[Federal Register Volume 61, Number 94 (Tuesday, May 14, 1996)]
[Rules and Regulations]
[Pages 24354-24388]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-11370]




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_______________________________________________________________________

Part II





Environmental Protection Agency





_______________________________________________________________________



40 CFR Part 141



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

Federal Register / Vol. 61, No. 94 / Tuesday, May 14, 1996 / Rules 
and Regulations

[[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 (8WM-
DW), 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 disease-
causing 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 5% and 
21% of 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 8% recovery 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

[[Page 24358]]

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

B. General Applicability

1. 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.
2. 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 EPA-
developed 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.
1. 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

1. 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.
2. 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.
3. 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

1. 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 Pilot-
Scale Treatment Studies and Treatment Study Applicability Monitoring

1. 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.
2. 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 pilot-
scale 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 single-
element bench test apparatus for membranes. Water to be used in bench-
scale 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 Bench- 
and 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 full-
scale practice. For membranes, the PWS must use a staged array to 
achieve a recovery of at least 75%. Pilot-scale testing must include 
the information specified in this rule and in the ``Manual for Bench- 
and Pilot-scale Treatment Studies'', EPA 814-B-96-003, April 1996.
3. 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.
1. 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.
2. 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.
3. 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.
4. 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 <a href="/cdn-cgi/l/email-protection#0839383b3b3a3f263a383d3f486b6765787d7b6d7a7e6d266b6765"><span class="__cf_email__" data-cfemail="2617161515141108141613116645494b565355435450430845494b">[email protected]</span></a>.

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 8% recovery 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.
1. 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.
2. 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 re-
disinfect.
    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 bench- 
and pilot-scale treatment studies. EPA has also finalized an option for 
utilities to contribute to a research fund in lieu of conducting pilot- 
and 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

[[Page 24365]]

[GRAPHIC] [TIFF OMITTED] TR14MY96.000



BILLING CODE 6560-50-C

[[Page 24366]]

1. 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.
2. 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.
3. 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).
4. 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.
5. 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

    1. 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 * * *
* * * * *
    3. 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.
    4. 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.                                                                
1. ``F'' indicates a flow value. The PWS must use million gallons per   
 day (MGD) to express the flow throughout its calculations.             
2. ``P'' indicates a population value, expressed as a number of people. 
Subscripts.                                                             
1. ``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.                  
2. 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)<SUP>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.              
                                  0.                                                                            
B..............................  <gr-thn-eq>100,00  <gr-thn-eq>100,000....  Zero.............  NA.              
                                  0.                                                                            
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.              
                                  0.                                                                            
B..............................  <gr-thn-eq>100,00  <gr-thn-eq>100,000....  zero.............  NA.              
                                  0.                                                                            
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.              
                                  0.                 and is not largest                                         
                                                     plant in PWS.                                              
F..............................  <gr-thn-eq>100,00  Plant serves <100,000   zero.............  <100,000.        
                                  0.                 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 plants<SUP>1                                
                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 2<SUP>2..............................................            X             X             X             X             X             X   .......<SUP>.....
Table 3<SUP>2..............................................            X             X             X             X             X             X   .......<SUP>.....
Table 4a and 4b<SUP>2......................................            X             X             X             X             X             X   ............
Table 5a and 5b<SUP>2......................................            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 monitoring<SUP>3............................            X   ............            X   ............            X   ............  ............
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                              Sec.  141.144--Applicability Monitoring and Treatment Studies                                             
--------------------------------------------------------------------------------------------------------------------------------------------------------
Treatment study applicability monitoring..............            X             X             X             X   ............  ............            X 
Pilot-scale treatment studies<SUP>4........................            X             X   ............  ............  ............  ............  ............
Bench- or pilot-scale treatment studies<SUP>4..............            X             X             X             X   ............  ............           X  
--------------------------------------------------------------------------------------------------------------------------------------------------------
<SUP>1 As determined by Appendix A to paragraph (a) of this section.                                                                                         
<SUP>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]]

