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

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.

Full text

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 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
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 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 100,000.                                                                                                                            
PWS using ground water serving     Yes--monthly for 18 months......................  NA..............................................  Yes.             
 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 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 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 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 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 
(g/l) for THM4 and less than 30 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. 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 103327.2057@compuserve.com.

B. Data Quality Objectives

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

C. Data System

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

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