National Primary Drinking Water Regulations: Revisions to the Total Coliform Rule, 40926-41016 [2010-15205]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 75, Number 134 (Wednesday, July 14, 2010)]
[Proposed Rules]
[Pages 40926-41016]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-15205]



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Part III





Environmental Protection Agency





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40 CFR Parts 141 and 142



National Primary Drinking Water Regulations: Revisions to the Total 
Coliform Rule; Proposed Rule

Federal Register / Vol. 75 , No. 134 / Wednesday, July 14, 2010 / 
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 141 and 142

[EPA-HQ-OW-2008-0878; FRL-9166-8]
RIN 2040-AD94


National Primary Drinking Water Regulations: Revisions to the 
Total Coliform Rule

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed Rule.

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SUMMARY: The Environmental Protection Agency (EPA or the Agency) is 
proposing revisions to the 1989 Total Coliform Rule. The proposed 
Revised Total Coliform Rule offers a meaningful opportunity for greater 
public health protection beyond the current Total Coliform Rule. The 
proposed revisions require systems that have an indication of coliform 
contamination in the distribution system to assess the problem and take 
corrective action that may reduce cases of illnesses and deaths due to 
potential fecal contamination and waterborne pathogen exposure. This 
proposal also updates provisions in other rules that reference 
analytical methods and other requirements in the current TCR (e.g., 
Public Notification and Ground Water Rules). These proposed revisions 
are in accordance with the Safe Drinking Water Act as amended, which 
requires EPA to review and revise, as appropriate, each national 
primary drinking water regulation promulgated under the Safe Drinking 
Water Act not less often than every six years. As with the current 
Total Coliform Rule, the proposed Revised Total Coliform Rule applies 
to all public water systems.

DATES: Comments must be received on or before September 13, 2010.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2008-0878, by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Mail: Water Docket, Environmental Protection Agency, 
Mailcode: 4101T, 1200 Pennsylvania Ave., NW., Washington, DC 20460, 
Attention Docket ID No. EPA-HQ-OW-2008-0878. In addition, please mail a 
copy of your comments on the information collection provisions to the 
Office of Information and Regulatory Affairs, Office of Management and 
Budget (OMB), Attn: Desk Officer for EPA, 725 17th St., NW., 
Washington, DC 20503.
     Hand Delivery: EPA Docket Center, (EPA/DC) EPA West, Room 
B102, 1301 Constitution Ave., NW., Washington, DC. Such deliveries are 
only accepted during the Docket's normal hours of operation, and 
special arrangements should be made for deliveries of boxed 
information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OW-2008-
0878. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at 
https://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through https://www.regulations.gov, or e-mail. The https://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through https://www.regulations.gov, your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket, visit the EPA Docket Center homepage at https://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the https://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, i.e., CBI or other information 
whose disclosure is restricted by statue. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in https://www.regulations.gov or in hard copy at the Water Docket, EPA 
Docket Center, EPA/DC, EPA West, Room B102, 1301 Constitution Ave., 
NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to 
4:30 p.m., Monday through Friday, excluding legal holidays. The 
telephone number for the Public Reading Room is (202) 566-1744, and the 
telephone number for the Water Docket is (202) 566-2426.

FOR FURTHER INFORMATION CONTACT: Sean Conley, Standards and Risk 
Management Division, Office of Ground Water and Drinking Water (MC-
4607M), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460; telephone number: (202) 564-1781; e-mail address: 
conley.sean@epa.gov. For general information, contact the Safe Drinking 
Water Hotline, telephone number: (800) 426-4791. The Safe Drinking 
Water Hotline is open Monday through Friday, excluding legal holidays, 
from 10 a.m. to 4 p.m. Eastern time.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Regulated Categories and Entities

    Entities potentially regulated by the proposed Revised Total 
Coliform Rule (RTCR) are all public water systems (PWSs). Regulated 
categories and entities include the following:

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                                                Examples of regulated
                 Category                             entities
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Industry..................................  Privately-owned community
                                             water systems (CWSs),
                                             transient non-community
                                             water systems (TNCWSs), and
                                             non-transient non-community
                                             water systems (NTNCWSs).
State, Tribal, and local governments......  Publicly-owned CWSs, TNCWSs,
                                             and NTNCWSs.
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    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities 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 the table could also be regulated. To determine whether your 
facility is regulated by this action, you should carefully examine the 
definition of ``public water system'' in Sec.  141.2 and the section 
entitled ``Coverage'' in Sec.  141.3 in title 40 of the Code of Federal 
Regulations (CFR), and the applicability criteria in Sec.  141.850(b) 
of this proposed rule. If you have questions regarding the 
applicability of this action to a particular entity, consult the person 
listed in the preceding FOR FURTHER INFORMATION CONTACT section.

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B. Copies of This Document and Other Related Information

    This document is available for download at https://www.epa.gov/safewater/disinfection/tcr/. For other related information, see 
preceding discussion on docket.

Abbreviations Used in This Document

ADWR Airline Drinking Water Rule
AGI Acute Gastrointestinal Illness
AIDS Acquired Immune Deficiency Syndrome
AIP Agreement in Principle
AWWA American Water Works Association
ATP Alternative Test Procedure
AWOP Area Wide Optimization Program
BAT Best Available Technology
C Celsius
CA Corrective Action
CBI Confidential Business Information
CCR Consumer Confidence Report
CDC Centers for Disease Control and Prevention
CFR Code of Federal Regulations
COI Cost of Illness
CWS Community Water System
DBPs Disinfection Byproducts
DWC Drinking Water Committee
EA Economic Analysis
EC E. coli
EC-MUG EC Medium with MUG
EPA United States Environmental Protection Agency
ETV Environmental Technology Verification
FR Federal Register
GW Ground Water
GWR Ground Water Rule
GWS Ground Water System
GWUDI Ground Water Under the Direct Influence of Surface Water
HRRCA Health Risk Reduction and Cost Analysis
HUS Hemolytic Uremic Syndrome
ICR Information Collection Request
IESWTR Interim Enhanced Surface Water Treatment Rule
M Million
MCL Maximum Contaminant Level
MCLG Maximum Contaminant Level Goal
mg/L Milligrams per Liter
ml Milliliters
MOU Memorandum of Understanding
MRDL Maximum Residual Disinfectant Level
MUG 4-methylumbelliferyl-Beta-D-glucuronide
NCWS Non-community Water System
NDWAC National Drinking Water Advisory Council
NPDWR National Primary Drinking Water Regulation
NTNCWS Non-Transient Non-Community Water System
NTU Nephelometric Turbidity Unit
OMB Office of Management and Budget
PN Public Notification
PWS Public Water System
RFA Regulatory Flexibility Act
RICP Research and Information Collection Partnership
RTCR Revised Total Coliform Rule
SAB Science Advisory Board
SBA Small Business Administration
SDWA Safe Drinking Water Act
SDWIS Safe Drinking Water Information System
SDWIS/FED Safe Drinking Water Information System Federal Version
SOP Standard Operating Procedure
Stage 1 DBPR Stage 1 Disinfectants and Disinfection Byproducts Rule
Stage 2 DBPR Stage 2 Disinfectants and Disinfection Byproducts Rule
SW Surface Water
SWTR Surface Water Treatment Rule
TC Total Coliforms
TCR Total Coliform Rule
TCRDSAC Total Coliform Rule/Distribution System Advisory Committee
TNCWS Transient Non-Community Water System
T&C Technology and Cost
US United States
UV Ultraviolet Radiation
WRF Water Research Foundation

