Water Sample Point (Plant Aldehydes \1\ and AOC/BDOC \2\.

Effluent).

\1\ EPA shall measure the following aldehydes: formaldehyde,
acetaldehyde, propanal, butanal, pentanal, glyoxal, and methyl
glyoxal. EPA may analyze for other aldehydes. EPA shall provide all
analytical results to the PWS. The PWS shall report all results in its

monthly report.

\2\ Analysis and submission of data for both assimilable organic carbon
(AOC) and biodegradable organic carbon (BDOC) are optional. Analytical
methods for AOC and BDOC are listed in ``DBP/ICR Analytical Methods

Manual,'' EPA 814-B-96-002, April 1996.

(5) Additional sampling requirements for PWSs using chlorine
dioxide. For each treatment plant that uses chlorine dioxide for
treatment or disinfection residual maintenance, a PWS shall also
conduct the additional sampling identified in Tables 5a and 5b of this
section. A PWS shall collect samples for bromate taken under the
provisions of this paragraph in duplicate, with the PWS analyzing one
aliquot and submitting the other aliquot for analysis to EPA, following
the procedures contained in the ``ICR Sampling Manual,'' EPA 814-B-96-
001, April 1996. A PWS shall submit samples for aldehydes taken under
the provisions of this paragraph for analysis to EPA, following the
procedures contained in the ``ICR Sampling Manual,'' EPA 814-B-96-001,
April 1996.

Table 5a.--Additional Monthly Monitoring for Treatment Plants Using

Chlorine Dioxide

Sampling point Monthly analyses

Treatment plant influent for purchased Chlorine Dioxide Residual,

finished water \1\. Chlorite, Chlorate.

Before first chlorine dioxide Chlorate, bromate 2,3.

application.

Before application of ferrous salts, Chlorine Dioxide Residual,
sulfur reducing agents, or GAC. Chlorite, Chlorate, pH.
Finished water sample point (plant Chlorine Dioxide Residual,

effluent). Chlorite, Chlorate, Bromate
\2\.

Three distribution system sampling Chlorine Dioxide Residual,
points (1 near first customer, 1 in Chlorite, Chlorate, pH, and
middle of distribution system, and 1 Temperature.

representative of maximum residence
time in the distribution system).

\1\ Applicable only when wholesale water provider is using chlorine

dioxide.

\2\ EPA shall provide all analytical results to the PWS. The PWS shall

report all results in its monthly report.

\3\ PWSs are not required to analyze a bromate sample at this location.
However, PWSs are still required to submit a sample to EPA for

analysis.

Table 5b.--Additional Quarterly Monitoring for Treatment Plants Using

Chlorine Dioxide

Sampling point Quarterly analyses

Before First Chlorine Dioxide Aldehydes \1\ and AOC/BDOC \2\.

Application.

Before First Point of Downstream Aldehydes \1\ and AOC/BDOC \2\.

Chlorine/Chloramine Application After
Chlorine Dioxide Addition.

Finished Water Sample Point (Plant Aldehydes \1\ and AOC/BDOC \2\.

Effluent).

\1\EPA shall measure the following aldehydes: formaldehyde,
acetaldehyde, propanal, butanal, pentanal, glyoxal, and methyl
glyoxal. EPA may analyze for other aldehydes. EPA shall provide all
analytical results to the PWS. The PWS shall report all results in its

monthly report.

Manual,'' EPA 814-B-96-002, April 1996.

(6) Additional requirements. A PWS shall also report the applicable
information in Tables 6a through 6e of this section. A PWS is required
to provide the information in paragraphs (a)(6)(i) through (iii) of
this section for each unit process listed in Table 6c. The PWS may
provide the information in paragraphs (a)(6)(iv) and (v) of this
section for each unit process listed in Table 6c. T<INF>10 and T<INF>50
tracer studies shall be conducted as specified in ``Guidance Manual for
Compliance with the Filtration and Disinfection Requirements for Public
Water Systems using Surface Water Sources'', Appendix C.
(i) Unit process flow (MGD) at time of sampling.
(ii) T<INF>10 (minutes). A PWS shall determine T<INF>10 based on a
one-time tracer study in the clearwell of all treatment plants required
to conduct

[[Page 24378]]

microbiological monitoring under the provisions of Sec. 141.141(d) of
this subpart. The PWS may use results of a tracer study conducted to
meet the requirements of subpart H (Filtration and Disinfection) of
this part to meet this requirement. For subsequent T<INF>10
determinations, the PWS shall use a flow-proportional interpolation of
the clearwell tracer study. For unit processes other than a clearwell,
a PWS shall either estimate T<INF>10 or use an interpolation of tracer
study T<INF>10 using multiple flows for each unit process in which a
disinfectant residual exists.
(iii) Chemicals in use at time of sampling. Report chemical name,
chemical dose at time of sampling, and measurement formula. Measurement
formulas (e.g., mg/l as Aluminum) shall be provided to determine the
correct amount of the chemical compound being added.
(iv) Short circuiting factor (optional). The short circuiting
factor is an assumed value for the ratio of T<INF>10 to nominal contact
time (volume divided by flow).
(v) T<INF>50 (minutes) (optional). T<INF>50 should be reported only
if based on a tracer study.

Table 6a.--Public Water System Information

Permanent data Design data Monthly data

Public Water System:
Utility Name .......................................... Sampling Dates: From
Public Water Supply Identification Number (date) To (date).
(PWSID) Retail population on day
Water Industry Data Base (WIDB) Number of sampling.
[Optional] Wholesale population on
Official Contact Person: day of sampling.
Name Monthly average Retail
Mailing Address flow (MGD).
Phone Number [optional] Monthly average
FAX Number [optional] Wholesale flow (MGD).
ICR Contact Person:
Name
Mailing Address
Phone Number [optional]
FAX Number [optional]
E-Mail Address [optional]
Treatment Plant: \1\
Plant name Plant type (e.g., Conventional Filtration, Hours of operation

ICR plant number assigned by EPA \2\ Direct Filtration, In-Line Filtration, (hours per day)
PWSID number of treatment plant \3\ Two Stage Softening, Disinfection Only/ Sludge solids production
State approved (permitted) plant capacity Groundwater, Other Groundwater treatment) (lb/day)

(MGD) Percent solids in sludge
Historical minimum water temperature ( ()
deg.C)
Installed sludge handling capacity (lb/
day)
Process Train:
Name Process Train Type (e.g., Conventional
Filtration, Direct Filtration, In-Line
Filtration, Two Stage Softening,
Disinfection Only/Groundwater, Other
Groundwater treatment)

\1\ A PWS that operates more than one treatment plant shall report treatment plant information in this table for

each treatment plant.
\2\ EPA shall assign ICR plant number after the PWS submits sampling plan.
\3\ PWSID of treatment plant if different from the PWSID reported in ``Public Water System''.