                                                                                                                                                        
<SUP>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.                                                  
<SUP>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 90% of 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 10% of 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 10% of 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 10% of 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 10% of 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 10% of 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 10% of 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 <SUP>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 <SUP>2.    Calcium and Total Hardness, TOC, UV <INF>254,
                                Disinfectant residual <SUP>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 <SUP>4.               <SUP>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     <SUP>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 <SUP>5.                Calcium and Total Hardness, TOC, and UV 
                                <INF>254.                                    
After every unit process that  Disinfectant Residual <SUP>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 <SUP>3.                
Entry point to distribution    pH, Alkalinity, Turbidity, Temperature,  
 system <SUP>6.                      Calcium and Total Hardness, TOC, UV <INF>254,
                                Disinfectant Residual <SUP>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 analyses<SUP>1           
------------------------------------------------------------------------
Treatment plant influent for   TOX.                                     
 non-finished water.                                                    
Treatment plant influent for   THM4, HAA6<SUP>7, 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, HAA6<SUP>7, HAN, CP, HK, CH, TOX.       
 disinfectant is applied at                                             
 any point in the treatment                                             
 plant prior to filtration.                                             
Finished water sample point    THM4, HAA6<SUP>7, HAN, CP, HK, CH, TOX.       
 (Plant Effluent).                                                      
Entry point to distribution    THM4, HAA6<SUP>7, HAN, CP, HK, CH, TOX.       
 system<SUP>2.                                                               
SDS<SUP>3.........................  THM4, HAA6<SUP>7, HAN, CP, HK, CH, TOX, pH,   
                                Alkalinity, Turbidity, Temperature,     
                                Calcium and Total Hardness, Disinfectant
                                Residual<SUP>5.                              

[[Page 24376]]

                                                                        
Four monitoring points in      THM4, HAA6<SUP>7, HAN, CP, HK, CH, TOX, pH,   
 distribution system<SUP>4,<SUP>6.        Alkalinity, Turbidity, Temperature,     
                                Calcium and Total Hardness, Disinfectant
                                Residual<SUP>5.                              
------------------------------------------------------------------------
\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 <SUP>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 <SUP>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.                                                       
\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.                               

    (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\ <SUP>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 (ft<SUP>2).                                                        
Baffling type\2\                                                             Projected Tube Settler Surface Area (ft\2\).                               
                                                                             Projected Plate Settler Surface Area (ft<SUP>2).                                
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   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).<SUP>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).<SUP>3                          
    Chamber sequence number                                                    Type of feed gas used to generate ozone (one of the following).          
    Liquid volume (ft<SUP>3)                                                            1  Air.                                                              
    Surface area (ft<SUP>2)                                                             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 <SUP>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<SUP>-1).<SUP>4                                     
                                                                             Liquid volume (gallons).                                                   
    1  Mechanical                                                                                                                                       
    2  Hydraulic                                                                                                                                        
    3  Static                                                                                                                                           
    4  Other                                                                                                                                            
Baffling type <SUP>2                                                                                                                                         
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Flocculation Basin                                                                   
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Type of mixer (one of the following):                                        Mean velocity gradient ``G'' (sec<SUP>-1) in each stage.<SUP>4                       
                                                                             Liquid volume of each stage (gallons).                                     
    1  Mechanical                                                                                                                                       
    2  Hydraulic                                                                                                                                        
Number of stages                                                                                                                                        
Baffling type <SUP>2                                                                                                                                         
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Sedimentation Basin                                                                  
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tube settler brand name                                                      Liquid volume (gallons).                                                   
Plate settler brand name                                                     Surface area (ft<SUP>2).                                                        
Baffling type <SUP>2                                                              Projected tube settler surface area (ft<SUP>2).                                 
                                                                             Projected plate settler surface area (ft<SUP>2).                                
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Solids Contact Clarifier                                                                
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Brand name:                                                                  Liquid volume (gallons).                                                   
                                                                             Surface area of settling zone (ft<SUP>2).                                       
                                                                             Projected tube settler surface area (ft<SUP>2).                                 
                                                                             Projected plate settler surface area (ft<SUP>2).                                
    Type (check all that apply):                                                                                                                        
        Rectangular basin                                                                                                                               
        Upflow                                                                                                                                          
        Reactor-clarifier                                                                                                                               
        Sludge blanket                                                                                                                                  
Tube settler brand name                                                                                                                                 
Plate settler brand name                                                                                                                                
Baffling type <SUP>2                                                                                                                                         
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Adsorption Clarifier                                                                  
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Brand Name                                                                   Liquid volume (gallons).                                                   
Baffling type <SUP>2                                                              Surface area (ft<SUP>2).                                                        
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Dissolved Air Flotation                                                                
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baffling type <SUP>2                                                              Liquid volume (gallons).                                                   
                                                                             Surface area (ft<SUP>2).                                                        
                                                                             Percent recycle rate (%).                                                  
                                                                             Recycle stream pressure (psi).                                             
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Recarbonation Basin                                                                  
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baffling type <SUP>2                                                              Liquid volume (gallons).                                                   
                                                                             Surface area (ft<SUP>2).                                                        
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 24381]]