Table of Contents

I. General Information
    A. Regulated Categories and Entities
    B. Copies of This Document and Other Related Information
II. Background
    A. Statutory Authority
    B. Total Coliform Rule Distribution System Advisory Committee 
(TCRDSAC)
    C. Other Outreach Processes
    D. Public Health Concerns Addressed by the Proposed Revised 
Total Coliform Rule
    1. Public health concerns, fecal contamination, and waterborne 
pathogens
    2. Indicators
    3. Occurrence of fecal contamination and waterborne pathogens
III. Proposed Revised Total Coliform Rule
    A. Proposed Rule Provisions and Rationale
    1. Terms used in the proposed RTCR
    2. MCLG and MCL for E. coli, and coliform treatment technique
    3. Monitoring
    4. Repeat samples
    5. Treatment technique requirements
    6. Violations
    7. Providing notification and information to the public
    8. Reporting and recordkeeping requirements for systems
    9. Analytical methods
    B. Proposed Compliance Date
    C. Links to Other Drinking Water Rule Requirements
    1. SWTR, Stage 1 and Stage 2 DBPRs, ADWR
    2. GWR
    3. Sanitary surveys
    D. Best Available Technology (BAT)
    1. Provisions
    2. EPA's rationale
    3. Request for comment
    E. Variances and Exemptions
    1. Provisions
    2. EPA's rationale
    3. Request for comment
    F. Request for Comment on Other Issues Related to the Proposed 
RTCR
    1. Consistency between the proposed RTCR and the GWR
    2. Storage tank inspection and cleaning
    3. States under EPA direct implementation
    G. Limitations to the Public Comment on the Proposed RTCR
IV. State Implementation
    A. State Special Primacy Requirements
    B. State Recordkeeping Requirements
    C. State Reporting Requirements
    D. Interim Primacy
    E. Request for Comment
V. Distribution System Research and Information Collection 
Activities
    A. Research and Information Collection Partnership
    B. Distribution System Optimization Activities
    C. Request for Comment
VI. Economic Analysis (Health Risk Reduction and Cost Analysis)
    A. Regulatory Options Considered
    B. Major Sources of Data and Information used in Supporting 
Analyses
    1. Safe Drinking Water Information System Federal Version data
    2. Six-Year Review 2 data
    3. Other information sources
    C. Occurrence and Predictive Modeling
    1. Model used for public water systems serving 4,100 or fewer 
people
    2. Model used for public water systems serving more than 4,100 
people
    D. Baseline Profiles
    E. Anticipated Benefits of the Proposed RTCR
    1. Relative risk analysis
    2. Changes in violation rates and corrective actions
    3. Nonquantifiable benefits
    F. Anticipated Costs of the Proposed RTCR
    1. Total annualized present value costs
    2. PWS costs
    3. State costs
    4. Nonquantifiable costs
    G. Potential Impact of the Proposed RTCR on Households
    H. Incremental Costs and Benefits
    I. Benefits from Simultaneous Reduction of Co-occurring 
Contaminants
    J. Change in Risk from Other Contaminants
    K. Effects of Fecal Contamination and/or Waterborne Pathogens on 
the General Population and Sensitive Subpopulations
    1. Risk to children, pregnant women, and the elderly
    2. Risk to immunocompromised persons
    L. Uncertainties in the Benefit and Cost Estimates for the 
Proposed RTCR
    1. Inputs and their uncertainties
    2. Sensitivity analysis
    M. Benefit Cost Determination for the Proposed RTCR
    N. Request for Comment on the Economic Analysis
VII. Statutory and Executive Order Review
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks

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    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    K. Consultations with the Science Advisory Board, National 
Drinking Water Advisory Council, and the Secretary of Health and 
Human Services
    L. Impacts on Sensitive Subpopulations as Required by Section 
1412(b)(3)(C)(i) of the 1996 Amendments of the Safe Drinking Water 
Act (SDWA)
    M. Plain Language
VIII. References

II. Background

A. Statutory Authority

    The Safe Drinking Water Act (SDWA) requires the EPA to review and 
revise, as appropriate, each existing national primary drinking water 
regulation (NPDWR) at least once every six years (SDWA section 
1412(b)(9), 42 U.S.C. 300g-1(b)(9)). In 2003, EPA completed its review 
of the Total Coliform Rule (TCR) and 68 NPDWRs for chemicals that were 
promulgated prior to 1997 (USEPA 2003, 68 FR 42908, July 18, 2003). The 
purpose of the review was to identify new health risk assessments, 
changes in technology, and other factors that would provide a health-
related or technological basis to support a regulatory revision that 
would maintain or improve public health protection. In the Six-Year 
Review 1 determination published in July 2003 (USEPA 2003, 68 FR 42908, 
July 18, 2003), EPA stated its intent to revise the 1989 TCR (also 
referred to as the ``current TCR'').