Table 6b.--Plant Influent Information

Permanent data Monthly data

Water Resource \1\

Name of resource: If Reservoir/Lake: Mean Residence Time (days).
Type of resource (One of the
following):
1 Flowing stream
2 Reservoir/Lake
3 Ground water classified as
under the direct influence of
surface water (GWUDI)
4 Ground water
5 Purchased finished water
6 Non-Fresh (such as salt water)

Intake-Surface Water \2\

Location of intake: \3\ Flow on day of sampling (MGD).
Latitude (deg/min/sec)
Longitude (deg/min/sec)
Hydrologic unit code (8 digit), if
known \4\
Stream Reach Code (3 digit) (if known)
River mile number (mile) (if known)
Is watershed control practiced? (yes/no)

[[Page 24379]]

Intake-Ground Water \5\ 6

Location of intake: Flow on day of sampling (MGD).
Latitude (deg/min/sec)
Longitude (deg/min/sec)
Hydrological unit code (8 digit), if
known \4\
Is wellhead protection practiced? (yes/no)

Intake-Purchased Finished Water \7\

Name of supplying utility................. Flow on day of sampling (MGD).
PWSID of supplying utility

Plant Influent \8\

Monthly average flow (MGD).
Flow at time of sampling (MGD).

\1\ Each treatment plant shall have at least one water resource. Each water resource shall have at least one
intake. A treatment plant that uses more than one water resource shall report water resource information in

this table for each water resource.

\2\ Intake-Surface Water describes the physical location of an intake structure located in a river, lake, or
other surface water resource or, for ground water under the direct influence of surface water, the physical

location of a well.

\3\ The location of the intake will allow cross referencing into other data bases containing information on

possible contamination threats to the intake.

\4\ The hydrologic unit code will allow cross referencing into other data bases containing information on

possible contamination threats to the intake.

\5\ An Intake-Ground Water describes the physical location of a well or well field (if multiple wells draw from

a common aquifer.
\6\ A PWS is not required to report information for ground water that is not treated.

\7\ A PWS is required to report information for purchased finished water only if that water is further treated.
\8\ Multiple ``Intakes'' combine into one ``Plant Influent.'' Each treatment plant has only one treatment plant
influent. The treatment plant influent shall mark the point in the treatment plant where the ``Plant

Influent'' sample shall be collected as described in Tables 1, 2, 3 and 5 of this section.

Table 6c.--Unit Process Information

Design data Monthly data

Presedimentation Basin \1\

Tube Settler Brand Name Liquid volume (gallons).
Plate Settler Brand Name Surface area (ft2).
Baffling type\2\ Projected Tube Settler Surface Area (ft\2\).
Projected Plate Settler Surface Area (ft2).

Ozone Contact Basin

Information for the complete ozone contact basin: Information for the complete ozone contact basin:
Type of Ozone Contactor (One of the following) Ozone CT (mg min/l).10
1 Bubble Diffusion Ozone Giardia Inactivation (logs).
2 Turbine Ozone Virus Inactivation (logs).
Number of Chambers Ozone concentration in feed gas (by weight).
Information for each ozone contact chamber: Total Ozone Gas Flow Rate to Contactor (SCFM).3
Chamber sequence number Type of feed gas used to generate ozone (one of the following).
Liquid volume (ft3) 1 Air.
Surface area (ft2) 2 Oxygen.
Water/Ozone flow regime (one of the following) Total Ozone Applied Dose (mg/l).
1 Counter-current Information for each ozone contact chamber:
2 Co-current Percent ozone gas flow split to this chamber ().
Hydrogen peroxide dose (mg/l).

Washwater Return Point 8

Indicate which washwater treatment processes are being used on day of Flow of returned washwater at time of sampling (MGD).
sampling 24 hr average flow prior to sampling (MGD).
Is there treatment (yes/no):

[[Page 24380]]

If yes:
Plain sedimentation (yes/no)
Coagulation/sedimentation (yes/no)
Filtration (yes/no)
Disinfection (yes/no)
Other Treatment (Text)

Rapid Mix

Type of mixer (one of the following): Mean velocity gradient ``G'' (sec-1).4
Liquid volume (gallons).
1 Mechanical
2 Hydraulic
3 Static
4 Other
Baffling type 2

Flocculation Basin

Type of mixer (one of the following): Mean velocity gradient ``G'' (sec-1) in each stage.4
Liquid volume of each stage (gallons).
1 Mechanical
2 Hydraulic
Number of stages
Baffling type 2

Sedimentation Basin

Tube settler brand name Liquid volume (gallons).
Plate settler brand name Surface area (ft2).
Baffling type 2 Projected tube settler surface area (ft2).
Projected plate settler surface area (ft2).

Solids Contact Clarifier

Brand name: Liquid volume (gallons).
Surface area of settling zone (ft2).
Projected tube settler surface area (ft2).
Projected plate settler surface area (ft2).
Type (check all that apply):
Rectangular basin
Upflow
Reactor-clarifier
Sludge blanket
Tube settler brand name
Plate settler brand name
Baffling type 2

Adsorption Clarifier

Brand Name Liquid volume (gallons).
Baffling type 2 Surface area (ft2).

Dissolved Air Flotation

Baffling type 2 Liquid volume (gallons).
Surface area (ft2).
Percent recycle rate ().
Recycle stream pressure (psi).