                                                                                                                                                        
                                                                       Filtration                                                                       
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Media Type (one of the following):                                           Liquid volume (gallons).                                                   
                                                                             Surface area (ft<SUP>2).                                                        
                                                                             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 (ft<SUP>2).                                                        
Media depth                                                                  Average filter run length.                                                 
Media size                                                                   Cleaning method.                                                           
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Diatomaceous Earth Filter                                                               
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Effective DE filter surface (ft<SUP>2).                                         
                                                                             Precoat (lb/ft<SUP>2).                                                          
                                                                             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 (ft<SUP>2).                                                        
                                                                             Carbon volume (ft<SUP>3).                                                       
                                                                             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/ft<SUP>2).                                                  
      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/ft<SUP>2)                                                                                                                                   
Design pressure (psi)                                                                                                                                   
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Air Stripping                                                                     
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Packing height (ft)                                                          Horizontal cross-section area (ft<SUP>2).                                       
Design air to water ratio (volume/volume)                                    Air flow (SCFM).<SUP>3                                                          
Type of packing (Name)                                                                                                                                  
Nominal size of packing (inch)                                                                                                                          
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Ion Exchange                                                                      
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Resin (Name)                                                                 Liquid volume (gallons).                                                   
Resin manufacturer                                                           Surface area (ft<SUP>2).                                                        
Design exchange capacity (equ/ft<SUP>3) <SUP>3                                                                                                                    
Bed depth (ft)                                                                                                                                          
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 24382]]

                                                                                                                                                        
                                                             Disinfection Contact Basin <SUP>5 <SUP>6                                                             
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baffling type <SUP>2                                                              Liquid volume (gallons).                                                   
                                                                             Surface area (ft<SUP>2).                                                        
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Clearwell <SUP>7                                                                      
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baffling type <SUP>2                                                              Liquid volume (gallons).                                                   
Minimum liquid volume (gallons)                                              Surface area (ft<SUP>2).                                                        
Covered or Open                                                                                                                                         
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Additional Water Sources <SUP>9                                                               
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Type of water source:                                                        Flow of additional source (MGD).<SUP>6                                          
    Purchased Finished water                                                                                                                            
    Untreated ground water                                                                                                                              
    Treated ground water                                                                                                                                
    Untreated surface water                                                                                                                             
    Treated surface water                                                                                                                               
    Other                                                                                                                                               
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Other Treatment                                                                    
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
Purpose                                                                      Surface area (ft<SUP>2) [optional].                                             
                                                                             Liquid Volume (gallons) [optional].                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
<SUP>1 A reservoir to which oxidants, disinfectants, or coagulants are added is considered a presedimentation basin.                                         
<SUP>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.                      
<SUP>3 ``SCFM'' is standard cubic feet per minute. ``Equ/ft\3\'' is equivalents per cubic foot.                                                              
<SUP>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.                 
<SUP>5 The disinfection contact basin shall have a stable liquid level.                                                                                      
<SUP>6 Disinfection Contact Basin can be used to represent a pipe with a long contact time.                                                                  
<SUP>7 A clear well may have a variable liquid level.                                                                                                        
<SUP>8 The ``Washwater Return'' shall mark the point in the process train where washwater joins the main flow.                                               
<SUP>9 Additional water sources includes water that is added to the process train after the influent.                                                        
<SUP>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 90% of 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 bench- 
and 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 70% of 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 10% of 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 70% of the average influent TOC within 20 
full-scale equivalent days on the EBCT=10 min test and within 30 full-
scale 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 Bench- 
and 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 70% of 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 10% of 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 Pilot-
scale 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

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