B. Total Coliform Rule Distribution System Advisory Committee (TCRDSAC)

    In June 2007, EPA established the Total Coliform Rule/Distribution 
System Advisory Committee (``TCRDSAC'' or ``the advisory committee'') 
in accordance with the provisions of the Federal Advisory Committee 
Act, 5 U.S.C. App.2, 9 (c), to provide recommendations to EPA on 
revisions to the 1989 TCR and on what information about distribution 
system issues is needed to better understand and address possible 
public health impacts from potential degradation of drinking water 
distribution systems (USEPA 2007a, 72 FR 35869, June 29, 2007). The 
decision to include a review of distribution system issues was made, in 
part, to address recommendations made by the Stage 2 Microbial and 
Disinfection Byproducts Federal Advisory Committee in December 2000 
(USEPA 2000b, 65 FR 83015, December 29, 2000). The TCRDSAC used 
available information to analyze options for revisions to the TCR. The 
TCRDSAC also considered research and information needed to better 
understand and address public health risks from contamination of 
distribution systems.
    The advisory committee consisted of representatives of EPA, State 
and local public health and regulatory agencies, consumer 
organizations, environmental organizations, local elected officials, 
Indian Tribes, and drinking water suppliers. A technical workgroup was 
also formed to provide the advisory committee with necessary technical 
support and analysis to facilitate the committee's discussions. The 
advisory committee met on 13 occasions between July 2007 and September 
2008. All advisory committee members agreed to and signed the final 
Agreement in Principle (AIP) in September 2008. All of the 
recommendations of the advisory committee are found in the signed AIP. 
Pursuant to the AIP, EPA agreed to propose revisions to the TCR that, 
to the maximum extent consistent with EPA's legal obligations, have the 
same substance and effect as the elements of the AIP. Each party 
represented on the advisory committee agreed in the AIP not to take any 
action to inhibit the adoption and implementation of final rule(s) to 
the extent it and the corresponding preamble have the same substance 
and effect as the elements of the AIP. EPA also agreed in the AIP to 
develop a Research and Information Collection Partnership (RICP) to 
``inform and support the drinking water community in developing future 
national risk management decisions pertaining to drinking water 
distribution systems'' by providing ``a formal process for systematic 
planning, implementation, analysis, and communication of distribution 
system research and information collection'' (USEPA 2008c). A 
discussion of the RICP can be found in section V of this preamble. The 
AIP and details about the advisory committee can be found at EPA's Web 
site at: https://www.epa.gov/safewater/disinfection/tcr/regulation_revisions.html.
    In addition to the outreach mentioned above, EPA agreed to engage 
in various future stakeholder meetings at least annually, to which all 
advisory committee members and the public at large would be invited. In 
April 2009, EPA held its first annual stakeholder meeting to provide 
draft proposed regulation updates and an opportunity for stakeholders 
to provide feedback on the development of the proposed RTCR.

C. Other Outreach Processes

    In addition to consulting with the advisory committee, EPA engaged 
in several other activities as part of the Agency's outreach to 
stakeholders in developing the proposed RTCR. EPA held a technical 
workshop in Washington, DC, from January 30 to February 1, 2007, to 
discuss available information on the current TCR and available 
information regarding risks in distribution systems in support of 
revisions to the TCR. Other EPA outreach activities, namely the 
National Drinking Water Advisory Council consultation, Science Advisory 
Board consultation, and the Tribal consultation, are discussed in 
section VII of this preamble.

D. Public Health Concerns Addressed by the Proposed Revised Total 
Coliform Rule

1. Public Health Concerns, Fecal Contamination, and Waterborne 
Pathogens
    The proposed RTCR aims to increase public health protection through 
the reduction of potential pathways of entry for fecal contamination 
into the distribution system. Since these potential pathways represent 
vulnerabilities in the distribution system whereby fecal contamination 
and/or waterborne pathogens, including bacteria, viruses and parasitic 
protozoa could possibly enter the system, the reduction of these 
pathways in general should lead to reduced exposure and associated risk 
from these contaminants. Fecal contamination and waterborne pathogens 
can cause a variety of illnesses, including acute gastrointestinal 
illness (AGI) with diarrhea, abdominal discomfort, nausea, vomiting, 
and other symptoms. Most AGI cases are of short duration and result in 
mild illness. Other more severe illnesses caused by waterborne 
pathogens include hemolytic uremic syndrome (HUS) (kidney failure), 
hepatitis, and bloody diarrhea (WHO 2004). Chronic disease such as 
irritable bowel syndrome, reduced kidney function, hypertension and 
reactive arthritis can result from infection by a waterborne agent 
(Clark et al. 2008).
    When humans are exposed to and infected by waterborne enteric 
pathogens, the pathogens become capable of reproducing in the 
gastrointestinal tract. As a result, healthy humans shed pathogens in 
their feces for a period ranging from days to weeks. This shedding of 
pathogens often occurs in the absence of any signs of clinical illness. 
Regardless of whether a pathogen causes clinical illness in the