Recarbonation Basin

Baffling type 2 Liquid volume (gallons).
Surface area (ft2).

[[Page 24381]]

Filtration

Media Type (one of the following): Liquid volume (gallons).
Surface area (ft2).
Average filter run time (hr).
1 Dual media (Anthracite/Sand)
2 GAC over sand
3 Tri media (Anthracite/Sand/Garnet)
4 Sand
5 Deep bed monomedia anthracite
6 Deep bed monomedia GAC
7 Greensand
8 Other
Design depth of GAC (inch)
Type and manufacturer of activated carbon
Design media depth (inch)
Minimum water depth to top of media (ft)
Depth from top of media to top of backwash trough (ft)

Slow Sand Filtration

Media type Surface area (ft2).
Media depth Average filter run length.
Media size Cleaning method.

Diatomaceous Earth Filter

Effective DE filter surface (ft2).
Precoat (lb/ft2).
Bodyfeed (mg/l).
Run length (hours).

Granular Activated Carbon--Post-Filter Adsorber

Manufacturer of activated carbon Liquid volume (gallons).
Type of activated carbon Surface area (ft2).
Carbon volume (ft3).
Empty bed contact time (minutes).
Operating reactivation frequency (days).

Membranes

Model name: Surface area (ft\2\).
Type (one of the following): Percent recovery ().
1 Reverse osmosis Operating pressure (psi).
2 Nanofiltration Operating flux (gpd/ft2).
3 Ultrafiltration Cleaning method (one of the following)
4 Microfiltration Hydraulic.
5 Electrodialysis Chemical.
Number of stages Cleaning frequency (days).
Molecular weight cutoff (daltons)
Design flux (gpd/ft2)
Design pressure (psi)

Air Stripping

Packing height (ft) Horizontal cross-section area (ft2).
Design air to water ratio (volume/volume) Air flow (SCFM).3
Type of packing (Name)
Nominal size of packing (inch)

Ion Exchange

Resin (Name) Liquid volume (gallons).
Resin manufacturer Surface area (ft2).
Design exchange capacity (equ/ft3) 3
Bed depth (ft)

[[Page 24382]]

Disinfection Contact Basin 5 6

Baffling type 2 Liquid volume (gallons).
Surface area (ft2).

Clearwell 7

Baffling type 2 Liquid volume (gallons).
Minimum liquid volume (gallons) Surface area (ft2).
Covered or Open

Additional Water Sources 9

Type of water source: Flow of additional source (MGD).6
Purchased Finished water
Untreated ground water
Treated ground water
Untreated surface water
Treated surface water
Other

Other Treatment

Purpose Surface area (ft2) [optional].
Liquid Volume (gallons) [optional].

1 A reservoir to which oxidants, disinfectants, or coagulants are added is considered a presedimentation basin.

2 Baffling type classified as one of the following: 1 (Unbaffled (mixed tank)), 2 (Poor (inlet/outlet only)), 3 (Average (Inlet/Outlet and
intermediate)), 4 (Superior (Serpentine)), or 5 (Perfect (Plug flow)). Information on classifying baffling types can be found in ``Guidance Manual for

Compliance with the Filtration and Disinfection Requirements for Public Water Systems using Surface Water Sources'', Appendix C.
3 ``SCFM'' is standard cubic feet per minute. ``Equ/ft\3\'' is equivalents per cubic foot.

4 The mean velocity gradient is typically computed as G=square root of (P/uV) where P=power expended, u=viscosity, and V=liquid volume.

5 The disinfection contact basin shall have a stable liquid level.
6 Disinfection Contact Basin can be used to represent a pipe with a long contact time.
7 A clear well may have a variable liquid level.
8 The ``Washwater Return'' shall mark the point in the process train where washwater joins the main flow.
9 Additional water sources includes water that is added to the process train after the influent.

10 Ozone CT calculated using the procedure contained in ``Guidance Manual for Compliance with the Filtration and Disinfection Requirements for Public

Water Systems using Surface Water Sources'', Appendix O, 1991.

Table 6d.--Additional Process Train Information

Design data Monthly data

Disinfectant Addition

Disinfectants in use at time of sampling.
Dose (mg/l).
Chemical formula (e.g., mg/l as chlorine).

Finished Water Sample Point (Plant Effluent) \1\ \2\

Monthly average flow (MGD).
Flow at time of sampling (MGD).

\1\ This shall mark the end of a treatment plant.

\2\ Unless the finished water of this treatment plant is blended with finished water from another treatment

plant, this point is also the entry point to the distribution system.

Table 6e.--Finished Water Distribution Information

Design data Monthly data

Entry Point to Distribution System \1\

Monthly average flow (MGD).
Flow at time of sampling (MGD).

[[Page 24383]]

Wholesale Information \2\

Name of purchaser...................................... Flow at time of sampling (MGD).
PWSID of purchaser

Distribution System

Typical maximum residence time (days) Maximum residence time (days).
Average residence time (days) Average residence time (days).

Design volume of distribution system storage (million Number of disinfection booster stations in operation at

gallon) time of sampling:
Total surface area of open reservoirs in distribution Chlorine.
system storage (ft\2\) Chloramine.
Chlorine dioxide.
Range of distribution system disinfectant dosages.
Chlorine: High (mg/l) Low (mg/l).
Chloramine: High (mg/l) Low (mg/l).
Chlorine dioxide: High (mg/l) Low (mg/l).

\1\ Multiple treatment plants can feed into one entry point to the distribution system. If there is only one
treatment plant then ``Finished Water Sample Point (Plant Effluent)'' and ``Entry Point to Distribution

System'' are the same.

\2\ The supplying public water system shall report ``Wholesale Information'' for each public water system which

purchases finished water.

(b) Analytical methods. (1) A PWS shall use the methods identified
in Table 7 of this section for conducting analyses required by this
subpart.