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person who sheds it in his or her feces, the pathogen being shed may 
infect other people directly by person-to-person spread, contact with 
contaminated surfaces, and other means which are referred to as 
secondary spread. As a result, waterborne pathogens that are initially 
waterborne may subsequently infect other people through a variety of 
routes (WHO 2004). Sensitive subpopulations are at greater risk from 
waterborne disease than the general population (Gerba et al. 1996). For 
a discussion of sensitive subpopulations, see section VII.L of this 
preamble.
2. Indicators
    Total coliforms are a group of closely related bacteria that, with 
a few exceptions, are not harmful to humans. Coliforms are abundant in 
the feces of warm-blooded animals, but can also be found in aquatic 
environments, in soil, and on vegetation. Coliform bacteria may be 
transported to surface water by run-off or to ground water by 
infiltration. Total coliforms are common in ambient water and may be 
injured by environmental stresses such as lack of nutrients, and water 
treatments such as chlorine disinfection, in a manner similar to most 
bacterial pathogens and many viral enteric pathogens (including fecal 
pathogens). EPA considers total coliforms to be a useful indicator that 
a potential pathway exists through which fecal contamination can enter 
the distribution system. The absence (versus the presence) of total 
coliforms in the distribution system indicates a reduced likelihood 
that fecal contamination and/or waterborne pathogens are occurring in 
the distribution system.
    Under the current TCR, each total coliform-positive sample is 
assayed for either fecal coliforms or E. coli. Fecal coliform bacteria 
are a subgroup of total coliforms that traditionally have been 
associated with fecal contamination. Since the promulgation of the TCR, 
more information and understanding of the suitability of fecal coliform 
and E. coli as indicators have become available. Study has shown that 
the fecal coliform assay is imprecise and too often captures bacteria 
that do not originate in the human or mammal gut (Edberg et al. 2000). 
On the other hand, E. coli is a more restricted group of coliform 
bacteria that almost always originate in the human or animal gut 
(Edberg et al. 2000). Thus, E. coli is a better indicator of fecal 
contamination than fecal coliforms.
3. Occurrence of Fecal Contamination and Waterborne Pathogens
    a. Presence of fecal contamination. Fecal contamination is a very 
general term that includes all of the organisms found in feces, both 
pathogenic and nonpathogenic. Fecal contamination can occur in drinking 
water both through use of contaminated source water as well as direct 
intrusion of fecal contamination into the drinking water distribution 
system. Lieberman et al. (1994) discuss the general association between 
fecal contamination and waterborne pathogens. Biofilms in distribution 
systems may harbor waterborne bacterial pathogens and accumulate 
enteric viruses and parasitic protozoa (Skraber et al. 2005; Helmi et 
al. 2008). Waterborne pathogens in biofilms may have entered the 
distribution system as fecal contamination from humans or animals.
    Co-occurrence of indicators and waterborne pathogens is difficult 
to measure. The analytical methods approved by EPA to assay for E. coli 
are able to detect indicators of fecal contamination. They do not 
specifically identify most of the pathogenic E. coli strains. There are 
at least 700 recognized E. coli strains (Kaper et al. 2004). About 10 
percent of recognized E. coli strains are pathogenic to humans (Feng 
1995; Hussein 2007; Kaper et al. 2004). Pathogenic E. coli include E. 
coli O157:H7, which is the primary cause of hemolytic uremic syndrome 
(HUS) in the United States (Rangel et al. 2005). The U.S. Centers for 
Disease Control and Prevention (CDC) estimates that there are 73,000 
cases of illness each year in the U.S. due to E. coli O157:H7 (Mead et 
al. 1999). The CDC estimates that about 15 percent of all reported E. 
coli O157:H7 cases are due to water contamination (Rangel et al. 2005). 
Active surveillance by CDC shows that 6.3 percent of E. coli O157:H7 
cases progress to HUS (Griffin and Tauxe 1991; Gould et al. 2009) and 
about 12 percent of HUS cases result in death within four years (Garg 
et al. 2003). About 4 to 15 percent of cases are transmitted within 
households by secondary transmission (Parry and Salmon 1998).
    Because EPA-approved standard methods for E. coli do not typically 
identify the presence of the pathogenic E. coli strains, an E. coli-
positive monitoring result is an indicator of fecal contamination but 
is not necessarily a measure of waterborne pathogen occurrence. 
Specialized assays and methods are used to identify waterborne 
pathogens, including pathogenic E. coli.
    One notable exception is the data reported by Cooley et al. (2007), 
which showed high concentrations of pathogenic E. coli strains in 
samples containing high concentrations of fecal indicator E. coli. 
These data are from streams and other poor quality surface waters 
surrounding California spinach fields associated with the 2006 E. coli 
O157:H7 foodborne outbreak. Data equivalent to these samples are not 
available from drinking water samples collected under the TCR.
    Because E. coli is an indicator of fecal contamination (Edberg et 
al. 2000), and because of the general association between fecal 
contamination and waterborne pathogens (Lieberman et al. 1994; 
Lieberman et al. 2002), E. coli is a meaningful indicator for fecal 
contamination and the potential presence of associated pathogen 
occurrence.
    b. Waterborne disease outbreaks. The CDC defines a waterborne 
disease outbreak as occurring when at least two persons (or one with 
amoebic meningoencephalitis) experience a similar illness after 
ingesting a specific drinking water (or after exposure to recreational 
water) contaminated with pathogens (or chemicals) (Kramer et al. 1996). 
The CDC maintains a database on waterborne disease outbreaks in the 
United States. The database is based upon responses to a voluntary and 
confidential survey form that is completed by State and local public 
health officials.
    The National Research Council strongly suggests that the number of 
identified and reported outbreaks in the CDC database for surface and 
ground waters represents only a small percentage of actual number of 
waterborne disease outbreaks (NRC 1997; Bennett et al. 1987; Hopkins 
et. al. 1985 for Colorado data). Under-reporting occurs because most 
waterborne outbreaks in community water systems are not recognized 
until a sizable proportion of the population is ill (Perz et al. 1998; 
Craun 1996), perhaps 1 percent to 2 percent of the population (Craun 
1996).
    EPA drinking water regulations are designed to protect against 
endemic waterborne disease and to minimize waterborne outbreaks. In 
contrast to epidemic, endemic refers to the persistent low to moderate 
level or the usual ongoing occurrence of illness in a given population 
or geographic area (Craun et al. 2006).

III. Proposed Revised Total Coliform Rule

    The proposed RTCR maintains and strengthens the objectives of the 
current

[[Page 40930]]