Table 7.--Analytical Methods Approved for Subpart M

Methodology \1\

Analyte --------------------------------------------------------------------------------------------------------------------

40 CFR reference \2\ EPA method Standard method \3\

pH, alkalinity, calcium hardness, Sec. 141.23(k)(1)
temperature.
Turbidity.......................... Sec. 141.74(a)(1)
Disinfectant residuals: free Sec. 141.74(a)(2) ................................ 4500-Cl B \9\
chlorine, total chlorine, chlorine
dioxide, ozone.
Trihalomethanes: chloroform, bro... Sec. 141.24(e) 551.1 \4\
modichloromethane, dibro...........
mochloromethane, bromoform.........
Haloacetic acids: mono-, di-, and ........................................ 552.1, \5\ 552.2 \4\ 6251 B
trichloroacetic acids; mono- and
dibromoacetic acid;
bromochloroacetic acid.
Chloral hydrate.................... ........................................ 551.1 \4\
Haloacetonitriles: di- and ........................................ 551.1 \4\
trichloroacetonitrile;
bromochloroacetonitrile;
dibromoacetonitrile.
Haloketones: 1,1-Dichloropropanone; ........................................ 551.1 \4\
1,1,1-trichloropropanone.
Chloropicrin....................... ........................................ 551.1 \4\
Chlorite........................... ........................................ 300.0 \6\
Chlorate........................... ........................................ 300.0 \6\
Bromide............................ ........................................ 300.0 \6\
Bromate............................ ........................................ 300.0 \6\
Total Organic Halide (TOX)......... ........................................ ................................ 5320 B

Total Organic Carbon............... ........................................ ................................ 5310 B, 5310 C, 5310 D

UV absorbance at 254 nm............ ........................................ ................................ 5910
Simulated Distribution System Test ........................................ ................................ 5710 C
(SDS).
Total Hardness..................... ........................................ ................................ 2340 B,\7\ 2340 C
Ammonia............................ Sec. 136.3, Table 1b \8\ 350.1 \6\ 4500-NH<INF>3 D, 4500-NH<INF>3 G
Chlorine Demand Test............... ........................................ ................................ 2350 B

\1\ Analyses shall be conducted by using mandatory analytical and quality control procedures contained in ``DBP/ICR Analytical Methods Manual'', EPA 814-

B-96-002.

\2\ Currently approved methodology for drinking water compliance monitoring is listed in Title 40 of the Code of Federal Regulations in the sections
referenced in this column. The 18th and 19th editions of Standard Methods for the Examination of Water and Wastewater, American Public Health
Association, 1015 Fifteenth Street NW, Washington, D.C. 20005, are equivalent for the methods cited in these sections. Therefore, either edition may

be used.

[[Page 24384]]

\3\ Except where noted, all methods refer to the 19th edition of Standard Methods for the Examination of Water and Wastewater, American Public Health

Association, 1015 Fifteenth Street NW, Washington, D.C. 20005.

\4\ Analytical method reprinted in ``Reprints of EPA Methods for Chemical Analyses Under the Information Collection Rule'', EPA 814-B-96-006. Originally
published in ``Methods for the Determination of Organic Compounds in Drinking Water--Supplement III,'' EPA/600/R-95/131, August 1995, PB95-261616.
\5\ Analytical method reprinted in ``Reprints of EPA Methods for Chemical Analyses Under the Information Collection Rule'', EPA 814-B-96-006. Originally
published in ``Methods for the Determination of Organic Compounds in Drinking Water--Supplement II,'' EPA/600/R-92/129, August 1992, PB92-207703.
\6\ Analytical method reprinted in ``Reprints of EPA Methods for Chemical Analyses Under the Information Collection Rule'', EPA 814-B-96-006. Originally
published in ``Methods for the Determination of Inorganic Substances in Environmental Samples,'' EPA/600/R-93/100, August 1993, PB94-121811.
\7\ The following methods, cited at Sec. 141.23(k)(1) of this part, can be used to determine calcium and magnesium concentrations for use in
conjunction with Standard Method 2340 B: EPA Method 200.7, Standard Method 3111 B, Standard Method 3120 B, or ASTM Method D511-93 B.

\8\ PWSs may use only the automated electrode method from Sec. 136.3, Table 1b.

\9\ Standard Method 4500-Cl B is approved only for determining free chlorine residual concentrations in hypochlorite stock solutions. This method may

not be used for any other disinfectant residual analyses.

(2) Analyses under this section shall be conducted by laboratories
that have received approval from EPA to perform sample analysis for
compliance with this rule. Laboratories that wish to become approved
shall contact EPA in writing at USEPA, Technical Support Division, ICR
Laboratory Coordinator, 26 W. Martin Luther King Drive, Cincinnati, OH
45268 not later than November 14, 1996. Requirements for approval are
included in ``DBP/ICR Analytical Methods Manual'', EPA 814-B-96-002.
(c) Reporting. (1) A PWS shall report required data and information
collected under the provisions of paragraph (a) of this section to EPA,
using an EPA-specified computer readable format. A PWS shall submit a
monthly report that indicates the analytical results of all samples
collected, including quarterly samples taken in that same month, and
all process train data. These reports shall be submitted on a diskette
no later than the fourth month following sampling. In addition to the
information in Tables 1 through 6 in paragraph (a) of this section,
reports shall include PWSID, ICR plant identification, sample date,
analysis date, laboratory identification numbers, analytical methods
used, sample identification numbers, quality assurance code, internal
standards, surrogate standards, and preserved sample pH, if
appropriate.
(2) Additional Requirements. A PWS shall submit a DBP and related
monitoring sampling plan for EPA approval, using software provided by
EPA, for each treatment plant specified in Sec. 141.141(b)(2) of this
subpart that indicates sampling point locations and monitoring to be
conducted at each point, and process treatment train information. This
sampling plan shall be submitted to EPA at the same time and on the
same diskette as the microbiological sampling plan required by
Sec. 141.143(c)(3) and no later than eight weeks after the PWS receives
the Notice of ICR Final Applicability Determination from EPA, using the
procedure specified in ``ICR Sampling Manual'', EPA 814-B-96-001, April
1996.
(3) All reports required by this section shall be submitted to
USEPA (ICR4600), ICR Data Center, Room 1111 East Tower, 401 M Street
SW., Washington, DC 20460.
(4) The PWS shall keep all data for at least three years following
data submission to EPA.
(d) Incorporation by reference. The documents and methods listed in
paragraphs (d) (1) and (2) of this section are incorporated by
reference for purposes specified in this section. This incorporation by
reference was approved by the Director of the Federal Register in
accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be
inspected at USEPA, Drinking Water Docket (4101), 401 M Street SW.,
Washington, DC 20460, or at Office of the Federal Register, 800 North
Capitol Street, NW., Suite 700, Washington, DC.
(1) ``Standard Methods for the Examination of Water and
Wastewater,'' 19th edition, 1995. Available from the American Public
Health Association, 1015 Fifteenth Street, NW., Washington, DC 20005.
(2) ``Guidance Manual for Compliance with the Filtration and
Disinfection Requirements for Public Water Systems using Surface Water
Sources'', Appendices C and O, 1991. Available from American Water
Works Association, 6666 West Quincy Avenue, Denver, CO 80235.

Sec. 141.143 Microbial monitoring.

(a) Monitoring requirements. (1) Parameters. A PWS shall sample for
the following parameters for the period specified in Sec. 141.141(d) of
this subpart and at the location specified and using the analytical
methods specified in paragraphs (a)(2) and (b), respectively, of this
section. For each sample, a PWS shall determine the densities of total
coliforms, fecal coliforms or Escherichia coli, Giardia,
Cryptosporidium, and total culturable viruses for each treatment plant
required to monitor under the provisions of Sec. 141.141(b) of this
subpart.
(2) Monitoring locations. (i) A PWS shall collect one sample of the
treatment plant influent at the frequency specified in Sec. 141.141(d)
of this subpart.
(A) A sample of treatment plant influent shall be taken at a
location at the upstream end of a treatment plant where waters from all
intakes are blended prior to any treatment or chemical addition.
(B) For treatment plants that have multiple intakes and add
chemicals at the intake, the PWS shall take an intake sample of the
water resource with the poorest microbiological quality (or, if that
cannot be determined, the water resource with the highest flow)
collected before chemical addition and before pretreatment. If the
intakes are expected to have the same source water quality, one
representative intake sample may be taken. If a disinfectant is added
at or before the intake (e.g., for zebra mussel control), the sample
shall be taken in the vicinity of the intake in such manner that the
sample is not contaminated by the disinfectant.
(ii) A PWS that, during any of the first twelve months of
monitoring at the treatment plant influent, detects 10 or more Giardia
cysts, or 10 or more Cryptosporidium oocysts, or one or more total
culturable viruses, in one liter of water; or calculates a numerical
value of the Giardia or Cryptosporidium concentration equal to or
greater than 1000 per 100 liters or virus concentration equal to or
greater than 100 per 100 liters; or detects no pathogens in the sample
and calculates a numerical value of the detection limit for Giardia or
Cryptosporidium concentration equal to or greater than 1000 per 100
liters or virus concentration equal to or greater than 100 per 100
liters; shall also collect one sample of finished water per month at
each such treatment plant, beginning in the first calendar month after
the PWS learns of such a result. The sample of finished water shall be
collected at a point after which all treatment

[[Page 24385]]