TCR and is consistent with the recommendations in the AIP. The 
objectives are: (1) To evaluate the effectiveness of treatment, (2) to 
determine the integrity of the distribution system, and (3) to signal 
the possible presence of fecal contamination. The proposed revision 
better addresses these objectives by requiring systems that may be 
vulnerable to fecal contamination (as indicated by their monitoring 
results) to do an assessment, to identify whether any sanitary 
defect(s) is (are) present, and to correct the defects. Therefore, the 
Agency anticipates greater public health protection under the proposed 
RTCR compared to the current TCR because of its more preventive 
approach to identifying and fixing problems that affect or may affect 
public health.
    The following is an overview of the key provisions of the proposed 
RTCR:
     MCLG and MCL for E. coli and coliform treatment technique 
for protection against potential fecal contamination. The proposed RTCR 
establishes a maximum contaminant level goal (MCLG) and maximum 
contaminant level (MCL) for E. coli. It takes a preventive approach to 
protecting public health by establishing a coliform treatment technique 
for protection against potential fecal contamination. The treatment 
technique uses both total coliforms and E. coli monitoring results to 
start an evaluation process that, where necessary, will require the PWS 
to conduct follow-up corrective action that could prevent future 
incidences of contamination and exposure to fecal contamination and/or 
waterborne pathogens. See section III.A.2 of this preamble for a 
detailed discussion on the MCLG, MCL, and treatment technique 
requirements.
     Monitoring. As with the current TCR, PWSs will continue to 
monitor for total coliforms and E. coli according to a sample siting 
plan and schedule specific to the system.
    Sample siting plans under the proposed RTCR must continue to be 
representative of the water throughout the distribution system. Under 
the proposed RTCR, systems have the flexibility to propose repeat 
sample locations that best verify and determine the extent of potential 
contamination of the distribution system rather than having to sample 
within five connections upstream and downstream of the total coliform-
positive sample location. In lieu of proposing new repeat sample 
locations, the systems may stay with the default used under the current 
TCR of five connections upstream and downstream of the total coliform-
positive sample location.
    As with the current TCR, the proposed RTCR allows reduced 
monitoring for some small ground water systems. The proposed RTCR is 
expected to improve public health protection compared to the current 
TCR by requiring small ground water systems that are on or wish to 
conduct reduced monitoring to meet certain eligibility criteria. 
Examples of the criteria include a sanitary survey showing that the 
system is free of sanitary defects, a clean TCR compliance history for 
12 months, and a recurring annual site visit by the State and/or a 
voluntary Level 2 assessment for systems on annual monitoring.
    For small ground water systems, the proposed RTCR requires 
increased monitoring for high-risk systems that meet certain criteria 
such as unacceptable compliance history under the RTCR. The proposed 
RTCR specifies conditions under which systems will no longer be 
eligible for reduced monitoring and be required to return to routine 
monitoring or to monitor at an increased frequency.
    The proposed RTCR requires systems on a quarterly or annual 
monitoring frequency (applicable only to ground water systems serving 
1,000 or fewer people) to conduct additional routine monitoring the 
month following one or more total coliform-positive samples. Under the 
proposed RTCR, systems must collect at least three routine samples 
during the next month, unless the State waives the additional routine 
monitoring. This is a reduction in the required number of additional 
routine samples from the current TCR, which requires at least five 
routine samples in the month following a total coliform-positive sample 
for all systems serving 4,100 or fewer people.
    The current TCR requires all systems serving 1,000 or fewer people 
to collect at least four repeat samples while PWSs serving 1,000 people 
or greater to collect three repeat samples. The proposed rule requires 
three repeat samples after a routine total coliform-positive sample, 
regardless of the system type and size.
    See sections III.A.3 and III.A.4 of this preamble for detailed 
discussions of the routine monitoring and repeat sampling requirements 
of the proposed RTCR.
     Seasonal systems. The proposed RTCR establishes monitoring 
requirements for seasonal systems for the first time. Seasonal systems 
represent a special case in that the shutdown and start-up of these 
water systems present additional opportunities for contamination to 
enter or spread through the distribution system. Seasonal systems must 
demonstrate completion of a State-approved start-up procedure. In 
addition, they must designate the time period(s) for monitoring based 
on site-specific considerations (such as during periods of highest 
demand or highest vulnerability to contamination) in their State-
approved sample siting plan. See section III.A.3 of this preamble for a 
detailed discussion of seasonal systems.
     Assessment and corrective action. As part of a treatment 
technique, all PWSs are required to assess their systems when 
monitoring results show that the system may be vulnerable to 
contamination. Systems must conduct a simple self-assessment (Level 1) 
or a more detailed assessment (Level 2) depending on the severity and 
frequency of contamination. The system is responsible for correcting 
any sanitary defect(s) found through either a Level 1 or Level 2 
assessment. See section III.A.5 of this preamble for more discussion of 
the treatment technique requirement of the proposed RTCR.
     Violations and public notification. The proposed RTCR 
establishes an E. coli MCL violation, a treatment technique violation, 
a monitoring violation, and a reporting violation. Public notification 
is required for each type of violation, with the type of notification 
dependent on the degree of potential public health concern. This is 
consistent with EPA's current public notification requirements under 40 
CFR part 141 subpart Q. The proposed RTCR also modifies the public 
notification and Consumer Confidence Report language to reflect the 
construct of the proposed rule. See sections III.A.6 and III.A.7 of 
this preamble for detailed discussions of violations and public 
notification under the proposed RTCR.
     Transition to the RTCR. The proposed RTCR allows all 
systems to transition to the new rule at their current TCR monitoring 
frequency, including systems on reduced monitoring under the current 
TCR. States will then evaluate the monitoring frequency during each 
sanitary survey conducted after the compliance effective date of the 
RTCR. This process reduces State burden by not requiring the State to 
determine appropriate monitoring frequency at the same time as when the 
State is trying to adopt primacy, develop policies, and train their own 
staff and the PWSs in the State.
    The provisions of the proposed RTCR are contained in the new 40 CFR 
part 141 subpart Y, superseding 40 CFR 141.21 beginning three years 
following the publication of the final revised rule.

[[Page 40931]]

A. Proposed Rule Provisions and Rationale

1. Terms used in the proposed RTCR
    a. Provisions. i. Clean compliance history. For the purposes of the 
proposed RTCR, EPA is proposing to define ``clean compliance history'' 
as a record of no maximum contaminant level (MCL) violations under 40 
CFR 141.63; no monitoring violations under 40 CFR 141.21 or subpart Y; 
and no coliform treatment technique trigger exceedances or coliform 
treatment technique violations under subpart Y.
    ii. Sanitary defect. EPA is proposing to define ``sanitary defect'' 
as a ``defect that could provide a pathway of entry for microbial 
contamination into the distribution system or that is indicative of a 
failure or imminent failure in a barrier that is already in place'' 
(USEPA 2008c).
    iii. Seasonal systems. EPA is proposing to define a seasonal system 
as a non-community water system that is operated in three or fewer 
calendar quarters per calendar year.
    b. EPA's rationale. i. Clean compliance history. EPA is proposing a 
definition of ``clean compliance history'' because without a 
definition, the use of the phrase could result in multiple 
interpretations. Clean compliance history is one of the criteria a 
system must meet to be eligible for reduced monitoring. The advisory 
committee recommended this definition (USEPA 2008c, AIP p. 10).
    ii. Sanitary defect. The advisory committee recommended the 
definition of sanitary defect. The proposed RTCR takes a more 
preventive approach to protect public health by establishing a 
framework for the assessment of public water systems to identify 
sanitary defects and to correct them as appropriate. The first part of 
the proposed definition of a ``sanitary defect'' focuses on problems in 
the distribution system that may provide a pathway for contaminants to 
enter the distribution system and its implication for potential 
exposure to both microbial and chemical contaminants. The second part 
of the definition also recognizes the importance of having barriers in 
place to prevent the entry of microbial contaminants into the 
distribution system. Indications of failure or imminent failure of 
these barriers are defects that require corrective action.
    Sanitary defect is a term specific to the proposed RTCR assessment 
and corrective action provisions. Sanitary defects are not intended to 
be linked directly to ``significant deficiencies'' under the Interim 
Enhanced Surface Water Treatment Rule (IESWTR) (USEPA 1998b, 63 FR 
69389, December 16, 1998) and Ground Water Rule (GWR) (USEPA 2006c, 71 
FR 65574, November 8, 2006), although some problems could meet either 
definition. Nothing in this proposed rule is intended to limit the 
existing authorities of States under other regulations.
    The following is a list of examples of sanitary defects and defects 
in the distribution system coliform monitoring practices (USEPA 2008c, 
AIP Appendix Y, p. 41).
    Examples of sanitary defects:
     Cross connection and backflow issues such as a required 
backflow prevention device not in place or not operating properly; or 
an unprotected cross connection found.
     Operator issues such as failure to follow standard 
operating procedures (SOPs) that protect distribution system integrity 
and sanitary conditions.
     Distribution system issues such as inadequate inspection 
and maintenance of the distribution system; loss of distribution system 
integrity such as main breaks; failure to maintain adequate pressure; 
improper flushing operations; improper construction of new, replaced, 
or renovated lines; inadequate disinfection during and after repair/
replacement activities; or inability to maintain required residual 
throughout the distribution system.
     Storage issues such as overflow, vents, hatches, and other 
penetrations not properly configured, screened, or sealed; inadequate 
maintenance of storage facilities; or inadequate disinfection during 
and after repair/replacement activities.
     Disinfection issues such as inability to maintain required 
residual throughout the distribution system.
    iii. Seasonal systems. Seasonal systems fall under the broader 
category of non-community water systems (NCWS) and therefore are 
subject to provisions applicable to that category of systems. However, 
seasonal systems have unique characteristics and timetables that make 
them particularly susceptible to contamination. Seasonal systems 
represent a special case in that the shut down and start-up of the 
water system present opportunities for contamination to enter or spread 
through the distribution system. For example, loss of pressure after a 
system's shut down can lead to intrusion of contaminants. Microbial 
growth prior to start-up can result in biofilm formation, which can 
lead to the accumulation of contaminants. These systems are also more 
susceptible to contamination due to changes in the conditions of the 
source water (such as variable contaminant loading due to increased 
septic tank or septic field use), the seasonal nature of the demand, 
and the stress that the system experiences. As a result, the Agency is 
establishing a definition for seasonal systems and setting forth 
provisions that mitigate the risk associated with the unique 
characteristics of this type of system. The advisory committee 
recommended that such provisions pertain to seasonal systems. See 
section III.A.3 of this preamble for specific provisions that seasonal 
systems must meet.
    c. Request for comment. EPA requests comment on the proposed 
definitions and whether they work within the construct of the proposed 
RTCR. Specifically, EPA requests comment on the proposed definition of 
seasonal systems. The advisory committee recommended that seasonal 
systems be identified and be subject to additional regulatory 
requirements because the shutdown and startup of the system presents 
opportunities for contaminants to enter or spread through the 
distribution system. These results are possible in any system that 
shuts down and does not maintain adequate pressure throughout the 
distribution system. The AIP describes a seasonal system as ``one which 
operates less than four calendar quarters per year'' (USEPA 2008c). EPA 
has interpreted this to mean that a seasonal system is one which is 
shut down for at least one full calendar quarter (i.e., it operates in 
three or fewer calendar quarters). EPA requests comment on whether this 
proposed definition of ``seasonal system'' is adequate to address the 
concern that motivated the advisory committee's recommendation and is 
consistent with its intent. For example, a system that operated from 
March to October would operate in all four calendar quarters and would 
not be considered a seasonal system, but would be subject to the same 
possibility of distribution system intrusion as a seasonal system that 
operated April to November (i.e., in only three calendar quarters). 
Should EPA modify the definition to address this issue? If so, how 
should the definition be modified? Should systems that close for some 
specified period (e.g., 30 days, 60 days, 90 days) be subject to 
seasonal system requirements? What should that specified period be?
    Systems that operate intermittently (e.g., only on weekends or only 
when a camp is open) may also be subject to distribution system 
contamination due to lack of adequate pressure. Should this be 
addressed? If so, how should it be addressed--through regulation, 
guidance, or some other approach? Is