processes for a particular treatment plant are complete (including the
clearwell and final point of disinfection) and before the distribution
system begins. For each sample of finished water, PWSs shall determine
the density of total coliforms, fecal coliforms or E. coli, Giardia,
Cryptosporidium, and total culturable viruses. A PWS shall continue
finished water monitoring monthly until 18 months of treatment plant
influent monitoring has been completed.
(iii) In lieu of conducting finished water monitoring of Giardia
and Cryptosporidium specified in paragraph (a)(2)(ii) of this section,
a PWS may notify EPA in its response to the notice of applicability
required by paragraph (c)(3)(i) of this section that the PWS will
comply with the alternative monitoring requirements in paragraphs
(a)(2)(iii) (A) and (B) of this section. The PWS shall still conduct
finished water monitoring for all other microorganisms, except for
Giardia and Cryptosporidium monitoring in the finished water.
(A) The PWS measures the particle counts in the treatment plant
influent, at points immediately prior to filtration and after
filtration (but before the addition of post-filtration chemicals).
Particle counting shall be conducted on the same treatment train as is
sampled for monitoring conducted under the provisions of
Sec. 141.142(a) of this subpart. Such samples shall be collected
monthly during the entire 18-month monitoring period, using the
procedures contained in the ``ICR Sampling Manual'', EPA 814-B-96-001,
April 1996. The PWS may use either grab or continuous particle
counting. Particle counting shall be conducted during the same time as
protozoa monitoring required by paragraph (a)(2)(iii)(B) of this
section.
(1) If grab sampling is conducted, the PWS shall collect 12 samples
per location at the treatment plant influent, filter influent, and
filter effluent, over either a 24-hour period or the duration of the
filter run, whichever is shorter.
(2) If continuous particle counting is conducted, the PWS shall
collect 12 instrument readings per location, evenly spaced in time, at
the treatment plant influent, filter influent, and filter effluent,
over either a 24-hour period or the duration of the filter run,
whichever is shorter.
(3) For each sample, the PWS shall measure particle counts per
milliliter in the size ranges of 3<greek-m>m-5<greek-m>m, 5<greek-m>m-
7<greek-m>m, 7<greek-m>m-10<greek-m>m, 10<greek-m>m-15<greek-m>m, and
>15<greek-m>m, and shall report to EPA the mean value in each size
range of the 12 values collected over the sampling period.
(B) The PWS collects and analyzes at least four consecutive months
of Giardia and Cryptosporidium samples at the same locations specified
in paragraph (a)(2)(iii)(A) of this section, within the first 12 months
of the 18 months of sampling. The PWS shall collect Giardia and
Cryptosporidium samples during the same time period as it is conducting
particle counting. The minimum sample volume for Giardia and
Cryptosporidium analyses shall be 100 liters for treatment plant
influent and 1,000 liters for water that has undergone any treatment.
The PWS may use results of monitoring for Giardia and Cryptosporidium
in the treatment plant influent specified in paragraph (a)(2) of this
section to meet the requirements of this paragraph as long as such
monitoring meets the requirements of both this paragraph and paragraph
(a)(2) of this section.
(iv) If a PWS has monitored total coliforms, fecal coliforms, or E.
coli in the treatment plant influent for at least five days/week for
any period of six consecutive months beginning after January 1, 1994
and 9012f all samples taken in that six-month period contained no
greater than 100 total coliforms/100 ml, or 20 fecal coliforms/100 ml,
or 20 E. coli/100 ml, the PWS may request to not conduct virus
monitoring for that treatment plant, for the duration of the
requirement. Even if approved, the PWS may subsequently be required to
monitor under the criteria in paragraph (a)(2)(iv)(A) of this section.
This request shall be submitted as part of the response to the notice
of applicability required by paragraph (c)(3)(i) of this section.
(A) If the PWS is subsequently required to monitor the finished
water under the provisions of paragraph (a)(2)(ii) of this section, the
PWS shall monitor, along with the other specified organisms, total
culturable viruses, as specified in paragraph (a)(2)(i) of this section
for treatment plant influent and as specified in paragraph (a)(2)(ii)
of this section for finished water, until 18 months of microbial
monitoring is completed.
(B) A PWS may use coliform data collected under Sec. 141.71(a)(1)
of this part for this purpose but, if this is done, the PWS shall
submit two separate monitoring reports. One report, to meet the
requirements of Sec. 141.71(a)(1) of this part, shall continue to be
submitted as required by subpart H of this part. The other report shall
be submitted to meet the requirements of paragraph (c)(3) of this
section.
(C) If a PWS does not provide EPA with six months of suitable
coliform results as part of its response to the notice of
applicability, the PWS shall begin virus monitoring. If a PWS begins
virus monitoring and subsequently provides EPA with six months of
coliform results that are at or below the indicated density limit, and
EPA approves the request to not conduct virus monitoring, the PWS may
avoid subsequent treatment plant virus monitoring.
(b) Analytical Methods. (1) A PWS shall use the methods listed in
paragraphs (b)(1)(i) through (v) of this section for monitoring under
this subpart.
(i) Fecal coliforms--specified at Sec. 141.74(a)(1) of this part,
except that whenever paired source water samples and finished water
samples are to be collected, only the fecal coliform procedure
(Standard Method 9221E), as specified in Sec. 141.74(a)(1) of this
part, using EC Medium, can be used. The time between sample collection
and initiation of sample analysis shall not exceed eight hours. Samples
shall be chilled, but not frozen, and shipped at a temperature of less
than 10 deg.C. Samples not processed immediately at the laboratory
shall be refrigerated. The laboratory must invalidate samples that
arrive frozen or at a temperature greater than 10 deg.C.
(ii) Total coliforms--specified at Sec. 141.74(a)(2) of this part.
The time between sample collection and initiation of sample analysis
shall not exceed eight hours. Samples shall be chilled, but not frozen,
and shipped at a temperature of less than 10 deg.C. Samples not
processed immediately at the laboratory shall be refrigerated. The
laboratory must invalidate samples that arrive frozen or at a
temperature greater than 10 deg.C.
(iii) E. coli--as specified by Sec. 141.21(f)(6)(i) through (iii)
of this part, except that the density shall be reported. PWSs using the
EC+MUG and ONPG-MUG tests shall use either a 5-tube or 10-tube 10-ml
configuration, with serial dilutions of the original sample as needed,
and report the Most Probable Number. PWSs may also use a commercial
multi-test system for E. coli enumeration, as long as they use M-Endo
medium for the initial isolation of the organisms, pick every colony on
the plate with the appearance of a total coliform, and streak it for
purification before subjecting the colony to a multi-test system. The
time between sample collection and initiation of sample analysis,
regardless of method used, shall not exceed eight hours. Samples shall
be chilled, but not frozen, and shipped at a temperature of less than
10 deg.C. Samples not processed immediately at the laboratory shall be

[[Page 24386]]

refrigerated. The laboratory must invalidate samples that arrive frozen
or at a temperature greater than 10 deg.C.
(iv) Giardia and Cryptosporidium--ICR Protozoan Method, as
described in ``ICR Microbial Laboratory Manual'', EPA 600/R-95/178,
April 1996.
(v) Total culturable viruses--Virus Monitoring Protocol, as
described in ``ICR Microbial Laboratory Manual'', EPA 600/R-95/178,
April 1996.
(2) Laboratories. A PWS shall use EPA-approved laboratories to
analyze for Giardia, Cryptosporidium, and total culturable viruses. A
PWS shall use laboratories certified for microbiology analyses by
either EPA or a State under the EPA or State drinking water program for
the analysis of total coliforms, fecal coliforms, and E. coli.
Laboratories that wish to become approved shall contact EPA in writing
at USEPA, Technical Support Division, ICR Laboratory Coordinator, 26 W.
Martin Luther King Drive, Cincinnati, OH 45268 not later than August
14, 1996. Laboratory approval criteria for Giardia, Cryptosporidium,
and total culturable viruses are found in the ``ICR Microbial
Laboratory Manual'', EPA 600/R-95/178, April 1996.
(3) A PWS shall send EPA a virus archive sample prepared as
described in Chapter VIII of ``ICR Microbial Laboratory Manual'', EPA
600/R-95/178, April 1996, for each water sample identified in paragraph
(b)(3)(i) or (ii) of this section.
(i) Samples of treatment plant influent and finished water, for
every month after the PWS learns that viruses were detected in any
previous sample of finished water.
(ii) Samples of treatment plant influent and finished water,
regardless of whether viruses are detected in the finished water, for
every month after the PWS learns that a density of at least 10 viruses/
L was detected in any previous treatment plant influent water sample.
(iii) A PWS may arrange to have virus samples shipped directly to
EPA by its virus laboratory for archiving.
(iv) Samples shall be sent on dry ice to ICR Virus Archiving
Coordinator following the procedures specified in ``ICR Microbial
Laboratory Manual'', EPA 600/R-95/178, April 1996.
(c) Reporting. (1) A PWS shall report data and information required
under paragraphs (a) and (b) of this section using an EPA-specified
computer readable format. A PWS shall submit a monthly report on a
diskette, no later than the fourth month following sampling, that
indicates the analytical results of all samples collected. Reports
shall include PWSID, ICR plant identification, sample date, analysis
date, laboratory identification numbers, analytical methods used,
sample identification numbers, analytical batch numbers, quality
assurance code, and processing batch numbers, if appropriate.
(2)(i) For a PWS using the alternative to Giardia and
Cryptosporidium monitoring in paragraph (a)(2)(iii) of this section,
the PWS shall report to EPA the mean value in each size range of the 12
particle counting values collected over the sampling period. In
addition, during the four consecutive months when the PWS collects
Giardia and Cryptosporidium samples specified in paragraph
(a)(2)(iii)(B) of this section, the PWS shall report to EPA, for each
measured site, the densities of Giardia and Cryptosporidium at each
measured site. This information shall be submitted at the same time as
the report required by paragraph (c)(1) of this section.
(ii) A PWS that is not required to monitor for total culturable
viruses under the provisions of paragraph (a)(2)(iv) of this section
shall report to EPA the dates and results of all total coliform, fecal
coliform, or E. coli monitoring used by the PWS to determine that
additional virus monitoring is unnecessary. The report shall indicate
all data collected during the six-month time period, and how the data
were used to calculate compliance with this requirement.
(3) Additional Requirements. A PWS shall submit a microbiological
sampling plan for EPA approval, using software provided by EPA, for
each treatment plant specified in Sec. 141.141(b) of this subpart that
indicates sampling point locations and monitoring to be conducted at
each point. This sampling plan shall be submitted to EPA at the same
time and on the same diskette as the DBP and related monitoring
sampling plan required by Sec. 141.142(c)(2) and no later than eight
weeks after the PWS receives the Notice of ICR Final Applicability
Determination from EPA, using the procedure specified in ``ICR Sampling
Manual'', EPA 814-B-96-001, April 1996.
(4) All reports required by this section shall be submitted to
USEPA (ICR4600), ICR Data Center, Room 1111 East Tower, 401 M Street
SW., Washington, DC 20460.
(5) The PWS shall keep all data for at least three years following
data submission to EPA.

Sec. 141.144 Disinfection byproduct precursor removal studies.

(a) TOC, UFCTOX, THM4, and HAA5 applicability monitoring. A PWS
required to comply with this section shall conduct TOC, UFCTOX, THM4,
and HAA5 monitoring specified in Sec. 141.141(e)(2) of this subpart. A
PWS may use monitoring results from samples required by Sec. 141.142(a)
of this subpart to meet this requirement to the extent that all
requirements in each section are met.
(b) Treatment study requirements. A PWS identified in
Sec. 141.141(b) of this subpart shall conduct disinfection byproduct
precursor removal studies (treatment studies). The treatment study
shall use bench-and/or pilot-scale systems for at least one of the two
appropriate candidate technologies (GAC or membrane processes) for the
reduction of organic DBP precursors. The treatment studies shall be
designed to yield representative performance data and allow the
development of national treatment cost estimates for different levels
of organic disinfection byproduct control. The treatment objective of
the studies is the achievement of levels of byproducts less than 40
<greek-m>g/L TTHM and 30 <greek-m>g/L HAA5, as an annual average. The
treatment study shall be conducted with the effluent from treatment
processes already in place that remove disinfection byproduct
precursors and TOC, to simulate the most likely treatment scenario.
PWSs are permitted to optimize these processes or pilot additional
processes appropriate for pretreatment for treatment studies. In order
to minimize the formation of DBPs, the test water for both the benchand
pilot-scale tests shall be obtained from a location before the
first point at which oxidants or disinfectants that form halogenated
disinfection byproducts are added. If the use of these oxidants or
disinfectants precedes any full-scale treatment process that removes
disinfection byproduct precursors, then bench- and pilot-scale
treatment processes that represent these full-scale treatment processes
are required prior to the GAC or membrane process. A PWS should
exercise sound judgement in its selection of treatment process to study
and the point at which to obtain water for study. Depending upon the
type of treatment study, the study shall be conducted in accordance
with the following criteria.
(1) Bench-scale tests are continuous flow tests using rapid small
scale column test (RSSCT) for GAC and small scale membrane test
apparatus as specified in ``ICR Manual for Bench- and Pilot-scale
Treatment Studies'' (EPA 814-B-96-003, April 1996).
(i) GAC bench-scale testing shall include information on the
experimental conditions and results necessary to adequately determine
the scaled-up breakthrough curves under

[[Page 24387]]