[[Page 40932]]

there a specific shutdown time that should be considered for 
intermittent systems in developing the approach and determining which 
systems should be included?
    In addition to the public health benefits associated with these 
requirements, EPA is aware of the burden that States will have in 
determining which systems must comply and in tracking compliance. 
Therefore, EPA requests comment on ways to reduce State burden and 
facilitate implementation of seasonal system provisions.
2. MCLG and MCL for E. coli, and Coliform Treatment Technique
    a. Provisions. The current TCR established a maximum contaminant 
level goal (MCLG) of zero for total coliforms (including fecal 
coliforms and E. coli) and an MCL for total coliforms. EPA is proposing 
in the RTCR to eliminate the MCLG for total coliforms (including fecal 
coliforms) and the MCL for total coliforms. Under the proposed RTCR, 
EPA establishes an MCLG of zero and an MCL for E. coli and a treatment 
technique for coliform. The proposed MCL for E. coli is based on the 
monitoring results for total coliforms and E. coli. A system is in 
compliance with the E. coli MCL unless any of the following conditions 
occur:
     A system has an E. coli positive repeat sample following a 
total coliform-positive routine sample; or
     A routine sample is E. coli-positive and one of its 
associated repeat samples is total coliform-positive; or
     A system fails to test for E. coli when any repeat sample 
tests positive for total coliforms; or
     A system fails to take all required repeat samples 
following a routine sample that is positive for E. coli.
    The proposed MCL is similar to the criteria that define the 
conditions (if exceeded) when a Tier 1 acute MCL violation occurs under 
the current TCR but with two modifications. First, the proposed MCL 
excludes fecal coliforms. Second, the proposed MCL also includes an 
additional condition by which a system violates the MCL, namely failing 
to collect all repeat samples following an initial E. coli-positive 
sample. Although not explicitly stated, as a logical consequence of the 
second condition, a system also violates the MCL when an E. coli-
positive routine sample is followed by an E. coli-positive repeat 
sample because E. coli are a subset of total coliforms. EPA is also 
proposing a coliform treatment technique, which uses total coliforms 
and E. coli as indicators of a possible breach in the distribution 
system that could lead to fecal contamination.
    b. EPA's rationale. i. Inclusion of MCLG for E. coli and removal of 
MCLG for total coliforms (including fecal coliforms). EPA is proposing 
in the RTCR to include an MCLG of zero for E. coli and to remove the 
current MCLG of zero for total coliforms (including fecal coliforms). 
This is because E. coli is a more specific indicator of fecal 
contamination and potential harmful pathogens in drinking water than 
are total coliforms (including fecal coliforms). Many of the organisms 
detected by total coliform and fecal coliform methods are not of fecal 
origin and do not have any direct public health implication. See also 
the discussion of fecal coliforms in section III.A.9 of this preamble. 
New information has become available since promulgation of the current 
TCR in 1989 that indicates that measurement of fecal coliforms 
sometimes detects organisms that may not have any connection to fecal 
contamination (Edberg et al. 2000). An MCLG of zero for E. coli is more 
appropriate than an MCLG of zero for total coliforms (including fecal 
coliforms) since E. coli is a more specific indicator of the presence 
of fecal contamination.
    Total coliforms (including fecal coliforms) do not in and of 
themselves pose a public health risk, but they may indicate the 
presence of a pathway by which fecal contamination can occur. 
Therefore, the removal of the MCLG for total coliforms (including fecal 
coliforms) would prevent possible public confusion as a result of 
attributing greater public health significance to the presence of total 
coliforms than is warranted. EPA believes that the removal of the MCLG 
for total coliforms, along with the other proposed changes discussed in 
the succeeding paragraphs, leads to a rule that is more protective of 
public health, and is less confusing to the public. The proposed MCLG 
of zero for E. coli and the removal of the MCLG for total coliforms 
(including fecal coliforms) are also consistent with the recommendation 
made by the advisory committee in the AIP.
    ii. Inclusion of MCL for E. coli and removal of MCLs for total 
coliforms and fecal coliforms. EPA is proposing to include in the RTCR 
an MCL for E. coli because approved analytical methods continue to be 
available to measure the presence of E. coli in water samples, i.e., 
the presence of E. coli is technologically feasible to ascertain. 
Violation of the proposed MCL for E. coli signifies fecal contamination 
occurrence and a possible high risk of exposure to pathogens. EPA is 
proposing to eliminate the MCLs for total coliforms and fecal coliforms 
because under the proposal there is no longer an MCLG for either total 
coliforms or fecal coliforms, for the reasons explained earlier. The 
proposed MCL for E. coli is consistent with the recommendation made by 
the advisory committee in the AIP.
    iii. Coliform treatment technique. The 1996 SDWA amendments 
authorize EPA to promulgate a treatment technique in lieu of an MCL if 
EPA determines that ``it is not economically or technologically 
feasible to ascertain the level of the contaminant'' (SDWA 
1412(b)(7)(A)). While it is technologically feasible to ascertain 
levels of E. coli (i.e., analytical methods continue to be available to 
measure the presence of E. coli in water samples), because of the 
intermittent nature of fecal contamination, it is not economically 
feasible to ascertain the level of E. coli occurrence below which the 
water may be deemed safe. This is because it is not economically 
feasible to monitor E. coli with sufficient frequency to ensure such 
safety.
    Because total coliform bacteria are part of the soil ecosystem, 
positive samples are indicators of fecal contaminant entry into 
drinking water via a pathway from the soil. EPA is proposing a coliform 
treatment technique, supplemental to directly measuring E. coli, to 
provide additional protection against fecal contamination. Under the 
proposed coliform treatment technique, as specified in the AIP, total 
coliform-positive samples, in the absence of E. coli, are still 
indicators of an E. coli or other fecal contaminant pathway.
    A PWS that exceeds a specified frequency of total coliform 
occurrence must conduct a Level 1 or Level 2 assessment to determine if 
any sanitary defect(s) exist(s) and, if found, to correct the 
defect(s). In addition, under the proposed treatment technique 
requirements, a PWS that incurs an E. coli MCL violation must conduct a 
Level 2 assessment and take remedial action if any sanitary defects are 
found. See section III.A.5 of this preamble for a full discussion of 
conditions that trigger and define Level 1 and Level 2 assessments.
    The treatment technique requirements as proposed enhance public 
health protection beyond the E. coli MCL for the following reasons:
     The assessment and corrective action provisions of the 
treatment technique when the MCL for E. coli is exceeded require PWSs 
to investigate the potential causes of the fecal contamination and 
require timely remedial action if any sanitary defects

[[Page 40933]]

are found. Under the current TCR, there are no requirements for 
investigation and corrective action after an MCL exceedance. Without 
such a find-and-fix provision, the pathway for contamination may not be 
identified and eliminated as sampling alone may not be adequate to 
identify intermittent sources of fecal contamination. The assessment 
and corrective action provisions of the proposed rule increase the 
likelihood of finding and correcting any sanitary defect and reduce the 
chance of recurrence of fecal contamination in the future.
     Using total coliforms in addition to E. coli as an 
indicator to prompt assessment and corrective action increases the 
sensitivity for identifying potential pathways for contamination. As 
discussed in section II.D.2 of this preamble, the presence of total 
coliforms indicates the potential existence of a pathway through which 
fecal contamination could follow. The absence (versus the presence) of 
total coliforms in the distribution system indicates a reduced 
likelihood that fecal contamination and/or waterborne pathogens are 
occurring in the distribution system. Analyses from EPA's 2005 Six-Year 
Review 2 data (USEPA 2006b; USEPA 2010e) (see section VI.B of this 
preamble for details on the Six-Year Review 2 data) and from the 
proposed RTCR Economic Analysis (EA) occurrence modeling show that 
total coliform presence in drinking water is approximately 20 to 40 
times higher than E. coli occurrence in drinking water (see chapter 4 
of the Proposed RTCR EA (USEPA 2010a)). Similarly, under the current 
TCR, non-acute MCL (also referred to as monthly MCL) violations 
(informed by total coliform occurrence) occur roughly 10 times more 
often than acute MCL violations (informed by total coliform and E. coli 
occurrence, essentially equivalent to the occurrence that triggers an 
E. coli MCL violation under this proposed rule). Thus, including 
monitoring of total coliforms, as well as E. coli, as part of a 
treatment technique to indicate when systems must find and fix any 
sanitary defects, substantially increases the likelihood of identifying 
such defects.
     The proposed treatment technique was supported by the 
advisory committee and is consistent with the recommendations in the 
AIP. See AIP, pages 6-7.
    c. Request for comment. EPA requests comment on its proposal to 
eliminate the MCLG and MCL provisions for total coliforms and fecal 
coliforms and to include an MCLG and MCL for E. coli and coliform 
treatment technique provisions based on monitoring for total coliforms 
and E. coli. EPA also requests comment on its proposed definition of 
the E. coli MCL.
3. Monitoring
    a. Provisions. As with the current TCR, the proposed RTCR requires 
all PWSs to collect and test samples for total coliforms and E. coli 
according to a sample siting plan and schedule specific to the system. 
Under the proposed RTCR, all PWSs are still required to take repeat 
samples within 24 hours of learning of any routine monitoring sample 
that is total coliform-positive. PWSs must comply with the repeat 
monitoring requirements and E. coli analytical requirement, discussed 
in detail in section III.A.4 of this preamble. All samples taken for 
proposed RTCR compliance (routine and repeat) may occur at a customer's 
premises, dedicated sampling station, or other designated compliance 
sampling location.
    Under the proposed RTCR, system sample siting plans must include 
routine and repeat sample sites and any sampling points necessary to 
meet the Ground Water Rule (GWR) requirements. The sample siting plan 
is subject to State review and revision. The PWS may propose repeat 
monitoring locations that are expected to be representative of a 
pathway for contamination into the distribution system (for example, 
near a storage tank). Instead of identifying set repeat sampling 
locations (i.e., within five service connections upstream and 
downstream of the original sampling location that tested total 
coliform-positive), systems may elect to specify criteria for selecting 
their repeat sampling locations on a situational basis in a standard 
operating procedure (SOP), which is part of the sample siting plan. 
Upon State review, the PWS must demonstrate to the State's satisfaction 
that the sample siting plan remains representative of the water quality 
in the distribution system. The State may modify the SOP as needed. To 
address access issues, small systems must specify in their sampling 
plans where the two additional samples will be taken. The State may 
determine that monitoring at the entry point to the distribution system 
(especially for undisinfected ground water systems) is effective to 
differentiate between potential source water and distribution problems.
    Under the proposed RTCR, PWSs may take more than the minimum 
required number of routine samples and include the results in 
calculating whether the total coliform treatment technique trigger for 
conducting an assessment has been exceeded only if the samples are 
taken in accordance with the sample siting plan and are representative 
of water throughout the distribution system (see sections III.A.3 and 
III.A.5 of this preamble).
    EPA is not proposing to make substantive changes to the current TCR 
requirements for (1) special purpose samples, and (2) invalidation of 
total coliform samples. EPA is proposing a minor modification to the 
provision for special purpose samples by changing ``total coliform 
MCL'' to ``coliform treatment technique trigger.''
    The following are the proposed monitoring requirements for 
different categories of systems.
    i. Ground water NCWSs serving <= 1,000 people. (a). Routine 
monitoring. The proposed RTCR requires ground water NCWS serving 1,000 
or fewer people to routinely monitor each quarter for total coliforms 
and E. coli. Seasonal systems under this category must routinely 
monitor every month (seasonal systems are discussed later in this 
section).
    (b). Transition to the RTCR. The proposed RTCR requires all ground 
water NCWSs serving 1,000 or fewer people, including seasonal systems, 
to continue with their TCR monitoring schedules as of the compliance 
date of the RTCR, unless or until any of the conditions for increased 
monitoring discussed later on in this section are triggered on or after 
the compliance date or unless otherwise directed by the State, 
including through the special monitoring evaluation conducted under a 
sanitary survey. In addition, systems on annual monitoring, including 
seasonal systems, must have an initial annual site visit by the State 
within one year of the compliance date (or an annual voluntary Level 2 
assessment by a party approved by the State) and an annual site visit 
each year thereafter to remain on annual monitoring.
    This rule proposes that after the compliance date of the final 
RTCR, during each sanitary survey the State (which would be either EPA 
or a State that has received primacy for this rule) must perform a 
special monitoring evaluation to review the status of the water system, 
including the distribution system, to determine whether the system is 
on an appropriate monitoring schedule and modify the monitoring 
schedule as necessary. States must evaluate system factors such as the 
pertinent water quality and compliance history, the establishment and 
maintenance of contamination barriers, and other appropriate 
protections and validate the appropriateness of the