the conditions of each RSSCT. At least two empty bed contact times
(EBCTs) shall be tested using the RSSCT. These RSSCT EBCTs shall be
designed to represent a full-scale EBCT of 10 min and a full-scale EBCT
of 20 min. Additional EBCTs may be tested. The RSSCT testing is
described in the ``ICR Bench- and Pilot-scale Treatment Study Manual''
(EPA 814-B-96-003, April 1996). The RSSCT tests at each EBCT shall be
run quarterly to ascertain the impact of seasonal variation. Thus a
total of four RSSCTs at each EBCT should be run. When seasonal
variation is not significant, as is the case in most ground waters, the
quarterly tests should be run to investigate other variables, as
described in the ``ICR Bench- and Pilot-scale Treatment Study Manual''
(EPA 814-B-96-003, April 1996). The RSSCT shall be run until the
effluent TOC concentration is at least 7012f the average influent TOC
concentration or the effluent TOC reaches a plateau at greater than 50
of the influent TOC (i.e., the effluent TOC does not increase over a
two-month full-scale-equivalent time period by more than 1012f the
average influent TOC concentration) or a RSSCT operation time that
represents the equivalent of one year of full-scale operation,
whichever is shorter. The average influent TOC is defined as the
running average of the influent TOC at the time of effluent sampling.
If, after completion of the first quarter RSSCTs, the PWS finds that
the effluent TOC reaches 7012f the average influent TOC within 20
full-scale equivalent days on the EBCT=10 min test and within 30 fullscale
equivalent days on the EBCT=20 min test, the last three quarterly
tests shall be conducted using membrane bench-scale testing with only
one membrane, as described in paragraph (b)(1)(ii) of this section.
(ii) Membrane bench-scale testing shall include information on the
experimental conditions and results necessary to determine the water
quality produced by the membrane treatment and a preliminary estimate
of productivity. The testing procedures and monitoring and reporting
requirements are described in the ``ICR Bench- and Pilot-scale
Treatment Study Manual'' (EPA 814-B-96-003, April 1996). A minimum of
two different membrane types with nominal molecular weight cutoffs of
less than 1000 shall be investigated. Membrane tests shall be conducted
quarterly over one year to determine the seasonal variation. Thus, a
total of four bench-scale tests with each membrane shall be run. If
seasonal variation is not significant, as is the case of most ground
waters, the quarterly tests should be run to evaluate the impact of
other variables, such as pretreatment, or additional membranes could be
tested. Alternatively, a PWS may choose to conduct a long-term, single
element study using a single membrane type in lieu of evaluating two
membranes in four quarterly short-term tests, using the protocol in the
``ICR Bench- and Pilot-scale Treatment Study Manual'' (EPA 814-B-96-
003, April 1996).
(2) A PWS shall conduct pilot-scale testing as continuous flow
tests. For GAC, the PWS shall use GAC of particle size representative
of that used in full-scale practice, a pilot GAC column with a minimum
inner diameter of 2.0 inches, and hydraulic loading rate (volumetric
flow rate/column cross-sectional area) representative of that used in
full-scale practice. The PWS shall design a pilot-scale membrane system
as a staged array of elements as described in ``ICR Manual for Benchand
Pilot-scale Treatment Studies'', EPA 814-B-96-003, April 1996.
(i) GAC pilot-scale testing. (A) The pilot testing procedures and
monitoring and reporting requirements are prescribed in the ``ICR
Bench- and Pilot-scale Treatment Study Manual'' (EPA 814-B-96-003,
April 1996).
(B) At least two EBCTs shall be tested, EBCT=10 min and EBCT=20
min, using the pilot-scale plant. Additional EBCTs may be tested.
(C) The pilot tests at each EBCT shall continue until the effluent
TOC concentration is at least 7012f the average influent TOC
concentration on two consecutive TOC sample dates that are at least two
weeks apart or the effluent TOC reaches a plateau at greater than 50
of the influent TOC (i.e., the effluent TOC does not increase over a
two-month period by more than 1012f the average influent TOC
concentration). If either of these criteria is met for the 20-minute
EBCT prior to six months run time, a second pilot test at each EBCT
shall be conducted following the same sampling requirements. In all
cases the maximum length of the pilot study (one or two tests) is one
year. The average influent TOC is defined as the running average of the
influent TOC at the time of sampling. The pilot-scale testing shall be
timed to capture seasonal variation. If seasonal variation is not
significant, as is the case with most ground waters, the pilot-scale
test runs shall be designed to evaluate the impact of other variables,
such as pretreatment.
(ii) Membrane pilot-scale testing.
(A) The membrane pilot testing procedures and monitoring and
reporting requirements are prescribed in the ``ICR Bench- and Pilotscale
Treatment Study Manual'' (EPA 814-B-96-003, April 1996).
(B) The membrane test system shall be designed to yield information
on loss of productivity (fouling), pretreatment requirements, cleaning
requirements, and permeate quality and operated at a recovery
representative of full-scale operation.
(C) The pilot-scale testing shall be run for one year.
(3) Chlorination under simulated distribution system (SDS)
conditions shall be used prior to the measurement of THM4, HAA6, TOX,
and chlorine demand. These conditions are described in ``ICR Manual for
Bench- and Pilot-scale Treatment Studies'' (EPA 814-B-96-003, April
1996) and represent the average conditions in the distribution system
at that time with regard to holding time, temperature, pH, and chlorine
residual. If chlorine is not used as the final disinfectant in
practice, then a chlorine dose shall be set to yield a free chlorine
residual of 1.0 to 0.5 mg/l after a holding time, temperature, and pH
equal to those representative of the distribution system averages.
(c) Analytical Methods. All analyses required by paragraphs (a) and
(b) of this section shall be conducted using the methods and the
mandatory analytical and quality control procedures contained in either
``DBP/ICR Analytical Methods Manual'' (EPA 814-B-96-002, April 1996) or
``ICR Manual for Bench- and Pilot-scale Treatment Studies'' (EPA 814-B-
96-003, April 1996). In addition, TOC analyses required by paragraph
(a) of this section shall be conducted by a laboratory approved under
the provisions of Sec. 141.142(b)(2) of this subpart.
(d) Reporting. (1) TOC and UFCTOX reporting. A PWS shall submit the
monthly results of 12 months of TOC or UFCTOX monitoring required by
paragraph (a)(1) of this section and the annual average of those
monthly results not later than October 14, 1997. This report is not
required to be submitted electronically. Although a PWS may use
monitoring results from samples required by Sec. 141.142(a) of this
subpart to meet this requirement, it shall submit separate reports to
meet this reporting requirement and the reporting requirement in
Sec. 141.142(c)(1) of this subpart.
(2) A PWS shall report all data collected under the provisions of
paragraph (b) of this section. In addition, a PWS shall report the
information for water resource and full-scale and pilot- or bench-scale

[[Page 24388]]

pretreatment processes that precede the bench/pilot systems. These data
and information shall be reported in the format specified in ``ICR
Manual for Bench- and Pilot-scale Treatment Studies'' (EPA 814-B-96-
003, April 1996) not later than July 14, 1999.
(3) All reports required by this section shall be submitted to
USEPA, Technical Support Division, ICR Precursor Removal Studies
Coordinator, 26 West Martin Luther King Drive, Cincinnati, OH 45268.

[FR Doc. 96-11370 Filed 5-13-96; 8:45 am]
BILLING CODE 6560-50-P

Notices For
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994

National Primary Drinking Water Regulations: Monitoring Requirements for Public Drinking Water Supplies; Final Rule

Table 6............................................... X X X X X X ............

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