[[Page 40934]]

water system's existing monitoring schedule and modify as necessary. 
For seasonal systems on quarterly or annual monitoring, this evaluation 
must also include review of the approved sample siting plan which 
designates the time period(s) for monitoring based on site-specific 
considerations (such as during periods of highest demand or highest 
vulnerability to contamination). The system must collect compliance 
samples during these time periods.
    (c). Reduced monitoring. The State has the discretion to reduce the 
monitoring frequency for well-operated ground water NCWSs from the 
quarterly routine monitoring to no less than annual monitoring, if the 
water system can demonstrate that it meets the criteria for reduced 
monitoring provided in this section.
    To be eligible to qualify for and remain on annual monitoring after 
the compliance date, a ground water NCWS serving 1,000 or fewer people 
must meet all of the following criteria:
     The most recent sanitary survey shows the system is free 
of sanitary defects, has a protected water source and meets approved 
construction standards;
     The system must have a clean compliance history (no MCL 
violations or monitoring violations under the current TCR and/or 
proposed RTCR, no Level 1 or Level 2 trigger exceedances or treatment 
technique violations under the proposed RTCR) for a minimum of 12 
months. (For a more detailed discussion on Level 1 and Level 2 
triggers, see section III.A.5 of this preamble); and
     An initial site visit by the State within the last 12 
months to qualify for reduced annual monitoring, and recurring annually 
to stay on reduced annual monitoring; and correction of all identified 
sanitary defects. A voluntary Level 2 assessment by a party approved by 
the State may be substituted for the State annual site visit in any 
given year.
    (d). Increased monitoring. Ground water NCWS serving 1,000 or fewer 
people on quarterly or annual monitoring that experience any of the 
following events must begin monthly monitoring the month following the 
event:
     The system triggers a Level 2 assessment or two Level 1 
assessments in a rolling 12 month period;
     The system has an E. coli MCL violation;
     The system has a coliform treatment technique violation 
(for example, if the system fails to conduct a Level 1 assessment or 
correct for sanitary defects if required to do so); or
     The system on quarterly monitoring has two monitoring 
violations in a rolling 12-month period or system on annual monitoring 
has one monitoring violation.
    The system must continue monthly monitoring until the requirements 
in this section for returning to quarterly or annual monitoring are 
met.
    (e). Requirements for returning to quarterly monitoring. To be 
eligible to return to quarterly monitoring, ground water NCWSs serving 
1,000 or fewer people must meet all of the following criteria:
     Within the last 12 months, the system must have a 
completed sanitary survey or a site visit by the State or a voluntary 
Level 2 assessment by a party approved by the State. The system is free 
of sanitary defects, and has a protected water source; and
     The system has a clean compliance history (no E. coli MCL 
violations, Level 1 or 2 triggers, coliform treatment technique 
violations or monitoring violations) for a minimum of 12 months.
    (f). Requirements for returning to reduced annual monitoring. To be 
eligible to return to reduced annual monitoring after being placed on 
increased monitoring, the system must meet the criteria to return to 
routine quarterly monitoring plus the following criteria:
     An annual site visit (recurring) by the State and 
correction of all identified sanitary defects. An annual voluntary 
Level 2 assessment may be substituted for the State annual site visit 
in any given year; and
     The system must have in place or adopt one or more 
additional enhancements to the water system barriers to contamination 
as approved by the State. These measures could include but are not 
limited to the following:

--Cross connection control, as approved by the State;
--An operator certified by an appropriate State certification program, 
which may include regular visits by a circuit rider;
--Continuous disinfection entering the distribution system and a 
residual in the distribution system in accordance with criteria 
specified by the State; and
--Maintenance of at least a 4-log inactivation or removal of viruses 
each day of the month based on daily monitoring as specified in the GWR 
(with allowance for a 4-hour exception).
--Other equivalent enhancements to water system barriers as approved by 
the State.

    (g). Seasonal systems. The proposed rule requires all seasonal 
systems to demonstrate completion of a State-approved start-up 
procedure on and after the compliance date of the final RTCR. Seasonal 
systems may conti